JP2017116660A - Image display device and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve control of video image expressions with a depth sense regarding an image display device and control method of the image display device.SOLUTION: An image display device 20 comprises: a light source 101; a scanning unit 106 that scans laser light emitted from the light source 101; a screen 108 on which an image is formed by the scanned laser light; an optical system that generates a virtual image by the image; a drive unit 109 that moves the screen 108 in parallel with an advance direction of the laser light; a screen drive circuit 204 that drives the drive unit 109; a mirror drive circuit 203 that drives the scanning unit 106; and an image processing circuit 201 that determines a drive pattern on the basis of video image information to be displayed to output the determined drive pattern to the screen drive circuit 204, and determines a scanning pattern on the basis of the drive pattern to output the determined scanning pattern to the mirror drive circuit 203.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image display device and a control method thereof, and is suitable for mounting on a moving body such as a passenger car, for example.

  In recent years, an image display device called a head-up display has been developed, and is mounted on a moving body such as a passenger car. For example, in a head-up display mounted on a passenger car, laser light modulated by image information is projected toward a windshield (front glass), and the reflected light is irradiated to the eyes of the driver. As a result, the driver can see a virtual image of the image in front of the windshield. For example, the vehicle speed, the outside temperature, etc. are displayed as a virtual image. Recently, displaying navigation images and images that call attention to passers-by are also considered as virtual images.

  In the head-up display, a laser light source such as a semiconductor laser can be used as a light source. In this configuration, while the laser beam is modulated in accordance with the video signal, the laser beam is scanned on the screen by controlling the reflection angle of the laser beam by the mirror actuator. The laser light is diffused by the screen, and the area of the light irradiated to the driver's eyes is expanded. As a result, even if the driver moves his head to some extent, the eyes do not come out of the irradiation area, and the driver can see the image (virtual image) well and stably.

  In such a head-up display, an image spread in the depth direction can be displayed by moving the screen in parallel with the traveling direction of the laser beam. Patent Document 1 below describes a configuration in which a screen is moved in parallel with the traveling direction of laser light.

JP 2009-150947 A

  In the image display device having the above configuration, it is necessary to consider the depth control accompanying the movement of the screen in addition to the two-dimensional scanning control of the video information on the screen. The current situation is not progressing.

  Therefore, an object of the present invention is to solve such a problem and to realize a control for performing a video expression with a sense of depth to a higher degree.

  An image display device according to a main aspect of the present invention includes a light source, a scanning unit that scans laser light emitted from the light source, a screen on which an image is formed by the scanned laser light, and an image that is transmitted or reflected through the screen. An optical system that generates a virtual image, a drive unit that moves the screen parallel to the traveling direction of the laser beam, a screen drive circuit that drives the drive unit, a mirror drive circuit that drives the scanning unit, and video information to be displayed An image processing circuit that determines a drive pattern based on the drive pattern and outputs it to the screen drive circuit and determines a scan pattern based on the drive pattern and outputs the scan pattern to the mirror drive circuit is provided.

  An image display apparatus control method according to a main aspect of the present invention includes: a light source; a scanning unit that scans laser light emitted from the light source; a screen on which an image is formed by the scanned laser light; An optical system that generates a virtual image from the reflected image, a drive unit that moves the screen in parallel with the traveling direction of the laser light, a screen drive circuit that drives the drive unit, a mirror drive circuit that drives the scanning unit, and a display An image processing circuit for controlling the screen drive circuit and the mirror drive circuit based on the video information, the image processing circuit determines a drive pattern of the drive unit based on the video information to be displayed and outputs the drive pattern to the screen drive circuit; and Based on the driving pattern, the scanning pattern of the scanning unit is determined and output to the mirror driving circuit.

  As described above, according to the present invention, the image processing circuit for controlling the screen drive circuit and the mirror drive circuit is also provided based on the video information to be displayed, and the drive pattern of the drive unit is determined based on the video information to be displayed. Since it outputs to the drive circuit and determines the scan pattern of the scanning unit based on the drive pattern and outputs it to the mirror drive circuit, the movement of the screen and the scan of the scanning unit such as the mirror actuator can be comprehensively performed. This makes it possible to perform more sophisticated visual expressions.

