Image sensor, electronic device, and display device

Abstract

The application discloses an image sensor, an electronic device and a display device. The image sensor comprises a photosensitive element layer and a color filter array. The plurality of filter units comprise a plurality of first filter units and at least one second filter unit. The plurality of first filter units are used for transmitting light of one of a first wavelength, a second wavelength or a third wavelength. The second filter unit comprises two wavelength reflection units stacked. The first wavelength reflection unit is used for reflecting incident light of the first wavelength when in a reflection state. The second wavelength reflection unit is used for reflecting incident light of the second wavelength when in the reflection state. The third wavelength reflection unit is used for reflecting incident light of the third wavelength when in the reflection state. The second filter unit formed by the stacked wavelength reflection units enables the photosensitive element to obtain more pixel three-color value information, thereby improving the accuracy of the reconstructed color picture.

Description

Technical Field

[0001] This application relates to the field of optical imaging technology, and more particularly to an image sensor, electronic device, and display device. Background Technology

[0002] An image sensor is a device that converts optical images into electronic signals. Its core is a pixel array, composed of millions or even hundreds of millions of tiny photosensitive elements. Each photosensitive subpixel includes a photosensitive element, typically a photodiode, which, controlled by a readout circuit, converts the optical image into an electrical signal for readout. However, photosensitive elements generally cannot distinguish colors. Therefore, a color filter array is usually placed on the photosensitive element. By using filter units of different basic colors (such as red, green, and blue), each photosensitive element position can only receive light signals of one basic color. Subsequently, the image processor uses interpolation algorithms to estimate the complete red, green, and blue values ​​of each pixel based on the color information of surrounding pixels, thereby reconstructing a color image.

[0003] However, each photosensitive sub-pixel can only receive light of one basic color after passing through a color filter, resulting in low light utilization by the sensor and low accuracy in reconstructing color images. Therefore, those skilled in the art urgently need a technical solution to address these problems. Summary of the Invention

[0004] The purpose of this application is to provide an image sensor and its control method, electronic device and display device. This application improves the accuracy of reconstructing color images by setting a second filter unit formed by stacking wavelength reflection units, so that the photosensitive element can obtain more pixel three color value information.

[0005] This application discloses an image sensor, including a photosensitive element layer and a color filter array. The photosensitive element layer includes a plurality of photosensitive elements arranged in an array, each photosensitive element corresponding to a photosensitive sub-pixel. The color filter array is disposed above the photosensitive element layer and includes a plurality of filter units arranged in an array, each filter unit corresponding to a plurality of photosensitive elements. The plurality of filter units include a plurality of first filter units and at least one second filter unit. The plurality of first filter units are used to transmit light of a first wavelength, a second wavelength, or a third wavelength. The second filter unit includes two wavelength reflection units stacked in an array, each second filter unit having two of the stacked wavelength reflection units being a first wavelength reflection unit, a second wavelength reflection unit, and a third wavelength reflection unit. The first wavelength reflection unit is used to reflect incident light of a first wavelength when in a reflection state. The second wavelength reflection unit is used to reflect incident light of a second wavelength when in a reflection state. The third wavelength reflection unit is used to reflect incident light of a third wavelength when in a reflection state.

[0006] Optionally, the first wavelength is a red wavelength, the second wavelength is a green wavelength, and the third wavelength is a blue wavelength; among the plurality of first filter units, the one used to transmit light of the red wavelength is a red filter unit; among the plurality of first filter units, the one used to transmit light of the green wavelength is a green filter unit; among the plurality of first filter units, the one used to transmit light of the blue wavelength is a blue filter unit; the first wavelength reflection unit includes a first electrode, a red cholesterol-type liquid crystal, and a second electrode, the red cholesterol-type liquid crystal being disposed between the first electrode and the second electrode; the red cholesterol-type liquid crystal is used to reflect light under the control of the first electrode and the second electrode. The second wavelength reflection unit includes a third electrode, a green cholesterol-type liquid crystal, and a fourth electrode, wherein the green cholesterol-type liquid crystal is disposed between the third electrode and the fourth electrode; the green cholesterol-type liquid crystal is used to switch between a transparent state and a reflective state under the control of the third electrode and the fourth electrode; the third wavelength reflection unit includes a fifth electrode, a blue cholesterol-type liquid crystal, and a sixth electrode, wherein the blue cholesterol-type liquid crystal is disposed between the fifth electrode and the sixth electrode; the blue cholesterol-type liquid crystal is used to switch between a transparent state and a reflective state under the control of the fifth electrode and the sixth electrode.

[0007] Optionally, every four adjacent photosensitive sub-pixels form a pixel, and each pixel is provided with a red filter unit, a green filter unit, a blue filter unit, and a second filter unit.

[0008] Optionally, the second filtering unit includes a first wavelength reflection unit and a third wavelength reflection unit stacked together; in each of the second filtering units, for a first preset time period, both the first wavelength reflection unit and the third wavelength reflection unit are in a reflective state, and the second filtering unit transmits light of green wavelength; for a second preset time period, the first wavelength reflection unit is in a transparent state, the third wavelength reflection unit is in a reflective state, and the second filtering unit transmits light of red wavelength and green wavelength; for a third preset time period, the third wavelength reflection unit is in a transparent state, the first wavelength reflection unit is in a reflective state, and the second filtering unit transmits light of blue wavelength and green wavelength.

