PATTERN RECOGNITION SUBSTRATE AND DISPLAY DEVICE
20250015103 ยท 2025-01-09
Inventors
- Xiaoquan HAI (Beijing, CN)
- Xiaochuan Chen (Beijing, CN)
- Lei Wang (Beijing, CN)
- Yingzi WANG (Beijing, CN)
Cpc classification
H10H29/142
ELECTRICITY
International classification
Abstract
A pattern recognition substrate and a display device are disclosed, the pattern recognition substrate includes: a base substrate; a photosensitive device arranged on the base substrate and including a first electrode, a photoelectric conversion layer and a second electrode that are stacked, where the photoelectric conversion layer includes an I-type semiconductor layer with a thickness enough to convert a part of fingerprint-reflected light to an electrical signal, the first electrode includes a light-transmitting region transmitting the fingerprint-reflected light which is converted by the photoelectric conversion layer; and a light absorbing layer arranged between the base substrate and a layer where the photosensitive device is located to absorb the fingerprint-reflected light not converted by the photoelectric conversion layer.
Claims
1. A pattern recognition substrate, comprising: a base substrate; a photosensitive device located on the base substrate, the photosensitive device comprising a first electrode, a photoelectric conversion layer and a second electrode that are stacked, wherein the photoelectric conversion layer comprises an I-type semiconductor layer with a thickness enough to convert a part of fingerprint-reflected light to an electrical signal, and the first electrode comprises a light-transmitting region transmitting fingerprint-reflected light that is not converted by the photoelectric conversion layer; and a light-absorbing layer located between the base substrate and a layer where the photosensitive device is located to absorb the fingerprint-reflected light that is not converted by the photoelectric conversion layer.
2. The pattern recognition substrate according to claim 1, wherein the first electrode is a metal electrode, the first electrode comprises a plurality of openings arranged in an array, and the plurality of openings is the light-transmitting region.
3. The pattern recognition substrate according to claim 2, wherein the openings are approximately circular.
4. The pattern recognition substrate according to claim 3, wherein an aperture ratio A of the first electrode satisfies a following relationship:
5. The pattern recognition substrate according to claim 2, wherein the openings are approximately square.
6. The pattern recognition substrate according to claim 5, wherein an aperture ratio A of the first electrode satisfies a following relationship:
7. The pattern recognition substrate according to claim 4, wherein 2 md6 m, 5 mq20 m, and 0.1A0.6.
8. The pattern recognition substrate according to claim 2, wherein a center of each of the openings is located at a vertex of a polygon.
9. The pattern recognition substrate according to claim 8, wherein the polygon is a rectangle or a hexagon.
10. The pattern recognition substrate according to claim 1, wherein the first electrode is a transparent electrode, and an entire region of the first electrode is the light-transmitting region.
11. The pattern recognition substrate according to claim 1, further comprising a transistor located between the base substrate and the light-absorbing layer, wherein the transistor is electrically connected to the first electrode, and the transistor is a double-gate transistor.
12. The pattern recognition substrate according to claim 11, wherein an orthographic projection of the transistor on the base substrate does not overlap with an orthographic projection of the photosensitive device on the base substrate.
13. The pattern recognition substrate according to claim 11, further comprising a planarization layer located between a layer where the transistor is located and a layer where the first electrode is located, wherein the planarization layer is multiplexed as the light-absorbing layer.
14. The pattern recognition substrate according to claim 13, wherein a material of the planarization layer is black resin.
15. The pattern recognition substrate according to claim 1, wherein a thickness of the I-type semiconductor layer in a direction perpendicular to the base substrate is less than 9000 .
16. The pattern recognition substrate according to claim 1, further comprising: a light-emitting device located on a side of the layer where the photosensitive device is located away from the base substrate; wherein an orthographic projection of the light-emitting device on the base substrate does not overlap with an orthographic projection of the photosensitive device on the base substrate.
