An under-screen image sensor, a camera module and an electronic device

Abstract

A kind of under-screen image sensor, camera module and electronic equipment, each pixel repetition unit includes 8 pixels, each pixel only gathers the light intensity information of one color in R / G / B;Wherein, the number of pixels R:G:B=2:3:3.The present application proposes a new pixel arrangement mode applied to under-screen, to make up for the different color light attenuation color cast problem caused by screen absorption and scattering, to improve the color cast problem of under-screen image from hardware aspect.

Description

Technical Field

[0001] This invention relates to the field of under-display imaging technology, specifically to an under-display image sensor, system, device, and storage medium. Background Technology

[0002] With the rapid iteration of full-screen smart terminal technology, under-display camera technology, with its ultra-high screen-to-body ratio advantage of being punch-free and notch-free, has become the core mainstream technology for the full-screen development of terminal devices. The core principle of under-display imaging is to hide the image sensor under the screen display area, using the screen's light transmission characteristics to collect external light to achieve imaging. This completely breaks through the appearance limitations of traditional punch-hole and pop-up cameras, greatly improving the visual integrity and user experience of the terminal screen. However, compared with traditional external camera imaging solutions, under-display imaging has unique optical interference problems. The light absorption, scattering, diffraction, and spectral selective attenuation effects caused by the screen's layered structure result in serious color shift, color distortion, and low signal-to-noise ratio defects in under-display imaging, which have long restricted the improvement of under-display camera imaging quality.

[0003] Currently, under-display image sensors in the industry all use the standard Bayer pixel arrangement for traditional imaging, with the mainstream being the RGGB layout. Its pixel ratio is fixed at R:G:B=1:2:1. The core design logic is to adapt to imaging scenarios in conventional air, leveraging the human eye's higher sensitivity to green light to ensure image brightness and clarity by increasing the proportion of green pixels. In conventional imaging scenarios, this arrangement can basically meet color reproduction requirements, and with mature de-mosaic interpolation and color correction algorithms, it can achieve accurate color reproduction. However, this traditional pixel ratio and arrangement structure are completely unsuitable for the special optical imaging environment under displays, exhibiting significant technical adaptation deficiencies.

[0004] In under-display imaging, light must penetrate multiple layers of the OLED screen, including pixel layers, metal wiring, and encapsulation layers. The penetration loss and scattering attenuation of the R, G, and B light wavelengths vary significantly. Short-wavelength blue light and medium-wavelength green light are more significantly affected by absorption by the screen materials and scattering during penetration, resulting in a much greater intensity attenuation than long-wavelength red light. This leads to a significant loss of blue and green channel light intensity signals and a relative excess of red channel signals in the original image captured by the sensor, ultimately causing color cast issues such as a reddish or dark image, color banding, etc. Simultaneously, the overall transmittance of the under-display area is generally low, resulting in insufficient overall light intake, further amplifying the signal imbalance problem of the three color channels. This is particularly pronounced in low-light environments, leading to color distortion and increased image noise.

[0005] To improve the color cast issue in under-display imaging, existing technologies rely on software methods such as backend ISP algorithm optimization, AI color compensation, and color correction matrix adjustment. However, software algorithm correction has inherent limitations; it can only passively repair distorted images after imaging and cannot compensate for the loss of original pixel signals caused by screen optical loss. When the original light-sensitive signals of the blue and green channels are excessively attenuated and the data distortion is severe, algorithm interpolation compensation is prone to secondary problems such as false colors, uneven color transitions, and loss of details. It cannot fundamentally balance the light-sensitive differences of the three color channels, resulting in the color reproduction accuracy of under-display imaging always falling short of the imaging level of external cameras, becoming the core bottleneck for the high-definition and high-quality development of under-display camera technology.

