JP2017015806A - Virtual image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a virtual image display device capable of simultaneously producing a plurality of virtual images at positions at different distances from a user as well as capable of suitably producing a virtual image that gives no uncomfortable feelings to the user.SOLUTION: In the virtual image display device, a screen for displaying an image projected by a projector 4 is constituted by a transmissive screen 5A and a reflective screen 5B; and images projected onto the transmissive screen 5A and the reflective screen 5B are reflected by a concave mirror 6 and a windshield 7 of a vehicle 2 and visually recognized by a crew 8 of the vehicle 2 to produce a virtual image of the images visually recognized by the crew 8 of the vehicle. The display device is configured to partially overlap a first optical path as an optical path of light from a light source transmitted by the transmissive screen 5A and a second optical path as an optical path of light from a light source reflected by the reflective screen 5B.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a virtual image display device that displays a virtual image visually recognized by a user.

  Conventionally, various means have been used as information providing means for providing driving information such as route guidance and obstacle warnings to passengers of moving bodies such as vehicles. For example, display on a liquid crystal display installed on a moving body, sound output from a speaker, and the like. In recent years, as one of such information providing means, a head-up display device (hereinafter referred to as HUD) is used in a space different from a position where an image is actually displayed using an illusion of human eyes. There is a virtual image display device for visually recognizing an image.

  Here, in order to provide more effective information by the virtual image display device, it is important to appropriately set the position for generating the virtual image (more specifically, the distance from the user viewing the virtual image to the virtual image) It is. For example, in order to generate a virtual image of a warning for an obstacle, it is desirable to generate a virtual image at a position where the obstacle actually exists. In addition, when generating a virtual image that guides a right or left turn of a road, it is desirable to generate a virtual image at a point where the right or left turns. On the other hand, it is desirable to generate a virtual image displaying a vehicle speed, a virtual image of a map image, and the like at a position as close to the user as possible so as not to be superimposed on the environment. That is, since the distance from the user suitable for generating the virtual image is different for each type of virtual image, when generating a plurality of virtual images, it is desirable to generate each virtual image at a position where the distance from the user is different. .

  However, since the distance from the user to the virtual image depends on the distance from the projection mirror (concave mirror, etc.) arranged inside the HUD to the video display surface (screen, liquid crystal display, etc.) for displaying the video, the video display surface is one surface. However, it is basically impossible to simultaneously generate a plurality of virtual images at positions at different distances from the user. Therefore, Japanese Patent Laid-Open No. 2013-83675 discloses that a screen is divided into a plurality of screens and a virtual image is generated from an image displayed for each screen, thereby simultaneously generating a plurality of virtual images at positions at different distances from the user. Has been disclosed.

JP 2013-83675 A (page 4-7, FIG. 1)

  However, in the technique described in Patent Document 1, a screen for displaying an image is divided into a plurality of screens. Therefore, as shown in FIG. 17, between the screens 101 and 102 (that is, the optical path of the screen 101 and the screen 102. A gap is generated between the optical paths. Since the image cannot be displayed in the gap, when generating a virtual image of a large image across the plurality of screens 101 and 102, there is a problem that the virtual image is divided by the gap.

  Furthermore, when the user visually recognizes the generated virtual image, the area corresponding to the gap portion is visually recognized darkly, which causes a problem that makes the user feel uncomfortable. For example, as shown in FIG. 18, in a HUD that generates a virtual image in front of a front window of a user driving a vehicle, an area 103 in which a virtual image is generated based on an image displayed on one screen is displayed on the other screen. The area 105 between the areas 104 where the virtual image based on the generated video is generated is visually recognized darkly.

  The present invention has been made to solve the above-described conventional problems, and allows a user to feel a sense of incongruity while simultaneously generating a plurality of virtual images at different positions from the user. It is an object of the present invention to provide a virtual image display device that can appropriately generate a virtual image that does not exist.

