JP2011215326A - Optical scanning device and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanning device and an image display device capable of accurately detecting the angle of a mirror part of an optical detection element even when characteristic change of a detection part for detecting the angle of the mirror part of the optical detection element occurs.SOLUTION: The optical scanning device is provided with the optical scanning element for swinging the mirror part 10 due to twisting displacement of a pair of beam parts supporting the mirror part 10 from both sides around a swinging axis Ly to scan an object with a light flux by the mirror part 10, a control part for outputting a drive signal to the optical scanning element to swing the mirror part 10 around the swinging axis, the detection part for detecting the angle around the swinging axis Ly of the mirror part 10, and regulating members 17a, 17b for regulating that the angle around the swinging axis Ly of the mirror part 10 is a prescribed angle or more out of a range of the angle of scanning with the light flux. The control part rotates the mirror part 10 around the swinging axis Ly so as to reach the regulating members 17a, 17b, and regulates the waveform of the drive signal on the basis of detection result with the detection part when it is determined that the mirror part reaches the regulating members 17a, 17b with the detection part.

Description

  The present invention relates to an optical scanning device and an image display device including an optical scanning element that scans an incident light beam in a predetermined direction by a mirror portion having a reflecting surface.

  Conventionally, an optical scanning element that scans an incident light beam in a predetermined direction by a mirror part having a reflecting surface, and a control part that swings the mirror part of the optical scanning element around a swing axis by a drive signal are provided. Optical scanning devices and image display devices are known.

  As an optical scanning element used in an optical scanning device or an image display device, it has a mirror part supported by a beam part, and the mirror part is oscillated around an oscillation axis by a torsional displacement of the beam part, and a light beam is emitted by the mirror part. An optical scanning element for scanning is known (see, for example, Patent Document 1).

  In such an optical scanning element, the mirror portion is displaced at an angle corresponding to the signal level of the drive signal, but due to the ambient temperature, aging, individual differences, etc., the signal level of the drive signal and the actual mirror portion angle The relationship changes. In order to scan the light beam in a desired direction by the mirror unit, it is necessary for the control unit that drives the optical scanning element to know the relationship between the signal level of the drive signal and the actual angle of the mirror unit. For this reason, a conventional optical scanning device or image display device is provided with a detection unit that detects an angle around the swing axis of the mirror unit (see Patent Documents 1 to 3).

  For example, Patent Document 1 describes a method in which a piezoresistive element is arranged as an optical scanning element as a detection unit, and an angle of a mirror unit is detected based on a voltage generated in the piezoresistive element in accordance with torsional displacement. . Patent Document 2 describes a method in which a piezoelectric actuator is arranged as a detection unit in an optical scanning element, and an angle of a mirror unit is detected based on an electromotive force generated in the piezoelectric actuator in accordance with torsional displacement. . Patent Document 3 proposes a method of detecting the angle of the mirror unit from the change in capacitance of the detection unit.

JP 2009-229517 A JP 2009-169325 A JP 2008-129069 A

  In the technique described in Patent Document 1, the relationship between the voltage generated in the piezoresistive element and the angle of the mirror part is stored in advance in a storage part as a table, or is obtained from a function of a linear approximation formula. .

  However, since the voltage generated in the piezoresistive element fluctuates due to ambient temperature, aging, individual differences, etc., in such a case, using a preset table or approximate expression, the angle calculated by these and the actual mirror There is a difference in the angle of the part. Therefore, the accuracy of mirror control using feedback is reduced. Although it is conceivable to set an approximate expression or a table for each individual difference in advance, it takes much time and effort. In addition, even in such a case, it is impossible to cope with a change in the piezoresistive element due to secular change or the like.

  In the techniques described in Patent Documents 2 and 3, it is necessary to grasp in advance the relationship between the detection value of the detection unit and the angle of the mirror unit, and the same can be said.

  Therefore, a light source that makes the light beam incident on the reflecting surface of the mirror part and a light detection means that makes the light beam reflected when the mirror part is at a predetermined angle are provided, and based on the detection result of the light beam by the light detection means, It is conceivable to detect the angle. However, in this case, a light source and light detection means are separately required, and there are problems in terms of downsizing and cost.

  The present invention has been made in view of the above-described problems. Even when there is a change in the characteristics of the detection unit that detects the angle of the mirror part of the light detection element, the angle of the mirror part of the light detection element is accurately determined. It is an object of the present invention to provide an optical scanning device and an image display device that can detect well.

  In order to achieve the above object, the invention according to claim 1 includes a mirror portion supported from both sides by a pair of beam portions, and the mirror portion swings around a swing axis due to torsional displacement of the beam portions. An optical scanning device comprising: an optical scanning element that scans a light beam by the mirror unit; and a control unit that outputs a drive signal to the optical scanning element and swings the mirror unit around the swing axis. A detection unit that detects an angle of the mirror unit around the oscillation axis, and a regulation that regulates that the angle of the mirror unit around the oscillation axis is greater than or equal to a predetermined angle outside the angular range for scanning the light beam. And the control unit rotates the mirror unit around the swing axis so as to reach the regulating member, and the detection unit determines that the mirror unit has reached the regulating member. Based on the detection result by the detection unit when And adjusting the waveform of the drive signal.

  According to a second aspect of the present invention, in the optical scanning device according to the first aspect, the restriction member has an angle around the swing axis of the mirror portion from a state where the mirror portion does not swing. The first restricting member that restricts the first angle around the swing axis from being greater than or equal to the predetermined angle, and the angle of the mirror portion around the swing shaft from the state where the mirror portion is not swung. A second restricting member for restricting the predetermined angle or more in a second direction opposite to the first direction, and the optical scanning element extends in a direction perpendicular to the swing axis, Each of the pair of beam portions has a pair of support portions that elastically support the other end of the pair of beam portions and both ends are fixed to the fixed portions, and the detection unit is provided on each of the support portions. A pair of piezoresistive elements arranged symmetrically with respect to the swing axis; The piezoresistive elements are connected in series and applied with a predetermined voltage, and the voltage value between the piezoresistive elements is output as information on the angle of the mirror portion around the swing axis. The voltage between the piezoresistive elements when the mirror portion is rotated around the swing axis so as to reach one regulating member and the detecting portion determines that the mirror portion has reached the first regulating member. The piezo when the mirror unit is rotated around the swing axis so as to reach the second regulating member, and the detecting unit determines that the mirror unit has reached the second regulating member. The waveform of the drive signal is adjusted based on the voltage value between the resistance elements.

