CN111459341B - Light sensing circuit, driving method of light sensing circuit and display panel - Google Patents
Light sensing circuit, driving method of light sensing circuit and display panel Download PDFInfo
- Publication number
- CN111459341B CN111459341B CN202010123056.1A CN202010123056A CN111459341B CN 111459341 B CN111459341 B CN 111459341B CN 202010123056 A CN202010123056 A CN 202010123056A CN 111459341 B CN111459341 B CN 111459341B
- Authority
- CN
- China
- Prior art keywords
- circuit
- sensing
- electrically connected
- node
- sensing circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Human Computer Interaction (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Spectrometry And Color Measurement (AREA)
- Liquid Crystal Display Device Control (AREA)
Abstract
A light sensing circuit, a driving method of the light sensing circuit and a display panel, wherein the light sensing circuit comprises: the sensing circuit, the compensating circuit and the sampling circuit. The sensing circuit is electrically coupled to the compensation circuit and the sampling circuit. The sensing circuit is used for receiving a first control signal, and outputting a first sensing signal along a first current path when receiving first color light. The compensation circuit is used for receiving the low voltage, and when the sensing circuit receives the first color light, the compensation circuit is used for maintaining the second current path and the third current path at the low voltage. The sampling circuit is used for receiving the first sensing signal and outputting a sampling signal.
Description
Technical Field
The present disclosure relates to a light sensing circuit, a driving method of the light sensing circuit, and a display panel, and more particularly, to a light sensing circuit for simultaneously detecting red, green, and blue light sources, a driving method of the light sensing circuit, and a display panel.
Background
The optical sensing circuit can be used for an optical touch device, and can achieve the effect of sensing specific chromatic light by matching with the optical filtering element through the characteristic that the amorphous silicon thin film transistor element generates leakage current due to illumination. However, if light of different colors is to be detected simultaneously, light sensing circuits for the different colors are required, respectively, thereby increasing the complexity of the circuits and affecting the aperture ratio of the pixel circuits. Therefore, a light sensing circuit capable of sensing different colors of light simultaneously is needed.
Disclosure of Invention
A first embodiment of the present disclosure provides a light sensing circuit, including: the sensing circuit, the compensating circuit and the sampling circuit. The sensing circuit is electrically coupled to the compensation circuit and the sampling circuit. The sensing circuit is used for receiving a first control signal, and outputting a first sensing signal along a first current path when receiving first color light; when receiving the second color light, the sensing circuit is used for outputting a second sensing signal along a second current path; when receiving the third color light, the sensing circuit is used for outputting a third sensing signal along a third current path. The compensation circuit is used for receiving low voltage, and when the sensing circuit receives the first color light, the compensation circuit is used for maintaining the second current path and the third current path at the low voltage; when the sensing circuit receives the second color light, the compensation circuit is used for maintaining the first current path and the third current path at low voltage; when the sensing circuit receives the third color light, the compensation circuit is used for maintaining the first current path and the second current path at a low voltage. The sampling circuit is used for receiving the first sensing signal, the second sensing signal and the third sensing signal and outputting a sampling signal.
A second embodiment of the present disclosure provides a driving method of a light sensing circuit, including: when the first color light is received, the sensing circuit is used for outputting a first sensing signal along a first current path according to a first control signal, and the compensation circuit is used for maintaining the second current path and a third current path at low voltage; when receiving the second color light, the sensing circuit outputs a second sensing signal along a second current path according to the first control signal, and the compensation circuit is used for maintaining the first current path and the third current path at a low voltage; and when the third color light is received, the sensing circuit is used for outputting a third sensing signal along a third current path according to the first control signal, and the compensation circuit is used for maintaining the first current path and the second current path at a low voltage.
A third embodiment of the present disclosure is to provide a display panel including: the liquid crystal display device comprises a source electrode driving circuit, a gate electrode driving circuit, a plurality of pixel circuits, a control circuit and a light sensing circuit. The source electrode driving circuit is electrically connected to the plurality of data lines and is used for providing data voltages. The gate driving circuit is electrically connected to the plurality of gate lines for providing gate driving signals. The pixel circuits are electrically connected to the data lines and the gate lines for receiving the data voltages. The control circuit is used for providing a first control signal. The light sensing circuit is electrically connected to the control circuit. The light sensing circuit comprises: the sensing circuit, the compensating circuit and the sampling circuit. The sensing circuit is used for receiving the first control signal and outputting a sensing signal according to the received chromatic light. The compensation circuit is electrically connected with the sensing circuit and is used for receiving the low voltage and maintaining the voltage of the sensing circuit according to the received chromatic light. The sampling circuit is electrically connected with the sensing circuit and the grid driving circuit and is used for receiving the sensing signal and outputting the sampling signal to the source driver.
The invention provides a light sensing circuit, a driving method of the light sensing circuit and a display panel, which mainly provide the light sensing circuit capable of detecting different color lights at the same time.
Drawings
The foregoing and other objects, features, advantages and embodiments of the disclosure will be apparent from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a circuit block diagram of a display panel according to an embodiment of the present disclosure;
FIG. 2 is a circuit block diagram of a light sensing circuit according to an embodiment of the present disclosure;
FIG. 3A is a circuit diagram of a photo-sensing circuit according to an embodiment of the disclosure;
FIG. 3B is a circuit diagram of a photo-sensing circuit according to an embodiment of the disclosure;
FIG. 4A is a flow chart of a driving method of a photo sensing circuit according to an embodiment of the disclosure;
FIG. 4B is a flow chart of a driving method of the photo sensing circuit according to an embodiment of the disclosure;
FIG. 5A is a timing diagram illustrating operation of a photo-sensing circuit according to one embodiment of the disclosure;
FIG. 5B is a timing diagram illustrating operation of the photo-sensing circuit according to one embodiment of the disclosure;
FIG. 6A is a schematic diagram illustrating the operation of the photo-sensing circuit during a sensing phase according to one embodiment of the disclosure;
FIG. 6B is a schematic diagram illustrating the operation of the photo-sensing circuit during a sensing phase according to one embodiment of the disclosure;
FIG. 6C is a schematic diagram illustrating the operation of the photo-sensing circuit during a sensing phase according to one embodiment of the disclosure;
FIG. 7A is a partial schematic view of a display panel shown according to some embodiments of the present disclosure;
FIG. 7B is a partial schematic view of a display panel shown according to some embodiments of the present disclosure; and
fig. 7C is a partial schematic view of a display panel shown according to some embodiments of the present disclosure.
