Pixel unit, pixel array, image sensor and vehicle

Abstract

The present application relates to a pixel unit, a pixel array, an image sensor and a vehicle, the pixel unit comprising: a first type of sub-pixels comprising at least one first type of photoelectric device to have a first pixel sensitivity; the second type of sub-pixels comprise at least one second type of photoelectric device so as to have second pixel sensitivity; the third type of sub-pixels comprise at least one third type of photoelectric device so as to have third pixel sensitivity; wherein the first pixel sensitivity is greater than the second pixel sensitivity; the second pixel sensitivity is greater than the third pixel sensitivity; the first type of sub-pixels are adjacent to the second type of sub-pixels and / or the third type of sub-pixels. The pixel unit, the pixel array, the image sensor and the vehicle have the beneficial effects that the compatibility of the image sensor is improved through the combination of the sub-pixels with different sensitivities.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle image sensors, and in particular to a pixel unit, a pixel array, an image sensor and a vehicle. Background Art

[0002] Currently, the vehicle's image sensors are unable to respond in a timely manner when lighting conditions change drastically, resulting in the captured images being unable to meet the requirements of applications in scenarios such as autonomous driving.

[0003] For example, driving from a dark basement to the outdoors facing the strong sunlight, or sensing pedestrians under the shade of trees under the illumination of oncoming high-beam headlights at night, all of these require the vehicle's image sensor to have a high dynamic response range.

[0004] Some circuit and software-based solutions are provided in the related art, but they still cannot effectively solve the problem that drastic changes in lighting conditions affect image acquisition. Summary of the invention

[0005] The embodiments of the present application provide a pixel unit, a pixel array, an image sensor and a vehicle to at least partially solve the above-mentioned technical problems.

[0006] In order to achieve the above-mentioned purpose, according to the first aspect of the present application, a pixel unit is provided, which includes: a first type of sub-pixel, including at least one first type of photoelectric device to have a first pixel sensitivity; a second type of sub-pixel, including at least one second type of photoelectric device to have a second pixel sensitivity; a third type of sub-pixel, including at least one third type of photoelectric device to have a third pixel sensitivity; wherein the first pixel sensitivity is greater than the second pixel sensitivity; the second pixel sensitivity is greater than the third pixel sensitivity; and the first type of sub-pixel is arranged adjacent to the second type of sub-pixel and / or the third type of sub-pixel.

[0007] Optionally, in some embodiments of the present application, in the pixel unit, the first type of sub-pixels, the second type of sub-pixels and the third type of sub-pixels are arranged in an array.

[0008] Optionally, in some embodiments of the present application, in the pixel unit, a plurality of the first-type sub-pixels, the second-type sub-pixels, and the third-type sub-pixels are arranged in an array.

[0009] Optionally, in some embodiments of the present application, there is at least one sub-pixel of the first type in each row of the array consisting of the first type of sub-pixels, the second type of sub-pixels, and the third type of sub-pixels.

[0010] Optionally, in some embodiments of the present application, there is at least one sub-pixel of the first type in each column of the array consisting of the first type of sub-pixels, the second type of sub-pixels, and the third type of sub-pixels.

[0011] Optionally, in some embodiments of the present application, there is at least one sub-pixel of the first type in each row or each column of the array consisting of the first type of sub-pixels, the second type of sub-pixels and the third type of sub-pixels.

[0012] Optionally, in some embodiments of the present application, one pixel unit includes more than two sub-pixels of the first type.

[0013] Optionally, in some embodiments of the present application, one of the first-category sub-pixels in the pixel unit and one of the second-category sub-pixels constitute a group of low-sensitivity pixel pairs; one of the first-category sub-pixels in the pixel unit and one of the third-category sub-pixels constitute a group of high-sensitivity pixel pairs; a group of the low-sensitivity pixel pairs and a group of the high-sensitivity pixel pairs are arranged side by side or in parallel.

[0014] Optionally, in some embodiments of the present application, one pixel unit includes two sub-pixels of the first type, one sub-pixel of the second type and one sub-pixel of the third type.

[0015] Optionally, in some embodiments of the present application, the first type of sub-pixels, the second type of sub-pixels and the third type of sub-pixels are all configured to have a rectangular sub-pixel outline; the sum of the numbers of the first type of sub-pixels, the second type of sub-pixels and the third type of sub-pixels in one pixel unit is an even number so that the pixel unit is configured to have a rectangular pixel outline.

