Optical lens and method for manufacturing the same

Abstract

The present disclosure provides an optical lens, which includes a lens barrel and a plurality of optical lenses, wherein the plurality of optical lenses are sequentially installed in the lens barrel in the direction from the object side to the image side, at least two of the plurality of optical lenses are optical lenses with a filtering function and uneven thickness, the optical lenses with the filtering function respectively have effective optical areas with different light absorption rates, and the light absorption rates of the corresponding effective optical areas in the optical lenses with the filtering function are complementary. In the present disclosure, the optical lens can achieve the same absorption rate of stray light at each point, thereby improving the imaging quality, and can achieve a reduction in overall thickness, meeting the demand for miniaturization.

Description

Technical Field

[0001] The present application relates to the field of optical imaging technology, and in particular, to an optical lens and a method for manufacturing the same. Background Art

[0002] The photosensitive elements used in the camera module can sense light waves outside the visible light band, such as infrared light waves, ultraviolet light waves, etc., which are invisible to the human eye. In the imaging process, unwanted stray light will cause image color distortion, that is, the captured image will show obvious differences from the actual object observed by the human eye, ghosting, halos and other problems.

[0003] In order to solve this problem, optical elements that filter stray light such as infrared light waves and ultraviolet light waves are usually required. In the light filtering process, it is usually necessary to set a filter above the photosensitive element to filter out stray light from the external light irradiating the photosensitive element. Due to the use of the filter, a certain space needs to be reserved for the filter in the camera module, thereby increasing the thickness of the camera module, which obviously does not meet the demand for the continuous pursuit of miniaturization of the camera module.

[0004] However, in the entire camera module, the optical lens cannot be cut arbitrarily, and it is difficult to reduce the thickness of the circuit board and the chip, so other technical concepts that can reduce the thickness of the camera module are urgently needed. Summary of the invention

[0005] The present application provides a solution that can overcome or partially overcome at least one of the deficiencies of the prior art.

[0006] According to one aspect of the present disclosure, there is provided an optical lens, comprising a lens barrel and a plurality of optical lenses, wherein the plurality of optical lenses are sequentially installed in the lens barrel in a direction from an object side to an image side, and characterized in that at least two of the plurality of optical lenses are optical lenses with a filtering function and with uneven thickness, the optical lenses with the filtering function respectively have effective optical areas with different light absorption rates, and the light absorption rates of corresponding effective optical areas in the optical lenses with the filtering function are complementary.

[0007] In an embodiment of the present disclosure, an effective optical area with different light absorption rates is formed on an optical lens with a filtering function by setting at least one of different thicknesses, light absorber density distributions and coatings.

[0008] In an embodiment of the present disclosure, the optical lens having a light filtering function is an optical lens mixed with a light absorber.

[0009] In an embodiment of the present disclosure, the density of the light absorber provided in all optical lenses with filtering function is the same, and the thickness of at least part of the corresponding effective optical areas of at least two optical lenses with filtering function cut along a direction parallel to the optical axis are complementary.

[0010] In an embodiment of the present disclosure, the density of the light absorber provided in all optical lenses with filtering function is the same, and the thickness of at least part of the corresponding effective optical areas in at least two optical lenses with filtering function cut along the light path direction is complementary.

[0011] In an embodiment of the present disclosure, at least a portion of corresponding effective optical areas in at least two optical lenses with filtering function are coated.

[0012] In the embodiment of the present disclosure, the density of the light absorber arranged in all optical lenses with filtering function is different, and the overall light absorber density of the corresponding effective optical areas in at least two optical lenses with filtering function is negatively correlated with the overall thickness.

[0013] In an embodiment of the present disclosure, the light absorber is at least one of an inorganic light absorber and an organic light absorber.

[0014] In an embodiment of the present disclosure, the material of the plurality of optical lenses is at least one of plastic, resin and glass.

[0015] In an embodiment of the present disclosure, the plurality of optical lenses are at least one of a liquid lens and a liquid crystal lens.

[0016] In an embodiment of the present disclosure, the optical lens with filtering function comprises at least a first filter lens and a second filter lens, and the first filter lens and the second filter lens respectively have optical areas with preset light absorption rates.

[0017] In an embodiment of the present disclosure, the first filter lens includes a first optical region having a first light absorption rate and a second optical region having a second light absorption rate, and the second filter lens includes a third optical region corresponding to the first optical region and a fourth optical region corresponding to the second optical region, the third optical region has a third light absorption rate, and the fourth optical region has a fourth light absorption rate, wherein the overall light absorption rate of the first optical region and the third optical region is substantially equal to the overall light absorption rate of the second optical region and the fourth optical region.

[0018] In an embodiment of the present disclosure, the multiple optical lenses include five lenses arranged in sequence along the optical path of the optical lens, the first filter lens is the lens among the five lenses, which is located on the side away from the photosensitive chip, and the second filter lens is the lens among the five lenses, which is located on the side close to the photosensitive chip.

[0019] In an embodiment of the present disclosure, the complementarity of light absorption rates of corresponding effective optical areas in the optical lens with filtering function is achieved by complementarity of thickness integrals of the corresponding effective optical areas.

[0020] In an embodiment of the present disclosure, the light absorption rates of the corresponding effective optical areas in the optical lens with filtering function are complemented by the thickness integral of the corresponding effective optical areas and the brightness weighting of the corresponding effective optical areas.

[0021] According to another aspect of the present disclosure, a method for manufacturing an optical lens is provided, the method comprising mixing a light absorber into at least two optical lenses among a plurality of optical lenses during a molding process; making corresponding effective optical areas of the at least two optical lenses mixed with the light absorber have complementary light absorption rates by at least one of thickness variation, light absorber density variation and coating; and arranging the plurality of optical lenses in sequence in a lens barrel.

[0022] In an embodiment of the present disclosure, the density of the light absorber in at least two optical lenses is the same, and the thickness of at least part of the corresponding effective optical areas in at least two optical lenses cut along a direction parallel to the optical axis are complementary.

[0023] In an embodiment of the present disclosure, the density of the light absorber in at least two optical lenses is the same, and the thickness of at least part of the corresponding effective optical areas in at least two optical lenses cut along the light path direction are complementary.

[0024] In an embodiment of the present disclosure, at least a portion of the corresponding effective optical areas in at least two optical lenses are coated.

[0025] In an embodiment of the present disclosure, the density of the light absorber in at least two optical lenses is different, and the overall light absorber density of the corresponding effective optical areas in the at least two optical lenses is correlated to the overall thickness.

[0026] In an embodiment of the present disclosure, the light absorber is at least one of an inorganic light absorber and an organic light absorber.

[0027] In an embodiment of the present disclosure, the material of the plurality of optical lenses is at least one of plastic, resin and glass.

[0028] In an embodiment of the present disclosure, the plurality of optical lenses are at least one of liquid lenses and liquid crystal lenses.

[0029] According to another aspect of the present disclosure, an optical lens is provided, which includes a lens barrel and a plurality of optical lenses, wherein the plurality of optical lenses are sequentially installed in the lens barrel, one of the plurality of optical lenses is an optical lens with a filtering function and having an uneven thickness, and the optical lens with the filtering function has a plurality of effective optical areas containing light absorbers, and is characterized in that the density of the light absorbers in the plurality of effective optical areas is different, and the overall light absorption rate of each of the plurality of effective optical areas is uniform.

