JP2017090524A - Image display device, control method, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device that can suitably attenuate or shield a laser beam for adjustment during calibration while preventing the laser beam from being visually recognized by a user.SOLUTION: A projection device 6 is to display an image formed on the basis of laser beams from laser elements LD1 to LD3 and includes an ND filter 25. The ND filter 25 has arranged thereon a gradation filter part 5G having transmittance varying according to a position on which the laser beams are made incident, and shielding parts 5BR and 5BL having a transmittance lower than that of the gradation filter part 5G.SELECTED DRAWING: Figure 5

Description

  The present invention relates to adjustment of laser light emitted from a light source.

  2. Description of the Related Art Conventionally, there has been known an image display device that visually recognizes an image configured based on laser light as a virtual image from the position of a user's eyes. For example, Patent Document 1 discloses a technique for performing calibration such as luminance adjustment based on a secular change of a light source immediately after power-on of a head mounted display.

JP 2012-222630 A

  In an image display device that visually recognizes an image configured based on laser light as a virtual image from the position of the user's eyes, calibration such as optical axis alignment between lasers and adjustment of light amount balance is required. On the other hand, when performing calibration, it is necessary to output an adjustment laser beam that does not need to be visually recognized by the user. Patent Document 1 does not disclose any method for suitably blocking the laser beam for adjustment without allowing the user to visually recognize the laser beam.

  Examples of the problem to be solved by the present invention are as described above. The main object of the present invention is to provide an image display device capable of suitably attenuating or blocking laser light for adjustment at the time of calibration without making the user visually recognize.

  The invention described in claim 1 is an image display device for displaying an image configured based on laser light from a light source, comprising a light amount adjusting means for adjusting a light amount of the laser light, and the light amount adjusting means. Is characterized in that a first transmission part having a different transmittance according to a position where the laser beam is incident and a second transmission part having a lower transmittance than the first transmission part are arranged.

  According to an eighth aspect of the present invention, a first transmission part having a different transmittance according to a position where a laser beam from a light source enters and a second transmission part having a lower transmittance than the first transmission part are arranged. An adjustment laser beam for adjusting the laser beam from the light source, the control method executed by the image display device that displays the image configured based on the laser beam And a moving step of moving the light amount adjusting means so that the adjustment laser beam is emitted to the second transmission part when the adjustment laser beam is emitted by the control step. It is characterized by having.

  The invention according to claim 9 is provided with a first transmission part having a different transmittance according to a position where the laser beam from the light source is incident, and a second transmission part having a lower transmittance than the first transmission part. A program executed by a computer that controls an image display device that displays an image configured based on the laser beam, the adjustment for adjusting the laser beam from the light source A control unit that emits a laser beam for adjustment, and when the adjustment laser beam is emitted by the control unit, the light amount adjustment unit is moved so that the adjustment laser beam is emitted to the second transmission portion. The computer is caused to function as moving means.

1 shows a schematic configuration of a head-up display according to an embodiment. The structure of a projection apparatus is shown. An example of each laser beam spot irradiated on the PSD is shown. The front view of ND filter is shown. (A) and (B) show the incident position of the laser beam on the ND filter when calibration is executed. (C) and (D) show the incident position of the laser beam on the ND filter at the time of content drawing. It is a figure explaining presence of a calibration line light, and its general interception method. The front view of ND filter concerning a modification is shown. The front view of ND filter concerning a modification is shown. A modification of the ND filter is shown.

  In a preferred embodiment of the present invention, the image display device displays an image configured based on laser light from a light source, and includes a light amount adjusting unit that adjusts the light amount of the laser light, and the light amount adjusting unit includes Are arranged such that a first transmissive part having a different transmittance according to a position where the laser beam is incident and a second transmissive part having a lower transmittance than the first transmissive part.

  The image display device displays an image configured based on laser light from a light source, and includes a light amount adjusting unit. The light amount adjusting means includes a first transmission part having a different transmittance depending on a position where the laser beam is incident, and a second transmission part having a lower transmittance than the first transmission part. According to this aspect, the image display device is more suitable for the laser beam to be transmitted to the second transmission unit so that the display based on the laser beam for adjustment is not visually recognized by the user even when the laser beam for adjustment is output during calibration. Can be attenuated or blocked.

