JP2009169082A - Image-forming optical system and electronic imaging device therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image-forming optical system or the like that is made smaller and thinner and capable of reducing chromatic aberration well, which needs to be strictly performed when magnification is increased. <P>SOLUTION: The image-forming optical system includes: a group of lenses disposed on the side closest to an object; an aperture disposed on the image side of the group of lenses; and another group of lenses disposed between the group of lenses and the aperture and having negative refractive power. The group of lenses with negative refractive power includes a joint lens component where a positive lens L<SB>AP</SB>and a negative lens L<SB>AN</SB>are joined together for magnification. In an orthogonal coordinate system where the horizontal axis is νdp and the vertical axis is θgFp, when a straight line represented by θgFp=αp×νdp+βp (αp=-0.00163) is set, the θgF and νdp of the positive lens L<SB>AP</SB>are contained within both an area defined by a straight line when βp assumes a minimum value and a straight line when βp assumes a maximum value, in the range of a conditional expression (1): 0.6650<βp<0.9000, and an area defined by a conditional expression (2): 3<νdp<27. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging optical system used for an imaging module, and an electronic imaging apparatus having the imaging optical system.

  Digital cameras have achieved practical levels in terms of increasing the number of pixels (higher image quality) and reducing the size and thickness. Such digital cameras have been replaced by silver salt 35 mm film cameras, both functionally and commercially. Therefore, as one of the next evolution directions, there is a strong demand for further increase in the number of pixels as well as the high zoom ratio with the small size and thinness.

  As an example of a zoom optical system that has been used so far as being strong against high zooming, there is an optical system disclosed in Patent Document 1, for example. The optical system of Patent Document 1 is a front-end type zoom optical system. The optical system includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a first lens group having a negative refractive power. It consists of four lens groups and a fifth lens group having positive refractive power. In the embodiment, an optical system having a high imaging performance is disclosed while the zoom ratio is 5 to 10 and the F value is 2.4 at the wide-angle end.

  Moreover, there is an optical system disclosed in Patent Document 2 as an example of reducing the thickness of the optical system while satisfactorily correcting chromatic aberration. In Patent Document 2, a material having characteristics not found in conventional glass is used as an optical material. In this optical system, a transparent medium having a dispersion characteristic or partial dispersion characteristic different from that of conventional glass is used. As a result, thinning is realized by thinning the lens element or reducing the number of lens components while satisfactorily correcting chromatic aberration.

JP 2003-255228 A JP 2006-145823 A

  As a method of storing the lens barrel unit, there is a method of storing the lens barrel unit in the thickness (depth) direction of the camera housing. A structure using this method is called a retractable lens barrel. This retractable lens barrel can also be applied to the optical system disclosed in Patent Document 1. However, in the optical system of Patent Document 1, the thickness of each lens group in the optical axis direction is large. Therefore, it is difficult to make the camera housing thin even if a retractable lens barrel is employed. Further, when the thickness is reduced, it is not easy to correct chromatic aberration.

  Further, in Patent Document 2, it is difficult to say that chromatic aberration is sufficiently corrected and thinned because use (for example, an arrangement location) of a lens using a transparent medium is not necessarily appropriate.

  The present invention has been made in view of the above-described conventional problems, and can satisfactorily perform chromatic aberration particularly strictly required for high zoom ratio while achieving both thinness and high zoom ratio. It is an object of the present invention to provide an imaging optical system and an electronic imaging apparatus having the same.

In order to achieve the above object, an optical system according to the present invention includes a lens group disposed closest to the object side, an aperture stop disposed on the image side of the lens group, and disposed between the lens group and the aperture stop. The lens group having negative refractive power includes a cemented lens component in which a positive lens _LAP and a negative lens _LAN are cemented, and the lens group and the negative lens group An imaging optical system that performs zooming by changing the interval between lens units having refractive power, in an orthogonal coordinate system in which the horizontal axis is νdp and the vertical axis is θgFp,
θgFp = αp × νdp + βp (where αp = −0.00163)
When the straight line represented by is set, the area defined by the straight line when the range is the lower limit of the range of the following conditional expression (1) and the straight line when the upper limit is set, and the following conditional expression (2) both the area of the defined area, the is characterized in that includes a positive lens L _AP of θgF and vdp.
0.6650 <βp <0.9000 (1)
3 <νdp <27 (2)
Where θgFp is the partial dispersion ratio (ng−nF) / (nF−nC), νdp is the Abbe number, (nd−1) / (nF−nC), nd, nC, nF and ng are the d line, C Refractive index of line, F line, and g line.

Further, according to a preferred aspect of the present invention, in an orthogonal coordinate system having a horizontal axis νd and a vertical axis θhgp different from the orthogonal coordinates,
θhgp = αhgp × νdp + βhgp (where αhgp = −0.00225)
When the straight line represented by is set, the area defined by the straight line when the range is the lower limit of the range of the following conditional expression (3) and the straight line when the upper limit is set, and the following conditional expression (2) both the area of the defined area, the is characterized in that includes a positive lens L _AP of θhgp and vdp.
0.6200 <βhgp <0.9500 (3)
3 <νdp <27 (2)
Here, θhgp is a partial dispersion ratio (nh−ng) / (nF−nC), and nh is a refractive index of h-line.

According to a preferred aspect of the present invention, the following conditions are satisfied.
0.07 ≦ θgFp−θgFn ≦ 0.50 (4)
Here, ShitagFp the said partial dispersion of the positive lens _{L AP (ng-nF) /} (nF-nC), θgFn is the in partial dispersion ratio of the negative lens _{L AN (ng-nF) /} (nF-nC) .

According to a preferred aspect of the present invention, the following conditions are satisfied.
0.10 ≦ θhgp−θhgn ≦ 0.60 (5)
Here, Shitahgp the said partial dispersion of the positive lens _{L AP (nh-ng) /} (nF-nC), θhgn is the in partial dispersion ratio of the negative lens _{L AN (nh-ng) /} (nF-nC) .

According to a preferred aspect of the present invention, the following conditions are satisfied.
νdp−νdn ≦ −10 (6)
Here, vdp is the positive lens L _AP Abbe number (nd-1) / (nF -nC), νdn is the Abbe number of the negative lens _{L AN (nd-1) /} (nF-nC).

According to a preferred aspect of the present invention, the following conditions are satisfied.
1.55 ≦ ndp ≦ 1.80 (7)
Here, ndp is the refractive index at the d-line of the positive lens L _AP.

According to a preferred embodiment of the present invention, the material of the positive lens L _AP is energy curable resin, characterized in that to form a cemented lens in a manner that molded directly onto the negative lens L _AN is there.

  According to a preferred aspect of the present invention, the cemented lens component is characterized in that the cemented surface is an aspherical surface.

According to a preferred embodiment of the present invention, wherein the surface shape of the positive lens L _AP has a shape the light beam convergence weakens as the distance from the optical axis than when the spherical lens by the paraxial radius of curvature It is what.

  According to a preferred aspect of the present invention, the cemented lens component has a negative refractive power, and the lens group having the negative refractive power includes the cemented lens component disposed closest to the object side and the cemented lens component. It has at least one positive lens arranged on the image side of the lens component.

  According to a preferred aspect of the present invention, the lens group having negative refractive power includes a negative single lens disposed closest to the object side, and the lens group disposed subsequent to the image side of the negative single lens. It has a cemented lens component.

  According to a preferred aspect of the present invention, the lens group having the negative refractive power has the cemented lens component disposed closest to the image side.

In addition, an electronic imaging device of the present invention is obtained by capturing an image formed through the imaging optical system with any one of the above-described imaging optical system of the present invention, an electronic imaging device, and the electronic imaging device. Image processing means for processing the obtained image data and outputting it as image data in which the shape of the image is changed. The imaging optical system is a zoom lens, and the zoom lens is focused on an object point at infinity. Sometimes the following condition is satisfied.
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.98 (17)
Here, y ₀₇ is y ₀₇ = 0.7 · y, where y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device. represented as _10, omega _07w angle relative to the central from the optical axis direction of an object point corresponding to an image point formed at a position of y ₀₇ on the imaging surface at the wide angle end, fw is the entire system at the wide-angle end of said zoom lens The focal length.

  According to the present invention, it is possible to obtain an imaging optical system in which the chromatic aberration that is particularly strictly demanded in the case of a high zoom ratio is well corrected while achieving both a reduction in the thickness of the optical system and a high zoom ratio. In addition, by using such an imaging optical system in an electronic imaging device, it is possible to sharpen an image and prevent color blurring.

  Prior to the description of the examples, the effects of the imaging optical system of the present embodiment will be described. A lens having a positive paraxial focal length is defined as a positive lens, and a lens having a negative paraxial focal length is defined as a negative lens.

The imaging optical system according to the present embodiment includes a lens group disposed closest to the object side, an aperture stop disposed on the image side of the lens group, and a negative refractive power disposed between the lens group and the aperture stop. A lens group. The lens group having negative refractive power includes a cemented lens component in which the positive lens _LAP and the negative lens _LAN are cemented. Furthermore, the imaging optical system of the present embodiment is an optical system that performs zooming by changing the distance between the lens unit disposed closest to the object side and the lens unit having negative refractive power.

In the imaging optical system of the present embodiment, in the orthogonal coordinate system in which the horizontal axis is νdp and the vertical axis is θgFp,
θgFp = αp × νdp + βp (where αp = −0.00163)
When the straight line represented by is set, the area defined by the straight line when the range is the lower limit of the range of the following conditional expression (1) and the straight line when the upper limit is set, and the following conditional expression (2) both the area of the defined region, the contains positive lens L _AP of θgF and vdp.
0.6650 <βp <0.9000 (1)
3 <νdp <27 (2)
Where θgFp is the partial dispersion ratio (ng−nF) / (nF−nC), νdp is the Abbe number, (nd−1) / (nF−nC), nd, nC, nF and ng are the d line, C Refractive index of line, F line, and g line.

  When the upper limit value of conditional expression (1) is exceeded, axial chromatic aberration due to the secondary spectrum is overcorrected. Therefore, it is difficult to ensure the sharpness of the captured image. If the lower limit value of conditional expression (1) is not reached, axial chromatic aberration due to the secondary spectrum, that is, g-line axial chromatic aberration correction when the F-line and C-line are achromatic is not sufficient. Therefore, it is difficult to ensure the sharpness of the captured image.

  If the upper limit of conditional expression (2) is exceeded, it is difficult to erase the F-line and C-line itself, resulting in a large variation in chromatic aberration during zooming. Therefore, it is difficult to ensure the sharpness of the captured image. Even when the value is below the lower limit, the same problem as when the value exceeds the upper limit occurs.

It is more preferable that the following conditional expression (1 ′) is satisfied instead of conditional expression (1).
0.6800 <βp <0.8700 (1 ′)
Furthermore, it is more preferable that the following conditional expression (1 ″) is satisfied instead of conditional expression (1).
0.6900 <βp <0.8500 (1 ″)

By the way, it is difficult to obtain an optical material satisfying the conditions (1) and (2) from among glass materials. On the other hand, if an organic material such as a resin, or an organic / inorganic material, an optical material that satisfies the conditions (1) and (2) may be easily realized. Here, the organic / inorganic material is a material in which optical properties are changed by diffusing inorganic fine particles in the organic material. Therefore, as the optical material of the positive lens L _AP, an organic material such as a resin, or better to use an organic-inorganic materials.

In addition, when an optical material that satisfies the conditions (1) and (2) is used as the optical material of the positive lens _LAP , it is preferable to use an energy curable resin as the optical material. Then, in the production of the cemented lens component, to a method of forming direct positive lens L _AP on the negative lens L _AN is preferred. Thus, by using an energy curable resin for the positive lens _LAP , the cemented lens component can be processed (molded) as thinly as possible. Examples of the energy curable resin include an ultraviolet curable resin and a composite material in which inorganic fine particles such as TiO ₂ are diffused. Thus, in this embodiment, the joining in the cemented lens component is different from the conventional method using a bonding agent (adhesive).

Further, in the imaging optical system of the present embodiment, the orthogonal coordinate having the horizontal axis νd and the vertical axis θhgp is different from the orthogonal coordinate (the orthogonal coordinate having the horizontal axis νd and the vertical axis θgF). In the coordinate system
θhgp = αhgp × νdp + βhgp (where αhgp = −0.00225)
When the straight line represented by is set, the area defined by the straight line when the range is the lower limit of the range of the following conditional expression (3) and the straight line when the upper limit is set, and the following conditional expression (2) both the area of the defined area includes θhgp and νdp of the positive lens L _AP.
0.6200 <βhgp <0.9500 (3)
3 <νdp <27 (2)
Here, θhgp is a partial dispersion ratio (nh−ng) / (nF−nC), and nh is a refractive index of h-line.

  If the upper limit of conditional expression (3) is exceeded, axial chromatic aberration due to the secondary spectrum when used for a concave lens, that is, correction of axial chromatic aberration for h line when achromatic is applied to the F line and C line will not be sufficient. . Therefore, purple color flare and color blur are likely to occur in the captured image. If the lower limit value of conditional expression (3) is not reached, axial chromatic aberration due to the secondary spectrum, that is, correction of axial chromatic aberration of the h line when the achromaticity is applied to the F line and the C line becomes insufficient. Therefore, purple color flare and color blur are likely to occur in the captured image.

It is more preferable that the following conditional expression (3 ′) is satisfied instead of conditional expression (3).
0.6400 <βhg <0.9200 (3 ′)
It is more preferable that the following conditional expression (3 ″) is satisfied instead of conditional expression (3).
0.6700 <βhg <0.9000 (3 ″)

In the imaging optical system of the present embodiment, it is preferable that the following conditional expression (4) is satisfied.
0.07 ≦ θgFp−θgFn ≦ 0.50 (4)
Here, ShitagFp the said partial dispersion of the positive lens _{L AP (ng-nF) /} (nF-nC), θgFn is the in partial dispersion ratio of the negative lens _{L AN (ng-nF) /} (nF-nC) .

  When the conditional expression (4) is satisfied, the effect of correcting the longitudinal chromatic aberration by the secondary spectrum is increased. As a result, the sharpness of the image increases in the captured image.

It is more preferable that the following conditional expression (4 ′) is satisfied instead of conditional expression (4).
0.09 ≦ θgFp−θgFn ≦ 0.40 (4 ′)
Further, it is more preferable that the following conditional expression (4 ″) is satisfied instead of conditional expression (4).
0.11 ≦ θgFp−θgFn ≦ 0.30 (4 ″)

In the imaging optical system of the present embodiment, it is preferable that the following conditional expression (5) is satisfied.
0.10 ≦ θhgp−θhgn ≦ 0.60 (5)
Here, Shitahgp the said partial dispersion of the positive lens _{L AP (nh-ng) /} (nF-nC), θhgn is the in partial dispersion ratio of the negative lens _{L AN (nh-ng) /} (nF-nC) .