[0016] Optionally, in some embodiments of the present application, the first type of sub-pixel is at least arranged at a diagonal corner of the pixel outline.

[0017] Optionally, in some embodiments of the present application, at least two of the first-type sub-pixels are arranged to form an edge of the pixel outline.

[0018] Optionally, in some embodiments of the present application, one pixel unit includes two of the first-category sub-pixels, one of the second-category sub-pixel and one of the third-category sub-pixel; two of the first-category sub-pixels, one of the second-category sub-pixel and one of the third-category sub-pixel all have a square sub-pixel outline.

[0019] Optionally, in some embodiments of the present application, two of the first-type sub-pixels, one of the second-type sub-pixels and one of the third-type sub-pixels form a 2×2 array arrangement; and the two of the first-type sub-pixels are located in the same row or column.

[0020] Optionally, in some embodiments of the present application, two of the first-type sub-pixels, one of the second-type sub-pixel and one of the third-type sub-pixel form a 2×2 array arrangement; the two of the first-type sub-pixels are located in different rows or different columns.

[0021] Optionally, in some embodiments of the present application, the first type of sub-pixel has a first opening area; the second type of sub-pixel has a second opening area; and the third type of sub-pixel has a third opening area.

[0022] Optionally, in some embodiments of the present application, the first type of sub-pixels has a first film layer thickness; the second type of sub-pixels has a second film layer thickness; and the third type of sub-pixels has a third film layer thickness.

[0023] Optionally, in some embodiments of the present application, the first type of sub-pixels has a first lens thickness; the second type of sub-pixels has a second lens thickness; and the third type of sub-pixels has a third lens thickness.

[0024] Optionally, in some embodiments of the present application, the ratio of the first pixel sensitivity to the second pixel sensitivity ranges from 2 to 5; the ratio of the second pixel sensitivity to the third pixel sensitivity ranges from 5 to 20.

[0025] Optionally, in some embodiments of the present application, the ratio of the first pixel sensitivity to the second pixel sensitivity is 4; the ratio of the second pixel sensitivity to the third pixel sensitivity is 10.

[0026] According to a second aspect of the present application, a pixel array is provided, comprising the aforementioned pixel units; the pixel units are arranged in an array; in particular, a Bayer array.

[0027] According to a third aspect of the present application, an image sensor is also provided, comprising the aforementioned pixel array.

[0028] According to a fourth aspect of the present application, a vehicle is also provided, comprising the aforementioned image sensor.

[0029] The beneficial effects of the present application are: providing a pixel unit, a pixel array, an image sensor and a vehicle that improve the compatibility of an image sensor by combining sub-pixels with different sensitivities.

[0030] More specifically, some embodiments of the present application may produce the following specific beneficial effects:

[0031] Using sub-pixels with three sensitivities in one pixel unit enables the pixel unit to have a good dynamic range while taking into account LFM (LED Flicker Mitigation) performance.

[0032] A specific array arrangement is used so that the sub-pixels in a pixel unit can be exposed and read synchronously to obtain a better SNR.

[0033] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0035] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0036] Figure 1 is a schematic structural diagram of a first pixel unit provided in an exemplary embodiment of the present application;

[0037] Figure 2 is a schematic structural diagram of a second pixel unit provided in an exemplary embodiment of the present application;

[0038] Figure 3 Schematic diagram of the photoelectric conversion relationship between LPD and SPD provided in an exemplary embodiment of the present application;

[0039] Figure 4 is an exposure timing diagram of LPD and SPD provided in an exemplary embodiment of the present application (in the figure, LPD represents a first photoelectric device, SPD1 represents a second photoelectric device, and SPD2 represents a third photoelectric device);

[0040] Figure 5 is a schematic structural diagram of a pixel array provided in an exemplary embodiment of the present application;

[0041] Figure 6 is a schematic structural diagram of another pixel array provided in an exemplary embodiment of the present application;

[0042] Figure 7 It is a schematic structural diagram of a vehicle provided in an exemplary embodiment of the present application.

[0043] Description of reference numerals:

[0044] 1. Vehicles;

[0045] 10. Pixel array;

[0046] 100, pixel unit;

[0047] 110. first type of sub-pixel;

[0048] 120, second type of sub-pixel;

[0049] 130. The third type of sub-pixel. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0051] Reference Figure 1 and Figure 2 As shown, as a first aspect of the present application, the present application provides a pixel unit 100 , and the pixel unit includes: a first type of sub-pixel 110 , a second type of sub-pixel 120 and a third type of sub-pixel 130 .

