CN217587648U

CN217587648U - Optical filter and camera module

Info

Publication number: CN217587648U
Application number: CN202221916693.5U
Authority: CN
Inventors: 张超; 王昌琴
Original assignee: Kunshanqiu Titanium Photoelectric Technology Co Ltd
Current assignee: Kunshanqiu Titanium Photoelectric Technology Co Ltd
Priority date: 2022-07-22
Filing date: 2022-07-22
Publication date: 2022-10-14
Anticipated expiration: 2032-07-22

Abstract

The utility model provides an optical filter, including the optical filter body and with lanthanum fluoride strengthening layer, lanthanum fluoride strengthening layer locates the first surface and the second surface of optical filter body, wherein, the first surface with the second surface does two relative surfaces of optical filter body. The utility model also provides a camera module including above-mentioned light filter. In the optical filter and the camera module, because the lanthanum fluoride strengthening layer is arranged on the optical filter body of the optical filter, the optical filter body can be protected from being corroded when a chemical method is adopted to eliminate microcracks, the influence on the reflectivity and the transmittance of the optical filter when the chemical method is adopted is avoided, and the optical performance of the optical filter is improved.

Description

Optical filter and camera module

Technical Field

The utility model relates to an imaging technology field especially relates to an optical filter and camera module.

Background

At present, camera modules are generally installed on electronic products such as mobile phones and notebook computers, so that users can take photos anytime and anywhere conveniently. The camera module generally includes a filter, which is composed of a transparent substrate and a film layer disposed on the transparent substrate to filter light.

In the production process of the optical filter, the process flow of film coating, silk screen printing and cutting is generally included, and finally the optical filter capable of being installed on a camera module is produced. However, during the cutting process, micro cracks are easily formed on the optical filter, which affects the strength of the optical filter, and the micro cracks may spread over time, further affecting the strength of the optical filter, especially the micro cracks may sharply spread when the optical filter is subjected to pressure, which may cause the optical filter to break.

At present, the micro-cracks on the optical filter can be eliminated by a chemical method, and particularly, the micro-cracks can be eliminated by corroding the optical filter by hydrofluoric acid or concentrated phosphoric acid. However, chemically removing the microcracks can affect the optical properties of the filter, including the reflectivity and transmittance of the filter.

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide an optical filter and a camera module with no or less microcracks and high optical performance.

The utility model provides an optical filter, including the optical filter body and with lanthanum fluoride strengthening layer, lanthanum fluoride strengthening layer locates the first surface and the second surface of optical filter body, wherein, the first surface with the second surface does two relative surfaces of optical filter body.

In an embodiment, the lanthanum fluoride strengthening layer is disposed on the first surface and the second surface of the filter body by plating.

In one embodiment, the lanthanum fluoride strengthening layer has a thickness of about 10nm.

In an embodiment, the filter includes a cut surface connected between the first surface and the second surface, and the first surface and the second surface are non-cut surfaces.

In one embodiment, the filter body comprises a substrate, and the lanthanum fluoride strengthening layer is directly attached to two sides of the substrate.

In an embodiment, the optical filter body includes a substrate, an infrared cut-off film and an antireflection film, the infrared cut-off film and the antireflection film are respectively disposed on two side surfaces of the substrate, the lanthanum fluoride strengthening layer is attached to a surface of the infrared cut-off film on a side away from the substrate, and the lanthanum fluoride strengthening layer is also attached to a surface of the antireflection film on a side away from the substrate; or the optical filter body comprises a substrate and an infrared cut-off film, the infrared cut-off film is respectively arranged on the surfaces of two sides of the substrate, and the two lanthanum fluoride strengthening layers are respectively attached to the surfaces of the two infrared cut-off films, which are far away from one side of the substrate; or the optical filter body comprises a substrate and an antireflection film, the antireflection film is respectively arranged on the surfaces of two sides of the substrate, and the two lanthanum fluoride strengthening layers are respectively attached to the surfaces of the two antireflection films, which are far away from one side of the substrate.

In an embodiment, the filter body includes a substrate, a silicon dioxide layer, a magnesium fluoride layer, and a titanium pentoxide layer, where the silicon dioxide layer, the magnesium fluoride layer, and the titanium pentoxide layer are respectively disposed on two sides of the substrate.

The utility model also provides a camera module, including above-mentioned light filter.

In an embodiment, the camera module further includes a lens, a base, a support, an imaging chip and a circuit board, the lens is installed in the base, the base is installed on the support, the optical filter is installed between the lens and the imaging chip in the optical axis direction of the lens, the imaging chip and the support are installed on the circuit board, a cavity is formed in the support, and the optical filter and the imaging chip are both located in the cavity of the support.