17. A display device, comprising the pattern recognition substrate according to claim 1.
Description
BRIEF DESCRIPTION OF FIGURES
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DETAILED DESCRIPTION
[0055] In order to make purposes, technical solutions and advantages of the disclosure clearer, the technical solutions of embodiments of the disclosure will be described clearly and completely below in combination with accompanying drawings of embodiments of the disclosure. It is necessary to note that the size and shape of each diagram in the accompanying drawings do not reflect the true proportion, and are merely for purpose of schematically illustrating the content of the disclosure. Also, the same or similar reference numbers represent the same or similar elements or the elements having the same or similar functions all the way.
[0056] Unless otherwise defined, the technical or scientific terms used here shall have the general meaning understood by those ordinary skilled in the art to which the disclosure belongs. The first, second and similar words used in the specification and claims of the disclosure do not represent any order, number or importance, and are only used to distinguish different components. The word such as include or contain or the like means that the element or object appearing before this word encompasses the elements or objects and their equivalents listed after this word, without excluding other elements or objects. The words such as inner, outer, up, down are only used to represent the relative position relationship. When the absolute position of a described object changes, the relative position relationship may also change accordingly.
[0057] During the fingerprint recognition process, in order to reduce interference of ambient light, a layer of light filter film is generally added to a light incident side of a photosensitive device to filter out the ambient light after 600 nm, thus increasing the cost of the mask. Inventors found through research that, as shown in
TABLE-US-00001 Characteristics of photosensitive device Cover Full well System Transmittance intensity PIN area capacity Integration of light from all (m.sup.2) (fc) EQE time (ms) filter film angles (lx) Conventional 500 250 1 25 0.01 10 W fingerprint recognition device with light filter film Fingerprint 500 2100 0.4 7-8 10 W recognition device with I layer thinned
[0058] However, when the I layer is thinned, unabsorbed light reflected by the finger may be reflected by a lower electrode (SD2) of the photosensitive device back to the finger touch position above the photosensitive device, and may be reflected again by the finger. Multiple reflections may interfere with the performance of the fingerprint recognition.
[0059] In order to alleviate the above technical problem in related art, an embodiment of the disclosure provides a an pattern recognition substrate, as shown in
[0063] In the above pattern recognition substrate according to an embodiment of the disclosure, the I-type semiconductor layer cannot completely absorb the fingerprint-reflected light when being thinned (that is, less than the conventional thickness). By setting the first electrode 1021 under the I-type semiconductor layer to include the light-transmitting region L, the fingerprint-reflected light that is not absorbed and converted by the I-type semiconductor layer passes through the light-transmitting region L and irradiates to the light-absorbing layer 103 and is then absorbed, thereby avoiding the fingerprint-reflected light that is not absorbed and converted by the I-type semiconductor layer from being reflected multiple times between the first electrode 1021 and the finger, and thus improving the accuracy of fingerprint recognition.
[0064] In some embodiments, the thickness of the I-type semiconductor layer according to the disclosure may be less than 9000 , for example, may be 500 . Furthermore, a set of data is provided for the pattern recognition substrate of the disclosure and two pattern recognition substrates as contrasts. In the pattern recognition substrate of the disclosure, the thickness of the I-type semiconductor layer is 500 , the first electrode 1021 includes the light-transmitting region L, and there is the light-absorbing layer 103 below the first electrode 1021; in the first pattern recognition substrate as a contrast, the thickness of the I-type semiconductor layer is 9000 (that can completely convert the fingerprint-reflected light), and the first electrode 1021 does not include the light-transmitting region L; and, in the second pattern recognition substrate as a contrast, the thickness of the I-type semiconductor layer is 500 , and the first electrode 1021 does not include the light-transmitting region L. Here, the fingerprint image in the first pattern recognition substrate is shown in
[0065] Furthermore, it is worth noting that, as shown in
[0066] In some embodiments, in the above-mentioned pattern recognition substrate according to an embodiment of the disclosure, as shown in
[0067] In some embodiments, as shown in
[0068] When the openings K are circular, an opening ratio A of the first electrode 1021 satisfies a following relationship:
[0069] Here, d is a diameter of a circle, and q is a distance between centers o of two adjacent circles.
