Camera array with suppressed crosstalk

Abstract

The imaging device comprises an image sensor and a plurality of optical elements arranged in an array, each optical element configured to direct light to different photosensitive areas of the image sensor to capture each image, the imaging device further comprises an aperture layer, the aperture layer comprises a plurality of apertures arranged to be aligned with each of the plurality of optical elements, and the imaging device further comprises a layer configured to suppress optical crosstalk within the imaging device.

Description

Technical Field

[0001] Background An array camera can be based on an array of lenses. In some cases, an image with a higher resolution than the individual images can be generated by combining the individual images generated by each lens of the array.

[0002] Summary This specification describes techniques related to an imaging device such as an array camera including a metalens, particularly an array camera designed to suppress optical crosstalk between lenses of the array.

Summary of the Invention

Means for Solving the Problems

[0003] Generally, in some aspects, the subject matter of the present disclosure can be embodied in an imaging device. The imaging device includes an image sensor and a plurality of optical elements arranged in an array, each optical element being configured to direct light to different photosensitive regions of the image sensor to capture each image, the imaging device further including an aperture layer, the aperture layer including a plurality of apertures arranged to be aligned with each of the plurality of optical elements, the imaging device further including an optical filter layer disposed adjacent to the aperture layer, the optical filter layer being configured to filter and remove light having an incident angle outside a predetermined visual field.

[0004] Implementations of these embodiments may include one or more features. For example, in some implementations, the optical filter layer is positioned in front of the aperture layer so that it is closer to the object being imaged by the imaging device than the aperture layer. Alternatively, the optical filter layer may be positioned behind the aperture layer so that it is further away from the object being imaged by the imaging device than the aperture layer. The imaging device may also include an additional optical filter layer, which is positioned in front of the aperture layer so that it is closer to the object being imaged by the imaging device than the aperture layer. The optical filter layer may be fixed to the aperture layer.

[0005] In some implementations, each aperture of a group of apertures has a substantially rectangular opening through which incident light passes. The shape of each optical element of the group of optical elements may also be substantially rectangular.

[0006] In some implementations, each optical element of the multiple optical elements may be configured to distort incident light and project a corresponding substantially rectangular image onto each photosensitive area of ​​the image sensor. Each aperture of the multiple apertures may have a substantially circular opening through which incident light passes.

[0007] In some implementations, each optical element in an array of optical elements has a metastructure. The phase shift induced by each optical element by incident light may differ across the region of the optical element.

[0008] In some implementations, the size of at least one of the multiple apertures increases from the first face to the second face of the aperture layer. At least one aperture may include a cone shape. In some implementations, the optical filter is an interference filter. In some implementations, the optical filter layer is configured to function as a spectral filter layer.

[0009] In some implementations, the device includes a baffle. The baffle may have an opening positioned to cover at least one aperture in the aperture layer. The opening in the baffle layer may be larger than at least one aperture. The side walls of the baffle opening may be positioned obliquely to the normal of the surface of the aperture layer facing the object to be imaged.

[0010] In some implementations, the imaging device includes a first spectral filter aligned to a first aperture among a plurality of apertures, and the first spectral filter is configured to filter out light having wavelengths within a first wavelength range. The imaging device may also include a second spectral filter aligned to the first aperture, and the second spectral filter is configured to filter out light having wavelengths within a second wavelength range different from the first wavelength range.

[0011] Generally, in some embodiments, the imaging device comprises an image sensor and a plurality of optical elements arranged in an array, each optical element configured to direct light to different photosensitive areas of the image sensor to capture each image; the imaging device further comprises an aperture layer, the aperture layer comprising a plurality of apertures arranged to be aligned with each of the plurality of optical elements; the imaging device further comprises a first spectral filter layer, the first spectral filter layer comprising a first plurality of spectral filters aligned with each of the plurality of apertures, each spectral filter of the first plurality of spectral filters configured to filter out a corresponding wavelength range. The imaging device may also comprise a second spectral filter layer, the second spectral filter layer comprising a second plurality of spectral filters aligned with each of the plurality of apertures, each spectral filter of the second plurality of spectral filters configured to filter out a corresponding wavelength range.

[0012] In general, in some embodiments, the subject matter of the present disclosure is embodied in an imaging device. The imaging device comprises an image sensor and a plurality of optical elements arranged in an array, each optical element configured to direct light to different photosensitive areas of the image sensor to capture each image, the imaging device further comprises an aperture layer, the aperture layer comprising a plurality of apertures arranged to be aligned with each of the plurality of optical elements, and the imaging device is configured to filter out light whose incident angle is outside a predetermined field of view so that it does not reach the image sensor.

[0013] The implementation of the imaging device may include one or more of the following features. For example, the aperture layer may be configured to filter out light whose incident angle is outside a predetermined field of view so that it does not reach the image sensor. The size of at least one of the multiple apertures may increase from the first surface to the second surface of the aperture layer.

[0014] In some implementations, the device includes a baffle layer. The baffle may have an opening positioned to cover at least one aperture of the aperture layer. The opening in the baffle layer may be larger than at least one aperture. The side walls of the opening in the baffle layer may be positioned obliquely to the normal of the surface of the aperture layer facing the object to be imaged.

