CN114627788A - Photoelectric sensing pixel compensation circuit, driving method and display device - Google Patents

Photoelectric sensing pixel compensation circuit, driving method and display device Download PDF

Info

Publication number
CN114627788A
CN114627788A CN202011461756.8A CN202011461756A CN114627788A CN 114627788 A CN114627788 A CN 114627788A CN 202011461756 A CN202011461756 A CN 202011461756A CN 114627788 A CN114627788 A CN 114627788A
Authority
CN
China
Prior art keywords
node
signal
module
transistor
control
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.)
Pending
Application number
CN202011461756.8A
Other languages
Chinese (zh)
Inventor
王志良
唐大伟
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BOE Technology Group Co Ltd
Beijing BOE Technology Development Co Ltd
Original Assignee
BOE Technology Group Co Ltd
Beijing BOE Technology Development Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by BOE Technology Group Co Ltd, Beijing BOE Technology Development Co Ltd filed Critical BOE Technology Group Co Ltd
Priority to CN202011461756.8A priority Critical patent/CN114627788A/en
Publication of CN114627788A publication Critical patent/CN114627788A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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
    • G09G3/22—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 using controlled light sources
    • G09G3/30—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 using controlled light sources using electroluminescent panels
    • G09G3/32—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0233—Improving the luminance or brightness uniformity across the screen
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00—Aspects of the architecture of display systems
    • G09G2360/14—Detecting light within display terminals, e.g. using a single or a plurality of photosensors
    • G09G2360/141—Detecting light within display terminals, e.g. using a single or a plurality of photosensors the light conveying information used for selecting or modulating the light emitting or modulating element
    • G09G2360/142—Detecting light within display terminals, e.g. using a single or a plurality of photosensors the light conveying information used for selecting or modulating the light emitting or modulating element the light being detected by light detection means within each pixel

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)
  • Solid State Image Pick-Up Elements (AREA)

Abstract

Disclosed herein are a photoelectric sensing pixel compensation circuit, a driving method and a display device. The photoelectric sensing pixel compensation circuit comprises a first switch control module, a driving module, a second switch control module, an energy storage module and a photoelectric conversion module; the first switch control module is configured to reset the potential of the first node in a reset phase and write the threshold voltage of the driving transistor into the first node; the driving module is configured to generate a current signal in response to a voltage signal of the first node; the second switch control module is configured to output the current signal generated by the driving module to the signal reading end in a data reading stage; the energy storage module is configured to store voltage difference information between the first node and the third node; the photoelectric conversion module is configured to receive an optical signal and convert the optical signal into an electrical signal. The output current of the photoelectric sensing pixel compensation circuit provided by the invention is not influenced by the threshold voltage of the driving transistor, so that the nonuniformity of brightness when a plurality of pixels are imaged is avoided.

