WO2013035142A1 - Optical axis offset correcting device, control method, and heads-up display - Google Patents

Optical axis offset correcting device, control method, and heads-up display Download PDF

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Publication number
WO2013035142A1
WO2013035142A1 PCT/JP2011/070147 JP2011070147W WO2013035142A1 WO 2013035142 A1 WO2013035142 A1 WO 2013035142A1 JP 2011070147 W JP2011070147 W JP 2011070147W WO 2013035142 A1 WO2013035142 A1 WO 2013035142A1
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WO
WIPO (PCT)
Prior art keywords
optical axis
scanning
light
light receiving
light source
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Application number
PCT/JP2011/070147
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French (fr)
Japanese (ja)
Inventor
英昭 鶴見
雄一 吉田
純也 村田
福田 雅文
和弥 笹森
Original Assignee
パイオニア株式会社
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Application filed by パイオニア株式会社 filed Critical パイオニア株式会社
Priority to PCT/JP2011/070147 priority Critical patent/WO2013035142A1/en
Publication of WO2013035142A1 publication Critical patent/WO2013035142A1/en

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    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • G02B27/0101Head-up displays characterised by optical features
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/10Scanning systems
    • G02B26/12Scanning systems using multifaceted mirrors
    • G02B26/127Adaptive control of the scanning light beam, e.g. using the feedback from one or more detectors

Definitions

  • the present invention relates to a technical field for correcting an optical axis shift of laser light.
  • a technique for detecting the deviation of the optical axis of each color light source used for drawing an image is known.
  • the first light source is turned on and off and the second light source is turned on and off, and the first light source in the light receiving region of the light receiver is controlled.
  • a technique for detecting a deviation between the optical axis of the first light source and the optical axis of the second light source is proposed based on the reception timing of the light and the reception timing of the second light in the light receiving region of the light receiver. Yes.
  • the main object of the present invention is to provide an optical axis deviation correction apparatus, a control method, and a head-up display capable of detecting and correcting an optical axis deviation without being affected by external factors such as vibration. To do.
  • an optical axis misalignment correction apparatus that corrects an optical axis misalignment between a first beam emitted from a first light source and a second beam emitted from a second light source.
  • Scanning means for scanning the scanning area over a predetermined scanning period with the one light source and the second light source turned on at the same time, and receiving the first beam and the second beam scanned in the scanning area
  • a light receiving element arranged at a certain position, and the light receiving element that receives the first beam or the second beam from the earliest time when the light receiving element receives light from the first beam or the second beam during the scanning period.
  • the first bi It characterized in that it has a correction means for correcting the optical axis deviation between the beam and the second beam, the.
  • the optical axis shift between the first beam emitted from the first light source and the second beam emitted from the second light source is corrected, and the first light source and the second light source are adjusted.
  • Scanning means that scans the scanning region over a predetermined scanning period in a state in which the light is turned on at the same time, and a light receiving element that is disposed at a position capable of receiving the first beam and the second beam scanned in the scanning region
  • a control method executed by the optical axis deviation correction apparatus comprising: the first beam or the first beam or the second beam from the earliest point in time during which the light receiving element receives light from the first beam or the second beam.
  • a detecting step for detecting a deviation direction of the optical axes of the first beam and the second beam, and detecting by the detecting step Misalignment Based on, and having a correction step of correcting the optical axis deviation between the first beam and the second beam.
  • a head having an optical axis deviation correction device for correcting an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source in the light source unit.
  • the optical axis misalignment correcting device scans a scanning region over a predetermined scanning period in a state where the first light source and the second light source are turned on simultaneously, and the scanning A light receiving element disposed at a position capable of receiving the first beam and the second beam scanned in a region, and a first light received by the light receiving element from the first beam or the second beam during the scanning period; Based on the width of the light receiving period from the time point to the last time point when the light receiving element receives the first beam or the second beam, the direction of deviation of the optical axes of the first beam and the second beam is detected. detection And stage, based on the deviation direction detected by said detecting means, and having a correction means for correcting the optical axis deviation between the first
  • FIG. 1 shows a configuration of an image drawing apparatus according to the present embodiment.
  • positioning of a micro lens array and a light receiving element is shown.
  • It is an image figure which shows the specific example of an optical axis offset.
  • It is a graph which shows the time change of the light reception level which a light receiving element detects.
  • It is a graph which shows the time change of the light reception level which the light receiving element detects in the light reception period when the optical axis deviation has not arisen.
  • It is a flowchart which shows the outline
  • an optical axis deviation correction device that corrects an optical axis deviation between a first beam emitted from a first light source and a second beam emitted from a second light source, Scanning means for scanning the scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously, and the first beam and the second beam scanned in the scanning region
  • the light receiving element disposed at a position capable of receiving light, and the first beam or the second beam from the earliest time when the light receiving element receives light from the first beam or the second beam during the scanning period.
  • the detecting means for detecting the deviation direction of the optical axis of the first beam and the second beam, and the deviation direction detected by the detecting means Before It has a correcting means for correcting the optical axis deviation of the first beam and the second beam, the.
  • the optical axis deviation correction device corrects an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source, and includes a scanning unit, a light receiving element, and a detecting unit. And a correction means.
  • the scanning unit scans the scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously.
  • the light receiving element is disposed at a position where the first beam and the second beam scanned in the scanning region can be received.
  • the detecting means is the width of the light receiving period from the earliest time when the light receiving element receives the first beam or the second beam to the last time when the light receiving element receives the first beam or the second beam during the scanning period. Based on the above, the deviation directions of the optical axes of the first beam and the second beam are detected.
  • the correction unit corrects the optical axis shift between the first beam and the second beam based on the shift direction detected by the detection unit.
  • the optical axis deviation correction apparatus has a width of the above-described light receiving period in accordance with the deviation direction of the optical axis when the optical axis deviation occurs, compared to the case where the optical axis deviation occurs. Since it becomes longer, detection and correction of the optical axis deviation are performed based on the width of the light receiving period. Further, the optical axis deviation correction device detects the optical axis deviation by simultaneously turning on the first beam and the second beam in order to eliminate the influence of the deviation of the received light caused by external factors such as vibration. Therefore, the optical axis deviation correction apparatus can detect and correct the optical axis deviation between the first beam and the second beam with high accuracy without being affected by vibration or the like due to the above-described configuration.
  • the correction means detects the optical axis deviation between the first beam and the second beam in the main scanning direction when the width of the light receiving period is a predetermined value or more. If the width of the light receiving period is less than the predetermined value, the optical axis deviation between the first beam and the second beam in the sub-scanning direction is corrected.
  • the optical axis deviation correction apparatus can reliably detect and correct the optical axis deviation in the main scanning direction.
  • the correcting unit corrects the optical axis deviation of the first beam or the second beam so that the width of the light receiving period is shortened.
  • the optical axis deviation correction device preferably corrects the optical axis deviation by correcting the optical axis deviation so that the width of the light receiving period is shortened when the optical axis deviation occurs. Can do.
  • the correction unit corrects the optical axis deviation by controlling the light emission timing of the first light source or the second light source in the scanning period.
  • the optical axis deviation correction apparatus can preferably correct the optical axis deviation so that the width of the light receiving period is shortened when the optical axis deviation occurs.
  • the scanning unit may include the first beam and the first beam at predetermined intervals between frames constituting an image drawn by the first beam and the second beam.
  • a frame for scanning the second beam with respect to the scanning region is inserted, and the scanning region is provided outside the region where the image is drawn.
  • the optical axis deviation correction apparatus can prevent the observer from visually recognizing the influence even when the optical axis deviation temporarily increases in the process of correcting the optical axis deviation.
  • the correction unit increases the adjustment amount of the light emission timing of the first light source or the second light source as the width of the light receiving period is longer. According to this aspect, the optical axis deviation correction apparatus can complete the correction of the optical axis deviation at an early stage.
  • the optical axis shift between the first beam emitted from the first light source and the second beam emitted from the second light source is corrected, and the first light source and the second light source are corrected.
  • the optical axis deviation correction apparatus can accurately detect and correct the optical axis deviation between the first beam and the second beam without being affected by vibration or the like.
  • an optical axis deviation correction apparatus that corrects an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source.
  • a head-up display in a light source unit wherein the optical axis deviation correction device scans a scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously.
  • the head-up display can detect and correct the optical axis deviation between the first beam and the second beam emitted from the light source unit with high accuracy without being affected by vibration or the like.
  • FIG. 1 shows a configuration of an image drawing apparatus 1 to which an optical axis deviation correction apparatus according to the present invention is applied.
  • the image drawing apparatus 1 includes an image signal input unit 2, a video ASIC 3, a frame memory 4, a ROM 5, a RAM 6, a laser driver ASIC 7, a MEMS control unit 8, and a laser light source unit 9. And comprising.
  • the image drawing apparatus 1 is used as a light source for a head-up display, for example, and emits light constituting a display image to an optical element such as a combiner.
  • the image signal input unit 2 receives an image signal input from the outside and outputs it to the video ASIC 3.
  • the video ASIC 3 is a block that controls the laser driver ASIC 7 and the MEMS control unit 8 based on the image signal input from the image signal input unit 2 and the scanning position information “Sc” input from the MEMS mirror 10, and the ASIC (Application) It is configured as Specific Integrated Circuit).
  • the video ASIC 3 includes a synchronization / image separation unit 31, a bit data conversion unit 32, a light emission pattern conversion unit 33, and a timing controller 34.
  • the synchronization / image separation unit 31 separates the image data displayed on the image display unit and the synchronization signal from the image signal input from the image signal input unit 2 and writes the image data to the frame memory 4.
  • the bit data conversion unit 32 reads the image data written in the frame memory 4 and converts it into bit data.
  • the light emission pattern conversion unit 33 converts the bit data converted by the bit data conversion unit 32 into a signal representing the light emission pattern of each laser.
  • the timing controller 34 controls the operation timing of the synchronization / image separation unit 31 and the bit data conversion unit 32.
  • the timing controller 34 also controls the operation timing of the MEMS control unit 8 described later.
  • the image data separated by the synchronization / image separation unit 31 is written.
  • the ROM 5 stores a control program and data for operating the video ASIC 3. Various data are sequentially read from and written into the RAM 6 as a work memory when the video ASIC 3 operates.
  • the laser driver ASIC 7 is a block that generates a signal for driving a laser diode provided in a laser light source unit 9 described later, and is configured as an ASIC.
  • the laser driver ASIC 7 includes a red laser driving circuit 71, a blue laser driving circuit 72, and a green laser driving circuit 73.
  • the red laser driving circuit 71 drives the red laser “LD1” based on the signal output from the light emission pattern conversion unit 33.
  • the blue laser driving circuit 72 drives the blue laser “LD2” based on the signal output from the light emission pattern conversion unit 33.
  • the green laser driving circuit 73 drives the green laser “LD3” based on the signal output from the light emission pattern conversion unit 33.
  • the MEMS control unit 8 controls the MEMS mirror 10 based on a signal output from the timing controller 34.
  • the MEMS control unit 8 includes a servo circuit 81 and a driver circuit 82.
  • the MEMS control unit 8 and the laser driver ASIC 7 function as irradiation control means.
  • the servo circuit 81 controls the operation of the MEMS mirror 10 based on a signal from the timing controller.
  • the driver circuit 82 amplifies the control signal of the MEMS mirror 10 output from the servo circuit 81 to a predetermined level and outputs the amplified signal.
  • the laser light source unit 9 emits laser light based on the drive signal output from the laser driver ASIC 7.
  • the laser light source unit 9 mainly includes a red laser LD1, a blue laser LD2, a green laser LD3, collimator lenses 91a to 91c, reflection mirrors 92a to 92c, a microlens array 94, and a lens. 95 and the light receiving element 100.
  • the red laser LD1 emits red laser light (also referred to as “red laser light LR”)
  • the blue laser LD2 emits blue laser light (also referred to as “blue laser light LB”)
  • Green laser light also referred to as “green laser light LG” is emitted.
  • the collimator lenses 91a to 91c convert the red, blue, and green laser beams LR, LB, and LG into parallel beams and emit the parallel beams to the reflection mirrors 92a to 92c.
  • the reflection mirror 92b reflects the blue laser light LB
  • the reflection mirror 92c transmits the blue laser light LB and reflects the green laser light LG.
  • the reflection mirror 92a transmits only the red laser beam LR and reflects the blue and green laser beams LB and LG.
  • the red laser light LR transmitted through the reflection mirror 92 a and the blue and green laser beams LB and LG reflected by the reflection mirror 92 a are incident on the MEMS mirror 10.
  • the arbitrary two laser beams of the lasers LD1, LD2, and LD3 are examples of the “first light source” and the “second light source” in the present invention, and the arbitrary two laser beams of the laser beams LR, LB, and LG. Are examples of the “first beam” and the “second beam” in the present invention.
  • the MEMS mirror 10 functions as “scanning means” in the present invention, and reflects the laser light incident from the reflection mirror 92a toward a microlens array 94 which is an example of EPE (Exit Pupil Expander).
  • the MEMS mirror 10 basically moves so as to scan the microlens array 94 as a screen under the control of the MEMS control unit 8 in order to display the image input to the image signal input unit 2.
  • the scanning position information at that time (for example, information such as the angle of the mirror) is output to the video ASIC 3.
  • the microlens array 94 a plurality of microlenses are arranged, and the laser beam reflected by the MEMS mirror 10 is incident thereon.
  • the lens 95 enlarges an image formed on the radiation surface of the microlens array 94.
  • the light receiving element 100 is provided in the vicinity of the microlens array 94. Specifically, the microlens array 94 is provided at a position including a drawing area “RR” (corresponding to an area for displaying an image (video) to be presented to the user; the same shall apply hereinafter). On the other hand, the light receiving element 100 is provided at a position corresponding to a predetermined area outside the drawing area RR. A specific arrangement of the light receiving element 100 will be described later with reference to FIG.
  • the light receiving element 100 is configured by a photoelectric conversion element such as a photodetector, and supplies a detection signal “Sd”, which is an electrical signal corresponding to the amount of incident laser light, to the video ASIC 3.
  • the video ASIC 3 detects the optical axis shift of the red laser light LR, the blue laser light LB, and the green laser light LG based on the detection signal Sd from the light receiving element 100. Further, the video ASIC 3 performs processing for correcting the optical axis deviation based on the detected optical axis deviation. Specifically, the video ASIC 3 corrects the optical axis deviation by changing the light emission timing of the red laser LD1, the blue laser LD2, and / or the green laser LD3. At this time, the video ASIC 3 changes the above-described adjustment amount of the light emission timing based on whether the optical axis shift direction is the main scanning direction or the sub-scanning direction. Thus, the video ASIC 3 functions as “detection means” and “correction means” in the present invention.
  • FIG. 2 is a diagram illustrating an arrangement example of the microlens array 94 and the light receiving element 100.
  • FIG. 2 shows a diagram in which the microlens array 94 and the light receiving element 100 are observed from the direction along the traveling direction of the laser light (the arrow “Z” direction in FIG. 1).
  • a scannable region “SR” represented by a broken line is a region corresponding to a range where scanning by the MEMS mirror 10 is possible, that is, a range where drawing is possible.
  • a microlens array 94 is disposed in the scannable region SR.
  • a region represented by a one-dot chain line in the microlens array 94 indicates a drawing region RR.
  • the light receiving element 100 is an area in the scannable area SR and is provided below the microlens array 94. That is, the light receiving element 100 is provided at a position corresponding to a region outside the drawing region RR so as not to disturb the display.
  • the MEMS mirror 10 draws an image (video) to be displayed in the drawing region RR by scanning the laser beam a plurality of times (that is, performing a raster scan) as indicated by an arrow in FIG.
  • the sub-scanning direction of the laser light is also referred to as “left-right direction”
  • the main scanning direction perpendicular to the sub-scanning direction is also referred to as “up-down direction”.
  • the position where the light receiving element 100 is arranged is not limited to that shown in FIG.
  • the light receiving element 100 can be arranged at various positions as long as it is located in the scannable area SR and corresponds to an area outside the drawing area RR.
  • the optical axis deviation correcting method As hereinafter, the optical axis deviation correcting method according to the present embodiment will be specifically described.