  In one aspect of the image display device, the second transmission part has a transmittance lower than the lowest transmittance among the transmittances of the first transmission part. According to this aspect, the image display apparatus can preferably attenuate or block the adjustment laser beam output during calibration by the second transmission unit.

  In a preferred example of the image display device, the second transmission part is disposed at both ends of the first transmission part.

  In another aspect of the image display device, the image display device emits adjustment laser light for adjusting laser light from the light source, and the adjustment laser light is emitted by the control means. And a moving means for moving the light quantity adjusting means so that the adjustment laser light is irradiated onto the second transmitting portion. According to this aspect, the image display apparatus can irradiate the second transmissive portion with the adjustment laser light by moving the light amount adjustment unit when the adjustment laser is emitted.

  In another aspect of the image display device, the image display device further includes a light detection unit on which a part of the adjustment laser light is incident before entering the second transmission unit. According to this aspect, the image display apparatus can appropriately execute necessary laser light calibration based on the output of the light detection unit even when the adjustment laser light is attenuated or blocked by the second transmission unit. it can.

  In a preferred example of the image display device, the image display device is a head-up display that visually recognizes an image configured based on the laser beam as a virtual image from the position of the user's eyes.

  In another embodiment of the present invention, a first transmission part having a different transmittance according to a position where a laser beam from a light source enters and a second transmission part having a lower transmittance than the first transmission part are arranged. An adjustment laser beam for adjusting the laser beam from the light source, the control method executed by the image display device that displays the image configured based on the laser beam And a moving step of moving the light amount adjusting means so that the adjustment laser beam is emitted to the second transmission part when the adjustment laser beam is emitted by the control step. Have. By executing this control method, the image display device outputs the laser light so that the display based on the adjustment laser light is not visually recognized by the user even when the adjustment laser light is output during calibration. It can be suitably attenuated or blocked by the two transmission parts.

  In another embodiment of the present invention, a first transmission part having a different transmittance according to a position where a laser beam from a light source enters and a second transmission part having a lower transmittance than the first transmission part are arranged. A program executed by a computer that controls an image display device that displays an image configured based on the laser beam, the adjustment for adjusting the laser beam from the light source A control unit that emits a laser beam for adjustment, and when the adjustment laser beam is emitted by the control unit, the light amount adjustment unit is moved so that the adjustment laser beam is emitted to the second transmission portion. The computer is caused to function as moving means. By executing this program, the computer transmits the laser beam to the second transmission unit so that the display based on the adjustment laser beam is not visually recognized by the user even when the adjustment laser beam is output during calibration. Can be more suitably attenuated or blocked. Preferably, the program is stored in a storage medium.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Configuration of head-up display]
FIG. 1 is a schematic configuration diagram of a head-up display 100 according to the present embodiment. As shown in FIG. 1, the head-up display 100 according to the present embodiment mainly includes a light source unit 1 and a concave mirror 10, and includes a front window 25, a ceiling portion 27, a bonnet 28, and a dashboard 29. It is attached to the vehicle provided with.

  The light source unit 1 is provided in the dashboard 29 and has a projection device 6 in the housing. The projection device 6 emits light constituting the display image (also referred to as “display light”) from the aperture 51 constituting the laser beam exit of the light source unit 1 and irradiates the concave mirror 10. In this case, the display light reflected by the concave mirror 10 reaches the front window 25 through the opening 89 provided in the dashboard 29 and further reflects by the front window 25 to reach the position of the driver's eyes. . In this manner, the light source unit 1 causes the display light to reach the position of the driver's eyes and causes the driver to visually recognize the virtual image “Iv”. The light source unit 1 or the projection device 6 is an example of the “image display device” in the present invention.

  The concave mirror 10 reflects the display light emitted from the light source unit 1 toward the opening 89 provided in the dashboard 29 so as to reach the front window 25. In this case, the concave mirror 10 magnifies and reflects the image indicated by the display light.