Description

Photoelectric sensing pixel compensation circuit, driving method and display device
Technical Field
The present disclosure relates to but not limited to the field of display technologies, and in particular, to a photo sensor pixel compensation circuit, a driving method and a display device.
Background
An APS (Active Pixel Sensor) circuit is commonly used in CMOS (Complementary Metal Oxide Semiconductor) image Sensor design, and can also be applied to a detection circuit design of a photoelectric Sensor, and the APS circuit has higher signal amplification capability than a PPS (Passive Pixel Sensor) circuit, and thus has higher noise resistance capability.
APS circuits typically include a photodetector and a plurality of transistors, one of which is a drive transistor and the other of which is a switching transistor. Under the action of light, a photoelectric detector (such as a photodiode) generates photocurrent, one end of the photoelectric detector is connected with a control electrode (gate electrode) of a driving transistor, so that the voltage of the control electrode (gate electrode) of the driving transistor is changed, and the driving transistor stably converts the voltage of the control electrode into current flowing through the driving transistor so as to amplify the current generated by the photoelectric detector.
For a substrate including a plurality of APS circuits, since the threshold voltages of the driving transistors of different APS circuits are different, there is a difference in current flowing through the driving transistors, thereby causing unevenness in pixel luminance.
Disclosure of Invention
In a first aspect, the present disclosure provides a photo-sensing pixel compensation circuit, comprising: the device comprises a first switch control module, a driving module, a second switch control module, an energy storage module and a photoelectric conversion module; the driving module comprises a driving transistor;
the first switch control module is respectively connected with a first control signal end, a first node and a second node, and is configured to respond to a first control signal provided by the first control signal end to reset the potential of the first node in a reset stage and write the threshold voltage of the driving transistor into the first node;
the driving module is respectively connected with a first node, a second node and a third node and is configured to respond to a voltage signal of the first node to generate a current signal; the third node is also connected with a first power supply signal end;
the second switch control module is respectively connected with a second control signal end, a second node and a signal reading end and is configured to respond to a second control signal provided by the second control signal end and output a current signal generated by the driving module to the signal reading end in a data reading stage;
the energy storage module is respectively connected with the first node and the third node and is configured to store voltage difference information between the first node and the third node;
and the photoelectric conversion module is respectively connected with the first reference signal end and the first node, and is configured to receive an optical signal and convert the optical signal into an electrical signal.
In a second aspect, the present disclosure provides a photo-sensing pixel compensation circuit, comprising: the energy storage device comprises a first switch control module, a second switch control module, a third switch control module, a fourth switch control module, a driving module, an energy storage module and a photoelectric conversion module; the driving module comprises a driving transistor;
the first switch control module is respectively connected with the first control signal terminal, the first reference signal terminal and the first node and is configured to respond to a first control signal provided by the first control signal terminal to provide a first reference signal provided by the first reference signal terminal to the first node in a reset stage and an exposure stage;
the second switch control module is respectively connected with the second control signal terminal, the second reference signal terminal and the second node and is configured to respond to a second control signal provided by the second control signal terminal and provide a second reference signal provided by the second reference signal terminal to the second node in a reset stage;
the third switch control module is respectively connected with a third control signal terminal, a second node and a signal reading terminal and is configured to respond to a third control signal provided by the third control signal terminal and output a current signal generated by the driving module to the signal reading terminal in a data reading stage;
the fourth switch control module is respectively connected with the third control signal terminal, the third node and the first power supply signal terminal, and is configured to respond to a third control signal provided by the third control signal terminal to provide the first power supply signal provided by the first power supply signal terminal to the third node in a data reading stage;
the driving module is respectively connected with a first node, a second node and a third node and is configured to respond to voltage difference signals of the first node and the third node to generate a current signal;
the energy storage module is respectively connected with the first node and the third node, and is configured to store information of threshold voltage of the driving transistor in a reset stage, store information of voltage variation of the third node in an exposure stage, and write the information of the threshold voltage and the information of the voltage variation of the third node into the first node in a data reading stage;
and the photoelectric conversion module is respectively connected with the third reference signal end and the third node and is configured to receive the optical signal and convert the optical signal into an electric signal.
In a third aspect, the present disclosure provides a driving method of a photo-sensing pixel compensation circuit, including the steps of:
in a reset stage, the first switch control module resets the potential of the first node under the control of a first control signal and writes the threshold voltage of the driving transistor into the first node;
in an exposure stage, the photoelectric conversion module receives an optical signal, converts the optical signal into an electrical signal, and stores generated charges in the energy storage module to change the potential of the first node;
in a data reading stage, the driving module generates a current signal according to the voltage signal of the first node; the second switch control module outputs the current signal to a signal reading end under the control of a second control signal.
In a fourth aspect, the present disclosure provides a driving method of a photo-sensing pixel compensation circuit, including the steps of:
in a reset stage, the first switch control module resets the potentials of the first node and the third node under the control of a first control signal, the second switch control module resets the potential of the second node under the control of a second control signal, and the energy storage module stores information of the threshold voltage of the driving transistor;
in an exposure stage, the photoelectric conversion module receives an optical signal and converts the optical signal into an electric signal to change the potential of the third node, and the energy storage module stores information of voltage variation of the third node;
in a data reading stage, the energy storage module writes information of threshold voltage of the driving transistor and information of voltage variation of the third node into the first node, and the driving module generates a current signal according to a voltage difference signal of the first node and the third node; the third switch control module outputs the current signal to a signal reading end under the control of a third control signal.
In a fifth aspect, the present disclosure provides a display device comprising the above-described photo-sensing pixel compensation circuit.
The photoelectric sensing pixel compensation circuit comprises a first switch control module, a driving module, a second switch control module, an energy storage module and a photoelectric conversion module, wherein the first switch control module resets the potential of a first node in a reset stage under the control of a first control signal and writes the threshold voltage of a driving transistor into the first node, the photoelectric conversion module changes the potential of the first node after generating photocurrent through photoelectric conversion, the driving module generates a current signal according to the voltage signal of the first node, and the threshold voltage of the driving transistor is written into the first node in advance, so that the magnitude of the current generated by the driving module is irrelevant to the threshold voltage of the driving transistor, and the output current of the photoelectric sensing pixel compensation circuit is not influenced by the threshold voltage of the driving transistor, thereby avoiding non-uniformity of brightness when a plurality of pixels are imaged.
Drawings
The accompanying drawings are included to provide an understanding of the disclosed embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the examples serve to explain the principles of the disclosure and not to limit the disclosure.
FIG. 1 is a schematic diagram of an APS circuit in the prior art;
fig. 2 is a schematic structural diagram of a photoelectric sensing pixel compensation circuit according to an embodiment of the present disclosure;
fig. 3 is an equivalent circuit schematic diagram of a photoelectric sensing pixel compensation circuit according to an embodiment of the present disclosure;
fig. 4 is a signal timing diagram of a compensation circuit of a photo-sensing pixel according to an embodiment of the present disclosure;
fig. 5 is a schematic diagram illustrating a driving method of a photo-sensing pixel compensation circuit according to an embodiment of the disclosure;
