CN101655644A - Substrate with touch control function, liquid crystal display and operation method for driving substrate - Google Patents

Abstract

The invention discloses a substrate with touch function. The touch device is arranged on a substrate. The touch device includes a power line, a light sensor and a reading line. The light sensor is electrically coupled to the power line and two specific gate lines among the gate lines, and generates different output signals according to different levels of illumination. The reading line is electrically coupled to the light sensor to output the above output signal. The light sensor includes a read switch and a photosensitive switch. The read switch is electrically coupled to one of the two specific gate lines to determine whether it is turned on according to the signal transmitted by it, and the photosensitive switch is electrically coupled to the other of the two specific gate lines and the power line and is illuminated by light. Leakage currents of different degrees are produced in different degrees. Wherein, the signal on the other one of the two specific gate lines and the power line is matched to control whether the photosensitive switch is operated in an off state. The invention also discloses a liquid crystal display with touch function and an operation method for driving the substrate with touch function.

Description

Substrate with touch function, liquid crystal display and operation method for driving the substrate

technical field

The invention relates to the field of touch detection, and in particular to a substrate with touch function, a display with touch function and an operation method for driving the substrate with touch function.

Background technique

With the development of technology, flat-panel displays (such as liquid crystal displays) are widely used in mobile phones, notebook computers, and desktop display devices due to their advantages of high image quality, small size, light weight, and wide application range. Various consumer electronic products such as TVs and TVs have gradually replaced traditional cathode ray tube display devices and become the mainstream of display devices.

The touch device provides a new human-computer interaction interface, which is more intuitive and more humane in use. It is a trend in the development of the flat-panel display to integrate the touch-control device with the flat-panel display so that the flat-panel display has a touch function. Existing flat panel displays with touch function generally use light sensors to detect whether a touch object (eg, a finger or a stylus) touches the touch device and its corresponding position. The flat panel display needs to be provided with various signal transmission lines electrically coupled with the light sensor to transmit various signals to the light sensor so that the light sensor can work normally. Therefore, the set signal transmission lines occupy a large area, thereby reducing the aperture ratio of the flat-panel display, losing the brightness of the flat-panel display, and increasing power consumption.

Contents of the invention

An object of the present invention is to provide a display substrate with a touch function, which has fewer signal transmission lines and can reduce power consumption.

Another object of the present invention is to provide a flat panel display with a touch function, which can effectively reduce the number of signal transmission lines and effectively increase the aperture ratio.

Another object of the present invention is to provide a touch device, which has fewer signal transmission lines and can reduce power consumption.

Another object of the present invention is to provide an operation method for driving a substrate with a touch function, which can use fewer signal transmission lines to provide a driving voltage to control the light sensor.

The present invention provides a display substrate with a touch function, which includes a plurality of gate lines and at least one touch device. Both the gate line and the touch device are disposed on a substrate. The touch device includes at least one reading line, at least one power line, a light sensor and a reading driving unit. Both the power line and the reading line are arranged on the substrate, and the reading line is arranged crossing the gate lines. The photosensor is arranged near the intersection of a specific gate line and a specific readout line among the gate lines, and the photosensor includes a readout switch and a photosensitive switch. The read switch includes a first access terminal, a second access terminal and a first control terminal, wherein the second access terminal is electrically coupled to a specific read line, and the first control terminal is electrically coupled to a specific gate line to control Whether the first access end is electrically connected to the second access end. The photosensitive switch includes a third access end, a fourth access end and a second control end, wherein the fourth access end is electrically coupled to the first access end of the read switch, and the second control end is electrically coupled to the power supply One of the lines is used to control whether the third access end is electrically connected to the fourth access end. When the photosensitive switch cuts off the electrical conduction path between the third access end and the fourth access end at the second control end due to different levels of illumination, leakage currents of different degrees are generated between the third access end and the fourth access end . The reading driving unit is electrically coupled to the specific reading line to read the leakage current generated by the photosensitive switch. Wherein, the third access terminal of the photosensitive switch is electrically coupled to a preset gate line except a specific gate line among the gate lines.

