CN114157356A

CN114157356A - Photosensitive circuit, photosensitive substrate and photosensitive device

Info

Publication number: CN114157356A
Application number: CN202111465410.XA
Authority: CN
Inventors: 郭玉珍; 李扬冰; 王佳斌; 王伟杰; 黄睿; 张振宇; 李必奇
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-03-08

Abstract

The utility model provides a photosensitive circuit, sensitization base plate and photosensitive device, photosensitive circuit includes: the first photosensitive element is used for converting an optical signal into a first electric signal, wherein the optical signal comprises a target optical signal and an ambient optical signal; a first amplifying circuit for amplifying the first electric signal and outputting a first target signal; the second photosensitive element is used for converting the optical signal into a second electric signal; the first filter element is used for filtering the electric signal corresponding to the target optical signal from the second electric signal according to the frequency difference between the target optical signal and the ambient optical signal to generate a third electric signal; a second amplifying circuit for amplifying the third electrical signal and outputting a second target signal; and the processing unit is used for determining the target optical signal according to the first target signal and the second target signal. The technical scheme of the disclosure can eliminate the interference of the ambient light and improve the signal-to-noise ratio of the optical communication based on the target optical signal.

Description

Photosensitive circuit, photosensitive substrate and photosensitive device

Technical Field

The present disclosure relates to the field of photoelectric technologies, and in particular, to a photosensitive circuit, a photosensitive substrate, and a photosensitive device.

Background

The visible light communication technology is to transmit information by means of high frequency light signal, which is invisible to naked eye and is emitted by fluorescent lamp, LED, etc. the wire device of high speed Internet is connected to lighting device and may be used after inserting power plug. The communication system made by the technology can cover the range of indoor lighting, and the computer does not need to be connected by wires, thereby having wide development prospect.

However, in visible light communication, ambient light is a major interference factor.

Disclosure of Invention

The disclosure provides a photosensitive circuit, a photosensitive substrate and a photosensitive device to eliminate ambient light interference.

The present disclosure provides a photosensitive circuit, including:

the optical signal processing device comprises a first photosensitive element, a second photosensitive element and a third photosensitive element, wherein the first photosensitive element is used for converting an optical signal into a first electric signal, the optical signal comprises a target optical signal and an environment optical signal, and the frequency of the target optical signal is greater than that of the environment optical signal;

the first amplifying circuit is connected with the first photosensitive element and used for amplifying the first electric signal and outputting a first target signal;

the second photosensitive element is used for converting the optical signal into a second electric signal;

the first filter element is connected with the second photosensitive element and used for filtering an electric signal corresponding to the target optical signal from the second electric signal according to the frequency difference between the target optical signal and the ambient optical signal to generate a third electric signal;

the second amplifying circuit is connected with the first filtering element and used for amplifying the third electric signal and outputting a second target signal;

and the processing unit is respectively connected with the first amplifying circuit and the second amplifying circuit and is used for determining the target optical signal according to the first target signal and the second target signal.

In an alternative implementation, the first photosensitive element includes a first photodiode, and the first amplifying circuit includes a first transistor;

the first pole of the first photosensitive diode is connected with a first bias voltage end, and the second pole of the first photosensitive diode is connected with a first node;

and the control electrode of the first transistor is connected with the first node, the first electrode of the first transistor is connected with a first power supply voltage end, and the second electrode of the first transistor is connected with the processing unit.

In an alternative implementation, the second photosensitive element comprises a second photodiode, the first filter element comprises a first capacitor, and the second amplifying circuit comprises a second transistor;

the first pole of the second photosensitive diode is connected with a second bias voltage end, and the second pole of the second photosensitive diode is connected with a second node;

the first end of the first capacitor is connected with a second power supply voltage end or the first pole of the second photosensitive diode, and the second end of the first capacitor is connected with the second node;

and the control electrode of the second transistor is connected with the second node, the first electrode of the second transistor is connected with a third power supply voltage end, and the second electrode of the second transistor is connected with the processing unit.

In an alternative implementation, the first capacitor is a parasitic capacitor of the second photodiode; alternatively, the first capacitance is a capacitance independent of the second photodiode.

In an alternative implementation, the optical signal further includes a display optical signal, and a frequency of the display optical signal is smaller than a frequency of the target optical signal and larger than a frequency of the ambient optical signal;

the photosensitive circuit further includes:

a third photosensitive element for converting the optical signal into a fourth electrical signal;

the second filter element is connected with the third photosensitive element and is used for filtering an electric signal corresponding to the target optical signal and an electric signal corresponding to the environment optical signal from the fourth electric signal according to the frequency difference of the target optical signal, the display optical signal and the environment optical signal to generate a fifth electric signal;

the third amplifying circuit is connected with the second filter element and used for amplifying the fifth electric signal and outputting a third target signal;

the second filter element is further configured to filter, according to the frequency difference between the target optical signal, the display optical signal, and the ambient optical signal, an electrical signal corresponding to the target optical signal and an electrical signal corresponding to the display optical signal from the second electrical signal, so as to generate a sixth electrical signal; the second amplifying circuit is further configured to amplify the sixth electrical signal and output a fourth target signal;

the processing unit is further connected to the third amplifying circuit, and is further configured to determine the target optical signal according to the first target signal, the third target signal, and the fourth target signal.

In an alternative implementation, the third photosensitive element includes a third photodiode, the second filter element includes a second capacitor, and the third amplifying circuit includes a third transistor;

the first pole of the third photosensitive diode is connected with a third bias voltage end, and the second pole of the third photosensitive diode is connected with a third node;

the first end of the second capacitor is connected with a fourth power supply voltage end or the first pole of the third photosensitive diode, and the second end of the second capacitor is connected with the third node;

and the control electrode of the third transistor is connected with the third node, the first electrode of the third transistor is connected with a fifth power supply voltage end, and the second electrode of the third transistor is connected with the processing unit.

In an alternative implementation, the second capacitance is a parasitic capacitance of the third photodiode; alternatively, the second capacitance is a capacitance independent of the third photodiode.

In an alternative implementation, when the first filter element includes the first capacitor, the capacitance value of the first capacitor is greater than the capacitance value of the second capacitor.

The present disclosure provides a photosensitive substrate including any one of the photosensitive circuits.

In an optional implementation manner, the photosensitive substrate includes a first region and a second region disposed at a periphery of the first region, the first region includes a plurality of first photosensitive elements arranged in an array, the second photosensitive elements are disposed in the second region and/or a preset region in the first region, and the preset region includes a gap between two adjacent columns of the first photosensitive elements and/or a gap between two adjacent rows of the first photosensitive elements.

In an optional implementation manner, the photosensitive substrate is a display substrate, the display substrate includes a display area and a frame area located at the periphery of the display area, the frame area includes at least one of the first photosensitive elements and at least one of the second photosensitive elements, and the at least one of the second photosensitive elements is uniformly distributed in the frame area.

In an optional implementation manner, the photosensitive substrate is a display substrate, the display substrate includes at least one second photosensitive element and a plurality of first pixel units arranged in an array, each first pixel unit includes a light emitting element and the first photosensitive element, and at least one second photosensitive element is uniformly disposed in a non-opening region of the display substrate.

In an optional implementation manner, when the photosensitive circuit further includes the third photosensitive element, the photosensitive substrate is a display substrate, the display substrate includes at least one second photosensitive element, at least one third photosensitive element, and a plurality of second pixel units arranged in an array, each second pixel unit includes a light emitting element and the first photosensitive element, and at least one second photosensitive element and/or at least one third photosensitive element are uniformly disposed in a non-opening region of the display substrate.

