JP2015040928A - Optical deflector, image forming apparatus, vehicle, and method of controlling optical deflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control a mirror section regardless of temporal characteristic changes of driving means.SOLUTION: An optical deflector 1000 includes a mirror section having a reflection surface, and a support section for supporting the mirror section, and deflects light incident on the reflection surface. A support section includes: driving means having driving piezoelectric members 15, 16 and driving the mirror section uniaxially (around a first axis and a second axis) at least; and detection piezoelectric members 25, 26 arranged integrally with the driving piezoelectric members 15, 16. The optical deflector 1000 also includes a controller 300 which applies a periodically changing driving voltage to the driving piezoelectric members 15, 16, and corrects the driving voltage on the basis of detection voltages to be generated by the detection piezoelectric members.

Description

  The present invention relates to a light deflection apparatus, an image forming apparatus, a vehicle, and a method for controlling the light deflection apparatus, and more particularly, a light deflection apparatus that deflects light, an image forming apparatus including the light deflection apparatus, and the image forming apparatus. The present invention relates to a vehicle including the same and a method for controlling the light deflection apparatus.

  2. Description of the Related Art Conventionally, a video display device that displays a video by scanning a screen with light is known (see, for example, Patent Document 1).

  This video display device has a deflecting reflector including a mirror unit that deflects light from a light source.

  In this deflecting reflector, the mirror unit is controlled using a so-called phase-locked loop circuit.

  However, the deflecting reflector disclosed in Patent Document 1 cannot properly control the mirror unit due to the change in characteristics over time of the driving means (actuator) that drives the mirror unit.

  The present invention includes a mirror unit having a reflection surface and a support unit that supports the mirror unit, and the light deflection apparatus that deflects light incident on the reflection surface, wherein the support unit includes a driving piezoelectric member. Drive voltage that periodically changes to the drive piezoelectric member, the drive means having a drive means for driving the mirror portion around at least one axis, and a detection piezoelectric member provided integrally with the drive piezoelectric member. The control device is configured to satisfy a predetermined relationship between a detection voltage generated by the detection piezoelectric member when the drive voltage is applied to the drive piezoelectric member and the drive voltage. An optical deflecting device characterized in that the drive voltage can be corrected.

  According to the present invention, it is possible to appropriately control the mirror portion regardless of the change in the characteristics of the driving means over time.

It is a figure which shows schematic structure of the projector apparatus which concerns on one Embodiment of this invention. FIG. 2A is a plan view of the light deflection apparatus, and FIG. 2B is a plan view of a state in which the piezoelectric member is removed from the light deflection apparatus. It is a figure which shows the electrode terminal to which a piezoelectric member is connected. It is a figure for demonstrating the connection state of a piezoelectric member and a GND electrode, and a corresponding electrode terminal. It is a figure for demonstrating the deflection | deviation operation | movement around the 1st axis | shaft of an optical deflection apparatus. It is a figure for demonstrating the deflection | deviation operation | movement around the 2nd axis | shaft of an optical deflection apparatus. FIGS. 7A and 7B are views (No. 1 and No. 2) for explaining the operation of the second drive unit of the optical deflector, respectively. FIGS. 8A and 8B are diagrams (No. 1 and No. 2) for explaining the deflection operation of the second drive unit, respectively. It is a block diagram which shows the structure of control of an optical deflection apparatus. It is a figure for demonstrating the connection state of each drive part and each detection part, and a corresponding electrode terminal. It is a flowchart for demonstrating the control method of an optical deflection apparatus. 12A is a graph showing the waveform of the drive voltage applied to the first drive piezoelectric member, and FIG. 12B is a graph showing the waveform of the detection voltage generated by the first detection piezoelectric member. It is. FIG. 13A is a graph showing an example of the gain characteristic with respect to the frequency of the first driving piezoelectric member, and FIG. 13B is a graph showing an example of the phase characteristic with respect to the frequency of the first driving piezoelectric member. is there. FIGS. 14A and 14B are diagrams illustrating target values of the phase difference between the drive voltage applied to the first drive piezoelectric member and the detection voltage generated by the first detection piezoelectric member. FIGS. 15A and 15B are diagrams in which the phase differences in FIGS. 14A and 14B are replaced with count values, respectively. FIGS. 16A and 16B are diagrams showing a deviation from the target value of the phase difference between the drive voltage applied to the first drive piezoelectric member and the detection voltage generated by the first detection piezoelectric member. is there. FIGS. 17A and 17B are diagrams in which the phases in FIGS. 16A and 16B are replaced with count values, respectively, and FIG. 17C is a drive voltage waveform after correction. FIG. FIG. 3 is a diagram (part 1) for explaining a scanning timing when an image is drawn. It is a figure for demonstrating a phase locked loop circuit. It is a figure for demonstrating the method to detect the direction of a mirror part using a photodiode. It is a figure for demonstrating the method of providing a detection element in the movable part of a flame | frame, and detecting the direction of a mirror part. FIG. 5 is a diagram (part 2) for explaining scanning timing when an image is drawn. It is a block diagram which shows the structure of control of the optical deflection | deviation apparatus of the modification 1. FIG. It is a figure which shows the coefficient with respect to ambient temperature, and a phase. It is a figure which shows a correction coefficient when room temperature 25 degreeC is made into a reference | standard (1.000). It is a block diagram which shows the structure of control of the optical deflection apparatus of the modification 2. It is a figure which shows a correction coefficient when elapsed time 0 is made into a reference | standard (1.000). It is a block diagram which shows the structure of control of the optical deflection apparatus of the modification 3. It is a figure which shows schematic structure of a head-up display.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a projector apparatus 10 as an image forming apparatus according to an embodiment.

  The projector device 10 is used, for example, in a state where it is placed on the floor or installation table of a building, a state where it is suspended from the ceiling of the building, or a state where it is hung on the wall of the building. In the following description, an XYZ three-dimensional orthogonal coordinate system whose vertical direction is the Z-axis direction shown in FIG. 1 will be used as appropriate.

  As an example, the projector device 10 includes a light source device 5, a light deflection device 1000, an image processing unit 40, and the like.

  As an example, the light source device 5 includes three laser diodes LD1 to LD3, three collimating lenses CR1 to CR3, three dichroic mirrors DM1 to DM3, and the like.

  The laser diode LD1 is, for example, a red laser, and is disposed so as to emit red light (wavelength 640 nm) in the + Y direction.

  The laser diode LD2 is a blue laser as an example, and is disposed on the + X side of the laser diode LD1 so as to emit blue light (wavelength 450 nm) in the + Y direction.

  The laser diode LD3 is a green laser as an example, and is disposed on the + X side of the laser diode LD2 so as to emit green light (wavelength 520 nm) in the + Y direction.

  Each laser diode is controlled by the LD control circuit 50.

  As an example, the collimator lens CR1 is disposed on the + Y side of the laser diode LD1, and the red light emitted from the laser diode LD1 is substantially parallel light.

  As an example, the collimator lens CR2 is disposed on the + Y side of the laser diode LD2, and the blue light emitted from the laser diode LD2 is substantially parallel light.

