TWI904688B - Wide-angle lens assembly - Google Patents

Abstract

A wide-angle lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The first lens is with refractive power and includes a concave surface facing an image side. The second lens is a meniscus lens with negative refractive power and includes a convex surface facing an object side and a concave surface facing the image side. The third lens is with refractive power. The fourth lens is a biconvex lens with positive refractive power and includes a convex surface facing the object side and another convex surface facing the image side. The fifth lens is with refractive power. The sixth lens is with refractive power. The seventh lens is with positive refractive power. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are arranged in order from the object side to the image side along an optical axis.

Description

Wide-angle lens (60)

This invention relates to a wide-angle lens.

The current trend in wide-angle lens development, besides continuously expanding the field of view, also demands miniaturization, high resolution, and resistance to environmental temperature changes to meet diverse application requirements. Conventional wide-angle lenses can no longer satisfy these needs, necessitating a new type of wide-angle lens architecture that can simultaneously achieve a large field of view, miniaturization, high resolution, and resistance to environmental temperature variations.

In view of this, the main objective of this invention is to provide a wide-angle lens with a large field of view, short overall length, high resolution, and resistance to environmental temperature changes, while still maintaining good optical performance.

This invention provides a wide-angle lens comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The first lens has refractive power and includes a concave surface facing the image side. The second lens is a meniscus lens with negative refractive power and includes a convex surface facing the object side and a concave surface facing the image side. The third lens has refractive power. The fourth lens is a biconvex lens with positive refractive power and includes a convex surface facing the object side and another convex surface facing the image side. The fifth lens has refractive power. The sixth lens has refractive power. The seventh lens has positive refractive power. The first, second, third, fourth, fifth, sixth, and seventh lenses are arranged sequentially along an optical axis from the object side to the image side. A wide-angle lens satisfies at least one of the following conditions: 4 TTL/BFL 7; 77.7 TTL/d56 127.2; 8.4 R12/T1 14.5; 47.1 degrees/mm FOV/f 51.6 degrees/mm; 45.5 degrees FOV/FNo 46.2 degrees; where TTL is the distance between the object side of the first lens and the imaging plane on the optical axis, BFL is the distance between the image side of the seventh lens and the imaging plane on the optical axis, f is an effective focal length of the wide-angle lens, R12 is the radius of curvature of the image side of the first lens, T1 is the distance between the object side of the first lens and the image side of the first lens on the optical axis, d56 is the air distance between the image side of the fifth lens and the object side of the sixth lens on the optical axis, FOV is the maximum field of view of the wide-angle lens, and FNo is the aperture value of the wide-angle lens. When the wide-angle lens of the present invention meets the above features and at least one condition, and no other additional conditions or features are required, the basic function of the wide-angle lens of the present invention can be achieved.

The first lens has negative refractive power, the third lens has positive refractive power, the fifth lens has negative refractive power, and the sixth lens has positive refractive power.

The first lens is a crescent-shaped lens and may further include a convex surface facing the object side; the third lens is a crescent-shaped lens and includes a concave surface facing the object side and a convex 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 includes a convex surface facing the object side.

The seventh lens is a biconvex lens, and may further include another convex surface facing the image side.

The seventh lens is a crescent-shaped lens and may further include a concave surface facing the image side.

The wide-angle lens of this invention may further include an aperture, and between the object side and the aperture are two lenses with negative refractive power.

The aperture is positioned between the third and fourth lenses.

The wide-angle lens meets at least one of the following conditions: -9 f1/f -3.5; 1.5 f4/f 3.5; 1 R21/f 6; -1.5 (R41+R42)/f4 1; 5.5 TTL/d67 24; where f is the effective focal length of the wide-angle lens, f1 is the effective focal length of the first lens, f4 is the effective focal length of the fourth lens, R21 is the radius of curvature of the object-side surface of the second lens, R41 is the radius of curvature of the object-side surface of the fourth lens, R42 is the radius of curvature of the image-side surface of the fourth lens, TTL is the distance from the object-side surface of the first lens to the imaging surface on the optical axis, and d67 is the air distance from the image-side surface of the sixth lens to the object-side surface of the seventh lens on the optical axis.

To make the aforementioned objectives, features, and advantages of this invention more apparent, preferred embodiments are described below in detail with reference to the accompanying drawings.

