High-resolution prime lens and camera device

Abstract

The utility model discloses a high resolution prime lens and camera shooting equipment, the prime lens comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged from an object plane to an image plane along an optical axis, the first lens is a negative focal power lens, the second lens is a positive focal power lens, the third lens is a positive focal power lens, and the fourth lens is a negative focal power lens. The third lens is a positive focal power lens, the fourth lens is a negative focal power lens, and the total focal length of the prime lens is f. By reasonably setting the number of the lenses in the prime lens and the focal power combination and reasonably setting the focal power value, the day and night confocal and high-resolution prime lens function is realized.

Description

Technical Field

[0001] The utility model relates to the field of optical photography, in particular to a high-resolution fixed-focus lens and a photography device. Background Art

[0002] A prime lens (primelens) is a lens with only one fixed focal length, only one focal length, or only one field of view. A prime lens does not have a zoom function. Usually, a prime lens has a simple design, fast focusing speed, and stable image quality. It is particularly suitable for large-scale landscape photography, large-scale group photo taking, and certain specific photography scenes.

[0003] In certain application scenarios, fixed-focus lenses need to have the ability to be confocal day and night. For example, when fixed-focus lenses are used in digital camera systems, there are a variety of specifications and models of micro camera lenses to match them. In special scenarios, fixed-focus lenses need to simultaneously meet the characteristics of high resolution, large relative aperture, day and night confocality, and low distortion.

[0004] However, the existing fixed-focus lenses have low performance indicators and large image distortion during use, which leads to larger image scene differences. In addition, the accuracy is low during the focusing process, and thus cannot meet people's needs. Fixed-focus lenses that can simultaneously meet the characteristics of high resolution, large relative aperture, day and night confocality, and low distortion have complex structures and high production costs. Utility Model Content

[0005] The utility model provides a high-resolution fixed-focus lens and a camera device, which realizes day and night confocality and high-resolution fixed-focus lens functions by simply and reasonably setting the number of lenses and the combination of optical focal lengths in the fixed-focus lens and reasonably setting the optical focal length value.

[0006] In order to solve the above technical problems, the technical solution of the utility model is: a high-resolution fixed-focus lens, wherein the fixed-focus lens is arranged in sequence from the object plane to the image plane along the optical axis as a first lens, a second lens, a third lens, and a fourth lens, wherein the first lens is a negative optical power lens, the second lens is a positive optical power lens, the third lens is a positive optical power lens, and the fourth lens is a negative optical power lens.

[0007] Optionally, the first lens is a plastic aspheric lens, the second lens is a glass spherical lens, the third lens is a plastic aspheric lens, and the fourth lens is a plastic aspheric lens.

[0008] Optionally, the third lens and the fourth lens are glued together to form a glued lens.

[0009] Optionally, the fixed-focus lens further includes an aperture and a plane protective glass, wherein the aperture is arranged in the light path between the first lens and the second lens; and the plane protective glass is behind the fourth lens.

[0010] Optionally, the aspheric surfaces of the first lens, the third lens and the fourth lens satisfy:

[0011]

[0012] Among them, z represents the axial vector height of the aspheric surface in the Z direction; r represents the distance from the point on the aspheric surface to the optical axis; c represents the curvature of the fitted sphere, which is the inverse of the radius of curvature; k represents the fitted cone coefficient; A, B, C, D, E and F represent the 4th, 6th, 8th, 10th, 12th and 14th order coefficients of the aspheric polynomial, respectively.

[0013] Optionally, the focal length of the first lens is f1, 1.50<|f1 / f|<2.50.

[0014] Optionally, the focal length of the second lens is f2, 1.13<|f2 / f|<2.13.

[0015] Optionally, the focal length of the third lens is f3, 0.74<|f3 / f|<1.74.

[0016] Optionally, the focal length of the fourth lens is f4, 0.77<|f4 / f|<1.77.

[0017] The utility model also provides a camera device, comprising the above-mentioned high-resolution fixed-focus lens.

[0018] The beneficial effects of the utility model are as follows: the fixed-focus lens provided by the utility model realizes the fixed-focus lens function of day and night confocality and high resolution by reasonably setting the number of lenses and the optical focal length combination in the fixed-focus lens, and reasonably setting the optical focal length value, and its imaging resolution can reach 6 million pixels; the fixed-focus lens provided by the utility model has small spherical aberration; and can better correct the aberration of the optical system; has lower chromatic aberration and aberration, solves the purple edge problem of imaging in each band, and can realize high-resolution imaging; by simply and reasonably setting the number of lenses and the optical focal length combination in the fixed-focus lens, and reasonably setting the optical focal length value, the fixed-focus lens function of day and night confocality and high resolution is realized while meeting the needs of low-cost production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the fixed-focus lens structure in an embodiment of the utility model;

[0020] Figure 2is a spherical aberration curve diagram of the fixed-focus lens in the embodiment of the utility model, specifically a schematic diagram of the spherical aberration curve when the pupil radius is 1 mm;

[0021] Figure 3 This is a light fan diagram of a fixed-focus lens in an embodiment of the utility model;

[0022] Figure 4 This is a field curvature distortion diagram of a fixed-focus lens in an embodiment of the utility model;

[0023] Figure 5 It is a spot diagram of the fixed-focus lens in the embodiment of the present utility model.