  As an example, the collimator lens CR3 is disposed on the + Y side of the laser diode LD3, and the green light emitted from the laser diode LD3 is made substantially parallel light.

  Each of the three dichroic mirrors DM1 to DM3 is made of a thin film such as a dielectric multilayer film, and reflects light of a specific wavelength and transmits light of other wavelengths.

  For example, the dichroic mirror DM1 is disposed on the + Y side of the collimating lens CR1 with an inclination of, for example, 45 ° with respect to the X axis and the Y axis, and reflects red light via the collimating lens CR1 in the + X direction.

  As an example, the dichroic mirror DM2 is disposed on the + X side of the dichroic mirror DM1 and the + Y side of the collimator lens CR2 at an inclination of, for example, 45 ° with respect to the X axis and the Y axis, and is red via the dichroic mirror DM1. Light is transmitted in the + X direction, and blue light via the collimating lens CR2 is reflected in the + X direction.

  Note that the red light that has passed through the dichroic mirror DM1 and the blue light that has passed through the collimator lens CR2 respectively enter the vicinity of the center of the dichroic mirror DM2.

  As an example, the dichroic mirror DM3 is disposed on the + X side of the dichroic mirror DM2 and the + Y side of the collimator lens CR3 with an inclination of, for example, 45 ° with respect to the X axis and the Y axis, and the red light passing through the dichroic mirror DM2 And blue light is transmitted in the + X direction, and green light via the collimating lens CR3 is reflected in the + X direction.

  Note that red light and blue light that have passed through the dichroic mirror DM2, and green light that has passed through the collimator lens CR3 respectively enter the vicinity of the center of the dichroic mirror DM3.

  Three lights (red light, blue light, and green light) that pass through the dichroic mirror DM3 are combined into one light. In this case, the color of the synthesized light is expressed by the balance of the emission intensity of the three laser diodes LD1 to LD3.

  As a result, the light source device 5 emits laser light (combined light) obtained by synthesizing the three laser beams from the three laser diodes LD1 to LD3 in the + X direction, that is, toward the optical deflecting device 1000.

  Here, the overall operation of the projector apparatus 10 will be briefly described. For example, image information from a host device such as a personal computer is input to the image processing unit 40, and predetermined processing (for example, distortion correction processing, image size change processing, resolution conversion processing, etc.) is performed by the image processing unit 40, and an LD control circuit 50. The LD control circuit 50 generates a drive signal (pulse signal) that has been intensity-modulated based on the image information from the image processing unit 40 and converts it into a drive current. Then, the LD control circuit 50 determines the light emission timing of each laser diode based on the synchronization signal from the optical deflecting device 1000, supplies the drive current at the light emission timing, and drives the laser diode. Note that the intensity modulation may modulate the pulse width of the drive signal or the amplitude of the drive signal. The light deflection apparatus 1000 is configured to rotate the laser light (combined light) from the light source device 5 around two axes orthogonal to each other toward the surface (scanned surface) of the screen S stretched in parallel to the XZ plane (here, It is deflected independently around the X axis and around the axis orthogonal to the X axis. As a result, the screen S is two-dimensionally scanned in the two-axis directions (here, the Z-axis direction and the X-axis direction) perpendicular to each other by the laser light, and a two-dimensional full-color image is formed on the screen S. Hereinafter, the X-axis direction is also referred to as a main scanning direction, and the Z-axis direction is also referred to as a sub-scanning direction. Instead of intensity modulation for directly modulating each laser diode, the laser light emitted from the laser diode may be modulated (externally modulated) by an optical modulator.

  Next, the optical deflection apparatus 1000 will be described in detail. As shown in FIG. 2A, for example, the light deflection apparatus 1000 includes a mirror unit 100 whose surface on the + Y side is a reflection surface, and a first axis (for example, a Z axis) orthogonal to the X axis. ) Around the first drive unit 150 (first piezoelectric actuator), the second drive unit 200 (second piezoelectric actuator) that drives the mirror unit 100 around the second axis parallel to the X axis, and the first of the mirror unit 100 A first detection unit 250 (see FIG. 9) that detects position information about one axis, a second detection unit (not shown) that detects position information about the second axis of the mirror unit 100, and a controller 300 ( 9) and a memory 400 (storage unit).

  In the optical deflection apparatus 1000, as an example, each structural part is integrally formed by a MEMS (Micro Electro Mechanical Systems) process. In short, the optical deflecting device 1000 is formed by cutting a single silicon substrate 1 to form a plurality of movable parts (elastically deforming parts), and providing each of the movable parts with a plurality of piezoelectric members. (See FIGS. 2B and 2A). The reflecting surface of the mirror unit 100 is, for example, a metal thin film such as aluminum, gold, or silver formed on the surface on the + Y side of the silicon substrate 1.

  As an example, as shown in FIGS. 2A and 2B, the first driving unit 150 has one end individually connected to both ends of the mirror unit 100 in the first axial direction, and the first driving unit 150 extends in the first axial direction. A pair of torsion bar portions 105a and 105b extending, a cantilever portion 106 having a free end continuous with the other end in the first axial direction of each of the pair of torsion bar portions 105a and 105b, and the mirror portion 100 are sandwiched in the first axial direction. As described above, the first drive piezoelectric members 15 and 16 are provided on the + Y side surface of the cantilever portion 106.

  Here, the pair of torsion bar portions 105a and 105b have the same diameter and the same length. The cantilever portion 106 has a rectangular plate shape whose longitudinal direction is the first axial direction. The two first driving piezoelectric members 15 and 16 have a rectangular plate shape having the same shape and the same second axis direction as the longitudinal direction. The length of the first driving piezoelectric member in the second axial direction (longitudinal direction) is approximately the same as the length of the cantilever portion 106 in the second axial direction. The length of the first driving piezoelectric member in the first axial direction (short direction) is somewhat shorter than the length of the torsion bar portion in the first axial direction.

  In the first drive unit 150, when a voltage (drive voltage) is applied in parallel to the pair of first drive piezoelectric members 15, 16, the pair of first drive piezoelectric members 15, 16 is deformed and cantilevers The portion 106 bends, a driving force in one direction around the first axis acts on the mirror portion 100 via the pair of torsion bar portions 105a and 105b, and the mirror portion 100 swings in one direction around the first axis.

  Therefore, by applying a positive sine wave voltage (for example, DC voltage + sine wave AC voltage) to the pair of first driving piezoelectric members 15 and 16 in parallel, the mirror unit 100 is rotated around the first axis. It can be made to vibrate with the period of a voltage (refer FIG. 5).

  As an example, as shown in FIG. 2A, FIG. 2B, and FIG. 9, the first detector 250 sandwiches a pair of first driving piezoelectric members 15 and 16 in the first axial direction. A pair of first detection piezoelectric members 25, 26 provided on the + Y side surface of the cantilever portion 106, a first amplifier 500 connected to each first detection piezoelectric member, and the first amplifier 500. And a comparator 600. Thus, the first drive piezoelectric member 15 and the first detection piezoelectric member 25 are provided integrally, that is, integrally with the cantilever portion 106. The first drive piezoelectric member 16 and the first detection piezoelectric member 26 are integrally provided, that is, integrally provided via the cantilever portion 106.