Reference numerals illustrate:
100: display panel
110: source electrode driving circuit
120: gate driving circuit
130: pixel circuit
130_1 to 130_6: sub-pixel circuit
140: control circuit
150: photo sensing circuit
151: sensing circuit
152: compensation circuit
153: sampling circuit
R, G, B: node
DL: data line
GL: gate line
S (n), G1 (n), G2 (n), G3 (n): control signal
CSr, CSg, CSb: capacitance device
SR, SG, SB: sensing signal
VL: low voltage
VH: high voltage
TP1, TP2, TP3, TP4, TP5, TP6: photosensitive element
T1, T2, T3: switch
I1, I2, I3, I4, I5, I6: current path
OUT, OUT1, OUT2, OUT3: an output terminal
VGL: disabling level
VGH: enable level
CFr, CFg, CFb: optical filter element
X: direction of
P1, P2, P3: stage(s)
710: display area
720: sensing area
400: driving method of light sensing circuit
S410 to S430a, S430b: step (a)
Detailed Description
Embodiments of the present invention will be described below with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or similar elements or method flows.
Please refer to fig. 1. Fig. 1 is a circuit block diagram of a display panel 100 according to an embodiment of the present disclosure. As shown in fig. 1, the display panel 100 includes a source driving circuit 110, a gate driving circuit 120, a plurality of pixel circuits 130, a control circuit 140, and a photo sensing circuit 150. The source driving circuit 110 is electrically connected to the plurality of data lines DL for providing data voltages. The gate driving circuit 120 is electrically connected to the plurality of gate lines GL for providing gate driving signals. The pixel circuit 130 is electrically connected to the data line DL and the gate line GL for receiving the data voltage. The control circuit 140 is used for providing a first control signal.
In view of the above, please refer to fig. 1 and 2. Fig. 2 is a circuit block diagram of a photo-sensing circuit 150 according to an embodiment of the present disclosure. As shown in fig. 2, the light sensing circuit 150 includes a sensing circuit 151 for receiving a first control signal S (n) and a low voltage VL and outputting a sensing signal according to the received color light. The compensation circuit 152 is electrically connected to the sensing circuit 151, and is configured to receive the low voltage VL and maintain the voltage of the sensing circuit 151 according to the received color light. The sampling circuit 153 is electrically connected to the sensing circuit 151 and the control circuit 140, and is configured to receive the sensing signal and output a sampling signal to the control circuit 140.
In detail, when the first color light is received, the sensing circuit 151 is configured to output the first sensing signal SR along the first current path I1, and the compensating circuit 152 is configured to maintain the second current path I2 and the third current path I3 at the low voltage VL. When receiving the second color light, the sensing circuit 151 is configured to output a second sensing signal SG along the second current path I2, and the compensation circuit 152 is configured to maintain the first current path I1 and the third current path I3 at the low voltage VL. When receiving the third color light, the sensing circuit 151 is configured to output a third sensing signal SB along the third current path I3, and the compensation circuit 152 is configured to maintain the first current path I1 and the second current path I2 at the low voltage VL. The sampling circuit 153 is configured to receive the first sensing signal SR, the second sensing signal SG and the third sensing signal SB and output a sampling signal.
With further reference to fig. 3A, fig. 3A is a circuit diagram of a photo-sensing circuit 150 according to an embodiment of the present disclosure. As shown in fig. 3A, the photo sensing circuit 150 includes a sensing circuit 151, a compensating circuit 152, and a sampling circuit 153. The compensation circuit 152 includes a photo-sensing element TP1, a photo-sensing element TP2, and a photo-sensing element TP3. The first end of the photo-sensing element TP1 is electrically connected to the control end of the photo-sensing element TP3, and the second end of the photo-sensing element TP1 is configured to receive the low voltage VL. The first end of the photo-sensing element TP2 is electrically connected to the control end of the photo-sensing element TP1, and the second end of the photo-sensing element TP2 is used for receiving the low voltage VL. The first end of the photo-sensing element TP3 is electrically connected to the control end of the photo-sensing element TP2, and the second end of the photo-sensing element TP3 is configured to receive the low voltage VL.
As shown in fig. 3A, the sensing circuit 151 includes a photosensitive element TP4, a photosensitive element TP5, and a photosensitive element TP6. The first end of the photo-sensing element TP4 is electrically connected to the node R, the second end of the photo-sensing element TP4 is configured to receive the first control signal S (n), and the control end of the photo-sensing element TP4 is electrically connected to the control end of the photo-sensing element TP1 and the first end of the photo-sensing element TP 2. The first end of the photo-sensing element TP5 is electrically connected to the node G, the second end of the photo-sensing element TP5 is configured to receive the first control signal S (n), and the control end of the photo-sensing element TP5 is electrically connected to the control end of the photo-sensing element TP2 and the first end of the photo-sensing element TP3. The first end of the photo-sensing element TP6 is electrically connected to the node B, the second end of the photo-sensing element TP6 is configured to receive the first control signal S (n), and the control end of the photo-sensing element TP6 is electrically connected to the control end of the photo-sensing element TP3 and the first end of the photo-sensing element TP 1.