[0030] In an embodiment of the present disclosure, the thickness of each of the plurality of effective optical regions is inversely proportional to the density of the light absorber.

[0031] In an embodiment of the present disclosure, the light absorber is at least one of an inorganic light absorber and an organic light absorber.

[0032] In an embodiment of the present disclosure, the material of the plurality of optical lenses is at least one of plastic, resin and glass.

[0033] In an embodiment of the present disclosure, the plurality of optical lenses are at least one of a liquid lens and a liquid crystal lens.

[0034] Compared with the prior art, the present invention has at least one of the following technical effects:

[0035] 1. In some embodiments of the present disclosure, an optical lens having effective optical areas with different light absorption rates is used, and the light absorption rates of corresponding effective optical areas of at least two optical lenses with color filtering functions are made complementary through at least one of thickness, light absorber distribution and coating.

[0036] 2. In some embodiments of the present disclosure, a coating is used to compensate for stray light absorption at positions where the stray light absorption rate is low, thereby making the stray light absorption rate at various positions of the optical lens the same.

[0037] 3. In some embodiments of the present disclosure, the optical lens can achieve the same absorption rate of stray light at each point, thereby improving the imaging quality.

[0038] 4. In some embodiments of the present disclosure, the optical lens can achieve a reduction in overall thickness, meeting the demand for miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Exemplary embodiments are shown in the referenced drawings. The embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive.

[0040] Figure 1 is a schematic cross-sectional view showing an optical lens according to an embodiment of the present disclosure.

[0041] Figure 2 is a cross-sectional view showing an optical lens with a filtering function according to an embodiment of the present disclosure.

[0042] Figure 3 is a schematic diagram showing the incident Figure 2 Schematic diagram of the eight light rays of the optical lens with filtering function.

[0043] Figure 4 is a schematic diagram showing the incident Figure 2 Schematic diagram of two groups of light beams in an optical lens with filtering function.

[0044] Figure 5 is a cross-sectional view showing an optical lens with a filtering function according to another embodiment of the present disclosure.

[0045] Figure 6 is a cross-sectional view showing an optical lens with a filtering function according to another embodiment of the present disclosure.

[0046] Figure 7 2 is a cross-sectional view showing an optical lens with a filtering function and an optical lens with a coating according to another embodiment of the present disclosure.

[0047] Figure 8 A method of manufacturing an optical lens according to an embodiment of the present disclosure is shown.

[0048] 9A to 9C is a schematic diagram showing the imaging effect of the detection optical lens according to an embodiment of the present disclosure.

[0049] Fig. 10A FIG. 4 is a schematic diagram showing that different effective optical areas in a filter lens have different densities of light absorbers according to an embodiment of the present disclosure.

[0050] Fig. 10B A schematic diagram of a mold for manufacturing optical lenses with different light absorber densities is shown.

[0051] Fig.11 Schematic diagram showing the change in the distribution of light absorbers by electric or magnetic fields.

[0052] Fig.12 and Fig.13 An optical lens with a filtering function according to another embodiment of the present disclosure is shown.

[0053] Fig.14 Detailed description is given of an optical lens with a light filtering function according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0054] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0055] It should be noted that in this specification, the expressions of first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Therefore, without departing from the teaching of this application, the first subject discussed below can also be referred to as the second subject.

[0056] It should be understood that when a first element is referred to as being "on", "connected to" or "coupled to" a second element, the first element may be directly on, directly connected to or coupled to the second element, or one or more intermediate elements may exist between the first and second elements. In contrast, when a first element is referred to as being directly "on", "directly connected to" or "directly coupled to" a second element, there are no intermediate elements between the first and second elements.

[0057] In the drawings, the thickness, size and shape of objects have been slightly exaggerated for ease of explanation. The drawings are only examples and are not drawn strictly to scale.

[0058] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, wholes, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, parts and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0059] As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation, not degree, and are intended to account for the inherent variations in measurements or calculations that would be recognized by those of ordinary skill in the art.

[0060] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0061] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. In this application, the vertical direction is a direction parallel to the optical axis of the optical lens.

[0062] In the present application, the term "complementary light absorption rates of corresponding areas" means that the overall light absorption rates of each effective optical area are uniform (for example, approximately uniform). Specifically, assuming that the first lens has a first optical area and a second optical area, and the second lens has a third optical area and a fourth optical area, the first optical area corresponds to the third optical area, and the second optical area corresponds to the fourth optical area, then the complementary light absorption rates of the corresponding optical areas means that the overall light absorption rates of the first optical area and the third optical area are equal to the overall light absorption rates of the second optical area and the fourth optical area (for example, approximately equal).

[0063] Similar to the term "light absorptivity of corresponding regions is complementary", the term "thickness of corresponding regions is complementary" means that the overall thickness of each effective optical region is uniform (eg, approximately uniform).

[0064] In the present application, the optical lens with filtering function forms optical areas with different light absorption rates through thickness design, light absorber density distribution design, and coating design. Figures 1 to 4 An optical lens with filtering function is described in which the light absorption rates of corresponding effective optical areas are complementary through thickness design.

[0065] Figure 1 is a schematic cross-sectional view showing an optical lens according to an embodiment of the present disclosure.

[0066] refer to Figure 1 The optical lens 100 includes a lens barrel 110 and optical lenses 120-160, and the optical lenses 120-160 are sequentially arranged in the lens barrel 110 from the object side to the image side. At least two of the optical lenses 120-160 are optical lenses with a filtering function, and the thickness of the at least two optical lenses with a filtering function is uneven.

[0067] In this embodiment, the optical lenses 120 and 140 are optical lenses with a filtering function, but the present disclosure is not limited thereto. A person skilled in the art should understand that the position and number of the optical lenses with a filtering function are not limited to Figure 1 For example, in other embodiments, the number of optical lenses with filtering function may be three, four, five, etc., and as long as the technical concept of the present disclosure can be realized and the optical requirements of the optical system can be met, the positional relationship between the optical lenses with filtering function and the ordinary optical lenses is not particularly limited. For example, in this embodiment, the optical lenses 120, 150 and 160 may be optical lenses with filtering function. Figure 2 and Figure 3 The structure and positional relationship between optical lenses with filtering function are specifically described.