  According to a third aspect of the present invention, in the optical scanning device according to the first or second aspect, the restriction member has elasticity.

  According to a fourth aspect of the present invention, in the optical scanning device according to any one of the first to third aspects, the control unit moves the mirror unit around the swing axis so as to reach the regulating member. When rotating the lens, the rotation speed of the mirror portion is reduced before reaching the restricting member.

  According to a fifth aspect of the present invention, in the optical scanning device according to any one of the first to fourth aspects, the control section rotates the mirror section about the swing axis, and the mirror section In order to maintain the state where the mirror portion has reached the restricting member, the voltage value of the drive signal is determined when the mirror portion has reached the restricting member. It is characterized in that it is maintained at a voltage value or higher of the drive signal.

  According to a sixth aspect of the present invention, in the optical scanning device according to the fifth aspect of the present invention, the mirror unit is rotated about the swing axis so as to reach the regulating member, and the mirror unit is moved by the detection unit. The detection results of the detection unit for a predetermined period after it is determined that has reached the regulating member are averaged, and the waveform of the drive signal is adjusted based on the averaged detection results.

  According to a seventh aspect of the present invention, in the optical scanning device according to the fifth aspect, the control section rotates the mirror section about the swing axis so as to reach the regulating member, and the detection is performed. The waveform of the drive signal is adjusted based on a detection result of the detection unit after a predetermined period has elapsed from when it is determined by the unit that the mirror unit has reached the regulating member.

  The invention according to claim 8 is a light source that emits a luminous flux having an intensity corresponding to an image signal, a first optical scanning element that scans the luminous flux emitted from the light source in a first direction at a relatively high speed, A mirror portion supported from both sides by a pair of beam portions, and the light beam scanned by the first scanning element by oscillating the mirror portion around an oscillation axis by the torsional displacement of the beam portion by the mirror portion; An image display device comprising: a scanning unit having a second optical scanning element that scans relatively slowly in a second direction substantially orthogonal to the first direction; and a control unit that controls the scanning unit. A detecting unit that detects an angle of the rotating unit about the swing axis, and a regulating member that controls that the angle of the mirror unit about the swing axis is greater than or equal to a predetermined angle outside the angular range for scanning the light beam; The control unit reaches the restricting member. The mirror unit is rotated about the swing axis, and the mirror unit is moved based on a detection result by the detection unit when the detection unit determines that the mirror unit has reached the regulating member. It is characterized in that the waveform of the drive signal that swings around the moving axis is adjusted.

  According to a ninth aspect of the present invention, in the image display device according to the eighth aspect, the light beam scanned by the scanning unit is made incident on a user's eye, and the image signal is applied to the retina of the user. A corresponding image is projected.

  According to the present invention, the detection unit that detects the angle of the mirror unit around the swing axis and the angle of the mirror unit around the swing axis are regulated to be equal to or greater than a predetermined angle outside the angular range for scanning the light beam. Detection results by the detection unit when the control unit 17a and 17b are provided, the mirror unit is rotated around the swing axis Ly so as to reach the control member, and the detection unit determines that the mirror unit has reached the control member Therefore, even if there is a change in the characteristics of the detection unit that detects the angle of the mirror part of the light detection element, the angle of the mirror part of the light detection element can be detected with high accuracy. .

It is a figure which shows the structure of the optical scanning device which concerns on one Embodiment of this invention. It is a figure which shows the waveform of the drive signal which drives the optical scanning element shown in FIG. It is a figure which shows the angle change of a mirror part of the optical scanning element shown in FIG. It is a figure which shows the specific structure of the optical scanning element shown in FIG. It is the equivalent circuit of the detection part comprised by a piezoresistive element. It is a figure which shows the change of the resistance value of a piezoresistive element by torsional displacement. It is a figure which shows arrangement | positioning of a control member. It is a figure which shows arrangement | positioning of another control member. It is a figure which shows arrangement | positioning of another control member. It is a figure which shows the structure of the control part shown in FIG. It is a figure which shows an example of a target angle table. It is a figure for demonstrating operation | movement of the waveform adjustment part shown in FIG. It is a figure which shows the method of detecting the detection characteristic of a detection part. It is a figure which shows the transition of the signal level of the drive signal which the waveform adjustment part shown in FIG. 10 outputs. It is a figure which shows the other transition of the signal level of the drive signal which the waveform adjustment part shown in FIG. 10 outputs. It is a figure for demonstrating the method to detect the detection voltage when it determines with the mirror part having arrived at the control member. It is a figure for demonstrating the other method of detecting the detection voltage when it determines with the mirror part having arrived at the control member. It is a figure which shows the structure of the image display apparatus which concerns on one Embodiment of this invention.

[1. Optical scanning device]
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the optical scanning device will be described first, and then the image display device will be described.

[1.1. Overview of optical scanning device]
First, the optical scanning device according to the present embodiment will be described. FIG. 1 is a diagram showing a configuration of an optical scanning device, FIG. 2 is a diagram showing a waveform of a drive signal, and FIG. 3 is a diagram showing a change in angle of a mirror part.

  As shown in FIG. 1, the optical scanning device 1 includes a control unit 2 that controls the entire optical scanning device 1 and a light source unit 3 that emits a luminous flux having an intensity corresponding to a drive signal Sa output from the control unit 2. And an optical scanning element 4 that scans the light beam emitted from the light source unit 3 in a predetermined direction.

  The control unit 2 is a drive current that forcibly drives the mirror unit 10 of the optical scanning element 4 in a non-resonant mode, and generates a drive signal Sb having a sawtooth waveform. A drive signal Sb is applied to the optical scanning element 4. As shown in FIG. 2, the sawtooth drive signal Sb is a signal in which the period of transition from the maximum level to the minimum level is sufficiently shorter than the period of transition from the minimum level to the maximum level. The mirror unit 10 of the optical scanning element 4 is configured to rotate around the swing axis Ly at an angle corresponding to the signal level of the drive signal Sb. The mirror unit 10 of the optical scanning element 4 is shown in FIG. As shown, it swings in a sawtooth shape around a swing axis Ly described later based on the signal waveform of the drive signal Sb.

[1.2. Specific Configuration of Optical Scanning Element 4]
Next, a specific configuration of the optical scanning element 4 will be described. FIG. 4 is a diagram showing a specific configuration of the optical scanning element 4.