The embodiment of the utility model provides an among light filter and the camera module, owing to set up lanthanum fluoride strengthening layer on the light filter body of light filter, can protect the light filter body not corroded when adopting chemical method to eliminate the crazing line, avoid influencing the reflectivity and the transmissivity of light filter when adopting chemical method to the optical property of light filter has been improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on these drawings without inventive efforts.

Fig. 1 is a schematic cross-sectional view of an optical filter according to a first embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of another optical filter according to the first embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view of another optical filter according to the first embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view of another optical filter according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating the reflectivity comparison of the filter of FIG. 2 after different treatments.

Fig. 6 is a schematic structural view of a camera module according to a second embodiment of the present invention.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It is obvious that the described embodiments are only some of the embodiments of the present invention, and not all of them. All other embodiments obtained by a person skilled in the art without any inventive work based on the description of the present invention belong to the protection scope of the present invention.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "mounted," "connected," and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms can be understood in a specific case to those of ordinary skill in the art.

The terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", and the like, refer to an orientation or positional relationship based on that shown in the drawings, or that is conventionally placed during use of the invention, for convenience of description and simplicity of illustration, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the invention.

The terms "first," "second," "third," and the like are used solely to distinguish between similar elements and not to indicate or imply relative importance or a particular order.

The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, including not only those elements listed, but also other elements not expressly listed.

First embodiment

Referring to fig. 1, the optical filter provided in the first embodiment of the present invention includes an optical filter body 11 and a lanthanum fluoride strengthening layer 13 disposed on a first surface and a second surface of the optical filter body 11, wherein the first surface and the second surface are two opposite surfaces of the optical filter body 11, and the first surface and the second surface are both non-cutting surfaces of the optical filter body 11. The lanthanum fluoride strengthening layer 13 is made of lanthanum fluoride (LaF 3). Lanthanum fluoride has excellent strong acid and alkali resistance, has good optical performance, and has good transmittance for light with wavelength of 0.2-10.5 um (micrometer). Like this, set up lanthanum fluoride strengthening layer on the one hand can effectively prevent the corrosion of strong acid to the non-cutting face when getting rid of the microcrack of the cutting face of light filter with strong acid, guarantee the reflectivity and the transmissivity of light filter, on the other hand its light transmissivity of focusing on itself is better, add the luminousness that lanthanum fluoride strengthening layer can not influence the light filter.

In this embodiment, the lanthanum fluoride strengthening layer 13 is disposed on the first surface and the second surface of the filter body 11 by plating. Generally, the filter body 11 is a multi-layer structure, which is usually a multi-layer structure formed by a plating method, and the lanthanum fluoride strengthening layer 13 is also formed by the plating method, so that the filter body 11 and the lanthanum fluoride strengthening layer 13 have the same processing technology, and thus the manufacturing process is relatively simple and fast. For example, a vacuum coating method can be adopted, the filter body 11 is formed in a vacuum coating chamber, and then the lanthanum fluoride strengthening layer 13 is formed in the same vacuum coating chamber, so that the process flow is simplified.

In this embodiment, the thickness of the lanthanum fluoride strengthening layer 13 can be about 10nm.

In this embodiment, the optical filter includes a cut surface, the cut surface connects the first surface and the second surface, and the cut surface is a side surface of the optical filter. Since the filter is generally formed by cutting a large intermediate filter in one piece, cut surfaces are formed on the side surfaces of the filter. The optical filter can be treated by a chemical method to eliminate microcracks formed by cutting on the cutting surface, so that the treated cutting surface is a smooth surface without microcracks, the strength of the optical filter is ensured, and the optical filter is prevented from being broken.

In this embodiment, the filter body 11 includes a substrate 112, and the lanthanum fluoride strengthening layer 13 is directly attached to two sides of the substrate 112. In particular, the substrate 112 may be a glass substrate, such as blue glass. In general, an infrared camera may employ such a filter body 11, since it is not necessary to provide an infrared cut film for the infrared camera since infrared light should be transmitted through the filter.