1, 2, 3, 4, 5, 6: Wide-angle lens

L11, L21, L31, L41, L51, L61: First lens

L12, L22, L32, L42, L52, L62: Second lens

L13, L23, L33, L43, L53, L63: Third lens

ST1, ST2, ST3, ST4, ST5, ST6: Aperture

L14, L24, L34, L44, L54, L64: Fourth lens

L15, L25, L35, L45, L55, L65: Fifth lens

L16, L26, L36, L46, L56, L66: Sixth lens

L17, L27, L37, L47, L57, L67: Seventh Lens

OF1, OF2, OF3, OF4, OF5, OF6: Filters

CG1, CG2, CG3, CG4, CG5, CG6: Protective Glass

IMA1, IMA2, IMA3, IMA4, IMA5, IMA6: Imaging planes

OA1, OA2, OA3, OA4, OA5, OA6: optical axis

S11, S21, S31, S41, S51, S61: Side view of the first lens object

S12, S22, S32, S42, S52, S62: Side view of the first lens image

S13, S23, S33, S43, S53, S63: Side of the second lens object

S14, S24, S34, S44, S54, S64: Side view of the second lens image

S15, S25, S35, S45, S55, S65: Third lens object side

S16, S26, S36, S46, S56, S66: Side view of the third lens image

S17, S27, S37, S47, S57, S67: Aperture planes

S18, S28, S38, S48, S58, S68: Fourth lens object side

S19, S29, S39, S49, S59, S69: Side view of the fourth lens image

S110, S210, S310, S410, S510, S610: Fifth lens object side

S111, S211, S311, S411, S511, S611: Side view of the fifth lens image

S112, S212, S312, S412, S512, S612: Sixth lens object side

S113, S213, S313, S413, S513, S613: Sixth lens image side view

S114, S214, S314, S414, S514, S614: Seventh lens object side view

S115, S215, S315, S415, S515, S615: Side view of the seventh lens image

S116, S216, S316, S416, S516, S616: Filter side

S117, S217, S317, S417, S517, S617: Filter image side view

S118, S218, S318, S418, S518, S618: Protective glass surfaces.

S119, S219, S319, S419, S519, S619: Protective glass for the side view

Figures 1, 2, 3, 4, 8, and 12 are schematic diagrams of the lens configuration and optical path according to the first, second, third, fourth, fifth, and sixth embodiments of the wide-angle lens of this invention.

Figures 5, 6, and 7 are, respectively, field curvature, distortion, and spot diagrams of the wide-angle lens according to the fourth embodiment of the present invention.

Figures 9, 10, and 11 are field curvature, distortion, and spot diagrams, respectively, based on the fifth embodiment of the wide-angle lens of this invention.

Figures 13, 14, and 15 are field curvature, distortion, and spot diagrams, respectively, based on the sixth embodiment of the wide-angle lens of this invention.

This invention provides a wide-angle lens, comprising: a first lens having refractive power, the first lens including a concave surface facing an image side; a second lens having negative refractive power, the second lens being a meniscus lens and including a convex surface facing an object side and a concave surface facing the image side; a third lens having refractive power; and a fourth lens having positive refractive power, the fourth lens being a biconvex lens and including a convex surface facing the object side. One side and another convex surface face the image side; a fifth lens has refractive power; a sixth lens has refractive power; and a seventh lens has positive refractive power; wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh 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: 4 TTL/BFL 7; 77.7 TTL/d56 127.2; 8.4 R12/T1 14.5; 47.1 degrees/mm FOV/f 51.6 degrees/mm; 45.5 degrees FOV/FNo 46.2 degrees; where TTL is the distance between the object side of the first lens and the imaging plane on the optical axis, BFL is the distance between the image side of the seventh lens and the imaging plane on the optical axis, f is an effective focal length of the wide-angle lens, R12 is the radius of curvature of the image side of the first lens, T1 is the distance between the object side of the first lens and the image side of the first lens on the optical axis, d56 is the air distance between the image side of the fifth lens and the object side of the sixth lens on the optical axis, FOV is the maximum field of view of the wide-angle lens, and FNo is the aperture value of the wide-angle lens. When the wide-angle lens of the present invention satisfies the above features and at least one condition, it is a preferred embodiment of the present invention.

Please refer to Tables 1, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16 and 17 below. Tables 1, 4, 7, 10, 13 and 16 are the relevant parameter tables for each lens of the first to sixth embodiments of the wide-angle lens according to the present invention. Tables 2, 5, 8, 11, 14 and 17 are the relevant parameter tables for the aspherical surface of the aspherical lens in Tables 1, 4, 7, 10, 13 and 16. In the following embodiments, the aspherical surface concavity 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 + ..., 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~F are the aspherical coefficients, which are expressed in scientific notation, for example, 2E-03 represents 2×10 ^-3 .

