CN102207647A - Liquid crystal display with light-sensing input mechanism - Google Patents

Abstract

The present invention discloses a liquid crystal display with a light sensing input mechanism, which includes a gate line for transmitting a gate signal, a data line for transmitting a data signal, a pixel unit for outputting an image signal according to the gate signal and the data signal, an energy storage unit for storing a sensing voltage, a first light sensing unit, a second light sensing unit, and a readout unit. The first light sensing unit is used to generate a first photocurrent according to a first common voltage and an incident light signal. The second light sensing unit is used to generate a second photocurrent according to a second common voltage and an incident light signal. The difference current between the second photocurrent and the first photocurrent is used to adjust the sensing voltage, and the readout unit outputs a readout signal according to the sensing voltage and the gate signal.

Description

LCD Display with Light Sensing Input Mechanism

technical field

The invention relates to a liquid crystal display, in particular to a liquid crystal display with a light-sensing input mechanism.

Background technique

In recent years, electronic products with panel input mechanisms have become a popular product trend. Using input displays as the communication interface between users and electronic products allows users to directly control the operation of electronic products through the display instead of the keyboard. or mouse. The input mechanism of the input display is divided into light-sensing input mode and touch input mode. In the touch input mode, the display will be easily damaged due to frequent touches on the display. Therefore, the light-sensing input mode display can have a longer life. service life. Generally speaking, the photocurrent/bias voltage characteristic curve of the light-sensing transistor used in the light-sensing input mode display changes with the brightness of the incident light. Basically, when the bias voltage is fixed, the higher the brightness of the incident light, the greater the photocurrent, so the corresponding The operating characteristics of different photocurrents at different incident light luminances are used for input sensing. For example, the first photocurrent generated under the first incident light luminance can be used to represent the first input state, and the first photocurrent generated at a lower than the first incident light luminance The second photocurrent generated under the second incident light brightness can be used to represent the second input state, wherein the first photocurrent is greater than the preset threshold, and the second photocurrent is smaller than the preset threshold. However, the long-time bias/illumination operation will cause the shift of the photocurrent/bias characteristic curve, so the photocurrent corresponding to the same bias voltage and the same incident light brightness will increase with the long-term bias/illumination operation. bigger. That is to say, after a long time of bias/illumination operation, if the bias operating range is not large enough, the above-mentioned second photocurrent may be higher than the preset critical value due to the shift of the characteristic curve, so that misjudgment of the input state will occur , resulting in malfunction of the subsequent circuit.

Contents of the invention

According to an embodiment of the present invention, a liquid crystal display with a light-sensing input mechanism is disclosed, which includes a gate line for transmitting a gate signal, a data line for transmitting a data signal, and a line for storing an induced voltage. An energy storage unit, a pixel unit, a first photosensitive unit, a second photosensitive unit, and a readout unit. The pixel units electrically connected to the gate line and the data line are used to output image signals according to the gate signal and the data signal. The first light sensing unit electrically connected to the energy storage unit is used for generating a first photocurrent according to the first common voltage and the incident light signal. The second light sensing unit electrically connected to the first light sensing unit and the energy storage unit is used to generate a second photocurrent according to a second common voltage different from the first common voltage and an incident light signal, wherein the second photocurrent is the same as the first common voltage. A difference current of the photocurrent is used to adjust the induced voltage. The readout unit electrically connected to the energy storage unit and the gate line is used to output a readout signal according to the induced voltage and the gate signal.

Description of drawings

1 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of the relationship between the differential current Ipdif and the variation of the bias voltage Vgs when the liquid crystal display shown in FIG. 1 is in operation;

Fig. 3 is a schematic diagram of the work-related signal waveform of the liquid crystal display shown in Fig. 1, wherein the horizontal axis is the time axis;

4 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a second embodiment of the present invention;

Fig. 5 is a schematic diagram of the work-related signal waveform of the liquid crystal display shown in Fig. 4, wherein the horizontal axis is the time axis;

6 is a schematic diagram of a liquid crystal display with a photosensitive input mechanism according to a third embodiment of the present invention;

7 is a schematic diagram of a liquid crystal display with a photosensitive input mechanism according to a fourth embodiment of the present invention;

8 is a schematic diagram of a liquid crystal display with a photosensitive input mechanism according to a fifth embodiment of the present invention;

9 is a schematic diagram of a liquid crystal display with a photosensitive input mechanism according to a sixth embodiment of the present invention;

10 is a schematic diagram of a liquid crystal display with a photosensitive input mechanism according to a seventh embodiment of the present invention;

FIG. 11 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to an eighth embodiment of the present invention.

