TWI701585B - Ultrasonic pixel circuit and related display device - Google Patents

Abstract

An ultrasonic pixel circuit includes a peak detection element, an output circuit, and a reset circuit. The peak detection element is coupled between a first node and a second node, and coupled with an ultrasonic transducer through the second node. The output circuit is coupled with the first node, configured to provide a sensing current according to a voltage of the first node, and configured to selectively output the sensing current to a control system. The reset circuit is coupled with the first node and the second node. When the reset circuit configures the voltage of the first node, the reset circuit also configures a voltage of the second node.

Description

Ultrasonic pixel circuit and related display device

This disclosure relates to a display device, especially an ultrasonic pixel circuit in the display device.

Fingerprint recognition can enhance the security of mobile devices. Solutions related to fingerprint recognition include capacitive sensing technology, ultrasonic sensing technology, and optical sensing technology. Among them, capacitive sensing technology is used in the consumer market in the past. It is widely used. However, when the mobile device is under water or equipped with a protective sticker, the sensitivity of the capacitive sensing technology will be affected, and the capacitive sensing technology is more difficult to install under the screen, which is not conducive to the application of mobile devices with full screens. In contrast, ultrasonic sensing technology can overcome the above-mentioned various problems, and is therefore expected to become the mainstream technology used in mobile devices in the future.

The present disclosure provides a display device, which includes a display module, a control system, and an ultrasonic sensing array. The ultrasonic sensor array is coupled to the control system and is arranged on one side of the display module, and includes a plurality of ultrasonic sensors. Sonic sensor and multiple ultrasonic pixel circuits. Each of the plurality of ultrasonic pixel circuits includes a peak detection element, an output circuit, and a reset circuit. The peak detection element is coupled between the first node and the second node, and is coupled to a corresponding ultrasonic sensor among the plurality of ultrasonic sensors through the second node. The output circuit is coupled to the first node for providing a sensing current according to the voltage of the first node, and for selectively outputting the sensing current to the control system. The reset circuit is coupled to the first node and the second node. When the reset circuit sets the voltage of the first node, the reset circuit also sets the voltage of the second node.

This disclosure provides an ultrasonic pixel circuit, which includes a peak detection element, an output circuit, and a reset circuit. The peak detection element is coupled between the first node and the second node, and is coupled to the ultrasonic sensor through the second node. The output circuit is coupled to the first node for providing a sensing current according to the voltage of the first node, and for selectively outputting the sensing current to the control system. The reset circuit is coupled to the first node and the second node. When the reset circuit sets the voltage of the first node, the reset circuit also sets the voltage of the second node.

The above-mentioned display device and ultrasonic pixel circuit have a simplified circuit structure.

100, 200‧‧‧Display device

101‧‧‧Object

103‧‧‧Ultrasonic

110‧‧‧Protection panel

120‧‧‧OLED display module

122‧‧‧OLED material layer

124‧‧‧TFT circuit layer

126‧‧‧Substrate

130‧‧‧Ultrasonic Sensor Module

132‧‧‧TFT circuit layer

134‧‧‧Substrate

W1‧‧‧Width

W2‧‧‧Width

310‧‧‧Ultrasonic sensor array

312‧‧‧Ultrasonic pixel circuit

320‧‧‧Control System

322‧‧‧Shift register

324‧‧‧Current detection circuit

326‧‧‧Analog-to-digital conversion circuit

Swo‧‧‧Output switch

PM‧‧‧Ultrasonic sensor

DI‧‧‧Peak detection element

400, 700, 800, 900, 1000‧‧‧Ultrasonic pixel circuit

410‧‧‧Reset circuit

420‧‧‧Output circuit

T1‧‧‧First switch

T2‧‧‧Second switch

Tr‧‧‧Drive Transistor

To‧‧‧Output switch

Cst‧‧‧Storage capacitor

Sint‧‧‧Reset control signal

Sread‧‧‧Output control signal

Ise‧‧‧Sensing current

Lse‧‧‧Sensing data line

N1‧‧‧First node

N2‧‧‧Second node

Vint1‧‧‧First reference voltage

Vbias‧‧‧Drive voltage

VDD‧‧‧System voltage

P1‧‧‧Reset phase

P2‧‧‧Sensing stage

P3‧‧‧Output stage

Vp‧‧‧Preset level

FIG. 1 is a simplified functional block diagram of a display device according to an embodiment of the present disclosure.

Figure 2 is a simplified display device according to another embodiment of the present disclosure The following functional block diagram.

