CN107561685B

CN107561685B - Optical filter, lens module and imaging module

Info

Publication number: CN107561685B
Application number: CN201710915564.1A
Authority: CN
Inventors: 曾元清
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2017-09-30
Filing date: 2017-09-30
Publication date: 2020-10-02
Anticipated expiration: 2037-09-30
Also published as: CN107561685A

Abstract

The invention discloses an optical filter. The optical filter comprises a first lens and a second lens which are oppositely arranged at intervals. The first lens includes a first lens surface opposite the second lens, and the second lens includes a second lens surface opposite the first lens. The first mirror surface and the second mirror surface are both provided with high-reflection film layers. At least one of the first mirror surface and the second mirror surface is a step surface, so that at least a first gap and a second gap with different sizes exist between the first lens and the second lens. The first lens and the second lens can move relatively to increase or decrease the first gap and the second gap synchronously. The invention also discloses a lens module and an imaging module. The first lens and the second lens of the optical filter disclosed by the invention at least have a first gap and a second gap with different sizes, when the first lens and the second lens move relatively to a fixed value, the optical filter can output emergent light with at least two different wavelengths, and the emergent light has a wide application range.

Description

Optical filter, lens module and imaging module

Technical Field

The invention relates to the technical field of imaging, in particular to an optical filter, a lens module and an imaging module.

Background

Generally, the variable filter includes two opposite mirror surfaces, and the emergent light with different wavelengths can be obtained by adjusting the size of the gap between the two mirror surfaces, and when the size of the gap between the two mirror surfaces is adjusted to a fixed value, the wavelength of the emergent light of the variable filter is single, and the purpose of the emergent light is single.

Disclosure of Invention

The embodiment of the invention provides an optical filter, a lens module and an imaging module.

The optical filter comprises a first lens and a second lens which are oppositely arranged at intervals, wherein the first lens comprises a first lens surface opposite to the second lens, the second lens comprises a second lens surface opposite to the first lens, high-reflection film layers are arranged on the first lens surface and the second lens surface respectively, at least one of the first lens surface and the second lens surface is a step surface so that at least a first gap and a second gap which are different in size exist between the first lens and the second lens, and the first lens and the second lens can move relatively so that the first gap and the second gap can be synchronously increased or reduced.

The lens module comprises a lens base, a lens barrel arranged on the lens base and the optical filter, wherein the optical filter is arranged in the lens barrel or the lens base.

The imaging module comprises a substrate, an image sensor arranged on the substrate and the lens module, wherein the lens module is fixed on the substrate, and the image sensor is accommodated in the lens module.

According to the optical filter, the lens module and the imaging module, at least a first gap and a second gap which are different in size exist between the first lens and the second lens, when the first lens and the second lens move relatively to a fixed value, the optical filter can output emergent light with at least two different wavelengths, and the emergent light is wide in application.

Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of an optical filter according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an optical filter according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an optical filter according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an optical filter according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an optical filter according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an optical filter according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a lens module according to an embodiment of the invention;

FIG. 8 is a schematic structural diagram of an imaging module according to an embodiment of the invention;

fig. 9 is a schematic structural view of a filter and a driving member according to an embodiment of the present invention.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. The same or similar reference numbers in the drawings identify the same or similar elements or elements having the same or similar functionality throughout.

In addition, the embodiments of the present invention described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the embodiments of the present invention, and are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1, a filter 10 according to an embodiment of the invention includes a first lens 11 and a second lens 12, where the first lens 11 and the second lens 12 are disposed opposite to each other at an interval. The first lens 11 includes a first mirror surface 111 opposite the second lens 12. The second lens 12 includes a second mirror surface 121 opposite the first lens 11. The first mirror surface 111 and the second mirror surface 121 are both provided with a high reflection film layer 13. At least one of the first mirror 111 and the second mirror 121 is a step surface, so that at least a first gap d1 and a second gap d2 with different sizes exist between the first lens 11 and the second lens 12. The first lens 11 and the second lens 12 can move relatively to increase or decrease the first gap d1 and the second gap d2 synchronously.