  • the image drawing apparatus 1 simultaneously turns on lasers of all colors for a predetermined range including the position of the light receiving element 100 in the scannable region SR (also simply referred to as “scan region Rtag”). In this state, scanning is performed, and the optical axis deviation is detected and corrected based on the time width when the light receiving element 100 receives the laser beam.
  • FIG. 3A shows an example of the red laser light LR, the blue laser light LB, and the green laser light LG emitted from the image drawing device 1.
  • FIG. 3B corresponds to each of the red laser light LR, the blue laser light LB, and the green laser light LG irradiated on the microlens array 94 arranged at the position “P” in FIG. An example of a spot to be performed is shown.
  • FIG. 3B corresponds to each of the red laser light LR, the blue laser light LB, and the green laser light LG irradiated on the microlens array 94 arranged at the position “P” in FIG.
  • the circles with the letters “R”, “B”, and “G” written therein indicate the spots of the red laser beam LR, the blue laser beam LB, and the green laser beam LG, respectively.
  • the optical axis of the blue laser light LB is shifted upward by 2 dots (pixels) with respect to the optical axis of the red laser light LR
  • the optical axis of the green laser light LG is red laser light.
  • the optical axis of LR it is shifted downward by 2 dots and is shifted rightward by 1 dot.
  • the image drawing apparatus 1 detects such an optical axis shift and the direction of the optical axis shift, and the lasers LD1 to LD3 are arranged so that the optical axes of the laser beams LR, LB, and LG coincide with each other. Controls the light emission timing.
  • the scanning region Rtag is repeatedly scanned 6 times according to an interval of 60 FPS (that is, about 16.7 ms) in a state where any one of the lasers LD1, LD2, and LD3 is turned on. It is the figure which represented on the time axis the light reception level which the light receiving element 100 detected in the case. 4A, in each scanning period for the scanning region Rtag, a period in which the light receiving element 100 detects light reception intermittently, that is, a period from the first light reception time to the last light reception time (“light reception period”). (Also referred to as “T”) indicates that the light reception level is high.
  • FIG. 4B is a graph showing details of the light receiving level in the light receiving period T with respect to the first scanning period of FIG. 4A.
  • the laser light is detected by the light receiving element 100 at every timing when scanning is performed on the scanning line at a position overlapping the light receiving element 100.
  • the light receiving element 100 detects the laser beam in scanning with each scanning line. Even when any one of the laser beams LR, LB, and LG is turned on, the width of the light receiving period T for each laser beam (also referred to as “monochromatic light receiving time width Tw1”) is the same.
  • FIG. 5A shows a temporal change in the light receiving level of the light receiving element 100 when scanning is performed with the red laser LD1, the blue laser LD2, and the green laser LD3 turned on simultaneously.
  • FIG. 5B is a graph obtained by extracting only the light receiving level for the red laser light LR in the case shown in FIG. 5A
  • FIG. 5C shows only the light receiving level for the blue laser light LB.
  • FIG. 5D is a graph obtained by extracting only the light reception level with respect to the green laser light LG.
  • the light receiving element 100 detects the respective laser beams at the same timing, so that the respective laser beams LR and LB are detected. , LG coincides with the light receiving period T.
  • the light receiving period T in which the light receiving element 100 detects the laser light when scanning is performed with the lasers LD1 to LD3 turned on simultaneously, only for one laser light. Coincides with the received light receiving period T. Accordingly, as shown in FIGS.
  • all-color light receiving time width Twa Is the same length as the monochromatic light reception time width Tw1.
  • FIG. 6A shows a temporal change in the light reception level when the MEMS mirror 10 is scanned by simultaneously turning on the red laser LD1, the blue laser LD2, and the green laser LD3.
  • FIG. 6B is a graph obtained by extracting only the light reception level for the red laser light LR in the case shown in FIG. 6A
  • FIG. 6C shows only the light reception level for the blue laser light LB.
  • FIG. 6D is an extracted graph, in which only the light reception level for the green laser light LG is extracted.
  • the light receiving period T of the light receiving element 100 for each laser beam is significantly different. Specifically, for example, when the blue laser beam LB is used as a reference, the red laser beam LR is shifted downward, so that the timing detected by the light receiving element 100 is earlier. Similarly, when the blue laser beam LB is used as a reference, since the green laser beam LG is shifted upward, the timing detected by the light receiving element 100 is delayed.
  • the light receiving period T in which the light receiving element 100 detects the laser light when scanning is performed with the lasers LD1 to LD3 turned on simultaneously targets only one laser light.
  • the all-color light reception time width Twa is longer than the single color light reception time width Tw1.
  • the optical axis deviation occurs only in the left-right direction (sub-scanning direction) because the light receiving element 100 detects light reception on the same scanning line. Compared to the case, the shift of the light receiving period T is small. Therefore, when the optical axis deviation occurs only in the sub-scanning direction, the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 is smaller than when the optical axis deviation occurs in the main scanning direction. .
  • the image drawing apparatus 1 calculates the all-color light reception time width Twa based on the detection signal of the light receiving element 100, and the monochromatic light reception time corresponding to the all-color light reception time width Twa when no optical axis deviation occurs. The difference from the width Tw1 is obtained. Then, when the difference is larger than a predetermined threshold (also referred to as “first threshold”), the image drawing apparatus 1 determines that an optical axis shift in the main scanning direction has occurred.
  • a predetermined threshold also referred to as “first threshold”
  • the above first threshold is an example of the “predetermined value” in the present invention, and is set to a value larger than the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 caused by the optical axis shift only in the sub-scanning direction. Is set.
  • the first threshold value is set to the light receiving interval (that is, the width of the arrow “Ax” in FIG. 4B) within the light receiving period T when only one laser is turned on to scan the scanning region Rtag. .
  • FIG. 7 is an example of a flowchart showing a procedure of optical axis deviation correction processing executed by the image drawing apparatus 1.
  • the flowchart shown in FIG. 7 is repeatedly executed according to a predetermined cycle or timing.
  • the image drawing apparatus 1 may perform the optical axis misalignment correction process when drawing a video in the drawing region RR.
  • the image drawing apparatus 1 measures the all-color light reception time width Twa (step S101). For example, the image drawing apparatus 1 designates a predetermined range including the entire light receiving element 100 arranged in the scannable region SR as the scan region Rtag, and performs scanning in a state where all color laser lights are turned on. At this time, the width of the light receiving period T from the time when the light receiving element 100 first detects the laser light to the time when the laser light is finally detected is determined as the all-color light receiving time width Twa.
  • the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa is larger than the single color light reception time width Tw1 by the first threshold (step S102).
  • the image drawing apparatus 1 stores in advance a single color light reception time width Tw1, in other words, the all color light reception time width Twa (see FIG. 5) when no optical axis deviation occurs in a memory or the like.
  • the first threshold value is set, for example, as a lower limit value of the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 when the optical axis shift occurs in the main scanning direction. This is determined experimentally or theoretically in consideration of the time width required to scan the dots on the scanning line, the position of the light receiving element 100, and the like.
  • step S102 When the all-color light reception time width Twa is larger than the single color light reception time width Tw1 by the first threshold value (step S102; Yes), the image drawing apparatus 1 determines that the optical axis shift in the main scanning direction has occurred, The optical axis deviation in the main scanning direction (vertical direction) is corrected (step S103). This specific process will be described later with reference to FIG.
  • step S102 when the deviation width between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the first threshold (step S102; No), the image drawing apparatus 1 has no optical axis deviation in the main scanning direction. And the process proceeds to step S104.
  • step S104 the image drawing apparatus 1 determines whether or not the all color light reception time width Twa is greater than the single color light reception time width Tw1 by a second threshold or more (step S104).
  • the second threshold is set to a lower limit value or the like of the difference between the all-color light reception time width Twa and the monochrome light reception time width Tw1 when the optical axis shift occurs in the sub-scanning direction.
  • the time width required to scan the minutes (for example, 23.2 us when scanning 720 pixels at 60 FPS) is set. Therefore, the second threshold value is set to a value smaller than the first threshold value described above.
  • step S104 When the all-color light reception time width Twa is larger than the single color light reception time width Tw1 by the second threshold or more (step S104; Yes), the image drawing apparatus 1 determines that an optical axis shift in the sub-scanning direction has occurred, Optical axis deviation correction in the sub-scanning direction (left-right direction) is performed (step S105). This specific processing will be described later with reference to FIG.
  • step S104 when the deviation width between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the second threshold (step S104; No), the image drawing apparatus 1 has no optical axis deviation in the sub-scanning direction. And the process of the flowchart is terminated.
  • the image drawing apparatus 1 when the optical axis deviation occurs in the main scanning direction, the all-color light reception time width Twa and the single color are compared with the case where the optical axis deviation occurs in the sub-scanning direction. Focusing on the fact that the difference from the light reception time width Tw1 increases, the direction of the optical axis deviation is detected based on these differences.
  • the image drawing apparatus 1 first corrects the optical axis deviation in the main scanning direction, and then appropriately corrects the optical axis deviation in the sub-scanning direction. Thereby, the image drawing apparatus 1 can preferably correct the optical axis deviation in the main scanning direction and the sub-scanning direction.
  • the image drawing apparatus 1 detects the optical axis deviation by simultaneously turning on the lasers LD1 to LD3 to be inspected, thereby eliminating the influence of the deviation of the received light caused by external factors such as vibration. To do. Therefore, the image drawing apparatus 1 can detect and correct the optical axis deviation with high accuracy without being affected by vibration or the like.
  • FIG. 8 is a flowchart showing an example of the procedure of main scanning direction optical axis deviation correction processing.
  • the image drawing apparatus 1 executes the processing of the flowchart shown in FIG. 8 when the processing proceeds to step S103 in FIG. Schematically, the image drawing apparatus 1 monitors the all-color light reception time width Twa so that the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 is less than the first threshold. Feedback control is performed to move the optical axis in the main scanning direction.
  • the image drawing apparatus 1 determines a laser that moves the optical axis (step S201). For example, the image drawing device 1 fixes (references) the optical axis position of one laser (for example, the red laser beam LR) of the red laser beam LR, the blue laser beam LB, and the green laser beam LG to another laser.
  • the other lasers blue laser light LB and green laser light LG in the above example
  • the other lasers are alternately designated as laser light that moves the optical axis every time step S201 is executed. To do.
  • the image drawing apparatus 1 moves the optical axis of the laser designated in step S201 in the upward direction, and then performs scanning in a state where the laser beams of all colors are turned on for the scanning region Rtag.
  • the color light reception time width Twa is measured (step S202).
  • the above-described movement width is set to a width corresponding to one dot, for example.
  • the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has increased (step S203). Specifically, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa measured in step S202 is larger than the all-color light reception time width Twa measured before that.
  • step S203 the image drawing apparatus 1 determines that the optical axis of the moved laser is not shifted upward, and lowers the optical axis of the laser. Then, the light reception time width Twa of all colors is measured again (step S204).
  • this movement width is set to a width twice the movement width in step S202 (for example, a width corresponding to 2 dots), and immediately after step S205. In this case, for example, it is set to be the same as the movement width in step S202 (one dot width).
  • the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S205).
  • the image drawing apparatus 1 determines that there is a possibility that the target laser is still shifted downward, and step S202 is performed again. Perform the process.
  • the image drawing apparatus 1 moves the optical axis of the laser light determined in step S201 upward to move the all-color light reception time width. Twa is measured again (step S206), and the process proceeds to step S211.
  • the movement width in this case is set to be the same as the movement width in step S204 (for example, a width for one dot).
  • step S203 determines whether or not the all-color light reception time width Twa has decreased (step S203). S207).
  • the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is further shifted upward. Then, the optical axis of the laser beam is moved upward, and then the all-color light reception time width Twa is measured again (step S208).
  • This movement width is set to be the same as the movement width in step S202 (one dot width), for example.
  • the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S209).
  • the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is still shifted upward. Then, the process of step S208 is performed again.
  • the image drawing apparatus 1 moves the optical axis of the target laser downward to remeasure the all-color light reception time width Twa. (Step S210), and the process proceeds to Step S211.
  • the movement width in this case is set to be the same as the movement width in step S208 (for example, a width for one dot).
  • step S207 if it is determined in step S207 that the all-color light reception time width Twa has not decreased (step S207; No), that is, if it is determined that the all-color light reception time width Twa has not increased or decreased, the image drawing apparatus 1 advances the process to step S211. In this case, the image drawing apparatus 1 may return the optical axis of the target laser downward by the amount that the optical axis is moved upward in step S202.
  • step S211 the image drawing apparatus 1 determines whether the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the first threshold (step S211). Thereby, the image drawing apparatus 1 determines whether or not the deviation of the optical axis in the main scanning direction has been eliminated. If the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the first threshold (step S211; Yes), the image drawing apparatus 1 determines that the optical axis shift in the main scanning direction is eliminated, The process of the flowchart ends.
  • step S211 when the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is equal to or larger than the first threshold value (step S211; No), the image drawing apparatus 1 does not eliminate the deviation of the optical axis in the main scanning direction. And the process returns to step S201. In this case, in step S201, the image drawing apparatus 1 selects a laser beam that is different from the laser beam whose optical axis was moved last time as a target for moving the optical axis.
  • FIG. 9 is a flowchart illustrating an example of a procedure of sub-scanning direction optical axis deviation correction processing.
  • the image drawing apparatus 1 executes the processing of the flowchart shown in FIG. 9 when the processing proceeds to step S105 in FIG. Schematically, the image drawing apparatus 1 monitors each color light reception time width Twa so that the deviation width between the all color light reception time width Twa and the single color light reception time width Tw1 is less than the second threshold. Feedback control for moving the optical axis in the sub-scanning direction is performed.
  • the image drawing apparatus 1 determines a laser that moves the optical axis (step S301). For example, the image drawing device 1 fixes (references) the optical axis position of one laser (for example, the red laser beam LR) of the red laser beam LR, the blue laser beam LB, and the green laser beam LG to another laser.
  • the other lasers blue laser light LB and green laser light LG in the above example
  • the other lasers are alternately designated as laser light that moves the optical axis every time step S301 is executed. To do.
  • the image drawing apparatus 1 moves the optical axis of the laser designated in step S301 in the right direction, and then performs scanning in a state where all color laser lights are turned on for the scanning region Rtag.
  • the color light reception time width Twa is measured (step S302).
  • the above-described movement width is set to a width corresponding to one dot, for example.
  • the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has increased (step S303). Specifically, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa measured in step S302 is larger than the all-color light reception time width Twa measured before that.
  • step S303 the image drawing apparatus 1 determines that the optical axis of the moved laser is not shifted to the right, and moves the optical axis of the laser to the left. Then, the all-color light reception time width Twa is measured again (step S304). In the case immediately after the optical axis is moved in the right direction in step S302, this movement width is set to a width twice the movement width in step S302 (for example, a width corresponding to 2 dots), and immediately after step S305. In this case, for example, it is set to the same movement width (one dot width) in step S302.
  • the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S305). If the all-color light reception time width Twa decreases (step S305; Yes), the image drawing apparatus 1 determines that there is a possibility that the target laser is still shifted leftward, and step S302 is performed again. Perform the process. On the other hand, when the all-color light reception time width Twa does not decrease (step S305; No), the image drawing apparatus 1 moves the optical axis of the laser light determined in step S301 to the right to shift the all-color light reception time width. Twa is measured again (step S306), and the process proceeds to step S311. In this case, the movement width is set to be the same as the movement width in step S304 (for example, a width corresponding to one dot).
  • step S303 determines whether or not the all-color light reception time width Twa has decreased (step S303). S307).
  • the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is further shifted to the right. Then, the optical axis of the laser beam is moved to the right, and then the all-color light reception time width Twa is measured again (step S308).
  • This movement width is set to be the same as the movement width in step S302 (one dot width), for example.
  • the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S309).
  • the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is still shifted to the right. Then, the process of step S308 is performed again.
  • the image drawing apparatus 1 moves the optical axis of the target laser in the left direction to remeasure the all-color light reception time width Twa. (Step S310), and the process proceeds to step S311.
  • the movement width is set to be the same as the movement width in step S308 (for example, a width corresponding to one dot).
  • step S307 determines whether the all-color light reception time width Twa has not decreased (step S307; No), that is, if it is determined that the all-color light reception time width Twa has not increased or decreased.