  When the conditional expression (5) is satisfied, color flare and color blur can be reduced in the captured image.

It is more preferable that the following conditional expression (5 ′) is satisfied instead of conditional expression (5).
0.13 ≦ θhgp−θhgn ≦ 0.55 (5 ′)
It is more preferable that the following conditional expression (5 ″) is satisfied instead of conditional expression (5).
0.16 ≦ θhgp−θhgn ≦ 0.50 (5 ″)

In the imaging optical system of the present embodiment, it is preferable that the following conditional expression (6) is satisfied.
νdp−νdn ≦ −10 (6)
Here, vdp is the positive lens L _AP Abbe number (nd-1) / (nF -nC), νdn is the Abbe number of the negative lens _{L AN (nd-1) /} (nF-nC).

  When the conditional expression (6) is satisfied, the C-line and F-line of the longitudinal chromatic aberration and lateral chromatic aberration can be satisfactorily erased.

It is more preferable that the following conditional expression (6 ′) is satisfied instead of conditional expression (6).
νdp−νdn ≦ −17 (6 ′)
Further, it is more preferable that the following conditional expression (6 ″) is satisfied instead of conditional expression (6).
νdp−νdn ≦ −24 (6 ″)

Further, when the imaging optical system is a zoom optical system, it is necessary to increase the refractive power in a lens group having a negative refractive power in order to achieve both high zooming and thinning. Therefore, in the imaging optical system of the present embodiment, it is preferable that the following conditional expression (7) is satisfied.
1.55 ≦ ndp ≦ 1.80 (7)
Here, ndp is the refractive index at the d-line of the positive lens L _AP.

  In the positive lens of the lens group having negative refractive power, the refractive index ndp of the d-line of the optical material is preferably slightly lower. Exceeding the upper limit of conditional expression (7) tends to be disadvantageous in terms of thinning. On the other hand, below the lower limit, it tends to be disadvantageous in correcting astigmatism.

It is more preferable that the following conditional expression (7 ′) is satisfied instead of conditional expression (7).
1.58 ≦ ndp ≦ 1.77 (7 ′)
It is more preferable that the following conditional expression (7 ″) is satisfied instead of conditional expression (7).
1.60 ≦ ndp ≦ 1.75 (7 ″)

In the imaging optical system of the present embodiment, it is preferable that the following conditional expression (8) is satisfied.
1.52 ≦ ndn ≦ 2.40 (8)
Here, ndn is the refractive index at the d-line of the negative lens L _AN.

  Exceeding the upper limit of conditional expression (8) tends to be disadvantageous in terms of thinning. On the other hand, it tends to be disadvantageous in correcting astigmatism below the lower limit.

It is more preferable that the following conditional expression (8 ′) is satisfied instead of conditional expression (8).
1.58 ≦ ndn ≦ 2.30 (8 ′)
Further, it is more preferable that the following conditional expression (8 ″) is satisfied instead of conditional expression (8).
1.67 ≦ ndn ≦ 2.20 (8 ″)

As described above, in the imaging optical system of this embodiment, the lens group having negative refractive power includes a cemented lens component. This cemented lens component is obtained by cementing the positive lens _LAP and the negative lens _LAN . Here, in this cemented lens component, it is preferably molded directly to the positive lens L _AP on the negative lens L _AN. In the case of such a molding method, it is easy to make the joining surface an aspherical surface. Therefore, by using such a molding method, it is preferable that the cemented surface of the cemented lens component be an aspheric surface also in the imaging optical system of the present embodiment.

In the image forming optical system of the present embodiment, out with the medium used and the negative lens L _AN medium used in the positive lens L _AP (optical material) (optical material), Abbe number and partial dispersion ratios are different. When media having different Abbe numbers and partial dispersion ratios are joined together, making the joining surface aspherical is effective in correcting higher-order components related to the image height of chromatic aberration of magnification and higher-order chromatic aberration components. High-order chromatic aberration components include chromatic coma and chromatic spherical aberration. As described above, when the joining surface is aspherical, an effect different from that of the aspherical surface of a normal air contact surface can be obtained.

  In the imaging optical system of the present embodiment, the negative lens group is located on the object side of the aperture stop. In particular, when the cemented surface of the negative lens group is made aspherical, it is possible to obtain a significant effect on the correction of higher-order components relating to the image height of chromatic aberration of magnification on the wide-angle side (wide-angle end) and chromatic coma aberration. Furthermore, it is better if the conditions (1) to (6) are satisfied together with the aspherical surface of the joint surface.

By the way, in description of this embodiment, the shape of a joint surface is represented by following formula (9).
z = h ² / [R [1+ {1− (1 + k) h ² / R ² } ^1/2 ]]
_{^{+ A 4 h 4 + A 6}} h 6 + A 8 h 8 + A 10 h 10 + ··· (9)

  As described above, the imaging optical system of the present embodiment has a cemented lens in a lens group having a negative refractive power. An aspheric surface is used as the cemented surface of the cemented lens. Here, as to which lens component is a cemented lens, there are a case where the second and subsequent negative lens components from the object side are cemented lenses and a case where the first negative lens component from the object side is a cemented lens. .

  First, a case where the second and subsequent negative lens components from the object side are cemented lenses will be described. In this case, the shape of the cemented surface of the cemented lens is a shape according to the above formula (9). It is preferable that the following conditional expression (10) or (11) is satisfied.

Conditional expression (10) is when the paraxial radius of curvature R _AC of the cemented surface is a positive value, that is, when the cemented lens component is constructed from the object side in the order of the negative lens L _AN and the positive lens _LAP. . In this case, it is preferable that the following conditional expression (10) is satisfied.
z _AC (h) <h ² / [R _AC [1+ {1−h ² / R _AC ² } ^1/2 ]] (10)

Conditional expression (11) indicates that when the paraxial radius of curvature R _AC of the cemented surface is a negative value, that is, when the cemented lens component is configured in the order of the positive lens L _AP and the negative lens L _AN from the object side. It is. In this case, it is preferable that the following conditional expression (11) is satisfied.
z _AC (h)> h ² / [R _AC [1+ {1−h ² / R _AC ² } ^1/2 ]] (11)

In conditional expressions (10) and (11), z _AC is the shape of the cemented surface of the cemented lens and is a shape according to the above formula (9), and h = 2.5a. Moreover, a is represented by the following formula | equation (12). Further, y ₁₀ is the distance (maximum image height) from the center to the farthest point within the effective imaging plane (within the imaging plane) of the electronic imaging device disposed in the vicinity of the imaging position of the zoom optical system of the present invention. It is. Further, fw is the focal length of the entire system at the wide-angle end of the zoom optical system, and γ is the zoom ratio (total focal length at the telephoto end / total focal length at the wide-angle end).
a = (y ₁₀ ) ² · log ₁₀ γ / fw (12)

Next, a case where the first negative lens component from the object side is a cemented lens will be described. In this case, it is preferable that conditional expression (11) is always satisfied regardless of whether the paraxial radius of curvature R _AC is positive or negative.

When z _AC exceeds the upper limit value of conditional expression (10), or lower than the lower limit value of (11), a high-order component related to the image height of chromatic aberration of magnification and the effect of correcting color coma aberration are sufficient near the wide-angle end. Can't get to. Conditional expression (10) or conditional expression (11) is preferably satisfied when the joint surface is an aspherical surface. When the joint surface is a spherical surface, the value on the left side and the value on the right side in Conditional Expression (10) and Conditional Expression (11) are the same.

Moreover, it is preferable that the imaging optical system of this embodiment satisfies the following conditional expression (13).
0.05 ≦ | z _AP (h) −z _AC (h) | /tp≦0.96 (13)
Here, z _AP is the shape of the air contact side surface of the positive lens L _AP and is a shape according to the above formula (9), and h = 2.5a. Moreover, a is represented by said Formula (12). Further, tp is the thickness on the optical axis of the positive lens L _AP, also, is always z (0) = 0.

If z _AP exceeds the upper limit value of the conditional expression (13), it is difficult to secure a peripheral edge when processing the thin positive lens _LAP . If the lower limit is not reached, correction of chromatic aberration tends to be insufficient.

It is more preferable that the following conditional expression (13 ′) is satisfied instead of conditional expression (13).
0.10 ≦ | z _AP (h) −z _AC (h) | /tp≦0.93 (13 ′)
Furthermore, it is more preferable that the following conditional expression (13 ″) is satisfied instead of conditional expression (13).
0.15 ≦ | z _AP (h) −z _AC (h) | /tp≦0.9 (13 ″)

In addition, the imaging optical system of the present embodiment may satisfy the following conditions.
0.3 ≦ tp / tn ≦ 1.4 (14)
Here, tp is the thickness on the optical axis of the positive lens L _AP, tn is the thickness on the optical axis of the negative lens L _AN.

As described above, in the imaging optical system of the present embodiment, the lens group having a negative refractive power has a cemented lens component (positive lens _LAP and negative lens L _AN ). The cemented lens component is preferably arranged in any of the following a to c in the lens group having negative refractive power.
a. The cemented lens component has a negative refractive power, and is disposed closest to the object side. At least one positive lens is arranged on the image side.
b. A negative single lens is arranged on the most object side. Then, a cemented lens component is disposed immediately on the image side.
c. The cemented lens component is arranged closest to the image side.

  The above arrangement is preferable because aberration correction at a high level can be realized in chromatic aberration correction, higher magnification, and astigmatism correction.

  As a configuration of the imaging optical system of the present embodiment, a configuration in which another lens group is disposed on the object side of the negative lens group is also conceivable. It is preferable that the other lens group has a positive refractive power. In this way, the effect when the cemented lens component is aspherical in the cemented lens component becomes more prominent. The other lens group may be the most object side lens group or a lens group different from the most object side lens group.

The imaging optical system of the present embodiment can have the following configuration when the lens group disposed on the object side is G1 and the lens group having negative refractive power is G2.
A configuration including four lens groups in order from the object side: a lens group G1, a lens group G2, a lens group G3 having a positive refractive power, and a lens group G4 having a positive refractive power.

  A configuration comprising four lens groups in order from the object side: a lens group G1, a lens group G2, a lens group G3 having a negative refractive power, and a lens group G4 having a positive refractive power.

  A configuration including four lens groups in order from the object side: a lens group G1, a lens group G2, a lens group G3 having a positive refractive power, and a lens group G4 having a negative refractive power.

  In order from the object side, a lens group G1, a lens group G2, a lens group G3 having a positive refractive power, a lens group G4 having a positive refractive power, and a lens group G5 having a negative refractive power are configured. .

  In order from the object side, a lens group G1, a lens group G2, a lens group G3 having a negative refractive power, a lens group G4 having a positive refractive power, and a lens group G5 having a positive refractive power are configured. .

  In order from the object side, the lens unit includes a lens group G1, a lens group G2, a lens group G3 having a positive refractive power, a lens group G4 having a negative refractive power, and a lens group G5 having a positive refractive power. .

  In order from the object side, a lens group G1, a lens group G2, a lens group G3 having a positive refractive power, a lens group G4 having a positive refractive power, and a lens group G5 having a positive refractive power are configured. .

By the way, suppose that an object at infinity is imaged by an optical system without distortion. In this case, since the image formed has no distortion,
f = y / tan ω (15)
Is established.
Here, y is the height of the image point from the optical axis, f is the focal length of the imaging system, and ω is the angle with respect to the optical axis in the object direction corresponding to the image point connected from the center on the imaging surface to the y position. It is.

On the other hand, if the optical system has barrel distortion,
f> y / tan ω (16)
It becomes. That is, if f and y are constant values, ω is a large value.

  Therefore, it is preferable to use an optical system that intentionally has a large barrel distortion, particularly at a focal length near the wide-angle end, for the electronic imaging device. In this case, it is possible to achieve a wider angle of view of the optical system as much as it is not necessary to correct distortion.

  However, the image of the object is formed on the electronic image pickup device in a state having barrel-shaped distortion. Therefore, in the electronic imaging device, image data obtained by the electronic imaging element is processed by image processing. In this processing, the image data (image shape) is changed so as to correct the barrel distortion.

  In this way, the finally obtained image data is image data having a shape substantially similar to the object. Therefore, an object image may be output to a CRT or printer based on the image data.

Therefore, it is preferable to use an imaging optical system that satisfies the following conditional expression (17) when focusing on an object point at infinity.
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.98 (17)
Here, y ₀₇ is y ₀₇ = 0.7 · y ₁₀ when the distance to the point farthest from the center (maximum image height) was y ₁₀ at effective imaging plane of the electronic imaging device (imaging possible plane) Ω _07w is the angle with respect to the optical axis in the object direction corresponding to the image point connecting from the center on the imaging surface at the wide angle end to the position of y ₀₇ , and fw is the focal length of the entire system at the wide angle end of the zoom lens is there.

  Conditional expression (17) defines the degree of barrel distortion at the zoom wide-angle end. If conditional expression (17) is satisfied, astigmatism can be corrected without difficulty. Further, the imaging optical system can be a bright optical system without enlarging the optical system.

  Note that an image distorted in a barrel shape is photoelectrically converted by an image sensor to become image data distorted in a barrel shape. The image data distorted into a barrel shape is electrically processed by an image processing means, which is a signal processing system of an electronic imaging device, corresponding to a change in the shape of the image. In this way, even if the image data finally output from the image processing means is reproduced on the display device, the distortion is corrected and an image substantially similar to the subject shape is obtained.

  Here, when the value exceeds the upper limit value of the conditional expression (17) and takes a value close to 1, an image in which distortion is optically corrected is obtained. Therefore, the correction performed by the image processing means can be small. However, the astigmatism of the optical system cannot be corrected sufficiently. In addition, it is difficult to widen the angle of view of the optical system while maintaining miniaturization.

  On the other hand, below the lower limit value of conditional expression (17), when the image distortion due to the distortion of the optical system is corrected by the image processing means, the stretching ratio in the radial direction around the angle of view becomes too high. As a result, in the image obtained by imaging, the sharpness degradation at the periphery of the image becomes conspicuous.

  Thus, astigmatism can be made favorable by satisfying conditional expression (17). In addition, the optical system can be thinned and the aperture ratio can be increased (for example, larger than F / 2.8 at the wide angle end).

It is more preferable that the following conditional expression (17 ′) is satisfied instead of conditional expression (17).
0.73 <y ₀₇ / (fw · tan ω _07w ) <0.96 (17 ′)
Furthermore, it is more preferable that the following conditional expression (17 ″) is satisfied instead of conditional expression (17).
0.76 <y ₀₇ / (fw · tan ω _07w ) <0.95 (17 ″)

Next, the imaging optical system of this embodiment will be described.
As the imaging optical system of the present embodiment, there are a four-group imaging optical system and a five-group imaging optical system. As the refractive power arrangement in the four-group imaging optical system, the following three are conceivable.
Positive / Negative (S) / Positive / Positive Positive / Negative (S) / Negative / Positive Positive / Negative (S) / Positive / Negative Positive is preferable. Therefore, in the embodiment, an imaging optical system having this refractive power arrangement is illustrated.