[0009] Optionally, every five adjacent photosensitive sub-pixels form a pixel, and within each pixel, one red filter unit, two green filter units, one blue filter unit, and one second filter unit are correspondingly provided; the red filter unit, two green filter units, and one blue filter unit are arranged in a 2:1 ratio. The two filters are arranged in a 2-fold pattern; the second filter unit is disposed in the middle region of the pixel.

[0010] Optionally, each of the second filter units includes a first filter portion, a second filter portion, a third filter portion, and a fourth filter portion; the first filter portion includes a first wavelength reflection unit and a second wavelength reflection unit, and the first filter portion is disposed adjacent to the blue filter unit; the second filter portion includes a first wavelength reflection unit and a third wavelength reflection unit, and the second filter portion is disposed adjacent to one of the green filter units; the third filter portion includes a first wavelength reflection unit and a third wavelength reflection unit, and the third filter portion is disposed adjacent to another green filter unit; the fourth filter portion includes a second wavelength reflection unit and a third wavelength reflection unit, and the fourth filter portion is disposed adjacent to the red filter unit; the photosensitive element disposed corresponding to the second filter unit is used to receive light transmitted from the first filter portion, the second filter portion, the third filter portion, and the fourth filter unit.

[0011] Optionally, in each of the second filter units, during a first preset time period, the first filter transmits light of blue wavelength, the second and third filter transmit light of green wavelength, and the fourth filter transmits light of red wavelength. The photosensitive element corresponding to the second filter unit is used to receive light of red, green, and blue wavelengths. During a second preset time period, the first, second, third, and fourth filter transmit mixed light of red, green, and blue wavelengths. The photosensitive element corresponding to the second filter unit is used to receive mixed light of red, green, and blue wavelengths at each position.

[0012] Optionally, the areas of the second filter unit, the red filter unit, the green filter unit, and the blue filter unit are all equal.

[0013] This application discloses an electronic device including the image sensor described above.

[0014] This application also discloses a display device, including a display panel and an image sensor disposed on the display panel, wherein the image sensor is the image sensor described above.

[0015] This application utilizes a second filter unit formed by two stacked wavelength reflection units. By leveraging the different wavelength reflection capabilities of these units, the photosensitive unit beneath the second filter unit can receive light of a single or multiple wavelengths under the influence of the wavelength reflection units, thus obtaining more pixel tri-color value information. Furthermore, based on the first filter unit, the photosensitive unit beneath the first filter unit can separately receive light of the first, second, and third wavelengths. Through the cooperation of the first and second filter units, not only is pixel tri-color value information collected, but detection errors can also be corrected based on the corresponding light absorption peaks of the first and second filter units, thereby improving the accuracy of reconstructing the color image. Attached Figure Description

[0016] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings: Figure 1 This is a top view schematic diagram of the image sensor according to the first embodiment of this application; Figure 2 This is a cross-sectional schematic diagram of the image sensor according to the first embodiment of this application; Figure 3 This is a schematic diagram of a first type of second filter unit according to the first embodiment of this application; Figure 4 This is a schematic diagram of a second type of second filter unit according to the first embodiment of this application; Figure 5 This is a top view schematic diagram of the image sensor according to the second embodiment of this application; Figure 6 This is a cross-sectional schematic diagram of the image sensor according to the second embodiment of this application; Figure 7 This is a top view schematic diagram of the second type of image sensor according to the second embodiment of this application; Figure 8 This is a cross-sectional schematic diagram of the second type of image sensor according to the second embodiment of this application; Figure 9 This is a schematic diagram of the electronic device of this application; Figure 10 This is a schematic diagram of the display device of this application.

[0017] Wherein, 100 is an image sensor; 101 is a pixel; 102 is a photosensitive subpixel; 110 is a photosensitive element layer; 111 is a photosensitive element; 120 is a color filter array; 121 is a filter unit; 122 is a first filter unit; 122R is a red filter unit; 122G is a green filter unit; 122B is a blue filter unit; 130 is a second filter unit; 131 is a first filter section; 132 is a second filter section; 133 is a third filter section; 134 is a fourth filter section; 140 is a first wavelength reflection unit; 141 is a first electrode; 142 is a second filter unit. 143. Red cholesterol-type liquid crystal; 144. Second electrode; 145. First edge sealant; 150. Second wavelength reflection unit; 151. Third electrode; 152. Green cholesterol-type liquid crystal; 153. Fourth electrode; 154. Second edge sealant; 160. Third wavelength reflection unit; 161. Fifth electrode; 162. Blue cholesterol-type liquid crystal; 163. Sixth electrode; 164. Third edge sealant; 165. Encapsulation substrate; 166. First alignment film; 167. Second alignment film; 200. Electronic device; 300. Display device; 310. Display panel. Detailed Implementation

