Mirror driving device, light source device, light scanning device, and correction method

Abstract

A mirror drive device (10) is provided with: a MEMS mirror (20); a MEMS drive unit (30) that outputs a drive signal to the MEMS mirror (20) and drives the MEMS mirror (20); a MEMS sensor unit (40) that outputs a sensor signal corresponding to the deflection angle of the MEMS mirror (20); a MEMS sensor correction circuit (126) having the same response delay time as the MEMS sensor unit (40); and a delay processing unit (110) that inputs the delay detection signal to the MEMS sensor correction circuit (126) and calculates the output delay.

Description

Technical Field

[0001] The present invention relates to a mirror driving device for driving a MEMS mirror, a light source device for making a light source emit light, an optical scanning device having the mirror driving device and the light source device, a method for correcting mirror driving timing, and a method for correcting light source driving timing. Background Art

[0002] Conventionally, optical deflectors that scan light and project images have been known to include a reflector manufactured using MEMS (Micro Electro Mechanical System) technology. During projection, the light source is controlled to light up or turn off in accordance with the displacement of the reflector.

[0003] In addition, there is also known a technique for detecting a response delay of a drive signal to a reflective mirror unit and a response delay of a control signal to a light source by various sensors to correct the delay.

[0004] For example, the image projection device of Patent Document 1 includes a compensation circuit, a light sensor, and a temperature sensor in addition to an LD module, a light scanning unit, and an optical system inside a housing. The optical system is composed of three reflection mirrors and a concave mirror.

[0005] The detection unit of the compensation circuit detects the phase deviation in the horizontal scanning direction of the laser and the deflection angle variation of the MEMS mirror based on the deviation of the first pixel detected by the optical sensor (the pixel detected by the optical sensor in the outward path of the horizontal scanning of the laser) from the expected value and the deviation of the second pixel detected by the optical sensor (the pixel detected by the optical sensor in the outward path of the same loop) from the expected value (Patent Document 1 / 0016, paragraph 0026, paragraph 0027, paragraph 0036, Figure 2 , Figure 4 ).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 6978659 Summary of the invention

[0009] Problems to be solved by the invention

[0010] In order to calibrate the driving of the mirror unit and the timing of igniting the laser, it is necessary to first detect the laser using a light sensor and adjust the timing of igniting the laser based on the information. The information about the driving state of the mirror obtained from the sensor for detecting the driving state of the mirror unit includes the response delay of the sensor itself.

[0011] The information on the lighting timing acquired from the sensor for detecting the lighting timing of the laser light also includes the response delay of the sensor itself.

[0012] In addition, the optical sensor and the sensor circuit have independent response characteristics, and the delay of the response may vary depending on the operating frequency of the device and the ambient temperature. Therefore, this variation may affect the correction of the lighting timing.

[0013] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a mirror driving device capable of accurately correcting the response time of a mirror and a light source and a delay in driving control regardless of driving conditions and ambient temperature.

[0014] Means for solving problems

[0015] In order to achieve the above-mentioned purpose, the reflector driving device of the present invention is characterized in that it comprises: an optical scanner, which has a reflector for scanning light; an optical scanner driving unit, which outputs a driving signal to the optical scanner to drive the optical scanner; an optical scanner sensor unit, which outputs an optical scanner sensor signal corresponding to the deflection angle of the optical scanner; an optical scanner sensor correction unit, which has the same response delay time as the optical scanner sensor unit; and a delay processing unit, which inputs a delay detection signal to the optical scanner sensor correction unit and calculates the output delay.

[0016] The reflector driving device of the present invention drives an optical scanner to scan light. The reflector driving device includes an optical scanner sensor unit, an optical scanner sensor correction unit, and a delay processing unit. The optical scanner sensor unit outputs an optical scanner sensor signal corresponding to the deflection angle of the optical scanner (reflector), so the deflection angle of the reflector in operation can be detected.

[0017] The delay processing unit inputs the delay detection signal to the optical scanner sensor correction unit and calculates the delay of the output. The optical scanner sensor correction unit has the same response delay time as the optical scanner sensor unit. The "same response delay time" mentioned here is not limited to completely the same time, but also includes substantially the same time.

[0018] By using the delay time calculated by the delay processing unit, it is possible to accurately correct the delay in the response time of the optical scanner without being affected by driving conditions or ambient temperature.

