A large target surface, large depth of field lens

Abstract

The application discloses a large-target-surface and large-depth-of-field lens, which is sequentially arranged from an object side to an image side along an optical axis of the lens and comprises a first lens of a non-spherical plastic lens with positive refractive power, a second lens of a non-spherical plastic lens with negative refractive power, a third lens of a non-spherical plastic lens with positive refractive power or a non-spherical plastic lens with negative refractive power, and a fourth lens of a non-spherical plastic lens with negative refractive power, wherein f of the lens is greater than or equal to 5.5 mm, TTL is less than or equal to 6.5 mm, IC / TTL is greater than or equal to 0.52, TTL / f is less than or equal to 1.05, and OBFL / TTL is greater than or equal to 0.48. The application adopts four non-spherical plastic lenses, and has the advantages of simple structure, low cost, short total length, large depth of field, large target surface, good resolving power and the like.

Description

Technical Field

[0001] This invention relates to the field of optical lenses, and more particularly to a large-aperture, large-depth-of-field lens. Background Technology

[0002] In recent years, with the continuous increase in the amount of barcode information, more and more image scanning technologies have replaced the previous laser barcode scanning technology. In certain situations, it is often necessary to use dedicated scanning equipment to accurately and efficiently scan and identify information. With the popularization of mobile payment, more and more situations require barcode scanning operations, so the demand for a barcode scanning lens with a large target area and a large depth of field is becoming more and more urgent. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a large-aperture, large-depth-of-field lens. It employs four aspherical plastic lenses, combines different lenses, and rationally allocates optical power. The total lens length (TTL) is ≤6.5mm, the aperture (F#) is ≥5.5, and it can be paired with a 1 / 2.6-inch high-pixel chip. It features low cost, short total length, large depth of field, large aperture, and good resolution.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A large-aperture, large-depth-of-field lens, arranged sequentially from the object side to the image side along the lens optical axis: An aperture stop is disposed on the side of the first lens. The first lens is an aspherical plastic lens with positive optical power, wherein the object side of the first lens is convex and the image side is concave. The second lens is an aspherical plastic lens with negative optical power. The object side of the second lens is concave, and its image side is also concave. The third lens can be either an aspherical plastic lens with negative optical power or an aspherical plastic lens with positive optical power. The object side of the third lens is concave, and its image side is convex. The fourth lens is an aspherical plastic lens with negative optical power. The object side of the fourth lens can be either concave or convex, and the image side can be either concave or convex. A filter, wherein the filter is disposed on the image-side surface of the fourth lens; A protective glass and an image acquisition element, wherein the protective glass is integrated on the image acquisition element, and the image acquisition element is disposed on the image side of the filter.

[0006] Furthermore, the lens also satisfies the following relationship: f≥5.5mm, TTL≤6.5mm, IC / TTL≥0.52, TTL / f≤1.05, OBFL / TTL≥0.48 In the formula, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focal length of the lens, and IC is the full-image height of the chip that is paired with the lens system, which can be matched with a target chip of up to 1 / 2.6 inches.

[0007] Furthermore, the lens satisfies the following relationship: 0.4 ≤ f1 / f ≤ 0.5 -1.3≤f² / f≤-1.1, -4.0≤f³ / f≤27.5, -5.8≤f4 / f≤-1.2, In the formula, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f4 is the focal length of the fourth lens.

[0008] Furthermore, the aperture of the lens is F#, where F# ≥ 5.5.

[0009] Furthermore, the focal length, refractive index, and radius of curvature of the first lens, the second lens, the third lens, and the fourth lens respectively satisfy the following conditions:

[0010] Wherein, f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the object-side radius of curvature of the first lens, and R12 is the image-side radius of curvature of the first lens; f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the object-side radius of curvature of the second lens, and R22 is the image-side radius of curvature of the second lens; f3 is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the object-side radius of curvature of the third lens, and R32 is the image-side radius of curvature of the third lens; f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, R41 is the object-side radius of curvature of the fourth lens, and R42 is the image-side radius of curvature of the fourth lens; where a "+" sign for the radius of curvature indicates that the lens surface bends towards the image plane, and a "-" sign indicates that the lens surface bends towards the object plane.

[0011] Furthermore, the filter is made of H-K9L glass.

[0012] The beneficial effects of this invention are: This invention's lens employs four lens elements with specific optical power. Through a specific surface shape combination and reasonable optical power distribution, the lens structure becomes more compact. Compared with existing lenses on the market, it has a focal length f≥5.5mm and an aperture F#≥5.5, ensuring a large depth of field. It also boasts a total length ≤6.5mm, meeting the advantages of small size and easy integration. It can be matched with up to 1 / 2.6-inch sensor chips, allowing for the use of chips with higher pixel counts; thus fulfilling the requirements of a large sensor size and large depth of field lens.

