JP2012230233A - Imaging lens, imaging apparatus and portable terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging lens whose F-value is smaller than F2.8, which uses a solid state imaging sensor having a curved imaging surface, is small and has high performance, and can suppress shading, and provide an imaging apparatus and a portable terminal using the imaging lens.SOLUTION: An imaging apparatus comprises: a solid state imaging sensor having a photoelectric conversion part; and an imaging lens for forming a subject image onto the photoelectric conversion part of the solid state imaging sensor. In the imaging lens of the imaging apparatus, an imaging surface of the solid state imaging sensor is curved and the imaging lens includes a first lens L1 having positive refractive power, a second lens L2 having negative refractive power and a third lens L3 having positive or negative refractive power in the order from the object side, which satisfies the following conditional expressions, -0.9<f1/f23<-0.1 and 0.11<D5/f<0.5, where f1 is the focal distance of the first lens (mm), f23 is the composite focal distance of the second lens and the third lens (mm), D5 is the thickness of the third lens on an axis (mm), and f is a focal distance of the whole imaging lens system (mm).

Description

  The present invention relates to an imaging lens, an imaging apparatus, and a portable terminal, and in particular, the present invention is a solid-state imaging device such as a CCD-type image sensor or a CMOS-type image sensor and suitable for a solid-state imaging device having a curved imaging surface. The present invention relates to a lens, an imaging device, and a portable terminal using the same.

  In recent years, small and thin imaging devices have been installed in portable terminals that are small and thin electronic devices such as mobile phones and PDAs (Personal Digital Assistants). Information can also be transmitted between each other.

  As an image pickup element used in these image pickup apparatuses, a solid-state image pickup element such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor is used. In recent years, the pixel pitch of the image sensor has been reduced, and higher resolution and higher performance have been achieved by increasing the number of pixels. On the other hand, downsizing of the image sensor has been achieved while maintaining high pixels. Furthermore, an attempt has been made to curve the imaging surface of the imaging element. There is a need for a compact and high-performance imaging lens suitable for such an imaging device.

Here, a three-lens configuration is suitable as a small and high-performance imaging lens. An imaging lens having a three-lens configuration with a curved imaging surface is disclosed in Patent Documents 1 and 2.
An imaging lens having a single lens configuration in which the imaging surface of a solid-state imaging device is curved is disclosed in Patent Document 3.

Japanese Patent Application Laid-Open No. 08-68935 JP 2000-292688 A JP 2004-356175 A

  Patent Documents 1 and 2 describe a photographing lens that is suitable for a compact camera or a lens-equipped film unit and has a photographing field angle of about 77 degrees and a brightness of F5.7 to F6.2. The lens configuration is a rear stop triplet type lens including a positive first lens, a negative second lens, a positive third lens, and an aperture stop.

  Here, an imaging lens used for a solid-state imaging device having a small pixel size needs to have a different characteristic from a lens for a film camera that requires high resolution in order to cope with a highly thinned pixel. . However, the resolving power of the lens is limited by the F value, and a bright lens with a small F value can obtain a high resolving power, so an imaging lens with a small F value is required.

  Moreover, since the lenses of Patent Document 1 and Patent Document 2 have an F value that is darker than F5, sufficient performance cannot be obtained. Furthermore, since the positive first lens is a meniscus shape with a convex surface facing the object side, and the positive third lens is a double convex triplet type, the third lens has a stronger positive refractive power than the first lens. It has become. For this reason, there is a problem that the back focus tends to be long, and the photographic lens and the imaging device are increased in size.

  Furthermore, Patent Documents 1 and 2 disclose photographing lenses for film cameras, which improve performance by curving the film surface (imaging surface) in accordance with the curvature of field generated by the lens. It is intended. However, since both are camera-use photographic lenses that use a roll film, the film surface is a so-called cylindrical imaging surface that curves only in the direction of the long side of the screen due to the structure of the camera. Therefore, although good performance can be obtained in the long side direction of the screen, the imaging surface in the short side direction of the screen remains flat, so performance cannot be improved and deterioration may occur depending on the correction status of field curvature. obtain. That is, it can be said that it is difficult to obtain high performance over the entire screen by bending only the long side direction of the imaging surface as in Patent Documents 1 and 2.

  Further, as disclosed in Patent Documents 1 and 2, as described above, since it is an imaging lens for a film camera, the principal ray incident angle of a light beam incident on the imaging surface is not necessarily sufficiently small in the periphery of the imaging surface. It is not designed. In an imaging lens for forming a subject image on the photoelectric conversion unit of a solid-state image sensor, when the chief ray incident angle of the light beam incident on the imaging surface, so-called telecentric characteristics, deteriorates, the light beam enters the solid-state image sensor obliquely. A phenomenon (shading) in which the substantial aperture efficiency decreases in the periphery of the imaging surface may occur, resulting in insufficient peripheral light amount.

  On the other hand, Patent Document 3 discloses a photographing device such as a mobile phone, which corrects the curvature of field and distortion generated by a lens in a well-balanced manner by curving a solid-state imaging device into a polynomial surface shape, and is small in size and resolution. An imaging device having a high value is disclosed. However, since the solid-state image sensor has a CIF size (352 pixels × 288 pixels), the image pickup lens has a single lens configuration, and thus the chromatic aberration is not sufficiently corrected. If there is, acquisition of high-quality images commensurate with it cannot be expected.

  The present invention has been made in view of such a problem. By using a solid-state imaging device having a curved imaging surface, the invention has a small size, high performance, can suppress shading, and has an F value smaller than F2.8. An object is to obtain an imaging lens, an imaging device using the imaging lens, and a portable terminal.

The imaging lens according to claim 1, wherein the imaging lens includes a solid-state imaging device including a photoelectric conversion unit, and an imaging lens that forms a subject image on the photoelectric conversion unit of the solid-state imaging device.
The imaging surface of the solid-state imaging device is curved,
The imaging lens includes a first lens having a positive refractive power in order from the object side, a second lens having a negative refractive power, and a third lens having a positive or negative refractive power,
The following conditional expression is satisfied.
−0.9 <f1 / f23 <−0.1 (1)
0.11 <D5 / f <0.5 (2)
However,
f1: Focal length (mm) of the first lens
f23: Composite focal length (mm) of the second lens and the third lens
D5: Axial thickness (mm) of the third lens
f: Focal length (mm) of the entire imaging lens system

  The imaging surface of the solid-state imaging device is curved. As described above, since the imaging surface of the solid-state imaging device is curved, it is possible to achieve both downsizing and high performance of the imaging device. More specifically, if the imaging surface is curved toward the imaging lens side, it becomes advantageous to correct the chief ray incident angle of the light beam incident on the imaging surface, so-called telecentric characteristics. When the imaging surface is curved rather than flat, the chief ray incident angle of the light beam incident on the imaging surface is smaller, so the imaging lens does not sufficiently correct the telecentric characteristics. However, the aperture efficiency does not decrease, and the occurrence of shading can be suppressed. Further, distortion and coma can be easily corrected, and the image pickup apparatus can be downsized. Furthermore, the imaging surface is preferably curved into a spherical shape. When curved in a spherical shape, both the long side direction and the short side direction of the screen are curved in the same manner and can be adjusted to the curvature of field of the imaging lens, so that the performance can be improved over the entire screen. Furthermore, since it is not necessary to sufficiently correct the curvature of field with the imaging lens, it is not necessary to reduce the Petzval sum, and the refractive power of each surface can be set relatively weak, so that the occurrence of chromatic aberration and coma is also suppressed. be able to.