[0024] The numbers or letters in the figure represent the names of the corresponding components or process names: 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Aperture; 6. Plane protection glass.

[0025] The drawings are only used for illustrative purposes and should not be construed as limitations on this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The same or similar numbers correspond to the same or similar parts. The terms describing the positional relationship in the drawings are only used for illustrative purposes and should not be construed as limitations on this patent. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] A prime lens (primelens) is a lens with only one fixed focal length, only one focal length, or only one field of view. A prime lens does not have a zoom function. Usually, a prime lens has a simple design, fast focusing speed, and stable image quality. It is particularly suitable for large-scale landscape photography, large-scale group photo taking, and certain specific photography scenes.

[0028] In certain application scenarios, fixed-focus lenses need to have the ability to be confocal day and night. For example, when fixed-focus lenses are used in digital camera systems, there are a variety of specifications and models of micro camera lenses to match them. In special scenarios, fixed-focus lenses need to simultaneously meet the characteristics of high resolution, large relative aperture, day and night confocality, and low distortion.

[0029] However, the existing fixed-focus lenses have low performance indicators and large image distortion during use, which leads to larger image scene differences. In addition, the accuracy is low during the focusing process, and thus cannot meet people's needs. Fixed-focus lenses that can simultaneously meet the characteristics of high resolution, large relative aperture, day and night confocality, and low distortion have complex structures and high production costs.

[0030] Embodiment 1:

[0031] In order to solve the above problems, this embodiment provides a high-resolution fixed-focus lens, such as Figure 1 As shown, the fixed-focus lens is arranged in sequence along the optical axis from the object plane to the image plane as a first lens 1, a second lens 2, a third lens 3, and a fourth lens 4; wherein the first lens 1 is a negative power lens, the second lens 2 is a positive power lens, the third lens 3 is a positive power lens, and the fourth lens 4 is a negative power lens.

[0032] In this embodiment, the total focal length of the lens is f. 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 combined focal length of the third lens 3 and the fourth lens 4 is f34.

[0033] Specifically, 1.50<|f1 / f∣<2.50; 1.13<|f2 / f∣<2.13; 0.74<|f3 / f∣<1.74; 0.77<|f4 / f∣<1.77; 10.99<|f34 / f∣<11.99.

[0034] In further description of this embodiment, the fixed-focus lens further includes an aperture 5 and a planar protective glass 6 , wherein the aperture is arranged in the optical path between the first lens 1 and the second lens 2 ; the planar protective glass 6 is on a side of the fourth lens 4 away from the third lens 3 .

[0035] As a further description of this embodiment, the aspheric surfaces of the first lens 1, the third lens 3 and the fourth lens 4 satisfy:

[0036] Among them, z represents the axial vector height of the aspheric surface in the Z direction; r represents the distance from the point on the aspheric surface to the optical axis; c represents the curvature of the fitted sphere, which is the inverse of the radius of curvature; k represents the fitted cone coefficient; A, B, C, D, E and F represent the 4th, 6th, 8th, 10th, 12th and 14th order coefficients of the aspheric polynomial, respectively.

[0037] The fixed-focus lens provided in this embodiment realizes the fixed-focus lens function of day and night confocality and high resolution by reasonably setting the number of lenses and the combination of optical power in the fixed-focus lens, and reasonably setting the optical power value, and its imaging resolution can reach 6 million pixels; the fixed-focus lens provided by the utility model has small spherical aberration; and can better correct the aberration of the optical system; has lower chromatic aberration and aberration, solves the purple edge problem of imaging in each band, and can realize high-resolution imaging; by simply and reasonably setting the number of lenses and the combination of optical power in the fixed-focus lens, and reasonably setting the optical power value, the fixed-focus lens function of day and night confocality and high resolution is realized while meeting the needs of low-cost production.

[0038] Embodiment 2:

[0039] This embodiment provides a high-resolution fixed-focus lens. Please refer to Table 1. Table 1 shows the design values ​​related to the surface type, curvature radius, thickness and material of the high-resolution fixed-focus lens provided in this embodiment.

[0040]

[0041] Table 1

[0042] It should be noted that the data listed in Table 1 are not intended to limit the present invention. Any person with ordinary knowledge in the technical field may make appropriate changes to the parameters or settings after referring to the present invention, but such changes should still fall within the scope of the present invention.