[0013] In terms of manufacturing, it uses four aspherical plastic lenses, which have low manufacturing costs, uniform and reasonable thickness of each lens and are not sensitive, making it easy to manufacture and with a high yield. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the optical structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the optical path structure of Embodiment 1 of the present invention; Figure 3 The field curvature curve and distortion curve of visible light at 0.555 μm are shown in Embodiment 1 of the present invention. Figure 4 This is the Thought Focus MTF curve under visible light at 83 lp / mm in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the optical structure of Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of the optical path structure of Embodiment 2 of the present invention; Figure 7 The field curvature curve and distortion curve of visible light at 0.555 μm are shown in Embodiment 2 of the present invention. Figure 8 This is the Thought Focus MTF curve under visible light at 83 lp / mm in Embodiment 2 of the present invention; Reference numerals: 1-First lens, 2-Second lens, 3-Third lens, 4-Fourth lens, 5-Filter, 6-Protective glass, 7-Image acquisition element, 8-Aperture. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. In this specification, the expressions "first," "second," "third," etc., are only used to distinguish one feature from another, and do not indicate any limitation on the features. The shape of a spherical or aspherical surface is not limited to the spherical or aspherical shapes shown in the drawings. The drawings are for illustrative purposes only and are not strictly drawn to scale.

[0016] In this invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region; if the lens surface is not defined as convex, concave, or flat, it means that the lens surface can be convex, concave, or flat. The surface of each lens closest to the object being photographed is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0017] Unless otherwise specified, all terms used in this invention (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the same meaning as they have in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so defined in this invention.

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. For better understanding and implementation, the invention will be described in detail below with reference to the accompanying drawings.

[0019] This invention provides a large-area, large-depth-of-field lens. The surface of the lens adjacent to the object plane is the object-side surface, and the surface of the lens adjacent to the image plane is the image-side surface. Along the lens optical axis from the object side to the image side, the following components are arranged sequentially: an aperture stop 8, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a filter 5, a protective glass 6, and an image acquisition element 7. The aperture stop 8 is located on the object-side surface of the first lens 1; the filter 5 is located on the image-side surface of the fourth lens 4 and is made of H-K9L glass. The image acquisition element 7 is located on the image-side surface of the protective glass 6, and the protective glass 6 is integrated into the image acquisition element 7.

[0020] In this invention, to achieve better performance of the optical system, we need to rationally select lens materials, rationally allocate the focal length of each lens, and rationally optimize the optical system during the design process. Ultimately, we aim to optimize the performance of the optical system. The presence of aberrations in the optical system usually affects the imaging quality. Correcting aberrations is the key to optimizing the optical system. There are many methods for correcting aberrations. For example, using lenses with different refractive indices and significantly different Abbe numbers can eliminate chromatic aberration and spherical aberration to a certain extent. Rationally allocating and optimizing the focal length and shape of each lens can also correct the aberrations of the system.

[0021] In this invention, the focal length of the first lens 1 is f1, the focal length of the second lens 2 is f2, the focal length of the third lens 3 is f3, the focal length of the fourth lens 4 is f4, and the total focal length of the entire lens is f. The ratio of the focal length of each lens to the total focal length of the lens satisfies the following condition: 0.4 ≤ f1 / f ≤ 0.5 -1.3≤f² / f≤-1.1, -4.0≤f³ / f≤27.5, -5.8≤f4 / f≤-1.3.

[0022] In this invention, the focal length, refractive index, and radius of curvature of the first lens 1, the second lens 2, the third lens 3, and the fourth lens 4 respectively satisfy the following conditions:

[0023] Wherein, f1 is the focal length of the first lens 1, ND1 is the refractive index of the first lens 1, R11 is the radius of curvature of the object side of the first lens 1, and R12 is the radius of curvature of the image side of the first lens 1; f2 is the focal length of the second lens 2, ND2 is the refractive index of the second lens 2, R21 is the radius of curvature of the object side of the second lens 2, and R22 is the radius of curvature of the image side of the second lens 2; f3 is the focal length of the third lens 3, ND3 is the refractive index of the third lens 3, R31 is the radius of curvature of the object side of the third lens 3, and R32 is the radius of curvature of the image side of the third lens 3; f4 is the focal length of the fourth lens 4, ND4 is the refractive index of the fourth lens 4, R41 is the radius of curvature of the object side of the fourth lens 4, and R42 is the radius of curvature of the image side of the fourth lens 4; where the "+" sign for the radius of curvature indicates that the lens surface bends towards the image plane, and the "-" sign indicates that the lens surface bends towards the object plane.

