A light-shielding sheet structure with a metal layer and a forming process

Abstract

The present invention discloses a light-shielding sheet structure with a metal layer, which has a circular sheet body. A light-transmitting hole is provided at the center of the sheet body. The sheet body comprises a first light-shielding layer, a first PET layer, a copper alloy layer, a second PET layer and a second light-shielding layer arranged in sequence. The inner wall of the light-transmitting hole is set to be concave. The light-shielding sheet structure with a metal layer provided by the present invention adopts a five-layer structure, and different concave diameters are formed on the copper alloy layer, the first PET layer and the second PET layer respectively. In this way, redundant light reflection into the viewfinder can be prevented, and the imaging quality can be improved. The light-shielding sheet forming process with a metal layer provided by the present invention forms at least three inner walls with different inner diameters through three times of forming, so that the formed light-shielding sheet can prevent redundant light from reflecting into the viewfinder, improve the imaging quality, and has good forming quality and is easy to control.

Description

Technical Field

[0001] The present invention relates to the technical field of optical device processing, and specifically relates to a light-shielding film structure with a metal layer and a forming process thereof. Background Art

[0002] A light-shielding film, also known as a light-blocking film, is an essential light-shielding component in fields such as cameras and mobile phone cameras. Its purpose is to prevent stray light from entering the viewfinder and affecting the imaging quality. The light-blocking film used in cameras is also called an aperture, a light shield, a mylar film, etc. The thickness of this kind of light-blocking film is generally between 0.025 and 0.012 mm, and its central hole is a light-passing hole. In fact, light rays do not always maintain parallel irradiation. Due to the difference in intensity within the light rays, the light rays will form intersections. Therefore, the side wall of the central hole will always reflect the light, and part of it will further enter the viewfinder.

[0003] Currently, in the field of light-shielding films, the main core process is how to reduce the reflection of the side wall of the central hole. Usually, the central hole is first punched, and then an absorbent coating is sprayed in the central hole to absorb and reduce light emission. This existing technology can usually only reduce light reflection to a certain extent. And as the use time of the camera extends (for example, the use time of mobile phones, iPads, cameras, etc. is usually more than three years), the coating is prone to falling off by itself and other defects, thus affecting the imaging of the camera due to the light-shielding film. Summary of the Invention

[0004] The purpose of the present invention is to provide a light-shielding film structure with a metal layer and a forming process thereof. This light-shielding film structure can significantly reduce light reflection into the viewfinder, and the forming process of the light-shielding film with the metal layer is not only easy to be formed in batches, but also will not affect the imaging of the imaging head during long-term use.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A light-shielding film structure with a metal layer has a circular film body. A light-passing hole is provided in the center of the film body. The film body includes a first light-shielding layer, a first PET layer, a copper alloy layer, a second PET layer, and a second light-shielding layer arranged in sequence. The inner wall of the light-passing hole is set to be concave.

[0006] Further, the inner diameter of the first light-shielding layer and the second light-shielding layer is D1, the inner diameter of the first PET layer and the second PET layer is D2, and the inner diameter of the copper alloy layer is D3, and D1 < D2 < D3.

[0007] Further, both the first light-shielding layer and the second light-shielding layer are ink layers.

[0008] The present invention also provides a forming process for a light-shielding film with a metal layer, including the following forming steps:

[0009] S1. Coat the upper surface of the copper alloy layer with a first PET layer and coat the lower surface of the copper alloy layer with a second PET layer;

[0010] S2. Coat a first light-shielding layer on the surface of the first PET layer and coat a second light-shielding layer on the surface of the second PET layer to form a light-shielding band;

[0011] S3. Punch the light-shielding band to form individual light-shielding sheet bodies;

[0012] S4. Pre-punch the light-shielding sheet body to form process holes;

[0013] S5. Place the light-shielding sheet body in a solution to perform surface dissolution molding on the PET layer in the process holes;

[0014] S6. Place the light-shielding sheet body in an electrolytic solution for electrolytic molding.

