WO2010001388A1 - A mems device comprising oscillations' measurements means - Google Patents

A mems device comprising oscillations' measurements means Download PDF

Info

Publication number
WO2010001388A1
WO2010001388A1 PCT/IL2009/000648 IL2009000648W WO2010001388A1 WO 2010001388 A1 WO2010001388 A1 WO 2010001388A1 IL 2009000648 W IL2009000648 W IL 2009000648W WO 2010001388 A1 WO2010001388 A1 WO 2010001388A1
Authority
WO
WIPO (PCT)
Prior art keywords
mirror
sensing means
sound sensing
electrical signals
operative
Prior art date
Application number
PCT/IL2009/000648
Other languages
French (fr)
Inventor
Ido Luft
Nir Goren
Original Assignee
Btendo Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Btendo Ltd. filed Critical Btendo Ltd.
Priority to US13/002,378 priority Critical patent/US8626468B2/en
Publication of WO2010001388A1 publication Critical patent/WO2010001388A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2201/00—Specific applications of microelectromechanical systems
    • B81B2201/04—Optical MEMS
    • B81B2201/042—Micromirrors, not used as optical switches

Definitions

  • the present invention relates to optical systems for scanning or deflecting light beams, and in particularly to systems which comprise periodically moving reflective elements, such as oscillating mirrors.
  • a typical optical scanning system for this purpose employs a tilting flat mirror to deflect the beam.
  • the tilting micro-mirror serves as a central element in many Micro Electro Mechanical Systems (“MEMS") devices. It typically comprises a flat plate (e.g. made of silicon) having a reflecting surface. The plate is held suspended by two torsional hinges aligned along a common torsion (and tilt) axis or a gimbal .
  • the two hinges allow the mirror to tilt clockwise and counterclockwise within a given range of angles, and a collimated laser beam that impinges on the reflecting surface of the mirror is redirected by the mirror to a projection area.
  • the tilting mirror is actuated by an actuation moment that can be provided by well-known MEMS actuation systems.
  • the collimated input beam is aimed perpendicular to the scanning mirror's rotational axis, so that the main deflected ray sweeps a plane in space. Beam collimation generally ensures that the spot size remains substantially the same at both the center and edges of the flat surface.
  • one of the problems associated with the operation of a MEMS type of mirror is how to confirm that the mirror is indeed oscillating, as a failure that causes the mirror (s) to stop oscillating would lead to safety hazards caused by the fact the all of the laser energy that should have been divided at the projection plane will now be focused onto a very small focal point.
  • certain applications require long term positioning accuracy such as in optical communication applications, e.g. in various optical switches and variable optical attenuators implemented in communication systems, and in light processing devices used in projection technology.
  • US 6538802 describes a movable MEMS mirror system with a mirror position detection system, such as a capacitive sensor, that is calibrated using a physical stop with a range of movement of the mirror structure.
  • a drift in the position detection system can be compensated without the need for a separate reference signal source as used in conventional systems.
  • US 7252394 discloses the use of a capacitance sensor embedded in a scanning mirror which is used to detect a change in capacitance from the movement of the reflecting mirror unit. Another alternative described therein is the use of a piezoelectric sensor embedded in a scanning mirror and used to detect a change in current from the movement of reflecting mirror unit.
  • US 6275326 describes a microelectromechanical sensor used to sense the position of a movable element in a microelectromechanical system.
  • the microelectromechanical sensor being a strain gage, a gage of a capacitive, piezoelectric, piezoresistive or pressure type, adjoins the movable element and the resulting signal is fed back to control the component for moving the movable element.
  • the signal of each sensor is specific to one movable element.
  • US 20070064300 teaches a method of using in a projection system a microphone for detecting non- soundtrack disturbances, such as sounds or vibrations, generated exteriorly of the projection device, such as from household appliances, people walking in close proximity to projection system, etc.
  • a signal generator generates a driving square wave signal.
  • the signals are received at a filter from an audio amplifier and contain one or more frequency components that either act to produce the unwanted oscillatory displacements of optical component and/or are the result of non-audio-component sources.
  • MEMS microelectromechanical systems
  • a MEMS apparatus for scanning an optical beam comprising: a. at least one mirror operative to perform an oscillation motion to a pre-defined rotation angle around a respective mirror rotation axis or a gimbal; 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 the one or more electrical signals.