  • the image drawing apparatus. 1 advances the process to step S311. In this case, the image drawing apparatus 1 may return the optical axis of the target laser to the left as much as the optical axis is moved to the right in step S302.
  • step S311 the image drawing apparatus 1 determines whether or not the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the second threshold (step S311). Thereby, the image drawing apparatus 1 determines whether or not the deviation of the optical axis in the sub-scanning direction has been eliminated.
  • step S311 the image drawing apparatus 1 determines that the optical axis shift in the sub-scanning direction is eliminated, The process of the flowchart ends.
  • step S311 when the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is equal to or greater than the second threshold value (step S311; No), the image drawing apparatus 1 has not eliminated the optical axis shift in the sub-scanning direction. And the process returns to step S301. In this case, in step S301, the image drawing apparatus 1 selects a laser beam different from the laser beam whose optical axis has been moved last time as a target for moving the optical axis.
  • the image drawing apparatus 1 detects and corrects the optical axis deviation with the red laser LD1, the blue laser LD2, and the green laser LD3 turned on simultaneously.
  • the method to which the present invention is applicable is not limited to this.
  • the image drawing apparatus 1 simultaneously turns on two of the red laser LD1, the blue laser LD2, and the green laser LD3, and detects and corrects the optical axis deviation of these two laser beams. May be.
  • the image drawing apparatus 1 first turns on the red laser LD1 and the blue laser LD2 at the same time, and corrects the optical axis shift of these two laser beams LR and LB. Thereafter, the image drawing apparatus 1 turns on either the red laser LD1 or the blue laser LD2 and the green laser LD3 at the same time, thereby shifting the optical axes of the red laser light LR, the blue laser light LB, and the green laser light LG. to correct.
  • the image drawing apparatus 1 can preferably correct the optical axis shift of the red laser light LR, the blue laser light LB, and the green laser light LG.
  • the image drawing apparatus 1 may correct the optical axis deviation for four or more lasers. Even in this case, the image drawing device 1 measures the all-color light reception time width Twa by simultaneously lighting them, and based on the all-color light reception time width Twa, the optical axis deviation correction in the main scanning direction or / and Optical axis deviation correction in the sub-scanning direction is performed.
  • Modification 2 In the image drawing apparatus 1, in the above-described optical axis misalignment correction processing in the main scanning direction or optical axis misalignment correction processing in the sub-scanning direction, the movement width for moving the optical axis is set to the all-color light reception time width Twa and the single color light reception time width Tw1. You may change according to the difference.
  • the image drawing apparatus 1 uses the difference between the all-color light reception time width Twa and the single color light reception time width Tw1. Is larger, the above-mentioned movement width, that is, the adjustment amount of the light emission timing is increased. Specifically, the image drawing apparatus 1 creates a map of the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 and the movement width to be set based on an experiment in advance and stores it in the memory. The above-described movement width is set with reference to the map. By doing so, the image drawing apparatus 1 can complete the correction of the optical axis deviation more quickly.
  • the image drawing apparatus 1 performs scanning using one frame per second as the above-described inspection frame and a region outside the drawing region RR and including the light receiving element 100 as the scanning region Rtag. Then, the image drawing apparatus 1 moves the optical axis of the specific laser beam so as to reflect only the inspection frame in the optical axis deviation correction process described above, so that the optical axis deviation is reduced. Specify the direction and width of movement. By doing in this way, the image drawing apparatus 1 does not affect the image visually recognized by the observer even when the optical axis deviation temporarily increases as a result of moving the optical axis. Deviation correction can be performed.
  • Modification 4 The above-described image drawing apparatus 1 is preferably applied to a head-up display. A specific example of this will be described with reference to FIG.
  • FIG. 10 shows a configuration example of a head-up display according to the present invention.
  • the head-up display shown in FIG. 10 makes the driver visually recognize the virtual image “Iv” via the combiner 26.
  • the light source unit 1A functions as the image drawing device 1 of the above-described embodiment.
  • the light source section 1A is attached to the ceiling section 22 in the passenger compartment via the support members 11a and 11b, and includes map information including the current location, route guidance information, traveling speed, and other information for assisting driving (hereinafter referred to as “driving assistance”).
  • driving assistance information for assisting driving
  • Light constituting a display image indicating “information” is emitted toward the combiner 26.
  • the light source unit 1A generates an original image (real image) of the display image in the light source unit 1, and emits light constituting the image to the combiner 26, thereby allowing the driver to visually recognize the virtual image Iv. .
  • the combiner 26 projects the display image emitted from the light source unit 1 and reflects the display image to the driver's viewpoint (eye point) “Pe” to display the display image as a virtual image Iv. And the combiner 26 has the support shaft part 27 installed in the ceiling part 22, and rotates the support shaft part 27 as a spindle.
  • the support shaft portion 27 is installed, for example, in the vicinity of the ceiling portion 22 near the upper end of the front window 20, in other words, in the vicinity of a position where a sun visor (not shown) for the driver is installed.
  • the configuration of the head-up display to which the present invention is applicable is not limited to this.
  • the head-up display does not include the combiner 26, and the light source unit 1A may reflect the display image on the front window 20 to the driver's eye point Pe by projecting the light onto the front window 20.
  • the position of the light source unit 1 ⁇ / b> A is not limited to being installed on the ceiling unit 22, and may be installed inside the dashboard 24.
  • the dashboard 24 is provided with an opening for allowing light to pass through the combiner 26 or the front window 20.
  • the present invention can be used for various video devices using RGB lasers, such as laser projectors, head-up displays, and head-mounted displays.
  • Image drawing device 3 Video ASIC 7 Laser driver ASIC 8 MEMS control unit 9 Laser light source unit 100 Light receiving element

Abstract

This optical axis offset correcting device is provided with a scanning means (10), a light receiving element (100), a detection means, and a correction means for correcting an optical axis offset of a first beam radiated by a first light source and a second beam radiated by a second light source. The scanning means (10) makes the first beam and second beam scan in a scanning region for a prescribed scanning period in a state where the first light source and second light source are turned on simultaneously. The detection means detects the offset direction for the optical axes of the first beam and second beam on the basis of the range of a light receiving period from the earliest time the first beam or the second beam is received by the light receiving element (100) to the final time the first beam or the second beam is received by the light receiving element (100). The correction means corrects the optical axis offset for the first beam and the second beam on the basis of the offset direction detected by the detection means.

Description

光軸ずれ補正装置、制御方法、及びヘッドアップディスプレイOptical axis deviation correction apparatus, control method, and head-up display
 本発明は、レーザ光の光軸ずれを補正する技術分野に関する。 The present invention relates to a technical field for correcting an optical axis shift of laser light.
 映像の描画に用いられる各色の光源の光軸のずれを検出する技術が知られている。例えば、特許文献1には、複数の光源を有する画像描画装置において、第1の光源の発光および消灯と第2の光源の発光および消灯とを制御すると共に、受光器の受光領域における第1の光の受信タイミングと、受光器の受光領域における第2の光の受信タイミングとに基づいて、第1の光源の光軸と第2の光源の光軸とのずれを検出する技術が提案されている。 A technique for detecting the deviation of the optical axis of each color light source used for drawing an image is known. For example, in Patent Document 1, in an image drawing apparatus having a plurality of light sources, the first light source is turned on and off and the second light source is turned on and off, and the first light source in the light receiving region of the light receiver is controlled. A technique for detecting a deviation between the optical axis of the first light source and the optical axis of the second light source is proposed based on the reception timing of the light and the reception timing of the second light in the light receiving region of the light receiver. Yes.
特開2010-20087号公報JP 2010-20087
 特許文献1に記載の技術などでは、各光源をそれぞれ個別に点灯させて光軸ずれの検出及び補正を行う場合、振動に起因して光軸ずれの検出及び補正の精度が低下する場合があった。 In the technique described in Patent Document 1, when detecting and correcting the optical axis deviation by individually lighting each light source, the accuracy of the optical axis deviation detection and correction may be reduced due to vibration. It was.
 本発明が解決しようとする課題は上記のようなものが例として挙げられる。本発明は、振動等の外部要因による影響を受けずに光軸ずれの検出及び補正を行うことが可能な光軸ずれ補正装置、制御方法、及びヘッドアップディスプレイを提供することを主な目的とする。 Examples of the problem to be solved by the present invention include the above. The main object of the present invention is to provide an optical axis deviation correction apparatus, a control method, and a head-up display capable of detecting and correcting an optical axis deviation without being affected by external factors such as vibration. To do.
 請求項1に記載の発明では、第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正する光軸ずれ補正装置であって、前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子と、前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出手段と、前記検出手段により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正手段と、を有することを特徴とする。 According to the first aspect of the present invention, there is provided an optical axis misalignment correction apparatus that corrects an optical axis misalignment between a first beam emitted from a first light source and a second beam emitted from a second light source. Scanning means for scanning the scanning area over a predetermined scanning period with the one light source and the second light source turned on at the same time, and receiving the first beam and the second beam scanned in the scanning area A light receiving element arranged at a certain position, and the light receiving element that receives the first beam or the second beam from the earliest time when the light receiving element receives light from the first beam or the second beam during the scanning period. Based on the width of the light receiving period until the last time when the light is received, detecting means for detecting the deviation direction of the optical axis of the first beam and the second beam, and based on the deviation direction detected by the detecting means, The first bi It characterized in that it has a correction means for correcting the optical axis deviation between the beam and the second beam, the.
 請求項7に記載の発明では、第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正し、前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子とを備える光軸ずれ補正装置が実行する制御方法であって、前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出工程と、前記検出工程により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正工程と、を有することを特徴とする。 In the invention according to claim 7, the optical axis shift between the first beam emitted from the first light source and the second beam emitted from the second light source is corrected, and the first light source and the second light source are adjusted. Scanning means that scans the scanning region over a predetermined scanning period in a state in which the light is turned on at the same time, and a light receiving element that is disposed at a position capable of receiving the first beam and the second beam scanned in the scanning region And a control method executed by the optical axis deviation correction apparatus comprising: the first beam or the first beam or the second beam from the earliest point in time during which the light receiving element receives light from the first beam or the second beam. Based on the width of the light receiving period up to the last time when the light receiving element received the second beam, a detecting step for detecting a deviation direction of the optical axes of the first beam and the second beam, and detecting by the detecting step Misalignment Based on, and having a correction step of correcting the optical axis deviation between the first beam and the second beam.
 請求項8に記載の発明では、第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正する光軸ずれ補正装置を光源部に有するヘッドアップディスプレイであって、前記光軸ずれ補正装置は、前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子と、前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出手段と、前記検出手段により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正手段と、を有することを特徴とする。 According to an eighth aspect of the present invention, a head having an optical axis deviation correction device for correcting an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source in the light source unit. In the up-display, the optical axis misalignment correcting device scans a scanning region over a predetermined scanning period in a state where the first light source and the second light source are turned on simultaneously, and the scanning A light receiving element disposed at a position capable of receiving the first beam and the second beam scanned in a region, and a first light received by the light receiving element from the first beam or the second beam during the scanning period; Based on the width of the light receiving period from the time point to the last time point when the light receiving element receives the first beam or the second beam, the direction of deviation of the optical axes of the first beam and the second beam is detected. detection And stage, based on the deviation direction detected by said detecting means, and having a correction means for correcting the optical axis deviation between the first beam and the second beam.
本実施例に係る画像描画装置の構成を示す。1 shows a configuration of an image drawing apparatus according to the present embodiment. マイクロレンズアレイ及び受光素子の配置例を示す。The example of arrangement | positioning of a micro lens array and a light receiving element is shown. 光軸ずれの具体例を示すイメージ図である。It is an image figure which shows the specific example of an optical axis offset. 受光素子が検出する受光レベルの時間変化を示すグラフである。It is a graph which shows the time change of the light reception level which a light receiving element detects. 光軸ずれが生じていない場合の受光素子が受光期間において検出する受光レベルの時間変化を示すグラフである。It is a graph which shows the time change of the light reception level which the light receiving element detects in the light reception period when the optical axis deviation has not arisen. 光軸ずれが生じている場合の受光素子が受光期間において検出する受光レベルの時間変化を示すグラフである。It is a graph which shows the time change of the light reception level which a light receiving element detects in the light reception period when the optical axis deviation has arisen. 光軸ずれ補正処理の概要を示すフローチャートである。It is a flowchart which shows the outline | summary of an optical axis offset correction process. 主走査方向光軸ずれ補正処理の手順を示すフローチャートである。It is a flowchart which shows the procedure of a main scanning direction optical axis deviation correction process. 副走査方向光軸ずれ補正処理の手順を示すフローチャートである。It is a flowchart which shows the procedure of a sub-scanning direction optical axis deviation correction process. 本発明に係るヘッドアップディスプレイの構成例を示す。The structural example of the head-up display which concerns on this invention is shown.
 本発明の1つの好適な実施形態では、第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正する光軸ずれ補正装置であって、前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子と、前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出手段と、前記検出手段により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正手段と、を有する。 In one preferred embodiment of the present invention, there is provided an optical axis deviation correction device that corrects an optical axis deviation between a first beam emitted from a first light source and a second beam emitted from a second light source, Scanning means for scanning the scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously, and the first beam and the second beam scanned in the scanning region The light receiving element disposed at a position capable of receiving light, and the first beam or the second beam from the earliest time when the light receiving element receives light from the first beam or the second beam during the scanning period. Based on the width of the light receiving period up to the last time when the light receiving element has received light, the detecting means for detecting the deviation direction of the optical axis of the first beam and the second beam, and the deviation direction detected by the detecting means Before It has a correcting means for correcting the optical axis deviation of the first beam and the second beam, the.
 上記の光軸ずれ補正装置は、第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正し、走査手段と、受光素子と、検出手段と、補正手段とを備える。走査手段は、第一光源及び第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる。受光素子は、走査領域に走査した第一ビーム及び第二ビームを受光可能な位置に配置される。検出手段は、走査期間中における、第一ビーム又は第二ビームを受光素子が受光した最先の時点から、第一ビーム又は第二ビームを受光素子が受光した最後の時点までの受光期間の幅に基づいて、第一ビーム及び第二ビームの光軸のずれ方向を検出する。補正手段は、検出手段により検出したずれ方向に基づいて、第一ビームと第二ビームとの光軸ずれを補正する。 The optical axis deviation correction device corrects an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source, and includes a scanning unit, a light receiving element, and a detecting unit. And a correction means. The scanning unit scans the scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously. The light receiving element is disposed at a position where the first beam and the second beam scanned in the scanning region can be received. The detecting means is the width of the light receiving period from the earliest time when the light receiving element receives the first beam or the second beam to the last time when the light receiving element receives the first beam or the second beam during the scanning period. Based on the above, the deviation directions of the optical axes of the first beam and the second beam are detected. The correction unit corrects the optical axis shift between the first beam and the second beam based on the shift direction detected by the detection unit.
 このように、光軸ずれ補正装置は、光軸ずれが生じている場合には、光軸ずれが生じている場合と比較して、光軸のずれ方向に応じて上述の受光期間の幅が長くなることから、受光期間の幅に基づき光軸ずれの検出及び補正を行う。また、光軸ずれ補正装置は、振動等などの外部要因に起因した受光のずれの影響を排除するため、第一ビーム及び第二ビームを同時に点灯させて光軸ずれの検出を行う。従って、光軸ずれ補正装置は、上述の構成により、振動等の影響を受けることなく、第一ビームと第二ビームとの光軸ずれの検出及び補正を高精度に行うことができる。 As described above, the optical axis deviation correction apparatus has a width of the above-described light receiving period in accordance with the deviation direction of the optical axis when the optical axis deviation occurs, compared to the case where the optical axis deviation occurs. Since it becomes longer, detection and correction of the optical axis deviation are performed based on the width of the light receiving period. Further, the optical axis deviation correction device detects the optical axis deviation by simultaneously turning on the first beam and the second beam in order to eliminate the influence of the deviation of the received light caused by external factors such as vibration. Therefore, the optical axis deviation correction apparatus can detect and correct the optical axis deviation between the first beam and the second beam with high accuracy without being affected by vibration or the like due to the above-described configuration.
