Optical lens system and surveillance camera device

Abstract

The application discloses an optical lens system and a monitoring camera device, and the optical lens system comprises a plurality of lens groups arranged in sequence from an object side to an image side, and a corresponding optical axis is formed between the plurality of lens groups, wherein the plurality of lens groups comprise a first lens group and a second lens group, the first lens group has a negative focal power and is movably arranged along the extension direction of the optical axis, and the second lens group has a positive focal power and is movably arranged along the extension direction of the optical axis. By arranging the first lens group and the second lens group, the refractive index and the Abbe number of light rays from the object side to the image side are complementary, the resolving effect of an infrared wave band is ensured under the condition that the chromatic aberration of a visible wave band is small, and by adjusting the positions of the first lens group and the second lens group, the conjugate distance change amount of the first lens group and the conjugate distance change amount of the second lens group after magnification are offset, image surface compensation is realized, and an optical lens system with a large aperture, high definition and low cost zoom is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to an optical lens system and a monitoring camera device. BACKGROUND

[0002] At present, the zoom optical system for monitoring generally has the following shortcomings: small aperture, high cost, the zoom process cannot realize infrared confocal at each magnification, the resolution of the lens decreases obviously in high and low temperature environment, etc. At present, only a few lenses on the market improve some aspects at the expense of other aspects, such as using all or more glass lenses to realize infrared confocal at full magnification, which increases the cost of the lens and affects the promotion and popularization of the lens. Or the actual use of the lens in high and low temperature environment is not considered, which causes the resolution of the lens in high and low temperature environment to decrease a lot and affects the picture clarity. Or the aperture of the lens is small in order to reduce the cost, which cannot meet the use of the lens in dark environment, etc. SUMMARY

[0003] The main purpose of the present application is to provide an optical lens system and a monitoring camera device, which aims to provide a large-aperture, high-definition, low-cost zoom optical lens system.

[0004] In order to achieve the above-mentioned purpose, the present application provides an optical lens system, wherein the optical lens system comprises a plurality of lens groups arranged in order from the object side to the image side, and a light axis is formed between the plurality of lens groups, wherein the plurality of lens groups comprise:

[0005] a first lens group with negative focal power, which is movably arranged along the extension direction of the light axis; and

[0006] a second lens group with positive focal power, which is movably arranged along the extension direction of the light axis;

[0007] Wherein, the image plane compensation is realized by changing the positions of the first lens group and the second lens group.

[0008] Optionally, the first lens group comprises a first lens, a second lens and a third lens arranged in order from the object side to the image side; and / or,

[0009] The second lens group comprises a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens arranged in order from the object side to the image side, wherein the focal power of the fourth lens is positive, the focal power of the fifth lens is negative, the focal power of the sixth lens is positive, the focal power of the seventh lens is positive, the focal power of the eighth lens is negative, the focal power of the ninth lens is positive, the focal power of the tenth lens is negative, and the focal power of the eleventh lens is positive or negative.

[0010] Optionally, the first lens is a glass spherical lens, and the second lens and the third lens are plastic aspherical lenses.

[0011] The fourth lens, the fifth lens, the seventh lens, the eighth lens and the eleventh lens are plastic aspherical lenses.

[0012] Optionally, the sixth lens, the ninth lens and the tenth lens are glass spherical lenses.

[0013] Optionally, the fifth lens is a negative lens, the sixth lens is a positive lens, and the fifth lens and the sixth lens are similar to a cemented structure.

[0014] The seventh lens is a positive lens, the eighth lens is a negative lens, and the seventh lens and the eighth lens are similar to a cemented structure.

[0015] The ninth lens is a positive lens, the tenth lens is a negative lens, and the eleventh lens is a positive lens, and the ninth lens, the tenth lens and the eleventh lens are similar to a three-cemented structure.

[0016] Optionally, a diaphragm is arranged between the first lens group and the second lens group.

[0017] Optionally, the distance between the side of the first lens group facing the image side and the diaphragm is L1, wherein 1mm≤L1≤8.49mm.

[0018] Optionally, the distance between the side of the second lens group facing the object side and the diaphragm is L2, wherein 0.39mm≤L2≤6.76mm.

[0019] Optionally, the optical lens system further comprises a photosensitive chip, the photosensitive chip is arranged on the side of the second lens group facing the image side, and the photosensitive surface of the photosensitive chip faces the second lens group.

[0020] Optionally, a filter is arranged between the photosensitive chip and the second lens group.

