JP2010256774A - Micro-mirror mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micro-mirror mechanism that correctly reflects light in a desired direction. <P>SOLUTION: A cover glass 200 is a flat cuboid, and a photosensing member is formed on a bottom surface 202 of the cover glass by vapor depositing CdS. The photosensing member is composed of first to sixth X-direction photosensing parts PDx1-PDx6, and first to sixth Y-direction photosensing parts PDy1-PDy6. On the cover glass bottom surface 202, the first micro-mirror mechanism 10 is controlled so that a first moving section 120 reflects a laser beam from between the first Y-direction photosensing part PDy1 and the second Y-direction photosensing part PDy2 to between the fifth Y-direction photosensing part PDy5 and the sixth Y direction photosensing part PDy6; and that a second moving section 130 reflects the laser beam, from between the first X-direction photosensing part PDx1 and the second X-direction photosensing part PDx2 to between the fifth X-direction photosensing part PDx5 and the sixth X-direction photosensing part PDx6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a micromirror device that reflects light in a desired direction.

  Conventionally, a micromirror device that reflects light in a desired direction using a micro electro mechanical system (MEMS) is known. The micromirror device controls the reflection direction of light by swinging a mirror included in the MEMS by an electric signal (Patent Document 1).

JP 2005-208164 A

  However, since MEMS is a device that simply vibrates in one or more directions depending on the applied voltage, voltage frequency, etc., it is necessary to grasp to some extent where the light emitted from the MEMS is on the irradiation target surface. Thus, the light cannot be accurately reflected in a desired direction.

  The present invention has been made in view of this problem, and an object thereof is to obtain a micromirror device that accurately reflects light in a desired direction.

  The micromirror device according to the present invention includes a first mirror member that reflects light while swinging around a first swing axis, and protects the first mirror member and reflects light by the first mirror member. A protective member that is provided in a direction and transmits light reflected by the first mirror member, and a first light detection that is provided outside the range from the range in which the light reflected by the first mirror member is transmitted in the protective member And a mirror control member that controls the amplitude of the first mirror member in accordance with the detection state of light by the first light detection member.

  The first mirror member has a planar mirror surface that reflects light, the protection member is plate-shaped, and is a protection that is parallel to the mirror surface when the first mirror member is at a substantially central position of amplitude. The first light detection member having a surface is preferably provided on the protective surface.

  The first light detection member is preferably provided on a surface of the protection member that faces the mirror surface.

  The first mirror member further includes a case having a recess that is housed in the bottom, and conductive wiring that extends from the recess to the opening end of the recess, and the protection member is attached to the case so as to seal the recess from the outside. The protective member is preferably provided so that the wiring comes into contact with the first light detection member when the protective member is attached to the case.

  It is preferable to further include a case having a recess for storing the first mirror member, and the protection member is attached to the case so as to close the opening of the recess.

  It is preferable that a 1st photon detection member is provided in the back surface of the surface which opposes a mirror surface in a protection member.

  The first mirror member swings within a predetermined angle around the first swing axis, and the light reflected by the first mirror member forms a line-shaped trajectory on the protective surface. The first light detection members are arranged in a straight line with respect to the direction in which the locus formed by the light reflected by the first mirror member on the protective surface extends, and the mirror control member is the first light detection member that detects the light. It is desirable to control the amplitude of the first mirror member according to the position.

  It is preferable that the plurality of first light detection members are arranged in the vicinity of both end portions of the line-shaped locus on the protective surface.

  A second mirror member that swings around a second swing axis that is orthogonal to the first swing axis is further provided, and the light reflected by the first and second mirror members is a line that is orthogonal to each other on the protective surface. The micromirror device has a plurality of first light detection members arranged in a straight line with respect to a direction in which the first locus extends, and the second locus extends. A plurality of second light detection members arranged in a straight line with respect to the direction, and the mirror control member includes first and second mirrors according to detection states of the first light detection member and the second light detection member. It is preferable to control the amplitude of the mirror member.

  It is preferable that a plurality of light detection members are arranged in the vicinity of both end portions of the first locus and the second locus on the protective surface.

  It is preferable that the first light detection member is CdS, and the current value changes when light is received, and the mirror control member controls the mirror member in accordance with a change in current by the light detection member.

  According to the present invention, a micromirror device that accurately reflects light in a desired direction is obtained.

It is a perspective view of the 1st micromirror device. It is a perspective sectional view of the 1st micromirror device in the II-II line of Drawing 1. It is a perspective view of a micromirror. FIG. 4 is a partial end view of the first micromirror device taken along line IV-IV in FIG. 1. It is the block diagram which showed the control apparatus of the micromirror. It is the graph which showed the vibration characteristic of the micromirror (MEMS). It is the flowchart which showed the 1st control processing. It is the graph which showed the phase change which arises by an amplitude change. It is the flowchart which showed the 2nd control processing. It is a perspective view of the 2nd micromirror device. It is a perspective sectional view of the 2nd micromirror device in the XI-XI line of Drawing 10.

  Hereinafter, a first micromirror device 10 according to a first embodiment of the present invention will be described with reference to the drawings.