Further, the following four refractive power arrangements in the five-group imaging optical system are conceivable.
Positive, negative, (S), positive, positive, negative Positive, negative, (S), positive, negative, positive, negative, (S), positive, positive, positive, negative, negative, (S), positive・ Positive, positive, negative, (S), positive, positive, negative, or positive, negative, (S), positive, negative, positive are preferred as the refractive power arrangement. A force-arranged imaging optical system is illustrated.

  (S) shows the aperture stop. The aperture stop may or may not be independent of the lens group.

  The imaging optical system of this embodiment has positive, negative, and positive lens groups in order from the object side, regardless of the number of groups. Therefore, the positive / negative / positive configuration is shared. Further, focusing on the aperture stop, a positive lens group and a negative lens group are provided on the object side of the aperture stop. Therefore, it can be said that the imaging optical system of the present embodiment has a basic configuration of positive / negative / (S) / positive.

In this basic configuration, the following lens _LAP is used for the negative lens group disposed on the object side of the stop.

  If another lens unit is provided on the image side of the aperture stop, the other lens unit is disposed on the image side of the positive lens unit or between the stop and the positive lens unit. Can be considered.

  The imaging optical system of this embodiment is based on a three-group configuration of positive, negative, and positive. The four-group imaging optical system is obtained by adding a positive lens group or a negative lens group to the three-group imaging optical system. In addition, the imaging optical system having a five-group configuration is obtained by adding a positive lens group or a negative lens group to an imaging optical system having a positive, negative, positive, and positive four-group configuration. For example, the configuration of a four-group imaging optical system is defined as three groups on the object side (positive / negative / positive) and the final group (positive). Then, the imaging optical system having the five-group configuration can be regarded as a positive or negative lens group disposed between the three groups on the object side and the final group. Alternatively, the imaging optical system having a five-group configuration can be regarded as a negative lens group disposed further behind the final group. For the positive / negative / negative / (S) / positive / positive configuration, the basic positive / negative / (S) / positive negative lens group is divided into two groups. It can be considered that a positive lens group is added to the image side.

  In the positive / negative / (S) / positive / positive configuration, the first positive lens group has one lens component. This lens component has one positive lens or a positive single lens and a negative lens. Here, when the lens component includes a positive single lens and a negative lens, the lens component may be a cemented lens.

The negative lens group on the object side of the aperture stop, the conditional expression (1) (2) is a lens L _AP satisfying the used. The lens _LAP may be a lens satisfying (1 ′) or (1 ″) instead of (1), or satisfying (2 ′) or (2 ″) instead of (2). It is particularly preferable that the negative lens group has a cemented lens formed by cementing a plurality of lenses, and the lens _LAP is used for the cemented lens. In the cemented lens in which the lens _LAP is used, the cemented surface is preferably an aspheric surface.

Here, the cemented lens is preferably composed of a cemented lens of a positive lens and a negative lens. As described above, the positive lens of the cemented lens, the conditional expression (1) (2) is a lens L _AP satisfying the used. The lens _LAP may be a lens satisfying (1 ′) or (1 ″) instead of (1), or satisfying (2 ′) or (2 ″) instead of (2).

  The second positive lens group has one lens component. This lens component has a positive lens and a negative lens. The positive lens and the negative lens may be joined, but may not be joined (each may be separated). In any case, the positive lens should be located on the object side. When the positive lens and the negative lens are separately arranged, each of the positive lens and the negative lens can be regarded as one lens component. In this case, it can be said that the negative lens group is composed of two lens components.

  The second positive lens group may further include another lens component. This other lens component is preferably arranged closer to the object side than the lens component having the cemented lens. The second positive lens group preferably has a negative lens closest to the image side.

  The third positive lens group has one lens component. This lens component may be a single lens. Furthermore, another lens component may be provided.

  In this imaging optical system, two positive lens groups are arranged after the negative lens group. As described above, in the optical system of the modified example, another lens group is arranged between the second and third positive lens groups. This other lens group has one lens component. This lens component may be composed of a single lens.

  Then, it demonstrates for every group structure. First, an imaging optical system having a four-group configuration will be described. As an imaging optical system having a four-group structure, in order from the object side, a positive first lens group G1, a negative second lens group G2, an aperture stop, a positive third lens group G3, and a positive fourth lens group G4. It consists of four lens groups.

  The positive first lens group G1 has one lens component. This lens component is composed of a positive single lens or a cemented lens of a positive lens and a negative lens. The cemented lens is preferably configured so that the negative lens and the positive lens are arranged in this order from the object side.

  The negative second lens group G2 has two lens components or three lens components. In either case, one of the lens components is composed of a positive lens and a negative lens.

  When there are two lens components, it is preferable that one of the two lens components is a negative lens component. The other lens component is composed of a cemented lens of a positive lens and a negative lens.

  When one lens component is a negative single lens, one lens component is located closer to the object side than the other lens component. When one lens is a cemented lens, one lens component is located on the image side with respect to the other lens component. At this time, one lens component is constituted by a cemented lens of a positive lens and a negative lens.

  When there are three lens components, as described above, one lens component is composed of a positive lens and a negative lens. This lens component is composed of a cemented lens of a positive lens and a negative lens. It is preferable that the cemented lens is configured in the order of the positive lens and the negative lens from the object side. The remaining two lens components are each composed of a positive single lens and a negative single lens.

Further, at least one positive lens of the negative second lens group G2, the condition (1), have been used lens L _AP (2) are satisfied. The lens _LAP may be a lens satisfying (1 ′) or (1 ″) instead of (1), or satisfying (2 ′) or (2 ″) instead of (2). In the cemented lens in which the lens _LAP is used, the cemented surface is preferably an aspheric surface.

  The positive third lens group G3 has two lens components. Of the two lens components, one lens component is a positive lens component. The other lens component is composed of a negative lens or a cemented lens of a positive lens and a negative lens. Further, it is preferable that one lens component is located closer to the object side than the other lens component. The most image side of the positive third lens group G3 is preferably a negative lens.

  Here, one lens component is composed of one positive lens. When one lens component is composed of one positive lens, one lens component may be a positive single lens.

  The other lens component is a negative single lens or a cemented lens. When the other lens component is composed of a cemented lens, it is preferable that the cemented lens be constructed in the order of a positive lens and a negative lens from the object side. Thus, it is preferable that the most image side of the cemented lens is a negative lens.

  Thus, the positive third lens group G3 has a lens component arranged in the order of a positive lens component (one lens component) and a lens component having the cemented lens (the other lens component). The most image side is a negative lens.

  Alternatively, it is preferable that one lens component has a biconvex shape and the other lens component has a meniscus shape that is convex toward the object side. One lens component is preferably located closer to the object side than the other lens component. The most image side of the cemented lens is a negative lens.

  The positive fourth lens group G4 has one lens component. This lens component is composed of one positive lens. This lens component may be a positive single lens.

  Next, an imaging optical system having a five-group configuration will be described. The first type of imaging optical system includes, in order from the object side, a positive first lens group G1, a negative second lens group G2, an aperture stop, a positive third lens group G3, and a positive fourth lens group. It consists of five lens groups, G4 and a negative fifth lens group G5.

  The positive first lens group G1 has one lens component. This lens component is composed of a cemented lens of a positive lens and a negative lens. The cemented lens is preferably configured so that the negative lens and the positive lens are arranged in this order from the object side.

  The negative second lens group G2 has two lens components. Of the two lens components, one lens component is preferably a negative lens component. The other lens component is composed of a cemented lens of a positive lens and a negative lens. The cemented lens is preferably configured so that the negative lens and the positive lens are arranged in this order from the object side. One lens component is positioned closer to the object side than the other lens component.

Further, the negative of the positive lens in the second lens group G2, the condition (1), have been used lens L _AP (2) are satisfied. The lens _LAP may be a lens satisfying (1 ′) or (1 ″) instead of (1), or satisfying (2 ′) or (2 ″) instead of (2). In the cemented lens in which the lens _LAP is used, the cemented surface is preferably an aspheric surface.

  The positive third lens group G3 has two lens components. Of the two lens components, one lens component is a positive lens component. The other lens component is composed of a cemented lens of a positive lens and a negative lens. At this time, it is preferable that one lens component is positioned closer to the object side than the other lens component.

  Here, one lens component is composed of one positive lens. This one lens component may be a positive single lens. Moreover, it is preferable that the cemented lens in the other lens component is configured in the order of a positive lens and a negative lens from the object side.

  Thus, the positive third lens group G3 has a lens component arranged in the order of a positive lens component (one lens component) and a lens component having the cemented lens (the other lens component). The most image side is a negative lens.

  Alternatively, it is preferable that one lens component has a biconvex shape and the other lens component has a meniscus shape that is convex toward the object side. One lens component is preferably located closer to the object side than the other lens component. The most image side of the cemented lens is a negative lens.

  The positive fourth lens group G4 has one lens component. This lens component is composed of one positive lens. This lens component may be a positive single lens.

  The negative fifth lens group G5 has one lens component. This lens component is composed of one negative lens. This lens component may be a negative single lens.

  The second type of imaging optical system includes, in order from the object side, a positive first lens group G1, a negative second lens group G2, an aperture stop, a positive third lens group G3, and a negative fourth lens group. It consists of five lens groups, G4 and a positive fifth lens group G5.

  The positive first lens group G1 has three lens components. The first lens component is a negative lens component. The first lens component is composed of one negative lens. This one lens component may be a negative single lens.

  The second lens component and the third lens component are positive lens components. These lens components are composed of one positive lens. These lens components may be positive single lenses. It is preferable that the first lens component, the second lens component, and the third lens component are arranged in this order from the object side.

  The negative second lens group G2 has four lens components. The first lens component is composed of a positive lens and a negative lens. The first lens component is composed of a cemented lens of a positive lens and a negative lens. It is preferable that the cemented lens is configured in the order of the positive lens and the negative lens from the object side.

  The second lens component and the third lens component are negative lens components. On the other hand, the fourth lens component is a positive lens component. These lens components are composed of one negative lens or positive lens. These lens components may be a negative single lens or a positive single lens. It is preferable that the first lens component, the second lens component, the third lens component, and the fourth lens component are arranged in this order from the object side.

Further, the negative of the positive lens in the second lens group G2, the condition (1), have been used lens L _AP (2) are satisfied. The lens _LAP may be a lens satisfying (1 ′) or (1 ″) instead of (1), or satisfying (2 ′) or (2 ″) instead of (2). In the cemented lens in which the lens _LAP is used, the cemented surface is preferably an aspheric surface.

  The positive third lens group G3 has two lens components. Of the two lens components, one lens component is a positive lens component. The other lens component is composed of a cemented lens of a positive lens and a negative lens. At this time, it is preferable that one lens component is positioned closer to the object side than the other lens component.

  Here, one lens component is composed of one positive lens. This one lens component may be a positive single lens. Further, it is preferable that the cemented lens in the other lens component is configured in the order of the negative lens and the positive lens from the object side.

  The negative fourth lens group G4 has one lens component. This lens component is composed of a cemented lens of a positive lens and a negative lens. The cemented lens is preferably configured so that the negative lens and the positive lens are arranged in this order from the object side.

  The positive fifth lens group G5 has two lens components. Of the two lens components, one lens component is a positive lens component. The other lens component is composed of a cemented lens of a positive lens and a negative lens. At this time, it is preferable that one lens component is positioned closer to the object side than the other lens component.

  Here, one lens component is composed of one positive lens. This one lens component may be a positive single lens. Moreover, it is preferable that the cemented lens in the other lens component is configured in the order of a positive lens and a negative lens from the object side.

  In addition, as described above, if the distortion generated in the imaging optical system is corrected by the image processing function of the electronic imaging apparatus, other aberrations can be corrected satisfactorily, and at the same time, a wider angle can be obtained. is there.

  In each of the imaging optical systems described so far, the lens satisfying the conditional expressions (1) and (2) is preferably a positive lens as described above. This positive lens preferably satisfies (1 ') or (1 ") instead of (1) and (2') or (2") instead of (2).

  Each imaging optical system described so far is a zoom lens. In such a zoom lens, it is preferable that the zoom lens is an optical system in which the relative distance between the lens groups changes during zooming.

  Each imaging optical system may include a prism. In the image forming optical system, when the lens unit closest to the object side includes a prism, it is preferable that the position of the lens group closest to the object side is fixed at the time of zooming from the wide-angle end to the telephoto end. If the most object-side lens group does not include a prism, the most object-side lens group draws a convex locus on the image side along the optical axis during zooming from the wide-angle end to the telephoto end. Move monotonously to the object side.

  In addition, the second positive lens unit from the object side monotonously moves to the object side with zooming from the wide angle end to the telephoto end.

  Note that the refractive power of one lens can be borne by a plurality of lenses. Therefore, in each lens group described above, for example, one lens can be replaced with two lenses. However, from the viewpoint of size reduction and thickness reduction, it is preferable that the number of lenses to be replaced is two. Although the replacement may be performed in each lens group, it is preferable that the number of lens groups to be replaced is small from the viewpoint of miniaturization and thinning.

In the case of using a lens L _AP in the cemented lens, the lens L _AP will be bonded to the lens L _AN. In this case, the optical axis center thickness of the lens L _AP is preferably thinner than the lens L _AN. The lens L _AP of the optical axis center thickness t1 is preferably satisfies the following conditional expression (18).
0.1 <t1 <2.5 (18)

By satisfying the above conditions, it is possible to reduce the size of the optical system. Also, if obtained by molding the lens L _AP, enabling stable molding.

It is more preferable that the following conditional expression (18 ′) is satisfied instead of conditional expression (18).
0.2 <t1 <2.0 (18 ′)
Furthermore, it is more preferable that the following conditional expression (18 ″) is satisfied instead of conditional expression (18).
0.3 <t1 <1.5 (18 ")

In addition, it is preferable that at least one surface of the lens _LAP is an aspherical surface. More preferably, both sides are aspherical.

  Incidentally, the chromatic aberration due to the secondary spectrum includes axial chromatic aberration (chromatic aberration at the focal position) and lateral chromatic aberration. Of these, the above conditions and configuration are very effective for correcting the axial chromatic aberration and the lateral chromatic aberration on the telephoto side of the entire zoom range. It may become. However, high-order component aberrations related to image height, such as lateral chromatic aberration, can be improved by other means. As an example, there is a means for improving aberration by image processing.