  Here, the two first detection piezoelectric members 25 and 26 have an elongated rectangular plate shape having the same shape and the same second axis direction as the longitudinal direction. The length of the first detection piezoelectric member in the second axial direction (longitudinal direction) is approximately the same as the length of the cantilever portion 106 in the second axial direction. The length of the first detecting piezoelectric member in the first axial direction (short direction) is, for example, about 1/10 to 1/2 of the length of the first driving piezoelectric member in the first axial direction. The first detecting piezoelectric member 25 is an end portion on the one side (−Z side) in the first axial direction of the cantilever portion 106, and the other end in the first axial direction (end on the −Z side) of the torsion bar portion 105 a. ) Is located near. The first detection piezoelectric member 26 is an end portion on the other side (+ Z side) of the cantilever portion 106 in the first axial direction, and is near the other end (+ Z side end) of the torsion bar portion 105b in the first axial direction. Is arranged.

  In the first detection unit 250, when the cantilever unit 106 is bent by applying a voltage to the pair of first driving piezoelectric members 15 and 16 in parallel, the pair of first detection piezoelectric members 25 and 26 is deformed, A voltage (detection voltage) corresponding to the deformation amount is generated, and the voltage signal is amplified by the amplifier 500 and binarized by the comparator 600.

  As an example, as shown in FIGS. 2A and 2B, the second driving unit 200 has one end continuous to the fixed end of the cantilever unit 106, and the second driving unit 200 continues in a meandering manner (turned back) 2. A pair of meandering portions 210a and 210b each including two beams, and two second driving piezoelectric members 11 and 12 and a meandering portion individually formed on the + Y side surface of the two beams 101 and 102 of the meandering portion 210a And two second driving piezoelectric members 13 and 14 formed individually on the + Y side surface of the two beams 103 and 104 of 210b.

  Here, the two beams of each meandering portion have a rectangular plate shape having the same shape and the same first axial direction as the longitudinal direction. Each of the second driving piezoelectric members has a rectangular plate shape having the same shape and the same first axial direction as the longitudinal direction. The length of the second driving piezoelectric member in the first axial direction (longitudinal direction) is approximately the same as the length of the beam in the first axial direction. The length of the second driving piezoelectric member in the second axial direction (short direction) is somewhat shorter than the length of the beam in the first axial direction.

  In the second driving unit 200, when a voltage is applied in parallel to the two second driving piezoelectric members 11 and 13, the two second driving piezoelectric members 11 and 13 are deformed, and the two second driving piezoelectric members 11 and 13 are deformed. The two beams 101 and 103 provided with the driving piezoelectric members 11 and 13 bend (see FIGS. 7A and 7B), and the mirror unit 100 swings in one direction around the second axis.

  In the second driving unit 200, when a voltage is applied in parallel to the two second driving piezoelectric members 12 and 14, the two second driving piezoelectric members 12 and 14 are deformed, and the two driving piezoelectric members 12 and 14 are deformed. The two beams 102 and 104 provided with the second driving piezoelectric members 12 and 14 bend (see FIGS. 7A and 7B), and the mirror unit 100 swings in the other direction around the second axis. To do. Hereinafter, for convenience, the two second driving piezoelectric members 11 and 13 are collectively referred to as a driving piezoelectric member pair DP1, and the two second driving piezoelectric members 12 and 14 are collectively referred to as a driving piezoelectric member pair DP2. .

  Therefore, by applying a sawtooth voltage having the same amplitude and period to the driving piezoelectric member pair DP1 and DP2 in reverse phase, the mirror unit 100 can be vibrated around the second axis at the period of the sawtooth voltage. (See FIG. 6).

  As a result, a driving unit that includes the first driving unit 150 and the second driving unit 200 and independently drives the mirror unit 100 around the first axis and the second axis is configured.

  The second detection unit includes two second detection piezoelectric members 21 and 22 provided individually on the + Y side surfaces of the two beams 101 and 102 of the meandering part 210a, and the two beams 103 and 104 of the meandering part 210b. And two second detection piezoelectric members 23 and 24 provided individually on the surface on the + Y side. More specifically, the second detecting piezoelectric member 21 is provided adjacent to the beam 101 adjacent to the second driving piezoelectric member 11 in the second axial direction. The second detecting piezoelectric member 22 is provided on the beam 102 adjacent to the second driving piezoelectric member 12 in the second axial direction. The second detecting piezoelectric member 23 is provided adjacent to the beam 103 adjacent to the second driving piezoelectric member 13 in the second axial direction. The second detection piezoelectric member 24 is provided adjacent to the beam 104 adjacent to the second drive piezoelectric member 14 in the second axial direction.

  Here, each of the second detection piezoelectric members has an elongated rectangular plate shape having the same shape and the same first axial direction as the longitudinal direction. The length of the second detection piezoelectric member in the first axial direction (longitudinal direction) is approximately the same as the length of the beam in the first axial direction. The length of the second detecting piezoelectric member in the second axial direction (short direction) is, for example, about 1/10 to 1/2 of the length of the second driving piezoelectric member in the first axial direction.

  In the second detection unit, when the two beams 101 and 103 are bent by applying a voltage to the drive piezoelectric member pair DP1, the two second detection piezoelectric members 21 provided on the two beams 101 and 103 are bent. , 23 is deformed to generate a voltage (detection voltage) according to the deformation amount, and the voltage signal is amplified by an amplifier and binarized by a comparator.

  Further, in the second detection unit, when the two beams 102 and 104 are bent by applying a voltage to the driving piezoelectric member pair DP2, two second detection piezoelectric elements provided on the two beams 102 and 104 are provided. The members 22 and 24 are deformed to generate a voltage (detection voltage) according to the deformation amount, and the voltage signal is amplified by an amplifier and binarized by a comparator.

  That is, a position information detection unit that individually detects position information about the first axis and the second axis of the mirror unit 100 is configured including the first detection unit 250 and the second detection unit.

  A support unit that supports the mirror unit 100 is configured including the first drive unit 150 and the second drive unit 200.

  As an example, each of the piezoelectric members of the first drive unit 150, the second drive unit 200, the first detection unit 250, and the second detection unit is made of PZT (lead zirconate titanate) as a piezoelectric material. The piezoelectric member exhibits a so-called reverse piezoelectric effect in which when a voltage is applied in the polarization direction, distortion (stretching) proportional to the potential of the applied voltage occurs. In addition, when a force is applied, the piezoelectric member exhibits a so-called piezoelectric effect in which a voltage corresponding to the force is generated in the polarization direction.

  FIG. 3 shows an example of wiring between each piezoelectric member and a corresponding electrode. Here, SDA (Sub Drive Ach) which is a common drive electrode is connected to the two second drive piezoelectric members 11 and 13 (connected via wiring). A common drive electrode SDB (Sub Drive Bch) is connected to the two second drive piezoelectric members 12 and 14. MD (Main Drive) which is a common drive electrode is connected to the two first drive piezoelectric members 15 and 16.