As mentioned above, the sensing circuit 151 further includes a capacitor CSr, a capacitor CSg, and a capacitor CSb. The first end of the capacitor CSr is electrically connected to the node R, and the second end of the capacitor CSr is configured to receive the low voltage VL. The first terminal of the capacitor CSg is electrically connected to the node G, and the second terminal of the capacitor CSg is for receiving the low voltage VL. The first end of the capacitor CSb is electrically connected to the node B, and the second end of the capacitor CSb is configured to receive the low voltage VL.
As described above, the sampling circuit 153 includes the switch T1, the switch T2, and the switch T3. The first end of the switch T1 is electrically connected to the node R, the second end of the switch T1 is electrically connected to the output terminal OUT1, and the control end of the switch T1 is configured to receive the second control signal G (n). The first end of the switch T2 is electrically connected to the node G, the second end of the switch T2 is electrically connected to the output terminal OUT2, and the control end of the switch T2 is configured to receive the second control signal G (n). The first end of the switch T3 is electrically connected to the node B, the second end of the switch T3 is electrically connected to the output terminal OUT3, and the control end of the switch T3 is configured to receive the second control signal G (n). The output terminal OUT1, the output terminal OUT2, and the output terminal OUT3 are further connected to the control circuit 140 (not shown in fig. 3A).
In another embodiment, the output terminals OUT1, OUT2 and OUT3 can be connected to a reading Circuit (Readout Circuit) for reading the sensing result of the photo-sensing Circuit 150.
As mentioned above, the light sensing elements TP1 and TP5 are covered by the filter element CFg, and the filter element CFg is configured to pass the first color light, for example, the first color light can be implemented as red light, and the wavelength range thereof is about 620-750 nanometers (nm). By this arrangement, red light passes through the filter element CFr more easily than other colored light outside this wavelength range.
As mentioned above, the light sensing elements TP2 and TP6 are covered by the filter element CFb, which is used to pass the second color light, for example, the second color light can be implemented as green light, and the wavelength range of the second color light is about 495-570 nanometers (nm). By this arrangement, green light passes through the filter element CFg more easily than other colors outside this wavelength range.
As mentioned above, the light sensing elements TP3 and TP4 are covered by the filter element CFr, and the filter element CFr is configured to pass the third color light, for example, the third color light can be implemented as blue light, and the wavelength range thereof is about 450-495 nanometers (nm). By this arrangement, blue light passes through the filter element CFb more easily than other colors outside this wavelength range.
In various embodiments, the relative arrangement of the first color light to the third color light can be changed according to practical applications, that is, the color distribution manner of the first color light to the third color light is not limited to green, blue and red. The embodiments of the filter CFg, the filter CFb, and the filter CFr are also adjusted accordingly to the color distribution of the first to third colors.
In another embodiment, please refer to fig. 3B, fig. 3B is a circuit diagram of the photo sensing circuit 150 according to an embodiment of the disclosure. The embodiment shown in fig. 3B is different from the embodiment shown in fig. 3A in that the second terminal of the switch T1, the second terminal of the switch T2, and the second terminal of the switch T3 of the sampling circuit 153 are electrically connected to the output terminal OUT, and the output terminal OUT is further connected to the control circuit 140 (not shown in fig. 3B).
In another embodiment, the output terminal OUT may be connected to a read Circuit (Readout Circuit) for reading the sensing result of the photo sensing Circuit 150.
As described above, in this embodiment, the photo-sensing circuit 150 is set as a charging photo-sensing circuit, so the voltage can be set as the low voltage VL. In another embodiment, if the photo-sensing circuit 150 sets the discharge type photo-sensing circuit, the low voltage VL can be changed to a high voltage.
In one embodiment, the photosensitive elements Tp 1-Tp 6 and the switches T1-T3 may be implemented by any of bipolar transistors (BJTs), field Effect Transistors (FETs), and/or Thin Film Transistors (TFTs). In this embodiment. The photosensitive elements Tp1 to Tp6 are described by way of example as N-type TFTs, but the present disclosure is not limited thereto. The various photosensitive elements of the present disclosure are implemented using various types of transistors, depending on the application. When the control terminal (e.g., gate) of each transistor receives a non-conductive signal (e.g., low voltage VL), the voltage difference between the control terminal and the second terminal (e.g., source) is lower than the threshold voltage (Threshold voltage) of the transistor, so that the transistor operates in a cut-off (cut) region or a sub-threshold (subthreshold) region. Under these operating conditions, different illumination intensities and input signal magnitudes will affect the leakage current (otherwise referred to as sub-threshold current (subthreshold leakage)) of the transistor.
Referring to fig. 4A and 5A, fig. 4A is a flowchart of a driving method 400 of the light sensing circuit according to an embodiment of the disclosure, and fig. 5A is a timing chart of an operation of the light sensing circuit 150 according to an embodiment of the disclosure. As shown in fig. 4A, the driving method 400 of the photo sensing circuit first performs step S410, in the initial stage P1, the first control signal S (n) is at the low voltage VL for resetting the voltage of the node R, the voltage of the node G and the voltage of the node B to the low voltage VL, and the second control signal G (n) is at the disable level VGL for turning off the sampling circuit 153. In one embodiment, since the sampling circuit 153 is in the off state, the capacitors Csr, csg, csb are discharged to reset the voltage of the node R, the voltage of the node G, and the voltage of the node B to the low voltage VL. Meanwhile, since the first control signal S (n) is at the low voltage VL, the photosensitive elements TP4 to TP6 are also reset to the low voltage VL.