[0006] In summary, the traditional 1:2:1 Bayer pixel arrangement is not adapted to the spectral attenuation characteristics of under-display imaging. Software compensation solutions are merely stopgap measures, lacking targeted hardware-level optimization solutions, and cannot fundamentally address the industry pain points of color shift and distortion in under-display imaging. Therefore, there is an urgent need to design a new pixel arrangement structure adapted to the optical attenuation characteristics of under-display imaging. By optimizing the RGB pixel ratio, the light-gathering capabilities of the three colors of light can be balanced at the hardware level, compensating for the attenuation differences of different colors of light, improving the color cast problem in under-display imaging from the source, and enhancing the color reproduction and image quality of under-display imaging.

[0007] The above background information is provided only to aid in understanding the inventive concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0008] To address this, the present invention proposes a new pixel arrangement mode for under-display applications, which improves the color distortion problem of under-display images from a hardware perspective by compensating for the color attenuation of different colors of light caused by screen absorption and scattering.

[0009] In a first aspect, the present invention provides an under-display image sensor, characterized in that it comprises: An under-display image sensor is characterized in that each pixel repeating unit includes 8 pixels, and each pixel only collects light intensity information of one color among R / G / B; wherein the number of pixels R:G:B=2:3:3.

[0010] Optionally, in the under-display image sensor, the pixel repeating unit is rectangular.

[0011] Optionally, the under-display image sensor is characterized in that the aspect ratio of the rectangle is 2:1.

[0012] Optionally, in the under-display image sensor, the pixel repeating unit is square.

[0013] Optionally, the under-display image sensor is characterized in that two Rs are located inside the square, and two Gs and two Bs are located at the top corners of the square.

[0014] Optionally, in the aforementioned under-display image sensor, the color of the filter for each pixel within the pixel repeating unit is different from that of the three adjacent pixels.

[0015] Secondly, the present invention provides an under-display image sensor, characterized in that each pixel repeating unit includes at least 3 pixels, and each pixel only collects light intensity information of one color among R / G / B; wherein the area ratio of each color pixel is R:G:B=2:3:3.

[0016] Optionally, the under-display image sensor is characterized in that each pixel is rectangular, and the pixel repeating unit is also rectangular.

[0017] Thirdly, the present invention provides a camera module, characterized in that it includes the under-display image sensor described in any of the preceding claims.

[0018] Fourthly, the present invention provides an electronic device, characterized in that it includes an electronic display screen and an under-display image sensor as described in any of the preceding claims; The under-display image sensor is located on the backlight side of the electronic display screen and receives visible light that penetrates the electronic display screen; The substrate of the electronic display screen is a polyimide substrate.

[0019] Compared with the prior art, the present invention has the following beneficial effects: This invention features a unique R:G:B ratio of 2:3:3, perfectly suited to the differentiated spectral attenuation characteristics of under-display stacked layers. Through hardware-level optimization of pixel layout and color sampling ratio, it precisely compensates for green and blue light path losses, balancing the RGB three-channel photosensitive signals from the root of imaging. Without relying on backend software correction, it efficiently solves the inherent color cast problem in under-display imaging, achieving accurate color reproduction at the hardware level. It completely avoids the color distortion and banding problems caused by traditional solutions relying on algorithmic color correction, significantly improving the realism and stability of color reproduction.

[0020] This invention optimizes the front-end hardware structure to directly output balanced, complete, and high-fidelity raw image photosensitive data, significantly reducing the computational and calibration burden on the back-end image processing chip. Compared to traditional solutions that rely on numerous ISP algorithms, interpolation algorithms, and color compensation algorithms to correct image defects, this invention greatly reduces the computational power consumption of the image processing chip, lowers device power consumption, simplifies imaging algorithm logic, and improves terminal imaging response speed. Based on high-quality raw hardware sampling data, it can easily handle complex imaging scenarios such as low light, backlight, and high dynamic range, accurately solving persistent color casts and color distortion problems under complex conditions, and comprehensively improving overall image quality.

[0021] The array structure of this invention is fully compatible with the existing wafer manufacturing, wiring and packaging processes of CMOS image sensors. It does not require modification of core production equipment and process parameters, and has low mass production difficulty and low modification cost, perfectly balancing the needs of high-performance imaging and industrial mass production.