[0068] In this embodiment, in order to realize an optical lens with a filtering function, a light absorber can be uniformly mixed into an ordinary optical lens. In this embodiment, the light absorber can be an organic light absorber or an inorganic light absorber. The organic light absorber can be, but is not limited to, a cyanine derivative (such as a cyanine dye), an indocyanine derivative (such as an indocyanine dye), a phthalocyanine derivative (such as a phthalocyanine dye), a naphthalocyanine derivative (such as a naphthalocyanine dye), a metal complex of a phthalocyanine derivative, a metal complex of a naphthalocyanine derivative, a metal complex of a dithiolene derivative, a benzoquinone derivative (such as a benzoquinone dye), an anthraquinone derivative (such as an anthraquinone dye), a naphthoquinone derivative (such as a naphthoquinone dye), an azo derivative (such as an azo dye), a porphyrin derivative (such as a porphyrin dye) , porphyrin derivatives (such as porphyrin dyes), corrole derivatives (such as corrole dyes), squaric acid derivatives (such as squaric acid dyes), squaric acid cyanine derivatives (such as squaric acid cyanine dyes), boron fluoride complex dipyrromethene compounds (such as boron fluoride complex dipyrromethene dyes), diimmonium derivatives (such as diimmonium dyes) and methylene blue derivatives (such as methylene blue dyes). The cyanine dye can be an organic light absorber such as Cy5, Cy5.5 or Cy7, which is available on the market or can theoretically achieve light absorption effects.

[0069] The inorganic light absorber can be light absorbing particles or nano-scale light absorbers, such as nano-silicon dioxide, nano-titanium dioxide, titanium pentoxide, zirconium dioxide, gallium pentoxide, niobium pentoxide, H4, silicon dioxide, magnesium fluoride, etc., but the present disclosure is not limited thereto, and other commonly used inorganic materials used as light absorbers can also be used.

[0070] The light absorber may be mixed into the corresponding lens in a particulate state that does not affect imaging, and may also be a material that is incorporated or dissolved into the lens.

[0071] In the embodiments of the present disclosure, the optical lens may be at least one of plastic, resin and glass. In addition, the optical lens may also be a liquid lens or a liquid crystal lens. Without departing from the present disclosure, other materials for manufacturing lenses may also be used.

[0072] In the embodiment of the present disclosure, the light absorber may be a light absorbing material that filters out light in the wavelength range of 760nm to 1500nm and the wavelength range of 10nm to 400nm, and may also be a light absorbing material that filters out light in the wavelength range of 760nm to 1500nm alone or a light absorbing material that filters out light in the wavelength range of 10nm to 400nm alone. However, the present disclosure is not limited thereto, and those skilled in the art may select a light absorbing material that can absorb a specific wavelength range according to design requirements. For example, in the application of infrared cameras, it is necessary to filter light waves in other bands except infrared light, so a light absorbing material that can filter out light in other bands except the infrared wavelength range is added to the filter lens. In addition, for example, if it is necessary to filter out light in the wavelength range of 200nm to 400nm, a light absorbing material that can filter out light in the wavelength range of 200nm to 400nm is added to the filter lens. Therefore, the optical system according to the present disclosure can be applied to applications where it is necessary to filter out light in a specific wavelength range, such as microscopic imaging, biological imaging or other special imaging. In an embodiment of the present disclosure, a plurality of light absorbers may be mixed into an optical lens simultaneously.

[0073] In the following we will refer to Figures 2 to 4 The structure and positional relationship of an optical lens with a filtering function according to the disclosed embodiment are described in detail. Figure 2 A cross-sectional view of an optical lens with a filtering function according to an embodiment of the present disclosure is shown. Figure 3 The schematic diagram shows the incident Figure 2 The eight rays of light from the optical lens with filtering function. Figure 4 The incident Figure 2 Two groups of light beams in the optical lens with filtering function.

[0074] exist Figures 2 to 4 In the description, the lens barrel and common optical lenses are omitted for the convenience of description. Figures 2 to 4 Only the cross-sectional view of the optical lens with filtering function is shown. Figures 2 to 4 In the description, an optical lens including two optical lenses with filtering function is taken as an example, wherein the density of the light absorber in the two optical lenses with filtering function is equal.

[0075] exist Figure 2In the embodiment, the first optical lens 210 and the second optical lens 220 are optical lenses with a filtering function. The materials of the optical lenses and the light absorbers contained therein are consistent with those described above, so their description will be omitted. Figure 2 In the embodiment, the first optical lens 210 is a convex lens and the second optical lens 220 is a concave lens, but the present disclosure is not limited thereto, and the first optical lens 210 may be a concave lens and the second optical lens 220 may be a convex lens. Figure 2 As shown in , the first optical lens 210 has a first optical region 211 and a second optical region 212, and the second optical lens 220 has a third optical region 221 and a fourth optical region 222, wherein the first optical region 211, the second optical region 212, the third optical region 221 and the fourth optical region 222 are effective optical regions. The first optical region 211 has a first thickness d1 cut along a direction parallel to the optical axis at points a and c, the second optical region 212 has a second thickness d2 cut along a direction parallel to the optical axis at point b, the third optical region 221 has a third thickness d3 cut along a direction parallel to the optical axis at points d and f, and the fourth optical region 222 has a fourth thickness d4 cut along a direction parallel to the optical axis at point e. Wherein, a, b, and c are three points randomly selected on the first optical lens 210, and d, e, and f are three points corresponding to a, b, and c respectively on the second optical lens 220. Since d, e, and f correspond to a, b, and c respectively, for the sake of simplicity, in the following description, a, b, and c points will be used instead of d, e, and f. Figure 2As shown in , the first thickness d1 is less than the second thickness d2, and the third thickness d3 is greater than the fourth thickness d4. However, the present embodiment is not limited thereto, for example, the first thickness d1 is greater than the second thickness d2, and the third thickness d3 is less than the fourth thickness d4. Ideally, the sum of the first thickness d1 and the third thickness d3 is equal to the sum of the second thickness d2 and the fourth thickness d4. That is, the thicknesses of the corresponding optical areas cut in the direction parallel to the optical axis in the first optical lens 210 and the second optical lens 220 have a complementary relationship. However, due to the existence of manufacturing errors, the ideal state is usually not met. Therefore, in this embodiment, d1, d2, d3 and d4 need to satisfy the following thickness relationship formula: ((d1+d3)-(d2+d4)) / D*100%≤Y%, where D is the sum of thicknesses at any point, that is, in this embodiment, D is the sum of thicknesses at point a or point c (i.e., d1+d3) or the sum of thicknesses at point b (i.e., d2+d4), 0≤Y≤30, further, 0≤Y≤10, and further, 0≤Y≤5. Since a, b, and c are three randomly selected points, the thicknesses of the corresponding optical areas cut along the direction parallel to the optical axis at other positions should also satisfy the above formula, that is, have a complementary relationship. However, those skilled in the art should understand that the above description is given only as an example, and the division and thickness of the optical area of ​​the optical lens with filtering function are not limited to the above example. Under the condition of meeting the overall optical system requirements of the optical lens, as long as the sum of the thicknesses cut along the direction parallel to the optical axis at the corresponding positions of the two filtering lenses at any two positions satisfies the above formula, the thicknesses of the two optical lenses with filtering function at various positions can be arbitrarily designed.