  The installation position of the light source unit 1 is not limited to being inside the dashboard 29 as shown in FIG. For example, the light source unit 1 may be in an aspect (including an aspect in which the light source unit 1 is attached to a sun visor not shown) attached to the ceiling portion 27. In this case, a combiner may be provided between the light source unit 1 and the front window 25.

[Configuration of Projection Device]
FIG. 2 shows the configuration of the projection device 6. As shown in FIG. 1, the projection device 6 includes an image signal input unit 2, a video processing unit 3, a frame memory 4 </ b> A, a ROM 4 </ b> B, a RAM 4 </ b> C, a laser driver 7, a MEMS driver 8, and a laser light source unit 9. A microlens array 13, a field lens 14, an MCU (Micro Controller Unit) 21, and a nonvolatile memory 22. The projection device 6 causes the observer to visually recognize the image by projecting light constituting the display image. As will be described later, the projection device 6 is configured to be able to change the amount of emitted light continuously (that is, steplessly) by the ND filter 25. Hereinafter, an image to be visually recognized by the observer is also referred to as a “content image”.

  The image signal input unit 2 receives an externally input image signal “Si” and outputs it to the video processing unit 3.

  The video processing unit 3 controls the laser driver 7 and the MEMS driver 8 based on the image signal Si input from the image signal input unit 2 and the scanning position information “Se” input from the MEMS mirror 95. In addition, the video processing unit 3 writes the image data input from the image signal input unit 2 into the frame memory 4A, and reads the data as needed according to the drive timing of the MEMS mirror 95, and the red (R), green (G), blue ( A control signal corresponding to the luminance of each pixel is sequentially transmitted to the laser driver 7 for each color of B). Further, the video processing unit 3 controls the read timing of the image data from the frame memory 4A. The video processing unit 3 is configured as, for example, an ASIC (Application Specific Integrated Circuit).

  The ROM 4B stores a control program and data for operating the video processing unit 3. Various data are sequentially read from and written into the RAM 4C as a work memory when the video processing unit 3 operates.

  The laser driver 7 is a block that generates a signal for driving a laser diode provided in a laser light source unit 9 described later. The laser driver 7 includes a red laser driving circuit 71, a blue laser driving circuit 72, and a green laser driving circuit 73. The red laser drive circuit 71 drives the red laser element LD1 based on the control signal output from the video processing unit 3. The blue laser driving circuit 72 drives the blue laser element LD2 based on the control signal output from the video processing unit 3. The green laser driving circuit 73 drives the green laser element LD3 based on a signal output from the video processing unit 3.

  In this embodiment, the laser driver 7 receives from the MCU 21 a correction signal “Sg” representing a correction coefficient related to the intensity of the emitted light. Then, the laser driver 7 corrects the signal representing the light emission pattern received from the video processing unit 3 based on the correction signal Sg, and drives the laser elements LD1 to LD3 of each color based on the signal representing the corrected light emission pattern. To control the current value.

  The MEMS driver 8 controls the MEMS mirror 95 based on a signal output from the video processing unit 3. The MEMS driver 8 includes a servo circuit and a driver circuit. The servo circuit controls the operation of the MEMS mirror 95 based on the signal from the video processing unit 3. The driver circuit amplifies the control signal for the MEMS mirror 95 output from the servo circuit 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 7. The laser light source unit 9 mainly includes a red laser element LD1, a blue laser element LD2, a green laser element LD3, a light amount detector 23, a PSD (Position Sensitive Detector) 24, an ND filter 25, an actuator 26, , Collimator lenses 91a to 91c, reflection mirrors 92a to 92c, a polarizing beam splitter 93, a beam splitter 94, a MEMS mirror 95, and a PSD lens 99.

  The red laser element LD1 emits red laser light (also referred to as “red laser light”), the blue laser element LD2 emits blue laser light (also referred to as “blue laser light”), and the green laser element LD3. Emits green laser light (also referred to as “green laser light”). The laser elements LD1 to LD3 are examples of the “light source” in the present invention. The collimator lenses 91a to 91c convert the red, blue, and green laser beams into parallel light and emit the parallel beams to the reflection mirrors 92a to 92c. The reflection mirror 92b reflects blue laser light. The reflection mirror 92c transmits blue laser light and reflects green laser light. The reflection mirror 92a transmits red laser light and reflects blue and green laser light. The red laser light transmitted through the reflection mirror 92 a and the blue and green laser light reflected by the reflection mirror 92 a are incident on the polarization beam splitter 93.