In an optional implementation manner, the photosensitive substrate includes a plurality of third pixel units arranged in an array, and each of the third pixel units includes the first photosensitive element or the second photosensitive element.

In an optional implementation manner, the photosensitive substrate is a display substrate, the display substrate includes a plurality of fourth pixel units arranged in an array, and each of the fourth pixel units includes a light emitting element and a photosensitive element;

the photosensitive elements are the first photosensitive elements or the second photosensitive elements, and the second photosensitive elements are uniformly distributed on the display substrate; or, when the photosensitive circuit further includes the third photosensitive element, the photosensitive element is the first photosensitive element, the second photosensitive element or the third photosensitive element, and the third photosensitive elements are uniformly distributed on the display substrate.

In an alternative implementation, when the first photosensitive element includes the first photodiode and the second photosensitive element includes the second photodiode, the area of the first photodiode is smaller than or equal to the area of the second photodiode;

when the photosensitive circuit further comprises the third photosensitive element, and the third photosensitive element comprises a third photosensitive diode, the area of the third photosensitive diode is smaller than or equal to that of the second photosensitive diode, and is larger than or equal to that of the first photosensitive diode.

The present disclosure provides a photosensitive device including any one of the photosensitive substrates.

Compared with the prior art, the present disclosure includes the following advantages:

the utility model provides a photosensitive circuit, photosensitive substrate and photosensitive device, through setting up the signal of telecommunication filtering that first filter element corresponds with the target light signal in with the second signal of telecommunication, the second target signal of second amplifier circuit output only includes the information of environment light signal, and because the first target signal of first amplifier circuit output is the mixing information of target light signal and environment light signal, consequently, processing unit can obtain the target light signal according to first target signal and second target signal, eliminate the interference of environment light, improve the SNR that carries out optical communication based on the target light signal.

The foregoing description is only an overview of the technical solutions of the present disclosure, and the embodiments of the present disclosure are described below in order to make the technical means of the present disclosure more clearly understood and to make the above and other objects, features, and advantages of the present disclosure more clearly understandable.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or technical solutions in related arts, the drawings used in the description of the embodiments or related arts will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present disclosure, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts. It should be noted that the scale in the drawings is merely schematic and does not represent actual scale.

FIG. 1 schematically illustrates a schematic structure diagram of a first photosensitive circuit provided by the present disclosure;

FIG. 2 schematically illustrates a structural schematic diagram of a second photosensitive circuit provided by the present disclosure;

FIG. 3 schematically illustrates a structural schematic diagram of a third photosensitive circuit provided by the present disclosure;

FIG. 4 schematically illustrates a structural schematic diagram of a fourth photosensitive circuit provided by the present disclosure;

FIG. 5 schematically illustrates an equivalent circuit schematic of a photosensitive circuit provided by the present disclosure;

FIG. 6 schematically illustrates a schematic structure diagram of a fifth photosensitive circuit provided by the present disclosure;

FIG. 7 schematically illustrates a structural diagram of a sixth photosensitive circuit provided by the present disclosure;

FIG. 8 is a schematic structural diagram of a first photosensitive substrate provided by the present disclosure;

fig. 9 schematically illustrates a structural view of a second photosensitive substrate provided by the present disclosure;

fig. 10 schematically illustrates a structural view of a third photosensitive substrate provided by the present disclosure;

fig. 11 schematically illustrates a structural view of a fourth photosensitive substrate provided by the present disclosure;

FIG. 12 is a schematic view illustrating a fifth photosensitive substrate provided by the present disclosure;

fig. 13 schematically illustrates a structural view of a sixth photosensitive substrate provided by the present disclosure;

fig. 14 schematically shows a structural view of a seventh photosensitive substrate provided by the present disclosure;

fig. 15 schematically illustrates a structural view of an eighth photosensitive substrate provided by the present disclosure;

fig. 16 schematically shows a cross-sectional structural diagram of a first photodiode and a first capacitor provided by the present disclosure;

fig. 17 schematically shows a cross-sectional structural diagram of a second type of first photodiode and first capacitor provided by the present disclosure;

fig. 18 schematically shows a structural view of a ninth photosensitive substrate provided by the present disclosure;

fig. 19 schematically shows a structural view of a tenth photosensitive substrate provided by the present disclosure;

FIG. 20 is a schematic view illustrating the structure of an eleventh photosensitive substrate provided by the present disclosure;

fig. 21 schematically illustrates a structural view of a twelfth photosensitive substrate provided by the present disclosure;

fig. 22 schematically shows a cross-sectional structural diagram of a third first photodiode and a first capacitor provided by the present disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are some, but not all embodiments of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

An embodiment of the present disclosure provides a photosensitive circuit, and referring to fig. 1, the photosensitive circuit includes: a first photosensitive element 11, a first amplifying circuit 12, a second photosensitive element 13, a first filter element 14, a second amplifying circuit 15, and a processing unit 16.

The first photosensitive element 11 is configured to convert an optical signal into a first electrical signal, where the optical signal includes a target optical signal and an ambient optical signal, and a frequency of the target optical signal is greater than a frequency of the ambient optical signal.

The first amplifying circuit 12 is connected to the first photosensitive element 11, and is configured to amplify the first electrical signal and output a first target signal.

And a second photosensitive element 13 for converting the optical signal into a second electrical signal.

And the first filter element 14 is connected to the second photosensitive element 13, and is configured to filter, according to a frequency difference between the target optical signal and the ambient optical signal, an electrical signal corresponding to the target optical signal from the second electrical signal, and generate a third electrical signal.

And a second amplifying circuit 15 connected to the first filter element 14, for amplifying the third electrical signal and outputting a second target signal.

And a processing unit 16, connected to the first amplifying circuit 12 and the second amplifying circuit 15, respectively, for determining the target optical signal according to the first target signal and the second target signal.

The first photosensitive element 11 and the second photosensitive element 13 may be any photosensitive sensor capable of converting an optical signal into an electrical signal, such as a photodiode, a photoresistor, and the like, which is not limited in this disclosure.

The first amplifier circuit 12 and the second amplifier circuit 15 may have any circuit configuration capable of amplifying an input signal, and the present disclosure does not limit the specific configuration of the first amplifier circuit 12 and the second amplifier circuit 15.

The first filter element 14 may include, for example, a capacitor or the like having a function of filtering a high-frequency signal. In a specific implementation, any element that can filter out an electrical signal with a specific frequency based on the frequency difference of the input signal may be used as the first filter element 14.

The target optical signal may be an optical communication signal, and the target optical signal may be a high frequency signal, for example, having a frequency of 3MHz to 30 MHz.

The ambient light signal may include an illumination light signal of an environment in which the light sensing circuit is located, and the frequency is generally below 10 Hz.

The processing unit 16 may include, for example, a microprocessor or the like, which is not limited by the present disclosure.

In this embodiment, the first electrical signal is an electrical signal generated after the optical signal irradiates the first photosensitive element 11, and includes an electrical signal corresponding to the target optical signal and an electrical signal corresponding to the ambient optical signal. By providing the first amplification circuit 12 between the first photosensitive element 11 and the processing unit 16, the electric signal output by the first photosensitive element 11 can be increased. The first electric signal is amplified by the first amplifying circuit 12 to obtain a first target signal.

The second electrical signal is an electrical signal generated after the optical signal irradiates the second photosensitive element 13, and includes an electrical signal corresponding to the target optical signal and an electrical signal corresponding to the ambient optical signal.