fig. 6 is a schematic structural diagram of another photoelectric sensing pixel compensation circuit provided in the embodiment of the present disclosure;
fig. 7 is an equivalent circuit schematic diagram of another photoelectric sensing pixel compensation circuit provided in the embodiments of the present disclosure;
FIG. 8 is a timing diagram of signals of another exemplary compensation circuit for a photo-sensing pixel according to the disclosure;
fig. 9 is a schematic diagram of another driving method of a photo-sensing pixel compensation circuit according to an embodiment of the present disclosure.
Detailed Description
To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the embodiments may be implemented in a plurality of different forms. Those skilled in the art can readily appreciate the fact that the forms and details may be varied into a variety of forms without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the contents described in the following embodiments. The embodiments and features of the embodiments in the present disclosure may be arbitrarily combined with each other without conflict.
In the drawings, the size of each component, the thickness of a layer, or a region may be exaggerated for clarity. Therefore, one aspect of the present disclosure is not necessarily limited to the dimensions, and the shapes and sizes of the respective components in the drawings do not reflect a true scale. Further, the drawings schematically show ideal examples, and one embodiment of the present disclosure is not limited to the shapes, numerical values, and the like shown in the drawings.
The ordinal numbers such as "first", "second", "third", and the like in the present specification are provided for avoiding confusion among the constituent elements, and are not limited in number.
In this specification, the terms "mounted," "connected," and "connected" are to be construed broadly unless otherwise specifically indicated and limited. For example, it may be a fixed connection, or a removable connection, or an integral connection; can be a mechanical connection, or an electrical connection; either directly or indirectly through intervening components, or both may be interconnected. The specific meaning of the above terms in the present disclosure can be understood in specific instances by those of ordinary skill in the art.
In this specification, a transistor refers to an element including at least three terminals, i.e., a gate electrode, a drain electrode, and a source electrode. The transistor has a channel region between a drain electrode (drain electrode terminal, drain region, or drain electrode) and a source electrode (source electrode terminal, source region, or source electrode), and current can flow through the drain electrode, the channel region, and the source electrode. Note that in this specification, a channel region refers to a region where current mainly flows.
In this specification, the first electrode may be a drain electrode and the second electrode may be a source electrode, or the first electrode may be a source electrode and the second electrode may be a drain electrode. In the case of using transistors of opposite polarities, or in the case of changing the direction of current flow during circuit operation, the functions of the "source electrode" and the "drain electrode" may be interchanged. Therefore, in this specification, "source electrode" and "drain electrode" may be exchanged with each other.
In this specification, "electrically connected" includes a case where constituent elements are connected together by an element having some kind of electrical action. The "element having a certain electric function" is not particularly limited as long as it can transmit and receive an electric signal between connected components. Examples of the "element having some kind of electric function" include not only an electrode and a wiring but also a switching element such as a transistor, a resistor, an inductor, a capacitor, other elements having various functions, and the like.
In the present specification, "film" and "layer" may be interchanged with each other. For example, the "conductive layer" may be sometimes replaced with a "conductive film". Similarly, the "insulating film" may be replaced with an "insulating layer".
"about" in this disclosure means that the limits are not strictly defined, and that the numerical values are within the tolerances allowed for the process and measurement.
The transistors used in the embodiments of the present disclosure may be thin film transistors or field effect transistors or other devices with the same characteristics. In the embodiments of the present disclosure, one of the source and the drain is referred to as a first pole, and the other of the source and the drain is referred to as a second pole.
Further, in the description of the embodiments of the present disclosure, the terms "first level" and "second level" are used only to distinguish that the amplitudes of the two levels are different. When the transistor is exemplified as a P-type thin film transistor, the signal level at which the trigger transistor is turned on is a low level, and when the transistor is exemplified as an N-type thin film transistor, the signal level at which the trigger transistor is turned on is a high level.
In the following examples, description is made on the case where the driving transistor is an N-type thin film transistor.
Fig. 1 shows a conventional APS circuit. As shown in fig. 1, the APS circuit includes three transistors, a photodetector (e.g., a photodiode) and a storage capacitor (optional). The transistor T1 is a reset transistor. A control electrode of the transistor T1 is connected to the first control signal terminal Reset, a first electrode of T1 is connected to the first reference signal terminal Vrst, and a second electrode of T1 is connected to the first node a. The transistor T1 operates in a switching state, and after each reading of the photocurrent generated by the photodiode, the transistor T1 is turned on to reset the potential of the first node a to the voltage U of the first reference signal provided by the first reference signal terminal VrstVrstThus being the next roundData reading is ready. The transistor T2 is an amplifying transistor. A control electrode of the transistor T2 is connected to the first node, a first electrode of T2 is connected to the first power signal terminal VDD, and a second electrode of T2 is connected to a first electrode of the third transistor T3. The transistor T2 operates in an amplifying state, and during the light irradiation of the photodiode, the potential of the first node is lowered due to the continuous accumulation of photoelectrons on the photodiode, and the transistor T2 stably converts the voltage of the first node into a current flowing through the transistor T2. The transistor T3 operates in a switching state, a control electrode of the transistor T3 is connected to the second control signal terminal Gate, a first electrode of the transistor T3 is connected to a second electrode of the transistor T2, and a second electrode of the transistor T3 serves as an output end of the APS circuit, and outputs the current Io amplified by the transistor T2 to the data acquisition module at the rear end.
In the above-described conventional APS circuit, the current I output from the transistor T2 is amplifiedo＝k(Vgs-Vth)2Related to the threshold voltage Vth of the amplifying transistor. Due to device variations of the amplifying transistors employed by different APS circuits, there is a variation in the threshold voltage Vth of the amplifying transistors of different APS circuits, causing unevenness in pixel luminance.
The embodiment of the disclosure provides a photoelectric sensing pixel compensation circuit. As shown in fig. 2, an embodiment of the present disclosure provides a photo sensing pixel compensation circuit, including: the device comprises a first switch control module 1, a driving module 2, a second switch control module 3, an energy storage module 4 and a photoelectric conversion module 5; the driving module 2 comprises a driving transistor;
a first switch control module respectively connected to a first control signal terminal G1, a first node N1 and a second node N2, and configured to reset a potential of the first node in a reset phase in response to a first control signal provided by the first control signal terminal, and write a threshold voltage of the driving transistor into the first node;
the driving module is respectively connected with a first node, a second node and a third node N3 and is configured to respond to a voltage signal of the first node to generate a current signal; the third node is also connected with a first power supply signal terminal VSS;
the second switch control module is respectively connected with a second control signal terminal G2, a second node and a signal reading terminal RD and is configured to respond to a second control signal provided by the second control signal terminal to output a current signal generated by the driving module to the signal reading terminal in a data reading stage;
the energy storage module is respectively connected with the first node and the third node and is configured to store voltage difference information between the first node and the third node;
and the photoelectric conversion module is respectively connected with the first reference signal terminal V1 and the first node and is configured to receive the optical signal and convert the optical signal into an electric signal.
In the photo-sensing pixel compensation circuit provided in the above embodiment, the first switch control module resets the potential of the first node in the reset stage under the control of the first control signal, and writes the threshold voltage of the driving transistor into the first node, the photo-electric conversion module changes the potential of the first node after generating a photo current through photo-electric conversion, and the driving module generates a current signal according to the voltage signal of the first node.
In some exemplary embodiments, the photoelectric conversion module includes a photodetector, one end of the photodetector is connected to the first node, and the other end of the photodetector is connected to the first reference signal terminal;
wherein the photodetector includes: a photodiode or MSM (Metal-Semiconductor-Metal) photodetector;
