CN114220373B

CN114220373B - Light detection module, light detection method and display device

Info

Publication number: CN114220373B
Application number: CN202111563571.2A
Authority: CN
Inventors: 胡耀
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2021-12-20
Filing date: 2021-12-20
Publication date: 2023-12-22
Anticipated expiration: 2041-12-20
Also published as: CN114220373A

Abstract

The invention provides a light detection module, a light detection method and a display device. The light detection module is contained in a display device, and the display device comprises a display panel; the light detection module comprises a light sensing circuit and an amplifying circuit; the light sensing circuit is used for sensing light signals and generating and outputting corresponding photocurrent through the photocurrent output end; the amplifying circuit is electrically connected with the photocurrent output end and is used for amplifying and converting the photocurrent to obtain a first output current, and the first output current is output through the first output end; the light sensing circuit and the amplifying circuit are integrated in the display panel. The invention can accurately obtain the illumination intensity of the corresponding optical signal and is beneficial to improving the screen occupation ratio of the display panel.

Description

Light detection module, light detection method and display device

Technical Field

The present invention relates to the field of optical detection technologies, and in particular, to an optical detection module, an optical detection method, and a display device.

Background

As the user's demand for screen space is increasing, more and more functional devices need to be integrated within the screen. In the prior art, an ambient light detection module cannot be well integrated in a display panel, so that the screen occupation ratio of the display panel is low, the problems of low light induction and large noise exist, and the illumination intensity of a light signal cannot be accurately obtained.

Disclosure of Invention

The invention mainly aims to provide a light detection module, a light detection method and a display device, which solve the problems that in the prior art, the ambient light detection module cannot be well integrated in a display panel, so that the screen occupation ratio of the display panel is low, and the illumination intensity of an optical signal cannot be accurately obtained.

In order to achieve the above objective, an embodiment of the present invention provides a light detection module, which is included in a display device, the display device includes a display panel; the light detection module comprises a light sensing circuit and an amplifying circuit;

the light sensing circuit is used for sensing light signals and generating and outputting corresponding photocurrent through the photocurrent output end;

the amplifying circuit is electrically connected with the photocurrent output end and is used for amplifying and converting the photocurrent to obtain a first output current, and the first output current is output through the first output end;

the light sensing circuit and the amplifying circuit are integrated in the display panel.

Optionally, the amplifying circuit includes an amplifying transistor and a storage capacitor;

the first end of the storage capacitor is electrically connected with the photocurrent output end, and the second end of the storage capacitor is electrically connected with the power supply voltage end;

The control electrode of the amplifying transistor is electrically connected with the photocurrent output end, the first electrode of the amplifying transistor is electrically connected with the power supply voltage end, and the second electrode of the amplifying transistor is electrically connected with the first output end.

Optionally, the light detection module according to at least one embodiment of the present invention further includes a processing circuit;

the processing circuit is electrically connected with the amplifying circuit and is used for obtaining the illumination intensity of the optical signal according to the first output current.

Optionally, the light detection module according to at least one embodiment of the present invention further includes an output control circuit and a reset control circuit;

the output control circuit is respectively and electrically connected with the output control end, the first output end and the second output end and is used for controlling the communication between the first output end and the second output end under the control of an output control signal provided by the output control end so as to output the first output current through the second output end;

the reset control circuit is respectively and electrically connected with the reset control end, the first end of the storage capacitor and the second end of the storage capacitor, and is used for controlling the communication between the first end of the storage capacitor and the second end of the storage capacitor under the control of a reset control signal provided by the reset control end.

Optionally, the light sensing circuit includes a photodiode; the light detection module further comprises a voltage control circuit;

the anode of the photodiode is electrically connected with the first voltage end, and the cathode of the photodiode is electrically connected with the photocurrent output end;

the voltage control circuit is electrically connected with the first voltage terminal and is used for providing a high voltage signal for the first voltage terminal in a reset stage and providing a low voltage signal for the first voltage terminal in a sampling stage;

the output control circuit is used for controlling the disconnection between the first output end and the second output end in a reset stage and controlling the communication between the first output end and the second output end in a sampling stage;

the reset control circuit is used for controlling the communication between the first end of the storage capacitor and the second end of the storage capacitor in a reset stage and is used for controlling the disconnection between the first end of the storage capacitor and the second end of the storage capacitor in a sampling stage.

Optionally, the output control circuit includes an output control transistor, and the reset control circuit includes a reset control transistor;

the control electrode of the output control transistor is electrically connected with the output control end, the first electrode of the output control transistor is electrically connected with the first output end, and the second electrode of the output control transistor is electrically connected with the second output end;

The control electrode of the reset control transistor is electrically connected with the reset control end, the first electrode of the reset control transistor is electrically connected with the first end of the storage capacitor, and the second electrode of the reset control transistor is electrically connected with the second end of the storage capacitor.

Optionally, the light detection module according to at least one embodiment of the present invention further includes a control circuit and a capacitance integration conversion circuit;

the control circuit is used for controlling the conversion parameters of the capacitance integration conversion circuit;

the capacitance integral conversion circuit is used for carrying out integral conversion on the first output current according to the conversion parameter and the integral time to obtain an analog output voltage.

Optionally, the capacitance integration conversion circuit comprises a conversion sub-circuit and a sampling sub-circuit; the sampling sub-circuit comprises M integrating capacitors, wherein M is a positive integer;

the control circuit is used for controlling the first end of each integrating capacitor to be communicated with the input end of the conversion sub-circuit in a time-sharing way under the control of the capacitor control signal; the second end of each integrating capacitor is electrically connected with the output end of the conversion subcircuit;

the conversion sub-circuit is used for converting the first output current to obtain and output the analog output voltage through the output end of the conversion sub-circuit.

Optionally, the control circuit is further configured to control, under control of an on-off control signal, communication between an input end of the conversion sub-circuit and an output end of the conversion sub-circuit.