  As shown in FIG. 4A, the optical scanning element 4 includes a mirror part 10 having a reflecting surface 10a, a pair of beam parts 11a and 11b, a pair of support parts 12a and 12b, a fixed part 13a, 13b and a base 14, and the mirror 10 is swung around the swing axis Ly to scan the light flux.

  The pair of beam portions 11a and 11b extend along the swing axis Ly and support each side of the mirror portion 10 with elasticity, and the mirror portion 10 is supported by the swing displacement Ly by its torsional displacement (twist deformation). It can swing around. Further, the pair of support portions 12a and 12b support the other ends of the pair of beam portions 11a and 11b with elasticity at the central portion thereof, and both fixed portions 13a and 13b fixed to the base 14 at both ends. It is fixed to. Thus, the mirror part 10 is supported by the pair of beam parts 11a and 11b and the pair of support parts 12a and 12b so as to be swingable.

  Permanent magnets 15 a and 15 b are arranged in proximity to two sides parallel to the swing axis Ly of the mirror unit 10. The direction of the magnetic field formed by the permanent magnets 15a and 15b is parallel to the reflecting surface 10a of the mirror unit 10 in a stationary state and is perpendicular to the swing axis Ly. Further, as shown in FIG. 4B, a coil 16 is formed on the back surface of the mirror portion 10 opposite to the reflecting surface 10a. The electrode of the coil 16 is connected to the control unit 2 via two beam portions 11a and 11b. With this configuration, when a drive current is passed through the coil 16, Lorentz force acts on the coil 16. For example, a Lorentz force acts on the lower half of the coil 16 from the swing axis Ly in the drawing as viewed from the front side of the paper, and a Lorentz force acts on the back side of the paper as viewed from the drawing. . As a result, a rotational torque is generated in the mirror portion 10 about the swing axis Ly. Therefore, by controlling the magnitude of the current of the drive signal Sb output from the control unit 2, the angle around the swing axis Ly of the mirror unit 10 can be controlled.

  The optical scanning element 4 is further provided with piezoresistive elements R1 to R4 as a detection unit 18 that detects an angle around the swing axis Ly of the mirror unit 10. The pair of piezoresistive elements R1 and R3 are disposed symmetrically with respect to the swing axis Ly on the support portion 12a. The piezoresistive element R1 is arranged on the support part 12a on the fixed part 13a side, and the piezoresistive element R3 is arranged on the support part 12a on the fixed part 13b side. Similarly, the pair of piezoresistive elements R2 and R4 are disposed symmetrically with respect to the swing axis Ly on the support portion 12b. The piezoresistive element R2 is arranged on the support part 12b on the fixed part 13a side, and the piezoresistive element R4 is arranged on the support part 12b on the fixed part 13b side.

  The resistance value of one pair of piezoresistive elements R1 and R3 changes depending on the stress field generated in the vicinity of the swing axis Ly according to the torsional displacement generated in the beam portion 11a, and the other pair of piezoresistive elements. The resistance values of the elements R2 and R4 change depending on the stress field generated in the vicinity of the swing axis Ly according to the torsional displacement generated in the beam portion 11b.

  As shown in FIG. 4C, the pair of piezoresistive elements R1 and R3 are arranged in series between the power supply potential Vc and the ground potential GND. Similarly, the pair of piezoresistive elements R4 and R2 are arranged in series with the power supply potential Vc and the ground potential GND. That is, one end of the piezoresistive elements R1 and R4 is connected to the power supply of the power supply potential Vc, and the other end is connected to one end of the piezoresistive elements R2 and R3. The other ends of the piezoresistive elements R2 and R3 are connected to the ground of the ground potential GND.

  FIG. 5 is an equivalent circuit of the detector 18 configured by the piezoresistive elements R1 to R4 shown in FIG. As shown in the figure, the detection unit 18 uses a connection point between a pair of piezoresistive elements R1 and R3 as a first output node N1, and a connection point between the other pair of piezoresistive elements R4 and R2 as a second output node. N2. The control unit 2 receives the voltage VPR + of the first output node N1 and the voltage VPR− of the second output node N2, and the voltage of the first output node N1 with reference to the voltage of the second output node N2. Is the detection voltage Vd (= [VPR +] − [VPR−]). When the drive signal Sb is not applied to the optical scanning element 4, that is, when the current value of the drive signal Sb is 0 [A], the resistance values of the piezoresistive elements R1 to R4 are not changed, and the piezoresistive element R1. When the initial resistance values of .about.R4 are the same, the detection voltage Vd is 0V.

  Here, each of the piezoresistive elements R1 to R4 has a characteristic that the resistance value increases due to compressive stress and the resistance value decreases due to tensile stress. Changes. Here, it is assumed that the piezoresistive elements R1 to R4 have the same material and the same shape, and the same characteristics.

  For example, as shown in FIG. 6, when the mirror section 10 is inclined at an angle θ about the swing axis Ly, the resistance values of the piezoresistive elements R1 and R2 increase due to compressive stress, and the piezoresistive elements R3, R3, The resistance value of R4 decreases due to the tensile stress. Therefore, the voltage VPR + of the first output node N1 decreases, the voltage VPR− of the second output node N2 increases, and the detection voltage Vd becomes positive. The detection voltage Vd increases as the angle θ of the mirror unit 10 around the swing axis Ly increases. On the other hand, when the mirror unit 10 is tilted in the direction opposite to the direction shown in FIG. 6, the detection voltage Vd has a negative polarity, and the detection voltage Vd increases as the angle of the mirror unit 10 around the swing axis Ly increases.

  As described above, the inclination direction of the mirror unit 10 from the equilibrium state shown in FIG. 4 can be determined by the polarity of the detection voltage Vd, and the inclination angle of the mirror unit 10 can be determined by the magnitude of the detection voltage Vd. Using this principle, the control unit 2 detects the actual tilt angle of the mirror unit 10 around the swing axis Ly by the detection voltage Vd.

  By the way, the resistance values of the piezoresistive elements R1 to R4 change due to individual differences or temperature changes, and the resistance values also change due to secular changes or the like. For this reason, the relationship between the detection voltage Vd and the angle of the mirror unit 10 varies, and the accuracy of mirror control using feedback may be reduced.

  Therefore, in the optical scanning element 4 according to the present embodiment, as shown in FIG. 7, a first restricting member 17a and a second restricting member 17b for detecting the angle of the mirror portion 10 are provided. FIG. 7 is a view showing a part of a cross section taken along line A-A ′ shown in FIG.

