MEMS DEVICE COMPRISING OSCILLATIONS MEASUREMENTS MEANS

• US 20110181931A1
• Filed: 06/21/2009
• Published: 07/28/2011
• Est. Priority Date: 07/02/2008
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: bTendo Ltd. (STMicroelectronics NV)
• Inventors: Goren, Nir, Luft, Ido
• Granted Patent: US 8,626,468 B2
• Time in Patent Office: Days
• US Class Current: 359/213.1
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 7/02 containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] B81B7/04 takes precedence

Abstract

A MEMS apparatus is provided for scanning an optical beam which comprises: a. at least one mirror operative to perform am oscillation motion to a pre-defined rotation angle around a mirror rotation axis; b. a sound sensing means; and c. a conversion means operative to convert sound vibrations detected by the sound sensing means into one or more electrical signals, and wherein the sound sensing means is located at the vicinity of the at least one mirror whereby the movement of the at least one mirror sensed by the sound sensing means and converted by the conversion means into the one or more electrical signals characterizing the oscillating motion of the at least one mirror.

Claims

1. A MEMS apparatus for scanning an optical beam comprising:

a. at least one mirror operative to perform am oscillation motion to a pre-defined rotation angle around a mirror rotation axis;

b. a sound sensing means; and

c. a conversion means operative to convert sound vibrations detected by the sound sensing means into one or more electrical signals,

and wherein the sound sensing means is located at the vicinity of the at least one mirror whereby the movement of the at least one mirror is sensed by the sound sensing means and converted into said one or more electrical signals.

2. An apparatus according to claim 1, wherein said one or more electrical signals are used in determining whether said mirror is oscillating.

3. An apparatus according to claim 2, wherein if the value of said one or more electrical signals is less than a pre-defined value, ceasing the operation of said MEMS apparatus.

4. An apparatus according to claim 1, wherein said one or more electrical signals are used in determining an absolute phase at which said mirror oscillates.

5. An apparatus according to claim 1, being a product of a surface micro machining process and comprising a plurality of mirrors, and wherein a single sound sensing means is used in generating one or more electrical signals for characterizing oscillating motion of each of said plurality of mirrors.

6. An apparatus according to claim 1, wherein said sound sensing means is operative in the audio and/or ultrasonic range.

7. An apparatus according to claim 6, wherein said sound sensing means comprises at least one microphone.

8. An apparatus according to claim 6, wherein said sound sensing means comprises at least one ultrasonic transducer.

9. An apparatus according to claim 1, wherein said sound sensing means is operative in a range extending from about few tens of Hz to about few tens of kHz.