Wide-angle lens assembly

Abstract

A wide-angle lens includes a first, a second, a third, a fourth, a fifth, a sixth, a seventh, and an eighth lens. The first lens has negative refractive power and includes a concave surface facing an image side. The third lens has positive refractive power and includes a convex surface facing an object side. The second, fourth, fifth, sixth, seventh, and eighth lenses have refractive power. The first, second, third, fourth, fifth, sixth, seventh, and eighth lenses are arranged sequentially along an optical axis from the object side to the image side. The wide-angle lens satisfies at least one of the following conditions: 0.8 ≤ f / D22 ≤ 3; 0.03°⁻¹ ≤ 1 / β ≤ 0.35°⁻¹; where f is an effective focal length of the wide-angle lens, D22 is an effective optical diameter of the image side surface of the second lens, and β is a maximum tangent angle of a cemented surface.

Description

Wide-angle lens (fifty) The present invention relates to a wide-angle lens. In order to increase the field of view and imaging quality, current wide-angle lenses often use an eight-lens structure to form a wide-angle lens. When the number of lenses increases, lens tilt and eccentricity are likely to occur during the assembly process of the wide-angle lens, resulting in a decrease in production yield. The conventional wide-angle lens can no longer meet the current needs, and a new structure of wide-angle lens is required to simultaneously meet the requirements of a large field of view, high imaging quality, and high production yield. In view of this, the main object of the present invention is to provide a wide-angle lens that uses a cemented lens design to reduce lens tilt and eccentricity caused by excessive lens numbers during the lens assembly process, enabling the wide-angle lens to simultaneously meet the requirements of a large field of view, high imaging quality, and high production yield. The present invention provides a wide-angle lens including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The first lens has a negative refractive power and includes a concave surface facing an image side. The second lens has a refractive power. The third lens has a positive refractive power and includes a convex surface facing an object side. The fourth lens has a refractive power. The fifth lens has a refractive power. The sixth lens has a refractive power. The seventh lens has a refractive power. The eighth lens has a refractive power. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are sequentially arranged along an optical axis from the object side to the image side. The wide-angle lens satisfies at least one of the following conditions: 0.8 f / D22 3; 0.03 degrees -1 1 / β 0.35 degrees -1 ; where f is an effective focal length of the wide-angle lens, D22 is an optical effective diameter of an image side surface of the second lens, and β is a maximum tangential angle of a cemented surface. When the wide-angle lens of the present invention satisfies the above characteristics and at least one of the conditions and does not require other additional characteristics or conditions, the basic functions of the wide-angle lens of the present invention can be achieved. Among them, the second lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a negative refractive power, the sixth lens has a positive refractive power, the seventh lens has a positive refractive power, and the eighth lens has a negative refractive power. Among them, the first lens is a biconcave lens, and the first lens further includes a concave surface facing the object side; the third lens is a biconvex lens, and the third lens further includes a convex surface facing the image side; the fourth lens includes a convex surface facing the image side. The second lens is a meniscus lens and includes a convex surface facing the object side and a concave surface facing the image side; the fifth lens is a biconcave lens and includes a concave surface facing the object side and another concave surface facing the image side; the sixth lens is a biconvex lens and includes a convex surface facing the object side and another convex surface facing the image side; the seventh lens is a biconvex lens and includes a convex surface facing the object side and another convex surface facing the image side; the eighth lens is a biconcave lens and includes a concave surface facing the object side and another concave surface facing the image side. The fourth lens is a plano-convex lens and further includes a flat surface facing the object side. The fourth lens is a biconvex lens and further includes another convex surface facing the object side. The wide-angle lens of the present invention may further include an aperture disposed between the second lens and the third lens. One image side surface of the seventh lens and one object side surface of the eighth lens are cemented to the cemented surface. The third lens is an aspherical lens and the sixth lens is an aspherical lens. The wide-angle lens satisfies at least one of the following conditions: -3 R51 / R72 3; 0 T1131 / T3152 3; 0 T1131 / T6182 3; 0 T3152 / T6182 3; 0.17 T11ST / TTL 0.2; -1.25 f1 / f -1.15; -1.6 f12 / f -1.4; where R51 is the radius of curvature of one object side surface of the fifth lens, R72 is the radius of curvature of one image side surface of the seventh lens, T1131 is the distance on the optical axis from one object side surface of the first lens to one object side surface of the third lens, T3152 is the distance on the optical axis from the object side surface of the third lens to one image side surface of the fifth lens, T6182 is the distance on the optical axis from one object side surface of the sixth lens to one image side surface of the eighth lens, T11ST is the distance on the optical axis from the object side surface of the first lens to an aperture surface, TTL is the distance on the optical axis from the object side surface of the first lens to an imaging surface, f is the effective focal length of the wide-angle lens, f1 is the effective focal length of the first lens, and f12 is the combined effective focal length of the combination of the first lens and the second lens. To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides preferred embodiments in conjunction with the accompanying drawings for detailed description. 