[0052] Among them, the first type of sub-pixel 110 includes at least one first type of photoelectric device (LPD) to have a first pixel sensitivity; the second type of sub-pixel 120 includes at least one second type of photoelectric device (SPD1) to have a second pixel sensitivity; the third type of sub-pixel 130 includes at least one third type of photoelectric device (SPD2) to have a third pixel sensitivity.

[0053] As an alternative, the first type of sub-pixel 110 may also include a plurality of first type of optoelectronic devices. The second type of sub-pixel 120 may also include a plurality of second type of optoelectronic devices. The third type of sub-pixel 130 may also include a plurality of third type of optoelectronic devices.

[0054] As an alternative, the first type of optoelectronic device, the second type of optoelectronic device and the third type of optoelectronic device may be photodiodes, in particular diodes formed by integrated circuits.

[0055] The first pixel sensitivity is greater than the second pixel sensitivity; the second pixel sensitivity is greater than the third pixel sensitivity; and the first type of sub-pixel 110 is disposed adjacent to the second type of sub-pixel 120 and / or the third type of sub-pixel 130 .

[0056] The first type of sub-pixel 110 is used in combination with the second type of pixel in the pixel unit 100; the first type of sub-pixel 110 is used in combination with the third type of pixel in the pixel unit 100, that is, in one pixel unit 100, there are three or more sub-pixels with pixel sensitivities from high to low.

[0057] Specifically, in the pixel unit 100, the first type of sub-pixel 110, the second type of sub-pixel 120 and the third type of sub-pixel 130 form an array arrangement. In particular, a plurality of the first type of sub-pixels 110, the second type of sub-pixels 120 and the third type of sub-pixels 130 form an array arrangement. In a pixel unit 100, each second type of sub-pixel 120 and each third type of sub-pixel 130 are respectively provided with a first type of sub-pixel 110. That is, a first type of sub-pixel and a second type of sub-pixel 120 in the pixel unit 100 form a group of low-sensitivity pixel pairs; a first type of sub-pixel and a third type of sub-pixel 130 in the pixel unit 100 form a group of high-sensitivity pixel pairs; a group of low-sensitivity pixel pairs and a group of high-sensitivity pixel pairs are arranged side by side or in parallel. Specifically, a pixel unit 100 includes two first type of sub-pixels 110, one second type of sub-pixel 120 and one third type of sub-pixel 130.

[0058] As a more specific solution, one pixel unit 100 includes more than two first-type sub-pixels 110 .

[0059] Specifically, in the pixel unit 100, each row of the array composed of the first sub-pixel 110, the second sub-pixel 120, and the third sub-pixel 130 has at least one first sub-pixel 110. Each column of the array composed of the first sub-pixel 110, the second sub-pixel 120, and the third sub-pixel 130 has at least one first sub-pixel 110. Each row or column of the array composed of the first sub-pixel 110, the second sub-pixel 120, and the third sub-pixel 130 has at least one first sub-pixel 110.

[0060] Reference Figure 1 and Figure 2 As shown, in some embodiments of the present application, the first type of sub-pixel 110, the second type of sub-pixel 120 and the third type of sub-pixel 130 are all configured to have a rectangular sub-pixel outline; the sum of the numbers of the first type of sub-pixel 110, the second type of sub-pixel 120 and the third type of sub-pixel 130 in a pixel unit 100 is an even number so that the pixel unit 100 is configured to have a rectangular pixel outline.

[0061] Reference Figure 1 and Figure 2 As shown, specifically, the first type of sub-pixel 110 is arranged at least at the diagonal corners of the pixel outline. Specifically, at least two first type of sub-pixels 110 are arranged to form the edge of the pixel outline.

[0062] Specifically, a pixel unit 100 includes two first-type sub-pixels 110 , one second-type sub-pixel 120 and one third-type sub-pixel 130 ; the two first-type sub-pixels 110 , one second-type sub-pixel 120 and one third-type sub-pixel 130 all have square sub-pixel outlines.

[0063] Reference Figure 1 As shown, two first-type sub-pixels 110 , one second-type sub-pixel 120 , and one third-type sub-pixel 130 form a 2×2 array arrangement; the two first-type sub-pixels 110 are located in the same row or the same column.

