TAP SENSITIVE ALARM CLOCK

• US 20130135973A1
• Filed: 08/04/2011
• Published: 05/30/2013
• Est. Priority Date: 08/12/2010
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Rozeboom, Frans Wiebe, Schallig, Michiel Allan Aurelius, Godlieb, Robert, Heeringa, Schelte, Wind, Roelof Jan, Botma, Jacob Hendrik, Van Oostrum, Hielke Simon
• Granted Patent: US 8,908,478 B2
• Time in Patent Office: Days
• US Class Current: 368/72
• CPC Class Codes: G04G 13/021 Details
• CPC Class Codes: G04G 13/023 Adjusting the duration or amplitude of signals
• CPC Class Codes: G04G 13/028 combined with a radio
• CPC Class Codes: G04G 21/08 Touch switches specially adapted for time-pieces

Abstract

A tap sensitive alarm clock has a housing (20), a vibration sensor (22) mechanically coupled to the housing for receiving a shock due to a user tapping the housing, and a control circuit (24) coupled to the vibration sensor for controlling a function of the alarm clock. An audio unit (26) is coupled to an audio circuit (25) for generating sound, e.g. a loudspeaker in an alarm clock or a wake up light. To avoid interference of the sound and the vibration sensor, the alarm clock is provided with a filter (23) coupled to the vibration sensor and the control circuit. The filter has a filter curve matched to block frequencies occurring in the sound. Advantageously it is avoided that the sound frequencies trigger the function, while the sensor is sensitive to other frequencies up to the frequency range of the sound for reliably detecting the tapping.

Claims

1. Tap sensitive alarm clock, comprising

a housing;

a vibration sensor mechanically coupled to the housing for receiving a shock due to a user tapping the housing,

a control circuit coupled to the vibration sensor for controlling a function of the alarm clock,

an audio unit coupled to an audio circuit for generating sound, and

a filter coupled to the vibration sensor and the control circuit, the filter having a filter curve matched to filter frequency components that are present in the sound, so that only frequency components caused by the mechanical shock acting on the vibration sensor are passed to the control circuit.

2. Alarm clock as claimed in claim 1, wherein the filter is a low-pass filter.

3. Alarm clock as claimed in claim 2, wherein the filter curve has a corner frequency between 50 and 200 Hz.

4. Alarm clock as claimed in claim 1, wherein the vibration sensor is arranged for generating an electrical signal that is coupled to the filter, and the filter is arranged for processing the electrical signal.

5. Alarm clock as claimed in claim 1, wherein the vibration sensor is mechanically arranged so as to be sensitive according to the filter curve.

6. Alarm clock as claimed in claim 1, wherein the filter has an adjustable amplification.

7. Alarm clock as claimed in claim 6, wherein the filter is arranged for adjusting the amplification in dependence on the level of the sound.

8. Alarm clock as claimed in claim 1, wherein the filter is arranged for adjusting the filter curve in dependence on the audio content of the sound.

9. Alarm clock as claimed in claim 8, wherein the filter is a low-pass filter having a corner frequency and is arranged for adjusting the corner frequency in dependence on the audio content of the sound.

10. Alarm clock as claimed in claim 1, wherein the audio circuit comprises a high-pass filter having a high-pass filter curve to control the frequencies occurring in the sound.

11. Alarm clock as claimed in claim 1, wherein the alarm clock comprises a wake-up light and/or a radio.

12. Alarm clock as claimed in claim 1, wherein the function is a snooze function.