[0022] Addressing the pain points of low overall light intake and poor low-light imaging in under-display cameras, this invention effectively increases the total light intake of the weaker green and blue channels by expanding the core green and blue photosensitive pixel units, significantly enhancing the photosensitivity and signal-to-noise ratio of the two color channels. This design can significantly improve color recognition capabilities in complex scenarios such as low light and backlight, effectively suppress imaging noise, improve image clarity, greatly expand the effective imaging scenarios of under-display cameras, and fully adapt to the high-definition shooting needs of smart terminals in all scenarios.

[0023] This invention abandons the fixed design of traditional universal pixel arrangement, and is specifically customized for under-display imaging scenarios. The pixel ratio and arrangement structure are highly matched with the optical transmission characteristics of under-display, achieving deep adaptation between hardware structure and imaging conditions. Relying on the hardware's native three-color signal equalization capability, it not only improves the image quality in normal scenarios, but also specifically solves the industry problems of algorithm correction failure and difficult-to-eradicate color cast in complex scenarios. While ensuring excellent imaging performance, it also takes into account low computing power consumption and high mass production adaptability, providing an efficient, reliable, and low-cost hardware solution for high-quality under-display imaging. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. Other features, objects, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 For ordinary sensor Bayer array pixels; Figure 2 This is a schematic diagram of the under-display sensor in operation. Figure 3 This is a diagram comparing the image on the screen with the image under the screen. Figure 4 This is a schematic diagram of the structure of a pixel repeating unit in an embodiment of the present invention; Figure 5 This is a schematic diagram of another pixel repeating unit in an embodiment of the present invention; Figure 6 This is a schematic diagram of another pixel repeating unit in an embodiment of the present invention; Figure 7 This is a schematic diagram of another pixel repeating unit in an embodiment of the present invention; Figure 8 This is a schematic diagram of another pixel repeating unit in an embodiment of the present invention; Figure 9 This is a schematic diagram of another pixel repeating unit in an embodiment of the present invention.

[0025] 1-The object being photographed; 2-screen; 3-Camera module; 4-Pixel arrangement in the screen's light-transmitting area; Detailed Implementation

[0026] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0027] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] The present invention provides an under-display image sensor, which aims to solve the problems existing in the prior art.

[0029] The technical solutions of the present invention and how they solve the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0030] like Figure 1 As shown, a typical sensor uses a Bayer array arranged in RGGB, with the area ratio of different colored pixels being R:G:B=1:2:1, which matches the human eye's perception ratio of different colors of light. The sensor image is closer to the actual sensory effect of the human eye. However, when the camera is placed under the screen, the incident light ratio changes. The screen itself acts like a multi-layered composite "filter," and different materials have different "interception" capabilities for different colors of light. Short-wavelength blue light is absorbed the most, while long-wavelength red light is absorbed the least, causing the original color ratio to change and the overall image to appear yellowish. like Figure 2 As shown, the light reflected from the object being photographed 1 passes through the screen 2, through the pixel arrangement 4 in the light-transmitting area of ​​the screen, and is incident into the camera module 3. The incident ratio of the light changes after passing through the screen.

[0031] like Figure 3 As shown, when a camera with a conventional pixel arrangement takes a grayscale image on the screen, the R:G:B color ratio of the image is 1:1:1. When the camera is placed under the screen, after absorption, diffraction, and scattering by the screen, the R:G:B color ratio of the image at the same position becomes 7:10:5 (actual measurement). This results in an overall yellowish tint to the image, requiring color correction using the ISP processing module of the computing chip. However, due to the large deviation, pure software color correction is still prone to color distortion in bright and dark scenes.

[0032] like Figure 4 As shown, each pixel repeating unit includes 8 pixels, and each pixel only collects the light intensity information of one color among R / G / B; wherein, the number of pixels R:G:B=2:3:3.

[0033] This embodiment belongs to the pixel array architecture of a dedicated image sensor for under-display imaging. It is designed to meet the pain points of under-display camera scenarios such as screen pixel layer occlusion, uneven light transmittance, light attenuation, stray light interference, and pixel miniaturization. Through customized 8-pixel repeating units and special RGB pixel ratio design, it balances under-display low-light imaging, color reproduction, signal-to-noise ratio, resolution and photosensitivity, which is different from conventional Bayer arrays (2 green, 1 red, 1 blue) and traditional four-pixel / six-pixel pixel arrangement schemes.