  Here, it is assumed that the image pickup optical system, the electronic image pickup device, and the image processing unit are mounted on the electronic image pickup apparatus. The image processing unit can process the image data and output it as image data having a changed shape. An image of a subject is captured using such an electronic imaging device. Image data obtained by imaging is color-separated by an image processing unit, and becomes image data for each color. Subsequently, after changing the shape (the size of the image of the subject) for each image data, these image data are synthesized. As a result, it is possible to prevent sharpness degradation and color blurring at the periphery of the image due to lateral chromatic aberration. This method is particularly effective for an electronic imaging apparatus having an electronic imaging element provided with a color separation mosaic filter. In the case where the electronic imaging apparatus has a plurality of (for each color) electronic imaging elements, it is not necessary to perform color separation on the obtained image data.

  The imaging optical system of the present invention can achieve both downsizing and thinning of the imaging optical system by satisfying or having the conditional expressions and structural features described above individually. Good aberration correction can be realized. In addition, the imaging optical system of the present invention can be provided with (satisfied with) the above conditional expressions and structural features in combination. In this case, the imaging optical system can be further reduced in size and thickness, or better aberration correction and a wider angle of the optical system can be achieved.

  In addition, the electronic imaging apparatus having the imaging optical system of the present invention is provided with such an imaging optical system, so that it is possible to sharpen the image and prevent color blur in the captured image.

  A zoom lens according to Example 1 of the present invention will be described. FIGS. 1A and 1B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to the first embodiment of the present invention when focusing on an object point at infinity. FIG. 1A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end. The numbers in r1, r2,... And the numbers in d1, d2,... Described in the lens cross-sectional views correspond to the numbers in the surface number column in the numerical data described later.

  2A and 2B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 1 is focused on an object point at infinity, where FIG. 2A is a wide angle end, and FIG. 2B is an intermediate focus. The distance state, (c) shows the state at the telephoto end. FIY represents the image height. The symbols in the aberration diagrams are the same in the examples described later.

  As shown in FIG. 1, the zoom lens according to the first embodiment includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4. In all the following examples, in the lens cross-sectional views, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a cemented lens of a negative meniscus lens L1 having a convex surface directed toward the object side and a positive biconvex lens L2, and has a positive refractive power as a whole.

The second lens group G2 includes a cemented lens of a negative meniscus lens L3 having a convex surface facing the object side, a positive meniscus lens L4 having a convex surface facing the image side, and a negative meniscus lens L5 having a convex surface facing the image side. And has a negative refractive power as a whole. A positive meniscus lens L4 having a convex surface directed toward the image side corresponds to a positive lens L _AP, a negative meniscus lens L5 having a convex surface directed toward the image side corresponds to a negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L6, a cemented lens including a positive meniscus lens L7 having a convex surface directed toward the object side and a negative meniscus lens L8 having a convex surface directed toward the object side, and is positively refracted as a whole. Have power.

  The fourth lens group G4 includes a positive biconvex lens L9, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 once moves to the image side, then the moving direction reverses and moves to the object side, and the second lens group G2 temporarily moves to the image side. Then, the moving direction reverses and moves to the object side, the third lens group G3 moves to the object side integrally with the aperture stop S, and the fourth lens group G4 once moves to the object side and then the moving direction is reversed. And move to the image side.

An aspherical surface is a negative image with the image side surface of the positive biconvex lens L2 in the first lens group G1, both surfaces of the positive meniscus lens L4 with the convex surface facing the image side in the second lens group G2, and the convex surface toward the image side. It is provided on the image side surface of the meniscus lens L5, on both sides of the positive biconvex lens L6 in the third lens group G3, and on the object side surface of the positive biconvex lens L9 in the fourth lens group G4. Thus, in this embodiment, an aspherical surface is used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 2 of the present invention will be described. FIGS. 3A and 3B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to the second embodiment of the present invention when focusing on an object point at infinity, where FIG. 3A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  4A and 4B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 2 is focused on an object point at infinity, where FIG. 4A is a wide angle end, and FIG. 4B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 3, the zoom lens of Example 2 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4 and the fifth lens group G5 are included.

  The first lens group G1 includes a cemented lens of a negative meniscus lens L1 having a convex surface directed toward the object side and a positive biconvex lens L2, and has a positive refractive power as a whole.

The second lens group G2 includes a negative biconcave lens L3, and a cemented lens of a negative biconcave lens L4 and a positive biconvex lens L5, and has a negative refracting power as a whole. Positive biconvex lens L5 corresponds to the positive lens L _AP, a negative biconcave lens L4 corresponds to the negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L6, a cemented lens including a positive meniscus lens L7 having a convex surface directed toward the object side and a negative meniscus lens L8 having a convex surface directed toward the object side, and is positively refracted as a whole. Have power.

  The fourth lens group G4 includes a positive meniscus lens L9 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fifth lens group G5 includes a negative meniscus lens L10 having a convex surface directed toward the image side, and has a negative refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 once moves to the image side, then the moving direction reverses and moves to the object side, and the second lens group G2 moves to the image side. The third lens group G3 moves to the object side integrally with the aperture stop S, and the fourth lens group G4 once moves to the object side, then the moving direction is reversed and moves to the image side, and the fifth lens group G5 is moved. Is fixed.

The aspheric surfaces are the image-side surface of the positive biconvex lens L2 in the first lens group G1, the double-sided negative biconcave lens L4 in the second lens group G2, the image-side surface of the positive biconvex lens L5, and the third lens group G3. The surfaces on both sides of the middle positive biconvex lens L6, the object side surface of the positive meniscus lens L9 with the convex surface facing the object side in the fourth lens group G4, and the negative surface with the convex surface facing the image side in the fifth lens group G5 It is provided on the object side surface of the meniscus lens L10. Thus, in this embodiment, an aspherical surface is used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

Next, a zoom lens according to embodiment 3 of the present invention will be described. FIGS. 5A and 5B are cross-sectional views along the optical axis showing an optical configuration when focusing on an object point at infinity of a zoom lens according to Example 3 of the present invention, where FIG. 5A is a wide-angle end, and FIG. 5B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  6A and 6B are diagrams illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 3 is focused on an object point at infinity, in which FIG. 6A is a wide-angle end, and FIG. 6B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 5, the zoom lens of Example 3 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4.

  The first lens group G1 includes a cemented lens of a negative meniscus lens L1 having a convex surface directed toward the object side and a positive biconvex lens L2, and has a positive refractive power as a whole.

The second lens group G2 includes a cemented lens of a negative biconcave lens L3 and a positive meniscus lens L4 having a convex surface facing the object side, a negative meniscus lens L5 having a convex surface facing the image side, and a positive meniscus lens having a convex surface facing the image side. It is composed of a cemented lens with L6 and has a negative refractive power as a whole. A positive meniscus lens L4 having a convex surface directed toward corresponds to the positive lens L _AP, a negative biconcave lens L3 corresponds to the negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L7, a cemented lens including a positive meniscus lens L8 having a convex surface directed toward the object side and a negative meniscus lens L9 having a convex surface directed toward the object side, and is positively refracted as a whole. Have power.

  The fourth lens group G4 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 moves to the image side, and the third lens group G3 is integrated with the aperture stop S. The fourth lens group G4 once moves to the object side and then moves in the reverse direction and moves to the image side.

The aspherical surface is the image side surface of the positive biconvex lens L2 in the first lens group G1, both surfaces of the negative biconcave lens L3 in the second lens group G2, and the image side of the positive meniscus lens L4 with the convex surface facing the object side. A surface on both sides of the positive biconvex lens L6 in the third lens group G3, and an object side surface of the positive meniscus lens L9 with the convex surface facing the object side in the fourth lens group G4. Thus, in this embodiment, an aspherical surface is used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 4 of the present invention will be described. FIGS. 7A and 7B are cross-sectional views along the optical axis showing the optical configuration when focusing on an object point at infinity of a zoom lens according to Example 4 of the present invention, where FIG. 7A is a wide angle end, and FIG. 7B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  8A and 8B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 4 is focused on an object point at infinity, in which FIG. 8A is a wide-angle end, and FIG. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 7, the zoom lens of Example 4 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4.

  The first lens group G1 includes a cemented lens of a negative meniscus lens L1 having a convex surface facing the object side and a positive meniscus lens L2 having a convex surface facing the object side, and has a positive refractive power as a whole. Yes.

The second lens group G2 includes a negative meniscus lens L3 having a convex surface facing the object side, a cemented lens of a positive meniscus lens L4 having a convex surface facing the image side and a negative biconcave lens (close to a plano-concave lens) L5, and a positive biconvex lens L6. It has a negative refractive power as a whole. A positive meniscus lens L3 having a convex surface directed toward the image side corresponds to a positive lens L _AP, a negative meniscus lens L4 having a convex surface directed toward the image side corresponds to a negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L7, a cemented lens including a positive meniscus lens L8 having a convex surface directed toward the object side and a negative meniscus lens L9 having a convex surface directed toward the object side, and is positively refracted as a whole. Have power.

  The fourth lens group G4 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 once moves to the image side, then the moving direction reverses and moves to the object side, and the second lens group G2 temporarily moves to the image side. Then, the moving direction reverses and moves to the object side, the third lens group G3 moves to the object side integrally with the aperture stop S, and the fourth lens group G4 once moves to the object side and then the moving direction is reversed. And move to the image side.

The aspherical surfaces are both surfaces of the positive meniscus lens L3 having a convex surface facing the image side in the second lens group G2, the image side surfaces of the negative biconcave lens L5, and both surfaces of the positive biconvex lens L7 in the third lens group G3. The positive meniscus lens L10 having a convex surface facing the object side in the fourth lens group G4 is provided on the object side surface. Thus, in this embodiment, an aspherical surface is used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 5 of the present invention will be described. 9A and 9B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 5 of the present invention when focusing on an object point at infinity, where FIG. 9A is a wide-angle end, and FIG. 9B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  10A and 10B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 5 is focused on an object point at infinity, where FIG. 10A is a wide-angle end, and FIG. 10B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 9, the zoom lens of Example 5 includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4.

  The first lens group G1 includes a cemented lens of a negative meniscus lens L1 having a convex surface facing the object side and a positive meniscus lens L2 having a convex surface facing the object side, and has a positive refractive power as a whole. Yes.

The second lens group G2 includes a cemented lens of a positive biconvex lens L3 and a negative biconcave lens L4, a positive meniscus lens L5 having a convex surface facing the image side, and a positive biconvex lens L6, and has a negative refractive power as a whole. Have. Positive biconvex lens L3 corresponds to the positive lens L _AP, a negative biconcave lens L4 corresponds to the negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L7, a cemented lens including a positive meniscus lens L8 having a convex surface directed toward the object side and a negative meniscus lens L9 having a convex surface directed toward the object side, and is positively refracted as a whole. Have power.

  The fourth lens group G4 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 once moves to the image side, then the moving direction reverses and moves to the object side, and the second lens group G2 temporarily moves to the image side. Then, the moving direction reverses and moves to the object side, the third lens group G3 moves to the object side integrally with the aperture stop S, and the fourth lens group G4 once moves to the object side and then the moving direction is reversed. And move to the image side. The second lens group G2 has a slight difference between the intermediate position and the telephoto end position.

The aspherical surfaces are both surfaces of the positive biconvex lens L3 in the second lens group G2, the image side surface of the negative biconcave lens L5, the surfaces on both sides of the positive biconvex lens L7 in the third lens group G3, and the fourth lens group G4. Is provided on the object side surface of the positive meniscus lens L10 having a convex surface facing the object side. Thus, in this embodiment, an aspherical surface is used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 6 of the present invention will be described. 11A and 11B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 6 of the present invention when focusing on an object point at infinity. FIG. 11A is a wide angle end, and FIG. 11B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  12A and 12B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 6 is focused on an object point at infinity, where FIG. 12A is a wide angle end, and FIG. 12B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 11, the zoom lens of Example 6 includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4 and the fifth lens group G5 are included.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface facing the object side, a positive meniscus lens L2 having a convex surface facing the object side, and a positive meniscus lens L3 having a convex surface facing the object side. Has positive refractive power.

The second lens group G2 includes a cemented lens of a positive biconvex lens L4 and a negative biconcave lens L5, a negative biconcave lens L6, a negative biconcave lens L7, and a positive biconvex lens L8, and has a negative refracting power as a whole. ing. Positive biconvex lens L4 corresponds to the positive lens L _AP, a negative biconcave lens L5 corresponds to the negative lens L _AN.

  The third lens group G3 includes a positive meniscus lens L9 having a convex surface directed toward the object side, and a cemented lens formed of a negative meniscus lens L10 having a convex surface directed toward the object side and a positive biconvex lens L11, and is positively refracted as a whole. Have power.

  The fourth lens group G4 includes a cemented lens which is formed by a negative biconcave lens L12 and a positive meniscus lens L13 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fifth lens group G5 includes a positive biconvex lens L14, a cemented lens including a positive meniscus lens L15 having a convex surface directed toward the image side, and a negative meniscus lens L16 having a convex surface directed toward the image side, and has a positive refracting power as a whole. have.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 once moves to the image side, then the moving direction reverses and moves to the object side, and the second lens group G2 moves to the image side. The aperture stop S is fixed, the third lens group G3 is moved to the object side, the fourth lens group G4 is once moved to the object side, and then the moving direction is reversed and moved to the image side, and the fifth lens group G5 is moved to the image side. After moving to the object side, the moving direction is reversed and moved to the image side.

The aspherical surfaces are the double-sided positive biconvex lens L4 in the second lens group G2, the object-side surface of the negative biconcave lens L7, and the object side of the positive meniscus lens L9 with the convex surface facing the object side in the third lens group G3. And the object side surface of the positive biconvex lens L14 in the fifth lens group G5. Thus, in this embodiment, an aspherical surface is used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 7 of the present invention will be described. FIGS. 13A and 13B are cross-sectional views along the optical axis showing the optical configuration when focusing on an object point at infinity of a zoom lens according to Example 7 of the present invention. FIG. 13A is a wide-angle end, and FIG. 13B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  14A and 14B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 7 is focused on an object point at infinity, where FIG. 14A is a wide angle end, and FIG. 14B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 13, the zoom lens according to the seventh exemplary embodiment includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4.

  The first lens group G1 is composed of a positive biconvex lens L1, and has a positive refractive power as a whole.

The second lens group G2 includes a negative biconcave lens L2, a cemented lens of a positive meniscus lens L3 having a convex surface directed toward the image side, and a negative biconcave lens L4, and has a negative refracting power as a whole. The positive meniscus lens L3 having a convex surface directed toward the image side corresponds to a positive lens L _AP, a negative biconcave lens L4 corresponds to the negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L5 and a negative meniscus lens L6 having a convex surface directed toward the object side, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a positive biconvex lens L7, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 moves to the object side, and the third lens group G3 is integrated with the aperture stop S. Then, the fourth lens group G4 once moves to the image side and then reverses its moving direction to move to the object side.