[0019] In addition, the light source device of the present invention is characterized in that it comprises: a light source; a light source driving unit, which outputs a driving signal to the light source to make the light source emit light; a light sensor unit, which detects light from the light source and outputs a light sensor signal; a light sensor correction unit, which has the same response delay time as the light sensor unit; and a delay processing unit, which inputs a delayed detection signal to the light sensor correction unit and calculates the output delay.

[0020] In the light source device of the present invention, the light source driving unit outputs a driving signal to the light source to make it emit light. The light source device includes a light sensor unit, a light sensor correction unit, and a delay processing unit. The light sensor unit detects light from the light source and outputs a light sensor signal, so it can detect the timing of light emission.

[0021] The delay processing unit inputs the delayed detection signal to the light sensor correction unit and calculates the output delay. The light sensor correction unit has the same response delay time as the light sensor unit, so by using the delay time calculated by the delay processing unit, the delay of the response time of the light source can be corrected with high accuracy without being affected by driving conditions and ambient temperature.

[0022] Furthermore, the optical scanning device of the present invention is characterized by comprising:

[0023] An optical scanner having a reflective mirror for scanning light; an optical scanner driving unit that outputs a driving signal to the optical scanner to drive the optical scanner; an optical scanner sensor unit that outputs an optical scanner sensor signal corresponding to a deflection angle of the optical scanner; and an optical scanner sensor correction unit having the same response delay time as the optical scanner sensor unit;

[0024] A light source; a light source driving unit that outputs a light source driving signal to the light source to cause the light source to emit light; a light sensor unit that detects light from the light source and outputs a light sensor signal; a light sensor correction unit that has the same response delay time as the light sensor unit; and a delay processing unit that inputs a delay detection signal to at least one of the light scanner sensor correction unit and the light sensor correction unit, and calculates the delays of the outputs of the light scanner sensor correction unit and the light sensor correction unit, respectively.

[0025] The optical scanning device of the present invention drives the optical scanner by the optical scanner driving unit to scan the light from the light source. The optical scanner sensor unit outputs an optical scanner sensor signal corresponding to the deflection angle of the optical scanner (reflector), so the deflection angle of the reflector in operation can be detected. In addition, the optical sensor unit detects the light from the light source and outputs the optical sensor signal, so the timing of light emission can be detected.

[0026] The delay processing unit inputs a delay detection signal to at least one of the optical scanner sensor correction unit and the optical sensor correction unit, and respectively calculates the delay of the output of the optical scanner sensor correction unit and the optical sensor correction unit. The optical scanner sensor correction unit and the optical sensor correction unit have the same response delay time as the optical scanner sensor unit and the optical sensor unit, respectively, so the calculated delay time is used for correction. That is, the response time of the optical scanner and the light source and the delay of the drive control can be corrected with high precision without being affected by the driving conditions and the ambient temperature.

[0027] In addition, the method for correcting the mirror driving timing of the present invention is a method for correcting the mirror driving timing of the following device, wherein the device comprises: an optical scanner having a mirror for scanning light; an optical scanner driving unit that outputs an optical scanner driving signal to the optical scanner to drive the optical scanner; and an optical scanner sensor unit that outputs an optical scanner sensor signal corresponding to a deflection angle of the optical scanner.

[0028] The method for correcting the mirror driving timing is characterized by comprising the following steps:

[0029] a step of acquiring a time from the output of the optical scanner driving signal to the output of the optical scanner sensor signal; and

[0030] a step of acquiring a light scanner sensor reproduced response delay time that reproduces the response delay of the light scanner sensor unit;

[0031] The step of calculating a response time until the optical scanner reaches a deflection angle corresponding to the optical scanner drive signal by subtracting a reproduction response delay time of the optical scanner sensor from a time from the output of the optical scanner drive signal to the output of the optical scanner sensor signal.

[0032] In the mirror drive timing correction method of the present invention, first, the time from outputting the optical scanner drive signal to outputting the optical scanner sensor signal is obtained (time T1), and then the optical scanner sensor reproduced response delay time (time T2) which reproduces the response delay of the optical scanner sensor unit is obtained.

[0033] Finally, the optical scanner sensor reproduced response delay time (time T2) is subtracted from the time (time T1) from the output of the optical scanner drive signal to the output of the optical scanner sensor signal. Thus, the response time (time T1-T2) until the optical scanner (reflector) reaches the deflection angle corresponding to the optical scanner drive signal can be calculated, so that the delay of the response time of the optical scanner can be corrected with high accuracy without being affected by the driving conditions and the ambient temperature.