Next, the driving method 400 of the light sensing circuit executes step S420, in the sensing phase P2, the first control signal S (n) is at the high voltage VH, when the light sensing element TP4 receives the first color light, the light sensing element TP4 is turned on, and the high voltage VH raises the voltage of the node R to the high voltage level along the first current path I1; when the photosensitive element TP5 receives the second color light, the photosensitive element TP5 is turned on, and the high voltage VH raises the voltage of the node G to a high voltage level along the second current path I2; when the light sensing element TP6 receives the third color light, the light sensing element TP6 is turned on, and the high voltage VH raises the voltage of the node B to a high voltage level along the third current path I3.
As mentioned above, referring to fig. 6A together, fig. 6A is a schematic diagram illustrating the operation of the photo-sensing circuit 150 in the sensing phase P2 according to an embodiment of the disclosure. In this embodiment, the circuit shown in fig. 3A is taken as an example to describe the operation of the sensing stage P2, and the circuit shown in fig. 3A also has the same operation, which is not described herein again. As shown in fig. 6A, if the light sensing circuit 150 is irradiated with the first color light (e.g., red light), the photosensitive element TP3 and the photosensitive element TP4 are excited by the red light to generate a current, as shown by the dotted arrow in fig. 6A, after the photosensitive element TP4 is turned on, the node R is charged by the high voltage VH along the first current path I1, and meanwhile, the potential of the control end of the photosensitive element TP1 is continuously pulled down to the low voltage VL by the photosensitive element TP2, so that the photosensitive element TP1 is not turned on, and the current on the first current path I1 is not dispersed.
In this period, the light sensing elements TP1, TP2, TP5 and TP6 generate currents due to illumination, but the currents generated by the illumination of the first color light are smaller than the currents generated by the light sensing elements TP3 and TP4, and the currents generated by the light sensing elements TP5 and TP6 are continuously pulled down to the low voltage VL along the fourth current path I4 and the fifth current path I5 respectively due to the compensation of the light sensing elements TP3 and TP1 in the compensation circuit 152, so as to maintain the voltages of the nodes G and B at the low voltage VL.
As mentioned above, referring to fig. 6B together, fig. 6B is a schematic diagram illustrating the operation of the photo-sensing circuit 150 in the sensing phase P2 according to an embodiment of the disclosure. As shown in fig. 6B, if the light sensing circuit 150 is irradiated with the second color light (e.g., green light), the light sensing elements TP1 and TP5 are excited by the green light to generate current. In this embodiment, the light sensing elements TP1 and TP5 are excited by green light, similar to the operation of the light sensing elements TP3 and TP4 excited by red light. As shown by the dotted arrow in fig. 6B, after the photosensitive element TP5 is turned on, the node G is charged by the high voltage VH along the second current path I2, and meanwhile, the potential of the control terminal of the photosensitive element TP2 is continuously pulled down to the low voltage VL by the photosensitive element TP3, and the photosensitive element TP2 is turned off, so that the current on the second current path I2 is not dispersed.
In this period, due to the compensation of the photo-sensing elements TP2 and TP3 in the compensation circuit 152, the currents generated by the photo-sensing elements TP4 and TP6 are continuously pulled down to the low voltage VL along the sixth current path I6 and the fifth current path I5, respectively, so as to maintain the voltages of the node R and the node B at the low voltage VL.
As mentioned above, referring to fig. 6C together, fig. 6C is a schematic diagram illustrating the operation of the photo-sensing circuit 150 in the sensing phase P2 according to an embodiment of the disclosure. As shown in fig. 6C, when the light sensing circuit 150 is irradiated with the third color light (e.g., blue light), the photosensitive elements TP2 and TP6 are excited by the blue light to generate a current. In this embodiment, the operation of the light sensing elements TP2 and TP6 excited by blue light is similar to the operation of the light sensing elements TP3 and TP4 excited by red light. As shown by the dotted arrow in fig. 6C, after the photo-sensing element TP6 is turned on, the node B is charged by the high voltage VH along the third current path I3, and meanwhile, the photo-sensing element TP1 continuously pulls the potential of the control terminal of the photo-sensing element TP3 down to the low voltage VL, and the photo-sensing element TP3 is turned off, so that the current on the third current path I3 is not dispersed.
In this period, due to the compensation of the photosensitive element TP1 and the photosensitive element TP3 in the compensation circuit 152, the currents generated by the photosensitive element TP4 and the photosensitive element TP5 are continuously pulled down to the low voltage VL along the sixth current path I6 and the fourth current path I4, respectively, so as to maintain the voltages of the node R and the node G at the low voltage VL.
Next, the driving method 400 of the photo sensing circuit performs step S430a, and in the sampling stage P3, the second control signal G (n) is at the enable level VGH, so that the switches T1, T2 and T3 are in the on state, and the voltage of the node R, the voltage of the node G and the voltage of the node B are respectively transmitted as sampling signals to the output terminal OUT1, the output terminal OUT2 and the output terminal OUT3. In an embodiment, as shown in fig. 5, after the second control signal G (n) is switched to the enable level VGH, the switches T1, T2 and T3 can output the voltage of the node R, the voltage of the node G and the voltage of the node B to the output terminal OUT1, the output terminal OUT2 and the output terminal OUT3, respectively.