[0076] exist Figure 3In the figure, eight light rays are respectively incident on the first optical lens 210. Among them, the optical path of the first light ray 1 in the first optical lens 210 is X1, and the optical path in the second optical lens 220 is X1', the optical path of the second light ray 2 in the first optical lens 210 is X2, and the optical path in the second optical lens 220 is X2', the optical path of the third light ray 3 in the first optical lens 210 is X3, and the optical path in the second optical lens 220 is X3', the optical path of the fourth light ray 4 in the first optical lens 210 is X4, and the optical path in the second optical lens 220 is X4', the optical path of the fifth light ray 5 in the first optical lens 210 is X5, and the optical path in the second optical lens 220 is X5', the optical path of the sixth light ray 6 in the first optical lens 210 is X6, and the optical path in the second optical lens 220 is X6', the optical path of the seventh light ray 7 in the first optical lens 210 is X7, and the optical path in the second optical lens 220 is X7', and the optical path of the eighth light ray 8 in the first optical lens 210 is X1, and the optical path in the second optical lens 220 is X8'. In the above description, the optical paths of the eight light rays in the first optical lens 210 and the second optical lens 220 may be the thickness cut in the first optical lens 210 and the second optical lens 220 along the optical path direction. In the embodiment of the present disclosure, through reasonable design, the thicknesses of the corresponding optical areas cut in the first optical lens 210 and the second optical lens 220 along the optical path direction have a complementary relationship, that is, X1+X1'=X2+X2'=X3+X3'=X4+X4'=X5+X5'=X6+X6'=X7+X7'=X8+X8', so that any two light rays have an equivalent light absorption effect in the two optical lenses with filtering functions, thereby improving the imaging quality.

[0077] However, those skilled in the art should understand that in the actual production and manufacturing process, there may be manufacturing tolerances, and it is difficult to achieve perfect complementarity between the different light absorption rate areas between the filter lenses, that is, it is difficult to achieve perfect complementarity in the thickness of the corresponding optical areas cut along the optical path. Therefore, in the embodiments of the present disclosure, the thicknesses of corresponding optical areas cut along the optical paths of any two light rays in two optical lenses with filtering functions must satisfy the following relationship formula, that is, assuming that the number of light rays is H, and any two of them are m and n, and the optical path difference between any two light rays is |Xm+Xm'-Xn-Xn'|, then it must satisfy 0≤|Xm+Xm'-Xn-Xn'| / ave{|X1+X1'-X2-X2'|,|X1+X1'-X3-X3'|,…,|X1+X1'-XH-XH'|,|X2+X2'-X3-X3'|,…,|Xm+Xm'-Xn-Xn'|,...,|XH-1+XH-1'-XH-XH'|}≤400%, and further, its range is 0 to 50%. The percentage of the difference in the absorption ratio of the specific wavelength band of each designated light beam to the total absorption is between 0% and 50%, and further, between 0.1% and 30%. In this way, the difference in the total thickness of any two light beams in the optical lens with filtering function is within a certain range, which minimizes the difference in the total thickness, making the light absorption rate at each position of the optical lens roughly the same, thereby improving the imaging quality.

[0078] Furthermore, when the light source is a non-uniform light source, the influence of the brightness distribution needs to be considered, that is, when calculating, it is necessary to perform weighted calculation according to the brightness of the light itself. Suppose the brightness at X1 is S1, the brightness at X2 is S2, ..., and the brightness at Xn is Sn. In the case where the light source is a non-uniform light source, the following formula needs to be satisfied. That is, assuming that the number of light rays is H, and any two of them are m and n, and the optical path difference between any two light rays is |Xm+Xm'-Xn-Xn'|, then the following formula needs to be satisfied: Formula 0≤|SmXm+SmXm'-SnXn-SnXn'| / ave{|S1X1+S1X1'-S2X2-S2X2'|,|S1X1+S1X1'-S3X3-S3X3'|,…,|S1X1+S1 X1'-SHXH-SHXH'|,|S2X2+S2X2'-S3X3-S3X3'|,…,|SmXm+SmXm'-SnXn-SnXn'|,…,|SH-1XH-1+Sh-1XH-1'-

[0079] SHXH-SHXH'|}≤400%, wherein S represents the brightness of light passing through the first filter lens, S' represents the brightness of light passing through the second filter lens, S" represents the thickness of light passing through the third filter lens, and so on. It can be seen that S>S'>S">….

[0080] Taking into account the brightness, that is, the non-uniform light source, and in combination with the design conditions described above, a secondary design can also be performed based on the distribution of the light source, that is, in places with higher brightness, while meeting optical conditions, additional light intensity reduction settings can be added, such as appropriately increasing the thickness, reflective film, absorption film, etc.

[0081] exist Figure 4 In FIG. 1 , it is assumed that there are H light beams in total. For the convenience of description, two arbitrary light beams are shown. Let light beam i be the first light beam i and light beam j be the second light beam j. The first light beam i and the second light beam j are incident on the first optical lens 210 and the second optical lens 220 respectively. Figure 4 As shown in , at the first optical lens 210. Define the leftmost light ray of the first light beam i as Xni, the rightmost light ray of the first light beam i as Xmi, the leftmost light ray of the second light beam j as Xnj, and the rightmost light ray of the second light beam j as Xmj. At the second optical lens 220, define the leftmost light ray of the first light beam i as Xni', the rightmost light ray of the first light beam i as Xmi', the leftmost light ray of the second light beam j as Xnj', and the rightmost light ray of the second beam j as Xmj'. In this embodiment, taking the first light beam i at the first optical lens 210 as an example, there are finite but difficult to count rays between Xni and Xmi, so by integrating between Xni and Xmi, the thickness integral of the first light beam i along the optical path direction at the first optical lens 210 can be obtained as Similarly, the thickness integral of the first light beam i along the light path direction at the second optical lens 220 is obtained as Therefore, the total thickness of the first light beam i in the first optical lens 210 and the second optical lens 220 along the optical path direction is Similarly, the total thickness of the second light beam j along the optical path in the first optical lens 210 and the second optical lens 220 is Among them, i and j are two groups of light beams randomly selected from all the light beams passing through the filter lens, which are consistent with the above reference Figure 3Similar to the relationship described, the relationship between the sum of the thicknesses of any two groups of light beams along the optical path in two optical lenses with filtering functions needs to satisfy the following relationship formula: 0≤|Fi(X)-Fj(x)| / ave{|F1(X)-F2(X)|,|F1(X)-F3(X)|,|F1(X)-F4(X)|,…,|Fi(X)-Fj(x)|,…,|F1(X)-FH(X)|,|F2(X)-F3(X)|,|F2(X)-F4(X)|,…,|F2(X)-FH(X)|,…,|F(H-1)(X)-FH(X)|}≤400%, furthermore, 0≤|Fi(X)-F j(x)| / ave{|F1(X)-F2(X)|,|F1(X)-F3(X)|,|F1(X)-F4(X)|,…,|Fi(X)-Fj(x)|,…,|F1(X)-FH(X)|,|F2(X)-F3(X)|,|F2(X)-F4(X)|,…,|F2(X)-FH(X)|,…,|F(H-1)(X)-FH(X)|}≤50%. In the above relationship formula, the numerator represents the difference in the sum of the thicknesses along the optical path direction between the first light beam i and the second light beam j, and the denominator represents the average value of the difference in the sum of the thicknesses along the optical path direction between any two groups of light beams incident into the optical lens.