[0034] The sensor's photosensitive array consists of identical, periodically repeating pixel units. Each pixel unit contains eight independent photosensitive pixels, and all imaging pixels are expanded from this eight-pixel module as the base array, with no mixed or irregular units.

[0035] Each pixel in the pixel repeating unit is equipped with a single color filter and can only collect one of the monochromatic light intensity signals: red (R), green (G), and blue (B). There are no RGB three-color combined pixels or dual-color co-pixel structures. Each pixel's light-sensing channel is completely independent, avoiding color crosstalk.

[0036] Within a pixel repeating unit, the ratio of red, green, and blue pixels is fixed at R:G:B = 2:3:3. That is, there are 2 red photosensitive pixels (R), 3 green photosensitive pixels (G), and 3 blue photosensitive pixels (B).

[0037] Traditional Bayer array 2 green pixels are designed based on the optical characteristic that the human eye is most sensitive to green light, but there are special light loss defects in under-display scenarios: The OLED / LCD screen's light-emitting layer, metal traces, and pixel light-shielding layer will cause different attenuation of light of different wavelengths: the light loss of short-wavelength blue light and long-wavelength red light after passing through the screen is much higher than that of green light; the conventional Bayer array has insufficient number of R and B pixels, and the red and blue channels have extremely low signal-to-noise ratio under weak screen conditions, resulting in severe color distortion and color banding.

[0038] This embodiment adjusts the proportions to specifically address the shortcomings of under-display imaging: - Retain a sufficient number of 3 G pixels: Maintain the basic brightness perception of the human eye, ensure the overall brightness of the image and the resolution of outline details, and meet the requirements of light and dark texture recognition; - The number of B pixels has been increased to 3 (traditionally only 1): Blue light has the shortest wavelength and is scattered and absorbed the most when it penetrates the multi-layer structure of the screen. Increasing the number of blue pixels increases the total photosensitive charge of the blue channel, significantly reduces blue noise, and improves the problem of yellowing and graying in night scenes and cool-toned images. - The number of R pixels has been increased to 2 (traditionally only 1): Red light is easily blocked and attenuated when it passes through the metal circuit of the screen. The addition of red pixel acquisition channels improves the color reproduction accuracy of skin color and red objects, and avoids whitening and distortion of skin color in portrait images. - The total number of pixels in the unit has been increased to 8. Compared with the 4-pixel Bayer unit, the single repeating unit has more photosensitive sampling points, higher color sampling density, smoother color transition when the interpolation algorithm restores the image, and reduces moiré patterns and color artifacts in the under-screen image.

[0039] With a ratio of 2+3+3=8, the value perfectly matches the total number of pixels in the unit, eliminating pixel redundancy and fractional splitting issues. The array is arranged regularly and periodically, eliminating the need for non-integer pixel interpolation in the backend ISP image signal processing. This simplifies the algorithm's computational power consumption and adapts to the low-power requirements of under-display chips.

[0040] like Figure 4 As shown, the array layout can be designed using a rectangular 2×4 arrangement (8-pixel unit). The 8 pixels are arranged into a 2x4 rectangular unit, with 2 R, 3 G, and 3 B pixels fixed within each unit. In this case, the aspect ratio of the rectangle is 2:1.

[0041] The layout design concept is as follows: three G pixels are distributed in the middle area of ​​the unit as the main brightness sampling points; two R pixels and three B pixels are evenly distributed around the unit to collect red and blue monochromatic light in a balanced manner, reduce the local deviation of color sampling caused by the concentration of pixels of the same color, and suppress the color moiré caused by the periodic grid of the under-screen.

[0042] like Figure 5 As shown, the array layout can adopt a 4×2 arrangement. The vertically stretched unit arrangement is adapted to the long strip photosensitive chip under the mobile phone screen, and the pixels of the same color are arranged in an alternating and dispersed manner to adapt to the light attenuation law of vertical pixel lines blocking the screen, resulting in stronger vertical color sampling uniformity.