The present invention also proposes a liquid crystal display with a touch function, which includes a substrate, a plurality of gate lines, a plurality of data lines, a plurality of reading lines, a plurality of power lines, a plurality of pixel transistors, a plurality of pixel electrodes, Light sensor and read drive unit. The gate lines, data lines, reading lines and power lines are arranged on the substrate, and the data lines and the gate lines are intersected so as to divide the liquid crystal display into a plurality of pixel areas. The pixel transistors are respectively disposed in the pixel areas and electrically coupled to the corresponding gate lines and data lines, and the pixel electrodes are respectively disposed in the pixel areas and electrically coupled to the corresponding pixel transistors. The light sensor is disposed in one of the pixel areas, and includes a readout switch and a photosensitive switch. The read switch includes a first access terminal, a second access terminal and a first control terminal, wherein the second access terminal is electrically coupled to a specific read line among the read lines, and the first control terminal is electrically coupled to A specific gate line among the gate lines is used to control whether the first access end is electrically connected to the second access end. The photosensitive switch includes a third access end, a fourth access end and a second control end, wherein the fourth access end is electrically coupled to the first access end of the read switch, and the second control end is electrically coupled to the power supply One of the lines is used to control whether the third access end is electrically connected to the fourth access end. When the photosensitive switch cuts off the electrical conduction path between the third access end and the fourth access end at the second control end due to different levels of illumination, leakage currents of different degrees are generated between the third access end and the fourth access end . The reading driving unit is electrically coupled to the specific reading line to read the leakage current generated by the photosensitive switch. Wherein, the third access terminal of the photosensitive switch is electrically coupled to a preset gate line except a specific gate line among the gate lines.

In a preferred embodiment of the present invention, the aforementioned preset gate line is the next gate line adjacent to the specific gate line.

In a preferred embodiment of the present invention, the aforementioned predetermined gate line is the last gate line adjacent to the specific gate line.

In a preferred embodiment of the present invention, the above light sensor further includes a first capacitor and a second capacitor. The first capacitor is electrically coupled between the third access end and the fourth access end of the photosensitive switch, and the second capacitor is electrically coupled between the second control end and the fourth access end of the photosensitive switch.

In a preferred embodiment of the present invention, the above read drive unit includes a charge amplifier, a capacitor and a switch element. The first input terminal of the charge amplifier is electrically coupled to a specific read line, the second input terminal is electrically coupled to the reference power supply, and the output terminal is obtained according to the signals obtained from the first input terminal and the second input terminal. The output voltage. The capacitor is electrically coupled between the first input end and the output end of the charge amplifier, and the switch element is electrically coupled between the first input end and the output end of the charge amplifier.

The present invention further provides a touch device, which is disposed on a substrate including a plurality of gate lines. The touch device includes a power line, a light sensor and a reading line. The light sensor is electrically coupled to the power line and two specific gate lines among the gate lines, and generates different output signals according to different levels of illumination. The reading line is electrically coupled to the light sensor to output the above output signal. The light sensor includes a read switch and a photosensitive switch. The read switch is electrically coupled to one of the two specific gate lines to determine whether to conduct according to the signal transmitted by it, and the photosensitive switch is electrically coupled to the other of the two specific gate lines and the power line And different degrees of leakage current are generated due to different levels of illumination. Wherein, the other one of the two specific gate lines is matched with the signal on the power line to control whether the photosensitive switch is operated in an off state.

The invention also proposes a method for operating the photosensor in a pixel, which is applicable to the photosensor arranged in a flat panel. The planar panel includes a plurality of gate lines arranged in parallel, and each gate line is used to control whether more than one pixel switch is turned on. The light sensor includes a photosensitive switch, and the photosensitive switch generates different degrees of leakage current in a closed state according to different degrees of illumination. The above operation method includes: electrically coupling the photosensitive switch to a power line and a specific gate line among the gate lines; and adjusting the voltage difference between the specific gate line and the power line to keep the photosensitive switch operating at Disabled.

The present invention also proposes an operation method for driving the substrate with touch function as claimed in claim 1, the operation method includes adjusting the voltage difference between the specific gate line and the power line to maintain the photosensitive switch Operate in a certain current state; transmit a signal value to the reading signal unit; and determine whether the light sensor is covered by an object.