  The effects and significance of the present invention will become more apparent from the following description of embodiments. However, the embodiment described below is merely an example when the present invention is implemented, and the present invention is not limited to what is described in the following embodiment.

The schematic diagram which saw through the inside from the side of the passenger car in the usage pattern of the image display apparatus which concerns on embodiment Schematic showing the front in the running direction from the inside of the passenger car in the same usage pattern The figure which shows the structure of the image display apparatus typically The figure which shows the structure of the circuit used for the irradiation light generation part of the same image display apparatus, and an irradiation light generation part The figure which shows the structure of the scanning part of the image display apparatus AA sectional view in FIG. The figure which shows the control signal applied to the vibration part of the vertical vibration beam of the scanning part The figure which shows the control signal applied to the vibration part of the horizontal vibration beam of the scanning part The figure which shows typically the scanning method of the laser beam with respect to the screen of the image display apparatus The figure which shows an example of the movement process of the screen which concerns on embodiment The figure which shows an example of the image displayed by moving the screen The figure which shows an example of the control signal applied to the vibration part of the vertical vibration beam according to the movement process of the screen The figure which shows the comparative example of the control signal applied to the vibration part of the vertical vibration beam according to the movement process of the screen The figure which shows the other example of the control signal applied to the vibration part of the vertical vibration beam according to the movement process of the screen

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. For convenience, X, Y, and Z axes that are orthogonal to each other are appended to each drawing as appropriate.

  FIG. 1 and FIG. 2 are diagrams schematically showing how the image display device 20 is used. FIG. 1 is a schematic view of the inside of the passenger car 1 seen through from the side of the passenger car 1, and FIG. 2 is a view of the inside of the passenger car 1 as viewed from the front in the running direction.

  In the present embodiment, the present invention is applied to an in-vehicle head-up display. As shown in FIG. 1, the image display device 20 is installed inside the dashboard 11 of the passenger car 1.

  As shown in FIGS. 1 and 2, the image display device 20 projects the laser light modulated by the video signal onto the projection area 13 near the driver seat below the windshield 12. The laser light is reflected by the projection region 13 and is irradiated to a horizontally long region (eye box region) around the eye position of the driver 2. Thus, the predetermined image 30 is displayed as a virtual image in the field of view ahead of the driver 2. The driver 2 can superimpose an image 30 that is a virtual image on the scenery in front of the windshield 12. That is, the image display device 20 forms an image 30 that is a virtual image in a space in front of the projection region 13 of the windshield 12.

  FIG. 3 is a diagram schematically illustrating the configuration of the image display device 20.

  The image display device 20 includes an irradiation light generation unit 21 and a mirror 22. The irradiation light generation unit 21 emits laser light modulated by the video signal. The mirror 22 has a curved reflecting surface, and reflects the laser light emitted from the irradiation light generation unit 21 toward the windshield 12. The laser beam reflected by the windshield 12 is applied to the eyes 2a of the driver 2. The optical system and the mirror 22 of the irradiation light generation unit 21 are designed so that a virtual image 30 is displayed in a predetermined size in front of the windshield 12.

  FIG. 4 is a diagram illustrating a configuration of the irradiation light generation unit 21 of the image display device 20 and a configuration of a circuit used for the irradiation light generation unit 21.

  The irradiation light generation unit 21 includes a light source 101, collimator lenses 102 a to 102 c, a mirror 103, dichroic mirrors 104 and 105, a scanning unit 106, a correction lens 107, a screen 108, and a driving unit 109.

  The light source 101 includes three laser light sources 101a to 101c. The laser light sources 101a to 101c emit laser beams in a red wavelength band, a green wavelength band, and a blue wavelength band, respectively. In the present embodiment, in order to display a color image as the image 30, the light source 101 includes three laser light sources 101a to 101c. When displaying a monochromatic image as the image 30, the light source 101 may include only one laser light source corresponding to the color of the image. The laser light sources 101a to 101c are made of semiconductor lasers, for example.