Optionally, the control circuit comprises an on-off control transistor and M capacitance control transistors;

the control electrode of the mth capacitance control transistor is electrically connected with the mth capacitance control end, the first electrode of the mth capacitance control transistor is electrically connected with the input end of the conversion sub-circuit, the second electrode of the mth capacitance control transistor is electrically connected with the first end of the mth integration capacitor, and the second end of the mth integration capacitor is electrically connected with the output end of the conversion sub-circuit; the mth capacitance control end is used for providing an mth capacitance control signal;

the control electrode of the on-off control transistor is electrically connected with the on-off control end, the first electrode of the on-off control transistor is electrically connected with the input end of the conversion sub-circuit, and the second electrode of the on-off control transistor is electrically connected with the output end of the conversion sub-circuit;

m is a positive integer less than or equal to M.

Optionally, the conversion sub-circuit includes an operational amplifier; the non-inverting input end of the operational amplifier is the input end of the conversion sub-circuit, and the output end of the operational amplifier is the output end of the conversion sub-circuit;

The inverting input terminal of the operational amplifier is electrically connected with the ground terminal.

Optionally, the light detection module according to at least one embodiment of the present invention further includes a processing circuit; the processing circuit comprises an analog-to-digital converter and a processing unit;

the analog-to-digital converter is electrically connected with the capacitance integral conversion circuit and is used for converting the analog output voltage into a digital output voltage;

the processing unit is electrically connected with the analog-to-digital converter and is used for receiving the digital output voltage and obtaining the illumination intensity of the optical signal according to the digital output voltage.

The embodiment of the invention also provides a light detection method which is applied to the light detection module and comprises the following steps:

the light sensing circuit senses a light signal, and generates and outputs corresponding light current through a light current output end;

the amplifying circuit amplifies and converts the photocurrent to obtain a first output current, and the first output current is output through a first output end.

Optionally, the light detection module further comprises a processing circuit; the light detection method further includes:

the processing circuit obtains the illumination intensity of the optical signal according to the first output current.

Optionally, the light detection module further comprises an output control circuit and a reset control circuit; the amplifying circuit comprises an amplifying transistor and a storage capacitor; the sampling period comprises a reset phase and a sampling phase which are arranged at intervals; the light detection method comprises the following steps:

in a reset stage, the output control circuit controls the disconnection between the first output end and the second output end, and the reset control circuit controls the communication between the first end of the storage capacitor and the second end of the storage capacitor;

in the sampling stage, the output control circuit controls the communication between the first output end and the second output end, and the reset control circuit controls the disconnection between the first end of the storage capacitor and the second end of the storage capacitor.

Optionally, the light sensing circuit includes a photodiode; the light detection module further comprises a voltage control circuit; the anode of the photodiode is electrically connected with the first voltage end, and the cathode of the photodiode is electrically connected with the photocurrent output end; the light detection method further includes:

in a reset stage, the voltage control circuit provides a high voltage signal to the first voltage terminal;

in a sampling stage, the voltage control circuit provides a low voltage signal to the first voltage terminal.

Optionally, the light detection module further comprises a control circuit and a capacitance integration conversion circuit; the light detection method further includes:

the control circuit controls the conversion parameters of the capacitance integration conversion circuit;

and the capacitance integration conversion circuit converts the first output current according to the conversion parameter and the integration time to obtain an analog output voltage.

Optionally, the capacitance integration conversion circuit comprises a conversion sub-circuit and a sampling sub-circuit; the sampling sub-circuit comprises M integrating capacitors, wherein M is a positive integer; the sampling period comprises a reset phase and a sampling phase which are arranged at intervals; the sampling phase comprises M+1 sampling time periods; m is a positive integer, M is a positive integer less than or equal to M; the light detection method comprises the following steps:

in a first sampling period, the control circuit controls the communication between the input end of the conversion sub-circuit and the output end of the conversion sub-circuit under the control of an on-off control signal; the conversion sub-circuit converts the first output current, and outputs a first analog output voltage when the first sampling period is over; when the voltage value of the first analog output voltage is smaller than a first voltage value, a corresponding current value of the first output current can be obtained according to the voltage value of the first analog output voltage;

In the (m+1) th sampling time period, the control circuit controls the first end of the (m) th integration capacitor to be communicated with the input end of the conversion sub-circuit under the control of the (m) th capacitor control signal; the conversion sub-circuit converts the first output current, and outputs an m+1th analog output voltage when the m+1th sampling time period is finished; when the m-th analog output voltage is greater than or equal to the m-th voltage value and the m+1-th analog output voltage is less than the m+1-th voltage value, a corresponding current value of the first output current can be obtained according to the m+1-th analog output voltage.

Optionally, the light detection module further comprises a processing circuit; the processing circuit comprises an analog-to-digital converter and a processing unit;

the light detection method further includes:

the analog-to-digital converter converts the analog output voltage to a digital output voltage;

and the processing unit obtains the illumination intensity of the optical signal according to the digital output voltage.

The embodiment of the invention also provides a display device which comprises a display panel and the light detection module;

According to the light detection module, the light detection method and the display device, the light sensing circuit senses the ambient light signals to generate the corresponding photocurrent, the amplifying circuit amplifies and converts the photocurrent to obtain the first output current, the illumination intensity of the corresponding light signals can be accurately obtained according to the first output current, and the light sensing circuit and the amplifying circuit included in the light detection module are integrated in the display panel, so that the screen occupation ratio of the display panel is improved.