1, 2, 3: Wide-angle lens L11, L21, L31: First lens L12, L22, L32: Second lens L13, L23, L33: Third lens L14, L24, L34: Fourth lens L15, L25, L35: Fifth lens L16, L26, L36: Sixth lens L17, L27, L37: Seventh lens L18, L28, L38: Eighth lens ST1, ST2, ST3: Aperture OF1, OF2, OF3: Filter IMA1, IMA2, IMA3: Imaging surface OA1, OA2, OA3: Optical axis S11, S21, S31: Object side of the first lens S12, S22, S32: Image side of the first lens S13, S23, S33: Object side of the second lens S14, S24, S34: Image side of the second lens S16, S26, S36: Object side of the third lens S17, S27, S37: Image side of the third lens S18, S28, S38: Object side of the fourth lens S19, S29, S39: Image side of the fourth lens S110, S210, S310: Object side of the fifth lens S111, S211, S311: Image side of the fifth lens S112, S212, S312: Object side of the sixth lens S113, S213, S313: Image side of the sixth lens S114, S214, S314: Object side of the seventh lens S115, S215, S315: Image side of the seventh lens S115, S215, S315: Object side of the eighth lens S116, S216, S316: Image side of the eighth lens S117, S217, S317: Object side of the filter S118, S218, S318: Image side of the filter S15, S25, S35: Aperture surface CS78: Bonding surface β: Maximum tangential angle of the bonding surface Figures 1, 5, and 9 are respectively the lens configurations and optical path schematic diagrams of the first embodiment, the second embodiment, and the third embodiment of the wide-angle lens according to the present invention. Figures 2, 3, and 4 are respectively the longitudinal aberration diagram, the field curvature diagram, and the distortion diagram of the first embodiment of the wide-angle lens according to the present invention. Figures 6, 7, and 8 are respectively the longitudinal aberration diagram, the field curvature diagram, and the distortion diagram of the second embodiment of the wide-angle lens according to the present invention. Figures 10, 11, and 12 are respectively the longitudinal aberration diagram, the field curvature diagram, and the distortion diagram of the third embodiment of the wide-angle lens according to the present invention. Figure 13 is a schematic diagram of the maximum tangential angle of the bonding surface of the first embodiment of the wide-angle lens according to the present invention. The present invention provides a wide-angle lens, comprising: a first lens having a negative refractive power, the first lens including a concave surface facing an image side; a second lens having a refractive power; a third lens having a positive refractive power, the third lens including a convex surface facing an object side; a fourth lens having a refractive power; a fifth lens having a refractive power; a sixth lens having a refractive power; a seventh lens having a refractive power; and an eighth lens having a refractive power; wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are arranged in sequence along an optical axis from the object side to the image side; wherein the wide-angle lens satisfies at least one of the following conditions: 0.8 f / D22 3; 0.03 degrees -1 1 / β 0.35 degrees -1 ; wherein, f is an effective focal length of the wide-angle lens, D22 is an optical effective diameter of an image side surface of the second lens, and β is a maximum tangential angle of a bonding surface. When the wide-angle lens of the present invention satisfies the above characteristics and at least one of the conditions, it is a preferred embodiment of the present invention. Please refer to Table 1, Table 2, Table 4, Table 5, Table 7 and Table 8 below. Among them, Table 1, Table 4 and Table 7 are the relevant parameter tables of each lens of the first to third embodiments of the wide-angle lens according to the present invention, and Table 2, Table 5 and Table 8 are the relevant parameter tables of the aspherical surfaces of the aspherical lenses in Table 1, Table 4 and Table 7 respectively. In the following embodiments, the aspherical surface depression z of the aspherical lens is obtained by the following formula: z = ch 2 / {1 + [1 - (k + 1)c 2 h 2 1 / 2}+Ah 4 +Bh 6 +Ch 8 +Dh 10 +Eh 12 +Fh 14 +Gh 16 +Hh 18 +Ih 20 , where: c is the curvature, h is the perpendicular distance from any point on the lens surface to the optical axis, k is the conic constant, and A to I are the aspherical coefficients. The aspherical coefficients can be expressed in scientific notation. For example, 2E-03 represents 2×10 -3 . Figures 1, 5, and 9 are respectively the lens configurations and optical path schematic diagrams of the first, second, and third embodiments of the wide-angle lens according to the present invention. Among them, the first lenses L11, L21, and L31 are biconcave lenses with negative refractive power, made of glass material. Their object sides S11, S21, and S31 are concave surfaces, and their image sides S12, S22, and S32 are concave surfaces. The object sides S11, S21, and S31 and the image sides S12, S22, and S32 are all spherical surfaces. The second lenses L12, L22, and L32 are meniscus lenses with positive refractive power, made of glass material. Their object sides S13, S23, and S33 are convex surfaces, and their image sides S14, S24, and S34 are concave surfaces. The object sides S13, S23, and S33 and the image sides S14, S24, and S34 are all spherical surfaces. ​The third lenses L13, L23, and L33 are biconvex lenses with positive refractive power, made of glass material. Their object sides S16, S26, S36 are convex surfaces, and their image sides S17, S27, S37 are convex surfaces. The object sides S16, S26, S36 and the image sides S17, S27, S37 are all aspherical surfaces. The fourth lenses L14, L24, and L34 have positive refractive power, made of glass material. Their image sides S19, S29, S39 are convex surfaces, and the image sides S19, S29, S39 are spherical surfaces. The fifth lenses L15, L25, and L35 are biconcave lenses with negative refractive power, made of glass material. Their object sides S110, S210, S310 are concave surfaces, and their image sides S111, S211, S311 are concave surfaces. The object sides S110, S210, S310 and the image sides S111, S211, S311 are all spherical surfaces. The sixth lenses L16, L26, and L36 are biconvex lenses with positive refractive power, made of glass material. Their object sides S112, S212, S312 are convex surfaces, and their image sides S113, S213, S313 are convex surfaces. The object sides S112, S212, S312 and the image sides S113, S213, S313 are all aspherical surfaces. The seventh lenses L17, L27, and L37 are biconvex lenses with positive refractive power, made