Touch panel input device

• US 20030067449A1
• Filed: 06/14/2002
• Published: 04/10/2003
• Est. Priority Date: 10/10/2001
• Status: Active Grant

• Current Assignee: SMK Corporation
• Original Assignee: SMK Corporation
• Inventors: Yoshikawa, Osamu, Ishibashi, Hirotoshi
• Granted Patent: US 7,215,329 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/0414 using force sensing means to determine a position

Abstract

A piezoelectric substrate is fixed to the movable plate or the support substrate directly or through a drive electrode of the piezoelectric substrate. When a pressure on an input operation surface is detected, a drive voltage is impressed on the drive electrodes of the piezoelectric substrate. In response, the piezoelectric substrate vibrates the movable plate or the support substrate, thereby providing tactile feedback to an operator. Because the movable plate or the support substrate directly vibrates without an independent vibrating source, there is no energy loss or transmission delay caused by transmitting the vibration, and finely control of the contraction and expansion of the piezoelectric substrate allows fine control of the vibration. In one embodiment, the drive voltage is modulated with signals dependent on the location of the pressure. In another embodiment, the drive voltage is modulated with audio frequencies to create a speaker.

Claims

1. A touch panel input device comprising:

a movable plate;

an input operation surface on a surface of said movable plate;

a support substrate facing said movable plate across an insulating gap;

a first conductor layer on a first surface of said movable plate facing said support substrate;

a second conductor layer on a second surface of said support substrate facing said movable plate;

pressure detecting means for detecting a pressure and a pressed position on said input operation surface based on a contact between said first and second conductor layers;

means for providing pressed position data indicating a position of said pressure;

a piezoelectric substrate mechanically fixed to one of said movable plate and said support substrate; and

means for applying a drive voltage to said piezoelectric substrate responsive to said pressure, whereby contracting and expanding of said piezoelectric substrate in response to said drive voltage vibrates the one of said movable plate and said support substrate to generate an input operation feeling.

2. A touch panel input device according to claim 1, wherein said piezoelectric substrate includes a pair of drive electrodes fixed on opposed surfaces thereof.

3. A touch panel input device according to claim 2, wherein said means for detecting pressure is connected through at least one of said drive electrodes.

4. The touch panel input device according to claim 1 further comprising:

a spacer member placed at peripheral frames between inner surfaces of said movable plate and said support substrate for laminating and spacing said movable plate and said support substrate facing each other over a slight gap;

a drive electrode for applying said drive voltage to said piezoelectric substrate;

said piezoelectric substrate is fixed directly or through said drive electrode on an inner surface of one of said movable plate and said support substrate; and

said piezoelectric substrate is installed in a space where said spacer member is placed.

5. The touch panel input device according to claim 4, wherein:

said pressure detecting means impresses a detecting voltage on, or detects a voltage of any leader electrode electrically connected with a peripheral edge of the individual conductor layers of said movable plate or said support substrate to detect said pressure and said pressed position on said input operation surface,

said leader electrode fixed on said inner surface of said frame of said movable plate or said support substrate serves as one of said drive electrodes of said piezoelectric substrate; and

said piezoelectric substrate is fixed through said leader electrode.

6. The touch panel input device according to claim 1, wherein said piezoelectric substrate is fixed directly on a rear surface of said support substrate.

7. The touch panel input device according to claim 1, wherein said piezoelectric substrate is fixed through a drive electrode on a rear surface of said support substrate.

8. The touch panel input device according to claim 6, wherein:

said movable plate and said support substrate are made of a transparent material for transmitting emitted light from a light-emitting element for illumination provided on a rear side of said support substrate; and

said piezoelectric substrate is fixed directly or through said drive electrode to a part of a rear surface of said support substrate where leader electrodes electrically connected with a peripheral edge of said conductor layer are formed.

9. The touch panel input device according to claim 1, further comprising:

a coil;

means for impressing a low voltage trigger pulse to said coil when said pressure is detected;

said coil being effective for producing said drive voltage in response to said trigger pulse.

10. The touch panel input device according to claim 1, further comprising means for modulating said drive voltage at audio frequencies whereby a sound representing an input operation is generated.