[0015] In some implementations, the device includes an optical filter layer positioned adjacent to the aperture layer, and the optical filter layer is configured to filter and remove light with an incident angle outside a predetermined field of view. The optical filter layer may be positioned in front of the aperture layer so that it is closer to the object being imaged by the imaging device than the aperture layer. The optical filter layer may be positioned behind the aperture layer so that it is further away from the object being imaged by the imaging device than the aperture layer. The optical filter layer may be an interference filter. The optical filter layer may also be a spectral filter layer. The optical filter layer may include a first filter aligned with a first aperture of the aperture layer, or a second filter aligned with a second aperture of the aperture layer, wherein the first filter is configured to allow light having a first wavelength range to pass through, and the second filter is configured to allow light having a different second wavelength range to pass through.

[0016] In some implementations, the imaging device includes a spectral filter layer, the spectral filter layer includes a first filter aligned to a first aperture of the aperture layer, and a second filter aligned to a second aperture of the aperture layer, the first filter being configured to allow light having a first wavelength range to pass through, and the second filter being configured to allow light having a different second wavelength range to pass through.

[0017] In some implementations, each aperture of a plurality of apertures has a substantially rectangular opening through which incident light passes. Each optical element of a plurality of optical elements may also be substantially rectangular. Each optical element of a plurality of optical elements may be configured to distort the incident light and project a corresponding substantially rectangular image onto each photosensitive area of ​​the image sensor. Each optical element of a plurality of optical elements arranged in an array may be a metastructure.

[0018] Certain embodiments of the subject matter described herein can be implemented to achieve one or more of the following advantages: The systems and techniques described herein can be used in some implementations to suppress or eliminate optical crosstalk between optical elements of an optical element array. Furthermore, the techniques described herein allow for greater utilization of the sensor area by enabling increased packing density in some implementations. By increasing the amount of sensor area used, the systems and techniques described herein can reduce the computational power required to generate the final image from individual images generated by the camera array because the need for post-processing is reduced in some implementations. Thus, the systems described herein will provide high imaging performance at a reduced cost.

[0019] Details of one or more embodiments of the subject matter described herein are illustrated in the accompanying drawings and the following description. Other features, aspects, and advantages of the present invention will become apparent from the description, drawings, and the accompanying claims. [Brief explanation of the drawing]

[0020] [Figure 1] This figure shows an example of an array imaging system configuration for suppressing optical crosstalk between optical elements of the array imaging system. [Figure 2A] This is a schematic diagram showing examples of components that may be used in an array imaging device. [Figure 2B] This is a schematic diagram showing examples of components that may be used in an array imaging device. [Figure 2C] This is a schematic diagram showing examples of components that may be used in an array imaging device. [Figure 3A] This is a schematic diagram showing examples of components that may be used in an array imaging device. [Figure 3B] This is a schematic diagram showing examples of components that may be used in an array imaging device. [Figure 3C] This is a schematic diagram showing examples of components that may be used in an array imaging device. [Figure 4A]It is a schematic diagram showing an example of an imaging device for suppressing optical crosstalk. [Figure 4B] It is a schematic diagram showing an example of an imaging device including both an aperture layer and a separate baffle layer. [Figure 5] It is a schematic diagram showing an example of an imaging device for suppressing optical crosstalk. **Embodiments for Carrying Out the Invention**

[0021] The same reference numerals and names in various drawings indicate the same elements. The shapes and dimensions of the objects shown in the drawings are not necessarily to scale.

[0022] **Detailed Description** FIG. 1 is a diagram showing an example of the configuration of an array imaging device (for example, an array camera) for suppressing optical crosstalk between optical elements of the array imaging device. In an array camera, by increasing the aperture area and generating a plurality of small images that combine to form a single high-resolution image, the optical aberration of a single-lens camera can be eliminated. To generate each of these plurality of small images, the array camera may include an array of refractive lenses and / or an array of meta-structures. In some implementations, the arrays of refractive structures and / or meta-structures are aligned with each of the plurality of apertures. Incident light from the imaging object enters through the plurality of apertures and then enters the respective photosensitive regions of the corresponding image sensors. Optical crosstalk in such a device can be caused, for example, by light that passes through the first aperture and enters the array camera but enters the photosensitive region associated with a different aperture, and / or by light that is manipulated by optical elements or meta-structures associated with different apertures. Stray light leads to an increase in noise signals, thus interfering with the operation of the array camera.

[0023] As shown in Figure 1, an example of an imaging device (e.g., an array camera) 100 comprises an aperture layer 101 containing multiple apertures (e.g., aperture 102A and aperture 102B). Although two apertures are illustrated, the aperture layer 101 may contain additional apertures. Light from an object enters the aperture of the aperture layer 101 and passes through the optical element array 106. This light is illustrated as a ray 120 in Figure 1. The aperture layer 101 comprises, but is not limited to, a transparent substrate (e.g., glass or plastic) on which a layer is formed, which has a pattern made of a material (e.g., chromium) that reflects or absorbs incident light. In the regions where this material is present, the incident light is reflected or absorbed. In the regions where this material is not present, the light can pass through the substrate.

[0024] The imaging device 100 further comprises an optical element array 106. The optical element array 106 may include, for example, an array of optical elements and / or an array of metastructures, each including a lens that focuses a ray 120 onto the photosensitive portions 104A and 104B of the image sensor 108 of the imaging device 100. The optical elements may include planar optical systems (e.g., diffractive optical elements) or optical systems with curved surfaces. The photosensitive portions 104A and 104B may correspond to different sensors or to different parts of the same sensor. Although two photosensitive regions are shown, the light sensor may include additional photosensitive regions. Furthermore, although only one image sensor is shown, multiple image sensors, each having a photosensitive region, may be used instead.

