WO2023226395A1

WO2023226395A1 - Image sensor, camera, and electronic device

Info

Publication number: WO2023226395A1
Application number: PCT/CN2022/140320
Authority: WO
Inventors: 王文涛; 韦怡
Original assignee: Oppo广东移动通信有限公司
Priority date: 2022-05-25
Filing date: 2022-12-20
Publication date: 2023-11-30
Also published as: CN115022562A

Abstract

An image sensor (10), a camera (100), and an electronic device (1000). The image sensor (10) comprises a pixel array (11) and a filter array (12). The filter array (12) comprises a plurality of minimum repeating units (121), and each minimum repeating unit (121) comprises a red filter (1211), a green filter (1212), a blue filter (1213), and a near-infrared filter (1214).

Description

Image sensors, cameras and electronic devices

priority information

This application requests the priority and rights of the patent application with patent application number 2022105797626, which was submitted to the State Intellectual Property Office of China on May 25, 2022, and its full text is incorporated herein by reference.

Technical field

The present application relates to the field of electronic devices, and in particular, to an image sensor, a camera and an electronic device.

Background technique

Among related technologies, mobile phone microscopy imaging technology is mainly based on Bayer color filter array (bayer CFA). Under the same incident spectrum, the filter array can only utilize signal light in the visible range, which will cause the incident light to The utilization rate is reduced, which in turn increases the system power consumption.

Contents of the invention

This application discloses an image sensor, a camera and an electronic device.

The image sensor provided by the embodiment of the present application includes a pixel array and a filter array. The filter array includes a plurality of minimum repeating units, and the minimum repeating units include red filters, green filters, blue filters and near-infrared filters.

The camera provided by the embodiment of the present application includes a lens and the image sensor described in the above embodiment. The lens is spaced apart from the image sensor and is used for imaging on the image sensor.

The electronic device provided by the embodiment of the present application includes the camera described in the above embodiment.

In the image sensor, camera and electronic device of the applied embodiment, the amount of light entering the image sensor is increased by adding a near-infrared filter, thereby reducing the demand for the light source of the camera, thereby reducing the heat dissipation of the system power consumption. In addition, near-infrared filters are added. The acquisition of infrared light band data can also be used to guide and correct microscopic images, reducing artifacts and false colors in imaging and improving imaging quality.

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

Description of the drawings

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

Figure 1 is a schematic structural diagram of an image sensor according to an embodiment of the present application;

Figure 2 is a schematic diagram of the arrangement of the smallest repeating units of the filter array according to the embodiment of the present application;

Figure 3 is a microscopic observation picture and a color chart of the original RGB image of the image sensor in the related art;

Figure 4 is a pattern of the image sensor 24 color card and a near-infrared microscopic collection pattern according to the embodiment of the present application;

Figure 5 is a schematic diagram of the simulation results of microscopic imaging results in the embodiment of the present application;

Figure 6 is another schematic diagram of the arrangement of the smallest repeating units of the filter array according to the embodiment of the present application;

Figure 7 is another structural schematic diagram of an image sensor according to an embodiment of the present application;

Figure 8 is an exploded schematic diagram of the camera according to the embodiment of the present application;

Figure 9 is a schematic structural diagram of a fill light according to an embodiment of the present application;

FIG. 10 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Description of main component symbols:

Image sensor 10, pixel array 11, filter array 12, minimum repeating unit 121, red filter 1211, green filter 1212, blue filter 1213, near-infrared filter 1214, camera 100, lens 20, Fill light 30, lens 40, lens holder 50, flexible circuit board 60, board-to-board connector 70, electronic device 1000, casing 200.

Detailed ways

The embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

The following disclosure provides many different embodiments or examples for implementing the various structures of the present application. To simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the application. Furthermore, this application may repeat reference numbers and/or reference letters in different examples, such repetition being for the purposes of simplicity and clarity and does not by itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, this application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

The image sensor 10 provided by the embodiment of the present application includes a pixel array 11 and a filter array 12 . The filter array 12 includes a plurality of minimum repeating units 121 , and the minimum repeating units 121 include a red filter 1211 , a green filter 1212 , a blue filter 1213 and a near-infrared filter 1214 .