 上記の光軸ずれ補正装置の一態様では、前記補正手段は、前記受光期間の幅が所定値以上の場合には、前記第一ビームと前記第二ビームとの主走査方向の光軸ずれを補正し、前記受光期間の幅が前記所定値未満の場合には、前記第一ビームと前記第二ビームとの副走査方向の光軸ずれを補正する。一般に、主走査方向に光軸ずれが生じている場合には、副走査方向のみに光軸ずれが生じている場合と比較して、上述の受光期間の幅が長くなる。従って、この態様により、光軸ずれ補正装置は、主走査方向の光軸ずれを確実に検出し、その補正を行うことができる。 In one aspect of the above optical axis deviation correction apparatus, the correction means detects the optical axis deviation between the first beam and the second beam in the main scanning direction when the width of the light receiving period is a predetermined value or more. If the width of the light receiving period is less than the predetermined value, the optical axis deviation between the first beam and the second beam in the sub-scanning direction is corrected. In general, when the optical axis deviation occurs in the main scanning direction, the width of the above-described light receiving period becomes longer than when the optical axis deviation occurs only in the sub-scanning direction. Therefore, according to this aspect, the optical axis deviation correction apparatus can reliably detect and correct the optical axis deviation in the main scanning direction.
 上記の光軸ずれ補正装置の他の一態様では、前記補正手段は、前記受光期間の幅が短くなるように、前記第一ビーム又は前記第二ビームの光軸ずれを補正する。上述のように、光軸ずれが生じている場合には、光軸ずれが生じている場合と比較して、上述の受光期間の幅が長くなる。従って、光軸ずれ補正装置は、光軸ずれが生じている場合には、この受光期間の幅が短くなるように光軸ずれの補正を行うことで、好適に、光軸ずれを補正することができる。 In another aspect of the optical axis deviation correcting apparatus, the correcting unit corrects the optical axis deviation of the first beam or the second beam so that the width of the light receiving period is shortened. As described above, when the optical axis deviation occurs, the width of the light receiving period described above becomes longer than when the optical axis deviation occurs. Therefore, the optical axis deviation correction device preferably corrects the optical axis deviation by correcting the optical axis deviation so that the width of the light receiving period is shortened when the optical axis deviation occurs. Can do.
 上記の光軸ずれ補正装置の他の一態様では、前記補正手段は、前記走査期間における、前記第一光源又は前記第二光源の発光のタイミングを制御することで、前記光軸ずれを補正する。この態様により、好適に、光軸ずれ補正装置は、光軸ずれが生じている場合には、この受光期間の幅が短くなるように光軸ずれの補正を行うことが可能となる。 In another aspect of the optical axis deviation correction apparatus, the correction unit corrects the optical axis deviation by controlling the light emission timing of the first light source or the second light source in the scanning period. . According to this aspect, the optical axis deviation correction apparatus can preferably correct the optical axis deviation so that the width of the light receiving period is shortened when the optical axis deviation occurs.
 上記の光軸ずれ補正装置の他の一態様では、前記走査手段は、前記第一ビーム及び前記第二ビームにより描かれる映像を構成するフレームの間に、所定間隔ごとに前記第一ビーム及び前記第二ビームを前記走査領域に対して走査させるフレームを挿入し、前記走査領域は、前記映像が描かれる領域の外に設けられる。この態様により、光軸ずれ補正装置は、光軸ずれの補正の過程で一時的に光軸ずれが増加した場合であっても、その影響を観察者に視認されるのを防ぐことができる。 In another aspect of the optical axis misalignment correction apparatus, the scanning unit may include the first beam and the first beam at predetermined intervals between frames constituting an image drawn by the first beam and the second beam. A frame for scanning the second beam with respect to the scanning region is inserted, and the scanning region is provided outside the region where the image is drawn. According to this aspect, the optical axis deviation correction apparatus can prevent the observer from visually recognizing the influence even when the optical axis deviation temporarily increases in the process of correcting the optical axis deviation.
 上記の光軸ずれ補正装置の他の態様では、前記補正手段は、前記受光期間の幅が長いほど、前記第一光源又は前記第二光源の発光のタイミングの調整量を大きくする。この態様により、光軸ずれ補正装置は、光軸ずれの補正を早期に完了させることが可能となる。 In another aspect of the optical axis misalignment correction apparatus, the correction unit increases the adjustment amount of the light emission timing of the first light source or the second light source as the width of the light receiving period is longer. According to this aspect, the optical axis deviation correction apparatus can complete the correction of the optical axis deviation at an early stage.
 本発明の他の好適な実施形態では、第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正し、前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子とを備える光軸ずれ補正装置が実行する制御方法であって、前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出工程と、前記検出工程により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正工程と、を有する。光軸ずれ補正装置は、この方法を使用することで、振動等の影響を受けることなく、第一ビームと第二ビームとの光軸ずれの検出及び補正を精度よく行うことができる。 In another preferred embodiment of the present invention, the optical axis shift between the first beam emitted from the first light source and the second beam emitted from the second light source is corrected, and the first light source and the second light source are corrected. Scanning means for scanning the scanning area over a predetermined scanning period with the light sources turned on at the same time, and the first beam and the second beam scanned in the scanning area are arranged at a position capable of receiving light A control method executed by an optical axis misalignment correction apparatus including a light receiving element, wherein the first beam is received from the earliest time point when the light receiving element receives light from the first beam or the second beam during the scanning period. Alternatively, a detection step of detecting a shift direction of the optical axes of the first beam and the second beam based on a width of a light receiving period until the last time when the light receiving element receives the second beam, and the detection step Detected by Re based on the direction, having a correction step of correcting the optical axis deviation between the first beam and the second beam. By using this method, the optical axis deviation correction apparatus can accurately detect and correct the optical axis deviation between the first beam and the second beam without being affected by vibration or the like.
 上記の光軸ずれ補正装置のさらに別の態様では、第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正する光軸ずれ補正装置を光源部に有するヘッドアップディスプレイであって、前記光軸ずれ補正装置は、前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子と、前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出手段と、前記検出手段により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正手段と、を有する。ヘッドアップディスプレイは、この態様により、振動等の影響を受けることなく、光源部が出射する第一ビームと第二ビームとの光軸ずれの検出及び補正を高精度に行うことができる。 In still another aspect of the above optical axis deviation correction apparatus, an optical axis deviation correction apparatus that corrects an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source is provided. A head-up display in a light source unit, wherein the optical axis deviation correction device scans a scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously. Means, a light receiving element disposed at a position capable of receiving the first beam and the second beam scanned in the scanning region, and the light receiving element from the first beam or the second beam during the scanning period. Based on the width of the light receiving period from the earliest received time to the last time when the light receiving element received the first beam or the second beam, the optical axes of the first beam and the second beam Slip Detection means for detecting the direction, based on the deviation direction detected by said detecting means, having a correction means for correcting the optical axis deviation between the first beam and the second beam. According to this aspect, the head-up display can detect and correct the optical axis deviation between the first beam and the second beam emitted from the light source unit with high accuracy without being affected by vibration or the like.
 以下、図面を参照して本発明の好適な実施例について説明する。 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
 [画像描画装置の構成]
 図1は、本発明に係る光軸ずれ補正装置が適用された画像描画装置1の構成を示す。図1に示すように、画像描画装置1は、画像信号入力部2と、ビデオASIC3と、フレームメモリ4と、ROM5と、RAM6と、レーザドライバASIC7と、MEMS制御部8と、レーザ光源部9と、を備える。画像描画装置1は、例えばヘッドアップディスプレイの光源として用いられ、コンバイナ等の光学素子に表示像を構成する光を出射する。
[Configuration of Image Drawing Device]
FIG. 1 shows a configuration of an image drawing apparatus 1 to which an optical axis deviation correction apparatus according to the present invention is applied. As shown in FIG. 1, the image drawing apparatus 1 includes an image signal input unit 2, a video ASIC 3, a frame memory 4, a ROM 5, a RAM 6, a laser driver ASIC 7, a MEMS control unit 8, and a laser light source unit 9. And comprising. The image drawing apparatus 1 is used as a light source for a head-up display, for example, and emits light constituting a display image to an optical element such as a combiner.
 画像信号入力部2は、外部から入力される画像信号を受信してビデオASIC3に出力する。 The image signal input unit 2 receives an image signal input from the outside and outputs it to the video ASIC 3.
 ビデオASIC3は、画像信号入力部2から入力される画像信号及びMEMSミラー10から入力される走査位置情報「Sc」に基づいてレーザドライバASIC7やMEMS制御部8を制御するブロックであり、ASIC(Application Specific Integrated Circuit)として構成されている。ビデオASIC3は、同期/画像分離部31と、ビットデータ変換部32と、発光パターン変換部33と、タイミングコントローラ34と、を備える。 The video ASIC 3 is a block that controls the laser driver ASIC 7 and the MEMS control unit 8 based on the image signal input from the image signal input unit 2 and the scanning position information “Sc” input from the MEMS mirror 10, and the ASIC (Application) It is configured as Specific Integrated Circuit). The video ASIC 3 includes a synchronization / image separation unit 31, a bit data conversion unit 32, a light emission pattern conversion unit 33, and a timing controller 34.
 同期/画像分離部31は、画像信号入力部2から入力された画像信号から、画像表示部に表示される画像データと同期信号とを分離し、画像データをフレームメモリ4へ書き込む。 The synchronization / image separation unit 31 separates the image data displayed on the image display unit and the synchronization signal from the image signal input from the image signal input unit 2 and writes the image data to the frame memory 4.
 ビットデータ変換部32は、フレームメモリ4に書き込まれた画像データを読み出してビットデータに変換する。 The bit data conversion unit 32 reads the image data written in the frame memory 4 and converts it into bit data.
 発光パターン変換部33は、ビットデータ変換部32で変換されたビットデータを、各レーザの発光パターンを表す信号に変換する。 The light emission pattern conversion unit 33 converts the bit data converted by the bit data conversion unit 32 into a signal representing the light emission pattern of each laser.
 タイミングコントローラ34は、同期/画像分離部31、ビットデータ変換部32の動作タイミングを制御する。また、タイミングコントローラ34は、後述するMEMS制御部8の動作タイミングも制御する。 The timing controller 34 controls the operation timing of the synchronization / image separation unit 31 and the bit data conversion unit 32. The timing controller 34 also controls the operation timing of the MEMS control unit 8 described later.
 フレームメモリ4には、同期/画像分離部31により分離された画像データが書き込まれる。ROM5は、ビデオASIC3が動作するための制御プログラムやデータなどを記憶している。RAM6には、ビデオASIC3が動作する際のワークメモリとして、各種データが逐次読み書きされる。 In the frame memory 4, the image data separated by the synchronization / image separation unit 31 is written. The ROM 5 stores a control program and data for operating the video ASIC 3. Various data are sequentially read from and written into the RAM 6 as a work memory when the video ASIC 3 operates.
 レーザドライバASIC7は、後述するレーザ光源部9に設けられるレーザダイオードを駆動する信号を生成するブロックであり、ASICとして構成されている。レーザドライバASIC7は、赤色レーザ駆動回路71と、青色レーザ駆動回路72と、緑色レーザ駆動回路73と、を備える。 The laser driver ASIC 7 is a block that generates a signal for driving a laser diode provided in a laser light source unit 9 described later, and is configured as an ASIC. The laser driver ASIC 7 includes a red laser driving circuit 71, a blue laser driving circuit 72, and a green laser driving circuit 73.
 赤色レーザ駆動回路71は、発光パターン変換部33が出力する信号に基づき、赤色レーザ「LD1」を駆動する。青色レーザ駆動回路72は、発光パターン変換部33が出力する信号に基づき、青色レーザ「LD2」を駆動する。緑色レーザ駆動回路73は、発光パターン変換部33が出力する信号に基づき、緑色レーザ「LD3」を駆動する。 The red laser driving circuit 71 drives the red laser “LD1” based on the signal output from the light emission pattern conversion unit 33. The blue laser driving circuit 72 drives the blue laser “LD2” based on the signal output from the light emission pattern conversion unit 33. The green laser driving circuit 73 drives the green laser “LD3” based on the signal output from the light emission pattern conversion unit 33.
 MEMS制御部8は、タイミングコントローラ34が出力する信号に基づきMEMSミラー10を制御する。MEMS制御部8は、サーボ回路81と、ドライバ回路82と、を備える。なお、MEMS制御部8及びレーザドライバASIC7は、照射制御手段として機能する。 The MEMS control unit 8 controls the MEMS mirror 10 based on a signal output from the timing controller 34. The MEMS control unit 8 includes a servo circuit 81 and a driver circuit 82. The MEMS control unit 8 and the laser driver ASIC 7 function as irradiation control means.
 サーボ回路81は、タイミングコントローラからの信号に基づき、MEMSミラー10の動作を制御する。 The servo circuit 81 controls the operation of the MEMS mirror 10 based on a signal from the timing controller.
 ドライバ回路82は、サーボ回路81が出力するMEMSミラー10の制御信号を所定レベルに増幅して出力する。 The driver circuit 82 amplifies the control signal of the MEMS mirror 10 output from the servo circuit 81 to a predetermined level and outputs the amplified signal.
 レーザ光源部9は、レーザドライバASIC7から出力される駆動信号に基づいて、レーザ光を出射する。具体的には、レーザ光源部9は、主に、赤色レーザLD1と、青色レーザLD2と、緑色レーザLD3と、コリメータレンズ91a~91cと、反射ミラー92a~92cと、マイクロレンズアレイ94と、レンズ95と、受光素子100と、を備える。 The laser light source unit 9 emits laser light based on the drive signal output from the laser driver ASIC 7. Specifically, the laser light source unit 9 mainly includes a red laser LD1, a blue laser LD2, a green laser LD3, collimator lenses 91a to 91c, reflection mirrors 92a to 92c, a microlens array 94, and a lens. 95 and the light receiving element 100.
 赤色レーザLD1は赤色のレーザ光(「赤色レーザ光LR」とも呼ぶ。)を出射し、青色レーザLD2は青色のレーザ光(「青色レーザ光LB」とも呼ぶ。)を出射し、緑色レーザLD3は緑色のレーザ光(「緑色レーザ光LG」とも呼ぶ。)を出射する。コリメータレンズ91a~91cは、それぞれ、赤色、青色及び緑色のレーザ光LR、LB、LGを平行光にして、反射ミラー92a~92cに出射する。反射ミラー92bは、青色レーザ光LBを反射させ、反射ミラー92cは、青色レーザ光LBを透過させ、緑色レーザ光LGを反射させる。そして、反射ミラー92aは、赤色レーザ光LRのみを透過させ、青色及び緑色のレーザ光LB、LGを反射させる。こうして反射ミラー92aを透過した赤色レーザ光LR及び反射ミラー92aで反射された青色及び緑色のレーザ光LB、LGは、MEMSミラー10に入射される。 The red laser LD1 emits red laser light (also referred to as “red laser light LR”), the blue laser LD2 emits blue laser light (also referred to as “blue laser light LB”), and the green laser LD3. Green laser light (also referred to as “green laser light LG”) is emitted. The collimator lenses 91a to 91c convert the red, blue, and green laser beams LR, LB, and LG into parallel beams and emit the parallel beams to the reflection mirrors 92a to 92c. The reflection mirror 92b reflects the blue laser light LB, and the reflection mirror 92c transmits the blue laser light LB and reflects the green laser light LG. The reflection mirror 92a transmits only the red laser beam LR and reflects the blue and green laser beams LB and LG. The red laser light LR transmitted through the reflection mirror 92 a and the blue and green laser beams LB and LG reflected by the reflection mirror 92 a are incident on the MEMS mirror 10.
 なお、レーザLD1、LD2、LD3の任意の2つのレーザ光は、本発明における「第一光源」及び「第二光源」の一例であり、レーザ光LR、LB、LGの任意の2つのレーザ光は、本発明における「第一ビーム」及び「第二ビーム」の一例である。 The arbitrary two laser beams of the lasers LD1, LD2, and LD3 are examples of the “first light source” and the “second light source” in the present invention, and the arbitrary two laser beams of the laser beams LR, LB, and LG. Are examples of the “first beam” and the “second beam” in the present invention.