Figures 1, 2, 3, 4, 8, and 12 are schematic diagrams of the lens configuration and optical path of the first, second, third, fourth, fifth, and sixth embodiments of the wide-angle lens of the present invention, respectively. The first lenses L11, L21, L31, L41, L51, and L61 are meniscus lenses with negative refractive power. Their object-side surfaces S11, S21, S31, S41, S51, and S61 are convex, while their image-side surfaces S12, S22, S32, S42, S52, and S62 are concave. Both the object-side surfaces S11, S21, S31, S41, S51, and S61 and the image-side surfaces S12, S22, S32, S42, S52, and S62 are aspherical surfaces.

The second lenses L12, L22, L32, L42, L52, and L62 are meniscus lenses with negative refractive power. Their object-side surfaces S13, S23, S33, S43, S53, and S63 are convex, while their image-side surfaces S14, S24, S34, S44, S54, and S64 are concave. Both the object-side surfaces S13, S23, S33, S43, S53, and S63 and the image-side surfaces S14, S24, S34, S44, S54, and S64 are aspherical surfaces.

The third lenses, L13, L23, L33, L43, L53, and L63, are meniscus lenses with positive refractive power. Their object-side surfaces S15, S25, S35, S45, S55, and S65 are concave, while their image-side surfaces S16, S26, S36, S46, S56, and S66 are convex. Both the object-side surfaces S15, S25, S35, S45, S55, and S65, and the image-side surfaces S16, S26, S36, S46, S56, and S66 are aspherical surfaces.

The fourth lenses, L14, L24, L34, L44, L54, and L64, are biconvex lenses with positive refractive power. Their object-side surfaces S18, S28, S38, S48, S58, and S68 are convex, as are their image-side surfaces S19, S29, S39, S49, S59, and S69. Both the object-side surfaces S18, S28, S38, S48, S58, and S68, and the image-side surfaces S19, S29, S39, S49, S59, and S69, are aspherical surfaces.

The fifth lenses, L15, L25, L35, L45, L55, and L65, are biconcave lenses with negative refractive power. Their object-side surfaces S110, S210, S310, S410, S510, and S610 are concave, as are their image-side surfaces S111, S211, S311, S411, S511, and S611. Both the object-side surfaces S110, S210, S310, S410, S510, and S610, and the image-side surfaces S111, S211, S311, S411, S511, and S611 are aspherical surfaces.

Lenses L16, L26, L36, L46, L56, and L66 are biconvex lenses with positive refractive power. Their object-side surfaces S112, S212, S312, S412, S512, and S612 are convex, and their image-side surfaces S113, S213, S313, S413, S513, and S613 are convex. Both the object-side surfaces S112, S212, S312, S412, S512, and S612, and the image-side surfaces S113, S213, S313, S413, S513, and S613 are aspherical surfaces.

The seventh lenses, L17, L27, L37, L47, L57, and L67, possess positive refractive power. Their object-side surfaces S114, S214, S314, S414, S514, and S614 are convex, while their image-side surfaces S115, S215, S315, S415, S515, and S615 are all aspherical surfaces.

In addition, wide-angle lenses 1, 2, 3, 4, 5, and 6 satisfy at least one of the following conditions (1) to (10):