In another embodiment, please refer to fig. 3B, fig. 4B and fig. 5B together, fig. 4B is a flowchart of a driving method 400 of the photo sensing circuit according to an embodiment of the disclosure, and fig. 5B is a timing chart of an operation of the photo sensing circuit 150 according to an embodiment of the disclosure. The embodiment shown in fig. 4B differs from the embodiment shown in fig. 4A in that the sampling phase P3 operates differently. As shown in fig. 4B, the driving method 400 of the photo sensing circuit executes step S430B, in the sampling phase P3, the second control signal G1 (n) is switched to the enable level VGH in the first sampling period, so that the switch T1 is in a conducting state for transmitting the voltage of the node R as the sampling signal to the output terminal OUT; the third control signal G2 (n) is switched to the enable level VGH in the second sampling period, so that the switch T2 is in a conducting state, and is used for transmitting the voltage of the node G as a sampling signal to the output terminal OUT; the fourth control signal G3 (n) is switched to the enable level VGH in the third sampling period, so that the switch T3 is in a conductive state, and is used for transmitting the voltage of the node B as the sampling signal to the output terminal OUT.
In an embodiment, as shown in fig. 5B, after the second control signal G1 (n) is switched to the enable level VGH, the switch T1 is turned on, the switch T2 and the switch T3 are turned off, and the switch T1 can output the voltage of the node R to the output terminal OUT. After the third control signal G2 (n) is switched to the enable level VGH, the switch T2 is turned on, the switch T1 and the switch T3 are turned off, and the switch T2 can output the voltage of the node G to the output terminal OUT. After the fourth control signal G3 (n) is switched to the enable level VGH, the switch T3 is turned on, the switch T1 and the switch T2 are turned off, and the switch T3 can output the voltage of the node B to the output terminal OUT. It is noted that the first sampling period, the second sampling period and the third sampling period do not overlap each other.
In an embodiment, please refer to fig. 7A, fig. 7A is a partial schematic diagram of a display panel 100 according to some embodiments of the disclosure. For easy understanding, please refer to fig. 3A and 3B together, and similar elements in fig. 7A and the above drawings will be designated by the same reference numerals. In one embodiment, the display panel 100 includes a plurality of pixel circuits 130 and a plurality of photo sensing circuits 150, and the pixel circuits 130 include a plurality of sub-pixel circuits. Each sub-pixel circuit is covered by a corresponding filter element. For example, along the direction X, the filter element CFr, the filter element CFg, and the filter element CFb are sequentially and repeatedly arranged.
As shown in fig. 7A, taking a sub-pixel circuit of 6*3 (and column 3 of 6) as an example, the sensing circuit 151 and the compensation circuit 152 are disposed on one side of the pixel circuit 130, and the light shielding element (BM) is disposed with a light-transmitting region corresponding to the sensing circuit 151 and the compensation circuit 152, so that the photosensitive elements Tp1 to Tp6 in the sensing circuit 151 and the compensation circuit 152 can sense ambient light. The photo-sensing circuits 150 are disposed between the pixel circuits 130 at intervals, and the distance between the photo-sensing circuits 150 is about 1-3 mm. In one embodiment, the sampling circuit 153 is covered by a light shielding element (not shown in fig. 7A). As mentioned above, the arrangement of the pixel circuit 130 and the light sensing circuit 150 shown in fig. 7A can be matched with the circuit connection shown in fig. 3A and 3B, and will not be described herein.
In another embodiment, please refer to fig. 7B, fig. 7B is a partial schematic diagram of the display panel 100 according to some embodiments of the disclosure. For easy understanding, please refer to fig. 3A and 3B together, and similar elements in fig. 7B and the above figures will be designated by the same reference numerals. In one embodiment, the display panel 100 includes a plurality of pixel circuits 130, wherein the pixel circuits 130 include a plurality of sub-pixel circuits, the sub-pixel circuits have a display area 710 therein, and a portion of the sub-pixel circuits 130 further include a sensing area 720. The display area 710 is provided with a display circuit for displaying an image. The light sensing circuit 150 is disposed in the sensing region 720 for sensing the external ambient light.
In one embodiment, the plurality of pixel circuits 130 in the display panel 100 are arranged in an array. Each sub-pixel circuit is covered by a corresponding filter element. For example, along the direction X, the filter element CFr, the filter element CFg, and the filter element CFb are sequentially and repeatedly arranged. The various photosensitive elements in the light sensing circuit 150 may be implemented by a plurality of parallel transistors, which may be respectively disposed in the plurality of pixel circuits 130 and connected in parallel with each other by interconnects (not shown) to equivalently form the light sensing circuit 150 discussed above.
As shown in fig. 7B, taking the example of the sub-pixel circuit 6*3 (and column 6 and column 3), the sensing region 720 of the sub-pixel circuit 130_1 is provided with the photosensitive element Tp4, the sensing region 720 of the sub-pixel circuit 130_2 is provided with the photosensitive element Tp5, the sensing region 720 of the sub-pixel circuit 130_3 is provided with the photosensitive element Tp2, the sensing region 720 of the sub-pixel circuit 130_4 is provided with the photosensitive element Tp3, the sensing region 720 of the sub-pixel circuit 130_5 is provided with the photosensitive element Tp1, and the sensing region 720 of the sub-pixel circuit 130_6 is provided with the photosensitive element Tp6. The photo-sensing circuits 150 are disposed between the pixel circuits 130 at intervals, and the distance between the photo-sensing circuits 150 is about 1-3 mm. In one embodiment, the sampling circuit 153 is covered by a light shielding element (not shown in fig. 7B). As mentioned above, the arrangement of the pixel circuit 130 and the light sensing circuit 150 shown in fig. 7B can be matched with the circuit connection shown in fig. 3B, and will not be described herein.
In another embodiment, please refer to fig. 7C, fig. 7C is a partial schematic diagram of the display panel 100 according to some embodiments of the present disclosure. For easy understanding, please refer to fig. 3A and 3B together, and similar elements in fig. 7C and the above figures will be designated by the same reference numerals. The difference between the embodiment shown in fig. 7C and the embodiment shown in fig. 7B is that the arrangement of the display area 710 and the sensing area 720 in the sub-pixel circuit is different, and will not be described herein.