[0025] A metastructure has a metasurface. A metasurface refers to a surface having dispersed microstructures (e.g., metaatoms) arranged to interact with light in a specific way. For example, a metasurface may have a dispersed array of nanostructures. The nanostructures are configured to interact with the light wave individually or collectively to alter the local amplitude, local phase, or both of the incident light wave. If the metaatoms (e.g., nanostructures) of the metasurface are in a specific arrangement, the metasurface can act as an optical element such as a lens, lens array, beam splitter, diffuser, polarizer, bandpass filter, or other optical element. In some cases, a metasurface may be able to perform optical functions that were conventionally performed by refractive and / or diffractive optical elements. In some cases, the metaatoms of the metastructure may be arranged in a pattern such that it functions as, for example, a lens, grating coupler, or other optical element. In other examples, the metaatoms do not need to be arranged in a pattern, and the metastructure can function as, for example, a fan-out grating, diffuser, or other optical element. In some implementations, the metasurface may perform other functions, including polarization control, negative refractive index transmission, beam deflection, vortex generation, polarization conversion, optical filtering, and plasmonic optics.

[0026] A metasurface may have carefully arranged “unit cells” or “metaatoms” having subwavelength structures (e.g., nanostructures). The term “subwavelength” refers to a nanostructure whose at least one lateral dimension (parallel to the substrate on which the nanostructure is located) is shorter than the wavelength of incident light. Metaatoms may be made of silicon, for example. Generally, the dimensions of the nanostructure correspond to the shortest wavelength of interest. For example, in some implementations, the nanostructure may be the shape of a nanoscale feature with dimensions less than 1 micron. By adjusting the shape of these unit cell elements, it is possible to change the phase above the element in response to a plane wave. Using phase knowledge with respect to shape parameters, it becomes possible to create a metalens with an arbitrary phase profile by placing metaatoms in the desired positions. Generally, ray bending is determined by the derivative of the phase profile. Each substrate is combined with its respective metasurface to form a metalens.

[0027] The metastructures 106A and 106B may be supported by glass or other substrates. This substrate may be, for example, made of glass (e.g., borosilicate glass, such as Schott's D263® glass) and may be attached (e.g., bonded) to the metastructures (e.g., metastructures 106A and 106B) using an adhesive such as an optically transparent polymer adhesive at the operating wavelength (e.g., infrared or visible wavelength). In some implementations, the adhesive is refractive index-matched to the substrate. In some cases, the metastructure includes multiple stacked metasurfaces. For example, in some implementations, the metastructure may include a substrate-metasurface-adhesive-metasurface-substrate stack, or a substrate-metasurface-adhesive-substrate-metasurface stack. Incorporating a stack of metasurfaces into the metastructure configuration can, in some cases, facilitate a wide range of optical functions by having resonance between the stacked metasurfaces. Such optical functions may include, for example, near-field interactions, filtering functions, and / or plasmonics.

[0028] In the example in Figure 1, the array camera 100 further includes a field of view (FOV) filter 110 that allows only rays within a predetermined FOV to pass through each aperture. For example, the FOV filter 110 can reflect and / or absorb rays with incident angles (e.g., measured relative to the slope of the FOV filter 110) outside a predetermined FOV value (e.g., 40 degrees) that would cause optical crosstalk on adjacent lenses if not filtered. The FOV filter 110 may include an interference filter. In this example, the first ray 103 has a first incident angle less than the incident angle 111 of the second ray 109. If the incident angle 111 is outside the predetermined FOV, the FOV filter 110 may be configured to reflect and / or absorb the ray 111 so that it cannot pass through aperture 120A. Rays with incident angles within the predetermined FOV are not filtered out by the FOV filter 110. The FOV filter 110 can be provided as a single continuous layer from edge to edge of the aperture layer 101, or it can include multiple separate filter sublayers placed on the aperture layer 101. Each filter sublayer may be positioned to cover the corresponding aperture of the aperture layer 101. Although the FOV filter 110 is shown positioned above the aperture layer 101, it can also be positioned below the aperture layer 101. In some implementations, two FOV filters can be used, with one FOV filter positioned above the aperture layer 101 as shown in Figure 1, and the other FOV filter positioned below the aperture layer 101. For narrowband irradiation, the FOV filter(s) 110 may be configured using interference filters. For example, the interference filter may be formed from a laminate of thin-film materials having alternating refractive indices between two values ​​(e.g., between a first refractive index n1 and a second refractive index n2). The thin-film laminate may be formed on a support substrate such as a glass substrate or a plastic substrate. The interference filter may be designed to meet specific target parameters. Alternatively, or in addition to this, the interference filter laminate may be applied to the same substrate used for the aperture layer 101.The thickness of the FOV filter 110 may be, for example, greater than 50 microns, greater than 100 microns, or greater than 200 microns. In some implementations, the FOV filter 110 can be fixed to the aperture layer 101 using, for example, an optical adhesive, or it may be formed using a thin-film deposition process.

[0029] The aperture layer 101 helps improve the image quality obtained by the imaging device 100. If the aperture within the aperture layer contains a circular opening, the light passing through the aperture layer toward the optical element array 106 is approximately disk-shaped. Therefore, a disk-shaped image will be obtained projected toward the image sensor 108. In contrast, by introducing an approximately rectangular (e.g., including a square) imaging aperture or approximately rectangular baffle, the light toward the optical element array 106 approaches a rectangle, and the projection onto the image sensor 108 also approaches a rectangle. An approximately rectangular projection toward the sensor makes it possible to maximize the packing density of the sensor.