[0018] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0019] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. Furthermore, terms such as "upper," "lower," "left," "right," "vertical," and "horizontal," indicating orientation or positional relationships, are based on the orientation or relative positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description of this application, not indicating that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0021] Figure 1 This is a top view schematic diagram of the image sensor according to the first embodiment of this application. Figure 2 This is a cross-sectional schematic diagram of the image sensor according to the first embodiment of this application. Figure 3This is a schematic diagram of the first type of second filter unit according to the first embodiment of this application, see [link]. Figures 1 to 3 As shown, this application discloses an image sensor 100, which includes a photosensitive element layer 110 and a color filter array 120. The photosensitive element layer 110 includes a plurality of photosensitive elements 111 arranged in an array, each photosensitive element 111 corresponding to a photosensitive sub-pixel 102. The color filter array 120 is disposed above the photosensitive element layer 110 and includes a plurality of filter units 121 arranged in an array, each filter unit 121 corresponding to a plurality of photosensitive elements 111. The plurality of filter units 121 include a plurality of first filter units 122 and at least one second filter unit 130. The plurality of first filter units 122 are used for... The light passes through a light of one of the first, second, or third wavelengths; the second filter unit 130 includes two stacked wavelength reflection units, wherein the two stacked wavelength reflection units in each second filter unit 130 are two of a first wavelength reflection unit 140, a second wavelength reflection unit 150, and a third wavelength reflection unit 160; the first wavelength reflection unit 140 is used to reflect incident light of the first wavelength when in a reflection state; the second wavelength reflection unit 150 is used to reflect incident light of the second wavelength when in a reflection state; and the third wavelength reflection unit 160 is used to reflect incident light of the third wavelength when in a reflection state.

[0022] This application utilizes a second filter unit 130 formed by two stacked wavelength reflection units. By leveraging the different wavelength reflection capabilities of these units, the photosensitive element 111 beneath the second filter unit 130 can receive light of a single wavelength or multiple wavelengths under the action of the wavelength reflection units, thereby obtaining more tri-color value information for the pixel 101. Furthermore, based on the first filter unit 122, the photosensitive element 111 beneath the first filter unit 122 can receive light of the first, second, and third wavelengths respectively. Through the cooperation of the first filter unit 122 and the second filter unit 130, not only is the tri-color value information of the pixel 101 collected, but detection errors can also be corrected based on the corresponding light absorption peaks of the first filter unit 122 and the second filter unit 130, thereby improving the accuracy of reconstructing the color image.

[0023] The multiple first filter units 122 are each formed of colored photoresist material, and their main function is to filter light of other wavelengths while allowing light of one wavelength to pass through. Taking the first wavelength as red, the second wavelength as green, and the third wavelength as blue as an example, through the function of the first filter units 122, red light, green light, and blue light can be filtered out from different positions of the first filter units 122 respectively.

[0024] Specifically, among the plurality of first filter units 122, the one used to transmit light of red wavelength is red filter unit 122R. Among the plurality of first filter units 122, the one used to transmit light of green wavelength is green filter unit 122G. Among the plurality of first filter units 122, the one used to transmit light of blue wavelength is blue filter unit 122B.

[0025] Generally, a pixel 101 includes at least three color filter units 122. By utilizing the three photosensitive elements 111 within a pixel 101 to recognize red, green, and blue light respectively, the RGB values ​​of a single pixel 101 are reconstructed, thereby reconstructing a color image. Since green better matches the visual characteristics of the human eye, color visibility is improved by increasing the number of green photosensitive sub-pixels 102 in the Bayer color filter array 120. The Bayer color filter array 120 is generally composed of filter units 121 of red, green, and blue colors arranged according to a specific pattern. For example, in a 2... In the photosensitive sub-pixel 102 of 2, there is one red filter unit 122R, one blue filter unit 122B, and two green filter units 122G. With "R" as the red filter unit 122R, "G" as the green filter unit 122G, and "B" as the blue filter unit 122B, the arrangement of the smallest repeating unit (i.e., one pixel 101) in the color filter array 120 can be "RGGB", "RGBG", "GRGB", etc.

[0026] Because an interpolation algorithm is used when reconstructing a color image, each photosensitive element 111 can only receive light of one color, and the other colors of the photosensitive sub-pixel 102 where the photosensitive element 111 is located depend on the information of adjacent photosensitive sub-pixels 102, this interpolation algorithm inevitably loses some detail information. Furthermore, the broad light absorption peak of the superimposed color photoresist material causes partial overlap of the wavelengths of red, green, and blue, resulting in loss of detail and stray light crosstalk. Although this can be compensated for by post-processing algorithms, the lost color information cannot be restored from scratch. Therefore, based on this, this application adds a second filter unit 130, which adopts a narrow absorption peak design.

[0027] Specifically, the first wavelength reflection unit 140, the second wavelength reflection unit 150, and the third wavelength reflection unit 160 utilize cholesteric liquid crystals. Cholesteric liquid crystals, also known as chiral nematic liquid crystals, are "soft" photonic crystals with a periodic helical superstructure. In cholesteric liquid crystals, molecules self-assemble into layers, with molecules within each layer arranged parallel to each other along a certain direction. Molecules between adjacent layers rotate at a certain angle along the normal direction of the layer, forming a periodic helical superstructure. The pitch is a crucial parameter characterizing the helical superstructure of cholesteric liquid crystals, representing the interlayer spacing where the molecular director rotates 360° along the helical axis. The periodic helical superstructure endows cholesteric liquid crystals with unique optical properties; that is, cholesteric liquid crystals can selectively reflect circularly polarized light with the same direction as their helical structure. According to Bragg's law of reflection, λ = np, where n is the average refractive index of the liquid crystal matrix, λ is the reflection wavelength of the cholesteric liquid crystal, and p is the pitch. This law indicates that the reflection wavelength λ is directly related to the pitch p of the helical superstructure.