[0021] The application further provides a monitoring camera device, which comprises an optical lens system, the optical lens system comprises a plurality of lens groups arranged in sequence from an object side to an image side, and a light axis is formed between the plurality of lens groups, wherein the plurality of lens groups comprise:

[0022] a first lens group having a negative focal length and being movably arranged along the extension direction of the light axis; and

[0023] a second lens group having a positive focal length and being movably arranged along the extension direction of the light axis.

[0024] The image surface compensation is realized by changing the positions of the first lens group and the second lens group.

[0025] In the technical solution, the first lens group and the second lens group are arranged to make the refractive index and Abbe number complementary from the object side to the image side, to ensure small chromatic aberration in the visible wave band and to ensure the resolving power in the infrared wave band, and the conjugate distance change of the first lens group is offset by the conjugate distance change of the second lens group after magnification by adjusting the positions of the first lens group and the second lens group, to realize image surface compensation, and to provide a low-cost, glass-plastic hybrid, high-reliability zoom optical lens system. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0027] Figure 1 The structural schematic diagram of an embodiment of the optical lens system provided by the present application is shown.

[0028] Explanation of reference numerals:

[0029] Reference Name Reference Name 1000 Optical lens system 7 Seventh lens 100 First lens group 8 Eighth lens 1 First lens 9 Ninth lens 2 Second lens 10 Tenth lens 3 Third lens 11 Eleventh lens 200 Second lens group 30 Diaphragm 4 Fourth lens 40 Photosensitive chip 5 Fifth lens 50 Filter 6 Sixth lens

[0030] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0033] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0034] At present, the zoom optical system for monitoring has the following shortcomings: small aperture, high cost, and the zoom process cannot realize infrared confocal at each magnification, the resolution of the lens decreases obviously in high and low temperature environment, etc. At present, only a few lenses on the market improve some aspects at the expense of other aspects, such as to realize infrared confocal at full magnification, all or more glass lenses are used, resulting in increased lens cost and affecting lens promotion and popularization. Or without considering the actual situation of lens use in high and low temperature environment, resulting in more resolution decrease of lens in high and low temperature environment, affecting the picture clarity. Or to reduce the cost of the lens aperture, which cannot meet the use of the lens in dark environment, etc.

[0035] In order to solve the above problems, the present application provides an optical lens system 1000, Figure 1 The specific embodiments of the optical lens system 1000 provided by the present application.

[0036] Please refer to Figure 1 The optical lens system 1000 includes a plurality of lens groups arranged in order from the object side to the image side, and a corresponding optical axis is formed between the plurality of lens groups, wherein the plurality of lens groups include a first lens group 100 and a second lens group 200, the first lens group 100 has a negative focal power and is movably arranged along the extension direction of the optical axis; the second lens group 200 has a positive focal power and is movably arranged along the extension direction of the optical axis; wherein the image plane compensation is realized by changing the positions of the first lens group 100 and the second lens group 200.

[0037] The technical scheme provided by the present application comprises the following steps: setting the first lens group 100 and the second lens group 200 to make the refractive index and the Abbe number complementary from the object side to the image side, to ensure that the chromatic aberration in the visible wave band is small and the resolving effect in the infrared wave band is ensured, and adjusting the positions of the first lens group 100 and the second lens group 200 to make the conjugate distance change amount of the first lens group 100 offset the conjugate distance change amount of the second lens group 200 after magnification, to realize image plane compensation, realize a large aperture of the lens, ensure the real restoration of the imaging picture and color in a dark environment, and provide a large-aperture, high-definition, low-cost zoom optical lens system 1000.

[0038] It can be understood that, in the present application, in order to realize the low cost of the optical lens system, the complementary of the refractive index and the Abbe number of different lens materials is fully considered in the design, and in the case of using as many plastic aspherical surfaces as possible, the performance of the lens and the resolving requirement in high and low temperature environments are ensured.

[0039] It should be noted that the optical power is equal to the difference between the converging degree of the image beam and the converging degree of the object beam, which represents the ability of the optical system to deflect light rays. The negative optical power of the first lens group 100 and the positive optical power of the second lens group 200 can project the light beam in the required design direction.

[0040] Further, in order to improve the imaging quality, in the present embodiment, a diaphragm 30 is arranged between the first lens group 100 and the second lens group 200. The diaphragm 30 limits the on-axis beam aperture to block part of the light in the zooming process, reduces the light spot, improves the image contrast, and helps to improve the image quality.

[0041] Specifically, the conjugate distance change amount of the first lens group 100 offsets the conjugate distance change amount of the second lens group 200 after longitudinal magnification, so as to realize image plane compensation. In order to specifically control the activity range of the first lens group 100 and the second lens group 200, in the present embodiment, the distance between the side of the first lens group 100 facing the image side and the diaphragm 30 is L1, wherein 1mm≤L1≤8.49mm; the distance between the side of the second lens group 200 facing the object side and the diaphragm 30 is L2, wherein 0.39mm≤L2≤6.76mm. It should be noted that the above two associated technical features can be set simultaneously or alternatively.