The aspheric surfaces are surfaces on both sides of the positive biconvex lens L1 in the first lens group G1, both surfaces of the negative biconcave lens L2 in the second lens group G2, and the object side surface of the positive meniscus lens L3 with the convex surface facing the image side. , Provided on both surfaces of the positive biconvex lens L5 in the third lens group G3, and on the object side surface of the positive biconvex lens L7 in the fourth lens group G4. In this embodiment, an aspheric surface is not used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 8 of the present invention will be described. 15A and 15B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 8 of the present invention when focusing on an object point at infinity, where FIG. 15A is a wide angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 16 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 8 is focused on an object point at infinity, where (a) is a wide angle end and (b) is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 15, the zoom lens of Example 8 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4.

  The first lens group G1 is composed of a positive biconvex lens L1, and has a positive refractive power as a whole.

The second lens group G2 includes a cemented lens including a negative biconcave lens L2, a negative biconcave lens L3, and a positive meniscus lens L4 having a convex surface directed toward the object side, and has a negative refractive power as a whole. The positive meniscus lens L4 having a convex surface directed toward the object side corresponds to the positive lens L _AP, a negative biconcave lens L3 corresponds to the negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L5 and a negative meniscus lens L6 having a convex surface directed toward the object side, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a positive meniscus lens L7 having a convex surface directed toward the image side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 moves to the object side, and the third lens group G3 is integrated with the aperture stop S. Then, the fourth lens group G4 once moves to the image side and then reverses its moving direction to move to the object side.

The aspherical surfaces are surfaces on both sides of the positive biconvex lens L1 in the first lens group G1, both surfaces of the negative biconcave lens L2 in the second lens group G2, and the image side surface of the positive meniscus lens L4 with the convex surface facing the object side. The positive biconvex lens L5 in the third lens group G3 is provided on both sides of the surface, and the positive meniscus lens L7 in the fourth lens group G4 is provided on the object side surface with the convex surface facing the image side. In this embodiment, an aspheric surface is not used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 9 of the present invention will be described. FIGS. 17A and 17B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 9 of the present invention when focusing on an object point at infinity, where FIG. 17A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  18A and 18B are diagrams illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 9 is focused on an object point at infinity, in which FIG. 18A is a wide angle end, and FIG. 18B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 17, the zoom lens according to the ninth embodiment includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4.

  The first lens group G1 is composed of a positive biconvex lens L1, and has a positive refractive power as a whole.

The second lens group G2 includes a cemented lens including a negative biconcave lens L2, a negative biconcave lens L3, and a positive meniscus lens L4 having a convex surface directed toward the object side, and has a negative refractive power as a whole. The positive meniscus lens L4 having a convex surface directed toward the object side corresponds to the positive lens L _AP, a negative biconcave lens L3 corresponds to the negative lens L _AN.

  The third lens group G3 includes a positive biconvex lens L5, a cemented lens including a positive meniscus lens L6 having a convex surface directed toward the object side and a negative meniscus lens L7 having a convex surface directed toward the object side, and has a positive refracting power as a whole. have.

  The fourth lens group G4 includes a positive meniscus lens L8 having a convex surface directed toward the image side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 moves to the image side, and the third lens group G3 is integrated with the aperture stop S. Then, the fourth lens group G4 once moves to the image side and then reverses its moving direction to move to the object side. The second lens group G2 has a slight difference between the intermediate position and the telephoto end position.

The aspherical surfaces are surfaces on both sides of the positive biconvex lens L1 in the first lens group G1, surfaces on both sides of the negative biconcave lens L2 in the second lens group G2, and surfaces on both sides of the positive biconvex lens L5 in the third lens group G3. It is provided on the object side surface of the positive meniscus lens L7 having a convex surface facing the image side in the four lens group G4. In this embodiment, an aspheric surface is not used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, a zoom lens according to embodiment 10 of the present invention will be described. 19A and 19B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 10 of the present invention when focusing on an object point at infinity. FIG. 19A is a wide-angle end, and FIG. 19B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  FIG. 20 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 10 is focused on an object point at infinity, where (a) is the wide-angle end and (b) is the intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 19, the zoom lens according to the tenth embodiment includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface directed toward the object side and a positive meniscus lens L2 having a convex surface directed toward the object side, and has a positive refractive power as a whole.

The second lens group G2 includes a negative meniscus lens L3 having a convex surface facing the object side, a cemented lens of a negative meniscus lens L4 having a convex surface facing the object side, and a positive meniscus lens L5 having a convex surface facing the object side. And has a negative refractive power as a whole. The negative meniscus lens L4 having a convex surface directed toward the object side corresponds to the positive lens L _AN, positive meniscus lens L5 having a convex surface directed toward the object side corresponds to the negative lens L _AP.

  The third lens group G3 includes a positive biconvex lens L6, a cemented lens including a positive meniscus lens L7 having a convex surface directed toward the object side and a negative meniscus lens L8 having a convex surface directed toward the object side, and is positively refracted as a whole. Have power.

  The fourth lens group G4 includes a positive biconvex lens L9, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 moves to the image side, and the third lens group G3 is integrated with the aperture stop S. Then, the fourth lens group G4 once moves to the image side and then reverses its moving direction to move to the object side.

The aspherical surface includes both surfaces of a negative meniscus lens L3 having a convex surface facing the object side in the second lens group G2, both surfaces of a negative meniscus lens L4 having a convex surface facing the object side, and a positive meniscus lens L5 having a convex surface facing the object side. On the image side, and on both sides of the positive biconvex lens L6 in the third lens group G3. Thus, in this embodiment, an aspherical surface is used for the cemented surface of the positive lens _LAP and the negative lens _LAN .

  Next, numerical data of optical members constituting the zoom lens of each of the above embodiments will be listed. In the numerical data of each example, the r column represents the radius of curvature of each lens surface, the d column represents the thickness or air spacing of each lens, the nd column represents the refractive index of each lens at the d-line, and νd Column represents the Abbe number of each lens. * Indicates an aspherical surface, and STO indicates an aperture.

The aspherical shape is expressed by the following equation when the optical axis direction is z, the direction orthogonal to the optical axis is y, the conical coefficient is K, and the aspherical coefficients are A4, A6, A8, and A10. .
z = (y ² / r) / [1+ {1− (1 + K) (y / r) ² } ^1/2 ]
+ A4y ⁴ + A6y ⁶ + A8y ⁸ + A10y ¹⁰
Here, in the aspheric data, E represents a power of 10. In addition, when the aspheric coefficient is not described, the value of the aspheric coefficient is zero. The symbols of these specification values are common to the numerical data of the examples described later.

Example 1
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 26.4450 0.8000 1.84666 23.78
2 13.8156 2.7000 1.73077 40.51
3 * -192.7244 Variable
4 43.7694 0.7000 1.69680 55.53
5 10.8906 2.2000
6 * -15.3637 1.0000 1.63494 23.22
7 * -6.7944 0.9000 1.74320 49.34
8 * -208.0010 Variable
9 (Aperture) ∞ 0.8000
10 * 24.1688 1.8000 1.74250 49.20
11 * -19.2188 0.1500
12 5.4497 2.7000 1.69680 55.53
13 13.4248 0.6000 1.84666 23.78
14 4.2048 Variable
15 * 10.9456 2.0000 1.58313 59.46
16 -35.4704 Variable
17 ∞ 0.7580 1.54771 62.84
18 ∞ 0.4787
19 ∞ 0.3989 1.51633 64.14
20 ∞ 1.3603
Image plane ∞

Aspheric coefficient third surface
K = -0.1059, A2 = 0.0000E + 00, A4 = 3.4600E-07, A6 = 4.6678E-09
6th page
K = -0.6957, A2 = 0.0000E + 00, A4 = -1.2458E-04, A6 = 3.0542E-06
7th page
K = -0.7528, A2 = 0.0000E + 00, A4 = -4.3041E-04, A6 = 2.1935E-05
8th page
K = -0.9690, A2 = 0.0000E + 00, A4 = -1.3472E-04, A6 = 7.2254E-06
10th page
K = 3.7659, A2 = 0.0000E + 00, A4 = -3.8282E-04, A6 = 1.5704E-05
11th page
K = -0.9658, A2 = 0.0000E + 00, A4 = -2.2045E-04, A6 = 1.4126E-05
15th page
K = -0.9236, A2 = 0.0000E + 00, A4 = 3.1124E-05, A6 = 2.9451E-07

Various data
Zoom ratio 4.99
Wide angle Medium telephoto Focal length 7.00943 15.64607 35.00249
F number 2.8400 2.9504 3.8784
Angle of view 30.3 ° 12.9 ° 5.8 °
Image height 3.600 3.600 3.600
Total lens length 46.9634 45.9916 55.4100
BF 1.36028 1.36028 1.36028

d3 0.65000 8.83784 14.65673
d8 17.19034 6.04002 1.50167
d14 7.65597 6.42400 15.77566
d16 2.12115 5.35351 4.13256

Zoom group data Group Start surface Focal length
1 1 36.57282
2 4 -9.33696
4 10 12.64978
5 15 14.57546

[Glass Material Refractive Index Table] ... List of Refractive Indexes by Wavelength of Medium Used in This Example Lens 587.56 656.27 486.13 435.84 404.66
L6 1.742499 1.737967 1.753057 1.761415 1.768384
LPF 1.547710 1.545046 1.553762 1.558427 1.562262
L4 1.634940 1.627290 1.654640 1.674080 1.693923
L2 1.730770 1.725416 1.743456 1.753787 1.762674
L9 1.583130 1.580140 1.589950 1.595245 1.599635
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L3, L7 1.696797 1.692974 1.705522 1.712339 1.718005
L5 1.743198 1.738653 1.753716 1.762046 1.769040
L1, L8 1.846660 1.836488 1.872096 1.894186 1.914294

(Example 2)
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 20.6255 0.8000 1.84666 23.78
2 13.9081 2.7000 1.72916 54.68
3 * -429.2393 Variable
4 -71.3036 0.7000 1.83400 47.50
5 7.0567 2.3000
6 * -17.7280 0.9000 1.52540 56.25
7 * 38.4125 1.0000 1.63494 23.22
8 * -24.7821 variable
9 (Aperture) ∞ 0.8000
10 * 46.7651 1.8000 1.74250 49.20
11 * -13.7731 0.1500
12 5.4388 2.7000 1.72916 54.68
13 14.9607 0.6000 1.84666 23.78
14 4.0856 Variable
15 * 12.5033 2.0000 1.80610 40.92
16 178.6526 Variable
17 * -16.6330 0.7000 1.68893 31.07
18 -495.0834 1.2000
19 ∞ 0.3989 1.51633 64.14
20 ∞ 1.3599
Image plane ∞

Aspheric coefficient third surface
K = -2.6460, A2 = 0.0000E + 00, A4 = 70048E-06, A6 = -7.8418E-09
6th page
K = -0.0888, A2 = 0.0000E + 00, A4 = -6.0756E-04, A6 = -1.1968E-05
7th page
K = -0.0352, A2 = 0.0000E + 00, A4 = 9.0930E-04, A6 = -9.5327E-05
8th page
K = 0.1403, A2 = 0.0000E + 00, A4 = -4.4746E-04, A6 = -1.8325E-05
10th page
K = 3.7752, A2 = 0.0000E + 00, A4 = -6.4542E-04, A6 = -1.8902E-05
11th page
K = -0.9643, A2 = 0.0000E + 00A4 = -5.0209E-04, A6 = -1.5123E-05
15th page
K = -0.9310, A2 = 0.0000E + 00, A4 = 3.1658E-05, A6 = -1.0681E-06
17th page
K = 0.2901, A2 = 0.0000E + 00, A4 = 6.7915E-05, A6 = 1.2105E-05

Various data
Zoom ratio 5.00
Wide angle Medium telephoto Focal length 6.99779 15.65043 34.99934
F number 2.8485 2.9580 3.3281
Angle of view 30.4 ° 13.0 ° 5.8 °
Image height 3.600 3.600 3.600
Total lens length 46.3860 46.0724 49.0017
BF 1.35992 1.35992 1.35992

d3 0.65000 8.14584 13.69497
d8 16.04662 6.82665 1.49962
d14 7.67358 6.43891 10.47855
d16 1.90694 4.55291 3.22220

Zoom group data Group Start surface Focal length
1 1 29.12695
2 4 -7.90511
3 10 12.31786
4 15 16.58901
5 17 -24.99746

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L4 1.525399 1.522577 1.531916 1.537043 1.541302
L6 1.742499 1.737967 1.753057 1.761415 1.768384
L3 1.833998 1.828719 1.846274 1.855936 1.863939
L5 1.634940 1.627290 1.654640 1.675046 1.696625
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L9 1.806098 1.800248 1.819945 1.831173 1.840781
L2, L7 1.729157 1.725101 1.738436 1.745696 1.751731
L1, L8 1.846660 1.836488 1.872096 1.894186 1.914294
L10 1.688931 1.682495 1.704665 1.717973 1.729809

(Example 3)
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 22.3011 0.8000 1.84666 23.78
2 14.5807 2.7000 1.72916 54.68
3 * -123.6163 variable
4 * -150.0110 0.7000 1.83481 41.20
5 * 6.2675 0.7000 1.63494 23.22
6 * 8.4255 2.2000
7 -5.4484 0.5000 1.73077 40.51
8 -21.1624 1.7000 1.84666 23.78
9 -8.9634 Variable
9 (Aperture) ∞ 0.8000
11 * 46.9891 1.8000 1.74250 49.20
12 * -12.9980 0.1500
13 4.8319 2.7000 1.72916 54.68
14 13.0488 0.6000 1.84666 23.78
15 3.4629 Variable
16 * 11.4921 2.0000 1.80610 40.92
17 31.5683 Variable
18 ∞ 0.7000 1.51633 64.14
19 ∞ 1.2000
20 ∞ 0.3989 1.51633 64.14
21 ∞ 1.3606
Image plane ∞

Aspheric coefficient third surface
K = -2.6001, A2 = 0.0000E + 00, A4 = 9.4098E-06, A6 = -1.0705E-08
4th page
K = -5.6535, A2 = 0.0000E + 00, A4 = -3.2210E-04, A6 = 1.5806E-05
5th page
K = 0.1554, A2 = 0.0000E + 00, A4 = 1.4592E-03, A6 = -1.1506E-04
6th page
K = -0.0369, A2 = 0.0000E + 00, A4 = -1.4646E-03, A6 = 6.8925E-05
11th page
K = -4.5289, A2 = 0.0000E + 00, A4 = -5.9132E-04, A6 = -1.3420E-05
12th page
K = -0.9753, A2 = 0.0000E + 00, A4 = -4.1911E-04, A6 = -1.0659E-05
16th page
K = -0.9276, A2 = 0.0000E + 00, A4 = 1.0972E-04, A6 = 1.9456E-06

