阅读说明：本技术 感光器件及阵列基板及显示装置及其亮度调节方法 (Photosensitive device, array substrate, display device and brightness adjusting method of display device ) 是由 贺强 祝宏勋 于 2019-10-31 设计创作，主要内容包括：本发明公开了一种感光器件,所述感光器件包括至少一个感光晶体管；所述感光晶体管包括栅极、源极、漏极以及均与源极和漏极接触的沟道感光区域；所述感光晶体管的栅极输入预定电压,所述感光晶体管的源极输入检测电压,所述感光晶体管通过沟道感光区域感应外界光线亮度产生对应的漏极电流信号。本发明利用光线强弱对感光晶体管的关态漏极电流的影响在显示装置内部集成一个光线感应器,使得光线感应器集成在显示装置周边,不会占用有效显示区域,降低整机成本。(The invention discloses a photosensitive device, which comprises at least one photosensitive transistor; the photosensitive transistor comprises a grid electrode, a source electrode, a drain electrode and a channel photosensitive area which is in contact with the source electrode and the drain electrode; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through the channel photosensitive area to generate a corresponding drain current signal. The invention integrates the light sensor in the display device by utilizing the influence of the light intensity on the off-state drain current of the photosensitive transistor, so that the light sensor is integrated at the periphery of the display device, the effective display area is not occupied, and the cost of the whole display device is reduced.)

1. A light sensing device, wherein said light sensing device comprises at least one light sensing transistor; the photosensitive transistor comprises a grid electrode, a source electrode, a drain electrode and a channel photosensitive area which is in contact with the source electrode and the drain electrode; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through the channel photosensitive area to generate a corresponding drain current signal.

2. An array substrate comprises a substrate layer, wherein the substrate layer comprises an effective display area and a frame area; the photosensitive device comprises at least one photosensitive transistor; the photosensitive transistor comprises a grid electrode, a source electrode, a drain electrode and a channel photosensitive area which is in contact with the source electrode and the drain electrode; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through the channel photosensitive area to generate a corresponding drain current signal.

3. The array substrate of claim 2, wherein the photo-sensing device comprises 4 photo-sensing transistors, and the photo-sensing transistors are distributed around the frame region of the base layer.

4. The array substrate of claim 2, wherein the predetermined voltage input to the gate of the light sensing transistor is negative 15 volts.

5. The display device is characterized by comprising an array substrate and a color film substrate;

the array substrate comprises a substrate layer, the substrate layer comprises an effective display area and a frame area, the frame area on the substrate layer is provided with a photosensitive device, and the photosensitive device comprises at least one photosensitive transistor; the photosensitive transistor comprises a grid electrode, a source electrode, a drain electrode and a channel photosensitive area which is in contact with the source electrode and the drain electrode; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through a channel photosensitive area to generate a corresponding drain current signal;

the color film substrate comprises a black matrix which is arranged in an array mode, and an opening is formed in the black matrix at the position corresponding to the photosensitive transistor.

6. The display device according to claim 5, further comprising a circuit board and a flexible connection circuit;

the circuit board inputs preset voltage to the grid electrode of the photosensitive transistor through the flexible connecting circuit, the circuit board inputs detection voltage to the source electrode of the photosensitive transistor through the flexible connecting circuit, the photosensitive transistor induces external light brightness through a channel photosensitive area to generate a corresponding drain current signal, and the drain electrode of the photosensitive transistor provides a drain current signal to the circuit board through the flexible connecting circuit.

7. The display device according to claim 6, wherein the circuit board is further configured to generate a corresponding brightness adjustment signal according to the read drain current signal; the brightness adjusting signal is used for adjusting the screen brightness of the display device.

8. The display device according to claim 5, wherein the photo sensing device comprises 4 photo sensing transistors, and the photo sensing transistors are distributed around a frame region of the substrate layer.

9. A method for adjusting brightness of a display device, wherein the method is applied to the display device according to any one of claims 5 to 8.

Technical Field

The invention relates to the field of liquid crystal display, in particular to a photosensitive device, an array substrate, a display device and a brightness adjusting method of the display device.

Background

With the development of display technology, TFT-LCD (Thin Film Transistor-Liquid crystal display) has a dominant position in the display field with its absolute advantages (low cost, good picture quality, low power consumption, etc.), such as being applicable to audio-visual devices such as computers, televisions, smart phones, etc. The Liquid Crystal display panel is generally composed of a Color Filter (CF) Substrate, an Array Substrate (TFT Substrate for short), and a Liquid Crystal Layer (Liquid Crystal Layer) disposed between the two substrates, and the Liquid Crystal display panel operates by applying a driving voltage to the two glass substrates to control the rotation of Liquid Crystal molecules in the Liquid Crystal Layer, so as to refract light from the backlight module to generate a picture.