In summary, the light sensing circuit, the driving method of the light sensing circuit and the display panel of the present disclosure mainly propose a light sensing circuit capable of detecting different colors of light simultaneously, and compared with a light sensing circuit in which different colors of light need to have different colors of light respectively, the light sensing circuit of the present disclosure can also utilize a compensation circuit to compensate the voltage of the sensing circuit under different ambient light intensities so as to maintain the stability of the circuit, and simultaneously reduce the number of transistors so as to increase the aperture ratio of the pixel circuit.
Certain terminology is used throughout the specification and related application to refer to particular elements. However, one skilled in the art will appreciate that like elements may be referred to by different names. The description and the related application documents do not use the difference of names as a way to distinguish elements, but use the difference of functions of the elements as a reference for distinguishing. The terms "comprising" and "comprises" as used in the specification and related application are to be construed as "including but not limited to". In addition, "coupled" herein encompasses any direct and indirect connection. Thus, if a first element couples to a second element, that connection may be through an electrical or wireless transmission, optical transmission, etc., directly to the second element, or through other elements or connections indirectly to the second element.
In addition, any singular reference is intended to encompass a plural reference unless the specification expressly states otherwise.
The foregoing is only one preferred embodiment of the present invention, and all equivalent changes and modifications made by the claims of the present invention shall fall within the scope of the present invention.
Claims (16)
1. A light sensing circuit comprising:
the sensing circuit is used for receiving a first control signal, and outputting a first sensing signal along a first current path when receiving a first color light; when receiving a second color light, the sensing circuit is used for outputting a second sensing signal along a second current path; when receiving a third color light, the sensing circuit is used for outputting a third sensing signal along a third current path;
the compensation circuit is electrically connected with the sensing circuit and used for receiving a low voltage, and when the sensing circuit receives the first color light, the compensation circuit is used for maintaining the second current path and the third current path at the low voltage; when the sensing circuit receives the second color light, the compensation circuit is used for maintaining the first current path and the third current path at the low voltage; when the sensing circuit receives the third color light, the compensation circuit is used for maintaining the first current path and the second current path at the low voltage; and
the sampling circuit is electrically connected with the sensing circuit and is used for receiving the first sensing signal, the second sensing signal and the third sensing signal and outputting a sampling signal.
2. The light sensing circuit of claim 1, wherein the compensation circuit further comprises:
a first photosensitive element having a first end, a second end and a first control end, wherein the second end is used for receiving the low voltage;
the second photosensitive element is provided with a third end, a fourth end and a second control end, wherein the third end is electrically connected to the first control end, and the fourth end is used for receiving the low voltage; and
the third photosensitive element is provided with a fifth end, a sixth end and a third control end, wherein the fifth end is electrically connected to the second control end, the sixth end is used for receiving the low voltage, and the third control end is electrically connected to the first end.
3. The light sensing circuit of claim 2, wherein the sensing circuit further comprises:
a fourth photosensitive element having a seventh end electrically connected to a first node, an eighth end for receiving the first control signal, and a fourth control end electrically connected to the first control end;
a fifth photosensitive element having a ninth end electrically connected to a second node, a tenth end for receiving the first control signal, and a fifth control end electrically connected to the second control end; and
the sixth photosensitive element is provided with a tenth end, a twelfth end and a sixth control end, wherein the eleventh end is electrically connected to a third node, the twelfth end is used for receiving the first control signal, and the sixth control end is electrically connected to the third control end.
4. The light sensing circuit of claim 3, wherein the sensing circuit further comprises:
the first capacitor is provided with a first end and a second end, the first end is electrically connected to the first node, and the second end is used for receiving the low voltage;
a second capacitor having a third terminal electrically connected to the second node and a fourth terminal for receiving the low voltage; and
the third capacitor is provided with a fifth end and a sixth end, wherein the fifth end is electrically connected to the third node, and the sixth end is used for receiving the low voltage.
5. The light sensing circuit of claim 3, wherein the sampling circuit further comprises:
the first switch is provided with a first end, a second end and a first control end, wherein the first end is electrically connected to the first node, the second end is electrically connected to an output end, and the first control end is used for receiving a second control signal;
the second switch is provided with a third end, a fourth end and a second control end, wherein the third end is electrically connected to the second node, the fourth end is electrically connected to the output end, and the second control end is used for receiving a third control signal; and
the third switch is provided with a fifth end, a sixth end and a third control end, wherein the fifth end is electrically connected to the third node, the sixth end is electrically connected to the output end, and the third control end is used for receiving a fourth control signal.
6. The light sensing circuit of claim 3, wherein the sampling circuit further comprises:
the first switch is provided with a first end, a second end and a first control end, wherein the first end is electrically connected to the first node, the second end is electrically connected to a first output end, and the first control end is used for receiving a second control signal;
the second switch is provided with a third end, a fourth end and a second control end, wherein the third end is electrically connected to the second node, the fourth end is electrically connected to a second output end, and the second control end is used for receiving the second control signal; and
the third switch is provided with a fifth end, a sixth end and a third control end, wherein the fifth end is electrically connected to the third node, the sixth end is electrically connected to a third output end, and the third control end is used for receiving the second control signal.
7. The light sensing circuit of claim 6, wherein in the initial stage, the first control signal is at the low voltage for resetting the voltage at the first node, the voltage at the second node and the voltage at the third node to the low voltage, the second control signal is at a disable level such that the sampling circuit is in an off state.