[0015] In step S5, the solution is potassium hydroxide, sodium hydroxide, or lithium hydroxide.

[0016] Preferably, the dissolution molding includes a first molding, a second molding, and cleaning. The concentration of the potassium hydroxide solution for the first molding is 50%, and the temperature is 40°C; the concentration of the potassium hydroxide solution for the second molding is 40%, and the temperature is 35°C. After the second molding, the light-shielding sheet body is subjected to residual cleaning.

[0017] Preferably, the dissolution molding includes a first molding, a second molding, and cleaning. The concentration of the sodium hydroxide solution for the first molding is 35%, and the temperature is 40°C; the concentration of the sodium hydroxide solution for the second molding is 30%, and the temperature is 35°C. After the second molding, the light-shielding sheet body is subjected to residual cleaning.

[0018] Furthermore, the copper alloy layer is a copper-tin alloy, wherein the proportion of copper is 80% and the proportion of tin is 20%.

[0019] Preferably, for the electrolytic molding, the light-shielding sheet body is used as the anode and placed in the electrolytic solution, and the current density is controlled to be 180 - 200 A / m².

[0020] Even further, the electrolytic solution includes water, sulfuric acid, and copper sulfate, wherein the copper ion content is 40 - 50 g / L and the sulfuric acid content is 180 - 200 g / L.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. A light-shielding sheet structure with a metal layer provided by the present invention. The light-shielding sheet adopts a five-layer structure, and different inner concave diameters are formed on the copper alloy layer, the first PET layer, and the second PET layer respectively. In this way, it is possible to prevent excess light from reflecting into the viewfinder and improve the imaging quality;

[0023] 2. The light-shielding sheet forming process provided by the present invention forms at least three inner walls with different inner diameters through three times of forming, so as to prevent the formed light-shielding sheet from reflecting redundant light into the viewfinder, improve the imaging quality, and has good forming quality and is easy to control. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0025] Figure 2 It is a light path reflection diagram of the present invention.

[0026] Figure 3 It is a schematic diagram of the partial structure of the present invention.

[0027] In the figure: sheet body - 1, first light-shielding layer - 11, first PET layer - 12, copper alloy layer - 13, second PET layer - 14, second light-shielding layer - 15, light-transmitting hole - 2. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" 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 directly connected or indirectly connected through an intermediate medium, and can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to Figures 1-3 , a light-shielding sheet structure with a metal layer provided by the present invention has a circular sheet body 1, and a light-transmitting hole 2 is provided at the center of the sheet body 1. The sheet body 1 includes a first light-shielding layer 11, a first PET layer 12, a copper alloy layer 13, a second PET layer 14, and a second light-shielding layer 15 arranged in sequence. The inner wall of the light-transmitting hole is set to be concave. This light-shielding sheet adopts a five-layer structure, and different concave diameters are formed for the copper alloy layer, the first PET layer, and the second PET layer respectively. In this way, redundant light reflection into the viewfinder can be prevented, and the imaging quality can be improved; in actual use, when light at different angles irradiates on the concave side wall, due to its concave characteristics, part of the light will be reflected again and significantly reduced from entering the viewfinder.

[0033] In this technical solution, the inner diameters of the first light-shielding layer and the second light-shielding layer are D1, the inner diameters of the first PET layer and the second PET layer are D2, and the inner diameter of the copper alloy layer is D3, and D1 < D2 < D3. That is, this solution forms a concave shape with a convex stage. In this way, compared with the arc-shaped concave, it has a better anti-reflection light effect. As a more preferred option, the inner wall surface of the copper alloy layer is a rough surface, so as to reduce reflection. This forming process needs to adopt a slightly rough surface formed on the surface of the copper alloy during electrolytic forming.

[0034] In this technical solution, both the first light-shielding layer 11 and the second light-shielding layer 15 are ink layers. The ink layer adopts light-proof and light-absorbing ink, and the function of this ink layer is to prevent the scattered light formed by the light passing through the PET layer from affecting imaging. Specifically, reference can be made to Figure 2 the optical path reflection diagram shown. Since the first light-shielding layer belongs to light-absorbing ink, the light will be directly absorbed, and visible light reflection can be basically eliminated. When other residual light is reflected to the PET layer and the copper alloy layer, corresponding blocking will be formed.

