A miniaturized high-resolution fixed-focus optical system and image pickup device

Abstract

The present invention discloses a miniaturized high-resolution fixed-focus optical system and an image pickup device. The miniaturized high-resolution fixed-focus optical system comprises a lens; a first lens group G1 with negative focal power and a second lens group G2 with positive focal power are arranged in sequence from the object side to the image side along the main optical axis of the lens; the first lens group G1 comprises a positive lens L1, a negative lens L2, a negative lens L3, and a positive lens L4 in sequence from the object side to the image side, and the surface of the negative lens L3 on the object side is a convex surface or a concave surface; the second lens group G2 comprises a first glued lens group B1 with positive focal power and a second glued lens group B2 with positive focal power in sequence from the object side to the image side; there is at least one positive lens L7 between the first glued lens group B1 and the second glued lens group B2. The composition of the optical system is realized by the first lens group G1 and the second lens group G2, the focal power of different lens groups is controlled, and the position of the first lens group G1 relative to the imaging surface remains unchanged during the focusing process, so that the coexistence of small volume and high resolution is achieved.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a miniaturized high-resolution fixed-focus optical system and an image pickup device. Background Art

[0002] Today's camera equipment has higher and higher requirements for lens resolution. In order to obtain a wider angle and better images, the chip size used for monitoring face recognition and machine vision automatic judgment is larger. However, when corresponding to larger sensors, the size of the lens tends to become larger, the cost is too high, and the camera may not provide enough installation space. In addition, the current industrial cameras used for machine vision processing are developing towards high pixels. There are modules with various usage conditions in the market. Some of these manufacturing equipment, substrate inspection equipment, etc. need to use lenses with good image capabilities at close range due to installation space limitations. Summary of the invention

[0003] The object of the present invention is to provide a miniaturized high-resolution fixed-focus optical system and an image pickup device to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

[0004] The technical solutions adopted to solve the above technical problems are:

[0005] The present invention provides a miniaturized high-resolution fixed-focus optical system, which comprises a lens; the lens comprises a first lens group G1 with negative optical power and a second lens group G2 with positive optical power, which are arranged in sequence from the object side to the image side along the main optical axis of the lens; wherein the first lens group G1 comprises a positive lens L1, a negative lens L2, a negative lens L3, and a positive lens L4 in sequence from the object side to the image side, and the surface of the negative lens L3 on the object side is a convex surface or a concave surface; the second lens group G2 comprises a first cemented lens group B1 with positive optical power and a second cemented lens group B2 with positive optical power in sequence from the object side to the image side; and there is at least one positive lens L7 between the first cemented lens group B1 and the second cemented lens group B2.

[0006] The beneficial effects of the present invention are:

[0007] The structure is simplified. The optical system is composed of the first lens group G1 and the second lens group G2. The optical power of different lens groups is controlled. During the focusing process, the position of the first lens group G1 relative to the imaging surface remains unchanged, achieving a small volume and high resolution. The second lens group G2 is glued together by multiple lenses to improve chromatic aberration and reduce the volume of the focusing group. The optical movable part of the lens moves a small amount, reducing the impact of camera vibration.

[0008] As a further improvement of the above technical solution, the first glued lens group B1 includes a first lens L5, which is the most object side lens of the first glued lens group B1, and the first lens L5 is a negative lens; the second glued lens group B2 includes a second lens L9, which is the most image side lens of the second glued lens group B2, and the second lens L9 is a second negative lens.

[0009] When the lens most on the object side of the first cemented lens group B1 is a negative lens, the lens most on the image plane side of the cemented lens group B2 is also a negative lens.

[0010] As a further improvement of the above technical solution, the first glued lens group B1 also includes a second lens L6, and the second lens L6 is a positive lens; the second glued lens group B2 includes a first lens L8, and the first lens L8 is a positive lens.

[0011] As a further improvement of the above technical solution, the first glued lens group B1 includes a first lens L55, the first lens L55 is the lens on the most object side of the first glued lens group B1, and the first lens L55 is a positive lens;

[0012] The second glued lens group B2 includes a second lens L99. The second lens L99 is a lens on the most image surface side of the second glued lens group B2. The second lens L99 is a positive lens.

[0013] As a further improvement of the above technical solution, the first glued lens group B1 also includes a second lens L66, and the second lens L66 is a negative lens; the second glued lens group B2 includes a first lens L88, and the first lens L88 is a negative lens.