the photodiode includes: PN-type or PIN-type photodiodes, avalanche photodiodes, and the like.
In some exemplary embodiments, the photoelectric conversion module includes a photodiode D1, an anode of the photodiode is connected to the first node, and a cathode of the photodiode is connected to the first reference signal terminal;
in some exemplary embodiments, the first switching control module includes a first transistor T1; a control electrode of the first transistor T1 is connected to a first control signal terminal, a first electrode of T1 is connected to a first node, and a second electrode of T1 is connected to a second node;
in some exemplary embodiments, the driving module includes a second transistor T2; a control electrode of the second transistor T2 is connected to the first node, a first electrode of T2 is connected to the second node, and a second electrode of T2 is connected to the third node;
in some exemplary embodiments, the second switch control module includes a third transistor T3; a control electrode of the third transistor T3 is connected to a second control signal terminal, a first electrode of T3 is connected to a second node, and a second electrode of T3 is connected to a signal reading terminal;
in some exemplary embodiments, the energy storage module includes a capacitor C1; the first pole of the capacitor C1 is connected to the first node, and the second pole of the capacitor C1 is connected to the third node.
Fig. 3 provides an equivalent circuit diagram of a photo-sensing pixel compensation circuit. As shown in fig. 3, the photo sensing pixel compensation circuit includes: a photodiode D1, a first transistor T1, a second transistor T2, a third transistor T3, and a capacitor C1; wherein the second transistor T2 is a driving transistor, and the first transistor T1 and the second transistor T2 are switching transistors;
the anode of the photodiode D1 is connected to the first node N1, and the cathode of D1 is connected to the first reference signal terminal V1;
a control electrode of the first transistor T1 is connected to a first control signal terminal G1, a first electrode of T1 is connected to a first node N1, and a second electrode of T1 is connected to a second node N2;
a control electrode of the second transistor T2 is connected to a first node N1, a first electrode of T2 is connected to a second node N2, and a second electrode of T2 is connected to a third node N3; the third node N3 is further connected to a first power signal terminal VSS;
a first pole of the capacitor C1 is connected to the first node N1, and a second pole of the capacitor C1 is connected to the third node N3.
The operation of one duty cycle of the photo-sensing pixel compensation circuit provided in fig. 3 is described below with reference to a signal timing diagram.
In the embodiment shown in fig. 3, the transistors T1, T2, and T3 may be N-type thin film transistors. In addition, considering that the leakage current of the low-temperature polysilicon thin film transistor is small, all the transistors can be low-temperature polysilicon thin film transistors, and the thin film transistor can be specifically selected from a thin film transistor with a bottom gate structure or a thin film transistor with a top gate structure.
Fig. 4 provides a timing diagram of signals during operation of the photo-sensing pixel compensation circuit. As shown in fig. 4, the operation of the photo sensing pixel compensation circuit can be divided into three stages. The first reference signal provided by the first reference signal terminal V1 and the first power signal provided by the first power signal terminal VSS are both direct current signals, and the voltage of the first reference signal is higher than the voltage of the first power signal. The first control signal provided by the first control signal terminal G1 and the second control signal provided by the second control signal terminal G2 are both pulse signals.
(1) First stage (stage t1 in FIG. 4)
The first control signal is a high level signal in the first stage, and the second control signal is a low level signal in the first stage.
In the first stage, the first control signal is a high level signal, the first transistor is turned on, the second transistor operates in a diode mode, the potential of the first node is equal to the potential of the second node, and U is equal toN1＝UN2＝UVSS+VthWherein V isthIs the threshold voltage, U, of the drive transistor (second transistor)VSSIs the voltage of the first power supply signal. The first stage may be regarded as a node (first node) reset stage, that is, the potential of the first node is reset, and the threshold voltage of the driving transistor is written to the first node.
In the first stage, the second control signal is a low level signal, the third transistor is in an off state, and the signal reading terminal RD does not output a current signal.
(2) Second stage (stage t2 in FIG. 4)
The first control signal is a low level signal in the second stage, and the second control signal is a low level signal in the second stage.
In the second phase, the first transistor and the third transistor are both turned off. The voltage of the first reference signal is higher than the voltage of the first node, and thus, the photodiode is in a reverse-biased state. The photodiode receives the optical signal and converts the optical signal into an electrical signal, and the potential of the first node is raised by delta U, U in the second stageN1＝UVSS+Vth+ Δ U. The second phase can be regarded as the photoelectric conversion phase of the photodiode, i.e. the exposure phase.
In the second stage, the third transistor is in the off state, and the signal reading terminal RD does not output the current signal.
(3) Third stage (stage t3 in FIG. 4)
The first control signal is a low level signal in the third stage, and the second control signal is a high level signal in the third stage.
In the third stage, the driving transistor generates a current I according to the voltage signal of the first nodeo，Io＝k(Vgs-Vth)2(ii) a k is a parameter related to the process parameters and feature size of the drive transistor;
Vgs＝UN1-UN3；
wherein, UN1＝UVSS+Vth+ΔU；UN3＝UVSS；
Thus, Vgs＝(UVSS+Vth+ΔU)-UVSS＝Vth+ΔU；
Io＝k(Vgs-Vth)2＝k(Vth+ΔU-Vth)2＝k(ΔU)2；
In the third stage, the third transistor is turned on, and the signal reading terminal RD outputs the current signal IoThe current signal has a current magnitude independent of the threshold voltage of the drive transistor. The third phase may be considered as the phase of reading the current data.
The working process of the photoelectric sensing pixel compensation circuit can be divided into three stages: the first stage is a reset stage of the potential of the node (first node), in which the threshold voltage of the driving transistor is written into the first node. The second stage is an exposure stage of the photoelectric conversion element, and the third stage is a stage of reading current data.
In the photoelectric sensing pixel compensation circuit of the embodiment of the disclosure, in a reset phase, the first transistor resets a potential of the first node under the control of the first control signal, and writes the threshold voltage of the driving transistor into the first node. In the exposure stage, the photoelectric conversion element generates an electric signal by photoelectric conversion and raises the potential of the first node. In a data reading stage, the driving transistor generates a current signal according to the voltage signal of the first node, and the threshold voltage of the driving transistor is written into the first node in advance, so that the magnitude of the current generated by the driving transistor is irrelevant to the threshold voltage of the driving transistor, the output current of the photoelectric sensing pixel compensation circuit is not influenced by the threshold voltage of the driving transistor, and the non-uniformity of the brightness when a plurality of pixels are imaged is avoided.
The embodiment of the disclosure provides a driving method of a photoelectric sensing pixel compensation circuit, which may include the following steps:
in a reset stage, the first switch control module resets the potential of the first node under the control of a first control signal and writes the threshold voltage of the driving transistor into the first node;
in an exposure stage, the photoelectric conversion module receives an optical signal, converts the optical signal into an electrical signal, and stores generated charges in the energy storage module to change the potential of the first node;
in a data reading stage, the driving module generates a current signal according to the voltage signal of the first node; the second switch control module outputs the current signal to a signal reading end under the control of a second control signal.
In the driving method of the photoelectric sensing pixel compensation circuit according to the embodiment of the disclosure, in the reset stage, the first switch control module resets the potential of the first node under the control of the first control signal, and writes the threshold voltage of the driving transistor into the first node. In an exposure stage, the photoelectric conversion module receives an optical signal and converts the optical signal into an electrical signal, and the generated charge is stored in the energy storage module to raise the potential of the first node. In a data reading stage, the driving module generates a current signal according to a voltage signal of a first node; the second switch control module outputs the current signal to a signal reading end under the control of a second control signal. Because the threshold voltage of the driving transistor is written into the first node in advance, the current generated by the driving module is irrelevant to the threshold voltage of the driving transistor, so that the output current of the photoelectric sensing pixel compensation circuit is not influenced by the threshold voltage of the driving transistor, and the non-uniformity of the brightness when a plurality of pixels are imaged is avoided.
In some exemplary embodiments, the driving module generates a current signal according to a voltage signal of the first node, including:
the current value I of the current signal generated by the driving module according to the voltage signal of the first nodeoComprises the following steps:
Io＝k(ΔU)2；
wherein k is a parameter related to a process parameter and a feature size of the driving transistor; Δ U is a voltage variation amount of the first node caused by the photoelectric conversion action of the photoelectric conversion module in the exposure phase.
The embodiment of the disclosure provides a photoelectric sensing pixel compensation circuit. As shown in fig. 6, an embodiment of the present disclosure provides a photo sensing pixel compensation circuit, including: the system comprises a first switch control module 1, a second switch control module 2, a third switch control module 3, a fourth switch control module 4, a driving module 5, an energy storage module 6 and a photoelectric conversion module 7; the driving module 5 comprises a driving transistor;
a first switch control module respectively connected to the first control signal terminal G1, the first reference signal terminal V1 and the first node N1, and configured to provide the first reference signal provided by the first reference signal terminal to the first node in the reset phase and the exposure phase in response to the first control signal provided by the first control signal terminal;
a second switch control module respectively connected to the second control signal terminal G2, the second reference signal terminal V2 and the second node N2, and configured to provide the second reference signal provided by the second reference signal terminal to the second node in the reset phase in response to the second control signal provided by the second control signal terminal;
a third switch control module respectively connected to the third control signal terminal G3, the second node and the signal reading terminal RD, and configured to output the current signal generated by the driving module to the signal reading terminal in a data reading phase in response to a third control signal provided by the third control signal terminal;
a fourth switch control module respectively connected to the third control signal terminal G3, the third node N3 and the first power signal terminal VSS, and configured to provide the first power signal provided by the first power signal terminal to the third node in a data reading phase in response to the third control signal provided by the third control signal terminal;
the driving module is respectively connected with a first node, a second node and a third node N3 and is configured to respond to voltage difference signals of the first node and the third node to generate a current signal;
the energy storage module is respectively connected with the first node and the third node, and is configured to store information of threshold voltage of the driving transistor in a reset stage, store information of voltage variation of the third node in an exposure stage, and write the information of the threshold voltage and the information of the voltage variation of the third node into the first node in a data reading stage;
and the photoelectric conversion module is respectively connected with the third reference signal terminal V3 and the third node and is configured to receive the optical signal and convert the optical signal into an electrical signal.
In the photo-sensing pixel compensation circuit provided in the above embodiment, the first switch control module provides the first reference signal to the first node in the reset phase and the exposure phase under the control of the first control signal, the second switch control module provides the second reference signal to the second node in the reset phase under the control of the second control signal, the fourth switch control module provides the first power signal to the third node in the data reading phase under the control of the third control signal, the photo-electric conversion module generates an electric signal through photo-electric conversion to change the potential of the third node, the energy storage module stores the information of the threshold voltage of the driving transistor in the reset phase, stores the information of the voltage variation of the third node in the exposure phase, and writes the information of the threshold voltage and the information of the voltage variation of the third node into the first node in the data reading phase, the driving module generates a current signal according to the voltage difference signal of the first node and the third node, and the third switch control module outputs the current signal generated by the driving module to the signal reading end in a data reading stage under the control of a third control signal. Because the threshold voltage of the driving transistor is stored in the energy storage module in advance and is written into the first node in the data reading stage, the magnitude of the current generated by the driving module is irrelevant to the threshold voltage of the driving transistor, so that the output current of the photoelectric sensing pixel compensation circuit is not influenced by the threshold voltage of the driving transistor, and the non-uniformity of the brightness during the imaging of a plurality of pixels is avoided.
In some exemplary embodiments, the photoelectric conversion module includes a photodetector, one end of the photodetector is connected to the first node, and the other end of the photodetector is connected to the first reference signal terminal;
the photodetector includes: a photodiode or metal-semiconductor-metal MSM photodetector;
the photodiode includes: PN-type or PIN-type photodiodes, avalanche photodiodes, and the like.
In some exemplary embodiments, the photoelectric conversion module includes a photodiode D1, an anode of the photodiode is connected to the third reference signal terminal, and a cathode of the photodiode is connected to the third node;
in some exemplary embodiments, the first switching control module includes a first transistor T1; a control electrode of the first transistor T1 is connected to a first control signal terminal, a first electrode of T1 is connected to a first reference signal terminal, and a second electrode of T1 is connected to a first node;
in some exemplary embodiments, the second switch control module includes a second transistor T2; a control electrode of the second transistor T2 is connected to a second control signal terminal, a first electrode of T2 is connected to a second reference signal terminal, and a second electrode of T2 is connected to a second node;
in some exemplary embodiments, the third switch control module includes a third transistor T3; a control electrode of the third transistor T3 is connected to a third control signal terminal, a first electrode of T3 is connected to the second node, and a second electrode of T3 is connected to the signal reading terminal;
in some exemplary embodiments, the fourth switch control module includes a fourth transistor T4; a control electrode of the fourth transistor T4 is connected to the third control signal terminal, a first electrode of T4 is connected to the third node, and a second electrode of T4 is connected to the first power signal terminal;
in some exemplary embodiments, the driving module includes a fifth transistor T5; a control electrode of the fifth transistor T5 is connected to the first node, a first electrode of T5 is connected to the second node, and a second electrode of T5 is connected to the third node;
in some exemplary embodiments, the energy storage module includes a capacitor C1; the first pole of the capacitor C1 is connected to the first node, and the second pole of the capacitor C1 is connected to the third node.
Fig. 7 provides an equivalent circuit diagram of a photo-sensing pixel compensation circuit. As shown in fig. 7, the photo sensing pixel compensation circuit includes: a photodiode D1, a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, and a capacitor C1; wherein the fifth transistor T5 is a driving transistor, and the first transistor T1, the second transistor T2, the third transistor T3 and the fourth transistor T4 are all switching transistors;
the anode of the photodiode is connected with a third reference signal end, and the cathode of the photodiode is connected with a third node;
a control electrode of the first transistor T1 is connected to a first control signal terminal, a first electrode of T1 is connected to a first reference signal terminal, and a second electrode of T1 is connected to a first node;
a control electrode of the second transistor T2 is connected to a second control signal terminal, a first electrode of T2 is connected to a second reference signal terminal, and a second electrode of T2 is connected to a second node;
a control electrode of the third transistor T3 is connected to a third control signal terminal, a first electrode of T3 is connected to the second node, and a second electrode of T3 is connected to the signal reading terminal;
a control electrode of the fourth transistor T4 is connected to the third control signal terminal, a first electrode of T4 is connected to the third node, and a second electrode of T4 is connected to the first power supply signal terminal;
a control electrode of the fifth transistor T5 is connected to the first node, a first electrode of T5 is connected to the second node, and a second electrode of T5 is connected to the third node;
the first pole of the capacitor C1 is connected to the first node, and the second pole of the capacitor C1 is connected to the third node.
The operation of one duty cycle of the photo-sensing pixel compensation circuit provided in fig. 7 will be described with reference to a signal timing diagram.
In the embodiment shown in fig. 7, the transistors T1, T2, T3, T4, and T5 may be N-type thin film transistors. In addition, considering that the leakage current of the ltps tft is small, all the transistors may be ltps tfts, and the tft may be specifically selected from a tft with a bottom gate structure or a tft with a top gate structure.
