CN110849472B - Light sense detection device and display terminal - Google Patents
Light sense detection device and display terminal Download PDFInfo
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- CN110849472B CN110849472B CN201911192746.6A CN201911192746A CN110849472B CN 110849472 B CN110849472 B CN 110849472B CN 201911192746 A CN201911192746 A CN 201911192746A CN 110849472 B CN110849472 B CN 110849472B
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- 238000001514 detection method Methods 0.000 title claims abstract description 73
- 230000035807 sensation Effects 0.000 claims abstract description 12
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 238000010586 diagram Methods 0.000 description 12
- 238000000034 method Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
- G01J1/4204—Photometry, e.g. photographic exposure meter using electric radiation detectors with determination of ambient light
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
- G01J1/44—Electric circuits
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
- G01J1/44—Electric circuits
- G01J2001/444—Compensating; Calibrating, e.g. dark current, temperature drift, noise reduction or baseline correction; Adjusting
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
- G01J1/44—Electric circuits
- G01J2001/4446—Type of detector
- G01J2001/4473—Phototransistor
Abstract
The invention provides a light sensation detection device and a display terminal applied to the technical field of display, wherein in the light sensation detection device, a power supply module comprises a control unit and a processing unit which are connected with each other so as to output a first voltage, a second voltage and a third voltage; the detection module is connected with the power supply module and comprises a first bridge arm and a second bridge arm which are connected in parallel to receive a first voltage, a second voltage and a third voltage, an upper switch tube of the first bridge arm and a lower switch tube of the second bridge arm are light-sensing switch tubes, a first detection signal is output from a midpoint of the first bridge arm, and a second detection signal is output from a midpoint of the second bridge arm; the working cycle of the light sensing device comprises a first time interval and a second time interval, wherein the first voltage is higher than the second voltage in the first time interval, and is lower than the second voltage in the second time interval. The light sensation detection device and the display terminal provided by the invention can reduce light sensation errors, enhance the stability of devices and improve the sensitivity of an automatic backlight system of the display terminal.
Description
Technical Field
The invention relates to the technical field of display, in particular to a light sensation detection device and a display terminal.
Background
In the backlight automatic adjustment system of the existing display terminal, the light sensing structure adopts a differential structure to improve the sensitivity and the linearity of a detection result and enhance the anti-interference capability. In the use of the light sensing structure, the bias voltage of the differential circuit is direct-current voltage, due to a charge trapping mechanism, the threshold voltage of a transistor device can drift along with the increase of grid biasing time, a transfer characteristic curve is integrally shifted, the shifting direction is related to the polarity of the grid voltage, the variation of the threshold voltage and the grid voltage time are in a logarithmic relation, so that the error of a light sensing signal is caused, and the deviation in 24 hours is found to be about 15-25% in actual tests.
Disclosure of Invention
The invention aims to provide a light sensing detection device and a display terminal, which can improve the stability of the threshold voltage of a transistor device and reduce the error of a light sensing signal.
Specifically, the invention provides a light sensing detection device, which comprises a power supply module, a light sensing detection module and a control module, wherein the power supply module comprises a control unit and a processing unit which are connected with each other, and the processing unit outputs a first voltage VDD, a second voltage VSS and a third voltage Vg under the control of the control unit; the detection module is connected with the power supply module and comprises a first bridge arm and a second bridge arm which are connected in parallel, each bridge arm comprises two switching tubes which are connected in series, the upper end of each bridge arm receives the first voltage, the lower end of each bridge arm receives the second voltage, the control ends of the switching tubes of the first bridge arm and the second bridge arm receive the third voltage, the upper switching tube of the first bridge arm and the lower switching tube of the second bridge arm are light-sensing switching tubes, the midpoint of the first bridge arm outputs a first detection signal, and the midpoint of the second bridge arm outputs a second detection signal; the working cycle of the light sensing device comprises a first time interval and a second time interval, and the first voltage is higher than the second voltage in the first time interval and is lower than the second voltage in the second time interval.