  The laser light incident on the polarization beam splitter 93 is divided into light that passes through the polarization beam splitter 93 and enters the ND filter 25, and light that reflects off the polarization beam splitter 93 and enters the beam splitter 94. Part of the light reflected by the polarizing beam splitter 93 and incident on the beam splitter 94 is transmitted through the beam splitter 94 and incident on the light amount detector 23, and the other light is reflected by the beam splitter 94 and enters the PSD lens 99. Incident.

  The light amount detector 23 generates a detection signal “Sa” that is an electrical signal corresponding to the light amount (intensity) of the laser light that has passed through the beam splitter 94, and supplies the detection signal “Sa” to the MCU 21. The PSD (semiconductor position detection element) 24 detects the position of the spot-like light and supplies a detection signal “Sb” relating to the detected position of the light to the MCU 21. FIG. 3 shows an example of spots corresponding to each of the red laser beam LR, the blue laser beam LB, and the green laser beam LG that are simultaneously irradiated onto the PSD 24. In FIG. 3, the circles in which the letters “R”, “B”, and “G” are written indicate the spots of the red laser beam LR, the blue laser beam LB, and the green laser beam LG, respectively (the same applies hereinafter). And). 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 the 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. The PSD 24 generates a detection signal Sb related to the position of the optical axis of each detected laser beam LB, LG, LR. The light quantity detector 23 and the PSD 24 are examples of the “light detection unit” in the present invention.

  With reference to FIG. 2 again, the configuration of the projection device 6 will be described. The laser beam that has passed through the polarization beam splitter 93 enters the ND filter 25. The ND filter 25 is configured to be movable in a direction (Z-axis direction in FIG. 2) perpendicular to the incident direction (X-axis direction in FIG. 2) of the combined beam of each color laser beam. The transmittance of the laser light through the ND filter 25 varies depending on the incident position on the Z-axis of the combined beam in the ND filter 25 (also referred to as “incident position Pin”).

  FIG. 4 is a view of the ND filter 25 observed from the incident direction of the laser light. The ND filter 25 includes a gradation filter unit 5G whose transmittance continuously changes in the Z-axis direction, and light shielding units 5BR and 5BL provided at both ends of the gradation filter unit 5G. In the example of FIG. 4, the transmittance of the light shielding portions 5BR and 5BL is set to 0%. Further, the transmittance of the gradation filter unit 5G is set from about 2% to about 90%, and is set so as to decrease as it approaches the light shielding unit 5BL and to increase as it approaches the light shielding unit 5BR. The transmittance in the gradation filter unit 5G may change linearly or logarithmically. In the case of providing a large attenuation characteristic, it is desirable that the transmittance changes logarithmically in order to reduce the size of the ND filter 25. The ND filter 25 is an example of the “light amount adjusting unit” in the present invention, the gradation filter unit 5G is an example of the “first transmission unit” in the present invention, and the light shielding units 5BR and 5BL are the “first” in the present invention. It is an example of “2 transmission part”.

  With reference to FIG. 2 again, the configuration of the projection device 6 will be described. The actuator 26 is typically configured with a stepping motor as a drive source, and moves the ND filter 25 in the Z-axis direction based on a control signal “Sd” transmitted from the MCU 21, so that the incident position Pin of the ND filter 25 Change the transmittance at.

  At a position where laser light is emitted from the laser light source unit 9, a microlens array 13, which is an example of EPE (Exit Pupil Expander), and a field lens 14 are provided. The MEMS mirror 95 reflects the laser light transmitted through the ND filter 25 toward the microlens array 13. The MEMS mirror 95 basically moves so as to scan the microlens array 13 under the control of the MEMS driver 8 in order to display an image indicated by the image signal Si, and scan position information at that time (for example, a mirror) And the like) are output to the video processing unit 3 as scanning position information “Se”.