Fig. 8 provides a timing diagram of signals during operation of the photo-sensing pixel compensation circuit. As shown in fig. 8, the operation of the photo sensing pixel compensation circuit can be divided into three stages. The first reference signal provided by the first reference signal terminal V1, the second reference signal provided by the second reference signal terminal V2, the third reference signal provided by the third reference signal terminal V3, and the first power signal provided by the first power signal terminal VSS are all dc signals. The first control signal provided by the first control signal terminal G1, the second control signal provided by the second control signal terminal G2, and the third control signal provided by the third control signal terminal G3 are all pulse signals.
(1) First stage (stage t1 in FIG. 8)
The first control signal is a high level signal in the first stage, the second control signal is a high level signal in the first stage, and the third control signal is a low level signal in the first stage.
In the first stage, the first control signal and the second control signal are high level signals, and the first transistor and the second transistor are conducted. Potential U of the first nodeN1Comprises the following steps: u shapeN1＝UV1(ii) a Wherein, UV1Is the voltage of the first reference signal. Potential U of the second nodeN3Comprises the following steps: u shapeN2＝UV2(ii) a Wherein, UV2Is the voltage of the second reference signal. The driving transistor (fifth transistor) is turned on, and the potential U of the third nodeN3Comprises the following steps: u shapeN3＝UV1-Vth(ii) a Wherein, VthIs the threshold voltage of the drive transistor.
The first pole of the capacitor C1 is connected to the first node, the second pole of the capacitor C1 is connected to the third node N3, and the voltage difference U between the first node and the third nodeGS＝UN1-UN3＝VthThat is, the capacitor C1 stores therein the threshold voltage information of the drive transistor.
The first stage may be regarded as a node (first node and third node) reset stage, that is, potentials of the first node and the third node are reset, and threshold voltage information of the driving transistor (second transistor) is stored in the capacitor C1.
In the first stage, the third control signal is a low level signal, the third transistor is in an off state, and the signal read terminal RD does not output a current signal.
(2) Second stage (stage t2 in FIG. 8)
The first control signal is a high level signal in the second stage, the second control signal is a low level signal in the second stage, and the third control signal is a low level signal in the second stage.
In the second stage, the first control signal is a high level signal, and the first transistor is turned on. Potential U of the first nodeN1Comprises the following steps: u shapeN1＝UV1. The second control signal is a low level signal and the second transistor is turned off. The potential of the third node is higher than the voltage value of the third reference signal, and therefore, the photodiode is in a reverse bias state. The photodiode receives an optical signal and converts the optical signal into electricitySignal, the potential of the third node is reduced by DeltaU, U in the second stageN3＝UV1-Vth- Δ U. The second phase can be regarded as the photoelectric conversion phase of the photodiode, i.e. the exposure phase.
In the second stage, the third control signal is a low level signal, the third transistor is in an off state, and the signal read terminal RD does not output a current signal.
(3) Third stage (stage t3 in FIG. 8)
The first control signal is a low level signal in the second stage, the second control signal is a low level signal in the second stage, and the third control signal is a high level signal in the second stage.
In the third stage, the first control signal and the second control signal are low level signals, and the first transistor and the second transistor are cut off. The third control signal is a high level signal, and the third transistor and the fourth transistor are turned on.
The fourth transistor is turned on, the potential of the third node jumps, and UN3＝UVSS(ii) a Wherein, UVSSIs the voltage of the first power supply signal. The first pole of the capacitor C1 is connected to the first node, the second pole of the capacitor C1 is connected to the third node N3, and when the potential of the third node changes, the potential of the other pole (first node) of the capacitor C1 also changes, and therefore, the potential of the first node changes: u shapeN1＝UVSS+Vth+ΔU。
The driving transistor generates a current I according to a voltage difference signal of the first node and the third nodeo，Io＝k(Vgs-Vth)2(ii) a k is a parameter related to the process parameters and feature size of the drive transistor;
Vgs＝UN1-UN3；
wherein, UN1＝UVSS+Vth+ΔU；UN3＝UVSS；
Thus, Vgs＝(UVSS+Vth+ΔU)-UVSS＝Vth+ΔU；
Io＝k(Vgs-Vth)2＝k(Vth+ΔU-Vth)2＝k(ΔU)2；
In the third stage, the third transistor is turned on, and the signal reading terminal RD outputs the current signal IoThe current signal has a current magnitude independent of the threshold voltage of the drive transistor. The third phase may be considered as the phase of reading the current data.
The working process of the photoelectric sensing pixel compensation circuit can be divided into three stages: the first stage is a reset stage of the node potential in which the potentials of the first node and the third node are reset, and the threshold voltage of the driving transistor is stored in the capacitor. The second stage is an exposure stage of the photoelectric conversion element which generates an electric signal by photoelectric conversion and pulls down the potential of the third node, and information of the voltage variation amount of the third node is stored in the capacitor. The third stage is a stage of reading current data, and the information of the threshold voltage and the information of the voltage variation of the third node are written into the first node, so that the magnitude of the current generated by the driving transistor is irrelevant to the threshold voltage of the driving transistor, the output current of the photoelectric sensing pixel compensation circuit is not influenced by the threshold voltage of the driving transistor, and the non-uniformity of the brightness when a plurality of pixels are imaged is avoided.
The embodiment of the disclosure provides a driving method of a photoelectric sensing pixel compensation circuit, which may include the following steps:
in a reset stage, the first switch control module resets the potentials of the first node and the third node under the control of a first control signal, the second switch control module resets the potential of the second node under the control of a second control signal, and the energy storage module stores information of the threshold voltage of the driving transistor;
in an exposure stage, the photoelectric conversion module receives an optical signal and converts the optical signal into an electric signal to change the potential of the third node, and the energy storage module stores information of voltage variation of the third node;
in a data reading stage, the energy storage module writes information of threshold voltage of the driving transistor and information of voltage variation of the third node into the first node, and the driving module generates a current signal according to a voltage difference signal of the first node and the third node; the third switch control module outputs the current signal to a signal reading end under the control of a third control signal.
In a reset stage, the first switch control module resets potentials of the first node and the third node under the control of the first control signal, the second switch control module resets a potential of the second node under the control of the second control signal, and the energy storage module stores information of a threshold voltage of the driving transistor. In an exposure stage, the photoelectric conversion module receives an optical signal and converts the optical signal into an electric signal to change the potential of the third node, and the energy storage module stores information of the voltage variation of the third node. In a data reading stage, the energy storage module writes information of threshold voltage of the driving transistor and information of voltage variation of the third node into the first node, and the driving module generates a current signal according to a voltage difference signal of the first node and the third node; the third switch control module outputs the current signal to a signal reading end under the control of a third control signal. Because the threshold voltage of the driving transistor is written into the first node in advance, the current generated by the driving module is irrelevant to the threshold voltage of the driving transistor, so that the output current of the photoelectric sensing pixel compensation circuit is not influenced by the threshold voltage of the driving transistor, and the non-uniformity of the brightness when a plurality of pixels are imaged is avoided.
In some exemplary embodiments, the driving module generates the current signal according to a voltage difference signal of the first node and the third node, including:
the driving module generates a current value I of a current signal according to a voltage difference signal of the first node and the third nodeoComprises the following steps:
Io＝k(ΔU)2；
wherein k is a parameter related to a process parameter and a feature size of the driving transistor; Δ U is a voltage variation amount of the third node caused by the photoelectric conversion action of the photoelectric conversion module in the exposure phase.
The embodiment of the disclosure also provides a display device, which comprises the photoelectric sensing pixel compensation circuit.
The display device may be an organic light emitting display device. The display device may be: any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like. Other essential components of the display device are understood by those skilled in the art, and are not described herein nor should they be construed as limiting the present disclosure.
Although the embodiments disclosed in the present disclosure are described above, the descriptions are only for the convenience of understanding the present disclosure, and are not intended to limit the present disclosure. It will be understood by those skilled in the art of the present disclosure that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure, and that the scope of the disclosure is to be limited only by the terms of the appended claims.

