A double lens focusing assembly for a film camera

Abstract

This invention provides a dual-lens fixed-focus assembly for film cameras, including a fixed-focus lens barrel. A first lens and a second lens are stacked from top to bottom within the fixed-focus lens barrel. The upper and lower ends of the fixed-focus lens barrel are the light-inlet and light-outlet ends, respectively. The upper and lower surfaces of the first lens are respectively provided with a first convex surface and a first concave surface. The upper and lower surfaces of the second lens are respectively provided with a second convex surface and a second concave surface. The curvature of the second convex surface is less than that of the first convex surface. The optical axes of the first convex surface, the first concave surface, the second convex surface, and the second concave surface coincide. Beneficial effects: Through the cooperation of the first and second lenses, light passes through the two lenses sequentially, undergoing multiple refractions. This corrects and focuses light of different wavelengths, reducing the impact of chromatic aberration on the image. Simultaneously, the light is refracted again after passing through the second lens, resulting in a smaller focal point and reducing the influence of spherical aberration. This effectively improves the user experience and enhances the product's competitiveness.

Description

Technical Field

[0001] This utility model relates to the field of film camera technology, and specifically to a dual-lens fixed-focus assembly for film cameras. Background Technology

[0002] A film camera (also known as a roll film camera or traditional camera) is a photographic device that records images using chemical photosensitive materials (film). Its core principle is that light is projected through a lens onto the silver halide coating of the film to form a latent image, which is then converted into a visible image through chemical processes such as development and fixing.

[0003] Most existing film cameras use a single lens for shooting. To achieve a wider field of view, the light-receiving surface is spherical. Different wavelengths of light have different refractive indices when passing through the lens, which causes chromatic aberration and blurring at the junction of two colors, also known as dispersion. Furthermore, because the lens is a convex lens, the refraction of light at the edge and center is different, causing the focus to shift and resulting in spherical aberration. This leads to poor image quality in film cameras, which cannot meet the needs of users. Utility Model Content

[0004] To address the problems in the prior art, this utility model provides a dual-lens fixed-focus assembly for film cameras, which solves the problem that chromatic aberration and spherical aberration easily affect the imaging effect when using single-lens imaging in the prior art.

[0005] This utility model discloses a dual-lens fixed-focus assembly for a film camera, comprising a fixed-focus lens barrel, in which a first lens and a second lens are stacked from top to bottom. The upper and lower ends of the fixed-focus lens barrel are respectively the light-inlet end and the light-outlet end. The upper and lower surfaces of the first lens are respectively provided with a first convex surface and a first concave surface, and the upper and lower surfaces of the second lens are respectively provided with a second convex surface and a second concave surface. The curvature of the second convex surface is less than that of the first convex surface. The optical axes of the first convex surface, the first concave surface, the second convex surface, and the second concave surface coincide. The curvature of the second concave surface is less than that of the second convex surface, and the curvature of the first concave surface is greater than that of the first convex surface.

[0006] The present invention is further improved in that the first lens includes a first light guide part and a first mounting part, the first mounting part being disposed around the first light guide part; the second lens includes a second light guide part and a second mounting part, the second mounting part being disposed around the second light guide part; a first convex surface and a first concave surface are disposed in the first light guide part; a second convex surface and a second concave surface are disposed in the second light guide part; and the light-emitting end of the fixed-focus lens barrel is provided with a light-emitting hole that matches the size of the second light guide part.

[0007] The present invention is further improved in that the first mounting part and the second mounting part are respectively the first mounting boss and the second mounting boss. The first mounting boss is disposed above the second mounting boss. The second mounting boss has an inclined surface on the side near the second light guide part. The inclined surface can avoid blocking the light from the first concave surface to the second convex surface.

[0008] The present invention is further improved by providing a first mounting position on the inner wall of the fixed-focus lens barrel, which cooperates with the first mounting boss. The diameter of the first mounting position is the same as the diameter of the first lens. Furthermore, a first mounting clearance position is provided at the upper end of the first mounting position, which can avoid the tool for mounting the first lens.

[0009] The present invention is further improved by providing a second mounting position on the inner wall of the fixed-focus lens barrel, which cooperates with the second mounting boss. The diameter of the second mounting position is the same as the diameter of the second lens. Furthermore, a second mounting clearance position is provided at the upper end of the second mounting position, which can avoid the tool for mounting the second lens.