[0043] Array arrangement can also be adopted Figure 6 and Figure 7 The arrangement shown is as described. Of course, those skilled in the art can also select other arrangement methods according to actual needs, based on the guidance of this invention.

[0044] The above arrangement satisfies periodic repetition, with seamless splicing of adjacent 8 pixel units, and a globally uniform pixel ratio across the entire photosensitive array, with no local color sampling imbalance areas.

[0045] Each pixel is independently configured with a microlens, a monochromatic filter, a photodiode (PD), and a pixel readout circuit. The R / G / B filters allow only the corresponding wavelength of visible light to pass through, while the cutoff wavelengths isolate stray light, reducing screen light leakage and ambient stray light crosstalk. The 8-pixel units can share some of the pixel readout control circuitry, reducing the number of array metal trace layers and the area of ​​metal light-blocking below the screen, further improving the overall light transmittance.

[0046] This embodiment uses 8 pixels as a pixel repeating unit, and the independent monochrome photosensitive pixels within the unit are arranged strictly according to the ratio of R:G:B=2:3:3. By increasing the number of red and blue photosensitive pixels, the screen's attenuation of red and blue wavelengths is compensated for, while sufficient green pixels are retained to ensure image brightness and detail. The regular 8-pixel integer ratio enables the array to be arranged periodically and seamlessly, simplifying the backend image processing algorithm. Compared with the traditional Bayer pixel array, it has significant technical advantages in under-display low-light imaging, color reproduction, noise suppression, and moiré pattern elimination, solving the industry pain points of color distortion and severe noise in night scenes in existing under-display cameras.

[0047] Unlike Example 1, such as Figure 8 As shown, the pixel repeating unit in this embodiment is a square. Two R's are located inside the square, and two G's and two B's are located at the top corners of the square.

[0048] The outer contour of the pixel repeating unit is a standard square with four equal sides and four right angles. Adjacent units can be copied and stitched into an array without misalignment or gaps. The square has four vertices, with one photosensitive pixel at each vertex, for a total of four vertices.

[0049] Place two green pixels and two blue pixels at the four corners of the square, preferably arranged diagonally in an alternating pattern. This is the optimal arrangement. Bottom left and bottom right corners: G pixels (2 G pixels diagonally distributed) Top right and top left corners: Pixel B (two Bs diagonally distributed) Advantages: G and B are diagonally symmetrically distributed, and the color sampling of the square is balanced in the horizontal, vertical and diagonal directions. This avoids the color bias caused by the concentration of the same color pixels at the top corner of one side and reduces the moiré pattern caused by the resonance between the screen grid and the sensor array.

[0050] The internal area does not touch the vertices of the four sides of the square, and four types of monochrome pixels are arranged in a concentrated manner: 2 R pixels, 1 G pixel, and 1 B pixel; The internal pixels can be arranged in a staggered pattern, with two R pixels placed on either side of the internal center, and one G and one B pixel arranged in the gaps between the R pixels, to achieve uniform mixing of the three colors and avoid large-area aggregation of single-color pixels.

[0051] In this embodiment, the top corner is the outermost sampling point of the unit. During image interpolation, edge pixels participate in the color calculation of multiple adjacent units. Placing the most numerous G and B pixels at the four corners can improve the color sampling density between adjacent units and weaken the edge color attenuation caused by the screen's metal traces. The diagonally staggered symmetrical layout of G and B pixels ensures uniform brightness sampling in the horizontal, vertical, and diagonal directions, significantly suppressing typical color moiré and grid stripe artifacts in under-display photography. All R pixels are built-in to specifically compensate for the weak sensitivity of red light. An additional 1G+1B pixel is added internally to balance the global sampling density of the three colors. The array is periodically regularized to reduce the computational power consumption of the ISP algorithm.

[0052] like Figure 9 As shown, an under-display image sensor includes at least 3 pixels in each pixel repeating unit, and each pixel collects light intensity information of only one color among R / G / B; wherein the area ratio of each color pixel is R:G:B=2:3:3.