[0035] The present invention also provides a forming process for a light-shielding sheet with a metal layer, and the implementation manner of this process is as follows.

[0036] Example 1, the forming steps are as follows:

[0037] S1. Coat the first PET layer on the upper surface of the copper alloy layer, and coat the second PET layer on the lower surface of the copper alloy layer;

[0038] S2. Coat a first light-shielding layer on the surface of the first PET layer and a second light-shielding layer on the surface of the second PET layer to form a light-shielding band. After forming, the light-shielding band is wound into a strip. The first light-shielding layer and the second light-shielding layer do not use anti-translucent ink, thereby preventing light from passing through the PET layer. This ink is carbon ink, which is acid-resistant and does not produce electrolytic reactions.

[0039] S3. Punch the light-shielding band to form individual light-shielding sheet bodies. The individual light-shielding sheet bodies can be punched into different sizes according to actual needs.

[0040] S4. Pre-punch the light-shielding sheet bodies to form process holes. After punching, a smooth mirror-like inner wall is formed, thereby ensuring the punching accuracy.

[0041] S5. Place the light-shielding sheet bodies in a solution to perform surface dissolution molding on the PET layer in the process holes.

[0042] S6. Place the light-shielding sheet bodies in an electrolytic solution for electrolytic molding.

[0043] In this embodiment, the molding process is carried out through three times of molding, thereby forming inner walls with at least three different inner diameters. Furthermore, the formed light-shielding sheet prevents excess light from reflecting into the viewfinder, improving the imaging quality. The quality of the molded product is good, and it is easy to accurately control the different inner diameters of each section, thereby realizing a stepped concave inner wall surface.

[0044] Embodiment 2, the molding steps are as follows:

[0045] S1. Coat a first PET layer on the upper surface of the copper alloy layer and a second PET layer on the lower surface of the copper alloy layer.

[0046] S2. Coat a first light-shielding layer on the surface of the first PET layer and a second light-shielding layer on the surface of the second PET layer to form a light-shielding band. After forming, the light-shielding band is wound into a strip. The first light-shielding layer and the second light-shielding layer do not use anti-translucent ink, thereby preventing light from passing through the PET layer.

[0047] S3. Punch the light-shielding band to form individual light-shielding sheet bodies. The individual light-shielding sheet bodies can be punched into different sizes according to actual needs.

[0048] S4. Pre-punch the light-shielding sheet bodies to form process holes. After punching, a smooth mirror-like inner wall is formed, thereby ensuring the punching accuracy.

[0049] S5. Place a batch of light-shielding sheet bodies (which can be determined according to the size of the solution pool and can corrode at least hundreds of thousands at a time) in strong alkali solutions such as potassium hydroxide, sodium hydroxide, and lithium hydroxide for dissolution and forming; the dissolution and forming include the first forming, the second forming, and cleaning. The concentration of the potassium hydroxide solution in the first forming is 50%, the temperature is 40 °C, and the corrosion time is 180 minutes. The concentration of the acetic acid solution in the second forming is 40%, the temperature is 35 °C, and the corrosion time is 60 - 80 minutes. After the second forming, clean the residues of the light-shielding sheet body. In this step, make the inner diameter of the PET layer reach the required value D2.

[0050] S6. The copper alloy layer is a copper-tin alloy, with copper accounting for 80% and tin accounting for 20%. Place the light-shielding sheet body in the electrolyte for electrolytic forming. The electrolytic forming is to place the light-shielding sheet body as the anode in the electrolyte and control the current density to be 180 A / square meter. The electrolyte includes water, sulfuric acid, and copper sulfate, with a copper ion content of 40 g / L and a sulfuric acid content of 180 g / L. In this step, make the inner diameter of the copper alloy layer reach the required value D3, and the overall electrolytic forming time is about 60 minutes.