[0043] The fixed-focus lenses shown in Table 1 are Figure 1 As shown in . The surface numbers are numbered according to the order of the surfaces of each lens. Generally, a lens includes two surfaces, each of which is a refractive surface.

[0044] Among them, the surface serial number "S1" represents the front surface of the first lens, "S2" represents the back surface of the first lens; "STO" represents the aperture; "S3" represents the front surface of the second lens, "S4" represents the back surface of the second lens; "S5" represents the front surface of the third lens; "S6" represents the bonding surface of the third lens and the fourth lens, "S7" represents the back surface of the fourth lens; "S8" represents the front surface of the plane protective glass; "S9" represents the back surface of the plane protective glass; the radius of curvature represents the degree of curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; the thickness represents the central axial distance from the current surface to the next surface.

[0045] The first lens, the second lens, the third lens and the fourth lens satisfy: f1= -8.2; f2=6.7; f3=5.1; f4=-5.2; f34=47.1; f=4.1; |f1 / f|=2; |f2 / f|=1.63; |f3 / f|=1.24; |f4 / f|=1.27; |f34 / f|=11.49.

[0046] Embodiment 3: This embodiment provides a high-resolution fixed-focus lens, see Table 2, Figure 2 are the parameter design values ​​of each surface of the aspherical lens in the high-resolution fixed-focus lens provided in this embodiment.

[0047]

[0048] Table 2

[0049] It should be noted that the data listed in Table 2 are not intended to limit the present invention. Any person with ordinary knowledge in the technical field may make appropriate changes to the parameters or settings after referring to the present invention, but such changes should still fall within the scope of the present invention.

[0050] Among them, "-3.86E-03" means -3.86*10-3.

[0051] The optical system of the utility model has achieved the following technical indicators:

[0052] Focal length: f=4.1mm; aperture: F=2.05; field of view FOV=101°; total length of optical system TTL=22mm.

[0053] This embodiment provides a high-resolution fixed-focus lens. Figure 2 : is a spherical aberration curve diagram of the high-resolution fixed-focus lens provided in this embodiment, specifically a schematic diagram of the spherical aberration curve when the pupil radius is 1 mm. Figure 2 As shown in the figure, the spherical aberration under different wavelengths (0.470μm, 0.510μm, 0.555μm, 0.610μm and 0.650μm) is within 0.04mm. It can be seen from the figure that the curves of different wavelengths are relatively concentrated, indicating that the spherical aberration of the fixed-focus lens is very small.

[0054] Embodiment 4:

[0055] This embodiment provides a high-resolution fixed-focus lens. Figure 3 is a light fan diagram of the high-resolution fixed-focus lens provided in this embodiment, such as Figure 3As shown in the figure, the imaging range of different wavelengths of light (0.470μm, 0.510μm, 0.555μm, 0.610μm and 0.650μm) at different field angles of the fixed-focus lens is all within 20μm and the curves are very concentrated, ensuring that the aberrations in different field areas are small, which means that the fixed-focus lens can better correct the aberrations of the optical system.

[0056] Embodiment 5:

[0057] This embodiment provides a high-resolution fixed-focus lens. Figure 4 is a field curvature distortion diagram of the high-resolution fixed-focus lens provided in this embodiment, such as Figure 4 As shown, in the left coordinate system, the horizontal coordinate represents the magnitude of field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss; Figure 4 It can be seen that the fixed-focus lens provided in this embodiment is effectively controlled in field curvature from light with a wavelength of 470nm to light with a wavelength of 650nm, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, in units of %; the vertical coordinate represents the normalized image height, without units; Figure 4 It can be seen that the distortion of the fixed-focus lens provided in this embodiment is well corrected, the imaging distortion is good, there is lower chromatic aberration and aberration, the purple fringing problem of imaging in each band is solved, and high-resolution imaging can be achieved.

[0058] Embodiment 6:

[0059] This embodiment provides a high-resolution fixed-focus lens. Figure 5 is the spot diagram of the high-resolution fixed-focus lens provided in this embodiment, wherein the spot diagram is one of the most commonly used evaluation methods in modern optical design. The spot diagram refers to a diffuse pattern formed by many light rays emitted by a point light source after passing through the optical system, where the intersection points with the image plane are no longer concentrated at the same point due to aberration, but are spread over a certain range.