In another embodiment, referring to fig. 2, the filter body 11 includes a substrate 112, an infrared cut-off film 113 and an anti-reflection film 114, the infrared cut-off film 113 and the anti-reflection film 114 are respectively disposed on two side surfaces of the substrate 112, the lanthanum fluoride strengthening layer 13 is attached to a surface of the infrared cut-off film 113 on a side away from the substrate 112, and the lanthanum fluoride strengthening layer 13 is further attached to a surface of the anti-reflection film 114 on a side away from the substrate 112. The infrared cut film 113 and the antireflection film 114 may each have a multilayer film structure. Specifically, the infrared cut film 113 includes a first silicon dioxide layer 1132, a first magnesium fluoride layer 1133 and a first trititanium pentoxide layer 1134, and the antireflection film 114 includes a second silicon dioxide layer 1142, a second magnesium fluoride layer 1143 and a second trititanium pentoxide layer 1144. Both the infrared cut film 113 and the antireflection film 114 may include three materials of silicon dioxide, magnesium fluoride, and titanium oxide, but the functions of the infrared cut film 113 and the antireflection film 114 are different, so that the material components constituting the infrared cut film 113 and the antireflection film 114 are still different. Wherein, the magnesium fluoride can realize the cancellation of reflection and enhance the transmission, thereby achieving the anti-reflection effect.

In another embodiment, referring to fig. 3, the filter body 11 includes a substrate 112 and an ir-cut film 113, the ir-cut film 113 is disposed on two side surfaces of the substrate 112, and two lanthanum fluoride strengthening layers 13 are respectively attached to the surfaces of the two ir-cut films 113 away from the substrate 112. The infrared cut film 113 may have a multi-layer film structure, and the infrared cut film 113 includes not only the first silicon oxide layer 1132, the first magnesium fluoride layer 1133, and the first trititanium pentoxide layer 1134.

In another embodiment, referring to fig. 4, the filter body 11 includes a substrate 112 and an anti-reflection film 114, the anti-reflection film 114 is disposed on each of two side surfaces of the substrate 112, and two lanthanum fluoride strengthening layers 13 are respectively attached to the surfaces of the two anti-reflection films 114 on the side away from the substrate 112. The antireflection film 114 may have a multilayer film structure. Specifically, in the present embodiment, the filter body 11 includes a substrate 112, a silicon dioxide layer, a magnesium fluoride layer, and a titanium pentoxide layer, where the silicon dioxide layer, the magnesium fluoride layer, and the titanium pentoxide layer are respectively disposed on two sides of the substrate 112.

Referring to fig. 5, L1 is a reflectance curve of the optical filter with the lanthanum fluoride reinforced layer without chemical removal of micro-cracks (i.e., without strengthening), L2 is a reflectance curve of the optical filter with the lanthanum fluoride reinforced layer with 5 minutes of chemical removal of micro-cracks (i.e., strengthening for 5 minutes), and L3 is a reflectance curve of the optical filter with the lanthanum fluoride reinforced layer with 8 minutes of chemical removal of micro-cracks (i.e., strengthening for 8 minutes). Therefore, when the lanthanum fluoride strengthening layer is arranged on the optical filter, the reflectivity of the optical filter is not increased much after strengthening, the reflectivity of the optical filter can be well ensured by the lanthanum fluoride strengthening layer, and the transmissivity is correspondingly higher under the condition that the reflectivity of the optical filter is lower due to less absorption of the optical filter to light, so that the reflectivity and the transmissivity of the optical filter can be ensured. The reflectivity of the optical filter without the lanthanum fluoride strengthening layer can generally reach more than 2.5 to 3 after the optical filter is strengthened. In addition, since the filter is generally used in a wavelength range of 430 to 680nm, the reflectance is high in wavelength bands of less than 430 and more than 680, and thus, the reflectance is not affected.

Specifically, the optical filter of the embodiment shown in fig. 2 may be manufactured by:

s11, providing a substrate 112, forming an infrared cut-off film 113 on one side of the substrate 112, forming an antireflection film 114 on the other side of the substrate 112, thereby forming a filter body 11, and forming lanthanum fluoride strengthening layers 13 on two sides of the filter body 11 respectively, thereby forming an intermediate filter; specifically, both the infrared cut film 113 and the antireflection film 114 may be formed by a plating method, and the lanthanum fluoride reinforcing layer 13 may also be formed by a plating method. It can be understood that the infrared cut-off film 113 or the antireflection film 114 may be formed on both sides of the substrate 112 in the optical filter of the embodiment shown in fig. 3 and 4 by a plating method.

And S13, cutting the intermediate filter into a plurality of filters. Specifically, the intermediate filter may be cut by laser cutting. Microcracks may be formed on the cut surface of the base material of the optical filter after cutting.