In the first to sixth embodiments, the important parameters are defined as follows: f is the effective focal length of one of the wide-angle lenses 1, 2, 3, 4, 5, and 6; f1 is the effective focal length of one of the first lenses L11, L21, L31, L41, L51, and L61; f4 is the effective focal length of one of the fourth lenses L14, L24, L34, L44, L54, and L64; and TTL is the effective focal length of the first lenses L11, L21, and L31. The distance between the object sides S11, S21, S31, S41, S51, S61 of lenses L41, L51, and L61 and the imaging planes IMA1, IMA2, IMA3, IMA4, IMA5, IMA6 on the optical axes OA1, OA2, OA3, OA4, OA5, OA6; and the distance between the image sides S115 and S61 of lenses L17, L27, L37, L47, L57, and L67. 215, S315, S415, S515, S615 are distances from the imaging planes IMA1, IMA2, IMA3, IMA4, IMA5, IMA6 on the optical axes OA1, OA2, OA3, OA4, OA5, OA6. R12 is the distance between the image sides S12, S22, S32, S42, S52, and S of the first lenses L11, L21, L31, L41, L51, L61. R21 is one of the curvature radii of the object sides S13, S23, S33, S43, S53, and S63 of the second lenses L12, L22, L32, L42, L52, and L62; R41 is one of the curvature radii of the object sides S18, S28, S38, S48, S58, and S68 of the fourth lenses L14, L24, L34, L44, L54, and L64; R42 is... The curvature radii of one of the image-side surfaces S19, S29, S39, S49, S59, and S69 of the fourth lenses L14, L24, L34, L44, L54, and L64, and T1 is the object-side surfaces S11, S21, S31, S41, S51, and S61 of the first lenses L11, L21, L31, L41, and L51. The distance between the image sides S12, S22, S32, S42, S52, and S62 of L61 on the optical axes OA1, OA2, OA3, OA4, OA5, and OA6; and d56 is the distance between the image sides S111, S211, S311, S411, S511, and S611 of the fifth lenses L15, L25, L35, L45, L55, and L65 and the sixth lenses L16, L26, L36, and L61. 46. The object-side S112, S212, S312, S412, S512, and S612 of L56 and L66 are one of the air gaps on the optical axes OA1, OA2, OA3, OA4, OA5, and OA6. d67 is the image-side S113, S213, S313, S413, S513, and S613 of the sixth lens L16, L26, L36, L46, L56, and L66 to the seventh lens. The air spacing of the object-side surfaces S114, S214, S314, S414, S514, and S614 of lenses L17, L27, L37, L47, L57, and L67 on the optical axes OA1, OA2, OA3, OA4, OA5, and OA6, respectively; FOV is the maximum field of view of wide-angle lenses 1, 2, 3, 4, 5, and 6; and FNo is the aperture value of wide-angle lenses 1, 2, 3, 4, 5, and 6. This allows wide-angle lenses 1, 2, 3, 4, 5, and 6 to effectively shorten the overall lens length, effectively increase the field of view, effectively improve resolution, and effectively correct aberrations.

When condition (1) is met: -9 f1/f -3.5 can effectively improve the light-gathering angle and provide sufficient negative refractive power. When condition (2): 1.5 is met. f4/f 3.5, which can effectively reduce the inconsistency in resolution at high and low temperatures. When condition (3) is met: 1 R21/f 6. It can effectively control the shape of the second lens to avoid excessive bending, thereby reducing manufacturing tolerances and facilitating manufacturing. When condition (4) is met: -1.5 (R41+R42)/f4 1. It can effectively control the surface shape and refractive power of the fourth lens, which helps to reduce the size of wide-angle lenses. When condition (5) is met: 5.5 TTL/d67 24. It can effectively adjust the lens distribution to help balance the field of view and volume, and helps correct off-axis aberration and field curvature. When condition (6): 4 TTL/BFL 7. This effectively ensures that wide-angle lenses have a better miniaturized configuration and a reasonable back focal length. When condition (7) is met: 77.7 TTL/d56 127.2, which can effectively adjust the lens spacing to facilitate assembly. When condition (8): 8.4 is met. R12/T1 14.5, which is beneficial for lens manufacturing. When condition (9) is met: 47.1 degrees/mm FOV/f 51.6 degrees/mm, which can effectively increase the aperture of a wide-angle lens to improve image brightness. When condition (10): 45.5 degrees is met. FOV/FNo The 46.2-degree field of view effectively increases the aperture of a wide-angle lens, thereby improving image brightness. When the first lens is a crescent-shaped lens with negative refractive power, it effectively expands the field of view and adjusts the optical path, making it less prone to large refractions. When the second lens is a crescent-shaped lens with negative refractive power, it effectively mitigates the optical path adjustment caused by the negative refractive power of the first lens, thus correcting some aberrations. When the third lens has positive refractive power, it effectively corrects the aberrations caused by the negative refractive power of the first and second lenses. When the fourth lens has positive refractive power, it compensates for the insufficient positive refractive power of the third lens and, through the use of molded glass lenses, compensates for aberrations caused by environmental temperature changes in plastic lenses. When the fifth lens has negative refractive power, it can effectively correct astigmatism. When the sixth lens has positive refractive power, it can effectively correct distortion. When the seventh lens has positive refractive power, it can significantly adjust the principal ray angle and increase the back focal length, which is beneficial for wide-angle lens assembly.