8. The light sensing circuit of claim 3, wherein during the sensing phase, the first control signal is at a high voltage, the fourth light sensing element is turned on when the fourth light sensing element receives the first color light, and the high voltage raises the voltage of the first node to a high voltage level along the first current path; when the fifth photosensitive element receives the second color light, the fifth photosensitive element is conducted, and the high voltage raises the voltage of the second node to a high voltage level along the second current path; when the sixth photosensitive element receives the third color light, the sixth photosensitive element is turned on, and the high voltage raises the voltage of the third node to a high voltage level along the third current path.
9. The light sensing circuit of claim 5, wherein during the sampling phase, the second control signal is switched to an enable level in a first period of time, such that the first switch is in an on state for transmitting the voltage of the first node as the sampling signal to an output terminal; the third control signal is switched to the enabling level in a second period of time, so that the second switch is in a conducting state and is used for transmitting the voltage of the second node to the output end as the sampling signal; the fourth control signal is switched to the enabling level in a third period, so that the third switch is in a conducting state and is used for transmitting the voltage of the third node as the sampling signal to the output end.
10. The light sensing circuit of claim 9, wherein the first period, the second period, and the third period do not overlap each other.
11. The light sensing circuit of claim 6, wherein the second control signal is at an enable level during the sampling phase such that the first switch, the second switch and the third switch are turned on to respectively transmit the voltage of the first node, the voltage of the second node and the voltage of the third node as the sampling signals to the first output terminal, the second output terminal and the third output terminal.
12. A driving method of a photo-sensing circuit as claimed in any one of claims 1 to 11, comprising:
when receiving a first color light, a sensing circuit is used for outputting a first sensing signal along a first current path according to a first control signal, so that a compensation circuit electrically connected with the sensing circuit is used for maintaining a second current path and a third current path at a low voltage;
when receiving a second color light, the sensing circuit outputs a second sensing signal along the second current path according to the first control signal, and the compensation circuit is used for maintaining the first current path and the third current path at the low voltage; and
when receiving a third color light, the sensing circuit is used for outputting a third sensing signal along a third current path according to the first control signal, and the compensation circuit is used for maintaining the first current path and the second current path at the low voltage.
13. The driving method according to claim 12, further comprising:
in the initial stage, the first control signal is at the low voltage for resetting the voltage of a first node, the voltage of a second node and the voltage of a third node to the low voltage, and the second control signal is at a forbidden energy level, so that a sampling circuit is in an off state.
14. The driving method as claimed in claim 13, wherein during the sensing phase, the first control signal is at a high voltage, and when a fourth photosensitive element receives the first color light, the fourth photosensitive element is turned on, and the high voltage raises the voltage of the first node to a high voltage level along the first current path; when a fifth photosensitive element receives the second color light, the fifth photosensitive element is conducted, and the high voltage raises the voltage of the second node to a high voltage level along the second current path; when a sixth photosensitive element receives the third color light, the sixth photosensitive element is turned on, and the high voltage raises the voltage of the third node to a high voltage level along the third current path.
15. The driving method according to claim 13, further comprising:
in the sampling stage, the second control signal is switched to an enabling level, so that the sampling circuit is conducted, and a sampling signal is output according to the first sensing signal, the second sensing signal and the third sensing signal.
16. A display panel, comprising:
the source electrode driving circuit is electrically connected to the plurality of data lines and used for providing a data voltage;
a gate driving circuit electrically connected to the gate lines for providing a gate driving signal;
a plurality of pixel circuits electrically connected to the plurality of data lines and the plurality of gate lines for receiving the data voltages;
a control circuit for providing a first control signal; and
a light sensing circuit electrically connected to the control circuit, the light sensing circuit comprising:
the sensing circuit is used for receiving the first control signal and outputting a sensing signal according to the received chromatic light;
the compensation circuit is electrically connected with the sensing circuit and is used for receiving a low voltage and maintaining the voltage of the sensing circuit according to the received chromatic light; and
the sampling circuit is electrically connected with the sensing circuit and the control circuit and is used for receiving the sensing signal and outputting a sampling signal to the control circuit.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW108116786A TWI703372B (en) | 2019-05-15 | 2019-05-15 | Optical sensor circuit, optical sensor driving method and display panel |
| TW108116786 | 2019-05-15 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111459341A CN111459341A (en) | 2020-07-28 |
| CN111459341B true CN111459341B (en) | 2023-06-13 |
Family
ID=71684175
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010123056.1A Active CN111459341B (en) | 2019-05-15 | 2020-02-27 | Light sensing circuit, driving method of light sensing circuit and display panel |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN111459341B (en) |