And S15, removing the microcracks on the optical filter by adopting a chemical corrosion method. Specifically, the optical filter may be immersed in a strong acid (e.g., hydrofluoric acid or concentrated sulfuric acid), which chemically reacts with the silicon dioxide, thereby removing the microcracks. In the process, the lanthanum fluoride strengthening layer 13 can effectively prevent corrosion of strong acid, and the emissivity and the transmittance of the optical filter are ensured.

In the optical filter of the embodiment, because the lanthanum fluoride strengthening layer is arranged on the optical filter body, the optical filter body can be protected from being corroded when a chemical method is adopted to eliminate microcracks, and the influence on the reflectivity and the transmittance of the optical filter when the chemical method is adopted is avoided, so that the optical performance of the optical filter is improved.

Second embodiment

The utility model discloses the camera module that provides in the second embodiment, including light filter 37, this light filter 37 is the light filter of above-mentioned first embodiment.

In this embodiment, referring to fig. 6, the camera module further includes a lens 31, a base 33, a bracket 35, an imaging chip 39 and a circuit board 41. The lens 31 is installed in the base 33, the base 33 is arranged on the support 35, the optical filter 37 is arranged between the lens 31 and the imaging chip 39 in the optical axis direction of the lens 31, the imaging chip 39 and the support 35 are arranged on the circuit board 41, a cavity is formed in the support 35, and the optical filter 37 and the imaging chip 39 are both located in the cavity of the support 35. Specifically, the filter 37 is fixed to the holder 35. The base 33 can be a voice coil motor, which is a zoom lens of the camera module, and of course, the camera module can also be a fixed focus lens.

It should be noted that, in this specification, each embodiment is described in a progressive manner, and each embodiment focuses on differences from other embodiments, and portions that are the same as and similar to each other in each embodiment may be referred to.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An optical filter is characterized by comprising an optical filter body (11) and a lanthanum fluoride strengthening layer (13), wherein the lanthanum fluoride strengthening layer (13) is arranged on a first surface and a second surface of the optical filter body (11), and the first surface and the second surface are two opposite surfaces of the optical filter body (11).

2. A filter as claimed in claim 1, wherein the lanthanum fluoride strengthening layer (13) is provided on the first surface and the second surface of the filter body (11) by plating.

3. A filter as claimed in claim 1, wherein the lanthanum fluoride strengthening layer (13) has a thickness of about 10nm.

4. The filter of claim 1, wherein the filter includes a cut surface connected between the first surface and the second surface, the first surface and the second surface being non-cut surfaces.

5. A filter as claimed in claim 1, wherein the filter body (11) comprises a substrate (112), and the lanthanum fluoride strengthening layer (13) is directly attached to both sides of the substrate (112).

6. The optical filter according to claim 1, wherein the optical filter body (11) comprises a substrate (112), an infrared cut-off film (113) and an antireflection film (114), the infrared cut-off film (113) and the antireflection film (114) are respectively disposed on two side surfaces of the substrate (112), the lanthanum fluoride strengthening layer (13) is attached to a surface of the infrared cut-off film (113) on a side away from the substrate (112), and the lanthanum fluoride strengthening layer (13) is further attached to a surface of the antireflection film (114) on a side away from the substrate (112); or the optical filter body (11) comprises a substrate (112) and an infrared cut-off film (113), the infrared cut-off film (113) is respectively arranged on the surfaces of the two sides of the substrate (112), and the two lanthanum fluoride strengthening layers (13) are respectively attached to the surfaces of the two infrared cut-off films (113) on the side far away from the substrate (112); or the optical filter body (11) comprises a substrate (112) and an antireflection film (114), the antireflection film (114) is respectively arranged on the surfaces of the two sides of the substrate (112), and the two lanthanum fluoride strengthening layers (13) are respectively attached to the surfaces of the two antireflection films (114) on the side far away from the substrate (112).

7. A filter as claimed in claim 1, wherein the filter body (11) comprises a substrate (112), a layer of silicon dioxide, a layer of magnesium fluoride and a layer of titanium pentoxide, the substrate (112) being provided on either side with the layers of silicon dioxide, magnesium fluoride and titanium pentoxide, respectively.

8. A camera module, comprising the optical filter according to any one of claims 1 to 7.

9. The camera module according to claim 8, further comprising a lens (31), a base (33), a bracket (35), an imaging chip (39), and a circuit board (41), wherein the lens (31) is mounted in the base (33), the base (33) is disposed on the bracket (35), the optical filter is disposed between the lens (31) and the imaging chip (39) in an optical axis direction of the lens (31), the imaging chip (39) and the bracket (35) are disposed on the circuit board (41), a cavity is disposed in the bracket (35), and the optical filter and the imaging chip (39) are both located in the cavity of the bracket (35).