  • the one or more electrical signals are used in determining whether the at least one mirror is oscillating, and preferably, if the value of the electrical signal is less than a pre-defined value, stopping the operation of the MEMS apparatus .
  • the one or more electrical signals are used in determining the absolute phase at which the at least one mirror oscillates. This embodiment is based on the fact that the sound sensing device is located at the vicinity of the mirror, and is capable of sensing the frequency of the mirror's oscillations.
  • the MEMS apparatus is a product of a surface micro machining process (also known as bulk micro-machining process) using materials such as bulk silicon, multi-layer substrate SOI
  • the MEMS apparatus is a pre-fabricated multi-layer substrate SOI comprising a plurality of mirrors and wherein a single sound sensing means is used to determine the absolute phase at which each of the plurality of mirrors oscillates, e.g. by carrying out a specific Fourier transform for each of the plurality of mirrors derived from the electrical signal received.
  • the sound sensing means is operative in the audio and/or ultrasonic range and preferably comprises at least one microphone and/or at least one ultrasonic transducer, respectively.
  • the sound sensing means is operative in a range extending from about few tens of Hz to about few tens of kHz.
  • FIG. 1 - presents a schematic block diagram of an apparatus for detecting oscillations of a MEMS' mirror
  • FIG. 2 - presents a schematic block diagram of an apparatus for detecting oscillations of a plurality of MEMS' mirrors.
  • FIG. 1 illustrates MEMS apparatus 100 construed in accordance with the present invention.
  • the apparatus comprises a MEMS mirror 110 being a resonating mirror which is operative to perform a periodical tilt movement in response to voltage pulses generated by mirror drive 115.
  • the pulses are generated by the mirror driver in response to signals received from controller 120.
  • the sound sensing means 125 being a microphone and/or ultrasonic transducer, is located at the vicinity of MEMS mirror 110 (either being attached to the mirror or unattached thereto) .
  • the combination that comprises both the MEMS mirror 110 and the sound sensing means 125 is isolated from the rest of the apparatus to ensure that the sounds detected by the sound sensing means are not affected by the operation of other components, thereby enabling more accurate measurement of the mirror oscillations.
  • the sound sensing means 125 picks up the audio/ultrasonic emissions from the MEMS mirror 110 and transforms them into corresponding electrical signals.
  • the electrical signals are fed according to this example into amplifier 130 which amplifies and shapes the signals received from the sound sending means 125 in order to allow optimal sampling conditions. In the alternative, the electrical signals may be fed directly to controller 120 without having them amplified.
  • Controller 120 is used to sample the signal, have it processed by using time domain or frequency domain signal processing techniques that are known in the art per se, and then optionally extract the amplitude and/or phase information associated with the electrical signals received. This information is then used to synchronize the entire apparatus to the actual position of the MEMS mirror. In addition or in the alternative, the extracted information is used to detect whether there is a failure in the oscillating operation of mirror 110, which in return may cause a shutdown of the MEMS apparatus and the associated devices (e.g. the source for generating the laser beam) .
  • the MEMS apparatus 100 may include more than one MEMS mirror, which operation can be monitored as described above by the sound sensing means.
  • FIG. 2 presents an arrangement similar to that presented in FIG. 1, but with the exception that the sound sensing means 225 illustrated, is operative to derive one or more electrical signals for characterizing the oscillations of each of the plurality of mirrors (210 and 210' ) , where these mirrors oscillate in response to receiving voltage pulses generated by their respective mirror drives 115 and 115' .
  • the remaining components illustrated in this FIG. 2 operate as described above in connection with FIG. 1, mutates mutandis .
  • the present invention provides an arrangement that allows monitoring the operation of one or more mirrors, but any similar arrangement that would yield a similar result, should be considered as being encompassed within the scope of the present invention. Furthermore, various calculation methods may be used in order to derive the information from the sound signals which are received by the microphone/ultrasonic transducer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Micromachines (AREA)
  • Mechanical Optical Scanning Systems (AREA)

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 is 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.