  The first micromirror device 10 mainly includes a bowl-shaped case 300 having an opening, a cover glass 200 that closes the opening of the case 300, and a micromirror 100 stored inside the case 300.

  A case recess 310 is formed in the case 300. The case recess 310 is formed by four rectangular inner surfaces 312 and a square bottom surface 311, and has a square opening provided on the top surface 313 of the case 300. The case 300 includes a flange 320 that protrudes from the two outer surfaces 314 at a right angle. These two outer surfaces 314 are surfaces connected to opposite sides of the bottom surface 311. The flange 320 has a surface that is flush with the bottom surface 311 of the case 300 and has a thickness in a direction perpendicular to the bottom surface 311.

  In the flange 320, a plurality of electrodes 400 are provided on a surface perpendicular to the outer surface 314 of the case 300. The electrode 400 penetrates the outer surface 314 of the case 300 to the case recess 310. The plurality of electrodes 400 protrude from the side surface of the case 300 at a right angle.

  A plurality of wirings 330 extending from the bottom surface 311 of the case recess 310 to the opening are provided on the inner side surface 312 of the case 300. The plurality of wirings 330 are respectively connected to the plurality of electrodes 400 protruding from the side surface of the case 300.

  Hereinafter, the direction parallel to the top surface 313 of the case 300 and perpendicular to the protruding direction of the flange 320 is the X direction, the protruding direction of the flange 320 is the Y direction, and the direction from the bottom surface 311 of the case 300 to the top surface 313 is Z. A description will be given using right-handed coordinates with the origin O as the center of the bottom surface 202 of the cover glass 200 in the positive direction.

  A micromirror 100 that is a MEMS is provided on the bottom surface 311 of the case recess 310. The micromirror 100 is mainly composed of a movable part 110 and an electrode 160.

  The movable part 110 is mainly composed of a disk-shaped first movable part 120, an annular second movable part 130, and an annular frame part 140.

  As for the 1st movable part 120, one of two circular surfaces comprises the mirror surface 121. FIG. The second movable portion 130 is provided so as to surround the outer peripheral surface 122 of the first movable portion 120, and the frame portion 140 is provided so as to surround the outer peripheral surface 131 of the second movable portion 130. The first movable part 120, the second movable part 130, and the frame part 140 are all substantially the same thickness. The centers of the first and second movable parts 120 and 130 and the frame part 140 are concentric.

  First support portions 123 and 124 that connect the outer peripheral surface 122 of the first movable portion 120 and the inner peripheral surface 132 of the second movable portion 130 are provided. The first support parts 123 and 124 are rectangular parallelepiped plate-like members, and are provided on a plane passing through the central axis of the first movable part 120. Due to this shape and position, the first support parts 123 and 124 have elasticity in the twisting direction. Thus, the first movable portion 120 is supported so as to be swingable with respect to the second movable portion 130 with the first support portions 123 and 124 as axes. That is, the first movable part 120 can swing around the X axis.

  Second support portions 133 and 134 that connect the outer peripheral surface 131 of the second movable portion 130 and the frame portion 140 are provided. The second support parts 133 and 134 are rectangular parallelepiped plate-like members on a plane perpendicular to the plane on which the first support parts 123 and 124 are provided and passing through the central axis of the first movable part 120. Provided. Due to this shape and position, the second support parts 133 and 134 have elasticity in the twisting direction. As a result, the second movable portion 130 is supported so as to be swingable with respect to the frame portion 140 about the second support portions 133 and 134. That is, the second movable part 130 can swing around the Y axis. The swing axis of the first movable part 120 and the swing axis of the second movable part 130 are orthogonal to each other.

  The electrode 160 includes an X direction electrode 170 for driving the first movable part 120 around the X axis and a Y direction electrode 180 for driving the second movable part 130 around the Y axis. The X-direction electrode 170 is composed of two substantially semicircles obtained by dividing a disk into two by diameter. In the figure, a substantially semicircle placed on the Y axis negative side of the X axis in the figure is called an X positive electrode 171, and a substantially semicircle placed on the Y axis positive side of the X axis is called an X negative electrode 172. The Y-direction electrode 180 is composed of two substantially half wheels obtained by dividing the ring shape by its diameter, and houses the X-direction electrode 170 on the inner periphery. In the figure, a substantially half wheel placed on the X axis negative side of the Y axis in the figure is called a Y negative electrode 181, and a substantially half wheel placed on the X axis positive side of the Y axis is called a Y positive electrode 182. In an idle state in which no potential difference is applied to the electrode 160, the Z axis orthogonal to the X axis and the Y axis coincides with the normal line of the mirror surface 121 of the first movable unit 120.

  The centers of the X direction electrode 170 and the Y direction electrode 180 are placed concentrically with the centers of the first and second movable parts 120 and 130 and the frame part 140 on the Z axis. The diameter of the X direction electrode 170 is substantially equal to the diameter of the first movable part 120, and the inner diameter and outer diameter of the Y direction electrode 180 are equal to the inner diameter and outer diameter of the second movable part 130. The first and second movable parts 120 and 130 and the X and Y direction electrodes 180 are, when viewed from their central axes (that is, the Z axis), the first movable part 120 and the X direction electrode 170, and the second The movable portion 130 and the Y-direction electrode 180 are provided so as to substantially overlap with each other.