[0010] This invention is further improved in that the diameter of the first lens is larger than the diameter of the second lens.

[0011] Compared with the prior art, the beneficial effects of this utility model are: it can effectively solve the problem that chromatic aberration and spherical aberration can easily affect the imaging effect when using single-lens imaging in the prior art. By cooperating with the first and second lenses, the light passes through the two lenses in sequence, and the light path undergoes multiple refractions to correct and focus light of different wavelengths, reducing the impact of chromatic aberration on the image. At the same time, the light is refracted again after passing through the second lens, making the focal point smaller and reducing the impact of spherical aberration, effectively improving the user experience and the competitiveness of the product. Attached Figure Description

[0012] To more clearly illustrate the solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the overall structure of the dual-lens fixed-focus assembly used in film cameras;

[0014] Figure 2 This is a cross-sectional view of the dual-lens fixed-focus assembly used in a film camera;

[0015] Figure 3 This is the optical path diagram of the dual-lens fixed-focus assembly used in film cameras. Detailed Implementation

[0016] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order.

[0017] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment to other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0019] like Figure 1-3 As shown, this utility model is a dual-lens fixed-focus assembly for film cameras, including a fixed-focus lens barrel 1. A first lens 2 and a second lens 3 are stacked from top to bottom inside the fixed-focus lens barrel 1. The upper and lower ends of the fixed-focus lens barrel 1 are the light-inlet end and the light-outlet end, respectively. The upper and lower surfaces of the first lens 2 are respectively provided with a first convex surface 21 and a first concave surface 22. The upper and lower surfaces of the second lens 3 are respectively provided with a second convex surface 31 and a second concave surface 32. The curvature of the second convex surface 31 is less than the curvature of the first convex surface 21. The optical axes of the first convex surface 21, the first concave surface 22, the second convex surface 31, and the second concave surface 32 coincide.

[0020] By combining the first lens 2 and the second lens 3, the light is refracted and corrected, so that the optical power (φ1, φ2) of the first lens 2 and the Abbe number (V1, V2) of the second lens 3 satisfy: V1φ1+V2φ2=0, which effectively cancels the dispersion of light and thus achieves the effect of controlling dispersion.

[0021] Furthermore, given that the curvature of the second convex surface 31 is less than that of the first convex surface 21, the light passes through the two lenses in sequence. Based on the existing use of a single lens, the light path passes through the first convex surface 21, the first concave surface 22, the second convex surface 31, and the second concave surface 32 in sequence, undergoing four refractions. This makes the focal point smaller, effectively reducing the influence of spherical aberration and thus achieving the effect of controlling spherical aberration.

[0022] By using a smaller focal point, the image can be made clearer. This can alleviate the problem of image distortion at the edges caused by using a single lens, and reduce the range of distortion.

[0023] The curvature of the second concave surface 32 is less than that of the second convex surface 31. This setting can effectively adjust the angle at which light enters and exits the second lens 3, thereby improving the control of spherical aberration.

[0024] The curvature of the first concave surface 22 is greater than that of the first convex surface 21. This setting enables the first lens 2 to have a better light-convexity focusing effect, concentrating the light beam onto the second convex surface 31 as much as possible.

[0025] The first lens 2 includes a first light guide and a first mounting part. The first mounting part is disposed around the first light guide. The second lens 3 includes a second light guide and a second mounting part. The second mounting part is disposed around the second light guide. A first convex surface 21 and a first concave surface 22 are disposed in the first light guide. A second convex surface 31 and a second concave surface 32 are disposed in the second light guide. The light-emitting end of the fixed-focus lens barrel 1 is provided with a light-emitting hole 100 that matches the size of the second light guide.

[0026] The first mounting part and the second mounting part facilitate the installation of the first lens 2 and the second lens 3, avoiding the need for auxiliary contact with the first light guide or the second light guide during the installation process. At the same time, the first light guide and the second light guide are spaced apart, which can reduce the possibility of wear caused by contact between the first light guide and the second light guide during the shaking of the film camera.

[0027] The first mounting part and the second mounting part are respectively the first mounting boss 23 and the second mounting boss 33. The first mounting boss 23 is located above the second mounting boss 33. The second mounting boss 33 has a slope 34 on the side near the second light guide part. By setting the slope 34, the light illuminating the second convex surface 31 from the first concave surface 22 can be avoided.