Among them, reference signs

100, 200, 300, 400, 500, 600, 700, 800 LCD display

101 Gate Line

102 Data cable

103 readout line

104 The first bias line

105 Second Bias Line

110 Optical sensor input device

120, 220, 420, 520, 620, 720, 820 The first light sensing unit

121, 221, 421, 521, 621, 721, 821 The first light-sensing transistor

129, 229, 429, 529, 629, 729, 829 The first color filter

130, 330, 430, 530, 630, 730, 830 Second light sensing unit

131, 331, 431, 531, 631, 731, 831 Second photosensitive transistor

139, 339, 439, 539, 639, 739, 839 Second color filter

140 Energy storage unit

141 Capacitance

150 readout unit

151 Transistor

180 Signal processing unit

190 Pixel Units

206, 406, 606, 806 Third bias line

333, 433, 533, 633, 733, 833 The third photosensitive transistor

523, 623, 723, 823 The fourth light sensing transistor

BXn+1 The first bias line

BYn+1 Second Bias Line

BZn+1 The third bias line

CAS_1, CAS_2, CBS_1, CBS_2 Relationship curve

DAn_m, DBn_m, DCn_m, DDn_m, DEn_m, DFn_m, light sensor input device

DGn_m, DHn_m,

GLn, GLn+1 Gate Lines

Ipdif differential current

Iph1 The first photocurrent

Iph2 Second photocurrent

Ith Critical Current

RLm readout line

SGn, SGn+1 Gate signal

Sro_m Readout signal

Ta1, Ta2, Ta3, Tb1, Tb2, Tb3 Time period

Va Induction voltage

Vc1 The first common voltage

Vc2 Second common voltage

Vc3 The third common voltage

Vgs, Vgs1, Vgs2, Vgs3, Vgs4 Bias voltage

Vout Output Voltage

Vst Initial Voltage

Detailed ways

Hereinafter, according to the liquid crystal display with light-sensing input mechanism of the present invention, specific embodiments will be described in detail with the accompanying drawings, but the provided embodiments are not intended to limit the scope of the present invention.

FIG. 1 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a first embodiment of the present invention. As shown in FIG. 1 , a liquid crystal display 100 includes a plurality of gate lines 101, a plurality of data lines 102, a plurality of readout lines 103, a plurality of first bias lines 104, a plurality of second bias lines 105, a plurality of A pixel unit 190 , a plurality of photosensitive input devices 110 , and a signal processing unit 180 . Each gate line 101 is used to transmit a corresponding gate signal. Each data line 102 is used to transmit a corresponding data signal. Each pixel unit 190 is used to perform a writing operation of a corresponding data signal according to a corresponding gate signal, so as to output a corresponding image signal. Each first bias line 104 is used to transmit the first common voltage Vc1. Each second bias line 105 is used to transmit the second common voltage Vc2. Each readout line 103 is electrically connected to a plurality of photosensitive input devices 110 for transmitting corresponding readout signals. The signal processing unit 180 electrically connected to the plurality of readout lines 103 is used to convert each readout signal into a corresponding output voltage Vout.

In the embodiment shown in FIG. 1 , each pixel unit 190 is adjacent to the light-sensing input device 110 . In another embodiment, the light-sensing input device 110 can be arranged at intervals between a plurality of gate lines 101, or at intervals of a plurality of data lines 102, that is, not every pixel unit 190 is adjacent to the light-sensing input device 110 . Similarly, the first bias lines 104 and the second bias lines 105 can be arranged correspondingly at intervals of a plurality of gate lines 101 , or the readout lines 103 can be arranged correspondingly at intervals of a plurality of data lines 102 . The coupling relation of each element and the operation principle of the circuit are described below according to the light-sensing input device DAn_m, and the rest of the light-sensing input devices 110 can be deduced in the same way.

The light-sensing input device DAn_m includes a first light-sensing unit 120 , a second light-sensing unit 130 , an energy storage unit 140 , and a readout unit 150 . The energy storage unit 140 is used for storing the induced voltage Va. The first photo-sensing unit 120 electrically connected to the energy storage unit 140, the gate line GLn+1 and the first bias line BXn+1 is used to generate the light according to the gate signal SGn+1, the first common voltage Vc1 and the incident light signal. A first photocurrent Iph1 is generated. The second photo-sensing unit 130 electrically connected to the second bias line BYn+1, the first photo-sensing unit 120 and the energy storage unit 140 is used for receiving the incident light signal according to the second common voltage Vc2 different from the first common voltage Vc1. The second photocurrent Iph2 is generated, and the difference current Ipdif between the second photocurrent Iph2 and the first photocurrent Iph1 is used to adjust the induced voltage Va. The readout unit 150 electrically connected to the energy storage unit 140 and the gate line GLn is used to output the readout signal Sro_m according to the induced voltage Va and the gate signal SGn.

In the embodiment shown in FIG. 1 , the first photo-sensing unit 120 includes a first photo-sensing transistor 121 and a first color filter 129, and the second photo-sensing unit 130 includes a second photo-sensing transistor 131 and a second color filter. 139 , the energy storage unit 140 includes a capacitor 141 , and the readout unit 150 includes a transistor 151 . The first photo-sensing transistor 121 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the gate signal SGn+1 , and a second terminal for receiving the first common voltage Vc1 . The first color filter 129 corresponding to the first photo-sensing transistor 121 is used to filter out the incident light component of the incident light signal falling in the first light wavelength range, that is, the photo-sensing wavelength band of the first photo-sensing unit 120 is the second A light wavelength range. The capacitor 141 is electrically connected between the first terminal and the second terminal of the first photo-sensing transistor 121 . The transistor 151 has a first terminal for receiving the induced voltage Va, a gate terminal for receiving the gate signal SGn, and a second terminal for outputting the readout signal Sro_m.

The second photosensitive transistor 131 includes a first terminal, a second terminal and a gate terminal, wherein the first terminal and the gate terminal are electrically connected to the capacitor 141 , and the second terminal is used to receive the second common voltage Vc2. The second color filter 139 corresponding to the second photo-sensing transistor 131 is used to filter out the incident light component of the incident light signal falling in the second light wavelength range, that is, the photo-sensing wavelength band of the second photo-sensing unit 130 is the first Two light wavelength ranges. The second optical wavelength range may or may not partially overlap the first optical wavelength range. In another embodiment, the first color filter 129 and the second color filter 139 can be omitted, and the first light sensing unit 120 and the second light sensing unit 130 have substantially the same light sensing wavelength band. In the operation of the liquid crystal display 100, since the deviation of the photocurrent/bias voltage characteristic curves of the first photo-sensing transistor 121 and the second photo-sensing transistor 131 can substantially compensate each other, the relational curve of the difference current Ipdif to the bias voltage Vgs Almost unaffected by long-term bias/light operation, it provides a highly reliable light-sensing input mechanism.

Figure 2 is a schematic diagram of the relationship between the differential current Ipdif and the variation of the bias voltage Vgs during the operation of the liquid crystal display shown in Figure 1, where the curve CBS_1 is used to show the difference corresponding to the height of the low incident light before long-term bias/illumination operation Value current Ipdif/bias voltage Vgs relationship, curve CBS_2 is used to display the difference current Ipdif/bias voltage Vgs relationship corresponding to high incident light height before long-term bias voltage/lighting operation, curve CAS_1 is used to display the long-term bias voltage/lighting operation The difference current Ipdif/bias voltage Vgs relationship corresponding to low incident light height after voltage/light operation, curve CAS_2 is used to show the difference current Ipdif/bias voltage corresponding to high incident light height after long time bias/light operation The bias voltage Vgs relationship, and the critical current Ith is used to determine the input state corresponding to the difference current Ipdif.

As shown in Figure 2, according to the relationship curves CBS_1 and CBS_2, the bias working range between Vgs1 and Vgs3 before long-time bias/lighting operation can be defined, and according to the relationship curves CAS_1 and CAS_2, the long-time bias working range can be defined. Bias working range between Vgs2 and Vgs4 after bias/illumination operation. As mentioned above, due to the offset compensation effect of the photocurrent/bias voltage characteristic curves of the first photo-sensing transistor 121 and the second photo-sensing transistor 131, the difference current Ipdif/bias voltage Vgs relationship curve after long-term bias/lighting operation Only a small amount of offset occurs, so the bias working range ΔVgs suitable for long-term bias/lighting operation is only slightly smaller than the bias working range before long-time bias/lighting operation. The difference between Vgs2 and Vgs1 is still It can provide a large enough bias working range ΔVgs to avoid misjudgment of the input state.

Please note that the offset compensation effect of the photocurrent/bias voltage characteristic curves of the first photo-sensing transistor 121 and the second photo-sensing transistor 131 is basically aimed at the condition that the incident light is background white light. If the user uses a light pen based on the first light wavelength range to perform light input operation, the light intensity of the incident light of the light pen after being filtered by the first color filter 129 is almost not attenuated, so the first light sensing unit 120 can sense The incident light of the light pen has almost no attenuation in intensity, and the light intensity of the incident light of the light pen after being filtered by the second color filter 139 is almost attenuated to zero, so the operation of the second photosensitive transistor 131 is hardly affected by the incident light of the light pen . That is, when the incident light of the light pen irradiates the light-sensing input device DAn_m, a relatively high differential current Ipdif can be generated accordingly, thereby providing high light-sensing sensitivity. From the above, it can be seen that the light-sensing input operation of the liquid crystal display 100 has both high reliability and high sensitivity.

FIG. 3 is a schematic diagram of working-related signal waveforms of the liquid crystal display shown in FIG. 1 , wherein the horizontal axis is the time axis. In FIG. 2 , the signals from top to bottom are gate signal SGn, gate signal SGn+1, induced voltage Va corresponding to low incident light brightness, and induced voltage Va corresponding to high incident light brightness. Referring to FIG. 3 and FIG. 1 , in the period Ta1 , the high potential voltage of the gate signal SGn+1 can turn on the first photo-sensing transistor 121 , thereby resetting the induced voltage Va to the initial voltage Vst. In the period Ta2, the low potential voltage of the gate signal SGn+1 can make the first photo-sensing transistor 121 enter the cut-off state. At this time, the first photo-sensing transistor 121 can sense the incident light signal to generate the first photocurrent Iph1, and the second The photo-sensing transistor 131 can sense the incident light signal to generate the second photo-current Iph2, and the difference current Ipdif between the first photo-current Iph1 and the second photo-current Iph2 is used to discharge the capacitor 141 to adjust the induced voltage Va. When the incident light signal only contains background white light (corresponding to low incident light brightness), due to the offset compensation effect of the photocurrent/bias characteristic curves of the first photo-sensing transistor 121 and the second photo-sensing transistor 131, whether or not after a long time Bias/illumination operation, as shown in FIG. 3 , the induced voltage Va corresponding to low incident light brightness only drops slightly according to the relatively low differential current Ipdif which is hardly affected by the operation time.

When the incident light signal includes the background white light and the incident light of the light pen, the second photocurrent Iph2 is hardly affected by the incident light of the light pen, while the first photocurrent Iph1 is significantly increased due to the incident light of the light pen, so the difference current Ipdif also increases significantly , at this time, as shown in FIG. 3 , the induced voltage Va corresponding to high incident light brightness will drop significantly according to the relatively high differential current Ipdif. During the period Ta3, the high potential voltage of the gate signal SGn can turn on the transistor 151 to output the read signal Sro_m, and the induced voltage Va will be pulled up during the read process.

FIG. 4 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a second embodiment of the present invention. As shown in FIG. 4, the liquid crystal display 200 is similar to the liquid crystal display 100 shown in FIG. Line 206, wherein the light-sensing input device DAn_m is replaced by the light-sensing input device DBn_m. Each third bias line 206 is used to transmit the third common voltage Vc3. The light-sensing input device DBn_m is similar to the light-sensing input device DAn_m, the main difference is that the first light-sensing unit 120 is replaced by the first light-sensing unit 220 . The first photo-sensing unit 220 includes a first photo-sensing transistor 221 and a first color filter 229 . The first photo-sensing transistor 221 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the third common voltage Vc3 , and a second terminal for receiving the first common voltage Vc1 . The first color filter 229 corresponding to the first photosensitive transistor 221 is used to filter out the incident light component of the incident light signal falling within the first light wavelength range. In one embodiment, the second common voltage Vc2 is greater than the first common voltage Vc1, and the first common voltage Vc1 is greater than the third common voltage Vc3, so that the first photo-sensing transistor 221 and the second photo-sensing transistor 131 are in operation. Both remain in the reverse biased state.

FIG. 5 is a schematic diagram of working-related signal waveforms of the liquid crystal display shown in FIG. 4 , wherein the horizontal axis is the time axis. In FIG. 5 , the signals from top to bottom are gate signal SGn, gate signal SGn+1, induced voltage Va corresponding to low incident light brightness, and induced voltage Va corresponding to high incident light brightness. Referring to FIG. 5 and FIG. 4, in the period Tb1, the high potential voltage of the gate signal SGn can turn on the transistor 151 to output the read signal Sro_m, and the induced voltage Va will be reset to the initial voltage during the read process. Vst. In the period Tb2, the low potential voltage of the gate signal SGn can make the transistor 151 enter the cut-off state, at this time, the first photo-sensing transistor 221 can sense the incident light signal to generate the first photo-current Iph1, and the second photo-sensing transistor 131 can sense The incident light signal generates the second photocurrent Iph2, and the difference current Ipdif between the first photocurrent Iph1 and the second photocurrent Iph2 is used to discharge the capacitor 141 to adjust the induced voltage Va. When the incident light signal only contains background white light, due to the offset compensation effect of the photocurrent/bias voltage characteristic curves of the first photo-sensing transistor 221 and the second photo-sensing transistor 131, regardless of whether it has been biased/illuminated for a long time, as shown in the figure As shown in FIG. 5 , the induced voltage Va corresponding to low incident light brightness only drops slightly according to the relatively low differential current Ipdif which is hardly affected by the operating time.

When the incident light signal includes the background white light and the incident light of the light pen, the second photocurrent Iph2 is hardly affected by the incident light of the light pen, while the first photocurrent Iph1 is significantly increased due to the incident light of the light pen, so the difference current Ipdif also increases significantly , at this time, as shown in FIG. 5 , the induced voltage Va corresponding to high incident light brightness will drop significantly according to the relatively high differential current Ipdif. During the period Tb3, the high potential voltage of the gate signal SGn can turn on the transistor 151 again to output the read signal Sro_m, and the induced voltage Va will be reset to the initial voltage Vst during the read process. Please note that the operation of the light-sensing input device DBn_m is not controlled by the gate signal SGn+1, and the reset operation of the initial voltage Vst is completed during the readout process, so there is no need for an additional reset-specific period for reset Starting voltage Vst. Basically, the light-sensing input mechanism of the liquid crystal display 200 is roughly similar to that of the liquid crystal display 100 shown in FIG. 1 , so its light-sensing input operation still has high reliability and high sensitivity.

FIG. 6 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a third embodiment of the present invention. As shown in FIG. 6 , the liquid crystal display 300 is similar to the liquid crystal display 100 shown in FIG. 1 , the main difference is that a plurality of light-sensing input devices 110 are replaced with a plurality of light-sensing input devices 310, wherein the light-sensing input device DAn_m is replaced by Light-sensing input device DCn_m. The light-sensing input device DCn_m is also similar to the light-sensing input device DAn_m, the main difference is that the second light-sensing unit 130 is replaced by the second light-sensing unit 330 . The second photo-sensing unit 330 includes a second photo-sensing transistor 331 , a third photo-sensing transistor 333 and a second color filter 339 . The second photo-sensing transistor 331 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the gate signal SGn+1 , and a second terminal electrically connected to the third photo-sensing transistor 333 . The third photosensitive transistor 333 has a first terminal electrically connected to the second terminal of the second photosensitive transistor 331, a gate terminal electrically connected to the first terminal of the second photosensitive transistor 331, and a gate terminal for receiving the second The second end of the common voltage Vc2. The second color filter 339 corresponding to the second photo-sensing transistor 331 and the third photo-sensing transistor 333 is used to filter out the incident light component of the incident light signal falling within the second light wavelength range. When the incident light signal only contains background white light, if the differential current Ipdif increases due to the deviation of the photocurrent/bias characteristic curve, the third photosensitive transistor 333 can increase its negative bias voltage due to the decrease of the induced voltage Va, thus The third photo-sensing transistor 333 will generate a higher second photo-current Iph2 to reduce the difference current Ipdif, so that a further compensation effect can be provided to make the operation of the photo-sensing input more reliable.

FIG. 7 is a schematic diagram of a liquid crystal display with light-sensing input mechanism according to a fourth embodiment of the present invention. As shown in FIG. 7, the liquid crystal display 400 is similar to the liquid crystal display 100 shown in FIG. Line 406, wherein the light-sensing input device DAn_m is replaced by the light-sensing input device DDn_m. Each third bias line 406 is used to transmit the third common voltage Vc3. The light-sensing input device DDn_m is similar to the light-sensing input device DAn_m, the main difference is that the first light-sensing unit 120 is replaced by the first light-sensing unit 420 , and the second light-sensing unit 130 is replaced by the second light-sensing unit 430 . The first photo-sensing unit 420 includes a first photo-sensing transistor 421 and a first color filter 429 . The second photo-sensing unit 430 includes a second photo-sensing transistor 431 , a third photo-sensing transistor 433 and a second color filter 439 .

The first photo-sensing transistor 421 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the third common voltage Vc3 , and a second terminal for receiving the first common voltage Vc1 . The first color filter 429 corresponding to the first photosensitive transistor 421 is used to filter out the incident light component of the incident light signal falling within the first light wavelength range. The second photo-sensing transistor 431 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the third common voltage Vc3 , and a second terminal electrically connected to the third photo-sensing transistor 433 . The third photo-sensing transistor 433 has a first terminal electrically connected to the second terminal of the second photo-sensing transistor 431, a gate terminal electrically connected to the first terminal of the second photo-sensing transistor 431, and a gate terminal for receiving the second The second end of the common voltage Vc2. The second color filter 439 corresponding to the second photo-sensing transistor 431 and the third photo-sensing transistor 433 is used to filter out the incident light component of the incident light signal falling within the second light wavelength range. In one embodiment, the second common voltage Vc2 is greater than the first common voltage Vc1, and the first common voltage Vc1 is greater than the third common voltage Vc3, so that the first light-sensing transistor 421, the second light-sensing transistor 431 and the third The photo-sensing transistor 433 is kept in a reverse-biased state during operation. The operating principle of the light-sensing input of the liquid crystal display 400 can be deduced according to the above-mentioned operating principle of the light-sensing input of the liquid crystal display 200 in FIG. 4 and the compensation effect of the third light-sensing transistor 333 in FIG.

FIG. 8 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a fifth embodiment of the present invention. As shown in FIG. 8 , the liquid crystal display 500 is similar to the liquid crystal display 100 shown in FIG. 1 , the main difference is that the multiple light-sensing input devices 110 are replaced by multiple light-sensing input devices 510, wherein the light-sensing input device DAn_m is replaced by Optical sensor input device DEn_m. The light-sensing input device DEn_m is also similar to the light-sensing input device DAn_m, the main difference is that the first light-sensing unit 120 is replaced by the first light-sensing unit 520 , and the second light-sensing unit 130 is replaced by the second light-sensing unit 530 . The first photo-sensing unit 520 includes a first photo-sensing transistor 521 , a fourth photo-sensing transistor 523 and a first color filter 529 . The second photo-sensing unit 530 includes a second photo-sensing transistor 531 , a third photo-sensing transistor 533 and a second color filter 539 .

The first photo-sensing transistor 521 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the gate signal SGn+1 , and a second terminal electrically connected to the fourth photo-sensing transistor 523 . The fourth photo-sensing transistor 523 has a first terminal electrically connected to the second terminal of the first photo-sensing transistor 521, a gate terminal for receiving the first common voltage Vc1, and a first terminal for receiving the first common voltage Vc1. Two ends. The first color filter 529 corresponding to the first photo-sensing transistor 521 and the fourth photo-sensing transistor 523 is used to filter out the incident light component of the incident light signal falling within the first light wavelength range. The second photo-sensing transistor 531 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the gate signal SGn+1, and a second terminal electrically connected to the third photo-sensing transistor 533 . The third photosensitive transistor 533 has a first terminal electrically connected to the second terminal of the second photosensitive transistor 531, a gate terminal electrically connected to the first terminal of the second photosensitive transistor 531, and a gate terminal for receiving the second The second end of the common voltage Vc2. The second color filter 539 corresponding to the second photo-sensing transistor 531 and the third photo-sensing transistor 533 is used to filter out the incident light component of the incident light signal falling within the second light wavelength range. When the incident light signal only contains background white light, if the differential current Ipdif increases due to the deviation of the photocurrent/bias characteristic curve, the fourth photosensitive transistor 523 will reduce the first photocurrent Iph1 according to a smaller voltage drop, Furthermore, the difference current Ipdif is reduced, so that a further compensation effect can be provided to make the operation of the light sensing input more reliable.

FIG. 9 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a sixth embodiment of the present invention. As shown in FIG. 9, the liquid crystal display 600 is similar to the liquid crystal display 100 shown in FIG. Line 606, wherein the light-sensing input device DAn_m is replaced by the light-sensing input device DFn_m. Each third bias line 606 is used to transmit the third common voltage Vc3. The light-sensing input device DFn_m is also similar to the light-sensing input device DAn_m, the main difference is that the first light-sensing unit 120 is replaced by the first light-sensing unit 620 , and the second light-sensing unit 130 is replaced by the second light-sensing unit 630 . The first photo-sensing unit 620 includes a first photo-sensing transistor 621 , a fourth photo-sensing transistor 623 and a first color filter 629 . The second photo-sensing unit 630 includes a second photo-sensing transistor 631 , a third photo-sensing transistor 633 and a second color filter 639 .

The first photo-sensing transistor 621 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the third common voltage Vc3 , and a second terminal electrically connected to the fourth photo-sensing transistor 623 . The fourth photo-sensing transistor 623 has a first terminal electrically connected to the second terminal of the first photo-sensing transistor 621, a gate terminal for receiving the first common voltage Vc1, and a first terminal for receiving the first common voltage Vc1. Two ends. The first color filter 629 corresponding to the first photo-sensing transistor 621 and the fourth photo-sensing transistor 623 is used to filter out the incident light component of the incident light signal falling within the first light wavelength range. The second photo-sensing transistor 631 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the third common voltage Vc3 , and a second terminal electrically connected to the third photo-sensing transistor 633 . The third photosensitive transistor 633 has a first terminal electrically connected to the second terminal of the second photosensitive transistor 631, a gate terminal electrically connected to the first terminal of the second photosensitive transistor 631, and a gate terminal for receiving the second The second end of the common voltage Vc2. The second color filter 639 corresponding to the second photo-sensing transistor 631 and the third photo-sensing transistor 633 is used to filter out the incident light component of the incident light signal falling within the second light wavelength range. The light-sensing input operation principle of the liquid crystal display 600 can be analogized according to the above-mentioned light-sensing input operation principle of the liquid crystal display 200 in FIG. 4 and the compensation effect of the third light-sensing transistor 333 in FIG. No longer.

FIG. 10 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to a seventh embodiment of the present invention. As shown in FIG. 10 , the liquid crystal display 700 is similar to the liquid crystal display 100 shown in FIG. 1 , the main difference is that a plurality of light-sensing input devices 110 are replaced with a plurality of light-sensing input devices 710, wherein the light-sensing input device DAn_m is replaced by Optical sensor input device DGn_m. The light-sensing input device DGn_m is also similar to the light-sensing input device DAn_m, the main difference is that the first light-sensing unit 120 is replaced by the first light-sensing unit 720 , and the second light-sensing unit 130 is replaced by the second light-sensing unit 730 . The first photo-sensing unit 720 includes a first photo-sensing transistor 721 , a fourth photo-sensing transistor 723 and a first color filter 729 . The second photo-sensing unit 730 includes a second photo-sensing transistor 731 , a third photo-sensing transistor 733 and a second color filter 739 .

The first photo-sensing transistor 721 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the gate signal SGn+1 , and a second terminal electrically connected to the fourth photo-sensing transistor 723 . The fourth photo-sensing transistor 723 has a first terminal electrically connected to the second terminal of the first photo-sensing transistor 721, a gate terminal for receiving the gate signal SGn+1, and a terminal for receiving the first common voltage Vc1. second end. The first color filter 729 corresponding to the first photo-sensing transistor 721 and the fourth photo-sensing transistor 723 is used to filter out the incident light component of the incident light signal falling within the first light wavelength range. The second photo-sensing transistor 731 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the gate signal SGn+1 , and a second terminal electrically connected to the third photo-sensing transistor 733 . The third photosensitive transistor 733 has a first terminal electrically connected to the second terminal of the second photosensitive transistor 731, a gate terminal electrically connected to the first terminal of the second photosensitive transistor 731, and a gate terminal for receiving the second The second end of the common voltage Vc2. The second color filter 739 corresponding to the second photo-sensing transistor 731 and the third photo-sensing transistor 733 is used to filter out the incident light component of the incident light signal falling within the second light wavelength range. When the incident light signal only contains background white light, if the difference current Ipdif increases due to the deviation of the photocurrent/bias characteristic curve, the fourth photosensitive transistor 723 will reduce the first photocurrent Iph1 according to a smaller voltage drop, Furthermore, the difference current Ipdif is reduced, so that a further compensation effect can be provided to make the operation of the light sensing input more reliable.