  Laser light emitted from the laser light sources 101a to 101c is converted into parallel light by the collimator lenses 102a to 102c, respectively. At this time, the laser beams emitted from the laser light sources 101a to 101c are each shaped into a circular beam shape by an aperture (not shown). Instead of the collimator lenses 102a to 102c, a shaping lens that shapes the laser beam into a circular beam shape and converts it into parallel light may be used. In this case, the aperture can be omitted.

  Thereafter, the optical axes of the laser beams of the respective colors emitted from the laser light sources 101a to 101c are aligned by the mirror 103 and the two dichroic mirrors 104 and 105. The mirror 103 substantially totally reflects the red laser light transmitted through the collimator lens 102a. The dichroic mirror 104 reflects the green laser light transmitted through the collimator lens 102 b and transmits the red laser light reflected by the mirror 103. The dichroic mirror 105 reflects the blue laser light transmitted through the collimator lens 102 c and transmits the red laser light and the green laser light transmitted through the dichroic mirror 104. The mirror 103 and the two dichroic mirrors 104 and 105 are arranged so that the optical axes of the laser beams of the respective colors emitted from the laser light sources 101a to 101c are aligned.

  The scanning unit 106 reflects the laser light of each color that passes through the dichroic mirror 105. The scanning unit 106 is composed of a MEMS (micro electro mechanical system) mirror, and rotates a mirror 106 a on which laser beams of various colors that have passed through the dichroic mirror 105 are incident, about a rotation axis parallel to the Y axis. A configuration and a configuration for rotating around a rotation axis parallel to the X axis are provided. By rotating the mirror 106a in this way, the reflected light of the laser beam from the mirror 106a can be scanned in the plane of the screen 108, as will be described later.

  FIG. 5 shows a configuration example of the scanning unit 106. The scanning unit 106 includes a mirror 106 a that reflects laser light, a vertical vibrating beam 303 that controls a reflection angle of the mirror 106 a, and a horizontal vibrating beam 304.

  The vertical vibrating beam 303 has a meander shape in which a plurality of linear portions along the rotation axis 301 parallel to the Y axis are connected to be folded back. A vibrating portion 305 is provided at each straight line portion. FIG. 6 shows a cross-sectional view taken along the line AA, which is a straight line portion including the vibration part 305. The vibration unit 305 has a structure in which the piezoelectric layer 305b is disposed between the lower electrode 305a and the upper electrode 305c, and is disposed on the substrate 306. Then, by applying a control signal to the vibration unit 305 from a mirror drive circuit 203 described later, the linear portion vibrates in the Z-axis direction as indicated by an arrow due to the inverse piezoelectric effect of the piezoelectric layer 305b. In the vertical vibrating beam 303 in which such straight portions are connected in a meander shape, the torsional vibration about the rotation shaft 302 is excited by combining the vibrations of the straight portions.

  7 is used as the control signal applied to the vibration unit 305 of the vertical vibrating beam 303, the reflection angle of the mirror 106a is controlled according to the period of the sawtooth signal, and the reflected light is transmitted to the vertical of the screen 108. Scan in the direction. At time t0 and time t2, the voltage of the control signal is Pv0, and the reflected light at this time is on the lower side of the projection region 13. At time t1, the voltage of the control signal is Pv1, and the reflected light at this time is on the upper side of the projection region 13. The driving cycle of the vertical vibrating beam 303, that is, the time from time t0 to t2, is 1/60 second, for example.

  The horizontal vibrating beam 304 has a meander shape in which a plurality of linear portions along the rotation shaft 302 are connected so as to be folded back. A vibrating portion 308 is provided in each straight line portion. Similar to the vibration unit 305 described above, the vibration unit 308 is vibrated in the Z-axis direction by applying a control signal from the mirror drive circuit 203. In the horizontal vibrating beam 304 in which such straight portions are connected in a meander shape, torsional vibration about the rotation shaft 301 is excited by combining the vibrations of the straight portions.

  As a control signal applied to the vibration unit 308 of the horizontal vibrating beam 304, a sine wave signal shown in FIG. 8 is used. Scan horizontally. The driving period of the horizontal driving beam is, for example, 1/40000 seconds.