[0070] When the openings K are square, an opening ratio A of the first electrode 1021 satisfies a following relationship:
[0071] Here, d is a side length of a square, and q is a distance between centers o of two adjacent squares.
[0072] In some embodiments, in order to effectively reduce the reflection of the fingerprint-reflected light that is not absorbed by the I-type semiconductor layer by the first electrode 102, the aperture ratio and the arrangement of openings need to be reasonably set. Optionally, a value range of the above d is 2 md6 m, a value range of the above q is 5 mq20 m, and a value range of the aperture ratio A is 0.1A0.6.
[0073] In some embodiments, in the above-mentioned pattern recognition substrate according to an embodiment of the disclosure, in order to transmit light evenly, as shown in
[0074] In some embodiments, in the above-mentioned pattern recognition substrate according to an embodiment of the disclosure, as shown in
[0075] In some embodiments, the above pattern recognition substrate according to an embodiment of the disclosure, as shown in
[0076] In some embodiments, in the above-mentioned pattern recognition substrate according to an embodiment of the disclosure, as shown in
[0077] In some embodiments, the above-mentioned pattern recognition module according to an embodiment of the disclosure, as shown in
[0078] In some embodiments, the region where one photosensitive device 102 is located is a pixel region. Optionally, one transistor T is arranged in one pixel region (as shown in
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[0090] Furthermore, a shielding layer (ITO) 115 has a block structure that completely covers each pixel region within the pixel region in the display region AA, and has a block structure that completely covers a bonding region within the bonding region BD shown in
[0091] In some embodiments, in the above-mentioned pattern recognition substrate according to an embodiment of the disclosure, as shown in
[0092] The above content only describes the pattern recognition substrate having the fingerprint recognition function. In some embodiments, the pattern recognition substrate may also have a display function. The above pattern recognition substrate according to an embodiment of the disclosure, as shown in
[0093] When the pattern recognition substrate according to the disclosure has both the display function and touch function, as shown in
[0094] During fingerprint recognition, when the finger F touches the pattern recognition substrate, the light reflected by the finger passes through the gap between the light-emitting devices 118 and reaches the photoelectric conversion layer 1022 of the photosensitive device 102. The I-type semiconductor layer of the photoelectric conversion layer 1022 absorbs a part of the light reflected by the finger, detecting the intensity of the fingerprint-reflected light. Due to different energy of diffusely reflected light downwards at the valleys and ridges, the light intensities detected by the array of the photosensitive device 102 are different, thus obtaining the fingerprint image information. Also, the fingerprint-reflected light that is not absorbed by the I-type semiconductor layer passes through the light-transmitting region L of the first electrode 1021 and is absorbed by the light-absorbing layer 103, avoiding the fingerprint-reflected light that is not absorbed and converted by the I-type semiconductor layer from being reflected multiple times between the first electrode 1021 and the finger, and thus improving the accuracy of fingerprint recognition.
[0095] Based on the same inventive concept, the disclosure further provides a display device, including the above pattern recognition substrate according to embodiments of the disclosure. Since the principle of the display device to solve the problem is similar to the principle of the above pattern recognition substrate to solve the problem, implementations of the display device can refer to embodiments of the above pattern recognition substrate, and the repeated description thereof will be omitted.
[0096] In some embodiments, the above display device according to an embodiment of the disclosure may be: a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, a smart watch, a fitness wristband, a personal digital assistant, and any other product or component with display function. The display device according to an embodiment of the disclosure may also include but not limited to: a radio frequency unit, a network module, an audio output unit, an input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply, etc. Those skilled in the art can understand that the composition of the above display device does not constitute a limitation on the display device, and the display device may include more or fewer components than the above components, or combine some components, or use different component arrangements.
[0097] Evidently, those skilled in the art can make various modifications and variations to embodiments of the disclosure without departing from the spirit and scope of embodiments of the disclosure. Thus, the disclosure is also intended to encompass these modifications and variations to embodiments of the disclosure as long as these modifications and variations come into the scope of the claims of the disclosure and their equivalents.