In some embodiments, in each minimum repeating unit 121, the red filter 1211, the green filter 1212, the blue filter 1213 and the near-infrared filter 1214 all transmit the same amount of light.

In some embodiments, in each minimal repeating unit 121, the areas of the red filter 1211, the green filter 1212, the blue filter 1213 and the near-infrared filter 1214 are all equal.

In some embodiments, each minimal repeating unit 121 is arranged in a 2*2 array, the green filter 1212 and the near-infrared filter 1214 are arranged diagonally, the red filter 1211 and the blue filter are arranged diagonally. The pieces 1213 are arranged diagonally.

In some embodiments, in the filter array 12, the number of red filters 1211, green filters 1212, blue filters 1213 and near-infrared filters 1214 each accounts for the number of filters in the filter array 12. 1/4 of the total number of pieces.

In some embodiments, the red filter 1211, the green filter 1212, the blue filter 1213, and the near-infrared filter 1214 are each in a square shape.

In some embodiments, the image sensor 10 may further include a microlens array 13 disposed on a side of the filter array 12 facing away from the pixel array 11 .

The camera 100 provided in the embodiment of the present application includes a lens 20 and the image sensor 10 described in the above embodiment. The lens 20 is spaced apart from the image sensor 10 , and the lens 20 is used for imaging on the image sensor 10 .

In some embodiments, the camera 100 may include a fill light 30, and the light emitted by the fill light 30 has a wavelength of 400 nm-1100 nm.

In some embodiments, the camera 100 may also include a macro camera.

The electronic device 1000 provided in the embodiment of the present application includes the camera 100 described in the above embodiment.

In some embodiments, the electronic device 1000 includes a casing 200 through which the camera 100 is exposed.

In some embodiments, camera 100 is a rear camera.

In some implementations, electronic device 1000 includes a smartphone.

Referring to FIG. 1 and FIG. 2 , the image sensor 10 provided by the embodiment of the present application includes a pixel array 11 and a filter array 12 . The filter array 12 includes a plurality of minimum repeating units 121 , and the minimum repeating units 121 include a red filter 1211 , a green filter 1212 , a blue filter 1213 and a near-infrared filter 1214 .

In related technologies, the camera includes an infrared filter. The light guide pillar of the camera emits a uniform light source as fill light. The light source reflected by the object enters the lens after passing through the cover glass. The infrared filter filters the infrared light in the light source and transmits it to On the image sensor, the transmission spectrum is the visible light spectrum. This will reduce the utilization rate of incident light, thereby increasing system power consumption.

In the image sensor 10, camera 100 and electronic device 1000 implemented in this application, by adding the near-infrared filter 1214 of the image sensor 10, the amount of light entering the image sensor 10 is increased, thereby reducing the demand for the light source 31 of the camera 100. To reduce the heat dissipation of system power consumption. In addition, the acquisition of near-infrared light band data can also be used to guide and correct microscopic images, reducing artifacts and false colors in imaging and improving imaging quality.

Among them, the filter array 12 is mainly used to filter the incident light in separate channels, that is, to modulate the incident signal. The incident light is modulated by the filter array 12 and then enters the pixel array 11 for photoelectric conversion and analog-to-digital conversion.

In related technologies, the generation of color images requires modulation by a filter array, which only includes red filters, green filters, and blue filters. Due to the modulation of the filter array, a complex demosaic algorithm needs to be used in the backend to interpolate the color signals collected by the image sensor. The data generated are artificially synthesized by interpolation, rather than the actual measurement results, so a lot of errors will be introduced in this process. Figure 3(a) is the microscopic observation picture of the original RGB image, and Figure 3(b) is Color chart. It can be seen that there are different color channels depending on the composition of the filter array, an example is shown for an image sensor with a Bayer pattern.

