JP5915254B2 - Image display device and control method thereof - Google Patents

Description

  The present invention relates to an image display device and a control method thereof, and more specifically to an image display device having a scanning mirror and a control method thereof.

  2. Description of the Related Art An image display device that reflects laser light with a scanning mirror and displays an image on a projection surface by raster scanning of light rays is known. In other words, a laser scanning projection display reciprocally swings the scanning mirror left and right to draw horizontal scanning lines, and simultaneously reciprocates the scanning mirror vertically according to the number of scanning lines constituting the image. Let

  Such image display devices may be very small by using semiconductor laser diodes and MEMS (Micro Electro Mechanical Systems) mirrors, and various application products such as head-up displays and head-mounted displays are currently being developed. Has been. For example, Patent Document 1 discloses a vehicle-mounted head-up display mounted on an automobile. In the head-up display device of Patent Document 1, input to a display source is turned off when an ABS (Antilock Brake System) control signal is output.

Japanese Patent Application Laid-Open No. 10-1000073 Japanese Patent Laid-Open No. 2004-161263

  Normally, in an automobile, when the key is in the ACC (accessory position), power is supplied to the in-vehicle device, and the operation starts. Moreover, in patent document 2, if a door is unlocked, the vehicle equipment will be started using the built-in secondary battery.

  A scanning mirror such as a MEMS mirror takes time to stabilize its operation. For this reason, it takes time until the image is displayed after the engine is started.

An image display device according to an aspect of the present invention is an image display device (100) installed in a vehicle having a door, and includes a light source unit (130) that converts a video signal into an optical signal, and a light flux of the optical signal. The scanning mirror unit (200) that reflects and scans and displays an image on the projection surface, and the light source unit (130) is not operated according to the open / close state or key state of the door (12). And a control unit (23) for operating the scanning mirror unit (200).
In the above image display device, the scanning mirror unit is a MEMS mirror including a first swing shaft that swings by resonance drive and a second swing shaft that swings by non-resonance drive, and the door The control unit (23) is controlled to operate the swing of the first swing shaft in a state where the swing of the second swing shaft is stopped according to the open / close state or the key state of the first swing shaft. May be.
In the above image display device, when the vehicle is an automobile that is unlocked and locked by a smart key, and the verification of the smart key is authenticated, the control unit (23) operates the scanning mirror unit (200). You may make it make it.
In the above image display device, when it is detected that the door (12) is in an open state or a key of the door (12) is in an unlocked state, the control unit is configured to scan the scanning mirror. The unit may be operated.
The image display device may further include a temperature adjustment unit (135) that adjusts a temperature of the light source unit, and the temperature adjustment unit (135) may change the temperature of the light source unit according to an open / closed state or a key state of the door. The adjustment may be started.
In the above image display device, after the scanning mirror unit (200) is operated in a state where the light source unit (130) is not operating, the image display device does not display an image for a certain period of time, The operation of the scanning mirror unit (200) may be stopped.
An image display apparatus control method according to an aspect of the present invention includes a light source unit that converts a video signal into an optical signal, a scanning mirror unit that reflects and scans the light beam of the optical signal, and displays an image on a projection surface. A method for detecting an open / close state or a key state of a door of a vehicle on which the image display device is installed, and a detection result of the open / close state or the key state of the door The power supply to the scanning mirror unit is controlled to operate the scanning mirror unit in a state where the light source unit is not operating.

  ADVANTAGE OF THE INVENTION According to this invention, the image display apparatus which can display an image rapidly, and its control method can be provided.

The figure which shows typically the motor vehicle carrying the image display apparatus concerning this Embodiment. It is a figure which shows the typical usage example of an image display apparatus. 1 is a functional block diagram showing an overall configuration of an image display apparatus and its power supply system. The figure which shows the flow of a process of a video signal. The figure for demonstrating the structure of image data. The perspective view of a light emission unit. The figure which shows the structure of a scanning mirror part. The figure which shows the optical path until the image light beam L1 emitted from the light emission unit reaches the eye of the viewer. The figure explaining a mode that the main scanning drive control signal SH is produced | generated from a vibration detection signal. The figure which illustrates subscanning drive signal SV. The flowchart which shows the control method of 1st Embodiment. The flowchart which shows the control method of a modification. The functional block diagram which shows the whole structure of the image display apparatus concerning 2nd Embodiment, and its power supply system.

An embodiment of the present invention will be illustrated and described with reference to reference numerals attached to elements in the drawing.
(First embodiment)
A first embodiment according to the image display device of the present invention will be described.
FIG. 1 is a side view showing a configuration of an automobile equipped with an image display device according to the present embodiment. As shown in FIG. 1, the driver P has a key 13 for unlocking and locking the door 12 of the automobile 10. That is, the driver P unlocks the locked door 12 using the key 13. Then, the driver P opens the unlocked door and gets on the automobile 10. The key 13 may be a mechanical key inserted into a keyhole, or a remote control key (wireless key) that can be remotely operated using wireless communication or the like.