FIG. 11 is a schematic diagram of a liquid crystal display with a light-sensing input mechanism according to an eighth embodiment of the present invention. As shown in FIG. 11, the liquid crystal display 800 is similar to the liquid crystal display 100 shown in FIG. Line 806, wherein the light-sensing input device DAn_m is replaced by the light-sensing input device DHn_m. Each third bias line 806 is used to transmit the third common voltage Vc3. The light-sensing input device DHn_m is also similar to the light-sensing input device DAn_m, the main difference is that the first light-sensing unit 120 is replaced by the first light-sensing unit 820 , and the second light-sensing unit 130 is replaced by the second light-sensing unit 830 . The first photo-sensing unit 820 includes a first photo-sensing transistor 821 , a fourth photo-sensing transistor 823 and a first color filter 829 . The second photo-sensing unit 830 includes a second photo-sensing transistor 831 , a third photo-sensing transistor 833 and a second color filter 839 .

The first photo-sensing transistor 821 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the third common voltage Vc3 , and a second terminal electrically connected to the fourth photo-sensing transistor 823 . The fourth photo-sensing transistor 823 has a first end electrically connected to the second end of the first photo-sensing transistor 821, a gate end for receiving the third common voltage Vc3, and a first end for receiving the first common voltage Vc1. Two ends. The first color filter 829 corresponding to the first photo-sensing transistor 821 and the fourth photo-sensing transistor 823 is used to filter out the incident light component of the incident light signal falling within the first light wavelength range. The second photo-sensing transistor 831 has a first terminal electrically connected to the capacitor 141 , a gate terminal for receiving the third common voltage Vc3 , and a second terminal electrically connected to the third photo-sensing transistor 833 . The third photosensitive transistor 833 has a first terminal electrically connected to the second terminal of the second photosensitive transistor 831, a gate terminal electrically connected to the first terminal of the second photosensitive transistor 831, and a gate terminal for receiving the second The second end of the common voltage Vc2. The second color filter 839 corresponding to the second photo-sensing transistor 831 and the third photo-sensing transistor 833 is used to filter out the incident light component of the incident light signal falling within the second light wavelength range. The light-sensing input operation principle of the liquid crystal display 800 can be analogized according to the above-mentioned light-sensing input operation principle of the liquid crystal display 200 in FIG. 4 and the compensation effect of the third light-sensing transistor 333 in FIG. No longer.

To sum up, in the operation of the liquid crystal display with light-sensing input mechanism of the present invention, through the offset compensation effect of the photocurrent/bias characteristic curve of the first photo-sensing transistor and the second photo-sensing transistor, the working range of the bias voltage is After a long time of bias/illumination operation, it is only slightly reduced, so it can still provide a large enough bias operating range to avoid misjudgment of input status. In addition, through the operation of the first color filter and the second color filter, high light sensing sensitivity can be provided. That is, the light-sensing input operation of the liquid crystal display of the present invention has both high reliability and high sensitivity.

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 (24)

1. the LCD of a tool photoinduction input mechanism is characterized in that it comprises:

One first grid polar curve is used for transmitting a first grid signal;

One data line is used for transmitting a data-signal;

One pixel cell is electrically connected on this first grid polar curve and this data line, and this pixel cell is used for according to this first grid signal and this data-signal to export a signal of video signal;

One energy-storage units is used for storing an induced voltage;

One first photoinduction unit is electrically connected on this energy-storage units, and this first photoinduction unit is used for according to one first common voltage and an incident optical signal to produce one first photocurrent;

One second photoinduction unit, be electrically connected on this first photoinduction unit and this energy-storage units, this second photoinduction unit is used for differing from second common voltage of this first common voltage and this incident optical signal to produce one second photocurrent according to one, and wherein a difference electric current of this second photocurrent and this first photocurrent is in order to adjust this induced voltage; And

One sensing element is electrically connected on this energy-storage units and this first grid polar curve, and this sensing element is used for according to this induced voltage and this first grid signal to export a read output signal.

2. LCD according to claim 1 is characterized in that, wherein this first photoinduction unit comprises:

One first photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and second end that is used for receiving this first common voltage.

3. LCD according to claim 1 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, and wherein this first photoinduction unit comprises:

One first photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and second end that is used for receiving this first common voltage.

4. LCD according to claim 1 is characterized in that, wherein this first photoinduction unit comprises:

One first photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and one second end; And

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving this first common voltage, and second end that is used for receiving this first common voltage.

5. LCD according to claim 1 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, and wherein this first photoinduction unit comprises:

One first photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and one second end; And

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving this first common voltage, and second end that is used for receiving this first common voltage.

6. LCD according to claim 1 is characterized in that, wherein this first photoinduction unit comprises:

One first photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and one second end; And

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving the 3rd common voltage, and second end that is used for receiving this first common voltage.

7. LCD according to claim 1 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, and wherein this first photoinduction unit comprises:

One first photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and one second end; And

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving this second grid signal, and second end that is used for receiving this first common voltage.

8. LCD according to claim 1 is characterized in that, wherein this second photoinduction unit comprises:

One second photoinduction transistor has second end, an and gate terminal that is electrically connected on this first end that first end, that is electrically connected on this energy-storage units is used for receiving this second common voltage.

9. LCD according to claim 1 is characterized in that, wherein this second photoinduction unit comprises:

One second photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and one second end; And

One the 3rd photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this second photoinduction is electrically connected on transistorized first end of this second photoinduction, and second end that is used for receiving this second common voltage.