[0082] Considering the light intensity at different positions, the light intensity of beam i is Si, the light intensity of beam j is Sj, and the light intensity at point H is SH, that is, the following formula exists at the beam: Therefore, the following relationship formula needs to be satisfied: 0≤|SiFi(X)-SjFj(x)| / ave{|S1F1(X)-S2F2(X)|,|S1F1(X)-S3F3(X)|,|S1F1(X)-S4F4(X)|,…,|SiFi(X)-SjFj(x)|,…,|S1F1(X)-SHFH(X)|,|S2F2(X)-S3F3(X)|,|S2F2(X)-S4F4(X)|,…,|S2F2(X)-SHFH(X)|,…,|S(H-1)F(H-1)(X)-SHFH(X)|}≤4 00%, further, satisfies 0≤|SiFi(X)-SjFj(x)| / ave{|S1F1(X)-S2F2(X)|,|S1F1(X)-S3F3(X)|,|S1F1(X)-S4F4(X)|,…,|SiFi(X)-SjFj(x)|,…,|S1F1(X)-SHFH(X)|,|S2F2(X)-S3F3(X)|,|S2F2(X)-S4F4(X)|,…,|S2F2(X)-SHFH(X)|,…,|S(H-1)F(H-1)(X)-SHFH(X)|}≤50%.

[0083] In this embodiment, the two optical sheets with filtering function need to meet the reference Figure 2 The relationship formula given, and also need to satisfy the reference Figure 3 and Figure 4 The relationship formula is given.

[0084] However, in order to satisfy the thickness relationship of the filter sheet cut along the direction parallel to the optical axis and the direction of the optical path, the filter sheet needs to be tested. The following description will respectively give the measurement of the thickness relationship of the corresponding optical area of ​​the filter sheet cut along the direction parallel to the optical axis and along the direction of the optical path.

[0085] For measuring the thickness of the corresponding optical area of ​​the filter lens along the direction parallel to the optical axis, firstly, slice the plurality of filter lenses along the direction parallel to the optical axis, and then scan and measure them by laser or directly measure them by high-precision measuring tools, such as reference Figure 2 As described above, when designing the shape of the filter lens, the thickness of the corresponding optical area cut along the direction parallel to the optical axis needs to be complementary, that is, to meet the reference Figure 2 By this method, the thickness of the corresponding optical areas at a limited and maximum number of positions is measured, so that the thickness of any two corresponding optical areas is complementary and meets the reference Figure 2 Furthermore, since the above thickness relationship formula is valid within a certain range, the relationship between the overall thickness and difference at each position of the filter lens and the corresponding imaging effect can be continuously measured, so as to find the acceptable variation of the overall thickness and difference at each position of the filter lens for imaging, which improves the design freedom of the optical system.

[0086] For the measurement of the thickness of the corresponding optical area of ​​the filter lens along the optical path direction, the filtering optical path of the light in the filter lens can be obtained by directly measuring the length of the optical path. That is, a laser with a very small diameter is used to illuminate any position of the optical system in a dark state (under a darker environment), and the thickness of the corresponding optical area cut along the optical path direction is represented by the laser path, and the optical path of the laser path is directly measured to obtain the filtering optical path.

[0087] In addition, the relationship between the filter optical path and the filter ratio can also be measured by indirect measurement methods.

[0088] First, in an absolutely dark environment, a point laser light source is used to illuminate a certain position of the optical system, and the laser intensity at the exit position corresponding to the laser light is collected. Then, the length of the filter optical path at this time is measured, and multiple random points are selected for measurement, and then the corresponding relationship between the laser intensity and the filter optical path is obtained.

[0089] Then, under dark conditions, a light source simulating the light in nature is given to the optical system in the light band that needs to be filtered. The optical system is illuminated by this light source, and the intensity of the stray light at multiple exit points is randomly selected. The percentage relationship between the stray light intensity at the exit point and the original stray light intensity is calculated, and the filtering ratio of each exit point is calculated at this time. Then, the filtering optical path of these multiple exit points is measured, and finally the corresponding relationship between the filtering optical path and the filtering ratio is calculated.

[0090] Since the correspondence between laser intensity and filter optical path and the correspondence between filter optical path and filter ratio have been obtained, the correspondence between laser intensity and filter ratio can be calculated. Optical path measurement is difficult and requires slicing and other means to achieve. In the mass production process, it cannot meet the production test requirements. Indirectly measuring the filter ratio with laser intensity can facilitate the test of lenses containing filter lenses and meet the test requirements.

[0091] Furthermore, the density of the light absorber in at least two optical lenses with filtering function may be different, wherein the overall thickness of the effective optical area with a high overall light absorber density is small, and the overall thickness of the effective optical area with a low overall light absorber density is large.

[0092] Furthermore, the overall light absorption rate of the corresponding effective optical areas in at least two optical lenses with filtering function can be changed by coating design, which will refer to Fig.14 Describe in detail.

[0093] Figure 5 is a cross-sectional view of an optical lens with a filtering function according to another embodiment of the present disclosure, which shows the incident light when shooting a close-up. Figure 6 is a cross-sectional view of an optical lens with a filtering function according to another embodiment of the present disclosure, which shows a case where parallel light is incident.

[0094] refer to Figure 5 and Figure 6 , except for the different light incidence method, the rest is the same as the reference Figures 2 to 4 Therefore, these two embodiments will not be described in detail. That is, in the case of blurry imaging when shooting close-up and in the case of incident parallel light, the thickness of the corresponding optical area of ​​the optical lens with filtering function needs to meet the reference Figure 2 The relationship formula given (thickness cut along the direction parallel to the optical axis) and meets the reference Figure 3 and Figure 4 The relationship formula given is (the thickness cut along the optical path direction). In addition, due to the reversibility of the optical path, the absorption optical path difference and absorption ratio difference between any two conjugate image points also need to satisfy the above formula.

[0095] Further, similar to the case where the optical lens includes two optical lenses with filtering functions, when the optical lens includes three optical lenses with filtering functions, it is necessary to design the thickness of the corresponding optical areas of the light and / or light beam in the three optical lenses with filtering functions so that the thickness of the corresponding optical areas at any position of the three optical lenses with filtering functions satisfies the above relationship formula, thereby improving the imaging quality. By analogy, in accordance with the teachings of the present disclosure, the optical lens may also include four or more optical lenses with filtering functions.

[0096] Figure 7 2 is a cross-sectional view showing an optical lens with a filtering function and an optical lens with a coating according to another embodiment of the present disclosure. For the convenience of description, the lens barrel and other common optical lenses in the optical lens are omitted. Figure 7 As shown in , the third optical lens 710 is an optical lens with a filtering function in which a light absorber is mixed, and the type of the light absorber is similar to the type of the light absorber described above. The fourth optical lens 720 is an ordinary optical lens used in an optical lens, and a coating 730 is provided on the fourth optical lens 720. In this embodiment, the coating 730 may be a reflective coating. The reflective coating may partially reflect stray light incident thereon, wherein the greater the incident angle between the stray light and the reflective coating, the higher the reflectivity of the reflective coating to the stray light, thereby compensating for the stray light absorption rate at a low stray light absorption rate.

