发明名称 |
Article removal alarm system for use with portable electronic device |
摘要 |
An article removal alarm system includes a base unit for generating an ultrasonic signal for transmission in the vicinity of the base unit. A remote unit accompanying an associated article includes a receiver for receiving the ultrasonic signal. A threshold detector provides a threshold signal upon failure of the receiver to receive the ultrasonic signal at predetermined strength. An alarm unit then generates an alarm signal in response to the threshold signal. In a particular implementation the system enables monitoring of the proximity of a stylus or other input utensil to a responsive user interface of an electronic device.
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申请公布号 |
US5614886(A) |
申请公布日期 |
1997.03.25 |
申请号 |
US19950543195 |
申请日期 |
1995.10.13 |
申请人 |
SNELL, PETER;FISCHER, ALFRED |
发明人 |
SNELL, PETER;FISCHER, ALFRED |
分类号 |
G08B13/14;(IPC1-7):G08B13/16 |
主分类号 |
G08B13/14 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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