  In addition, the detection electrode SSA1 (Sub Sense Ach-1) is connected to the second detection piezoelectric member 21. A detection electrode SSB1 (Sub Sense Bch-1) is connected to the second detection piezoelectric member 22. A detection electrode SSA2 (Sub Sense Ach-2) is connected to the second piezoelectric member 23 for detection. A detection electrode SSB2 (Sub Sense Bch-2) is connected to the second detection piezoelectric member 24.

  FIG. 4 shows positions corresponding to the first driving piezoelectric members and the first detecting piezoelectric members on the −Y side surface of the cantilever portion 106, and on the −Y side surfaces of the two meandering portions 210 a and 210 b. A GND electrode (xxxG, G means GND) provided at a position corresponding to each second driving piezoelectric member and each second detection piezoelectric member is shown. The GND electrode corresponding to each piezoelectric member is indicated by a symbol in which the symbol “′” is added to the symbol of the piezoelectric member. When a voltage having the same polarity as the voltage applied at the time of polarization, for example, a voltage having a positive polarity (for example, +30 V) based on the GND at the time of polarization is applied to each driving piezoelectric member, a pulling force is generated on the driving piezoelectric member. That is, the whole deforms in the “shrink” direction. Conversely, when a force is applied to each detection piezoelectric member, a weak voltage is generated. Charge is charged by this voltage, and a current flows between the detection piezoelectric member and the corresponding electrode terminal (detection electrode). .

  Here, the case where the piezoelectric member is provided only on one surface of the silicon substrate 1 (for example, the surface on the + Y side) has been described as an example. However, in order to improve the wiring layout and the degree of freedom in creating the piezoelectric member, You may provide only in the other surface (for example, -Y side surface) of the silicon substrate 1, and you may provide in both one surface and other surfaces (for example, + Y side and -Y side surface) of a silicon substrate. In any case, the formation of these piezoelectric members and electrodes is almost in accordance with the semiconductor process, and the cost can be reduced by mass production.

  FIG. 5 is a diagram for explaining the operation of the first driving unit 150, that is, the operation around the first axis of the mirror unit 100. In FIG. 5, a schematic view of the mirror unit 100 and the first driving unit 150 viewed from one side in the first axial direction is shown in time series below the graph.

  At time t1, the voltage between MD and MDG (positive sine wave voltage) is zero, the displacement of each first driving piezoelectric member of the first driving unit 150 is zero, and the inclination of the mirror unit 100 is also 0. At time t2 (after ¼ period from time t1), the first driving piezoelectric member is bent (bends) so as to protrude downward in FIG. 5, and the mirror unit 100 becomes lower toward the left side in FIG. Somewhat like so. At time t3 (1/2 cycle after time t1), each first driving piezoelectric member is curved to the maximum so as to protrude downward in FIG. 5, and the mirror portion 100 is lowered toward the left side in FIG. Leans to the maximum. At time t4 (3/4 cycle after time t1), the state is the same as at time t2, and at time t5 (one cycle after time t1), the state is the same as at time t1. Thereafter, at times t6, t7, t8..., The same state as that at times t2, t3, t4.

  In this way, the mirror unit 100 periodically oscillates around the first axis with substantially the same period as the positive sine wave voltage and with an amplitude substantially corresponding to the amplitude of the sine wave voltage. In FIG. 5, when the mirror unit 100 is vibrated around the first axis, it is operated at “resonance” in order to obtain as large an amplitude as possible with less input energy.

  FIG. 6 is a diagram for explaining the operation of the second drive unit 200, that is, the operation around the second axis of the mirror unit 100. In FIG. 6, a schematic view of the mirror unit 100 and the second driving unit 200 viewed from one side in the second axis direction is shown in time series below the graph. The upper waveform in the graph of FIG. 6 shows the voltage between SDA and SDAG, and the lower waveform shows the voltage between SDB and SDBG. These voltages are sawtooth waves having the same amplitude and period, and phases reversed by 180 degrees.

  At time t0, the voltage between SDA and SDAG is maximum, the voltage between SDB and SDBG is zero, and the mirror unit 100 is tilted to the maximum so that the right side in FIG. . At time t1, the voltage between SDA and SDAG is about 1/4 of the maximum voltage, the voltage between SDB and SDBG is about 3/4 of the maximum voltage, and the mirror unit 100 is lowered toward the right side in FIG. Tilt by half the angle of maximum tilt. At time t2, between SDA and SDAG and between SDB and SDBG, the voltage is approximately the middle of the maximum voltage, and the slope is 0 in FIG. At time t3, the voltage between SDA and SDAG is approximately 3/4 of the maximum voltage, and the voltage between SDB and SDBG is approximately 1/4 of the maximum voltage. In FIG. Tilt by half the angle of maximum tilt (lower left). At time t4, the voltage between SDA and SDAG is zero, and the voltage between SDB and SDBG is the maximum voltage. In FIG. 6, the maximum inclination state is opposite to the maximum inclination state at time t0. At time t5, the voltage between SDA and SDAG is the maximum, the voltage between SDB and SDBG is zero, and in FIG. At time t6, t7, t8..., The same state as at time t2, t3, t4.

  In this way, the mirror unit 100 periodically oscillates around the second axis with substantially the same period as the sawtooth voltage and with an amplitude substantially corresponding to the amplitude of the sawtooth voltage.

  FIGS. 7A and 7B are perspective views showing the operating state of the second drive unit 200 of the optical deflection apparatus 1000 (the mirror unit 100 and each piezoelectric member are omitted). FIG. 7A shows a state at times t0 and t5 in FIG. 6, that is, a state where the voltage between SDA and SDAG is the maximum and the voltage between SDB and SDBG is zero. FIG. 7B shows a state at time t4 in FIG. 6, that is, a state where the voltage between SDA and SDAG is 0 and the voltage between SDB and SDBG is maximum.

  FIGS. 8A and 8B are diagrams for explaining the states shown in FIGS. 7A and 7B in more detail. As can be seen from FIGS. 8A and 8B, when light is incident on the mirror unit 100 that vibrates around the second axis, the reflected light is scanned (deflection scan) around the second axis. I understand. Since the mirror unit 100 also vibrates around the first axis, the light incident on the mirror unit 100 is scanned linearly around the first axis, and the scanning line is scanned around the second axis. In this way, the raster scan operation is performed.

  The driving frequency of the vibration of the mirror unit 100 by the second driving unit 200 is about several tens of Hz. When a general image or video is handled, it is often operated at 60 Hz.

  As described above, the first driving unit 150 is operated with as little energy as possible by using the resonance phenomenon, whereas the second driving unit 200 is operated with non-resonance, so that the displacement amount of each second driving piezoelectric member is small. small.

  Therefore, as described above, in the second drive unit 200, the pair of meandering portions 210a and 210b is formed on the silicon substrate 1, and two second driving piezoelectric members are individually provided on the two beams of each meandering portion. The displacement amount is earned by operating the two second driving piezoelectric members in parallel.