[0034] In addition, the method for correcting the timing of driving a light source of the present invention is a method for correcting the timing of driving a light source of the following device, wherein the device comprises a light source, a light source driving unit that outputs a light source driving signal to the light source to cause the light source to emit light, and a light sensor unit that detects light from the light source and outputs a light sensor signal.

[0035] The method for correcting the light source driving timing is characterized by comprising the following steps:

[0036] a step of obtaining a time from the output of the light source driving signal to the output of the light scanner sensor signal;

[0037] A step of obtaining a photosensor reproduced response delay time that reproduces the response delay of the photosensor unit; and

[0038] A step of calculating a response time until the light source emits light according to the light source driving signal by subtracting the light sensor reproduction response delay time from the delay time from the output of the light source driving signal to the output of the light sensor signal.

[0039] In the light source drive timing correction method of the present invention, first, the time from outputting the optical scanner drive signal to outputting the optical scanner sensor signal is obtained (time T3), and then the optical sensor reproduced response delay time (time T4) which reproduces the response delay of the optical sensor unit is obtained.

[0040] Finally, the optical sensor reproduction response delay time (time T4) is subtracted from the time from when the optical scanner drive signal is output to when the optical scanner sensor signal is output (time T3). Thus, the response time (time T3-T4) until the light source emits light according to the light source drive signal can be calculated, and therefore, the delay in the response time of the light source can be corrected with high accuracy without being affected by the drive conditions and the ambient temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the optical scanning device of the present invention.

[0042] Figure 2 It is a block diagram of the optical system of the light scanning device.

[0043] Figure 3 It is a diagram for explaining the details of the delay processing unit and the sensor correction unit.

[0044] Figure 4 This is a schematic diagram of the optical scanning device (modification) of the present invention. DETAILED DESCRIPTION

[0045] The preferred embodiments of the present invention are described below. However, they can also be appropriately changed and combined. In the following description and drawings, substantially the same or equivalent parts are marked with the same reference symbols for description.

[0046] [Implementation Method]

[0047] Figure 1 A schematic diagram showing an optical scanning device 1 according to an embodiment of the present invention. Figure 2 1 is a block diagram of an optical system of the optical scanning device 1. The optical scanning device 1 is mainly composed of a mirror driving device 10 and a light source device 50.

[0048] like Figure 1 As shown, the mirror driving device 10 is composed of a MEMS mirror 20, a MEMS driving unit 30, a MEMS sensor unit 40, an integrated control unit 100, a drive signal generating unit 105, a delay processing unit 110, and a sensor correction unit 120. It should be noted that the part composed of the integrated control unit 100, the drive signal generating unit 105, and the delay processing unit 110 is sometimes referred to as a control circuit 150.

[0049] The MEMS mirror 20 is a rotating mirror that reflects laser light incident from a certain direction and performs scanning. The light deflector 25 includes the MEMS mirror 20, and the MEMS mirror 20 only needs to be able to reciprocate around at least one axis.

[0050] The optical deflector 25 of this embodiment is a device made by semiconductor process or MEMS technology. The optical deflector 25 has, for example, a semi-annular piezoelectric actuator, a torsion bar, or a corrugated piezoelectric actuator constituting the MEMS drive unit 30 (the "optical scanner drive unit" of the present invention). In this case, by using the resonant drive (horizontal direction) of the semi-annular piezoelectric actuator and the non-resonant drive (vertical direction) of the corrugated piezoelectric actuator, the incident light can be scanned in two mutually perpendicular axial directions.

[0051] The integrated control unit 100 controls the drive signal generation unit 105 to generate a drive signal for the MEMS mirror 20 and transmits it to the MEMS drive unit 30 to operate the MEMS mirror 20. When laser light is incident on the operating MEMS mirror 20, the laser light is scanned and an image is projected.

[0052] like Figure 2As shown in FIG. 1 , the MEMS sensor unit 40 (the “light scanner sensor unit” of the present invention) is composed of a piezoelectric sensor 27 provided on the light deflector 25 and a MEMS sensor signal processing circuit 45 (the “light scanner sensor signal processing circuit” of the present invention). The MEMS sensor unit 40 detects the deflection angle of the MEMS mirror 20 through the piezoelectric sensor 27, and generates a sensor signal corresponding to the deflection angle using the MEMS sensor signal processing circuit 45. Furthermore, the MEMS sensor signal processing circuit 45 outputs the sensor signal to the control circuit 150 (delay processing unit 110).

[0053] The delay processing unit 110 inputs the delay detection signal to the MEMS sensor correction circuit 126 (“optical scanner sensor correction unit” of the present invention) of the sensor correction unit 120 , and calculates the delay of the output, which will be described in detail later.

[0054] The MEMS sensor correction circuit 126 has a response characteristic equivalent to that of the MEMS sensor unit 40 (particularly, the same delay time). It should be noted that the "same delay time" in this specification is not limited to the case where the delay time is completely the same. The "same delay time" includes a delay time that is negligible relative to the response time of the output signal to the input signal of the sensor circuit or the like, or a substantially identical delay time within a certain error range (hereinafter the same).

[0055] The MEMS sensor correction circuit 126 is composed of, for example, a circuit that combines a circuit having a response characteristic equivalent to that of the piezoelectric sensor 27 and a circuit having a response characteristic equivalent to that of the MEMS sensor signal processing circuit 45. It should be noted that the "circuit having a response characteristic equivalent" in this specification includes a circuit having a response characteristic equivalent to changes in driving conditions, ambient temperature, etc.

[0056] Therefore, the MEMS sensor correction circuit 126 can correct the phase difference between the drive signal of the MEMS mirror 20 and the sensor signal of the piezoelectric sensor 27. That is, the response time of the MEMS mirror 20 and the delay of the drive control can be corrected with high accuracy without being affected by the drive conditions and the ambient temperature.

[0057] The light source 60 of this embodiment uses a pulsed laser diode. The color of the laser can be single color or a mixture of multiple colors. The integrated control unit 100 controls and sends a control signal to the light source driving unit 70, and the light source driving unit 70 makes the light source 60 emit light.

[0058] Specifically, the laser light emitted from the light source 60 passes through the half mirror 65 and enters the MEMS mirror 20 (see Figure 2 ). The MEMS mirror 20 scans the incident light, thereby projecting an image onto the screen S.

[0059] The optical sensor unit 80 is composed of a photodetector 82 and a photosensor signal processing circuit 85. The photodetector 82 detects the laser light reflected by the half mirror 65. The optical sensor unit 80 generates a photosensor signal corresponding to the detection timing of the laser light by the photosensor signal processing circuit 85, and outputs it to the control circuit 150 (delay processing unit 110).

[0060] Figure 3 The details of the delay processing unit 110 and the sensor correction unit 120 are shown.

[0061] The delay processing unit 110 includes a state monitoring unit 111 , an optical delay measuring unit 112 , a MEMS delay measuring unit 113 , a delay calculating unit 114 , an optical sensor correction processing unit 115 , and a MEMS sensor correction processing unit 116 .

[0062] The state monitoring unit 111 monitors the input of the emission timing signal from the integrated control unit 100. The emission timing signal is, for example, a signal generated simultaneously with or immediately after the emission of laser light is instructed. Then, the state monitoring unit 111 sends the emission timing signal to the optical delay measuring unit 112.

[0063] The light emission timing signal may be a signal with a known delay time relative to the timing when light emission is instructed, and is not limited to a signal generated simultaneously with or immediately after the instruction to emit laser light.

[0064] The optical delay measurement unit 112 receives the light emission timing signal and the optical sensor signal from the optical sensor unit 80. Thus, the optical delay measurement unit 112 can measure the delay time t1 from the instruction to emit light to the optical sensor unit 80 detecting the light.

[0065] On the other hand, the MEMS delay measuring unit 113 receives the MEMS drive signal and the MEMS sensor signal to measure the delay time t2 thereof. Both the delay times t1 and t2 are sent to the delay calculating unit 114 .

[0066] In addition, the optical sensor correction processing unit 115 outputs a signal (e.g., a pulse signal) to the optical sensor correction circuit 125 of the sensor correction unit 120 (the "optical sensor correction unit" of the present invention) and measures the delay time t3 until the signal returns (the "optical sensor reproduction response delay time" of the present invention).

[0067] The optical sensor correction circuit 125 has a response characteristic equivalent to that of the optical sensor unit 80 and therefore outputs a signal having the same phase difference as that of the optical sensor unit 80 with respect to the input signal. Therefore, the delay time t3 can be regarded as the same value as the delay time of the optical sensor unit 80.

[0068] The photosensor correction circuit 125 is configured by, for example, a circuit that combines a circuit having a response characteristic equivalent to that of the photodetector 82 and a circuit having a response characteristic equivalent to that of the photosensor signal processing circuit 85 .

[0069] Similarly, the MEMS sensor correction processing unit 116 outputs a signal (e.g., a signal of the same frequency) to the MEMS sensor correction circuit 126 of the sensor correction unit 120 (the "MEMS sensor correction unit" of the present invention), and measures the delay time t4 until the signal returns (the "optical scanner sensor reproduction response delay time" of the present invention).

[0070] The MEMS sensor correction circuit 126 has a response characteristic equivalent to that of the MEMS sensor unit 40 (MEMS sensor signal processing circuit 45), and therefore outputs a signal having the same phase difference as that of the MEMS sensor unit 40 relative to the input signal. Therefore, the delay time t4 can be regarded as the same value as the delay time of the MEMS sensor unit 40.

[0071] Then, the delay processing unit 110 calculates and outputs the correction phase amount for driving the MEMS mirror 20 and controlling the light source 60 based on the delay times t1 to t4. For the MEMS mirror 20, the delay time t4 is subtracted from the delay time t2 to obtain the delay time without the influence of the response characteristics of the MEMS sensor unit 40.

[0072] In addition, for the light source 60 , the delay time t3 is subtracted from the delay time t1 , thereby obtaining the delay time from which the influence of the response characteristics of the optical sensor unit 80 is eliminated.

[0073] The delay processing unit 110 is connected to the drive signal generating unit 105 (see Figure 1 ). The drive signal generating unit 105 generates a drive signal for the MEMS mirror 20 and a drive signal for the light source 60 whose phase is shifted by the same amount as the correction phase amount with respect to the drive signal based on the correction phase amount.

[0074] The optical scanning device 1 generates a new drive signal through the above-mentioned processing, and corrects the timing of the operation of the MEMS mirror 20 and the light emission of the light source 60. As a result, the response time and the time difference of the drive control of the MEMS mirror 20 and the light source 60 can be adjusted with high precision. In the case where there is a deviation between the operation of the MEMS mirror 20 and the light emission of the light source 60, for example, in the case where the light image is projected toward the center of the screen S (projection area) by only scanning the laser in one direction, the light image is projected deviated from the center of the screen S, but by correcting the deviation of the timing, the light image appears in the center of the screen S.

[0075] The correction process may be performed periodically, such as when the optical scanning device 1 is started, or in response to changes in the external environment. In addition, when only the resonance drive of the MEMS mirror 20 is performed in the optical scanning device 1, the timing of performing the correction process (correction of the light emission timing of the light source 60) and the like may be appropriately determined.

[0076] Figure 4 A schematic diagram showing an optical scanning device 11 according to a modification of the present invention.

[0077] The present invention can also be used Figure 4 As shown in the structure Figure 1 The difference from the illustrated embodiment is that the drive signal generation unit 105 sends a signal indicating whether the MEMS mirror 20 is being driven to the delay processing unit 119 .

[0078] In addition, the delay processing unit 119 sends a driving signal to the light source driving unit 70. Thus, the timing of starting light emission of the light source 60 can be controlled.

[0079] According to this modification, it is not necessary to control the start of light emission through external components such as the integrated control unit 100. In addition, the processing capability of the external control device and the simplification of the communication path can be achieved, and modularization of the present invention is also facilitated.

[0080] As mentioned above, the optical scanning devices 1 and 11 according to the present embodiment have been described. However, the present invention is not limited to the above-mentioned embodiment, and the present invention can be implemented in various forms within the scope not departing from the gist of the invention.

[0081] The present invention is mainly applicable to a laser scanning type projection device including a MEMS mirror, but can also be applied to a vehicle lamp or a LiDAR device including a MEMS mirror.

[0082] The above-described correction process may be performed on a single mirror drive device 10 or a single light source device 50 using the MEMS sensor correction circuit 126 or the optical sensor correction circuit 125 , respectively.

[0083] Explanation of symbols

[0084] 1, 11…optical scanning device, 10…mirror driving device, 20…MEMS mirror, 25…optical deflector, 27…piezoelectric sensor, 30…MEMS driving unit, 40…MEMS sensor unit, 45…MEMS sensor signal processing circuit, 50…light source device, 60…light source, 65…half mirror, 70…light source driving unit, 80…optical sensor unit, 82…photodetector, 85…optical sensor signal processing circuit, 100…integrated control unit, 105…driving signal generating unit, 110, 119…delay processing unit, 111…state monitoring unit, 112…optical delay measuring unit, 113…MEMS delay measuring unit, 114…delay calculation unit, 115…optical sensor correction processing unit, 116…MEMS sensor correction processing unit, 120…sensor correction unit, 125…optical sensor correction circuit, 126…MEMS sensor correction circuit, 150…control circuit.

Claims

1. A reflector driving device, characterized in that: have: a light scanner having a mirror that scans the light; an optical scanner driving unit that outputs a driving signal to the optical scanner to drive the optical scanner; an optical scanner sensor section that outputs an optical scanner sensor signal corresponding to a deflection angle of the optical scanner; an optical scanner sensor calibration section having the same response delay time as the optical scanner sensor section; as well as The delay processing unit inputs the delay detection signal to the optical scanner sensor correction unit and calculates the delay of the output.

2. The reflector driving device according to claim 1, characterized in that: The optical scanner sensor unit is composed of a piezoelectric sensor and an optical scanner sensor signal processing circuit. The optical scanner sensor correction section is a circuit having the same response delay time as both the piezoelectric sensor and the optical scanner sensor signal processing circuit.

3. A light source device, characterized in that: have: light source; a light source driving unit, which outputs a driving signal to the light source to make the light source emit light; a light sensor unit that detects light from the light source and outputs a light sensor signal; a light sensor correction section having the same response delay time as the light sensor section; as well as, The delay processing unit inputs the delay detection signal to the optical sensor correction unit and calculates the delay of the output.

4. The light source device according to claim 3, characterized in that: The optical sensor unit is composed of a photodetector and an optical sensor signal processing circuit. The photosensor correction unit is a circuit having the same response delay time as both the photodetector and the photosensor signal processing circuit.

5. An optical scanning device, characterized in that: have: a light scanner having a mirror that scans the light; an optical scanner driving unit that outputs a driving signal to the optical scanner to drive the optical scanner; an optical scanner sensor section that outputs an optical scanner sensor signal corresponding to a deflection angle of the optical scanner; an optical scanner sensor calibration section having the same response delay time as the optical scanner sensor section; light source; a light source driving unit, which outputs a light source driving signal to the light source to make the light source emit light; a light sensor unit that detects light from the light source and outputs a light sensor signal; a light sensor correction section having the same response delay time as the light sensor section; as well as, A delay processing unit inputs a delay detection signal to at least one of the optical scanner sensor correction unit and the optical sensor correction unit, and calculates delays of outputs of the optical scanner sensor correction unit and the optical sensor correction unit, respectively.

6. The optical scanning device according to claim 5, characterized in that: The optical sensor correction unit corrects the delay of the output during a period in which the optical scanner is resonantly driven.

7. A method for correcting mirror driving timing, the method being a method for correcting mirror driving timing of the following device, the device comprising: an optical scanner having a reflector for scanning light; an optical scanner driving unit that outputs an optical scanner driving signal to the optical scanner to drive the optical scanner; and an optical scanner sensor unit that outputs an optical scanner sensor signal corresponding to a deflection angle of the optical scanner, The method for correcting the mirror driving timing is characterized by comprising the following steps: a step of acquiring a time from the output of the optical scanner driving signal to the output of the optical scanner sensor signal; a step of acquiring a light scanner sensor reproduced response delay time that reproduces the response delay of the light scanner sensor unit; The step of calculating a response time until the optical scanner reaches a deflection angle corresponding to the optical scanner drive signal by subtracting a time from the output of the optical scanner drive signal to the output of the optical scanner sensor signal from a reproduced response delay time of the optical scanner sensor.

8. A method for correcting the timing of driving a light source, which is a method for correcting the timing of driving a light source of a device comprising a light source, a light source driving unit that outputs a light source driving signal to the light source to cause the light source to emit light, and a light sensor unit that detects light from the light source and outputs a light sensor signal. The method for correcting the light source driving timing is characterized by comprising the following steps: a step of obtaining a time from the output of the light source driving signal to the output of the light sensor signal; A step of obtaining a photosensor reproduced response delay time that reproduces the response delay of the photosensor unit; and A step of calculating a response time until the light source emits light according to the light source driving signal by subtracting the light sensor reproduction response delay time from the delay time from the output of the light source driving signal to the output of the light sensor signal.

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