of glass material. Their object sides S114, S214, S314 are convex surfaces, and their image sides S115, S215, S315 are convex surfaces. The object sides S114, S214, S314 and the image sides S115, S215, S315 are all spherical surfaces. The eighth lenses L18, L28, and L38 are biconcave lenses with negative refractive power, made of glass material. Their object sides S115, S215, S315 are concave surfaces, and their image sides S116, S216, S316 are concave surfaces. The object sides S115, S215, S315 and the image sides S116, S216, S316 are all spherical surfaces. The image sides S115, S215, S315 of the seventh lenses L17, L27, L37 and the object sides S115, S215, S315 of the eighth lenses L18, L28, L38 are cemented on a cemented surface, and this cemented surface is the image side S115, S215, S315 of the seventh lenses L17, L27, L37, or the object side S115, S215, S315 of the eighth lenses L18, L28, L38. In addition, the wide-angle lenses 1, 2, 3 satisfy at least one of the following conditions (1) to (9): Among them, f is the effective focal length of one of the wide-angle lenses 1, 2, and 3 in the first to third embodiments; D22 is the optical effective diameter of one of the image-side surfaces S14, S24, and S34 of the second lenses L12, L22, and L32 in the first to third embodiments; R51 is the radius of curvature of one of the object-side surfaces S110, S210, and S310 of the fifth lenses L15, L25, and L35 in the first to third embodiments; R72 is the radius of curvature of one of the image-side surfaces S115, S215, and S315 of the seventh lenses L17, L27, and L37 in the first to third embodiments; β is the maximum tangent angle of one of the cemented surfaces where the seventh lenses L17, L27, and L37 are cemented to the eighth lenses L18, L28, and L38 in the first to third embodiments. For the illustration of β, reference can be made to Fig. 13 (taking the first embodiment as an example), where the symbol L17 represents the seventh lens, the symbol L18 represents the eighth lens, and the symbol CS78 represents the cemented surface. Here, the tangent angle refers to the angle formed by the tangent t and the cemented surface CS78, and the symbol β represents the maximum tangent angle of the cemented surface CS78; T1131 is the distance on the optical axes OA1, OA2, and OA3 between the object-side surfaces S11, S21, and S31 of the first lenses L11, L21, and L31 and the object-side surfaces S16, S26, and S36 of the third lenses L13, L23, and L33 in the first to third embodiments; T3152 is the distance on the optical axes OA1, OA2, and OA3 between the object-side surfaces S16, S26, and S36 of the third lenses L13, L23, and L33 and the image-side surfaces S111, S211, and S311 of the fifth lenses L15, L25, and L35 in the first to third embodiments; T6182 is the distance on the optical axes OA1, OA2, and OA3 between the object-side surfaces S112, S212, and S312 of the sixth lenses L16, L26, and L36 and the image-side surfaces S116, S216, and S316 of the eighth lenses L18, L28, and L38 in the first to third embodiments; T11ST is the distance on the optical axes OA1, OA2, and OA3 between the object-side surfaces S11, S21, and S31 of the first lenses L11, L21, and L31 and the aperture surfaces S15, S25, and S35 in the first to third embodiments; TTL is the distance on the optical axes OA1, OA2, and OA3 between the object-side surfaces S11, S21, and S31 of the first lenses L11, L21, and L31 and the imaging surfaces IMA1, IMA2, and IMA3 in the first to third embodiments; f1 is the effective focal length of one of the first lenses L11, L21, and L31 in the first to third embodiments; f12 is the combined effective focal length of the combination of the first lenses L11, L21, and L31 and the second lenses L12, L22, and L32 in the first to third embodiments. This enables the wide-angle lenses 1, 2, and 3 to effectively reduce the aperture value, effectively increase the field of view, effectively improve the resolution, and effectively correct the aberration. When the condition (3) is satisfied: 0.03 degrees -1 1 / β 0.35 degrees -1 , it can effectively reduce the lens tilt and decentration errors. Since it is the reciprocal of β, the unit is recorded as degrees -1 ; when the condition (7) is satisfied: 0.17 T11ST / TTL 0.2, it can effectively control the optical effective diameters of the first lens and the second lens; when the condition (8) is satisfied: -1.25 f1 / f -1.15, it can effectively control the effective focal length of the first lens and make it fall within a reasonable range to reduce the sensitivity of the first lens; when the condition (9) is satisfied: -1.6 f12 / f -1.4, it can effectively ensure the balance between the front and rear groups of the lens; the first lens has a negative refractive power and can converge and adjust the optical path of the incident large-angle light so that it is not easy to have a large turn; the second lens is a high-refractive-index lens with a positive refractive power and can shorten the distance from the object side surface of the first lens to the aperture, making the front end effective diameter of the lens smaller and the lens appearance more compact; the third lens is an aspherical lens with a positive refractive power and can effectively reduce the spherical aberration, distortion and field curvature caused by the first lens and the second lens; the fourth lens is a low-dispersion lens with a positive refractive power and can effectively reduce chromatic aberration; the fifth lens is a biconcave lens with a negative refractive power and can effectively adjust the optical path; the sixth lens is an aspherical lens with a positive refractive power and can effectively reduce coma, astigmatism and field curvature; the seventh lens and the eighth lens are glued together to form a cemented lens, which can effectively eliminate chromatic aberration, improve the assembly stability and increase the production yield. Now, a first embodiment of the wide-angle lens of the present invention will be described in detail. The wide-angle lens 1 sequentially includes a first lens L11, a second lens L12, an aperture ST1, a third lens L13, a fourth lens L14, a fifth lens L15, a sixth lens L16, a seventh lens L17, an eighth lens L18 and a filter OF1 along an optical axis OA1 from an object side to an image side. When imaging, the light from the object side is finally imaged on an imaging surface IMA1. According to the first to eleventh paragraphs of the