FIG. 2 is a typical use example of the image display apparatus 100 assumed by the present invention.
The image display device 100 reflects laser light with a scanning mirror and displays an image on a projection surface by raster scanning of light rays.
In FIG. 2, the image display device 100 is built in the automobile 10.
The image display device 100 emits an image light beam L1 adjusted to display a desired image.
The image light beam L1 is incident on the eyes of the driver P through reflection on the windshield 11, and forms an image on the retina. At the same time, light L2 from the outside also enters the windshield 11 and is transmitted therethrough. Therefore, the light L2 from the outside and the image light beam L1 from the light emitting unit are overlaid (superimposed), and the actual scene of the outside and the image adjusted by the image display device 100 can be simultaneously seen in the field of view of the driver P. Become.

FIG. 3 is a functional block diagram showing the overall configuration of the image display apparatus 100.
The image display device 100 includes an image signal processing unit 110, a light emission unit 120, an imaging optical system 150, and a timing processing unit 160. The configuration and operation of each functional unit will be described below.

  The image signal processing unit 110 includes a video interface 111, a video decoder 112, a memory controller 113, a frame memory 114, a data buffer 115, and a light source driving unit 116.

A video signal is input via the video interface 111. The video decoder 112 decodes the video signal according to the type of the input video signal.
For example, when the input video signal is an analog video signal (component video signal), the video signal is horizontally synchronized with the digital video signal composed of digital color signals of three colors (RGB) by decoding processing. And a sync signal including a vertical sync signal.

The memory controller 113 includes a writing unit 113W and a reading unit 113R.
FIG. 4 is a diagram illustrating a flow of processing of a video signal.
The writing unit 113W temporarily writes image data for one frame of the video signal processed by the video decoder 112 into the frame memory 114 and buffers it. Then, the reading unit 113R reads image data from the frame memory 114 line by line on the main scanning line based on the designated dot clock.
Here, the reading unit 113R reads the image data at a timing suitable for the laser scanning projection display and outputs it to the subsequent stage.
That is, the reading unit 113R reads the image data in accordance with the timing signal (dot clock, display period instruction signal) adjusted by the timing processing unit 160. The image data read in this way is temporarily stored in the data buffer 115.
The configuration and operation of the timing processing unit 160 will be described later.

  The data buffer 115 temporarily stores the image data read out line by line, and the image data is sequentially output to the light source driving unit 116.

The light source driving unit 116 includes a D / A conversion unit, and applies a driving current to each semiconductor laser diode that is a light source of the light emitting unit 120 according to image data to cause each semiconductor laser diode to emit light with a desired luminance.
As a light source of the light emitting unit 120, a red laser diode, a blue laser diode, and a green laser diode are provided to obtain three colors of RGB (see FIG. 5 for a specific structure). Accordingly, the light source driver 116 also includes a red driver 116R, a green driver 116G, and a blue driver 116B.

  As a matter of course, each pixel data constituting the image data is composed of three colors of R (red), G (green), and B (blue) for each pixel as shown in FIG. Has color information. Each of the drivers 116R, 116G, and 116B applies a current to the semiconductor laser diode in accordance with information on each color of each pixel.

The light emission unit 120 includes a light source unit 130 and a scanning mirror unit 200.
FIG. 6 is a perspective view of the light emitting unit 120, and the light source unit 130 and the scanning mirror unit 200 are unitized.
The light source unit 130 includes three color laser diodes 132R, 132G, and 132B, a plurality of mirrors 133A, 133B, 133C, and 133D, and a plurality of condenser lenses 134.
As the laser diode, a red laser diode 132R, a green laser diode 132G, and a blue laser diode 132B are provided for each color of R (red), G (green), and B (blue).

Each of the mirrors 133B and 133C is a dichroic mirror that transmits or reflects a color having a predetermined wavelength.
The light path in the light source unit 130 will be briefly described. The first mirror 133A reflects the green laser at a right angle and guides the reflected light to the optical path of the red laser. The second mirror 133B transmits the red laser and reflects the green laser to multiplex both. The third mirror 133C transmits the light from the second mirror 133B and reflects the blue laser.
As a result, finally, the fourth laser beam 133D is incident on the scanning mirror unit 200 at a predetermined angle as a light beam obtained by combining the three laser beams on one axis. In this way, the light source unit 130 converts the video signal into an optical signal.
A condensing lens 134 is appropriately disposed on the optical path to condense the laser light.
The optical characteristics and arrangement positions of the respective condensing lenses are determined in relation to the imaging optical system 150 at the next stage.