[0030] An example using a rectangular aperture is shown in Figure 2A. In particular, Figure 2A shows a top view of an aperture layer 201 having multiple apertures (202A, 202B). The dark areas outside the aperture do not allow incident light to pass through. The aperture layer 201 may also be used as the aperture layer 101 in the imaging device shown in Figure 1. Although two apertures are shown, the aperture layer 201 may contain additional apertures. Each aperture 202A, 202B of the aperture layer 201 is configured to be approximately rectangular (for example, square). The aperture layer 201 may be referred to as a baffle layer, or simply a baffle.

[0031] The apertures 202A and 202B of the aperture layer 201 may be aligned to cover the corresponding optical elements of the optical element layer. Figure 2B shows a top view of an exemplary optical element layer 206 that can be used in conjunction with the aperture layer 201. The optical element layer 206 may be used as the optical element layer 106 in the imaging device 100 of Figure 1. The optical element layer 206 comprises a plurality of optical elements (e.g., elements 206A and 206B) each aligned with each aperture of the aperture layer 201. The optical elements 206A and 206B may include either lenses or metastructures. In order to utilize rectangular apertures, the optical elements must also be rectangular (e.g., rectangular prisms). By forming the optical elements rectangular, the packing density can be increased. That is, to maximize the packing density, the optical elements 206A and 206B may be substantially adjacent to each other with substantially no gaps between them.

[0032] By using a rectangular aperture in conjunction with a rectangular optical element, a roughly rectangular image is generated on the image sensor. In the case of a rectangular image, the photosensitive area of ​​the image sensor can also be made rectangular, which increases the packing density of the image sensor. Figure 2C shows a top view of an image generated on an image sensor using a rectangular aperture and a rectangular optical element. As shown in Figure 2C, images 220A and 220B are roughly rectangular (with rounded corners). Each image 220A and 220B is incident on different photosensitive areas 204A and 204B of the image sensor. These roughly rectangular images are close to each other with little or no gap between them.

[0033] In general, it is useful to avoid rectangular apertures having sharp corners, as such features can lead to unwanted diffraction effects in the projected image. For this reason, in some cases, rectangular apertures may be designed such that the radius of curvature at the corners is greater than 0 (where a radius of curvature equal to 0 corresponds to a right angle at the corner). In some implementations, the radius of curvature may be greater than 1 micron and less than 500 microns, for example, greater than 5 microns and less than 200 microns, but other values ​​may be used instead. In some implementations, the projected images produced using this technique may have little to no gap between adjacent images in the photosensitive region (e.g., less than 50 microns, less than 10 microns, less than 5 microns, less than 1 micron, less than 0.5 microns). In some implementations, these adjacent projected images may overlap in the photosensitive region of the image sensor. For example, adjacent projected images may overlap by 0.5 microns, 1 micron, or 2 microns. Other overlap distances are also possible.

[0034] In this example, a single aperture layer with a rectangular aperture is provided. However, in some other implementations, an additional aperture layer may be provided, which includes a circular aperture aligned with the rectangular aperture of aperture layer 201. The imaging aperture is a parameter that can be adjusted when designing the imaging device to improve image performance. However, if the same aperture is used to match the packing density (what kind of rectangle the image will be), image performance may degrade. Therefore, instead of providing a single aperture layer, an additional aperture layer may be provided to adjust the packing density of the projected image, while the original aperture layer may be used to adjust other properties of the projected image.

[0035] Figure 2 shows how a rectangular image can be created by using a rectangular aperture and a corresponding rectangular optical element, but these rectangular images can be created alternately as a result of the intentional distortion of a single image. For example, one or more optical elements (lenses or metastructures) can be designed to create different phase functions across the entire region where distortion occurs in the light passing through the optical element. In some cases, multiple optical elements are aligned with corresponding apertures to generate distortion in the light. The resulting distorted light is approximately rectangular, which can increase the packing density of the photosensitive area of ​​the image sensor. Alternatively, the distorted image may not be rectangular, but the packing density can be increased by the distorted light continuing to shape it so that it occupies a large portion of the sensor area. An example of this is shown in Figures 3A and 3C. Similar to Figure 2A, Figure 3C shows an aperture layer 301 with multiple apertures 302A and 302B. However, in contrast to aperture layer 201, apertures 302A and 302B are circular, or otherwise have a shape other than rectangular. Similarly, unlike the optical element layer 206, the optical elements 306A and 306B of the optical element layer 306 in Figure 3B are circular, or otherwise have a shape other than rectangular. However, the optical elements 306A and 306B are configured to exhibit different phase shifts across their entire regions in order to create distorted light. Depending on the specific amount of phase shift occurring in different parts of the optical elements 306A and 306B, a distorted image (320A, 320B) may be generated that occupies a larger portion of the photosensitive region (304A, 304B) on the image sensor (see Figure 3C).

[0036] In some implementations, optical crosstalk can be suppressed by changing the shape of the aperture within the aperture layer. Figure 4A is a schematic diagram showing an example of an imaging device 400 for suppressing optical crosstalk. The imaging device comprises an image sensor 108 having multiple photosensitive regions (e.g., 104A, 104B) and an optical element layer 406 containing multiple lenses and / or multiple metastructures. In this example, the optical elements 406A and 406B are represented as metastructure layers. The imaging device 400 may optionally further include an optical filter 410, such as an FOV filter similar to the FOV filter described in Figure 1, positioned in front of the optical element layer 406. The imaging device 400 also includes a baffle / aperture layer 401 positioned in front of the optical element layer 406 and the optional filter layer 410. The aperture layer 401 includes multiple apertures (e.g., 402A, 402B) into which light (e.g., light rays 420) is incident. Unlike the aperture of aperture layer 101, the side walls of apertures 402A and 402B may be inclined to block incident light with an incident angle that would normally cause optical crosstalk, for example, light with an incident angle outside a predetermined FOV.