[0014] As a further improvement of the above technical solution, the lens comprises an effective aperture St, and the effective aperture St is arranged between the first lens group G1 and the second lens group G2.

[0015] In order to limit the light beam or the size of the field of view (imaging range), an effective aperture St is provided to optimize the light beam shaping and improve the light beam quality.

[0016] As a further improvement of the above technical solution, the effective aperture St is fixed or movable relative to the imaging surface IMG, and the effective aperture St is set according to the actual needs of the lens.

[0017] As a further improvement of the above technical solution, the lens satisfies the following conditional formula:

[0018] (1)1.625<f2 / EFL<1.875;

[0019] (2)1.5<f2 / TL2;

[0020] (3)0.58<nd3 / (nd1+nd2)<0.65;

[0021] (4) 56<vd2<76;

[0022] in:

[0023] f2: synthetic focal length of the second lens group G2;

[0024] EFL: focal length of the lens when it is focused at infinity;

[0025] TL2: the distance on the optical axis between the vertex of the object side surface and the vertex of the image side surface of the second lens group G2;

[0026] nd1: the refractive index of the positive lens in the first glued lens group B1; nd2: the refractive index of the positive lens in the second glued lens group B2; nd3: the refractive index of the positive lens L7 between the first glued lens group B1 and the second glued lens group B2; vd2: the average value of the Abbe numbers of all the positive lenses in the second lens group G2.

[0027] As a further improvement of the above technical solution, (5) 0.25<TL34 / TL1; TL1: the distance on the optical axis between the vertex of the object side surface and the vertex of the image side surface of the first lens group G1; TL34: the interval on the optical axis between the lens L3 and the lens L4.

[0028] The present invention also provides an image pickup device, comprising the miniaturized high-resolution fixed-focus optical system of any one of the above items and a solid-state image pickup element, wherein the solid-state image pickup element is configured to receive light of an image formed by the miniaturized high-resolution fixed-focus optical system.

[0029] The image pickup device has a small-sized high-resolution fixed-focus optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments;

[0031] Figure 1 This is a structural schematic diagram of a scheme 1 of a miniaturized high-resolution fixed-focus optical system provided by the present invention;

[0032] Figure 2 This is a structural schematic diagram of a second embodiment of a miniaturized high-resolution fixed-focus optical system provided by the present invention;

[0033] Figure 3 It is shown Figure 1A diagram of longitudinal aberrations of a specific example of an embodiment of the present invention;

[0034] Figure 4 It is shown Figure 2 Graphs of longitudinal aberrations of specific examples of embodiments. DETAILED DESCRIPTION

[0035] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0037] In the description of the present invention, if there are words such as "several", it means one or more, "more" means more than two, greater than, less than, exceed, etc. are understood as not including the number, and above, below, within, etc. are understood as including the number.

[0038] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0039] Reference Figures 1 to 4 The present invention provides a miniaturized high-resolution fixed-focus optical system and an image pickup device in the following embodiments:

[0040] Figure 1The figure is a diagram of an embodiment of a miniaturized high-resolution fixed-focus optical system, wherein the miniaturized high-resolution fixed-focus optical system comprises a lens, wherein the lens comprises a first lens group G1 with negative focal power, an effective aperture St, and a second lens group G2 with positive focal power, which are arranged in sequence from the object side to the image side along the main optical axis of the lens; wherein the first lens group G1 comprises a positive lens L1, a negative lens L2, a negative lens L3, and a positive lens L4 in sequence from the object side to the image side, and the surface of the negative lens L3 on the object side is a convex surface or a concave surface; the second lens group G2 comprises a first cemented lens group B1 with positive focal power and a second cemented lens group B2 with positive focal power in sequence from the object side to the image side; there is at least one positive lens L7 between the first cemented lens group B1 and the second cemented lens group B2. The lens comprises an effective aperture St, and the effective aperture St is arranged between the first lens group G1 and the second lens group G2.

[0041] In order to limit the light beam or the size of the field of view (imaging range), an effective aperture St is provided to optimize the light beam shaping and improve the light beam quality. The effective aperture St is fixed or movable relative to the imaging surface IMG and is provided according to the actual needs of the lens.

[0042] Among them, the first glued lens group B1 includes a first lens L5 and a second lens L6 which are positive lenses, the first lens L5 is the most object side lens of the first glued lens group B1, the first lens L5 is a negative lens, and the second lens L6 is a positive lens; the second glued lens group B2 includes a second lens L9, the first lens L8 and the second lens L9 are the most image side lenses of the second glued lens group B2, the second lens L9 is a negative lens, and the first lens L8 is a positive lens.