[0064] Reference Figure 2 As shown, two first-type sub-pixels 110 , one second-type sub-pixel 120 , and one third-type sub-pixel 130 are arranged in a 2×2 array; the two first-type sub-pixels 110 are located in different rows or different columns.

[0065] That is, Figure 1 In the illustrated 'T-shaped' layout, the two first-type sub-pixels 110 may be disposed at diagonal positions or at the same side.

[0066] In some embodiments of the present application, the first type of sub-pixel 110 has a first opening area; the second type of sub-pixel 120 has a second opening area; and the third type of sub-pixel 130 has a third opening area. That is, different pixel sensitivities can be achieved through the opening area or the opening ratio. Here, the opening area can be achieved through the design of the pixel grid, and the specific means are conventional means of those skilled in the art, which will not be elaborated here.

[0067] In some embodiments of the present application, specifically, the first type of sub-pixel 110 has a first film thickness; the second type of sub-pixel 120 has a second film thickness; and the third type of sub-pixel 130 has a third film thickness. Furthermore, the film thickness referred to here is the thickness of the optical attenuation film of the sub-pixel structure, and of course, it can also be the thickness of any other film layer disposed between the optoelectronic device and the light incident interface or the sum of the thicknesses of these film layers.

[0068] Specifically, the first type of sub-pixel 110 has a first lens thickness, the second type of sub-pixel 120 has a second lens thickness, and the third type of sub-pixel 130 has a third lens thickness, which refers to the maximum thickness of the sub-pixel microlens.

[0069] Specifically, the ratio of the first pixel sensitivity to the second pixel sensitivity ranges from 2 to 5; the ratio of the second pixel sensitivity to the third pixel sensitivity ranges from 5 to 20. As a step-by-step option, the ratio of the first pixel sensitivity to the second pixel sensitivity is 4; the ratio of the second pixel sensitivity to the third pixel sensitivity is 10, that is, the ratio of the first pixel sensitivity, the second pixel sensitivity and the third full pixel sensitivity is 1:10:40.

[0070] Reference Figure 3 As shown, taking photodiodes with two sensitivities (SPD and LPD) as an example, the dynamic range is undoubtedly expanded based on the difference in sensitivity.

[0071] When three photodiodes with three sensitivities are used to form three sub-pixels, two are used as LPDs, one is used as a medium-sensitivity SPD, and one is used as a low-sensitivity SPD, that is, they are respectively used as the first type of photoelectric device, the second type of photoelectric device, and the third type of photoelectric device. When the first type of photoelectric device, the second type of photoelectric device, and the third type of photoelectric device are respectively used as the only photoelectric device in the first type of sub-pixel 110, the second type of sub-pixel 120, and the third type of sub-pixel 130, the sub-pixel can also be equated with a photoelectric device. In this way, a high dynamic range can be guaranteed while taking into account LFM performance.

[0072] Reference Figure 4 As shown, in terms of timing design, the three sub-pixels of the present application perform two exposures within one exposure time, which can better ensure that the LFM range is consistent with the dynamic range, and can ensure a higher dynamic range while effectively achieving LED flash suppression.

[0073] Reference Figure 5 or Figure 6 As shown, as a second aspect of the present application, the present application provides a pixel array 10; in particular, a Bayer array.

[0074] As a third aspect of the present application, the present application provides an image sensor; the image sensor includes the aforementioned pixel unit 100 or pixel array 10 .

[0075] Reference Figure 7 As shown, the vehicle 1 of the present application includes the aforementioned image sensor, which can provide images for applications such as automatic driving of the vehicle 1.

[0076] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0077] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0078] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0079] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A pixel unit, characterized in that: include: A first type of sub-pixel, comprising at least one first type of optoelectronic device to have a first pixel sensitivity; A second type of sub-pixel, comprising at least one second type of optoelectronic device to have a second pixel sensitivity; A third type of sub-pixel, comprising at least one third type of optoelectronic device to have a third pixel sensitivity; Among them, the first pixel sensitivity is greater than the second pixel sensitivity; the second pixel sensitivity is greater than the third pixel sensitivity.

2. The pixel unit according to claim 1, characterized in that: At least one of the second type of sub-pixel and the third type of sub-pixel is disposed adjacent to the first type of sub-pixel.