Embodiment

Claims

1. A wide-angle lens, comprising: A first lens has negative refractive power, the first lens including a concave surface facing an image side; A second lens has refractive power; a third lens has positive refractive power, the third lens including a convex surface facing an object side; a fourth lens has refractive power; a fifth lens has refractive power; a sixth lens has refractive power; a seventh lens has refractive power; and an eighth lens has refractive power and includes a concave surface facing the object side; wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are arranged sequentially along an optical axis from the object side to the image side; wherein the wide-angle lens satisfies at least one of the following conditions: 0.8 ≤ f / D22 ≤ 3; 0.03 degrees - 1 ≤ 1 / β ≤ 0.35 degrees - 1; wherein f is an effective focal length of the wide-angle lens, D22 is an optically effective diameter of an image-side surface of the second lens, and β is a maximum tangent angle of a cemented surface.

2. The wide-angle lens as claimed in claim 1, wherein the second lens has positive refractive power, the fourth lens has positive refractive power, the fifth lens has negative refractive power, the sixth lens has positive refractive power, the seventh lens has positive refractive power, and the eighth lens has negative refractive power.

3. The wide-angle lens as described in claim 2, wherein: The first lens is a biconcave lens, and the first lens further includes a concave surface facing the object side; the third lens is a biconvex lens, and the third lens further includes a convex surface facing the image side; and the fourth lens includes a convex surface facing the image side and another convex surface or a flat surface facing the object side.