  FIG. 9 is a block diagram showing the configuration of the controller 300. The controller 300 controls each first driving piezoelectric member based on the detection result of the first detection unit 250, and controls each second driving piezoelectric member based on the detection result of the second detection unit. Since the control of the first driving piezoelectric member and the control of the second driving piezoelectric member are performed in substantially the same manner, the control of the first driving piezoelectric member will be described below. That is, in FIG. 9, illustration of each second driving piezoelectric member and the second detection unit is omitted.

  As shown in FIG. 9, the controller 300 includes a control unit 300a, a waveform generation unit 300b, a counter A, a counter B, and the like. For example, an enable signal (EN) is input to the control unit 300a when image information from a host device such as a personal computer is input to the image processing unit 40.

  Here, the memory 400 is connected to the controller 300. The memory 400 stores an initial value Ti of the cycle of the drive voltage (sine wave voltage) and an initial value Ai of the amplitude of the drive voltage.

  When the enable signal is input, the control unit 300a reads Ti and Ai from the memory 400 and sends them to the waveform generation unit 300b. Further, the control unit 300a compares the count value in the counter A and the count value in the counter B, and if they are equal, the control unit 300a sends the count value in the counter A or the counter B to the waveform generation unit 300b. If they are different, the count value in the counter B is sent to the waveform generation unit 300b.

  The waveform generation unit 300b generates a drive voltage waveform based on Ti and Ai from the control unit 300a, and outputs the drive voltage waveform (voltage signal) to each first drive piezoelectric member via the amplifier 700. At the same time, it is binarized and sent to the counter A. Then, the waveform generation unit 300b corrects the drive voltage waveform as necessary based on the count value from the control unit 300a, and the corrected drive voltage waveform is applied to each first drive piezoelectric member via the amplifier 700. Output. As described above, the waveform correction means for correcting the drive voltage waveform is configured including the control unit 300a, the waveform generation unit 300b, and the counters A and B.

  The counter A counts the number of pulses of the binarized signal for, for example, one period (Ti) of the drive voltage from the waveform generation unit 300b, and sends the count value (Cdrv) to the control unit 300a.

  The counter B counts the number of pulses of the binarized signal, for example, for one cycle of the detection voltage from the comparator 600, and sends the count value (Csns) to the control unit 300a.

  FIG. 10 is a diagram illustrating a specific connection state between each driving piezoelectric member, each detecting piezoelectric member, and each electrode. The two first drive piezoelectric members 15 and 16 of the first drive unit 150 are connected to the MD terminal via an amplifier a (amplifier 700). The two first detection piezoelectric members 25 and 26 of the first detection unit 250 are connected to the MS terminal via an amplifier b (amplifier 500).

  The driving piezoelectric member pair DP1 composed of the two second driving piezoelectric members 11 and 13 and the driving piezoelectric member pair DP2 composed of the two second driving piezoelectric members 12 and 14 of the second driving unit 200 are respectively differential. The amplifier is connected to the SDA terminal and the SDB terminal via the amplifier d.

  The four second detection piezoelectric members 21, 22, 23, and 24 are connected to the SSA1, SSB1, SSA2, and SSB2 terminals through the differential amplifier c, respectively.

  Next, the control performed by the controller 300 will be described with reference to the flowchart of FIG. This control is started when an enable signal is input to the control unit 300a.

  In the first step S1, the control unit 300a reads Ti and Ai from the memory 400 and sends them to the waveform generation unit 300b.

  In the next step S3, the waveform generation unit 300b generates a drive voltage waveform based on Ti and Ai from the control unit 300a, outputs the drive voltage waveform to each first drive piezoelectric member via the amplifier 700, and binary. Sent to the counter A.

  In the next step S5, the control unit 300a acquires the count value Cdrv in the counter A.

  In the next step S7, the controller 300a determines whether or not the counter B has received the detection voltage. If the determination in step S7 is negative, the same determination is made again. If the determination in step S7 is affirmative, the process proceeds to step S9.

  In step S9, the control unit 300a acquires the count value Csns from the counter B.

  In the next step S11, the control unit 300a determines whether Cdrv and Csns are equal. If the determination in step S11 is negative, the process proceeds to step S13. On the other hand, if the determination in step S11 is affirmed, the process proceeds to step S15.

  In step S13, the control unit 300a selects Csns. That is, the control unit 300a sends Csns to the waveform generation unit 300b as a count value for correcting the drive voltage waveform. When step S13 is executed, the process proceeds to step S17.

  In step S15, the control unit 300a selects Cdrv or Csns. In this case, Cdrv and Csns have the same value, which means that the drive voltage waveform is not corrected. When step S15 is executed, the process proceeds to step S17.

  In step S17, it is determined whether the enable signal (EN) is zero. If the determination in step S17 is negative, the process returns to step S3. In this case, in step S3, the waveform generator 300b generates a drive voltage waveform using Ai and Cdrv or Csns. For example, when Cdrv = 1000 counts and Csns = 1100 counts (see FIGS. 17A and 17B), that is, when the period of the detected voltage waveform is longer than the period of the drive voltage waveform, the drive voltage waveform is The binary signal for one period is generated so that the pulse count number becomes 1100 counts, that is, the same period as the detected voltage waveform (see FIG. 17C). As a result, the phase difference between the drive voltage waveform and the detection voltage waveform can be made constant (target value (for example, 90 °)), and the mirror unit 100 can be stably vibrated around the first axis.

  On the other hand, if the determination in step S17 is affirmative, the flow ends.

  FIG. 12A shows a driving voltage waveform applied to each first driving piezoelectric member, and FIG. 12B shows a detection voltage waveform generated by each first detecting piezoelectric member. ing. Here, as can be seen from FIGS. 12A and 12B, the phase of the detected voltage waveform is delayed by 90 ° with respect to the drive voltage waveform. A delay of 90 ° corresponds to a quarter of a cycle of 360 °. This phase difference does not necessarily indicate a phase difference at the resonance frequency. Further, as shown in FIGS. 12A and 12B, a threshold voltage Vth is provided in the detected voltage waveform, and a timing (pixel clock) for drawing an image at timing t3 that exceeds the threshold voltage Vth is generated. Is possible. Note that the pixel clock is not generated at the timings t1 and t5.

  FIGS. 13A and 13B show an example of the frequency characteristics of the piezoelectric member. FIG. 13A shows gain characteristics, and FIG. 13B shows phase characteristics. The frequency F0 is a resonance frequency, and the frequency F1 is an arbitrary frequency that is not resonant.

  As shown in FIGS. 13A and 13B, when the piezoelectric member is driven on the lower frequency side and the higher frequency side than the resonance frequency F0, the gain and phase may become asymmetric. Phase characteristics are particularly important in a phase-locked loop circuit. That is, the phase-locked loop circuit is premised on having good symmetry around the resonance frequency, and in such a case, the phase-locked loop circuit is difficult to control.

  Therefore, in the present embodiment, the operation is performed at the frequency F1 slightly higher than the resonance frequency, shifted from the vicinity of the resonance point where the characteristic change is steep to the high frequency side. The phase at the frequency F1 may be different for each piezoelectric member, and is recorded individually by measurement.

