Optical filter, camera and television system

Abstract

The invention discloses an optical filter, a camera and a television system, and relates to the technical field of optical elements, the optical filter comprises a substrate and an antireflection film, and the antireflection film is attached to a first preset area on the substrate, so that the transmissivity of the optical filter in the first preset area is smaller than that of the substrate. According to the technical scheme provided by the invention, the relative illumination of the camera can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical elements, and in particular to a filter, a camera and a television system. Background Art

[0002] Cameras can be used as sensors to capture ambient light information. This creates special requirements for the camera, such as requiring a higher relative illumination (RI) for the image to facilitate analysis of ambient light information. However, the camera may need to capture light across the largest possible field of view to fully reflect the ambient light information. This can result in significant keystone distortion in the camera image, reducing the RI of the image. Summary of the Invention

[0003] The main purpose of the present invention is to provide a filter, a camera and a television system, aiming to improve the relative illumination of the camera.

[0004] To achieve the above object, the present invention provides an optical filter comprising a substrate and an anti-reflection film. The anti-reflection film is attached to a first predetermined area on the substrate so that the transmittance of the optical filter in the first predetermined area is lower than the transmittance of the substrate.

[0005] In some embodiments, the filter has an optical axis perpendicular to the substrate and an effective area for filtering light; the first preset area is arranged around the optical axis and within the effective area.

[0006] In some embodiments, the antireflection film is circular, with the center of the circle on the optical axis; or the antireflection film is annular, with the center of the circle on the optical axis.

[0007] In some embodiments, the first preset area occupies an area percentage of the effective area that is greater than or equal to 50%.

[0008] In some embodiments, the optical filter further includes a filter film, the filter film is attached to the second preset area on the substrate, and the filter film and the anti-reflection film are distributed in an array.

[0009] In some embodiments, the anti-reflection films and the light filter films are both rectangular, and there are four of them in total; the anti-reflection films and the light filter films are distributed in a rectangular array and are arranged in contact with each other.

[0010] In some embodiments, the filter has an optical axis perpendicular to the substrate and an effective area for filtering; the edge of the first preset area close to the optical axis is a straight edge, and the straight edge is spaced apart from or connected to the optical axis; on the side of the straight edge facing away from the optical axis, the first preset area covers the effective area.

[0011] In some embodiments, the antireflection film includes a SiO2 layer and a Ta2O5 layer, and the SiO2 layer and the Ta2O5 layer are alternately stacked; the thickness of the multiple SiO2 layers is greater than or equal to 15nm and less than or equal to 78nm; and / or the thickness of the multiple Ta2O5 layers is greater than or less than 24nm and less than or equal to 118nm.

[0012] The present invention also discloses a camera comprising an imaging lens, a photosensitive element, and the aforementioned filter. The imaging lens is used to form an image on the photosensitive element, and the filter is disposed between the imaging lens and the photosensitive element. The first predetermined area at least partially corresponds to the photosensitive area of ​​the photosensitive element, so that the anti-reflection film reduces the amount of light entering the position on the photosensitive area corresponding to the anti-reflection film.

[0013] The present invention also discloses a television system comprising a display screen, the aforementioned camera, a light, and a controller. The camera is configured to capture light emission information from the display screen; the light is disposed around the display screen; and the controller is communicatively connected to the camera and the light, and is configured to control the light emission state of the light based on the light emission information captured by the camera.

[0014] In the technical solution of the present invention, the filter can be applied to a camera. In this case, the first preset area on the substrate can correspond to the specific field of view of the camera, and the illumination of the image formed in the specific field of view of the camera can be higher than the illumination of the image formed in other fields of view. Since the anti-reflection film reduces the transmittance of the first preset area of ​​the substrate, the amount of light passing through the field of view corresponding to the first preset area of ​​the substrate is reduced, thereby reducing the illumination of the position with higher illumination in the image formed by the camera, thereby increasing the relative illumination. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0016] Figure 1 A schematic structural diagram of a first embodiment of the optical filter provided by the present invention; Figure 2 A schematic structural diagram of a second embodiment of the optical filter provided by the present invention; Figure 3 A schematic structural diagram of a third embodiment of the optical filter provided by the present invention; Figure 4A schematic structural diagram of a fourth embodiment of the optical filter provided by the present invention; Figure 5 A schematic structural diagram of a first embodiment of a mask provided by the present invention; Figure 6 A schematic structural diagram of a second embodiment of a mask provided by the present invention; Figure 7 A schematic structural diagram of a third embodiment of a mask provided by the present invention; Figure 8 A schematic structural diagram of a fourth embodiment of a mask provided by the present invention; Figure 9 for Figure 6 Enlarged view of part C; Figure 10 A schematic structural diagram of an embodiment of a camera provided by the present invention; Figure 11 A schematic structural diagram of an embodiment of a television system provided by the present invention; Figure 12 This is a transmittance distribution diagram of a multi-layer filter film; Figure 13 This is a diagram showing the relative illumination effect of the first embodiment of the optical filter provided by the present invention when a multi-layer filter film is used.