  The imaging lens includes, in order from the object side, a first lens having a positive refractive power, a second lens having a negative refractive power, and a third lens having a positive or negative refractive power. This so-called telephoto type lens configuration in which a positive group consisting of a first lens and a negative group consisting of a second lens and a third lens are arranged is advantageous in reducing the overall length of the imaging lens. In addition, since the second lens has a negative refractive power, chromatic aberration can be corrected, so that high performance can be realized.

Conditional expression (1) is a conditional expression for appropriately setting the focal length of the positive lens group of the first lens and the negative focal length of the second lens and the third lens so as to balance downsizing and aberration correction. It is. When the value of conditional expression (1) is less than the upper limit, it is possible to satisfactorily reduce the overall lens length and correct field curvature and off-axis aberrations. On the other hand, if the value of conditional expression (1) exceeds the lower limit, distortion and coma can be corrected well. More preferably, the range of the following formula is good.
−0.8 <f1 / f23 <−0.15 (1 ′)
Furthermore, the range of the following formula is desirable.
−0.7 <f1 / f23 <−0.2 (1 ″)

Conditional expression (2) is a conditional expression for appropriately setting the thickness of the third lens. When the value of conditional expression (2) exceeds the lower limit, it is possible to prevent the third lens from becoming too thin and increase the difficulty of workability. On the other hand, if the value of conditional expression (2) is below the upper limit, the third lens will not be too thick, the occurrence of lateral chromatic aberration can be suppressed, the overall length of the lens can be easily reduced, and the imaging lens and imaging apparatus can be made smaller. Can be planned. More preferably, the range of the following formula is good.
0.12 <D5 / f <0.4 (2 ′)
Furthermore, the range of the following formula is desirable.
0.14 <D5 / f <0.3 (2 ")

The imaging lens described in claim 2 is characterized in that, in the invention described in claim 1, the following conditional expression is satisfied.
−50.0 <RI / Y <−2.0 (3)
However,
RI: radius of curvature (mm) of the imaging surface of the solid-state imaging device
Y: Maximum image height (mm)

Conditional expression (3) is a conditional expression for appropriately setting the curvature of the imaging surface. If the value of conditional expression (3) is less than the upper limit, the curvature of the imaging surface becomes large, and it is possible to prevent an increase in the telecentric characteristics and the correction burden of the curvature of field in the imaging lens. Coma and chromatic aberration can be corrected well. On the other hand, when the value of conditional expression (3) exceeds the lower limit, the curvature of the imaging surface becomes small, and overcorrection of the curvature of field can be prevented. Further, it is possible to prevent the final surface of the imaging lens from being too close to the imaging surface, and to sufficiently secure an air space for inserting an IR cut filter or the like. More preferably, the range of the following formula is good. However, it is sufficient that the imaging surface is curved, and it is not always necessary to have a spherical shape.
−30 <RI / Y <−5 (3 ′)

The imaging lens described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the following conditional expression is satisfied.
0.5 <P _air23 /P<5.0 (4)
However,
P: Refractive power of the entire imaging lens system (reciprocal of focal length)
P _air23 is the refractive power of a so-called air lens formed by the image side surface of the second lens and the object side surface of the third lens, and is determined by the following conditional expression.
P _air23 = (1-N2) / R4 + (N3-1) / R5-{((1-N2) · (N3-1)) / (R4 · R5)} · D4
However,
N2: Refractive index with respect to d line of the second lens N3: Refractive index with respect to d line of the third lens R4: Radius of curvature of the image side surface of the second lens R5: Radius of curvature of the object side surface of the third lens D4: Air spacing on the axis of the second lens and the third lens

Conditional expression (4) is a conditional expression for correcting the telecentric characteristic and off-axis aberration in a well-balanced manner by making the refractive power of the air lens formed by the second lens and the third lens appropriate. By curving the imaging surface, the burden of correcting the telecentric characteristic in the imaging lens can be reduced, so that the refractive power of the air lens can be set to a relatively weak positive refractive power. When the value of conditional expression (4) is below the upper limit, the positive refracting power by the air lens can be appropriately secured, so that various off-axis aberrations occurring in the third lens can be corrected well. On the other hand, when the value of conditional expression (4) exceeds the lower limit, the positive refractive power by the air lens does not become too strong, and the occurrence of coma flare and distortion of off-axis light flux can be suppressed. More preferably, the range of the following formula is good.
0.6 <P _{air23 /P<3.5} (4 ′)
Furthermore, the range of the following formula is desirable.
0.7 <P _{air23 /P<2.5} (4 ")

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the second lens satisfies the following conditional expression.
−40 <(R3 + R4) / (R3-R4) <0 (5)
Where R3: radius of curvature of object side surface of the second lens (mm)
R4: radius of curvature of the image side surface of the second lens (mm)

Conditional expression (5) is a conditional expression related to the shaping factor of the second lens. If the range of the conditional expression (5) is satisfied, the object side surface has a shape having a stronger refractive power than the image side surface, and both size reduction and aberration correction can be achieved. When the value of conditional expression (5) is below the upper limit, the position of the principal point of the lens system is prevented from moving to the image plane side and the back focus is lengthened, and the imaging lens can be reduced in size. On the other hand, if the value of conditional expression (5) exceeds the lower limit, the curvature radius of the object side surface becomes too small and the occurrence of coma aberration can be suppressed, and good imaging performance can be obtained. become. More preferably, the range of the following formula is good.
−30 <(R3 + R4) / (R3−R4) <− 0.3 (5 ′)
Furthermore, the range of the following formula is desirable.
−20 <(R3 + R4) / (R3−R4) <− 0.6 (5 ″)

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the third lens has negative refractive power and satisfies the following conditional expression: .
−0.8 <f / f3 <0 (6)
However,
f: focal length of all lens systems f3: focal length of the third lens