By providing the first filter element 14 between the second photosensitive element 13 and the second amplifying circuit 15, and because there is a frequency difference between the target light signal and the ambient light signal, the first filter element 14 can filter out an electrical signal corresponding to the target light signal in the second electrical signal based on the frequency difference, thereby generating an electrical signal including only the ambient light signal, i.e., a third electrical signal. By providing the second amplifying circuit 15 between the first filter element 14 and the processing unit 16, the third electrical signal can be amplified, and the second target signal can be obtained after the third electrical signal is amplified by the second amplifying circuit 15.

In specific implementation, the amplification factors of the first amplification circuit 12 and the second amplification circuit 15 are reasonably set, and if the amplification factors are the same, the accuracy of the finally determined target optical signal can be improved, and the signal-to-noise ratio of optical communication can be improved.

Since the first target signal includes the mixed information of the target optical signal and the ambient optical signal, and the second target signal includes only the information corresponding to the ambient optical signal, the processing unit 16 may determine the target optical signal according to the difference between the first target signal and the second target signal, for example, so as to eliminate the interference of the ambient light on the optical communication signal.

In the light sensing circuit provided in this embodiment, the first filter element 14 is arranged to filter the electrical signal corresponding to the target optical signal in the second electrical signal, the second target signal output by the second amplifying circuit 15 only includes information of the ambient optical signal, and the first target signal output by the first amplifying circuit 12 is mixed information of the target optical signal and the ambient optical signal, so that the processing unit 16 can obtain the target optical signal according to the first target signal and the second target signal, eliminate interference of the ambient light, and improve the signal-to-noise ratio of optical communication based on the target optical signal.

In an alternative implementation, as shown in fig. 1, the first photosensitive element 11 may include a first photodiode P1, a first pole of the first photodiode P1 is connected to the first bias voltage terminal Vbias1, and a second pole is connected to the first node a.

The first amplifying circuit 12 may include a first transistor T1, a control electrode of the first transistor T1 being connected to the first node a, a first electrode being connected to the first power voltage terminal VDD1, and a second electrode being connected to the processing unit 16.

The first photodiode P1 may be a Metal-Semiconductor-Metal (MSM) photodiode, and may also be a PIN photodiode, which is not limited in this disclosure.

The voltage input by the first bias voltage terminal Vbias1 can be set according to the type of the first photodiode P1, and the first photodiode P1 is in a cut-off state under the condition of no illumination.

The second pole of the first photodiode P1 is connected to the control pole of the first transistor T1, so that the output of the first photodiode P1 can adjust the first voltage of the first transistor T1, so that the first transistor T1 operates in the saturation region, so that the first transistor T1 outputs an amplified current signal at the second pole under the action of the control voltage, and thus the first transistor T1 can function to amplify the signal.

The first amplifying circuit 12 amplifies the electrical signal outputted from the first photodiode P1 by using a switching transistor, so that the manufacturing difficulty of the signal amplifying circuit can be simplified and the space occupied by the signal amplifying circuit can be reduced.

In a specific implementation, the first photodiode P1 and the first transistor T1 may form a repeating unit, the light sensing circuit may include a plurality of repeating units connected in parallel, and accordingly, the signal received by the processing unit 16 is the summation of the output signals of the plurality of first amplifying circuits 12, in which case the processing unit 16 may first calculate the average output of each repeating unit, and then determine the target light signal according to the subtraction result of the average output and the second target signal.

In an alternative implementation, as shown in fig. 1 and 2, the second photosensitive element 13 may include a second photodiode P2, a first pole of the second photodiode P2 is connected to the second bias voltage terminal Vbias2, and a second pole is connected to the second node B.

The first filter element 14 may include a first capacitor C1, a first terminal of the first capacitor C1 being connected to the second power supply voltage terminal VDD2 (shown in fig. 2) or a first pole of the second photodiode P2 (shown in fig. 1), and a second terminal being connected to the second node B.

The second amplifying circuit 15 may include a second transistor T2, a control electrode of the second transistor T2 being connected to the second node B, a first electrode being connected to the third power voltage terminal VDD3, and a second electrode being connected to the processing unit 16.

The second photodiode P2 may be a Metal-Semiconductor-Metal (MSM) photodiode, and may also be a PIN photodiode, which is not limited in this disclosure.

The voltage inputted from the second bias voltage terminal Vbias2 can be set according to the type of the second photodiode P2, and the second photodiode P2 is in a cut-off state under the condition of no illumination.

The second node B is connected to the control electrode of the second transistor T2, so that the voltage of the second node B can adjust the first voltage of the second transistor T2, so that the second transistor T2 operates in the saturation region, and thus the second transistor T2 outputs the amplified current signal at the second electrode under the action of the control electrode voltage, so that the second transistor T2 can play a role in amplifying the signal.

The second amplifying circuit 15 amplifies the electrical signal output by the second photodiode P2 by using a switching transistor, which can simplify the manufacturing difficulty of the signal amplifying circuit and reduce the space occupied by the signal amplifying circuit.

When the first terminal of the first capacitor C1 is connected to the first pole of the second photodiode P2 and the second terminal is connected to the second pole of the second photodiode P2, as shown in fig. 1, the first capacitor C1 is connected in parallel with the second photodiode P2.

In a specific implementation, as shown in fig. 2, the first terminal of the first capacitor C1 may also be connected to the second power voltage terminal VDD2, and the second terminal is connected to the second pole of the second photodiode P2.

To filter out the target optical signal with higher frequency, the capacitance of the first capacitor C1 may be larger than the capacitance of the parasitic capacitor of the first photodiode P1. When the frequency of the target optical signal is on the order of megahertz MHz, the capacitance of the first capacitor C1 may be on the order of μ F. According to the frequency of the target optical signal and the frequency of the environment optical signal, the first capacitor C1 can be reasonably designed, so that the effect of effectively filtering the target optical signal is achieved.

By providing the first capacitor C1, the target optical signal in the second electrical signal can be filtered out, and only the ambient optical signal is output to the second amplifying circuit 15. Since the parasitic capacitance of the first photodiode P1 is low and no filter element is connected, a mixed signal of the target light signal and the ambient light signal can be output to the first amplification circuit 12. Therefore, the processing unit 16 can obtain a simple target optical signal, i.e., a high-frequency optical signal carrying communication information, based on the output signal of the first amplifier circuit 12 and the output signal of the second amplifier circuit 15.

Alternatively, the first capacitor C1 may be a parasitic capacitor of the second photodiode P2. Fig. 5 is a schematic diagram showing an equivalent circuit structure in which the first capacitance is a parasitic capacitance of the second photodiode.

As shown in fig. 5, the parasitic capacitance of the second photodiode P2 is the capacitance formed by the two opposite plates of the second photodiode P2 itself and the photosensitive layer therein. The parasitic capacitance of the second photodiode P2 can be multiplexed into the first capacitance C1, and accordingly, two electrodes of the first capacitance C1, i.e., two electrodes of the two photodiodes.

When the first capacitor C1 is a parasitic capacitor of the second photodiode P2, the target light signal applied to the second photosensitive cell cannot be effectively converted into an electrical signal, and the ambient light signal can be converted into an electrical signal through the second photodiode P2, so that the parasitic capacitor of the second photodiode P2 can function to filter the high frequency signal, i.e., the target light signal.

In order to make the second photodiode P2 have larger parasitic capacitance, the second photodiode P2 can be designed to have larger device area, or larger dielectric constant of the photosensitive layer, or thinner thickness of the photosensitive layer.