  When viewed from the central axis of the first and second movable parts 120 and 130, the X-direction electrode 170 is divided into an X positive electrode 171 and an X negative electrode 172 by the swing axis of the first movable part 120, The Y direction electrode 180 is divided into a Y negative electrode 181 and a Y positive electrode 182 by the swing axis of the second movable part 130.

  An X positive wiring 173 and an X negative wiring 174 for transferring electric charges to the X positive electrode 171 and the X negative electrode 172 are provided on the substantially semicircular tops of the X positive electrode 171 and the X negative electrode 172, respectively. A Y negative wire 183 and a Y positive wire 184 for transferring charges to the Y negative electrode 181 and the Y positive electrode 182 are respectively provided at the substantially semicircular tops of the Y negative electrode 181 and the Y positive electrode 182. The X positive wiring 173, the X negative wiring 174, the Y positive wiring 184, and the Y negative wiring 183 are connected to a power supply device (not shown), and the first and second movable parts 120 and 130 and the frame part 140 are electrically grounded. The

  The cover glass 200 is a flat rectangular parallelepiped, and includes a square cover glass top surface 201 and a cover glass bottom surface 202, and four rectangular cover glass side surfaces 203xp, 203xn, 203yp, and 203yn. The cover glass side surface 203xp is located on the X axis positive direction side of the cover glass 200, the cover glass side surface 203xn is located on the X axis negative direction side of the cover glass 200, and the cover glass side surface 203yp is the Y axis positive direction side of the cover glass 200 The cover glass side surface 203yn is positioned on the Y axis negative direction side of the cover glass 200. Cover glass 200 is attached to case 300 such that cover glass bottom surface 202 closes the opening of case 300. The cover glass bottom surface 202 is provided with a light detection member formed by vapor deposition of cadmium sulfide (CdS).

  The light detection member includes first to sixth X-direction light detection units PDx1 to PDx6 and first to sixth Y-direction light detection units PDy1 to PDy6.

  The first to sixth X-direction light detection units PDx1 to PDx6 are rectangular, and the longitudinal direction thereof extends in a direction parallel to the Y axis. That is, the first to sixth X-direction light detection units PDx1 to PDx6 are arranged in order so as to be parallel to each other from the X-axis negative direction toward the positive direction. The first to third X-direction light detection units PDx1-PDx3 are provided close to the cover glass side surface 203xn located on the X-axis negative direction side, and the fourth to sixth X-direction light detection units PDx4-PDx6 are provided. , Provided close to the cover glass side surface 203xp. That is, an interval larger than the interval with the other X direction detection units is provided between the third X direction light detection unit PDx3 and the fourth X direction light detection unit PDx4. The first to third X-direction light detection units PDx1-PDx3 and the fourth to sixth X-direction light detection units PDx4-PDx6 are linear with respect to a straight line passing through the center of the cover glass bottom surface 202 and parallel to the Y axis. They are in a symmetrical relationship and in a point-symmetrical relationship with respect to the center of the cover glass bottom surface 202.

  The first to sixth Y-direction light detection units PDy1-PDy6 are also rectangular, and their longitudinal direction extends in a direction parallel to the X axis. That is, the first to sixth Y-direction light detection units PDy1-PDy6 are arranged so as to be parallel to each other from the Y-axis negative direction toward the positive direction. The first to third Y-direction light detection units PDy1-PDy3 are provided close to the cover glass side surface 203yn, and the fourth to sixth Y-direction light detection units PDy4-PDy6 are close to the cover glass side surface 203yp. Provided. That is, an interval larger than the interval with the other Y direction detection units is provided between the third Y direction light detection unit PDy3 and the fourth Y direction light detection unit PDy4. The first to third Y-direction light detection units PDy1-PDy3 and the fourth to sixth Y-direction light detection units PDy4-PDy6 are linear with respect to a straight line passing through the center of the cover glass bottom surface 202 and parallel to the X axis. They are in a symmetrical relationship and in a point-symmetrical relationship with respect to the center of the cover glass bottom surface 202.

  Distances from the first X-direction light detection unit PDx1, the sixth X-direction light detection unit PDx6, the first Y-direction light detection unit PDy1, and the sixth Y-direction light detection unit PDy6 to the center of the cover glass bottom surface 202 Are equal. Second X direction light detection unit PDx2, fifth X direction light detection unit PDx5, second Y direction light detection unit PDy2, fifth Y direction light detection unit PDy5, and third X direction light detection unit The same applies to the PDx3, the fourth X-direction light detection unit PDx4, the third Y-direction light detection unit PDy3, and the fourth Y-direction light detection unit PDy4.

  The first to sixth X-direction light detection units PDx1-PDx6 and the first to sixth Y-direction light detection units PDy1-PDy6 are connected to a plurality of wirings 330 provided on the inner side surface 312 of the case recess 310 ( (See FIG. 4). Since the plurality of wirings 330 extend to the opening of the case 300, when the cover glass 200 is attached to the case 300, the first to sixth X-direction light detection parts PDx1-PDx6 and the first to sixth Y Each of the directional light detectors PDy1-PDy6 is in contact with each one. Thereby, the light detection member is electrically connected to the electrode 400.