Description

A MEMS DEVICE COMPRISING OSCILLATIONS ' MEASUREMENTS MEANS
Field of the Invention
The present invention relates to optical systems for scanning or deflecting light beams, and in particularly to systems which comprise periodically moving reflective elements, such as oscillating mirrors.
Background of the Invention Certain devices such as wafer defect scanners, laser printers, document scanners, projectors and the like make use of a narrow collimated laser beam that is usually scanned across a flat surface along a straight line path. A typical optical scanning system for this purpose employs a tilting flat mirror to deflect the beam. The tilting micro-mirror serves as a central element in many Micro Electro Mechanical Systems ("MEMS") devices. It typically comprises a flat plate (e.g. made of silicon) having a reflecting surface. The plate is held suspended by two torsional hinges aligned along a common torsion (and tilt) axis or a gimbal . The two hinges allow the mirror to tilt clockwise and counterclockwise within a given range of angles, and a collimated laser beam that impinges on the reflecting surface of the mirror is redirected by the mirror to a projection area. The tilting mirror is actuated by an actuation moment that can be provided by well-known MEMS actuation systems. The collimated input beam is aimed perpendicular to the scanning mirror's rotational axis, so that the main deflected ray sweeps a plane in space. Beam collimation generally ensures that the spot size remains substantially the same at both the center and edges of the flat surface.
However, one of the problems associated with the operation of a MEMS type of mirror is how to confirm that the mirror is indeed oscillating, as a failure that causes the mirror (s) to stop oscillating would lead to safety hazards caused by the fact the all of the laser energy that should have been divided at the projection plane will now be focused onto a very small focal point. In addition, certain applications require long term positioning accuracy such as in optical communication applications, e.g. in various optical switches and variable optical attenuators implemented in communication systems, and in light processing devices used in projection technology.
Several attempts were made to solve these challenges. Some of these attempts are described in the following publications .
US 6538802 describes a movable MEMS mirror system with a mirror position detection system, such as a capacitive sensor, that is calibrated using a physical stop with a range of movement of the mirror structure. Thus, a drift in the position detection system can be compensated without the need for a separate reference signal source as used in conventional systems.
US 7252394 discloses the use of a capacitance sensor embedded in a scanning mirror which is used to detect a change in capacitance from the movement of the reflecting mirror unit. Another alternative described therein is the use of a piezoelectric sensor embedded in a scanning mirror and used to detect a change in current from the movement of reflecting mirror unit.
US 6275326 describes a microelectromechanical sensor used to sense the position of a movable element in a microelectromechanical system. The microelectromechanical sensor being a strain gage, a gage of a capacitive, piezoelectric, piezoresistive or pressure type, adjoins the movable element and the resulting signal is fed back to control the component for moving the movable element. In an array of movable elements and sensors, the signal of each sensor is specific to one movable element.
US 20070064300 teaches a method of using in a projection system a microphone for detecting non- soundtrack disturbances, such as sounds or vibrations, generated exteriorly of the projection device, such as from household appliances, people walking in close proximity to projection system, etc. In operation, a signal generator generates a driving square wave signal. The signals are received at a filter from an audio amplifier and contain one or more frequency components that either act to produce the unwanted oscillatory displacements of optical component and/or are the result of non-audio-component sources. However, there is still a need for a solution which can ensure that the MEMS structure is oscillating as required and will allow determining the phase of these oscillations to ensure that there is no deformation in the mirror' s movement which in turn would lead to the distortion of the image that will be projected onto the projection plane.
Summary of the Invention
It is an object of the present invention to provide a device to allow proper operation of scanning and projecting the scanned image using microelectromechanical systems (MEMS) .
It is another object of the present invention to provide a device that can provide a high quality of projected images that can be used among others, in hand held projectors.
Other objects of the invention will become apparent as the description of the invention proceeds. In accordance with a first embodiment of the present invention there is provided a MEMS apparatus for scanning an optical beam comprising: a. at least one mirror operative to perform an oscillation motion to a pre-defined rotation angle around a respective mirror rotation axis or a gimbal; 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 the one or more electrical signals.
According to a preferred embodiment of the invention, the one or more electrical signals are used in determining whether the at least one mirror is oscillating, and preferably, if the value of the electrical signal is less than a pre-defined value, stopping the operation of the MEMS apparatus .