Optionally, the first capacitor C1 may also be an auxiliary capacitor independent of the second photodiode P2.

As shown in fig. 1, two ends of the first capacitor C1 are respectively connected to two poles of the second photodiode P2, i.e., the first capacitor C1 is connected in parallel with the second photodiode P2. Alternatively, as shown in fig. 2, the first terminal of the first capacitor C1 may be further connected to the second power voltage terminal VDD2, and the second terminal thereof is connected to the second pole of the second photodiode P2.

In a specific implementation, the first photosensitive element 13 may include a plurality of second photodiodes P2, and the plurality of second photodiodes P2 may share one second amplifying circuit 15, as illustrated in fig. 7; or a plurality of second photodiodes P2 each correspond to one second amplification circuit 15, as shown in fig. 6.

In practical applications, if the light sensing circuit is disposed in a display screen, the display light signal of the display screen may also interfere with optical communication. The frequency of the display light signal is typically between 10Hz and 1000 Hz.

In an alternative implementation manner, the first capacitor C1 may be used to filter a high-frequency target optical signal, the output third electrical signal includes an electrical signal corresponding to the ambient optical signal and an electrical signal corresponding to the display optical signal, and the second target signal amplified by the second amplifying circuit 15 is a mixed signal of the ambient optical signal and the display optical signal. Since the parasitic capacitance of the first photodiode P1 is small and no filter element is provided, the first target signal output by the first amplification circuit 12 includes a mixed signal of the target light signal, the ambient light signal, and the display light signal. In this way, the processing unit 16 obtains the target light signal according to the difference between the first target signal and the second target signal, thereby eliminating the interference of the ambient light signal and the display light signal. In this implementation, the first capacitor C1 can filter signals with frequencies of low frequency and below, the circuit structure is simple, and the occupied space of the photosensitive circuit is small.

In order to be able to eliminate the ambient light signal and the display light signal more completely, in another implementation, two filter elements may be provided, which output the ambient light signal and the display light signal, respectively.

In particular, the optical signal may include a target optical signal, an ambient optical signal, and a display optical signal having a frequency (e.g., 10Hz to 1000Hz) that is less than the frequency of the target optical signal (e.g., on the order of MHz) and greater than the frequency of the ambient optical signal (e.g., < 10 Hz).

Accordingly, as shown in fig. 3, the light sensing circuit may further include: a third photosensitive element 31, a second filter element 32, and a third amplification circuit 33.

Wherein, the third photosensitive element 31 is used for converting the optical signal into a fourth electrical signal.

And the second filter element 32 is connected to the third photosensitive element 31, and is configured to filter, according to the frequency difference between the target optical signal, the display optical signal, and the ambient optical signal, the electrical signal corresponding to the target optical signal and the electrical signal corresponding to the ambient optical signal from the fourth electrical signal, so as to generate a fifth electrical signal.

And a third amplifying circuit 33 connected to the second filter element 32, for amplifying the fifth electric signal and outputting a third target signal.

In this implementation, the second filter element 32 is further configured to filter, according to the frequency difference between the target optical signal, the display optical signal, and the environment optical signal, the electrical signal corresponding to the target optical signal and the electrical signal corresponding to the display optical signal from the second electrical signal, so as to generate a sixth electrical signal; the second amplifying circuit 15 is also configured to amplify the sixth electrical signal and output a fourth target signal.

In this implementation, the processing unit 16 is further connected to the third amplifying circuit 33, and is further configured to determine the target optical signal according to the first target signal, the third target signal and the fourth target signal.

In this implementation, the third photosensitive element 31 may be any photosensitive sensor capable of converting an optical signal into an electrical signal, such as a photodiode, a photoresistor, and the like, which is not limited in this disclosure.

The third amplification circuit 33 may have any circuit configuration capable of amplifying an input signal, and the present disclosure does not limit the specific configuration of the third amplification circuit 33.

The second filter element 32 may include, for example, a capacitor or the like having a function of filtering a high-frequency signal. In a specific implementation, any element that can filter out an electrical signal with a specific frequency based on the frequency difference of the input signal may be used as the second filter element 32.

In this embodiment, the first electrical signal is an electrical signal generated after the optical signal irradiates the first photosensitive element 11, and includes an electrical signal corresponding to the target optical signal, an electrical signal corresponding to the ambient optical signal, and an electrical signal corresponding to the display optical signal. By providing the first amplification circuit 12 between the first photosensitive element 11 and the processing unit 16, the electric signal output by the first photosensitive element 11 can be increased. The first electric signal is amplified by the first amplifying circuit 12 to obtain a first target signal.

The second electrical signal is an electrical signal generated after the optical signal irradiates the second photosensitive element 13, and includes an electrical signal corresponding to the target optical signal, an electrical signal corresponding to the ambient optical signal, and an electrical signal corresponding to the display optical signal.

The fourth electrical signal is an electrical signal generated after the optical signal irradiates the third photosensitive element 31, and includes an electrical signal corresponding to the target optical signal, an electrical signal corresponding to the ambient optical signal, and an electrical signal corresponding to the display optical signal.

By providing the second filter element 32 between the third photosensitive element 31 and the third amplifying circuit 33, and because there is a frequency difference between the target light signal, the display light signal, and the ambient light signal, the second filter element 32 can filter out the electrical signal corresponding to the target light signal and the electrical signal corresponding to the ambient light signal in the fourth electrical signal based on the frequency difference, so as to generate an electrical signal including only the display light signal, that is, a fifth electrical signal. By providing the third amplifying circuit 33 between the second filter element 32 and the processing unit 16, the fifth electrical signal can be amplified, and the third electrical signal is amplified by the third amplifying circuit 33 to obtain the third target signal.

Since there is a frequency difference between the target optical signal, the display optical signal, and the ambient optical signal, the first filter element 14 may filter, based on the frequency difference, an electrical signal corresponding to the target optical signal and an electrical signal corresponding to the display optical signal in the second electrical signal from the second electrical signal, so as to generate an electrical signal including only the ambient optical signal, that is, a sixth electrical signal. The sixth electrical signal is amplified by the second amplifying circuit 15 to obtain a fourth target signal.

In specific implementation, the amplification factors of the first amplification circuit 12, the second amplification circuit 15 and the third amplification circuit 33 are reasonably set, and if the amplification factors are the same, the accuracy of the finally determined target optical signal can be improved, and the signal-to-noise ratio of optical communication can be improved.

Since the first target signal includes the mixed information of the target optical signal, the ambient optical signal and the display optical signal, the third target signal includes only the information corresponding to the display optical signal, and the fourth target signal includes only the information corresponding to the ambient optical signal, the processing unit 16 can determine the target optical signal according to the difference between the first target signal, the third target signal and the fourth target signal, for example, so as to efficiently and thoroughly eliminate the interference of the ambient light and the display light on the optical communication signal. According to the implementation mode, the capacitance values of the first capacitor C1 and the second capacitor C2 can be respectively designed in a targeted manner according to the frequency difference between the ambient light and the display light, and the filtering accuracy is improved.

Alternatively, as shown in fig. 3 and 4, the third photosensitive element 31 includes a third photodiode P3, a first pole of the third photodiode P3 is connected to the third bias voltage terminal Vbias3, and a second pole is connected to the third node C.

The second filter element 32 includes a second capacitor C2, a first terminal of the second capacitor C2 is connected to the fourth power supply voltage terminal VDD4 (as shown in fig. 4) or a first pole of the third photodiode P3 (as shown in fig. 3), and a second terminal is connected to the third node C.