[0097] Further, in accordance with the technical teachings of the present disclosure, the number of optical lenses with a filtering function may be two or more. In addition, a reflective coating may also be provided on the optical surface of the optical lens with a filtering function. The reflective coating may further be provided on the surface of the optical lens away from the photosensitive element. In this case, an anti-reflection film may be provided on the surface of the optical lens close to the photosensitive element to increase the transmittance of visible light. In addition, two or more reflective coatings may also be provided. Further, a reflective coating may be provided on a partial optical surface (i.e., not on all optical surfaces) of any optical lens of the optical lens. The reflective coating may also be a combination of multilayer coatings.

[0098] In the embodiments of the present disclosure, the coating is a reflective optical film, and there are multiple types of reflective optical films. Multiple types of optical films can be used in combination to reflect light waves in the wavelength range of 760nm to 1500nm (infrared light) and light waves in the wavelength range of 10nm to 400nm (ultraviolet light) in natural light, so as to achieve the function of assisting the filter lens to filter light. In addition, a coating that can filter out stray light in a specific wavelength range can be selected according to design requirements. For example, during infrared imaging or ultraviolet imaging, visible light is filtered out as stray light. In the following, the structure and positional relationship between the coating and the optical lens with filtering function will be described in detail.

[0099] like Figure 7 As shown in , the third light beam 740 and the fourth light beam 750 are respectively incident on the third optical lens 710. Since the third optical lens 710 is a concave lens, which is a structure that is thin in the middle and thick on both sides and is mixed with a uniform light absorber, the light absorption rate of the optical area of ​​the third optical lens 710 where the third light beam 740 passes through is lower than the light absorption rate of another optical area of ​​the third optical lens 710 where the fourth light beam 750 passes through, that is, the optical path represented by the thickness of the filter lens passed by the third light beam 740 in the third optical lens 710 is shorter than the optical path represented by the thickness of the filter lens passed by the fourth light beam 750 in the third optical lens 710. Therefore, the third optical lens 710 has different absorbances to stray light (for example, infrared light and ultraviolet light) in the third light beam 740 and the fourth light beam 750. As shown in Figure 7 As shown in , when the third light beam 740 is incident, the optical path represented by the thickness of the filter lens traveling in the third optical lens 710 is shorter, and the filter lens has a lower absorption rate of stray light for the light beam 740, thereby allowing more stray light to pass through. When the fourth light beam 750 is incident, the optical path represented by the thickness of the filter lens traveling in the third optical lens 710 is longer than the optical path represented by the thickness of the filter lens traveling in the third optical lens 710 of the third light beam 740. Therefore, compared with the third light beam 740, the light absorption rate of the filter lens for the fourth light beam 750 is higher. This results in obvious filtering differences in the stray light filtered out of the light emitted from different positions of the third optical lens 710, resulting in large differences in the intensity of light emitted from different positions.

[0100] In this embodiment, in order to ultimately make the light absorbance at each position of the entire optical lens the same, a coating 730 may be provided on the fourth optical lens 720. The coating 730 may be a reflective coating, which may partially reflect stray light incident thereon. When the angle between the reflective coating and the stray light incident thereon is smaller (i.e., the larger the incident angle), the higher the reflection efficiency of the stray light is, and thus the stray light absorption at the low stray light absorption rate can be compensated. Therefore, in this embodiment, the angle between the coating at the central position and the stray light incident thereon has a first angle α, and the angle between the coating at the edge position and the stray light incident thereon has a second angle β, and the first angle α is less than the second angle β, that is, the incident angle of the stray light incident on the coating at the central position is greater than the incident angle of the stray light incident on the edge position. In this embodiment, the fourth optical lens 720 is designed to be relatively flat in the central position and relatively steep in the edge position, so the angle between the coating 730 at the central position and the stray light incident thereon is smaller than the angle between the coating 730 at the edge position and the coating 730 at the edge position, that is, the first angle α is smaller than the second angle β, that is, the incident angle of the stray light at the central position is greater than the incident angle of the stray light at the edge position. As described above, the coating 730 at the central position can reflect more stray light, thereby compensating for the stray light absorption rate of the third light beam 740, so that the stray light absorption rate of the optical lens at each position finally achieves an equivalent imaging effect. This improves the imaging quality.

[0101] Furthermore, in other embodiments of the present disclosure, as long as the stray light absorption rate of a light beam with a lower stray light absorption rate can be compensated, the location and type of the coating are not particularly limited.

[0102] Figure 8 A method of manufacturing an optical lens according to an embodiment of the present disclosure is shown.

[0103] refer to Figure 8 In step 810, a light absorber is mixed into at least two of the plurality of optical lenses during the molding process, wherein the light absorber may be an organic light absorber and an inorganic light absorber as described above. Further, a light absorber that filters out stray light of a specific wavelength band may be selected according to design requirements. In addition, the material of the plurality of optical lenses may be at least one of plastic, resin, and glass. Further, the plurality of optical lenses may be liquid lenses.

[0104] In step 820, on the basis of satisfying the optical imaging conditions, at least two optical lenses mixed with light absorbers are further processed by at least one of thickness change, light absorber density change and coating, so that the corresponding effective optical areas in at least two optical lenses with filtering function have complementary light absorption rates, wherein the implementation method of making the corresponding effective optical areas have complementary light absorption rates by light absorber density change and coating will be described in detail below.

[0105] In step 830, a plurality of optical lenses are sequentially arranged in a lens barrel.

[0106] 9A to 9C is a schematic diagram showing the imaging effect of the detection optical lens according to an embodiment of the present disclosure. Fig. 9A , Fig. 9B and Fig. 9C The imaging effects of the optical lens at the focal position, the upper limit position and the lower limit position are respectively shown.

[0107] When the optical lens according to the disclosed implementation is completed according to the design, it is necessary to perform an open image test on the optical lens, that is, to test its imaging effects at the focal position, the upper limit position, and the lower limit position respectively. Since the optical path of the incident light in the optical lens with a filtering function will also change when the position of the optical lens changes, it is necessary not only to test its imaging effect at the focal point, but also to measure and set its imaging effect at the upper and lower limit positions. Only when the imaging effects at the three positions meet the requirements can the various parameters of the optical lens be finally determined. Otherwise, it is necessary to continue to modify so that the optical lens has approximately the same stray light absorption rate at the three positions.

[0108] Fig. 10A 2 is a schematic diagram of a filter lens according to an embodiment of the present disclosure in which the density of light absorbers in different effective optical areas is different. It is the same as the optical lens described above except that light absorbers of different densities are mixed therein, so repeated description will be omitted. Fig. 10A In the present invention, the light absorption rate difference is reduced by controlling the density of the light absorber in different areas of the filter lens. This will be described in detail below.

[0109] like Fig. 10AAs shown, the first lens 1010 is a convex lens with a filtering function, which has a characteristic that the thickness of the central area is greater than that of the edge area. The second lens 1020 is an ordinary optical lens. If a uniform light absorber is mixed in the first lens 1010, the optical lens with a filtering function will show a characteristic that the light absorption rate of the central area 1030 is high and the light absorption rate of the edge area 1040 is low, which will cause the emitted light to show different light residual amounts at different positions, resulting in poor final imaging effect on the photosensitive element.