  A laser light source (not shown) is provided outside the first micromirror device 10 and irradiates the mirror surface 121 with laser light. The laser light passes through the cover glass 200 and reaches the mirror surface 121. The first and second movable portions 120 and 130 reflect the laser light while swinging toward an irradiation target surface (not shown) that is a two-dimensional plane. The laser light again passes through the cover glass 200 and is scanned on the irradiation target surface. By adjusting the emission timing of the laser light, it is possible to draw a desired image at a desired position on the irradiation target surface. The swing angle, period, and phase shift of the first and second movable parts 120 and 130 are controlled so that the laser beam is scanned in a desired region on the irradiation target surface. In order to control these, the light detection member detects the position of the laser beam reflected by the first and second movable parts 120 and 130.

  In the first micromirror device 10, the first movable unit 120 is arranged between the first Y-direction light detection unit PDy <b> 1 and the second Y-direction light detection unit PDy <b> 2 on the cover glass bottom surface 202. Between the Y direction light detection unit PDy5 and the sixth Y direction light detection unit PDy6, the second movable unit 130 is connected between the first X direction light detection unit PDx1 and the second X direction light detection unit PDx2. The laser beam is controlled to be reflected between the fifth X-direction light detection unit PDx5 and the sixth X-direction light detection unit PDx6. When the laser beam is reflected in this range, the first to sixth X-direction light detectors PDx1 to PDx6 and the first to the sixth detectors are arranged so that the laser beam is irradiated into the imaging region provided on the irradiation target surface. The positions of the six Y-direction light detection units PDy1-PDy6 are determined in advance. Thereby, the user can recognize information formed in the imaging region provided on the irradiation target surface, for example, character information and image information. Hereinafter, a region on the cover glass bottom surface 202 corresponding to the imaging region on the irradiation target surface is referred to as an imaging laser transmission region 210.

  Next, the operation of the first movable unit 120 will be described.

  First, a case where the first movable part 120 swings clockwise around the X axis will be described.

  A power supply device (not shown) applies an AC voltage to the X positive electrode 171 through the X positive wiring 173. When the AC voltage increases from 0 V, a voltage difference is generated between the grounded first movable part 120 and the X positive electrode 171, and the first movable part 120 and the X positive electrode 171 are generated by this voltage difference. An electrostatic force is generated between By this electrostatic force, the first movable part 120 and the X positive electrode 171 attract each other, and the first movable part 120 rotates clockwise around the X axis. When the AC voltage becomes maximum, the first movable unit 120 rotates at the maximum rotation angle.

  As the AC voltage decreases from the maximum voltage, the electrostatic force decreases, and the first movable portion 120 is parallel to the second movable portion 130 and the frame portion 140 due to the elastic force of the first support portions 123 and 124. Approaching the state. When the AC voltage becomes 0 V, the potential difference between the first movable part 120 and the X positive electrode 171 disappears and the electrostatic force disappears, and the first movable part 120 includes the second movable part 130 and the frame part 140. It becomes a parallel state.

  By repeating this, the first movable part 120 swings clockwise around the X axis.

  Next, a case where the first movable unit 120 swings counterclockwise on the X axis will be described.

  In this case, the power supply device applies an AC voltage to the X negative electrode 172 via the X negative wiring 174. When the AC voltage increases from 0 V, a voltage difference is generated between the grounded first movable part 120 and the X negative electrode 172, and the first movable part 120 and the X negative electrode 172 are generated by this voltage difference. An electrostatic force is generated between By this electrostatic force, the first movable part 120 and the X negative electrode 172 attract each other, and the first movable part 120 rotates counterclockwise on the X axis. When the AC voltage becomes maximum, the first movable unit 120 rotates at the maximum rotation angle.

  As the AC voltage decreases from the maximum voltage, the electrostatic force decreases, and the first movable portion 120 is parallel to the second movable portion 130 and the frame portion 140 due to the elastic force of the first support portions 123 and 124. Approaching the state. When the AC voltage becomes 0 V, the potential difference between the first movable part 120 and the X negative electrode 172 disappears and the electrostatic force disappears, and the first movable part 120 includes the second movable part 130 and the frame part 140. It becomes a parallel state.

  By repeating this, the first movable part 120 swings counterclockwise on the X axis.

  Next, the operation of the second movable part 130 will be described.

  First, the case where the second movable part 130 swings counterclockwise in the Y axis will be described.

  A power supply device (not shown) applies an AC voltage to the Y negative electrode 181 through the Y negative wiring 183. When the AC voltage increases from 0 V, a voltage difference is generated between the second movable part 130 and the Y negative electrode 181 that are grounded, and the second movable part 130 and the Y negative electrode 181 are generated by this voltage difference. An electrostatic force is generated between By this electrostatic force, the second movable part 130 and the Y negative electrode 181 attract each other, and the second movable part 130 rotates counterclockwise in the Y axis. When the AC voltage is maximized, the second movable unit 130 rotates at the maximum rotation angle.