In accordance with yet another embodiment of the present invention, the one or more electrical signals are used in determining the absolute phase at which the at least one mirror oscillates. This embodiment is based on the fact that the sound sensing device is located at the vicinity of the mirror, and is capable of sensing the frequency of the mirror's oscillations.
By still another embodiment of the invention, the MEMS apparatus is a product of a surface micro machining process (also known as bulk micro-machining process) using materials such as bulk silicon, multi-layer substrate SOI
(silicon-on-insulator) , DSOI (double SOI) , Glass On
Silicon and the like, wherein the product comprises a plurality of mirrors and wherein a single sound sensing means is used in generating one or more electrical signals for characterizing oscillations of each of said plurality of mirrors. According to yet another embodiment of the invention, the MEMS apparatus is a pre-fabricated multi-layer substrate SOI comprising a plurality of mirrors and wherein a single sound sensing means is used to determine the absolute phase at which each of the plurality of mirrors oscillates, e.g. by carrying out a specific Fourier transform for each of the plurality of mirrors derived from the electrical signal received.
By still another preferred embodiment of the invention, the sound sensing means is operative in the audio and/or ultrasonic range and preferably comprises at least one microphone and/or at least one ultrasonic transducer, respectively.
Preferably, the sound sensing means is operative in a range extending from about few tens of Hz to about few tens of kHz.
Brief description of the Drawings
FIG. 1 - presents a schematic block diagram of an apparatus for detecting oscillations of a MEMS' mirror; and
FIG. 2 - presents a schematic block diagram of an apparatus for detecting oscillations of a plurality of MEMS' mirrors.
Detailed description of preferred embodiments
A better understanding of the present invention is obtained when the following non-limiting detailed example is considered in conjunction with the accompanying drawings . FIG. 1 illustrates MEMS apparatus 100 construed in accordance with the present invention. The apparatus comprises a MEMS mirror 110 being a resonating mirror which is operative to perform a periodical tilt movement in response to voltage pulses generated by mirror drive 115. The pulses are generated by the mirror driver in response to signals received from controller 120.
The sound sensing means 125 being a microphone and/or ultrasonic transducer, is located at the vicinity of MEMS mirror 110 (either being attached to the mirror or unattached thereto) . Preferably, the combination that comprises both the MEMS mirror 110 and the sound sensing means 125 (irrespective whether the two are physically connected to each other or not) , is isolated from the rest of the apparatus to ensure that the sounds detected by the sound sensing means are not affected by the operation of other components, thereby enabling more accurate measurement of the mirror oscillations. The sound sensing means 125 picks up the audio/ultrasonic emissions from the MEMS mirror 110 and transforms them into corresponding electrical signals. The electrical signals are fed according to this example into amplifier 130 which amplifies and shapes the signals received from the sound sending means 125 in order to allow optimal sampling conditions. In the alternative, the electrical signals may be fed directly to controller 120 without having them amplified.
Controller 120 is used to sample the signal, have it processed by using time domain or frequency domain signal processing techniques that are known in the art per se, and then optionally extract the amplitude and/or phase information associated with the electrical signals received. This information is then used to synchronize the entire apparatus to the actual position of the MEMS mirror. In addition or in the alternative, the extracted information is used to detect whether there is a failure in the oscillating operation of mirror 110, which in return may cause a shutdown of the MEMS apparatus and the associated devices (e.g. the source for generating the laser beam) .
Also, the MEMS apparatus 100 may include more than one MEMS mirror, which operation can be monitored as described above by the sound sensing means. FIG. 2 presents an arrangement similar to that presented in FIG. 1, but with the exception that the sound sensing means 225 illustrated, is operative to derive one or more electrical signals for characterizing the oscillations of each of the plurality of mirrors (210 and 210' ) , where these mirrors oscillate in response to receiving voltage pulses generated by their respective mirror drives 115 and 115' . The remaining components illustrated in this FIG. 2, operate as described above in connection with FIG. 1, mutates mutandis . The present invention provides an arrangement that allows monitoring the operation of one or more mirrors, but any similar arrangement that would yield a similar result, should be considered as being encompassed within the scope of the present invention. Furthermore, various calculation methods may be used in order to derive the information from the sound signals which are received by the microphone/ultrasonic transducer.
It is to be understood that the above description only includes some embodiments of the invention and serves for its illustration. Numerous other ways for constructing the optical device provided by the present invention may be devised by a person skilled in the art without departing from the scope of the invention, and are thus encompassed by the present invention.