Various data
Zoom ratio 5.00
Wide angle Medium telephoto Focal length 6.99739 15.64844 35.00010
F number 2.8574 3.2489 3.3981
Angle of view 30.4 ° 13.1 ° 5.8 °
Image height 3.600 3.600 3.600
Total lens length 44.4352 46.2219 48.9999
BF 1.36057 1.36057 1.36057

d3 1.00000 7.25094 13.61920
d9 13.20900 5.59593 1.00016
d15 7.70269 7.43689 10.04045
d17 1.51403 4.92959 3.33339

Zoom group data Group Start surface Focal length
1 1 28.11859
2 4 -7.20124
4 11 11.36437
5 16 21.46279

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L7 1.742499 1.737967 1.753057 1.761415 1.768384
L3 1.834808 1.828801 1.849061 1.860573 1.870337
L4 1.634940 1.627290 1.654640 1.674562 1.695271
L5 1.730770 1.725416 1.743456 1.753787 1.762674
LPG, CG 1.516330 1.513855 1.521905 1.526213 1.529768
L10 1.806098 1.800248 1.819945 1.831173 1.840781
L2, L8 1.729157 1.725101 1.738436 1.745696 1.751731
L1, L6, L9 1.846660 1.836488 1.872096 1.894186 1.914294

Example 4
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 26.8390 0.6000 1.84666 23.78
2 16.3344 3.8000 1.72000 43.69
3 251.2140 Variable
4 79.0802 0.8000 1.88300 38.50
5 10.4013 3.9000
6 * -15.6402 0.5000 1.63494 23.22
7 * -11.2194 0.8000 1.83481 42.71
8 * 2.084E + 04 0.2000
9 29.3362 2.0000 1.80810 22.76
10 -42.8587 Variable
11 (Aperture) ∞ 0.4000
12 * 12.5777 1.8000 1.69350 51.80
13 * -87.4358 0.2000
14 5.3985 2.4000 1.49700 81.54
15 9.5055 0.8000 1.84666 23.78
16 4.5362 Variable
17 * 14.1406 1.6000 1.69350 53.18
18 39.9405 Variable
19 ∞ 0.9010 1.54771 62.84
20 ∞ 0.5300
21 ∞ 0.5300 1.51633 64.14
22 ∞ 1.3601
Image plane ∞

Aspheric coefficient 6th surface
K = -0.0535, A2 = 0.0000E + 00, A4 = 3.4485E-05, A6 = -3.6491E-08, A8 = 0.0000E + 00
7th page
K = -0.1837, A2 = 0.0000E + 00, A4 = -6.5454E-06, A6 = 4.1099E-06, A8 = 0.0000E + 00
8th page
K = 8.5769, A2 = 0.0000E + 00, A4 = 6.0909E-05, A6 = 5.5779E-07, A8 = 0.0000E + 00
12th page
K = -0.6890, A2 = 0.0000E + 00, A4 = 1.0899E-04, A6 = 1.6473E-05, A8 = 3.5467E-07
13th page
K = 0, A2 = 0.0000E + 00, A4 = 1.9328E-04, A6 = 1.9010E-05, A8 = 4.8815E-07
17th page
K = 0, A2 = 0.0000E + 00, A4 = -1.2785E-05, A6 = 6.0991E-07, A8 = -2.5404E-09

Various data
Zoom ratio 8.00
Wide angle Medium telephoto Focal length 6.99897 19.80013 56.00002
F number 3.1000 3.7979 5.0423
Angle of view 31.7 ° 10.9 ° 3.8 °
Image height 3.800 3.800 3.800
Total lens length 67.2592 58.2183 71.9432
BF 1.36011 1.36011 1.36011

d3 0.59976 10.08933 22.11095
d10 31.33058 8.25005 1.59000
d16 7.69341 5.84941 21.84350
d18 4.51433 10.90817 3.27745

Zoom group data Group Start surface Focal length
1 1 47.20195
2 4 -12.34780
3 12 17.08297
4 17 30.78406

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L7 1.693499 1.689469 1.702855 1.710240 1.716386
L3 1.882998 1.876228 1.899160 1.912305 1.923515
LPF 1.547710 1.545046 1.553762 1.558427 1.562261
L4 1.634940 1.627290 1.654640 1.673656 1.692736
L10 1.693500 1.689551 1.702591 1.709739 1.715701
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L8 1.496999 1.495136 1.501231 1.504506 1.507205
L5 1.834807 1.828975 1.848520 1.859547 1.868911
L2 1.720000 1.715105 1.731585 1.740976 1.749012
L6 1.808095 1.798009 1.833513 1.855902 1.876580
L1, L9 1.846660 1.836488 1.872096 1.894186 1.914294

(Example 5)
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 27.5413 0.6000 1.84666 23.78
2 16.5179 4.5000 1.72000 43.69
3 312.5610 Variable
4 * 54.8906 0.4000 1.63494 23.22
5 * -233.0859 0.8000 1.88300 40.76
6 * 9.6383 3.7563
7 -13.6251 0.8000 1.83481 42.71
8 -430.1497 0.2000
9 37.4857 2.0000 1.80810 22.76
10 -26.9458 Variable
11 (Aperture) ∞ 0.4000
12 * 13.4238 1.8000 1.69350 53.18
13 * -63.0741 0.2000
14 5.3574 2.4000 1.50507 81.59
15 9.2802 0.8000 1.84666 23.78
16 4.4759 Variable
17 * 14.2543 1.6000 1.69350 53.18
18 40.5776 Variable
19 ∞ 0.9010 1.54771 62.84
20 ∞ 0.5300
21 ∞ 0.5300 1.51633 64.14
22 ∞ 1.3602
Image plane ∞

Aspherical coefficient fourth surface
K = -7.4305, A2 = 0.0000E + 00, A4 = -6.7057E-05, A6 = 2.9509E-07, A8 = 0.0000E + 00
5th page
K = -1.3338, A2 = 0.0000E + 00, A4 = 1.1949E-05, A6 = 1.3329E-06, A8 = 0.0000E + 00
6th page
K = 0.5245, A2 = 0.0000E + 00, A4 = -1.1579E-04, A6 = -8.2780E-07, A8 = 0.0000E + 00
12th page
K = -0.6884, A2 = 0.0000E + 00, A4 = 1.0136E-04, A6 = 8.9099E-06, A8 = 4.1660E-07
13th page
K = 0, A2 = 0.0000E + 00, A4 = 1.8512E-04, A6 = 1.0246E-05, A8 = 5.2639E-07
17th page
K = 0, A2 = 0.0000E + 00, A4 = -9.4780E-06, A6 = 4.4573E-07, A8 = 3.0169E-09

Various data
Zoom ratio 8.00
Wide angle Medium telephoto Focal length 6.99886 19.80054 55.99975
F number 3.1000 3.8542 5.0463
Angle of view 31.7 ° 10.9 ° 3.8 °
Image height 3.800 3.800 3.800
Total lens length 67.7300 58.7396 72.2818
BF 1.36020 1.36020 1.36020

d3 0.59975 9.65798 22.10322
d10 31.42721 8.26304 1.59000
d16 7.61604 6.48435 21.73368
d18 4.50946 10.75577 3.27721

Zoom group data Group Start surface Focal length
1 1 47.59866
2 4 -12.35247
3 12 17.03460
4 17 30.91484

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L8 1.505071 1.503181 1.509371 1.512779 1.515662
LPF 1.547710 1.545046 1.553762 1.558427 1.562261
L3 1.634940 1.627290 1.654640 1.673243 1.691579
L7 1.693500 1.689551 1.702591 1.709739 1.715701
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L5 1.834807 1.828975 1.848520 1.859547 1.868911
L4 1.882997 1.876560 1.898221 1.910495 1.920919
L2 1.720000 1.715105 1.731585 1.740976 1.749012
L6 1.808095 1.798009 1.833513 1.855902 1.876580
L1, L9 1.846660 1.836488 1.872096 1.894186 1.914294

(Example 6)
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 73.8912 1.5000 1.84666 23.78
2 51.1458 0.2000
3 55.7971 4.7000 1.49700 81.54
4 840.8341 0.1500
5 36.9883 4.8000 1.49700 81.54
6 164.5963 Variable
7 * 141.6525 0.9000 1.68500 15.80
8 * -571.5929 0.9000 1.88300 40.76
9 12.4510 5.5000
10 -23.1044 0.9000 1.80610 40.92
11 63.5490 1.0000
12 * -55.4565 0.9000 1.69350 53.21
13 37.0080 0.1500
14 31.6843 4.0000 1.68893 31.07
15 -21.2907 Variable
16 (Aperture) ∞ Variable
17 * 13.7548 2.2000 1.49700 81.54
18 857.8901 0.1500
19 20.4868 0.7000 1.77250 49.60
20 9.4621 3.3000 1.49700 81.54
21 -53.6516 Variable
22 -35.9945 0.6000 1.51633 64.14
23 9.8199 1.2000 1.84666 23.78
24 13.7888 Variable
25 * 23.8489 2.7000 1.49700 81.54
26 -13.6215 0.1500
27 -375.2738 2.2000 1.49700 81.54
28 -9.9864 0.7000 1.84666 23.78
29 -28.5726 Variable
30 ∞ 1.0000 1.54771 62.84
31 ∞ 0.7000
32 ∞ 0.6000 1.51633 64.14
33 ∞ 2.1601
Image plane ∞

Aspheric coefficient 7th surface
K = 0.0923, A2 = 0.0000E + 00, A4 = -1.2157E-05, A6 = 3.4591E-08, A8 = 0.0000E + 00
8th page
K = -0.0228, A2 = 0.0000E + 00, A4 = -1.1619E-06, A6 = 4.2726E-08, A8 = 0.0000E + 00
12th page
K = 0, A2 = 0.0000E + 00, A4 = 3.3500E-05, A6 = -6.8444E-08, A8 = -8.4140E-10
17th page
K = 0, A2 = 0.0000E + 00, A4 = -5.1388E-05, A6 = 6.6096E-09, A8 = -2.0803E-10
25th page
K = 0, A2 = 0.0000E + 00, A4 = -5.1827E-05, A6 = -6.6588E-08, A8 = 7.8406E-09

Various data
Zoom ratio 10.01
Wide angle Medium telephoto Focal length 4.99739 15.80048 50.00009
F number 2.8000 3.3617 3.2912
Angle of view 39.3 ° 12.9 ° 4.1 °
Image height 3.600 3.600 3.600
Total lens length 109.5633 101.6083 112.6630
BF 2.16006 2.16006 2.16006
Effective aperture radius 3.40414 3.41519 4.79195

d6 0.79902 20.30685 38.78629
d15 36.38664 8.92234 1.49911
d16 12.61615 7.00134 1.00004
d21 1.20217 4.22149 11.35576
d24 4.50134 3.75306 3.29433
d29 10.09792 13.44572 12.76740

Zoom group data Group Start surface Focal length
1 1 73.15236
2 7 -12.39847
3 17 19.21443
4 22 -24.10352
5 25 20.11327

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
LPF 1.547710 1.545046 1.553762 1.558428 1.562262
L4 1.684996 1.673486 1.716835 1.747796 1.778192
L12, CG 1.516330 1.513855 1.521905 1.526214 1.529768
L2, L3, L9, L11, L14, L15 1.496999 1.495138 1.501233 1.504509 1.507203
L6 1.806098 1.800248 1.819945 1.831174 1.840781
L5 1.882997 1.876560 1.898221 1.910497 1.920919
L10 1.772499 1.767798 1.783374 1.791972 1.799174
L7 1.693501 1.689548 1.702582 1.709715 1.715662
L1, L13, L16 1.846660 1.836491 1.872096 1.894187 1.914278
L8 1.688931 1.682495 1.704665 1.717975 1.729809

(Example 7)
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 * 16.4189 2.2423 1.49700 81.54
2 * -49.9548 variable
3 * -40.0473 0.7000 1.52542 50.50
4 * 7.1803 1.3239
5 * -129.9255 0.5752 1.63494 23.22
6 -19.3026 0.8000 1.58313 59.38
7 16.3014 Variable
8 (Aperture) ∞ -0.1000
9 * 4.4912 1.9000 1.74320 49.34
10 * -40.0312 0.1000
11 6.2476 1.1000 1.92286 20.10
12 2.9815 Variable
13 * 37.0133 2.4341 1.52542 55.78
14 -9.2906 Variable
15 ∞ 1.0000 1.51633 64.14
16 ∞ 1.2014
Image plane ∞

First surface of aspheric coefficient
K = -0.9358, A2 = 0.0000E + 00, A4 = 1.7221E-05, A6 = -8.4549E-07, A8 = 2.0978E-08,
A10 = -3.8409E-11
Second side
K = -1.4315, A2 = 0.0000E + 00, A4 = 1.7746E-06, A6 = 4.2666E-08, A8 = 1.7609E-08,
A10 = -1.8044E-10
Third side
K = 8.5291, A2 = 0.0000E + 00, A4 = -9.1235E-04, A6 = 3.3157E-05, A8 = -5.2667E-07,
A10 = 4.2126E-09
4th page
K = -1.6973, A2 = 0.0000E + 00, A4 = 6.6240E-04, A6 = -4.9690E-06, A8 = -1.8842E-06,
A10 = 3.4072E-08
5th page
K = 122.9470, A2 = 0.0000E + 00, A4 = 1.2621E-03, A6 = -5.1794E-05, A8 = 4.4515E-08,
A10 = 0.0000E + 00
9th page
K = -0.8591, A2 = 0.0000E + 00, A4 = 1.0435E-04, A6 = -1.1049E-07, A8 = -1.9982E-06,
A10 = -2.4152E-07
10th page
K = 29.2890, A2 = 0.0000E + 00, A4 = 4.4251E-04, A6 = -4.6420E-05, A8 = -4.3674E-07,
A10 = 0.0000E + 00
13th page
K = -4.9538, A2 = 0.0000E + 00, A4 = -2.0035E-05, A6 = 4.9528E-06, A8 = -2.3417E-07,
A10 = 3.0514E-09

Various data
Zoom ratio 3.75
Wide angle Medium telephoto Focal length 6.77084 12.45173 25.40909
F number 3.6000 4.5950 5.4487
Angle of view 32.6 ° 17.6 ° 8.9 °
Image height 3.840 3.840 3.840
Total lens length 31.5188 34.7815 38.2644
BF 1.20139 1.20139 1.20139

d2 0.46811 3.55999 6.84730
d7 10.58492 6.65979 0.80013
d12 3.53462 8.16389 11.69102
d14 3.65428 3.11734 5.65619

Zoom group data Group Start surface Focal length
1 1 25.14596
2 3 -7.57674
3 9 9.61953
4 13 14.39503