When scanning the light beam, the mirror unit 10 of the optical scanning element 4 swings around the swing axis Ly within an angle range of + θ ₁ to −θ ₁ (hereinafter referred to as a scanning angle range) as shown in FIG. As shown in FIG. 7B, the first restricting member 17a and the second restricting member 17b restrict the predetermined angle + θ ₂ , −θ ₂ beyond the scanning angle range. Is.

That is, the first regulating member 17a is swing axis Ly around angle of the mirror portion 10 becomes a predetermined angle theta ₂ or more in a first direction of the pivot axis Ly direction from the state in which the mirror unit 10 is not swung To regulate that. Further, the second restricting member 17b has an angle about the swing axis Ly of the mirror portion 10 that is greater than or equal to a predetermined angle θ _{2 in a} second direction opposite to the first direction from the state where the mirror portion 10 is not swinging. To be

  Thus, by providing the 1st control member 17a and the 2nd control member 17b, the relationship of the angle of the mirror part 10 with respect to the detection voltage Vd of the detection part 18 in which the detection characteristic changed is detected with high precision so that it may mention later. be able to. In addition, you may make it form the 1st control member 17a and the 2nd control member 17b integrally, as shown in FIG.

Further, as shown in FIGS. 9A and 9B, instead of the regulating members 17a and 17b, when the mirror portion 10 has angles + θ ₂ and −θ _2, a plane on which the back surface of the mirror portion 10 abuts is used. The regulating members 17a ′ and 17b ′ and the regulating members 17a ″ and 17b ″ may be provided. By doing in this way, the contact area of the mirror part 10 and a control member can be increased, compared with the case where the angle of the mirror part 10 is controlled at the end of the mirror part 10 like the control members 17a and 17b. It becomes possible to make deformation of the mirror part 10 difficult to occur. In the example shown in FIGS. 9A and 9B, by tilting at an angle of θ ₂ with respect to the surface of the base 14 parallel to the reflecting surface 10a of the mirror portion 10 when not tilted, When the mirror unit 10 is at angles + θ ₂ and −θ ₂ , the rear surface of the mirror unit 10 is in contact.

  These restricting members 17a, 17b, 17a ', 17b', 17a ", 17b" are made of an elastic member such as rubber, so that the deformation of the mirror part 10 due to the impact of the contact of the mirror part 10 and the reverse force. Can be suppressed, which is desirable.

[1.3 Processing of control unit 2]
As described above, the control unit 2 generates the drive signal Sb, swings the mirror unit 10 in the scanning angle range, reflects the light beam by the reflecting surface 10a of the mirror unit 10, and scans the light beam. The configuration is as shown in FIG.

  As shown in FIG. 10, the control unit 2 includes a target command generation unit 21, a comparison dimension conversion unit 22, a subtraction unit 23, and a drive signal generation unit 24.

The target command generation unit 21 outputs the target angle of the mirror unit 10 corresponding to the direction in which the optical scanning element 4 is intended to scan as a target angle command. The target command generation unit 21 stores information on the target angle of the mirror unit 10 in one scanning period T (see FIG. 3) in an internal storage unit. The information stored in the storage unit is sequentially read out and the target is generated. Output as an angle command. For example, as information on the target angle of the mirror unit 10 in one scanning period, a target angle table having information from 1 to 1000th is stored in the storage unit, and information from 1 to 1000th is sequentially read out as a target angle command Output. As described above, the target angle is in the range of + θ ₁ to −θ ₁ , and the target angle table is, for example, a table as shown in FIG. Note that the target angle of the mirror unit 10 may not be stored in advance, but may be obtained by sequential calculation.

The comparison dimension conversion unit 22 stores prescribed values α and β that define the relationship between the target angle of the mirror unit 10 and the control voltage Vct, and performs control according to the target angle command output from the target command generation unit 21. The voltage Vct is output. In the optical scanning element 4 according to the present embodiment, the control voltage Vct and the angle of the mirror unit 10 are in a proportional relationship, and the control voltage Vct is calculated based on the following equation (1) based on the target angle θ.
Vct = α × θ + β (1)
The comparison dimension conversion unit 22 stores therein a conversion table that defines the relationship between the target angle of the mirror unit 10 and the control voltage Vct, and the target angle of the mirror unit 10 is determined based on this conversion table. You may make it convert into Vct.

  The subtraction unit 23 subtracts the voltage value of the detection voltage Vd from the voltage value of the control voltage Vct, calculates a differential voltage Vs between the control voltage Vct and the detection voltage Vd, and outputs the differential voltage Vs.

  The drive signal generator 24 generates a drive signal Sb having a current value that is increased or decreased according to the differential voltage Vs, and outputs this drive signal Sb to the coil 16 of the optical scanning element 4. That is, in the case of the positive polarity of the differential voltage Vs, the drive signal Sb whose current value is increased by a value proportional to the voltage level of the differential voltage Vs is generated, and in the case of the negative polarity of the differential voltage Vs, the differential voltage Vs. The drive signal Sb is generated by reducing the current value by a value proportional to the voltage level. The drive signal generator 24 can be configured by an integrator that integrates the differential voltage Vs, for example. In this way, the optical scanning element 4 is driven by the drive signal Sb having a current value corresponding to the differential voltage Vs, and feedback control is performed, so that the oscillation of the mirror unit 10 according to the control voltage Vct is accurately performed. I am doing so.

  Furthermore, the control unit 2 includes a waveform adjustment unit 25 that adjusts the waveform of the drive signal Sb.

  The waveform adjusting unit 25 rotates the mirror unit 10 about the swing axis Ly so as to reach the regulating member 17, and a detecting unit when the detecting unit 18 determines that the mirror unit 10 has reached the regulating member 17. Based on the detection result by 18, the waveform of the drive signal Sb is adjusted. This waveform adjustment unit 25 suppresses deterioration in detection accuracy of the detection unit 18 due to individual differences, aging, temperature changes, and the like of the piezoresistive elements R1 to R4.

  The waveform adjustment unit 25 performs the following process when starting control of the optical scanning element 4 and every predetermined period after starting control of the optical scanning element 4, thereby Adjust the waveform.