[0028] In this embodiment, three different colors of cholesterol-type liquid crystals are utilized, employing a three-layer stacked structure of red cholesterol-type liquid crystal 142, green cholesterol-type liquid crystal 152, and blue cholesterol-type liquid crystal 162. This three-layer stacked structure allows red, green, and blue light to selectively pass through, thereby enabling each photosensitive element 111 to receive red, green, and blue light respectively in a time-division manner.

[0029] The first wavelength reflection unit 140 includes a first electrode 141, a red cholesterol liquid crystal 142, and a second electrode 143. The red cholesterol liquid crystal 142 is disposed between the first electrode 141 and the second electrode 143. The red cholesterol liquid crystal 142 is used to switch between a transparent state and a reflective state under the control of the first electrode 141 and the second electrode 143.

[0030] The first wavelength is red light, with a wavelength range of approximately 635 nm. In this embodiment, the red cholesterol-type liquid crystal 142 reflects wavelengths between 620 nm and 650 nm. When the first wavelength reflecting unit 140 is in a reflective state, the red light of the first wavelength is reflected, but other wavelengths, such as the second and third wavelengths, can pass through it. When the first wavelength reflecting unit 140 is in a transparent state, all wavelengths of light can pass through it. It can be understood that, theoretically, light of other wavelengths, except for the reflected wavelength range, can pass through this wavelength reflecting unit.

[0031] The structure of the second wavelength reflection unit 150 is the same as that of the first wavelength reflection unit 140, as can be referred to. Figure 4As shown, it includes a third electrode 151, a green cholesterol-type liquid crystal 152, and a fourth electrode 153, wherein the green cholesterol-type liquid crystal 152 is disposed between the third electrode 151 and the fourth electrode 153. The green cholesterol-type liquid crystal 152 is used to switch between a transparent state and a reflective state under the control of the third electrode 151 and the fourth electrode 153.

[0032] The second wavelength is green light, with a wavelength range of approximately 530 nm. The green cholesterol-type liquid crystal 152 used in this embodiment reflects wavelengths between 520 nm and 550 nm. When the second wavelength reflecting unit 150 is in a reflective state, the green light of the second wavelength is reflected, but other wavelengths, such as the first and third wavelengths, can pass through it smoothly. When the second wavelength reflecting unit 150 is in a transparent state, all wavelengths of light can pass through it.

[0033] The third wavelength reflection unit 160 includes a fifth electrode 161, a blue cholesterol-type liquid crystal 162, and a sixth electrode 163. The blue cholesterol-type liquid crystal 162 is disposed between the fifth electrode 161 and the sixth electrode 163. The blue cholesterol-type liquid crystal 162 is used to switch between a transparent state and a reflective state under the control of the fifth electrode 161 and the sixth electrode 163.

[0034] Similarly, the third wavelength is blue light, with a wavelength range of approximately 420 nm. The blue cholesterol-type liquid crystal 162 used in this embodiment reflects wavelengths between 410 nm and 430 nm. When the third wavelength reflecting unit 160 is in a reflective state, the blue light of the third wavelength is reflected by the third wavelength reflecting unit 160, but other wavelengths, such as the first and second wavelengths, can pass through the third wavelength reflecting unit 160 smoothly. When the third wavelength reflecting unit 160 is in a transparent state, all wavelengths of light can pass through the third wavelength reflecting unit 160.

[0035] In this embodiment, the color filtering peak of the cholesterol-type liquid crystal is a narrow peak. Due to the Bragg selective reflection of its helical structure, the full width at half maximum (FWHM) of a conventional single-pitch liquid crystal is typically only 20nm to 50nm, much narrower than the broad absorption peak of 50nm to 120nm in its first filter unit 122. Therefore, the absorption peak of the second filter unit 130 is narrower, resulting in a richer color spectrum of the actual light passing through compared to the first filter unit 122. Subsequent algorithmic calculations can then compensate for the color information missing in the first filter unit 122. By collecting and comparing the light absorption intensity under the first filter unit 122 and the second filter unit 130, more color value information of pixel 101 can be obtained, improving the accuracy of the reconstructed color image.

[0036] See also Figure 1 As shown, in this embodiment, every four adjacent photosensitive sub-pixels 102 form a pixel 101, and each pixel 101 is provided with a red filter unit 122R, a green filter unit 122G, a blue filter unit 122B and a second filter unit 130.

[0037] In this embodiment, the red filter unit 122R, green filter unit 122G, blue filter unit 122B, and second filter unit 130 have equal areas, and the above four filter units 121 are arranged in a 2:1 ratio. The arrangement of 2. The position of its second filter unit 130 is not limited.

[0038] In a pixel 101, its three photosensitive elements 111 can receive light of red, green and blue wavelengths, respectively. The photosensitive element 111 corresponding to the second filter unit 130 can receive different color wavelengths by adjusting the wavelength reflection unit set inside the second filter unit 130.

[0039] In one specific embodiment, the second filtering unit 130 includes a first wavelength reflection unit 140 and a third wavelength reflection unit 160. In each of the second filtering units 130, during a first preset time period, both the first wavelength reflection unit 140 and the third wavelength reflection unit 160 are in a reflective state, and the second filtering unit 130 transmits light of green wavelength. During a second preset time period, the first wavelength reflection unit 140 is in a transparent state, and the third wavelength reflection unit 160 is in a reflective state, and the second filtering unit 130 transmits light of red wavelength and green wavelength. During a third preset time period, the third wavelength reflection unit 160 is in a transparent state, the first wavelength reflection unit 140 is in a reflective state, and the second filtering unit 130 transmits light of blue wavelength and green wavelength.