[0043] Figure 1 The lens in satisfies the following conditions:

[0044] (1)1.625<f2 / EFL<1.875;

[0045] (2)1.5<f2 / TL2;

[0046] (3)0.58<nd3 / (nd1+nd2)<0.65;

[0047] (4) 56<vd2<76;

[0048] (5) 0.25<TL34 / TL1;

[0049] in:

[0050] f2: synthetic focal length of the second lens group G2;

[0051] EFL: focal length of the lens when it is focused at infinity;

[0052] TL2: the distance on the optical axis between the vertex of the object side surface and the vertex of the image side surface of the second lens group G2;

[0053] nd1: the refractive index of the positive lens in the first cemented lens group B1;

[0054] nd2: the refractive index of the positive lens in the second cemented lens group B2;

[0055] nd3: the refractive index of the positive lens L7 between the first glued lens group B1 and the second glued lens group B2;

[0056] vd2: the average value of the Abbe numbers of all positive lenses in the second lens group G2.

[0057] TL1: the distance on the optical axis between the vertex of the object side surface and the vertex of the image side surface of the first lens group G1;

[0058] TL34: The distance between the lens L3 and the lens L4 on the optical axis.

[0059] Reference Figure 2 , another embodiment of the present invention, wherein the first glued lens group B1 includes a first lens L55 and a second lens L66, the first lens L55 is the lens on the most object side of the first glued lens group B1, the first lens L55 is a positive lens, and the second lens L66 is a negative lens;

[0060] The second glued lens group B2 includes a second lens L99 and a first lens L88. The second lens L99 is the lens on the most image side of the second glued lens group B2. The second lens L99 is a positive lens, and the first lens L88 is a negative lens. The structure is simplified. The composition of the optical system is realized by the first lens group G1 and the second lens group G2. The optical focal length of different lens groups is controlled. During the focusing process, the position of the first lens group G1 relative to the imaging surface remains unchanged, achieving a small volume and high resolution. In the second lens group G2, multiple lenses are glued together to improve chromatic aberration and reduce the volume of the focusing group. The optical movable part of the lens moves a small amount, reducing the impact of camera vibration.

[0061] The following are listed Figure 1 A specific example of a miniaturized high-resolution fixed-focus optical system of the illustrated embodiment.

[0062] noodle Curvature radius (mm) Interval(mm) Refractive Index Abbe number S1 20.69648 2.540365 1.883 40.8054 S2 66.43175 0.2 S3 14.19849 0.7 1.507786 77.8261 S4 6.137377 2.430037 S5 40.07641 0.7 1.95906 17.4713 S6 7.221418 6.815757 S7 23.9092 1.575056 1.958964 17.6171 S8 -44.1218 2.860772 S9 (Aperture) 6.593351 S10 -63.9216 0.7 1.956639 22.0794 S11 19.56815 2.449411 1.496997 81.6084 S12 -13.0776 0.2 S13 35.66206 1.928139 1.883 40.8054 S14 -33.6086 0.2 S15 17.41931 2.738023 1.500247 80.4133 S16 -17.0985 0.7 1.773825 23.5496 S17 -601.726 12.40927 S18 infinity - - -

[0063] Figure 3 Shown in Figure 1Aberration diagrams of a miniaturized high-resolution fixed-focus optical system of an embodiment of the illustrated embodiment. It is obvious from these aberration diagrams that Figure 1 The aberrations of the miniaturized high-resolution fixed-focus optical system of the embodiment shown in the embodiment are all well corrected and the performance is good. The spacing distance refers to the spacing between the two surfaces on the main optical axis.

[0064] The following are listed Figure 2 A specific example of a miniaturized high-resolution fixed-focus optical system of the illustrated embodiment.

[0065] noodle Curvature radius (mm) Interval(mm) Refractive Index Abbe number S1 17.332 3.86 1.6968 55.5 S2 104.232 0.20 S3 16.561 0.70 1.5935 67.0 S4 6.478 3.25 S5 -49.962 0.70 1.9591 17.5 S6 8.461 4.80 S7 22.690 3.40 1.9459 18.0 S8 -29.115 6.98 S9 (Aperture) 5.12 S10 -55.031 2.40 1.4970 81.6 S11 -6.977 0.70 1.9229 20.9 S12 -11.541 0.20 S13 56.580 1.81 1.8348 42.7 S14 -31.460 0.20 S15 16.198 0.70 1.7283 28.3 S16 8.851 2.66 1.4970 81.6 S17 234.499 13.06 S18 infinity - - -

[0066] Figure 4 Shown in Figure 2 Aberration diagrams of a miniaturized high-resolution fixed-focus optical system of an embodiment of the illustrated embodiment. It is obvious from these aberration diagrams that Figure 2 The aberrations of the miniaturized high-resolution fixed-focus optical system of the embodiment shown are all well corrected and the performance is good.