The first embodiment of the wide-angle lens of the present invention will now be described in detail. Referring to Figure 1, the wide-angle lens 1 includes, in sequence along an optical axis OA1 from the object side to the image side, a first lens L11, a second lens L12, a third lens L13, an aperture ST1, a fourth lens L14, a fifth lens L15, a sixth lens L16, a seventh lens L17, a filter OF1, and a protective glass CG1. During imaging, the light from the object side is finally imaged onto an imaging plane IMA1. According to paragraphs one through nine of the [Implementation Method], the image-side surface S115 of the seventh lens L17 is convex; the object-side surface S116 and image-side surface S117 of the filter OF1 are both flat; the object-side surface S118 and image-side surface S119 of the protective glass CG1 are both flat. By utilizing the above-mentioned lens, aperture ST1, and the design of at least one of conditions (1) to (10), the wide-angle lens 1 can effectively shorten the overall length of the lens, effectively increase the field of view, effectively improve resolution, and effectively correct aberrations. When the wide-angle lens of this invention only satisfies condition (1) and the refractive surface shape characteristics in the independent claim, it can achieve the basic operational requirements.

Table 1 shows the relevant parameters of each lens in wide-angle lens 1 in Figure 1.

Table 2 presents the relevant parameters for the aspherical surfaces of the aspherical lenses listed in Table 1.

Table 3 shows the relevant parameter values of the wide-angle lens 1 in the first embodiment and their corresponding calculated values under conditions (1) to (10). As can be seen from Table 3, the wide-angle lens 1 in the first embodiment meets all the requirements of conditions (1) to (10).

The second embodiment of the wide-angle lens of the present invention will now be described in detail. Referring to Figure 2, the wide-angle lens 2, along an optical axis OA2 from the object side to the image side, sequentially includes a first lens L21, a second lens L22, a third lens L23, an aperture ST2, a fourth lens L24, a fifth lens L25, a sixth lens L26, a seventh lens L27, a filter OF2, and a protective glass CG2. During imaging, the light from the object side is finally imaged onto an imaging plane IMA2. According to paragraphs one through nine of the [Implementation Method], the image-side surface S215 of the seventh lens L27 is convex; the object-side surface S216 and image-side surface S217 of the filter OF2 are both flat; the object-side surface S218 and image-side surface S219 of the protective glass CG2 are both flat. By utilizing the above-mentioned lens, aperture ST2, and the design of at least one of conditions (1) to (10), the wide-angle lens 2 can effectively shorten the overall length of the lens, effectively increase the field of view, effectively improve resolution, and effectively correct aberrations. When the wide-angle lens of this invention only satisfies condition (2) and the refractive surface shape characteristics in the independent claim, it can achieve the basic operational requirements.

Table 4 shows the relevant parameters of each lens in wide-angle lens 2 in Figure 2.

Table 5 presents the relevant parameters for the aspherical surfaces of the aspherical lenses listed in Table 4.

Table 6 shows the relevant parameter values of the wide-angle lens 2 in the second embodiment and their corresponding calculated values under conditions (1) to (10). As can be seen from Table 6, the wide-angle lens 2 in the second embodiment meets the requirements of conditions (1) to (10).

The third embodiment of the wide-angle lens of the present invention will now be described in detail. Referring to Figure 3, the wide-angle lens 3, along an optical axis OA3 from the object side to the image side, sequentially includes a first lens L31, a second lens L32, a third lens L33, an aperture ST3, a fourth lens L34, a fifth lens L35, a sixth lens L36, a seventh lens L37, a filter OF3, and a protective glass CG3. During imaging, the light from the object side is finally imaged onto an imaging plane IMA3. According to paragraphs one through nine of the [Implementation Method], the image-side surface S315 of the seventh lens L37 is convex; the object-side surface S316 and image-side surface S317 of the filter OF3 are both flat; the object-side surface S318 and image-side surface S319 of the protective glass CG3 are both flat. By utilizing the above-mentioned lens, aperture ST3, and the design of at least one of conditions (1) to (10), the wide-angle lens 3 can effectively shorten the overall length of the lens, effectively increase the field of view, effectively improve resolution, and effectively correct aberrations. When the wide-angle lens of this invention only satisfies condition (3) and the refractive surface shape characteristics in the independent claim, it can achieve the basic operational requirements.

Table 7 shows the relevant parameters of each lens in wide-angle lens 3 in Figure 3.