In the optical filter 10 of the embodiment of the present invention, at least the first gap and the second gap having different sizes exist between the first lens 11 and the second lens 12, when the first lens 11 and the second lens 12 relatively move to a fixed value, the optical filter 10 can output at least two emergent lights with different wavelengths, and the emergent lights have a wide application range.

Referring to fig. 1, the first lens 11 and the second lens 12 may be plate glass or quartz plate. The first mirror surface 111 is opposite to the second mirror surface 121, the first mirror surface 111 and the second mirror surface 121 are provided with high-reflection films, and the high-reflection film layer 13 may be a metal film or a multilayer dielectric film, wherein the metal film may be a silver film, an aluminum film, or the like.

At least one of the first mirror 111 and the second mirror 121 is a step surface, and the first mirror 111 and the second mirror 121 may be both step surfaces (as shown in fig. 2); alternatively, one of the first mirror 111 and the second mirror 121 may be a step surface, and the other may be a plane, for example, the first mirror 111 is a step surface and the second mirror 121 is a plane (as shown in fig. 1 and 3). The step surface at least comprises two parallel mirror surfaces which are not in the same plane pairwise, namely, the step surface can comprise two parallel mirror surfaces which are not in the same plane (as shown in figure 1); the stepped surface may also be a mirror surface including three parallel mirrors, and two mirrors are not in the same plane (as shown in fig. 3). Of course, the number of the mirror surfaces in the stepped surface, which are parallel and not in the same plane two by two, may be four, five or more, and is not limited herein.

There are at least two gaps of different sizes between the first mirror 111 and the second mirror 121. As shown in fig. 1 and 2, two gaps with different sizes, namely a first gap d1 and a second gap d2, exist between the first mirror 111 and the second mirror 121; as shown in fig. 3, three gaps with different sizes, namely, a third gap d3, a fourth gap d4 and a fifth gap d5, exist between the first mirror 111 and the second mirror 121, but the number of the gaps with different sizes may be four, five or other numbers, and is not limited herein. When the first lens 11 and the second lens 12 are relatively moved, the plurality of gaps are synchronously increased or synchronously decreased.

In the optical filter 10 according to the embodiment of the present invention, the first lens 11 and the second lens 12 are disposed opposite to each other at an interval, and the first lens 11 and the second lens 12 form a fabry-perot interferometer, wherein a space between the first mirror 111 and the second mirror 121 forms a fabry-perot cavity. After incident light with various wavelengths enters the optical filter 10 and enters the fabry-perot cavity, light with wavelengths meeting resonance conditions has a very high peak value on a transmission frequency spectrum and corresponds to high transmittance, so that the light can be reflected for multiple times in the fabry-perot cavity to form interference light beams and finally passes through the optical filter 10 to be completely transmitted, and light which does not meet the resonance conditions cannot pass through the optical filter 10. The transmittance of light in the fabry-perot cavity is related to the gap between the first mirror 111 and the second mirror 121, and in general, the resonance condition means that the width (d) of the gap is one half of the wavelength (λ) of the light, i.e., d ═ λ/2, when the light has a high transmittance.

Specifically, at least two gaps with different sizes exist between the first mirror 111 and the second mirror 121, each different gap correspondingly forms a fabry-perot cavity, and the wavelengths of the light transmitted from the optical filter 10 after passing through the different fabry-perot cavities are also different. For example, referring to fig. 1, a first fabry-perot cavity C1 and a second fabry-perot cavity C2 correspond to the first gap d1 and the second gap d2, respectively, and the wavelengths of light transmitted from C1 and C2 are λ 1 and λ 2, respectively, where λ 1 is 2 × d1 and λ 2 is 2 × d 2. The light transmitted out of C1 and C2 may both be visible light, such as red and blue light, respectively, of visible light; or both may be invisible light, for example both infrared light; but also visible light and invisible light, respectively, for example red light and infrared light, respectively, in visible light.