Further, the detection module comprises a first switch tube and a second switch tube in the first bridge arm, and a third switch tube and a fourth switch tube in the second bridge arm, the detection module further comprises a fifth switch tube and a sixth switch tube, the first end of the first switch tube and the first end of the third switch tube are connected to the power module to receive the first voltage, the second end of the first switch tube is connected to the first end of the second switch tube, the second end of the third switch tube is connected to the first end of the fourth switch tube, the second end of the second switch tube and the second end of the fourth switch tube are connected to the power module to receive the second voltage, the control ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are connected to the power module to receive the third voltage, and the control end of the fifth switch tube is connected to the second end of the second switch tube, the first end of the fifth switch tube is connected with the power module to receive the second voltage, the second end of the fifth switch tube is connected with the second end of the first switch tube to output the first detection signal, the control end of the sixth switch tube is connected with the second end of the first switch tube, the first end of the sixth switch tube is connected with the power module to receive the second voltage, and the second end of the sixth switch tube is connected with the second end of the third switch tube to output the second detection signal.
Further, the first switch tube and the fourth switch tube are light-sensing switch tubes, or the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are light-sensing switch tubes.
Further, the control unit outputs a square wave signal, and the processing unit comprises a first amplifier circuit and a second amplifier circuit; the first amplifier circuit outputs the first voltage according to the square wave signal, and the second amplifier circuit outputs the second voltage according to the square wave signal or the first voltage.
Further, the third voltage is an alternating current voltage, and the working frequency is greater than or equal to twice the working frequency of the first voltage and/or the second voltage.
Further, the first period is equal in duration to the second period.
Further, the first voltage and the second voltage are both alternating voltages and are opposite in phase.
Further, the first voltage is an alternating current voltage, and the second voltage is a direct current voltage.
Further, the first voltage is a direct current voltage, and the second voltage is an alternating current voltage.
The invention also provides a display terminal, and particularly the display terminal comprises a display panel and the light sensation detection device.
The light sensation detection device and the display terminal provided by the invention can greatly reduce the error of a light sensation signal, enhance the stability of the threshold voltage of a transistor device and improve the sensitivity of an automatic backlight system of the display terminal.
Drawings
FIG. 1 is a block diagram of a light sensing device according to an embodiment of the present invention.
Fig. 2 is a first circuit diagram of a processing unit and a differential detection circuit according to an embodiment of the invention.
Fig. 3 is a circuit diagram of a processing unit and a differential detection circuit according to an embodiment of the invention.
FIG. 4 is a timing diagram of a square wave signal, a first voltage, a second voltage and a third voltage of the photo sensing device according to an embodiment of the invention.
FIG. 5 is a timing diagram showing the first voltage and the second voltage of the photo sensing device according to an embodiment of the present invention.
FIG. 6 is a second timing diagram of the first voltage and the second voltage of the photo sensing device according to an embodiment of the invention.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
In a first aspect, the present invention provides a light-sensing device. FIG. 1 is a block diagram of a light sensing device according to an embodiment of the present invention.
As shown in fig. 1, in one embodiment, the light sensing device includes a power module 11 and a detection module 12.
The power module 11 is connected to the detection module 12, and includes a control unit 111 and a processing unit 112 connected to each other, and the processing unit 112 provides the detection module 12 with a first voltage VDD, a second voltage VSS and a third voltage Vg under the control of the control unit 111.
In one embodiment, the power module 11 includes a control unit 111 and a processing unit 112 connected to each other, the control unit 111 outputs a first square wave, and the processing unit 112 outputs a first voltage VDD through an inverting amplifier according to the first square wave and then outputs a second voltage VSS through an inverter. The control unit 111 outputs a second square wave, and the processing unit 112 outputs a third voltage Vg via the comparison amplifier according to the second square wave. The invention is not limited thereto, and in other embodiments, the control unit 111 and the processing unit 112 may generate the required first voltage VDD, second voltage VSS and third voltage Vg in other manners.
The control unit 111 may be, but is not limited to, one selected from a single chip microcomputer, an MCU, and a timing controller. The first square wave and the second square wave may be clock signals or enable signals.
And the detection module 12 is connected with the power module 11 and comprises a first bridge arm and a second bridge arm which are connected in parallel.
Each bridge arm comprises two switching tubes connected in series, the upper end of each bridge arm receives a first voltage VDD, and the lower end of each bridge arm receives a second voltage VSS. And the control ends of the switching tubes of the first bridge arm and the second bridge arm receive a third voltage Vg.
The upper switching tube of the first bridge arm and the lower switching tube of the second bridge arm are light-sensing switching tubes, so that the two bridge arms form a differential detection circuit. And outputting a first detection signal by the midpoint of the first bridge arm, and outputting a second detection signal by the midpoint of the second bridge arm.
The detection module 12 detects the external light environment condition under the driving of the first voltage VDD, the second voltage VSS and the third voltage Vg.