Table 8 presents the relevant parameters for the aspherical surfaces of the aspherical lenses listed in Table 7.

Table 9 shows the relevant parameter values of the wide-angle lens 3 in the third embodiment and their corresponding calculated values under conditions (1) to (10). As can be seen from Table 9, the wide-angle lens 3 in the third embodiment meets the requirements of conditions (1) to (10).

The fourth embodiment of the wide-angle lens of the present invention will now be described in detail. Referring to Figure 4, the wide-angle lens 4, along an optical axis OA4, sequentially includes a first lens L41, a second lens L42, a third lens L43, an aperture ST4, a fourth lens L44, a fifth lens L45, a sixth lens L46, a seventh lens L47, a filter OF4, and a protective glass CG4 from the object side to the image side. During imaging, the light from the object side is finally imaged onto an imaging plane IMA4. According to paragraphs one through nine of the [Implementation Method], the image-side surface S415 of the seventh lens L47 is concave; the object-side surface S416 and image-side surface S417 of the filter OF4 are both flat; the object-side surface S418 and image-side surface S419 of the protective glass CG4 are both flat. By utilizing the above-mentioned lens, aperture ST4, and the design of satisfying at least one of conditions (1) to (10), the wide-angle lens 4 can effectively shorten the overall length of the lens, effectively increase the field of view, effectively improve resolution, and effectively correct aberrations. When the wide-angle lens of this invention satisfies only condition (4) and the refractive surface shape characteristics in the independent item, it can achieve the basic operational requirements.

Table 10 shows the relevant parameters of each lens in wide-angle lens 4 in Figure 4.

Table 11 contains the relevant parameters for the aspherical surfaces of the aspherical lenses listed in Table 10.

Table 12 shows the relevant parameter values of the wide-angle lens 4 in the fourth embodiment and their corresponding calculated values under conditions (1) to (10). As can be seen from Table 12, the wide-angle lens 4 in the fourth embodiment meets the requirements of conditions (1) to (10).

Furthermore, the optical performance of the wide-angle lens 4 in the fourth embodiment also meets the requirements. As shown in Figure 5, the field curvature of the wide-angle lens 4 in the fourth embodiment is between -0.28mm and 0.16mm. As shown in Figure 6, the distortion of the wide-angle lens 4 in the fourth embodiment is between -13% and 0%. As shown in Figure 7, when the image height is 0.000mm, the root mean square (RMS) of the light spot of the wide-angle lens 4 in the fourth embodiment is... The root mean square radius of the light spot is 0.789 μm, and the geometrical radius of the light spot is 1.662 μm. When the image height is 1.725 mm, the root mean square radius of the light spot is 1.092 μm, and the geometrical radius of the light spot is 2.346 μm. When the image height is 3.242 mm, the root mean square radius of the light spot is 2. The image size is 373 μm, and the geometric radius of the spot is 6.051 μm. When the image height is 4.886 mm, the root mean square radius of the spot is 6.777 μm, and the geometric radius of the spot is 17.178 μm. When the image height is 5.350 mm, the root mean square radius of the spot is 10.795 μm, and the geometric radius of the spot is 29.990 μm. Clearly, the field curvature and distortion of the wide-angle lens 4 in the fourth embodiment can be effectively corrected, thus achieving better optical performance.

The fifth embodiment of the wide-angle lens of the present invention will now be described in detail. Referring to Figure 8, the wide-angle lens 5, along an optical axis OA5 from the object side to the image side, sequentially includes a first lens L51, a second lens L52, a third lens L53, an aperture ST5, a fourth lens L54, a fifth lens L55, a sixth lens L56, a seventh lens L57, a filter OF5, and a protective glass CG5. During imaging, the light from the object side is finally imaged onto an imaging plane IMA5. According to paragraphs one through nine of the [Implementation Method], the image-side surface S515 of the seventh lens L57 is concave; the object-side surface S516 and image-side surface S517 of the filter OF5 are both flat; the object-side surface S518 and image-side surface S519 of the protective glass CG5 are both flat. By utilizing the above-mentioned lens, aperture ST5, and the design of at least one of conditions (1) to (10), the wide-angle lens 5 can effectively shorten the overall length of the lens, effectively increase the field of view, effectively improve resolution, and effectively correct aberrations. When the wide-angle lens of this invention only satisfies condition (5) and the refractive surface shape characteristics in the independent claim, it can achieve the basic operational requirements.