Drawings

FIG. 1 is a block diagram of a light detection module according to an embodiment of the present invention;

FIG. 2 is a block diagram of a light detection module according to at least one embodiment of the present invention;

FIG. 3 is a block diagram of a light detection module according to at least one embodiment of the present invention;

FIG. 4 is a block diagram of a light detection module according to at least one embodiment of the present invention;

FIG. 5 is a block diagram of a light detection module according to at least one embodiment of the present invention;

FIG. 6 is a circuit diagram of a light detection module according to at least one embodiment of the invention;

FIG. 7 is a timing diagram illustrating operation of at least one embodiment of the light detection module shown in FIG. 6 according to the present invention;

FIG. 8 is a block diagram of a light detection module according to at least one embodiment of the present invention;

FIG. 9 is a block diagram of a light detection module according to at least one embodiment of the present invention;

FIG. 10 is a block diagram of a light detection module according to at least one embodiment of the present invention;

FIG. 11 is an illuminance-sensitivity curve;

FIG. 12 is a timing diagram illustrating operation of at least one embodiment of the light detection module shown in FIG. 10 according to the present invention;

fig. 13 is a block diagram of a light detection module according to at least one embodiment of the invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The transistors used in all embodiments of the present invention may be transistors, thin film transistors or field effect transistors or other devices having the same characteristics. In the embodiment of the invention, in order to distinguish the two poles of the transistor except the control pole, one pole is called a first pole, and the other pole is called a second pole.

In actual operation, when the transistor is a thin film transistor or a field effect transistor, the first electrode may be a drain electrode, and the second electrode may be a source electrode; alternatively, the first pole may be a source and the second pole may be a drain.

As shown in fig. 1, the light detection module according to the embodiment of the invention is included in a display device, where the display device includes a display panel; the light detection module comprises a light sensing circuit 11 and an amplifying circuit 12;

the light sensing circuit 11 is used for sensing a light signal, generating and outputting a corresponding light current through a light current output end P0;

the amplifying circuit 12 is electrically connected to the photocurrent output end P0, and is configured to amplify and convert the photocurrent to obtain a first output current, and output the first output current through a first output end O1;

the light sensing circuit 11 and the amplifying circuit 12 are integrated in the display panel.

When the embodiment of the light detection module shown in fig. 1 works, the light sensing circuit 11 senses an ambient light signal to generate a corresponding photocurrent, the photocurrent is output through the photocurrent output end P0, the amplifying circuit 12 amplifies and converts the photocurrent to obtain a first output current, and the illumination intensity of the corresponding light signal can be accurately obtained according to the first output current.

By adopting the light detection module provided by the embodiment of the invention, the light sensing circuit 11 and the amplifying circuit 12 included in the light detection module are integrated in the display panel, so that the screen duty ratio of the display panel is improved.

In at least one embodiment of the present invention, the light sensing circuit 11 and the amplifying circuit 12 may be disposed on a display substrate included in the display panel, and the transistor included in the amplifying circuit 12 may be fabricated while fabricating a thin film transistor on the display substrate, so as to improve the integration level of the display panel.

In a specific implementation, the amplifying circuit may include an amplifying transistor and a storage capacitor;

the control electrode of the amplifying transistor is electrically connected with the photocurrent output end, the first electrode of the amplifying transistor is electrically connected with the power supply voltage end, and the second electrode of the amplifying transistor is electrically connected with the first output end;

the first end of the storage capacitor is electrically connected with the photocurrent output end, and the second end of the storage capacitor is electrically connected with the power supply voltage end.

As shown in fig. 2, the amplifying circuit 12 may include an amplifying transistor T2 and a storage capacitor Cs on the basis of the embodiment of the light detection module shown in fig. 1;

The grid electrode of the amplifying transistor T2 is electrically connected with the photocurrent output end P0, the source electrode of the amplifying transistor T2 is electrically connected with the power supply voltage end Vcc, and the drain electrode of the amplifying transistor T2 is electrically connected with the first output end O1;

the first end of the storage capacitor Cs is electrically connected to the photocurrent output end P0, and the second end of the storage capacitor Cs is electrically connected to the power supply voltage end Vcc.

In at least one embodiment of the light detection module shown in fig. 2, T2 is a p-type thin film transistor, but not limited thereto.

In operation, at least one embodiment of the photo detection module shown in fig. 2 of the present invention induces a photo signal to generate and output a corresponding photo current through a photo current output end P0, so as to charge the storage capacitor Cs with the photo current to raise the potential VP0 of the photo current output end P0, wherein the potential VP0 of the photo current output end P0 is related to the charging time for charging the storage capacitor Cs with the photo current, and the longer the charging time is, the greater the current value of the photo current is, the higher the potential VP0 of the photo current output end P0 is, and the calculation formula of the current value I1 of the first output current is as follows:

I1＝1/2×Cox×(W/L)×K(VP0–Vc1-Vth) ² ；

Wherein Cox is the interface capacitance of the gate oxide layer of T0, W/L is the channel width-to-length ratio of T0, K is a constant, vc1 is the voltage value of the power supply voltage signal provided by the power supply voltage terminal, and Vth is the threshold voltage of T0;

as can be seen from the above calculation formula, when VP0 is larger, I1 is larger, and the illumination intensity of the optical signal can be obtained according to I1.

In at least one embodiment of the present invention, the light sensing circuit may include a photodiode;

the anode of the photodiode is electrically connected with the first voltage end, and the cathode of the photodiode is electrically connected with the photocurrent output end.

As shown in fig. 3, based on at least one embodiment of the light detection module shown in fig. 1, the light detection module according to at least one embodiment of the present invention may further include a processing circuit 20;

the processing circuit 20 is electrically connected to the amplifying circuit 12, and is configured to obtain the illumination intensity of the optical signal according to the first output current.

In an embodiment, the processing circuit 20 may be disposed in the micro-control unit, and the processing circuit 20 may be disposed in an integrated chip included in a display device, where the display device includes the display panel and the integrated chip, and the integrated chip may be attached to a side of the display panel, but not limited to this.

As shown in fig. 4, based on at least one embodiment of the light detection module shown in fig. 2, the light detection module according to at least one embodiment of the present invention further includes an output control circuit 31 and a reset control circuit 32;

the output control circuit 31 is electrically connected to the output control terminal S3, the first output terminal O1, and the second output terminal O2, and is configured to control, under control of an output control signal provided by the output control terminal S3, communication between the first output terminal O1 and the second output terminal O2, so as to output the first output current through the second output terminal O2;

the reset control circuit 32 is electrically connected to the reset control terminal S1, the first terminal of the storage capacitor Cs, and the second terminal of the storage capacitor Cs, and is configured to control communication between the first terminal of the storage capacitor Cs and the second terminal of the storage capacitor Cs under the control of the reset control signal provided by the reset control terminal S1, so as to release the charge stored in the storage capacitor Cs.