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L2 1.525419 1.522301 1.532704 1.538508 1.543381
L6 1.922856 1.909932 1.955840 1.984877 2.011316
L3 1.634940 1.627290 1.654640 1.675524 1.697965
L4 1.583126 1.580139 1.589960 1.595296 1.599721
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L1 1.496999 1.495136 1.501231 1.504506 1.507205
L5 1.743198 1.738653 1.753716 1.762046 1.769040
L7 1.525420 1.522680 1.532100 1.537050 1.540699

(Example 8)
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 * 16.7505 2.3212 1.49700 81.54
2 * -34.9627 Variable
3 * -22.8401 0.7000 1.52542 55.78
4 * 6.4242 1.8740
5 -21.1421 0.8000 1.58313 59.38
6 17.8005 0.6046 1.63494 23.22
7 * 131.5083 Variable
8 (Aperture) ∞ -0.1000
9 * 4.3682 1.8843 1.74320 49.34
10 * -63.9755 0.1000
11 5.7772 1.1000 1.92286 18.90
12 2.9400 Variable
13 * -166.6984 2.3259 1.52542 55.78
14 -8.1475 Variable
15 ∞ 1.0000 1.51633 64.14
16 ∞ 1.0793
Image plane ∞

First surface of aspheric coefficient
K = 0.2390, A2 = 0.0000E + 00, A4 = -7.2413E-06, A6 = -4.0959E-06, A8 = 6.1260E-11,
A10 = -2.3019E-09
Second side
K = 4.6801, A2 = 0.0000E + 00, A4 = 8.0872E-05, A6 = -3.3793E-06, A8 = -1.8316E-07,
A10 = 2.9694E-09
Third side
K = 1.9022, A2 = 0.0000E + 00, A4 = -4.8586E-04, A6 = 5.9661E-05, A8 = -2.1406E-06,
A10 = 2.6928E-08
4th page
K = -0.0906, A2 = 0.0000E + 00, A4 = -6.5916E-04, A6 = 5.0762E-05, A8 = 2.5205E-06,
A10 = -1.1728E-07
7th page
K = 7.1865, A2 = 0.0000E + 00, A4 = -3.2402E-04, A6 = -8.4797E-06, A8 = 0.0000E + 00,
A10 = 0.0000E + 00
9th page
K = -3.0231, A2 = 0.0000E + 00, A4 = 3.6716E-03, A6 = -1.3025E-04, A8 = 1.2545E-05,
A10 = -3.0304E-07
10th page
K = -1.4301, A2 = 0.0000E + 00, A4 = 8.5325E-04, A6 = 2.7829E-05, A8 = 4.3372E-06,
A10 = 0.0000E + 00 13th page
K = 9.6449, A2 = 0.0000E + 00, A4 = -3.3648E-04, A6 = 2.1031E-05, A8 = -8.7568E-07,
A10 = 1.2082E-08

Various data
Zoom ratio 3.95
Wide angle Medium telephoto Focal length 6.45208 12.51638 25.49743
F number 2.9708 4.1804 5.6000
Angle of view 33.8 ° 17.4 ° 8.8 °
Image height 3.840 3.840 3.840
Total lens length 30.2791 38.7554 38.7554
BF 1.13082 1.13082 1.13082

d2 0.31924 2.25737 5.02792
d7 9.45827 5.36130 1.34833
d12 2.77791 9.11561 15.30831
d14 4.03440 2.78209 3.39431

Zoom group data Group Start surface Focal length
1 1 23.13109
2 3 -7.05804
3 9 8.95029
4 13 16.22156

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L4 1.634940 1.627290 1.654640 1.672908 1.690644
L3 1.583126 1.580139 1.589960 1.595296 1.599721
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L1 1.496999 1.495136 1.501231 1.504506 1.507205
L5 1.743198 1.738653 1.753716 1.762046 1.769040
L6 1.922860 1.909158 1.957996 1.989713 2.019763
L2, L7 1.525420 1.522680 1.532100 1.537050 1.540699

Example 9
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 * 20.3861 2.5000 1.49700 81.54
2 * -30.1760 0.2679
3 * -12.0719 0.8000 1.52542 55.78
4 * 29.9980 1.2048
5 -20.0364 0.8000 1.77250 49.60
6 10.1199 0.9000 1.63494 23.22
7 94.6054 11.2642
8 (Aperture) ∞ 0
9 * 4.3099 1.7167 1.74320 49.34
10 * -14.9302 0.1000
11 13.1231 0.9000 1.77250 49.60
12 89.8778 0.6000 1.78472 25.68
13 2.9574 2.7615
14 * -32.0113 1.8000 1.80610 40.92
15 -8.6669 4.1237
16 ∞ 1.0000 1.51633 64.14
17 ∞ 1.1127
Image plane ∞

First surface of aspheric coefficient
K = 0.2510, A2 = 0.0000E + 00, A4 = -5.1052E-05, A6 = -1.8664E-07, A8 = -1.0788E-08,
A10 = -1.7609E-10
Second side
K = -1.1747, A2 = 0.0000E + 00, A4 = -2.4058E-05, A6 = 1.2824E-06, A8 = -6.4526E-08,
A10 = 7.1872E-10
Third side
K = -0.8816, A2 = 0.0000E + 00, A4 = 9.8622E-04, A6 = -1.3495E-05, A8 = 8.5475E-08,
A10 = -3.0437E-10
4th page
K = -0.3662, A2 = 0.0000E + 00, A4 = 5.5069E-04, A6 = 8.8765E-06, A8 = -8.9154E-08,
A10 = -6.1767E-09
9th page
K = -0.9539, A2 = 0.0000E + 00, A4 = -2.0028E-05, A6 = -7.9938E-05, A8 = -3.2148E-07,
A10 = 1.8380E-07
10th page
K = -1.3462, A2 = 0.0000E + 00, A4 = 6.6323E-04, A6 = -1.2474E-04, A8 = -4.8038E-06,
A10 = 5.3203E-07
14th page
K = -4.8773, A2 = 0.0000E + 00, A4 = -1.2615E-04, A6 = 5.7485E-06, A8 = -2.4527E-07,
A10 = 3.6035E-09

Various data
Zoom ratio 3.98
Wide angle Medium telephoto Focal length 6.44 354 12.80633 25.66297
F number 3.4886 4.5702 5.6000
Angle of view 32.7 ° 16.6 ° 8.6 °
Image height 3.840 3.840 3.840
Total lens length 31.8515 34.3023 37.4800
BF 1.11270 1.11270 1.11270

d2 0.26789 3.50597 6.77948
d7 11.26421 6.19999 0.96590
d13 2.76146 7.42578 11.44462
d15 4.12374 3.75284 4.82735

Zoom group data Group Start surface Focal length
1 1 24.88880
2 3 -7.84990
3 9 9.48778
4 14 14.25278

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L4 1.634940 1.627290 1.654640 1.672908 1.690644
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L1 1.496999 1.495136 1.501231 1.504506 1.507205
L8 1.806098 1.800248 1.819945 1.831173 1.840781
L3, L6 1.772499 1.767798 1.783374 1.791971 1.799174
L5 1.743198 1.738653 1.753716 1.762046 1.769040
L7 1.784723 1.775965 1.806519 1.825342 1.842388
L2 1.525420 1.522680 1.532100 1.537050 1.540699

(Example 10)
Unit mm
Surface data Surface number rd nd νd
Object ∞ ∞
1 18.3434 0.9000 1.92286 20.88
2 12.0213 0.0500
3 12.1943 2.5000 1.77250 49.60
4 156.8354 0.5003
5 * 80.6534 0.7000 1.74320 49.34
6 * 5.3837 2.1002
7 * 26.4437 0.8000 1.58313 59.38
8 * 4.9844 1.0000 1.63387 23.38
9 * 16.6289 10.3183
10 (Aperture) ∞ 0
11 * 6.0040 1.9999 1.58313 59.38
12 * -7.7105 0.1500
13 6.0294 1.1984 1.57099 50.80
14 7.7745 0.5000 1.92286 20.88
15 3.5080 4.0066
16 127.0367 1.5000 1.58313 59.38
17 -24.7245 4.2823
18 ∞ 0.5000 1.51633 64.14
19 ∞ 0.4999
Image plane ∞

Aspherical coefficient fifth surface
K = 5.2501, A2 = 0.0000E + 00, A4 = 8.9072E-04, A6 = -3.1699E-05, A8 = 3.1989E-07,
A10 = 0.0000E + 00
6th page
K = 0.1555, A2 = 0.0000E + 00, A4 = 1.2429E-03, A6 = 4.2142E-05, A8 = 6.1900E-07,
A10 = 0.0000E + 00
7th page
K = 36.7740, A2 = 0.0000E + 00, A4 = -8.6035E-04, A6 = 0.0000E + 00, A8 = 0.0000E + 00,
A10 = 0.0000E + 00
8th page
K = -5.7568, A2 = 0.0000E + 00, A4 = -4.7835E-04, A6 = 0.0000E + 00, A8 = 0.0000E + 00,
A10 = 0.0000E + 00
9th page
K = -6.9032, A2 = 0.0000E + 00, A4 = -1.5346E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00,
A10 = 0.0000E + 00
11th page
K = 0.0017, A2 = 0.0000E + 00, A4 = -2.5030E-03, A6 = -1.0297E-04, A8 = -3.0400E-05,
A10 = 0.0000E + 00
12th page
K = -1.2426, A2 = 0.0000E + 00, A4 = -1.1249E-03, A6 = -1.5896E-04, A8 = -1.3731E-05,
A10 = 0.0000E + 00

Various data
Zoom ratio 4.82
Wide angle Medium telephoto Focal length 6.59943 14.49978 31.79959
F number 3.3000 4.4199 5.3644
Angle of view 31.6 ° 14.5 ° 6.7 °
Image height 3.840 3.840 3.840
Total lens length 33.5057 37.3628 41.8617
BF 0.4999 0.4999 0.4999

d4 0.50026 5.66462 11.11080
d9 10.31827 5.36588 0.99977
d15 4.00656 10.21939 13.30831
d17 4.28226 1.71477 2.04461

Zoom group data Group Start surface Focal length
1 1 30.55444
2 5 -7.18292
3 10 8.48655
4 16 35.62198

[Glass Material Refractive Index Table] ... List of refractive indexes by wavelength of the medium used in this example
587.56 656.27 486.13 435.84 404.66
L1, L8 1.922860 1.910380 1.954570 1.982810 2.009196
L5 1.633870 1.626381 1.653490 1.671610 1.688826
L7 1.570989 1.567616 1.578856 1.585136 1.590445
L4, L6, L9 1.583126 1.580139 1.589960 1.595296 1.599721
L10 1.516330 1.513855 1.521905 1.526213 1.529768
L2 1.772499 1.767798 1.783374 1.791971 1.799174
L3 1.743198 1.738653 1.753716 1.762046 1.769040

Next, (-) which lists the parameter values in each example indicates that there is no corresponding numerical value.
Example 1 Example 2 Example 3 Example 4 Example 5
fw 7.009 6.998 6.997 6.999 6.999
y ₁₀ 3.6 3.6 3.6 3.8 3.8
ndp 1.63494 1.63494 1.63494 1.63494 1.63494
νdp 23.22 23.22 23.22 23.22 23.22
θgFp 0.7108 0.7461 0.7284 0.6953 0.6802
βp 0.7486 0.7839 0.7662 0.7331 0.7180
θhgp 0.7255 0.7890 0.7572 0.6976 0.6704
βhgp 0.7777 0.8412 0.8094 0.7498 0.7226
ndn 1.74320 1.52540 1.83481 1.83481 1.88300
νdn 49.34 56.25 41.20 42.71 40.76
θgFn 0.5528 0.5490 0.5682 0.5645 0.5669
θhgn 0.4638 0.4560 0.4819 0.4790 0.4811
y ₀₇ 2.52 2.52 2.52 2.66 2.66
_tanω 07w 0.3819 0.3801 0.3835 0.4059 0.4058
tp 1.0 1.0 0.7 0.5 0.4
tn 0.9 0.9 0.7 0.8 0.8
R _AC -6.794 38.413 6.268 -11.219 -233.086
z _AC (h) -0.7997 0.1268 0.9411 -0.9647 -0.0273
Right side of equation (10) (-) 0.1367 (-) (-) (-)
Right side of equation (11) -0.8158 (-) 0.9012 -1.0127 -0.0466
a 1.291 1.295 1.295 1.863 1.863
h (= 2.5a) 3.228 3.238 3.238 4.658 4.658
γ 4.994 5.001 5.002 8.001 8.001
z _AP (h) -0.3503 -0.2829 0.5645 -0.6930 0.1669

Example 6 Example 7 Example 8 Example 9 Example 10
fw 4.997 6.771 6.452 6.444 6.599
y ₁₀ 3.6 3.84 3.84 3.84 3.84
ndp 1.68500 1.63494 1.63494 1.63494 1.63387
νdp 15.80 23.22 23.22 23.22 23.38
θgFp 0.7142 0.7636 0.6679 0.6679 0.6684
βp 0.7400 0.8014 0.7057 0.7057 0.7065
θhgp 0.7012 0.8205 0.6485 0.6485 0.6351
βhgp 0.7364 0.8727 0.7007 0.7007 0.6877
ndn 1.88300 1.58313 1.58313 1.77250 1.58313
νdn 40.76 59.38 59.38 49.60 59.38
θgFn 0.5669 0.5438 0.5438 0.5523 0.5438
θhgn 0.4811 0.4501 0.4501 0.4624 0.4501
y ₀₇ 2.52 2.69 2.69 2.69 2.69
_tanω 07w 0.5391 0.4219 0.4412 0.4387 0.4218
tp 0.9 0.5752 0.6046 0.9 1.0
tn 0.9 0.8 0.8 0.8 0.8
R _AC -571.593 -19.303 17.801 10.120 4.984
z _AC (h) -0.0357 -0.2551 0.3297 0.6001 0.8899
Right side of equation (10) (-) (-) (-) (-) 1.7766
Right side of equation (11) -0.0368 (-) (-) (-) (-)
a 2.594 1.251 1.364 1.373 1.526
h (= 2.5a) 6.485 3.128 3.410 3.433 3.815
γ 10.005 3.753 3.952 3.983 4.819
z _AP (h) 0.1296 0.0344 -0.0129 0.0623 0.0830