Table 13 shows the relevant parameters for each lens in wide-angle lens 5 in Figure 8.

Table 14 presents the relevant parameters for the aspherical surfaces of the aspherical lenses listed in Table 13.

Table 15 shows the relevant parameter values of the wide-angle lens 5 in the fifth embodiment and their corresponding calculated values under conditions (1) to (10). As can be seen from Table 15, the wide-angle lens 5 in the fifth embodiment meets the requirements of conditions (1) to (10).

Furthermore, the optical performance of the wide-angle lens 5 in the fifth embodiment also meets the requirements. As shown in Figure 9, the field curvature of the wide-angle lens 5 in the fifth embodiment is between -0.36mm and 0.20mm. As shown in Figure 10, the distortion of the wide-angle lens 5 in the fifth embodiment is between -13% and 0%. As shown in Figure 11, the wide-angle lens 5 in the fifth embodiment, when the image height is 0.000mm, has a root mean square radius of 0.650μm and a geometric radius of 1.265μm; when the image height is 1.726mm, its root mean square radius of 1.133μm and geometric radius of 2.547μm; and when the image height is 3.227mm, its… The root mean square radius (RMS radius) of the light spot is 2.318 μm, and the geometric radius of the light spot is 6.931 μm. When the image height is 4.882 mm, the RMS radius of the light spot is 7.876 μm, and the geometric radius of the light spot is 18.280 μm. When the image height is 5.350 mm, the RMS radius of the light spot is 13.013 μm, and the geometric radius of the light spot is 35.018 μm. Clearly, the field curvature and distortion of the wide-angle lens 5 in the fifth embodiment can be effectively corrected, thus achieving better optical performance.

The sixth embodiment of the wide-angle lens of the present invention will now be described in detail. Referring to Figure 12, the wide-angle lens 6, along an optical axis OA6 from the object side to the image side, sequentially includes a first lens L61, a second lens L62, a third lens L63, an aperture ST6, a fourth lens L64, a fifth lens L65, a sixth lens L66, a seventh lens L67, a filter OF6, and a protective glass CG6. During imaging, the light from the object side is finally imaged onto an imaging plane IMA6. According to paragraphs one through nine of the [Implementation Method], the image-side surface S615 of the seventh lens L67 is concave; the object-side surface S616 and image-side surface S617 of the filter OF6 are both flat; the object-side surface S618 and image-side surface S619 of the protective glass CG6 are both flat. By utilizing the above-mentioned lens, aperture ST6, and the design of satisfying at least one of conditions (1) to (10), the wide-angle lens 6 can effectively shorten the overall length of the lens, effectively increase the field of view, effectively improve resolution, and effectively correct aberrations. The wide-angle lens of this invention can achieve the basic operational requirements by satisfying only conditions (6), (7), (8), (9), or (10) and the refractive surface characteristics in the independent item.

Table 16 shows the relevant parameters for each lens in wide-angle lens 6 in Figure 12.

Table 17 presents the relevant parameters for the aspherical surfaces of the aspherical lenses listed in Table 16.

Table 18 shows the relevant parameter values of the wide-angle lens 6 in the sixth embodiment and their corresponding calculated values under conditions (1) to (10). As can be seen from Table 18, the wide-angle lens 6 in the sixth embodiment meets the requirements of conditions (1) to (10).

Furthermore, the optical performance of the wide-angle lens 6 in the sixth embodiment also meets the requirements. As shown in Figure 13, the field curvature of the wide-angle lens 6 in the sixth embodiment is between -0.16mm and 0.28mm. As shown in Figure 14, the distortion of the wide-angle lens 6 in the sixth embodiment is between -7.5% and 0%. As shown in Figure 15, the root mean square radius of the light spot of the wide-angle lens 6 in the sixth embodiment is 0.853μm and the geometric radius of the light spot is 1.835μm when the image height is 0.000mm; when the image height is 1.678mm, the root mean square radius of the light spot is 1.217μm and the geometric radius of the light spot is 3.323μm; and when the image height is 3.252mm, its… The root mean square radius (RMS radius) of the light spot is 2.381 μm, and the geometric radius of the light spot is 7.244 μm. When the image height is 4.888 mm, the RMS radius of the light spot is 5.978 μm, and the geometric radius of the light spot is 16.604 μm. When the image height is 5.350 mm, the RMS radius of the light spot is 12.407 μm, and the geometric radius of the light spot is 33.307 μm. It is evident that the field curvature and distortion of the wide-angle lens 6 in the sixth embodiment can be effectively corrected, thereby achieving better optical performance.