FIG. 3 is a simplified functional block diagram of the ultrasonic sensor array and related control system according to an embodiment of the present disclosure.

FIG. 4 is a functional block diagram of an ultrasonic pixel circuit according to an embodiment of the present disclosure.

FIG. 5 is a schematic diagram of waveforms of multiple control signals and node voltages of the ultrasonic pixel circuit in FIG. 4. FIG.

FIGS. 6A to 6C are schematic diagrams of equivalent circuit operations of the ultrasonic pixel circuit of FIG. 4 in different operating stages.

FIG. 7 is a functional block diagram of an ultrasonic pixel circuit according to another embodiment of this disclosure.

FIG. 8 is a functional block diagram of an ultrasonic pixel circuit according to another embodiment of the present disclosure.

FIG. 9 is a functional block diagram of an ultrasonic pixel circuit according to another embodiment of the present disclosure.

FIG. 10 is a functional block diagram of an ultrasonic pixel circuit according to another embodiment of the present disclosure.

FIG. 11 is a simulation diagram of the ultrasonic pixel circuit of FIG. 4 in an embodiment.

Fig. 12 is a schematic diagram of the simulation of the ultrasonic pixel circuit of Fig. 4 in another embodiment.

The embodiments of the present disclosure will be described below in conjunction with related drawings. In the drawings, the same reference numerals indicate the same or similar elements or method flows.

FIG. 1 is a simplified functional block diagram of the display device 100 according to an embodiment of the present disclosure. The display device 100 includes a protection panel 110, an Organic Light-Emitting Diode (OLED) display module 120, and an ultrasonic sensing module 130. The OLED display module 120 is sandwiched between the protection panel (Cover Lens ) 110 and the ultrasonic sensing module 130. In order to make the drawing concise and easy to explain, other elements and connection relationships in the display device 100 are not shown in the first figure.

The OLED display module 120 includes an OLED material layer 122, a thin film-transistor (TFT) circuit layer 124, and a substrate 126. The TFT circuit layer 124 includes a plurality of display pixel circuits (not shown in FIG. 1), and the display pixel circuits are used to light up the OLED particles in the OLED material layer 122.

In another embodiment, the OLED display module 120 of the display device 100 is replaced by a micro LED (Micro LED) display module. In another embodiment, the OLED display module 120 of the display device 100 is replaced by an LCD display module, and the LCD display module includes a polarizer layer, a filter layer, a liquid crystal layer, a TFT circuit layer, and a backlight module and many more.

The ultrasonic sensor module 130 includes a TFT circuit layer 132 and a substrate 134. The TFT circuit layer 132 includes an ultrasonic sensor array (not shown in FIG. 1) arranged by a plurality of ultrasonic pixel circuits. The ultrasonic sensing module is used for generating ultrasonic waves 103 and used for sensing the ultrasonic waves 103 reflected by an object 101 (for example, a user's finger). In an embodiment, when the object 101 is located above the protection panel 110 and is not in contact with the protection panel 110, the ultrasonic sensing module 130 performs gesture sensing on the object 101. In another embodiment, when the object 101 contacts the protection panel 110, the ultrasonic sensing module 130 performs fingerprint sensing on the object 101, or performs touch operation sensing. In another embodiment, the ultrasonic sensing module 130 can perform gesture sensing, fingerprint sensing, and/or touch operation sensing on the object 101 at the same time.

FIG. 2 is a simplified functional block diagram of the display device 200 according to an embodiment of the present disclosure. The display device 200 is similar to the display device 100 in FIG. 1. The difference is that the width W1 of the ultrasonic sensor module 130 of the display device 200 is smaller than the width W2 of the OLED display module 120. Therefore, compared with the display device 100, the display device 200 has additional internal space, which can increase the flexibility of the hardware architecture design.

FIG. 3 is a simplified functional block diagram of the ultrasonic sensor array 310 and the related control system 320 according to an embodiment of the present disclosure. The ultrasonic sensing array 310 includes a plurality of ultrasonic pixel circuits 312 and a plurality of ultrasonic sensors PM. The ultrasonic pixel circuit 312 includes a peak detection element DI and an output switch SWo. When the ultrasonic sensor PM receives the reflected ultrasonic wave, the peak detection element DI converts the voltage signal generated by the ultrasonic sensor PM into electric charge and accumulates it at one end of the output switch SWo. The output switch SWo uses the accumulated charge as the sensing result, and selectively outputs the sensing result to the control system 320 in the form of current.