The third amplifying circuit 33 includes a third transistor T3, a control electrode of the third transistor T3 is connected to the third node C, a first electrode is connected to the fifth power voltage terminal VDD5, and a second electrode is connected to the processing unit 16.

The third photodiode P3 may be a Metal-Semiconductor-Metal (MSM) photodiode, and may also be a PIN photodiode, which is not limited in this disclosure.

The voltage inputted from the third bias voltage terminal Vbias3 can be set according to the type of the third photodiode P3, and the third photodiode P3 is in a cut-off state under the condition of no illumination.

The second pole of the third photodiode P3 is connected to the control pole of the third transistor T3, so that the output of the third photodiode P3 can adjust the first voltage of the third transistor T3, so that the third transistor T3 operates in the saturation region, and thus the third transistor T3 outputs an amplified current signal at the second pole under the action of the control voltage, so that the third transistor T3 can function to amplify the signal.

The third amplifying circuit 33 amplifies the electrical signal outputted from the third photodiode P3 by using a switching transistor, which can simplify the manufacturing difficulty of the signal amplifying circuit and reduce the space occupied by the signal amplifying circuit.

As shown in fig. 3, when the first terminal of the second capacitor C2 is connected to the first pole of the third photodiode P3 and the second terminal is connected to the second pole of the third photodiode P3, the second capacitor C2 is connected in parallel with the third photodiode P3.

In a specific implementation, as shown in fig. 4, the first terminal of the second capacitor C2 may also be connected to the fourth power voltage terminal VDD4, and the second terminal is connected to the second pole of the third photodiode P3.

In this implementation, the capacitance of the second capacitor C2 may be greater than the capacitance of the parasitic capacitor of the first photodiode P1 and less than the capacitance of the first capacitor C1.

When the frequency of the target optical signal is in the order of MHz and the frequency of the display optical signal is in the order of KHz, the capacitance values of the first capacitor C1 and the second capacitor C2 may be both in the order of microfarad muf, but the capacitance value of the second capacitor C2 is smaller than that of the first capacitor C1.

By providing the first capacitor C1, the target optical signal and the display optical signal in the second electrical signal can be filtered out, and only the ambient optical signal is output to the second amplifying circuit 15. By providing the second capacitor C2, the target optical signal and the ambient optical signal in the second electrical signal can be filtered out, and only the display optical signal is output to the second amplifying circuit 15. Since the parasitic capacitance of the first photodiode P1 is low and no filter element is connected, a mixed signal of the target light signal, the ambient light signal, and the display light signal can be output to the first amplification circuit 12. Therefore, the processing unit 16 can obtain a simple target optical signal, that is, a high-frequency optical signal carrying communication information, based on the output signal of the first amplifier circuit 12, the output signal of the second amplifier circuit 15, and the output signal of the third amplifier circuit 33.

Alternatively, the second capacitor C2 may be a parasitic capacitor of the third photodiode P3.

The parasitic capacitance of the third photodiode P3 is the capacitance formed by the two opposing plates of the third photodiode P3 itself and the photosensitive layer therein. The parasitic capacitance of the third photodiode P3 can be multiplexed into the second capacitance C2, and accordingly, two electrodes of the second capacitance C2, i.e., two electrodes of the third photodiode P3.

When the second capacitor C2 is a parasitic capacitor of the third photodiode P3, the target light signal and the display light signal are not effectively converted into electrical signals when they act on the third photosensitive unit, and the ambient light signal can be converted into electrical signals through the third photodiode P3, so that the parasitic capacitor of the third photodiode P3 can function to filter the target light signal and the display light signal.

In order to make the third photodiode P3 have a larger parasitic capacitance, the third photodiode P3 can be implemented by designing to have a larger device area, or a larger dielectric constant of the photosensitive layer, or a thinner thickness of the photosensitive layer.

Optionally, the second capacitor C2 may also be a capacitor independent of the second photodiode P2.

As shown in fig. 3, two ends of the second capacitor C2 are respectively connected to two poles of the third photodiode P3, i.e., the second capacitor C2 is connected in parallel with the third photodiode P3. Alternatively, as shown in fig. 4, the first terminal of the second capacitor C2 may be further connected to the fourth power voltage terminal VDD4, and the second terminal is connected to the second pole of the third photodiode P3.

In this embodiment, the first power voltage terminal VDD1, the third power voltage terminal VDD3 and the fifth power voltage terminal VDD5 are the same power voltage terminal. In a specific implementation, the first power voltage terminal VDD1, the third power voltage terminal VDD3, and the fifth power voltage terminal VDD5 may be different or partially different from each other.

In addition, the first bias voltage terminal Vbias1, the second bias voltage terminal Vbias2, and the third bias voltage terminal Vbias3 are the same bias voltage terminal. In a specific implementation, the first bias voltage terminal Vbias1, the second bias voltage terminal Vbias2 and the third bias voltage terminal Vbias3 may be different or partially different from each other.

An embodiment of the present disclosure provides a photosensitive substrate including the photosensitive circuit provided in any embodiment.

Those skilled in the art will appreciate that the photosensitive substrate has the advantages of the previous photosensitive circuit.

In this embodiment, it is assumed that the photosensitive layers of the first photosensitive element 11, the second photosensitive element 13, and the third photosensitive element 31 are the same in thickness and material. When the first photosensitive element 11 includes the first photodiode P1 and the second photosensitive element 13 includes the second photodiode P2, the area of the first photodiode P1 may be less than or equal to the area of the second photodiode P2.

Specifically, when the first capacitor C1 is a parasitic capacitor of the second photodiode P2, the area of the first photodiode P1 is smaller than the area of the second photodiode P2; when the first capacitor C1 is an auxiliary capacitor independent of the second photodiode P2, the area of the first photodiode P1 may be equal to the area of the second photodiode P2.

Further, when the light sensing circuit further includes the third light sensing element 31, and the third light sensing element 31 includes the third photodiode P3, the area of the third photodiode P3 may be less than or equal to the area of the second photodiode P2, and greater than or equal to the area of the first photodiode P1.

When the second capacitor C2 is a parasitic capacitor of the third photodiode P3, the area of the third photodiode P3 is smaller than the area of the second photodiode P2 and larger than the area of the first photodiode P1; when the second capacitor C2 is an auxiliary capacitor independent of the third photodiode P3, the areas of the first photodiode P1, the second photodiode P2 and the third photodiode P3 may be equal.

In a first alternative implementation manner, as shown in fig. 8 and 9, the photosensitive substrate includes a first region and a second region disposed at the periphery of the first region, the first region includes a plurality of first photosensitive elements 11 arranged in an array, the second photosensitive element 13 is disposed in the second region and/or a preset region in the first region, and the preset region includes a gap between two adjacent columns of the first photosensitive elements 11 and/or a gap between two adjacent rows of the first photosensitive elements 11.

Here, the second photosensitive element 13 may be disposed only in the second region, or only in a preset region in the first region, or partially in the second region and partially in the preset region in the first region.

The preset region may include a gap between two adjacent columns of the first photosensitive elements 11, or a gap between two adjacent rows of the first photosensitive elements 11, or a gap between two adjacent columns of the first photosensitive elements 11 and a gap between two adjacent rows of the first photosensitive elements 11.

As shown in fig. 8, the second photosensitive element 13 is disposed in the second area, i.e., the second photosensitive element 13 is designed in a frame shape around the first area. As shown in fig. 9, the second photosensitive elements 13 may also be disposed in the second area, the gap between two adjacent columns of the first photosensitive elements 11, and the gap between two adjacent rows of the first photosensitive elements 11, that is, one grid-shaped second photosensitive element 13 is designed.