Although the present invention has been disclosed above in a preferred embodiment, it is not intended to limit the invention. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the appended patent claims.

1: Wide-angle lens

L11: First Lens

L12: Second Lens

L13: Third Lens

ST1: Aperture

L14: Fourth Lens

L15: Fifth Lens

L16: Sixth Lens

L17: Seventh Lens

OF1: Filter

CG1: Protective Glass

IMA1: Imaging Surface

OA1: optical axis

S11: Side view of the first lens object

S12: Side view of the first lens image

S13: Second lens side view

S14: Side view of the second lens image

S15: Third lens side view

S16: Side view of the third lens image

L17: Aperture plane

S18: Fourth lens side view

S19: Side view of the fourth lens image

S110: Fifth lens object side view

S111: Side view of the fifth lens image

S112: Sixth lens object side view

S113: Side view of the sixth lens image

S114: Seventh lens object side view

S115: Side view of the seventh lens image

S116: Filter side

S117: Filter image side view

S118: Protect the sides of glass objects

S119: Protective glass for the side view

Claims (8)

A wide-angle lens includes: a first lens having refractive power, the first lens including a concave surface facing an image side; a second lens having negative refractive power, the second lens being a meniscus lens, and including a convex surface facing an object side and a concave surface facing the image side; a third lens having refractive power; and a fourth lens having positive refractive power, the fourth lens being a biconvex lens, and including a convex surface facing the object side and another convex surface facing the image side. The wide-angle lens has the following characteristics: a fifth lens with refractive power; a sixth lens with refractive power; and a seventh lens with positive refractive power; wherein the number of lenses with refractive power is no more than seven; wherein the first, second, third, fourth, fifth, sixth, and seventh lenses 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: 8.4 R12/T1 14.5; 47.1 degrees/mm FOV/f 51.6 degrees/mm; 45.5 degrees FOV/FNo 46.2 degrees; -1.5 (R41+R42)/f4 1; where f is an effective focal length of the wide-angle lens, R12 is a radius of curvature of an image-side surface of the first lens, T1 is the distance between the object-side surface of the first lens and the image-side surface of the first lens on the optical axis, FOV is a maximum field of view of the wide-angle lens, FNo is an aperture value of the wide-angle lens, R41 is a radius of curvature of an object-side surface of the fourth lens, R42 is a radius of curvature of an image-side surface of the fourth lens, and f4 is an effective focal length of the fourth lens. The wide-angle lens as described in claim 1, wherein: the first lens has negative refractive power; the third lens has positive refractive power; the fifth lens has negative refractive power; and the sixth lens has positive refractive power. The wide-angle lens as described in claim 2, wherein: the first lens is a crescent-shaped lens, and further includes a convex surface facing the object side; the third lens is a crescent-shaped lens, and includes a concave surface facing the object side and a convex 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; and the seventh lens includes a convex surface facing the object side. The wide-angle lens as described in claim 3, wherein the seventh lens is a biconvex lens, and further includes another convex surface facing the image side. As described in claim 3, the wide-angle lens, wherein the seventh lens is a crescent-shaped lens and further includes a concave surface facing the image side. The wide-angle lens as described in claim 1 further includes an aperture, and two negatively refractive lenses are included between the object side and the aperture. The wide-angle lens as described in claim 6, wherein the aperture is positioned between the third lens and the fourth lens. The wide-angle lens described in any of claims 1 through 7 of the patent application, wherein the wide-angle lens meets at least one of the following conditions: -9 f1/f -3.5; 1.5 f4/f 3.5; 1 R21/f 6; 5.5 TTL/d67 24; 4 TTL/BFL 7; 77.7 TTL/d56 127.2; where f is the effective focal length of the wide-angle lens, f1 is the effective focal length of the first lens, f4 is the effective focal length of the fourth lens, R21 is the radius of curvature of the object-side surface of the second lens, TTL is the distance between the object-side surface of the first lens and an imaging plane on the optical axis, BFL is the distance between the image-side surface of the seventh lens and the imaging plane on the optical axis, d67 is the air distance between the image-side surface of the sixth lens and the object-side surface of the seventh lens on the optical axis, and d56 is the air distance between the image-side surface of the fifth lens and the object-side surface of the sixth lens on the optical axis.