The control system 320 includes a shift register 322, a plurality of current detection circuits 324, and an analog-to-digital conversion circuit 326. The shift register 322 is used to sequentially drive (for example, drive from top to bottom column by column) the ultrasonic pixel circuit 312 and an ultrasonic sensor PM to emit ultrasonic waves, sense ultrasonic waves, and output sensing results. Each current detection circuit 324 is coupled to a part of the ultrasonic pixel circuits 312 (for example, coupled to a row of ultrasonic pixel circuits 312) to receive corresponding sensing results. As shown in FIG. 3, the current detection circuit 324 includes an amplifier, and also includes a capacitor and a switch connected in parallel between the output terminal of the amplifier and one of the input terminals. The current detection circuit 324 converts the received current sensing result into a corresponding voltage, and outputs the corresponding voltage to the analog-to-digital conversion circuit 326.

In an embodiment, the current detection circuit 324 is implemented by a current source. One end of the current source is used to receive the aforementioned sensing result, and used to convert the sensing result in the form of current into a corresponding divided voltage, and used to output the corresponding divided voltage to the analog-to-digital conversion circuit 326.

In some embodiments, the display devices 100 and 200 of FIG. 1 and FIG. 2 include the ultrasonic sensing array 310 and the control system 320 of FIG. 3 to implement the aforementioned various ultrasonic sensing functions. The ultrasonic sensing array 310 can be disposed in the TFT circuit layer 132. The control system 320 may be entirely disposed in the TFT circuit layer 132, or partly disposed in the TFT circuit layer 132 and another part disposed on an additional substrate (for example, a flexible printed circuit board).

FIG. 4 is a functional block diagram of an ultrasonic pixel circuit 400 according to an embodiment of the present disclosure. The ultrasonic pixel circuit 400 includes a peak detection element DI, a reset circuit 410, and an output circuit 420. The peak detection element DI is coupled between the first node N1 and the second node N2, and is coupled to one end of the ultrasonic sensor PM through the second node N2. Ultrasonic sensor PM The other end is used to receive the driving voltage Vbias, and the driving voltage Vbias is used to use the oscillation waveform to drive the ultrasonic sensor PM to emit ultrasonic waves.

The peak detection element DI is used to convert the voltage oscillation generated by the ultrasonic sensor PM at the second node N2 into a corresponding charge and store it in the first node N1. In practice, the peak detection element DI can be implemented by a PN diode element or a PIN diode element, wherein the anode terminal and the cathode terminal of the diode element are respectively coupled to the second node N2 and the first node N1.

The reset circuit 410 is coupled to the first node N1 and the second node N2 for setting the voltage of the first node N1 and the second node N2, and includes a first switch T1 and a second switch T2. The first terminal of the first switch T1 is coupled to the first node N1. The first terminal of the second switch T2 is coupled to the second node N2. The second terminal of the first switch T1 and the second terminal of the second switch T2 are used to receive the first reference voltage Vint1. The control terminal of the first switch T1 and the control terminal of the second switch T2 are used to receive the reset control signal Sint, that is, when the reset circuit 410 sets the voltage of the first node N1, the reset circuit 410 also sets the second node The voltage of N2.

The output circuit 420 is coupled to the first node N1 for providing a sensing current Ise according to the voltage of the first node N1, and includes a driving transistor Tr, an output switch To, and a storage capacitor Cst. The first terminal of the driving transistor Tr is used to receive the system voltage VDD, and the control terminal of the driving transistor Tr is coupled to the first node N1. The first end of the output switch To is coupled to the second end of the driving transistor Tr, the second end of the output switch To is coupled to the sensing data line Lse, and the control end of the output switch To is used to receive the output control signal Sread. Storage capacitor Cst The first terminal of is coupled to the first node N1, and the second terminal of the storage capacitor Cst is used to receive the system voltage VDD.

In this embodiment, the storage capacitor Cst is a parasitic capacitance element between the first terminal (for example, the source) and the control terminal (for example, the gate) of the driving transistor Tr, but the present disclosure is not limited to this . In one embodiment, the storage capacitor Cst and the driving transistor Tr are different components. For example, the storage capacitor Cst may be a capacitive element formed by overlapping different metal layers.

In practice, the first switch T1, the second switch T2, the driving transistor Tr, and the output switch To in FIG. 4 can be implemented by various suitable types of P-type transistors. For example, P-type thin film transistor or P-type metal oxide half field effect transistor.