The touch control device and the liquid crystal display of the present invention provide voltages for the reading switch and the photosensitive switch of the photosensor respectively through their original gate lines, especially provide voltage for the source of the photosensitive switch through the gate lines, so , the liquid crystal display with touch function does not need to set up a large number of signal transmission lines to provide various signals to the light sensor in realizing the touch function, which saves the setting area of signal transmission lines, increases the aperture ratio of the liquid crystal display, and improves The brightness of the liquid crystal display is improved, and the required power supply is reduced.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

In order to make the above and other objects, features, advantages and embodiments of the present invention more comprehensible, the accompanying drawings are described as follows:

FIG. 1 is a schematic diagram of an equivalent circuit of a flat panel display with a touch function disclosed by an embodiment of the present invention.

FIG. 2 is a schematic diagram of an equivalent circuit of a light sensor and its reading driving unit disclosed by an embodiment of the present invention.

FIG. 3 is a schematic diagram of an equivalent circuit of a light sensor and its reading driving unit disclosed in another embodiment of the present invention.

FIG. 4 is a schematic diagram of an equivalent circuit of a flat panel display with a touch function disclosed by another embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation method of an in-pixel light sensor according to an embodiment of the invention.

Among them, reference signs

100, 200: Flat panel display 110: Substrate

111, 211: pixel transistor 112: pixel electrode

120, 180, 220: light sensor 121, 186, 221: read switch

1211, 2211: Read the gate of the switch 1212: Read the source of the switch

1213: Read the drain of the switch 126, 226: Photosensitive switch

1261: Gate of photosensitive switch 1262, 1862, 2262: Source of photosensitive switch

1263: The drain of the photosensitive switch 128: The first capacitor

129: Second capacitor 130: Read drive unit

131: Charge Amplifier 132: Capacitor

133: Switching element G(n-1), Gn, G(n+1): gate line

D(n-1), Dn, D(n+1): data line Vg: power line

R(n-1), Rn: read line Vout: output voltage

Vr: reference voltage

Detailed ways

Referring to FIG. 1 , it shows a schematic diagram of an equivalent circuit of a flat panel display with touch function proposed by an embodiment of the present invention. In this embodiment, the flat panel display 100 is, for example, a liquid crystal display, including a substrate 110 , another substrate (not shown) corresponding to the substrate, and a liquid crystal layer (not shown) between the two substrates. The flat panel display 100 includes a plurality of gate lines, such as G(n-1), G(n) and G(n+1), and a plurality of data lines, such as D(n-1), D(n) and D(n+1). These gate lines and these data lines are intersected to divide the flat panel display 100 into a plurality of pixel areas, for example, gate lines G(n-1), G(n) and G(n+1) and data lines D( n−1), D(n), and D(n+1) intersect each other to form four pixel regions. The flat panel display 100 is respectively provided with a pixel transistor 111 and a pixel electrode 112 in each pixel area, wherein the pixel transistor 111 is electrically coupled to the gate line and the data line corresponding to it, and the pixel electrode 112 is electrically coupled to the corresponding The pixel transistor 111. The flat panel display 100 transmits the gate signal to the pixel transistor 111 through the corresponding gate line to control the switching state of the pixel transistor 111, and when the pixel transistor 111 is turned on, the data signal is passed through the pixel transistor 111 through the corresponding data line. The information is transmitted to the pixel electrode 112, so that the flat panel display 100 displays a corresponding picture. This technique is well known to those skilled in the art, and will not be repeated here.

In order to enable the flat panel display 100 to have a touch function, the flat panel display 100 further includes a light sensor 120 constituting a touch device, a power line Vg, and reading lines R(n-1), R(n), which are all arranged on the substrate 110 on. Wherein, in this embodiment, each pixel area is respectively provided with a photosensor 120, and the reading lines R(n-1), R(n) are respectively connected with the gate lines G(n-1), G( n) and G(n+1) cross each other. The present invention is not limited thereto, and those skilled in the art can also arrange the light sensor 120 only in certain specific pixel areas among several adjacent pixel areas according to actual needs. Please also refer to FIG. 2 , which shows a schematic diagram of an equivalent circuit of the photosensor and its reading and driving unit in a pixel area shown in FIG. 1 . The light sensor 120 includes a read switch 121 and a photosensitive switch 126 . Preferably, the read switch 121 is a thin-film transistor (thin-film transistor, TFT), such as a metal-oxide semiconductor field-effect transistor (MOSFET), or other various transistors. The present invention is described by taking a metal oxide field effect transistor as an example, but the present invention is not limited thereto.