Next, the values of the conditional expressions in each example are listed. (-) Indicates that the condition is not met.
Example 1 Example 2 Example 3 Example 4 Example 5
(1) βp 0.7486 0.7839 0.7662 0.7331 0.7180
(2) νdp 23.22 23.22 23.22 23.22 23.22
(3) βhgp 0.7777 0.8412 0.8094 0.7498 0.7226
(4) θgFp-θgFn 0.1580 0.1971 0.1602 0.1308 0.1133
(5) θhgp-θhgn 0.2617 0.3330 0.2753 0.2186 0.1893
(6) νdp-νdn -26.12 -33.03 -17.98 -19.49 -17.54
(7) ndp 1.63494 1.63494 1.63494 1.63494 1.63494
(8) ndn 1.74320 1.52540 1.83481 1.83481 1.88300
(10) z _AC (h) <(-) 0.1268 (-) (-) (-)
Right side (-) 0.1367 (-) (-) (-)
(11) z _AC (h)> -0.7997 (-) 0.9411 -0.9647 -0.0273
Right side -0.8158 (-) 0.9012 -1.0127 -0.0466
(13) | z _AP (h) -z _AC (h) | 0.4494 0.4097 0.5380 0.5434 0.4855
/ tp
(14) tp / tn 1.111 1.111 1.0 0.625 0.5
(17) y ₀₇ / (fw ・_{tanω 07w} ) 0.9414 0.9474 0.9391 0.9363 0.9366

Example 6 Example 7 Example 8 Example 9 Example 10
(1) βp 0.7400 0.8014 0.7057 0.7057 0.7065
(2) νdp 15.80 23.22 23.22 23.22 23.38
(3) βhgp 0.7364 0.8727 0.7007 0.7007 0.6877
(4) θgFp-θgFn 0.1473 0.2198 0.1241 0.1156 0.1246
(5) θhgp-θhgn 0.2201 0.3704 0.1984 0.1861 0.1850
(6) νdp-νdn -24.96 -36.16 -36.16 -26.38 -36.00
(7) ndp 1.68500 1.63494 1.63494 1.63494 1.63387
(8) ndn 1.88300 1.58313 1.58313 1.77250 1.58313
(10) z _AC (h) <(-) (-) (-) (-) 0.8899
Right side (-) (-) (-) (-) 1.7766
(11) z _AC (h)> -0.0357 (-) (-) (-) (-)
Right side -0.0368 (-) (-) (-) (-)
(13) | z _AP (h) -z _AC (h) | 0.1837 0.5033 0.5667 0.5976 0.8069
/ tp
(14) tp / tn 1.0 0.719 0.756 1.125 1.25
(17) y ₀₇ / (fw ・_{tanω 07w} ) 0.9355 0.9417 0.9450 0.9515 0.9657

(Example 10)
The imaging optical system of the present invention as described above is a photographing apparatus for photographing an image of an object with an electronic image sensor such as a CCD or CMOS, in particular, a digital camera, a video camera, a personal computer or an example of an information processing apparatus, a telephone. It can be used for portable terminals, especially mobile phones that are convenient to carry. The embodiment is illustrated below.

  FIG. 21 to FIG. 23 show conceptual diagrams of a configuration in which the imaging optical system according to the present invention is incorporated in a photographing optical system 41 of a digital camera. 21 is a front perspective view showing the appearance of the digital camera 40, FIG. 22 is a rear perspective view thereof, and FIG. 23 is a cross-sectional view showing an optical configuration of the digital camera 40.

  In this example, the digital camera 40 includes a photographing optical system 41 having a photographing optical path 42, a finder optical system 43 having a finder optical path 44, a shutter 45, a flash 46, a liquid crystal display monitor 47, and the like. Then, when the photographer presses the shutter 45 disposed on the upper part of the camera 40, photographing is performed through the photographing optical system 41, for example, the zoom lens 48 of the first embodiment in conjunction therewith.

  The object image formed by the photographing optical system 41 is formed on the image pickup surface of the CCD 49. The object image received by the CCD 49 is displayed as an electronic image on the liquid crystal display monitor 47 provided on the back of the camera via the image processing means 51. Further, the image processing means 51 is provided with a memory or the like, and can record a captured electronic image. This memory may be provided separately from the image processing means 51, or may be configured to perform recording and writing electronically using a flexible disk, memory card, MO, or the like.

  Further, a finder objective optical system 53 is disposed on the finder optical path 44. The finder objective optical system 53 includes a cover lens 54, a first prism 10, an aperture stop 2, a second prism 20, and a focusing lens 66. An object image is formed on the imaging surface 67 by the finder objective optical system 53. This object image is formed on the field frame 57 of the Porro prism 55 which is an image erecting member. Behind the Porro prism 55, an eyepiece optical system 59 for guiding an erect image to the observer eyeball E is disposed.

  According to the digital camera 40 configured as described above, an electronic imaging device having a compact and thin zoom lens in which the number of components of the photographing optical system 41 is reduced can be realized. The present invention is not limited to the above-described retractable digital camera, but can also be applied to a folding digital camera that employs a bending optical system.

  Next, a personal computer which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as an objective optical system is shown in FIGS. 24 is a front perspective view of the personal computer 300 with the cover open, FIG. 25 is a sectional view of the photographing optical system 303 of the personal computer 300, and FIG. 26 is a side view of FIG. As shown in FIGS. 24 to 26, the personal computer 300 includes a keyboard 301, information processing means and recording means, a monitor 302, and a photographing optical system 303.

  Here, the keyboard 301 is for an operator to input information from the outside. The information processing means and recording means are not shown. The monitor 302 is for displaying information to the operator. The photographing optical system 303 is for photographing an image of the operator himself or a surrounding area. The monitor 302 may be a liquid crystal display element, a CRT display, or the like. As the liquid crystal display element, there are a transmissive liquid crystal display element that is illuminated from the back by a backlight (not shown), and a reflective liquid crystal display element that reflects and displays light from the front. In the drawing, the photographic optical system 303 is built in the upper right of the monitor 302, but is not limited to that location, and may be anywhere around the monitor 302 or the keyboard 301.

  The photographing optical system 303 includes, on the photographing optical path 304, the objective optical system 100 including, for example, the zoom lens according to the first embodiment, and the electronic imaging element chip 162 that receives an image. These are built in the personal computer 300.

A cover glass 102 for protecting the objective optical system 100 is disposed at the tip of the mirror frame.
The object image received by the electronic image sensor chip 162 is input to the processing means of the personal computer 300 via the terminal 166. Finally, the object image is displayed on the monitor 302 as an electronic image. FIG. 24 shows an image 305 taken by the operator as an example. The image 305 can also be displayed on a communication partner's personal computer from a remote location via the processing means. The Internet and telephone are used for image transmission to remote places.

  Next, FIG. 27 shows a telephone which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as a photographing optical system, particularly a portable telephone which is convenient to carry. 27A is a front view of the mobile phone 400, FIG. 257B is a side view, and FIG. 27C is a cross-sectional view of the photographing optical system 405. As shown in FIGS. 27A to 27C, the mobile phone 400 includes a microphone unit 401, a speaker unit 402, an input dial 403, a monitor 404, a photographing optical system 405, an antenna 406, and processing. Means.

  Here, the microphone unit 401 is for inputting an operator's voice as information. The speaker unit 402 is for outputting the voice of the other party. An input dial 403 is used by an operator to input information. The monitor 404 is for displaying information such as a photographed image of the operator himself or the other party, a telephone number, and the like. The antenna 406 is for transmitting and receiving communication radio waves. The processing means (not shown) is for processing image information, communication information, input signals, and the like.

  Here, the monitor 404 is a liquid crystal display element. Further, in the drawing, the arrangement positions of the respective components, in particular, are not limited thereto. The photographing optical system 405 includes an objective optical system 100 disposed on a photographing optical path 407 and an electronic image sensor chip 162 that receives an object image. As the objective optical system 100, for example, the zoom lens of Example 1 is used. These are built in the mobile phone 400.

A cover glass 102 for protecting the objective optical system 100 is disposed at the tip of the mirror frame.
The object image received by the electronic imaging element chip 162 is input to an image processing unit (not shown) via the terminal 166. Finally, the object image is displayed as an electronic image on the monitor 404, the monitor of the communication partner, or both. The processing means includes a signal processing function. When transmitting an image to a communication partner, this function converts information on the object image received by the electronic image sensor chip 162 into a signal that can be transmitted.

  The present invention can take various modifications without departing from the spirit of the present invention.

(A) of the zoom lens according to Example 1 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 3 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 1 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 2 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 6 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 2 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 3 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 9 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 3 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c) is a diagram. The state at the telephoto end is shown. (A) of the zoom lens according to Example 4 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 4 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 5 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 5 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 6 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 8 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 6 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 7 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 9 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 7 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 8 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 8 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 9 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 9 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 10 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 10 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. It is a front perspective view which shows the external appearance of the digital camera 40 incorporating the zoom optical system by this invention. 2 is a rear perspective view of the digital camera 40. FIG. 2 is a cross-sectional view showing an optical configuration of a digital camera 40. FIG. 1 is a front perspective view of a state in which a cover of a personal computer 300 which is an example of an information processing apparatus in which a zoom optical system of the present invention is built as an objective optical system is opened. 2 is a cross-sectional view of a photographing optical system 303 of a personal computer 300. FIG. 2 is a side view of a personal computer 300. FIG. 1A and 1B are views showing a mobile phone as an example of an information processing apparatus in which the zoom optical system of the present invention is built in as a photographing optical system, where FIG. 1A is a front view of the mobile phone 400, FIG. FIG. 6 is a cross-sectional view of the photographing optical system 405.

Explanation of symbols

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group L1 to L12 Each lens LPF Low pass filter CG Cover glass I Imaging surface E Observer's eye 40 Digital camera 41 Imaging optics System 42 Optical path for photographing 43 Viewfinder optical system 44 Optical path for viewfinder 45 Shutter 46 Flash 47 LCD monitor 48 Zoom lens 49 CCD
DESCRIPTION OF SYMBOLS 50 Image pick-up surface 51 Processing means 53 Finder objective optical system 55 Porro prism 57 Field frame 59 Eyepiece optical system 66 Focusing lens 67 Imaging surface 100 Objective optical system 102 Cover glass 162 Electronic image pick-up element chip | tip 166 Terminal 300 Personal computer 301 Keyboard 302 Monitor 303 Imaging Optical System 304 Imaging Optical Path 305 Image 400 Mobile Phone 401 Microphone Unit 402 Speaker Unit 403 Input Dial 404 Monitor 405 Imaging Optical System 406 Antenna 407 Imaging Optical Path

Claims (13)

A lens group disposed closest to the object side, an aperture stop disposed on the image side of the lens group, and a lens group having a negative refractive power disposed between the lens group and the aperture stop,
The lens group having negative refractive power includes a cemented lens component in which a positive lens _LAP and a negative lens _LAN are cemented,
An imaging optical system that performs zooming by changing an interval between the lens group and the lens group having negative refractive power,
In an orthogonal coordinate system with the horizontal axis νdp and the vertical axis θgFp,
θgFp = αp × νdp + βp (where αp = −0.00163)
When the straight line represented by is set, the area defined by the straight line when the range is the lower limit of the range of the following conditional expression (1) and the straight line when the upper limit is set, and the following conditional expression (2) both the area of the defined region, the positive lens L _AP of θgF and imaging optical system, characterized in that it contains vdp.
0.6650 <βp <0.9000 (1)
3 <νdp <27 (2)
Where θgFp is the partial dispersion ratio (ng−nF) / (nF−nC), νdp is the Abbe number, (nd−1) / (nF−nC), nd, nC, nF and ng are the d line, C Refractive index of line, F line, and g line. In the Cartesian coordinate system different from the Cartesian coordinates, the horizontal axis is νd and the vertical axis is θhgp.
θhgp = αhgp × νdp + βhgp (where αhgp = −0.00225)
When the straight line represented by is set, the area defined by the straight line when the range is the lower limit of the range of the following conditional expression (3) and the straight line when the upper limit is set, and the following conditional expression (2) both the area of the determined area, the imaging optical system according to claim 1, characterized in that the contain the positive lens L _AP of θhgp and vdp.
0.6200 <βhgp <0.9500 (3)
3 <νdp <27 (2)
Here, θhgp is a partial dispersion ratio (nh−ng) / (nF−nC), and nh is a refractive index of h-line. The imaging optical system according to claim 1, wherein the following condition is satisfied.
0.07 ≦ θgFp−θgFn ≦ 0.50 (4)
Here, ShitagFp the said partial dispersion of the positive lens _{L AP (ng-nF) /} (nF-nC), θgFn is the in partial dispersion ratio of the negative lens _{L AN (ng-nF) /} (nF-nC) . The imaging optical system according to claim 3, wherein the following condition is satisfied.
0.10 ≦ θhgp−θhgn ≦ 0.60 (5)
Here, Shitahgp the said partial dispersion of the positive lens _{L AP (nh-ng) /} (nF-nC), θhgn is the in partial dispersion ratio of the negative lens _{L AN (nh-ng) /} (nF-nC) . The imaging optical system according to claim 3 or 4, wherein the following condition is satisfied.
νdp−νdn ≦ −10 (6)
Here, vdp is the positive lens L _AP Abbe number (nd-1) / (nF -nC), νdn is the Abbe number of the negative lens _{L AN (nd-1) /} (nF-nC). The imaging optical system according to any one of claims 1 to 5, wherein the following condition is satisfied.
1.55 ≦ ndp ≦ 1.80 (7)
Here, ndp is the refractive index at the d-line of the positive lens L _AP. The material of the positive lens L _AP is energy curable resin, any one of claims 1 to 6, characterized in that to form a cemented lens in a manner that molded directly onto the negative lens L _AN The imaging optical system described.   The imaging optical system according to any one of claims 1 to 7, wherein the cemented lens component has a cemented surface aspherical. The surface shape of the positive lens L _AP, any of claims 1 to 8, characterized in that the a shape the light beam convergence weakens as the distance from the optical axis than when the spherical lens by a paraxial radius of curvature The imaging optical system according to claim 1. The cemented lens component has a negative refractive power;
2. The lens group having negative refractive power includes the cemented lens component arranged closest to the object side and at least one positive lens arranged on the image side of the cemented lens component. The imaging optical system according to any one of claims 9 to 9.   The lens group having negative refractive power includes a negative single lens disposed closest to the object side, and the cemented lens component disposed subsequent to the image side of the negative single lens. The imaging optical system according to any one of claims 1 to 9.   10. The imaging optical system according to claim 1, wherein the lens group having a negative refractive power includes the cemented lens component arranged closest to the image side. 11. An image forming optical system according to any one of claims 1 to 12, an electronic image pickup device, and image data obtained by picking up an image formed through the image forming optical system with the electronic image pickup device. Image processing means for processing and outputting as image data in which the shape of the image is changed, and the imaging optical system is a zoom lens, and when the zoom lens is focused on an object point at infinity, the following conditional expression An electronic imaging device characterized by satisfying
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.98 (17)
Here, y ₀₇ is y ₀₇ = 0.7 · y, where y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device. represented as _10, omega _07w angle relative to the central from the optical axis direction of an object point corresponding to an image point formed at a position of y ₀₇ on the imaging surface at the wide angle end, fw is the entire system at the wide-angle end of said zoom lens The focal length.

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