Fig. 2 is a first circuit diagram of a processing unit and a differential detection circuit according to an embodiment of the invention.
With continued reference to fig. 1 and with reference to fig. 2, in one embodiment, the differential detection circuit 43 in the detection module 12 includes a first switch transistor T1, a second switch transistor T2, a third switch transistor T3, and a fourth switch transistor T4.
The first terminal of the first switch transistor T1 and the first terminal of the third switch transistor T3 are connected to the power module 11 to receive the first voltage VDD. The second end of the first switch tube T1 is connected to the first end of the second switch tube T2 to output the first detection signal Vp and form the first leg, and the second end of the third switch tube T3 is connected to the first end of the fourth switch tube T4 to output the second detection signal Vn and form the second leg. A second terminal of the second switching transistor T2 and a second terminal of the fourth switching transistor T4 are connected to the power module 11 to receive the second voltage VSS. The control terminals of the first switch transistor T1, the second switch transistor T2, the third switch transistor T3 and the fourth switch transistor T4 are connected to the power module 11 to receive the third voltage Vg.
In one embodiment, the first switch transistor T1 and the fourth switch transistor T4 are photo-sensing switch transistors, and the second switch transistor T2 and the third switch transistor T3 are non-photo-sensing switch transistors. In another embodiment, the first switch transistor T1, the second switch transistor T2, the third switch transistor T3, and the fourth switch transistor T4 are all photo-sensing switch transistors.
Specifically, in an embodiment, the first switch tube T1, the second switch tube T2, the third switch tube T3 and the fourth switch tube T4 have the same structure, wherein the first switch tube T1 and the fourth switch tube T4 are disposed below the light-transmitting portion, so that after ambient light passes through the light-transmitting portion, the corresponding transmitted light can directly irradiate on the first switch tube T1 and the fourth switch tube T4, and in addition, the irradiation of the in-plane light inside the display panel, so that the first switch tube T1 and the fourth switch tube T4 generate a strong photoelectric effect, and accordingly, the generated induced current is large. However, the second switch tube T2 and the third switch tube T3 are not disposed below the light-transmitting portion, so ambient light cannot irradiate the second switch tube T2 and the third switch tube T3, the second switch tube T2 and the third switch tube T3 can only receive the irradiation of the in-plane light inside the display panel, and accordingly, the generated induced current is small.
In an embodiment, the voltage value of the third voltage Vg may be set to a voltage value close to the threshold voltage of the conduction of the photo-sensing switch tube, and the induced currents generated by the first switch tube T1 to the fourth switch tube T4 during sensing may be effectively output along with the intensity of the light, so as to improve the sensitivity of the detection.
Referring to fig. 2, the first switch tube T1 outputting a larger induced current is connected in series with the second switch tube T2 outputting a smaller induced current, and the first terminal of the first switch tube T1 receives the first voltage VDD, the second terminal of the second switch tube T2 receives the second voltage VSS, so that the first detection signal Vp output by the second terminal of the first switch tube T1 is a voltage close to the first voltage VDD. The third switch tube T3 outputting a smaller induced current is connected in series with the fourth switch tube T4 outputting a larger induced current, the first terminal of the third switch tube T3 receives the first voltage VDD, the second terminal of the fourth switch tube T4 receives the second voltage VSS, and the second detection signal Vn output by the second terminal of the third switch tube T3 is a voltage close to the second voltage VSS. Both the first detection signal Vp and the second detection signal Vn can be used to reflect the intensity of the transmitted light. For example, the closer the first detection signal Vp is to the first voltage VDD or the closer the second detection signal Vn is to the second voltage VSS, the greater the intensity of the transmitted light is, and the greater the intensity of the ambient light is. The back-end circuit performs subtraction on the first detection signal Vp and the second detection signal Vn, and the difference is used for judgment, so that a common-mode signal can be suppressed.
In one embodiment, the duty cycle of the photo sensing device includes a first period and a second period, and the first voltage VDD is higher than the second voltage VSS in the first period and lower than the second voltage VSS in the second period. In the light sensing detection device, the high-low bias voltage applied to the light sensing circuit is set as the voltage of periodic high-low switching, so that the input end and the output end of the first switch tube T1, the second switch tube T2, the third switch tube T3 and the fourth switch tube T4 do not work under the same bias voltage, the problem of transfer characteristic curve deviation of the switch tubes is restrained, and the degradation speed of the switch tubes is reduced.
In one embodiment, the photo-sensing switch tube may be, but is not limited to, a thin film transistor.