  The microlens array 13 has a plurality of microlenses arranged thereon, and the laser beam reflected by the MEMS mirror 95 is incident thereon. The field lens 14 enlarges an image (that is, an intermediate image) formed on the radiation surface of the microlens array 13. The light emitted from the field lens 14 passes through the aperture 51 and enters the concave mirror 10.

  The external light sensor 27 detects the amount of external light and supplies a detection signal “Sc” to the MCU 21.

  The non-volatile memory 22 stores data defining the position on the Z axis of the ND filter 25 according to the external light amount at the time of image drawing based on the image signal Si (also referred to as “content drawing”). As will be described later, the above-described data is set such that the incident position Pin is within the gradation filter unit 5G during content rendering, and the transmittance at the incident position Pin decreases as the external light amount decreases. The nonvolatile memory 22 stores information necessary for calibration described later.

  The MCU 21 performs processing (that is, calibration) for adjusting the optical axis alignment of the laser beams LR, LB, and LG and adjusting the light amount balance of the laser beams to be output to the laser elements LD1 to LD3 at a predetermined timing not during content drawing. Run. Specifically, the MCU 21 detects the optical axis deviation and the direction of the optical axis deviation based on the detection signal Sb received from the PSD 24, and generates a correction signal “Sf” for correcting the light emission timing of each of the lasers LD1 to LD3. To the video processing unit 3. Thereby, the optical axes of the laser beams LR, LB, and LG are made to coincide. Further, the MCU 21 determines a correction coefficient for correcting the current value for driving the laser beam for each of R, G, and B based on the detection signal Sa received from the light amount detector 23, and sets each of the correction coefficients. The correction signal Sg shown is output to the laser driver 7. Note that the video processing unit 3 may reflect the correction based on the correction signal Sg on the laser driver 7 by receiving the correction signal Sg from the MCU 21.

  The video processing unit 3, the laser driver 7, and the MCU 21 are examples of a “control unit”, a “moving unit”, and a computer that executes a program in the present invention.

[ND filter position adjustment]
Next, a method for adjusting the position of the ND filter 25 will be described. Schematically, the MCU 21 controls the position of the ND filter 25 so that the incident position Pin is in the gradation filter unit 5G during content rendering, and the incident position Pin is within the light shielding unit 5BL or the light shielding unit 5BR during calibration. The position of the ND filter 25 is controlled so that This suitably suppresses unnecessary display for adjustment being visually recognized by the user during the execution of calibration.

  FIGS. 5A and 5B are diagrams illustrating the position of the incident position Pin when the calibration is performed. When performing calibration, the MCU 21 controls the position of the ND filter 25 so that the incident position Pin is within the light shielding portion 5BL or the light shielding portion 5BR as shown in FIG. 5A or 5B. 5A and 5B, the laser beam does not pass through the ND filter 25, and the laser beam does not reach the MEMS mirror 95. Therefore, the laser beam is not visually recognized by the user during calibration.

  Preferably, the MCU 21 may determine whether the incident position Pin is to be in the light shielding portion 5BL or the light shielding portion 5BR based on the immediately preceding incident position Pin of the ND filter 25. Specifically, the MCU 21 controls the actuator 26 so that the incident position Pin is within the light shielding portion 5BL when the incident position Pin before the calibration is performed is closer to the light shielding portion 5BL than the light shielding portion 5BR. Then, the ND filter 25 is moved. On the other hand, when the incident position Pin before the calibration is performed is closer to the light shielding portion 5BR than the light shielding portion 5BL, the MCU 21 controls the actuator 26 so that the incident position Pin is within the light shielding portion 5BR. The filter 25 is moved. As described above, the MCU 21 moves the incident position Pin to the light shielding portion near the incident position Pin before the calibration is performed, thereby minimizing the moving distance of the ND filter 24 and the time required for moving the ND filter 25. Can be suitably shortened.