[0042] Further, in the optical design process, the functions and tasks achieved by the lens group are grouped, and the first lens group 100 includes a first lens 1, a second lens 2, and a third lens 3 arranged in order from the object side to the image side; the second lens group 200 includes a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and an eleventh lens 11 arranged in order from the object side to the image side, wherein the optical power of the fourth lens 4 is positive, the optical power of the fifth lens 5 is negative, the optical power of the sixth lens 6 is positive, the optical power of the seventh lens 7 is positive, the optical power of the eighth lens 8 is negative, the optical power of the ninth lens 9 is positive, the optical power of the tenth lens 10 is negative, and the optical power of the eleventh lens 11 is positive or negative. The surface shape of any one of the above lenses needs to satisfy the following formula:

[0043]

[0044] wherein c corresponds to the reciprocal of the radius R, y is the radial coordinate, k is the conic quadratic curve coefficient, and a1 to a8 are coefficients corresponding to each radial coordinate.

[0045] Further, in the prior art, in order to achieve confocal, control costs, the same type of optical lens system 1000 uses plastic aspherical surface, which results in poor lens reliability and cannot adapt to environments with large temperature differences. In order to make the optical lens system 1000 have good stability, specifically, in the first lens group 100, the first lens 1 is a glass spherical lens, and the second lens 2 and the third lens 3 are plastic aspherical lenses. In the second lens group 200, the sixth lens 6, the ninth lens 9, and the tenth lens 10 are glass spherical lenses, and the fourth lens 4, the fifth lens 5, the seventh lens 7, the eighth lens 8, and the eleventh lens 11 are plastic aspherical lenses. Such arrangement can well correct lens chromatic aberration, achieve infrared confocal under the condition of ensuring lens purple edge control, correct spherical aberration and sinusoidal aberration at high magnification position, and reasonably consider the layout of the lenses, especially the collocation of plastic and glass lenses, which greatly controls the cost.

[0046] Therefore, by reasonably designing the optical parameters and materials of the lenses, the optical lens system 1000 considers the actual use of high and low temperature changes, ensures the focusing state at room temperature 20℃, and ensures the clear resolution in high and low temperature environments (high temperature 70℃ or low temperature -40℃) without the need for refocusing. The system uses plastic materials with small refractive index differences at high and low temperatures, and considers the matching of the change amounts of various lens materials, Abbe numbers, high and low temperature, and the change of air spacing to realize the positive and negative matching of the change amounts of various elements in the high and low temperature environment, and ensure the synchronization and clarity of the image plane in the high and low temperature environment.

[0047] Further, in order to reduce or eliminate chromatic aberration, in the embodiment, the fifth lens 5 is a negative lens, the sixth lens 6 is a positive lens, the fifth lens 5 and the sixth lens 6 are a kind of cemented structure, thereby realizing correction of high-order aberration and chromatic aberration, the seventh lens 7 is a positive lens, the eighth lens 8 is a negative lens, the seventh lens 7 and the eighth lens 8 are a kind of cemented structure; the ninth lens 9 is a positive lens, the tenth lens 10 is a negative lens, the eleventh lens 11 is a positive lens, the ninth lens 9, the tenth lens 10 and the eleventh lens 11 are a kind of three-cemented structure. The overall structure balances the aberration of the whole system, realizes the correction of chromatic aberration, and each lens is provided with vignetting, which blocks the peripheral stray light without affecting the illumination, so that the center and the edge of the image plane ensure the same resolution requirement.

[0048] Specifically, in the embodiment, the optical lens system 1000 further comprises a photosensitive chip 40, which is arranged on the side of the second lens group 200 facing the image side, and the photosensitive surface of the photosensitive chip 40 is arranged to face the second lens group 200, so as to receive an object image on the image side and process the received object image through the photosensitive chip 40.

[0049] Further, the photosensitive chip 40 and the second lens group 200 are provided with a filter 50. The filter 50 can effectively filter out stray light in the non-working waveband to reduce light noise and reduce the difficulty of subsequent photoelectric module processing. The filter 50 can also be used to adjust the color degree of the object image in the final imaging.

[0050] The first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, the tenth lens 10 and the eleventh lens 11 can make the W-end FNO of the optical lens system 1000 reach 1.35, and the lens still has better image surface and color restoration in a darker environment, the entire zooming process realizes complete confocal of infrared, and ensures that the lens can also work normally in a night environment. The optical lens system 1000 still has relatively high clarity in environments of temperatures of 70 DEG C and -40 DEG C, and meets the use in a normal temperature range in a real environment. The optical lens system 1000 can be widely applied to monitoring and meets the resolution requirement of high definition 4K.