The light sensors inside the smart phone and the smart wearable product at present must occupy certain space of the frame, and the basic principle of the light sensors is that the light sensors are used for sensing the change of light, so that the process is relatively complex and the cost is high.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a photosensitive device, an array substrate, a display device and a brightness adjusting method thereof, and an area occupied by the display device can be saved by arranging a photosensitive transistor on the array substrate instead of an additional light sensor.

The technical scheme provided by the invention is as follows:

the invention discloses a photosensitive device, which comprises at least one photosensitive transistor; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through the channel photosensitive area to generate a corresponding drain current signal.

The invention also discloses an array substrate which comprises a substrate layer, wherein the substrate layer comprises an effective display area and a frame area, and the frame area on the substrate layer is provided with a photosensitive device; the photosensitive device comprises at least one photosensitive transistor; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through the channel photosensitive area to generate a corresponding drain current signal.

Preferably, the photosensitive device comprises 4 photosensitive transistors, and the photosensitive transistors are distributed around the frame region of the substrate layer.

Preferably, the predetermined voltage input to the gate of the light sensing transistor is negative 15 volts.

The invention also discloses a display panel, which comprises an array substrate and a color film substrate;

the array substrate comprises a substrate layer, the substrate layer comprises an effective display area and a frame area, the frame area on the substrate layer is provided with a photosensitive device, and the photosensitive device comprises at least one photosensitive transistor; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through a channel photosensitive area to generate a corresponding drain current signal;

the color film substrate comprises a black matrix which is arranged in an array mode, and an opening is formed in the black matrix at the position corresponding to the photosensitive transistor.

Preferably, the display device further comprises a circuit board and a flexible connection circuit;

the circuit board inputs preset voltage to the grid electrode of the photosensitive transistor through the flexible connecting circuit, the circuit board inputs detection voltage to the source electrode of the photosensitive transistor through the flexible connecting circuit, the photosensitive transistor induces external light brightness through a channel photosensitive area to generate a corresponding drain current signal, and the drain electrode of the photosensitive transistor provides a drain current signal to the circuit board through the flexible connecting circuit.

Preferably, the circuit board is further configured to generate a corresponding brightness adjustment signal according to the read drain current signal; the brightness adjusting signal is used for adjusting the screen brightness of the display device.

Preferably, the photosensitive device comprises 4 photosensitive transistors, and the photosensitive transistors are distributed around the frame region of the substrate layer.

The invention also discloses a brightness adjusting method of the display device, and the method is suitable for the display device.

Compared with the prior art, the light sensor is integrated in the display device by utilizing the influence of the light intensity on the off-state leakage current of the photosensitive transistor, so that the light sensor is integrated at the periphery of the display device, the AA effective display area is not occupied, and the cost of the whole display device is reduced.

Drawings

The present invention will be further described in the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.

FIG. 1 is a schematic circuit diagram of a photosensitive device of the present invention;

FIG. 2 is a graph of the variation of drain current with illumination brightness of a phototransistor according to the present invention;

FIG. 3 is a diagram showing the relationship between drain current and light brightness of the phototransistor according to the present invention;

fig. 4 is a schematic diagram of the distribution of the photo-sensing transistors on the array substrate according to the present invention.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

The existing light sensor is an independent part in the whole machine, is arranged above a screen of a display device and occupies an opening of the display device assembly, so that the area of a display area is reduced, and the cost of the display device is increased.

To this end, the present invention discloses a photosensitive device, fig. 1 is a schematic circuit diagram of the photosensitive device of the present invention, as shown in fig. 1, the photosensitive device includes at least one photosensitive transistor; the photosensitive transistor comprises a grid G, a source S, a drain D and a channel photosensitive area which is in contact with the source S and the drain D; the gate G of the light sensing transistor receives a predetermined voltage Vgate, the source S of the light sensing transistor receives a detection voltage V input from the outside, and the light sensing transistor senses the brightness of the outside light through a channel light sensing region (indicated by an arrow in the figure) to generate a corresponding drain current signal Id and outputs the drain current signal Id through the drain D of the light sensing transistor.

FIG. 2 is a graph of the variation of drain current with illumination brightness of the phototransistor according to the present invention. Fig. 3 is a diagram showing the relationship between the drain current and the light brightness of the phototransistor according to the present invention, and as shown in fig. 2 and fig. 3, the external light brightness and the drain current of the phototransistor show a linear relationship. Specifically, the channel region of the photosensitive transistor is used as a photosensitive region, can sense the brightness of external light, and is embodied by drain current, so that the photosensitive transistor arranged in the display device replaces a traditional independent light sensor to achieve the purpose of reducing the area of the display region.