  Then, by combining the vertical vibrating beam 303 and the horizontal vibrating beam 304, the reflected light of the laser beam can be scanned in the plane of the screen 108.

  Here, the scanning unit 106 is configured by a biaxially driven MEMS mirror, but the scanning unit 106 may have other configurations. For example, the mirror 106a that is driven to rotate about an axis parallel to the Y axis and the mirror 106a that is driven to rotate about an axis parallel to the X axis are separated, and the scanning unit 106 is configured by combining them separately. May be.

  The correction lens 107 is designed to direct the laser light of each color in the positive direction of the Z axis regardless of the swing angle of the laser light by the scanning unit 106.

  The screen 108 scans the laser beam to form an image, and has an action of diffusing the incident laser beam to a region around the position of the eyes 2a of the driver 2 (eye box region).

  The drive unit 109 reciprocates the screen 108 in a direction (Z-axis direction) parallel to the traveling direction of the laser light.

  The image processing circuit 201 includes an arithmetic processing unit such as a CPU (Central Processing Unit) and a memory, and processes an input video signal to control the laser driving circuit 202, the mirror driving circuit 203, and the screen driving circuit 204. The laser drive circuit 202 changes the emission intensity of the laser light sources 101a to 101c in accordance with a control signal from the image processing circuit 201. The mirror driving circuit 203 drives the mirror 106 a of the scanning unit 106 in accordance with a control signal from the image processing circuit 201. The screen drive circuit 204 drives the screen 108 according to the control signal from the image processing circuit 201.

  FIG. 9 schematically shows the scanning trajectory of the laser beam with respect to the screen 108.

  The beam B1 on which the laser beams of the respective colors are superimposed is scanned in the X-axis direction by the rotation of the mirror 106a associated with the torsional vibration of the horizontal vibration beam 304 of the scanning unit 106, and the mirror 106a associated with the torsional vibration of the vertical vibration beam 303. Scanning is performed in the Y-axis direction by rotation. A so-called raster scanning method is employed. On the surface of the screen 108, scanning lines L1 to Ln through which the beam B1 passes are set in advance in the Y-axis direction at regular intervals. The start position and the end position of the scanning lines L1 to Ln coincide with each other in the X-axis direction. Therefore, the area surrounding the scanning lines L1 to Ln is a rectangle. The diameter of the beam B1 is set to about 100 μm, for example.

  The scanning lines L1 to Ln are scanned at high speed by the beam B1 in which the laser beams of the respective colors are modulated by the video signal, thereby forming an image. The image thus configured is projected onto an area (eye box) around the position of the eye 2a of the driver 2 via the screen 108, the mirror 22 and the windshield 12 (see FIG. 1C). As a result, the driver 2 visually recognizes the image 30 as a virtual image in the space in front of the windshield 12.

  FIG. 10 is a diagram illustrating an example of the moving process of the screen 108, and FIG. 11 is a diagram illustrating an example of an image displayed by moving the screen 108. The moving process of FIG. 10 is a moving process of the screen 108 when displaying an image as shown in FIG.

  As shown in FIG. 10, the screen 108 is repeatedly moved with time t0 to t2 as one cycle. Between times t0 and t1, the screen 108 is moved from the initial position Ps0 to the farthest position Ps1, and between times t1 and t2, the screen 108 is returned from the farthest position Ps1 to the initial position Ps0. The moving period of the screen 108, that is, the time from time t0 to t2, is 1/60 second, for example.

  Time t0 to t1 is a period for displaying the depth image N1 that extends in the depth direction in FIG. 11, and time t1 to t2 displays the vertical image M1 and the vertical image M2 that extend in the vertical direction in FIG. It is a period for. In the example of FIG. 11, the depth image N1 is an arrow for suggesting to the driver 2 the direction in which the passenger car 1 should turn the road R1 by the navigation function, and the vertical image M1 is a pedestrian detected by a radar device or the like. This is a marking for alerting the driver 2 that H1 is in the back of the screen, and the vertical image M2 alerts the driver 2 that the pedestrian H2 detected by the radar device or the like is in front of the screen. It is marking for. In the figure, Hm1 indicates the height of the vertical image M1, and Hm2 indicates the height of the vertical image M2.