  FIGS. 14A and 14B show a case where the target value of the phase difference Δθ between the drive voltage waveform and the detected voltage waveform is 90 °, for example, when operating at the frequency F1. FIGS. 15A and 15B are obtained by replacing the phases in FIGS. 14A and 14B with the count values of the counters A and B, and assuming that one cycle is 1000 counts. If the phase difference ΔP is 90 °, the difference (count difference) ΔC between the count values of the counters A and B is 250.

  FIGS. 16A and 16B show the case where the phase difference Δθ between the drive voltage waveform and the detected voltage waveform is, for example, 99 °. Referring to FIG. It can be seen that the member is operating with a lower gain (at a frequency higher than the frequency F1) than when Δθ is 90 °. 17A and 17B are obtained by replacing the phases of FIGS. 16A and 16B with the count values of the counters A and B, and ΔC = 275.

  Therefore, the drive voltage waveform may be corrected by the waveform generator 300b so that Δθ becomes the target value 90 °. Specifically, the period of the driving voltage waveform may be corrected by the waveform generation unit 300b so that the count value for one period becomes 275 × 4 = 1100. Also in this case, the gain (amplitude of vibration around the first axis of the mirror unit 100) can be kept constant. More specifically, a target value of 360 ° / Δθ (for example, 90 °) or a count number (for example, 1000) / count difference ΔC (for example, 250) of one cycle of the drive voltage is stored in the memory 400 in advance and is appropriately stored. By reading and multiplying the count value of the counter B, the cycle of the drive voltage waveform can be corrected.

  FIG. 18 shows the method shown in FIGS. 12A and 12B, that is, a method of drawing an image by generating timing t3 (pixel clock) for drawing an image from a voltage signal (detection voltage). An example is shown. In FIG. 18, for the sake of convenience, the drawing of the going (outward path) and the returning (returning path) is not overlapped, but in reality, the timing of hitting the same image may occur due to the overlapping of the going and the returning.

  Therefore, in the present embodiment, the drawing timing is generated from either going or returning. This is because, if generated in both reciprocations, the timing is greatly shifted if the symmetry of the detected voltage waveform is not good. In FIG. 18, the drawing timing for going and returning is generated at the timing of going (t3). Conventionally, the frequency around the first axis (main scanning direction) is kept constant, and the drawing timing is obtained as shown in FIG. 19, or from a photodiode or a detection element as shown in FIGS. I was trying to get it.

  FIG. 19 shows an example of an actuator drive system configured by a general phase-locked loop circuit, which includes a phase comparator, a low-pass filter (or loop filter), a voltage control oscillator, a drive unit, and a detection unit. In this case, in order to stably control the mirror unit, it is necessary that the change in the physical characteristics of the drive unit with time is small and the performance stability with respect to the change in the ambient temperature is high, that is, the characteristic change with time is small. is there.

  FIG. 20 shows an example of a conventional actuator drive system. A photodetector such as a photodiode is arranged outside the image drawing area, and the timing at which the light crosses the photodetector is detected to detect the first axis. A drawing timing signal around the second axis (sub scanning direction) is generated (in the main scanning direction). In this case, the actual movement of the mirror unit can be detected, but a light source and a light detector for detecting the movement of the mirror unit are required in addition to the actuator that drives the mirror unit, which increases costs and complicates the system. It was.

  FIG. 21 shows an example of a conventional actuator drive system. The actuator is an electromagnetic type, and a detection element is provided in a movable part of a frame including a mirror part, and a signal from the detection element is used around the first axis ( A drawing timing signal around the second axis (sub scanning direction) is generated. In this case, even if the frame is formed of a piezoelectric element, a detection system element and a processing circuit are required in addition to the drive system, resulting in an increase in cost and complexity of the system.

  By the way, as shown in FIG. 22, if the actual mirror movement and the drawing timing t3 are deviated, the same image cannot be drawn in the same place by reciprocation, that is, a reciprocal deviation occurs.

  Note that with respect to the reciprocal deviation as shown in FIG. 22, in this embodiment, since both the frequency and timing for drawing are determined based on the phase, the reciprocal deviation can be made zero or extremely small. it can.

  By the way, if the change in the characteristics of the actuator (driving means) with time is small, the phase locked loop circuit can be suitably used as in the prior art. However, each component of the phase locked loop circuit is an analog circuit, and a constant is once set. Once decided, it is very difficult to change. Therefore, when the above characteristic change of the actuator is large, it is not preferable to use a phase locked loop circuit. Further, in an actuator using a piezoelectric member (piezoelectric actuator), variations in various characteristics of the piezoelectric member are large in a process or a process. It suffices to evaluate a sufficient number of samples to grasp the variation and ensure a sufficient yield, but there are cases where the variation is large and the yield cannot be ensured. In addition, the piezoelectric member has characteristics that change over time, such as characteristics that change its physical characteristics over time and temperature characteristics (characteristics that change its performance in response to changes in ambient temperature). It was extremely difficult.

  The optical deflecting device 1000 of the present embodiment described above includes the mirror unit 100 having a reflective surface and a support unit that supports the mirror unit 100, and deflects light incident on the reflective surface. The support portion includes a drive piezoelectric member, and includes a drive means for driving the mirror portion 100 around at least one axis (first axis and second axis), and a detection piezoelectric device provided integrally with the drive piezoelectric member. And a member. The optical deflection apparatus 1000 further includes a controller 300 that applies a driving voltage to the driving piezoelectric member, and a detection voltage and a driving voltage generated by the detecting piezoelectric member when the driving voltage is applied to the driving piezoelectric member. Can satisfy the predetermined relationship (for example, so that the phase difference between the drive voltage and the detection voltage becomes the target value).

  In this case, even if there is a change in characteristics of the driving piezoelectric member over time, the voltage generated by the detecting piezoelectric member, that is, the voltage applied to the driving piezoelectric member based on the position information about at least one axis of the mirror unit 100. Can be controlled properly.

  That is, the mirror unit can be appropriately controlled regardless of the change in the characteristics of the driving means over time.

  Further, in the optical deflection apparatus 1000, the mirror unit 100 can be stably and accurately controlled without using a phase-locked loop circuit, an external photodiode, a detection element, or the like. That is, it is possible to stably control the mirror unit 100 while suppressing an increase in cost.

  In addition, the drive voltage changes periodically, and the controller 300 corrects the drive voltage so that the phase difference between the drive voltage and the detection voltage becomes a target value (for example, 90 °). It can be controlled well.

  In addition, since the controller 300 adjusts the cycle of the drive voltage to the cycle of the detection voltage, the controller 300 can adjust the cycle of the drive voltage to the cycle of vibration of the mirror unit 100, and the mirror unit 100 can be vibrated stably and efficiently. it can.

  Further, the waveform of the drive voltage is an analog waveform (for example, sawtooth wave), and the controller 300 detects the counter A that counts the number of pulses of the binarized signal in which the drive voltage (for example, one cycle) is binarized, and the detection. A second counter that counts the number of pulses of the binarized signal in which the voltage (for example, one period) is binarized, and the count value in counter A is different from the count value in counter B In addition, the drive voltage is corrected using the count value of the counter B. In this case, the mirror unit 100 can be vibrated stably and efficiently with simple control.