[0040] Of course, within a fourth preset time after the third preset time, the first wavelength reflection unit 140 and the third wavelength reflection unit 160 can be controlled to be in the transmission state at the same time. At this time, light of all wavelengths can pass through the second filter unit 130. The photosensitive element 111 receives red, green and blue light as well as light of all wavelengths, that is, the light intensity detected by the photosensitive element 111 is the light intensity of white light.

[0041] In this embodiment, during the first to fourth preset time periods, the second filter unit 130 transmits green light, a mixture of red and green light, a mixture of blue and green light, and white light, respectively. By identifying the light intensity of multiple colors in the time domain of the photosensitive element 111 under the second filter unit 130, and then using an algorithm to compare the light intensity data collected under the first filter unit 122, the color light intensity missing in the first filter unit 122 in each pixel 101 can be calculated. Moreover, the light intensity data collected by the second filter unit 130 can also be used to correct the light intensity data collected by the first filter unit 122, thereby resulting in richer details when reconstructing the image.

[0042] Of course, the second filter unit 130 is not limited to the combination of the first wavelength reflection unit 140 and the third wavelength reflection unit 160, and can be other cases. When the first wavelength reflection unit 140 and the third wavelength reflection unit 160 are used, when the first wavelength reflection unit 140 and the third wavelength reflection unit 160 are in a reflective state at the same time, the second filter unit 130 transmits green light, which combines with the light transmitted by the other three first filter units 122 in the pixel 101 to form red-green-green-blue.

[0043] Figure 4 This is a schematic diagram of the second type of second filter unit according to the first embodiment of this application, see [link]. Figure 4 As shown, in another embodiment, its second filter unit 130 further includes three layers of stacked wavelength reflection units, such as the stack of the first wavelength reflection unit 140, the second wavelength reflection unit 150 and the third wavelength reflection unit 160 described above, and the stacking order is not limited.

[0044] In this embodiment, by stacking the first wavelength reflection unit 140, the second wavelength reflection unit 150, and the third wavelength reflection unit 160, and utilizing their different wavelength reflection functions, the photosensitive element 111 can only receive light of one of these three wavelengths at the same time, avoiding interference from other wavelengths when the photosensitive element 111 receives light of a specific wavelength. Simultaneously, by sequentially controlling the first wavelength reflection unit 140, the second wavelength reflection unit 150, and the third wavelength reflection unit 160, the first wavelength light, the second wavelength light, and the third wavelength light enter the photosensitive element 111 in a time-division manner. This ensures that each photosensitive element 111 corresponding to the second filter unit 130 can receive light of all three wavelengths in the time domain, allowing subsequent algorithms to identify the actual color and light intensity of the photosensitive sub-pixel 102.

[0045] Taking the first wavelength reflection unit 140 as an example, the specific control method is explained. Its cholesteric liquid crystal can be made of polymer-stabilized cholesteric phase (PSCLC) material. By adding a small amount of polymer monomers, a polymer network is formed after ultraviolet curing, fixing the basic morphology of the helical structure while retaining its electric field responsiveness. An AC electric field of 0V to 5V with a frequency of 50Hz to 1000Hz can be applied to the first electrode 141 and the second electrode 143. By continuously adjusting the pitch p by changing the voltage amplitude, the reflection wavelength can be continuously varied within the visible light range (first wavelength, second wavelength, and third wavelength range). The advantage of this material is that different wavelengths of reflection can be achieved by adjusting the voltage. The first wavelength reflection unit 140, the second wavelength reflection unit 150, and the third wavelength reflection unit 160 achieve different wavelength reflections through voltage regulation. It can also employ pulse voltage regulation, which allows for rapid switching. For example, by using a short pulse electric field (pulse width of about 1ms to 10ms) to drive a cholesterol-type liquid crystal, the pitch p can be adjusted by controlling the amplitude and duration of the pulse voltage to achieve reflection of different wavelengths. This can avoid excessive power consumption and material aging caused by applying voltage for a long time.

[0046] In each of the two layers of wavelength reflection units stacked in the second filter unit 130, an encapsulation substrate 165 is provided on both sides of the cholesteric liquid crystal of each wavelength reflection unit. When the two wavelength reflection units are stacked, they share a common encapsulation substrate 165.

[0047] Each of the first wavelength reflective units 140 further includes a first sealing adhesive 144, which is located between two encapsulation substrates 165 and is used to encapsulate the red cholesterol-type liquid crystal 142. Similarly, each of the second wavelength reflective units 150 further includes a second sealing adhesive 154, which is used to encapsulate the green cholesterol-type liquid crystal 152. Each of the third wavelength reflective units 160 further includes a third sealing adhesive 164, which is used to encapsulate the blue cholesterol-type liquid crystal 162.