Claims

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.
PCT/IL2009/000648 2008-07-02 2009-06-21 A mems device comprising oscillations' measurements means WO2010001388A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/002,378 US8626468B2 (en) 2008-07-02 2009-06-21 MEMS device comprising oscillations measurements means

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IL192583A IL192583A (en) 2008-07-02 2008-07-02 Mems device comprising oscillations measurement means
IL192583 2008-07-02

Publications (1)

Publication Number Publication Date
WO2010001388A1 true WO2010001388A1 (en) 2010-01-07

Family

ID=41137020

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IL2009/000648 WO2010001388A1 (en) 2008-07-02 2009-06-21 A mems device comprising oscillations' measurements means

Country Status (3)

Country Link
US (1) US8626468B2 (en)
IL (1) IL192583A (en)
WO (1) WO2010001388A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2339390A1 (en) 2009-10-29 2011-06-29 Btendo Ltd. Method and device for monitoring movement of mirrors in a MEMS device
CN112752209A (en) * 2019-10-31 2021-05-04 华为技术有限公司 Piezoelectric MEMS sensor and related equipment
KR20230036935A (en) 2021-09-08 2023-03-15 주식회사 위멤스 Optical Scanner Including Rotation Angle Sensor of Mirror and Detecting Method thereof

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013030842A1 (en) 2011-09-04 2013-03-07 Maradin Technologies Ltd. Apparatus and methods for locking resonating frequency of a miniature system
ITTO20131014A1 (en) 2013-12-12 2015-06-13 St Microelectronics Int Nv ELECTROSTATICALLY ACTIVATED OSCILLATING STRUCTURE WITH CONTROL OF THE START OSCILLATION PHASE, AND RELATED METHOD OF MANUFACTURE AND PILOT METHOD
CN106644052B (en) * 2016-12-14 2019-12-20 西北工业大学 Feedback system and method of micro-vibration mirror
DE102018200054A1 (en) 2018-01-03 2019-07-04 Ford Global Technologies, Llc Device for blind spot monitoring of a motor vehicle
CN111487762B (en) * 2019-01-25 2023-06-09 青岛海信激光显示股份有限公司 Adjustment method of laser display device and laser display device
US11467131B2 (en) * 2020-06-19 2022-10-11 Beijing Voyager Technology Co., Ltd. Systems and methods for detecting resonant frequency of MEMS mirrors

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007017648A (en) * 2005-07-07 2007-01-25 Seiko Epson Corp Optical scanner and image display device
US20080043304A1 (en) * 2006-06-02 2008-02-21 Microzeus Llc Methods and systems for micro transmissions