  In FIG. 6, a circuit board is provided on the back side of the light emitting unit 120, and the image signal processing unit 110 and the timing processing unit 160 are incorporated on the circuit board, and are modularized as a whole.

Next, the configuration of the scanning mirror unit 200 will be described.
The scanning mirror unit 200 is a so-called MEMS device, and is manufactured by applying a semiconductor integrated circuit processing technique. The scanning mirror unit 200 can be driven biaxially with two swing axes orthogonal to each other, and has a mirror on one surface. The image light beam is raster scanned by swinging the mirror. The scanning mirror unit 200 reflects and scans the light beam of the optical signal from the light source unit 130, and displays an image on the projection surface.

A typical structure of the scanning mirror unit 200 will be described with reference to FIG.
7A is a plan view of the scanning mirror unit 200, and FIG. 7B is a schematic cross-sectional view.
In the schematic cross-sectional view, hatching is omitted in a range where there is no misunderstanding for easy viewing.
For convenience of explanation, in FIG. 7A, the vertical direction is described as the y-axis direction and the horizontal direction is described as the x-axis direction.

The scanning mirror unit 200 includes a light deflection element 210 that is biaxially driven so as to deflect light in the main scanning direction and the sub-scanning direction, and a support base portion 250 that supports the light deflection element 210.
The optical deflection element 210 is manufactured from a Si (silicon) wafer by a known semiconductor process.
The optical deflection element 210 includes two support portions 220L and 220R disposed at both ends in the x-axis direction in FIG. 7A and a sub-scanning swing that swings in the sub-scanning direction as a whole between the two support portions. The moving body 230 includes two arms 240 </ b> L and 240 </ b> R that connect the two supporting parts and the sub-scanning rocking body 230.
The two arms 240L and 240R connect the support parts 220L and 220R and the sub-scanning rocking body part 230 at substantially the center in the vertical direction, whereby the sub-scanning rocking body part 230 with the sub-scanning rocking axis Xs as the rocking axis. Is swingable.

  Next, the sub-scanning oscillating body 230 includes a frame 231 constituting the frame, a main scanning oscillating piece 232 supported in a state of being separated from the frame 231 within the frame 231, and the frame 231. Four L-shaped beam portions 233A, 233B, 233C, and 233D, four piezoelectric elements 234A, 234B, 234C, and 234D, a mirror 235, two magnets 236U, 236D.

The L-shaped beam portions 233A, 233B, 233C, and 233D connect the inner side parallel to the y-axis of the frame body 231 and the side parallel to the x-axis of the main scanning swing piece 232.
At this time, the L-shaped beam portions 233 </ b> A, 233 </ b> B, 233 </ b> C, and 233 </ b> D are connected to the main scanning rocking piece portion 232 at a position close to the left and right center of the main scanning rocking piece portion 232. Thereby, the main scanning oscillating piece 232 can oscillate about the main scanning oscillating axis Ys as the oscillating axis.

  In the four L-shaped beam portions 233A, 233B, 233C, and 233D, piezoelectric elements 234A, 234B, 234C, and 234D are arranged in portions parallel to the x-axis. Although not shown in detail, the piezoelectric elements 234A, 234B, 234C, and 234D have a laminated structure in which a piezoelectric film is sandwiched between a lower electrode and an upper electrode.

The mirror 235 is formed on one surface of the main scanning swing piece 232. The mirror can be formed by vapor deposition of a highly reflective metal (for example, Al or Au).
As apparent from the structure so far, the mirror 235 swings in the sub-scanning direction by the support by the arms 240L and 240R, and also swings in the main scanning direction by the support of the L-shaped beam portions 233A, 233B, 233C, and 233D. I can move.

The two magnets 236U and 236D are respectively arranged above and below the y-axis in the main scanning swing piece 232.
When the surface on which the mirror 235 is formed is the front surface, the magnets 236U and 236D are pasted on the back surface of the sub-scanning rocking body 230.

The support base portion 250 includes a base portion 251 and two electromagnetic coils 252U and 252D.
The electromagnetic coils 252U and 252D are arranged to be paired with the magnets 236U and 236D, respectively.

Finally, electrical wiring will be described.
When four piezoelectric elements 234A, 234B, 234C, and 234D are provided, vibration is induced in the main scanning oscillating piece 232 by the two piezoelectric elements 234A and 234B, and main scanning oscillating is performed by the two piezoelectric elements 234C and 234D. The vibration of the moving piece portion 232 is detected.
That is, in FIG. 7A, a drive signal is applied to the two drive piezoelectric elements 234A and 234B arranged on the left side with the main scanning swing axis Ys in between. Then, the vibrations of the two left driving piezoelectric elements 234A and 234B are transmitted to the main scanning oscillating piece 232 via the L-shaped beam portions 233A and 233B, and the main scanning oscillating piece 232 is moved to the main scanning oscillating shaft. Oscillates with Ys as the oscillation axis.
Further, the vibration of the main scanning oscillating piece 232 is detected by two detection piezoelectric elements 234C and 234D arranged on the right side with the main scanning oscillating axis Ys interposed therebetween.
Here, by feeding back to the driving piezoelectric elements 234A and 234B a driving voltage signal having a predetermined phase difference with respect to the vibration detection signals obtained from the detecting piezoelectric elements 234C and 234D, the main scanning oscillating piece 232 is provided. Can be driven to resonate.

In addition, a drive current that swings the sub-scanning swinging body 230 at a predetermined cycle is applied to the electromagnetic coils 252U and 252D.
As a result, the electromagnetic coils 252U and 252D and the magnets 236U and 236D repeat repulsion and approach alternately, and the sub-scanning rocking body 230 swings using the sub-scanning rocking axis Xs as the rocking axis.
The oscillation in the sub-scanning direction is non-resonant driving and is adjusted according to the period of vertical driving of image data.

Next, the imaging optical system 150 will be described.
FIG. 8 is a diagram showing an optical path until the image light beam L1 emitted from the light emitting unit 120 reaches the eye of the viewer.
Note that the configuration of the imaging optical unit 150 is not limited to a specific configuration as long as it can guide the image light beam L1 emitted from the light emission unit 120 to the eyes of a person who sees it.
The imaging optical unit 150 includes a plane mirror 151, a screen 152, a plane mirror 153, a concave mirror 154, and a windshield 11 as a combiner.
The screen 152 is of a light transmission type, and is configured by a so-called microlens array in which a diffusion plate and microlenses are arranged in a matrix.
The micro lens array has an effect of reducing speckle peculiar to a laser, and is optimally designed in consideration of a radiation angle and color unevenness.
The light beam L 1 reflected by the scanning mirror unit 200 forms an intermediate image once on the screen 152. Thereafter, the image light beam L1 reaches the eyes of the viewer through reflection on the flat mirror 153, the concave mirror 154, and the windshield 11.
Further, on the windshield 11 as a combiner, the image light beam L1 and the actual scene from the outside are overlaid.

  The timing processing unit 160 includes a mirror drive control circuit 161, a vibration detection unit 162, and a timing adjustment unit 170.

  The timing processing unit 160 performs main scanning drive control of the scanning mirror unit 200, sub-scanning drive control of the scanning mirror unit 200, and timing for matching the image processing timing in the image signal processing unit 110 with the driving of the scanning mirror unit 200. Generate signals and so on.

  The mirror drive control circuit 161 includes a main scan drive control unit 161H that performs main scan drive control of the scan mirror unit 200, and a sub scan drive control unit 161V that performs sub scan drive control of the scan mirror unit 200.

First, the main scanning drive control of the scanning mirror unit 200 will be described. Detection signals from the detection piezoelectric elements 234C and 234D of the scanning mirror unit 200 are detected by the vibration detection unit 162.
The vibration detection unit 162 can be configured by an amplifier circuit or a filter, for example. The vibration detection unit 162 outputs the detected vibration detection signal Sn to the main scanning drive control unit 161H and the timing adjustment unit 170.
The vibration detection signal Sn is fed back to the main scanning drive control unit 161H, and phase adjustment is performed so that the scanning mirror unit 200 resonates in the main scanning direction as shown in FIG. 9B, and driving is performed as the main scanning drive control signal SH. Applied to the piezoelectric elements 234A, 234B. As can be seen from FIG. 9, the vibration detection signal Sn and the main scanning drive control signal SH are out of phase but have the same wavelength.
The main scanning drive control signal SH may be pulsed.
As a result, the scanning mirror unit 200 is driven to resonate in the main scanning direction.

On the other hand, the sub-scanning drive control unit 161V causes the scanning mirror unit 200 to perform non-resonant driving in the sub-scanning direction in accordance with the vertical driving cycle of the image data.
The vibration frequency in the sub-scanning direction is 60 Hz for VGA, for example.
The sub-scanning drive control unit 161V generates a sub-scanning drive signal SV that swings the scanning mirror unit 200 in the sub-scanning direction at 60 Hz while matching the timing with the main scanning drive control signal SH output from the main scanning drive control unit 161H. Output.
FIG. 10 exemplifies the sub-scanning drive signal SV. The sub-scanning drive signal SV is a triangular wave, and swings relatively slowly from the top to the bottom in order to secure time for drawing 480 main scanning lines. The return from bottom to top is driven quickly.

  The timing adjustment unit 170 outputs a timing signal for adjusting the timing of the image signal processing unit 110 based on the vibration detection signal Sn. Examples of the timing signal include a dot clock and a display period instruction signal. The read / write process of the memory controller 113, the drive process of the light source driver 116, and the transfer process from the data buffer 115 are controlled by the timing signal from the timing adjustment unit 170. By synchronizing the luminance of each color, the driving of the main scanning, and the sub-scanning, each pixel is appropriately drawn, and thereby desired image data is drawn. About timing adjustment, since a known method can be used, description is abbreviate | omitted.

  Further, as illustrated in FIG. 3, the image display apparatus 100 includes a control unit 23. Further, the automobile 10 is provided with a battery 21 and a door / key state detection unit 22. The battery 21 supplies power to the image display device 100 and electric devices (not shown) such as an air conditioner, audio, instrument panel, power window, and wiper. The door / key state detection unit 22 includes a mechanical or electrical sensor and detects whether the door 12 is open and whether the door 12 is locked. That is, the door / key state detection unit 22 detects the opening / closing state of the door 12 and the key state of the door 12. Then, the door / key state detection unit 22 outputs a detection signal corresponding to the detection result to the control unit 23. The control unit 23 controls power supply from the battery 21 to the image display apparatus 100. For example, when the driver P turns the key to reach the ACC position, the door / key state detection unit 22 detects that the ACC is turned on. Then, the door / key state detection unit 22 outputs a detection signal to the control unit 23. Accordingly, the control unit 23 supplies power to the entire image display device 100 so that the image display device 100 performs image display.

  Further, the control unit 23 selectively controls power supply to the image display device 100 in accordance with the open / closed state or key state of the door 12 detected by the door / key state detection unit 22. That is, the control unit 23 starts supplying power to a part of the image display device. For example, the control unit 23 supplies power to the scanning mirror unit 200 in a state where power is not supplied to the light source unit 130, the image signal processing unit 110, the timing processing unit 160, and the like. Therefore, before the light from the light source unit 130 is emitted, power supply to the scanning mirror unit 200 is started. By doing so, the scanning mirror unit 200 operates in advance. The scanning mirror unit 200 operates in a state where the light source unit 130 is not operating. As a result, the operation of the scanning mirror unit 200 can be quickly stabilized, and the substantial startup time of the image display apparatus 100 can be shortened. The control unit 23 switches between a display mode in which the entire image display apparatus 100 operates to display an image and an aging mode in which only the MEMS mirror of the scanning mirror unit 200 is operated in advance. Therefore, it is possible to quickly display an image.

  A specific control method will be described with reference to FIG. FIG. 11 is a flowchart showing a control method of the image display apparatus 100 according to the present embodiment. First, in a state where the driver P is not in the car, no power is supplied and the image display device 100 that is a HUD is stopped (step S11). Then, the door / key state detection unit 22 detects that the door 12 is opened or that the door lock is unlocked (step S12). Then, the door / key state detection unit 22 outputs a detection signal to the control unit 23. Then, the control unit 23 immediately starts supplying power to the scanning mirror unit 200 and operates the scanning mirror unit 200 (step S13). That is, the aging mode is set, and only the scanning mirror unit 200 operates. At this time, the control unit 23 does not supply power to the light source unit 130 or the like. Therefore, the light source unit 130 is not operating, and the laser diode of the light source unit 130 does not emit laser light.

  Then, the door / key state detection unit 22 determines whether or not ACC is ON (step S14). If the key is not in the ACC position (No in step S14), the process returns to step S12. Therefore, when the door 12 is in the open state or the door lock is in the unlocked state, the scanning mirror unit 200 continues to operate. In addition, when the driver P closes and locks the door 12 before turning on the ACC, the operation of the MEMS mirror of the scanning mirror unit 200 is stopped.

  On the other hand, when ACC is turned on (Yes in step S14), the image display apparatus 100 that is a HUD is activated (step S15). That is, the control unit 23 supplies power to the entire image display device 100 to set the image display mode. Accordingly, power is supplied to the image signal processing unit 110, the light source unit 130, the timing processing unit 160, and the like. Therefore, the image display apparatus 100 starts operation and displays a desired image.

