Title:
【発明の名称】タッチ入力装置
Document Type and Number:
Japanese Patent JP2683699
Kind Code:
B2
Abstract:
A touch input device which continuously samples and digitally stores ambient light readings and compares these with previously stored readings is taught. Briefly stated, a phototransistor (Q) is turned on before, during and after an LED (CR) emitter energization. A digital ambient value (210, 460, 690) is calculated which is subtracted (220, 470, 700) from the value obtained during LED firing (130, 370, 630) so as to develop a signal indicative of the presence or absence of the LED pulse, irrespective of ambient light fluctuations. The ambient level is stored for comparison purposes (270, 520, 750) during the next sampling of the associated phototransistor/emitter pair.
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Inventors:
Casted, Jiyoung Keith
Gearlett, The Ames Edward
Lucas, Paul Berkeley
Masters, Timothy Elton
Gearlett, The Ames Edward
Lucas, Paul Berkeley
Masters, Timothy Elton
Application Number:
JP50216585A
Publication Date:
December 03, 1997
Filing Date:
May 20, 1985
Export Citation:
Assignee:
Amplifier Incorporated
International Classes:
G06F3/042; G06F3/041; G06K11/06; (IPC1-7): G06F3/033
Domestic Patent References:
| JP57117039A |
Attorney, Agent or Firm:
Yanagida Seishi