  As the AC voltage decreases from the maximum voltage, the electrostatic force decreases, and the second movable part 130 is parallel to the first movable part 120 and the frame part 140 by the elastic force of the second support parts 133 and 134. Approaching the state. When the AC voltage becomes 0 V, the potential difference between the second movable part 130 and the Y negative electrode 181 disappears and the electrostatic force disappears, and the second movable part 130 includes the first movable part 120 and the frame part 140. It becomes a parallel state.

  By repeating this, the second movable portion 130 swings counterclockwise in the Y axis.

  Next, a case where the second movable unit 130 swings clockwise in the Y axis will be described.

  In this case, the power supply device applies an AC voltage to the Y positive electrode 182 via the Y positive wiring 184. When the AC voltage increases from 0 V, a voltage difference is generated between the second movable part 130 and the Y positive electrode 182 that are grounded. Due to this voltage difference, the second movable part 130 and the Y positive electrode 182 are generated. An electrostatic force is generated between By this electrostatic force, the second movable part 130 and the Y positive electrode 182 attract each other, and the second movable part 130 rotates in the Y-axis clockwise direction. When the AC voltage is maximized, the second movable unit 130 rotates at the maximum rotation angle.

  As the AC voltage decreases from the maximum voltage, the electrostatic force decreases, and the second movable part 130 is parallel to the first movable part 120 and the frame part 140 by the elastic force of the second support parts 133 and 134. Approaching the state. When the AC voltage becomes 0 V, the potential difference between the second movable part 130 and the Y positive electrode 182 disappears and the electrostatic force disappears, and the second movable part 130 includes the first movable part 120 and the frame part 140. It becomes a parallel state.

  By repeating this, the second movable part 130 swings in the Y-axis clockwise direction.

  Next, a control device 500 that controls the operation of the first micromirror device 10 will be described with reference to FIG.

  The control device 500 includes a microcomputer 561, an oscillator 562, an X direction inverter 563, an X direction positive voltage amplifier 564, an X direction negative voltage amplifier 565, a counter 566, a Y direction inverter 567, a Y direction positive voltage amplifier 568, and a Y direction negative. Mainly composed of a voltage amplifier 569.

  The microcomputer 561 is connected to the light detection member, and controls the oscillator 562, the Y-direction positive voltage amplifier 568, and the Y-direction negative voltage amplifier 569 according to an analog signal received from the light detection member that has received light. A control signal is sent to the oscillator 562 to control the amplitudes in the X and Y directions.

  The microcomputer 561 records the state of the analog signal received from the light detection member.

  The oscillator 562 transmits an AC signal having a frequency corresponding to the control signal from the microcomputer 561 to the X-direction positive voltage amplifier 564, the X-direction inverter 563, and the counter 566. As the oscillator 562, a VCO (voltage controlled oscillator) or a DDS (direct digital synthesizer) is used.

  The X direction inverter 563 inverts the phase of the received AC signal and transmits the inverted AC signal to the X direction negative voltage amplifier 565. The X-direction positive voltage amplifier 564 and the X-direction negative voltage amplifier 565 amplify the AC signal to a voltage sufficient to drive the movable unit 110 and transmit the AC signal to the electrode 160 included in the micromirror 100.

  The movable part 110 oscillates at an oscillating frequency corresponding to the frequency of the AC signal from the X direction positive voltage amplifier 564 and the X direction negative voltage amplifier 565. When the amplitude of the AC signal is increased, the amplitude of the movable part 110 increases. When the amplitude of the AC signal is lowered, the amplitude of the movable part 110 is reduced. In this way, the laser beam reflected by the movable part 110 is scanned in the X axis positive / negative direction on the cover glass bottom surface 202.

  The counter 566 divides the frequency of the signal transmitted from the oscillator 562 by 3/4. Then, the frequency-divided signal is transmitted to the Y-direction positive voltage amplifier 568 and the Y-direction inverter 567. Similar to the X direction inverter 563, the Y direction inverter 567 transmits the inverted AC signal to the Y direction negative voltage amplifier 569. The Y-direction positive voltage amplifier 568 and the Y-direction negative voltage amplifier 569 change the voltage of the received AC signal, that is, the amplitude according to the voltage control signal from the microcomputer 561, and then transmit it to the electrode 160 provided in the micromirror 100. .

  The movable part 110 oscillates at an oscillation frequency corresponding to the frequency of the AC signal from the Y-direction positive voltage amplifier 568 and the Y-direction negative voltage amplifier 569 and an amplitude corresponding to the voltage. When the amplitude of the AC signal is increased, the amplitude of the movable part 110 increases. When the amplitude of the AC signal is lowered, the amplitude of the movable part 110 is reduced. In this way, the laser light reflected by the movable portion 110 is scanned in the Y axis positive / negative direction on the cover glass bottom surface 202.

  Control means for controlling the first micromirror device 10 will be described with reference to FIGS. The first micromirror device 10 is controlled to scan the laser beam within a predetermined range on the bottom surface 202 of the cover glass.

  First, a means for scanning laser light in the X-axis direction on the cover glass bottom surface 202 will be described.