In order to achieve the above object, a virtual image display device according to the present invention includes a projector that projects an image generated based on light output from a light source, and an image projected from the projector by transmitting light from the light source. A transmissive screen that displays a first image that is part of the image, a reflective screen that displays a second image that is part of the image projected from the projector by reflecting light from the light source, and the transmissive screen. A projection mirror that generates a virtual image of the first image and the second image by reflecting the first image displayed on the mold screen and the second image displayed on the reflective screen to allow the user to visually recognize the image. A first optical path that is an optical path of the light source that is transmitted by the transmissive screen, and is reflected by the reflective screen. And to overlap a portion of the second optical path is an optical path of the light source.
The “optical path” means a path through which light output from the light source passes. For example, the optical path from the transmissive screen to the projection mirror is a path of light from the transmissive screen to the projection mirror, and is basically a transmissive screen (particularly the position where the image is displayed). This is a path connecting the projector to the projection mirror with a straight line. However, when a means for changing the traveling direction of light by refracting or reflecting light (for example, a mirror or a lens) is disposed between the transmissive screen and the projection mirror, the means makes a predetermined angle. This applies to refracted or reflected paths.

  According to the virtual image display device according to the present invention having the above-described configuration, by using two screens of a transmissive screen and a reflective screen as video display surfaces for displaying video, a plurality of positions at different distances from the user are used. A virtual image can be generated simultaneously. On the other hand, by overlapping the optical path of the light source transmitted by the transmissive screen and the optical path of the light source reflected by the reflective screen, even when a plurality of screens are used, It is possible to solve problems such as the virtual image being divided without the area corresponding to the gap being visually recognized dark. As a result, it is possible to generate an appropriate virtual image that does not make the user feel uncomfortable.

It is the figure which showed the installation aspect to the vehicle of HUD which concerns on this embodiment. It is the figure which showed the internal structure of HUD which concerns on this embodiment. It is the figure which showed the structure of the projector. It is the figure which showed the screen. It is the figure which showed the projection aspect of the image | video on a screen. It is the figure which showed the 1st mirror and the 2nd mirror. It is the figure which showed the change aspect of the optical path length by moving a 1st mirror and a 2nd mirror. It is the figure which each showed the optical path which permeate | transmits a transmissive screen, and the optical path reflected by a reflective screen. It is the figure which showed the position of the virtual image visually recognized from the passenger | crew of a vehicle. It is the figure which showed the duplication aspect of the optical path which permeate | transmits a transmissive screen, and the optical path reflected by a reflective screen. It is the figure which showed the correspondence of the image projected on a screen, and the virtual image visually recognized from the passenger | crew of a vehicle. It is the block diagram which showed the structure of HUD which concerns on this embodiment. It is a flowchart of the virtual image generation processing program which concerns on this embodiment. It is the figure which showed an example of the virtual image which can be visually recognized from the passenger | crew of a vehicle, when a 1st mirror and a 2nd mirror are in a reference position. It is the figure which showed the obstacle interrupted ahead of the advancing direction of a vehicle. It is the figure which showed an example of the virtual image which can be visually recognized from the passenger | crew of a vehicle, when a 1st mirror and a 2nd mirror exist in a panel display position. It is a figure explaining the problem of the prior art. It is a figure explaining the problem of the prior art.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a virtual image display device according to the invention will be described in detail with reference to the drawings with regard to an embodiment in which the virtual image display device is embodied in a head-up display device mounted on a vehicle.

  First, the configuration of a head-up display device (hereinafter referred to as HUD) 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an installation mode of the HUD 1 according to the present embodiment on the vehicle 2.

  As shown in FIG. 1, the HUD 1 is installed inside the dashboard 3 of the vehicle 2, and includes a projector 4 and a screen 5 on which an image from the projector 4 is projected. Then, the image projected on the screen 5 is reflected on the front window 7 in front of the driver's seat through the mirror and concave mirror 6 provided in the HUD 1 as will be described later, and is made visible to the passenger 8 of the vehicle 2. ing. The image projected on the screen 5 includes information related to the vehicle 2 and various information used for assisting driving of the occupant 8. For example, warnings for obstacles (other vehicles and pedestrians), guidance information set by the navigation device, guidance information based on the guidance route (arrows indicating right and left turn directions, etc.), warnings to be displayed on the road surface (attention to rear-end collision, speed limit, etc.) ), Current vehicle speed, information signs, map images, traffic information, news, weather forecast, time, connected smartphone screen, TV program, and the like.

  Moreover, in HUD1 of this embodiment, when the passenger | crew 8 visually recognizes the image which reflected the front window 7 and was projected on the screen 5, it is not the position of the front window 7, but the front of the front window 7 on the passenger | crew 8. An image projected on the screen 5 at a distant position is configured to be visually recognized as a virtual image 9. The virtual image 9 that can be seen by the occupant 8 is an image projected on the screen 5, but the vertical direction and the horizontal direction may be reversed via the concave mirror 6 or the mirror. It is necessary to project the image to the camera. Further, the size is also changed through the Fresnel lens and the concave mirror 6.