[0067] The present invention also provides an image pickup device, comprising the miniaturized high-resolution fixed-focus optical system of any one of the above items and a solid-state image pickup element, wherein the solid-state image pickup element is configured to receive light of an image formed by the miniaturized high-resolution fixed-focus optical system. The image pickup device has a miniaturized high-resolution fixed-focus optical system.

[0068] The preferred embodiments of the present invention are specifically described above, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A miniaturized high-resolution fixed-focus optical system, characterized in that: The miniaturized high-resolution fixed-focus optical system comprises a lens; The lens comprises a first lens group G1 with negative optical power and a second lens group G2 with positive optical power, which are arranged in sequence along the main optical axis of the lens from the object side to the image side; the first lens group G1 comprises a positive lens L1, a negative lens L2, a negative lens L3, and a positive lens L4 in sequence from the object side to the image side, and the surface of the negative lens L3 on the object side is a convex surface or a concave surface; the second lens group G2 comprises a first cemented lens group B1 with positive optical power and a second cemented lens group B2 with positive optical power in sequence from the object side to the image side, and the lens comprises an effective aperture St, and the effective aperture St is arranged between the first lens group G1 and the second lens group G2; There is a positive lens L7 between the first glued lens group B1 and the second glued lens group B2; Wherein: the first glued lens group B1 includes a first lens L5, the first lens L5 is the lens closest to the object side of the first glued lens group B1, and the first lens L5 is a negative lens; the second glued lens group B2 includes a second lens L9, the second lens L9 is the lens closest to the image plane side of the second glued lens group B2, and the second lens L9 is a negative lens; the first glued lens group B1 also includes a second lens L6, and the second lens L6 is a positive lens; the second glued lens group B2 also includes a first lens L8, and the first lens L8 is a positive lens; or The first glued lens group B1 includes a first lens L55, which is the lens closest to the object side of the first glued lens group B1 and is a positive lens; the second glued lens group B2 includes a second lens L99, which is the lens closest to the image plane side of the second glued lens group B2 and is a positive lens; the first glued lens group B1 also includes a second lens L66, which is a negative lens; the second glued lens group B2 also includes a first lens L88, which is a negative lens; The components having optical refractive power in the fixed-focus optical system are only the nine lenses mentioned above.

2. A miniaturized high-resolution fixed-focus optical system according to claim 1, characterized in that: The lens comprises an imaging surface IMG, and the effective aperture St is fixed or movable relative to the imaging surface IMG.

3. The miniaturized high-resolution fixed-focus optical system according to claim 1, characterized in that: The lens satisfies the following conditional formula: (1)1.625<f2 / EFL<1.875; (2) 1.5<f2 / TL2; (3)0.58<nd3 / (nd1+nd2)<0.65; (4) 56<vd2<76; in: f2: synthetic focal length of the second lens group G2; EFL: focal length of the lens when it is focused at infinity; TL2: the distance on the optical axis between the vertex of the object side surface and the vertex of the image side surface of the second lens group G2; nd1: the refractive index of the positive lens in the first cemented lens group B1; nd2: the refractive index of the positive lens in the second cemented lens group B2; nd3: the refractive index of the positive lens L7 between the first glued lens group B1 and the second glued lens group B2; vd2: the average value of the Abbe numbers of all positive lenses in the second lens group G2.

4. The miniaturized high-resolution fixed-focus optical system according to claim 3, characterized in that: (5) 0.25<TL34 / TL1; TL1: the distance on the optical axis between the vertex of the object side surface and the vertex of the image side surface of the first lens group G1; TL34: The distance between the lens L3 and the lens L4 on the optical axis.

5. An image pickup device comprising the miniaturized high-resolution fixed-focus optical system of any one of claims 1 to 4 and a solid-state image pickup element, the solid-state image pickup element being configured to receive light of an image formed by the miniaturized high-resolution fixed-focus optical system.

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