Capacitance sensing apparatus and control method

Patent metadata

Field	Value
Publication number	US-9501180-B2
Application number	US-201213344996-A
Country	US
Kind code	B2
Filing date	Jan 6, 2012
Priority date	May 26, 2011
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

A capacitance sensing apparatus applied to a touch panel is provided. The capacitance sensing apparatus includes a plurality of sensor channels including a first sensor channel and a second sensor channel neighboring to each other. A first voltage signal is outputted to the first sensor channel. A plurality of capacitances of the first sensor channel are detected to generate a first capacitance result for touch sensing. A second voltage signal is outputted to the second sensor channel. A first voltage difference is present when the first voltage signal and the second voltage signal are respectively outputted to the first sensor channel and the second sensor channel, and a second voltage difference is present when the capacitance of the first sensor channel. The first voltage difference and the second voltage difference are substantially the same.

First claim

What is claimed is:

1. A control method for capacitance sensing, applied to a single-layer self-capacitance type touch panel comprising a plurality of triangle or trapezoidal electrodes that undergo a charging/discharging operation, the method comprising:
outputting a first voltage signal to a first triangle or trapezoidal electrode for self-capacitance touch sensing while outputting a second voltage signal to a second triangle or trapezoidal electrode next to the first triangle or trapezoidal electrode, the second voltage signal being applied not for self-capacitance touch sensing, wherein the first and second voltage signals are different, and when the first voltage signal and the second voltage signal are respectively outputted to the first triangle or trapezoidal electrode and the second triangle or trapezoidal electrode a first voltage difference is present between the first and second triangle or trapezoidal electrodes, and
a second voltage difference is present between the first and second triangle or trapezoidal electrodes when capacitances of the first triangle or trapezoidal electrode are sensed with no touch event sensing occurring with respect to the second triangle or trapezoidal electrode; and the first voltage difference and the second voltage difference are substantially the same,
wherein the first voltage difference is present before the charging/discharging operation and the second voltage difference is present after the charging/discharging operation, and
wherein the touch panel comprises a plurality of triangle or trapezoidal electrodes, and touches of different sections of each electrode generate different self capacitances.

2. The control method according to claim 1 , wherein occurrence of a touch event upon the first triangle or trapezoidal electrode is determined when at least one of the sensed capacitances is greater than a predetermined value.

3. The control method according to claim 1 , wherein no occurrence of touch event upon the first triangle or trapezoidal electrode is determined when none of the sensed capacitances is greater than a predetermined value.

4. The control method according to claim 1 , wherein the first and second voltage signals are step signals having an approximately same voltage step height.

5. The control method according to claim 1 , wherein the first and second voltage signals are cyclic signals and have an approximately same phase.

6. A capacitance sensing apparatus, applied to a single-layer self-capacitance type touch panel, the self-capacitance type touch panel comprising a plurality of triangle or trapezoidal electrodes comprising a first triangle or trapezoidal electrode and a second triangle or trapezoidal electrode, the capacitance sensing apparatus comprising:
a plurality of capacitance sensors, respectively coupled to the triangle or trapezoidal electrodes comprising a first capacitance sensor and a second capacitance sensor that undergo a charging/discharging operation;
wherein, while the first capacitance sensor outputs a first voltage signal to the first triangle or trapezoidal electrode for self-capacitance touch sensing,
the second capacitance sensor outputs a second voltage signal to the second triangle or trapezoidal electrode next to the first sensor channel, the second voltage signal being applied not for self-capacitance touch sensing;
wherein the first and second voltage signals are different,
wherein when the first voltage signal and the second voltage signal are respectively outputted to the first triangle or trapezoidal electrode and the second triangle or trapezoidal electrode a first voltage difference is present between the first and second triangle or trapezoidal electrodes, and
a second voltage difference is present between the first and second triangle or trapezoidal electrodes when capacitances of the first triangle or trapezoidal electrode are sensed with no touch event sensing occurring with respect to the second triangle or trapezoidal electrode,
wherein the first voltage difference and the second voltage difference are substantially the same, and
wherein the first voltage difference is present before the charging/discharging operation and the second voltage difference is present after the charging/discharging operation.

7. The capacitance sensing apparatus according to 6 , wherein when at least one of the sensed capacitances in the first triangle or trapezoidal electrode is greater than a predetermined value, it is determined that a touch event occurs upon the first triangle or trapezoidal electrode.

8. The capacitance sensing apparatus according to 6 , wherein if none of the sensed capacitances in the first triangle or trapezoidal electrode is greater than a predetermined value, it is determined that no touch event occurs upon the first triangle or trapezoidal electrode.

9. The capacitance sensing apparatus according to 6 , wherein the first and second voltage signals are step signals having an approximately same voltage step height.

10. The capacitance sensing apparatus according to 6 , wherein the first and second voltage signals are cyclic signals and have an approximately same phase.

Assignees

• Hung Guo-Kiang
• Pan Hsuan-I
• Yeh Ting-Hao
• Ho Kai-Ting
• Mstar Semiconductor Inc

Inventors

• Hung Guo-Kiang
• Pan Hsuan-I
• Yeh Ting-Hao
• Ho Kai-Ting

Classifications

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/044 Primary

  by capacitive means · CPC title

• G06F3/041662 Primary

  using alternate mutual and self-capacitive scanning · 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