If the third lens is a negative lens, a telephoto type configuration can be obtained, which facilitates downsizing. When the value of conditional expression (6) is below the upper limit, an increase in the total length of the optical system can be prevented. On the other hand, when the value of conditional expression (6) exceeds the lower limit, it is possible to suppress the deterioration of aberrations, particularly the distortion and curvature of field. Furthermore, it is desirable that the third lens has a meniscus shape with a convex surface facing the object side. If the object side surface of the third lens is convex and the image side surface is concave, the principal point position of the lens system can be arranged closer to the object side, which prevents the back focus from becoming long and is advantageous for downsizing of the imaging lens. . More preferably, the range of the following formula is good.
−0.7 <f / f3 <0 (6 ′)
Furthermore, the range of the following formula is desirable.
-0.6 <f / f3 <0 (6 ")

An imaging lens according to a sixth aspect of the invention is characterized in that, in the invention according to any one of the first to fourth aspects, the third lens has a positive refractive power and satisfies the following conditional expression: .
0 <f / f3 <0.8 (7)
However,
f: focal length of all lens systems f3: focal length of the third lens

If the third lens is a positive lens, a triplet type configuration can be obtained, so that the entire lens system has a configuration close to symmetry, and aberration correction is easy. When the value of conditional expression (7) is less than the upper limit, an increase in the total length of the optical system can be prevented. On the other hand, when the value of conditional expression (7) exceeds the lower limit, it is possible to suppress aberration deterioration, in particular, distortion and field curvature. Furthermore, it is desirable that the third lens has a meniscus shape with a convex surface facing the object side. If the object side surface of the third lens is convex and the image side surface is concave, the principal point position of the lens system can be arranged closer to the object side, which prevents the back focus from becoming long and is advantageous for downsizing of the imaging lens. . More preferably, the range of the following formula is good.
0 <f / f3 <0.7 (7 ')
Furthermore, the range of the following formula is desirable.
0 <f / f3 <0.6 (7 ")

  According to a seventh aspect of the present invention, in the invention of any one of the first to sixth aspects, an aperture stop is disposed between the first lens and the second lens.

  When it is necessary to sufficiently correct the telecentric characteristics with the imaging lens, it is advantageous to dispose the aperture stop as far away from the imaging surface as possible, but with an imaging lens with a curved imaging surface as in the present invention. Since it is almost unnecessary, it is desirable to arrange an aperture stop between the first lens and the second lens because it is easy to correct lateral chromatic aberration and distortion.

  An imaging lens according to an eighth aspect of the present invention is the imaging lens according to any one of the first to sixth aspects, wherein the aperture stop is located closer to the object side than the object side surface position in the periphery of the first lens within the effective diameter of the first lens. It is characterized by arranging.

  A so-called front stop in which the aperture stop is disposed on the object side of the first lens is advantageous in correcting telecentric characteristics because the exit pupil position is separated from the image plane. Even in an imaging lens that does not need to sufficiently correct the telecentric characteristics by curving the imaging surface as in the present invention, the correction of the telecentric characteristics becomes almost unnecessary if the front aperture configuration is used. Since the aberration can be corrected sufficiently, high performance can be realized. Furthermore, even when a mechanical shutter is required, it can be advantageously arranged at the most object side.

  An imaging lens according to a ninth aspect is the invention according to any one of the first to eighth aspects, further comprising a lens having substantially no power. That is, even when a dummy lens having substantially no power is added to the configuration of claim 1, it is within the scope of application of the present invention.

  An imaging device according to claim 10 is a solid-state imaging device including a photoelectric conversion unit, a substrate on which the solid-state imaging device is held and a connection terminal unit for transmitting and receiving electrical signals is formed, and Item 10. The image pickup lens according to any one of Items 1 to 9, and a housing formed of a light-shielding material that includes the image pickup lens and has an opening for light incidence from the object side. .

  By using the imaging lens of the present invention, a smaller and higher performance imaging device can be obtained.

  A portable terminal according to an eleventh aspect includes the imaging device according to the tenth aspect.

  By using the imaging device of the present invention, a smaller and higher performance portable terminal can be obtained.

  According to the present invention, by using a solid-state imaging device having a curved imaging surface, an imaging lens having a small size, high performance, suppressing shading, and having an F value smaller than F2.8 and imaging using the imaging lens An apparatus and a portable terminal can be obtained.

It is a perspective view of the imaging device concerning this embodiment. It is the figure which showed typically the cross section along the optical axis of the imaging lens of the imaging device which concerns on this Embodiment. It is an external view of the mobile telephone which is an example of the portable terminal provided with the imaging device which concerns on this Embodiment. 2 is a cross-sectional view of an imaging lens of Example 1. FIG. FIG. 6 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 1. 6 is a cross-sectional view of an imaging lens of Example 2. FIG. FIG. 6 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 2. 6 is a cross-sectional view of an imaging lens of Example 3. FIG. FIG. 6 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 3. 6 is a cross-sectional view of an imaging lens of Example 4. FIG. FIG. 10 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 4. 6 is a cross-sectional view of an imaging lens of Example 5. FIG. FIG. 10 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 5. 6 is a cross-sectional view of an imaging lens of Example 6. FIG. FIG. 10 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 6. 10 is a cross-sectional view of an imaging lens of Example 7. FIG. FIG. 10 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 7. 10 is a cross-sectional view of an imaging lens of Example 8. FIG. FIG. 10 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 8. 10 is a cross-sectional view of an imaging lens of Example 9. FIG. FIG. 10 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 9. 10 is a cross-sectional view of an imaging lens of Example 10. FIG. FIG. 10 is an aberration diagram (spherical aberration, astigmatism, distortion) of the imaging lens of Example 10.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a top view of an imaging apparatus 50 according to the present embodiment, and FIG. 2 is a cross-sectional view obtained by cutting the configuration of FIG. 1 along a cross section including an optical axis.

  As illustrated in FIG. 1 or FIG. 2, the imaging device 50 includes a CMOS type imaging device 51 as a solid-state imaging device having a photoelectric conversion unit 51 a and an imaging lens that captures a subject image on the photoelectric conversion unit 51 a on the imaging device 51. 10 and a casing 53 made of a light shielding member having an opening for light incidence from the object side, and these are integrally formed.

  As shown in FIG. 2, the image sensor 51 is spherically curved with a predetermined radius of curvature, and a pixel (photoelectric conversion element) is two-dimensionally arranged at the center of the curved light receiving side surface. A photoelectric conversion unit 51a as a unit is formed, and a signal processing circuit 51b is formed around the photoelectric conversion unit 51a. The signal processing circuit 51b includes a driving circuit unit that sequentially drives each pixel to obtain a signal charge, an A / D conversion unit that converts each signal charge into a digital signal, and a signal that forms an image signal output using the digital signal. It consists of a processing unit and the like. Note that the image pickup element is not limited to the above-described CMOS type image sensor, and may be one to which another one such as a CCD is applied.