  At time t0 to t1, the screen 108 is linearly moved from the initial position Ps0 to the farthest position Ps1. As the screen 108 moves, the position where the virtual image in front of the windshield 12 is formed moves in the depth direction. Therefore, when the screen 108 is present at each position in the depth direction of the depth image N1, the laser light sources 101a to 101c are located at the timing corresponding to the depth image N1 on the scanning line corresponding to the depth image N1. 11 can be displayed as a virtual image in front of the projection region 13 of the windshield 12 as shown in FIG.

  On the other hand, since the vertical image M1 and the vertical image M2 in FIG. 11 do not change in the depth direction but spread only in the vertical direction, the screen 108 is fixed at a position corresponding to the vertical image M1 or the vertical image M2. Therefore, it is necessary to generate a virtual image.

  The stop position Ps2 is the position of the screen 108 corresponding to the depth position of the vertical image M1 determined according to the distance information of the pedestrian H1 input to the image processing circuit 201. The screen 108 is stopped from time t5 to time t6 at the stop position Ps2 while returning from the farthest position Ps1 to the initial position Ps0. During this time, at the timing corresponding to the vertical image M1 on the scanning line corresponding to the vertical image M1, the laser light sources 101a to 101c are caused to emit light to the front back side of the projection region 13 of the windshield 12 as shown in FIG. A vertical image M1 as shown can be displayed as a virtual image.

  The stop position Ps3 is a position of the screen 108 corresponding to the depth position of the vertical image M2 determined according to the distance information of the pedestrian H2 input to the image processing circuit 201. The screen 108 is stopped from time t7 to time t8 at the stop position Ps3 while returning from the farthest position Ps2 to the initial position Ps0. During this time, the laser light sources 101a to 101c are caused to emit light at the timing corresponding to the vertical image M2 on the scanning line corresponding to the vertical image M2, so that the front side of the projection area 13 of the windshield 12 is shown in FIG. A vertical image M2 as shown can be displayed as a virtual image.

  Next, an example of scanning control of the scanning unit 106 according to the above-described movement control of the screen 108 will be described with reference to FIG. In addition, about the time t0-t8 used in this description, it corresponds with the time t0-t8 shown in FIG. The voltages Pv0 and Pv1 coincide with the voltages Pv0 and Pv1 shown in FIG.

  The scanning control in the scanning unit 106 is divided into a depth image display period in which an image having a sense of depth such as the depth image N1 is displayed, and a vertical image display period in which there is no sense of depth such as the vertical image M1 and the vertical image M2. . The depth display period coincides with the forward period in FIG. 10, and the vertical image display period coincides with the return period in FIG.

  In the depth image display period from time t0 to t1, the sine wave signal shown in FIG. 8 is used as the control signal applied to the vibration unit 308 provided in the horizontal drive beam 304 in FIG. The laser beam reflected by the scanning unit 106 in accordance with the sine wave signal is scanned in the X axis direction of the screen 108. Note that the scanning width in the X-axis direction is determined by the amplitude of the sine wave signal. As the control signal applied to the vibration unit 305 provided in the vertical drive beam 303 in FIG. 5, the signal in the section of the time t0 to t1 in the sawtooth signal shown in FIG. 7 is used, and the scanning unit according to the sawtooth signal The laser beam reflected by 106 is scanned in the Y-axis direction of the screen 108. The control voltage of the control signal when displaying the depth image N1 is in the range of Pv2 to Pv3.

  In the vertical image display period from time t1 to time t2, there are a vertical image M1 scanned on the screen 108 at the stop position Ps2 and a vertical image M2 scanned on the screen 108 at the stop position Ps3. For this reason, the control signal applied to the vibration unit 305 provided in the vertical drive beam 303 is a non-linear control signal that is different from the signal at the time t1 to t2 in the sawtooth signal shown in FIG. The laser beam reflected by the scanning unit 106 is scanned in the Y-axis direction of the screen 108 according to the signal.