[0051] It should be noted that the basic parameter table of the optical lens system 1000 in the embodiment is shown in Table 1, wherein the units of the curvature radius and the thickness are millimeters (mm).

[0052] Table 1

[0053]

[0054]

[0055] The aspheric coefficients of the surfaces are shown in Table 2:

[0056] Table 2

[0057] k [a2] [a3] [a4] a5 <!-- 6 -->]]> S3 1.3461 0 0 0 0 S4 -5.2494 0 0 0 0 S5 -2.466 0 0 0 0 S6 574.26 0 0 0 0 S7 0.56507 -7.5123e-006 -6.5814e-006 0 0 S8 -184.246 0 0 0 0 S9 -4.348 -0.0001194 1.635243e-006 0 0 S10 0.87015 0 0 0 0 S13 16.333 -0.0003316 -3.6214e-006 0 0 S14 -4.094 0 0 0 0 S15 -1.484 0.0006042 -3.6622e-006 3.17247e-008 -2.3948e-008 S16 -3.182 0.0002202 2.76834e-006 0 0 S20 -4.100 -2.4389e-005 -4.0493e-005 0 0 S21 11.687 -0.0003683 -3.9714e-005 0 0

[0058] The application also provides a monitoring camera device, which comprises the optical lens system 1000 described above. The monitoring camera device comprises the optical lens system 1000, and the specific structure of the optical lens system 1000 is referred to the above embodiment. Since the optical lens system 1000 of the monitoring camera device adopts all the technical solutions of the above embodiments, at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0059] The above only describes the preferred embodiments of the application, and does not limit the patent scope of the application. Any equivalent structure transformation based on the application concept, or direct / indirect application in other related technical fields is included in the patent protection scope of the application.

Claims

1. An optical lens system characterized in that, The optical lens system comprises a plurality of lens groups arranged in sequence from an object side to an image side, and an optical axis is formed between the plurality of lens groups correspondingly, wherein the plurality of lens groups comprise: a first lens group having a negative focal length and being movably arranged along an extension direction of the optical axis; and a second lens group having a positive focal length and being movably arranged along the extension direction of the optical axis; wherein image plane compensation is achieved by changing the positions of the first lens group and the second lens group; the first lens group comprises a first lens, a second lens and a third lens arranged in sequence from the object side to the image side; the second lens group comprises a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens arranged in sequence from the object side to the image side, wherein the fourth lens has a positive focal length, the fifth lens has a negative focal length, the sixth lens has a positive focal length, the seventh lens has a positive focal length, the eighth lens has a negative focal length, the ninth lens has a positive focal length, the tenth lens has a negative focal length, and the eleventh lens has a positive or negative focal length; the fifth lens is a negative lens, the sixth lens is a positive lens, and the fifth lens and the sixth lens are a kind of cemented structure; the seventh lens is a positive lens, the eighth lens is a negative lens, and the seventh lens and the eighth lens are a kind of cemented structure; the ninth lens is a positive lens, the tenth lens is a negative lens, the eleventh lens is a positive lens, and the ninth lens, the tenth lens and the eleventh lens are a kind of three cemented structure; an optical stop is arranged between the first lens group and the second lens group.

2. The optical lens system of claim 1, wherein, the first lens is a glass spherical lens, and the second lens and the third lens are plastic aspherical lenses; the fourth lens, the fifth lens, the seventh lens, the eighth lens and the eleventh lens are plastic aspherical lenses.

3. The optical lens system of claim 1, wherein, the sixth lens, the ninth lens and the tenth lens are glass spherical lenses.

4. The optical lens system of claim 1, wherein, a distance between a side of the first lens group facing the image side and the optical stop is L1, wherein 1mm≤L1≤8.49mm; and / or a distance between a side of the second lens group facing the object side and the optical stop is L2, wherein 0.39mm≤L2≤6.76mm.

5. The optical lens system of claim 1, wherein, The optical lens system further comprises a photosensitive chip, the photosensitive chip is arranged on a side of the second lens group facing the image side, and a photosensitive surface of the photosensitive chip faces the second lens group.

6. The optical lens system of claim 5, wherein, A filter is arranged between the photosensitive chip and the second lens group.

7. A surveillance camera device, characterized by comprising: The optical lens system comprises the optical lens system according to any one of claims 1 to 6. The optical lens system comprises the optical lens system according to any one of claims 1 to 6.

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