[0048] It is understandable that this individual package only separates the cholesterol-type liquid crystals in adjacent second filter units 130 using edge sealing adhesive, while the packaging substrate 165 is still shared. The area of ​​this individual package can be at least equal to the area of ​​a single photosensitive sub-pixel 102, but the size of a single second filter unit 130 can also be appropriately increased, i.e., the area of ​​the individual photosensitive sub-pixel 102 can be increased to reduce the manufacturing difficulty. Each photosensitive sub-pixel 102 corresponds to one photosensitive element 111 and one filter unit 121 (such as a first filter unit 122 or a second filter unit 130).

[0049] In one specific embodiment, each wavelength reflection unit generally has an alignment film disposed on both sides of the cholesterol-type liquid crystal. For example, in the first wavelength reflection unit 140, a first alignment film 166 is disposed between the first electrode 141 and the red cholesterol-type liquid crystal 142, and a second alignment film 167 is disposed between the second electrode 143 and the red cholesterol-type liquid crystal 142. The first alignment film 166 and the second alignment film 167 are used to control the twisted state of the liquid crystal molecules, so that the molecules on its surface can only be arranged regularly in a certain direction. The first alignment film 166 can be formed of polyimide film or other materials, which are not limited here. The second wavelength reflection unit 150 and the third wavelength reflection unit 160 are similar to the first wavelength reflection unit 140, and are also provided with the first alignment film 166 and the second alignment film 167, respectively, which will not be described in detail here.

[0050] In this application, when each pixel 101 is provided with a second filter unit 130, multiple second filter units 130 can be controlled as a whole. For example, taking the first wavelength reflection unit 140 as an example, by arranging the first wavelength reflection units 140 in the same layer and connecting the first electrodes 141 of multiple first wavelength reflection units 140 to each other, and connecting the second electrodes 143 of multiple second wavelength reflection units 150 to each other, voltage is applied simultaneously at a first preset time, controlling multiple first wavelength reflection units 140 to be in a transparent or reflective state simultaneously, thereby reducing the complexity of the control circuit and reducing the cost of the image sensor 100. Multiple embodiments of this application can be configured in this way, and the second wavelength reflection unit 150 and the third wavelength reflection unit 160 can refer to the configuration of the first wavelength reflection unit 140, which will not be described in detail here. When each wavelength reflection unit in the second filter unit needs to be driven individually, it can be driven by setting an active switch array.

[0051] In one embodiment, the first filter unit 122 and the second filter unit 130 may be arranged in the same layer or in different layers.

[0052] When the two are set in different layers, the position of the layer where the first filter unit 122 is located, corresponding to the position of the second filter unit 130, is set as a non-filtering area, that is, no color filter unit 121 is provided. This position does not filter the light, allowing all light to pass through.

[0053] When both are set in the same layer, the first filter unit 122 is sandwiched between the two encapsulation substrates 165, or the first filter unit 122 is set in layers and sandwiched between the three encapsulation substrates 165 respectively, and the area where no cholesteric liquid crystal is set is filled by the first filter unit 122.

[0054] Figure 5 This is a top view schematic diagram of the image sensor according to the second embodiment of this application. Figure 6This is a cross-sectional schematic diagram of the image sensor according to the second embodiment of this application, see below. Figures 5 to 6 As shown, this application also discloses another image sensor 100, the difference being that each pixel 101 is composed of five adjacent photosensitive sub-pixels 102, that is, five photosensitive elements 111 are provided in one pixel 101.

[0055] Specifically, every five adjacent photosensitive sub-pixels 102 form a pixel 101. Within each pixel 101, one red filter unit 122R, two green filter units 122G, one blue filter unit 122B, and one second filter unit 130 are correspondingly arranged. The red filter unit 122R, two green filter units 122G, and one blue filter unit 122B are arranged in a 2:1 ratio. The second filter unit 130 is arranged in the middle region of the pixel 101.

[0056] In this embodiment, the orthographic projection of the first filter unit 122 onto the photosensitive element layer 110 is L-shaped, the pixel 101 is rectangular or square in shape, and the second filter unit 130 is rectangular or square and is disposed in the middle region of the pixel 101. The four first filter units 122 are arranged around the second filter unit 130.

[0057] In one specific embodiment, the red filter unit 122R, the green filter unit 122G, the blue filter unit 122B, and the second filter unit 130 have equal areas. The design of the second filter unit 130 can refer to the design of the above embodiment, and will not be repeated here.

[0058] The second filter unit 130, as described in the above embodiment, can employ a stacked arrangement of two or three wavelength reflection units to acquire data for multiple colors in the time domain. By comparing this data with that of the first filter unit 122, more information on the distribution of the three color values ​​can be obtained. This is achieved by using one red filter unit 122R, two green filter units 122G, and one blue filter unit 122B in a 2:1 configuration. The two filters are arranged in a 2-dimensional array, thereby enabling the complete acquisition of the current three-color values ​​of pixel 101 within the detection area formed by the color filter material. The second filter unit 130 is placed in the middle region of pixel 101, and the light transmitted through the second filter unit 130 compensates for the light intensity data of the detection area formed by the color filter material.