  Here, regarding the position where the virtual image 9 is generated, more specifically, the distance L from the occupant 8 to the virtual image 9 (hereinafter referred to as a generation distance) L, the curvature of the concave mirror 6 and the Fresnel lens provided in the HUD 1, the screen 5 and the concave mirror 6 It is possible to set appropriately depending on the relative position and the like. For example, if the curvature of the concave mirror 6 or the Fresnel lens is fixed, the generation distance L is determined by the distance (optical path length) along the optical path from the position where the image is displayed on the screen 5 to the concave mirror 6.

  Here, in the HUD 1 of this embodiment, as described later, the screen 5 reflects the light of the light source and the transmission type screen 5A that displays the image projected from the projector 4 by transmitting the light of the light source. It consists of a combination of a reflective screen 5B for displaying an image projected from the projector 4. Then, a virtual image 9 based on the video displayed on the transmissive screen 5A and a virtual image 9 based on the video displayed on the reflective screen 5B are generated. The generation distance L of the virtual image 9 based on the image displayed on the reflective screen 5B is fixed (for example, 2.5 m), but the generation distance L of the virtual image 9 based on the image displayed on the transmission screen 5A is The distance between the transmissive screen 5A and the concave mirror 6 can be changed by moving the position of the mirror that changes the direction of the optical path. For example, the generation distance L can be changed between 3 m and 40 m.

  A front camera 10 is installed above the front bumper of the vehicle, behind the rearview mirror, and the like. The front camera 10 is an imaging device configured by a camera using a solid-state imaging device such as a CCD, for example, and is installed with the optical axis direction facing forward in the traveling direction of the vehicle. Then, by performing image processing on the captured image captured by the front camera 10, the situation of the front environment (that is, the environment in which the virtual image 9 is superimposed) viewed by the occupant 8 through the front window 7 is detected. Is done. A sensor such as a millimeter wave radar may be used instead of the front camera 10.

  Next, a more specific configuration of the HUD 1 will be described with reference to FIG. FIG. 2 is a diagram showing an internal configuration of the HUD 1 according to the present embodiment.

  As shown in FIG. 2, the HUD 1 includes a projector 4, a screen 5, a concave mirror 6, a first mirror 11, a second mirror 12, a third mirror 13, a cover glass 15, a control circuit unit 16, This is basically composed of a CAN interface 17.

  Here, the projector 4 is an image projection apparatus using an LED light source, a lamp light source, or a laser light source as a light source, and is, for example, a laser scanning projector. The projector 4 may be a DLP projector, a liquid crystal projector, or an LCOS projector. When a projector other than the laser scanning projector is used, it is necessary to separately arrange a projection lens for the projector 4.

  FIG. 3 is a diagram showing the configuration of the projector 4. As shown in FIG. 3, the projector 4 includes a laser light source 18 inside. For example, in a laser scanning projector, the laser light output from the light source 18 is reflected by the MEMS mirror 19 and scanned on the screen 5. As a result, a desired image is projected onto the screen 5.

  On the other hand, the screen 5 is a projection medium onto which the image projected from the projector 4 is projected. The screen 5A displays the image projected from the projector 4 by transmitting the light from the light source 18, and the light source 18. It is composed of a combination of a reflective screen 5B that displays an image projected from the projector 4 by reflecting the light. FIG. 4 shows the screen 5. As shown in FIG. 4, the transmission type screen 5A and the reflection type screen 5B are integrally connected in the vertical direction with respect to the optical path of the light source 18 so as to form one continuous surface. The area ratio between the transmission screen 5A and the reflection screen 5B is, for example, 3: 1, but the ratio can be changed as appropriate. For example, the area ratio may be 1: 1.

  Here, the transmissive screen 5A constituting the screen 5 is made of, for example, a diffusion plate such as ground glass, a microlens array, or the like. The transmissive screen 5A displays the image projected from the projector 4 by transmitting light from the light source 18 as shown in FIG. In addition, the passenger | crew 8 will visually recognize the image | video projected by the projector 4 from the opposite side to a projection side.

  On the other hand, the reflection type screen 5B constituting the screen 5 is constituted by arranging a special paint, glass beads, a metal layer, etc. as a reflection layer on the surface of polyvinyl chloride (PVC), for example. As shown in FIG. 5, the reflection type screen 5 </ b> B reflects the light from the light source 18 to display the image projected from the projector 4. The occupant 8 visually recognizes the image projected by the projector 4 from the projection side.

  In the transmissive screen 5A and the reflective screen 5B, the viewing direction of the occupant 8 is opposite, but the optical path of the light source 18 transmitted by the transmissive screen 5A as will be described later (hereinafter referred to as the first optical path 22). Is turned back by the first mirror 11 and the second mirror 12 and made the same direction as the optical path of the light source 18 reflected by the reflective screen 5B (hereinafter referred to as the second optical path 23), from the occupant 8 to the transmissive screen 5A. And the image displayed on the reflective screen 5B can be viewed at the same time (ie, the virtual image 9 based on the image displayed on the transmissive screen 5A and the virtual image 9 based on the image displayed on the reflective screen 5B). It can be viewed at the same time.

  The concave mirror 6 is a projection mirror that generates a virtual image 9 (see FIG. 1) in front of the occupant 8 by enlarging and reflecting the image displayed on the screen 5 and causing the occupant 8 to visually recognize the image. In particular, in the present embodiment, a virtual image 9 (hereinafter referred to as a first virtual image 9A) based on an image displayed on the transmissive screen 5A and a virtual image 9 (hereinafter referred to as a second virtual image 9B) based on the image displayed on the reflective screen 5B. Each). As the concave mirror 6, a spherical concave mirror, an aspherical concave mirror, or a free-form curved mirror for correcting distortion of a projected image is used.

  On the other hand, the first mirror 11 is disposed between the transmissive screen 5A and the concave mirror 6 along the first optical path 22 connecting the transmissive screen 5A and the concave mirror 6, and is arranged in the X direction (first direction) from the transmissive screen 5A. ) Is a light reflecting means for changing the first optical path 22 incident in the Y direction different from the X direction. Similarly, the second mirror 12 is disposed between the transmissive screen 5A and the concave mirror 6 along the first optical path 22 connecting the transmissive screen 5A and the concave mirror 6, and enters the first direction from the transmissive screen 5A in the Y direction. This is a light reflecting means for changing the optical path 22 to a Z direction (second direction) different from the Y direction. In particular, in this embodiment, as shown in FIG. 6, the angle formed by the reflecting surface of the first mirror 11 with the reflecting surface of the second mirror is 90 degrees, and further, the angle formed by the reflecting surface of the first mirror 11 with the X direction is The first mirror 11 and the second mirror 12 are arranged so that the angle formed by the reflection surface of the second mirror 12 with respect to the Z direction is 45 degrees. That is, in the present embodiment, the X direction and the Z direction are configured to be parallel and opposite to each other.

  Moreover, the 1st mirror 11 and the 2nd mirror 12 are comprised so that a movement is possible integrally along a X direction. Specifically, by driving a mirror drive motor 24 (moving mechanism) on the back side of the first mirror 11 and the second mirror 12, the first mirror 11 and the second mirror 12 are moved to X as shown in FIG. It is possible to move in the front-rear direction with respect to the direction parallel to the direction.

  Then, by moving the first mirror 11 and the second mirror 12, the optical path length of the first optical path 22 connecting the transmission screen 5A to the concave mirror 6 is changed. Specifically, as shown in FIG. 7, when the first mirror 11 and the second mirror 12 are moved in a direction approaching the screen 5, the optical path length is shortened. On the other hand, when the first mirror 11 and the second mirror 12 are moved in the direction away from the screen 5, the optical path length becomes longer. Specifically, the optical path length is displaced by a distance that is twice the amount of movement of the first mirror 11 and the second mirror 12. That is, if the first mirror 11 and the second mirror 12 are moved 5 mm toward the screen 5, the optical path length is shortened by 1 cm, and the first mirror 11 and the second mirror 12 are moved 3 mm away from the screen 5. If this is done, the optical path length becomes 6 mm longer. As a result of changing the optical path length, the length of the generation distance L, which is the distance from the occupant 8 to the first virtual image 9A generated based on the video displayed on the transmission screen 5A, is changed as will be described later. Is possible.

  In this embodiment, as shown in FIG. 6, the Z direction and the Z direction are parallel to each other and opposite to each other, but the X direction and the Z direction are necessarily parallel to each other and opposite to each other. do not have to. Specifically, if the first mirror 11 and the second mirror 12 are arranged so that the X direction and the Z direction are different from each other by 90 degrees or more, the first mirror 11 and the second mirror 12 are moved to transmit the first mirror 11 and the second mirror 12. The optical path length of the first optical path 22 connecting the mold screen 5A to the concave mirror 6 can be changed.

  In the present embodiment, the first mirror 11 and the second mirror 12 are configured to move in a direction parallel to the X direction. However, the first mirror 11 and the second mirror 12 are not necessarily moved in a direction parallel to the X direction. For example, it may be configured to move in different directions (5 degrees or 10 degrees). Even in this case, it is possible to change the optical path length of the first optical path 22 connecting the transmission screen 5A to the concave mirror 6 by moving the first mirror 11 and the second mirror 12.

  The mirror drive motor 24 is a stepping motor. And HUD1 controls the mirror drive motor 24 based on the pulse signal transmitted from the control circuit part 16, and positions the position along the 1st optical path 22 of the 1st mirror 11 and the 2nd mirror 12 appropriately. Is possible.

  In the HUD 1 of the present embodiment configured so that the positions of the first mirror 11 and the second mirror 12 can be moved as described above, the first connection from the transmission screen 5A to the concave mirror 6 is performed as shown in FIGS. By configuring the distance of the optical path length X1 of one optical path 22 to be changeable, a position (specifically, from the occupant 8 to the first virtual image 9A from which the first virtual image 9A based on the image projected on the transmission screen 5A is generated). It is possible to change the generation distance L) which is the distance up to. Specifically, when the first mirror 11 and the second mirror 12 are moved away from the screen 5, the optical path length X1 of the first optical path 22 connecting the transmissive screen 5A to the concave mirror 6 is increased, and as a result , The generation distance L becomes long (that is, the first virtual image 9A is viewed farther from the passenger 8). On the other hand, when the first mirror 11 and the second mirror 12 are moved in the direction approaching the screen 5, the optical path length X1 of the first optical path 22 connecting the transmission screen 5A to the concave mirror 6 is shortened, resulting in generation. The distance L is shortened (that is, the first virtual image 9A is viewed closer to the passenger 8).

  Therefore, when the position at which the HUD 1 according to the present embodiment generates the first virtual image 9A (specifically, the generation distance L that is the distance from the occupant 8 to the first virtual image 9A) is determined, the determined generation distance L is determined. The optical path length X1 (that is, the position of the first mirror 11 and the second mirror 12) for generating the first virtual image 9A at the corresponding position is determined, and then the first mirror is set to the optical path length X1 determined thereafter. 11 and the second mirror 12 are configured to move.

  The range in which the generation distance L can be changed is determined by the range in which the first mirror 11 and the second mirror 12 can be moved. In particular, in this embodiment, the first mirror 11 and the second mirror 12 are designed so that the generation distance L of the first virtual image 9A is 3 m in a state where the first mirror 11 and the second mirror 12 are moved to the most screen 5 side. On the other hand, when the first mirror 11 and the second mirror 12 are moved to the position farthest from the screen 5, the generation distance L of the first virtual image 9A is designed to be 40 m.

  On the other hand, as shown in FIGS. 8 and 9, the second optical path 23 connecting the reflective screen 5B to the concave mirror 6 does not pass through the first mirror 11 and the second mirror 12, so No matter how the position of the two mirrors 12 changes, the optical path length X2 of the second optical path 23 does not change. Accordingly, the position where the second virtual image 9B based on the image projected on the reflective screen 5B is generated (specifically, the generation distance L that is the distance from the occupant 8 to the second virtual image 9B) is always fixed. Here, if the optical path length X1 of the first optical path 22 connecting the transmissive screen 5A to the concave mirror 6 and the optical path length X2 of the second optical path 23 connecting the reflective screen 5B to the concave mirror 6 are different distances, the occupant 8 It is possible to simultaneously generate the first virtual image 9A and the second virtual image 9B at positions having different distances from each other.