10. LCD according to claim 1 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, and wherein this second photoinduction unit comprises:

One second photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and one second end; And

One the 3rd photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this second photoinduction is electrically connected on transistorized first end of this second photoinduction, and second end that is used for receiving this second common voltage.

11. LCD according to claim 1 is characterized in that, wherein this energy-storage units comprises an electric capacity that is electrically connected on this first photoinduction unit, this second photoinduction unit and this sensing element.

12. LCD according to claim 1 is characterized in that, wherein this sensing element comprises:

One transistor has gate terminal that first end, that is used for receiving this induced voltage is used for receiving this first grid signal, and second end that is used for exporting this read output signal.

13. LCD according to claim 1 is characterized in that, wherein:

The light sensing wave band of this first photoinduction unit is one first optical wavelength range; And

The light sensing wave band of this second photoinduction unit is one to differ from second optical wavelength range of this first optical wavelength range.

14. LCD according to claim 13 is characterized in that, wherein this not overlapping or this first optical wavelength range of overlapping of second optical wavelength range system.

15. LCD according to claim 13 is characterized in that, wherein this first photoinduction unit comprises:

One first photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and second end that is used for receiving this first common voltage; And

One corresponding to transistorized first colored filter of this first photoinduction, is used for leaching the incident light component that falls within this first optical wavelength range of this incident optical signal.

16. LCD according to claim 13 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, wherein this first photoinduction unit comprises:

One first photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and second end that is used for receiving this first common voltage; And

One corresponding to transistorized first colored filter of this first photoinduction, is used for leaching the incident light component that falls within this first optical wavelength range of this incident optical signal.

17. LCD according to claim 13 is characterized in that, wherein this first photoinduction unit comprises:

One first photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and one second end;

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving this first common voltage, and second end that is used for receiving this first common voltage; And

One corresponding to transistorized first colored filter of this first photoinduction transistor AND gate the 4th photoinduction, is used for leaching the incident light component that falls within this first optical wavelength range of this incident optical signal.

18. LCD according to claim 13 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, wherein this first photoinduction unit comprises:

One first photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and one second end;

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving this first common voltage, and second end that is used for receiving this first common voltage; And

One corresponding to transistorized first colored filter of this first photoinduction transistor AND gate the 4th photoinduction, is used for leaching the incident light component that falls within this first optical wavelength range of this incident optical signal.

19. LCD according to claim 13 is characterized in that, wherein this first photoinduction unit comprises:

One first photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and one second end;

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving the 3rd common voltage, and second end that is used for receiving this first common voltage; And

One corresponding to transistorized first colored filter of this first photoinduction transistor AND gate the 4th photoinduction, is used for leaching the incident light component that falls within this first optical wavelength range of this incident optical signal.

20. LCD according to claim 13 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, wherein this first photoinduction unit comprises:

One first photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and one second end;

One the 4th photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this first photoinduction is used for receiving this second grid signal, and second end that is used for receiving this first common voltage; And

One corresponding to transistorized first colored filter of this first photoinduction transistor AND gate the 4th photoinduction, is used for leaching the incident light component that falls within this first optical wavelength range of this incident optical signal.

21. LCD according to claim 13 is characterized in that, wherein this second photoinduction unit comprises:

One second photoinduction transistor has second end, an and gate terminal that is electrically connected on this first end that first end, that is electrically connected on this energy-storage units is used for receiving this second common voltage; And

One corresponding to transistorized second colored filter of this second photoinduction, is used for leaching the incident light component that falls within this second optical wavelength range of this incident optical signal.

22. LCD according to claim 13 is characterized in that, wherein this second photoinduction unit comprises:

One second photoinduction transistor has first end, that is electrically connected on this energy-storage units and is used for receiving a gate terminal that differs from the 3rd common voltage of this first and second common voltage, and one second end;

One the 3rd photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this second photoinduction is electrically connected on transistorized first end of this second photoinduction, and second end that is used for receiving this second common voltage; And

One corresponding to transistorized second colored filter of this second photoinduction transistor AND gate the 3rd photoinduction, is used for leaching the incident light component that falls within this second optical wavelength range of this incident optical signal.

23. LCD according to claim 13 is characterized in that, also comprises a second grid line that is used for transmitting a second grid signal, wherein this second photoinduction unit comprises:

One second photoinduction transistor has gate terminal that first end, that is electrically connected on this energy-storage units is used for receiving this second grid signal, and one second end;

One the 3rd photoinduction transistor has gate terminal that first end, that is electrically connected on transistorized second end of this second photoinduction is electrically connected on transistorized first end of this second photoinduction, and second end that is used for receiving this second common voltage; And

One corresponding to transistorized second colored filter of this second photoinduction transistor AND gate the 3rd photoinduction, is used for leaching the incident light component that falls within this second optical wavelength range of this incident optical signal.

24. LCD according to claim 1 is characterized in that, also comprises:

One sense wire is electrically connected on this sensing element, and this is read linear system and is used for transmitting this read output signal; And

One signal processing unit is electrically connected on this sense wire, and this signal processing unit system is used for this read output signal is converted to an output voltage.

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