JP6865552B2 - Video projection system - Google Patents

Description

The present invention relates to a headlight composed of a plurality of image projection devices.

In recent years, a system that forms one image using multiple image projection devices has been developed, and various effects can be produced as a replacement for the conventional multi-monitor display system or as projection mapping using the outer wall of a building as a screen. Is used for. As a projection method using a plurality of image projection devices, a method of partially changing the resolution of an image by superimposing and projecting a plurality of projected images is known.

For example, Patent Document 1 below employs a projection method in which an image superimposing portion is created by using two projectors, a projector for whole projection and a projector for local projection, and the resolution can be partially changed (paragraph). 0005, FIG. 1). The technique of projecting an image forward by a plurality of projectors is applied to vehicle headlights.

In recent years, automobiles equipped with a camera that monitors the front of the vehicle have appeared. As a typical example of the system, there is a system in which a warning sound is output when a pedestrian or the like is recognized from an image captured by a camera, and a warning mark is superimposed on an image of a monitor provided near the dashboard.

However, it is not preferable for the driver to move his / her line of sight from the front of the vehicle to the monitor in order to confirm the warning mark. Therefore, a system has been proposed in which a spotlight (marking lamp) is applied to a recognized pedestrian to keep the driver's line of sight in front of the vehicle and to make the driver recognize the presence of the pedestrian. ..

Japanese Unexamined Patent Publication No. 2004-070257

However, if a function of irradiating a spot light is added to a system that irradiates a predetermined range such as a headlight for a vehicle, there is a problem that the system configuration becomes complicated and the cost increases.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a headlight capable of guiding a viewer's line of sight to a predetermined area of a projection range by a simple configuration.

The headlight of the present invention combines a plurality of raster scan type image projection devices and a plurality of sub-images projected from the plurality of image projection devices having different projection ranges to generate one composite image. The headlight includes a composite image generation unit, a brightness adjustment unit that adjusts the brightness of the sub image, and an attention area setting unit that sets a predetermined area of interest in the composite image. The plurality of sub-images constituting the composite image in a normal time when the attention area is not set outside the image projection range of the sub-image having the highest maximum brightness among the plurality of sub-images by the attention area setting unit. In each of the image projection ranges, the luminance distribution in the central portion is the highest, and the luminance gradually decreases toward the outer peripheral portion. when the region of interest outside the region of the inner maximum luminance is the highest sub-picture is set for the sub-image projected from at least one of the plurality of the image projection apparatus, the combined image at the time of the normal From the generated video distribution process, the brightness of the entire image projection range of the sub image is set to a predetermined level, and then gradually from the outer peripheral portion of the image projection range of the sub image toward the area of interest with the passage of time. It is characterized by switching to the line-of-sight guidance process for converging the image projection range.

The headlight of the present invention is composed of a plurality of image projection devices having different projection ranges, and a composite image generation unit combines sub-images from each image projection device to generate one composite image.

Further, the attention area is set by the attention area setting unit, but when the attention area is set outside the area of the sub image having the highest maximum brightness among the plurality of sub images, the brightness of the attention area is increased. However, since the difference from the originally high brightness part is small, it is difficult to attract the attention of the viewer.

Therefore, the luminance adjusting unit first performs a video distribution process for generating a composite video at the normal time for at least one video projection device. Further, the brightness adjusting unit raises the brightness of the entire image projection range to a predetermined level, and then the image projection range gradually converges with the passage of time from the outer peripheral portion of the image projection range toward the region of interest. Performs line-of-sight guidance processing . Once to draw attention of the viewer by the front of the composite video image becomes brighter, further, since the gradual darkened finally bright portion from the outer peripheral portion of the combined image is gradually converged to the target area, the headlamps The light can guide the line of sight of the viewer to the region of interest.

In the headlight of the present invention, the image projection device includes a light source, a rotary mirror unit that reflects light from the light source, and a mirror control unit that controls a swing angle range of the mirror unit. The brightness adjusting unit controls the mirror control unit to gradually reduce the swing angle range with the passage of time, so that the outer peripheral portion of the sub image is changed from the initial state in the normal state to the attention region. It is preferable to gradually converge the image projection range toward the end.

According to this configuration, the brightness adjusting unit can control the mirror control unit of each image projection device to adjust the brightness. Specifically, when the image projection range is gradually converged from the outer peripheral portion of the composite image toward the region of interest, the deflection angle range of the mirror portion is controlled to gradually decrease with the passage of time. As a result, the headlight has the effect that the bright part gradually converges on the region of interest.

Further, in the headlight of the present invention, it is preferable to further include a projection range switching unit in charge of switching the image projection device for projecting an image into the projection range of the plurality of sub-images according to a predetermined condition.

Since the image projection device that is in charge of a relatively wide projection range always has a large deflection angle of the mirror portion, the load on the device is large. According to this configuration, the load of each image projection position is distributed by the responsible projection range switching unit switching the image projection device that projects the image into the projection range of each sub image according to a predetermined condition. As a result, the product life (usable period) of this headlight can be extended.

The schematic diagram of the image projection system of an embodiment. The schematic diagram of the image projection apparatus of the image projection system of embodiment. The explanatory view of the image signal processing part of the image projection apparatus of embodiment. The perspective view of the MEMS used for the image projection apparatus of an embodiment. The figure which shows the relationship between the semiconductor light source, the MEMS mirror, and the image projection range projected from the image projection apparatus. The figure which shows the waveform change of the drive signal of the MEMS mirror and the semiconductor light source which rotates in the sub-scanning direction with the passage of time. The figure which shows the waveform change of the drive signal of the MEMS mirror and the semiconductor light source rotating in the main scanning direction with the passage of time. 6A and 6B are diagrams showing the relationship between the drawing range of the projected image based on the drive signals of the MEMS mirror and the semiconductor light source and the scanning locus. The figure which shows the relationship between the projection angle range (image projection range) of each image projection apparatus, and the maximum brightness. The figure which shows the relationship between the luminance distribution of an input image, and the image projection range of the 1st image projection apparatus to the 4th image projection apparatus. The figure (1) explaining the example of the line-of-sight guidance processing. The figure (2) explaining the example of the line-of-sight guidance processing. The figure (3) explaining the example of the line-of-sight guidance processing. The figure which shows the image projection range of an image projection system. The figure explaining the switching of the image projection range of the 1st image projection apparatus to the 4th image projection apparatus.

Hereinafter, a vehicle in which the image projection system 1 of the present embodiment is mounted together with a vehicle headlight, an in-vehicle camera, an image processing unit thereof, and the like will be described as an example.

As shown in FIG. 1, the video projection system 1 includes first to fourth video projection devices 10A to 10D (hereinafter, may be referred to as a video projection device 10), a video signal representing an input video, and an MP described later. A video signal distribution unit 20 that receives a signal and outputs an individual video signal representing a brightness distribution in the video projection range and an offset signal described later to each video projection device 10 is provided. Hereinafter, the image projection system of the present embodiment will be described using an image projection system including four image projection devices, but the number of devices is not limited to four, and may be two or more.

First, the video signal distribution unit 20 of the present embodiment (corresponding to the "synthetic image generation unit", "luminance adjustment unit", "attention area setting unit", and "charged projection range switching unit" of the present invention) is a CPU. , ROM, RAM, and electronic circuits such as I / O circuits and A / D circuits (not shown), and each image projection device 10 is based on the luminance distribution of the input image expressed by the image signal obtained from the image source. The brightness distribution of the image projection range given to is extracted. Then, the video signal distribution unit 20 outputs an individual video signal representing the brightness distribution of the extracted video projection range to each video projection device 10.

Further, the video signal distribution unit 20 identifies the position of the highest luminance point in the brightness distribution of the input video, and individually sets an offset signal capable of setting the center of the video projection range of each video projection device 10 to the position of the highest luminance point. It is output to each image projection device 10 together with the image signal.

The offset signal is used to offset (position) the image projection range to a desired range of the drawing range with respect to the image projection device having a range in which the image can be projected due to the limitation of the deflection angle of the MEMS mirror 106 described later. It is a signal. Specifically, the offset signal is a signal indicating the amount of displacement to be moved in the horizontal and vertical directions from the reference position with the center of the entire screen on which the image is projected as the reference position.

Each image projection device 10 can move the image to be projected in response to the offset signal in the up, down, left, and right directions. The movement of the projected image in the vertical and horizontal directions is carried out by providing each image projection device 10 with a moving mechanism using a stepping motor or the like.

Further, the video signal distribution unit 20 increases the brightness of a specific region (marking point) within the video projection range, receives an MP signal for guiding the driver's line of sight to the specific region, and transmits each individual video signal. Output to the image projection device 10.

The MP signal is a signal processed by the image processing unit 50 based on the image captured by the vehicle-mounted camera 40, and includes coordinate information in the image projection range (maximum range) of the marking point.

As shown in FIG. 2, each image projection device 10 of the present embodiment includes a MEMS mirror 106, a semiconductor light source 112, a MEMS mirror 106, and a control unit 30 that outputs a signal to the semiconductor light source 112, and is a raster described later. It is a device that performs scanning.

The control unit 30 of each image projection device 10 is an individual image signal input unit 102 into which an individual image signal generated based on an image signal output from an image source such as a personal computer or a camera system is input, and an individual received individual image signal input unit 102. An individual video signal storage unit 104 that writes / reads each predetermined bit to process a video signal, a MEMS drive unit 108 that outputs an AC wave drive signal to the MEMS mirror 106, and a MEMS drive unit 108 that outputs an AC wave drive signal to the MEMS mirror 106, depending on the drive signal. When the MEMS mirror 106 rotates around the rotation axis, the sensor signal input unit 110 to which a signal from a sensor that outputs a voltage corresponding to the deflection angle of the MEMS mirror 106 is input and the MEMES mirror 106 are irradiated with light. It is composed of a light source driving unit 114 that outputs pixel data to a semiconductor light source 112 such as an LED or a semiconductor laser, and an individual video signal processing unit 116 that processes individual video signals and controls each image projection device 10. ..

Here, for convenience of explanation, a sine wave-shaped drive signal will be used as the AC wave drive signal for driving the MEMS mirror 106, but a cosine whose phase is delayed by 90 ° with respect to the sine wave-shaped drive signal. A wave-shaped signal or the like may be used.

The individual video signal input unit 102 outputs the input individual video signal to the individual video signal processing unit 116 in order to process the video signal. As the individual video signal input unit 102, a video signal receiver such as VGA (analog RGB), DVI, HDMI (registered trademark), DisplayPort or the like can be used.

The individual video signal storage unit 104 writes and reads signals in order to process the individual video signal output from the individual video signal input unit 102. As the individual video signal storage unit 104, SDRAM or the like can be used. In the video projection system of the present embodiment, since the video signal is generated as a high-speed signal, DDR2- SDRAM and DDR3-SDRAM are suitable.

The MEMS drive unit 108 (corresponding to the “mirror control unit” of the present invention) is a D / A that converts a digital signal from the individual video signal processing unit 116 into an analog signal in order to output a drive signal to the MEMS mirror 106. It consists of a converter and an operational amplifier that amplifies its output signal to the drive voltage level of the MEMS mirror 106.

The sensor signal input unit 110 is a signal from the sensor that outputs a voltage corresponding to the deflection angle of the MEMS mirror 106 when the MEMS mirror 106 rotates around the rotation axis in response to the drive signal and rotates in the scanning direction. Is the signal input unit to which is input. The sensor signal input unit 110 includes an A / D converter that converts the received analog signal into a digital signal output to the individual video signal processing unit 116, and an operational amplifier that secures an appropriate input level for the A / D converter. To.

The light source drive unit 114 is composed of a high-speed D / A converter that converts a digital signal output from the individual video signal processing unit 116 into an analog signal, a driver transistor having a current capacity that can drive the semiconductor light source 112 of each RGB color, and the like. It is composed.

The individual video signal processing unit 116 processes the individual video signals and controls each video projection device 10. The individual video signal processing unit 116 can use, for example, an FPGA (Field-Programmable Gate Array), a microprocessor, or a hybrid device (EPP (Extensible Processing Platform) or SoC (System on Chip)) thereof.

Further, as shown in FIG. 3, the individual video signal processing unit 116 includes an input video processing unit 120 as an interface for outputting the individual video signal from the individual video signal input unit 102 to the individual video signal storage unit 104, and the individual video. Based on the signal output from the signal storage unit 104, the drive signal is generated to generate the drive signal of the MEMS mirror 106 to be sent to the MEMS drive unit 108 and the signal to be the basis of pixel data extraction to be sent to the light source drive unit 114. A drive signal calculation processing unit 124 that performs resonance frequency tracking control and sends a signal to the pixel data extraction unit 126 based on the signals output from the sensor signal input unit 110 and the drive signal generation unit 122. The pixel data extraction unit 126 that extracts the pixel data to be sent to the light source drive unit 114 based on the signals output from the signal generation unit 122 and the drive signal calculation processing unit 124, and the control parameters for each of these signal processing are controlled. It is composed of a comprehensive control unit 128 that functions as an interface with an external control means (not shown) such as a switch and a UART (Universal Asynchronous Receiver Transmitter).

Further, as shown in FIG. 4, the MEMS 130 including the MEMS mirror 106 of the present embodiment has a first support portion 132 in which the MEMS mirror 106 having a reflecting surface is supported by a pair of torsion bars 131A and 131B, and a MEMS mirror 106. The pair of torsion bars 131A and 131B with respect to the first support portion 132, that is, the first actuators 134 and 136 that rotate in the main scanning direction (around the Y axis) and the second support portion 132. A two-axis capable of two-dimensional scanning provided with a support portion 138 and second actuators 140 and 142 that rotate the first support portion 132 with respect to the second support portion 138 in the sub-scanning direction (around the X-axis). It is a type light deflector.

In each image projection device 10 provided with the MEMS 130, the semiconductor light source 112 is turned on so that light is projected only in the drawing range in the image projection range described later in accordance with the two-dimensional scanning, so that the light utilization efficiency is improved. Can be planned.

As the actuator of the MEMS 130, a piezoelectric type, an electrostatic type, or an electromagnetic type actuator can be used. In this embodiment, a piezoelectric actuator is adopted as the first actuators 134 and 136. Further, each of the second actuators 140 and 142 is configured by connecting four piezoelectric cantilever levers. The piezoelectric cantilever 140A to 140D and 142A to 142D include a laminate composed of a support, a lower electrode, a piezoelectric body, and an upper electrode.

The projection of the image based on the image signal is executed by high-speed scanning in the horizontal direction and low-speed scanning in the vertical direction. Therefore, the MEMS mirror 106 rotates in the main scanning direction by the resonance drive of the first actuators 134 and 136 corresponding to the high-speed operation, and the sub-scanning is performed by the non-resonant drive of the second actuators 140 and 142 corresponding to the low-speed operation. Rotate in the direction.

In the present embodiment, since the rotation in the sub-scanning direction is a low-speed operation, a non-resonant drive actuator is used, but the present invention is not limited to this, and a resonance drive actuator may be used.

In order to detect the rotational state of the MEMS mirror 106, the first support portion 132 has a sensor 144 at a position adjacent to the torsion bars 131A and 131B, and a sensor 146 near the second actuators 140 and 142. It is provided. As the position sensor, a sensor using the piezoelectric effect or a sensor using the piezoresistive effect can be adopted. The sensor using the piezoelectric effect operates as a velocity sensor that returns a differential value with respect to the displacement amount of the deflection angle of the MEMS mirror 106. Further, the sensor using the piezoresistive effect operates as a position sensor that returns a value proportional to the displacement amount of the deflection angle of the MEMS mirror 106.

It is preferable to use an actuator and a sensor using a piezoelectric effect in that a laminated structure of an actuator and a sensor can be formed by the same manufacturing process.

Further, at least one of the sensors 144 and 146 needs to be provided, respectively, but in order to improve the rotational stability of the MEMS mirror 106 in the main scanning direction and the sub-scanning direction and the noise canceling effect of the differential signal, FIG. As shown in 4, it is preferable to provide two lines symmetrically about the Y-axis and the X-axis.

Next, a raster scan mainly using the semiconductor light source 112 and the MEMS mirror 106 of the MEMS 130 will be described with reference to FIGS. 5 to 7.

As shown in FIG. 5, the light incident on and reflected from the semiconductor light source 112 on the MEMS mirror 106 draws an image (scanning locus) in the image projection range. Regarding the drawing of the image, the MEMS mirror 106 that rotates in the sub-scanning direction executes the scanning in the vertical direction in the image projection range of FIG. The waveform of the drive signal of the MEMS mirror 106 rotating in the sub-scanning direction of the present embodiment preferably has a sawtooth shape shown in FIG. 6A.

Since the MEMS mirror 106 rotating in the sub-scanning direction is driven at a low speed, either a resonance drive actuator or a non-resonance drive actuator can be used, but a sawtooth-shaped drive signal suitable for the non-resonance drive actuator can be used. By securing a long effective drawing time by using the above, it is possible to improve the brightness of the image projection range.

Specifically, in the sawtooth-shaped drive signal, a section in which the slope of the waveform of the drive signal is gentle with respect to the passage of time and a section in which the slope is steep appear alternately (see FIG. 6A). Then, the semiconductor light source 112 is turned on and drawn in a section where the sawtooth-shaped drive signal has a gentle slope (drawing interval), and the semiconductor light source 112 is turned off in a section where the slope is steep (vertical blanking interval). ) Is provided.

In the vicinity of the apex where the inclination of the sawtooth-shaped drive signal changes, the MEMS mirror 106 rotating in the sub-scanning direction is in a very low-speed drive state, so that the drawing portion corresponding to the section near the apex is the drawing range. It looks particularly bright when compared to other parts. Therefore, in the section near the apex, the uniformity of the brightness of the entire screen represented by the drawing range can be realized by turning off the semiconductor light source 112.

On the other hand, the MEMS mirror 106 that rotates in the main scanning direction performs horizontal scanning in the image projection range of FIG. The waveform of the drive signal of the MEMS mirror 106 rotating in the main scanning direction of the present embodiment is preferably an AC wave shown in FIG. 6B, for example, a sine wave shape. Since the MEMS mirror 106 rotating in the main scanning direction is driven at high speed, it is preferable to use a resonance-driven actuator, and the sinusoidal drive signal is suitable for the resonance-driven actuator.

Specifically, in the sinusoidal drive signal, a section near the apex of the waveform of the drive signal with respect to the passage of time and a section other than the apex appear alternately (see FIG. 6B). Therefore, as shown in FIG. 5, it is preferable to perform drawing by reciprocating scanning, that is, both rightward scanning and leftward scanning, from the viewpoint of ensuring an effective drawing time. One-sided scanning, for example, drawing is performed only in the right direction (left direction scanning), and in the left direction scanning (right direction scanning), reciprocating scanning, that is, as compared with a method in which a non-drawing section (horizontal return section) is provided. , Drawing can be performed by both right-hand scanning and left-hand scanning, and a long effective drawing time can be secured.

Further, in the vicinity of the apex of the sinusoidal drive signal (horizontal folding section), the MEMS mirror 106 rotating in the main scanning direction is in a very low speed driving state, so that the drawing portion corresponding to the section near the apex is It looks particularly bright when compared to other parts of the drawing range. In order to realize the uniformity of the brightness of the entire screen represented by the drawing range, as shown in FIG. 6B, in the section between the sections near the apex adjacent to the elapsed time (horizontal folding section). The semiconductor light source 112 is turned on to draw one line of the scanning locus in the horizontal direction of FIG. 5, and the semiconductor light source 112 is turned off in the horizontal folding section to provide a non-drawing section.

By performing the above-mentioned raster scan, as shown in FIG. 7, the drawing range in which the peripheral region of the image projection range of FIG. 5 is cut out in the horizontal and vertical directions from the entire scanning locus on the scanned surface is obtained. can get.

Next, the video produced by the distribution processing by the video signal distribution unit 20 will be described. In the distribution processing of the video signal distribution unit 20, a video signal having a distribution in which the brightness in the horizontal direction and the brightness in the vertical direction decrease monotonically is processed centering on the highest brightness point existing on the screen.

FIG. 8 shows a projection angle range (image projection range) represented by the horizontal and vertical deflection angles of the MEMS mirror 106 by the first to fourth image projection devices 10A to 10D of the image projection system 1 of the present embodiment. It is a figure which illustrated the relationship with the maximum brightness expressed by a relative brightness.

As shown in FIG. 8, the projection angle range and the maximum brightness of the first to fourth image projection devices 10A to 10D are narrower in order from the image projection device having the largest maximum brightness, which is the upper limit of the relative brightness. It is set to be. The pixel pitches of the first to fourth image projection devices 10A to 10D are set to be the same from the viewpoint of ease of control, but the pixel pitch is not particularly limited to this, and the pixel pitch is set to a different value depending on each device. You may. When the pixel pitches of the first to fourth image projection devices 10A to 10D are set to different values, the resolution is scaled in each device.

Next, FIG. 9 shows a series of video distribution processing results that are normally performed by the video signal distribution unit 20. The first image projection device 10A is in charge of projecting the first image projection range having the lowest maximum brightness and the widest projection angle range. Further, the second to fourth image projection devices 10B to 10D are in charge of projection of the second to fourth image projection ranges, respectively. Then, the images (sub-images) of the luminance distribution represented by the individual image signals output to the first to fourth image projection devices 10A to 10D are combined to generate the final image (composite image).

The images projected from the first to fourth image projection devices 10A to 10D have a luminance distribution in which the central portion is the brightest (highest luminance point) and gradually becomes darker toward the peripheral portions. The brightness distribution does not necessarily have to be symmetrical in the vertical and horizontal directions, and there may be a partial non-projection range (mask portion X).

It should be noted that each image projection range does not have to be exclusive, but rather by positively superimposing, even if vibration is applied from the outside to any of the first to fourth image projection devices 10A to 10D. , There is an advantage that the seam of the image due to the distribution becomes inconspicuous.

Here, a process (line-of-sight guidance process) executed by the luminance adjusting unit of the present invention will be described. The line-of-sight guidance process is a process performed when a monitored object such as a person or an animal is recognized within an image projection range having low relative brightness from an image captured by the vehicle-mounted camera 40 (see FIG. 1). Further, the line-of-sight guidance process is executed by the video signal distribution unit 20 receiving the above-mentioned MP signal.

A possible case is when a pedestrian appears from the driver's blind spot when using the vehicle headlights. In FIG. 9, the marking point MP that guides the driver's line of sight is within the second image projection range in which the projection angle range is relatively wide and the relative brightness is low.

The video signal distribution unit 20 that has received the MP signal from the image processing unit 50 first grasps where the marking point MP is located in the composite video. Next, in order to realize the local brightness, at least one of the first to fourth image projection devices 10A to 10D is switched from the image distribution process for generating the composite image at the normal time to the line-of-sight guidance process.

Normally, the first image projection device 10A, which has the least influence on the formation of the composite image, is in charge of the local luminance, but the region is not particularly limited to this, and in some cases, two or more devices may be in charge. The device in charge of the local luminance (this time, the first image projection device 10A) performs each process described later.

Next, an example of the line-of-sight guidance process will be described with reference to FIGS. 10 to 12.

In the video signal distribution unit 20, the individual video signal generated based on the MP signal is input to the individual video signal input unit 102 of the first video projection device 10A (see FIG. 2). As a result, the individual video signal processing unit 116 generates a drive signal for the MEMS 130.

After that, as shown in FIG. 10, the brightness of the composite image (the entire image projection range) is once set to the maximum. This draws the driver's attention with the exceptional illumination of the vehicle headlights, even if the driver is unaware of the pedestrian. The brightness at this time is not limited to the maximum brightness, and may be at a certain level or higher.

The maximum brightness is momentary, but at this point the driver may not yet be aware of the presence of pedestrians. Therefore, after that, the brightness is gradually reduced with the passage of time from the outer peripheral portion of the composite image toward the marking point MP (attention region).

Specifically, as shown in FIG. 11, the first image projection range is reduced while leaving the marking point MP. The vertical direction of the image projection range depends on the sub-scanning direction (around the X-axis) runout angle of the MEMS mirror 106, but the amplitude of the MEMS mirror 106 is gradually reduced. If the image projection range is converged to the marking point MP to improve the brightness and an effect such as zooming in is performed, the line-of-sight guidance effect is expected to be further improved.

In the present embodiment, since the first to fourth image projection devices 10A to 10D have basically the same performance, the image projection range and the maximum brightness are in an inversely proportional relationship. That is, by reducing the image projection range, even if the first image projection range has the lowest relative brightness, the brightness is equivalent to the fourth image projection range having the highest relative brightness (relative brightness 2048). It is possible to obtain.

After that, as shown in FIG. 12, the first image projection range is reduced to a narrow area including the marking point MP. As a result, the driver's line of sight is guided to the marking point MP, and the presence of a pedestrian is always noticed.

Since the horizontal direction of the image projection range depends on the deflection angle of the MEMS mirror 106 in the main scanning direction (around the Y axis), the image is in the region including the marking point MP and only up to a position symmetrical with respect to the amplitude center of the MEMS mirror 106. The projection range cannot be narrowed.

By providing the first image projection device 10A with a moving mechanism using a stepping motor, the first image projection range can be moved in the horizontal direction. Since the amplitude center of the MEMS mirror 106 is deviated by the movement in the horizontal direction, the final first image projection range can be further narrowed.

When the pedestrian moves to cross the road, the marking point MP may be moved to follow the pedestrian. Further, at this time, only the face portion may be used as the mask portion so that the pedestrian is not dazzled by the light of the vehicle headlight.

Finally, switching of the image projection range of the image projection system 1 will be described with reference to FIGS. 13 and 14.

In the image projection system 1 of the present embodiment, the image projection range in charge of the first to fourth image projection devices 10A to 10D can be switched at a predetermined timing. The first image projection device 10A is in charge of projecting the image projection range a (see FIG. 13) having the lowest maximum brightness and the widest projection angle range. Further, the second image projection device 10B is in charge of projection of the image projection range b, the third image projection device 10C is in charge of projection of the image projection range c, and the fourth image projection device 10D has the highest maximum brightness and the highest projection angle range. It is in charge of projecting a narrow image projection range d (“state 1” in FIG. 14).