| TW (1) | TWI703372B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI782722B (en) * | 2021-09-28 | 2022-11-01 | 友達光電股份有限公司 | Sensing device and operation method thereof |
| CN114046881B (en) * | 2021-11-15 | 2024-05-28 | 深圳知微创新技术有限公司 | High-sensitivity color sensor based on thin film transistor |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200632290A (en) * | 2004-11-24 | 2006-09-16 | Eastman Kodak Co | Light detection circuit |
| JP2011014127A (en) * | 2009-07-03 | 2011-01-20 | Samsung Mobile Display Co Ltd | Light sensing circuit, touch panel including the same and method of driving the optical sensing circuit |
| CN103984448A (en) * | 2014-02-17 | 2014-08-13 | 友达光电股份有限公司 | Optical sensing circuit and touch display panel thereof |
| CN104182098A (en) * | 2014-07-21 | 2014-12-03 | 友达光电股份有限公司 | Light sensing circuit |
| CN105890749A (en) * | 2016-03-23 | 2016-08-24 | 友达光电股份有限公司 | Light sensing circuit and display panel using the same |
| US9576542B1 (en) * | 2014-12-02 | 2017-02-21 | Amazon Technologies, Inc. | Using display components for light sensing |
| CN107204172A (en) * | 2017-06-02 | 2017-09-26 | 京东方科技集团股份有限公司 | Image element circuit and its driving method, display panel |
| TW201734585A (en) * | 2016-03-23 | 2017-10-01 | 友達光電股份有限公司 | A panel structure with a photo-sensing circuit |
| CN107359870A (en) * | 2017-05-04 | 2017-11-17 | 友达光电股份有限公司 | Light sensing circuit |
| CN107665673A (en) * | 2016-07-29 | 2018-02-06 | 乐金显示有限公司 | Organic light-emitting display device and its driving method |
| CN108877649A (en) * | 2017-05-12 | 2018-11-23 | 京东方科技集团股份有限公司 | Pixel circuit and its driving method, display panel |
| CN109448626A (en) * | 2018-11-19 | 2019-03-08 | 友达光电股份有限公司 | Display panel |
| CN109473066A (en) * | 2018-11-20 | 2019-03-15 | 友达光电股份有限公司 | Display panel |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006520490A (en) * | 2003-03-12 | 2006-09-07 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Luminescent active matrix display with timing effective optical feedback to combat aging |
| TWI718208B (en) * | 2016-06-30 | 2021-02-11 | 日商半導體能源研究所股份有限公司 | Display device, working method thereof and electronic device |
-
2019
- 2019-05-15 TW TW108116786A patent/TWI703372B/en active
-
2020
- 2020-02-27 CN CN202010123056.1A patent/CN111459341B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200632290A (en) * | 2004-11-24 | 2006-09-16 | Eastman Kodak Co | Light detection circuit |
| JP2011014127A (en) * | 2009-07-03 | 2011-01-20 | Samsung Mobile Display Co Ltd | Light sensing circuit, touch panel including the same and method of driving the optical sensing circuit |
| CN103984448A (en) * | 2014-02-17 | 2014-08-13 | 友达光电股份有限公司 | Optical sensing circuit and touch display panel thereof |
| TW201533632A (en) * | 2014-02-17 | 2015-09-01 | Au Optronics Corp | Photo sensing circuit and touch display panel |
| CN104182098A (en) * | 2014-07-21 | 2014-12-03 | 友达光电股份有限公司 | Light sensing circuit |
| US9576542B1 (en) * | 2014-12-02 | 2017-02-21 | Amazon Technologies, Inc. | Using display components for light sensing |
| CN105890749A (en) * | 2016-03-23 | 2016-08-24 | 友达光电股份有限公司 | Light sensing circuit and display panel using the same |
| TW201734585A (en) * | 2016-03-23 | 2017-10-01 | 友達光電股份有限公司 | A panel structure with a photo-sensing circuit |
| CN107665673A (en) * | 2016-07-29 | 2018-02-06 | 乐金显示有限公司 | Organic light-emitting display device and its driving method |
| CN107359870A (en) * | 2017-05-04 | 2017-11-17 | 友达光电股份有限公司 | Light sensing circuit |
| CN108877649A (en) * | 2017-05-12 | 2018-11-23 | 京东方科技集团股份有限公司 | Pixel circuit and its driving method, display panel |
| CN107204172A (en) * | 2017-06-02 | 2017-09-26 | 京东方科技集团股份有限公司 | Image element circuit and its driving method, display panel |
| CN109448626A (en) * | 2018-11-19 | 2019-03-08 | 友达光电股份有限公司 | Display panel |
| CN109473066A (en) * | 2018-11-20 | 2019-03-15 | 友达光电股份有限公司 | Display panel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111459341A (en) | 2020-07-28 |
| TWI703372B (en) | 2020-09-01 |
| TW202043860A (en) | 2020-12-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10311774B2 (en) | Display apparatus | |
| KR101537868B1 (en) | Touch display circuit, drive method thereof, array substrate and display device | |
| US7158105B2 (en) | Electronic circuit, method of driving electronic circuit, electro-optical device, method of driving electro-optical device, and electronic apparatus | |
| CN111459341B (en) | Light sensing circuit, driving method of light sensing circuit and display panel | |
| WO2020151233A1 (en) | Pixel driving circuit, pixel unit and driving method, array substrate, and display device | |
| CN107359870B (en) | Light sensing circuit | |
| CN103377619B (en) | Display device, for the drive unit of luminescent device and image processing system | |
| US10665147B2 (en) | Photosensitive circuit, method of driving photosensitive circuit and display device | |
| US11495155B2 (en) | Pixel circuit | |
| US11132930B2 (en) | Display device, source drive circuit and display system | |
| US20220076622A1 (en) | Pixel driving circuit and driving method therefor, display panel and display apparatus | |
| US11506537B2 (en) | Optical sensing circuit, optical sensing circuit array, and method for determining light color by using the same | |
| CN111341251B (en) | Pixel circuit | |
| TWI658695B (en) | Output circuit and method for providing an output current | |
| CN111427470B (en) | Light sensing circuit, display panel and display sensing panel | |
| US11393379B2 (en) | Driving unit, gate driving circuit, array substrate, and display apparatus | |
| JP2000194327A (en) | Display device | |
| US20200020275A1 (en) | Emissive pixel array and self-referencing system for driving same | |
| CN114047843B (en) | Photo-sensing pixel and display device with photo-sensing function | |
| US20210136306A1 (en) | Ir pixel reconfigurable in di or bdi mode | |
| US11151915B2 (en) | Electro-optical device, electronic apparatus, and inspection method for electro-optical device | |
| US7382365B2 (en) | Semiconductor device and driver | |
| CN115862510B (en) | Display device | |
| US11941210B2 (en) | Sensing circuit improving magnification in pixel circuit and reducing influence of shift in threshold voltage preliminary class | |
| US12027108B1 (en) | Display device and operating method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |