TOUCH PANEL DEVICE

• US 20100066693A1
• Filed: 09/09/2009
• Published: 03/18/2010
• Est. Priority Date: 09/12/2008
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: SATO, Iwao, Murai, Hiroyuki, Mori, Seiichiro
• Granted Patent: US 8,094,133 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0441 using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch panel device according to the present invention includes: a stylus pen including a conductive stylus pen electrode portion at a tip portion thereof; a plurality of capacitance detecting interconnections formed on a substrate in row and column directions; an oscillator circuit which outputs an oscillation signal for performing charging/discharging to each of the plurality of capacitance detecting interconnections, the oscillation signal having a cycle which changes in accordance with an amount of electric charges in the charging/discharging; and a counter circuit and a computing circuit/control circuit which compute, based on a change of the cycle being in accordance with a capacitance formed between the electrode portion of the stylus pen and the capacitance detecting interconnections, positional coordinates of the stylus pen brought in proximity to the capacitance detecting interconnections in a non-contact manner, wherein the stylus pen outputs to the electrode portion of the stylus pen an input pen signal which is in synchronization with the oscillation signal, has a phase different from a phase of the oscillation signal, and has a larger voltage amplitude compared with the oscillation signal.

Claims

1. A touch panel device, comprising:

an input pen including a conductive electrode at a tip portion thereof;

a plurality of capacitance detecting interconnections formed on a substrate in row and column directions;

an oscillating section which outputs an oscillation signal for performing charging/discharging to each of said plurality of capacitance detecting interconnections, said oscillation signal having a cycle which changes in accordance with an amount of electric charges in said charging/discharging; and

a computing section which computes, based on a change of said cycle being in accordance with a capacitance formed between said electrode and said capacitance detecting interconnections, positional coordinates of said input pen brought in proximity to said capacitance detecting interconnections in a non-contact manner,

wherein said input pen outputs to said electrode an input pen signal which is in synchronization with said oscillation signal, has a phase different from a phase of said oscillation signal, and has a larger voltage amplitude compared with said oscillation signal.

2. The touch panel device according to claim 1, wherein a phase of said input pen signal is different from a phase of said oscillation signal by 180 degrees.

3. The touch panel device according to claim 1, wherein an amplitude of voltage of said input pen signal is set so that an amount of electric charges to be charged/discharged when the input pen is used is equal to an amount of electric charges to be charged/discharged when finger input is performed.

4. The touch panel device according to claim 1, wherein said oscillating section and said computing section are used in common when a finger input is performed and when said input pen is used.

5. The touch panel device according to claim 1, wherein said electrode of said input pen is conical in shape with a pen tip being as a vertex.