  First, the waveform adjustment unit 25 outputs a drive signal Sc1 whose current value gradually increases to the coil 16 of the optical scanning element 4, and rotates the mirror unit 10 about the swing axis Ly so as to reach the first regulating member 17a. (Timing t1 to t1 in FIG. 12). The waveform adjustment unit 25 monitors the detection voltage Vd, and detects that the mirror unit 10 has reached the first regulating member 17a based on the detection voltage Vd. That is, the voltage value of the detection voltage Vd increases as the current value of the drive signal Sc1 increases until the mirror unit 10 reaches the first regulating member 17a, but the mirror unit 10 reaches the first regulating member 17a. Then, the voltage value of the detection voltage Vd does not increase as the current value of the drive signal Sc1 increases (timing t2 to t3 in FIG. 12). The waveform adjustment unit 25 stores the voltage value of the detection voltage Vd when the voltage value of the detection voltage Vd does not increase (timing t2 in FIG. 12) as the first voltage value Vd1.

  Similarly, the drive signal Sc2 whose current value gradually decreases is output to the coil 16 of the optical scanning element 4, and the mirror portion 10 is rotated about the swing axis Ly so as to reach the second restricting member 17b (FIG. 12). Timing t3-). The waveform adjustment unit 25 stores the voltage value of the detection voltage Vd when the voltage value of the detection voltage Vd does not decrease (timing t4 in FIG. 12) as the second voltage value Vd2.

In the optical scanning element 4, as described above, the signal level of the detection voltage Vd and the inclination of the mirror unit 10 are in a proportional relationship. Therefore, when the angle of the mirror section 10 changes at a constant speed from + θ ₂ to −θ ₂ , the detection voltage Vd changes linearly from the first voltage value Vd1 to the second voltage value Vd2, as shown in FIG. . Further, when the detection voltage Vd is an intermediate voltage between the first voltage value Vd1 and the second voltage value Vd2, the angle of the mirror unit 10 becomes zero.

Therefore, the waveform adjustment unit 25 calculates α ′ and β ′ defined by the following equations (2) and (3) based on the first voltage value Vd1 and the second voltage value Vd2.
α ′ = (Vd1−Vd2) / 2θ ₂ (2)
β ′ = (Vd1 + Vd2) / 2 (3)

  After calculating α ′ and β ′, the waveform adjustment unit 25 outputs α ′ and β ′ to the comparison dimension conversion unit 22. The comparison dimension conversion unit 22 sets α ′ as the specified value α, sets β ′ as the specified value β, and performs subsequent conversion processing. By doing in this way, the angle of the mirror part 10 can be detected with high accuracy, and the mirror part 10 can be controlled with high accuracy so as to become the control target angle.

  As described above, in the optical scanning device 1, the restriction members 17a and 17b are provided, and the mirror unit 10 is rotated around the swing axis Ly so as to reach the restriction members 17a and 17b. Then, based on the detection voltage Vd of the detection unit 18 when the detection unit 18 determines that the mirror unit 10 has reached the regulating members 17a and 17b, the detection characteristic of the detection unit 18 is detected, and the waveform of the drive signal Sd is obtained. I try to adjust it. For this reason, in the optical scanning device 1, even when there is a change in the detection result by the detection unit 18 due to a temperature change or aging deterioration, the light beam can be scanned with high accuracy.

  In the above description, the detection characteristic of the detection unit 18 is detected using the first restriction member 17a and the second restriction member 17b. However, the detection part is detected using any one of the restriction members. You may make it detect 18 detection characteristics.

  For example, when using the 1st control member 17a, the waveform adjustment part 25 operate | moves as follows. First, the waveform adjustment unit 25 stores the signal level of the detection voltage Vd as the second voltage value Vd2 'in a state where no current flows through the coil 16 of the optical scanning element 4. Next, a drive signal Sc1 whose current value gradually increases is output to the coil 16 of the optical scanning element 4, and the mirror portion 10 is rotated about the swing axis Ly so as to reach the first regulating member 17a. The waveform adjustment unit 25 stores the voltage value of the detection voltage Vd when the signal level of the detection voltage Vd does not increase as the first voltage value Vd1 '.

Then, the waveform adjustment unit 25 calculates α ″, β ″ defined by the following equations (4) and (5) based on the first voltage value Vd1 ′ and the second voltage value Vd2 ′.
α ″ = (Vd2′−Vd1 ′) / θ ₂ (4)
β ″ = Vd2 ′ (5)

  After calculating α ″, β ″, the waveform adjustment unit 25 outputs α ″, β ″ to the comparison dimension conversion unit 22. The comparison dimension conversion unit 22 sets α ″ as the specified value α, sets β ″ as the specified value β, and performs subsequent conversion processing. By doing in this way, although detection accuracy falls compared with the case where the 2nd of the 1st control member 17a and the 2nd control member 17b is used, the detection characteristic of detection part 18 can be made quick by one control member. Can be detected.

  By the way, when the mirror unit 10 is rotated around the swing axis Ly so as to reach the regulating members 17a and 17b, when the rotating speed is constant, the impact due to the contact with the regulating members 17a and 17b is caused. The force acts in the direction opposite to the rotation direction and vibrates. Therefore, as shown in FIG. 12, the detection voltage Vd does not become a constant voltage, and there is a possibility that the detection characteristic of the detection unit 18 cannot be detected with high accuracy. Therefore, as described above, the restriction members 17a and 17b are made of an elastic member such as rubber to suppress the vibration of the mirror portion 10. However, this also causes a case where the detection characteristic of the detection unit 18 is not sufficiently detected with high accuracy.

  Therefore, as shown in FIG. 14, the waveform adjusting unit 25 rotates the mirror unit 10 before reaching the regulating members 17a and 17b when rotating the mirror unit 10 to reach the regulating members 17a and 17b. Drive signals Sc1 and Sc2 that decelerate the moving speed can be output to the optical scanning element 4. By doing in this way, it becomes possible to reduce the impact when the mirror part 10 contacts the control members 17a and 17b, and to suppress the vibration of the mirror part 10. Note that the drive signal Sc2 is omitted in FIG. 14 because it has only a polarity different from that of the drive signal Sc1. In addition, the waveform adjustment unit 25 stores drive signal Sc1 and Sc2 such that a change in signal level is reduced immediately before reaching the regulating members 17a and 17b by storing in advance variations in detection characteristics of the detection unit 18. Can be generated. Further, based on α ′, β ′ (α ″, β ″) calculated last time, drive signals Sc1, Sc2 are generated so that the change in signal level is reduced immediately before reaching the regulating members 17a, 17b. May be. Further, the drive signals Sc1 and Sc2 may be output to the optical scanning element 4 so that the change in signal level becomes smaller as the mirror unit 10 approaches the regulating members 17a and 17b. By doing in this way, the vibration of the mirror part 10 can be suppressed more.