[0017] Description of Figure Numbers: Filter 10; substrate 11; Anti-reflection film 12; Filter film 13; Vertical field of view reference line a; Horizontal field of view reference line b; Optical center o; Valid area s; Reticle 20; main body 21; baffle 22; connecting portion 23; mask hole 24; Camera 100; first camera 100a; second camera 100b; imaging lens 101; photosensitive element 102; housing 103; Television system 1000; controller 1001; display screen 1002; light 1003; housing 1004.

[0018] The realization of the objectives, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0020] It should be noted that if the implementation methods of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship and movement status of the various components under a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0021] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various implementation methods can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] The present invention provides a filter.

[0023] Please refer to Figure 1 The optical filter 10 of the present invention includes a substrate 11 and an anti-reflection film 12. The anti-reflection film 12 is attached to a first predetermined area on the substrate 11 so that the transmittance of the optical filter 10 in the first predetermined area is lower than the transmittance of the substrate 11.

[0024] The substrate 11 of the optical filter 10 serves as a carrier element, onto which an anti-reflection film 12 is attached to maintain a stable shape. Substrate 11 can be made of materials such as glass, resin, SiC, or plastic (PC, PMMA, or PET), and maintains a fixed shape at room temperature. However, substrate 11 should be substantially transparent. This allows the anti-reflection film 12 to be attached to the substrate 11, thereby filtering light within the target wavelength band.

[0025] The substrate 11 generally also serves as a mounting device, that is, the substrate 11 can be used to be fixed to a device that requires the filter 10. In one example, a portion of the edge of the substrate 11 is not used for filtering, but is used to connect with other components; please refer to Figure 10 The substrate 11 can be snap-fitted, threaded, screwed, or bonded to the housing 103 of the camera 100 , thereby being fixed inside the housing 103 .

[0026] The portion of the substrate 11 that is not used for filtering light, that is, the portion of the substrate 11 that is used for filtering light, can be defined as an effective area s. Figure 1 The active area s is outlined by a dotted circular line. Light passing through the active area s of the substrate 11 is received by a photosensitive element (e.g., a charge-coupled device or complementary metal-oxide semiconductor) and used for imaging. Light passing outside the active area s is stray light and does not contribute to imaging.

[0027] Therefore, the effective area s may correspond to the field of view of the camera device (eg, camera 100). Figure 1 In the figure, this correspondence is represented by the vertical field of view reference line a and the horizontal field of view reference line b. It can be seen that the vertical field of view reference line a and the horizontal field of view reference line b are mutually orthogonal and intersect at the optical center o. Along the extension direction of the vertical field of view reference line a, the field of view angle of the camera device changes in the vertical direction; along the extension direction of the horizontal field of view reference line b, the field of view angle of the camera device changes in the horizontal direction. The optical center o is the intersection of the effective area s and the optical axis of the camera device.

[0028] However, not all embodiments require a portion not used for filtering. In other embodiments, the filter 10 can be attached to the light-receiving surface of the photosensitive element 102, so the portion not used for filtering can be omitted for mounting the filter 10. As a result, the entire surface of the filter 10 is the effective area s. In still other embodiments, the filter 10 can be fixed directly by clamping or gluing the edges of the filter 10, thereby ensuring that the entire surface of the filter 10 is the effective area s.

[0029] In more specialized application scenarios, the photosensitive element itself may not distinguish between horizontal and vertical fields of view. For example, if the light-receiving surface of the photosensitive element is circular rather than rectangular, and the structure distribution on the filter (the antireflection film or the filter film in the embodiments below) has rotational symmetry with an infinitesimal angular period (i.e., it remains identical to itself at any angle along the axis of symmetry), then the horizontal and vertical fields of view will be indistinguishable. Therefore, the vertical and horizontal field of view reference lines a and b are marked with dashed lines and are not essential features.

[0030] In the aforementioned application conditions without horizontal and vertical fields of view, any two mutually orthogonal lines that intersect the optical axis of the device in which the filter is applied can be selected as the vertical field of view reference line a and the horizontal field of view reference line b, respectively. These two mutually orthogonal lines can also intersect at the center of rotational symmetry of the structure distribution on the filter (see below for a detailed explanation of rotational symmetry).

[0031] In addition, it should be noted that Figures 1 to 4 In the figures, a circular dotted line is used to represent the effective area s, but the effective area s may also be a square or other shape, because the area of ​​the light passing through the filter 10 and used for imaging may be square.

[0032] The first predetermined area is the area covered by the anti-reflection film 12, which at least partially overlaps with the effective area s mentioned above. In this way, the anti-reflection film 12 (and the filter film in the following embodiments) is at least partially within the effective area s, thereby modulating the light beam participating in imaging. In some embodiments (for example Figure 2 or Figure 3 In the embodiment shown, the antireflection film 12 (or filter film in the embodiments described below) is partially outside the active area s. Although the antireflection film 12 outside the active area s does not participate in light modulation, it can ensure a more uniform structural distribution at the edge of the active area s, preventing sudden changes in transmittance and ensuring imaging quality. Furthermore, it can prevent cracks in the antireflection film (or filter film) within the active area s during the filter production process, thereby improving the filter's yield rate.

[0033] The anti-reflection film 12 is a film that can reduce the transmittance. It can be a single-layer film, such as a chemically or physically deposited metal film. By adjusting the thickness of the film, the duty cycle of the metal atoms on the substrate 11 can be adjusted, thereby adjusting the transmittance of the position on the substrate 11 covered with the anti-reflection film 12.

[0034] The anti-reflection film 12 may also be a film system (one-dimensional photonic crystal structure) formed by multiple layers of films with different refractive indices. In one example, the anti-reflection film 12 may be configured as shown in the following table:

[0035] The reference numbers indicate the number of film layers, measured outward from the substrate normal. For example, the first film layer, closest to the substrate, is made of silicon dioxide, has a refractive index of 1.46181, and is 15.34 nm thick. The second film layer is made of tantalum pentoxide, has a refractive index of 2.14455, and is 60.40 nm thick. And so on. The thickness of the substrate is not indicated because the refractive index of the substrate 11 affects the transmittance of the film system, not its thickness.

[0036] Please refer to Figure 12, which represents the transmittance of the film system at different wavelengths of light in the table above. It can be seen that its transmittance for visible light is basically maintained at 50%. When such a film system is attached to the corresponding substrate 11, the portion of the substrate 11 where the anti-reflection film 12 is attached creates a "semi-reflective, semi-transparent" effect.

[0037] It should be noted that the film structure can be designed to have a specific transmittance for light in a specific wavelength band, such as 40% or 60% for visible light. For another example, the film structure can be designed not for visible light but for infrared light or ultraviolet light, so that the film structure can have a transmittance of, for example, 40%, 50%, or 60% for infrared light or ultraviolet light. In this way, the anti-reflection film 12 can achieve a target percentage transmittance for light in the target wavelength band, meeting the needs of various application scenarios.

[0038] Please refer to Figure 1 , Figure 1 In the embodiment shown, the anti-reflection film 12 (i.e., the first predetermined area) occupies the central viewing angle. In one example, the circular anti-reflection film 12 can occupy 50% of the viewing angle, and the film structure in the above table is used as the anti-reflection film 12. Please refer to Figure 13 , wherein the “RI curve of the low relative illumination optical system” is the relative illumination distribution curve of the image before the filter 10 is added.

[0039] It can be seen that when the filter 10 is not added, the relative illumination at the center position (the position with the horizontal coordinate of 0.0) is 1.0, and the relative illumination at the edge position (the position with the horizontal coordinate of 1.0) is about 0.25. Therefore, the relative illumination at the edge position is 0.25 / 1.0, which is equal to 25%. After adding the filter 10, the anti-reflection film 12 reduces the transmittance at the center of the field of view. Therefore, the relative illumination at the center of the image is reduced by 50% compared to when the filter 10 is not added (that is, in the "RI curve after superimposing 50% field of view and 50% filter 10", the relative illumination is 0.5 at the position of 0.0 on the horizontal axis). After normalization, the illumination at the center is 0.85, and the illumination at the edge is 0.4 (that is, the relative illumination at the positions of 0.0 and 1.0 on the horizontal axis of the "normalized RI curve after superimposing the filter 10"). In this way, the illumination at the edge is 0.4 / 0.85, which is equal to 47%. Compared with 25%, the relative illumination is significantly improved.

[0040] It can be seen from the above that under the above application conditions, for the relative illumination of the edge field of view, this application Figure 1 The embodiment shown can significantly improve the relative illumination of the edge field of view. Figure 13 From the curve shown, it can be seen that the relative illumination has also been improved in other fields of view. This improvement can also be referred to as Figure 13The improvement of the integral average of the middle curve increases the average relative illumination of each part in the entire field of view.

[0041] Furthermore, the substrate 11 generally has a high transmittance. Therefore, the antireflection film 12 can be provided to reduce the transmittance of specific regions of the substrate 11, thereby effectively improving the relative illumination. In some embodiments, an antireflection film can also be provided to increase the transmittance of regions on the substrate 11 corresponding to regions of low imaging illumination, thereby improving the relative illumination. For details, please refer to the following embodiments.

[0042] It can be seen that in the technical solution of the present invention, since the anti-reflection film 12 is provided on the substrate 11, the anti-reflection film 12 can be provided in the area of ​​the substrate 11 corresponding to the field of view with high illumination (i.e., the first preset area), so that the relative illumination of the final imaged pattern is improved.

[0043] Please refer to Figure 1 and Figure 2 In some embodiments, the filter 10 has an optical axis perpendicular to the substrate 11 and an effective area s for filtering light; the first preset area is arranged around the optical axis and within the effective area s.

[0044] The optical axis of the filter 10, that is, the axis preset by the filter 10 for coinciding with the optical axis of the device to which the filter 10 is applied, can be seen. Figure 1 or Figure 2 In FIG, the optical center o is the intersection of the optical axis of the filter and the substrate 11.

[0045] When the intensity of incident light entering the optical filter 10 is relatively uniform at different field angles, since the entrance pupil of the device in which the optical filter 10 is used cannot be infinitely large, the illumination of the image formed by incident light at large field angles is often lower, while the illumination of the image formed by incident light at small field angles is higher. This is reflected in the optical filter 10, namely, the illumination distribution is generally uniform around the optical axis. Therefore, the provision of an antireflection film 12 around the optical axis and within the effective area s (that is, the first predetermined area surrounds the optical axis and is distributed within the effective area s) can often reduce the illumination at high-intensity locations in the final image, thereby improving the relative illumination of the image.

[0046] The first preset area surrounds the optical axis and may be in the shape of a polygonal ring around the optical axis, with its geometric center at the optical center o. The first preset area may also be in the shape of a polygon, with its geometric center at the optical center o.

[0047] Please refer to Figure 1 In some embodiments, the antireflection film 12 is circular, and the center of the circle is on the optical axis.

[0048] like Figure 13As shown, in some application scenarios, the relative illumination of the central field of view is the highest. Therefore, a circular anti-reflection film 12 is provided at the optical axis to reduce the relative illumination of the image formed by the light in the central field of view, thereby improving the relative illumination of the image.

[0049] Also, please refer to Figure 11 When the filter 10 is applied to the television system 1000, the camera 100 equipped with the filter 10 may face the display screen 1002 of the television system 1000 in a straight-on manner to capture the light emitted by the display screen 1002. At this time, the relationship between the camera 100 and the display screen 1002 is exactly as mentioned above. The light from the display screen 1002 incident on the camera 100 has a relatively uniform intensity at all angles of the camera 100's field of view. Therefore, the relative illumination of the central field of view is the highest, and the light intensity distribution has obvious rotational symmetry with respect to the optical axis. In this case, the simple circular anti-reflection film 12 can effectively improve the relative illumination (such as Figure 13 ).

[0050] Please refer to Figure 2 In some embodiments, the antireflection film 12 is annular, and the center of the circle is on the optical axis.

[0051] The antireflection film 12 may be in the form of a continuous ring or a discontinuous ring. Figure 2 The ring shape shown is a discontinuous ring shape, which makes it easier to produce the filter 10 .

[0052] The device used with the filter 10 may not be a conventional camera 100, but may be a more specialized imaging device, such as a wavefront sensor. This type of device also has a photosensitive element 102 and can produce an image, but the image may be a far-field diffraction image. In this case, if the wavefront at the entrance pupil has an odd number of half-wavelength bands relative to the center of the imaging position, the center will be a dark spot, resulting in lower illumination. Bright annular stripes may appear outside the center. In this case, an annular anti-reflection film 12 may be used to increase relative illumination.

[0053] Please refer to Figure 1 In some embodiments, the first preset area occupies an area percentage greater than or equal to 50% of the effective area s. That is, the quotient of the area of ​​the first preset area and the area of ​​the effective area s is greater than or equal to 50%.

[0054] When the field of view corresponding to the area with high relative illumination is the central field of view, please refer to Figure 13 If the first preset area occupies too small an area of ​​the effective area s, it will not be able to cover the center position, and the area with overall high illumination (for example Figure 13In the example, the horizontal axis is in the range of 0.0 to 0.2, so the relative illumination is not significantly improved. Therefore, the quotient of the area of ​​the first preset area and the area of ​​the effective area s is set to be greater than or equal to 50%, so that the relative illumination is more significantly improved.

[0055] Please refer to Figure 3 In some embodiments, the filter 10 further includes a filter film 13 , which is attached to the second preset area on the substrate 11 ; the filter film 13 and the anti-reflection film 12 are distributed in an array.

[0056] The filter film 13 is a film that modifies the transmittance of the filter 10 in the second predetermined region. This modification can increase, decrease, or even maintain transmittance. When the filter film 13 increases transmittance, it functions as an antireflection film. When it decreases transmittance, it functions as an antireflection film (which can be identical to the antireflection film 12 mentioned above). When the filter film 13 does not change transmittance, it functions as a protective film.

[0057] In some application scenarios, the illumination distribution of the image may not be symmetrical with respect to the optical axis, but may be arranged according to a certain pattern in different areas of the image plane. Figure 11 In the embodiment of the television system 1000 shown, when two cameras 100 (i.e., the first camera 100a and the second camera 100b) shoot the display screen 1002, since the display screen 1002 is generally provided with a focusing structure (such as a prism array or a lens array, etc.), generally when observing the display screen 1002 in a direction with a large angle to the surface normal of the display screen 1002, it will be found that the brightness of the display screen 1002 is significantly reduced.

[0058] Therefore, for Figure 11 The illumination distribution of the first camera 100a in the image may show a rule of gradually increasing or decreasing along the horizontal field of view direction or the vertical field of view direction; similarly, for Figure 11 The illumination distribution of the imaging of the second camera 100b may be mirror-symmetrical with respect to the oblique field of view.

[0059] In this way, at least one of the filter film 13 and the anti-reflection film 12 can be provided with multiple sheets, and the filter film 13 and the anti-reflection film 12 are distributed in an array to adapt to the illumination change trend. Figure 3 , in some imaging laws, it may be Figure 3In the illustrated filter film 13, the lower left, upper right, and lower right regions correspond to higher field of view imaging illumination, while the upper left region corresponds to lower field of view imaging illumination. This allows the second predetermined region to cover the upper left region, meaning the filter film 13 in the figure can be an antireflection film, while the first predetermined region covers the lower left, upper right, and lower right regions, meaning the filter 10 in the figure is provided with three antireflection films 12. The three antireflection films 12 can have different transmittances. For example, the lower left and upper right antireflection films 12 can have higher transmittances, while the lower right antireflection film 12 can have lower transmittances, because the lower right region may correspond to higher imaging illumination.

[0060] In other embodiments, the filter film 13 may be provided in multiple pieces, while the anti-reflection film 12 may be provided in a single piece, or both the filter film 13 and the anti-reflection film 12 may be provided in multiple pieces. Figure 3 The rectangular array of the 2X2 structure can be a triangular array, a hexagonal array, etc. The rectangular array can also be a 3X3 or 4X4 rectangular array, where the numbers on both sides of X represent the number of rows and columns respectively.

[0061] Since the illumination distribution in the image may be in the form of intermittent patches, the anti-reflection films 12, the filter films 13, and the anti-reflection films 12 and the filter films 13 may be spaced apart. Of course, if the illumination of the image varies uniformly, the relationships between the above three types may also be continuous.

[0062] In other embodiments, the filter film 13 and the anti-reflection film 12 may be provided in a single piece each and arranged adjacently or spaced apart. The filter film 13 and the anti-reflection film 12 may also be provided in the same or different shapes according to actual needs. Such a filter film 13 and the anti-reflection film 12 are equivalent to forming a 1X2 (or 2X1) array.

[0063] Please refer to Figure 3 In some embodiments, the anti-reflection film 12 and the filter film 13 are both rectangular, and there are four of them in total; the anti-reflection film 12 and the filter film 13 are distributed in a rectangular array and are connected to each other.

[0064] The anti-reflection film 12 and the filter film 13 are both rectangular, so the anti-reflection film 12 and the filter film 13 can uniformly cover the entire effective area s. Figure 3 In the illustrated embodiment, it can be seen that the first preset area and the second preset area cover the entire effective area s, increasing the area that can be modulated by the anti-reflection film 12 and the filter film 13 (i.e., the sum of the area where the first preset area overlaps with the effective area s and the area where the second preset area overlaps with the effective area s).

[0065] Please refer to Figure 4In some embodiments, the filter 10 has an optical axis perpendicular to the substrate 11 and an effective area s for filtering; the edge of the first preset area close to the optical axis is a straight edge, and the straight edge is separated from or connected to the optical axis; on the side of the straight edge facing away from the optical axis, the first preset area covers the effective area s.

[0066] exist Figure 4 In the illustrated embodiment, it can be seen that the first preset area (the area covered by the anti-reflection film 12) has a straight edge intersecting with the optical center o. This is the case where the straight edge of the first preset area intersects with the optical axis. Since it intersects with the optical axis and the side of the straight edge facing away from the optical axis covers the effective area s, the field of view that can be modulated by the anti-reflection film 12 at this time is 50% of the overall field of view.

[0067] In other embodiments, the straight edge may be spaced apart from the optical center o, so that the field of view that can be modulated by the antireflection film 12 is less than 50% of the entire field of view.

[0068] In many scenarios, the location with high imaging illumination is biased to one side of the image, e.g. Figure 11 In the image captured by the first camera 100a, the high-illuminance area may be on one side of the image in the vertical field of view. Therefore, setting the straight edge of the first preset area to be distributed on one side of the optical axis can further improve the relative illumination of the image in this case.

[0069] In some embodiments, the antireflection film includes SiO2 layers and Ta2O5 layers, which are alternately stacked; the thickness of the multiple SiO2 layers is greater than or equal to 15 nm and less than or equal to 78 nm; The SiO2 and Ta2O5 layers are both film layers. Due to the different refractive indices of silicon dioxide and tantalum pentoxide, alternating SiO2 and Ta2O5 layers can form a one-dimensional photonic crystal. Referring to the implementation scheme in the table above, it can be seen that this allows the anti-reflection film to have a predetermined transmittance for light in the target wavelength band.

[0070] In the implementation manner in the above table, the film layers labeled with odd numbers represent different SiO2 layers, and there are a total of 8 SiO2 layers; the film layers labeled with even numbers represent different Ta2O5 layers, and there are a total of 8 Ta2O5 layers.

[0071] In the embodiments shown in the table above, it can be seen that among the SiO2 layers, the thinnest is the first film layer, with a thickness of 15.34 nm, and the thickest is the seventh film layer, with a thickness of 77.90 nm. The inventors have discovered that when the thickness of the SiO2 layer is too small, the manufacturing difficulty increases significantly. This is because when molecules are deposited to form the corresponding film layer, the error in the film layer thickness does not decrease as the film layer thickness decreases. Therefore, the smaller the film layer thickness, the greater the percentage of the thickness occupied by the same error (for example, if the error is 1 nm, then compared to a 10 nm film layer, the error accounts for 10%, and for a 100 nm film layer, the error accounts for 1%). Thus, the thinner the film layer thickness, the smaller the manufacturing error required to ensure the normal operation of the anti-reflection film.

[0072] When the SiO2 layer is too thick, the transmittance variation tends to weaken with the thickness of the SiO2 layer, making the film design more difficult. However, when the SiO2 layer thickness is greater than or equal to 15nm and less than or equal to 78nm, the anti-reflection film can be manufactured with lower difficulty and design difficulty.

[0073] In one example, the thickness of the SiO2 layer can be 15 nm, 18 nm, 23 nm, 26 nm, 30 nm, 33 nm, 38 nm, 43 nm, 48 nm, 56 nm, 59 nm, 64 nm, 72 nm, or 78 nm. It should be noted that different SiO2 layers of an antireflection film can have different thicknesses.

[0074] In some embodiments, the thickness of the multiple Ta2O5 layers is greater than or less than 24 nm, and less than or equal to 118 nm.

[0075] Similar to the SiO2 layer, when the thickness of the Ta2O5 layer is too small, the manufacturing difficulty of the anti-reflection film is too great; when the thickness of the Ta2O5 layer is too large, the design difficulty of the anti-reflection film is too great; and when the thickness of the Ta2O5 layer is greater than or less than 24 nm, and less than or equal to 118 nm, the anti-reflection film has lower manufacturing difficulty and design difficulty.

[0076] In one example, the thickness of the Ta2O5 layer can be 24 nm, 28 nm, 35 nm, 46 nm, 58 nm, 63 nm, 69 nm, 78 nm, 86 nm, 94 nm, 102 nm, 110 nm, 115 nm, or 118 nm. It should be noted that different Ta2O5 layers of an antireflection film can have different thicknesses.

[0077] Please refer to Figure 5 The present invention further provides a mask 20 for manufacturing the above-mentioned filter 10. The specific structure of the filter 10 is referred to the above-mentioned embodiment.

[0078] Please refer to Figure 5 and Figure 1 During the manufacture of the optical filter 10, a reticle 20 can be placed on the surface of the substrate 11. The reticle 20 can block locations on the substrate 11 where the filter film 13 and / or anti-reflection film 12 are not required, while exposing the first and second predetermined locations. Specifically, the main body 21 of the reticle 20 can block locations where the filter film 13 and / or anti-reflection film 12 are not required, while the mask holes 24 can expose the first and second predetermined locations. This allows the anti-reflection film 12 to be placed at the first predetermined location and the filter film 13 to be placed at the second predetermined location.

[0079] There can be multiple mask holes 24 on the mask plate 20, so that a mask plate 20 can be used to form multiple filters 10 on a larger substrate 11. After the film layer is formed, the larger substrate 11 is cut into multiple filters 10 to form the required filters 10.

[0080] Please refer to Figure 7 In some embodiments, a mask hole 24 is opened on the mask plate 20, and there are multiple mask holes 24, and the multiple mask holes 24 are distributed in an array; the array formed by the multiple mask holes 24 has a rotational symmetry with a rotation period of 90°, and the axis of rotation of the rotational symmetry is perpendicular to the plane where the mask plate 20 is located.

[0081] Rotational symmetry refers to the property of a structure with rotational symmetry that allows it to be aligned with itself after being rotated around a desired axis and angle. Therefore, the rotational symmetry of the array of mask apertures 24 described above means that there is at least one axis perpendicular to the plane of the reticle 20, so that the array can be aligned with itself after being rotated 90° around this axis.

[0082] For this axis position, Figure 7 In the embodiment shown, the intersection of the diagonals of the mask holes 24 in the third row and the third column (the axis of rotation is perpendicular to the mask 20, so the intersection of the axis of rotation and the mask 20 is visible in the figure). It can be seen that Figure 7 The array in the figure can be aligned with itself after rotating 90° around the axis.

[0083] for Figure 5 and Figure 6 In the embodiment, the above-mentioned rotational symmetry is also present, and the rotation period is also 90°. Figure 5 In the embodiment shown, the axis of symmetry is at the center of the mask hole 24 in the third row and third column. Figure 6 In the illustrated embodiment, the axis of symmetry is at the center of the mask hole 24 in the third row and third column (the center is on the baffle 22 , that is, the center of the baffle 22 ).

[0084] The mask 20 having the rotational symmetry thus set is Figure 5 and Figure 6In the illustrated embodiment, the mask 20 and the substrate 11 can correspond to each other in multiple directions, that is, they can remain corresponding after being rotated 90° around the axis of symmetry, which is convenient for operators to use.

[0085] for Figure 7 In the embodiment shown, after the mask 20 rotates along with the array, the mask 20 does not actually overlap with itself, but only the array of mask holes 24 overlaps with itself. In this case, the mask 20 can be rotated around a predetermined axis parallel to the symmetry axis instead of the symmetry axis of the array. Specifically, for Figure 7 In the embodiment shown, the preset axis is the axis passing through the lower right corner of the mask hole 24 in the third row and third column. It can be seen that after rotating around this axis, the mask hole 24 moves.

[0086] Figure 7 The reticle 20 of the illustrated embodiment can be used to manufacture Figure 3 The filter 10 shown. Figure 7 In the state shown, the mask hole 24 is just open. Figure 3 The filter film 13 at the upper left of the filter 10 is shown; after rotating 90° about the predetermined axis, the anti-reflection film 12 at the upper right of the filter 10 is exposed. It can be seen that after the mask 20 is rotated 90° twice more, the anti-reflection films 12 at the lower right and lower left can be exposed in sequence.

[0087] In this way, one mask 20 can be used to manufacture the filter films 13 and / or anti-reflection films 12 at different positions on the filter 10, which helps to reduce the manufacturing cost.

[0088] In addition, it should be noted that Figure 5 The reticle 20 of the illustrated embodiment can be used to manufacture Figure 1 The filter 10 shown; Figure 6 The reticle 20 of the illustrated embodiment can be used to manufacture Figure 2 The filter 10 shown; Figure 7 The reticle 20 of the illustrated embodiment can be used to manufacture Figure 3 The filter 10 shown; Figure 8 The reticle 20 of the illustrated embodiment can be used to manufacture Figure 4 The filter 10 is shown.

[0089] Please refer to Figure 6 and Figure 9 In some embodiments, the mask 20 includes a main body 21, a baffle 22 and a connecting portion 23. The main body 21 and the baffle 22 are spaced apart to form a mask hole 24 surrounding the baffle 22 between the main body 21 and the baffle 22; the main body 21 and the baffle 22 are connected by the connecting portion 23.

[0090] The connecting portion 23 and the baffle 22 can form a stable connection relationship, ensuring that the relative position relationship between the main body 21 and the baffle 22 remains unchanged, thereby ensuring the stable formation of the annular mask hole 24. In addition, the connecting portion 23 can be as Figure 6 In the embodiment shown, four connecting portions 23 are provided, but only one, two, three, or five connecting portions 23 may be provided. When there are multiple connecting portions 23, the multiple connecting portions 23 may be spaced and evenly distributed in the axial direction of the baffle 22, thereby evenly connecting the main body 21 and the baffle 22.

[0091] Please refer to Figure 10 The present invention also proposes a camera 100 comprising an imaging lens 101, a photosensitive element 102, and the aforementioned optical filter 10. The specific structure of the optical filter 10 is similar to the above-described embodiments. Since the present camera 100 employs all the technical solutions of all the above-described embodiments, it at least has all the beneficial effects brought about by the technical solutions of the above-described embodiments, which will not be described in detail here. The imaging lens 101 is used to form an image on the photosensitive element 102, and the optical filter 10 is disposed between the imaging lens 101 and the photosensitive element 102; the first preset area at least partially corresponds to the photosensitive area of ​​the photosensitive element 102, so that the anti-reflection film 12 reduces the amount of light entering the position on the photosensitive area corresponding to the anti-reflection film 12.

[0092] The lens is a component for receiving external light, integrating the external light, and finally forming an image on the photosensitive element 102. The lens can be installed on the housing 103 of the camera 100, which is a component including the outer shell of the camera 100 and other components.

[0093] The meaning of photosensitive element 102 can be referred to above. Photosensitive element 102 can be installed in housing 103 of camera 100. The photosensitive area of ​​photosensitive element 102 is the area occupied by the pixel units on photosensitive element 102 that participate in light sensing. Therefore, the effective area mentioned above can also be considered as the area on the filter through which light can pass and enter the photosensitive area after passing through.

[0094] The camera 100 may need to image a distant scene. In this case, light emitted by different object points enters the entrance pupil of the camera 100 approximately as parallel light. Consequently, on the light-entry side of the lens, the light beams corresponding to image points at different field angles of view of the camera 100 overlap, making them difficult to distinguish. On the light-exit side of the lens, as the image gradually forms (because the image ultimately forms on the photosensitive element 102), the light beams corresponding to different image points gradually separate. Furthermore, the first predetermined area at least partially corresponds to the photosensitive area of ​​the photosensitive element 102, so the anti-reflection film 12 also at least partially corresponds to the photosensitive area. The portion of the photosensitive area corresponding to the anti-reflection film 12 effectively occupies a portion of the camera's field of view, allowing the anti-reflection film 12 to accurately reduce the amount of light entering that portion of the camera's field of view, specifically reducing the amount of light entering the portion of the photosensitive area corresponding to the anti-reflection film 12.

[0095] Therefore, setting the filter 10 between the lens and the photosensitive element 102 can separate the light corresponding to different field angles in the space where the filter 10 is located, which helps the filter 10 to more accurately block the light corresponding to the field angle with high illumination, thereby making the effect of improving the relative illumination of the final imaging more significant.

[0096] Please refer to Figure 11 The present invention also proposes a television system 1000, comprising a controller 1001, a display screen 1002, a lamp 1003 and the above-mentioned camera 100. The specific structure of the camera 100 refers to the above-mentioned embodiment. Since the television system 1000 adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above-mentioned embodiments, which will not be described one by one here. Among them, the controller 1001 is communicatively connected to the camera 100. The camera 100 is used to capture the light output information of the display screen 1002. The lamp 1003 is communicatively connected to the controller 1001. The controller 1001 is configured to control the light-emitting state of the lamp 1003 through the light output information captured by the camera 100.

[0097] The display screen 1002 is the main display device of the television system 1000. The image that the television system 1000 needs to display is basically displayed through the display screen 1002. The lamp 1003 can be a lamp bead or a Figure 11 As shown in the light strip. Figure 11 As shown, the light 1003 can be set independently of the display screen 1002, or it can be set on the housing 1004 of the display screen 1002. The light 1003 can assist the display screen 1002 in displaying, for example, the light 1003 can provide an atmosphere, a sense of space or a three-dimensional display effect.

[0098] Thus, the lighting state of lamp 1003 needs to be changed according to the display content of display screen 1002 to provide the desired display effect. The lighting state of lamp 1003 can be the state of the brightness and color of the emitted light. For a light strip, it can also be the distribution of brightness and / or color on the light strip.

[0099] The light emission information of the display screen 1002 is the spatial distribution information of the light emitted by the display screen 1002. The camera 100 may be a wide-angle camera 100, so as to capture the light emission information of the display screen 1002 in a wider range as possible.

[0100] The controller 1001 is connected to the camera 100 to obtain the light emission information of the display screen 1002 collected by the camera 100. The controller 1001 can control the light emission state of the light 1003 based on the light emission information to achieve the desired display state, thereby improving the display effect of the television system 1000.

[0101] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformation made by using the contents of the present invention description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the scope of protection of the present invention.

Claims

1. A filter, characterized in that: include: substrate; An anti-reflection film is attached to a first preset area on the substrate, so that the transmittance of the filter in the first preset area is lower than the transmittance of the substrate.

2. The optical filter according to claim 1, wherein The filter has an optical axis perpendicular to the substrate and an effective area for filtering light; the first preset area is arranged around the optical axis and within the effective area.

3. The optical filter according to claim 2, wherein: The antireflection film is circular, with its center on the optical axis; or the antireflection film is annular, with its center on the optical axis.

4. The optical filter according to claim 2, wherein: The first preset area occupies an area percentage of the effective area that is greater than or equal to 50%.

5. The optical filter according to claim 1, wherein The optical filter further includes a filter film, which is attached to the second preset area on the substrate. The filter film and the anti-reflection film are distributed in an array.

6. The optical filter according to claim 5, wherein The anti-reflection films and the light filter films are both rectangular, and there are four of them in total; the anti-reflection films and the light filter films are distributed in a rectangular array and are connected to each other.

7. The optical filter according to claim 1, wherein The filter has an optical axis perpendicular to the substrate and an effective area for filtering; the edge of the first preset area close to the optical axis is a straight edge, and the straight edge is spaced apart from or connected to the optical axis; on the side of the straight edge facing away from the optical axis, the first preset area covers the effective area.

8. The optical filter according to any one of claims 1 to 7, wherein: The antireflection film includes a SiO2 layer and a Ta2O5 layer, and the SiO2 layer and the Ta2O5 layer are alternately stacked; the thickness of the multiple SiO2 layers is greater than or equal to 15nm and less than or equal to 78nm; and / or the thickness of the multiple Ta2O5 layers is greater than or less than 24nm and less than or equal to 118nm.

9. A camera, characterized in that: comprising an imaging lens, a photosensitive element, and the filter according to any one of claims 1 to 8; The imaging lens is used to form an image on the photosensitive element, and the filter is arranged between the imaging lens and the photosensitive element; the first preset area at least partially corresponds to the photosensitive area of ​​the photosensitive element, so that the anti-reflection film reduces the amount of light entering the position on the photosensitive area corresponding to the anti-reflection film.

10. A television system, characterized in that: include: Display screen; The camera according to claim 9, wherein the camera is used to capture light output information of the display screen; Lights, arranged around the display screen; A controller is communicatively connected with the camera and the lamp, and the controller is configured to control the lighting state of the lamp through the light emission information captured by the camera.

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