Here, the first image projection device 10A, which is in charge of the image projection range a having the widest projection area, has a large load on the device because the deflection angle of the MEMS mirror 106 is always large. Therefore, for example, the image projection range is switched at the timing when the image projection is interrupted. Specifically, the RAM of the video signal distribution unit 20 stores the states of the first to fourth video projection devices 10A to 10D, and when the projection is restarted, the state information is read out and stored in each device. Assign a different image projection range from the one in charge of the previous time.

As shown in FIG. 14, four types of "state 1" to "state 4" are defined, and the states are switched at the timing when the image projection of the first to fourth image projection devices 10A to 10D is interrupted. When shifting to "state 2" after "state 1", the first image projection device 10A switches from the image projection range a to the image projection range b, and the second to fourth image projection devices also project images in a predetermined order. The range switches. It is preferable to switch between "state 1" and "state 4" in the same period. As a result, in the image projection system 1, the load applied to the first to fourth image projection devices 10A to 10D can be dispersed to extend the product life (usable period).

The above embodiment is an example of the present invention, and various other modifications can be considered. Since the image projection system 1 was composed of four image projection devices, the image projection range was also four, but the image is composed of two or more image projection devices and has an image projection range corresponding to the number of the image projection devices. It may be a projection system.

In the description after FIG. 9, an example in which the marking point MP exists in the second image projection range is shown, but the present invention is not limited to this. Responsible for local brightness even when the marking point MP exists in the boundary portion between the first image projection range and the second image projection range within the first image projection range or the third image projection range. The same line-of-sight guidance process can be performed by the image projection device of 1.

1 ... Video projection system, 10, 10A, 10B, 10C, 10D ... Video projection device, 20 ... Video signal distribution unit (composite video generation unit, brightness adjustment unit, attention area setting unit, responsible projection area switching unit), 30 ... Control unit, 40 ... In-vehicle camera, 50 ... Image processing unit, 106 ... MEMS mirror, 112 ... Semiconductor light source, 130 ... MEMS (optical deflector), 131A, 131B ... Torsion bar, 134, 136 ... First actuator, 140 , 142 ... Second actuator, 144, 146 ... Sensor.

Claims (3)

Multiple raster scan type video projection devices and
A composite image generation unit that generates one composite image by combining a plurality of sub-images with different projection ranges projected from the plurality of image projection devices.
A brightness adjustment unit that adjusts the brightness of the sub image,
A headlight provided with a region of interest setting unit for setting a predetermined region of interest in the composite image.
The composite image constitutes the composite image in a normal time when the attention area is not set outside the image projection range of the sub image having the highest maximum brightness among the plurality of sub images by the attention area setting unit. In each of the image projection ranges of the sub-images of the above, the luminance distribution in the central portion is the highest, and the luminance gradually decreases toward the outer peripheral portion.
When the attention area is set outside the area of the sub-image having the highest maximum brightness among the plurality of sub-images by the attention area setting unit, the brightness adjusting unit is at least one of the plurality of image projection devices. for the sub-image projected from One, the from the composite video distribution processing for generating an image of a normal, after the luminance of the entire image projection range of the sub-image with a predetermined level, the video projection range of the sub-picture A headlight characterized by switching to a line-of-sight guidance process that gradually converges the image projection range with the passage of time from the outer peripheral portion of the headlight toward the region of interest. In the headlight according to claim 1,
The image projection device includes a light source, a rotary mirror unit that reflects light from the light source, and a mirror control unit that controls a swing angle range of the mirror unit.
The brightness adjusting unit controls the swing angle range to be gradually reduced with the passage of time by the mirror control unit, so that the outer peripheral portion of the sub image is directed from the initial state at the normal time to the attention region. A headlight characterized by gradually converging the image projection range. In the headlight according to claim 1 or 2.
A headlight that further includes a projection range switching unit in charge of switching an image projection device that projects an image into a projection range of the plurality of sub-images according to a predetermined condition.

Images