  The optical deflecting device 1000 further includes an amplifier 500 connected to the detection piezoelectric member, and a comparator 600 connected to the amplifier 500 and the counter B. Therefore, the detection piezoelectric member generates the light deflection device 1000. The voltage can be binarized and stably supplied to the counter B.

  The projector device 10 is an image forming device that forms an image by scanning the surface (scanned surface) of the screen S with light modulated based on image information. The light source device 5 that emits light, And an optical deflecting device 1000 that deflects light from the light source device 5.

  In this case, the surface of the screen S can be scanned stably and accurately, and a high-quality image can be formed.

  23, a temperature sensor TS may be provided, and a correction table P corresponding to the temperature around the apparatus may be stored in the memory 400, as in the optical deflection apparatus 2000 of the first modification shown in FIG. In the first modification, the controller 310 corrects the drive voltage waveform based on the temperature information from the temperature sensor TS and the correction table P.

  FIG. 24 shows the correction table P, that is, the relationship between the coefficient related to the temperature around the apparatus and the phase difference [deg] between the drive voltage and the detected voltage. The coefficient is a value obtained by dividing the phase difference [deg] by 360 [deg]. Thus, it can be seen that the coefficient has temperature characteristics and varies greatly from the room temperature of 25 ° C. FIG. 25 shows correction coefficients obtained by converting the above coefficient at each temperature to room temperature 25 ° C. as 1.000. When the temperature around the apparatus changes, the controller 310 multiplies the count number in the counter B by a correction coefficient corresponding to the changed temperature included in the correction table P, thereby driving voltage waveforms corresponding to the temperature change. Is generated.

  According to the optical deflecting device 2000 of Modification 1, even when the piezoelectric member has temperature characteristics, the mirror unit 100 can be stably controlled regardless of the surrounding temperature change.

  Further, like the optical deflecting device 3000 of the second modification shown in FIG. 26, the controller 320 is provided with a time counter T (operation time measuring unit) for measuring the operation time, and the correction table Q corresponding to the time is stored in the memory. 400 may be stored. In the second modification, the controller 320 corrects the drive voltage waveform based on the temperature information from the temperature sensor TS and the correction tables P and Q.

  FIG. 27 shows a correction coefficient relating to the correction table Q, that is, the operation time (elapsed time). As in FIG. 25, the correction coefficient is obtained by converting the coefficient at each elapsed time with the elapsed time 0 as 1.000. Thus, it can be seen that the coefficient also has a time-dependent characteristic and greatly fluctuates from the elapsed time 0, which is the operation start time.

  In the second modification, the controller 320 multiplies the count value of the counter B by a correction coefficient for each operation time, thereby generating a drive voltage waveform corresponding to the change in characteristics of the piezoelectric member over time. Of course, it is possible to multiply the correction coefficient related to the operating time by the count value of the counter B together with the above-described correction coefficient related to the temperature. In this case, both the change of the environmental temperature and the physical change of the piezoelectric member over time can be used. Can respond. FIG. 27 shows only the time until 3000 hours have passed, but since it is known that there is no change in characteristics over time, values after 3000 hours (correction coefficient) ) May be used.

  According to the light deflecting device 3000 of the second modification, the mirror unit 100 can be stably controlled regardless of the physical change even when there is at least one of the environmental temperature change and the physical change of the piezoelectric member over time.

  28, the detection voltage generated by the detection piezoelectric member may be sent to the counter B via the amplifier 500 and the A / D converter 800, as in the optical deflection device 4000 of the third modification shown in FIG. .

  In this case, since the timing of phase detection can be determined with high accuracy and the amplitude can be measured, the phase difference between the drive voltage and the detected voltage is corrected (phase control), and the amplitude of the drive voltage is corrected (amplitude control). ) And the mirror unit 100 can be controlled with higher accuracy.

  By performing phase control and amplitude control at different timings (time zones), the influence of mutual interference between phase control and amplitude control can be suppressed, and phase control and amplitude control can be performed with higher accuracy. .

  For example, the correction of the amplitude of the drive voltage is performed by setting a target value of the detection voltage amplitude in advance (for example, storing in the memory 400), and when the detection voltage amplitude is less than the target value, And the amplitude of the drive voltage may be reduced when the amplitude of the detection voltage is larger than the target value. In this case, since the amplitude of the detection voltage corresponds to the amplitude of vibration around one axis of the mirror unit 100, the mirror unit 100 can be stably vibrated with a constant amplitude around one axis. When the amplitude of the detection voltage matches the target value, no correction is necessary.

  Also, as an example, a target value for the ratio or difference between the amplitude of the drive voltage and the detected voltage is set in advance (for example, stored in the memory 400), and the ratio or difference between the amplitude of the drive voltage and the detected voltage becomes the target value. As described above, the amplitude of the drive voltage may be corrected (so as to satisfy a predetermined relationship). Also in this case, the mirror unit 100 can be stably vibrated with a constant amplitude around one axis. When the amplitude ratio or difference between the drive voltage and the detection voltage matches the target value, there is no need for correction.

  In the above embodiment, in order to correct the phase difference between the drive voltage and the detection voltage, the cycle of the drive voltage is adjusted to the cycle of the detection voltage. Instead of or in addition to this, the amplitude of the drive voltage is adjusted. You may do it. For example, by increasing the amplitude of the drive voltage, the rising characteristics of the detection voltage can be improved, and the phase delay of the detection voltage with respect to the drive voltage can be eliminated.

  Moreover, the structure of the support part including a drive means is not restricted to what was demonstrated in the said embodiment, It can change suitably. For example, the drive unit of the above embodiment independently drives the mirror unit around two axes (first axis and second axis) orthogonal to each other. However, for example, the mirror unit 100 may be driven only around one axis. . In this case, two optical deflecting devices may be combined to drive the two mirror portions around two axes orthogonal to each other. Moreover, although the 1st drive part has a cantilever part (cantilever), it may replace with this and may have a cantilever. Further, the number of beams in each meandering portion of the second drive portion can be changed as appropriate. For example, the first drive unit may have the same configuration as the second drive unit. For example, the second drive unit may have the same configuration as the first drive unit.

  In the above-described embodiment, the light deflecting device 1000 is provided in the projector device 10 as the image forming device. However, the present invention is not limited to this. Any of the devices 1000-4000 may be deployed. The head-up display 7 is mounted on, for example, a vehicle, an aircraft, a ship, or the like.

  More specifically, as shown in FIG. 29 as an example, the head-up display 7 includes a plurality of microlenses that are two-dimensionally arranged along the XZ plane arranged on the optical path of the laser light deflected by the optical deflector. A microlens array 60 (light transmitting member) including 60a, and a translucent member 70 (for example, a combiner) disposed on the optical path of the laser light via the microlens array 60. In this case, the microlens array 60 is two-dimensionally scanned by the laser light along with the deflection operation of the laser light around the first axis and the second axis by the optical deflecting device, and an image is formed on the microlens array 60. Then, the image light that has passed through the microlens array 60 enters the translucent member 70, and a virtual image of the image light is formed. That is, the observer can visually recognize the virtual image of the image light through the translucent member 70. At this time, since the image light is diffused by the micro lens array 60, so-called speckle noise can be reduced.