[0051] The forming process in this embodiment forms at least three inner walls with different inner diameters through three times of forming, thereby preventing the formed light-shielding sheet from reflecting excess light into the viewfinder, improving the imaging quality, having good quality of the formed product, and being easy to accurately control the different inner diameter sizes of each section, so as to realize a stepped concave inner wall surface.

[0052] Example 3, the forming steps are as follows:

[0053] S1. Coat the first PET layer on the upper surface of the copper alloy layer and coat the second PET layer on the lower surface of the copper alloy layer;

[0054] S2. Coat the first light-shielding layer on the surface of the first PET layer and coat the second light-shielding layer on the surface of the second PET layer to form a light-shielding band; the light-shielding band is wound up with the strip material after forming. The first light-shielding layer and the second light-shielding layer do not use anti-transparent ink, so as to prevent light from passing through the PET layer.

[0055] S3. Punch the light-shielding band to form individual light-shielding sheet bodies; the individual light-shielding sheet bodies can be punched into different sizes according to actual needs.

[0056] S4. Pre-punch the light-shielding sheet body to form a process hole; a smooth mirror-like inner wall is formed after punching, so as to ensure the punching accuracy.

[0057] S5. Place a batch of light-shielding sheet bodies (which can be determined according to the size of the solution pool and can corrode at least hundreds of thousands at a time) into the solution for dissolution molding; the dissolution molding includes the first molding, the second molding and cleaning. The concentration of the sodium hydroxide solution for the first molding is 35%, the temperature is 40 °C, and the corrosion time is 240 minutes. The concentration of the sodium hydroxide solution for the second molding is 30%, the temperature is 35 °C, and the corrosion time is 100 minutes. By dissolving separately twice, the inner diameter size can be better controlled. After the second molding, the light-shielding sheet body is subjected to residue cleaning. In this step, the inner diameter of the PET layer reaches the required value D2.

[0058] S6. The copper alloy layer is a copper-tin alloy, with copper accounting for 80% and tin accounting for 20%. Place the light-shielding sheet body into the electrolyte for electrolytic molding. The electrolytic molding is to place the light-shielding sheet body as the anode into the electrolyte and control the current density to be 190 A / square meter. The electrolyte includes water, sulfuric acid and copper sulfate, with the copper ion content being 45 g / L and the sulfuric acid content being 190 g / L. In this step, the inner diameter of the copper alloy layer reaches the required value D3, and the overall electrolytic molding time is about 50 minutes.

[0059] The molding process in this embodiment forms at least three inner walls with different inner diameters through three times of molding, thereby enabling the formed light-shielding sheet to prevent excess light from reflecting into the viewfinder, improving the imaging quality, having good quality of the molded product, and being easy to accurately control the different inner diameter sizes of each section, so as to realize a stepped concave inner wall surface.

[0060] Example 4, the molding steps are as follows:

[0061] S1. Coat the first PET layer on the upper surface of the copper alloy layer and coat the second PET layer on the lower surface of the copper alloy layer;

[0062] S2. Coat the first light-shielding layer on the surface of the first PET layer and coat the second light-shielding layer on the surface of the second PET layer to form a light-shielding band; the light-shielding band is wound up in a strip after molding. The first light-shielding layer and the second light-shielding layer do not use anti-transparent ink, so as to prevent light from passing through the PET layer.

[0063] S3. Punch the light-shielding band to form individual light-shielding sheet bodies; the individual light-shielding sheet bodies can be punched into different sizes according to actual needs.

[0064] S4. Pre-punch the light-shielding sheet body to form a process hole; a smooth mirror-like inner wall is formed after punching, so as to ensure the punching accuracy.

[0065] S5. Place a batch of light-shielding sheet bodies (which can be determined according to the size of the solution tank, and at least hundreds of thousands can be etched at a time) in a lithium hydroxide solution for dissolution and shaping; the dissolution and shaping includes the first shaping, the second shaping and cleaning. The concentration of the lithium hydroxide solution for the first shaping is 40%, the temperature is 40 °C, and the etching time is 240 minutes. The concentration of the acetic acid solution for the second shaping is 30%, the temperature is 35 °C, and the etching time is 80 - 100 minutes. After the second shaping, the light-shielding sheet body is cleaned of residues. In this step, the inner diameter of the PET layer reaches the required value D2.