  The seal glass C is fixed to the photoelectric conversion unit 51 a side of the image sensor 51 through the spacer B, and the seal glass C or the side surface of the image sensor 51 is fixed to the housing 53. The seal glass C is a flat plate here, but may be curved in accordance with the photoelectric conversion unit 51a.

  A plurality of external electrodes 52 used for connection to an external circuit are formed on the other surface of the image sensor 51 (surface opposite to the photoelectric conversion unit 51a). The external electrode 52 and an external circuit (not shown) (for example, a control circuit included in a host device on which the imaging device is mounted) are connected to receive a voltage or a clock signal for driving the imaging device 51 from the external circuit. In addition, it is possible to output a digital YUV signal to an external circuit.

  Although not shown, a substrate is disposed on the surface opposite to the photoelectric conversion unit 51a of the image sensor 51, the substrate and the image sensor 51 are connected by wire bonding, and an external surface is connected to the surface of the substrate opposite to the image sensor. A plurality of external electrodes used for connection with a circuit may be formed.

  As shown in FIG. 2, the housing 53 made of a light-shielding member is screwed into a lens frame 55 that holds the imaging lens 10 on the photoelectric conversion unit 51 a side of the imaging element 51, whereby the imaging lens 10 is Adjustable in the optical axis direction.

  The imaging lens 10 includes, in order from the object side, a positive first lens L1, an aperture stop S, a positive second lens L2, and a negative third lens L3. A subject image is captured on the photoelectric conversion surface 51a of the imaging element 51. It is configured to form an image. In addition, the dashed-dotted line in FIG. 2 is an optical axis of each lens L1-L3.

  Any one surface of the first lens L1, the second lens L2, the third lens L3, and the seal glass C is coated with an infrared light cut coat. Although not shown, an infrared light cut filter may be disposed in front of the seal glass instead of the infrared cut coat.

  Each lens L1 to L3 constituting the imaging lens 10 is held by a lens frame 55 made of a light shielding member. Each of the lenses L1 to L3 has an outer diameter that increases from the object side toward the image side, and a disc-shaped light shielding member SH1 having an aperture stop S formed in the center between the flange portions of the lenses L1 and L2. Is arranged. Further, the light shielding member SH2 is fixed to the lens frame 55 so as to contact the image side flange portion of the lens L2. The surfaces of the light shielding members SH1 and SH2 that cut unnecessary light may be stepped or roughened. Further, a light shielding member may be disposed between the third lens L3 and the seal glass C. By arranging the light shielding member outside the light beam path, it is possible to suppress the occurrence of ghost and flare. In the case of the imaging apparatus shown in FIG. 2, H in the figure is the height of the imaging lens in the optical axis direction of the imaging apparatus.

  FIG. 3 is an external view of a mobile phone 100 that is an example of a mobile terminal including the imaging device 50 according to the present embodiment. In the mobile phone 100 shown in the figure, an upper casing 71 as a case having display screens D1 and D2 and a lower casing 72 having an operation button 60 as an input unit are connected via a hinge 73. Yes. The imaging device 50 is built below the display screen D <b> 2 in the upper casing 71, and is arranged so that the imaging device 50 can capture light from the outer surface side of the upper casing 71. Note that the position of the imaging device may be disposed above or on the side of the display screen D2 in the upper casing 71. Of course, the mobile phone is not limited to a folding type.

(Example)
Next, examples suitable for the above-described embodiment will be described. However, the present invention is not limited to the following examples. Symbols used in each example are as follows.
f: Focal length of the entire imaging lens system fB: Back focus F: F number Y: Imaging surface diagonal maximum image height R of solid-state imaging device R: Radius of curvature D: Axis upper surface distance Nd: Refractive index νd of lens material with respect to d-line : Abbe number of lens material
ENTP: Entrance pupil position (distance from first surface to entrance pupil position)
EXTP: Exit pupil position (distance from imaging surface to exit pupil position)
H1: Front principal point position (distance from the first surface to the front principal point position)
H2: Rear principal point position (distance from the final surface to the rear principal point position)

  In each embodiment, the surface described with “*” after each surface number is a surface having an aspheric shape, and the shape of the aspheric surface has the vertex of the surface as the origin and the X axis in the optical axis direction. The height in the direction perpendicular to the optical axis is represented by the following “Equation 1”.

However,
Ai: i-order aspheric coefficient R: radius of curvature K: conic constant

Example 1
Lens data is shown in Table 1. In the following (including the lens data in the table), a power of 10 (for example, 2.5 × 10 ⁻⁰² ) is expressed using E (for example, 2.5E-02). 4 is a sectional view of the lens of Example 1. FIG. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 5A is a spherical aberration diagram of Example 1, FIG. 5B is an astigmatism diagram, and FIG. 5C is a distortion diagram. Here, in the spherical aberration diagram and the coma aberration diagram, g represents the amount of spherical aberration with respect to the g line, and d represents the amount of spherical aberration with respect to the d line. In the astigmatism diagram, the solid line S represents the sagittal plane, and the dotted line M represents the meridional plane (the same applies hereinafter). The aperture stop S is between the first lens L1 and the second lens L2.

[table 1 ]
Example 1

f = 2.88mm fB = 0.45mm F = 2.6 2Y = 3.7mm
ENTP = 0.62mm EXTP = -1.6mm H1 = -0.54mm H2 = -2.42mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 0.974 0.64 1.54400 55.9 0.73
2 * 3.524 0.05 0.48
3 (Aperture) ∞ 0.36 0.43
4 * -0.955 0.40 1.63200 23.4 0.51
5 * -1.357 0.35 0.74
6 * 2.186 0.60 1.54400 55.9 1.27
7 * 1.858 0.31 1.48
8 ∞ 0.15 1.51680 64.0 1.69
9 ∞ 1.73
Imaging surface -25.000 1.85

Aspheric coefficient

1st side 5th side
K = -0.43992E + 00 K = 0.10351E + 01
A4 = 0.53794E-01 A4 = -0.29740E + 00
A6 = 0.12150E + 00 A6 = 0.61980E + 00
A8 = -0.40448E + 00 A8 = -0.59821E-02
A10 = 0.11427E + 01 A10 = 0.73533E + 00
A12 = -0.15870E + 01 A12 = -0.36864E + 00