Fig. 3 is a circuit diagram of a processing unit and a differential detection circuit according to an embodiment of the invention.
As shown in fig. 3, the differential detection circuit 43 in the detection module 12 further includes a fifth switch transistor T5 and a sixth switch transistor T6. A control terminal of the fifth switch transistor T5 is connected to the second terminal of the third switch transistor T3, a first terminal of the fifth switch transistor T5 is connected to the power module 11 for receiving the second voltage VSS, and a second terminal of the fifth switch transistor T5 is connected to the second terminal of the first switch transistor T1 for outputting the first detection signal Vp. The control terminal of the sixth switch transistor T6 is connected to the second terminal of the first switch transistor T1, the first terminal of the sixth switch transistor T6 is connected to the power module 11 for receiving the second voltage VSS, and the second terminal of the sixth switch transistor T6 is connected to the second terminal of the third switch transistor T3 for outputting the second detection signal Vn.
Since the control terminal of the fifth switch tube T5 is controlled by the second detection signal Vn, the voltage value of the first detection signal Vp output by the second terminal of the fifth switch tube T5 is closer to the voltage value of the first voltage VDD as the voltage value of the second detection signal Vn is closer to the voltage value of the second voltage VSS. Since the control terminal of the sixth switch tube T6 is controlled by the first detection signal Vp, the voltage value of the second detection signal Vn output by the second terminal of the sixth switch tube T6 is closer to the voltage value of the second voltage VSS as the voltage value of the first detection signal Vp is closer to the voltage value of the first voltage VDD. The fifth switch tube T5 and the sixth switch tube T6 constitute an amplification feedback part in the circuit, which can further amplify the difference between the first detection signal Vp and the second detection signal Vn, thereby further improving the sensitivity of the ambient light detection.
Because the first voltage VDD is higher than the second voltage VSS in the first period and lower than the second voltage VSS in the second period, the control terminals of the fifth switching transistor T5 and the sixth switching transistor T6 do not operate under the same bias voltage due to the periodically high-low converted voltage, so that the shift problem of the transfer characteristic curve of the switching transistors is suppressed, the degradation speed of the switching transistors is reduced, and the stability of the threshold voltage of the device is enhanced.
In one embodiment, the third voltage Vg is a fixed dc voltage. In another embodiment, the third voltage Vg is an ac voltage to improve the shift of the transfer characteristic curve of the control terminals of the first switch transistor T1, the second switch transistor T2, the third switch transistor T3 and the fourth switch transistor T4, and the ac voltage with zero level alternating up and down is very helpful to improve the component characteristic shift of these switch transistors.
In one embodiment, the first period is equal in duration to the second period. For square waves, in the working period of the light sensing detection device, the high-level duty ratio of the first voltage VDD and the second voltage VSS is 50%, so that the positive voltage excitation duration and the negative voltage excitation duration of the control ends of the fifth switching tube T5 and the sixth switching tube T6 are the same, and the condition that the transfer characteristic curve of the switching device is shifted integrally is better improved.
Referring to fig. 2 and fig. 3, in an embodiment, the processing unit 112 includes a first amplifier circuit 41 and a second amplifier circuit 42. The first amplifier circuit 41 is connected to the control unit 111 to receive the square wave signal T and output a first voltage VDD according to the square wave signal T. The second amplifier circuit 42 is connected to the first amplifier circuit 41 to receive the first voltage VDD and output the second voltage VSS according to the first voltage VDD.
In one embodiment, the first amplifier circuit 41 includes a first resistor R41, a second resistor R42, and a first operational amplifier F41. The positive input terminal of the first operational amplifier F41 is grounded, and the negative input terminal of the first operational amplifier F41 receives the square wave signal T from the control unit 111 through the first resistor R41 connected in series. A second resistor R42 is connected between the negative input and the output of the first operational amplifier F41. The positive power supply of the first operational amplifier F41 is connected to the positive power supply VCC, and the negative power supply is grounded. The output end of the first operational amplifier F41 outputs the first voltage VDD to implement the inverting amplification function.
As shown in fig. 2 and 3, in an embodiment, the second amplifier circuit 42 includes a third resistor R43, a fourth resistor R44, and a second operational amplifier F42. The positive input terminal of the second operational amplifier F42 is grounded, and the negative input terminal of the second operational amplifier F42 receives the first voltage VDD outputted from the first amplifier circuit 41 through the serially connected third resistor R43. A fourth resistor R44 is connected between the negative input and the output of the second operational amplifier F42. The positive power supply of the second operational amplifier F42 is connected with the positive power supply VCC, and the negative power supply is grounded. The output terminal of the second operational amplifier F42 outputs the second voltage VSS to implement an inverting function.