3. The pixel unit according to claim 2, characterized in that: In the pixel unit, the first type of sub-pixels, the second type of sub-pixels and the third type of sub-pixels are arranged in an array.

4. The pixel unit according to claim 3, characterized in that: In each row of the array formed by the first-type sub-pixels, the second-type sub-pixels and the third-type sub-pixels, there is at least one sub-pixel of the first type.

5. The pixel unit according to claim 3, characterized in that: Each column of the array formed by the first-type sub-pixels, the second-type sub-pixels, and the third-type sub-pixels has at least one sub-pixel of the first type.

6. The pixel unit according to claim 3, characterized in that: There is at least one sub-pixel of the first type in each row or each column of the array formed by the sub-pixels of the first type, the sub-pixels of the second type, and the sub-pixels of the third type.

7. The pixel unit according to any one of claims 1 to 6, characterized in that: One pixel unit includes more than two sub-pixels of the first type.

8. The pixel unit according to claim 7, characterized in that: in, One of the first-category sub-pixels in the pixel unit and one of the second-category sub-pixels constitute a group of low-sensitivity pixel pairs; one of the first-category sub-pixels in the pixel unit and one of the third-category sub-pixels constitute a group of high-sensitivity pixel pairs; a group of low-sensitivity pixel pairs and a group of high-sensitivity pixel pairs are arranged side by side or in parallel.

9. The pixel unit according to claim 8, characterized in that: One pixel unit includes two sub-pixels of the first type, one sub-pixel of the second type and one sub-pixel of the third type.

10. The pixel unit according to any one of claims 1 to 6, characterized in that: The first type of sub-pixels, the second type of sub-pixels and the third type of sub-pixels are all configured to have a rectangular sub-pixel outline; the sum of the numbers of the first type of sub-pixels, the second type of sub-pixels and the third type of sub-pixels in one pixel unit is an even number so that the pixel unit is configured to have a rectangular pixel outline.

11. The pixel unit according to claim 10, characterized in that: The first type of sub-pixels are arranged at least at diagonal corners of the pixel outline.

12. The pixel unit according to claim 11, characterized in that: At least two of the first-type sub-pixels are arranged to form an edge of the pixel outline.

13. The pixel unit according to claim 12, characterized in that: One pixel unit includes two first-type sub-pixels, one second-type sub-pixel and one third-type sub-pixel; the two first-type sub-pixels, one second-type sub-pixel and one third-type sub-pixel all have square sub-pixel outlines.

14. The pixel unit according to claim 13, characterized in that: Two sub-pixels of the first type, one sub-pixel of the second type and one sub-pixel of the third type are arranged in a 2×2 array; and the two sub-pixels of the first type are located in the same row or the same column.

15. The pixel unit according to claim 13, characterized in that: Two sub-pixels of the first type, one sub-pixel of the second type and one sub-pixel of the third type are arranged in a 2×2 array; the two sub-pixels of the first type are located in different rows or different columns.

16. The pixel unit according to any one of claims 1 to 6, characterized in that: The first type of sub-pixels has a first opening area; the second type of sub-pixels has a second opening area; and the third type of sub-pixels has a third opening area.

17. The pixel unit according to any one of claims 1 to 6, characterized in that: The first type of sub-pixels has a first film layer thickness; the second type of sub-pixels has a second film layer thickness; and the third type of sub-pixels has a third film layer thickness.

18. The pixel unit according to any one of claims 1 to 6, characterized in that: The first type of sub-pixels has a first lens thickness; the second type of sub-pixels has a second lens thickness; and the third type of sub-pixels has a third lens thickness.

19. The pixel unit according to any one of claims 1 to 6, characterized in that: The ratio of the first pixel sensitivity to the second pixel sensitivity ranges from 2 to 5; The ratio of the second pixel sensitivity to the third pixel sensitivity ranges from 5 to 20.

20. The pixel unit according to claim 19, characterized in that: The ratio of the first pixel sensitivity to the second pixel sensitivity is 4; A ratio of the second pixel sensitivity to the third pixel sensitivity is 10.

21. A pixel array, characterized in that: It comprises the pixel unit according to any one of claims 1 to 20; the pixel units are arranged in an array.

22. The pixel array according to claim 21, characterized in that: The pixel units form a Bayer array.

23. An image sensor, characterized in that: Comprising the pixel array described in claim 21 or 22.

24. A vehicle, characterized in that: Comprising the image sensor of claim 23.

Images