Alarm shut-off device, with a wake up signal delivering integrated circuit and a receiving and signal shaping network

US4894813A · kind A · utility

Assignee

• The Braun Corporation · DE

Inventors

• Lothar Pacher · Mainz, DE
• Heinz Schiebelhuth · Frankfurt am Main, DE

Key dates

• Filing date: May 26, 1988
• Grant date: Jan 16, 1990
• Expiry date: May 26, 2008

Classification

• Technology area (CPC G): Physics
• CPC primary: G04G13/021
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention is directed to an alarm shut-off device for an alarm clock or timer permitting a signal delivered by the clock to be interupted or to be cancelled in that the user of the clock approaches the clock or merely moves a part of his body, for example, his hand, towards the clock. Preferably, the clock is equipped with a transmitter 2, 2' emitting infrared radiation or ultrasonic waves and a corresponding receiver 3, 3' which detects the infrared radiation or the ultasonic waves reflected by the moved body part 1. A signal shaping network 4, 5 and 6 determines the variation of the intensity with time, which variation is compared in a threshold switching stage 7 with a predeterminable value which, when exceeded, causes the alarm signal A to be shut off.