Input apparatus having electrostatic sensor

• US 7,199,789 B2
• Filed: 12/17/2003
• Issued: 04/03/2007
• Est. Priority Date: 12/20/2002
• 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
• Primary Examiner(s): Liang; Regina
• Application Number:
  US10/738,823
• Publication Number:
  US 20040130527A1
• Time in Patent Office: 1,203 Days
• Field of Search: 345173-179, 178/18.01, 178/18.05, 340/562
• US Class Current: 345/173
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3231 Monitoring the presence, absence or movement of users
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An input apparatus having a reduced-size electrostatic sensor that can precisely detect an input and then output a signal and, thus, has excellent responsiveness and reliability contains the following: clock signal generating means for generating clock signals; delaying means for generating delayed signals by delaying the signal rise time of the clock signal according to the capacitance detected when a human appendage approaches or contacts the electrostatic sensor; AND means for receiving the clock signal and the delayed signal as input signals and then outputting these signals as an output signal; and smoothing means for smoothing and outputting the output of the analog switch.

Claims

1. An input apparatus having an electrostatic sensor, comprising:

clock signal generating means for generating clock signals;

delaying means for generating delayed signals by delaying signal rise times of the clock signals according to a capacitance detected when a human appendage approaches or contacts the electrostatic sensor;

AND means for receiving the clock signals and the delayed signals as input signals and outputting the clock and delayed signals as an output signal; and

smoothing means for smoothing and outputting an output of the AND means,

wherein the delaying means extends a pulse length of a first clock signal generated at the clock signal generating means to a length required for obtaining an intended output from the smoothing means when the electrostatic sensor is started up by the human appendage contacting the electrostatic sensor in a standby mode with no clock signal output.

2. An input apparatus having an electrostatic sensor, comprising:

clock signal generating means for generating clock signals;

delaying means for generating delayed signals by delaying signal rise times of the clock signals according to a capacitance detected when a human appendage approaches or contacts the electrostatic sensor;

AND means for receiving the clock signals and the delayed signals as input signals and then outputting the clock and delayed signals as an output signal;

an analog switch for switching and outputting an output of the AND means with a clock signal; and

smoothing means for smoothing and outputting an output of the analog switch,

wherein the delaying means extends a pulse length of a first clock signal generated at the clock signal generating means to a length required for obtaining an intended output from the smoothing means when the electrostatic sensor is started up by the human appendage contacting the electrostatic sensor in a standby mode with no clock signal output.