[0024] In this invention, f is the total focal length of the lens; TTL is the total optical length of the lens; OBFL is the optical back focal length of the lens, which is defined as the distance from the point on the fourth lens's fourth image side closest to the image plane to the image plane; IC is the full image height of the 1 / 2.6-inch chip used with the lens system, and they satisfy the following conditions: f≥5.5mm, TTL≤6.5mm, IC / TTL≥0.52, TTL / f≤1.05, OBFL / TTL≥0.48 In this invention, the aperture of the lens is F#, which satisfies F#≥5.5; the lens angle is FOV, which satisfies FOV≥55°.

[0025] Example 1 refer to Figure 1 , Figure 2 As shown, these are schematic diagrams of the optical structure and optical path structure of Embodiment 1, respectively.

[0026] In this embodiment, the field of view (FOV) is 55.1°, and the principal ray angle of the lens is defined as CRA. This satisfies CRA≤27°. By reasonably allocating the focal length and optical power of each lens, the optical system is optimized, and the thickness of each lens is uniform and insensitive, making it easy to mass-produce.

[0027] In this embodiment, the lenses are arranged sequentially from the object side to the image side along the lens optical axis: Aperture 8, wherein the aperture 8 is disposed on the side of the first lens 1; The first lens 1 is an aspherical plastic lens with positive optical power. The object side of the first lens 1 is convex, and its image side can be concave. The second lens 2 is an aspherical plastic lens with negative optical power. The object side of the second lens 2 is concave, and its image side is also concave. The third lens 3 can be an aspherical plastic lens with negative optical power. The object side of the third lens 3 is concave, and its image side is convex. The fourth lens 4 is an aspherical plastic lens with negative optical power. The object side of the fourth lens 4 is convex, and its image side is also convex. Filter 5, the filter 5 being disposed on the image side of the fourth lens 4; The protective glass 6 and the image acquisition element 7 are integrated on the image acquisition element 7, which is disposed on the image side of the filter 5.

[0028] In this embodiment, the first lens 1 is an aspherical plastic lens with positive optical power, its object side is convex and its image side is concave, forming a meniscus lens with positive optical power, which facilitates the rapid convergence of light. The second lens 2 is a high-refractive-index plastic aspherical lens with a refractive index greater than 1.66 and an Abbe number less than 21, and its main function is to correct the resolution so that it can be matched with higher pixel chips. The third lens 3 has a concave object side and a convex image side, forming a meniscus lens with negative optical power, and its main function is to guide the expansion of light to facilitate the realization of a larger target surface. The fourth lens 4 has a convex object side and a convex image side, and its main function is to control CRA and improve resolution.

[0029] Table 1 provides the radius of curvature R (in mm), center thickness d (in mm), refractive index (ND), Abbe constant (VD), and aspherical K value (Conic) for each lens.

[0030] Table 1

[0031] In Table 1, the radius of curvature R represents the curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INFINITY" indicates that the surface is flat. The center thickness D represents the central axial distance from the current surface to the next surface. The refractive index ND represents the ability of the current lens material to deflect light. The Abbe number VD represents the dispersion characteristics of the current lens material. The k value represents the magnitude of the best-fit conic coefficient of the aspherical surface. 11 represents the object surface of the first lens 1, 12 represents the image surface of the first lens 1, and so on.

[0032] In this embodiment, the aspherical surfaces of the first lens 1, the second lens 2, the third lens 3, and the fourth lens 4 can all be defined by the following equation for even-order aspherical surfaces: , In the formula, Z is the sag of the lens along the optical axis, k is the surface conic coefficient, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, G, H, and I are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, and 20th order terms of the aspherical polynomial.

[0033] Table 2 gives the coefficients of the aspherical surfaces of each optical surface of the first lens 1, the second lens 2, the third lens 3, and the fourth lens 4.

[0034] Table 2

[0035] refer to Figure 3 The image shows the field curvature and distortion curves of the lens at 0.555μm in this embodiment. In the field curvature curves, the vertical axis "ASTIGMATIC FIELD CURVES" represents different fields of view, and the horizontal axis "FOCUS (MILLIMETERS)" represents the field area (mm). Figure 3 As can be seen from the graph, the field curvature offsets in both the meridional and sagittal directions on the image plane are controlled within ±0.03mm, indicating that the lens has good field curvature correction. The distortion curve graph shows the horizontal axis representing F... The tan(Theta) distortion (unit: %), with the vertical axis representing the half-image height value (unit: mm). As can be seen from the figure, the distortion is well corrected when it is within -0.5% of the lens's full field of view.