  By doing in this way, the scanning of the scanning mirror part 200 can be stabilized quickly, and the substantial starting time of the image display apparatus 100 can be shortened. An image can be displayed simultaneously with the start of the engine. Furthermore, the control unit 23 operates only the scanning mirror unit 200. That is, prior to supplying power to the image signal processing unit 110, the light source unit 130, and the timing processing unit 160, the control unit 23 controls power supply so that power supply to the scanning mirror unit 200 is started. Since no power is supplied to any part other than the scanning mirror unit 200, power consumption can be reduced. For example, since no power is supplied to the light source unit 130, laser light can be prevented from being emitted without the driver P. Further, the microcomputer constituting the image signal processing unit 110 and the timing processing unit 160 may not be operated. Thereby, power consumption can be reduced.

  Furthermore, when the period until the key of the door 12 is unlocked and the ACC is turned on exceeds a certain time, the operation of the scanning mirror unit 200 may be stopped. By doing so, power consumption can be further reduced. For example, when the scanning mirror unit 200 operates, a timer is started. When the time of the timer becomes equal to or longer than a preset time, the control unit 23 stops the power supply to the scanning mirror unit 200. That is, the operation of the scanning mirror unit 200 is stopped when the time from the operation of the scanning mirror unit 200 until the image display is performed exceeds a predetermined time. By doing so, it is possible to prevent the scanning mirror unit 200 from continuing to operate even when the driver P forgets to lock. Therefore, power consumption can be reduced.

  There is an automobile 10 that is automatically locked when the unlocked state continues for a predetermined time or longer without the driver P getting on after unlocking. In such an automobile 10, the operation of the scanning mirror unit 200 may be stopped together with locking by automatic locking. In this way, power consumption can be reduced.

  The door / key state detection unit 22 can use an existing sensor in the automobile 10. That is, a signal from a door 12 provided in the automobile 10 or a sensor that detects a key state of the door may be used. Thereby, it is not necessary to provide a new sensor or the like in the automobile 10. Therefore, the scanning mirror unit 200 can be stabilized with a simple configuration.

  Further, as described above, the scanning mirror unit 200 is resonantly driven in the main scanning direction (horizontal direction) and non-resonantly driven in the sub-scanning direction (vertical direction). In this case, the control unit 23 may control power supply so as to operate only in the main scanning direction of resonance driving. For example, the main scanning drive controller 161H performs drive control so that a predetermined voltage is applied only to the two piezoelectric elements 234A and 234B. Only the scanning direction of resonance driving is operated, and self-resonates in advance. That is, only the oscillating shaft of resonance drive that requires a longer time for stable operation than non-resonance drive is operated in advance. It is possible to reduce the number of devices that are activated in advance, thereby further reducing power consumption. Further, a constant voltage may be applied to the two piezoelectric elements 234A and 234B. By doing so, feedback control or the like becomes unnecessary, and fewer devices can be started up in advance. For example, since it is not necessary to start up the timing processing unit 160 that is a microcomputer, power consumption can be further reduced.

(Modification)
In the modification of the present embodiment, the key 13 is a smart key. The configuration and the like of the image display device 100 are the same as those in the first embodiment, and thus description thereof is omitted. In the smart key, a built-in transmitter transmits radio waves including key data (unique ID). Therefore, when the driver P having the appropriate key 13 approaches the automobile 10, the automobile 10 receives this radio wave. Then, the automobile 10 collates key data included in the radio wave. If it is authenticated that the collation result is correct, the door 12 can be unlocked and locked. When the driver P pushes a switch provided on a knob or the like of the door 12 in a state in which the verification is authenticated, the door 12 is unlocked. On the other hand, when the verification is not authenticated, that is, when the driver P having the appropriate key 13 is away from the automobile 10 by a certain distance or more, the door 12 is not unlocked.

  A control method according to the modification will be described with reference to FIG. FIG. 12 is a flowchart illustrating a control method according to the modification. First, in a state where the driver P is away from the automobile 10 by a certain distance or more, the image display device 100 that is a HUD is stopped (step S21). When the driver P approaches the automobile 10, communication between the key 13 and the automobile 10 is performed. Then, the door / key state detection unit 22 performs collation to determine whether or not the key is an appropriate smart key (step S22). If it is not an appropriate smart key (No in step S22), the determination in step S22 is performed until it is detected that the smart key is appropriate.

  If it is detected that the key is an appropriate smart key (Yes in step S22), the scanning mirror unit 200 is operated (step S23). That is, when smart key authentication is performed, the scanning mirror unit 200 is operated in advance to enter the aging mode. When the ACC is turned on after the mirror operation (step S24), the image display device 100 that is a HUD is activated (step S25). That is, the control unit 23 supplies power to the entire image display device 100. Accordingly, power is supplied to the image signal processing unit 110, the light source unit 130, the timing processing unit 160, and the like, and the display mode is set. Therefore, the image display apparatus 100 starts operation and displays a desired image.

  Even with this control, the same effect as in the first embodiment can be obtained. For example, after the smart key is authenticated, the driver P unlocks the door to get on the automobile 10. Then, the driver P gets on the automobile 10 and starts the engine. During this time, the scanning mirror unit 200 is operating as in the first embodiment. Therefore, an image can be displayed immediately after the engine is started. After the authentication of the smart key, the scanning mirror unit 200 operates until ACC is turned on. Before the ACC is turned on and the image display apparatus 100 displays an image, the scanning mirror unit 200 can be operated. Therefore, it becomes possible to stabilize quickly. Further, when communication with the smart key is interrupted, the operation of the scanning mirror unit 200 is stopped. By doing so, power consumption can be further reduced.

  Furthermore, in this modification, power can be supplied to the scanning mirror unit 200 earlier than the unlocking of the door 12 or the opening of the door 12. Thereby, the operation of the scanning mirror unit 200 can be stabilized more quickly. In addition, after operating the scanning mirror unit 200, the driver P may leave the automobile 10 without unlocking the door lock. In this case, after the smart key is detected once, the smart key is not detected. Therefore, when the smart key is no longer detected, the process may return to step S21 to stop the power supply to the scanning mirror unit 200. Thereby, when driver P does not board, it can prevent that scanning mirror part 200 continues operating. Further, by using the smart key collation result, it is not necessary to provide a new sensor in the automobile 10. Thereby, it can control with a simple structure.

(Second Embodiment)
An image display apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 13 is a block diagram illustrating a configuration of a control system of the image display apparatus 100 according to the second embodiment. In the present embodiment, a temperature adjustment unit 135 including a Peltier element 136, a temperature sensor 137, and a temperature controller 138 is provided. Note that the configuration other than the temperature adjustment unit 135 is the same as that of the first embodiment, and a description thereof will be omitted. The Peltier element 136 is a thermoelectric element attached to the light source unit 130 and changes the temperature of the laser diode of the light source unit 130. That is, the Peltier element 136 heats or cools the light source unit 130. An element other than the Peltier element 136 may be used, or an element that performs only one of heating and cooling may be used.

  The temperature sensor 137 measures the environmental temperature of the light source unit 130 or its surroundings. The temperature controller 138 controls the Peltier element 136 based on the temperature measured by the temperature sensor 137. Specifically, the battery 21 is connected to the temperature controller 138. The temperature controller 138 controls the power supply from the battery 21 to the Peltier element 136. Thereby, temperature control is performed so that the light source unit 130 has a desired temperature. Thus, the temperature adjustment unit 135 adjusts the temperature of the light source unit 130. Then, similarly to the scanning mirror unit 200 of the first embodiment, the temperature adjustment unit 135 is operated in advance.

  That is, the control unit 23 supplies power so as to operate the temperature adjustment unit 135 according to the detection result of the door / key state detection unit 22. As a result, similar to the operation of the scanning mirror unit 200, the temperature adjustment unit 135 can be operated in advance. Specifically, as shown in the first embodiment, when the door 12 is in an open state or when the door 12 is unlocked, the temperature of the temperature adjusting unit 135 is controlled. Alternatively, as shown in the modification, temperature control of the temperature adjustment unit 135 is performed according to the detection result of the smart key. The control of the temperature adjustment unit 135 can be the same as the control of the scanning mirror unit 200. The temperature of the light source unit 130 can be stabilized, and the laser diode of the light source unit 130 can be within an operable temperature range (for example, 0 ° C. to 60 ° C.).

  For example, when the automobile 10 is in a cold region, the environmental temperature may be lower than the lower limit value of the operable temperature range of the laser diode of the light source unit 130. In this case, the Peltier element 136 of the temperature adjustment unit 135 heats the light source unit 130 in advance. Thereby, before the image display of the image display apparatus 100 starts, the laser diode of the light source unit 130 falls within the operable temperature range. Further, when the automobile 10 is in an extremely hot region, the environmental temperature becomes higher than the upper limit value of the operable temperature range of the laser diode of the light source unit 130. In this case, the Peltier element 136 of the temperature adjustment unit 135 cools the light source unit 130. Thereby, before the image display of the image display apparatus 100 starts, the laser diode of the light source unit 130 falls within the operable temperature range.

  The temperature adjustment may be performed in anticipation of a temperature rise due to light emission of the laser diode. In this case, temperature adjustment is performed so that the temperature becomes a certain level lower than the upper limit value of the operable temperature range. For example, when the operable temperature range is 0 to 60 ° C., the temperature is adjusted so as to be 55 ° C. or less. Further, the Peltier element 136 may cool or heat only a part of the laser diodes instead of cooling or heating all the laser diodes of the light source unit 130. For example, only the laser diode having the most severe temperature condition may be temperature-controlled. Further, similarly to the first embodiment, the temperature adjustment of the temperature adjustment unit 135 may be stopped by a timer.

  The operation by the temperature adjustment unit 135 may be performed in combination with the operation by the scanning mirror unit 200, or only the operation by the temperature adjustment unit 135 may be performed without performing the operation by the scanning mirror unit 200. That is, only the temperature adjustment unit 135 may be operated without operating the scanning mirror unit 200 according to the detection result of the door / key state detection unit 22.

  Note that the image display device 100 is not limited to the normal automobile 10 and may be mounted on other vehicles such as other special vehicles. As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

10 ... automobile, 11 ... windshield, 12 ... door, 13 ... key,
21 ... Battery, 22 ... Door key state detection unit, 23 ... Control unit,
DESCRIPTION OF SYMBOLS 100 ... Image display apparatus, 110 ... Image signal processing part, 111 ... Video interface, 112 ... Video decoder, 113 ... Memory controller, 113R ... Reading part, 113W ... Writing 114, frame memory, 115 data buffer, 116 light source driver, 116B blue driver, 116G green driver, 116R red driver, 120 light Emitting unit 130 ... light source unit 132B ... blue laser diode 132G ... green laser diode 132R ... red laser diode 133A ... mirror 133B ... mirror 133D ... Mirror, 134 ... Condensing lens, 135 ... Temperature adjustment unit, 136 ... Peltier element, 1 7 ... Temperature sensor, 138 ... Temperature controller, 150 ... Imaging optical system, 151 ... Flat mirror, 152 ... Screen, 153 ... Flat mirror, 154 ... Concave mirror , 160 ... Timing processing unit, 161 ... Mirror drive control circuit, 161 H ... Main scanning drive control unit, 161 V ... Sub-scanning drive control unit, 162 ... Vibration detection unit, 170 ... Timing adjustment unit, 171 ... period detection unit, 172 ... frequency multiplication unit, 173 ... dot clock supply unit, 174 ... display period instruction unit, 200 ... scanning mirror unit, 210 ... Optical deflection element, 230 ... sub-scanning oscillating body, 231 ... frame, 232 ... main scanning oscillating piece, 233A, 233B, 233C, 233D ... L-shaped beam, 234A, 234B 234C, 23 D ... piezoelectric element, 235 a mirror, 236U, 236D ... magnet, 240L, 240R ... arm, ... support base portions, 251 ... base section, 252U, 252D ... electromagnetic coil.

Claims (7)

An image display device installed in a vehicle having a door,
A light source unit for converting a video signal into an optical signal by a laser beam ;
A scanning mirror unit that reflects and scans the light flux of the optical signal, transmits and reflects the light flux on a windshield provided in the vehicle , and displays an image;
When the door is in the open state or the door key is in the unlocked state , the scanning mirror unit is operated in a state in which laser light is not emitted from the light source unit , and the accessory mode is set as the key state of the vehicle. There the image display apparatus and a control unit Ru is emitted laser light from the light source unit when turned on. The scanning mirror unit, and swung by the resonant drive at a first pivot shaft, a MEMS mirror which swings by non-resonant drive at the second swing axis,
If the door is the Hirakijo state or key is unlocking state, the control unit operates the swinging of the first swinging shaft in a state where the rocking was stopped in the second swing shaft The image display device according to claim 1, which is controlled as described above. The vehicle is a car that is unlocked and locked by a smart key;
The image display device according to claim 1, wherein the control unit operates the scanning mirror unit when authentication of key data of the smart key is authenticated.   The control unit operates the scanning mirror unit when it is detected that the door is opened or the door key is unlocked. The image display device described. A temperature adjusting unit for adjusting the temperature of the light source unit;
5. The image display device according to claim 1, wherein the temperature adjustment unit starts temperature adjustment of the light source unit according to an open / closed state or a key state of the door.   After operating the scanning mirror unit in a state where the light source unit is not operating, the operation of the scanning mirror unit is stopped when the image display device does not display an image for a predetermined time or longer. The image display device according to claim 1. A light source unit for converting the video signal into an optical signal by a laser beam, and the optical signal is scanned by reflecting a light beam, said light beam into the windshield transmittance and is reflected by scanning mirror unit for displaying the images included in the vehicle A method for controlling an image display device comprising:
Detecting an open / closed state or a key state of a vehicle door on which the image display device is installed; and
If the door is open state or a key is unlocking state, and controls the power supply to the scanning mirror, in a state where the laser light is not emitted from the light source unit, to operate the scanning mirror unit, control method for an image display device Ru is emitted laser light from the light source unit when the accessory mode is turned on as the state of the key of the vehicle.