  In addition, the HUD 1 according to the present embodiment includes the first mirror 11 and the first mirror 11 so as to overlap a part of the first optical path 22 transmitted by the transmissive screen 5A and the second optical path 23 reflected by the reflective screen 5B. A second mirror 12 is arranged. Specifically, as shown in FIG. 10, in particular, the first optical path 22 between the second mirror 12 and the concave mirror 6 that passes through a location adjacent to the boundary with the reflective screen 5B in the transmissive screen 5A, Of the reflection type screen 5B, the second optical path 23 between the reflection type screen 5B and the concave mirror 6 that is reflected at a position farthest from the boundary with the transmission type screen 5A overlaps. And the 1st optical path 22 will be interrupted | blocked by the reflective screen 5B about the overlapping part, and the 2nd optical path 23 will reach the concave mirror 6 preferentially. In order to widen the range in which the virtual image can be generated, it is desirable to make the overlapping areas as narrow as possible.

  Accordingly, as shown in FIG. 11, when areas A to C are set in order from the top with respect to the transmissive screen 5A and the area D is set with respect to the reflective screen 5B, the area adjacent to the boundary with the reflective screen 5B. As described above, the first optical path 22 that transmits C is reflected by the first mirror 11 and the second mirror 12 and then blocked by the reflective screen 5B. Therefore, a virtual image of the video displayed in area C is not generated. On the other hand, the first optical path 22 that passes through the area B is reflected by the first mirror 11 and the second mirror 12 and passes below the second optical path 23 that is reflected by the area D. At this time, there is no gap between the first optical path 22 that transmits the area B and the second optical path 23 that is reflected by the area D. Further, the first optical path 22 that passes through the area A passes below the first optical path 22 that passes through the area B without a gap. Accordingly, in front of the front window 7, an area where a virtual image based on the video displayed in the area A is displayed, an area where a virtual image based on the video displayed in the area B is displayed, and an area D are displayed. The area where the virtual image based on the video is displayed is arranged without a gap. Since the vertical direction is reversed by being reflected by the concave mirror 6, the area where the virtual image based on the video displayed in the area A is displayed is located at the uppermost position, and the virtual image based on the video displayed in the area D is displayed. The area where is displayed is located at the bottom.

  On the other hand, as shown in FIG. 2, the third mirror 13 receives the light from the light source 18 reflected by the first mirror 11 and the second mirror 12 and the light from the light source 18 reflected by the reflective screen 5B. The light reflecting means changes the first optical path 22 and the second optical path 23 in the HUD 1 by further reflecting in the direction of.

  The cover glass 15 is a transmissive plate-like member disposed on the upper surface of the HUD 1. The image displayed on the screen 5 is reflected by the concave mirror 6 and is made visible to the occupant 8 through the cover glass 15. Note that a Fresnel lens may be used as the cover glass 15. When a Fresnel lens is used as the cover glass 15, a flat mirror can be used instead of the concave mirror 6.

  The control circuit unit 16 is an electronic control unit that controls the entire HUD 1. Here, FIG. 12 is a block diagram showing a configuration of the HUD 1 according to the present embodiment.

  As shown in FIG. 12, the control circuit unit 16 includes a CPU 31 as an arithmetic device and a control device, a RAM 32 used as a working memory when the CPU 31 performs various arithmetic processes, a control program, and a virtual image generation described later. A ROM 33 in which a processing program (see FIG. 13) and the like are recorded, an internal storage device such as a flash memory 34 for storing a program read from the ROM 33 and a position setting table to be described later are provided. The control circuit unit 16 is connected to the projector 4 and the mirror drive motor 24, respectively, and controls the drive of the projector 4 and various motors.

  The CAN (controller area network) interface 17 is an interface for inputting / outputting data to / from CAN, which is a vehicle-mounted network standard that performs multiplex communication between various vehicle-mounted devices and vehicle equipment control devices installed in the vehicle. It is. The HUD 1 is connected to a control device (for example, the navigation device 48, the AV device 49, etc.) of various vehicle-mounted devices and vehicle equipment via the CAN so as to be able to communicate with each other. Thereby, the HUD 1 is configured to be able to project information acquired from the navigation device 48, the AV device 49, and the like.

  Next, a virtual image generation processing program executed by the CPU 31 in the HUD 1 having the above configuration will be described with reference to FIG. FIG. 13 is a flowchart of the virtual image generation processing program according to the present embodiment. Here, the virtual image generation processing program is a program that is executed after an ACC power supply (accessory power supply) of the vehicle is turned on, and generates a virtual image 9 that is visually recognized by the passenger 8 of the vehicle. The program shown in the flowchart of FIG. 13 below is stored in the RAM 32 or ROM 33 provided in the HUD 1 and executed by the CPU 31.