2nd side 6th side
K = 0.21492E + 02 K = -0.14647E + 02
A4 = -0.10440E + 00 A4 = -0.40002E + 00
A6 = -0.72296E + 00 A6 = 0.31165E + 00
A8 = 0.38550E + 01 A8 = -0.10105E + 00
A10 = -0.25472E + 02 A10 = 0.15343E-01
A12 = 0.51252E + 02 A12 = -0.98196E-03

4th surface 7th surface
K = -0.74767E + 00 K = -0.42546E + 01
A4 = -0.53444E + 00 A4 = -0.31361E + 00
A6 = -0.11355E + 00 A6 = 0.19485E + 00
A8 = -0.53639E + 01 A8 = -0.99285E-01
A10 = 0.33212E + 02 A10 = 0.26513E-01
A12 = -0.85556E + 02 A12 = -0.25007E-02

Single lens data

Lens Start surface Focal length (mm)
1 1 2.27
2 4 -8.33
3 6 -64.13

(Example 2)
Table 2 shows the lens data. 6 is a sectional view of the lens of Example 2. FIG. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 7A is a spherical aberration diagram of Example 2, FIG. 7B is an astigmatism diagram, and FIG. 7C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 2]
Example 2
f = 2.78mm fB = 0.55mm F = 2.6 2Y = 3.7mm
ENTP = 0.4mm EXTP = -1.76mm H1 = -0.17mm H2 = -2.23mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.197 0.52 1.53 100 56.0 0.68
2 * -14.789 0.00 0.54
3 (Aperture) ∞ 0.39 0.48
4 * -0.731 0.31 1.58500 30.0 0.54
5 * -0.872 0.48 0.67
6 * -82.140 0.57 1.53100 56.0 1.18
7 * 5.440 0.30 1.42
8 ∞ 0.15 1.51680 64.0 1.65
9 ∞ 1.69
Imaging surface -15.000 1.85

Aspheric coefficient

1st side 5th side
K = -0.18303E + 01 K = -0.30761E + 00
A4 = 0.62003E-01 A4 = 0.41580E + 00
A6 = -0.16896E + 00 A6 = 0.71327E + 00
A8 = 0.16086E + 00 A8 = 0.16358E + 01
A10 = -0.13208E + 01 A10 = -0.23811E + 01

2nd side 6th side
K = 0.30000E + 02 K = 0.30000E + 02
A4 = -0.23751E + 00 A4 = -0.50950E-01
A6 = -0.18949E + 00 A6 = 0.73309E-02
A8 = -0.82802E + 00 A8 = -0.28154E-01
A10 = 0.15113E + 01 A10 = 0.13538E-01
A12 = 0.14274E-02

4th surface 7th surface
K = 0.18560E + 00 K = 0.37104E + 01
A4 = 0.35837E + 00 A4 = -0.13004E + 00
A6 = 0.18806E + 01 A6 = 0.32925E-01
A8 = 0.27267E + 00 A8 = -0.22771E-01
A10 = -0.10674E + 01 A10 = 0.51155E-02
A12 = -0.12556E-02
Single lens data

Lens Start surface Focal length (mm)
1 1 2.11
2 4 -38.76
3 6 -9.59

(Example 3)
Table 3 shows lens data. FIG. 8 is a sectional view of the lens of Example 3. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 9A is a spherical aberration diagram of Example 3, FIG. 9B is an astigmatism diagram, and FIG. 9C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 3]
Example 3

f = 4.44mm fB = 0.44mm F = 2.55 2Y = 5.7mm
ENTP = 0.78mm EXTP = -2.5mm H1 = -1.47mm H2 = -4mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.453 0.82 1.54400 55.9 1.06
2 * 4.153 0.07 0.73
3 (Aperture) ∞ 0.55 0.72
4 * -1.621 0.47 1.63200 23.4 0.82
5 * -1.806 1.14 1.06
6 * 7.272 0.70 1.54400 55.9 2.06
7 * 2.920 0.48 2.34
8 ∞ 0.15 1.51680 64.0 2.68
9 ∞ 2.71
Imaging surface -32.000 2.85

Aspheric coefficient

1st side 5th side
K = -0.37205E + 00 K = 0.96128E + 00
A4 = 0.18906E-01 A4 = -0.14916E-03
A6 = 0.12902E-01 A6 = 0.55779E-01
A8 = -0.14259E-01 A8 = 0.16898E-01
A10 = 0.26454E-01 A10 = 0.36031E-01
A12 = -0.14837E-01 A12 = -0.16621E-01

2nd side 6th side
K = 0.19190E + 02 K = -0.18767E + 02
A4 = -0.26221E-01 A4 = -0.10405E + 00
A6 = -0.73608E-01 A6 = 0.31575E-01
A8 = 0.15641E + 00 A8 = -0.43589E-02
A10 = -0.38623E + 00 A10 = 0.34824E-03
A12 = 0.21325E + 00 A12 = -0.14702E-04

4th surface 7th surface
K = -0.46694E + 00 K = -0.47722E + 01
A4 = -0.10720E + 00 A4 = -0.86264E-01
A6 = 0.42561E-01 A6 = 0.21598E-01
A8 = -0.19032E + 00 A8 = -0.41827E-02
A10 = 0.57203E + 00 A10 = 0.44784E-03
A12 = -0.61258E + 00 A12 = -0.18107E-04

Single lens data

Lens Start surface Focal length (mm)
1 1 3.71
2 4 -1231.2
3 6 -9.51

Example 4
Table 4 shows the lens data. FIG. 10 is a sectional view of the lens of Example 4. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 11A is a spherical aberration diagram of Example 4, FIG. 11B is an astigmatism diagram, and FIG. 11C is a distortion diagram. The aperture stop S is located closer to the object side than the object side surface position around the first lens L1 within the effective diameter of the first lens L1.

[Table 4]
Example 4

f = 4.39mm fB = 0.83mm F = 2.6 2Y = 5.7mm
ENTP = 0.83mm EXTP = -2.52mm H1 = -0.53mm H2 = -3.55mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.521 0.85 1.54400 55.9 1.09
2 * 5.366 0.09 0.77
3 (Aperture) ∞ 0.59 0.69
4 * -1.531 0.63 1.63200 23.4 0.81
5 * -2.089 0.63 1.15
6 * 2.987 0.82 1.54400 55.9 1.96
7 * 2.691 0.48 2.26
8 ∞ 0.15 1.51680 64.0 2.55
9 ∞ 2.58
Imaging surface -54.000 2.85

Aspheric coefficient

1st side 5th side
K = -0.39791E + 00 K = 0.14301E + 01
A4 = 0.19030E-01 A4 = -0.60056E-01
A6 = -0.11186E-02 A6 = 0.70505E-01
A8 = 0.10310E-02 A8 = 0.92140E-03
A10 = 0.10578E-01 A10 = 0.16126E-01
A12 = -0.12271E-01 A12 = -0.35495E-02

