Pressure detecting circuit and method, display panel, and display apparatus

Patent metadata

Field	Value
Publication number	US-11385109-B2
Application number	US-201816346200-A
Country	US
Kind code	B2
Filing date	Dec 12, 2018
Priority date	Jan 31, 2018
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A pressure detecting circuit may include a pressure sensing circuit ( 101 ), a signal generating circuit ( 102 ), and a frequency detecting circuit ( 103 ). The pressure sensing circuit ( 101 ) and the signal generating circuit ( 102 ) may be configured to constitute an oscillating circuit ( 104 ). The signal generating circuit ( 102 ) may be configured to generate an oscillating signal based on a pressure sensed by the pressure sensing circuit ( 101 ). The frequency detecting circuit ( 103 ) may be configured to detect a frequency of the oscillating signal and determine a value of the pressure sensed by the pressure sensing circuit ( 101 ) based on the frequency of the oscillating signal.

First claim

What is claimed is:

1. A pressure detecting circuit, comprising:
a pressure sensing circuit;
a signal generating circuit; and
a frequency detecting circuit,
wherein the pressure sensing circuit and the signal generating circuit are configured to constitute an oscillating circuit; the signal generating circuit is configured to generate an oscillating signal based on charging and discharging of the pressure sensing circuit; and the frequency detecting circuit is configured to detect a frequency of the oscillating signal and determine a pressure based on the frequency of the oscillating signal;
wherein the signal generating circuit comprises:
a comparing circuit, a first input terminal of the comparing circuit being coupled to a first terminal of the pressure sensing circuit, and an output terminal of the comparing circuit being coupled to a second terminal of the pressure sensing circuit; and
a feedback circuit, a first terminal of the feedback circuit being coupled to a second input terminal of the comparison circuit, and a second terminal of the feedback circuit being coupled to the output terminal of the comparing circuit;
wherein the comparing circuit is configured to generate the oscillating signal by comparing a voltage of the first terminal of the pressure sensing circuit with a voltage of the first terminal of the feedback circuit, and outputs the oscillating signal through the output terminal of the comparing circuit; and
wherein the pressure sensing circuit comprises:
M pressure sensing subcircuits, each of the M pressure sensing subcircuits comprising a pressure sensitive component, a first transistor, and a first capacitor, where M is a positive integer,
wherein a first terminal of each of the M pressure sensing subcircuits is coupled to the first input terminal of the comparing circuit, a second terminal of each of the M pressure sensing subcircuits is coupled to the output terminal of the comparing circuit, and each of the M pressure sensing circuits is configured to participate in oscillation of the oscillating circuit when the corresponding first transistor is turned on.

2. The pressure detecting circuit according to claim 1 , wherein the pressure detecting circuit comprises M scanning signal lines, and a gate of the first transistor of each of the M pressure sensing subcircuits is respectively coupled to one of the M scanning signal lines, and each of the scanning signal lines is configured to control whether a pressure sensing subcircuit participates in oscillation or not by controlling opening or closing of the first transistor of the pressure sensing subcircuit.

3. The pressure detecting circuit according to claim 1 , wherein one terminal of the first capacitor is grounded, the other terminal of the first capacitor is coupled to one terminal of the pressure sensitive component, a first node is between the first capacitor and the pressure sensitive component, the other terminal of the pressure sensitive component is coupled to the output terminal of the comparing circuit, the first terminal of the first transistor is coupled to the first node, and the second terminal of the first transistor is coupled to the first input terminal of the comparing circuit.

4. The pressure detecting circuit according to claim 1 , wherein the feedback circuit comprising a first resistor and a second resistor, and one terminal of the first resistor is coupled to the output terminal of the comparing circuit, the other terminal of the first resistor is coupled to one terminal of the second resistor, a second node is disposed between the first resistor and the second resistor and coupled to the second input terminal of the comparing circuit, and the other terminal of the second resistor is grounded.

5. The pressure detecting circuit according to claim 1 , wherein the signal generating circuit further comprises a voltage stabilizing diode, one terminal of the voltage stabilizing diode is coupled to the output terminal of the comparing circuit and the other terminal of the voltage stabilizing diode is grounded.

6. The pressure detecting circuit according to claim 1 , wherein the comparing circuit is a comparator or an operational amplifier.

7. The pressure detecting circuit according to claim 1 , wherein the frequency detecting circuit comprises:
a shaper;
a monostable flip-flop;
an RS flip-flop;
a counter; and
a latch,
wherein the shaper is configured to shape the oscillating signal to generate and output a shaped oscillating signal;
the monostable flip-flop is configured to convert the shaped oscillating signal to a pulse signal;
the RS flip-flop is configured to generate a trigger signal based on the pulse signal;
the counter is configured to count under control of the trigger signal to record a number of count pulses between two adjacent pulse signals; and
the latch is configured to latch the number of count pulses between the two adjacent pulse signals.

8. The pressure detecting circuit according to claim 1 , wherein the oscillating signal is a square wave signal.

9. The pressure detecting circuit according to claim 1 , wherein the M pressure sensing subcircuits are in a same column.

10. The pressure detecting circuit according to claim 1 , wherein the pressure sensitive component is a varistor.

11. A display panel, comprising N pressure detecting circuits according to claim 1 , wherein N is a positive integer.

12. The display panel according to claim 11 , wherein the display panel comprises a pressure sensing array comprising M rows and N columns of the pressure sensing subcircuits of the N pressure detecting circuits, wherein gates of first transistors of N pressure sensing subcircuits in a same row are coupled to a same scanning signal line, and the first transistors in the M rows of the pressure sensing subcircuits are turned on row by row.

13. The display panel according to claim 12 , further comprising a pixel array comprising M rows and N columns of pixel units, wherein the M rows and N columns of pixel units are respectively disposed corresponding to the M rows and N columns of the pressure sensing subcircuits, and each of pressure sensing subcircuits is arranged in an interval between two of the pixel units.

14. A display apparatus comprising the display panel according to claim 11 .

15. A pressure detecting method, comprising:
constructing an oscillating circuit comprising a signal generating circuit and a pressure sensing circuit, wherein the signal generating circuit is configured to generate an oscillating signal based on charging and discharging of the pressure sensing circuit;
detecting a frequency of the oscillating signal; and
determining a pressure based on the frequency of the oscillating signal;
wherein the signal generating circuit comprises:
a comparing circuit, a first input terminal of the comparing circuit being coupled to a first terminal of the pressure sensing circuit, and an output terminal of the comparing circuit being coupled to a second terminal of the pressure sensing circuit; and
a feedback circuit, a first terminal of the feedback circuit being coupled to a second input terminal of the comparison circuit, and a second terminal of the feedback circuit being coupled to the output terminal of the comparing circuit;
wherein the comparing circuit is configured to generate the oscillating signal by comparing a voltage of the first terminal of the pressure sensing circuit with a voltage of the first terminal of the feedback circuit, and outputs the oscillating signal through the output terminal of the comparing circuit; and
wherein the pressure sensing circuit compr

Assignees

• Boe Technology Group Co Ltd

Inventors

• Wang Pengpeng
• Ding Xiaoliang
• Cheng Chih-Jen

Classifications

• G01L1/183 Primary

  by measuring variations of frequency of vibrating piezo-resistive material · CPC title

• G01L1/225 Primary

  Measuring circuits therefor · CPC title