[0053] This embodiment abandons the conventional design of equal pixels and fixed 2:1:1 red, green and blue ratio of traditional Bayer arrays. By optimizing the photosensitive area of ​​customized RGB pixels, it adapts to the optical characteristics of under-display screen light transmission attenuation and different color light transmission loss. Without increasing the overall size of the sensor or affecting the screen display effect, it significantly improves the signal-to-noise ratio, color accuracy and dynamic imaging capability of under-display imaging, perfectly adapting to the under-display camera imaging needs of smartphones, tablets and other terminals.

[0054] The sensor's pixel array consists of several groups of periodically arranged pixel repeating units. To ensure the integrity and uniformity of imaging color sampling, each pixel repeating unit contains at least three independent functional pixels, corresponding to the three basic color light channels R (red), G (green), and B (blue), respectively. There are no color mixing light-sensing pixels or blank filling pixels. The unit structure is simple and the sampling coverage is 100%.

[0055] The three pixels within each repeating unit are independent and symmetrically arranged. Dedicated optical and circuit isolation layers are used between the pixels to effectively prevent crosstalk and electrical interference between adjacent pixels, ensuring the photosensitive accuracy and signal output stability of each pixel. Simultaneously, the periodic array arrangement achieves uniform pixel distribution across the sensor's entire imaging area, avoiding localized color deviations and uneven brightness. The shape of the pixels can be various, such as rectangles or squares. Correspondingly, the pixel repeating units can also be rectangles or squares. When each pixel is rectangular and the pixel repeating unit is also rectangular, the solution in this embodiment can be implemented with minimal modifications to existing processes.

[0056] This embodiment employs a single-pixel, single-color dedicated photosensitive design. Each pixel only collects light intensity information for a single color among R, G, and B, eliminating cross-color light sensing and mixed photosensitive conditions. Specifically, the red pixel only responds to the red spectral signal in the visible light band and collects red light intensity data; the green pixel only collects green light intensity data; and the blue pixel only collects blue light intensity data.

[0057] Each pixel is precisely fitted with a corresponding monochromatic filter, coupled with a pixel-level microlens structure, to accurately select the target color light and filter out stray light interference. An independent photodiode completes the conversion of light signals to electrical signals. The raw monochromatic light intensity data output by each group of pixels is interpolated and fused by the backend ISP image processing algorithm to reconstruct a complete color image. This independent photosensitive structure significantly improves the authenticity of the raw imaging data.

[0058] Within a single pixel repeating unit, the effective photosensitive areas of red, green, and blue pixels strictly adhere to a 2:3:3 ratio. The effective photosensitive area specifically refers to the light-receiving area of ​​the pixel's photodiode (excluding ineffective areas such as pixel isolation borders, circuit traces, and light-blocking structures), and is a core parameter determining the amount of light received and the photosensitivity of the pixel. Within the overall unit, G and B pixels have equal and largest areas, while R pixels have relatively smaller areas, forming a differentiated photosensitive layout.

[0059] The overall workflow of the sensor is as follows: 1. Optical incident stage: After external light penetrates the multi-layer medium of the terminal screen, it is incident on the sensor pixel array. Each group of pixel microlenses and monochromatic filters complete the selection of target color light and filter stray light and reflected light interference.

[0060] 2. Photoelectric sampling stage: R, G, and B independent pixels complete the light intensity acquisition of the corresponding color light according to the 2:3:3 area ratio. The photodiode linearly converts the light signal into an analog electrical signal, and the pixel isolation structure ensures that there is no crosstalk between the signals of each channel.

[0061] 3. Signal processing stage: The sensor readout circuit synchronously acquires the original electrical signals of each pixel, which are then converted from analog to digital and transmitted to the ISP image processing chip. The three-color pixel data are interpolated through the de-mosaic algorithm to supplement the global color information.

[0062] Those skilled in the art can further optimize the image based on the output image of this embodiment.

