Capacitance detection circuit and method, and electronic device

Patent metadata

Field	Value
Publication number	US-12224745-B2
Application number	US-202217944061-A
Country	US
Kind code	B2
Filing date	Sep 13, 2022
Priority date	Jul 21, 2020
Publication date	Feb 11, 2025
Grant date	Feb 11, 2025

Abstract

This application provides a capacitance detection circuit for detecting capacitance of a capacitor element within a capacitor array. The circuit includes a capacitance detection module for detecting a first capacitance of a first capacitor set, a second capacitance of a second capacitor set, and a third capacitance of the third capacitor set, the first capacitor set comprising the capacitor element and a row capacitor element in the same row of the capacitor array as the capacitor element, the second capacitor set comprising the capacitor element and a column capacitor element in the same column of the capacitor array as the capacitor element, the third capacitor set comprising the row capacitor element and the column capacitor element; and a processing module, configured to obtain the capacitance of the capacitor element according to the first capacitance, the second capacitance and the third capacitance.

First claim

What is claimed is:

1. A circuit for detecting capacitance of a capacitor element within a capacitor array, the circuit comprising:
a capacitance detection module, configured to detect a first capacitance of a first capacitor set, a second capacitance of a second capacitor set, and a third capacitance of a third capacitor set, the first capacitor set comprising the capacitor element and a row capacitor element in a same row of the capacitor array as the capacitor element, the second capacitor set comprising the capacitor element and a column capacitor element in a same column of the capacitor array as the capacitor element, the third capacitor set comprising the row capacitor element and the column capacitor element; and
a processing module, configured to obtain the capacitance of the capacitor element according to the first capacitance, the second capacitance and the third capacitance by:
determining the capacitance of the capacitor element by the formula:
C t =(C 1 +C 2 −C 3 )/2,

wherein C t is the capacitance of the capacitor element, C 1 is the first capacitance, C 2 is the second capacitance, and C 3 is the third capacitance.

2. The circuit according to claim 1 , further comprising a switching module, wherein the switching module is configured to connect the capacitance detection module to the first capacitor set, the second capacitor set and the third capacitor set, respectively.

3. The circuit according to claim 2 , wherein the switching module comprises a first switch and a second switch, and both the first switch and the second switch each comprise a first contact, a second contact, and a third contact, wherein the first contact of the first switch and the first contact of the second switch are both connected to the capacitance detection module; the second contact of the first switch and the second contact of the second switch are both grounded; the third contact of the first switch is connected to a first terminal of the capacitor element, and grounded through the row capacitor element; and the third contact of the second switch is connected to a second terminal of the capacitor element, and grounded through the column capacitor element.

4. The circuit according to claim 3 , wherein the processing module is configured to control the connection of the contacts in the first switch and the second switch to form three connection states, wherein
in a first connection state of the three connection states, the capacitance detection module is respectively connected to one terminal of the capacitor element and the row capacitor element, and the other terminal of the capacitor element and the row capacitor element is grounded; and both terminals of the column capacitor element are grounded;
in a second connection state of the three connection states, the capacitance detection module is respectively connected to one terminal of the capacitor element and the column capacitor element, and the other terminal of the capacitor element and the column capacitor element is grounded; and both terminals of the row capacitor element are grounded; and
in a third connection state of the three connection states, the capacitance detection module is respectively connected to one terminal of the row capacitor element and the column capacitor element, and the other terminal of the capacitor row element and the column capacitor element is grounded; and both terminals of the capacitor element are connected to the capacitance detection module.

5. The circuit according to claim 1 , further comprising: a switch module, wherein the capacitance detection module is configured to be connected to the capacitor array through the switch module; and
the processing module is connected to the switch module, and configured to determine the capacitor element, and control the switch module to connect the capacitance detection module to the capacitor element.

6. The circuit according to claim 5 , wherein the switch module comprises a plurality of row switches and a plurality of column switches, wherein each of the capacitor elements corresponds to one of the column switches and one of the row switches, and the processing module is configured to
determine a target row switch and a target column switch corresponding to the capacitor element; and
connect the target row switch and the target column switch to the capacitance detection module, ground other row switches than the target row switch in the plurality of row switches, and ground other column switches than the target column switch in the plurality of column switches.

7. The circuit according to claim 6 , wherein each of the row switches and each of the column switches comprise a first connection terminal, wherein the first terminal of each of the capacitor elements is connected to the first connection terminal of one of the column switches, and the second terminal of each of the capacitor elements is connected to the first connection terminal of one of the row switches; and the processing module is further configured to
connect the first connection terminal of the target row switch and the first connection terminal of the target column switch to the capacitance detection module, ground the first connection terminals of other row switches than the target row switch in the plurality of row switches, and ground the first connection terminals of other column switches than the target column switch in the plurality of column switches.

8. The circuit according to claim 7 , wherein each of the row switches and each of the column switches further comprises a second connection terminal and a third connection terminal, wherein the second connection terminals of each of the row switches and each of the column switches are grounded, and the third connection terminals of each of the row switches and each of the column switches are connected to the capacitance detection module; and the processing module is further configured to:
connect the first connection terminal to the third connection terminal of the target column switch, and disconnect the first connection terminal from the second connection terminal;
connect the first connection terminal to the third connection terminal of the target row switch, and disconnect the first connection terminal from the second connection terminal;
connect the first connection terminals to the second connection terminals of other row switches than the target row switch in the plurality of row switches, and disconnect the first connection terminals from the third connection terminal; and
connect the first connection terminals to the second connection terminals of other column switches than the target column switch in the plurality of column switches, and disconnect the first connection terminals from the third connection terminal.

9. The circuit according to claim 1 , wherein the processing module is further configured to determine a capacitor element following the capacitor element as a newly capacitor element according to a preset detection sequence, and inform the capacitance detection module of the capacitor element; and
the capacitance detection module is further configured to implement the operation of detecting the first capacitance, the second capacitance and the third capacitance and subsequent operations on the newly capacitor element, until all capacitor elements that require the detection of capacitance are detected according to the preset detection sequence.

10. An electronic device, comprising the capacitance detection circuit according to claim 1 , the electronic device being provided with an electronic skin including the capacitor array on a surface.

11. The electronic device according to claim 10 , wherein the electronic device

Assignees

• Tencent Tech Shenzhen Co Ltd

Inventors

• Dai Yuan
• Zhang Ruirui
• Chen Ke
• Lai Jie
• Liu Siyuan
• Zhang Zhengyou

Classifications

• H03K2217/96074

  Switched capacitor · CPC title

• G06F3/0418

  for error correction or compensation, e.g. based on parallax, calibration or alignment · CPC title

• G01R27/2605

  Measuring capacitance (capacitive sensors G01D5/24) · CPC title

• B25J13/084

  Tactile sensors (in general G01L5/16, G01L5/22) · CPC title

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title