[0036] refer to Figure 4The figure shows the Thought Focus MTF curve of the lens in this embodiment at a frequency of 83 lp / mm in the visible light range of 0.435-0.656 μm. The horizontal axis represents the defocus amount (unit: mm), and the horizontal axis is relatively wide, ranging from -0.2 mm to +0.2 mm. The vertical axis represents the MTF value, from... Figure 4 As can be seen from this, the lens has a small defocusing amount and a wide depth of field in each field of view of visible light (0.435-0.656μm), thus ensuring a large depth of field range.

[0037] Depend on Figure 3 , 4 As can be seen, in this embodiment, the field curvature, distortion, and MTF of the lens can be well corrected.

[0038] In this embodiment 1, the total focal length of the lens system is f=6.2mm, the aperture value is F#=5.5, the total length of the lens (TTL) is 6.5mm, the optical back focal length (OBFL) is 3.17mm, and the field of view (DFOV) of the lens matched with the 1 / 2.6-inch sensor is 55.1°. Example 2 refer to Figure 5 , Figure 6 As shown, these are schematic diagrams of the optical structure and optical path structure of Embodiment 2, respectively.

[0039] In this embodiment, the field of view (DFOV) is 55°, and the principal ray angle of the lens is defined as CRA. This satisfies CRA ≤ 30°. By rationally selecting lens materials and rationally allocating the focal length and optical power of each lens, the optical system is optimized, achieving uniform and insensitive thickness of each lens, which is easy for large-scale mass production.

[0040] In this embodiment, the lenses are arranged sequentially from the object side to the image side along the lens optical axis: Aperture 8, wherein the aperture 8 is disposed on the side of the first lens 1; The first lens 1 is an aspherical plastic lens with positive optical power. The object side of the first lens 1 is convex, and its image side can be concave. The second lens 2 is an aspherical plastic lens with negative optical power. The object side of the second lens 2 is concave, and its image side is also concave. The third lens 3 can be an aspherical plastic lens with positive optical power. The object side of the third lens 3 is concave, and its image side is convex. The fourth lens 4 is an aspherical plastic lens with negative optical power. The object side of the fourth lens 4 is concave, and its image side is also concave. Filter 5, the filter 5 being disposed on the image side of the fourth lens 4; The protective glass 6 and the image acquisition element 7 are integrated on the image acquisition element 7, which is disposed on the image side of the filter 5.

[0041] In this embodiment, the first lens 1 is an aspherical plastic lens with positive optical power, its object side is convex and its image side is concave, forming a meniscus lens with positive optical power, which facilitates the rapid convergence of light. The second lens 2 is a high-refractive-index plastic aspherical lens with a refractive index greater than 1.64 and an Abbe number less than 24. Its main function is to correct the resolution, making it compatible with higher pixel chips, and it can further reduce costs compared to embodiment 1. The third lens 3 has a concave object side and a convex image side, forming a meniscus lens with negative optical power. Its main function is to guide the expansion of light, making it easier to achieve a larger target surface. The fourth lens 4 has a concave object side and a concave image side, which mainly improves the resolution.

[0042] Table 1 provides the radius of curvature R (in mm), center thickness d (in mm), refractive index (ND), Abbe constant (VD), and aspherical K value (Conic) for each lens.

[0043] Table 3

[0044] In Table 3, the radius of curvature R represents the curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INFINITY" indicates that the surface is flat. The center thickness D represents the central axial distance from the current surface to the next surface. The refractive index ND represents the ability of the current lens material to deflect light. The Abbe number VD represents the dispersion characteristics of the current lens material. The k value represents the magnitude of the best-fit conic coefficient of the aspherical surface. 11 represents the object surface of the first lens 11, 12 represents the image surface of the first lens 11, and so on.

[0045] In this embodiment, the aspherical surfaces of the first lens 1, the second lens 2, the third lens 3, and the fourth lens 4 can all be defined by the following equation for even-order aspherical surfaces: , In the formula, Z is the sag of the lens along the optical axis, k is the surface conic coefficient, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, G, H, and I are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, and 20th order terms of the aspherical polynomial.

[0046] Table 4 gives the coefficients of the aspherical surfaces of each optical surface of the first lens 1, the second lens 2, the third lens 3, and the fourth lens 4.