Claims (13)

1. A photo-sensing pixel compensation circuit, comprising: the device comprises a first switch control module, a driving module, a second switch control module, an energy storage module and a photoelectric conversion module; the driving module comprises a driving transistor;
the first switch control module is respectively connected with a first control signal end, a first node and a second node, and is configured to respond to a first control signal provided by the first control signal end to reset the potential of the first node in a reset stage and write the threshold voltage of the driving transistor into the first node;
the driving module is respectively connected with a first node, a second node and a third node and is configured to respond to a voltage signal of the first node to generate a current signal; the third node is also connected with a first power supply signal end;
the second switch control module is respectively connected with a second control signal end, a second node and a signal reading end and is configured to respond to a second control signal provided by the second control signal end and output a current signal generated by the driving module to the signal reading end in a data reading stage;
the energy storage module is respectively connected with the first node and the third node and is configured to store voltage difference information between the first node and the third node;
and the photoelectric conversion module is respectively connected with the first reference signal end and the first node, and is configured to receive an optical signal and convert the optical signal into an electrical signal.
2. The photo-sensing pixel compensation circuit of claim 1, wherein:
the first switch control module comprises a first transistor; a control electrode of the first transistor T1 is connected to a first control signal terminal, a first electrode of T1 is connected to a first node, and a second electrode of T1 is connected to a second node;
the second switch control module includes a third transistor T3; a control electrode of the third transistor T3 is connected to a second control signal terminal, a first electrode of T3 is connected to a second node, and a second electrode of T3 is connected to a signal reading terminal;
the driving module includes a second transistor T2; a control electrode of the second transistor T2 is connected to the first node, a first electrode of T2 is connected to the second node, and a second electrode of T2 is connected to the third node.
3. The photo-sensing pixel compensation circuit of claim 1, wherein:
the energy storage module comprises a capacitor C1; the first pole of the capacitor C1 is connected to the first node, and the second pole of the capacitor C1 is connected to the third node.
4. The photo-sensing pixel compensation circuit of claim 1, wherein:
the photoelectric conversion module comprises a photoelectric detector, one end of the photoelectric detector is connected with a first node, and the other end of the photoelectric detector is connected with a first reference signal end;
the photodetector includes: a photodiode or a metal-semiconductor-metal MSM photodetector.
5. The photo-sensing pixel compensation circuit of claim 1, wherein:
the first control signal provided by the first control signal terminal is a pulse signal; the second control signal provided by the second control signal terminal is a pulse signal.
6. A photo-sensing pixel compensation circuit, comprising: the energy storage device comprises a first switch control module, a second switch control module, a third switch control module, a fourth switch control module, a driving module, an energy storage module and a photoelectric conversion module; the driving module comprises a driving transistor;
the first switch control module is respectively connected with the first control signal terminal, the first reference signal terminal and the first node and is configured to respond to a first control signal provided by the first control signal terminal to provide a first reference signal provided by the first reference signal terminal to the first node in a reset stage and an exposure stage;
the second switch control module is respectively connected with the second control signal terminal, the second reference signal terminal and the second node and is configured to respond to a second control signal provided by the second control signal terminal and provide a second reference signal provided by the second reference signal terminal to the second node in a reset stage;
the third switch control module is respectively connected with a third control signal terminal, a second node and a signal reading terminal and is configured to respond to a third control signal provided by the third control signal terminal and output a current signal generated by the driving module to the signal reading terminal in a data reading stage;
the fourth switch control module is respectively connected with the third control signal terminal, the third node and the first power supply signal terminal, and is configured to respond to a third control signal provided by the third control signal terminal to provide the first power supply signal provided by the first power supply signal terminal to the third node in a data reading stage;
the driving module is respectively connected with a first node, a second node and a third node and is configured to respond to voltage difference signals of the first node and the third node to generate a current signal;
the energy storage module is respectively connected with the first node and the third node, and is configured to store information of threshold voltage of the driving transistor in a reset stage, store information of voltage variation of the third node in an exposure stage, and write the information of the threshold voltage and the information of the voltage variation of the third node into the first node in a data reading stage;
and the photoelectric conversion module is respectively connected with the third reference signal end and the third node and is configured to receive the optical signal and convert the optical signal into an electric signal.
7. The photo-sensing pixel compensation circuit of claim 6, wherein:
the first switching control module includes a first transistor T1; a control electrode of the first transistor T1 is connected to a first control signal terminal, a first electrode of T1 is connected to a first reference signal terminal, and a second electrode of T1 is connected to a first node;
the second switch control module comprises a second transistor T2; a control electrode of the second transistor T2 is connected to a second control signal terminal, a first electrode of T2 is connected to a second reference signal terminal, and a second electrode of T2 is connected to a second node;
the third switch control module comprises a third transistor T3; a control electrode of the third transistor T3 is connected to a third control signal terminal, a first electrode of T3 is connected to the second node, and a second electrode of T3 is connected to the signal reading terminal;
the fourth switch control module includes a fourth transistor T4; a control electrode of the fourth transistor T4 is connected to the third control signal terminal, a first electrode of T4 is connected to the third node, and a second electrode of T4 is connected to the first power signal terminal;
the driving module includes a fifth transistor T5; a control electrode of the fifth transistor T5 is connected to the first node, a first electrode of T5 is connected to the second node, and a second electrode of T5 is connected to the third node;
the energy storage module comprises a capacitor C1; the first pole of the capacitor C1 is connected to the first node, and the second pole of the capacitor C1 is connected to the third node.
8. The photo-sensing pixel compensation circuit of claim 6, wherein:
the photoelectric conversion module comprises a photoelectric detector, one end of the photoelectric detector is connected with a first node, and the other end of the photoelectric detector is connected with a first reference signal end;
the photodetector includes: a photodiode or a metal-semiconductor-metal MSM photodetector.
9. A method of driving a photo-sensing pixel compensation circuit according to any one of claims 1 to 5, comprising the steps of:
in a reset stage, the first switch control module resets the potential of the first node under the control of a first control signal and writes the threshold voltage of the driving transistor into the first node;
in an exposure stage, the photoelectric conversion module receives an optical signal, converts the optical signal into an electrical signal, and stores generated charges in the energy storage module to change the potential of the first node;
in a data reading stage, the driving module generates a current signal according to the voltage signal of the first node; the second switch control module outputs the current signal to a signal reading end under the control of a second control signal.
10. The driving method according to claim 9, characterized in that:
the driving module generates a current signal according to a voltage signal of a first node, and comprises:
the current value I of the current signal generated by the driving module according to the voltage signal of the first nodeoComprises the following steps:
Io＝k(ΔU)2；
wherein k is a parameter related to a process parameter and a feature size of the driving transistor; Δ U is a voltage variation amount of the first node caused by the photoelectric conversion action of the photoelectric conversion module in the exposure phase.
11. A method of driving a photo-sensing pixel compensation circuit according to any one of claims 6 to 8, comprising the steps of:
in a reset stage, the first switch control module resets the potentials of the first node and the third node under the control of a first control signal, the second switch control module resets the potential of the second node under the control of a second control signal, and the energy storage module stores information of the threshold voltage of the driving transistor;
in an exposure stage, the photoelectric conversion module receives an optical signal and converts the optical signal into an electric signal to change the potential of the third node, and the energy storage module stores information of voltage variation of the third node;
in a data reading stage, the energy storage module writes information of threshold voltage of the driving transistor and information of voltage variation of the third node into the first node, and the driving module generates a current signal according to a voltage difference signal of the first node and the third node; the third switch control module outputs the current signal to a signal reading end under the control of a third control signal.
12. The driving method according to claim 11, characterized in that:
the driving module generates a current signal according to a voltage difference signal of the first node and the third node, and comprises:
the driving module generates a current value I of a current signal according to a voltage difference signal of the first node and the third nodeoComprises the following steps:
Io＝k(ΔU)2；
wherein k is a parameter related to a process parameter and a feature size of the driving transistor; Δ U is a voltage variation amount of the third node caused by the photoelectric conversion action of the photoelectric conversion module in the exposure phase.
13. A display device comprising a photo-sensing pixel compensation circuit according to any one of claims 1 to 5 or comprising a photo-sensing pixel compensation circuit according to any one of claims 6 to 8.
CN202011461756.8A 2020-12-11 2020-12-11 Photoelectric sensing pixel compensation circuit, driving method and display device Pending CN114627788A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011461756.8A CN114627788A (en) 2020-12-11 2020-12-11 Photoelectric sensing pixel compensation circuit, driving method and display device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011461756.8A CN114627788A (en) 2020-12-11 2020-12-11 Photoelectric sensing pixel compensation circuit, driving method and display device