  Further, as shown in FIG. 15, in the waveform adjustment unit 25, the voltage values of the drive signals Sc1 and Sc2 are set to the voltage values of the drive signals Sc1 and Sc2 when the mirror unit 10 reaches the regulating members 17a and 17b or just after that. Can also be maintained. By doing in this way, you may make it suppress the vibration of the mirror part 10 by suppressing that the force around the rocking axis Ly concerning the mirror part 10 raises.

  As described above, even if the configuration for suppressing the vibration of the mirror unit 10 as described above is adopted, the vibration of the mirror unit 10 may not be sufficiently suppressed. In such a case, A minute variation occurs in the detection voltage Vd output from the detection unit 18. Therefore, the detection voltage Vd when the mirror unit 10 reaches the regulating members 17a and 17b cannot be obtained with high accuracy.

  Therefore, in the waveform adjustment unit 25, as shown in FIG. 16, a predetermined period Ta has elapsed from when the signal level of the detection voltage Vd no longer changes with the change in the signal level of the drive signals Sc1 and Sc2 (timing t11). The detected voltage Vd at this time is defined as a first voltage value Vd1 and a second voltage value Vd2. As described above, since the detection unit 18 uses the detection result of the detection unit 18 after a predetermined period Ta has elapsed since it is determined that the mirror unit 10 has reached the regulating members 17a and 17b, the influence of the vibration of the mirror unit 10 is affected. It can suppress and can detect the detection characteristic of the detection part 18 accurately.

  Further, when it takes time for the fluctuation of the detection voltage Vd to converge, the detection voltage Vd for a predetermined period Ta is averaged from the time when it is determined that the mirror unit 10 has reached the regulating members 17a and 17b, and the averaging is performed. The result is defined as a first voltage value Vd1 and a second voltage value Vd2. By doing in this way, you may make it suppress the influence by the vibration of the mirror part 10. FIG.

  Further, as described above, the detection voltage Vd is not averaged, but the detection voltage Vd output from the detection unit 18 is filtered by the low-pass filter, and the first voltage value Vd1 and the second voltage value Vd2 are obtained. Good.

  Further, the averaging process and the filtering process of the detection voltage Vd do not use the detection voltage Vd for a predetermined period immediately after it is determined that the mirror unit 10 has reached the regulating members 17a and 17b, but as shown in FIG. Alternatively, the detection voltage Vd of the predetermined period Tc may be used after a predetermined period Tb has elapsed since it is determined that the mirror unit 10 has reached the regulating members 17a and 17b. Immediately after the mirror unit 10 reaches the regulating members 17a and 17b, the noise of the vibration of the mirror unit 10 is large. Therefore, the first voltage value Vd1 and the detection voltage Vd during the period when the vibration of the mirror unit 10 is large are not used. The second voltage value Vd2 can be detected with high accuracy.

  As described above, in the optical scanning device 1 according to the present embodiment, the regulation members 17a and 17b are provided, and the detection unit 18 is based on the detection voltage Vd when the mirror unit 10 reaches the regulation members 17a and 17b by the detection unit 18. 18 detection characteristics are detected, and the waveform of the drive signal Sd is adjusted. Therefore, even when there is a change in the detection result by the detection unit 18 due to temperature change or aging deterioration, the light beam can be scanned with high accuracy.

  In the above description, the detection unit 18 is used. Although constituted by two pairs of piezoresistive elements R1 to R4, a voltage between a pair of piezoresistive elements R1 and R3 (or a pair of piezoresistive elements R2 and R4) may be used as the detection voltage Vd.

[2. Image display device]
Next, an image display apparatus including the above-described optical scanning element will be described.

  As shown in FIG. 18, the image display apparatus 100 according to the present embodiment includes a control unit 110, a light source unit 120, a scanning unit 140, a second relay optical system 180, a half mirror 185, and the like.

  The control unit 110 includes a drive signal supply unit 111, a main scanning drive signal generation unit 112, a sub scanning drive signal generation unit 113, and a main control unit 114. Based on an image signal S (for example, NTSC composite signal, component signal) input from the outside, the drive signal supply unit 111 receives RGB pixel signals 115r, 115g, and 115b of the three primary colors that are elements for forming an image. Generated in pixel units. The main scanning drive signal generating unit 112 generates and outputs a main scanning driving signal 116 used in the main scanning unit 160 so that an optical scanning element 161 (described later) of the main scanning unit 160 is in a predetermined scanning range in a resonance state. To do. Further, the sub-scanning drive signal generation unit 113 generates and outputs a sawtooth-shaped sub-scanning drive signal 117 used in the sub-scanning unit 170 in synchronization with the main scanning drive signal 116.

  The light source unit 120 is provided with an R laser driver 121, a G laser driver 122, and a B laser driver 123. The laser drivers 121, 122, and 123 supply drive currents to the lasers 124, 125, and 126 based on the R, G, and B drive signals 115r, 115g, and 115b output from the drive signal supply unit 111, respectively. To do. Each laser 124, 125, 126 emits laser light whose intensity is modulated in accordance with the drive current supplied from each laser driver 121, 122, 123. The R (red) laser light Lr, G (green) laser light Lg, and B (blue) laser light Lb emitted from the lasers 124, 125, and 126 were collimated by collimating optical systems 127, 128, and 129, respectively. Later, the light enters the dichroic mirrors 130, 131, and 132. Thereafter, the laser beams Lr, Lg, and Lb of the three primary colors are wavelength-selectively reflected and transmitted by these dichroic mirrors 130, 131, and 132, reach the coupling optical system 133, and are combined to the optical fiber cable 135. Emitted. Thus, the laser light emitted to the optical fiber cable 135 is a combination of intensity-modulated laser light of each color.

  The scanning unit 140 includes a collimating optical system 151, a main scanning unit 160, a first relay optical system 165, a sub-scanning unit 170, and the like.

  The collimating optical system 151 collimates the laser beam generated by the light source unit 120 and emitted through the optical fiber cable 135.

  The main scanning unit 160 and the sub-scanning unit 170 are arranged in the main scanning direction and the sub-scanning direction so that the laser light incident from the optical fiber cable 135 can be projected on the retina 190b of the user's eye 190 as an image. An optical system for scanning. The main scanning unit 160 includes an optical scanning element 161 that reciprocally scans incident laser light that has been collimated by the collimating optical system 151 in the main scanning direction. The sub-scanning unit 170 scans the optical scanning element 171 that scans in the main scanning direction by the main scanning unit 160 and scans the laser light incident through the first relay optical system 165 at a relatively low speed in the sub-scanning direction. Have. This sub-scanning direction is a direction substantially orthogonal to the main scanning direction. For example, the main scanning direction can be the horizontal direction and the sub-scanning direction can be the vertical direction.