[0047] Table 4

[0048] refer to Figure 7 The figure shows the field curvature and distortion curves of the lens at 0.555μm in this embodiment. In the field curvature curves, the vertical axis "ASTIGMATIC FIELD CURVES" represents different fields of view, and the horizontal axis "FOCUS (MILLIMETERS)" represents the field area (mm). Figure 7 As can be seen from the graph, the field curvature offsets in both the meridional and sagittal directions on the image plane are controlled within ±0.07mm, indicating that the lens has good field curvature correction; in the distortion curve graph, the horizontal axis represents F... The tan(Theta) distortion (unit: %), with the vertical axis representing the half-image height value (unit: mm). As can be seen from the figure, the distortion is well corrected when it is within -0.5% of the lens's full field of view.

[0049] refer to Figure 8 The figure shows the Thought Focus MTF curve of the lens in this embodiment at a frequency of 83 lp / mm in the visible light range of 0.435-0.656 μm. The horizontal axis represents the defocus amount (unit: mm), and the horizontal axis is relatively wide, ranging from -0.2 mm to +0.2 mm. The vertical axis represents the MTF value, from... Figure 8 As can be seen from this, the lens has a small defocusing amount and a wide depth of field in each field of view of visible light (0.435-0.656μm), thus ensuring a large depth of field range.

[0050] Depend on Figure 7 , 8 As can be seen, in this embodiment, the field curvature, distortion, and MTF of the lens can be well corrected.

[0051] In this embodiment 2, the total focal length of the lens system is f=6.2mm, the aperture value is F#=5.6, the total length of the lens is TTL=6.4mm, the optical back focal length of the lens is OBFL=3.14mm, and the field of view (DFOV) of the 1 / 2.6-inch chip matched with the lens is 55°.

[0052] As can be seen from the F-Tan(θ) distortion curves, field curvature curves, and MTF curves of the above embodiments, the optical lens provided by the present invention has the advantages of small size, high imaging quality and high pixel count with a large target surface, large depth of focus to accommodate a larger depth of field range, and good manufacturability and yield.

[0053] Based on the disclosure in the foregoing specification, those skilled in the art can make appropriate changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A large-area, large-depth-of-field lens, comprising four lenses, characterized in that: The lens consists of a first lens, a second lens, a third lens, and a fourth lens arranged sequentially from the object side to the image side along the optical axis of the lens. The first lens is an aspherical plastic lens with positive optical power, and the object side of the first lens is convex and the image side is concave. The second lens is an aspherical plastic lens with negative optical power. The object side of the second lens is concave, and the image side is concave. The third lens is an aspherical plastic lens with positive optical power, and the object side of the third lens is concave and the image side is convex. The fourth lens is an aspherical plastic lens with negative optical power. The object side of the fourth lens is concave, and its image side is also concave. The lens satisfies the following relationship: f≥5.5mm, TTL≤6.5mm, IC / TTL≥0.52, TTL / f≤1.05, OBFL / TTL≥0.48 In the formula, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focal length of the lens, and IC is the full-image height of the chip paired with the lens system.

2. The large target area and large depth of field lens according to claim 1, characterized in that: The lens also satisfies the following relationship: 0.4≤f1 / f≤0.5, -1.3≤f² / f≤-1.1, -5.8≤f4 / f≤-1.2, In the formula, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, and f4 is the focal length of the fourth lens.

3. The large target area and large depth of field lens according to claim 1, characterized in that: The aperture of the lens is F#, which satisfies F#≥5.

5.

4. The large target area and large depth of field lens according to claim 1, characterized in that: The focal lengths of the first lens, the second lens, and the fourth lens are respectively +2.7 to +3.0, -7.9 to -7.2, and -36.4 to -7.9; where "+" indicates that the focal length of the lens is positive, and "-" indicates that the focal length of the lens is negative.

5. The large target area and large depth of field lens according to claim 1, characterized in that: The refractive index ranges of the first lens, the second lens, the third lens, and the fourth lens are 1.50–1.55, 1.60–1.68, 1.50–1.55, and 1.50–1.55, respectively.

6. A large-area, large-depth-of-field lens according to any one of claims 1 to 5, characterized in that: Along the lens optical axis from the object side to the image side, the following are also provided: An aperture stop is disposed on the side of the first lens. A filter, wherein the filter is disposed on the image-side surface of the fourth lens, and the filter is made of H-K9L glass; A protective glass and an image acquisition element, wherein the protective glass is integrated on the image acquisition element, and the image acquisition element is disposed on the image side of the filter.

Images