[0063] This embodiment is specifically adapted to various under-display camera imaging scenarios on mobile terminals, including under-display front-facing selfies, under-display face recognition, and under-display image capture. It can be widely used in full-screen mobile phones, full-screen tablets, and under-display smart terminal devices. It features significantly improved color reproduction accuracy, significantly optimized low-light imaging performance, strong screen adaptability, no display conflicts, and excellent imaging consistency and stability.

[0064] The camera module protected by this solution is an integrated under-display camera module adapted to the full-screen display requirements of smart terminals. The overall structure adopts an integrated structure of screen stacking + optical lens + imaging chip + driving processing circuit. The core consists of six parts: terminal display screen, optical lens assembly, pure visible light filter structure, under-display image sensor, module bracket, driving circuit, and image processing unit. The components cooperate and work together to achieve hidden imaging function without screen openings and without compromising the integrity of the entire screen.

[0065] The specific composition and functions of each core component are as follows: 1. Terminal Display Screen Layered Structure: As the outermost light-transmitting and display carrier of the camera module, it includes multiple layers of media such as a screen glass protective layer, a touch sensing layer, an OLED / LCD display light-emitting layer, and a polarizing layer. This structure is responsible for the overall screen display and touch operation functions on a daily basis. During the imaging stage, it serves as a light incident channel, allowing ambient light to penetrate through the multiple layers of the screen and enter the camera module below. This is the core structure that distinguishes under-display camera modules from traditional external camera modules.

[0066] 2. Optical Lens Assembly: Located directly below the display screen and above the image sensor, this assembly consists of multiple plastic / glass lenses, an aperture, a lens barrel, and an image stabilization structure. The lens assembly is responsible for converging and correcting incident light passing through the screen, correcting light distortion and dispersion caused by under-screen light transmission, compressing stray light incident angles, and focusing a regular, uniform optical image onto the photosensitive surface of the under-screen image sensor, ensuring a complete image frame and clear picture.

[0067] 3. Visible light filter structure: Located between the lens and the image sensor, it adopts a fully visible light-transmitting filter structure with no infrared filter interception design. It can transmit light in the entire RGB visible light band without loss, perfectly matching the photosensitive spectrum range of the sensor's RGB monochrome pixels. This ensures that red, green, and blue visible light are fully incident on the sensor pixel area, maximizing the amount of RGB light entering and the integrity of sampling, and adapting to the needs of pure color visible light imaging.

[0068] 4. Under-display image sensor: This is the core photosensitive device dedicated to this camera module. It adopts the aforementioned monochromatic pixel repeating array structure of R:G:B=2:3:3 and is the core carrier for imaging in the camera module. It is responsible for collecting visible light intensity signals and photoelectric conversion, providing raw data for image generation.

[0069] 5. Module fixing and light-shielding bracket: The sealed light-shielding bracket structure is adopted to wrap around the lens and sensor. On the one hand, it can achieve precise positioning and fixing of each component to ensure optical focusing accuracy; on the other hand, it can isolate light leakage from the side of the screen and stray light reflected from inside the body, avoid stray light interference with light-sensing imaging, and improve image purity.

[0070] 6. Driving and readout circuit: Includes sensor driver chip, signal readout line, and power supply line. It is responsible for providing stable operating voltage to the image sensor, controlling the sampling timing and exposure time of the pixel array, synchronously reading the analog electrical signals of each RGB pixel, and completing signal transmission and preliminary noise reduction processing.

[0071] 7. Back-end image processing unit: It interfaces with the raw image signal output from the camera module, integrates a dedicated ISP processing algorithm, matches the 2:3:3 pixel ratio characteristics of this sensor, and completes image processing operations such as de-mosaic interpolation, color correction, brightness equalization, noise suppression, and dynamic range adjustment, and finally outputs a usable high-definition color image.

[0072] The camera module in this embodiment is merely an example and should not be construed as limiting the scope of protection of this invention. Those skilled in the art can apply the under-display image sensor to any type of camera module.

[0073] This embodiment is specifically adapted to various under-display camera imaging scenarios on mobile terminals, including under-display front-facing selfies, under-display face recognition, and under-display image capture. It can be widely used in full-screen mobile phones, full-screen tablets, and under-display smart terminal devices. It features significantly improved color reproduction accuracy, significantly optimized low-light imaging performance, strong screen adaptability, no display conflicts, and excellent imaging consistency and stability.