Specifically, since the near-infrared light band has no color information, the image sensor 10 according to the embodiment of the present application does not need interpolation when generating images. In one embodiment, a pattern of 24 color cards captured in the same state is shown in Figure 4(a). The acquired pattern has no color information, and Figure 4(a) is only an object intensity reflection map in the near-infrared band. Figure 4(b) shows the near-infrared microscopic collection pattern in the same area. Each area represents the gray value of the object. Since the modulations are consistent, there will be no Bayer pattern as mentioned above, so there is no need for it. Interpolation processing. As a result, the pattern in the near-infrared light band can accurately reflect the reflectivity of the object and the edge information of the shape, and can be revised and verified for subsequent demosaicing.

In another embodiment, an image sensor with a filter array including only red filters, green filters, and blue filters and an image sensor including the near-infrared filter 1214 provided by the embodiment of the present application are respectively used. 10 carried out simulation of related microscopic imaging results. Figure 5(a) is a real target object image, Figure 5(b) is an imaging pattern of the traditional image sensor 10 that only contains red filters, green filters, and blue filters, and Figure 5(c) is the application The imaging pattern of the image sensor 10 provided by the embodiment. It can be seen in Figure 5(b) that due to the interpolation error of the edge texture caused by demosaic, obvious artifacts and false colors appear in the transition area. In the image acquired by the image sensor 10 in the embodiment of the present application, that is, in Figure 5(c), since the infrared light information of the image is combined and then demosaiced, the artifacts and false colors of the image can be well corrected. It reduces the granularity of flat areas and improves the signal-to-noise ratio, thus improving the quality of imaging.

In summary, by adding the near-infrared filter 1214 of the image sensor 10 and then combining it with specific data processing algorithms and processes, the granularity of the flat areas in the image can be reduced, the signal-to-noise ratio can be improved, and the quality of imaging can be improved. At the same time, it can also reduce the heat dissipation of fill light power consumption and improve the shooting experience.

In some embodiments, in each minimum repeating unit 121, the red filter 1211, the green filter 1212, the blue filter 1213 and the near-infrared filter 1214 all transmit the same amount of light. In this way, the color distribution of the imaged image can be uniform, ensuring the imaging effect of the image sensor 10 .

Referring to Figure 2, in some embodiments, in each minimum repeating unit 121, the areas of the red filter 1211, the green filter 1212, the blue filter 1213 and the near-infrared filter 1214 are all equal. . In this way, the area of each filter is the same, which facilitates installation in the image sensor 10 and facilitates mass production to reduce production costs.

Please refer to Figure 1 and Figure 2. In some embodiments, each minimum repeating unit 121 is arranged in a 2*2 array, the green filter 1212 and the near-infrared filter 1214 are arranged diagonally, and the red filter is arranged diagonally. The light sheet 1211 and the blue filter 1213 are arranged diagonally.

It can be understood that in the filter array 12, the number of red filters 1211, green filters 1212, blue filters 1213 and near-infrared filters 1214 each account for the total number of filters in the filter array 12. 1/4 of the quantity.

In one embodiment, each minimal repeating unit 121 is arranged in a 2*2 array, and the green filter 1212, the red filter 1211, the near-infrared filter 1214 and the blue filter in each minimal repeating unit 121 The optical filters 1213 can be arranged in a clockwise order to form a grid shape to form a minimum repeating unit 121 (as shown in FIG. 2 ). Four minimum repeating units 121 are arrayed to form the filter array 12 .

In some embodiments, each minimum repeating unit 121 may also be arranged in a 4*4 array, as shown in FIG. 6 . It should be noted that there can be multiple minimum repeating units 121 in the filter array 12 , and the multiple minimum repeating units 121 can also be arranged in other ways according to actual imaging requirements, which is not limited here.

Please refer to Figure 1, Figure 2 and Figure 6. In some embodiments, the red filter 1211, the green filter 1212, the blue filter 1213 and the near-infrared filter 1214 are all square. In this way, the structural arrangement of each minimum repeating unit 121 can be made more compact.

In some embodiments, the red filter 1211, the green filter 1212, the blue filter 1213 and the near-infrared filter 1214 can also be in the shape of a circle, a regular hexagon or a regular octagon, etc., which are not used here. Make restrictions.

