Patent Application
20220043325
The subject matter herein generally relates to optical lenses, and more particularly to a light-shielding sheet of an optical lens.
An optical lens generally includes a lens and a light-shielding sheet. The light-shielding sheet is an optical element used to control the amount of light in an optical system. When external light enters the lens, the light-shielding sheet can block stray light. However, due to structural characteristics of the light-shielding sheet, when light at a specific incident light angle irradiates a side wall of a through hole of the light-shielding sheet, reflection or diffuse reflection will occur at the inner wall, which will interfere with the optical system and produce stray light spots, which negatively affects an imaging quality of the optical lens.
Implementations of the present disclosure will now be described, by way of embodiments, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. Additionally, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.
The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series, and the like.
A thickness of the base 10 has an important effect on whether stray light can form a spot that affects a quality of an optical lens. Normally, when an incident light angle is within a range from 0° to 45°-55°, the light-shielding sheet 100 will form stray light spots that affect a light shooting effect. When a thickness of the base 10 is W and a diameter of the first through hole 3 is D, the following relationship needs to be satisfied for the incident light angle so that stray light spots that affect the quality of the optical lens will not be formed: 0.01≤W≤0.02; 3≤D≤3.5; 0.0122≤W/sinθ≤0.0283.
As shown in
The second body 2 includes a third surface 21 and a second side wall 22. The second side wall 12 is a side wall of the second through hole 4.
A plurality of microstructures 5 is formed on the second side wall 22. The light-shielding coating 6 is covered on the first surface 11, the second surface 12, the third surface 21, the first side wall 13, and the microstructure 5.
In one embodiment, the first body 1 and the second body 2 are integrally formed, and the first through hole 3 and the second through hole 4 are coaxially defined. The inner diameter D of the first through hole 3 is smaller than the inner diameter of the second through hole 4, so that a step is formed at an interface between the first through hole 3 and the second through hole 4. The step can suppress stray light reflection or diffuse reflection in the optical lens to an imaging surface, thereby ensuring a shooting effect and improving a quality of a captured image.
In one embodiment, a width of the second surface 12 is 0.1 mm to 0.5 mm, and the light-shielding coating 6 is provided on the second surface 12 to enhance an effect of eliminating stray light spots.
In one embodiment, the first body 1 and the second body 2 are made of plastic, such as polyethylene terephthalate (PET) or other materials.
As shown in
As shown in
In one embodiment, a radius of curvature of the first arcuate portions 51 is greater than or equal to a radius of curvature of the second arcuate portions 52. In other embodiments, the radius of curvature of each of the first arcuate portions 51 and each of the second arcuate portions 52 may be different for changing a propagation path of light in different directions.
In one embodiment, the microstructures 5 and the second body 2 are integrally formed, and the microstructures 5 may be formed on the second side wall 22 by etching. By etching, the vertex a of the microstructure 5 will not extend beyond the edge of the second surface 12 adjacent to the first through hole 3, so that the step and the microstructures 5 cooperatively change the propagation path of the stray light, thereby preventing the stray light from entering the imaging surface, improving the extinction efficiency of the stray light, and improving the quality of the captured image.
As shown in
In one embodiment, the light-shielding coating 6 is a black light-shielding ink layer, which has light-shielding and matting functions. For example, the light-shielding coating 6 may be a light-shielding ink with carbon black.
A method for manufacturing the light-shielding sheet 100 may include the following steps.
In a first step, the base 10 is provided in which the first through hole 3 and the second through hole 4 are defined by a punching process. A diameter of the first through hole 3 is smaller than the diameter of the second through hole 4, thereby forming a step.
In a second step S2, the second side wall 22 of the second through hole 4 is etched to form the plurality of microstructures 5.
In a third step, the light-shielding coating 6 is sprayed on upper and lower surfaces (the first surface 11 and the third surface 21) of the base 10 by an ink sprayer.
The light-shielding coating 6 may be a light-shielding ink, and the light-shielding ink flows toward the first through hole 3 and the second through hole 4, so that the light-shielding ink covers surfaces of the first through hole 3 and the second through hole 4, and then the light-shielding ink is cured to form the light-shielding coating.
In the second step S2, the microstructure 5 may be formed by the following process.
First, a film is attached to the second side wall 22 and an edge of the third surface 21 adjacent to the second through hole 4. The film on the edge of the third surface 21 is pre-processed into a shape consistent with a shape of the microstructures 5.
After the film is attached, a layer of anti-corrosion coating is sprayed onto the first surface 11, the second surface 12, a portion of the third surface 21 not attached by the film, and the first side wall 13.
Then, the film is removed, and the light-shielding sheet is placed into an etching solution for etching. The etching solution may be an etching solution that corrodes the base 10 but not the anti-corrosion coating, or may be an etching solution that corrodes the anti-corrosion coating at a rate less than a rate of corroding the base 10.
After etching is finished, the light-shielding sheet is taken out of the etching solution and washed and dried.
The optical lens 200 is suitable to be applied in most products with lenses, such as mobile phones, notebook computers, desktop computers, game consoles, TVs, and so on.
Compared with the related art, the light-shielding sheet 100 has the following beneficial effects.
1. The thickness and diameter of the light-shielding sheet is designed according to the specific incident light angle, which is more effective to prevent the formation of stray light spots.
2. A step is formed at the interface between the first through hole and the second through hole. The step design can suppress stray light reflection or diffuse reflection in the optical lens to the imaging surface, thereby ensuring the shooting effect and improving the quality of the captured image.
3. The design of the microstructures changes the path of light reflection, so as to prevent stray light rays from entering the imaging surface. In addition, the microstructure design can also increase the light receiving area and increase the absorption of stray light.
4. The light-shielding coating is not only applied on the upper and lower surfaces of the light-shielding sheet, but also on the surfaces of the first through hole and the second through hole and the surfaces of the microstructures, which can effectively prevent stray light rays from entering the imaging surface of the optical lens.
The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including, the full extent established by the broad general meaning of the terms used in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202010781348.4 | Aug 2020 | CN | national |