In one embodiment, the ultrasonic pixel circuit 400 and the ultrasonic sensor PM in FIG. 4 can be used to implement the ultrasonic pixel circuit 312 and the ultrasonic sensor PM in FIG. 3, respectively. In this case, the sensing data line Lse is coupled to a row of ultrasonic pixel circuits 312 and a corresponding current detection circuit 324 in FIG. 3. The ultrasonic pixel circuit 400 (ie, the ultrasonic pixel circuit 312) can use the sensing current Ise as a sensing result and output it to the current detection circuit 324 through the sensing data line Lse.

FIG. 5 is a schematic diagram of waveforms of multiple control signals and node voltages of the ultrasonic pixel circuit 400 of FIG. 4. FIGS. 6A to 6C are schematic diagrams of equivalent circuit operations of the ultrasonic pixel circuit 400 of FIG. 4 in different operation stages.

Please refer to Figure 5 and Figure 6A. In the reset phase P1, the reset control signal Sint has a logic high level (for example, a low voltage level), and outputs The control signal Sread has a logic low level (for example, a high voltage level), and the driving voltage Vbias has an oscillating waveform. Therefore, the first switch T1 and the second switch T2 are turned on to maintain the voltages of the first node N1 and the second node N2 at the first reference voltage Vint1, thereby turning off the peak detection element DI. The output switch To is turned off, and the ultrasonic sensor PM generates ultrasonic waves.

Referring to FIGS. 5 and 6B, in the sensing phase P2, the reset control signal Sint and the output control signal Sread both have a logic low level, and the driving voltage Vbias is maintained at a fixed level. Therefore, the first switch T1, the second switch T2, and the output switch To are turned off. When the ultrasonic sensor PM receives the reflected ultrasonic wave and vibrates, the voltage of the second node N2 will have a corresponding oscillating waveform. If the voltage of the second node N2 is higher than a predetermined level Vp, the peak detection element DI will be turned on to transfer the charge of the second node N2 to the first node N1.

In other words, the amount of charge obtained by the first node N1 in the sensing phase P2 will correspond to factors such as the vibration intensity and frequency of the ultrasonic sensor PM.

Referring to FIGS. 5 and 6C, in the output stage P3, the reset control signal Sint has a logic low level, the output control signal Sread has a logic high level, and the driving voltage Vbias is maintained at a fixed level. Therefore, the first switch T1 and the second switch T2 are turned off, and the output switch To is turned on. Since the driving transistor Tr works in the saturation region, the driving transistor Tr will provide the sensing current Ise, and the magnitude of the sensing current Ise will correspond to the voltage of the first node N1. The sensing current Ise is output to the sensing data line Lse through the output switch To.

Figure 7 is an ultrasound picture according to an embodiment of the present disclosure The functional block diagram of the pixel circuit 700. The ultrasonic pixel circuit 700 in FIG. 7 is similar to the ultrasonic pixel circuit 400 in FIG. 4. The difference is that the coupling direction of the peak detection element DI of the ultrasonic pixel circuit 700 is opposite to that of the ultrasonic pixel circuit 400. Peak detection element DI. For example, in an embodiment in which the peak detection element DI of the ultrasonic pixel circuit 700 is implemented by a diode, the peak detection element DI of the ultrasonic pixel circuit 700 is coupled to the first node N1 with an anode terminal, The cathode terminal is coupled to the second node N2.

In the sensing phase P2, if the voltage of the second node N2 is lower than another preset level, the peak detection element DI of the ultrasonic pixel circuit 700 will be turned on, and the charge of the first node N1 is transferred to the second node N2.

FIG. 8 is a functional block diagram of an ultrasonic pixel circuit 800 according to an embodiment of the present disclosure. The ultrasonic pixel circuit 800 of Figure 8 is similar to the ultrasonic pixel circuit 400 of Figure 4, except that the second end of the first switch T1 of the ultrasonic pixel circuit 800 is coupled to the second node N2 (also That is, the first end of the second switch T2).

FIG. 9 is a functional block diagram of an ultrasonic pixel circuit 900 according to an embodiment of the present disclosure. The ultrasonic pixel circuit 900 in Figure 9 is similar to the ultrasonic pixel circuit 400 in Figure 4, except that the second end of the second switch T2 of the ultrasonic pixel circuit 900 is coupled to the first node N1 (also That is, the first end of the first switch T1).