  The uppermost curve in FIG. 6 shows the time change of the laser beam irradiation position in the X-axis direction on the cover glass bottom surface 202. When the laser beam is irradiated far beyond the imaging area on the irradiation target surface, and when the laser beam is irradiated only within the imaging area, the shape of information formed in the imaging area, for example, the shape of character information or image information Collapses and the user cannot recognize the information. Therefore, the first control means is executed so that the laser beam is scanned within a range that slightly removes the imaging region. That is, the laser beam is scanned in a range that slightly removes the imaging laser transmission region 210 on the bottom surface 202 of the cover glass.

  When the laser beam outside the imaging laser transmission region 210 enters the fourth X-direction light detection unit PDx4, the fourth X-direction light detection unit PDx4 transmits an analog signal to the microcomputer 561.

  The microcomputer 561 receives the analog signal and turns on the fourth X-direction state variable Vx4.

  Further, when the laser light is incident on the fifth and sixth X-direction light detection units PDx5 and PDx6, the fifth and sixth X-direction light detection units PDx5 and PDx6 transmit analog signals to the microcomputer 561. The microcomputer 561 receives the analog signal and turns on the fifth and sixth X-direction state variables Vx5 and Vx6.

  Next, when the laser beam turns back at the maximum position in the X-axis positive direction and starts moving in the X-axis negative direction, it enters the sixth X-direction light detection unit PDx6. When the sixth X-direction light detection unit PDx6 that has received the laser beam transmits an analog signal to the microcomputer 561, the microcomputer 561 receives the analog signal and turns off the sixth X-direction state variable Vx6.

  Further, when the laser light is incident on the fifth and fourth X-direction light detectors PDx5 and PDx4, the fifth and fourth X-direction light detectors PDx5 and PDx4 transmit analog signals to the microcomputer 561. The microcomputer 561 receives the analog signal and turns off the fifth and fourth X-direction state variables Vx5 and Vx4.

  The time required for the laser light to leave the imaging laser transmission region 210 and return to the imaging laser transmission region 210 again is shorter than half of the period of the movable unit 110 in the X-axis direction, that is, a half period.

  On the other hand, when the X-direction state variable in the microcomputer 561 is OFF, the laser light may move from the maximum position in the X-axis positive direction toward the imaging laser transmission region 210. At this time, the laser light is not detected within a half cycle of the movable unit 110 after each X-direction light detection unit first detects the laser light. In other words, each X-direction light detection unit does not sense the laser beam twice within a half cycle of the movable unit 110. Therefore, the microcomputer 561 changes the X-direction state variable that was turned ON when first sensed to OFF, and waits for an analog signal from the X-direction light detection unit again.

  Thereby, it is possible to determine in what range the laser light is irradiated in the X-axis direction of the cover glass 200.

  Note that the amplitude in the negative X-axis direction can be controlled by performing the same process on the first to third X-direction light detection units PDx1-PDx3. At this time, the first X-direction light detection unit PDx1 is in the sixth X-direction light detection unit PDx6, the second X-direction light detection unit PDx2 is in the fifth X-direction light detection unit PDx5, and the third X-direction is detected. The light detection unit PDx3 has a function corresponding to the fourth X-direction light detection unit PDx4.

  By performing the same process in the Y-axis direction, it is possible to determine in what range the laser light is irradiated in the Y-axis direction of the cover glass 200. At this time, the fourth, fifth, and sixth X-direction light detection units PDx4, PDx5, and PDx6 in FIG. 6 are replaced with the fourth, fifth, and sixth Y-direction light detection units PDy4, PDy5, and PDy6, respectively.

  First control processing for scanning laser light in the X-axis direction on the cover glass bottom surface 202 will be described with reference to FIGS. The first control processing is performed only when it is determined that the amplitude of the first micromirror device 10 is narrow, that is, between the fourth X-direction light detection unit PDx4 and the fifth X-direction light detection unit PDx5. It is executed when no light is irradiated.

  In step S171, the voltage of the AC signal applied to the electrode 160 is increased. As a result, the amplitude of the second movable part 130 increases. On the other hand, the phase of the AC signal changes due to the voltage rise of the AC signal. Thereby, the phase of the 2nd movable part 130 also changes.

  In step S172, the phase of the AC signal changed by the process in step S171 is adjusted. This adjustment is performed by adjusting the output timing of the drive pulse constituting the AC signal. Thereby, the phase of the 2nd movable part 130 is returned to the phase before the voltage of an alternating current signal is raised.

  In step S703, it is determined whether the amplitude of the second movable unit 130 is within a specified range. That is, it is determined whether or not the laser beam is irradiated between the fifth X-direction light detection unit PDx and the sixth X-direction light detection unit PDx6. When the amplitude of the second movable unit 130 is within a specified range, the process ends. If the amplitude of the second movable unit 130 is not within the specified range, the process returns to step S171 to adjust the amplitude and phase again.

  By this processing, the range from the imaging laser transmission region 210 to the fifth X-direction light detection unit PDx5 is between the fifth X-direction light detection unit PDx5 and the sixth X-direction light detection unit PDx6. Laser light is irradiated inside.