2nd side 6th side
K = 0.25689E + 02 K = -0.11266E + 02
A4 = -0.28205E-01 A4 = -0.10426E + 00
A6 = -0.72881E-01 A6 = 0.33284E-01
A8 = 0.18176E + 00 A8 = -0.48234E-02
A10 = -0.47201E + 00 A10 = 0.32590E-03
A12 = 0.34730E + 00 A12 = -0.73648E-05

4th surface 7th surface
K = -0.15864E + 00 K = -0.34531E + 01
A4 = -0.11698E + 00 A4 = -0.88353E-01
A6 = 0.41218E-01 A6 = 0.22243E-01
A8 = -0.23839E + 00 A8 = -0.44999E-02
A10 = 0.59113E + 00 A10 = 0.51161E-03
A12 = -0.58359E + 00 A12 = -0.25313E-04

Single lens data

Lens Start surface Focal length (mm)
1 1 3.62
2 4 -16.14
3 6 -2445.8

(Example 5)
Table 5 shows the lens data. 12 is a sectional view of the lens of Example 5. FIG. In the figure, L1 is a first lens, L2 is a second lens, L3 is a positive third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. FIG. 13A is a spherical aberration diagram of Example 5, FIG. 13B is an astigmatism diagram, and FIG. 13C is a distortion diagram. The aperture stop S is located closer to the object side than the object side surface position around the first lens L1 within the effective diameter of the first lens L1.

[Table 5]
Example 5
f = 4.46mm fB = 0.76mm F = 2.35 2Y = 5.7mm
ENTP = 0.88mm EXTP = -2.52mm H1 = -0.73mm H2 = -3.7mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.577 0.90 1.54400 55.9 1.16
2 * 4.936 0.09 0.81
3 (Aperture) ∞ 0.61 0.77
4 * -3.163 0.94 1.63200 23.4 0.92
5 * -5.633 0.48 1.40
6 * 2.618 0.80 1.54400 55.9 1.94
7 * 2.575 0.48 2.27
8 ∞ 0.15 1.51680 64.0 2.59
9 ∞ 2.63
Imaging surface -23.000 2.85

Aspheric coefficient

1st side 5th side
K = -0.40406E + 00 K = 0.36262E + 01
A4 = 0.17428E-01 A4 = -0.11078E + 00
A6 = 0.77360E-02 A6 = 0.10071E + 00
A8 = -0.92800E-03 A8 = -0.54276E-01
A10 = 0.36961E-02 A10 = 0.20639E-01
A12 = -0.40512E-03 A12 = -0.31412E-02

2nd side 6th side
K = 0.13059E + 02 K = -0.10640E + 02
A4 = 0.94873E-03 A4 = -0.12188E + 00
A6 = -0.28710E-01 A6 = 0.34921E-01
A8 = 0.87757E-01 A8 = -0.44350E-02
A10 = -0.14267E + 00 A10 = 0.32210E-03
A12 = 0.75649E-01 A12 = -0.15758E-04

4th surface 7th surface
K = -0.22747E + 01 K = -0.13336E + 01
A4 = -0.10395E + 00 A4 = -0.10934E + 00
A6 = 0.14309E + 00 A6 = 0.26685E-01
A8 = -0.43730E + 00 A8 = -0.52002E-02
A10 = 0.56034E + 00 A10 = 0.59289E-03
A12 = -0.31438E + 00 A12 = -0.31402E-04

Single lens data

Lens Start surface Focal length (mm)
1 1 3.89
2 4 -13.38
3 6 51.48

(Example 6)
Table 6 shows the lens data. FIG. 14 is a sectional view of the lens of Example 6. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 15A is a spherical aberration diagram of Example 6, FIG. 15B is an astigmatism diagram, and FIG. 15C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 6]
Example 6
f = 2.95mm fB = 0.41mm F = 2.45 2Y = 3.7mm
ENTP = 0mm EXTP = -1.89mm H1 = -0.84mm H2 = -2.54mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.02 0.60
2 * 1.419 0.71 1.53070 55.7 0.67
3 * -3.008 0.17 0.78
4 * -1.321 0.31 1.63200 23.4 0.79
5 * -2.321 0.60 0.77
6 * 4.911 0.72 1.53070 55.7 0.96
7 * 2.152 0.34 1.44
8 ∞ 0.20 1.51680 64.0 1.67
9 ∞ 1.72
Imaging surface -15.000 1.85

Aspheric coefficient

2nd side 5th side
K = -0.90615E + 00 K = -0.56919E + 01
A4 = -0.56222E-01 A4 = -0.13553E + 00
A6 = 0.27445E-01 A6 = 0.11690E + 01
A8 = -0.52694E + 00 A8 = -0.10166E + 01
A10 = 0.60681E + 00

3rd side 6th side
K = 0.53380E + 01 K = 0.68098E + 01
A4 = -0.37723E + 00 A4 = -0.38157E + 00
A6 = 0.14693E + 00 A6 = 0.11876E + 00
A8 = 0.24964E + 00 A8 = 0.13363E-01
A10 = -0.38344E + 00 A10 = -0.11322E + 00

4th surface 7th surface
K = -0.19639E + 00 K = -0.10669E + 02
A4 = -0.30451E + 00 A4 = -0.13106E + 00
A6 = 0.15848E + 01 A6 = 0.36011E-01
A8 = -0.12818E + 01 A8 = -0.10160E-01
A10 = 0.42197E + 00 A10 = -0.92068E-03

Single lens data

Lens Start surface Focal length (mm)
1 2 1.92
2 4 -5.53
3 6 -7.94

(Example 7)
Table 7 shows the lens data. FIG. 16 is a sectional view of the lens of Example 7. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. FIG. 17A is a spherical aberration diagram of Example 7, FIG. 17B is an astigmatism diagram, and FIG. 17C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 7]
Example 7
f = 4.6mm fB = 0.86mm F = 2.45 2Y = 5.7mm
ENTP = 0mm EXTP = -2.79mm H1 = -1.2mm H2 = -3.74mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.21 0.94
2 * 1.802 1.20 1.54400 55.9 0.97
3 * -8.657 0.32 1.08
4 * -1.419 0.45 1.63200 23.4 1.03
5 * -2.104 0.63 1.08
6 * -14.028 1.22 1.54400 55.9 1.38
7 * 11.028 0.30 2.10
8 ∞ 0.30 1.51680 64.0 2.48
9 ∞ 2.55
Imaging surface -26.000 2.85

Aspheric coefficient

2nd side 5th side
K = 0.96101E + 00 K = 0.17813E + 00
A4 = -0.30464E-01 A4 = 0.41957E-01
A6 = -0.30975E-01 A6 = 0.12565E + 00
A8 = 0.20609E-01 A8 = 0.24136E-02
A10 = 0.73083E-01 A10 = -0.72912E-02
A12 = -0.34494E + 00 A12 = -0.79590E-02
A14 = 0.40348E + 00 A14 = 0.42734E-02
A16 = -0.16106E + 00 A16 = 0.19315E-02

3rd side 6th side
K = 0 K = -0.34059E + 01
A4 = -0.96403E-01 A4 = -0.95550E-01
A6 = -0.20038E-01 A6 = 0.65995E-01
A8 = -0.68920E-01 A8 = -0.82791E-01
A10 = 0.17892E + 00 A10 = 0.50952E-01
A12 = -0.18264E + 00 A12 = -0.55373E-02
A14 = 0.90883E-01 A14 = -0.10261E-01
A16 = -0.19855E-01 A16 = 0.36169E-02

4th surface 7th surface
K = 0.29763E + 00 K = -0.25000E + 02
A4 = -0.28669E-01 A4 = -0.41828E-01
A6 = 0.29589E + 00 A6 = 0.51563E-02
A8 = -0.43217E + 00 A8 = -0.97269E-03
A10 = 0.66262E + 00 A10 = -0.48945E-04
A12 = -0.59652E + 00 A12 = -0.90677E-05
A14 = 0.25357E + 00 A14 = 0.10625E-04
A16 = -0.33712E-01 A16 = -0.18936E-05

Single lens data

Lens Start surface Focal length (mm)
1 2 2.86
2 4 -9.29
3 6 -11.16

(Example 8)
Table 8 shows the lens data. FIG. 18 is a sectional view of the lens of Example 8. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 19A is a spherical aberration diagram of Example 8, FIG. 19B is an astigmatism diagram, and FIG. 19C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 8]
Example 8
f = 4.71mm fB = 0.78mm F = 2.5 2Y = 5.7mm
ENTP = 0mm EXTP = -2.97mm H1 = -1.21mm H2 = -3.93mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.08 0.94
2 * 2.246 1.08 1.53070 55.7 1.02
3 * -5.224 0.27 1.17
4 * -2.187 0.48 1.63200 23.4 1.19
5 * -3.777 1.00 1.18
6 * 8.210 1.06 1.53070 55.7 1.51
7 * 3.772 0.50 2.19
8 ∞ 0.30 1.51680 64.0 2.51
9 ∞ 2.60
Imaging surface -19.000 2.85

Aspheric coefficient

2nd side 5th side
K = -0.93908E + 00 K = -0.77045E + 01
A4 = -0.14550E-01 A4 = -0.31389E-01
A6 = 0.26017E-02 A6 = 0.11856E + 00
A8 = -0.21725E-01 A8 = -0.40692E-01
A10 = 0.95579E-02

3rd side 6th side
K = 0.62562E + 01 K = 0.21235E + 02
A4 = -0.97980E-01 A4 = -0.92826E-01
A6 = 0.14790E-01 A6 = 0.95645E-02
A8 = 0.10052E-01 A8 = 0.91524E-03
A10 = -0.62898E-02 A10 = -0.18899E-02

4th surface 7th surface
K = -0.22145E + 00 K = -0.12380E + 02
A4 = -0.76017E-01 A4 = -0.33846E-01
A6 = 0.15934E + 00 A6 = 0.35036E-02
A8 = -0.51468E-01 A8 = -0.33362E-03
A10 = 0.67174E-02 A10 = -0.32608E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.12
2 4 -9.32
3 6 -14.33

Example 9
Table 9 shows the lens data. FIG. 20 is a sectional view of the lens of Example 9. In the drawing, L1 is a first lens, L2 is a second lens, L3 is a negative third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 21A is a spherical aberration diagram of Example 9, FIG. 21B is an astigmatism diagram, and FIG. 21C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 9]
Example 9
f = 3.47mm fB = 0.36mm F = 2.55 2Y = 4.5mm
ENTP = 0mm EXTP = -2.23mm H1 = -1.18mm H2 = -3.11mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.24 0.68
2 * 1.090 0.60 1.56910 71.3 0.69
3 * 2.743 0.46 0.66
4 * -3.932 0.37 1.81360 25.7 0.69
5 * -6.759 0.49 0.88
6 * 11.503 0.81 1.58310 59.4 1.31
7 * 5.563 0.30 1.70
8 ∞ 0.50 1.51680 64.0 2.04
9 ∞ 2.17
Imaging surface -17.000 2.25

Aspheric coefficient

2nd side 5th side
K = -0.18983E + 00 K = -0.15930E + 02
A4 = 0.23954E-01 A4 = -0.98706E-01
A6 = 0.85038E-01 A6 = 0.19297E + 00
A8 = -0.78502E-01 A8 = -0.10888E-01
A10 = 0.12026E + 00 A10 = -0.20295E-01
A12 = -0.32767E-01 A12 = -0.28850E-01
A14 = 0.11575E + 00 A14 = 0.61487E-01
A16 = -0.53866E-01

3rd side 6th side
K = 0.13783E + 01 K = 0.30000E + 02
A4 = 0.69790E-01 A4 = -0.20589E + 00
A6 = -0.17257E + 00 A6 = 0.58786E-01
A8 = 0.63615E + 00 A8 = 0.32575E-02
A10 = 0.28402E + 00 A10 = 0.22747E-02
A12 = -0.36635E + 01 A12 = -0.70891E-03
A14 = 0.38575E + 01 A14 = -0.75545E-03
A16 = 0.15234E-03

4th surface 7th surface
K = 0.30000E + 02 K = 0.41037E + 01
A4 = -0.96590E-01 A4 = -0.12092E + 00
A6 = 0.22546E + 00 A6 = 0.25132E-01
A8 = -0.24496E + 00 A8 = -0.91638E-02
A10 = 0.76711E-02 A10 = 0.17836E-02
A12 = -0.55121E + 00 A12 = 0.49635E-04
A14 = 0.32520E + 01 A14 = -0.13264E-03
A16 = -0.52433E + 01 A16 = 0.80524E-05

Single lens data

Lens Start surface Focal length (mm)
1 2 2.81
2 4 -12.29
3 6 -19.45

(Example 10)
Table 10 shows the lens data. FIG. 22 is a sectional view of the lens of Example 10. In the figure, L1 is a first lens, L2 is a second lens, L3 is a positive third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. FIG. 23A is a spherical aberration diagram of Example 10, FIG. 23B is an astigmatism diagram, and FIG. 23C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 10]
Example 10
f = 3.42mm fB = 0.24mm F = 2.5 2Y = 4.5mm
ENTP = 0mm EXTP = -2.16mm H1 = -1.45mm H2 = -3.18mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.22 0.68
2 * 1.156 0.59 1.56910 71.3 0.69
3 * 3.195 0.74 0.69
4 * -4.132 0.42 1.81360 25.7 0.76
5 * 20.000 0.28 1.09
6 * 1.794 0.84 1.58310 59.4 1.52
7 * 2.169 0.30 1.85
8 ∞ 0.50 1.51680 64.0 2.09
9 ∞ 2.20
Imaging surface -56.000 2.25