In operation, at least one embodiment of the light detection module of the present invention as shown in fig. 4 requires that the charge stored in the storage capacitor Cs be released by the reset control circuit 32 prior to the sampling phase.

As shown in fig. 5, in at least one embodiment of the light detection module shown in fig. 4, the light sensing circuit includes a photodiode PD; the light detection module further comprises a voltage control circuit 40;

the anode of the photodiode PD is electrically connected with the first voltage end V1, and the cathode of the photodiode PD is electrically connected with the photocurrent output end P0;

the voltage control circuit 40 is electrically connected to the first voltage terminal V1, and is configured to provide a low voltage signal to the first voltage terminal V1 during a sampling stage, so that the photodiode PD is in a reverse bias state, and the photodiode PD can perform photoelectric conversion; the voltage control circuit 40 is further configured to provide a high voltage signal to the first voltage terminal V1 during a reset phase, so as to reset the photodiode PD, and release redundant defect states and dipoles in the PN junction of the photodiode PD;

the output control circuit 31 is configured to control, in a reset phase, disconnection between the first output terminal O1 and the second output terminal O2, and further configured to control, in a sampling phase, communication between the first output terminal O1 and the second output terminal O2, so as to output the first output current through the second output terminal O2;

The reset control circuit 32 is configured to control communication between the first terminal of the tank circuit 11 and the second terminal of the tank circuit 11 during a reset phase, so as to release charges stored in the tank circuit 11, and is configured to control disconnection between the first terminal of the tank circuit 11 and the second terminal of the tank circuit 11 during a sampling phase.

In operation, in at least one embodiment of the light detection module shown in fig. 5, the voltage control circuit 40 provides a high voltage signal to the first voltage terminal V1 during the reset phase, so that the potential of the anode of the photodiode PD is higher than the potential of the cathode of the photodiode, the photodiode PD is reset, and the redundant defect states and dipoles in the PN junction of the photodiode PD are released.

As shown in fig. 6, on the basis of at least one embodiment of the light detection module shown in fig. 4,

the light sensing circuit 10 includes a photodiode PD;

the output control circuit 31 includes an output control transistor T3, and the reset control circuit 32 includes a reset control transistor T1;

the grid electrode of the output control transistor T3 is electrically connected with the output control end S3, the source electrode of the output control transistor T3 is electrically connected with the first output end O1, and the drain electrode of the output control transistor T3 is electrically connected with the second output end O2;

the control electrode of the reset control transistor T1 is electrically connected to the reset control end S1, the source electrode of the reset control transistor T1 is electrically connected to the first end of the storage capacitor Cs, and the drain electrode of the reset control transistor T1 is electrically connected to the second end of the storage capacitor Cs.

In at least one embodiment of the light detection module shown in fig. 6, T1, T2 and T3 are p-type thin film transistors, but not limited thereto.

In operation, at least one embodiment of the light detection module of the present invention as shown in fig. 6, the sampling period may include a reset phase and a sampling phase that are disposed at intervals; in fig. 7, a first reset phase is denoted by t11, a first sampling phase is denoted by t21, and a second reset phase is denoted by t 12;

in a first reset stage t11 and a second reset stage t12, the first voltage terminal V1 is connected to a high voltage signal to reset the photodiode PD, and release redundant defect states and dipoles in the PN junction of the photodiode PD; s1, outputting a low-voltage signal, wherein T1 is conducted, and the communication between the first end of the storage capacitor Cs and the second end of the storage capacitor Cs is controlled so as to release charges in the storage capacitor Cs; s3, outputting a high-voltage signal to control the turn-off of T3 and control the disconnection between the first output end O1 and the second output end O2;

in a first sampling stage t21, the first voltage terminal V1 is connected to a low voltage signal, so that the photodiode PD can perform photoelectric conversion; s3, outputting a low-voltage signal to control the opening of T3, and controlling the communication between the first output end O1 and the second output end O1 to output the first output current through the second output end O2; s1 outputs a high-voltage signal, T1 is turned off, and the first end of the storage capacitor Cs is controlled to be disconnected from the second end of the storage capacitor Cs.

In practice, a second sampling phase may also be provided after the second reset phase t 12.

In an implementation, the light detection module according to at least one embodiment of the present invention may further include a control circuit and a capacitance integration conversion circuit;

In at least one embodiment of the present invention, the light detection module controls the conversion parameter of the capacitive integration conversion circuit through the control circuit, the capacitive integration conversion circuit uses a current integration method to convert the first output current according to the conversion parameter and the integration time, so as to obtain an analog output voltage, and the illumination intensity of the light signal can be obtained according to the analog output voltage.

In at least one embodiment of the present invention, the photo detection module converts the photocurrent into a sampling voltage (the sampling voltage is the analog output voltage) by using a capacitive integration conversion circuit according to a current capacitive integration principle, wherein a ratio between an absolute value of a variation of a voltage value of the analog output voltage and an absolute value of a variation of the photocurrent is a transfer coefficient of the capacitive integration conversion circuit, and the transfer coefficient is related to a capacitance value of an integration capacitor and an integration time.

In at least one embodiment of the present invention, the integration time of the capacitive integrating amplifying circuit is the time for performing the integral conversion on the first output current.

As shown in fig. 8, based on at least one embodiment of the light detection module shown in fig. 4, the light detection module according to at least one embodiment of the present invention may further include a control circuit 81 and a capacitance integration conversion circuit 82;

the control circuit 81 is electrically connected with the capacitance integration conversion circuit 82, and is used for controlling conversion parameters of the capacitance integration conversion circuit 82;

the capacitive integrating conversion circuit 82 is electrically connected to the second output terminal O2, and is configured to perform integrating conversion on the first output current from the second output terminal O2 according to the conversion parameter and the integration time, so as to obtain an analog output voltage.