 MEMSミラー10は、本発明における「走査手段」として機能し、反射ミラー92aから入射されたレーザ光をEPE(Exit Pupil Expander)の一例であるマイクロレンズアレイ94に向けて反射する。また、MEMSミラー10は、基本的には、画像信号入力部2に入力された画像を表示するためにMEMS制御部8の制御により、スクリーンとしてのマイクロレンズアレイ94上を走査するように移動し、その際の走査位置情報(例えばミラーの角度などの情報)をビデオASIC3へ出力する。マイクロレンズアレイ94は、複数のマイクロレンズが配列されており、MEMSミラー10で反射されたレーザ光が入射される。レンズ95は、マイクロレンズアレイ94の放射面に形成された画像を拡大する。 The MEMS mirror 10 functions as “scanning means” in the present invention, and reflects the laser light incident from the reflection mirror 92a toward a microlens array 94 which is an example of EPE (Exit Pupil Expander). The MEMS mirror 10 basically moves so as to scan the microlens array 94 as a screen under the control of the MEMS control unit 8 in order to display the image input to the image signal input unit 2. The scanning position information at that time (for example, information such as the angle of the mirror) is output to the video ASIC 3. In the microlens array 94, a plurality of microlenses are arranged, and the laser beam reflected by the MEMS mirror 10 is incident thereon. The lens 95 enlarges an image formed on the radiation surface of the microlens array 94.
 受光素子100は、マイクロレンズアレイ94の近傍に設けられている。具体的には、マイクロレンズアレイ94は描画領域「RR」(ユーザに提示するための画像(映像)を表示する領域に相当する。以下同様とする。)を含む位置に設けられているのに対して、受光素子100は描画領域RR外の所定の領域に対応する位置に設けられている。受光素子100の具体的な配置については、図2を用いて後述する。受光素子100は、フォトディテクタなどの光電変換素子で構成され、入射したレーザ光の光量に応じた電気信号である検出信号「Sd」をビデオASIC3へ供給する。 The light receiving element 100 is provided in the vicinity of the microlens array 94. Specifically, the microlens array 94 is provided at a position including a drawing area “RR” (corresponding to an area for displaying an image (video) to be presented to the user; the same shall apply hereinafter). On the other hand, the light receiving element 100 is provided at a position corresponding to a predetermined area outside the drawing area RR. A specific arrangement of the light receiving element 100 will be described later with reference to FIG. The light receiving element 100 is configured by a photoelectric conversion element such as a photodetector, and supplies a detection signal “Sd”, which is an electrical signal corresponding to the amount of incident laser light, to the video ASIC 3.
 ビデオASIC3は、受光素子100からの検出信号Sdに基づいて、赤色レーザ光LR、青色レーザ光LB及び緑色レーザ光LGの光軸ずれを検出する。また、ビデオASIC3は、検出した光軸ずれに基づいて、当該光軸ずれを補正するための処理を行う。具体的には、ビデオASIC3は、赤色レーザLD1、青色レーザLD2、又は/及び緑色レーザLD3の発光タイミングを変更することで光軸ずれの補正を行う。このとき、ビデオASIC3は、光軸のずれ方向が主走査方向又は副走査方向のいずれの方向であるかに基づいて、上述の発光タイミングの調整量を変更する。このように、ビデオASIC3は、本発明における「検出手段」及び「補正手段」として機能する。 The video ASIC 3 detects the optical axis shift of the red laser light LR, the blue laser light LB, and the green laser light LG based on the detection signal Sd from the light receiving element 100. Further, the video ASIC 3 performs processing for correcting the optical axis deviation based on the detected optical axis deviation. Specifically, the video ASIC 3 corrects the optical axis deviation by changing the light emission timing of the red laser LD1, the blue laser LD2, and / or the green laser LD3. At this time, the video ASIC 3 changes the above-described adjustment amount of the light emission timing based on whether the optical axis shift direction is the main scanning direction or the sub-scanning direction. Thus, the video ASIC 3 functions as “detection means” and “correction means” in the present invention.
 図2は、マイクロレンズアレイ94及び受光素子100の配置例を示す図である。図2は、レーザ光の進行方向に沿った方向(図1の矢印「Z」方向)から、マイクロレンズアレイ94及び受光素子100を観察した図を示している。破線で表された走査可能領域「SR」は、MEMSミラー10による走査が可能な範囲、即ち描画が可能な範囲に対応する領域である。この走査可能領域SR内には、マイクロレンズアレイ94が配置される。そして、マイクロレンズアレイ94内の一点鎖線で表された領域は描画領域RRを示す。 FIG. 2 is a diagram illustrating an arrangement example of the microlens array 94 and the light receiving element 100. FIG. 2 shows a diagram in which the microlens array 94 and the light receiving element 100 are observed from the direction along the traveling direction of the laser light (the arrow “Z” direction in FIG. 1). A scannable region “SR” represented by a broken line is a region corresponding to a range where scanning by the MEMS mirror 10 is possible, that is, a range where drawing is possible. A microlens array 94 is disposed in the scannable region SR. A region represented by a one-dot chain line in the microlens array 94 indicates a drawing region RR.
 受光素子100は、走査可能領域SR内の領域であって、マイクロレンズアレイ94の下方に設けられている。つまり、受光素子100は、表示を阻害しないように、描画領域RR外の領域に対応する位置に設けられている。 The light receiving element 100 is an area in the scannable area SR and is provided below the microlens array 94. That is, the light receiving element 100 is provided at a position corresponding to a region outside the drawing region RR so as not to disturb the display.
 MEMSミラー10は、図2中の矢印に示すようにレーザ光を複数回走査する(つまりラスタースキャンを実施する)ことで、表示すべき画像(映像)を描画領域RRに描画させる。本明細書では、図2の下に示すように、レーザ光の副走査方向を「左右方向」とも呼び、当該副走査方向に垂直な主走査方向を「上下方向」とも呼ぶ。 The MEMS mirror 10 draws an image (video) to be displayed in the drawing region RR by scanning the laser beam a plurality of times (that is, performing a raster scan) as indicated by an arrow in FIG. In this specification, as shown in the lower part of FIG. 2, the sub-scanning direction of the laser light is also referred to as “left-right direction”, and the main scanning direction perpendicular to the sub-scanning direction is also referred to as “up-down direction”.
 なお、受光素子100を配置する位置は図2に示したものに限定はされない。受光素子100は、走査可能領域SR内であって描画領域RR外の領域に対応する位置であれば、種々の位置に配置可能である。 The position where the light receiving element 100 is arranged is not limited to that shown in FIG. The light receiving element 100 can be arranged at various positions as long as it is located in the scannable area SR and corresponds to an area outside the drawing area RR.
 [光軸ずれ補正方法]
 以下では、本実施例に係る光軸ずれ補正方法について具体的に説明する。概略的には、画像描画装置1は、走査可能領域SR内の受光素子100の位置を含む所定範囲(単に「走査領域Rtag」とも呼ぶ。)を対象にして、全色のレーザを同時に点灯させた状態で走査を行い、受光素子100がレーザ光を受光した時間幅に基づき、光軸ずれの検出及び補正を行う。
[Optical axis deviation correction method]
Hereinafter, the optical axis deviation correcting method according to the present embodiment will be specifically described. Schematically, the image drawing apparatus 1 simultaneously turns on lasers of all colors for a predetermined range including the position of the light receiving element 100 in the scannable region SR (also simply referred to as “scan region Rtag”). In this state, scanning is performed, and the optical axis deviation is detected and corrected based on the time width when the light receiving element 100 receives the laser beam.
 以下では、まず、本実施例の光軸ずれ補正方法に関する基本事項について説明した後、具体的な処理手順について説明する。 In the following, first, basic items regarding the optical axis deviation correction method of the present embodiment will be described, and then specific processing procedures will be described.
 (1)基本説明
 まず、図3を参照して、光軸ずれの具体例について説明する。図3(a)は、画像描画装置1から出射された赤色レーザ光LR、青色レーザ光LB及び緑色レーザ光LGの一例を示している。ここでは、赤色レーザ光LR、青色レーザ光LB及び緑色レーザ光LGにおいて光軸ずれが生じている場合を例示している。図3(b)は、図3(a)中の位置「P」に配置されたマイクロレンズアレイ94上に照射された、赤色レーザ光LR、青色レーザ光LB及び緑色レーザ光LGのそれぞれに対応するスポットの一例を示している。図3(b)において、文字「R」、「B」、「G」が内部に記載された円は、それぞれ、赤色レーザ光LR、青色レーザ光LB及び緑色レーザ光LGのスポットを示している(以下同様とする)。この例では、青色レーザ光LBの光軸は、赤色レーザ光LRの光軸に対して、2ドット(画素)分だけ上方向にずれており、緑色レーザ光LGの光軸は、赤色レーザ光LRの光軸に対して、2ドット分だけ下方向にずれている共に、1ドット分だけ右方向にずれている。本実施例では、画像描画装置1は、このような光軸ずれ及び当該光軸ずれの方向を検出し、各レーザ光LR、LB、LGの光軸が一致するように各レーザLD1~LD3の発光タイミングを制御する。
(1) Basic description First, a specific example of the optical axis deviation will be described with reference to FIG. FIG. 3A shows an example of the red laser light LR, the blue laser light LB, and the green laser light LG emitted from the image drawing device 1. Here, the case where the optical axis shift has arisen in red laser beam LR, blue laser beam LB, and green laser beam LG is illustrated. FIG. 3B corresponds to each of the red laser light LR, the blue laser light LB, and the green laser light LG irradiated on the microlens array 94 arranged at the position “P” in FIG. An example of a spot to be performed is shown. In FIG. 3B, the circles with the letters “R”, “B”, and “G” written therein indicate the spots of the red laser beam LR, the blue laser beam LB, and the green laser beam LG, respectively. (The same shall apply hereinafter). In this example, the optical axis of the blue laser light LB is shifted upward by 2 dots (pixels) with respect to the optical axis of the red laser light LR, and the optical axis of the green laser light LG is red laser light. With respect to the optical axis of LR, it is shifted downward by 2 dots and is shifted rightward by 1 dot. In the present embodiment, the image drawing apparatus 1 detects such an optical axis shift and the direction of the optical axis shift, and the lasers LD1 to LD3 are arranged so that the optical axes of the laser beams LR, LB, and LG coincide with each other. Controls the light emission timing.
 次に、受光素子100が検出する受光レベルの時間変化について図4を参照して説明する。図4(a)は、走査領域Rtagに対し、レーザLD1、LD2、LD3のいずれか一つを点灯させた状態で60FPS(即ち約16.7ms)の間隔に従い6回反復して走査を行った場合の受光素子100が検出した受光レベルを時間軸上で表した図である。図4(a)では、走査領域Rtagに対する各走査期間のうち、受光素子100が断続的に受光を検知した期間、即ち、最初に受光した時点から最後に受光した時点までの期間(「受光期間T」とも呼ぶ。)において、受光レベルが高くなっていることが示されている。 Next, the temporal change in the light receiving level detected by the light receiving element 100 will be described with reference to FIG. In FIG. 4A, the scanning region Rtag is repeatedly scanned 6 times according to an interval of 60 FPS (that is, about 16.7 ms) in a state where any one of the lasers LD1, LD2, and LD3 is turned on. It is the figure which represented on the time axis the light reception level which the light receiving element 100 detected in the case. 4A, in each scanning period for the scanning region Rtag, a period in which the light receiving element 100 detects light reception intermittently, that is, a period from the first light reception time to the last light reception time (“light reception period”). (Also referred to as “T”) indicates that the light reception level is high.
 そして、図4(b)は、図4(a)の最初の走査期間に対する受光期間T内の受光レベルの詳細を示すグラフである。図4(b)では、受光素子100と重なる位置の走査線を対象に走査を行うタイミングごとに、受光素子100によりレーザ光が検知されている。具体的に、図4(b)では、主走査方向に連続する8行分のドットが走査された際に、受光素子100は、各走査線での走査において、レーザ光を検知している。そして、各レーザ光LR、LB、LGのいずれを点灯させた場合であっても、各レーザ光に対する受光期間Tの幅(「単色受光時間幅Tw1」とも呼ぶ。)は、同一である。 FIG. 4B is a graph showing details of the light receiving level in the light receiving period T with respect to the first scanning period of FIG. 4A. In FIG. 4B, the laser light is detected by the light receiving element 100 at every timing when scanning is performed on the scanning line at a position overlapping the light receiving element 100. Specifically, in FIG. 4B, when eight consecutive dots in the main scanning direction are scanned, the light receiving element 100 detects the laser beam in scanning with each scanning line. Even when any one of the laser beams LR, LB, and LG is turned on, the width of the light receiving period T for each laser beam (also referred to as “monochromatic light receiving time width Tw1”) is the same.
 次に、図5を参照し、光軸ずれが生じていない場合の受光期間Tでの受光素子100の受光レベルの時間変化について説明する。図5(a)は、赤色レーザLD1、青色レーザLD2、及び緑色レーザLD3を同時に点灯させて走査を行った場合の受光素子100の受光レベルの時間変化を示す。また、図5(b)は、図5(a)に示す場合において、赤色レーザ光LRに対する受光レベルのみを抽出したグラフであり、図5(c)は、青色レーザ光LBに対する受光レベルのみを抽出したグラフであり、図5(d)は、緑色レーザ光LGに対する受光レベルのみを抽出したグラフである。 Next, with reference to FIG. 5, the temporal change of the light receiving level of the light receiving element 100 in the light receiving period T when no optical axis deviation occurs will be described. FIG. 5A shows a temporal change in the light receiving level of the light receiving element 100 when scanning is performed with the red laser LD1, the blue laser LD2, and the green laser LD3 turned on simultaneously. FIG. 5B is a graph obtained by extracting only the light receiving level for the red laser light LR in the case shown in FIG. 5A, and FIG. 5C shows only the light receiving level for the blue laser light LB. FIG. 5D is a graph obtained by extracting only the light reception level with respect to the green laser light LG.
 図5(b)~(d)に示すように、各レーザ光の光軸が一致している場合、受光素子100は、各レーザ光を同じタイミングで検知することから、各レーザ光LR、LB、LGに対する受光期間Tは一致する。その結果、図5(a)に示すように、レーザLD1~LD3を同時に点灯させて走査を行った際に受光素子100がレーザ光を検知する受光期間Tは、一つのレーザ光のみを対象にした受光期間Tと一致する。従って、図5(a)~(d)に示すように、光軸にずれが生じていない場合には、全レーザを同時点灯させた場合の受光期間Tの幅(「全色受光時間幅Twa」と呼ぶ。)は、単色受光時間幅Tw1と同じ長さになる。 As shown in FIGS. 5B to 5D, when the optical axes of the respective laser beams coincide with each other, the light receiving element 100 detects the respective laser beams at the same timing, so that the respective laser beams LR and LB are detected. , LG coincides with the light receiving period T. As a result, as shown in FIG. 5A, the light receiving period T in which the light receiving element 100 detects the laser light when scanning is performed with the lasers LD1 to LD3 turned on simultaneously, only for one laser light. Coincides with the received light receiving period T. Accordingly, as shown in FIGS. 5A to 5D, when there is no deviation in the optical axis, the width of the light receiving period T when all the lasers are turned on simultaneously (“all-color light receiving time width Twa”). Is the same length as the monochromatic light reception time width Tw1.
 次に、図6を参照し、主走査方向に光軸ずれが生じている場合の受光素子100の受光期間Tにおける受光レベルの時間変化について説明する。図6(a)は、赤色レーザLD1、青色レーザLD2、及び緑色レーザLD3を同時に点灯させてMEMSミラー10の走査を行った場合の受光レベルの時間変化を示す。また、図6(b)は、図6(a)に示す場合において、赤色レーザ光LRに対する受光レベルのみを抽出したグラフであり、図6(c)は、青色レーザ光LBに対する受光レベルのみを抽出したグラフであり、図6(d)は、緑色レーザ光LGに対する受光レベルのみを抽出したグラフである。 Next, with reference to FIG. 6, a description will be given of a temporal change in the light receiving level in the light receiving period T of the light receiving element 100 when an optical axis shift occurs in the main scanning direction. FIG. 6A shows a temporal change in the light reception level when the MEMS mirror 10 is scanned by simultaneously turning on the red laser LD1, the blue laser LD2, and the green laser LD3. FIG. 6B is a graph obtained by extracting only the light reception level for the red laser light LR in the case shown in FIG. 6A, and FIG. 6C shows only the light reception level for the blue laser light LB. FIG. 6D is an extracted graph, in which only the light reception level for the green laser light LG is extracted.
 図6(b)~(d)に示すように、各レーザ光の光軸が主走査方向にずれている場合、各レーザ光に対する受光素子100の受光期間Tが顕著に異なる。具体的には、例えば青色レーザ光LBを基準とした場合、赤色レーザ光LRは、下方向にずれているため、受光素子100により検知されるタイミングが早くなっている。また、同じく青色レーザ光LBを基準とした場合、緑色レーザ光LGは、上方向にずれているため、受光素子100により検知されるタイミングが遅くなっている。 As shown in FIGS. 6B to 6D, when the optical axis of each laser beam is shifted in the main scanning direction, the light receiving period T of the light receiving element 100 for each laser beam is significantly different. Specifically, for example, when the blue laser beam LB is used as a reference, the red laser beam LR is shifted downward, so that the timing detected by the light receiving element 100 is earlier. Similarly, when the blue laser beam LB is used as a reference, since the green laser beam LG is shifted upward, the timing detected by the light receiving element 100 is delayed.
 その結果、図6(a)に示すように、レーザLD1~LD3を同時に点灯させて走査を行った際に受光素子100がレーザ光を検知する受光期間Tは、一つのレーザ光のみを対象にした受光期間Tと一致せず、全色受光時間幅Twaは、単色受光時間幅Tw1よりも長くなる。 As a result, as shown in FIG. 6A, the light receiving period T in which the light receiving element 100 detects the laser light when scanning is performed with the lasers LD1 to LD3 turned on simultaneously, targets only one laser light. The all-color light reception time width Twa is longer than the single color light reception time width Tw1.
 一方、左右方向(副走査方向)にのみ光軸ずれが生じた場合には、同一の走査線上で受光素子100が受光を検知するため、上下方向(主走査方向)に光軸ずれが生じた場合と比較して、受光期間Tのずれが小さい。従って、副走査方向にのみ光軸ずれが生じた場合には、主走査方向に光軸ずれが生じた場合と比較して、全色受光時間幅Twaと単色受光時間幅Tw1との差が小さい。 On the other hand, when the optical axis deviation occurs only in the left-right direction (sub-scanning direction), the optical axis deviation occurs in the vertical direction (main scanning direction) because the light receiving element 100 detects light reception on the same scanning line. Compared to the case, the shift of the light receiving period T is small. Therefore, when the optical axis deviation occurs only in the sub-scanning direction, the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 is smaller than when the optical axis deviation occurs in the main scanning direction. .
 以上を勘案し、画像描画装置1は、受光素子100の検出信号に基づき全色受光時間幅Twaを算出し、光軸ずれが生じていない場合の全色受光時間幅Twaに相当する単色受光時間幅Tw1との差分を求める。そして、画像描画装置1は、当該差分が所定の閾値(「第1閾値」とも呼ぶ。)よりも大きい場合には、主走査方向の光軸ずれが生じていると判断する。上述の第1閾値は、本発明における「所定値」の一例であり、副走査方向のみの光軸ずれに起因した全色受光時間幅Twaと単色受光時間幅Tw1との差分よりも大きい値に設定される。例えば、第1閾値は、一つのレーザのみを点灯させて走査領域Rtagを走査した場合の受光期間T内における受光間隔(即ち、図4(b)の矢印「Ax」の幅)に設定される。 In consideration of the above, the image drawing apparatus 1 calculates the all-color light reception time width Twa based on the detection signal of the light receiving element 100, and the monochromatic light reception time corresponding to the all-color light reception time width Twa when no optical axis deviation occurs. The difference from the width Tw1 is obtained. Then, when the difference is larger than a predetermined threshold (also referred to as “first threshold”), the image drawing apparatus 1 determines that an optical axis shift in the main scanning direction has occurred. The above first threshold is an example of the “predetermined value” in the present invention, and is set to a value larger than the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 caused by the optical axis shift only in the sub-scanning direction. Is set. For example, the first threshold value is set to the light receiving interval (that is, the width of the arrow “Ax” in FIG. 4B) within the light receiving period T when only one laser is turned on to scan the scanning region Rtag. .
 (2)具体的処理
 次に、図7~図9を参照し、画像描画装置1が実行する具体的な光軸ずれ補正処理について説明する。
(2) Specific Processing Next, specific optical axis deviation correction processing executed by the image drawing apparatus 1 will be described with reference to FIGS.
 (2-1)処理概要
 図7は、画像描画装置1が実行する光軸ずれ補正処理の手順を示すフローチャートの一例である。図7に示すフローチャートは、所定の周期又はタイミングに従い繰り返し実行される。なお、画像描画装置1は、光軸ずれ補正処理を、描画領域RRでの映像の描画時に行ってもよい。
(2-1) Process Overview FIG. 7 is an example of a flowchart showing a procedure of optical axis deviation correction processing executed by the image drawing apparatus 1. The flowchart shown in FIG. 7 is repeatedly executed according to a predetermined cycle or timing. Note that the image drawing apparatus 1 may perform the optical axis misalignment correction process when drawing a video in the drawing region RR.
 まず、画像描画装置1は、全色受光時間幅Twaを測定する(ステップS101)。例えば、画像描画装置1は、走査可能領域SRに配置された受光素子100の全体を含む所定範囲を走査領域Rtagに指定して、全色のレーザ光を点灯させた状態で走査を行い、その際に受光素子100がレーザ光を最初に検出した時点から最後に検出した時点までの受光期間Tの幅を、全色受光時間幅Twaに定める。 First, the image drawing apparatus 1 measures the all-color light reception time width Twa (step S101). For example, the image drawing apparatus 1 designates a predetermined range including the entire light receiving element 100 arranged in the scannable region SR as the scan region Rtag, and performs scanning in a state where all color laser lights are turned on. At this time, the width of the light receiving period T from the time when the light receiving element 100 first detects the laser light to the time when the laser light is finally detected is determined as the all-color light receiving time width Twa.
 次に、画像描画装置1は、全色受光時間幅Twaが単色受光時間幅Tw1よりも第1閾値だけ大きいか否か判定する(ステップS102)。この場合、画像描画装置1は、単色受光時間幅Tw1、言い換えると、光軸ずれが生じていない場合の全色受光時間幅Twa(図5参照)を予めメモリ等に記憶しておく。また、第1閾値は、例えば、主走査方向に光軸ずれが生じた際の全色受光時間幅Twaと単色受光時間幅Tw1との差の下限値に設定され、具体的には、一列分の走査線上のドットを走査するのに要する時間幅や受光素子100の位置等を勘案し、実験又は理論的に定められる。 Next, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa is larger than the single color light reception time width Tw1 by the first threshold (step S102). In this case, the image drawing apparatus 1 stores in advance a single color light reception time width Tw1, in other words, the all color light reception time width Twa (see FIG. 5) when no optical axis deviation occurs in a memory or the like. The first threshold value is set, for example, as a lower limit value of the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 when the optical axis shift occurs in the main scanning direction. This is determined experimentally or theoretically in consideration of the time width required to scan the dots on the scanning line, the position of the light receiving element 100, and the like.
 そして、全色受光時間幅Twaが単色受光時間幅Tw1よりも第1閾値だけ大きい場合(ステップS102;Yes)、画像描画装置1は、主走査方向の光軸ずれが生じていると判断し、主走査方向(上下方向)の光軸ずれの補正を行う(ステップS103)。この具体的な処理については、図8を参照して後述する。 When the all-color light reception time width Twa is larger than the single color light reception time width Tw1 by the first threshold value (step S102; Yes), the image drawing apparatus 1 determines that the optical axis shift in the main scanning direction has occurred, The optical axis deviation in the main scanning direction (vertical direction) is corrected (step S103). This specific process will be described later with reference to FIG.
 一方、全色受光時間幅Twaと単色受光時間幅Tw1とのずれ幅が第1閾値未満である場合(ステップS102;No)、画像描画装置1は、主走査方向の光軸ずれが生じていないと判断し、ステップS104へ処理を進める。 On the other hand, when the deviation width between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the first threshold (step S102; No), the image drawing apparatus 1 has no optical axis deviation in the main scanning direction. And the process proceeds to step S104.
 次に、ステップS104において、画像描画装置1は、全色受光時間幅Twaが単色受光時間幅Tw1よりも第2閾値以上大きいか否か判定する(ステップS104)。ここで、第2閾値は、副走査方向に光軸ずれが生じた際の全色受光時間幅Twaと単色受光時間幅Tw1との差の下限値等に設定され、具体的には、1ドット分を走査するのに要する時間幅(例えば720画素を60FPSで走査する場合には23.2us)に設定される。従って、第2閾値は、上述の第1閾値よりも小さい値に設定される。 Next, in step S104, the image drawing apparatus 1 determines whether or not the all color light reception time width Twa is greater than the single color light reception time width Tw1 by a second threshold or more (step S104). Here, the second threshold is set to a lower limit value or the like of the difference between the all-color light reception time width Twa and the monochrome light reception time width Tw1 when the optical axis shift occurs in the sub-scanning direction. The time width required to scan the minutes (for example, 23.2 us when scanning 720 pixels at 60 FPS) is set. Therefore, the second threshold value is set to a value smaller than the first threshold value described above.
 そして、全色受光時間幅Twaが単色受光時間幅Tw1よりも第2閾値以上大きい場合(ステップS104;Yes)、画像描画装置1は、副走査方向の光軸ずれが生じていると判断し、副走査方向(左右方向)の光軸ずれ補正を行う(ステップS105)。この具体的な処理については、図9を参照して後述する。 When the all-color light reception time width Twa is larger than the single color light reception time width Tw1 by the second threshold or more (step S104; Yes), the image drawing apparatus 1 determines that an optical axis shift in the sub-scanning direction has occurred, Optical axis deviation correction in the sub-scanning direction (left-right direction) is performed (step S105). This specific processing will be described later with reference to FIG.
 一方、全色受光時間幅Twaと単色受光時間幅Tw1とのずれ幅が第2閾値未満である場合(ステップS104;No)、画像描画装置1は、副走査方向の光軸ずれが生じていないと判断し、フローチャートの処理を終了する。 On the other hand, when the deviation width between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the second threshold (step S104; No), the image drawing apparatus 1 has no optical axis deviation in the sub-scanning direction. And the process of the flowchart is terminated.
 このように、画像描画装置1は、主走査方向に光軸ずれが生じている場合には、副走査方向に光軸ずれが生じている場合と比較して、全色受光時間幅Twaと単色受光時間幅Tw1との差が大きくなることに着目し、これらの差に基づき光軸ずれの方向を検出する。そして、画像描画装置1は、主走査方向に光軸ずれが生じている場合には、まず主走査方向の光軸ずれを補正し、その後に、副走査方向の光軸ずれを適宜補正する。これにより、画像描画装置1は、好適に、主走査方向及び副走査方向の光軸ずれを補正することができる。また、この場合、画像描画装置1は、検査対象であるレーザLD1~LD3を同時に点灯させて光軸ずれの検出を行うことにより、振動等などの外部要因に起因した受光のずれの影響を除外する。従って、画像描画装置1は、振動等の影響を受けることなく、光軸ずれの検出及び補正を高精度に行うことができる。 As described above, in the image drawing apparatus 1, when the optical axis deviation occurs in the main scanning direction, the all-color light reception time width Twa and the single color are compared with the case where the optical axis deviation occurs in the sub-scanning direction. Focusing on the fact that the difference from the light reception time width Tw1 increases, the direction of the optical axis deviation is detected based on these differences. When the optical axis deviation occurs in the main scanning direction, the image drawing apparatus 1 first corrects the optical axis deviation in the main scanning direction, and then appropriately corrects the optical axis deviation in the sub-scanning direction. Thereby, the image drawing apparatus 1 can preferably correct the optical axis deviation in the main scanning direction and the sub-scanning direction. Further, in this case, the image drawing apparatus 1 detects the optical axis deviation by simultaneously turning on the lasers LD1 to LD3 to be inspected, thereby eliminating the influence of the deviation of the received light caused by external factors such as vibration. To do. Therefore, the image drawing apparatus 1 can detect and correct the optical axis deviation with high accuracy without being affected by vibration or the like.
 (2-2)主走査方向光軸ずれ補正処理
 図8は、主走査方向光軸ずれ補正処理の手順の一例を示すフローチャートである。画像描画装置1は、図8に示すフローチャートの処理を、図7のステップS103へ処理を進めた際に実行する。概略的には、画像描画装置1は、全色受光時間幅Twaと単色受光時間幅Tw1との差が第1閾値未満になるように、全色受光時間幅Twaを監視しつつ各レーザ光の光軸を主走査方向に移動させるフィードバック制御を行う。
(2-2) Main Scanning Direction Optical Axis Deviation Correction Processing FIG. 8 is a flowchart showing an example of the procedure of main scanning direction optical axis deviation correction processing. The image drawing apparatus 1 executes the processing of the flowchart shown in FIG. 8 when the processing proceeds to step S103 in FIG. Schematically, the image drawing apparatus 1 monitors the all-color light reception time width Twa so that the difference between the all-color light reception time width Twa and the single-color light reception time width Tw1 is less than the first threshold. Feedback control is performed to move the optical axis in the main scanning direction.
 まず、画像描画装置1は、光軸を移動させるレーザを決定する(ステップS201)。画像描画装置1は、例えば、赤色レーザ光LR、青色レーザ光LB、及び緑色レーザ光LGのうち一つのレーザ(例えば赤色レーザ光LR)の光軸の位置を固定(基準)にして他のレーザ光の光軸を補正する場合、当該他のレーザ(上述の例では青色レーザ光LB及び緑色レーザ光LG)を、ステップS201を実行する度に、交互に、光軸を移動させるレーザ光として指定する。 First, the image drawing apparatus 1 determines a laser that moves the optical axis (step S201). For example, the image drawing device 1 fixes (references) the optical axis position of one laser (for example, the red laser beam LR) of the red laser beam LR, the blue laser beam LB, and the green laser beam LG to another laser. When correcting the optical axis of light, the other lasers (blue laser light LB and green laser light LG in the above example) are alternately designated as laser light that moves the optical axis every time step S201 is executed. To do.
 次に、画像描画装置1は、ステップS201で指定したレーザの光軸を上方向に移動させ、その後、走査領域Rtagを対象にして全色のレーザ光を点灯させた状態で走査を行い、全色受光時間幅Twaを計測する(ステップS202)。ここで、上述の移動幅は、例えば1ドット分の幅に設定される。 Next, the image drawing apparatus 1 moves the optical axis of the laser designated in step S201 in the upward direction, and then performs scanning in a state where the laser beams of all colors are turned on for the scanning region Rtag. The color light reception time width Twa is measured (step S202). Here, the above-described movement width is set to a width corresponding to one dot, for example.
 そして、画像描画装置1は、全色受光時間幅Twaが増加したか否か判定する(ステップS203)。具体的には、画像描画装置1は、ステップS202で計測した全色受光時間幅Twaが、その前に計測した全色受光時間幅Twaよりも大きいか否か判定する。 Then, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has increased (step S203). Specifically, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa measured in step S202 is larger than the all-color light reception time width Twa measured before that.
 そして、全色受光時間幅Twaが増加した場合(ステップS203;Yes)、画像描画装置1は、移動させたレーザの光軸は上方向にはずれていないと判断し、当該レーザの光軸を下方向に移動させ、その後再び全色受光時間幅Twaを計測する(ステップS204)。この移動幅は、ステップS202で上方向に光軸を移動させた直後の場合には、ステップS202での移動幅の2倍の幅(例えば2ドット分の幅)に設定され、ステップS205の直後の場合には、例えばステップS202での移動幅と同一(1ドット分の幅)に設定される。 When the all-color light reception time width Twa increases (step S203; Yes), the image drawing apparatus 1 determines that the optical axis of the moved laser is not shifted upward, and lowers the optical axis of the laser. Then, the light reception time width Twa of all colors is measured again (step S204). In the case immediately after the optical axis is moved upward in step S202, this movement width is set to a width twice the movement width in step S202 (for example, a width corresponding to 2 dots), and immediately after step S205. In this case, for example, it is set to be the same as the movement width in step S202 (one dot width).
 そして、画像描画装置1は、全色受光時間幅Twaが減少したか否か判定する(ステップS205)。そして、全色受光時間幅Twaが減少した場合には(ステップS205;Yes)、画像描画装置1は、対象となるレーザがまだ下方向にずれている可能性があると判断し、再びステップS202の処理を行う。一方、全色受光時間幅Twaが減少しなかった場合(ステップS205;No)、画像描画装置1は、ステップS201で決定されたレーザ光の光軸を上方向に移動させて全色受光時間幅Twaを再計測し(ステップS206)、ステップS211へ処理を進める。この場合の移動幅は、ステップS204での移動幅と同一(例えば1ドット分の幅)に設定される。 Then, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S205). When the all-color light reception time width Twa decreases (step S205; Yes), the image drawing apparatus 1 determines that there is a possibility that the target laser is still shifted downward, and step S202 is performed again. Perform the process. On the other hand, if the all-color light reception time width Twa does not decrease (step S205; No), the image drawing apparatus 1 moves the optical axis of the laser light determined in step S201 upward to move the all-color light reception time width. Twa is measured again (step S206), and the process proceeds to step S211. The movement width in this case is set to be the same as the movement width in step S204 (for example, a width for one dot).
 一方、ステップS203で、全色受光時間幅Twaが増加していないと判断した場合(ステップS203;No)、画像描画装置1は、全色受光時間幅Twaが減少したか否か判定する(ステップS207)。そして、全色受光時間幅Twaが減少した場合には(ステップS207;Yes)、画像描画装置1は、対象とするレーザ光の光軸がさらに上方向にずれている可能性があると判断し、当該レーザ光の光軸を上方向に移動させ、その後再び全色受光時間幅Twaを再計測する(ステップS208)。この移動幅は、例えばステップS202での移動幅と同一(1ドット分の幅)に設定される。そして、画像描画装置1は、全色受光時間幅Twaが減少したか否か判定する(ステップS209)。そして、全色受光時間幅Twaが減少した場合には(ステップS209;Yes)、画像描画装置1は、対象となるレーザ光の光軸がまだ上方向にずれている可能性があると判断し、再びステップS208の処理を行う。一方、全色受光時間幅Twaが減少しなかった場合(ステップS209;No)、画像描画装置1は、対象となるレーザの光軸を下方向に移動させて全色受光時間幅Twaを再計測し(ステップS210)、ステップS211へ処理を進める。この場合の移動幅は、ステップS208での移動幅と同一(例えば1ドット分の幅)に設定される。 On the other hand, when it is determined in step S203 that the all-color light reception time width Twa has not increased (step S203; No), the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S203). S207). When the all-color light reception time width Twa decreases (step S207; Yes), the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is further shifted upward. Then, the optical axis of the laser beam is moved upward, and then the all-color light reception time width Twa is measured again (step S208). This movement width is set to be the same as the movement width in step S202 (one dot width), for example. Then, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S209). When the all-color light reception time width Twa decreases (step S209; Yes), the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is still shifted upward. Then, the process of step S208 is performed again. On the other hand, when the all-color light reception time width Twa does not decrease (step S209; No), the image drawing apparatus 1 moves the optical axis of the target laser downward to remeasure the all-color light reception time width Twa. (Step S210), and the process proceeds to Step S211. The movement width in this case is set to be the same as the movement width in step S208 (for example, a width for one dot).
 一方、ステップS207で、全色受光時間幅Twaが減少していない場合(ステップS207;No)、即ち、全色受光時間幅Twaが増加も減少もしていないと判断した場合には、画像描画装置1は、ステップS211へ処理を進める。この場合、画像描画装置1は、ステップS202で上方向に光軸を移動させた分、対象となるレーザの光軸を下方向に戻してもよい。 On the other hand, if it is determined in step S207 that the all-color light reception time width Twa has not decreased (step S207; No), that is, if it is determined that the all-color light reception time width Twa has not increased or decreased, the image drawing apparatus 1 advances the process to step S211. In this case, the image drawing apparatus 1 may return the optical axis of the target laser downward by the amount that the optical axis is moved upward in step S202.
 そして、ステップS211では、画像描画装置1は、全色受光時間幅Twaと単色受光時間幅Tw1との差が第1閾値未満であるか否か判定する(ステップS211)。これにより、画像描画装置1は、主走査方向の光軸のずれが解消した否か判定する。そして、全色受光時間幅Twaと単色受光時間幅Tw1との差が第1閾値未満の場合(ステップS211;Yes)、画像描画装置1は主走査方向の光軸のずれが解消と判断し、フローチャートの処理を終了する。一方、全色受光時間幅Twaと単色受光時間幅Tw1との差が第1閾値以上の場合(ステップS211;No)、画像描画装置1は、主走査方向の光軸のずれが解消していないと判断し、ステップS201に処理を戻す。この場合、画像描画装置1は、ステップS201では、前回光軸を移動させたレーザ光とは異なるレーザ光を、光軸を移動させる対象に選ぶ。 In step S211, the image drawing apparatus 1 determines whether the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the first threshold (step S211). Thereby, the image drawing apparatus 1 determines whether or not the deviation of the optical axis in the main scanning direction has been eliminated. If the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the first threshold (step S211; Yes), the image drawing apparatus 1 determines that the optical axis shift in the main scanning direction is eliminated, The process of the flowchart ends. On the other hand, when the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is equal to or larger than the first threshold value (step S211; No), the image drawing apparatus 1 does not eliminate the deviation of the optical axis in the main scanning direction. And the process returns to step S201. In this case, in step S201, the image drawing apparatus 1 selects a laser beam that is different from the laser beam whose optical axis was moved last time as a target for moving the optical axis.
 (2-3)副走査方向光軸ずれ補正処理
 図9は、副走査方向光軸ずれ補正処理の手順の一例を示すフローチャートである。画像描画装置1は、図9に示すフローチャートの処理を、図7のステップS105へ処理を進めた際に実行する。概略的には、画像描画装置1は、全色受光時間幅Twaと単色受光時間幅Tw1とのずれ幅が第2閾値未満になるように、全色受光時間幅Twaを監視しつつ各レーザ光の光軸を副走査方向に移動させるフィードバック制御を行う。
(2-3) Sub-Scanning Direction Optical Axis Deviation Correction Processing FIG. 9 is a flowchart illustrating an example of a procedure of sub-scanning direction optical axis deviation correction processing. The image drawing apparatus 1 executes the processing of the flowchart shown in FIG. 9 when the processing proceeds to step S105 in FIG. Schematically, the image drawing apparatus 1 monitors each color light reception time width Twa so that the deviation width between the all color light reception time width Twa and the single color light reception time width Tw1 is less than the second threshold. Feedback control for moving the optical axis in the sub-scanning direction is performed.
 まず、画像描画装置1は、光軸を移動させるレーザを決定する(ステップS301)。画像描画装置1は、例えば、赤色レーザ光LR、青色レーザ光LB、及び緑色レーザ光LGのうち一つのレーザ(例えば赤色レーザ光LR)の光軸の位置を固定(基準)にして他のレーザ光の光軸を補正する場合、当該他のレーザ(上述の例では青色レーザ光LB及び緑色レーザ光LG)を、ステップS301を実行する度に、交互に、光軸を移動させるレーザ光として指定する。 First, the image drawing apparatus 1 determines a laser that moves the optical axis (step S301). For example, the image drawing device 1 fixes (references) the optical axis position of one laser (for example, the red laser beam LR) of the red laser beam LR, the blue laser beam LB, and the green laser beam LG to another laser. When correcting the optical axis of the light, the other lasers (blue laser light LB and green laser light LG in the above example) are alternately designated as laser light that moves the optical axis every time step S301 is executed. To do.
 次に、画像描画装置1は、ステップS301で指定したレーザの光軸を右方向に移動させ、その後、走査領域Rtagを対象にして全色のレーザ光を点灯させた状態で走査を行い、全色受光時間幅Twaを計測する(ステップS302)。ここで、上述の移動幅は、例えば1ドット分の幅に設定される。 Next, the image drawing apparatus 1 moves the optical axis of the laser designated in step S301 in the right direction, and then performs scanning in a state where all color laser lights are turned on for the scanning region Rtag. The color light reception time width Twa is measured (step S302). Here, the above-described movement width is set to a width corresponding to one dot, for example.
 そして、画像描画装置1は、全色受光時間幅Twaが増加したか否か判定する(ステップS303)。具体的には、画像描画装置1は、ステップS302で計測した全色受光時間幅Twaが、その前に計測した全色受光時間幅Twaよりも大きいか否か判定する。 Then, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has increased (step S303). Specifically, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa measured in step S302 is larger than the all-color light reception time width Twa measured before that.
 そして、全色受光時間幅Twaが増加した場合(ステップS303;Yes)、画像描画装置1は、移動させたレーザの光軸は右方向にはずれていないと判断し、当該レーザの光軸を左方向に移動させ、その後再び全色受光時間幅Twaを計測する(ステップS304)。この移動幅は、ステップS302で右方向に光軸を移動させた直後の場合には、ステップS302での移動幅の2倍の幅(例えば2ドット分の幅)に設定され、ステップS305の直後の場合には、例えばステップS302での移動幅と同一(1ドット分の幅)に設定される。 When the all-color light reception time width Twa increases (step S303; Yes), the image drawing apparatus 1 determines that the optical axis of the moved laser is not shifted to the right, and moves the optical axis of the laser to the left. Then, the all-color light reception time width Twa is measured again (step S304). In the case immediately after the optical axis is moved in the right direction in step S302, this movement width is set to a width twice the movement width in step S302 (for example, a width corresponding to 2 dots), and immediately after step S305. In this case, for example, it is set to the same movement width (one dot width) in step S302.
 そして、画像描画装置1は、全色受光時間幅Twaが減少したか否か判定する(ステップS305)。そして、全色受光時間幅Twaが減少した場合には(ステップS305;Yes)、画像描画装置1は、対象となるレーザがまだ左方向にずれている可能性があると判断し、再びステップS302の処理を行う。一方、全色受光時間幅Twaが減少しなかった場合(ステップS305;No)、画像描画装置1は、ステップS301で決定されたレーザ光の光軸を右方向に移動させて全色受光時間幅Twaを再計測し(ステップS306)、ステップS311へ処理を進める。この場合の移動幅は、ステップS304での移動幅と同一(例えば1ドット分の幅)に設定される。 Then, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S305). If the all-color light reception time width Twa decreases (step S305; Yes), the image drawing apparatus 1 determines that there is a possibility that the target laser is still shifted leftward, and step S302 is performed again. Perform the process. On the other hand, when the all-color light reception time width Twa does not decrease (step S305; No), the image drawing apparatus 1 moves the optical axis of the laser light determined in step S301 to the right to shift the all-color light reception time width. Twa is measured again (step S306), and the process proceeds to step S311. In this case, the movement width is set to be the same as the movement width in step S304 (for example, a width corresponding to one dot).
 一方、ステップS303で、全色受光時間幅Twaが増加していないと判断した場合(ステップS303;No)、画像描画装置1は、全色受光時間幅Twaが減少したか否か判定する(ステップS307)。そして、全色受光時間幅Twaが減少した場合には(ステップS307;Yes)、画像描画装置1は、対象とするレーザ光の光軸がさらに右方向にずれている可能性があると判断し、当該レーザ光の光軸を右方向に移動させ、その後再び全色受光時間幅Twaを再計測する(ステップS308)。この移動幅は、例えばステップS302での移動幅と同一(1ドット分の幅)に設定される。そして、画像描画装置1は、全色受光時間幅Twaが減少したか否か判定する(ステップS309)。そして、全色受光時間幅Twaが減少した場合には(ステップS309;Yes)、画像描画装置1は、対象となるレーザ光の光軸がまだ右方向にずれている可能性があると判断し、再びステップS308の処理を行う。一方、全色受光時間幅Twaが減少しなかった場合(ステップS309;No)、画像描画装置1は、対象となるレーザの光軸を左方向に移動させて全色受光時間幅Twaを再計測し(ステップS310)、ステップS311へ処理を進める。この場合の移動幅は、ステップS308での移動幅と同一(例えば1ドット分の幅)に設定される。 On the other hand, when it is determined in step S303 that the all-color light reception time width Twa has not increased (step S303; No), the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S303). S307). When the all-color light reception time width Twa decreases (step S307; Yes), the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is further shifted to the right. Then, the optical axis of the laser beam is moved to the right, and then the all-color light reception time width Twa is measured again (step S308). This movement width is set to be the same as the movement width in step S302 (one dot width), for example. Then, the image drawing apparatus 1 determines whether or not the all-color light reception time width Twa has decreased (step S309). When the all-color light reception time width Twa decreases (step S309; Yes), the image drawing apparatus 1 determines that there is a possibility that the optical axis of the target laser beam is still shifted to the right. Then, the process of step S308 is performed again. On the other hand, if the all-color light reception time width Twa has not decreased (step S309; No), the image drawing apparatus 1 moves the optical axis of the target laser in the left direction to remeasure the all-color light reception time width Twa. (Step S310), and the process proceeds to step S311. In this case, the movement width is set to be the same as the movement width in step S308 (for example, a width corresponding to one dot).
 一方、ステップS307で、全色受光時間幅Twaが減少していない場合(ステップS307;No)、即ち、全色受光時間幅Twaが増加も減少もしていないと判断した場合には、画像描画装置1は、ステップS311へ処理を進める。この場合、画像描画装置1は、ステップS302で右方向に光軸を移動させた分、対象となるレーザの光軸を左方向に戻してもよい。 On the other hand, if it is determined in step S307 that the all-color light reception time width Twa has not decreased (step S307; No), that is, if it is determined that the all-color light reception time width Twa has not increased or decreased, the image drawing apparatus. 1 advances the process to step S311. In this case, the image drawing apparatus 1 may return the optical axis of the target laser to the left as much as the optical axis is moved to the right in step S302.
 そして、ステップS311では、画像描画装置1は、全色受光時間幅Twaと単色受光時間幅Tw1との差が第2閾値未満であるか否か判定する(ステップS311)。これにより、画像描画装置1は、副走査方向の光軸のずれが解消した否か判定する。そして、全色受光時間幅Twaと単色受光時間幅Tw1との差が第2閾値未満の場合(ステップS311;Yes)、画像描画装置1は副走査方向の光軸のずれが解消と判断し、フローチャートの処理を終了する。一方、全色受光時間幅Twaと単色受光時間幅Tw1との差が第2閾値以上の場合(ステップS311;No)、画像描画装置1は、副走査方向の光軸のずれが解消していないと判断し、ステップS301に処理を戻す。この場合、画像描画装置1は、ステップS301では、前回光軸を移動させたレーザ光とは異なるレーザ光を、光軸を移動させる対象に選ぶ。 In step S311, the image drawing apparatus 1 determines whether or not the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the second threshold (step S311). Thereby, the image drawing apparatus 1 determines whether or not the deviation of the optical axis in the sub-scanning direction has been eliminated. When the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is less than the second threshold (step S311; Yes), the image drawing apparatus 1 determines that the optical axis shift in the sub-scanning direction is eliminated, The process of the flowchart ends. On the other hand, when the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 is equal to or greater than the second threshold value (step S311; No), the image drawing apparatus 1 has not eliminated the optical axis shift in the sub-scanning direction. And the process returns to step S301. In this case, in step S301, the image drawing apparatus 1 selects a laser beam different from the laser beam whose optical axis has been moved last time as a target for moving the optical axis.
 [変形例]
 次に、本発明に好適な変形例について説明する。以下に示す変形例は、組み合わせて上述の実施例に適用されてもよい。
[Modification]
Next, modified examples suitable for the present invention will be described. The following modifications may be applied to the above-described embodiments in combination.
 (変形例1)
 上述の実施例では、画像描画装置1は、赤色レーザLD1、青色レーザLD2、及び緑色レーザLD3を同時に点灯させた状態で、光軸ずれの検出及び補正を行った。しかし、本発明が適用可能な方法は、これに限定されない。
(Modification 1)
In the above-described embodiment, the image drawing apparatus 1 detects and corrects the optical axis deviation with the red laser LD1, the blue laser LD2, and the green laser LD3 turned on simultaneously. However, the method to which the present invention is applicable is not limited to this.
 これに代えて、画像描画装置1は、赤色レーザLD1、青色レーザLD2、及び緑色レーザLD3のうち2つのレーザを同時に点灯させて、これらの2つのレーザ光の光軸ずれの検出及び補正を行ってもよい。この場合、例えば、画像描画装置1は、まず、赤色レーザLD1及び青色レーザLD2を同時に点灯させて、これらの2つのレーザ光LR、LBの光軸ずれを補正する。その後、画像描画装置1は、赤色レーザLD1又は青色レーザLD2のいずれか一方と緑色レーザLD3とを同時点灯させて、赤色レーザ光LR及び青色レーザ光LBと緑色レーザ光LGとの光軸ずれを補正する。この場合であっても、画像描画装置1は、好適に、赤色レーザ光LR、青色レーザ光LB、及び緑色レーザ光LGの光軸ずれを補正することができる。 Instead, the image drawing apparatus 1 simultaneously turns on two of the red laser LD1, the blue laser LD2, and the green laser LD3, and detects and corrects the optical axis deviation of these two laser beams. May be. In this case, for example, the image drawing apparatus 1 first turns on the red laser LD1 and the blue laser LD2 at the same time, and corrects the optical axis shift of these two laser beams LR and LB. Thereafter, the image drawing apparatus 1 turns on either the red laser LD1 or the blue laser LD2 and the green laser LD3 at the same time, thereby shifting the optical axes of the red laser light LR, the blue laser light LB, and the green laser light LG. to correct. Even in this case, the image drawing apparatus 1 can preferably correct the optical axis shift of the red laser light LR, the blue laser light LB, and the green laser light LG.
 また、他の例では、画像描画装置1は、4つ以上のレーザを対象に光軸ずれを補正してもよい。この場合であっても、画像描画装置1は、これらを同時点灯させて全色受光時間幅Twaを測定し、当該全色受光時間幅Twaに基づき、主走査方向の光軸ずれ補正又は/及び副走査方向の光軸ずれ補正を行う。 In another example, the image drawing apparatus 1 may correct the optical axis deviation for four or more lasers. Even in this case, the image drawing device 1 measures the all-color light reception time width Twa by simultaneously lighting them, and based on the all-color light reception time width Twa, the optical axis deviation correction in the main scanning direction or / and Optical axis deviation correction in the sub-scanning direction is performed.
 (変形例2)
 画像描画装置1は、上述した主走査方向の光軸ずれ補正処理又は副走査方向の光軸ずれ補正処理において、光軸を移動させる移動幅を、全色受光時間幅Twaと単色受光時間幅Tw1との差に応じて変更してもよい。
(Modification 2)
In the image drawing apparatus 1, in the above-described optical axis misalignment correction processing in the main scanning direction or optical axis misalignment correction processing in the sub-scanning direction, the movement width for moving the optical axis is set to the all-color light reception time width Twa and the single color light reception time width Tw1. You may change according to the difference.
 特に、上述の変形例1のように、2つのレーザを対象にして光軸ずれの補正を行う場合には、画像描画装置1は、全色受光時間幅Twaと単色受光時間幅Tw1との差が大きいほど、上述の移動幅、即ち発光するタイミングの調整量を大きくする。具体的には、画像描画装置1は、全色受光時間幅Twaと単色受光時間幅Tw1との差と、設定すべき移動幅とのマップ等を予め実験等に基づき作成してメモリに記憶しておき、当該マップを参照して上述の移動幅を設定する。このようにすることで、画像描画装置1は、光軸ずれの補正をより迅速に完了することができる。 In particular, when the optical axis deviation correction is performed for two lasers as in the above-described modification 1, the image drawing apparatus 1 uses the difference between the all-color light reception time width Twa and the single color light reception time width Tw1. Is larger, the above-mentioned movement width, that is, the adjustment amount of the light emission timing is increased. Specifically, the image drawing apparatus 1 creates a map of the difference between the all-color light reception time width Twa and the single color light reception time width Tw1 and the movement width to be set based on an experiment in advance and stores it in the memory. The above-described movement width is set with reference to the map. By doing so, the image drawing apparatus 1 can complete the correction of the optical axis deviation more quickly.
 (変形例3)
 画像描画装置1は、描画領域RRでの映像の描画時に上述の光軸ずれ補正処理を行う場合には、映像を構成するフレームの間に、所定間隔ごとに、描画領域RR外の走査領域Rtagを対象に走査する検査用のフレームを挿入してもよい。
(Modification 3)
When the image drawing apparatus 1 performs the above-described optical axis deviation correction processing at the time of drawing a video in the drawing area RR, the scanning area Rtag outside the drawing area RR is provided at predetermined intervals between frames constituting the video. An inspection frame for scanning the object may be inserted.
 例えば、画像描画装置1は、1秒間ごとに1つのフレームを上述の検査フレームとして、描画領域RR外であって、受光素子100を含む領域を走査領域Rtagとした走査を行う。そして、画像描画装置1は、上述の光軸ずれ補正処理において、検査用のフレームに対してのみ反映するように特定のレーザ光の光軸を移動させて、光軸ずれが減少する光軸の移動方向及び移動幅を特定する。このようにすることで、画像描画装置1は、光軸を移動させた結果一時的に光軸ずれが大きくなる場合であっても、観察者が視認する映像に影響を及ぼすことなく、光軸ずれの補正を実行することができる。 For example, the image drawing apparatus 1 performs scanning using one frame per second as the above-described inspection frame and a region outside the drawing region RR and including the light receiving element 100 as the scanning region Rtag. Then, the image drawing apparatus 1 moves the optical axis of the specific laser beam so as to reflect only the inspection frame in the optical axis deviation correction process described above, so that the optical axis deviation is reduced. Specify the direction and width of movement. By doing in this way, the image drawing apparatus 1 does not affect the image visually recognized by the observer even when the optical axis deviation temporarily increases as a result of moving the optical axis. Deviation correction can be performed.
 (変形例4)
 上述の画像描画装置1は、ヘッドアップディスプレイに好適に適用される。これについて、図10を参照して具体例を示す。
(Modification 4)
The above-described image drawing apparatus 1 is preferably applied to a head-up display. A specific example of this will be described with reference to FIG.
 図10は、本発明に係るヘッドアップディスプレイの構成例を示す。図10に示すヘッドアップディスプレイは、コンバイナ26を介して虚像「Iv」を運転者に視認させるものである。 FIG. 10 shows a configuration example of a head-up display according to the present invention. The head-up display shown in FIG. 10 makes the driver visually recognize the virtual image “Iv” via the combiner 26.
 図10に示す構成では、光源部1Aは、上述した実施例の画像描画装置1として機能する。そして、光源部1Aは、支持部材11a、11bを介して車室内の天井部22に付設され、現在地を含む地図情報や経路案内情報、走行速度、その他運転を補助する情報(以後、「運転補助情報」とも呼ぶ。)を示す表示像を構成する光を、コンバイナ26に向けて出射する。具体的には、光源部1Aは、光源ユニット1内に表示像の元画像(実像)を生成し、その画像を構成する光をコンバイナ26へ出射することで、運転者に虚像Ivを視認させる。 In the configuration shown in FIG. 10, the light source unit 1A functions as the image drawing device 1 of the above-described embodiment. The light source section 1A is attached to the ceiling section 22 in the passenger compartment via the support members 11a and 11b, and includes map information including the current location, route guidance information, traveling speed, and other information for assisting driving (hereinafter referred to as “driving assistance”). Light constituting a display image indicating “information” is emitted toward the combiner 26. Specifically, the light source unit 1A generates an original image (real image) of the display image in the light source unit 1, and emits light constituting the image to the combiner 26, thereby allowing the driver to visually recognize the virtual image Iv. .
 コンバイナ26は、光源部1から出射される表示像が投影されると共に、表示像を運転者の視点(アイポイント)「Pe」へ反射することで当該表示像を虚像Ivとして表示させる。そして、コンバイナ26は、天井部22に設置された支持軸部27を有し、支持軸部27を支軸として回動する。支持軸部27は、例えば、フロントウィンドウ20の上端近傍の天井部22、言い換えると運転者用の図示しないサンバイザが設置される位置の近傍に設置される。 The combiner 26 projects the display image emitted from the light source unit 1 and reflects the display image to the driver's viewpoint (eye point) “Pe” to display the display image as a virtual image Iv. And the combiner 26 has the support shaft part 27 installed in the ceiling part 22, and rotates the support shaft part 27 as a spindle. The support shaft portion 27 is installed, for example, in the vicinity of the ceiling portion 22 near the upper end of the front window 20, in other words, in the vicinity of a position where a sun visor (not shown) for the driver is installed.
 なお、本発明が適用可能なヘッドアップディスプレイの構成は、これに限られない。例えば、ヘッドアップディスプレイは、コンバイナ26を有さず、光源部1Aは、フロントウィンドウ20へ投影することで、フロントウィンドウ20に表示像を運転者のアイポイントPeへ反射させてもよい。また、光源部1Aの位置は、天井部22に設置される場合に限らず、ダッシュボード24の内部に設置されてもよい。この場合、ダッシュボード24には、コンバイナ26又はフロントウィンドウ20に光を通過させるための開口部が設けられる。 Note that the configuration of the head-up display to which the present invention is applicable is not limited to this. For example, the head-up display does not include the combiner 26, and the light source unit 1A may reflect the display image on the front window 20 to the driver's eye point Pe by projecting the light onto the front window 20. The position of the light source unit 1 </ b> A is not limited to being installed on the ceiling unit 22, and may be installed inside the dashboard 24. In this case, the dashboard 24 is provided with an opening for allowing light to pass through the combiner 26 or the front window 20.
 本発明は、レーザプロジェクタ、ヘッドアップディスプレイ、ヘッドマウントディスプレイなど、RGBレーザを利用した種々の映像機器に利用することができる。 The present invention can be used for various video devices using RGB lasers, such as laser projectors, head-up displays, and head-mounted displays.
 1 画像描画装置
 3 ビデオASIC
 7 レーザドライバASIC
 8 MEMS制御部
 9 レーザ光源部
 100 受光素子
1 Image drawing device 3 Video ASIC
7 Laser driver ASIC
8 MEMS control unit 9 Laser light source unit 100 Light receiving element

Claims (8)

  1.  第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正する光軸ずれ補正装置であって、
     前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、
     前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子と、
     前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出手段と、
     前記検出手段により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正手段と、
     を有することを特徴とする光軸ずれ補正装置。
    An optical axis deviation correction device that corrects an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source,
    Scanning means for scanning a scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously;
    A light receiving element disposed at a position capable of receiving the first beam and the second beam scanned in the scanning region;
    A light receiving period from the earliest time at which the light receiving element receives light from the first beam or second beam to the last time at which the light receiving element receives the first beam or second beam during the scanning period. Detecting means for detecting a deviation direction of the optical axes of the first beam and the second beam based on the width of the first beam;
    Correction means for correcting the optical axis deviation between the first beam and the second beam based on the deviation direction detected by the detection means;
    An optical axis misalignment correction apparatus comprising:
  2.   前記補正手段は、
     前記受光期間の幅が所定値以上の場合には、前記第一ビームと前記第二ビームとの主走査方向の光軸ずれを補正し、
     前記受光期間の幅が前記所定値未満の場合には、前記第一ビームと前記第二ビームとの副走査方向の光軸ずれを補正することを特徴とする請求項1に記載の光軸ずれ補正装置。
    The correction means includes
    When the width of the light receiving period is equal to or greater than a predetermined value, the optical axis deviation in the main scanning direction between the first beam and the second beam is corrected,
    2. The optical axis shift according to claim 1, wherein when the width of the light receiving period is less than the predetermined value, the optical axis shift between the first beam and the second beam in the sub-scanning direction is corrected. Correction device.
  3.  前記補正手段は、前記受光期間の幅が短くなるように、前記第一ビーム又は前記第二ビームの光軸ずれを補正することを特徴とする請求項1または2に記載の光軸ずれ補正装置。 The optical axis deviation correction device according to claim 1, wherein the correction unit corrects an optical axis deviation of the first beam or the second beam so that a width of the light receiving period is shortened. .
  4.  前記補正手段は、前記走査期間における、前記第一光源又は前記第二光源の発光のタイミングを制御することで、前記光軸ずれを補正することを特徴とする請求項1乃至3のいずれか一項に記載の光軸ずれ補正装置。 The said correction | amendment means correct | amends the said optical axis offset by controlling the light emission timing of the said 1st light source or the said 2nd light source in the said scanning period. The optical axis misalignment correction apparatus according to the item.
  5.  前記走査手段は、前記第一ビーム及び前記第二ビームにより描かれる映像を構成するフレームの間に、所定間隔ごとに前記第一ビーム及び前記第二ビームを前記走査領域に対して走査させるフレームを挿入し、
     前記走査領域は、前記映像が描かれる領域の外に設けられることを特徴とする請求項4に記載の光軸ずれ補正装置。
    The scanning means includes a frame that scans the scanning region with the first beam and the second beam at predetermined intervals between frames constituting an image drawn by the first beam and the second beam. Insert,
    The optical axis misalignment correction apparatus according to claim 4, wherein the scanning area is provided outside an area where the image is drawn.
  6.  前記補正手段は、前記受光期間の幅が長いほど、前記第一光源又は前記第二光源の発光のタイミングの調整量を大きくすることを特徴とする請求項1乃至5のいずれか一項に記載の光軸ずれ補正装置。 The said correction | amendment means enlarges the adjustment amount of the timing of light emission of said 1st light source or said 2nd light source, so that the width | variety of the said light reception period is long. Optical axis deviation correction device.
  7.  第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正し、
     前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、
     前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子とを備える光軸ずれ補正装置が実行する制御方法であって、
     前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出工程と、
     前記検出工程により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正工程と、
     を有することを特徴とする制御方法。
    Correct the optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source,
    Scanning means for scanning a scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously;
    A control method executed by an optical axis misalignment correction apparatus including a light receiving element arranged at a position capable of receiving the first beam and the second beam scanned in the scanning region,
    A light receiving period from the earliest time at which the light receiving element receives light from the first beam or second beam to the last time at which the light receiving element receives the first beam or second beam during the scanning period. A detection step of detecting a deviation direction of the optical axes of the first beam and the second beam based on the width of the first beam;
    A correction step of correcting an optical axis shift between the first beam and the second beam based on the shift direction detected by the detection step;
    A control method characterized by comprising:
  8.  第一光源から照射される第一ビームと、第二光源から照射される第二ビームとの光軸ずれを補正する光軸ずれ補正装置を光源部に有するヘッドアップディスプレイであって、
      前記光軸ずれ補正装置は、
     前記第一光源及び前記第二光源を同時に点灯させた状態で、所定の走査期間かけて走査領域に対して走査させる走査手段と、
     前記走査領域に走査した前記第一ビーム及び前記第二ビームを受光可能な位置に配置された受光素子と、
     前記走査期間中における、前記第一ビーム又は第二ビームから前記受光素子が受光した最先の時点から、前記第一ビーム又は前記第二ビームを前記受光素子が受光した最後の時点までの受光期間の幅に基づいて、前記第一ビーム及び前記第二ビームの光軸のずれ方向を検出する検出手段と、
     前記検出手段により検出したずれ方向に基づいて、前記第一ビームと前記第二ビームとの光軸ずれを補正する補正手段と、
     を有することを特徴とするヘッドアップディスプレイ。
    A head-up display having an optical axis deviation correction device for correcting an optical axis deviation between the first beam emitted from the first light source and the second beam emitted from the second light source,
    The optical axis deviation correcting device is
    Scanning means for scanning a scanning region over a predetermined scanning period with the first light source and the second light source turned on simultaneously;
    A light receiving element disposed at a position capable of receiving the first beam and the second beam scanned in the scanning region;
    The light receiving period from the earliest time when the light receiving element receives light from the first beam or the second beam to the last time when the light receiving element receives the first beam or the second beam during the scanning period. Detecting means for detecting a deviation direction of the optical axes of the first beam and the second beam based on the width of the first beam;
    Correction means for correcting the optical axis deviation between the first beam and the second beam based on the deviation direction detected by the detection means;
    A head-up display comprising:
PCT/JP2011/070147 2011-09-05 2011-09-05 Optical axis offset correcting device, control method, and heads-up display WO2013035142A1 (en)

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