  FIG. 5C shows an incident position Pin when transmitting a high-luminance laser beam, and FIG. 5D shows an incident position Pin when transmitting a low-luminance laser beam. The MCU 21 refers to a predetermined map or the like stored in the nonvolatile memory 22 based on the external light amount indicated by the detection signal Sc received from the external light sensor 24 at the time of content drawing, and the incident position Pin in the gradation filter unit 5G. To decide. In this case, the MCU 21 determines the incident position Pin so that the brightness of the content image becomes darker as the detected external light amount becomes smaller.

  Specifically, the MCU 21 determines that the content image needs to be brightened when the external light amount detected by the external light sensor 24 is relatively high. Therefore, in this case, the MCU 21 controls the actuator 26 so that the incident position Pin is positioned in the gradation filter portion 5G having a high transmittance (for example, near 90% transmittance) as shown in FIG. Then, the ND filter 25 is moved. Thereby, the MCU 21 can make the viewer clearly see the content image even when the ambient light is relatively bright. On the other hand, the MCU 21 determines that it is necessary to darken the content image when the external light amount detected by the external light sensor 24 is relatively low. Therefore, in this case, the MCU 21 controls the actuator 26 so that the incident position Pin is positioned in the gradation filter portion 5G having a low transmittance (for example, near 2% transmittance) as shown in FIG. Then, the ND filter 25 is moved. Thereby, MCU21 can make an observer visually recognize a content image with moderate brightness.

  Next, the effect of the present embodiment will be supplementarily described with reference to FIG.

  6A shows an area that can be scanned by the MEMS mirror 95 (also referred to as “MEMS movable area SR”) and an area that can be irradiated with display light of a content image (also referred to as “content display area RR”). The positional relationship is shown. As shown in FIG. 6A, the content display area RR is an area inside the microlens array 13, and the MEMS movable area SR is an area including the microlens array 13 and the content display area RR. The MEMS mirror 95 draws a content image (video) to be displayed in the content display area RR by scanning the laser light a plurality of times (that is, performing a raster scan) as indicated by an arrow in FIG. Let In this embodiment, the video processing unit 3 displays a calibration line (also referred to as “calibration line light CL”) different from the content display outside the content display area RR during calibration.

  Since the calibration line light CL is light that does not need to be visually recognized by the observer, it is generally displayed at the outermost position (the upper end in FIG. 6A) of the MEMS movable area SR and shielded by the aperture 51. It is the target. FIG. 6B is a view of the light emitted from the projection device 6 observed from the side. In the example of FIG. 6B, the range sandwiched between the alternate long and short dash lines 82 and 83 corresponds to the content display area RR, and the range sandwiched between the calibration line light CL and the broken line 84 corresponds to the MEMS movable area SR. FIG. 6C is an enlarged view of the vicinity of the aperture 51 shown in FIG.

  In the example of FIG. 6B and FIG. 6C, the calibration line light CL is shielded by a part of the aperture 51 and is not emitted from the light source unit 1. On the other hand, the alternate long and short dash line 82 constituting the upper end of the content display area RR is separated from the aperture 51 so that a part of the content image visually recognized by the observer is not lost. As described above, when the calibration line light CL is shielded by the aperture 51, it is necessary to sufficiently overlap the upper end portion of the MEMS movable area SR with respect to the aperture 51, and the aperture 51 and the content display area RR. It is necessary to provide a sufficient clearance between them (see FIG. 6C). On the other hand, when the content display area RR is narrowed in order to provide the overlap width and clearance width as shown in FIG. 6C, there is a problem that the brightness of the content image decreases due to the decrease in the duty ratio.

  In consideration of the above, in this embodiment, the ND filter 25 is provided with the light shielding portions 5BR and 5BL, and the calibration line light CL is shielded by matching the incident position Pin with the light shielding portions 5BR and 5BL during calibration. As a result, the projection device 6 does not need to irradiate the aperture 51 with the calibration line light CL to shield it, and the content display area RR is not limited in terms of overlap and clearance as shown in FIG. Can be as wide as possible. Therefore, it is possible to suitably prevent the brightness of the content image from being reduced by narrowing the content display area RR.

  As described above, the projection apparatus 6 according to the present embodiment displays an image configured based on the laser light from the laser elements LD1 to LD3 and includes the ND filter 25. The ND filter 25 is provided with gradation filters 5G having different transmittances depending on the position where the laser beam is incident, and light shielding portions 5BR and 5BL having transmittances lower than those of the gradation filter 5G. According to this aspect, the projection device 6 transmits the laser light to the light shielding portions 5BR and 5BL so that the display based on the adjustment laser light is not visually recognized by the user even when the adjustment laser light is output during calibration. Can be suitably blocked.

[Modification]
Hereinafter, modified examples suitable for the above-described embodiments will be described. The following modifications may be applied in any combination to the above-described embodiments.

(Modification 1)
The projection device 6 may change the brightness of the content image based on the user input instead of changing the brightness of the content image according to the external light amount indicated by the detection signal Sd of the external light sensor 24 at the time of content drawing. . In this case, the MCU 21 of the projection device 6 refers to a predetermined table or the like, determines the position on the Z axis of the ND filter 25 for realizing the brightness specified by the user input, and the ND filter 25 by the actuator 26. Move.

(Modification 2)
The transmittance at the light shielding portions 5BL and 5BR is not limited to 0%, and the transmittance should be low enough that the observer cannot visually recognize the calibration line light CL when the incident position Pin is aligned with the light shielding portions 5BL and 5BR. That's fine.

  FIG. 7 shows a front view of the ND filter 25A according to this modification. In the example of FIG. 7, the transmittance of the light shielding portions 5BL and 5R is set to 0.5%. Even in this case, when the calibration is executed, the calibration line light CL is substantially visually recognized by the observer by adjusting the incident position Pin to either the light shielding part 5BL or the light shielding part 5BR. Can be prevented.

(Modification 3)
Although the two light shielding portions 5BL and 5R are provided at both ends of the ND filter 25, the arrangement and the number of light shielding portions to which the present invention can be applied are not limited thereto.

  For example, the light shielding unit may be provided only on one of both ends of the ND filter 25. In another example, the light shielding portions may be provided at two arbitrary positions instead of the both end positions of the ND filter 25. In yet another example, three or more light shielding portions may be provided. In still another example, the light shielding part may be provided at any one location.

  FIG. 8 shows a front view of the ND filter 25B according to this modification. In the ND filter 25B of FIG. 8, the gradation filter portion 5GL in which the transmittance continuously changes from about 0.5% to about 45%, the light shielding portion 5B in which the transmittance is set to 0%, and the transmittance is about A gradation filter unit 5GR continuously changing from 45% to about 90% is provided in order. Thus, the ND filter 25B is provided with one light shielding portion 5B at a position between the gradation filter portions 5GL and 5GR.

  In the example of FIG. 8, for example, the nonvolatile memory 22 stores in advance the relationship between the position of the ND filter 25B on the Z axis and the transmittance at the incident position Pin at that position. Then, the MCU 21 controls the actuator 26 so that the incident position Pin becomes a position that realizes a desired transmittance of the gradation filter units 5GL and 5GR during content drawing. On the other hand, when performing calibration, the MCU 21 controls the actuator 26 so that the incident position Pin is positioned at the light shielding portion 5B.

  As described above, the light shielding portions may be provided at arbitrary positions in the ND filter 25, and the number of light shielding portions is not limited to two.

(Modification 4)
The ND filter 25 is not limited to a flat filter whose transmittance continuously changes along the Z axis.

  FIG. 9A shows an example in which a circular ND filter 25 </ b> C is arranged instead of the ND filter 25. As shown in the figure, the ND filter 25 </ b> C is configured in a disk shape including a circle centered on the center point C.

  The ND filter 25C has a gradation filter portion 5G whose transmittance continuously changes between about 0.5% and about 90% along the circumferential direction of a circle centered on the center point C on the incident surface. And a light shielding portion 5B having a transmittance of 0%. In the example of FIG. 9A, the ND filter 25C has the same transmittance in the radial direction of the circle centered on the center point C.

  In this case, the actuator 26 rotates the ND filter 25C around the center point C as indicated by an arrow D2 in FIG. In this case, for example, the nonvolatile memory 22 stores in advance information on the rotation angle of the ND filter 25C with respect to a predetermined position as a reference and the transmittance at the incident position Pin at the rotation angle. Then, the MCU 21 refers to the information stored in the nonvolatile memory 22 based on the external light amount indicated by the detection signal Sc, and controls the actuator 26 so that the ND filter 25C has a desired rotation angle. Specifically, at the time of normal image drawing, the MCU 21 causes the actuator 26 so that a position on the gradation filter unit 5G from which a desired transmittance corresponding to the amount of light to be emitted by the projection device 6 is obtained is the incident position Pin. Then, the ND filter 25C is rotated. On the other hand, at the time of calibration, the MCU 21 rotates the ND filter 25C via the actuator 26 so that the incident position Pin is on the light shielding portion 5B.

  FIG. 9B shows an example in which, instead of the ND filter 25, an ND filter 25D whose transmittance varies stepwise along the Z axis is shown. The ND filter 25D includes light shielding portions 5BR and 5BL provided at both ends, and a gradation filter portion 5G sandwiched between them, and the gradation filter portion 5G has a transmittance stepwise along the Z axis. It is configured to change gradually. In the example of FIG. 9B, in the gradation filter unit 5G, three rectangular regions having the same transmittance in the region are formed along the Z axis. Thus, the gradation filter unit 5G is not limited to a mode in which the transmittance continuously changes along the Z axis.

DESCRIPTION OF SYMBOLS 1 Light source unit 3 Image processing part 6 Projection apparatus 7 Laser driver 8 MEMS driver 10 Concave mirror 21 MCU
22 Non-volatile memory 23 Light quantity detector 25, 25A-25D ND filter 26 Actuator 27 External light sensor 95 MEMS mirror

Claims (10)

An image display device that displays an image configured based on laser light from a light source,
A light amount adjusting means for adjusting the light amount of the laser light;
The light amount adjusting means includes a first transmission part having a different transmittance depending on a position where the laser light is incident, and a second transmission part having a lower transmittance than the first transmission part. A characteristic image display device.   The image display apparatus according to claim 1, wherein the second transmission unit has a transmittance that is lower than the lowest transmittance among the transmittances of the first transmission unit.   3. The image display device according to claim 1, wherein the second transmissive portion is disposed at both ends of the first transmissive portion. Control means for emitting adjustment laser light for adjusting laser light from the light source;
Moving means for moving the light amount adjusting means so that when the adjusting laser light is emitted by the control means, the adjusting laser light is irradiated to the second transmitting portion;
The image display apparatus according to claim 1, further comprising: A plurality of the second transmission parts are provided,
The moving means moves the second transmission amount with the smallest amount of movement of the light amount adjusting means when moving the light amount adjusting means so that the adjustment laser light is irradiated to any one of the second transmitting portions. The image display apparatus according to claim 4, wherein the light amount adjusting unit is moved so that the adjustment laser light is irradiated to a part.   6. The image display device according to claim 4, further comprising a light detection unit on which a part of the adjustment laser light is incident before entering the second transmission unit.   The image display device according to claim 1, wherein the image display device is a head-up display that visually recognizes an image configured based on the laser light as a virtual image from a position of a user's eyes. A light amount adjusting means in which a first transmission part having different transmittance according to a position where laser light from a light source is incident and a second transmission part having a lower transmittance than the first transmission part are disposed; A control method executed by an image display device that displays an image configured based on the laser beam,
A control step of emitting an adjustment laser beam for adjusting the laser beam from the light source;
A moving step of moving the light amount adjusting means so that when the adjustment laser beam is emitted by the control step, the adjustment laser beam is applied to the second transmission unit;
A control method characterized by comprising: A light amount adjusting means in which a first transmission part having different transmittance according to a position where laser light from a light source is incident and a second transmission part having a lower transmittance than the first transmission part are disposed; A program executed by a computer that controls an image display device that displays an image configured based on the laser beam,
Control means for emitting adjustment laser light for adjusting laser light from the light source;
When the adjustment laser beam is emitted by the control unit, the computer is caused to function as a moving unit that moves the light amount adjustment unit so that the adjustment laser beam is irradiated onto the second transmission unit. A featured program.   A storage medium storing the program according to claim 9.