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6275326B1 (en) 1999-09-21 2001-08-14 Lucent Technologies Inc. Control arrangement for microelectromechanical devices and systems
US6538802B2 (en) 2001-07-31 2003-03-25 Axsun Technologies, Inc System and method for tilt mirror calibration due to capacitive sensor drift
US7129473B2 (en) * 2003-05-16 2006-10-31 Olympus Corporation Optical image pickup apparatus for imaging living body tissue
US7252394B1 (en) 2003-07-03 2007-08-07 Advanced Numicro Systems, Inc. Laser projection display and illumination device with MEMS scanning mirror for indoor and outdoor applications
US7494226B2 (en) 2005-09-21 2009-02-24 Hewlett-Packard Development Company, L.P. Methods and apparatus for controlling projectors
JP2008051556A (en) * 2006-08-22 2008-03-06 Sii Nanotechnology Inc Optical displacement detecting mechanism, and surface information measuring device using the same
US7586659B2 (en) * 2008-01-18 2009-09-08 Texas Instruments Incorporated Audio MEMS mirror feedback
JP2009193008A (en) * 2008-02-18 2009-08-27 Sharp Corp Image display device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007017648A (en) * 2005-07-07 2007-01-25 Seiko Epson Corp Optical scanner and image display device
US20080043304A1 (en) * 2006-06-02 2008-02-21 Microzeus Llc Methods and systems for micro transmissions

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2339390A1 (en) 2009-10-29 2011-06-29 Btendo Ltd. Method and device for monitoring movement of mirrors in a MEMS device
EP3232246A1 (en) 2009-10-29 2017-10-18 STMicroelectronics International N.V. Method and device for monitoring movement of mirrors in a mems device
CN112752209A (en) * 2019-10-31 2021-05-04 华为技术有限公司 Piezoelectric MEMS sensor and related equipment
CN112752209B (en) * 2019-10-31 2022-03-25 华为技术有限公司 Piezoelectric MEMS sensor and related equipment
KR20230036935A (en) 2021-09-08 2023-03-15 주식회사 위멤스 Optical Scanner Including Rotation Angle Sensor of Mirror and Detecting Method thereof

Also Published As

Publication number Publication date
IL192583A0 (en) 2009-02-11
IL192583A (en) 2014-01-30
US20110181931A1 (en) 2011-07-28
US8626468B2 (en) 2014-01-07

Similar Documents

Publication Publication Date Title
US8626468B2 (en) MEMS device comprising oscillations measurements means
JP5987510B2 (en) Optical scanning device and optical scanning control device
JP6019866B2 (en) Distance measuring device, light emission timing control device, and program
US20200033452A1 (en) Distance measurement apparatus
JP6641031B2 (en) System and method for light beam position detection
JP2012237788A (en) Optical scanner and image projection device equipped with the same
JP2009236774A (en) Three dimensional ranging device
US20050225743A1 (en) Laser range finder having reflective micro-mirror and laser measuring method
JP2005292627A (en) Optical scanner
JP2011180294A (en) Drive control device of optical scanning apparatus
JP7505004B2 (en) Optical scanning device, driving method thereof, and image drawing system
CN116171526A (en) Optical scanning device, driving method thereof, and image drawing system
JP2012226020A (en) Distance measuring instrument
JP4794677B1 (en) Mirror amplitude control device for optical scanning device
WO2023053840A1 (en) Optical scanning device
JP3114397B2 (en) Optical device
JPH0749462A (en) Resonance scanner
JP2003194518A (en) Laser distance measuring apparatus
JP2018205369A (en) Optical scanner
JP2008249412A (en) Object detection device
JPH0470562A (en) Transmission type ultrasonic microscope
JP2012027336A (en) Sensor device
JP6658291B2 (en) Ultrasonic transducer device, ultrasonic probe and ultrasonic measuring device
JP2008046369A (en) Actuator, projecting device, optical device, optical scanner and image forming apparatus
JP2017090793A (en) Projector

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09773043

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 13002378

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09773043

Country of ref document: EP

Kind code of ref document: A1