  The vertical image M1 has a scanning pattern determined based on the information of the pedestrian H1 input to the image processing circuit 201. The control signal voltage Pv4 corresponding to the upper limit position of the vertical image M1 and the lower limit of the vertical image M1. The voltage Pv5 of the control signal corresponding to the position is determined, and the slope of the control signal between times t5 and t6 is determined. In the vertical image M2, the scanning pattern is determined based on the information of the pedestrian H2 input to the image processing circuit 201. The control signal voltage Pv6 corresponding to the upper limit position of the vertical image M2 and the lower limit position of the vertical image M2 Is determined, and the slope of the control signal between times t7 and t8 is determined. In addition, the times 1 to t5, t6 to t7, and t8 to t2, which are periods during which no video is displayed, are linearly connected so that the control signals are continuous. Thus, by setting the control signal based on the information of the pedestrians H1 and H2 serving as the video information, the degree of freedom of the display areas of the vertical images M1 and M2 in the projection area 13 can be ensured.

  In particular, the voltage displacement at times t6 to t7 when no video is displayed is opposite to the voltage displacement at times t5 to t6 when the adjacent vertical image M1 is displayed and times t6 to t7 when the vertical image M1 is displayed. That is, by providing a section in which the scanning direction is reversed including a point where the speed component in the vertical scanning of the scanning unit 106 becomes 0 in the return pass period, the degree of freedom of the projection range of the vertical image M1 and the vertical image M2 is secured. Yes. Specifically, the vertical image M1 in FIG. 11 is projected with an image height Hm1 in a sense of depth corresponding to the screen position Ps2, and the vertical image M2 is projected with an image height Hm2 in a sense of depth according to the screen position Ps3. These realize an overlapping region in the height direction (height direction) in the projection region 13.

  Note that the sine wave signal shown in FIG. 8 is used as the control signal applied to the vibration unit 308 provided in the horizontal driving beam 304 during the vertical image display period from time t1 to t2, and scanning is performed according to the sine wave signal. The laser beam reflected by the unit 106 is scanned in the X-axis direction of the screen 108.

  Here, FIG. 13 shows a comparative example in which a simple sawtooth signal is used as the control signal for the vertical image display period, and the difference from the case in which the control signal shown in FIG. 12 is used will be described. Note that the times t0 to t8 used in this description coincide with the times t0 to t8 and the voltages Pv0 to Pv7 shown in FIG.

  In this comparative example, during the time t0 to t4, that is, the forward period of the screen 108 is the same as the control signal shown in FIG. 12, the voltage at the times t3 to t4 is set to Pv2 to Pv3, and the depth image N1 is displayed. indicate. On the other hand, during the time t1 to t2, that is, during the return path of the screen 108, the control signal decreases linearly. Therefore, the voltage Pv4 ′ at time t5 and the voltage Pv5 ′ at time t6 for displaying the vertical image M1 are controlled. It is uniquely determined by the slope of the signal. Similarly, the voltage Pv6 ′ at time t7 for displaying the vertical image M2 and the voltage Pv7 ′ at time t8 are also uniquely determined by the inclination of the control signal. That is, in this comparative example, the vertical image M1 and the vertical image M2 are limited by the inclination of the control signal, and the vertical image M1 and the vertical image M2 overlap in the height direction in the projection region 13 in FIG. There is a restriction that the area cannot be formed.

  As described above, the image processing circuit 201 determines the movement pattern of the screen 108 and the scanning pattern of the scanning unit 106 based on the video information, and outputs them to the screen driving circuit 204 and the mirror driving circuit 203. This is a structure in which a control signal corresponding to a scanning pattern is formed and laser beam scanning control is performed by the scanning unit 106, and a movement signal of the screen 108 is controlled in the driving unit 109 by forming a control signal corresponding to the driving pattern. Thus, the video display with a sense of depth in the image display device 20 can be performed at a higher level.