  In addition, the same processing is performed on the first to third X-direction light detection units PDx1-PDx3 and the first to sixth Y-direction light detection units PDy1-PDy6, so that the X-axis negative direction, Y The irradiation range of the laser beam can be adjusted with respect to the positive and negative axial directions.

  A second control process for scanning laser light in the X-axis direction on the cover glass bottom surface 202 will be described with reference to FIGS. The second control process is performed when it is determined that the amplitude of the first micromirror device 10 is wide, that is, when the laser beam is irradiated beyond the sixth X-direction light detection unit PDx6 in the X-axis positive direction. Executed.

  In step S901, the voltage of the AC signal applied to the electrode 160 is lowered. Thereby, the amplitude of the 2nd movable part 130 becomes small. On the other hand, the phase of the AC signal changes due to the voltage rise of the AC signal. Thereby, the phase of the 2nd movable part 130 also changes.

  In step S902, the phase of the AC signal changed by the process in step S901 is adjusted. This adjustment is performed by adjusting the output timing of the drive pulse constituting the AC signal. Thereby, the phase of the 2nd movable part 130 is returned to the phase before the voltage of an alternating current signal is raised.

  In step S903, it is determined whether the amplitude of the second movable unit 130 is within a specified range. That is, it is determined whether or not the laser beam is irradiated between the fifth X-direction light detection unit PDx and the sixth X-direction light detection unit PDx6. When the amplitude of the second movable unit 130 is within a specified range, the process ends. If the amplitude of the second movable unit 130 is not within the specified range, the process returns to step S901, and the amplitude and phase are adjusted again.

  By this process, the range from the imaging laser transmission region 210 to the fifth X-direction light detection unit PDx is between the fifth X-direction light detection unit PDx5 and the sixth X-direction light detection unit PDx6. Laser light is irradiated inside.

  In addition, the same processing is performed on the first to third X-direction light detection units PDx1-PDx3 and the first to sixth Y-direction light detection units PDy1-PDy6, so that the X-axis negative direction, Y The irradiation range of the laser beam can be adjusted with respect to the positive and negative axial directions.

  According to this embodiment, the laser irradiation range can be accurately controlled without providing a light detection member on the laser irradiation object.

  Next, a second micromirror device 20 according to the second embodiment will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light detection member is provided on the cover glass top surface 201 and includes first and second inner light detection portions PDi1 and PDi2 and first and second outer light detection portions PDo1 and PDo2. The first inner light detection unit PDi1 and the first outer light detection unit PDo1 are provided on the cover glass side surface 203yp side, and the second inner light detection unit PDi2 and the second outer light detection unit PDo2 are provided on the cover glass side surface. Provided on the 203yn side.

  The first outer light detection unit PDo1 includes a first outer Y-direction detection unit 611 extending along the X-axis and two first outer X-direction detection units 612 extending along the Y-axis. The first outer Y-direction detection unit 611 is provided along one side of the opening. The two first outer X-direction detectors 612 extend from both ends of the first outer Y-direction detector 611 in the negative Y-axis direction and are approximately 1/3 of the length of one side of the opening toward the negative Y-axis direction. Have The first outer Y-direction detection unit 611 has a certain length (width) in the Y-axis direction, and the first outer X-direction detection unit 612 has a certain length (width) in the X-axis direction. . In each corner, the first outer Y-direction detection unit 611 is connected to a wiring (not shown).

  The first inner light detection unit PDi1 is connected to the first inner Y direction detection unit 622 extending in the X axis direction, the two first inner X direction detection units 623 extending in the Y axis direction, and the wiring 330. A first inner connecting portion 624. A first inner Y direction detection unit 622 is provided in a recess formed by the first outer Y direction detection unit 611 and the first outer X direction detection unit 612. A predetermined interval is provided between the first inner Y-direction detection unit 622, the first outer Y-direction detection unit 611, and the first outer X-direction detection unit 612. The two first inner X direction detectors 623 extend in the Y axis direction from both ends of the first inner Y direction detector 622. The first inner connecting portion 624 extends from the Y-axis negative direction side end portion of the first inner X-direction detecting portion 623 toward the outside of the opening portion along the X-axis. The first inner connecting portion 624 reaching the outside of the opening extends along the top surface 313 of the case 300 to each corner. At each corner, the first inner connecting portion 624 is connected to a wiring (not shown).

  The second outer light detection unit PDo2 is in a line-symmetric relationship with respect to the first outer light detection unit PDo1 with a straight line passing through the center of the cover glass top surface 201 and parallel to the X axis as a symmetry axis. Similarly, the second inner light detection unit PDi2 is also in a line-symmetric relationship with the first inner light detection unit PDi1 with the same straight line as the axis of symmetry.

  The first and second inner light detection units PDi1 and PDi2 and the first and second outer light detection units PDo1 and PDo2 are connected to a plurality of wirings provided on the inner side surface 312 of the case recess 310. Thereby, the light detection member is electrically connected to the electrode 400.

  The first and second movable parts 120 and 130 are arranged between the first inner light detection part PDi1 and the first outer light detection part PDo1, and from the second inner light detection part PDi2 and the second outer light detection. Control is performed so as to reflect the laser beam up to the portion PDo2. The positions of the first and second inner light detection units PDi1 and PDi2 and the first and second outer light detection units PDo1 and PDo2 on the cover glass 200 are the positions of the micromirror 100, the cover glass 200, and the irradiation target surface. Predetermined by relationship.