In at least one embodiment of the present invention, the capacitance integration conversion circuit includes a conversion sub-circuit and a sampling sub-circuit; the sampling sub-circuit comprises M integrating capacitors, wherein M is a positive integer;

The conversion sub-circuit is used for converting the first output current to obtain and output the analog output voltage through the output end of the conversion sub-circuit;

the conversion parameter is the capacitance value of an integrating capacitor which is currently communicated with the input end of the conversion sub-circuit.

Furthermore, the control circuit can also be used for controlling the communication between the input end of the conversion sub-circuit and the output end of the conversion sub-circuit under the control of the on-off control signal.

M is a positive integer less than or equal to M.

In specific implementation, the parasitic capacitance of the on-off control transistor can be regarded as an integral capacitance with a smaller capacitance value; when the on-off control transistor is turned on, the conversion parameter is a capacitance value of a parasitic capacitance of the on-off control transistor.

In at least one embodiment of the present invention, M is equal to 5, but in actual operation, M may be a positive integer, and the value of M may be selected according to the actual situation.

As shown in fig. 9, in at least one embodiment of the light detection module shown in fig. 8, the capacitive integration conversion circuit includes a conversion sub-circuit 90 and a sampling sub-circuit; the sampling sub-circuit comprises a first integrating capacitor C1, a second integrating capacitor C2, a third integrating capacitor C3, a fourth integrating capacitor C4 and a fifth integrating capacitor C5;

the control circuit 81 is electrically connected to the first end of the first integrating capacitor C1, the first end of the second integrating capacitor C2, the first end of the third integrating capacitor C3, the first end of the fourth integrating capacitor C4, the first end of the fifth integrating capacitor C5, the input end of the converting sub-circuit 90 and the output end of the converting sub-circuit 90, and is configured to control the first end of the first integrating capacitor C1, the first end of the second integrating capacitor C2, the first end of the third integrating capacitor C3, the first end of the fourth integrating capacitor C4 and the first end of the fifth integrating capacitor C5 to be in time-sharing communication with the input end of the converting sub-circuit 90 under the control of a capacitance control signal, and to control the input end of the converting sub-circuit 90 to be in communication with the output end of the converting sub-circuit 90 under the control of an on-off control signal;

The input end of the conversion sub-circuit 90 is electrically connected with the second output end O2, and the conversion sub-circuit 90 is configured to convert the first output current from the second output end O2 to obtain and output the analog output voltage through the output end of the conversion sub-circuit 90;

the second end of the first integrating capacitor C1, the second end of the second integrating capacitor C2, the second end of the third integrating capacitor C3, the second end of the fourth integrating capacitor C4 and the second end of the fifth integrating capacitor C5 are all electrically connected to the output end of the conversion sub-circuit 90.

In operation, at least one embodiment of the light detection module of the present invention as shown in fig. 9, the control circuit 81 controls the integrating capacitor connected to the input terminal of the conversion sub-circuit 90, or the control circuit 81 controls the connection between the input terminal of the conversion sub-circuit 90 and the output terminal of the conversion sub-circuit 90 to control the conversion parameter of the capacitive-integrating conversion circuit, and the conversion sub-circuit 90 converts the first output current to obtain an analog output voltage.

In operation, according to at least one embodiment of the light detection module shown in fig. 9, when the control circuit 81 controls the first end of the first integrating capacitor C1, the first end of the second integrating capacitor C2, the first end of the third integrating capacitor C3, the first end of the fourth integrating capacitor C4 and the first end of the fifth integrating capacitor C5 to communicate with the input end of the converting sub-circuit 90, the conversion parameter is a capacitance value of the integrating capacitor communicating with the input end of the converting sub-circuit 90, and when the control circuit 81 controls the communication between the input end of the converting sub-circuit 90 and the output end of the converting sub-circuit 90, the conversion parameter is a capacitance value of the parasitic capacitor of the on-off control transistor included in the control circuit 81.

As shown in fig. 10, in at least one embodiment of the light detection module shown in fig. 9, the control circuit 81 includes an on-off control transistor TG0, a first capacitance control transistor TG1, a second capacitance control transistor TG2, a third capacitance control transistor TG3, a fourth capacitance control transistor TG4, and a fifth capacitance control transistor TG5; the conversion sub-circuit comprises an operational amplifier A0;

the grid electrode of the first capacitance control transistor TG1 is electrically connected with a first capacitance control end G1, the source electrode of the first capacitance control transistor TG1 is electrically connected with the non-inverting input end of the operational amplifier A0, the drain electrode of the first capacitance control transistor TG1 is electrically connected with the first end of the first integration capacitor C1, and the second end of the first integration capacitor C1 is electrically connected with the output end O0 of the operational amplifier A0; the first capacitance control terminal G1 is configured to provide a first capacitance control signal;

The grid electrode of the second capacitance control transistor TG2 is electrically connected with a second capacitance control end G2, the source electrode of the second capacitance control transistor TG2 is electrically connected with the non-inverting input end of the operational amplifier A0, the drain electrode of the second capacitance control transistor TG2 is electrically connected with the first end of the second integration capacitor C2, and the second end of the second integration capacitor C2 is electrically connected with the output end O0 of the operational amplifier A0; the second capacitance control terminal G2 is configured to provide a second capacitance control signal;

the gate of the third capacitance control transistor TG3 is electrically connected to the third capacitance control terminal G3, the source of the third capacitance control transistor TG3 is electrically connected to the non-inverting input terminal of the operational amplifier A0, the drain of the third capacitance control transistor TG3 is electrically connected to the first terminal of the third integration capacitor C3, and the second terminal of the third integration capacitor C3 is electrically connected to the output terminal O0 of the operational amplifier A0; the third capacitance control terminal G3 is configured to provide a third capacitance control signal;

the gate of the fourth capacitance control transistor TG4 is electrically connected to the fourth capacitance control terminal G4, the source of the fourth capacitance control transistor TG4 is electrically connected to the non-inverting input terminal of the operational amplifier A0, the drain of the fourth capacitance control transistor TG4 is electrically connected to the first terminal of the fourth integration capacitor C4, and the second terminal of the fourth integration capacitor C4 is electrically connected to the output terminal O0 of the operational amplifier A0; the fourth capacitance control terminal G4 is configured to provide a fourth capacitance control signal;

