CN103984083B - A kind of optical lens assembly - Google Patents

Abstract

The invention relates to an optical lens assembly of a high-definition 1/2.5-inch specification 5 million-pixel camera group used in the field of electronic products of automotive visual systems, including a fixed diaphragm, a group of lenses, and a glass filter. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are arranged in order from the image side of the object direction on the axis. The collocation of each lens can effectively shorten the height of the lens, and at the same time adopt a The aspheric lens refracts the light through the high-order curved surface, which can ensure that the light is precisely focused on one point, effectively eliminates various aberrations of the light, and ensures the high-quality imaging of the lens; the matching of each lens of the optical lens can effectively shorten the The height of the lens is less than 24mm, the field of view is 150 degrees, and the aperture number F/NO is controlled at 2.2; by placing the aperture in the middle, it can reduce the occurrence of various aberrations in the lens system, ensure the quality of the lens, and reduce the manufacturing cost.

Description

An optical lens assembly

technical field

The invention relates to the field of optical devices, in particular to an optical lens assembly used for a high-definition 1/2.5-inch 5 million-pixel camera group in the field of electronic products for automotive visual systems.

Background technique

The rapid development of the economy has improved people's living standards, and there are more and more cars, which has caused great pressure on road management. Bus is an essential means of transportation in cities, so the government has always advocated bus priority, and it has also become an important part of the smart traffic rules of each city, so that it can relieve urban traffic pressure, avoid more accidents, and strengthen Public transport management makes people travel safer. Of course, traffic management also needs to be upgraded in an all-round way, and a more advanced monitoring system "vehicle monitoring" is specially developed for vehicles to conduct comprehensive monitoring, so that managers can understand the situation inside and outside the vehicle more timely and clearly, and can guide the road , so that every city can step into a smooth traffic environment.

The introduction of on-board monitoring into urban traffic will definitely welcome more car owners. First, it can make the road smooth, relieve road congestion, and make smooth traffic without delay. Secondly, it can also provide car owners with road information, which road is congested ahead, so that they can turn to other roads in time to pass smoothly. The most important point is to better ensure driving safety. The application of vehicle monitoring is very extensive, and the application in China has reached a climax, mainly used in the field of public transportation and transportation. In this process, the vehicle-mounted monitoring has been upgraded, from the previous single vehicle-mounted monitoring to 3G monitoring, which can realize remote monitoring, which cannot be realized by a single vehicle-mounted monitoring system. Real-time monitoring can be carried out in a shorter time. At present, high-definition, high-pixel surveillance products have become the mainstream of the surveillance market. However, the existing lens components in the camera module used in the field of electronic products of automotive visual systems, such as Chinese Patent No. 201110307278. Small, optically large defects. In order to meet the needs of the domestic market, it is necessary to develop and design high pixel and reduce its production cost for the purpose, and to solve the defects of current technologies such as Chinese patent No. 201110307278.X and Chinese patent No. 201310010341, and Chinese patent No. lens to seize the market.

Contents of the invention

The purpose of the present invention is to solve various defects such as poor imaging effect, small field of view and long optical total length in current technologies such as Chinese Patent No. Good effect, large aperture, high brightness optical 5 million pixel lens assembly. In order to achieve the above object, the technical solution adopted in the present invention is: an optical lens assembly, comprising a fixed aperture, a group of lenses, a glass filter, the group of lenses includes a series of lenses arranged in sequence from the object direction image side on the same optical axis The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the surface of the fourth lens are all aspherical, and the aspheric formula is:

Among them, Z represents the Z coordinate value of each point on the lens surface, Y represents the Y-axis coordinate value of each point on the lens surface, CURV is the reciprocal of the curvature radius of the lens surface, K is the cone coefficient, A, B, C, D, E , F, G, and H are high-order aspheric coefficients, and the surface parameters of the front and rear surfaces of the fourth lens are shown in Table 1 and Table 2, respectively:

The fixed aperture is arranged between the third lens and the fourth lens, the glass filter is located behind the sixth lens and before the imaging surface of the optical lens assembly, wherein the center thickness of the first lens is 0.79-0.82 mm, The center thickness of the second lens is 1.52-1.54mm, the center thickness of the third lens is 4.14-4.16mm, the center thickness of the fourth lens is 3.85-3.87mm, the center thickness of the fifth lens is 3.12-3.15mm, the sixth lens The central thickness of the lens is 0.72-0.76mm.

Wherein, the material of the first lens is optical glass HOYA BACED5, the material of the second lens is optical glass HOYA FD15, the material of the third lens is optical glass HOYA FD110, and the material of the fourth lens is optical glass HOYA TAFD45, the material of the fifth lens is optical glass HOYA TAF1, the material of the sixth lens is optical glass HOYA S-NPH2, and the material of the glass filter is optical glass Schott D263T.

Among them, the first lens has a refractive index of 1.658435 and a dispersion coefficient of 50.854579; the second lens has a refractive index of 1.698945 and a dispersion coefficient of 30.050548; the third lens has a refractive index of 1.784719 and a dispersion coefficient of 25.720798; the fourth lens has a refractive index of 1.953747, the dispersion coefficient is 32.318760, the fifth lens has a refractive index of 1.772500, the dispersion coefficient is 49.624286, the sixth lens has a refractive index of 1.922860, and the dispersion coefficient is 18.896912.

Wherein, the front surface of the first lens is a convex spherical surface and is convex to the object side, and the radius of the convex spherical surface is 16-17 mm; The upper and lower ends of the front surface of the second lens are planes, the middle part is a convex spherical surface and convex to the object, and the radius of the convex spherical surface is 7.5-7.7mm; the upper and lower ends of the rear surface are planes, and the middle part is a concave spherical surface with a concave center To the object side, and the radius of the concave spherical surface is 3.6~3.8mm; the front surface of the third lens is a convex spherical surface and convex to the object side, and the radius of the convex spherical surface is 16.5~16.7mm; the rear surface is flat; the upper and lower ends of the front surface of the fourth lens The middle part of the plane is concave and the center is concave toward the object side, and the back surface is convex and convex toward the image side; the front surface of the fifth lens is a convex spherical surface and the center is convex toward the object side, and the radius of the convex spherical surface is 41.3-41.5mm; the back surface It is a convex spherical surface and is convex to the image side, and the radius of the convex spherical surface is 3.4-3.6mm; the upper and lower ends of the front surface of the sixth lens are planes, and the middle part is a concave spherical surface with the center concave toward the object side, and the radius of the concave spherical surface is 3.4-3.6mm; The back surface is a convex spherical surface and is convex to the image side, and the radius of the convex spherical surface is 12.4-12.6mm.

Wherein, the fourth lens is an aspheric glass lens, and the fifth lens and the sixth lens are glass cemented bodies.

Wherein, the total optical length of the optical lens assembly is less than 24 mm, the field of view is 150 degrees, and the aperture number F/NO is controlled at 2.2 to ensure high brightness.

The beneficial effect after adopting the above technical scheme is reflected in: the lens group of the present invention adopts a glass aspheric lens and five glass spherical lenses to mix and match, and has the advantage of high brightness compared to the optical lenses of other lens groups. The spherical lens refracts the light through the high-order curved surface, which can ensure that the light is precisely focused on one point, effectively eliminates various aberrations of the light, and ensures high-quality imaging. The collocation of each lens of the optical lens can effectively shorten the height of the lens to less than 24mm, the field of view is 150 degrees, and the aperture number F/NO is controlled at 2.2 to ensure high brightness; The occurrence of various aberrations can ensure the imaging quality of the lens and improve the production efficiency.

The present invention will become clearer through the following description in conjunction with the accompanying drawings, which are used to explain the embodiments of the present invention.

Description of drawings

The structural representation of Fig. 1 optical lens group of the present invention;

The MTF (modulated optical transfer function) schematic diagram of Fig. 2 optical lens assembly of the present invention

Fig. 3 is a schematic diagram of field curvature of the optical lens assembly of the present invention

The distortion schematic diagram of Fig. 4 optical lens assembly of the present invention

The relative illuminance schematic diagram of Fig. 5 optical lens assembly of the present invention

Description of drawings: 1-first lens; 2-second lens; 3-third lens; 4-fixed diaphragm;

5-fourth lens; 6-fifth lens; 7-sixth lens; 8-filter; 9-image square.

detailed description

The specific embodiment of the present invention is described in detail below in conjunction with accompanying drawing: As shown in Figure 1, a kind of optical lens assembly comprises fixed aperture (4), a group of lenses, a glass filter (8), and this group of lenses comprises A first lens (1), a second lens (2), a third lens (3), a fourth lens (5), and a fifth lens (6) arranged in sequence from the image side (9) in the object direction on the same optical axis, The sixth lens (7), the surface of the fourth lens (5) is aspherical, and its aspheric formula is:

Among them, Z represents the Z coordinate value of each point on the lens surface, Y represents the Y-axis coordinate value of each point on the lens surface, CURV is the reciprocal of the curvature radius of the lens surface, K is the cone coefficient, A, B, C, D, E , F, G, and H are high-order aspheric coefficients, and the surface parameters of the front and rear surfaces of the fourth lens (5) are as shown in Table 1 and Table 2 respectively:

The fixed aperture (4) is arranged between the third lens (3) and the fourth lens (5), the glass filter (8) is located behind the sixth lens (7), and the imaging of the optical lens assembly Before the surface (9), wherein the central thickness of the first lens (1) is 0.79-0.82mm, preferably 0.81mm; the central thickness of the second lens (2) is 1.52-1.54mm, preferably 1.53mm; the third lens (3 ) center thickness is 4.14-4.16mm, preferably 4.155mm; the center thickness of the fourth lens (5) is 3.85-3.87mm, preferably 3.86mm; the center thickness of the fifth lens (6) is 3.12-3.15mm, preferably 3.13 mm; the center thickness of the sixth lens (7) is 0.72-0.76 mm, preferably 0.73 mm.

The material of the first lens (1) is optical glass HOYA BACED5, the material of the second lens (2) is optical glass HOYA FD15, the material of the third lens (3) is optical glass HOYA FD110, the fourth The material of the lens (5) is optical glass HOYA TAFD45, the material of the fifth lens (6) is optical glass HOYA TAF1, the material of the sixth lens (7) is optical glass HOYA S-NPH2, and the glass filter ( 8) The material is optical glass Schott D263T.

The first lens (1) has a refractive index of 1.658435 and a dispersion coefficient of 50.854579; the second lens (2) has a refractive index of 1.698945 and a dispersion coefficient of 30.050548; the third lens (3) has a refractive index of 1.784719 and a dispersion coefficient of 25.720798 The fourth lens (5) has a refractive index of 1.953747 and a dispersion coefficient of 32.318760, the fifth lens (6) has a refractive index of 1.772500 and a dispersion coefficient of 49.624286, and the sixth lens (7) has a refractive index of 1.922860 and a dispersion coefficient of 18.896912.

The total optical length of the optical lens assembly is less than 24mm, wherein, the front surface of the first lens (1) is a convex spherical surface and is convex to the object side, and the radius of the convex spherical surface is 16-17mm; the upper and lower ends of the rear surface are the middle part of the plane It is a concave spherical surface with the center concave toward the object side, and the radius of the concave spherical surface is 3.7-3.9mm; the upper and lower ends of the front surface of the second lens (2) are planes, and the middle part is a convex spherical surface and convex toward the object side, and the radius of the convex spherical surface is 7.5mm- 7.7mm; the upper and lower ends of the rear surface are planes, and the middle part is a concave spherical surface with the center concave toward the object side, and the radius of the concave spherical surface is 3.6-3.8mm; the front surface of the third lens (3) is a convex spherical surface and convex toward the object side, and the convex The radius of the spherical surface is 16.5-16.7mm; the rear surface is plane; the upper and lower ends of the front surface of the fourth lens (5) are plane, the middle part is concave and the center is concave toward the object side, and the rear surface is convex and convex toward the image side; the fifth lens ( 6) The front surface is a convex spherical surface and the center is convex to the object space, and the radius of the convex spherical surface is 41.3-41.5mm; the rear surface is a convex spherical surface and convex to the image side, and the radius of the convex spherical surface is 3.4-3.6mm; the sixth lens (7 ) The upper and lower ends of the front surface are planes, and the middle part is a concave spherical surface with the center concave toward the object side, and the radius of the concave spherical surface is 3.4-3.6mm;

The fourth lens (5) is an aspheric glass lens, and the fifth lens (6) and the sixth lens (7) are glass cemented bodies.

The effective focal length of the optical lens assembly of the present invention is 3.07mm, the back focal length is 4.4mm, the total optical length is 23.8mm, and the aperture number F/NO is controlled at 2.2 to ensure a large aperture, the field of view is 150 degrees, and various aberrations Perform good corrections to obtain ideal optical performance. It provides a solution for the development of high-pixel wide-angle automotive visual system electronic products.

Fig. 2 is the modulation transfer function (Modulation Transfer Function, be called for short MTF) graph of the optical lens assembly of the present invention, in the figure abscissa represents spatial frequency, unit: line pair per millimeter (lp/mm); Vertical coordinate represents modulation transfer function The value of (MTF), the value of MTF is used to evaluate the imaging clarity of the lens assembly, and the value range is 0 to 1. The MTF curve represents the imaging clarity of the lens and the ability to restore the image. It can be seen from Figure 2 that the MTF curves in the meridional direction (T) and sagittal direction (S) of each field of view are relatively dense, which means that the lens assembly has good consistency on the entire imaging surface and can Clear imaging on the surface can meet the reception requirements of complementary metal oxide semiconductor (CMOS) and charge coupled device (CCD) image sensors.

Fig. 3 and Fig. 4 are the field curvature and distortion diagrams of the optical lens assembly of the present invention respectively. It can be seen from Fig. 3 and Fig. 4 that the field curvature of the lens assembly is less than 0.2 mm and the distortion is less than 65%, which can meet the requirements of complementary metals on the market. Oxide Semiconductor (CMOS) and Charge Coupled Device (CCD) image sensors receive requirements.

5 is a relative illuminance diagram of the optical lens assembly of the present invention, in which the abscissa in the figure represents the field of view of the lens, and the ordinate represents the illuminance value of the lens, and the value range is 0-1. It can be seen from the figure that the illuminance value of the middle field of view and the peripheral field of view is very high and the difference is small, which means that the lens assembly has high brightness on the entire imaging surface and the brightness consistency between the center range and the edge range is good.

From the above specific implementation methods, it can be seen that by using aspheric lenses to refract the light through the high-order curved surface, it can ensure that the light is accurately focused on one point, effectively eliminate various aberrations of the light, and ensure the imaging quality of the lens; through the optical lens The matching of each lens can effectively shorten the height of the lens to less than 24mm, the field of view is 150 degrees, and the number of apertures is controlled at 2.2 to ensure a large aperture; by placing the aperture in the middle, the generation of various aberrations in the lens system can be reduced to ensure that the lens Imaging quality: Two glass lenses are glued together, which can improve the refractive index of the edge of the lens to light, make the edge of the lens image better, reduce the weight of the lens, effectively control the length of the lens, reduce manufacturing costs, and improve production efficiency.

The above are only preferred implementation cases of the present invention, and are not intended to limit the technical scope of the present invention. Those skilled in the art can make some deformations and modifications under the inspiration of this technical solution. Any modifications, equivalent changes and modifications made to the above embodiments according to the technical essence still belong to the scope of the technical solution of the present invention.

Claims (5)

1. A kind of 1. optical lens assembly, it is characterised in that：It is saturating including fixed aperture, one group of lens, a glass filter, the group Mirror is included with the first lens being arranged in order on optical axis from object space to image space, the second lens, the 3rd lens, the 4th lens, and the 5th Lens, the 6th lens, the 4th lens surface are aspherical, and its aspherical formula is：

   <mfenced open = "" close = ""> <mtable> <mtr> <mtd> <mrow> <mi>Z</mi> <mo>=</mo> <mfrac> <mrow> <mo>(</mo> <mi>C</mi> <mi>U</mi> <mi>R</mi> <mi>V</mi> <mo>)</mo> <msup> <mi>Y</mi> <mn>2</mn> </msup> </mrow> <mrow> <mn>1</mn> <mo>+</mo> <msup> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mo>(</mo> <mn>1</mn> <mo>+</mo> <mi>K</mi> <mo>)</mo> <msup> <mrow> <mo>(</mo> <mi>C</mi> <mi>U</mi> <mi>R</mi> <mi>V</mi> <mo>)</mo> </mrow> <mn>2</mn> </msup> <msup> <mi>Y</mi> <mn>2</mn> </msup> <mo>)</mo> </mrow> <mrow> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msup> </mrow> </mfrac> <mo>+</mo> <mrow> <mo>(</mo> <mi>A</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>2</mn> </msup> <mo>+</mo> <mrow> <mo>(</mo> <mi>B</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>4</mn> </msup> <mo>+</mo> <mrow> <mo>(</mo> <mi>C</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>6</mn> </msup> <mo>+</mo> <mrow> <mo>(</mo> <mi>D</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>8</mn> </msup> <mo>+</mo> <mrow> <mo>(</mo> <mi>E</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>10</mn> </msup> <mo>+</mo> <mrow> <mo>(</mo> <mi>F</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>12</mn> </msup> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <mo>+</mo> <mrow> <mo>(</mo> <mi>G</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>14</mn> </msup> <mo>+</mo> <mrow> <mo>(</mo> <mi>H</mi> <mo>)</mo> </mrow> <msup> <mi>Y</mi> <mn>16</mn> </msup> </mrow> </mtd> </mtr> </mtable> </mfenced>

   Wherein, Z represents the Z coordinate value of lens surface each point, and Y represents the Y-axis coordinate value of each point on lens surface, and CURV is lens The inverse of the radius of curvature on surface, K are circular cone coefficient, and A, B, C, D, E, F, G, H are order aspherical coefficients, the 4th lens The face shape parameter on forward and backward surface is respectively such as table 1, table 2：

   The fixed aperture is arranged between the 3rd lens and the 4th lens, and the glass filter is located at after the 6th lens, and should Before the imaging surface of optical lens assembly, wherein the center thickness of the first lens is 0.79~0.82mm, the center of the second lens Thickness is 1.52~1.54mm, and the center thickness of the 3rd lens is 4.14~4.16mm, and the center thickness of the 4th lens is 3.85 ~3.87mm, the center thicknesses of the 5th lens are 3.12~3.15mm, and the center thicknesses of the 6th lens is 0.72~0.76mm, institute The first lens front surface stated is convex spherical and is convex to object space, and convex spherical radius is 16~17mm；Surface upper and lower side is flat afterwards Face center section is concave spherical surface and center concaves towards object space, and concave spherical surface radius is 3.7~3.9mm；Above and below second lens front surface Hold and be convex spherical for planar central portion and be convex to object space, and convex spherical radius is 7.5~7.7mm；Surface upper and lower side is flat afterwards Face center section is concave spherical surface and center concaves towards object space, and concave spherical surface radius is 3.6~3.8mm；3rd lens front surface is convex Sphere and object space is convex to, and convex spherical radius is 16.5~16.7mm；Surface is plane afterwards；4th lens front surface upper and lower side is Planar central portion is concave surface and center concaves towards object space, and rear surface is convex surface and is convex to image space；5th lens front surface is convex ball Face and center are convex to object space, and convex spherical radius is 41.3~41.5mm；Surface is convex spherical and is convex to image space, and convex spherical afterwards Radius is 3.4~3.6mm；6th lens front surface upper and lower side is that planar central portion is concave spherical surface and center concaves towards object space, and Concave spherical surface radius is 3.4~3.6mm；Surface is convex spherical and is convex to image space afterwards, and convex spherical radius is 12.4~12.6mm.
2. 2. according to a kind of optical lens assembly described in claim 1, it is characterised in that：The material of the first described lens is light Glass HOYA BACED5 are learned, the material of second lens is optical glass HOYA FD15, and the material of the 3rd lens is optics Glass HOYA FD110, the material of the 4th lens is optical glass HOYA TAFD45, and the material of the 5th lens is optics glass Glass HOYA TAF1, the material of the 6th lens is optical glass HOYA S-NPH2, and the material of the glass filter is optics glass Glass Xiao Te D263T.
3. A kind of 3. optical lens assembly according to claim 1, it is characterised in that：The first described index of refraction in lens is 1.658435 abbe number 50.854579；Second index of refraction in lens is 1.698945, abbe number 30.050548；The Three index of refraction in lens are 1.784719, abbe number 25.720798；4th index of refraction in lens is 1.953747, abbe number For 32.318760, the 5th index of refraction in lens is 1.772500, abbe number 49.624286, and the 6th index of refraction in lens is 1.922860 abbe number 18.896912.
4. 4. optical lens assembly according to claim 1, the 4th lens are aspherical glass lens, the 5th lens and the 6th Lens are glass veneer.
5. 5. optical lens assembly according to claim 1, it is characterised in that：Described optical lens assembly optics overall length is small In 24mm, the angle of visual field is 150 degree, and F-number F/NO is controlled 2.2.