  First, in step (hereinafter abbreviated as S) 1 in the virtual image generation processing program, the CPU 31 sets the positions of the first mirror 11 and the second mirror 12 to the “reference position”. Here, the “reference position” is a position that realizes the optical path length of the first optical path 22 in which the generation distance L of the first virtual image 9A generated based on the image projected on the transmission screen 5A is 40 m. For example, the position farthest from the screen 5 is the “reference position”.

  When the current positions of the first mirror 11 and the second mirror 12 are not arranged at the “reference position (for example, the position farthest from the screen 5)”, the mirror drive motor 24 is driven to “reference”. The first mirror 11 and the second mirror 12 are moved to “position”. In this embodiment, the “reference position” is a position where the generation distance L is 40 m, but may be other than 40 m (for example, 20 m or 30 m).

  Next, in S <b> 2, the CPU 31 transmits a signal to the projector 4 and starts projecting an image on the screen 5 by the projector 4. The video projected by the projector 4 includes information related to the vehicle 2 and various information used for assisting the driving of the occupant 8. For example, a warning for an obstacle (another vehicle or a pedestrian), a guidance route (scheduled travel route) set by the navigation device 48, guidance information based on the guidance route (such as an arrow indicating the traveling direction of the vehicle), and a warning displayed on the road surface (Notes of rear-end collision, speed limit, etc.), current vehicle speed, information signs, map images, traffic information, news, weather forecast, time, connected smartphone screen, TV screen, etc. In particular, in this embodiment, the transmissive screen 5A and the reflective screen 5B display different types of images. The transmission screen 5A outputs an image for generating a virtual image for guidance by being superimposed on the surrounding environment and visually recognized by the occupant 8. For example, an arrow indicating the traveling direction of the vehicle, which is guidance information based on the guidance route set by the navigation device 48, is output. On the other hand, on the reflective screen 5B, an image for generating a virtual image for guidance by outputting it to the occupant 8 without being superimposed on the surrounding environment is output. For example, the current vehicle speed of the vehicle and a map image around the vehicle are output.

  As a result, for example, when a guidance route is set in the navigation device 48, and there is no intersection to be turned right or left in front of the vehicle in the traveling direction, the vehicle travels straight ahead in the traveling direction of the vehicle as shown in FIG. A first virtual image 9A indicating a direction and a second virtual image 9B indicating the current vehicle speed of the vehicle are respectively generated. The first virtual image 9A indicated by the arrow is desirably generated on the ground, more specifically, such that the lower end of the first virtual image 9A is positioned on the ground. Note that when an intersection to be turned left or right approaches in front of the traveling direction of the vehicle, the first virtual image 9A of the arrow indicating the right / left turn is generated instead of the arrow indicating the straight traveling direction. As a result, a virtual image of an arrow indicating the traveling direction of the vehicle is generated in the vicinity of 40 m ahead of the occupant 8, and the occupant 8 can minimize the movement of the line of sight when viewing the virtual image. However, when there is an obstacle ahead in the traveling direction of the vehicle as will be described later, the distance from the occupant 8 to the first virtual image 9A is shorter than the distance to the obstacle (S7). .

  In addition, when a virtual image of an arrow indicating a right / left turn is generated as the first virtual image 9A, it is desirable to generate a virtual image corresponding to the position of the guidance intersection that is the target of the right / left turn. For example, the distance from the occupant 8 to the guidance intersection to be turned left and right is calculated, and the first mirror 11 is set so that the generation distance L of the first virtual image 9A (particularly the distance to the tip position of the arrow) is the calculated distance. In addition, the position of the second mirror 12 is changed. If the distance from the occupant 8 to the guidance intersection to be turned left and right changes as the vehicle moves thereafter, the positions of the first mirror 11 and the second mirror 12 are changed accordingly. As a result, the occupant 8 can clearly identify the position of the guidance intersection to be turned left or right.

  Subsequently, in S <b> 3, the CPU 31 acquires a captured image captured by the front camera 10. Thereafter, an obstacle and a lane marking located in front of the traveling direction of the vehicle are detected by performing image processing on the acquired captured image. In addition, other vehicles, bicycles, pedestrians, etc., which are moving bodies moving on the road, correspond to the obstacles.