  The first relay optical system 165 that relays the laser beam between the main scanning unit 160 and the sub-scanning unit 170 converges the laser beam scanned in the main scanning direction by the optical scanning element 161 on the mirror unit of the optical scanning element 171. Let The laser beam is scanned in the sub-scanning direction by the optical scanning element 171. The laser beam scanned by the optical scanning element 171 is a half mirror 185 positioned in front of the eye 190 via a second relay optical system 180 in which two lenses 180a and 180b having positive refractive power are arranged in series. And is incident on the user's pupil 190a. As a result, an image corresponding to the image signal S is projected on the retina 190b, and the user recognizes the laser light incident on the pupil 190a as an image. Further, the half mirror 185 transmits the external light L2 so as to enter the pupil 190a of the user, so that the user visually recognizes an image in which the image based on the laser light L1 is superimposed on the external scene based on the external light L2. can do. As described above, the image display device 100 is a see-through retinal scanning image display device that forms an image on the retina of the user's eye 190 by superimposing an image according to the image signal S and an outside scene.

  In the image display device 100 configured as described above, the optical scanning element 171 has the same configuration as that of the optical scanning element 4, and the sub-scanning drive signal generation unit 113 includes the control unit 2 of the optical scanning device 1 described above. Similarly, the optical scanning element 171 having the same configuration as that of the optical scanning element 4 is driven. That is, the optical scanning element 171 is provided with a regulating member and a detection unit that detects the angle of the mirror part of the optical scanning element 171. Then, the sub-scanning drive signal generation unit 113 detects the detection characteristic of the detection unit based on the detection voltage Vd of the detection unit when the mirror unit reaches the regulating member, and adjusts the waveform of the sub-scanning drive signal 117. . Therefore, even when there is a change in the detection result by the detection unit 18 due to temperature change, aging deterioration, or the like, the laser beam can be scanned with high accuracy.

  Here, laser light that is advantageous in terms of efficiency is used as an example of the light flux, but the light flux is not limited to laser light.

  In addition, although the detection unit that detects the angle of the mirror unit of the optical scanning element is configured by a piezoresistive element, a detection method using a piezoelectric element or a detection method using a change in capacitance may be used.

  Although the present invention has been described through the above-described embodiments, the following effects can be expected according to this embodiment.

(1) It has the mirror part 10 supported from both sides by a pair of beam parts 11a and 11b, and the mirror part 10 rock | fluctuates around the rocking | fluctuation axis Ly by the torsional displacement of the beam parts 11a and 11b, and the mirror part 10 The optical scanning element 4 (171) that scans the light beam, and the control unit 2 (110) that outputs the drive signal Sd (117) to the optical scanning element 4 (171) and swings the mirror unit 10 about the swing axis Ly. The angle of the mirror unit 10 around the swing axis Ly is outside the angle range (+ θ ₁ to −θ ₁ ) for scanning the light beam. Restriction members 17a and 17b for restricting the predetermined angles + θ ₂ and −θ ₂ or more are provided. Then, the control unit 2 (110) rotates the mirror unit 10 around the swing axis Ly so as to reach the regulating members 17a and 17b, and the mirror unit 10 reaches the regulating members 17a and 17b by the detecting unit 18. The waveform of the drive signal Sd (117) is adjusted based on the detection voltage Vd (detection result) of the detection unit 18 when it is determined that the detection result of the detection unit 18 varies due to temperature change, aging degradation, and the like. Even in such a case, the light beam can be scanned with high accuracy.

(2) The restricting members 17a and 17b have a predetermined angle θ ₂ (+ θ) around the swing axis Ly of the mirror unit 10 in a first direction around the swing axis Ly from a state where the mirror unit 10 is not swinging. ₂ ) The first regulating member 17a that regulates the above and the angle around the swing axis Ly of the mirror unit 10 is the second direction opposite to the first direction from the state in which the mirror unit 10 is not swinging. And a second restricting member 17b that restricts the direction to a predetermined angle θ ₂ (−θ ₂ ) or more. The optical scanning element 4 (171) extends in a direction perpendicular to the swing axis Ly, and Each of the beam portions 11a and 11b has a pair of support portions that are elastically supported at the central portion thereof and have both end portions fixed to the fixing portions 13a and 13b. A pair of piezoelectric resistors arranged symmetrically with respect to the swing axis Ly on 12a and 12b The pair of piezoresistive elements R1, R3 (R4, R2) are connected in series and applied with a predetermined voltage, and the piezoresistive elements R1, R3 (R4, R4) have resistance elements R1, R3 (R4, R2). R2) is output as detection voltage Vd, which is information about the angle of the mirror unit 10 about the swing axis Ly, and the control unit 2 (110) is configured to reach the first regulating member 17a. Is rotated around the swing axis Ly, and the voltage value between the piezoresistive elements R1, R3 (R4, R2) when the detection unit 18 determines that the mirror unit 10 has reached the first regulating member 17a, 2 When the mirror unit 10 is rotated about the swing axis Ly so as to reach the regulating member 17b, and the detection unit 18 determines that the mirror unit has reached the second regulating member 17b, the piezoresistive elements R1, R3 ( R4 and R2) based on the voltage value Te, so adjusts the waveform of the driving signal Sd (117), it is possible to detect the angle of the mirror portion 10 with a small number of parts and space saving.

(3) Since the regulating members 17a and 17b have elasticity, it is possible to reduce the impact when the mirror unit 10 contacts the regulating members 17a and 17b, and to suppress the vibration of the mirror unit 10.

(4) When the control unit 2 (110) rotates the mirror unit 10 around the swinging axis Ly so as to reach the regulating members 17a and 17b, the control unit 2 (110) before reaching the regulating members 17a and 17b. Since the rotation speed of the mirror unit 10 is reduced, the impact when the mirror unit 10 contacts the regulating members 17a and 17b can be reduced, and the vibration of the mirror unit 10 can be suppressed.

