JP6015442B2 - Image display device - Google Patents

Description

  The present invention relates to an image display device, and more particularly, to a laser scanning projection display.

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 (for example, Japanese Translation of PCT International Publication No. 2010-539525). 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 an image display device may be very miniaturized by using a semiconductor laser diode or a MEMS mirror, and various application products such as a head-up display and a head-mounted display have been developed.

  By the way, it is assumed that a laser scanning projection display is mounted on an automobile. In this case, a laser scanning projection display is installed on the dashboard of the car and the windshield is used as a combiner (or a hologram combiner may be attached to the windshield separately), or a combiner is installed near the windshield. Or

  Laser light emitted from a laser scanning projection display enters the driver's eye via reflection on the windshield (combiner) and forms an image on the retina. At the same time, light from the outside enters the windshield 11 and passes through. Therefore, the light L2 from the outside world and the image light beam L1 of the image display device 100 are overlaid (superimposed), and the actual scene of the outside world and the image emitted by the image display device 100 can be simultaneously seen in the field of view of the driver P. Become.

Special table 2010-539525 gazette

  The laser light emitted from the projection display is incident on the driver's eyes via reflection on the windshield, but the total amount of laser light is not reflected on the windshield. That is, there is a part that passes through the windshield and goes upward as it is, and is emitted outside the vehicle (see FIG. 11). Therefore, it is desirable to prevent light from a light source such as laser light output outside the vehicle from entering the human eye.

Therefore, the present invention provides
In an image display device,
A light source that outputs a luminous flux;
A light source driving unit for driving the light source unit based on input image data;
A scanning mirror unit that is driven in a main scanning direction and a sub-scanning direction to reflect a light beam from the light source unit so as to perform raster scanning;
Based on information indicating whether or not the vehicle on which the image display device is mounted is moving, when the vehicle is stopped at a specific attention place, the light source unit is more There is provided an image display device comprising: an output control unit that controls an output state of a light beam so as to reduce an intensity of the light beam or stop output of the light beam from the light source unit .

The present invention also provides:
In an image display device,
A light source that outputs a luminous flux;
A light source driving unit for driving the light source unit based on input image data;
A scanning mirror unit that is driven in a main scanning direction and a sub-scanning direction to reflect a light beam from the light source unit so as to perform raster scanning;
A proximity sensor that detects the approach of an object in the same direction as the direction in which the light beam scanned by the scanning mirror unit is emitted from the image display device;
When the presence of an object is detected by the proximity sensor, the output state of the light beam is controlled so that the intensity of the light beam from the light source unit is weakened or the output of the light beam from the light source unit is stopped. And an output control unit for providing an image display device.

  According to such a configuration, it is possible to prevent light from a light source such as laser light output outside the vehicle from entering the human eye.

The figure which shows the typical usage example of an image display apparatus. 1 is a functional block diagram showing the overall configuration of an image display device. 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. 6 is a flowchart showing the operation of Operation Example 1; 10 is a flowchart showing the operation of Operation Example 2; 10 is a flowchart showing the operation of Operation Example 3; The figure for demonstrating a subject.

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 typical use example of an image display apparatus 100 assumed by the present invention. In addition, although the example which gave the function as a combiner to the windshield 11 is demonstrated, the structure which provides a combiner separately in the vicinity of a windshield may be sufficient.
The image display device 100 reflects laser light with a scanning mirror and displays (draws) an image on a projection surface by raster scanning of light rays.
In FIG. 1, the image display device 100 is mounted on an automobile 10.
The image display device 100 emits (outputs) 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 (combiner) 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 world and the image light beam L1 of the image display device 100 are overlaid (superimposed), and the actual scene of the outside world and the image emitted by the image display device 100 can be simultaneously seen in the field of view of the driver P. Become.

FIG. 2 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, a timing processing unit 160, a central control unit 180, and a proximity sensor 300.
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.

An original image signal is input to the image signal processing unit 110 via the video interface 111.
The image source is not limited and can be variously considered. For example, there are an image signal from a car navigation device, a speed display signal from a vehicle, etc. Can be considered.
The video decoder 112 decodes the original image signal according to the image type.
For example, when the original image signal is an analog image signal (component video signal), the decoding process is performed to convert the original image signal into a digital image signal composed of digital color signals of three colors (RGB) and a horizontal synchronization signal. And a synchronizing signal including a vertical synchronizing signal.

The memory controller 113 includes a writing unit 113W and a reading unit 113R.
FIG. 3 is a diagram showing a flow of processing of the video signal.
The writing unit 113W temporarily writes 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.
At this time, 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 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 according to information on each color of each pixel, thereby causing each semiconductor laser diode to emit light with a luminance corresponding to the color information.

The light emission unit 120 includes a light source unit 130 and a scanning mirror unit 200.
FIG. 5 is a perspective view of the light emitting unit 120. The light source unit 130 and the scanning mirror unit 200 are unitized as an example.
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, there are provided a red laser diode 132R, a green laser diode 132G and a blue laser diode 132B which respectively output lasers (laser lights) of R (red), G (green) and B (blue). ing.
Note that this embodiment can be applied to a configuration using more than three colors of laser diodes, and can also be applied to a configuration using laser diodes of one color or two colors.

Each of the mirrors 133B and 133C is a dichroic mirror that transmits or reflects a color having a predetermined wavelength.
The path of the light output from the light source unit 130 will be briefly described. The first mirror 133A reflects the green laser output from the green laser diode 132G 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 output from the red laser diode 132R and reflects the green laser to multiplex the two.
The third mirror 133C transmits the light from the second mirror 133B and reflects the blue laser output from the blue laser diode 132B.
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.
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. 5, a circuit board is provided on the back side of the light emitting unit 120, and an image signal processing unit 110, a timing processing unit 160, and a central control unit 180 are incorporated on the circuit board. It has become.

Next, the configuration of the scanning mirror unit 200 will be described.
The scanning mirror unit 200 is a so-called MEMS (Micro Electro Mechanical Systems) 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. By oscillating the mirror, the image light beam output from the light source unit 130, which is a light beam obtained by combining three laser beams on one axis, is reflected so as to be raster-scanned (raster scan).

A typical structure of the scanning mirror unit 200 will be described with reference to FIG.
6A is a plan view of the scanning mirror unit 200, and FIG. 6B is a schematic cross-sectional view. In the schematic cross-sectional view, some hatchings are omitted for easy viewing. For convenience of explanation, the vertical direction in FIG. 6A will be described as the y-axis direction, and the horizontal direction will be 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 light deflection element 210 swings in the sub-scanning direction as a whole between the two support portions 220L and 220R disposed at both ends in the x-axis direction in FIG. 6A and the two support portions 220L and 220R. It has a sub-scanning rocking body part 230 and two arms 240L and 240R that connect the two support parts 220L and 220R and the sub-scanning rocking body part 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 has 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 235 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.

Next, 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. 6A, a drive signal is applied to the two drive piezoelectric elements 234A and 234B disposed on the left side with the main scanning oscillation axis Ys interposed therebetween. 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, the drive voltage signal having a predetermined phase difference with respect to the vibration detection signals obtained from the detection piezoelectric elements 234C and 234D is fed back to the drive piezoelectric elements 234A and 234B, whereby the main scanning oscillating piece 232 is obtained. Can be driven to resonate.
Further, when the vibration detection signal obtained from the detection piezoelectric elements 234C and 234D indicates that the mirror 235 does not swing, the output control unit 182 weakens the intensity of the light beam from the light source unit 130. Alternatively, it is preferable to stop the output of the light beam from the light source unit 130. This is because when the mirror 235 is not oscillating, the light concentrates at one point and a powerful laser beam may enter the eye.

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 unit 150 will be described.
FIG. 7 is a diagram schematically showing an optical path until the image light beam L1 emitted from the light emitting unit 120 reaches the eye PE of the driver P who sees.
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 microlens array 152, a plane mirror 153, and a concave mirror 154. FIG. 7 also shows a windshield 11 as a combiner.

  The microlens array 152 is of a light transmission type and has microlenses arranged in a matrix. The microlens array 152 has an effect of reducing speckle peculiar to a laser, and is optimally designed in consideration of a radiation angle and color unevenness. Then, laser light is diffused (radiated) by the microlens array 152, thereby reducing the laser intensity per unit area. This reduces the burden on the eye and is safe even if light flux enters the eye.

  The light beam L1 reflected by the scanning mirror unit 200 once forms an intermediate image on the microlens array 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.

  Here, a proximity sensor 300 is disposed adjacent to the laser emission port of the image display device 100. The proximity sensor 300 is a so-called human sensor, for example, and detects the approach of an object such as a person using infrared rays or the like. The proximity sensor 300 can be configured to include, for example, a light source and a photosensor. The proximity sensor 300 has a detection direction in the same direction as the direction in which the image light beam L1 is emitted, and thus detects that a person or an object has approached the windshield 11. A detection signal from the proximity sensor 300 is output to the central control unit 180. The proximity sensor 300 may be provided outside the vehicle.

Next, the timing processing unit 160 will be described.
The timing processing unit 160 includes a mirror drive control circuit 161, a vibration detection unit 162, and a timing adjustment unit 170.
Here, the items that require timing processing include main scanning drive control of the scanning mirror unit 200, sub-scanning drive control of the scanning mirror unit 200, and image processing timing in the image signal processing unit 110. There is generation of a timing signal for adjusting to driving.

  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.

  The main scanning drive control of the scanning mirror unit 200 will be described. The vibration detection unit 162 detects detection signals from the detection piezoelectric elements 234C and 234D of the scanning mirror unit 200. The vibration detection unit 162 can be configured by an amplifier circuit or a filter, for example. The detected vibration detection signal Sn is fed back to the main scanning drive control unit 161H, phase adjustment is performed so that the scanning mirror unit 200 resonates in the main scanning direction, and the driving piezoelectric elements 234A and 234B are used as the main scanning drive control signal SH. Apply to. 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 outputs 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 signal SH output from the main scanning drive control unit 161H. To do.

  The timing adjustment unit 170 performs timing processing so that the operation of the memory controller matches the drive of the scanning mirror unit. Specifically, the dot clock is generated by multiplying the resonance frequency of the scanning mirror unit in the main scanning direction. The dot clock is supplied to the reading unit 113R, the RGB data buffer 115, and the light source driving unit 116 as a timing signal.

The operation of drawing based on the timing signal (dot clock, display period instruction signal) generated in this way will be described in order.
First, the reading unit 113R reads the image data line by line at the timing of the dot clock and outputs it to the RGB data buffer 115. The image data temporarily stored in the RGB data buffer 115 is sent to the light source driving unit 116 in order. Then, each color semiconductor laser diode is driven to emit light with the brightness indicated by the image data. 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.

Next, the operation of the central control unit 180 will be described.
The central control unit 180 controls the overall operation of the image display apparatus 100.
Particularly in the present embodiment, the central control unit 180 has an output control unit 182.
The output control unit 182 monitors the state of the vehicle and the surrounding situation, and controls the on / off operation of the laser emission according to the vehicle state and the surrounding situation. The central control unit 180 receives a vehicle signal, a position information signal, and a sensor signal from the proximity sensor 300 in order to monitor the vehicle state and the surrounding situation.

The vehicle signal is a signal for monitoring the vehicle state. For example, the vehicle signal includes a speed signal indicating the speed of the vehicle, a signal indicating the opening / closing state of the fuel filler opening, a signal indicating the opening / closing state of the window, and the like.
The position information signal is obtained from, for example, a car navigation device, and in addition to the coordinates of the current location specified by GPS, in the present embodiment, the facility where the vehicle is located (or close) It contains information. The facility information can be specified for the facility information where the vehicle is located by acquiring the coordinates of the current location and referring to the coordinates and the map information.
The information on the facility where the vehicle is located is information on the facility such as a gas station, a parking lot, and a drive-through store.

  The output control unit 182 turns off the laser emission when there is a possibility that laser light may enter the eyes of a person outside the vehicle. A specific control operation by the output control unit 182 will be described with reference to a flowchart.

The operation of the output control unit will be described with reference to the flowchart.
(Operation example 1)
FIG. 8 shows an operation example 1.
In the operation example 1, on / off control of laser emission is performed according to the place where the vehicle is stopped.
The output control unit monitors whether the vehicle is stopped.
Whether the vehicle is stopped can be determined, for example, by referring to a vehicle speed detection signal. Moreover, you may judge that it has stopped when the coordinate of the present location specified by GPS does not change.

  When the vehicle is traveling, in other words, when the vehicle is not stopped (ST110: NO), light source driving is permitted (ST150). This is because when the vehicle is running, it is unlikely that there is a person who takes a posture of looking into the interior of the vehicle through the windshield. In this case, normal operation is performed, and light from the semiconductor laser diodes 132R, 132G, and 132B enters the eyes of the driver or the like to form an image.

  On the other hand, when the vehicle is stopped (ST110: YES), an operation for specifying a place where the vehicle is stopped is further performed. That is, with reference to the position information from the car navigation device (ST120), it is determined whether or not the stop position of the vehicle is a specific attention place.

  Here, the specific attention place is a place where a situation in which a person protrudes in front of the windshield can be assumed, and the specific attention place is registered (stored) in the output control unit in advance. Examples are gas stations and drive-throughs. In addition, the user may be allowed to set and register an arbitrary place as the specific attention place. For example, if there is a possibility that a child may look into the windshield in a parking lot at home, the user may set and register the home parking lot as a specific attention location.

If the stop position of the vehicle does not correspond to the specific attention place (ST130: NO), the output control unit permits light source driving as a normal operation. On the other hand, when the stop position of the vehicle corresponds to the specific attention place (ST130: YES), the output control unit stops the operation of the light source driving unit 116 (ST107). Then, the light emission of the semiconductor laser diodes 132R, 132G, and 132B is stopped.
(Note that if the semiconductor laser diodes 132R, 132G, and 132B have not yet emitted light, they are not permitted to emit light.)

  According to the first operation example, the light emission of the semiconductor laser diodes 132R, 132G, and 132B is stopped in a place where the laser light may enter the eyes of a person outside the vehicle. Therefore, since the laser beam does not pass through the windshield and is emitted outside the vehicle, the light from the light source such as the laser beam output outside the vehicle is prevented from entering the human eye. be able to. Note that the processing based on ST130 may be omitted, and the driving of the light source may be stopped even when the vehicle stops outside the specific place of interest. Even in this case, it is possible to prevent light from a light source such as a laser beam output outside the vehicle from entering the human eye. However, if the processing based on ST130 is performed, the driving of the light source is stopped when it is not necessary. There is a further effect that there is nothing.

(Operation example 2)
FIG. 9 shows an operation example 2.
In the operation example 2, the optimization is performed by adding the determination based on the specific attention operation. The same processes as those in the operation example 1 are denoted by the same reference numerals. As an example, in addition to the determination based on the specific attention location in the operation example 1, the determination based on the specific attention operation is further performed.
In the operation example 2, when the stop position of the vehicle is the specific attention place (ST130: YES), it is further determined with reference to the vehicle signal (ST131) whether the specific attention operation has been performed (ST131). ST132).

Here, the specific attention operation is an operation that can assume a situation in which a person protrudes in front of the windshield after the operation, and the specific attention operation is registered in the output control unit in advance. It shall be. The specific attention operation is, for example, an operation of opening a fuel filler opening of a vehicle or an operation of opening a vehicle window.
For example, if the vehicle stops at a specific point of interest (gas station) and the fuel filler port is opened, there is a possibility that there are people around the vehicle and then a person sticks out in front of the windshield. For example, if you stop at a specific place of interest (drive-through) and open a window, there will still be people around the vehicle, and then people may stick out in front of the windshield. . Therefore, when it is detected that the vehicle is stopped at the specific attention location and the specific attention operation is performed, the output control unit stops the driving of the light source.

In this operation example 2, even if it is detected that the vehicle stops at the specific attention place (ST130: YES), the light source drive is not stopped only by that. For example, even if the vehicle stops at a gas station (or in the vicinity of the gas station), the vehicle may simply stop at that location regardless of the work such as refueling. It is inconvenient if the image display is stopped until such a case. Therefore, in the operation example 2, the light source drive is stopped only when the place and the operation should be particularly noted so that the laser emission on / off control can be performed more appropriately.
According to the operation example 2, both safety and convenience can be achieved.

(Operation example 3)
FIG. 10 shows an operation example 3.
In the operation example 3, on / off control of laser emission is performed with reference to the detection result by the proximity sensor. That is, when the vehicle is stopped (ST210: YES), the output control unit refers to the sensor signal from the proximity sensor (ST220), and whether or not there is a person (or object) near the windshield. Is determined (ST230). When a person (object) is detected by the proximity sensor (ST230: YES), the laser emission is stopped (ST240).
In this operation example 3, it is more directly detected whether or not there is a person outside the vehicle. Therefore, when a person protrudes through the windshield, it can be detected and laser emission can be stopped reliably.

  In the operation examples 1 and 2, the light source drive on / off is controlled based on the specific attention location and the specific attention operation, but there is a concern that the situation that is not registered as the specific attention location or the specific attention operation cannot be handled. There is. In this respect, since the operation example 3 directly detects whether or not a person is present in the laser beam emission direction outside the vehicle, light from a light source such as a laser beam output outside the vehicle is applied to the human eye. The effect of preventing incidence is increased. In the operation example 3, the process in ST210 may be omitted.

(Modification)
In the above operation example, the light source drive is stopped. However, the light emission of all the semiconductor laser diodes 132R, 132G, and 132B is not stopped, but the intensity of the laser beam is reduced within a range in which safety can be ensured. Of course, you can do it. For example, the applied current value from the light source driving unit 116 to the light source unit 130 may be smaller than that during normal operation, for example, may be halved. According to this, even if light enters the eyes of a person outside the vehicle, the burden on the eyes is reduced. Alternatively, one or more of red light, green light, and blue light may be stopped. For example, the emission of green light and blue light may be stopped and only red light may be emitted. Alternatively, one or more of red light, green light and blue light may be stopped and light emitted may be weakened. For example, only the red semiconductor laser diode 132R is driven, and the drive current is also reduced. This further reduces the burden on the eyes of people outside the vehicle. Further, a shutter that enters and exits the optical path may be provided to block the light so that the light is not output to the outside of the image display device. In the present invention, stopping the output of light includes providing a shutter or the like to block light.

The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
In the above description, as the scanning mirror unit, the MEMS mirror capable of being integrally and biaxially driven is exemplified, but the mirror that swings in the horizontal direction and the mirror that swings in the vertical direction are separate, Various modifications are possible without being limited to the above examples.
Moreover, you may combine each above-mentioned operation example and modification.
In addition, the present invention includes a program for causing a computer to realize the functions of the central control unit 180. These programs may be read from a recording medium and loaded into a computer, or may be transmitted via a communication network and loaded into a computer.

The image display device may be applied not only to a vehicle-mounted type as a head-up display, but also to a head-mounted display such as a helmet built-in type or a glasses type.
(In other words, the present invention is not intended only for the case of being mounted on a four-wheeled vehicle.)
For example, if an image display device with a built-in helmet is assumed, and a motorcycle driver wears this helmet and goes out, the same problem as described above will occur, and such a problem will be It will be understood that the invention solves in the same way.

DESCRIPTION OF SYMBOLS 10 ... Automobile, 11 ... Windshield, 100 ... Image display apparatus, 110 ... Image signal processing part, 116 ... Light source drive part, 120 ... Light emission unit, 130 ... Light source unit, 150 ... imaging optical system, 160 ... timing processing unit, 180 ... central control unit, 182 ... output control unit, 200 ... scanning mirror unit, 300 ... proximity sensor .

Claims (5)

In an image display device,
A light source that outputs a luminous flux;
A light source driving unit for driving the light source unit based on input image data;
A scanning mirror unit that is driven in a main scanning direction and a sub-scanning direction to reflect a light beam from the light source unit so as to perform a raster scan toward a windshield of a vehicle on which the image display device is mounted;
A sensor unit for detecting the presence of a person outside the vehicle near the windshield;
Based on the information indicating whether or not the vehicle is moving and the current position information of the vehicle, the vehicle stops at a specific attention place where a situation in which a person protrudes in front of the windshield is assumed. When the sensor unit detects the presence of a person outside the vehicle, the light intensity from the light source unit is made weaker than when the vehicle is moving, or from the light source unit. An image display apparatus comprising: an output control unit that controls an output state of the light beam so as to stop the output of the light beam. With a shutter to enter and exit the optical path,
The output control unit inserts the shutter into the optical path when the vehicle on which the image display device is mounted is stopped at a specific place of interest and the sensor unit detects the presence of a person outside the vehicle. The image display device according to claim 1, wherein the output of the light beam is stopped. The image display device according to claim 1, wherein the specific attention place where a situation in which a person protrudes in front of the windshield is assumed is a gas station, a parking lot, or a drive-through store. The output controller controls an output state of a light beam based on information indicating whether or not a specific attention operation has been performed on a vehicle on which the image display device is mounted. The image display device according to item. The image display device according to claim 4, wherein the specific attention operation is an operation of opening a fuel filler port of a vehicle or an operation of opening a window of the vehicle.