In the above embodiment, the positive input terminal of the operational amplifier is grounded, and the negative input terminal inputs a single-ended signal, so that the output signals of the first amplifier circuit 41 and the second amplifier circuit 42 vary from 0 to VCC. The first voltage VDD and the second voltage VSS are periodically switched voltages according to timing requirements under the control of the square wave signal T of the first square wave output by the control unit 111.
In an embodiment, when the third voltage Vg is an ac voltage, the operating frequency is greater than or equal to twice the operating frequency of the first voltage VDD and/or the second voltage VSS.
The third voltage Vg is the control terminal voltage of the first switch tube T1, the second switch tube T2, the third switch tube T3 and the fourth switch tube T4, and setting the third voltage Vg to be an alternating voltage helps to improve the problem of the shift characteristic curve shift of the first switch tube T1, the second switch tube T2, the third switch tube T3 and the fourth switch tube T4 for the same reason as the above-described embodiment. The working frequency of the third voltage Vg is greater than or equal to twice the switching frequency of the first voltage VDD and/or the second voltage VSS bias, so that it can be ensured that the control terminals of the fifth switch tube T5 and the sixth switch tube T6 are in the correct voltage bias state for a part of time in each period of the forward bias voltage, and the correct differential signals can be output.
In one embodiment, the operating frequency of the first voltage VDD and/or the second voltage VSS is 1Hz, and the operating frequency of the third voltage Vg is 2 Hz. Tests show that the bias conversion frequency of the first voltage VDD and/or the second voltage VSS is set to be 1Hz, and the working frequency of the third voltage Vg is set to be 2Hz, so that both the light sensing detection sensitivity and the characteristic recovery degree of the element can be considered, and the optimal matching effect can be achieved, but the method is not limited to the method.
In one embodiment, the first voltage VDD and the second voltage VSS are ac voltages and are opposite phases of each other.
FIG. 4 is a timing diagram of a square wave signal, a first voltage, a second voltage and a third voltage of the photo sensing device according to an embodiment of the invention.
As shown in fig. 4, in an embodiment, the square wave signal T is a square wave clock signal with a frequency of 1Hz, and VCC is a 9V dc voltage. The first voltage VDD and the second voltage VSS are both square waves with a frequency of 1Hz and a high level duty ratio of 50%, the high level is both 9V, the low level is both 0V, but the first voltage VDD and the second voltage VSS are mutually inverse square waves, but the invention is not limited thereto.
As shown in fig. 4, in an embodiment, the third voltage Vg is a square wave with a high level of 2V, a low level of-2V, a frequency of 2Hz, and a high level duty ratio of 50%.
FIG. 5 is a timing diagram showing the first voltage and the second voltage of the photo sensing device according to an embodiment of the present invention.
In one embodiment, as shown in fig. 5, the first voltage VDD is an ac voltage, and the second voltage VSS is a dc voltage. For example, the first voltage VDD is a square wave having a high level of 9V, a low level of-9V and a high level duty ratio of 50%, and the second voltage VSS is a voltage of 0V of dc ground. In other embodiments, in the waveform timing shown in fig. 5, the high-low level voltage values of the first voltage VDD and the second voltage VSS may be set to other voltage values.
FIG. 6 is a second timing diagram of the first voltage and the second voltage of the photo sensing device according to an embodiment of the invention.
In one embodiment, as shown in fig. 6, the first voltage VDD is a dc voltage, and the second voltage VSS is an ac voltage. For example, the first voltage VDD is a 0V voltage of dc ground, and the second voltage VSS is an ac square wave with a high level of 9V, a low level of-9V, and a high level duty ratio of 50%. In other embodiments, in the waveform timing shown in fig. 6, the high-low level voltage values of the first voltage VDD and the second voltage VSS may be set to other voltage values.
The invention also provides a display terminal, and particularly the display terminal comprises a display panel and the light sensation detection device. The implementation principle of the display terminal is the same as that of the light-sensing detection device in the above embodiments, and the description thereof is omitted.
In the display terminal of an embodiment, after an actual simulation test, after 24 hours of normal temperature operation, the deviation of the light sensing signal in the display terminal is less than 3%.