Aspheric coefficient

2nd side 5th side
K = -0.23799E + 00 K = 0.19859E + 02
A4 = 0.22448E-01 A4 = -0.32906E + 00
A6 = 0.29793E-01 A6 = 0.24696E + 00
A8 = -0.17199E-01 A8 = -0.74258E-01
A10 = 0.12708E + 00 A10 = -0.36370E-01
A12 = -0.25518E + 00 A12 = -0.24702E-01
A14 = 0.23565E + 00 A14 = 0.11207E + 00
A16 = -0.53866E-01

3rd side 6th side
K = -0.17722E + 01 K = -0.90473E + 01
A4 = 0.47896E-01 A4 = -0.23358E + 00
A6 = -0.47641E-01 A6 = 0.63544E-01
A8 = 0.11659E + 00 A8 = 0.54789E-02
A10 = 0.35654E + 00 A10 = 0.11664E-02
A12 = -0.14238E + 01 A12 = -0.98560E-03
A14 = 0.13272E + 01 A14 = -0.60566E-03
A16 = 0.17977E-03

4th surface 7th surface
K = 0.28265E + 02 K = -0.17157E + 01
A4 = -0.16886E + 00 A4 = -0.16749E + 00
A6 = -0.94800E-01 A6 = 0.44510E-01
A8 = 0.23805E + 00 A8 = -0.10801E-01
A10 = -0.36824E + 00 A10 = 0.12616E-02
A12 = -0.11076E + 01 A12 = 0.16269E-03
A14 = 0.37419E + 01 A14 = -0.10473E-03
A16 = -0.38976E + 01 A16 = 0.12797E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 2.88
2 4 -4.18
3 6 9.76

  Table 11 summarizes the values of the conditional expressions described in the claims.

  Regarding the meaning of the paraxial radius of curvature described in the claims and the examples, in the actual lens measurement scene, in the vicinity of the center of the lens (specifically, the central region within 10% of the lens outer diameter) ) Can be regarded as the paraxial curvature radius when fitting the shape measurement value in the least square method. For example, when a secondary aspherical coefficient is used, a curvature radius that takes into account the secondary aspherical coefficient in the reference curvature radius of the aspherical definition formula can be regarded as a paraxial curvature radius (for example, reference literature). (See pages 41 to 42 of “Lens Design Method” by K. Matsui, Kyoritsu Publishing Co., Ltd.).

  The present invention is not limited to the embodiments described in the specification, and other embodiments and modifications are apparent to those skilled in the art from the embodiments and ideas described in the present specification. It is. For example, even when a dummy lens having substantially no power is further provided, it is within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Imaging lens 50 Imaging device 51a Photoelectric conversion part 51b Signal processing circuit 52 External electrode 53 Housing | casing 55 Mirror frame 60 Operation button 71 Upper housing | casing 72 Lower housing | casing 73 Hinge 100 Mobile phone B Spacer C Seal glass D1, D2 Display screen L1 First lens L2 Second lens L3 Third lens S Aperture stop SH1 Light blocking member SH2 Light blocking member

Claims (11)

In an imaging lens of an imaging apparatus, comprising: a solid-state imaging device including a photoelectric conversion unit; and an imaging lens that forms a subject image on the photoelectric conversion unit of the solid-state imaging device.
The imaging surface of the solid-state imaging device is curved,
The imaging lens includes a first lens having a positive refractive power in order from the object side, a second lens having a negative refractive power, and a third lens having a positive or negative refractive power,
An imaging lens satisfying the following conditional expression:
−0.9 <f1 / f23 <−0.1 (1)
0.11 <D5 / f <0.5 (2)
However,
f1: Focal length (mm) of the first lens
f23: Composite focal length (mm) of the second lens and the third lens
D5: Axial thickness (mm) of the third lens
f: Focal length (mm) of the entire imaging lens system The imaging lens according to claim 1, wherein the following conditional expression is satisfied.
−50.0 <RI / Y <−2.0 (3)
However,
RI: radius of curvature (mm) of the imaging surface of the solid-state imaging device
Y: Maximum image height (mm) The imaging lens according to claim 1, wherein the following conditional expression is satisfied.
0.5 <P _air23 /P<5.0 (4)
However,
P: Refractive power of the entire imaging lens system (reciprocal of focal length)
P _air23 is the refractive power of a so-called air lens formed by the image side surface of the second lens and the object side surface of the third lens, and is determined by the following conditional expression.
P _air23 = (1-N2) / R4 + (N3-1) / R5-{((1-N2) · (N3-1)) / (R4 · R5)} · D4
However,
N2: Refractive index with respect to d line of the second lens N3: Refractive index with respect to d line of the third lens R4: Radius of curvature of the image side surface of the second lens R5: Radius of curvature of the object side surface of the third lens D4: Air spacing on the axis of the second lens and the third lens The imaging lens according to claim 1, wherein the second lens satisfies the following conditional expression.
−40 <(R3 + R4) / (R3-R4) <0 (5)
Where R3: radius of curvature of object side surface of the second lens (mm)
R4: radius of curvature of the image side surface of the second lens (mm) The imaging lens according to claim 1, wherein the third lens has negative refractive power and satisfies the following conditional expression.
−0.8 <f / f3 <0 (6)
However,
f: focal length of all lens systems f3: focal length of the third lens The imaging lens according to claim 1, wherein the third lens has positive refractive power and satisfies the following conditional expression.
0 <f / f3 <0.8 (7)
However,
f: focal length of all lens systems f3: focal length of the third lens   The imaging lens according to claim 1, wherein an aperture stop is disposed between the first lens and the second lens.   The imaging lens according to claim 1, wherein an aperture stop is disposed closer to the object side than an object side surface position of the periphery of the first lens within an effective diameter of the first lens.   The imaging lens according to claim 1, further comprising a lens having substantially no power.   The solid-state imaging device provided with a photoelectric conversion unit, a substrate on which the solid-state imaging device is held and a connection terminal unit for transmitting and receiving an electrical signal is formed, and any one of claims 1 to 9 An imaging apparatus comprising: an imaging lens; and a housing made of a light-shielding material that includes the imaging lens and has an opening for light incidence from the object side.   A portable terminal comprising the imaging device according to claim 10.