Referring to FIGS. 1 and 7 , in some embodiments, the image sensor 10 may further include a microlens array 13 , and the microlens array 13 is disposed on a side of the filter array 12 away from the pixel array 11 . In this way, the microlens array 13 can converge the incident light, thereby improving the filling factor and quantum efficiency of the pixel.

Specifically, the microlens array 13 includes a plurality of microlenses arranged in an array. Each microlens has positive refractive power to focus light on the pixel array 11 . The surface of the microlens away from the filter array 12 may be convex, and the surface close to the filter array 12 may be flat, so that the microlens has positive refractive power.

Referring to FIG. 1 and FIG. 8 , the camera 100 provided by the embodiment of the present application includes a lens 20 and the image sensor 10 described in the above embodiment. The lens 20 is spaced apart from the image sensor 10 , and the lens 20 is used for imaging on the image sensor 10 .

Referring to FIG. 8 , in some embodiments, the camera 100 may include a fill light 30 , and the light emitted by the fill light 30 has a wavelength of 400 nm to 1100 nm. In this way, the fill light 30 can emit light as fill light, and the spectrum has real photon signals from 400nm to 1100nm. The light source 31 reflected by the object enters the macro camera 100 after passing through the lens 40, and then is transmitted to the image sensor 10.

Specifically, the light source 31 may be a light emitting diode light source 31 (Light Emitting Diode, LED). The light emitting diode light source 31 has the advantages of small size, long life, and high efficiency. In some embodiments, the light source 31 may also be a xenon lamp, which has relatively high energy density and illumination intensity.

In one embodiment, the fill light 30 may be in an annular shape, and the light source 31 of the fill light 30 may be an annular surface light source 31 , and the light source 31 is configured to emit light in a direction away from the image sensor 10 . In this way, the annular surface light source 31 can provide uniform illumination and improve imaging quality.

In another embodiment, the fill light 30 is annular, and multiple sets of light sources 31 are spaced on the fill light 30 (as shown in FIG. 9 ), thereby reducing the manufacturing cost of the fill light 30 , wherein at least one set of light sources is 31 is configured to emit light in a direction away from the image sensor 10 .

In some embodiments, the camera 100 may also include a macro camera. In this way, since the camera 100 provided by the embodiment of the present application includes the above image sensor 10, by adding the near-infrared filter 1214 of the image sensor 10, the acquisition of near-infrared light band data can also be used to guide and correct microscopic images. , reducing artifacts and false colors in imaging, improving imaging quality, and improving the experience when taking photos with the macro camera 100.

Specifically, referring to FIG. 8 , the camera 100 may also include a lens 40 , a lens holder 50 , a flexible circuit board 60 and a board-to-board connector 70 . The lens 40 has the function of protecting the lens 20, effectively preventing external objects from intruding into the interior of the camera 100, and preventing external objects from damaging the lens 20 due to friction. In one embodiment, the lens 40 may be a glass cover plate, and the glass cover plate has better light transmission effect.

The flexible circuit board 60 (Flexible Printed Circuit, FPC) and the board to board connector 70 (Board to board, BTB) are used to transmit digitally processed electrical signals. The flexible circuit board 60 may be a flexible printed circuit board made of polyimide or polyester film as a base material. The flexible printed circuit board has the advantages of light weight, thin thickness, and good bendability. The board-to-board connector 70 has the advantage of strong transmission capability.

Referring to FIG. 1 , FIG. 8 and FIG. 10 , an electronic device 1000 provided by an embodiment of the present application includes a casing 200 and the camera 100 described in the above embodiment. The camera 100 is exposed through the casing 200 .

The electronic device 1000 may be a terminal device with a camera function. For example, the electronic device 1000 may include a smartphone, a tablet computer, or other terminal equipment with a camera function. The electronic device 1000 in the embodiment of the present application takes a smartphone as an example, which should not be understood as a limitation of the present application.