Since the available space of the second region and the preset region is large, both the frame-shaped second photosensitive element 13 and the grid-shaped second photosensitive element 13 have large areas and large parasitic capacitances, and in this case, the parasitic capacitance of the second photosensitive element 13 itself can be used as the first capacitance C1 to filter high-frequency signals. In addition, the frame-shaped second photosensitive element 13 or the grid-shaped second photosensitive element 13 can surround the first area more uniformly, so that the second amplifying circuit 15 can output the ambient light signal in a larger range, and further effectively filter the ambient light signal in a larger range from the first target signal, thereby eliminating the ambient light interference more thoroughly.

It should be noted that the second photosensitive element 13 is not limited to the frame shape and the grid shape, and the second photosensitive element 13 may be designed in other shapes, which is not limited in the present disclosure.

In order to reduce the stress problem caused by the large area, in a specific implementation, a plurality of second photosensitive elements 13 may be separately disposed in the second region and the preset region, which is not limited in this disclosure.

In a second alternative implementation manner, as shown in fig. 10, 13 and 19, the photosensitive substrate is a display substrate, the display substrate includes a display area and a frame area located at the periphery of the display area, and the frame area includes at least one first photosensitive element 11 and at least one second photosensitive element 13. The at least one second photosensitive element 13 may be uniformly distributed within the frame area.

Wherein the second photosensitive element 13 comprises a second photodiode. The parasitic capacitance of the second photodiode shown in fig. 10 is multiplexed into the first capacitance C1. The first capacitor C1 in fig. 13 is independent of and in parallel with the second photodiode. In fig. 19, the first capacitor C1 is independent of the second photodiode, and has only one end connected to the second photodiode and the other end connected to the second power supply voltage terminal VDD 2.

The number of the second photosensitive elements 13 may be plural, and the plural second photosensitive elements 13 may be disposed at different positions on the photosensitive substrate, so that the signal output by the second amplifying circuit 15 includes the ambient light signal at each different position, or includes the ambient light signal and the display light signal at each different position.

In this implementation, the integration of the display and optical communication functions can be realized by integrating the photosensitive circuit into the display substrate. In addition, by arranging the first photosensitive element 11 and the second photosensitive element 13 in the frame region, the area of the effective display region can be prevented from being occupied, and the area and the pixel density of the effective display region can be improved.

When the plurality of second photosensitive elements 13 are disposed in the frame region, the plurality of second photosensitive elements 13 may be uniformly distributed in the frame region. For example, one or more second photosensitive elements 13 may be symmetrically disposed at positions near the opposite two sides in the frame region (as shown in fig. 13 and 19), or one second photosensitive element 13 may be disposed at each of positions near the four corners in the frame region (as shown in fig. 10).

In this implementation, the second photosensitive element 13 and the first photosensitive element 11 may have the same area, in which case, in order to filter high-frequency signals, a first capacitor C1 independent from the second photosensitive element 13 may be provided; or the area of the second light sensing element 13 is larger than that of the first light sensing element 11, in which case the parasitic capacitance of the second light sensing element 13 itself may be multiplexed as the first capacitance C1.

In a third alternative implementation manner, as shown in fig. 11, the photosensitive substrate is a display substrate, the display substrate includes at least one second photosensitive element 13 and a plurality of first pixel units 111 arranged in an array, and each first pixel unit 111 includes a light emitting element and a first photosensitive element 11. The at least one second photosensitive element 13 may be uniformly disposed in the non-opening area of the display substrate.

In a fourth alternative implementation, as shown in fig. 12, when the photosensitive circuit further includes a third photosensitive element 31, the photosensitive substrate is a display substrate, the display substrate includes at least one second photosensitive element 13, at least one third photosensitive element 31, and a plurality of second pixel units 121 arranged in an array, and each second pixel unit 121 includes a light emitting element and a first photosensitive element 11. The at least one second photosensitive element 13 and/or the at least one third photosensitive element 31 may be uniformly disposed in a non-opening area of the display substrate.

Among them, the light emitting elements may include, for example, a red light emitting element R, a green light emitting element G, and a blue light emitting element B. As shown in fig. 12, the light emitting elements are arranged in the column direction, the first photosensitive elements 11 are arranged in the column direction, and the light emitting elements and the first photosensitive elements 11 are alternately arranged in the row direction. In a specific implementation, it may also be provided that the light emitting elements are arranged in a row direction, the first photosensitive elements 11 are arranged in the row direction, and the light emitting elements and the first photosensitive elements 11 are alternately arranged in a column direction; or the light emitting elements and the first photosensitive elements 11 are alternately arranged in both the row direction and the column direction; and so on.

In a third implementation, the first filter element 14 connected to the second light sensing element 13 may output an ambient light signal or a mixed signal of the ambient light signal and the display light signal. A photosensitive circuit having an optical communication function is incorporated in the display substrate, and as shown in fig. 11, the first photosensitive element 11 is disposed with a gap between the light emitting elements. Since the difference of the display light signals of different regions in the display substrate is large, the number of the second photosensitive elements 13 may be plural, and the plurality of second photosensitive elements 13 may be uniformly disposed in the non-opening region of the display substrate. The density of the second photosensitive elements 13 is not suitable to be too small, and the denser the second photosensitive elements 13 are arranged, the stronger the interference resistance is. For example, it may be every 2mm or less²A second photosensitive element 13 is disposed in the area of the first photosensitive element.

In the third implementation manner, when the first photosensitive element 11 includes the first photodiode P1 and the second photosensitive element 13 includes the second photodiode P2, since the available space of the non-opening area of the display substrate is larger, the second photodiode P2 with a larger area may be disposed, so that the area of the second photodiode P2 is larger than the area of the first photodiode P1, as shown in fig. 11, in this case, the parasitic capacitance of the second photodiode P2 itself may be reused as the first capacitance C1, which is not limited by the present disclosure. That is, the area of the second photodiode P2 may be larger than the area of the first photodiode P1, ensuring that the first capacitance C1 is larger than the parasitic capacitance of the first photodiode P1. Of course, the area of the second photodiode P2 may be equal to the area of the first photodiode P1, in which case the first capacitor C1 may be provided independently of the second photodiode P2.

In a fourth implementation, as shown in fig. 12, the first filter element 14 connected to the second photosensitive element 13 may output an ambient light signal, and the second filter element 32 connected to the third photosensitive element 31 may output a display light signal. A photosensitive circuit having an optical communication function is incorporated in the display substrate, and as shown in fig. 12, the first photosensitive element 11 is disposed with a gap between the light emitting elements. Since the difference of the display light signals of different regions in the display substrate is large, the number of the third photosensitive elements 31 may be multiple, and the multiple third photosensitive elements 31 are uniformly arranged in the non-opening region of the display substrate. The density of the third photosensitive elements 31 is not suitable to be too small, and the denser the third photosensitive elements 31 are arranged, the stronger the interference resistance is. For example, it may be every 2mm or less²A third photosensitive element 31 is disposed in the area of the first photosensitive element. Since the difference of the ambient light signals in different areas of the display substrate is relatively small, one second photosensitive element 13 may be disposed in the non-opening area of the display substrate. Of course, in a specific implementation, the second photosensitive element 13 may be provided in plurality, and the plurality of second photosensitive elements 13 may also be uniformly provided in the non-opening area.