[0074] This embodiment provides an electronic device whose core imaging and display system mainly includes an electronic display screen and the aforementioned under-screen image sensor. It can achieve high-definition imaging under the visible light screen while ensuring the integrity of the device's full-screen display and without any front opening. It is suitable for full-screen electronic devices such as smartphones, smart tablets, and foldable screen terminals.

[0075] The under-display image sensor is fixedly mounted on the backlight side of the electronic display screen (the back of the screen is not the light-emitting surface), completely hidden beneath the screen, without obstructing the display area or compromising the overall aesthetics. When the device is operating, ambient visible light passes through the electronic display screen and strikes the photosensitive surface of the under-display image sensor on the backlight side. The sensor receives the RGB visible light signals penetrating the screen and completes photoelectric imaging, thus achieving the hidden under-display camera function.

[0076] The electronic display screen uses a polyimide (PI) substrate as its carrier substrate. Polyimide substrates are characterized by high visible light transmittance, ultra-thin thickness, excellent flexibility, and high material uniformity. They exhibit less attenuation and scattering interference of RGB visible light, maximizing the integrity of the visible light spectrum and the uniformity of light transmitted through the screen, perfectly matching the sensor's differentiated photosensitive ratio design of R:G:B=2:3:3.

[0077] In normal standby and working states, the electronic display screen displays images and performs touch interaction functions as usual. When the device triggers imaging commands such as taking pictures, facial recognition, and image acquisition, visible light from the outside penetrates the polyimide substrate display screen and is evenly incident on the under-screen image sensor below. The sensor, through independent RGB monochrome pixel units, completes the acquisition and photoelectric conversion of the intensity of three-color visible light using an optimal 2:3:3 area ratio, outputting the raw image signal. After optimization processing by the back-end image processing unit, a high-definition, low-noise, and color-accurate under-screen image is generated, achieving bidirectional compatibility between full-screen display and lossless under-screen imaging.

[0078] This embodiment is specifically adapted to various under-display camera imaging scenarios on mobile terminals, including under-display front-facing selfies, under-display face recognition, and under-display image capture. It can be widely used in full-screen mobile phones, full-screen tablets, and under-display smart terminal devices. It features significantly improved color reproduction accuracy, significantly optimized low-light imaging performance, strong screen adaptability, no display conflicts, and excellent imaging consistency and stability.

[0079] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0080] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. An under-display image sensor, characterized in that, Each pixel repeating unit includes 8 pixels, and each pixel only collects light intensity information of one color among R / G / B; wherein, the number of pixels R:G:B=2:3:

3.

2. The under-display image sensor according to claim 1, characterized in that, The pixel repeating unit is rectangular.

3. The under-display image sensor according to claim 2, characterized in that, The aspect ratio of the rectangle is 2:

1.

4. The under-display image sensor according to claim 1, characterized in that, The pixel repeating unit is square.

5. An under-display image sensor according to claim 4, characterized in that, Two R's are located inside the square, and two G's and two B's are located at the top corners of the square.

6. The under-display image sensor according to claim 5, characterized in that, Within the pixel repeating unit, each pixel has a different filter color from its three surrounding adjacent pixels.

7. An under-display image sensor, characterized in that, Each pixel repeating unit includes at least 3 pixels, and each pixel only collects light intensity information of one color among R / G / B; wherein the area ratio of each color pixel is R:G:B=2:3:

3.

8. An under-display image sensor according to claim 7, characterized in that, Each pixel is a rectangle, and the pixel repeating unit is also a rectangle.

9. A camera module, characterized in that, Includes the under-display image sensor according to any one of claims 1-8.

10. An electronic device, characterized in that, Includes an electronic display screen and an under-display image sensor as described in any one of claims 1-8; The under-display image sensor is located on the backlight side of the electronic display screen and receives visible light that penetrates the electronic display screen; The substrate of the electronic display screen is a polyimide substrate.

Images