[0110] In this embodiment, the light absorber is arranged non-uniformly to achieve the same light absorption rate at different positions of the non-uniform / uniform filter lens. Since the light blocking agent in the filter lens is a light absorber, the distribution of the light absorber on the light path determines the light filtering effect. In this embodiment, the density of the light absorber is arranged inversely proportional to the thickness of the optical lens, so that the central area 1030 with a large thickness has a smaller light absorber density, and the edge area 1040 with a small thickness has a larger light absorber density, so that in the direction of the light path, the amount of light absorber that the light passes through in the filter lens is the same, so the non-uniform / uniform first lens 1010 achieves the same light filtering effect at each position. Assuming that the density of the light absorber is ρ, the thickness is d, and the cross-sectional area of ​​each light ray is idealized as S, then the amount of light absorber that the light passes through the filter lens is V = S*d*ρ, where S remains unchanged. Then, in the area with large thickness, the value of d is large, and ρ is controlled to decrease; in the area with small thickness, the value of d is small, and ρ is controlled to increase; then overall, the value of V remains unchanged, that is, the amount of light absorber that the light passes through remains the same at each position, that is, the light absorption rate is the same at each position. That is, per unit area, the content of the light absorber is basically the same along the parallel direction of the optical axis. In this embodiment, the fluctuation difference of the value of V is controlled within 0 to 50%. In this way, a uniform filtering effect can be achieved by only providing a first lens 1010 with a filtering function.

[0111] In this embodiment, during the manufacturing process of the lens with color filtering function, a special method is adopted to make the distribution of the light absorber present a regular and controllable non-uniform distribution.

[0112] First, the light absorber is mixed into the raw material of the lens and the mixture is transferred into a corresponding mold.

[0113] When the lens is solidified and still has good fluidity, the mold is rotated at a uniform and stable speed with the optical axis center of the molded lens as the rotation center, and the centrifugal effect is used to distribute the part containing the light absorber to the edge area, so that the light absorber density in the edge area is greater than the light absorber density in the central area.

[0114] To achieve this function, the mold can be set in a spatial stacking mode, that is, the stacking of single molding modules on one axis. Fig. 10B A schematic diagram of a mold for manufacturing optical lenses with different light absorber densities is shown.

[0115] like Fig. 10B As shown in , the mold is arranged vertically and rotates around the dotted line (i.e., the optical axis of the molded lens) at a uniform and stable speed. According to design requirements, the distribution of the light absorber density can be controlled by the speed of rotation and other means, so as to balance the light absorption rate difference problem of the lens with a filtering function. That is, the light absorber density of the lens with a filtering function is low in the area where the lens thickness is relatively large, and the light absorber density is high in the area where the lens thickness is relatively small. In this way, the difference in light absorber content between the area with a large lens thickness and the area with a small lens thickness is balanced, and the difference between the light absorption rate of the area with a large filter lens thickness and the light absorption rate of the area with a small filter lens thickness is corrected.

[0116] Another manufacturing method is to configure filter lens raw materials with different light absorber densities. During the lens manufacturing process, raw materials with different light absorber densities are injected into different areas of the lens, and then formed into a complete filter lens.

[0117] However, the present disclosure is not limited thereto, and other means may be used to change the density distribution of the light absorber according to the type of light absorber. For example, when using certain light absorbers, they are sensitive to field effects such as electric fields and magnetic fields, and the density distribution of the light absorber may be effectively controlled by field effects, such as a circular electric field or a circular magnetic field that is perpendicular to the lens light or forms a certain angle, so that the light absorber moves in a directional manner along the direction of the electric field or magnetic field.

[0118] Fig.11 Schematic diagram showing the change in the distribution of light absorbers by electric or magnetic fields.

[0119] like Fig.11 As shown in , the mold is placed in a circular electric field or a circular magnetic field, and the distribution of all light absorbers in the lens is changed by the electric field or the magnetic field. Fig.11 Two electric field directions are shown in FIG. 1 , where the direction of the electric field 1110 points to the optical axis, and the direction of the electric field 1120 is away from the optical axis. Further, as required, the magnetic field or electric field strength can be changed to obtain the desired distribution of the light absorber. However, the present disclosure is not limited thereto, and those skilled in the art can design the electric field and magnetic field as required, as long as the desired distribution effect of the light absorber can be obtained.

[0120] Fig.12 and Fig.13 An optical lens with a filtering function according to another embodiment of the present disclosure is shown.

[0121] In another embodiment of the present disclosure, under the condition of meeting the requirements of optical design, some shape features of the filter lens for achieving optical performance can be transferred to ordinary lenses, thereby reducing the shape difference of the filter lens.

[0122] like Fig.12 As shown in , an optical lens with a relatively flat lower surface can be set as a filter lens. At the same time, the density of the color filter material mixed into the lens is greater than the density of the lens material itself. During the lens molding process, a static sedimentation process is set so that the color filter material is evenly deposited near the relatively flat surface of the lens. If the lower surface is relatively flat, normal static sedimentation can be performed. If the upper surface is relatively flat, the lens is placed upside down for deposition. Further, as Fig.13 As shown in the figure, in this embodiment, the color filter material is a material that can be controlled by a magnetic field. By setting a magnetic field generating device 1310 on both sides of the required color filter lens and applying a magnetic field thereto, the color filter material 1320 mixed in the optical lens is evenly distributed in a certain area of ​​the lens due to the magnetic field force. As described above, the shape difference of the filter lens is reduced.

[0123] Fig.14 Detailed description is given of an optical lens with a light filtering function according to yet another embodiment of the present disclosure.

[0124] As mentioned above, the distance that light travels in the filter lens can affect the light emission state, that is, the longer the distance traveled in the filter lens, the stronger the light filtering effect, and the shorter the distance traveled, the worse the light filtering effect. In optical design, affected by the process and design, the shapes of at least two filter lenses may not be complementary in all effective optical areas. Therefore, there may be a situation where the thickness in a certain effective optical area cannot be complementary. For example, Fig.14As shown in , in the upper and lower optical lenses with filtering functions, the thicknesses of the effective optical areas 1401 and 1402 are complementary. That is, in the effective optical area 1401, the center of the upper lens is thick and the periphery is thin, while the center of the lower lens is thin and the periphery is thick. In the effective optical area 1402, the area of ​​the upper lens close to the center of the entire lens is thick and the area away from the center of the entire lens is thin, while the area of ​​the lower lens close to the center of the entire lens is thin and the area away from the center of the entire lens is thick. As described above, through this design, the thicknesses of the effective optical areas 1401 and 1402 can be complementary, so that the light absorption rates of the two areas are roughly equal. In the effective optical area 1403, the area of ​​the upper lens close to the center of the entire lens is thin and the area away from the center of the entire lens is thick. Similarly, the area of ​​the lower lens close to the center of the entire lens is thin and the area away from the center of the entire lens is thick. In this case, the thicknesses of the upper and lower lenses are not complementary in the effective optical area 1403, thereby causing the problem of optical path difference. In order to solve this problem, coating can be performed in the effective optical area 1403 to make the light absorption rate of the effective optical area 1403 approximately equal to the light absorption rate of the effective optical areas 1401 and 1402. Specifically, an infrared cut-off film is coated on the area of ​​the color filter lens with a smaller total thickness. Since it is difficult to coat an infrared cut-off film on a small area alone, the following method is adopted. That is, firstly, a thin film is coated on the area on the lens other than the area to be coated with the infrared cut-off film, and then the infrared cut-off film is coated on the entire surface of the lens, and then the first coated film is removed by using a liquid or method that can dissolve the above-mentioned film but cannot dissolve the infrared cut-off film. In this way, the infrared cut-off film in the area other than the area to be coated with the infrared cut-off film can be removed, so that the infrared cut-off film is only coated on the area with a smaller total thickness. In this way, the light absorption rates of the corresponding effective optical areas of the two optical lenses are complementary through thickness and coating design.