The light sensation detection device and the display terminal provided by the invention can greatly reduce the error of a light sensation signal, enhance the stability of the threshold voltage of a transistor device, improve the sensitivity of an automatic backlight system of the display terminal, improve the user experience and enhance the product competitiveness.
In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. It will be understood that when an element such as a layer, region or substrate is referred to as being "formed on," "disposed on" or "located on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there are no intervening elements present.
In this document, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms can be understood in a specific case to those of ordinary skill in the art.
As used herein, the ordinal adjectives "first", "second", etc., used to describe an element are merely to distinguish between similar elements and do not imply that the elements so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.
As used herein, the meaning of "a plurality" or "a plurality" is two or more unless otherwise specified.
It will be understood by those skilled in the art that all or part of the steps of implementing the above method embodiments may be implemented by hardware associated with program instructions, and the program may be stored in a computer readable storage medium, and when executed, performs the steps including the above method embodiments. The foregoing storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, including not only those elements listed, but also other elements not expressly listed.
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present disclosure, and all such changes or substitutions are included in the scope of the present disclosure. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (10)
1. A light sensation detecting device, comprising:
the power supply module comprises a control unit and a processing unit which are connected with each other, wherein the processing unit outputs a first voltage VDD, a second voltage VSS and a third voltage Vg under the control of the control unit;
the detection module is connected with the power supply module and comprises a first bridge arm and a second bridge arm which are connected in parallel, each bridge arm comprises two switching tubes which are connected in series, the upper end of each bridge arm receives the first voltage, the lower end of each bridge arm receives the second voltage, the control ends of the switching tubes of the first bridge arm and the second bridge arm receive the third voltage, the upper switching tube of the first bridge arm and the lower switching tube of the second bridge arm are light-sensing switching tubes, the midpoint of the first bridge arm outputs a first detection signal, and the midpoint of the second bridge arm outputs a second detection signal;
the working cycle of the light sensing device comprises a first time interval and a second time interval, and the first voltage is higher than the second voltage in the first time interval and is lower than the second voltage in the second time interval.
2. The light sense detecting device as claimed in claim 1, wherein the detecting module comprises a first switch tube and a second switch tube in the first bridge arm, a third switch tube and a fourth switch tube in the second bridge arm, the detecting module further comprises a fifth switch tube and a sixth switch tube, a first end of the first switch tube and a first end of the third switch tube are connected to the power module to receive the first voltage, a second end of the first switch tube is connected to the first end of the second switch tube, a second end of the third switch tube is connected to the first end of the fourth switch tube, a second end of the second switch tube and a second end of the fourth switch tube are connected to the power module to receive the second voltage, and control ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are connected to the power module to receive the third voltage, the control end of the fifth switch tube is connected with the second end of the third switch tube, the first end of the fifth switch tube is connected with the power module to receive the second voltage, the second end of the fifth switch tube is connected with the second end of the first switch tube to output the first detection signal, the control end of the sixth switch tube is connected with the second end of the first switch tube, the first end of the sixth switch tube is connected with the power module to receive the second voltage, and the second end of the sixth switch tube is connected with the second end of the third switch tube to output the second detection signal.
3. The photo detection device as claimed in claim 2, wherein the first switch and the fourth switch are photo switches;
or, the first switching tube, the second switching tube, the third switching tube and the fourth switching tube are light sensing switching tubes.
4. The photo-sensing device as claimed in claim 1, wherein the control unit outputs a square wave signal, and the processing unit comprises a first amplifier circuit and a second amplifier circuit; the first amplifier circuit outputs the first voltage according to the square wave signal, and the second amplifier circuit outputs the second voltage according to the square wave signal or the first voltage.
5. The photo-sensing device as claimed in claim 1, wherein the third voltage is an ac voltage and the operating frequency is greater than or equal to twice the operating frequency of the first voltage and/or the second voltage.
6. The photo detection device as claimed in claim 1, wherein the first period is equal to the second period.
7. The photo detecting device as claimed in any one of claims 1 to 6, wherein the first voltage and the second voltage are both AC voltages and have opposite phases.
8. The photo-sensing device as claimed in any one of claims 1 to 6, wherein the first voltage is an AC voltage and the second voltage is a DC voltage.
9. The photo-sensing device as claimed in any one of claims 1 to 6, wherein the first voltage is a DC voltage and the second voltage is an AC voltage.
10. A display terminal comprising a display panel and the light-sensation detecting device according to any one of claims 1 to 9.
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