[0059] Figure 7 This is a top view schematic diagram of the second type of image sensor according to the second embodiment of this application. Figure 8 This is a cross-sectional schematic diagram of the second type of image sensor according to the second embodiment of this application. See also... Figures 7 to 8As shown, in another specific embodiment, each of the second filter units 130 includes a first filter portion 131, a second filter portion 132, a third filter portion 133, and a fourth filter portion 134; the first filter portion 131 includes a first wavelength reflection unit 140 and a second wavelength reflection unit 150, and the first filter portion 131 is disposed adjacent to the blue filter unit 122B; the second filter portion 132 includes a first wavelength reflection unit 140 and a third wavelength reflection unit 160, and the second filter portion 132 is disposed adjacent to one of the green filter units 122G; the third filter portion... 133 includes a first wavelength reflection unit 140 and a third wavelength reflection unit 160, and the third filter unit 133 is disposed adjacent to another green filter unit 122G; the fourth filter unit 134 includes a second wavelength reflection unit 150 and a third wavelength reflection unit 160, and the fourth filter unit 134 is disposed adjacent to a red filter unit 122R; the photosensitive element 111 disposed corresponding to the second filter unit 130 is used to detect light transmitted from the first filter unit 131, the second filter unit 132, the third filter unit 133 and the fourth filter unit 134.

[0060] It is understood that the first wavelength reflection unit 140, the second wavelength reflection unit 150, and the third wavelength reflection unit 160 within the first filter unit 131, the second filter unit 132, the third filter unit 133, and the fourth filter unit 134 need to be individually packaged so that each wavelength reflection unit can be individually controlled. A photosensitive element 111 is disposed below the second filter unit 130, and this photosensitive element 111 is used to receive the light transmitted through the first filter unit 131, the second filter unit 132, the third filter unit 133, and the fourth filter unit 134.

[0061] In this embodiment, the area containing the red filter unit 122R, the two green filter units 122G, and the blue filter unit 122B is referred to as the first detection area, and the second filter unit 130 is referred to as the second detection area. Within the first detection area, the intensity of red light, the intensity of green light at the locations of the two green filter units 122G, and the intensity of blue light can be detected respectively. By calculating the area of ​​each photosensitive sub-pixel 102, the intensities of red, green, and blue light per unit area, as well as the total light intensity of the first detection area, can be calculated.

[0062] In the second detection region, the photosensitive element 111 can output a total light intensity equal to the sum of the red light intensity under the first filter 131, the green light intensity under the second and third filters 132 and 133, and the blue light intensity under the fourth filter 134. By making the areas of the first filter 131, the second filter 132, the third filter 133, and the fourth filter 134 the same, the theoretical values ​​of the red, green, and blue light intensities per unit area in the second detection region can be calculated by comparing the intensities of red, green, and blue light per unit area. By comparing the actual values, the detection error can be corrected based on the corresponding light absorption peaks of the first and second detection regions, and more information on the distribution of the three colors can be obtained.

[0063] In one specific embodiment, by adding a time domain, the light of different colors in the second detection area at different times can be controlled. For example, the aforementioned first preset time, second preset time, third preset time, and fourth preset time. This allows for the detection of single-color light and mixed light of two or more colors, and subsequent algorithms can be used to improve color reproduction accuracy.

[0064] For example, in each of the second filter units 130, during a first preset time period, the first filter part 131 transmits light of blue wavelength, the second filter part 132 and the third filter part 133 respectively transmit light of green wavelength, and the fourth filter part 134 transmits light of red wavelength. The photosensitive element 111 provided corresponding to the second filter unit 130 is used to receive light of red wavelength, green wavelength and blue wavelength.

[0065] During a second preset time period, the first filter section 131, the second filter section 132, the third filter section 133, and the fourth filter section 134 transmit mixed light of red wavelength, green wavelength, and blue wavelength respectively. The photosensitive element 111 provided corresponding to the second filter unit 130 is used to receive mixed light of red wavelength, green wavelength, and blue wavelength at each position respectively.

[0066] During the second preset time period, all wavelength reflection units in the first filter unit 131, the second filter unit 132, the third filter unit 133, and the fourth filter unit 134 are in a light-transmitting state. At this time, the photosensitive element 111 below the second filter unit 130 receives the intensity of white light. By comparing the intensity of white light, the intensity of the mixed red-green-green-blue light collected during the first preset time period, and the intensity of the mixed red-green-green-blue light collected in the first detection area, more tri-color value information of pixel 101 is obtained, and the tri-color values ​​at the position of pixel 101 are optimized to improve the accuracy of reconstructing the color image.

[0067] Figure 9This is a schematic diagram of the electronic device of this application, see [link / reference]. Figure 9 As shown, this application discloses an electronic device 200, which includes an image sensor 100 in any of the above embodiments.

[0068] Figure 10 This is a schematic diagram of the display device of this application, see below. Figure 10 As shown, this application also discloses a display device 300, which includes a display panel 310 and an image sensor 100 disposed on the display panel 310. The image sensor 100 includes the image sensor 100 in any of the above embodiments.

[0069] The display panel 310 in this embodiment is a display panel with a built-in image sensor 100, which can be used for taking pictures, videos, face recognition, or fingerprint recognition, etc.

[0070] In one specific embodiment, the display panel 310 includes a punch-hole area, within which an image sensor 100 is disposed for detecting external light and can be used for taking photos, videos, facial recognition, or fingerprint recognition. In this embodiment, the photosensitive element 111 and the color filter array 120 can be disposed on the substrate of the punch-hole area, thereby achieving deep integration with the display panel.