The gate 1211 (or referred to as the first control terminal) of the read switch 121 is electrically coupled to a gate line G(n) to control the switching state of the read switch 121, and the drain 1213 (or referred to as the second access end) is electrically coupled to a readout line R(n), and its source 1212 (or referred to as the first access end) is electrically coupled to the drain 1263 of the photosensitive switch 126 (or referred to as the fourth access end). The gate 1261 (or referred to as the second control terminal) of the photosensitive switch 126 is electrically coupled to the power line Vg to control the switching state of the photosensitive switch 126, and its source 1262 (or referred to as the third access terminal) is electrically coupled to to another gate line, such as the next gate line G(n+1) adjacent to the gate line G(n). The read line R(n) can be electrically coupled to a read drive unit 130 . Wherein, the photosensitive switch 126 generates different degrees of leakage current between the drain 1263 and the source 1262 of the photosensitive switch 126 when it is in the off state due to different illumination levels.

Further, the light sensor 120 may further include a first capacitor 128 and a second capacitor 129 . Wherein, the first capacitor 128 is electrically coupled between the drain 1263 (or called the fourth access end) and the source 1262 (or called the third access end) of the photosensitive switch 126, and the second capacitor 129 is electrically coupled It is coupled between the drain 1263 (or called the fourth access terminal) and the gate 1261 (or called the second control terminal) of the photosensitive switch 126 . Wherein, the first capacitor 128 and the second capacitor 129 are charged/discharged by the leakage current generated by the photosensitive switch 126 . The read driving unit 130 may include a charge amplifier 131 , a capacitor 132 and a switch element 133 . Wherein, the first input end of the charge amplifier 131 is electrically coupled to the read line R(n), the second input end is electrically coupled to the reference power supply Vr, and the output end thereof is used for the output according to the first input end and the reference power supply. The signal obtained at the second input terminal is used to obtain an output voltage Vout. The capacitor 132 is electrically coupled between the first input terminal and the output terminal of the charge amplifier 131, and the switch element 133 is connected in parallel with the capacitor 132, that is, it is also electrically coupled between the first input terminal and the output terminal of the charge amplifier 131. between.

The flat-panel display 100 with touch function disclosed in the embodiment of the present invention provides voltages for the gate 1261 and the source 1262 of the photosensitive switch 126 respectively through the gate line G(n+1) and the power line Vg and makes the voltage between them The difference Vgs is always less than its threshold voltage. In this way, the photosensitive switch 126 can be maintained in the closed state without affecting the leakage current generated by the photosensitive switch 126 . When the read switch 121 is turned on, that is, when the read switch 121 is in a conducting state, a signal value can be transmitted to the read line Rn at this time. In this embodiment, the signal value is preferably generated by the photosensitive switch 126. The result of charging/discharging the capacitors 128 and 129 by the leakage current is transmitted to the read line Rn through the turned-on read switch 121 and read by the read drive unit 130 . The reading drive unit 130 can determine whether the photosensitive switch 126 is covered by an object (for example, a finger or a touch pen) according to the read result (or called a signal value), and thus can determine whether the photosensitive switch 120 is blocked by an object (such as a finger or a touch pen). Whether this pixel area at is touched. Techniques such as how to interpret the read signal by the read drive unit 130 are known to those skilled in the art and will not be repeated here.