  The microcomputer 561 detects the irradiation position of the laser light by observing the state of the analog signal received from the light detection member.

  When the analog signal is received from the first outer light detection unit PDo1 after receiving the analog signal from the first inner light detection unit PDi1, it is detected that the laser light is irradiated in the positive direction of the Y axis. To do. On the other hand, when the analog signal is received from the second inner light detection unit PDi2 after receiving the analog signal from the first inner light detection unit PDi1, the laser beam is emitted toward the negative Y-axis direction. Is detected. The same applies to the second inner light detection unit PDi2. Thereby, it is possible to detect the irradiation position and range of the laser beam.

  According to this embodiment, the laser irradiation range can be accurately controlled without providing a large number of light detection members.

DESCRIPTION OF SYMBOLS 10 1st micromirror apparatus 100 Micromirror 110 Movable part 120 1st movable part 121 Mirror surface 123 1st support part 130 2nd movable part 133 2nd support part 140 Frame part 160 Electrode 170 X direction electrode 171 X Positive electrode 172 X negative electrode 173 X positive wiring 174 X negative wiring 180 Y direction electrode 181 Y negative electrode 182 Y positive electrode 183 Y negative wiring 184 Y positive wiring 200 Cover glass 201 Cover glass top surface 202 Cover glass bottom surface 210 Imaging laser Transmission area 300 Case 310 Case recess 320 Flange 400 Electrode 500 Control device 561 Microcomputer 562 Oscillator 563 X direction inverter 564 X direction positive voltage amplifier 565 X direction negative voltage amplifier 566 Counter 567 Y direction inverter 568 Y direction positive voltage amplifier 569 Y Direction Negative voltage amplifier PDx1 First X direction light detection unit PDx2 Second X direction light detection unit PDx3 Third X direction light detection unit PDx4 Fourth X direction light detection unit PDx5 Fifth X direction light detection unit PDx6 First 6 X direction light detectors PDy1 First Y direction light detectors PDy2 Second Y direction light detectors PDy3 Third Y direction light detectors PDy4 Fourth Y direction light detectors PDy5 Fifth Y direction lights Detection unit PDy6 Sixth Y-direction light detection unit

Claims (11)

A first mirror member that reflects light while swinging around a first swing axis;
A protective member that protects the first mirror member, and that is provided in a direction in which light is reflected by the first mirror member and transmits light reflected by the first mirror member;
In the protection member, a first light detection member provided from outside the range through which light reflected by the first mirror member is transmitted; and
A micromirror device comprising: a mirror control member that controls an amplitude of the first mirror member according to a detection state of light by the first light detection member. The first mirror member has a planar mirror surface that reflects light;
The protective member is plate-shaped, and has a protective surface that is parallel to the mirror surface when the first mirror member is at a substantially central position of amplitude,
The micromirror device according to claim 1, wherein the first light detection member is provided on the protective surface.   The micromirror device according to claim 2, wherein the first light detection member is provided on a surface of the protection member that faces the mirror surface. A case having a recess in which the first mirror member is stored at the bottom;
Further comprising conductive wiring extending from the recess to the opening end of the recess,
The protective member is attached to the case so as to seal the concave portion from the outside,
The micromirror device according to claim 3, wherein the protective member is provided so that the wiring contacts the first light detection member when the protective member is attached to the case. A case having a recess for storing the first mirror member;
The micromirror device according to claim 1, wherein the protection member is attached to the case so as to close an opening of the recess.   The micromirror device according to claim 2, wherein the first light detection member is provided on a back surface of a surface of the protection member that faces the mirror surface. The first mirror member swings within a predetermined angle around a first swing axis;
The light reflected by the first mirror member forms a linear segment on the protective surface,
A plurality of the first light detection members are arranged in a straight line with respect to a direction in which a trajectory formed on the protective surface by the light reflected by the first mirror member extends,
The micromirror device according to claim 2, wherein the mirror control member controls the amplitude of the first mirror member in accordance with the position of the first light detection member that detects light.   The micromirror device according to claim 7, wherein a plurality of the first light detection members are arranged in the vicinity of both end portions of the line-shaped locus on the protective surface. A second mirror member that swings around a second swing axis that is orthogonal to the first swing axis;
The light reflected by the first and second mirror members forms linear first and second trajectories orthogonal to each other on the protective surface,
The micromirror device includes a plurality of first light detection members arranged linearly with respect to a direction in which the first locus extends, and a plurality of elements arranged linearly with respect to a direction in which the second locus extends. A second light detection member,
3. The micromirror device according to claim 2, wherein the mirror control member controls amplitudes of the first and second mirror members according to detection states of the first light detection member and the second light detection member. .   The micromirror device according to claim 9, wherein a plurality of the light detection members are arranged in the vicinity of both end portions of the first locus and the second locus on the protective surface.   The first light detection member is CdS, and when receiving light, a current value changes, and the mirror control member controls the mirror member according to a change in current by the light detection member. Micromirror device.

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