[0037] For example, apertures 402A and 402B may be conical. The conical cross-section shown in Figure 4A has inclined sidewalls such that the size of the opening forming the aperture increases from a first size on the front surface of the aperture layer 401 (facing the imaging object) to a larger opening on the back surface of the aperture layer 401 (facing the image sensor 108). The shape of the aperture may be approximately frustoconical or approximately frustopyramidal. The angle 411 of the sidewalls may be adjusted to change the range of incident angles that the aperture layer 401 blocks. The advantage of designing the sidewalls to be inclined rather than straight (i.e., vertical) is that in some implementations, straight walls would result in aperture designs requiring very thin walls, which can be difficult to manufacture. Apertures with inclined walls allow for the use of greater thickness.

[0038] In another example, a baffle separate from the aperture layer may be provided in the imaging device. In this imaging device, the baffle comprises one or more openings configured to prevent incident light from outside a given FOV from entering unrelated optical elements of the optical element array. For example, Figure 4B is a schematic diagram showing an example of an imaging device having both an aperture layer 401 and a separate baffle layer 430. As previously mentioned, the aperture layer 401 includes a plurality of apertures through which incident light can pass, aligned with the optical elements of the optical element layer 406. The optical element layer 406 may include an array of lenses or an array of metastructures. Figure 4B shows metastructures 406A and 406B, but lenses may be used instead. The optical element layer 406 may be located above or below the filter layer 410. The filter layer 410 may include an FOV filter layer as described herein.

[0039] The baffle layer 430 is positioned above the aperture layer 401. For example, in some implementations, the baffle layer 430 is fixed to the aperture layer 401 by an optical adhesive. In this case, since only two apertures are used, the baffle layer 430 only needs to block incident light rays directed toward adjacent optical elements, and therefore may include a larger (e.g., wider) aperture region 436 than the aperture 401 of the aperture layer. However, if more apertures are used, the baffle may have a smaller aperture region, as it may be designed to block additional incident light rays. The aperture region 436 of the baffle may include inclined sidewalls that allow light with an incident angle within a given FOV (e.g., ray 432) to enter the aperture of the aperture layer while blocking light with an incident angle outside the given FOV (e.g., ray 434). For example, the sidewalls of the aperture region 436 may be positioned obliquely to the normal to the aperture layer surface facing the object being imaged. For example, the angle of the side wall may be greater than 0 degrees relative to the normal and less than 90 degrees relative to the normal. For example, it may be greater than 5 degrees and less than 85 degrees, for example, greater than 10 degrees and less than 80 degrees, for example, greater than 20 degrees and less than 70 degrees.

[0040] In some implementations, spectral filters can be used to suppress optical crosstalk. For example, in some cases, a first photosensitive region of the image sensor may be configured to sense light having a first spectrum (e.g., red or blue light), and a second adjacent photosensitive region of the image sensor may be configured to sense light having a different second spectrum (e.g., green light). A spectral filter may then be placed in front of each photosensitive region to prevent light of unrelated wavelengths from reaching the photosensitive region.

[0041] Figure 5 is a schematic diagram showing an example of an imaging device 500 for suppressing optical crosstalk caused by light of unrelated wavelengths reaching the imaging area. The features described in conjunction with Figure 5 may be used in conjunction with any of the devices described in Figures 1 to 4, as needed. The imaging device 500 comprises an image sensor 108 having a plurality of photosensitive areas (e.g., areas 104A, 104B). The device 500 further includes an aperture layer 501 having a plurality of apertures (e.g., 502A, 502B). The optical element layer 506 may include an array of optical elements (e.g., lenses or an array of metastructures) each aligned with the apertures of the aperture layer 501. In this example, the optical elements are depicted as metastructures, but lenses may be used in addition to or instead of these. The imaging device 500 further includes an optional filter layer 510. The filter layer 510 may include an FOV filter as described herein.

[0042] The imaging device 500 may include optional spectral filter layers (e.g., 512, 514, 516). The spectral filter layers may include passband filters formed from a laminate of thin films having alternating refractive indices, aligned to the corresponding apertures of the aperture layers. The passband filters can be configured to allow only specific wavelengths or wavelength ranges to pass through. In some implementations, there are at least two spectral filters (i.e., multiple spectral filter layers) aligned to each aperture. These at least two spectral filters may be configured to allow the same wavelength range to pass through. In some implementations, the spectral filter aligned to the first aperture is configured to allow a different wavelength range to pass through than the spectral filter aligned to the second aperture. In some implementations, the filter layer 510 serves as both an FOV filter and a spectral filter as described herein. In these cases, the imaging device may or may not include one additional spectral filter aligned to each aperture.