In the fourth implementation manner, when the first photosensitive element 11 includes the first photodiode P1, the second photosensitive element 13 includes the second photodiode P2, and the third photosensitive element 31 includes the third photodiode P3, since the non-opening area of the display substrate can utilize a large space, the second photodiode P2 and the third photodiode P3 with large areas can be provided, as shown in fig. 12, the areas of the second photodiode P2 and the third photodiode P3 are both larger than the area of the first photodiode P1, in this case, the parasitic capacitance of the second photodiode P2 itself can be reused as the first capacitance C1, and the parasitic capacitance of the third photodiode P3 itself can be reused as the second capacitance C2, which is not limited by the present disclosure.

Specifically, the area of the third photodiode P3 may be smaller than the area of the second photodiode P2 and larger than the area of the first photodiode P1, as shown in fig. 12, ensuring that the second capacitance C2 is larger than the parasitic capacitance of the first photodiode P1 and smaller than the first capacitance C1. In practical applications, the parasitic capacitances of the third photodiode P3 and the second photodiode P2 are different, that is, the device areas are different, the second photodiode P2 with a larger parasitic capacitance outputs an electrical signal corresponding to the lowest-frequency ambient light signal (< 10Hz), and the third photodiode P3 with a smaller parasitic capacitance outputs an electrical signal corresponding to the lower-frequency display light (10Hz to 1000 Hz).

In the third implementation manner and the fourth implementation manner, the second photosensitive element and the third photosensitive element are both arranged in the non-opening area of the display substrate, so that the occupation of the opening space of the display substrate can be avoided, and the opening ratio is improved.

In a fifth alternative implementation manner, as shown in fig. 18, the photosensitive substrate includes a plurality of third pixel units 181 arranged in an array, and each third pixel unit 181 includes the first photosensitive element 11 or the second photosensitive element 13.

When the first photosensitive element 11 includes the first photodiode P1 and the second photosensitive element 13 includes the second photodiode P2, the areas of the first photodiode P1 and the second photodiode P2 may be the same, as shown in fig. 18, in which case a first capacitor C1 may be provided independently of the second photodiode P2 in order to filter high frequency signals. When the areas of the first pixel unit and the second pixel unit are the same, the pixel density of the third pixel unit 181 can be increased. Of course, the area of the first photodiode P1 may be smaller than that of the second photodiode P2, in which case the parasitic capacitance of the second photodiode P2 itself can be multiplexed as the first capacitance C1.

In a sixth alternative implementation manner, as shown in fig. 14, 15, 20 and 21, the photosensitive substrate is a display substrate, the display substrate includes a plurality of fourth pixel units 141 arranged in an array, and each fourth pixel unit 141 includes a light emitting element and a photosensitive element.

As shown in fig. 14 and 20, the photosensitive element is the first photosensitive element 11 or the second photosensitive element 13. The second photosensitive elements 13 may be uniformly distributed on the display substrate.

When the first photosensitive element 11 includes the first photodiode P1 and the second photosensitive element 13 includes the second photodiode P2, as shown in fig. 14 and 20, the first photodiode P1 and the second photodiode P2 have the same area, and in this case, a first capacitor C1 independent from the second photodiode P2 may be provided in order to filter high frequency signals. In fig. 14, a first capacitor C1 is separately provided in parallel with the second photodiode P2 (cross-sectional views are shown in fig. 16 and 17, and the detailed description is referred to later); in fig. 20, one end of a first capacitor C1 independently provided is connected to the second photodiode P2, and the other end is connected to the second power voltage terminal VDD2 (the cross-sectional view is shown in fig. 22, and the detailed description is referred to later).

Among them, the light emitting elements may include, for example, a red light emitting element R, a green light emitting element G, and a blue light emitting element B. As shown in fig. 14, the light emitting elements are arranged in the column direction, the light receiving elements are arranged in the column direction, and the light emitting elements and the light receiving elements are alternately arranged in the row direction. In a specific implementation, the light emitting elements may be arranged along a row direction, the light sensing elements may be arranged along the row direction, and the light emitting elements and the light sensing elements may be alternately arranged in a column direction; or the light-emitting elements and the light-sensing elements are alternately arranged in the row direction and the column direction; and so on.

In this implementation, the first filter element 14 connected to the second photosensitive element 13 may output an ambient light signal or a mixed signal of the ambient light signal and the display light signal. The photosensitive circuit having the optical communication function is incorporated in the display substrate, and as shown in FIGS. 14 and 20, the second photosensitive circuit is disposed with the gap between the light emitting elementsA photosensitive element 11 or a second photosensitive element 13. Since the difference of the display light signals of different regions in the display substrate is large, the number of the second photosensitive elements 13 may be multiple, and the multiple second photosensitive elements 13 are uniformly disposed in the display substrate. The density of the second photosensitive elements 13 is not suitable to be too small, and the denser the second photosensitive elements 13 are arranged, the stronger the environmental interference resistance is. For example, it may be every 2mm or less²A second photosensitive element 13 is disposed in the area of the first photosensitive element.

In a seventh alternative implementation manner, as shown in fig. 15 and fig. 21, the photosensitive substrate is a display substrate, the display substrate includes a plurality of fourth pixel units 141 arranged in an array, and each fourth pixel unit 141 includes a light emitting element and a photosensitive element. When the photosensitive circuit further comprises a third photosensitive element 31, the photosensitive elements are the first photosensitive element 11, the second photosensitive element 13 or the third photosensitive element 31, and the third photosensitive elements 31 are uniformly distributed on the display substrate.

When the first photosensitive element 11 includes the first photodiode P1, the second photosensitive element 13 includes the second photodiode P2, and the third photosensitive element 31 includes the third photodiode P3, as shown in fig. 15 and 21, the areas of the first photodiode P1, the second photodiode P2, and the third photodiode P3 are the same, in which case, in order to filter high frequency signals, a first capacitor C1 independent of the second photodiode P2 may be provided, and a second capacitor C2 independent of the third photodiode P3 may be provided. In fig. 15, a first capacitor C1 is separately provided in parallel with the second photodiode P2 (cross-sectional views are shown in fig. 16 and 17, and detailed description is referred to later), and a second capacitor C2 is separately provided in parallel with the third photodiode P3; in fig. 21, one end of the independently disposed first capacitor C1 is connected to the second photodiode P2, and the other end is connected to the second power voltage terminal VDD2 (the cross-sectional view is shown in fig. 22, and the detailed description refers to the following), and one end of the independently disposed second capacitor C2 is connected to the third photodiode P3, and the other end is connected to the second power voltage terminal VDD 2.

As shown in fig. 15 and 21, the first photodiode P1, the second photodiode P2, and the third photodiode P3 have the same area, and in this case, a first capacitor C1 independent of the second light sensing element 13 and a second capacitor C2 independent of the third light sensing element 31 may be provided. The first capacitor C1 is larger than the second capacitor C2, the first capacitor C1 with a larger capacitance outputs the ambient light signal, and the second capacitor C2 with a smaller capacitance outputs the display light signal.

As shown in fig. 15 and 21, the light emitting elements may include, for example, a red light emitting element R, a green light emitting element G, and a blue light emitting element B. The light emitting elements are arranged in a column direction, the light sensing elements are arranged in a column direction, and the light emitting elements and the light sensing elements are alternately arranged in a row direction. In a specific implementation, the light emitting elements may be arranged along a row direction, the light sensing elements may be arranged along the row direction, and the light emitting elements and the light sensing elements may be alternately arranged in a column direction; or the light-emitting elements and the light-sensing elements are alternately arranged in the row direction and the column direction; and so on.