  Instead of the microlens array 60, a light transmissive member other than the microlens array (for example, a transmissive screen) may be used. Further, for example, a mirror such as a concave mirror or a plane mirror may be provided on the optical path between the light transmissive member such as a microlens array or a transmissive screen and the translucent member 70. Moreover, you may substitute the translucent member 70 for light transmission window parts (for example, window glass), such as a vehicle, an aircraft, a ship, for example.

  Therefore, a vehicle including a head-up display 7 and a light transmission window (for example, a window glass) disposed on an optical path of light deflected by the light deflection device of the head-up display 7 and transmitted through the light transmission member ( For example, a car, a train, etc.) can be provided. In this case, the image light transmitted through the light transmitting member is incident on the light transmitting window, and a virtual image of the image light is formed. That is, the observer can visually recognize the virtual image of the image light through the light transmission window.

  Further, any one of the light deflection devices 1000 to 4000 may be arranged in a head mounted display having the same configuration as the head-up display 7.

  In addition, the arrangement, size, shape, number, material, and the like of each component of the optical deflecting device in the above embodiment can be changed as appropriate.

  Moreover, the structure of the light source device 5 in the said embodiment can be changed suitably. For example, the light source device 5 includes three laser diodes corresponding to the three primary colors of light, but may include one or four or more laser diodes. In this case, the number of collimating lenses and dichroic mirrors (including 0) may be changed according to the number of laser diodes.

  Moreover, in the said embodiment, although the laser diode (edge-emitting laser) is used as a light source, it is not restricted to this. For example, a surface emitting laser may be used, or a light source other than a laser may be used.

  Further, the configuration of the controller of the light deflection apparatus can be changed as appropriate. In short, the controller applies a driving voltage to the driving piezoelectric member so that the detection voltage generated by the detecting piezoelectric member provided integrally with the driving piezoelectric member and the driving voltage satisfy a predetermined relationship. It is sufficient if the drive voltage can be corrected. In the above embodiment, the memory 400 is provided separately from the controller 300, but may be built in the controller.

  Moreover, in the said embodiment, although the waveform of the drive voltage is a sine wave or a sawtooth wave, it is not restricted to this, In short, it is preferable that it is a periodic analog waveform.

  In the above-described embodiment, the counter A counts the number of pulses of the binarized signal of the driving voltage for one cycle, and the counter B counts the number of pulses of the binarized signal of the driving voltage for one cycle. However, the present invention is not limited to this, and the point is that the number of pulses of the drive voltage binarization signal for K cycles (K> 0) is counted by the counter A, and the binarization signal of the drive voltage for K cycles by the counter B The number of pulses may be counted.

  7 ... Head-up display (image forming apparatus), 10 ... Projector apparatus (image forming apparatus), 11, 12, 13, 14 ... Second driving piezoelectric member, 15, 16 ... First driving piezoelectric member, 21 and 22 , 23, 24 ... second detection piezoelectric member, 25, 26 ... first detection piezoelectric member, 100 ... mirror part, 105a, 105b ... torsion bar part (part of support part), 106 ... cantilever part (support part) 210a, 210b ... meandering part (part of support part), 300 ... controller (control device), 500 ... amplifier, 600 ... comparator, 800 ... A / D converter, T ... time counter (operation time measurement) Part), TS ... temperature sensor, 1000, 2000, 3000 ... light deflecting device.

JP 2010-026443 A

Claims (13)

In a light deflection apparatus comprising a mirror part having a reflection surface and a support part for supporting the mirror part, and deflecting light incident on the reflection surface,
The support portion includes a drive piezoelectric member, and includes a drive unit that drives the mirror portion around at least one axis, and a detection piezoelectric member provided integrally with the drive piezoelectric member,
A control device for applying a driving voltage to the driving piezoelectric member;
The control device can correct the drive voltage so that the detection voltage generated by the detection piezoelectric member when the drive voltage is applied to the drive piezoelectric member and the drive voltage satisfy a predetermined relationship. An optical deflecting device characterized in that: The drive voltage changes periodically,
The optical deflection apparatus according to claim 1, wherein the control device corrects the drive voltage so that a phase difference between the drive voltage and the detection voltage becomes a target value.   The optical deflection apparatus according to claim 2, wherein the control device matches a cycle of the drive voltage with a cycle of the detection voltage. The waveform of the drive voltage is an analog waveform,
The control device includes: a first counter that counts the number of pulses of a binarized signal in which the driving voltage for a predetermined period is binarized; and a binary that the binarized detection voltage for the predetermined period A second counter that counts the number of pulses of the activation signal, and when the count value in the first counter is different from the count value in the second counter, The optical deflection apparatus according to claim 2, wherein the drive voltage is corrected using a count value.   The optical deflection according to any one of claims 2 to 4, further comprising: an amplifier connected to the detection piezoelectric member; and a comparator connected to the amplifier and the second counter. apparatus.   5. The amplifier according to claim 2, further comprising: an amplifier connected to the detection piezoelectric member; and an A / D converter connected to the amplifier and the second counter. Light deflection device.   The control device acquires the amplitude of vibration about the one axis of the mirror unit using the AD converter, and corrects the period of the driving voltage and the amplitude of the driving voltage in different time zones. The light deflection apparatus according to claim 6. A temperature sensor for detecting temperature information of the surrounding environment;
The optical deflection apparatus according to claim 1, wherein the control device can correct the drive voltage based on a detection result from the temperature sensor. An operating time measuring unit for measuring the operating time of the driving piezoelectric element;
The optical deflection apparatus according to claim 1, wherein the control device is capable of correcting the drive voltage based on the operation time measured by the operation time measurement unit. An image forming apparatus that forms an image by scanning a surface to be scanned with light modulated based on image information,
A light source device including a light source and emitting the light;
An image forming apparatus comprising: the light deflecting device according to claim 1, which deflects light from the light source device.   The image forming apparatus according to claim 10, further comprising a light transmitting member having the scanned surface, which is disposed on an optical path of light deflected by the light deflecting device. An image forming apparatus according to claim 11;
A vehicle comprising: a light transmission window portion disposed on an optical path of light deflected by a light deflection device of the image forming apparatus and transmitted through the light transmission member. A control method of an optical deflection apparatus comprising a mirror part having a reflection surface and a support part for supporting the mirror part, and deflecting light incident on the reflection surface,
Applying a driving voltage to the driving piezoelectric member included in the support portion to drive the mirror portion around at least one axis; and
A step of correcting the drive voltage so that a detection voltage and a drive voltage generated by a detection piezoelectric member included in the support portion and provided integrally with the drive piezoelectric member satisfy a predetermined relationship; A method of controlling an optical deflection apparatus including:

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