Publications (1)

Publication Number Publication Date
CN114627788A true CN114627788A (en) 2022-06-14

Family

ID=81895525

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011461756.8A Pending CN114627788A (en) 2020-12-11 2020-12-11 Photoelectric sensing pixel compensation circuit, driving method and display device

Country Status (1)

Country Link
CN (1) CN114627788A (en)

Similar Documents

Publication Publication Date Title
JP4825982B2 (en) Solid-state imaging device and signal readout method thereof
EP2178293B1 (en) Active pixel sensor circuit
CN108447443B (en) Pixel circuit, driving method and display device
US11085817B2 (en) Device and method for detecting light intensity, and display device
JP5222240B2 (en) Optical sensor circuit and optical sensor array
EP2375728B1 (en) Solid-state image pickup element and method for controlling same
US20100123812A1 (en) Photoelectric Conversion Circuit and Solid State Imaging Device Including Same
CN111312161B (en) Pixel driving circuit and display panel
CN108766341B (en) Pixel circuit, display panel, display device, and control method of pixel circuit
US20200162688A1 (en) Pixel sensing circuit and driving method thereof, image sensor and electronic device
JP2018092990A (en) Photoelectric conversion device and imaging system
US20220084466A1 (en) Pixel circuit and pixel control method
WO2018086342A1 (en) Pixel sensing circuit, driving method thereof, image sensor, and electronic device
US10734422B2 (en) Semiconductor apparatus having a reset transistor for resetting a potential in a semiconductor region
US8835829B2 (en) Image sensor formed by silicon rich oxide material
JP5654305B2 (en) Photosensor array
CN114627788A (en) Photoelectric sensing pixel compensation circuit, driving method and display device
JP5661399B2 (en) Optical sensor and optical sensor array
KR20190108372A (en) Pixel for image sensor, photodiode and driving method for image sensor
CN112532899B (en) Photoelectric conversion circuit, driving method, photoelectric detection substrate, and photoelectric detection device
JP2011199050A (en) Solid-state imaging device and electronic apparatus
CN112333404A (en) Photosensitive unit, photosensitive device, driving method and display device
KR20030067550A (en) Solid-state image pickup device and electronic information apparatus
US20240184405A1 (en) Photoelectric detection circuit, method of controlling photoelectric detection circuit, and pixel unit
CN114500893A (en) Image sensor, control method thereof and display panel

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