The relative movement of the first lens 11 and the second lens 12 can synchronously change the size of the first gap d1 and the second gap d2, and simultaneously change the wavelengths lambda 1 and lambda 2 of the transmitted light. For example, the light entering the filter 10 is white light (including visible light, infrared light, ultraviolet light, and other types of light), when the first gap d1 has an initial value, the light transmitted from the first fabry-perot cavity C1 may be blue light, and after the value of the first gap d1 is adjusted to a desired value, the light transmitted from the first fabry-perot cavity C1 may be changed to infrared light. Similarly, the light incident into the optical filter 10 is white light, and when the first lens 11 and the second lens 12 move relatively, the light transmitted from the second fabry-perot cavity C2 also changes, which is not described herein.

Referring to fig. 1, the embodiment of the invention will be described in detail by taking the first mirror 111 as a step surface, the second mirror 121 as a plane, and a first gap d1 and a second gap d2 between the first mirror 111 and the second mirror 121 as examples. When the optical filter 10 is used in an imaging module, the size of the first gap d1 and the size of the second gap d2 can be adjusted so that the light transmitted from the C1 and the C2 are both visible light, and the imaging module can realize visible light imaging to acquire a color image; the size of the first gap d1 and the size of the second gap d2 can also be adjusted so that the light transmitted from the C1 and the C2 are both infrared light, and the imaging module can realize infrared imaging to acquire an infrared image. Further, if the imaging module is applied to the mobile device with the iris recognition function, the mobile device can realize color image shooting and iris image shooting only by arranging one imaging module, so that multiplexing of visible light imaging and infrared imaging is realized, the hardware cost of the mobile device is reduced, and meanwhile, the available space of a screen of the mobile device is increased.

Referring to fig. 1, in some embodiments, the optical filter 10 includes an exit surface 122 formed on the first lens 11 or the second lens 12, the exit surface 122 is formed with a first light exit port 1221 and a second light exit port 1222, the first light exit port 1221 corresponds to the first gap d1, and the second light exit port 1222 corresponds to the second gap d 2.

The first light outlet 1221 and the second light outlet 1222 can be used as light outlets for light with two different wavelengths, and different image effects can be obtained by guiding the light emitted from the first light outlet 1221 and the second light outlet 1222 to different image sensors respectively. In the embodiment shown in fig. 1, the light enters the filter 10 from the first lens 11 and exits the filter 10 from the second lens 12, the first mirror 111 is a step surface, the second mirror 121 is a plane surface, the light-emitting surface 122 is formed on the second lens 12, and the light-emitting surface 122 is opposite to the second mirror 121. In the embodiment shown in fig. 4, the light enters the filter 10 from the second lens 12 and exits the filter 10 from the first lens 11, the first mirror 111 is a step surface, the second mirror 121 is a plane surface, the light-emitting surface 122 is formed on the first lens 11, and the light-emitting surface 122 is opposite to the first mirror 111. It should be noted that the first light outlet 1221 and the second light outlet 1222 may be grooves formed on the light outlet surface 122, so as to facilitate positioning of the first light outlet 1221 and the second light outlet 1222 by a user and facilitate assembly with an external device. The first light outlet 1221 and the second light outlet 1222 may also be specific regions on the light emitting surface 122.

Referring to fig. 1, in some embodiments, the first mirror 111 is a step surface, the second mirror 121 is a plane surface, the first mirror 111 includes a first sub-mirror 1121 and a second sub-mirror 1131, and both the first sub-mirror 1121 and the second sub-mirror 1131 are parallel to the second mirror 121.

Specifically, the gap between the first sub-mirror 1121 and the second mirror 121 is a first gap d1, the first sub-mirror 1121 and the second mirror 121 together form a first fabry-perot cavity C1, the gap between the second sub-mirror 1131 and the second mirror 121 is a second gap d2, and the second sub-mirror 1131 and the second mirror 121 together form a second fabry-perot cavity C2. The areas of the first sub-mirror 1121 and the second sub-mirror 1131 may be equal or different, and the size of the first gap d1 and the size of the second gap d2 can be changed synchronously by moving the first lens 11 or the second lens 12.

Referring to fig. 1, in some embodiments, the first lens 11 includes a first sub-lens 112 and a second sub-lens 113, the first sub-lens 1121 is formed on the first sub-lens 112, the second sub-lens 1131 is formed on the second sub-lens 113, and the thicknesses of the first sub-lens 112 and the second sub-lens 113 are equal.

The thicknesses of the first sub-lens 112 and the second sub-lens 113 are equal, and the optical paths of the light rays passing through the first sub-lens 112 and the second sub-lens 113 are equal, so that the attenuation degree of the light rays passing through the first sub-lens 112 and the second sub-lens 113 is the same. When the intensity of incident light is the same everywhere, the intensity of light entering the first and second fabry-perot cavities C1 and C2 is the same. And the thicknesses of the first sub-lens 112 and the second sub-lens 113 are equal, so that part of parameters for processing the first sub-lens 112 and the second sub-lens 113 can be the same, and the first sub-lens 112 and the second sub-lens 113 can be conveniently processed.

Referring to fig. 1, in some embodiments, the first lens 11 further includes a connection lens 114, and the connection lens 114 is obliquely connected to the first sub-lens 112 and the second sub-lens 113.

The thicknesses of the connection lens 114 and the first sub-lens 112 and the second sub-lens 113 may be equal, the materials of the connection lens 114 and the first sub-lens 112 and the second sub-lens 113 may be the same or different, and the connection lens 114 may be a transparent lens or a non-transparent lens.

In one embodiment, the connection lens 114 is obliquely connected to the first sub-lens 112 and the second sub-lens 113, which means that the connection lens 114 is not perpendicular to the first sub-lens 112 and the connection lens 114 is not perpendicular to the second sub-lens 113.

Of course, in other embodiments, the connecting lens 114 can also be connected to the first sub-lens 112 or the second sub-lens 113 perpendicularly. In combination with different connection modes, the first lens 11 has different overall structural stability.

Referring to fig. 5, in some embodiments, the first lens 11 includes a back surface 115 opposite the first mirror surface 111, the back surface 115 being planar.

The first mirror 111 is a stepped surface, the back surface 115 is a plane surface, the structure of the back surface 115 is simple, the processing is easy, and the first lens 11 has high strength and is not easy to break.

Referring to FIG. 1, in some embodiments, the distance between the first sub-mirror 1121 and the second sub-mirror 1131 along the direction perpendicular to the second mirror 121 is (0, 50] nm.

The wavelength range of visible light is [380, 780] nm, and the wavelength range of commonly used infrared light is [800, 900] nm. Since it is generally desirable that the light passed by the filter 10 is one type of light when the filter 10 is used for imaging, for example, the light passed by the filter 10 is visible light to acquire a color image, or the light passed by the filter 10 is infrared light to acquire an infrared image. For example, when the light transmitted through the filter 10 is expected to be the above-mentioned commonly used infrared light, according to the resonance condition of d ═ λ/2, the first gap d1 and the second gap d2 should both be in the range of [400, 450] nm, and if the distance Δ d (Δ d ═ d 1-d 2) between the first mirror 111 and the second mirror 121 is greater than 50 nm, the wavelengths of the light transmitted through the first fabry-perot cavity C1 and the second fabry-perot cavity C2 may not both be in the range of [800, 900] nm. Therefore, the distance between the first mirror 111 and the second mirror 121 can be set within the range of (0, 50] nm, such as 10 nm, 23 nm, 44 nm, 50 nm, etc., according to the practical requirement.

Referring to fig. 1, in some embodiments, the filter 10 further includes an actuator 14, and the actuator 14 is configured to drive the first lens 11 to move the first lens 11 relative to the second lens 12.

Referring to fig. 6, in some embodiments, the actuator 14 is used for driving the second lens 12 to move the first lens 11 and the second lens 12 relatively.

In particular, the actuator 14 may be a magnetostrictive actuator. The magnetostrictive actuator utilizes the magnetostrictive property of a magnetic material, and the magnetic material can expand or contract after an electric field is applied to the material. Therefore, when the actuator 14 is connected to the first lens 11 or the second lens 12, the actuator 14 can drive the first lens 11 or the second lens 12 to move by stretching and contracting so as to change the sizes of the first gap d1 and the second gap d2, thereby realizing tuning and filtering of light.

In one example, the filter 10 may be operated in a visible mode for visible light imaging, and the actuator 14 may drive the first lens 11 or the second lens 12 a plurality of times to acquire light of a plurality of colors. For example, when the actuator 14 changes the first gap d1 and the second gap d2 three times, six different wavelengths of light passing through the optical filter 10 can be obtained, and specifically, when the distance Δ d between the first gap d1 and the second gap d2 is 20 nanometers, the actuator 14 can change the first gap d1 and the second gap d2 three times to obtain wavelengths of light of 700 nanometers and 740 nanometers, 510 nanometers and 550 nanometers, 440 nanometers and 480 nanometers, respectively, and use the light for subsequent imaging, so that the color of the finally obtained image is more realistic and rich.

In another example, the filter 10 may be operated in an infrared light mode for infrared imaging, and the actuator 14 may drive the first lens 11 or the second lens 12 one or more times to acquire infrared light of a plurality of different wavelengths. For example, when the distance Δ d between the first gap d1 and the second gap d2 is 25 nm, the actuator 14 is actuated once such that the first gap d1 is 445 nm and the second gap d2 is 470 nm, and infrared light having a wavelength of 890 nm and a wavelength of 940 nm passing through the filter 10 can be acquired.

It is understood that the driver 50 can also be used to drive the first lens 11 and the second lens 12 simultaneously to move the first lens 11 and the second lens 12 relatively.

Referring to fig. 7, a lens module 100 according to an embodiment of the present invention includes a lens base 20, a lens barrel 30 mounted on the lens base 20, and a filter 10 according to any one of the above embodiments. The optical filter 10 is disposed in the lens barrel 30 or the lens holder 20.

Referring to fig. 7, in some embodiments, the lens module 100 further includes a focusing lens 40, and the focusing lens 40 and the filter 10 are located on the same optical path. Specifically, the focusing lens 40 is disposed in the lens barrel 30, and the optical filter 10 may be disposed in the lens barrel 30 or the lens holder 20. When the filter 10 is located in the lens holder 20, the focusing lens 40 is disposed above the filter 10, i.e., in the lens barrel 30. When the filter 10 is located in the barrel 30, the focusing lens 40 may be disposed above or below the filter 10, in other words, when the filter 10 is located in the barrel 30, the external light may sequentially pass through the filter 10 and the focusing lens 40, or sequentially pass through the focusing lens 40 and the filter 10.

The number of the focusing lenses 40 may be plural, and the lens module 100 may be a zoom lens. Specifically, the lens module 100 further includes an actuator 50, the plurality of focusing lenses 40 are connected to the actuator 50, and the actuator 50 drives the focusing lenses 40 to move to change the focusing focal length of the lens module 100. Of course, the lens module 100 may also be a fixed focus lens, i.e. the focusing lens 40 is fixed in the lens barrel 30 and is not movable.

Referring to fig. 8, an imaging module 1000 according to an embodiment of the present invention includes a substrate 300, an image sensor 200 disposed on the substrate 300, and the lens module 100 according to any of the above embodiments. The lens module 100 is fixed on the substrate 300. The image sensor 200 is housed in the lens module 100.

The image sensor 200 receives the light passing through the optical filter 10 and generates a corresponding electrical signal output, which is processed by a processor connected to the imaging module 1000 to obtain a photographed image. When the optical filter 10 operates in the visible light mode, the image sensor 200 receives a plurality of visible lights (e.g., red light, green light, and blue light) with different wavelengths passing through the optical filter 10 and outputs corresponding electrical signals for a plurality of times, and the processor performs signal processing to obtain a color image. When the optical filter 10 works in the infrared light mode, the image sensor 200 receives infrared light of a plurality of different wavelengths passing through the optical filter 10 and outputs corresponding electrical signals, and the processor performs signal processing to obtain an infrared image.

Referring to fig. 8, in some embodiments, the imaging module 1000 further includes a filter 400, the filter 400 is disposed on a light path between the image sensor 200 and the filter 10, and the filter 400 is configured to selectively pass visible light or infrared light.

It is understood that the fabry-perot interference cavity (C1 and C2) formed between the first lens 11 and the second lens 12 in the optical filter 10 can pass only predetermined types of light under ideal conditions, for example, infrared light, where the transmittance of the optical filter 10 for infrared light accounts for up to 99% of the actual incident light, and the transmittance of other wavelengths of light accounts for almost zero, where the transmittance of the optical filter 10 at the boundary position of the wavelengths of infrared light has a tendency of vertically decreasing. However, in actual operation, the ratio of the transmittance of the filter 10 is decreased to a certain extent at the boundary position of the wavelength of the infrared light. That is, in this case, the filter 10 can pass not only infrared light but also light of a wavelength other than infrared light in a small amount. Similarly, in practice, the filter 10 can pass a small amount of light of wavelengths other than visible light when passing a large amount of visible light. Therefore, in order to make the light received by the image sensor 200 more accurate and obtain better image quality, a filter 400 may be disposed in the imaging module 1000 to selectively filter out visible light or infrared light.

Referring to fig. 8, in some embodiments, the lens barrel 30 or the lens base 20 has a mounting hole 22, and the light passes through the filter 10 and then passes through the mounting hole 22 to further reach the image sensor 200. The filter 400 is movably mounted in the mounting hole 22. The imaging module 1000 further includes a driver 500. The driving member 500 is used to drive the filter 400 to move to open or block the mounting hole 22.

The driver 500 includes a stator 502 and a rotor 504. The stator 502 is mounted on the inner wall of the lens barrel 30 or the lens holder 20. One end of the filter 400 is fitted over the rotor 504. The rotation of the rotor 504 rotates the filter 400 to open or block the mounting hole 22.

Specifically, when the mounting hole 22 is opened on the lens barrel 30, the driving member 500 is correspondingly disposed on the lens barrel 30, and the stator 502 is correspondingly disposed on the lens barrel 30; when the mounting hole 22 is opened in the mirror base 20, the driving member 500 is correspondingly disposed on the mirror base 20, and the stator 502 is correspondingly disposed on the mirror base 20.

In one example, when the image sensor 200 is used for visible light imaging, if the filter 400 is an infrared cut filter (only used for passing light other than infrared light), the driving member 500 can be used to drive the filter 400 to block or open the mounting hole 22 when the filter 10 is in the visible light mode (only passing visible light); if the filter 400 is an infrared pass filter (only used for passing infrared light), the driving member 500 can be used to drive the filter 400 to open the mounting hole 22 when the filter 10 is in the visible mode.

In another example, when the image sensor 200 is used for infrared imaging, if the filter 400 is an infrared cut filter, and the filter 10 is in an infrared mode (only passing infrared light), the driving member 500 can be used to drive the filter 400 to open the mounting hole 22; if the filter 400 is an infrared pass filter, the driving member 500 can be used to drive the filter 400 to block or block the mounting hole 22 when the filter 10 is in the infrared mode.

Referring to fig. 8 and 9, in some embodiments, the filter 400 includes a visible light filter portion 402 and an infrared light filter portion 404. The imaging module 1000 further includes a driving member 500, and the driving member 500 is used for switching one of the visible light filter portion 402 and the infrared light filter portion 404 to be located on the optical path between the image sensor 200 and the optical filter 10.

Specifically, in some embodiments, the driving member 500 includes a stator 502 and a rotor 504, the stator 502 is mounted on the inner wall of the lens barrel 30 or the lens holder 20, and both the visible light filter portion 402 and the infrared light filter portion 404 are fixedly connected to the rotor 504. The rotor 504 can rotate to drive one of the visible light filter portion 402 and the infrared light filter portion 404 to rotate to the optical path between the image sensor 200 and the optical filter 10.

The visible light filter portion 402 is used to pass visible light and filter out light in other wavelength bands. The infrared light filter portion 404 is used to pass infrared light and filter out other bands of light.