[0066] S6. The copper alloy layer is a copper-tin alloy, with copper accounting for 80% and tin accounting for 20%. Place the light-shielding sheet body in an electrolyte for electrolytic shaping. The electrolytic shaping is to place the light-shielding sheet body as the anode in the electrolyte and control the current density at 200 A / square meter. The electrolyte includes water, sulfuric acid and copper sulfate, with a copper ion content of 50 g / L and a sulfuric acid content of 200 g / L. In this step, the inner diameter of the copper alloy layer reaches the required value D3, and the overall electrolytic shaping time is about 45 minutes.

[0067] The shaping process in this embodiment undergoes three shapings to form at least three inner walls with different inner diameters, thereby preventing excess light from being reflected into the viewfinder in the formed light-shielding sheet, improving the imaging quality. The formed product has good quality and is easy to precisely control the different inner diameter sizes of each section, thereby achieving a stepped concave inner wall surface.

[0068] The above are only the embodiments of the present invention, and common knowledge such as the specific structures and characteristics in the solutions is not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A forming process for a light-shielding sheet with a metal layer, characterized in that, it includes the following forming steps: S1. Coat a first PET layer on the upper surface of the copper alloy layer and a second PET layer on the lower surface of the copper alloy layer; S2. Coat a first light-shielding layer on the surface of the first PET layer and a second light-shielding layer on the surface of the second PET layer to form a light-shielding band; S3. Punch the light-shielding band to form individual light-shielding sheet bodies; S4. Pre-punch the light-shielding sheet bodies to form process holes, so that the inner diameters of the first light-shielding layer and the second light-shielding layer are D1; S5. Place the light-shielding sheet bodies in a solution to perform surface dissolution forming on the PET layers in the process holes, so that the inner diameters of the first PET layer and the second PET layer are D2; S6. Place the light-shielding sheet bodies in an electrolyte for electrolytic forming, so that the inner diameter of the copper alloy layer is D3, and D1 < D2 < D3.

2. The forming process for a light-shielding sheet with a metal layer according to claim 1, characterized in that: In step S5, the solution is potassium hydroxide, sodium hydroxide, or lithium hydroxide.

3. The forming process for a light-shielding sheet with a metal layer according to claim 1, characterized in that: The dissolution forming includes a first forming, a second forming, and cleaning. The concentration of the potassium hydroxide solution in the first forming is 50%, and the temperature is 40°C; the concentration of the potassium hydroxide solution in the second forming is 40%, and the temperature is 35°C. After the second forming, the light-shielding sheet bodies are subjected to residual cleaning.

4. The forming process for a light-shielding sheet with a metal layer according to claim 1, characterized in that: The dissolution forming includes a first forming, a second forming, and cleaning. The concentration of the sodium hydroxide solution in the first forming is 35%, and the temperature is 40°C; the concentration of the sodium hydroxide solution in the second forming is 30%, and the temperature is 35°C. After the second forming, the light-shielding sheet bodies are subjected to residual cleaning.

5. The forming process for a light-shielding sheet with a metal layer according to claim 1, characterized in that: The copper alloy layer is a copper-tin alloy, wherein the proportion of copper is 80% and the proportion of tin is 20%.

6. The forming process for a light-shielding sheet with a metal layer according to claim 5, characterized in that: The electrolytic forming is to place the light-shielding sheet bodies as anodes in the electrolyte, and control the current density to be 180 - 200 A / square meter.

7. The forming process for a light-shielding sheet with a metal layer according to claim 6, characterized in that: The electrolyte includes water, sulfuric acid, and copper sulfate, wherein the copper ion content is 40 - 50 g / L and the sulfuric acid content is 180 - 200 g / L.

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