In this implementation, the first filter element 14 connected to the second photosensitive element 13 may output an ambient light signal, and the second filter element 32 connected to the third photosensitive element 31 may output a display light signal. The photosensitive circuit having the optical communication function is built into the display substrate, and as shown in fig. 15 and 21, the first photosensitive element 11, the second photosensitive element 13, or the third photosensitive element 31 is arranged with a gap of the light emitting element. Since the difference of the display light signals of different regions in the display substrate is large, the number of the third photosensitive elements 31 may be multiple, and the multiple third photosensitive elements 31 are uniformly arranged in the display region of the display substrate. The density of the third photosensitive elements 31 is not small, and the denser the second photosensitive elements 13 are, the stronger the environmental interference resistance is. For example, it may be every 2mm or less²A third photosensitive element 31 is disposed in the area of the first photosensitive element.

Since the difference of the ambient light signals in different areas of the display substrate is relatively small, one second photosensitive element 13 may be disposed in the display area of the display substrate. Of course, in a specific implementation, the second photosensitive element 13 may be provided in plurality, and the plurality of second photosensitive elements 13 may be uniformly provided in the display region.

Referring to fig. 16, 17 and 18, schematic cross-sectional structural diagrams of the second photodiode and the independently disposed first capacitor are shown. As shown in fig. 16, the photosensitive base plate includes a substrate and a first metal layer 161, a photosensitive layer 162, a first insulating layer 163, and a second metal layer 164 stacked and disposed on the substrate, one pole of the second photodiode P2 and one end of the first capacitor C1 may be both disposed on the first metal layer 161 and connected to each other, and the other pole of the second photodiode P2 and the other end of the first capacitor C1 may be both disposed on the second metal layer 164 and connected to each other.

As shown in fig. 17, the photosensitive substrate includes a substrate, and a first metal layer 161, a photosensitive layer 162, a first insulating layer 163, and a second metal layer 164 stacked on the substrate, and further includes a second insulating layer 171 and a third metal layer 172 stacked on the second metal layer 164, one pole of the second photodiode P2 and one end of the first capacitor C1 may be both disposed on the first metal layer 161 and connected to each other, and the other pole of the second photodiode P2 and the other end of the first capacitor C1 may be connected via the third metal layer 172.

As shown in fig. 22, the photosensitive substrate includes a substrate, and a first metal layer 161, a photosensitive layer 162, a first insulating layer 163, and a second metal layer 164 stacked on the substrate, one pole of a second photodiode P2 and one end of a first capacitor C1 may be both disposed on the first metal layer 161 and connected to each other, the other pole of the second photodiode P2 and the other end of the first capacitor C1 may be both disposed on the second metal layer 164, but the second end of the first capacitor C1 is connected to a second power voltage terminal VDD 2.

When the light sensing circuit includes the third light sensing element 31 and the third light sensing element 31 includes the third photodiode P3, the structures of the third photodiode P3 and the independently disposed second capacitor C2 may be the same as the structures of the second photodiode P2 and the first capacitor C1, and are not described herein again.

An embodiment of the present disclosure provides a photosensitive device, including a photosensitive substrate as provided in any embodiment.

As can be appreciated by those skilled in the art, the photosensitive device has the advantages of the photosensitive substrate described above.

In some embodiments, the photosensitive device may be, for example, an electronic device with an optical communication function, a display device integrated with an optical communication function, and the like, which is not limited in this disclosure.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The photosensitive circuit, the photosensitive substrate and the photosensitive device provided by the present disclosure are introduced in detail above, and specific examples are applied in the present disclosure to explain the principle and the implementation manner of the present disclosure, and the description of the above embodiments is only used to help understand the method and the core idea of the present disclosure; meanwhile, for a person skilled in the art, based on the idea of the present disclosure, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present disclosure should not be construed as a limitation to the present disclosure.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Reference herein to "one embodiment," "an embodiment," or "one or more embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Moreover, it is noted that instances of the word "in one embodiment" are not necessarily all referring to the same embodiment.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The disclosure may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solutions of the present disclosure, not to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present disclosure.

Claims

1. A light sensing circuit, comprising:

2. The light sensing circuit of claim 1, wherein the first light sensing element comprises a first photodiode, the first amplification circuit comprises a first transistor;

3. The light sensing circuit of claim 1, wherein the second light sensing element comprises a second photodiode, the first filter element comprises a first capacitor, and the second amplification circuit comprises a second transistor;

4. The photosensitive circuit of claim 3, wherein the first capacitance is a parasitic capacitance of the second photodiode; alternatively, the first capacitance is a capacitance independent of the second photodiode.

5. The light sensing circuit of any one of claims 1 to 4, wherein the light signal further comprises a display light signal, the frequency of the display light signal being less than the frequency of the target light signal and greater than the frequency of the ambient light signal;

the photosensitive circuit further includes:

6. The light sensing circuit of claim 5, wherein the third light sensing element comprises a third photodiode, the second filter element comprises a second capacitor, and the third amplification circuit comprises a third transistor;

7. The photosensitive circuit of claim 6, wherein the second capacitance is a parasitic capacitance of the third photodiode; alternatively, the second capacitance is a capacitance independent of the third photodiode.

8. The light sensing circuit of claim 6, wherein when the first filter element comprises the first capacitor, a capacitance of the first capacitor is greater than a capacitance of the second capacitor.

9. A photosensitive substrate comprising the photosensitive circuit according to any one of claims 1 to 8.

10. The photosensitive substrate according to claim 9, wherein the photosensitive substrate comprises a first region and a second region disposed at a periphery of the first region, the first region comprises a plurality of the first photosensitive elements arranged in an array, the second photosensitive elements are disposed in the second region and/or a predetermined region in the first region, and the predetermined region comprises a gap between two adjacent columns of the first photosensitive elements and/or a gap between two adjacent rows of the first photosensitive elements.

11. The substrate according to claim 9, wherein the substrate is a display substrate, the display substrate includes a display area and a frame area located at a periphery of the display area, the frame area includes at least one of the first photosensitive elements and at least one of the second photosensitive elements, and the at least one of the second photosensitive elements is uniformly distributed in the frame area.

12. The substrate according to claim 9, wherein the substrate is a display substrate, the display substrate includes at least one second photosensitive element and a plurality of first pixel units arranged in an array, each first pixel unit includes a light emitting element and a first photosensitive element, and at least one second photosensitive element is uniformly disposed in a non-opening area of the display substrate.

13. The substrate according to claim 9, wherein when the photosensitive circuit further includes the third photosensitive element, the substrate is a display substrate, the display substrate includes at least one second photosensitive element, at least one third photosensitive element, and a plurality of second pixel units arranged in an array, each second pixel unit includes a light emitting element and the first photosensitive element, and at least one second photosensitive element and/or at least one third photosensitive element is uniformly disposed in a non-opening area of the display substrate.

14. The photosensitive substrate according to claim 9, wherein the photosensitive substrate comprises a plurality of third pixel units arranged in an array, and each of the third pixel units comprises the first photosensitive element or the second photosensitive element.

15. The photosensitive substrate according to claim 9, wherein the photosensitive substrate is a display substrate, the display substrate includes a plurality of fourth pixel units arranged in an array, and each of the fourth pixel units includes a light-emitting element and a photosensitive element;

16. The photosensitive substrate according to any one of claims 9 to 15, wherein when the first photosensitive element comprises the first photodiode and the second photosensitive element comprises the second photodiode, an area of the first photodiode is smaller than or equal to an area of the second photodiode;

17. A photosensitive device comprising the photosensitive substrate according to any one of claims 9 to 16.