The gate of the fifth capacitance control transistor TG5 is electrically connected to the fifth capacitance control terminal G5, the source of the fifth capacitance control transistor TG5 is electrically connected to the non-inverting input terminal of the operational amplifier A0, the drain of the fifth capacitance control transistor TG5 is electrically connected to the first terminal of the fifth integration capacitor C5, and the second terminal of the fifth integration capacitor C5 is electrically connected to the output terminal O0 of the operational amplifier A0; the fifth capacitance control terminal G5 is configured to provide a fifth capacitance control signal;

the grid electrode of the on-off control transistor TG0 is electrically connected with an on-off control end G0, the source electrode of the on-off control transistor T0 is electrically connected with the input end of the operational amplifier A0, and the drain electrode of the on-off control transistor T0 is electrically connected with the output end O0 of the operational amplifier A0;

the inverting input terminal of the operational amplifier A0 is electrically connected with the ground terminal GND.

In at least one embodiment shown in fig. 10, TG0, TG1, TG2, TG3, TG4 and TG5 are p-type thin film transistors, but not limited thereto.

In at least one embodiment of the light detection module shown in fig. 10, the capacitance values C0z, C1z, C2z, C3z, C4z and C5z of the parasitic capacitance of TG0, C2, C3, C4 and C5 are sequentially increased; when the capacitance value of the capacitor connected to the non-inverting input end of the operational amplifier A0 is smaller, the detection accuracy is higher.

In at least one embodiment of the light detection module shown in fig. 10, C0z may be 0.1pF, C1z may be 1pF, C2z may be 5pF, C3z may be 25pF, C4z may be 150pF, C5z may be 750pF, but not limited thereto.

The optical detection module provided by the embodiment of the invention needs different ranges and has different precision ranges. According to the visual perception condition of human eyes on brightness, the sensitivity of human eyes on low brightness is higher.

Fig. 11 is a graph of illuminance-sensitivity, in which the vertical axis is illuminance and the horizontal axis is the number of samples, and as shown in fig. 11, the smaller the illuminance, the larger the slope of the illuminance-sensitivity graph, that is, the larger the number of samples selected in the same amount of change in illuminance (the illuminance, that is, illuminance intensity), and the smaller the illuminance, the higher the corresponding sensitivity.

In operation of at least one embodiment of the light detection module shown in fig. 10, five integrating capacitors and one on-off control transistor (the parasitic capacitance of the on-off control transistor may be regarded as one integrating capacitor) are used, when the integration time (the integration time may be, for example, 0.2ms, but not limited thereto) is the same, when different integrating capacitors are connected to the non-inverting input terminal of the operational amplifier A0, the current range of the first output current that can be detected is different,

When at least one embodiment of the light detection module shown in fig. 10 is in operation, when the on-off control transistor TG0 is turned on, the current value range of the first output current that can be accurately detected may be 0-Iz1; when the first capacitance control transistor TG1 is turned on, a current value range of the first output current that can be accurately detected may be Iz1 to Iz2; when the second capacitance control transistor TG2 is turned on, a current value range of the first output current that can be accurately detected may be Iz2 to Iz3; when the third capacitance control transistor TG3 is turned on, a current value range of the first output current that can be accurately detected may be Iz3 to Iz4; when the fourth capacitance control transistor TG4 is turned on, the current value range of the first output current that can be accurately detected may be Iz4 to Iz5; when the fifth capacitance control transistor TG5 is turned on, a current value range of the first output current that can be accurately detected may be Iz5 to Iz6;

wherein, iz1 is a first current value, iz2 is a second current value, iz3 is a third current value, iz4 is a fourth current value, iz5 is a fifth current value, and Iz6 is a sixth current value;

Iz6＞Iz5＞Iz4＞Iz3＞Iz2＞Iz1。

as shown in fig. 12, in operation, at least one embodiment of the light detection module of the present invention as shown in fig. 10 may include a first sampling period P1, a second sampling period P2, a third sampling period P3, a fourth sampling period P4, a fifth sampling period P5, and a sixth sampling period P6, which are sequentially set;

Providing a low voltage signal in a first sampling period P1, G0, providing a high voltage signal in each of G1, G2, G3, G4 and G5, switching on each of TG0, TG1, TG2, TG3, TG4 and TG5, switching on each of TG0 and parasitic capacitance of TG0 at a non-inverting input end of the operational amplifier A0, detecting a first analog output voltage Vo1 output by an output end O0 of the operational amplifier A0 at the end of the first sampling period P1, and obtaining a corresponding current value of a first output current according to Vo1 when the voltage value of Vo1 is judged to be smaller than the first voltage value; when the voltage value of Vo1 is greater than or equal to the first voltage value, obtaining a current value of a corresponding first output current according to the analog output voltage sampled in the later sampling time period;

providing a low voltage signal in a second sampling period P2, G1, providing a high voltage signal in each of G0, G2, G3, G4 and G5, switching on each of TG1, TG0, TG2, TG3, TG4 and TG5, switching off each of TG1, and communicating a non-inverting input end of an operational amplifier A0 with each of TG1, detecting a second analog output voltage Vo2 output by an output end O0 of the operational amplifier A0 at the end of the second sampling period P2, and obtaining a corresponding current value of a first output current according to Vo2 by referring to Vo1 when the voltage value of Vo2 is judged to be smaller than the second voltage value; when the voltage value of Vo2 is greater than or equal to the second voltage value, obtaining a current value of the corresponding first output current according to the analog output voltage sampled in the later sampling time period;