  Note that the control signal of the vertical drive beam 303 described in FIG. 12 includes the scanning range from the lower end to the upper end of the projection area 13 in the forward period of time t0 to t1, and linearly connects the control signal voltages Pv0 to Pv1. As described in the embodiment, for the period from time t4 to t5 and time t6 to t7 when no video is displayed, as shown in FIG. By reducing the range, the power consumption of the image display device 20 can be reduced. In generating such a control signal, a control signal is generated by combining resonance frequency components equal to or lower than the natural resonance frequency of the scanning unit 106, thereby connecting a period in which an image is displayed and a period in which no image is displayed. The portion can be formed in a smooth curved shape, and generation of unnecessary stress on the scanning unit 106 can be reduced.

  The above control is performed by the image processing circuit 201 shown in FIG. By this control, the depth image N1, the vertical image M1, and the vertical image M2 are displayed as virtual images between time t0 and time t2. In the above control, the display timing of the depth image N1, the display timing of the vertical image M1, and the display timing of the vertical image M2 are shifted. However, since this shift is extremely short, the driver 2 An image obtained by superimposing the vertical image M1 and the vertical image M2 is recognized. Thus, the driver 2 superimposes an image based on the video signal (depth image N1, vertical image M1, vertical image M2) in front of the projection area 13 on a landscape including the road R1, the pedestrian H1, and the pedestrian H2. Can see.

  The present invention has the effect of being able to perform video expression with a sense of depth to a higher degree, and is particularly effective in an in-vehicle head-up display.

20 Image display device 22 Mirror (optical system)
DESCRIPTION OF SYMBOLS 101 Light source 106 Scan part 108 Screen 109 Drive part 201 Image processing circuit 203 Mirror drive circuit 204 Screen drive circuit

Claims (5)

A light source that emits laser light;
A scanning unit that scans the laser light emitted from the light source;
A screen on which an image is formed by the scanned laser beam;
An optical system that generates a virtual image from the image transmitted through or reflected by the screen;
A drive unit that moves the screen parallel to at least the traveling direction of the laser beam;
A screen driving circuit for driving the driving unit, a mirror driving circuit for driving the scanning unit to control scanning of the laser beam, and a driving pattern of the driving unit are determined based on video information to be displayed and output to the screen driving circuit. And an image display device including an image processing circuit that determines a scanning pattern of the scanning unit based on the video information and the driving pattern and outputs the scanning pattern to the mirror driving circuit. A light source that emits laser light;
A scanning unit that scans the laser light emitted from the light source;
A screen on which an image is formed by the scanned laser beam;
An optical system that generates a virtual image from the image transmitted through or reflected by the screen;
A drive unit that moves the screen parallel to at least the traveling direction of the laser beam;
A screen driving circuit for driving the driving unit; a mirror driving circuit for controlling scanning of the laser beam by driving the scanning unit; and an image processing circuit for controlling the screen driving circuit and the mirror driving circuit based on video information to be displayed. With
The image processing circuit determines a driving pattern of the driving unit based on video information to be displayed and outputs the driving pattern to the driving circuit, and determines a scanning pattern of the scanning unit based on the video information and the driving pattern. Then, a method for controlling the image display device that outputs to the mirror drive circuit. The determination of the driving pattern is as follows:
Determining a stop position of the screen based on video information to be displayed;
Determining the timing of the screen stop start relative to the screen stop position, and determining the screen stop end timing;
The determination of the scanning pattern is as follows:
The method for controlling an image display device according to claim 2, further comprising a step of determining based on the timing of the stop start, the timing of the stop end, and the video information. The drive pattern has first and second stop periods with different stop positions;
The video information includes a first scanning period in which the laser beam is scanned on the screen in the first stop period, and a second scan in which the screen is scanned on the screen in the second stop period. A non-display period during which the laser beam is not scanned on the screen between the first stop period and the second stop period,
When the mirror drive circuit forms a control signal formed by the mirror drive circuit and applied to the scanning unit, the control signal in the non-display period is combined with only a frequency component equal to or lower than the natural frequency of the scanning unit. The method of controlling an image display device according to claim 3, wherein 5. The method of controlling an image display device according to claim 4, wherein a velocity component in a vertical scanning direction of the scanning unit becomes zero in the non-display period.