[0028] The inner wall of the fixed-focus lens barrel 1 is provided with a first mounting position that mates with the first mounting boss 23. The diameter of the first mounting position is the same as the diameter of the first lens 2. A first mounting clearance position 101 is provided at the upper end of the first mounting position. The tool for mounting the first lens 2 can be cleared by the first mounting clearance position 101.

[0029] The inner wall of the fixed-focus lens barrel 1 is provided with a second mounting position that mates with the second mounting boss 33. The diameter of the second mounting position is the same as the diameter of the second lens 3. A second mounting clearance position 102 is provided at the upper end of the second mounting position. The tool for mounting the second lens 3 can be cleared by the second mounting clearance position 102.

[0030] The diameter of the first lens 2 is larger than the diameter of the second lens 3. This condition, combined with the fact that the curvature of the first concave surface 22 is greater than the curvature of the first convex surface 21, allows the size of the second light guide part to be perfectly matched with the light emitted by the first concave surface 22 for full coverage reception.

[0031] As can be seen from the above, the beneficial effects of this utility model are: it can effectively solve the problem that chromatic aberration and spherical aberration easily affect the imaging effect when using single-lens imaging in the prior art. Through the cooperation of the first lens 2 and the second lens 3, the light passes through the two lenses in sequence, and the light path undergoes multiple refractions to correct and focus the light of different wavelengths, reducing the impact of chromatic aberration on the image. At the same time, the light is refracted again after passing through the second lens 3, making the focal point smaller and reducing the impact of spherical aberration, effectively improving the user experience and the competitiveness of the product.

[0032] The specific embodiments described above are preferred embodiments of this utility model, and are not intended to limit the specific scope of this utility model. The scope of this utility model includes but is not limited to the specific embodiments described above. All equivalent changes made in accordance with this utility model are within the protection scope of this utility model.

Claims

1. A dual-lens fixed-focus assembly for a film camera, characterized in that: The lens includes a fixed-focus lens barrel, in which a first lens and a second lens are stacked from top to bottom. The upper and lower ends of the fixed-focus lens barrel are the light-inlet end and the light-outlet end, respectively. The upper and lower surfaces of the first lens are respectively provided with a first convex surface and a first concave surface. The upper and lower surfaces of the second lens are respectively provided with a second convex surface and a second concave surface. The curvature of the second convex surface is less than the curvature of the first convex surface. The optical axes of the first convex surface, the first concave surface, the second convex surface, and the second concave surface coincide. The curvature of the second concave surface is less than the curvature of the second convex surface, and the curvature of the first concave surface is greater than the curvature of the first convex surface.

2. The dual-lens fixed-focus assembly for a film camera according to claim 1, characterized in that: The first lens includes a first light guide portion and a first mounting portion, the first mounting portion being disposed around the first light guide portion. The second lens includes a second light guide portion and a second mounting portion, the second mounting portion being disposed around the second light guide portion. The first convex surface and the first concave surface are disposed in the first light guide portion, the second convex surface and the second concave surface are disposed in the second light guide portion, and the light-emitting end of the fixed-focus lens barrel is provided with a light-emitting hole that matches the size of the second light guide portion.

3. The dual-lens fixed-focus assembly for a film camera according to claim 2, characterized in that: The first mounting part and the second mounting part are respectively a first mounting boss and a second mounting boss. The first mounting boss is disposed above the second mounting boss. The second mounting boss has an inclined surface on the side near the second light guide part. The inclined surface can avoid blocking the light from the first concave surface to the second convex surface.

4. The dual-lens fixed-focus assembly for a film camera according to claim 3, characterized in that: The inner wall of the fixed-focus lens barrel is provided with a first mounting position that mates with the first mounting boss. The diameter of the first mounting position is the same as the diameter of the first lens. Furthermore, a first mounting clearance position is provided at the upper end of the first mounting position, which can allow the tool for mounting the first lens to pass through.

5. The dual-lens fixed-focus assembly for a film camera according to claim 3, characterized in that: The inner wall of the fixed-focus lens barrel is provided with a second mounting position that mates with the second mounting boss. The diameter of the second mounting position is the same as the diameter of the second lens. Furthermore, a second mounting clearance position is provided at the upper end of the second mounting position, which can allow the tool for mounting the second lens to pass through.

6. The dual-lens fixed-focus assembly for a film camera according to claim 3, characterized in that: The diameter of the first lens is larger than the diameter of the second lens.

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