(5) When the control unit 2 (110) rotates the mirror unit 10 about the swinging axis Ly and determines that the mirror unit 10 has reached the regulating members 17a and 17b, the mirror unit 10 includes the regulating members 17a and 17b. In order to maintain the state reaching 17b, the voltage value of the drive signal Sd (117) is maintained to be equal to or higher than the voltage value of the drive signal Sd (117) when the mirror unit 10 reaches the regulating members 17a and 17b. Therefore, it is possible to suppress an increase in the force around the peristaltic axis Ly applied to the mirror unit 10 and to suppress the vibration of the mirror unit 10.

(6) A predetermined period after the mirror unit 10 is rotated about the swing axis Ly so as to reach the regulating members 17a and 17b, and the detection unit 18 determines that the mirror unit 10 has reached the regulating members 17a and 17b. Since the detection voltage Vd (detection result) of the detection unit 18 of Ta and Tc is averaged and the waveform of the drive signal Sd (117) is adjusted based on the averaged detection result, the influence of vibration of the mirror unit 10 is suppressed. The waveform of the drive signal Sd (117) can be adjusted with high accuracy.

(7) The control unit 2 (110) rotates the mirror unit 10 around the swing axis Ly so as to reach the regulating members 17a and 17b, and the mirror unit 10 reaches the regulating members 17a and 17b by the detecting unit 18. Since the waveform of the drive signal Sd (117) is adjusted on the basis of the detection voltage Vd (detection result) of the detection unit 18 after a predetermined period Ta has elapsed from the time when it is determined that it has been determined, the influence of vibration of the mirror unit 10 is suppressed. Thus, the waveform of the drive signal Sd (117) can be adjusted with high accuracy.

DESCRIPTION OF SYMBOLS 1 Optical scanning device 2 Control part 3 Light source part 4,171 Optical scanning element 10 Mirror part 10a Reflecting surface 11a, 11b Beam part
12a, 12b Support parts 13a, 13b Fixing part 14 Base 17a First restriction member 17b Second restriction member 18 Detection part 21 Target command generation part 22 Comparison dimension conversion part 23 Subtraction part 24 Drive signal generation part 25 Waveform adjustment part 100 Image Display device 113 Sub-scanning drive signal generator 117 Sub-scanning drive signal Sd Drive signal Vd Detection voltage

Claims (9)

An optical scanning element having a mirror portion supported from both sides by a pair of beam portions, wherein the mirror portion swings around a swing axis due to torsional displacement of the beam portion, and the light beam is scanned by the mirror portion; A control unit that outputs a drive signal to a scanning element and swings the mirror unit around the swing axis;
A detection unit for detecting an angle of the mirror unit around the swing axis;
A regulating member that regulates that the angle of the mirror portion around the swing axis is greater than or equal to a predetermined angle outside the angular range for scanning the light beam;
The controller is
Based on the detection result by the detection unit when the detection unit determines that the mirror unit has reached the regulation member by rotating the mirror unit around the swing axis so as to reach the regulation member, An optical scanning device that adjusts a waveform of the drive signal. The regulating member is
A first regulating member that regulates that the angle of the mirror portion around the swing axis is not less than the predetermined angle in a first direction around the swing shaft from a state where the mirror portion does not swing;
A second restriction for restricting an angle of the mirror portion around the swing axis from being in a state where the mirror portion is not swinging to be equal to or greater than the predetermined angle in a second direction opposite to the first direction; And consists of members,
The optical scanning element is
Extending in a direction perpendicular to the swing axis, and having a pair of support portions that elastically support the other ends of the pair of beam portions at the center thereof and both ends fixed to a fixed portion ,
The detector is
Each of the support portions has a pair of piezoresistive elements arranged symmetrically with respect to the swing axis, and the pair of piezoresistive elements are connected in series and applied with a predetermined voltage, and between the piezoresistive elements Is output as information on the angle of the mirror portion around the swing axis,
The controller is
Between the piezoresistive elements when the mirror portion is rotated about the swing axis so as to reach the first restricting member, and the detection portion determines that the mirror portion has reached the first restricting member. And when the detection unit determines that the mirror part has reached the second restricting member by rotating the mirror part around the swing axis so as to reach the second restricting member. The optical scanning device according to claim 1, wherein a waveform of the drive signal is adjusted based on a voltage value between the piezoresistive elements. The optical scanning device according to claim 1, wherein the restriction member has elasticity. The controller is
2. The rotating speed of the mirror portion is reduced before reaching the restricting member when the mirror portion is rotated about the swing axis so as to reach the restricting member. The optical scanning device according to any one of? The controller is
In order to maintain the state in which the mirror portion reaches the regulating member when the mirror portion is rotated about the swing axis and it is determined that the mirror portion has reached the regulating member, the drive signal 5. The optical scanning device according to claim 1, wherein the voltage value is maintained to be equal to or higher than the voltage value of the drive signal when the mirror portion reaches the regulating member. The detection result of the detection unit for a predetermined period after the mirror unit is rotated about the swing axis so as to reach the regulation member, and the detection unit determines that the mirror unit has reached the regulation member. The optical scanning device according to claim 5, wherein the waveform of the drive signal is adjusted based on the averaged detection result. The controller is
The mirror unit is rotated about the swing axis so as to reach the restricting member, and the detection unit has a predetermined period after the detection unit determines that the mirror unit has reached the restricting member. 6. The optical scanning device according to claim 5, wherein a waveform of the drive signal is adjusted based on a detection result. A light source that emits a luminous flux having an intensity according to an image signal;
A first optical scanning element that scans a light beam emitted from the light source in a first direction at a relatively high speed;
A mirror portion supported from both sides by a pair of beam portions, and the light beam scanned by the first scanning element by oscillating the mirror portion around an oscillation axis by the torsional displacement of the beam portion by the mirror portion; A scanning unit having a second optical scanning element that scans relatively slowly in a second direction substantially orthogonal to the first direction;
An image display device comprising: a control unit that controls the scanning unit;
A detection unit for detecting an angle of the mirror unit around the swing axis;
A regulating member that regulates that the angle of the mirror portion around the swing axis is greater than or equal to a predetermined angle outside the angular range for scanning the light beam;
The controller is
Based on the detection result by the detection unit when the detection unit determines that the mirror unit has reached the regulation member by rotating the mirror unit around the swing axis so as to reach the regulation member, An image display device characterized by adjusting a waveform of a drive signal for swinging the mirror portion around the swing axis.   The image display apparatus according to claim 8, wherein a light beam scanned by the scanning unit is incident on a user's eye and an image corresponding to the image signal is projected onto the retina of the user.

Images