Therefore, the invention also discloses an array substrate which comprises a substrate layer, wherein the substrate layer comprises an effective display area and a frame area, and the frame area on the substrate layer is provided with a photosensitive device; the photosensitive device comprises at least one photosensitive transistor; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through the channel photosensitive area to generate a corresponding drain current signal.

Specifically, fig. 4 is a schematic diagram of the distribution of the photo-sensing transistors on the array substrate according to the present invention. As shown in fig. 4, the base layer of the array substrate 100 is divided into an effective display area AA and a frame area BB, photosensitive devices are disposed around the frame area BB, the photosensitive devices include 4 photosensitive transistors, which are 1/2/3/4 marked in the figure, four photosensitive transistors are disposed around the frame area BB of the base layer, wherein gates and sources of the four photosensitive transistors are respectively connected to the flexible circuit 200 through wires and electrically connected to a circuit board (not shown in the figure), the circuit board inputs a predetermined voltage Vgate (S-Vgate in the figure represents a connection line between the gate of the photosensitive transistor and the flexible circuit) to the gates of the photosensitive transistors through the flexible circuit 200, inputs a detection voltage V (S-V in the figure represents a connection line between the source of the photosensitive transistor and the flexible circuit) to the sources of the photosensitive transistors, the drain of the photo transistor is also connected to the flexible circuit 200 by a wire (labeled as S-Id in the figure) and electrically connected to the circuit board, and the circuit board reads the drain current signal Id to the drain of the photo transistor through the flexible circuit 200. 1/2/3/4 the four phototransistors are all the same device structure, so as to make the device sensitive, the four phototransistors are arranged in the frame area of the base layer of the array substrate to increase the sensitive area of the device, so as to improve the accuracy.

Specifically, the predetermined voltage Vgate input to the gate of the light sensing transistor is negative 15 volts.

Therefore, the invention also discloses a display device which comprises an array substrate and a color film substrate; the array substrate comprises a substrate layer, the substrate layer comprises an effective display area and a frame area, the frame area on the substrate layer is provided with a photosensitive device, and the photosensitive device comprises at least one photosensitive transistor; the grid electrode of the photosensitive transistor inputs preset voltage, the source electrode of the photosensitive transistor inputs detection voltage, and the photosensitive transistor induces the brightness of external light through a channel photosensitive area to generate a corresponding drain current signal; the color film substrate comprises a black matrix which is arranged in an array mode, and an opening is formed in the black matrix at the position corresponding to the photosensitive transistor.

Preferably, the photosensitive device comprises 4 photosensitive transistors, and the photosensitive transistors are distributed around the frame region of the substrate layer.

Specifically, the black matrix is provided with an opening for exposing a channel photosensitive area of the photosensitive transistor to sense the brightness of external light.

Specifically, the display device further comprises a circuit board and a flexible connection circuit; the circuit board inputs preset voltage to the grid electrode of the photosensitive transistor through the flexible connecting circuit, the circuit board inputs detection voltage to the source electrode of the photosensitive transistor through the flexible connecting circuit, the photosensitive transistor induces external light brightness through a channel photosensitive area to generate a corresponding drain current signal, and the drain electrode of the photosensitive transistor provides a drain current signal to the circuit board through the flexible connecting circuit.

Specifically, the circuit board is further configured to generate a corresponding brightness adjustment signal according to the read drain current signal; the brightness adjusting signal is used for adjusting the screen brightness of the display device.

Specifically, when the external light is weak, the light intensity sensed by the photosensitive region of the photosensitive transistor is small, the drain current signal generated by the drain is also small, and the current detected by the circuit board is also small, so that the circuit board generates a corresponding brightness adjusting signal which adjusts the screen brightness to the brightness matched with the low-brightness environment.

Specifically, when the external light is strong, the light intensity sensed by the photosensitive region of the photosensitive transistor is large, the drain current signal generated by the drain is also large, and the current detected by the circuit board is also large, so that the circuit board generates a corresponding brightness adjusting signal, and the brightness adjusting signal adjusts the screen brightness to the brightness matched with the high-brightness environment.

Under the condition of the embodiment, the detection voltage input by the source electrode of the photosensitive transistor is 20V, the predetermined voltage Vgate applied by the grid electrode (Gate) of the photosensitive transistor is-15V, and when W/L is between 105um/5um (the width-length ratio is large), the drain current Id of the Ioff photosensitive transistor can reach 3 x 10-6A under the indoor normal illumination condition (about 500 lux).

The invention also discloses a brightness adjusting method of the display device, and the method is suitable for the display device.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.