The casing 200 is an external component of the electronic device 1000 and plays a role in protecting the internal components of the electronic device 1000 . The casing 200 may be a back cover of the electronic device 1000 , and the back cover covers components such as batteries of the electronic device 1000 . Specifically, the casing 200 can be made of metal material or plastic material, which is not limited here. The casing 200 made of metal material has the advantage of being strong and durable, and the casing 200 made of plastic material can reduce the mass of the electronic device 1000 . The camera 100 and the casing 200 may be detachably connected, or may be fixedly connected by welding, gluing, or other methods.

In the embodiment of the present application, the camera 100 is rear-facing, or in other words, the camera 100 is disposed on the back of the electronic device 1000 so that the electronic device 1000 can perform rear-facing photography. As shown in the example of FIG. 9 , the camera 100 is disposed at the upper middle position of the casing 200 . Of course, it can be understood that the camera 100 can be disposed at other positions such as the upper left position or the upper right position of the casing 200. The position of the camera 100 disposed on the casing 200 is not limited to the example of this application.

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

Although the embodiments of the present application have been shown and described, those of ordinary skill in the art will understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principles and purposes of the present application. The scope of the application is defined by the claims and their equivalents.

Claims

An image sensor, characterized by including:

pixel array;

A filter array, the filter array includes a plurality of minimum repeating units, and the minimum repeating units include a red filter, a green filter, a blue filter and a near-infrared filter.
The image sensor according to claim 1, characterized in that, in each of the minimum repeating units, the red filter, the green filter, the blue filter and the near-infrared filter are The amount of light transmitted by the filters is the same.
The image sensor according to claim 1, characterized in that, in each of the minimum repeating units, the red filter, the green filter, the blue filter and the near-infrared filter are The areas of the filters are all equal.
The image sensor according to claim 1, wherein each of the minimum repeating units is arranged in a 2*2 array, and the green filter and the near-infrared filter are arranged diagonally, The red filter and the blue filter are arranged diagonally.
The image sensor according to claim 4, wherein the red filter, the green filter, the blue filter and the near-infrared filter are all square.
The image sensor according to claim 4, characterized in that, in the filter array, the red filter, the green filter, the blue filter and the near-infrared filter The number of pieces each accounts for 1/4 of the total number of filters in the filter array.
The image sensor according to claim 1, wherein the image sensor further includes a microlens array, and the microlens array is disposed on a side of the filter array away from the pixel array.
A camera is characterized by including:

Image sensor, the image sensor includes a pixel array and a filter array, the filter array includes a plurality of minimum repeating units, the minimum repeating units include a red filter, a green filter, a blue filter and a near Infrared filters; and

A lens is provided at a distance from the image sensor and is used for imaging on the image sensor.
The camera according to claim 8, wherein the camera includes a fill light, and the light emitted by the fill light has a wavelength of 400nm-1100nm.
The camera of claim 8, wherein the camera includes a macro camera.
The camera of claim 8, wherein in each of the minimum repeating units, the red filter, the green filter, the blue filter and the near-infrared filter are The amount of light transmitted through the light sheets is the same.
The camera of claim 8, wherein in each of the minimum repeating units, the red filter, the green filter, the blue filter and the near-infrared filter are The areas of the light sheets are all equal.
The camera according to claim 8, characterized in that each of the minimum repeating units is arranged in a 2*2 array, and the green filter and the near-infrared filter are arranged diagonally, so The red filter and the blue filter are arranged diagonally.
The camera according to claim 13, wherein the red filter, the green filter, the blue filter and the near-infrared filter are all in a square shape.
The camera of claim 13, wherein in the filter array, the red filter, the green filter, the blue filter and the near-infrared filter Each accounts for 1/4 of the total number of filters in the filter array.
The camera of claim 8, wherein the image sensor further includes a microlens array, and the microlens array is disposed on a side of the filter array away from the pixel array.
An electronic device, characterized by comprising the camera according to any one of claims 8-16.
The electronic device according to claim 17, wherein the electronic device includes a casing, and the camera is exposed through the casing.
The electronic device according to claim 17, wherein the camera is a rear camera.
The electronic device of claim 17, wherein the electronic device includes a smartphone.