Electronic device having touch sensor

• US 20040119342A1
• Filed: 10/20/2003
• Published: 06/24/2004
• Est. Priority Date: 10/22/2002
• Status: Active Grant

• Current Assignee: Alps Alpine Co., Ltd.
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Sato, Kunio, Endo, Yoshihisa, Soma, Masahiro
• Granted Patent: US 7,242,323 B2
• Time in Patent Office: Days
• US Class Current: 307/652
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01D 5/2405 by varying dielectric
• CPC Class Codes: H01H 2231/01 Toy
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/96072 Phase comparison, i.e. where a phase comparator receives at one input the signal directly from the oscillator, at a second input the same signal but delayed, with a delay depending on a sensing capacitance

Abstract

A variable capacitance unit is formed between one portion of a human body and an opposed electrode facing it through a casing of a robot toy (electronic device) when the one portion of the human body such as a hand or a finger approaches the surface of the casing of the robot. Since the capacitance of the variable capacitance unit varies according to the facing area and the facing distance of the one portion of the human body and the opposed electrode, it is possible to detect the one portion of the human body approaching or touching the robot toy by detecting this change. Since the opposed electrode forming the touch sensor can be provided within the casing, the touch sensor cannot be seen directly from the outside of the robot toy.

Claims

1. An electronic device having a touch sensor capable of detecting a human body approaching or touching its casing, in which

the touch sensor comprises an electrode of a predetermined area provided in an inner portion of the casing at a distance from an outer surface of the casing and detecting means for detecting a change of capacitance from the electrode when the human body approaches or touches the outer surface of the casing.

2. The electronic device according to claim 1, in which the detecting means includes:

clock signal generating means for generating a clock signal;

delaying means for giving a delay in rising up the clock signal according to the capacitance detected by the electrode when the human body approaches or touches the outer surface of the casing,

means for generating a signal depending on the amount of the delay, with the clock signal not passing through the delaying means defined as a reference; and

A/D converting means for A/D converting a signal depending on the amount of the change from analog to digital.

3. The electronic device according to claim 2, in which the detecting means detects a change of a facing area of the electrode and the human body.

4. The electronic device according to claim 2 or claim 3, in which

the detecting means detects an interval that the human body faces the electrode.

5. The electronic device according to one of claims 2 to 4, in which

a plurality of the electrodes are provided, each electrode including the delaying means and the means for generating a signal depending on the amount of the delay of a signal passing through the corresponding delaying means, with a common clock signal as a reference.

6. The electronic device according to one of claims 1 to 5, in which

the electrodes are arranged along a shape of the outer surface so as to make each portion of the electrodes at equal distance from the outer surface of the casing.

7. The electronic device according to one of claims 1 to 6, in which

the casing forms an appearance of a toy and the outer surface of the casing corresponding to a portion provided with the electrode is defined as a touch portion with the human body.