[0060] like Figure 5As shown, the diffusion patterns of light of different wavelengths (0.470μm, 0.510μm, 0.555μm, 0.610μm and 0.650μm) of the high-resolution fixed-focus lens provided in this embodiment are relatively concentrated and evenly distributed in each field of view. There is no phenomenon in which the diffusion pattern in a certain field of view is separated up and down with the wavelength, indicating that there is no obvious purple fringing. At the same time, the root mean square radius values ​​(RMS radius) of light with different wavelengths (0.470μm, 0.510μm, 0.555μm, 0.610μm and 0.650μm) at each field of view of the fixed-focus lens are 0.588μm, 0.604μm, 0.845μm, 0.733μm, 0.656μm and 0.828μm, respectively, indicating that the RMS radius of each field of view is less than 2μm; at the same time, the root mean square radius values ​​(RMS radius) of light with different wavelengths (0.470μm, 0.510μm, 0.555μm, 0.610μm and 0.650μm) at each field of view of the fixed-focus lens are 0.588μm, 0.604μm, 0.845μm, 0.733μm, 0.656μm and 0.828μm, respectively, indicating that the RMS radius of each field of view is less than 2μm. .650μm) the geometric radius values ​​(GEO radius) at each field of view of the fixed-focus lens are 1.531μm, 1.909μm, 2.680μm, 2.225μm, 3.137μm and 4.193μm respectively, indicating that the GEO radius of each field of view is less than 5μm. This also shows that the fixed-focus lens has low chromatic aberration and aberration, solves the purple fringing problem of imaging in each band, and can achieve high-resolution imaging.

[0061] Embodiment 7:

[0062] This embodiment provides a camera device, which can be a digital camera, a mobile phone, a monitoring device or other device with a photography function. The camera device includes an image sensor, such as a CMOS, a CCD, and also includes a high-resolution lens provided by any of the above embodiments. The fixed-focus lens is arranged in sequence from the object plane to the image plane along the optical axis as a first lens, a second lens, a third lens, and a fourth lens, wherein the first lens is a negative focal lens, the second lens is a positive focal lens, the third lens is a positive focal lens, and the fourth lens is a negative focal lens. The total focal length of the fixed-focus lens is f. In addition, the camera device may also include components such as a control circuit and a battery. The specific components included in the camera device can be designed according to actual conditions, and this application does not limit this.

[0063] The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "top", "bottom", "inside", "outside" and the like indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. In addition, if there are terms such as "first", "second", etc., they are only used for descriptive purposes, mainly to distinguish different devices, components or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, components or components, and cannot be understood as indicating or implying relative importance.

[0064] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] Obviously, the above embodiments of the utility model are only examples for clearly explaining the utility model, and are not intended to limit the implementation methods of the utility model. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. A high-resolution fixed-focus lens, characterized in that: The fixed-focus lens is arranged in sequence along the optical axis from the object plane to the image plane as a first lens, a second lens, a third lens, and a fourth lens, wherein the first lens is a negative power lens, the second lens is a positive power lens, the third lens is a positive power lens, and the fourth lens is a negative power lens, and the total focal length of the fixed-focus lens is f; the third lens and the fourth lens are cemented to form a cemented lens; the combined focal length of the third lens and the fourth lens is f34, 10.99<|f34 / f|<11.

99.

2. The high-resolution fixed-focus lens according to claim 1, characterized in that: The first lens is a plastic aspheric lens, the second lens is a glass spherical lens, the third lens is a plastic aspheric lens, and the fourth lens is a plastic aspheric lens.

3. The high-resolution fixed-focus lens according to claim 1, characterized in that: The fixed-focus lens further includes an aperture and / or a plane protective glass, wherein the aperture is arranged in the optical path between the first lens and the second lens; and the plane protective glass is located behind the fourth lens.

4. The high-resolution fixed-focus lens according to any one of claims 1 to 3, characterized in that: The aspheric surfaces of the first lens, the third lens and the fourth lens satisfy: Among them, z represents the axial vector height of the aspheric surface in the Z direction; r represents the distance from the point on the aspheric surface to the optical axis; c represents the curvature of the fitted sphere, which is the inverse of the radius of curvature; k represents the fitted cone coefficient; A, B, C, D, E and F represent the 4th, 6th, 8th, 10th, 12th and 14th order coefficients of the aspheric polynomial, respectively.

5. The high-resolution fixed-focus lens according to claim 1, characterized in that: The focal length of the first lens is f1, 1.50<|f1 / f|<2.

50.

6. The high-resolution fixed-focus lens according to claim 1, characterized in that: The focal length of the second lens is f2, 1.13<|f2 / f|<2.

13.

7. The high-resolution fixed-focus lens according to claim 1, characterized in that: The focal length of the third lens is f3, 0.74<|f3 / f|<1.

74.

8. The high-resolution fixed-focus lens according to claim 1, characterized in that: The focal length of the fourth lens is f4, 0.77<|f4 / f|<1.

77.

9. A camera device, characterized in that: The invention comprises a high-resolution fixed-focus lens as described in any one of claims 1 to 8.

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