When the optical filter 10 is in the visible light mode, the driving member 500 drives the visible light filter portion 402 to rotate to the light path between the image sensor 200 and the optical filter 10, specifically, when the visible light filter portion 402 blocks the mounting hole 22. When the optical filter 10 is in the infrared light mode, the driving member 500 drives the infrared light filter portion 404 to rotate to the optical path between the image sensor 200 and the optical filter 10, specifically, the infrared light filter portion 404 blocks the mounting hole 22. Referring to fig. 9, in the embodiment of the invention, an included angle α between the visible light filter portion 402 and the infrared light filter portion 404 is greater than or equal to 90 degrees. So that the infrared light filter portion 404 completely opens the mounting hole 22 when the visible light filter portion 402 completely blocks the mounting hole 22, and similarly, the visible light filter portion 402 completely opens the mounting hole 22 when the infrared light filter portion 404 completely blocks the mounting hole 22.

In the description of the specification, reference to the terms "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, unless specifically limited otherwise.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and those skilled in the art can make changes, modifications, substitutions and alterations to the above embodiments within the scope of the present invention, which is defined by the claims and their equivalents.

Claims

1. An optical filter, comprising a first lens and a second lens which are oppositely arranged at an interval, wherein the first lens comprises a first lens surface opposite to the second lens, the second lens comprises a second lens surface opposite to the first lens, the first lens surface and the second lens surface are both provided with high reflection film layers, at least one of the first lens surface and the second lens surface is a step surface, at least a first gap and a second gap which are different in size exist between the first lens and the second lens, and the first lens and the second lens can relatively move to enable the first gap and the second gap to be synchronously increased or synchronously decreased;

the first lens comprises a first sub lens and a second sub lens, the first lens further comprises a connecting lens, the connecting lens is obliquely connected with the first sub lens and the second sub lens, and the connecting lens is an opaque lens.

2. The filter of claim 1, wherein the filter includes a light exit surface formed on the first lens or the second lens, the light exit surface is formed with a first light exit port and a second light exit port, the first light exit port corresponds to the first gap, and the second light exit port corresponds to the second gap.

3. The filter of claim 1, wherein the first mirror surface is a step surface, the second mirror surface is a plane surface, the first mirror surface comprises a first sub-mirror surface and a second sub-mirror surface, and the first sub-mirror surface and the second sub-mirror surface are both parallel to the second mirror surface.

4. The filter of claim 3, wherein the first sub-mirror is formed on the first sub-mirror, the second sub-mirror is formed on the second sub-mirror, and the first sub-mirror and the second sub-mirror have equal thicknesses.

5. The filter of claim 3, wherein the first lens piece comprises a back surface opposite the first mirror surface, the back surface being planar.

6. A filter as claimed in claim 3, in which the distance between the first and second sub-mirror surfaces in a direction perpendicular to the second mirror surface is (0, 50] nanometres.

7. The filter of claim 1, further comprising an actuator for driving the first lens and/or the second lens to move the first lens and the second lens relatively.

8. A lens module, comprising:

a lens base; a lens barrel mounted on the lens base; and the optical filter of any one of claims 1 to 7, disposed within the lens barrel or the lens holder.

9. The lens module as claimed in claim 8, further comprising a focusing lens disposed in the lens barrel, wherein the focusing lens and the filter are located on the same optical path.

10. An imaging module, comprising:

a substrate; an image sensor disposed on the substrate; and the lens module set of claim 8 or 9, the lens module set being fixed on the substrate, the image sensor being housed in the lens module set.

11. The imaging module of claim 10, further comprising a filter disposed in an optical path between the image sensor and the filter, the filter configured to selectively pass visible light or infrared light.

12. The imaging module of claim 11, wherein the optical filter comprises a visible light filter portion and an infrared light filter portion, and further comprising a driving member for switching one of the visible light filter portion and the infrared light filter portion on an optical path between the image sensor and the optical filter.

13. The imaging module of claim 12, wherein the driving member includes a stator and a rotor, the stator is mounted on an inner wall of the lens barrel or the lens holder, the visible light filter portion and the infrared light filter portion are both fixedly connected to the rotor, and the rotor is capable of rotating to drive one of the visible light filter portion and the infrared light filter portion to rotate to an optical path between the image sensor and the optical filter.