According to the above, the touch device disclosed in the present invention is mainly composed of the photosensor 120, which is disposed on the substrate 110 with a plurality of gate lines, and utilizes the original gate line G(n) of the flat panel display 100 and G(n+1) provide various driving signals for the light sensor 120 , so as to integrate the touch device with the flat-panel display, so that the flat-panel display 100 has a touch function. In addition, it should be pointed out that the touch device mainly composed of the light sensor 120 of the present invention can also be applied to, for example, an organic light emitting device with an excitation light emitting diode (organic light emitting device) in addition to the aforementioned liquid crystal display of the present invention. , OLED), flexible display (flexible display) and other types of flat-panel displays, as long as the flat-panel display has multiple gate lines, the light sensor proposed by the present invention can be used, so that the touch device and the flat-panel display are integrated Together.

In addition, although in the flat panel display 100 with touch function disclosed in the embodiment of the present invention shown in FIG. 1 , each pixel area corresponds to a light sensor, those skilled in the art can understand that a A sensor may correspond to a plurality of pixel regions, for example, on gate lines G(n-1), G(n) and G(n+1) and data lines D(n-1), D(n) and Only one light sensor may be provided in the 4 pixel areas formed by crossing D(n+1) with each other.

Please refer to FIG. 3 , which shows a schematic diagram of an equivalent circuit of a photosensitive sensor and its reading driving unit disclosed in another embodiment of the present invention. The light sensor 180 of this embodiment is similar to the light sensor 120 shown in FIG. The last gate line G(n-1) adjacent to the pole line G(n) provides source voltage to the source 1862 of the photosensitive switch 186 through the gate line G(n-1).

Please refer to FIG. 4 , which shows a schematic diagram of an equivalent circuit of a flat panel display with touch function disclosed by another embodiment of the present invention. The flat-panel display 200 is the same as the flat-panel display 100 shown in FIG. The line is another gate line adjacent to the gate line electrically coupled to the pixel transistor 211 in the pixel area. For example, in the pixel area corresponding to the gate line Gn and the data line Dn, the pixel transistor 211 thereof is electrically coupled to the gate line Gn, and the gate 2211 of the read switch 221 of the photosensor 220 is electrically coupled to the The next gate line G(n+1) adjacent to the gate line Gn, and the source 2262 of the photosensitive switch 226 is electrically coupled to the gate line Gn.

In addition, the present invention also provides an operation method of an in-pixel light sensor, which can be used to drive the flat panel display as shown in FIG. 1 or FIG. 4 . Please refer to FIG. 5 , which shows a flow chart of the above operation method. The above operation method includes: adjusting the voltage difference between a specific gate line electrically coupled to a photosensitive switch and a power supply line to keep the photosensitive switch operating at a certain current state; transmitting a signal value to a readout a signal unit; and judging whether the light sensor is covered by an object.

Wherein, the step of adjusting the voltage difference between the specific gate line electrically coupled with the photosensitive switch and the power line to keep the photosensitive switch operating at a certain current state is carried out through the specific gate line and the power line A voltage value smaller than the threshold voltage of the light sensor is provided. In addition, the step of transmitting the signal value to the read driving unit includes turning on a read switch of the photosensor, and the above step further includes transferring the result obtained by charging/discharging a capacitor with the photosensitive switch to a read line. In the step of judging whether the photosensor is covered by the object, it is judged whether the photosensor is covered by the object according to the magnitude of the charging/discharging result.

In summary, the present invention makes the photosensitive switch electrically coupled to the power line and one of the gate lines of the display device, and keeps the photosensitive switch in an off state by adjusting the voltage difference between the gate line and the power line. In this way, the layout of some circuits can be omitted, and both the manufacturing cost and the aperture ratio can be improved.

To sum up, the flat panel display with touch function disclosed in the present invention uses the difference in the leakage current generated by the photosensitive switch of the photosensor to judge whether the photosensor is touched by a touch object so that the liquid crystal display has touch function. Moreover, the flat-panel display disclosed in the present invention uses its original gate lines as the gate lines, and provides voltages for the reading switch and the photosensitive switch of the photosensor respectively through two adjacent gate lines, especially The voltage is provided to the source of the photosensitive switch through the gate line. Therefore, the flat panel display with touch function does not need to set a large number of signal transmission lines to provide various signals to the photosensor, which saves The arrangement area of the signal transmission line is increased, the aperture ratio of the flat-panel display is increased, the brightness of the flat-panel display is improved, and the related power supply is reduced.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention.