[0071] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0072] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. An image sensor, characterized in that, include: The photosensitive element layer includes a plurality of photosensitive elements arranged in an array, each photosensitive element corresponding to a photosensitive sub-pixel; as well as A color filter array is disposed above the photosensitive element layer, comprising multiple filter units arranged in an array, each filter unit corresponding to a multiple photosensitive element; The plurality of filter units include a plurality of first filter units and at least one second filter unit. The plurality of the first filter units are used to transmit light of one of the first wavelength, the second wavelength, or the third wavelength; The second filter unit includes two stacked wavelength reflection units, wherein the two stacked wavelength reflection units in each second filter unit are two of the first wavelength reflection unit, the second wavelength reflection unit, and the third wavelength reflection unit; The first wavelength reflection unit is used to reflect incident light of a first wavelength when in a reflection state; the second wavelength reflection unit is used to reflect incident light of a second wavelength when in a reflection state; and the third wavelength reflection unit is used to reflect incident light of a third wavelength when in a reflection state.

2. The image sensor according to claim 1, characterized in that, The first wavelength is the red wavelength, the second wavelength is the green wavelength, and the third wavelength is the blue wavelength; Among the plurality of first filter units, the one used to transmit light of red wavelength is a red filter unit; among the plurality of first filter units, the one used to transmit light of green wavelength is a green filter unit; among the plurality of first filter units, the one used to transmit light of blue wavelength is a blue filter unit; The first wavelength reflection unit includes a first electrode, a red cholesterol-type liquid crystal, and a second electrode, wherein the red cholesterol-type liquid crystal is disposed between the first electrode and the second electrode; the red cholesterol-type liquid crystal is used to switch between a transparent state and a reflective state under the control of the first electrode and the second electrode; The second wavelength reflection unit includes a third electrode, a green cholesterol-type liquid crystal, and a fourth electrode, wherein the green cholesterol-type liquid crystal is disposed between the third electrode and the fourth electrode; the green cholesterol-type liquid crystal is used to switch between a transparent state and a reflective state under the control of the third electrode and the fourth electrode; The third wavelength reflection unit includes a fifth electrode, a blue cholesterol-type liquid crystal, and a sixth electrode. The blue cholesterol-type liquid crystal is disposed between the fifth electrode and the sixth electrode. The blue cholesterol-type liquid crystal is used to switch between a transparent state and a reflective state under the control of the fifth electrode and the sixth electrode.

3. The image sensor according to claim 2, characterized in that, Each set of four adjacent photosensitive sub-pixels forms a pixel, and each pixel is provided with a red filter unit, a green filter unit, a blue filter unit and a second filter unit.

4. The image sensor according to claim 3, characterized in that, The second filter unit includes a first wavelength reflection unit and a third wavelength reflection unit stacked together; In each of the second filter units, during a first preset time period, both the first wavelength reflection unit and the third wavelength reflection unit are in a reflective state, and the second filter unit transmits light of the green wavelength. During the second preset time period, the first wavelength reflection unit is in the light-transmitting state, the third wavelength reflection unit is in the reflective state, and the second filter unit transmits light of red and green wavelengths. During a third preset time period, the third wavelength reflection unit is in a light-transmitting state, the first wavelength reflection unit is in a reflective state, and the second filter unit transmits light of blue and green wavelengths.

5. The image sensor according to claim 2, characterized in that, Every five adjacent photosensitive sub-pixels form a pixel, and each pixel is provided with one red filter unit, two green filter units, one blue filter unit, and one second filter unit. One red filter unit, two green filter units, and one blue filter unit are arranged in a 2:1 ratio.

2. Arrangement; The second filter unit is disposed in the middle region of the pixel.

6. The image sensor according to claim 5, characterized in that, Each of the second filter units includes a first filter section, a second filter section, a third filter section, and a fourth filter section; The first filter unit includes a first wavelength reflection unit and a second wavelength reflection unit, and the first filter unit is disposed adjacent to the blue filter unit; The second filter unit includes a first wavelength reflection unit and a third wavelength reflection unit, and the second filter unit is disposed adjacent to one of the green filter units; The third filter unit includes a first wavelength reflection unit and a third wavelength reflection unit, and the third filter unit is disposed adjacent to another green filter unit; The fourth filter unit includes a second wavelength reflection unit and a third wavelength reflection unit, and the fourth filter unit is disposed adjacent to the red filter unit; The photosensitive element provided corresponding to the second filter unit is used to receive light transmitted from the first filter, the second filter, the third filter, and the fourth filter.

7. The image sensor according to claim 6, characterized in that, In each of the second filter units, within a first preset time period, the first filter part transmits light of blue wavelength, the second filter part and the third filter part respectively transmit light of green wavelength, and the fourth filter part transmits light of red wavelength. The photosensitive element provided with the second filter unit is used to receive light of red wavelength, green wavelength and blue wavelength. During a second preset time period, the first filter, the second filter, the third filter, and the fourth filter transmit mixed light of red wavelength, green wavelength, and blue wavelength respectively. The photosensitive element provided with the second filter unit is used to receive mixed light of red wavelength, green wavelength, and blue wavelength at each position respectively.

8. The image sensor according to claim 6, characterized in that, The areas of the second filter unit, the red filter unit, the green filter unit, and the blue filter unit are all equal.

9. An electronic device, characterized in that, Including the image sensor as described in any one of claims 1-8.

10. A display device, characterized in that, It includes a display panel and an image sensor disposed on the display panel, the image sensor including the image sensor as described in any one of claims 1-8.

Images