4. The wide-angle lens as described in claim 3, wherein: The second lens is a meniscus lens, and includes a convex surface facing the object side and a concave surface facing the image side; the fifth lens is a biconcave lens, and includes a concave surface facing the object side and another concave surface facing the image side; the sixth lens is a biconvex lens, and includes a convex surface facing the object side and another convex surface facing the image side; the seventh lens is a biconvex lens, and includes a convex surface facing the object side and another convex surface facing the image side; The eighth lens is a biconcave lens, and further includes another concave surface facing the image side.

5. The wide-angle lens as described in claim 1, wherein the third lens is an aspherical lens and the sixth lens is an aspherical lens.

6. A wide-angle lens, comprising: A first lens has negative refractive power, the first lens including a concave surface facing an image side; A second lens has refractive power; a third lens has positive refractive power, the third lens including a convex surface facing an object side; a fourth lens has refractive power; a fifth lens has refractive power; a sixth lens has refractive power; a seventh lens has refractive power; and an eighth lens has refractive power and includes a concave surface facing the object side; wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are arranged sequentially along an optical axis from the object side to the image side; wherein the wide-angle lens satisfies at least one of the following conditions: 0.8 ≤ f / D22 ≤ 3; 0.03 degrees - 1 ≤ 1 / β ≤ 0.35 degrees - 1; wherein f is an effective focal length of the wide-angle lens, D22 is an optically effective diameter of an image-side surface of the second lens, and β is a maximum tangent angle of a cemented surface; The fourth lens is a plano-convex lens, and further includes a plane facing the object.

7. A wide-angle lens, comprising: A first lens has negative refractive power, the first lens including a concave surface facing an image side; A second lens has refractive power; a third lens has positive refractive power, the third lens including a convex surface facing an object side; a fourth lens has refractive power; a fifth lens has refractive power; a sixth lens has refractive power; a seventh lens has refractive power; and an eighth lens has refractive power and includes a concave surface facing the object side; wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are arranged sequentially along an optical axis from the object side to the image side; wherein the wide-angle lens satisfies at least one of the following conditions: 0.8 ≤ f / D22 ≤ 3; 0.03 degrees - 1 ≤ 1 / β ≤ 0.35 degrees - 1; wherein f is an effective focal length of the wide-angle lens, D22 is an optically effective diameter of an image-side surface of the second lens, and β is a maximum tangent angle of a cemented surface; It also includes an aperture positioned between the second lens and the third lens.

8. A wide-angle lens, comprising: A first lens has negative refractive power, the first lens including a concave surface facing an image side; A second lens has refractive power; a third lens has positive refractive power, the third lens including a convex surface facing an object side; a fourth lens has refractive power; a fifth lens has refractive power; a sixth lens has refractive power; a seventh lens has refractive power; and an eighth lens has refractive power and includes a concave surface facing the object side; wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are arranged sequentially along an optical axis from the object side to the image side; wherein the wide-angle lens satisfies at least one of the following conditions: 0.8 ≤ f / D22 ≤ 3; 0.03 degrees - 1 ≤ 1 / β ≤ 0.35 degrees - 1; wherein f is an effective focal length of the wide-angle lens, D22 is an optically effective diameter of an image-side surface of the second lens, and β is a maximum tangent angle of a cemented surface; The image side of the seventh lens and the object side of the eighth lens are glued together on the glued surface.

9. A wide-angle lens as described in any one of claims 1, 2, 5, 7, or 8, wherein the fourth lens is a biconvex lens and further includes another convex surface facing the object side.

10. A wide-angle lens as described in any one of claims 1 to 8, wherein the wide-angle lens satisfies at least one of the following conditions: -3 ≤ R51 / R72 ≤ 3; 0 ≤ T1131 / T3152 ≤ 3; 0 ≤ T1131 / T6182 ≤ 3; 0 ≤ T3152 / T6182 ≤ 3; 0.17 ≤ T11ST / TTL ≤ 0.2; -1.25 ≤ f1 / f ≤ -1.15; -1.6 ≤ f12 / f ≤ -1.4; where, R51 is the radius of curvature of the object side of the fifth lens, R72 is the radius of curvature of the image side of the seventh lens, T1131 is the distance on the optical axis between the object side of the first lens and the object side of the third lens, T3152 is the distance on the optical axis between the object side of the third lens and the image side of the fifth lens, T6182 is the distance on the optical axis between the object side of the sixth lens and the image side of the eighth lens, T11ST is the distance on the optical axis between the object side of the first lens and an aperture plane, TTL is the distance on the optical axis between the object side of the first lens and an imaging plane, f is the effective focal length of the wide-angle lens, f1 is the effective focal length of the first lens, and f12 is the combined effective focal length of the combination of the first lens and the second lens.

Images