Providing a low voltage signal in a third sampling period P3, G2, providing a high voltage signal in each of G0, G1, G3, G4 and G5, switching on each of TG2, TG0, TG1, TG3, TG4 and TG5, switching off each of TG2, communicating a non-inverting input end of the operational amplifier A0 with each of TG2, detecting a third analog output voltage Vo3 output by an output end O0 of the operational amplifier A0 at the end of the third sampling period P3, and obtaining a corresponding current value of the first output current according to Vo3 by referring to Vo1 and Vo2 when the voltage value of Vo3 is judged to be smaller than the third voltage value; when the voltage value of Vo3 is greater than or equal to the third voltage value, obtaining a current value of the corresponding first output current according to the analog output voltage sampled in the later sampling period;

providing a low voltage signal in a fourth sampling period P4, G3, providing a high voltage signal in each of G0, G1, G2, G4 and G5, turning on each of TG3, TG0, TG1, TG2, TG4 and TG5, and turning off each of TG3, wherein a non-inverting input end of the operational amplifier A0 is communicated with each of TG3, detecting a fourth analog output voltage Vo4 output by an output end O0 of the operational amplifier A0 at the end of the fourth sampling period P4, and obtaining a corresponding current value of the first output current according to Vo4 by referring to Vo1, vo2 and Vo3 when the voltage value of Vo4 is judged to be smaller than the fourth voltage value; when the voltage value of Vo4 is greater than or equal to the fourth voltage value, obtaining a current value of the corresponding first output current according to the analog output voltage sampled in the later sampling period;

Providing a low voltage signal in a fifth sampling period P5, G4, providing a high voltage signal in each of G0, G1, G2, G3 and G5, turning on each of TG4, and turning off each of TG0, TG1, TG2, TG3 and TG5, wherein a non-inverting input end of the operational amplifier A0 is communicated with the TG4, detecting a fifth analog output voltage Vo5 output by an output end O0 of the operational amplifier A0 at the end of the fifth sampling period P5, and obtaining a corresponding current value of a first output current according to Vo5 by referring to Vo1, vo2, vo3 and Vo4 when the voltage value of Vo5 is judged to be smaller than the fifth voltage value; when the voltage value of Vo5 is greater than or equal to the fifth voltage value, obtaining a current value of the corresponding first output current according to the analog output voltage sampled in the later sampling period;

in the sixth sampling period P6, G5, G0, G1, G2, G3 and G4, G5 is turned on, TG0, TG1, TG2, TG3 and TG4 are all turned off, the non-inverting input terminal of the operational amplifier A0 is connected to TG5, the sixth analog output voltage Vo6 outputted from the output terminal O0 of the operational amplifier A0 at the end of the sixth sampling period P6 is detected, and when it is determined that the voltage value of Vo6 is smaller than the sixth voltage value, the corresponding current value of the first output current can be obtained according to Vo6 with reference to Vo1, vo2, vo3, vo4 and Vo 5.

In fig. 12, reference numeral Vout is a voltage value of an analog output voltage outputted from the output terminal O0 of the operational amplifier A0.

In specific implementation, the duration of the first sampling period P1, the duration of the second sampling period P2, the duration of the third sampling period P3, the duration of the fourth sampling period P4, the duration of the fifth sampling period P5, and the duration of the sixth sampling period P6 may be 0.2ms, but are not limited thereto.

In particular embodiments, the first voltage value may be set according to Iz1, the second voltage value may be set according to Iz2, the third voltage value may be set according to Iz3, the fourth voltage value may be set according to Iz4, the fifth voltage value may be set according to Iz5, and the sixth voltage value may be set according to Iz 6.

In operation, at least one embodiment of the light detection module shown in fig. 10 can provide a low voltage signal to the output terminal O0 of the operational amplifier A0 during the reset phase to release the residual charges in each integrating capacitor.

In a specific implementation, the light detection module according to at least one embodiment of the present invention may further include a processing circuit; the processing circuit comprises an analog-to-digital converter and a processing unit;

As shown in fig. 13, based on at least one embodiment of the light detection module shown in fig. 8, the light detection module according to at least one embodiment of the present invention may further include a processing circuit, where the processing circuit includes an analog-to-digital converter 131 and a processing unit 132;

the analog-to-digital converter 131 is electrically connected to the capacitance integration conversion circuit 82, and is configured to convert the analog output voltage into a digital output voltage;

the processing unit 132 is electrically connected to the analog-to-digital converter 131, and is configured to receive the digital output voltage, and obtain the illumination intensity of the optical signal according to the digital output voltage.

In practice, the processing unit 132 may be disposed in an MCU (micro control unit), but is not limited thereto.

The light detection method of the embodiment of the invention is applied to the light detection module, and comprises the following steps:

In the light detection method disclosed by the embodiment of the invention, the light sensing circuit senses an ambient light signal to generate a corresponding photocurrent, the photocurrent is output through the photocurrent output end, the amplifying circuit amplifies and converts the photocurrent to obtain a first output current, and the illumination intensity of the corresponding light signal can be obtained according to the first output current.

In at least one embodiment of the present invention, the light detection module further includes a processing circuit; the light detection method further includes:

In specific implementation, the light detection module may further include an output control circuit and a reset control circuit; the amplifying circuit comprises an amplifying transistor and a storage capacitor; the sampling period comprises a reset phase and a sampling phase which are arranged at intervals; the light detection method comprises the following steps:

In the light detection module according to at least one embodiment of the present invention, before the sampling phase, in the reset phase, the charge stored in the storage capacitor needs to be released by the reset control circuit.

in a reset stage, the voltage control circuit provides a high-voltage signal for the first voltage end so as to reset the photodiode and release redundant defect states and dipoles in a PN junction of the photodiode;

in a sampling stage, the voltage control circuit provides a low voltage signal to the first voltage terminal so that the photodiode is in a reverse bias state, and the photodiode can perform photoelectric conversion.

In specific implementation, the light detection module further comprises a control circuit and a capacitance integration conversion circuit; the light detection method further includes:

In the light detection method according to at least one embodiment of the present invention, the control circuit controls the conversion parameter of the capacitive integration conversion circuit, the capacitive integration conversion circuit uses a current integration method to convert the first output current according to the conversion parameter and the integration time, so as to obtain an analog output voltage, and the illumination intensity of the light signal can be obtained according to the analog output voltage.

In a first sampling period, the control circuit controls the communication between the input end of the conversion sub-circuit and the output end of the conversion sub-circuit under the control of an on-off control signal; the conversion sub-circuit converts the first output current, and outputs a first analog output voltage when the first sampling period is over; when the voltage value of the first analog output voltage is smaller than a first voltage value, obtaining a corresponding current value of the first output current according to the voltage value of the first analog output voltage;

in the (m+1) th sampling time period, the control circuit controls the first end of the (m) th integration capacitor to be communicated with the input end of the conversion sub-circuit under the control of the (m) th capacitor control signal; the conversion sub-circuit converts the first output current, and when the (m+1) th sampling time period is finished, the conversion sub-circuit outputs an (m+1) th analog output voltage; when the m-th analog output voltage is larger than or equal to the m-th voltage value and the m+1-th analog output voltage is smaller than the m+1-th voltage value, obtaining a corresponding current value of the first output current according to the m+1-th analog output voltage.

In a specific implementation, when the sampling sub-circuit includes M integrating capacitors, the sampling stage may include m+1 sampling periods, in each sampling period, the control circuit controls the capacitance value of the input terminal of the conversion sub-circuit, and according to the voltage value of the analog output voltage obtained by conversion of the conversion sub-circuit at the end of each sampling period, the current value of the corresponding first output current may be obtained.

In a specific implementation, the light detection module may further include a processing circuit; the processing circuit comprises an analog-to-digital converter and a processing unit;

the light detection method further includes:

The display device provided by the embodiment of the invention comprises a display panel and the light detection module;

The display device provided by the embodiment of the invention can be any product or component with a display function, such as a mobile phone, a tablet personal computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like.

While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.

Claims

1. The light detection module comprises a display device, wherein the display device comprises a display panel; the light detection module is characterized by comprising a light sensing circuit and an amplifying circuit;

the light sensing circuit and the amplifying circuit are integrated in the display panel

The amplifying circuit comprises an amplifying transistor and a storage capacitor;

the light detection module further comprises an output control circuit and a reset control circuit;

The reset control circuit is respectively and electrically connected with the reset control end, the first end of the storage capacitor and the second end of the storage capacitor and is used for controlling the communication between the first end of the storage capacitor and the second end of the storage capacitor under the control of a reset control signal provided by the reset control end;

the light sensing circuit includes a photodiode; the light detection module further comprises a voltage control circuit;

the reset control circuit is used for controlling the communication between the first end of the storage capacitor and the second end of the storage capacitor in a reset stage and is used for controlling the disconnection between the first end of the storage capacitor and the second end of the storage capacitor in a sampling stage;

The output control circuit comprises an output control transistor, and the reset control circuit comprises a reset control transistor;

2. The light detection module of claim 1, further comprising a processing circuit;

3. The light detection module as claimed in claim 1 or 2, further comprising a control circuit and a capacitance integration conversion circuit;

4. The light detection module of claim 3, wherein the capacitive integrating conversion circuit comprises a conversion sub-circuit and a sampling sub-circuit; the sampling sub-circuit comprises M integrating capacitors, wherein M is a positive integer;

5. The light detection module of claim 4, wherein the control circuit is further configured to control communication between the input of the conversion sub-circuit and the output of the conversion sub-circuit under control of an on-off control signal.

6. The light detection module of claim 5, wherein the control circuit comprises an on-off control transistor and M capacitance control transistors;

m is a positive integer less than or equal to M.

7. The light detection module of claim 4, wherein the conversion sub-circuit comprises an operational amplifier; the non-inverting input end of the operational amplifier is the input end of the conversion sub-circuit, and the output end of the operational amplifier is the output end of the conversion sub-circuit;

8. The light detection module of claim 3, further comprising a processing circuit; the processing circuit comprises an analog-to-digital converter and a processing unit;

9. A light detection method applied to the light detection module set according to any one of claims 1 to 8, wherein the light detection method comprises:

the amplifying circuit amplifies and converts the photocurrent to obtain a first output current, and the first output current is output through a first output end;

the sampling period comprises a reset phase and a sampling phase which are arranged at intervals; the light detection method comprises the following steps:

in a sampling stage, the output control circuit controls the communication between the first output end and the second output end, and the reset control circuit controls the disconnection between the first end of the storage capacitor and the second end of the storage capacitor;

the light detection method further includes:

in a reset stage, the voltage control circuit provides a high-voltage signal to the first voltage terminal;

10. The light detection method of claim 9, wherein the light detection module further comprises a processing circuit; the light detection method further includes:

11. The light detection method according to claim 9 or 10, wherein the light detection module further comprises a control circuit and a capacitance integration conversion circuit; the light detection method further includes:

12. The light detection method of claim 11, wherein the capacitive integrating conversion circuit comprises a conversion sub-circuit and a sampling sub-circuit; the sampling sub-circuit comprises M integrating capacitors, wherein M is a positive integer; the sampling period comprises a reset phase and a sampling phase which are arranged at intervals; the sampling phase comprises M+1 sampling time periods; m is a positive integer, M is a positive integer less than or equal to M; the light detection method comprises the following steps:

13. The light detection method of claim 11, wherein the light detection module further comprises a processing circuit; the processing circuit comprises an analog-to-digital converter and a processing unit;

the light detection method further includes:

14. A display device comprising a display panel and the light detection module according to any one of claims 1 to 8;