[0043] In the example shown in Figure 5, an optional first spectral filter layer 512 is positioned between the aperture layer 501 and the optional filter 510. The first spectral filter layer 512 may be fixed to the aperture layer and / or the optional filter layer 510, for example, using an optical adhesive. An optional second spectral filter layer 514 may be positioned below the optical element layer 506. The optional second spectral filter layer 514 may be fixed to the optical elements of the optical element layer 506, for example, using an optical adhesive. An optional third spectral filter layer 516 may be positioned on the image sensor 108. The optional third spectral filter layer 516 may be fixed to the image sensor, for example, using an optical adhesive. While the spectral filter layers 512, 514, and 516 are illustrated in specific positions relative to the other components, other arrangements are also possible. For example, the first spectral filter layer 512 may be located below the optional filter 510, in front of the aperture layer 501, or in front of the optical element layer 506, but not behind the optional filter 510. The spectral filter layer may be formed on a separate substrate or applied on other substrates provided by the imaging device 500.

[0044] Each spectral filter layer may contain multiple spectral filters. In this example, the first spectral filter layer 512 contains a first spectral filter 512A and a second spectral filter 512B, while layer 512 may contain more spectral filters. The first spectral filter 512A may be aligned with the first aperture 502A of the aperture layer 501. The first spectral filter 512A may be configured to filter out light having wavelengths not intended to reach the first photosensitive region 104A. For example, the first photosensitive region 104A may be configured to detect a first wavelength range (e.g., red light) and may be provided for detecting a first wavelength range (e.g., red light). Therefore, the first spectral filter 512A may be configured to filter out light outside the red wavelength band. For example, the first spectral filter 512A may be configured to filter out blue light, green light, or blue and green light.

[0045] Similarly, the second spectral filter 512B of the first spectral filter layer 512 may be aligned with the second aperture 502A of the aperture layer 501. The second spectral filter 512B may be configured to filter out light having wavelengths not intended to reach the second photosensitive region 104B. For example, the second photosensitive region 104B may be configured to detect a second wavelength range (e.g., blue light) and may be provided for detecting a second wavelength range (e.g., blue light). Thus, the second spectral filter 512B may be configured to filter out light outside the blue wavelength band. For example, the second spectral filter 512B may be configured to filter out green light, red light, or red and green light.

[0046] Furthermore, the second spectral filter layer 514 may include multiple spectral filters. In this example, the second spectral filter layer 514 includes the first spectral filter 514A and the second spectral filter 514B, but the layer 514 may include many more spectral filters. The first spectral filter 514A may be aligned with the first aperture 502A of the aperture layer 501. The first spectral filter 514A may be configured to filter and remove light having wavelength ranges that are not intended to reach the first photosensitive region 104A. For example, the first photosensitive region 104A may be configured to detect a first wavelength range (e.g., red light) and may be provided for detecting a first wavelength range (e.g., red light). Therefore, the first spectral filter 514A may be configured to filter and remove light outside the red wavelength band. When both the first spectral filter 514A and the first spectral filter 512A are used, each filter may be configured to filter and remove different wavelength ranges, or to filter and remove the same wavelength range. For example, the first spectral filter 512A may be configured to filter and remove blue light and the first spectral filter 514A may be configured to filter and remove green light, or the first spectral filter 512A may be configured to filter and remove green light and the first spectral filter 514A may be configured to filter and remove blue light.

[0047] Similarly, the second spectral filter 514B may be aligned with the second aperture 502A of the aperture layer 501. The second spectral filter 514B may be configured to filter out light having wavelength ranges not intended to reach the second photosensitive region 104B. For example, the second photosensitive region 104B may be configured to detect a second wavelength range (e.g., blue light), or may be provided for detecting a second wavelength range (e.g., blue light). Thus, the second spectral filter 514B may be configured to filter out light outside the blue wavelength band. When both the second spectral filter 514B and the second spectral filter 512B are used, each filter may be configured to filter out different wavelength ranges, or to filter out the same wavelength range. For example, the second spectral filter 512B may be configured to filter out red light and the second spectral filter 514B may be configured to filter out green light, or the second spectral filter 512B may be configured to filter out green light and the second spectral filter 514B may be configured to filter out red light.

[0048] Alternatively, the third spectral filter layer 516 may include multiple spectral filters. In this example, the third spectral filter layer 516 includes a first spectral filter 516A and a second spectral filter 516B, but layer 516 may include many more spectral filters. The first spectral filter 516A may be aligned with the first aperture 502A of the aperture layer 501. The first spectral filter 516A may be configured to filter out light having wavelength ranges not intended to reach the first photosensitive region 104A. For example, the first photosensitive region 104A may be configured to detect a first wavelength range (e.g., red light) and may be provided for detecting a first wavelength range (e.g., red light). Thus, the first spectral filter 516A may be configured to filter out light outside the red wavelength band. When the first spectral filter 516A and the first spectral filters 512A and 514A are all utilized, each filter may be configured to filter and remove different wavelength ranges, or to filter and remove the same wavelength range. For example, the first spectral filter 516A may be configured to filter and remove blue light, the first spectral filter 514A may be configured to filter and remove green light, and the first spectral filter 512A may be configured to filter and remove a combination of green and blue light.

[0049] Similarly, the second spectral filter 516B may be aligned with the second aperture 502A of the aperture layer 501. The second spectral filter 516B may be configured to filter out light having wavelength ranges not intended to reach the second photosensitive region 104B. For example, the second photosensitive region 104B may be configured to detect a second wavelength range (e.g., blue light), or may be provided for detecting a second wavelength range (e.g., blue light). Therefore, the second spectral filter 516B may be configured to filter out light outside the blue wavelength band. When the second spectral filter 516B and the second spectral filters 514B, 512B are all used, each filter may be configured to filter out different wavelength ranges, or to filter out the same wavelength range. For example, the second spectral filter 516B may be configured to filter out red light, the second spectral filter 514B may be configured to filter out green light, and the second spectral filter 512B may be configured to filter out both green and red light.

[0050] As described above, in some implementations, the imaging device may employ a filter layer configured to function as both an FOV filter and a spectral filter for filtering and removing incident light having an incident angle outside a predetermined FOV. For example, instead of the imaging device 500 having layers 512, 514, and 516, the device may have a single filter layer 510 that performs the functions of both an FOV filter and a spectral filter. In some implementations, the imaging device may employ a single filter layer (e.g., 510 or 512) that functions as both an FOV filter and a spectral filter, and a second additional layer that functions as an additional FOV filter and / or an additional spectral filter. In some implementations, the imaging device employs two or more filter layers (e.g., 512, 514). Each filter layer comprises multiple filters aligned to each of multiple apertures, but does not include the optical filter 510.

[0051] This specification includes details of many implementations, which should not be interpreted as limitations imposed on the claims or the scope of the claimed content, but rather as descriptions of features specific to particular embodiments of the disclosed subject matter. Certain features described in this specification as separate embodiments can also be realized in combination in a single embodiment. Conversely, various features described as a single embodiment can also be realized in multiple separate embodiments or any suitable partial combination. Furthermore, features may be described above as operating in several specific combinations and may be initially claimed as such, but one or more features from a claimed combination may, in some cases, be removed from the combination, and the claimed combination may cover partial combinations or variations of partial combinations.

[0052] Similarly, while the drawings show operations in a specific order, it should not be understood that such operations must be performed in a specific illustrated order or sequence to achieve the desired result, or that all illustrated operations must be performed. Furthermore, the separation of various systems and components in the embodiments described above should not be understood as requiring such separation in all embodiments.

[0053] Therefore, specific embodiments of the present invention have been described. Other embodiments are also included in the appended claims. In addition, the operations described in the claims can be performed in a different order and still achieve the desired results.

Claims

1. An imaging device, Image sensor and The imaging device comprises a plurality of optical elements arranged in an array, each optical element configured to direct light to different photosensitive areas of the image sensor to capture each image, and the imaging device further comprises: The imaging device further comprises an aperture layer, the aperture layer comprising a plurality of apertures arranged to be aligned with each of the plurality of optical elements, and the imaging device further comprises An imaging device comprising an optical filter layer disposed adjacent to the aperture layer, wherein the optical filter layer is configured to filter and remove light having an incident angle outside a predetermined field of view.

2. The imaging apparatus according to claim 1, wherein the optical filter layer is positioned in front of the aperture layer such that the optical filter layer is closer to the object to be imaged by the imaging apparatus than the aperture layer.

3. The imaging apparatus according to claim 1, wherein the optical filter layer is positioned behind the aperture layer such that the optical filter layer is further away from the object to be imaged by the imaging apparatus than the aperture layer.

4. The imaging apparatus according to claim 3, further comprising an additional optical filter layer, wherein the additional optical filter layer is positioned in front of the aperture layer so as to be closer to the object to be imaged by the imaging apparatus than the aperture layer.

5. The imaging apparatus according to any one of claims 1 to 4, wherein the optical filter layer is fixed to the aperture layer.

6. The imaging apparatus according to any one of claims 1 to 5, wherein each of the plurality of apertures has a substantially rectangular opening through which incident light passes.

7. The imaging apparatus according to claim 6, wherein the shape of each of the plurality of optical elements is substantially rectangular.

8. The imaging apparatus according to any one of claims 1 to 5, wherein each of the plurality of optical elements is configured to distort incident light and project a corresponding substantially rectangular image onto each photosensitive area of ​​the image sensor.

9. The imaging apparatus according to claim 8, wherein each of the plurality of apertures has a substantially circular opening through which incident light passes.

10. The imaging apparatus according to any one of claims 1 to 9, wherein each of the plurality of optical elements arranged in the array comprises a metastructure.

11. The imaging apparatus according to any one of claims 1 to 10, wherein the optical filter is an interference filter.

12. The imaging apparatus according to any one of claims 1 to 10, wherein the size of at least one of the plurality of apertures increases from the first surface to the second surface of the aperture layer.

13. The imaging apparatus according to claim 12, wherein the at least one aperture includes a conical shape.

14. The imaging apparatus according to any one of claims 1 to 13, wherein the optical filter layer is configured to function as a spectral filter layer.

15. The imaging apparatus according to claim 14, wherein the optical filter layer comprises at least two filters aligned with a first aperture of the aperture layer, and at least two filters aligned with a second aperture of the aperture layer, the at least two filters aligned with the first aperture being configured to allow light having a first wavelength range to pass through, and the at least two filters aligned with the second aperture being configured to allow light having a different second wavelength range to pass through.

16. The imaging device further comprises a third filter aligned with the first aperture, the third filter aligned with the first aperture being configured to allow light having the first wavelength range to pass through, and the imaging device further comprises The imaging apparatus according to claim 15, further comprising a third filter aligned with the second aperture, wherein the third filter aligned with the second aperture is configured to allow light having the second wavelength range to pass through.

17. The first filter aligned with the first aperture is positioned adjacent to the aperture layer and in front of the second filter aligned with the first aperture layer, the second filter aligned with the first aperture layer is positioned adjacent to the first optical element among the plurality of optical elements, and the third filter aligned with the first aperture is positioned adjacent to the first photosensitive area of ​​the image sensor. The imaging apparatus according to claim 16, wherein the first filter aligned with the second aperture is adjacent to the aperture layer and positioned in front of the second filter aligned with the second aperture layer, the second filter aligned with the second aperture layer is positioned adjacent to the second optical element among the plurality of optical elements, and the third filter aligned with the second aperture is positioned adjacent to the second photosensitive region of the image sensor.

18. An imaging apparatus according to any one of claims 1 to 17, comprising a baffle.

19. The imaging apparatus according to claim 18, wherein the baffle comprises an opening arranged to cover at least one aperture of the aperture layer.

20. The imaging apparatus according to claim 19, wherein the opening of the baffle is larger than the at least one aperture.

21. The imaging apparatus according to claim 20, wherein the side wall of the opening of the baffle is arranged at an oblique angle with respect to the normal to the surface of the aperture layer facing the object to be imaged.

22. An imaging device, Image sensor and The imaging device comprises a plurality of optical elements arranged in an array, each optical element configured to direct light to different photosensitive areas of the image sensor to capture each image, and the imaging device further comprises: It comprises an aperture layer, and the aperture layer comprises a plurality of apertures arranged to be aligned with each of the plurality of optical elements, The imaging device is configured to filter out light whose incident angle is outside a predetermined field of view so that it does not reach the image sensor.

23. The imaging apparatus according to claim 22, wherein the aperture layer is configured to filter out light whose incident angle is outside a predetermined field of view so that it does not reach the image sensor.

24. The imaging apparatus according to claim 23, wherein the size of at least one of the plurality of apertures increases from the first surface to the second surface of the aperture layer.

25. The imaging apparatus according to claim 24, wherein the at least one aperture includes a conical shape.

26. An imaging apparatus according to any one of claims 22 to 25, comprising a baffle layer.

27. The imaging apparatus according to claim 26, wherein the baffle comprises an opening arranged to cover at least one aperture of the aperture layer.

28. The imaging apparatus according to claim 27, wherein the opening in the baffle layer is larger than the at least one aperture.

29. The imaging apparatus according to claim 28, wherein the side wall of the opening in the baffle layer is arranged at an oblique angle with respect to the normal to the surface of the aperture layer facing the object to be imaged.

30. The imaging apparatus according to any one of claims 22 to 29, further comprising an optical filter layer disposed adjacent to the aperture layer, wherein the optical filter layer is configured to filter and remove light having an incident angle outside a predetermined field of view.

31. The imaging apparatus according to claim 30, wherein the optical filter layer is positioned in front of the aperture layer such that the optical filter layer is closer to the object to be imaged by the imaging apparatus than the aperture layer.

32. The imaging apparatus according to claim 30, wherein the optical filter layer is positioned behind the aperture layer such that the optical filter layer is further away from the object to be imaged by the imaging apparatus than the aperture layer.

33. The imaging apparatus according to any one of claims 30 to 32, wherein the optical filter layer is an interference filter.

34. The imaging apparatus according to any one of claims 30 to 33, wherein the optical filter layer is also a spectral filter layer.

35. The imaging apparatus according to claim 34, wherein the optical filter layer comprises at least two filters aligned with a first aperture of the aperture layer, and at least two filters aligned with a second aperture of the aperture layer, the at least two filters aligned with the first aperture being configured to allow light having a first wavelength range to pass through, and the at least two filters aligned with the second aperture being configured to allow light having a different second wavelength range to pass through.

36. The imaging apparatus according to claim 22, comprising a spectral filter layer, wherein the spectral filter layer comprises at least two filters aligned to a first aperture of the aperture layer, and at least two filters aligned to a second aperture of the aperture layer, the at least two filters aligned to the first aperture being configured to allow light having a first wavelength range to pass through, and the at least two filters aligned to the second aperture being configured to allow light having a different second wavelength range to pass through.

37. The imaging device further comprises a third filter aligned with the first aperture, the third filter aligned with the first aperture being configured to allow light having the first wavelength range to pass through, and the imaging device further comprises The imaging apparatus according to claim 36, further comprising a third filter aligned with the second aperture, wherein the third filter aligned with the second aperture is configured to allow light having the second wavelength range to pass through.

38. The first filter aligned with the first aperture is positioned adjacent to the aperture layer and in front of the second filter aligned with the first aperture layer, the second filter aligned with the first aperture is positioned adjacent to the first optical element among the plurality of optical elements, and the third filter aligned with the first aperture is positioned adjacent to the first photosensitive area of ​​the image sensor. The imaging apparatus according to claim 37, wherein the first filter aligned with the second aperture is adjacent to the aperture layer and positioned in front of the second filter aligned with the second aperture layer, the second filter aligned with the second aperture is positioned adjacent to the second optical element among the plurality of optical elements, and the third filter aligned with the second aperture is positioned adjacent to the second photosensitive region of the image sensor.

39. The imaging apparatus according to claim 22, wherein each of the plurality of apertures has a substantially rectangular opening through which incident light passes.

40. The imaging apparatus according to claim 39, wherein the shape of each of the plurality of optical elements is substantially rectangular.

41. The imaging apparatus according to any one of claims 22 to 40, wherein each of the plurality of optical elements is configured to distort incident light and project a corresponding substantially rectangular image onto each photosensitive area of ​​the image sensor.

42. The imaging apparatus according to any one of claims 22 to 40, wherein each of the plurality of optical elements arranged in the array comprises a metastructure.

Images