Claims (16)

1. A substrate with a touch function, characterized in that, comprising: A plurality of gate lines are arranged on a substrate; At least one touch device is arranged on the substrate, and the touch device includes: a power line, arranged on the substrate; At least one reading line is arranged on the substrate and correspondingly intersects with the gate line; A light sensor, disposed near the intersection of a specific gate line among the gate lines and a specific read line among the read lines, the light sensor includes: a read switch, comprising: a first access port; a second access terminal electrically coupled to the specific read line; and a first control terminal electrically coupled to the specific gate line; and A photosensitive switch, comprising: a third channel end; a fourth via terminal electrically coupled to the first via terminal; and a second control terminal electrically coupled to the power line; as well as a read drive unit electrically coupled to the specific read line; Wherein, the third access end of the photosensitive switch is electrically coupled to a preset gate line except the specific gate line among the gate lines. 2. The substrate according to claim 1, wherein the predetermined gate line is a next gate line adjacent to the specific gate line. 3. The substrate according to claim 1, wherein the preset gate line is a previous gate line adjacent to the specific gate line. 4. The substrate according to claim 1, wherein the light sensor further comprises: a first capacitor electrically coupled between the third access end and the fourth access end of the photosensitive switch; and A second capacitor is electrically coupled between the second control end and the fourth access end of the photosensitive switch. 5. The substrate according to claim 1, wherein the read drive unit comprises: A charge amplifier, comprising: a first input terminal electrically coupled to the specific read line; a second input terminal electrically coupled to a reference power supply; and an output terminal, which obtains an output voltage according to the signals obtained from the first input terminal and the second input terminal; a capacitor electrically coupled between the first input terminal and the output terminal of the charge amplifier; and A switch element is electrically coupled between the first input terminal and the output terminal of the charge amplifier. 6. A liquid crystal display with a touch function, characterized in that it comprises: The substrate of claim 1; Another substrate is correspondingly arranged on the other side of the substrate; and A liquid crystal layer is arranged between the two substrates. 7. The liquid crystal display of claim 6, comprising: a plurality of data lines arranged on the substrate and intersecting with the gate lines so as to divide the liquid crystal display into a plurality of pixel regions; A plurality of pixel transistors are respectively arranged in the pixel area and electrically coupled to corresponding gate lines and data lines; A plurality of pixel electrodes are respectively disposed in the pixel area, and one of the pixel electrodes is electrically coupled to a corresponding one of the pixel transistors. 8. The liquid crystal display as claimed in claim 7, wherein The light sensor is disposed in one of the pixel areas. 9. The liquid crystal display as claimed in claim 6, wherein the preset gate line is a previous gate line adjacent to the specific gate line. 10 . The liquid crystal display as claimed in claim 8 , wherein the specific gate line is the same gate line as the gate line electrically coupled to the pixel transistor in the pixel region where the readout switch is located. 11 . 11. The liquid crystal display as claimed in claim 8, wherein the specific gate line is another adjacent gate line electrically coupled to the pixel transistor in the pixel region where the read switch is located. a gate line. 12. An operation method, characterized in that it is used to drive the substrate with touch function as claimed in claim 1, the operation method comprising: adjusting the voltage difference between the specific gate line and the power line to keep the photosensitive switch operating at a certain current state; sending a signal value to the read signal unit; and Determine whether the light sensor is covered by an object. 13. The operation method according to claim 12, characterized in that, adjusting the voltage difference between the specific gate line and the power line to keep the photosensitive switch operating at a certain current state, through the specific gate line And the power line provides a voltage value less than the threshold voltage of the light sensor. 14. The operation method according to claim 12, wherein transmitting the signal value to the read signal unit comprises turning on the read switch. 15 . The operation method according to claim 13 , wherein transmitting the signal value to the reading signal unit further comprises transmitting a result obtained by charging/discharging a capacitor by the photosensitive switch to a reading line. 16 . 16 . The operation method according to claim 15 , wherein judging whether the light sensor is covered by an object or not is determined by the size of the result of charging/discharging to determine whether the light sensor is covered by an object. 17 .

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