[0125] It should be understood that the above exemplary embodiments are exemplary and illustrative, and the above exemplary embodiments can be implemented in any combination without departing from the concept of the present application. For example, the concept of the present invention can be realized by using different distributions of light absorbers combined with different designs of the thickness of multiple filter lenses, different distributions of light absorbers combined with the application of infrared cut-off films, or a combination of the above three.

[0126] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. An optical lens, comprising: Lens tube; as well as A plurality of optical lenses, wherein the plurality of optical lenses are sequentially installed in the lens barrel from the object side to the image side, and the plurality of optical lenses include convex lenses and / or concave lenses; It is characterized in that At least two of the plurality of optical lenses are optical lenses having a filtering function and having uneven thickness, The optical lenses with filtering function respectively have effective optical areas with different light absorption rates, and The light absorption rates of the corresponding effective optical areas in the optical lens with filtering function are complementary; Wherein, by setting at least one of different thicknesses, light absorber density distributions and coatings, the effective optical area with different light absorption rates is formed on the optical lens with filtering function.

2. The optical lens according to claim 1, characterized in that: The optical lens with filtering function is an optical lens mixed with light absorber.

3. The optical lens according to claim 2, characterized in that: The density of the light absorber arranged in all the optical lenses with filtering function is the same, and the thickness of at least part of the corresponding effective optical areas of at least two optical lenses with filtering function cut along the direction parallel to the optical axis are complementary.

4. The optical lens according to claim 2, characterized in that: The density of the light absorber arranged in all the optical lenses with filtering function is the same, and the thickness of at least part of the corresponding effective optical areas in the at least two optical lenses with filtering function cut along the light path direction are complementary.

5. The optical lens according to claim 1, characterized in that: At least a portion of the corresponding effective optical areas of the at least two optical lenses with filtering function is coated.

6. The optical lens according to claim 2, characterized in that: The density of the light absorber arranged in all the optical lenses with filtering function is different, and the overall light absorber density of the corresponding effective optical areas in the at least two optical lenses with filtering function is negatively correlated with the overall thickness.

7. The optical lens according to claim 2, characterized in that: The light absorber is at least one of an inorganic light absorber and an organic light absorber.

8. The optical lens according to claim 1, characterized in that: The material of the multiple optical lenses is at least one of plastic, resin and glass.

9. The optical lens according to claim 1, characterized in that: The multiple optical lenses are at least one of liquid lenses and liquid crystal lenses.

10. The optical lens according to claim 1, characterized in that: The optical lens with filtering function comprises at least a first filter lens and a second filter lens, wherein the first filter lens and the second filter lens respectively have optical areas with preset light absorption rates.

11. The optical lens according to claim 10, characterized in that: The first filter sheet includes a first optical region having a first light absorption rate and a second optical region having a second light absorption rate, the second filter sheet includes a third optical region corresponding to the first optical region and a fourth optical region corresponding to the second optical region, the third optical region has a third light absorption rate, and the fourth optical region has a fourth light absorption rate. The overall light absorption rate of the first optical region and the third optical region is substantially equal to the overall light absorption rate of the second optical region and the fourth optical region.

12. The optical lens according to claim 10, characterized in that: The multiple optical lenses include five lenses arranged in sequence along the optical path of the optical lens, the first filter lens is the lens among the five lenses located on the side away from the photosensitive chip, and the second filter lens is the lens among the five lenses located on the side close to the photosensitive chip.

13. The optical lens according to claim 1, characterized in that: The complementation of light absorption rates of corresponding effective optical areas in the optical lens with filtering function is achieved by complementation of thickness integrals of the corresponding effective optical areas.

14. The optical lens according to claim 13, characterized in that: The complementation of light absorption rates of corresponding effective optical areas in the optical lens with filtering function is achieved by complementation of thickness integral of the corresponding effective optical area and brightness weighting of the corresponding effective optical area.

15. A method for manufacturing an optical lens, the method comprising: mixing a light absorber into at least two of the plurality of optical lenses during a molding process; By at least one of thickness variation, light absorber density variation and coating, the corresponding effective optical areas in the at least two optical lenses mixed with the light absorber have complementary light absorption rates; and The plurality of optical lenses are arranged in sequence in the lens barrel.

16. The method according to claim 15, characterized in that The density of the light absorber in the at least two optical lenses is the same, and the thickness of at least parts of the corresponding effective optical areas in the at least two optical lenses cut along a direction parallel to the optical axis are complementary.

17. The method according to claim 15, characterized in that The density of the light absorber in the at least two optical lenses is the same, and the thickness of at least part of the corresponding effective optical areas in the at least two optical lenses cut along the light path direction is complementary.

18. The method according to claim 15, characterized in that At least a portion of the corresponding effective optical areas in the at least two optical lenses is coated.

19. The method according to claim 15, characterized in that The density of the light absorber in the at least two optical lenses is different, and the overall light absorber density of the corresponding effective optical areas in the at least two optical lenses is negatively correlated with the overall thickness.

20. The method according to claim 15, characterized in that The light absorber is at least one of an inorganic light absorber and an organic light absorber.

21. The method according to claim 15, characterized in that The material of the multiple optical lenses is at least one of plastic, resin and glass.

22. The method according to claim 15, characterized in that The multiple optical lenses are at least one of liquid lenses and liquid crystal lenses.

23. An optical lens, comprising: Lens tube; as well as A plurality of optical lenses, the plurality of optical lenses are sequentially installed in the lens barrel, one of the plurality of optical lenses is an optical lens with a filtering function and a non-uniform thickness, the optical lens with a filtering function has a plurality of effective optical areas containing a light absorber, and the plurality of optical lenses include convex lenses and / or concave lenses; The invention is characterized in that the density of the light absorber in the plurality of effective optical regions is different, and the overall light absorption rate of each of the plurality of effective optical regions is uniform.

24. The optical lens according to claim 23, characterized in that: The thickness of each of the plurality of effective optical regions is inversely proportional to the density of the light absorber.

25. The optical lens according to claim 23, characterized in that: The light absorber is at least one of an inorganic light absorber and an organic light absorber.

26. The optical lens according to claim 23, characterized in that: The material of the multiple optical lenses is at least one of plastic, resin and glass.

27. The optical lens according to claim 23, characterized in that: The multiple optical lenses are at least one of liquid lenses and liquid crystal lenses.

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