FIG. 10 is a functional block diagram of an ultrasonic pixel circuit 1000 according to an embodiment of the present disclosure. The ultrasonic pixel circuit 1000 in Figure 10 is similar to the ultrasonic pixel circuit 400 in Figure 4, except that the second end of the first switch T1 of the ultrasonic pixel circuit 1000 is used to receive the first parameter. Taking the test voltage Vint1, the second terminal of the second switch T2 of the ultrasonic pixel circuit 1000 is used to receive the second reference voltage Vint2, and the first reference voltage Vint1 is different from the second reference voltage Vint2. In an embodiment, the first reference voltage Vint1 is lower than the second reference voltage Vint2.

It can be seen from the above that the display device and the ultrasonic pixel circuit in the above-mentioned multiple embodiments have a simplified circuit structure, and thus can achieve high-resolution fingerprint, gesture, or touch detection, and reduce manufacturing complexity.

FIG. 11 is a simulation diagram of the ultrasonic pixel circuit 400 of FIG. 4 in an embodiment. FIG. 12 is a simulation diagram of the ultrasonic pixel circuit 400 of FIG. 4 in another embodiment. It can be seen from FIG. 11 that in the sensing phase P2, when the voltage of the second node N2 has an oscillating waveform with a peak value of about 2.5V, the voltage of the first node N1 will rise from 0V to about 1.7V. It can be seen from FIG. 12 that in the sensing phase P2, when the voltage of the second node N2 has an oscillating waveform with a peak value of about 3.0V, the voltage of the first node N1 will rise from 0V to about 2.2V.

Therefore, when the system voltage VDD is set to about 4~6V and the voltage of the sensing data line Lse is reasonably set to about 1.4V, the driving transistor Tr can work in the saturation region, and the output corresponding to the first The driving current Ise of the voltage of the node N1.

In the above embodiments, the system voltage VDD is higher than the voltage of the sensing data line Lse, but the present disclosure is not limited to this. In some embodiments, the system voltage VDD in Figures 4 and 7 to 10 is lower than the voltage of the sensing data line Lse, so that the driving transistor Tr will draw the sensing current Ise from the sensing data line Lse in the output stage P3. .

In other embodiments, the first switch T1 and the second switch T2 in Figs. 4 and 7 to 10 can be implemented by N-type transistors, and the reset control signal Sint will have the opposite phase to that of Fig. 5. Waveform. In addition, the output switch To can also be implemented with an N-type transistor, and the output control signal Sread will correspondingly have an inverted waveform from that shown in Figure 5.

Certain words are used in the specification and the scope of the patent application to refer to specific elements. However, those with ordinary knowledge in the technical field should understand that the same element may be called by different terms. The specification and the scope of the patent application do not use the difference in names as a way of distinguishing elements, but the difference in function of the elements as the basis for distinguishing. The "including" mentioned in the specification and the scope of the patent application is an open term, so it should be interpreted as "including but not limited to". In addition, "coupling" here includes any direct and indirect connection means. Therefore, if the text describes that the first element is coupled to the second element, it means that the first element can be directly connected to the second element through electrical connection, wireless transmission, optical transmission, or other signal connection methods, or through other elements or connections. The means is indirectly connected to the second element electrically or signally.

The description method of "and/or" used herein includes any combination of one or more of the listed items. In addition, unless otherwise specified in the specification, any term in the singular case also includes the meaning of the plural case.

The above are only the preferred embodiments of the present disclosure, and all equal changes and modifications made in accordance with the requirements of the present disclosure should fall within the scope of the disclosure.

400‧‧‧Ultrasonic pixel circuit

410‧‧‧Reset circuit

420‧‧‧Output circuit

T1‧‧‧First switch

T2‧‧‧Second switch

Tr‧‧‧Drive Transistor

To‧‧‧Output switch

Cst‧‧‧Storage capacitor

Sint‧‧‧Reset control signal

Sread‧‧‧Output control signal

Ise‧‧‧Sensing current

Lse‧‧‧Sensing data line

DI‧‧‧Peak detection element

N1‧‧‧First node

N2‧‧‧Second node

Vint1‧‧‧First reference voltage

Vbias‧‧‧Drive voltage

VDD‧‧‧System voltage

PM‧‧‧Ultrasonic sensor

Claims (10)

A display device includes: a display module; a control system; and an ultrasonic sensing array, coupled to the control system, arranged on one side of the display module, and including a plurality of ultrasonic sensors and An ultrasonic pixel circuit, wherein each of the plurality of ultrasonic pixel circuits includes: a peak detection element, coupled between a first node and a second node, and coupled through the second node A corresponding ultrasonic sensor in the plurality of ultrasonic sensors; an output circuit, coupled to the first node, for providing a sensing current according to the voltage of the first node, and for selectively The sensing current is output to the control system; and a reset circuit, coupled to the first node and the second node, wherein when the reset circuit sets the voltage of the first node, the reset circuit also sets the The voltage of the second node. The display device according to claim 1, wherein the reset circuit includes: a first switch including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the first switch is coupled Connected to the first node; and a second switch, including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the second switch is coupled to the second node; wherein the first terminal The second end of a switch and the second end of the second switch The terminal is used for receiving a first reference voltage, and the control terminal of the first switch and the control terminal of the second switch are used for receiving a reset control signal. The display device according to claim 1, wherein the reset circuit includes: a first switch including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the first switch is coupled Connected to the first node; and a second switch including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the second switch is coupled to the second node and the first The second terminal of the switch, the second terminal of the second switch is used to receive a first reference voltage; wherein the control terminal of the first switch and the control terminal of the second switch are used to receive a reset control Signal. The display device according to claim 1, wherein the reset circuit includes: a first switch including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the first switch is coupled Connected to the first node, the second terminal of the first switch is used to receive a first reference voltage; and a second switch includes a first terminal, a second terminal, and a control terminal, wherein the first switch The first terminal of the two switches is coupled to the second node, and the second terminal of the second switch is coupled to the first terminal of the first switch; wherein the control terminal of the first switch and the second terminal The control of the switch The terminal is used to receive a reset control signal. The display device according to claim 1, wherein the reset circuit includes: a first switch including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the first switch is coupled Connected to the first node, the second terminal of the first switch is used to receive a first reference voltage; and a second switch includes a first terminal, a second terminal, and a control terminal, wherein the first switch The first terminal of the two switches is coupled to the second node, the second terminal of the second switch is used to receive a second reference voltage; the control terminal of the first switch and the control terminal of the second switch Used to receive a reset control signal. An ultrasonic pixel circuit includes: a peak detection element, coupled between a first node and a second node, and coupled to an ultrasonic sensor through the second node; an output circuit, coupled to The first node is used to provide a sensing current according to the voltage of the first node, and is used to selectively output the sensing current to a control system; and a reset circuit, coupled to the first node And the second node, wherein when the reset circuit sets the voltage of the first node, the reset circuit also sets the voltage of the second node. The ultrasonic pixel circuit according to claim 6, wherein: The reset circuit includes: a first switch including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the first switch is coupled to the first node; and a second switch , Including a first terminal, a second terminal, and a control terminal, wherein the first terminal of the second switch is coupled to the second node; wherein the second terminal of the first switch and the second switch The second terminal is used for receiving a first reference voltage, and the control terminal of the first switch and the control terminal of the second switch are used for receiving a reset control signal. The ultrasonic pixel circuit according to claim 6, wherein the reset circuit includes: a first switch including a first terminal, a second terminal, and a control terminal, wherein the second terminal of the first switch One end is coupled to the first node; and a second switch includes a first end, a second end, and a control end, wherein the first end of the second switch is coupled to the second node and The second terminal of the first switch, the second terminal of the second switch are used to receive a first reference voltage; wherein the control terminal of the first switch and the control terminal of the second switch are used to receive a Reset the control signal. The ultrasonic pixel circuit according to claim 6, wherein the reset circuit includes: a first switch including a first terminal, a second terminal, and a control Terminal, wherein the first terminal of the first switch is coupled to the first node, the second terminal of the first switch is used to receive a first reference voltage; and a second switch includes a first terminal, A second terminal and a control terminal, wherein the first terminal of the second switch is coupled to the second node, and the second terminal of the second switch is coupled to the first terminal of the first switch; The control terminal of the first switch and the control terminal of the second switch are used for receiving a reset control signal. The ultrasonic pixel circuit according to claim 6, wherein the reset circuit includes: a first switch including a first terminal, a second terminal, and a control terminal, wherein the second terminal of the first switch One end is coupled to the first node, the second end of the first switch is used to receive a first reference voltage; and a second switch includes a first end, a second end, and a control end, Wherein the first terminal of the second switch is coupled to the second node, the second terminal of the second switch is used to receive a second reference voltage; the control terminal of the first switch and the second switch The control terminal is used to receive a reset control signal.

Images