  Thereafter, in S4, the CPU 31 determines whether or not there is an obstacle that has interrupted ahead of the vehicle in the traveling direction, that is, an obstacle that approaches the virtual image generation position. Specifically, as shown in FIG. 15, the obstacle (two-wheeled vehicle in the example shown in FIG. 15) enters the lane 52 where the vehicle 2 travels beyond the lane marking 53 of the lane 52 where the vehicle 2 travels. In this case, it is determined that there is an obstacle that has interrupted in front of the traveling direction of the vehicle. Note that, on a road without the lane marking 53, for example, a straight line connecting the vehicle to the virtual image generation position is set, and when an obstacle approaches within a predetermined distance (for example, 5 m) from the straight line, the vehicle travels forward. It may be configured to determine that there is an obstacle that has interrupted.

  Then, when it is determined that there is an obstacle that has interrupted ahead in the traveling direction of the vehicle, that is, there is an obstacle approaching the virtual image generation position (S4: YES), the process proceeds to S5. On the other hand, when it is determined that there is no obstacle that interrupts in the forward direction of the vehicle, that is, there is no obstacle approaching the virtual image generation position (S4: NO), the transmissive screen 5A and the reflection The process returns to S3 while continuing to project the image on the mold screen 5B.

  In S5, the CPU 31 obtains the distance R from the vehicle to the obstacle that interrupted. Specifically, it is acquired based on the detection result of an image captured by the front camera 10 or other sensors such as a distance measuring sensor installed in the vehicle.

  Next, in S6, the CPU 31 compares the distance R from the vehicle acquired in S5 to the interrupted obstacle with the current generation distance L (that is, 40 m) of the first virtual image 9A. It is determined whether the distance is longer than the generation distance L, that is, whether the position of the obstacle is between the first virtual image 9A and the occupant 8.

  If it is determined that the distance R is longer than the current generation distance L of the first virtual image 9A, that is, the position of the obstacle is not between the first virtual image 9A and the occupant 8 (S6: YES), Even if the obstacle moves in the direction of the first virtual image 9A, the obstacle and the first virtual image 9A do not overlap on the optical path. That is, it becomes possible for the occupant 8 who visually recognizes the front in the traveling direction of the vehicle to visually recognize the first virtual image 9A and the obstacle without overlapping. Accordingly, the process returns to S3 while continuing to project the image on the transmission screen 5A and the reflection screen 5B.

  On the other hand, when it is determined that the distance R is equal to or shorter than the current generation distance L of the first virtual image 9A, that is, the position of the obstacle is between the first virtual image 9A and the occupant 8 (S6: NO) If the obstacle moves in the direction of the first virtual image 9A, the obstacle may be seen from the occupant 8 overlapping with the first virtual image 9A. As a result, the first virtual image 9A is in the obstacle. It is estimated that there is a risk of being visually recognized as embedded. Accordingly, the process proceeds to S7 in order to change the guidance mode by the first virtual image 9A.

  In S7, the CPU 31 drives the mirror drive motor 24 to change the positions of the first mirror 11 and the second mirror 12 from “reference position” to “panel display position”. Here, the “panel display position” is a position that realizes the optical path length of the first optical path 22 in which the generation distance L of the first virtual image 9A generated based on the image projected on the transmission screen 5A is 3 m. . For example, the position closest to the screen 5 is the “panel display position”.

  The driving of the mirror drive motor 24 in S7 is performed using the position setting table read from the flash memory 34. Here, the position setting table is associated with each settable generation distance L (in this embodiment, two types of 3 m (panel display position) and 40 m (reference position)), and the first mirror 11 and the second mirror 12. (That is, the optical path length of the first optical path 22) is defined. Then, the CPU 31 sets the drive amount (number of pulses) of the mirror drive motor 24 necessary to move the first mirror 11 and the second mirror 12 from the “reference position” to the “panel display position” based on the position setting table. decide. Thereafter, the CPU 31 transmits to the mirror drive motor 24 a pulse signal for driving the mirror drive motor 24 by the determined drive amount. The mirror drive motor 24 that has received the pulse signal drives based on the received pulse signal. As a result, the first mirror 11 and the second mirror 12 move from the “reference position” to the “panel display position”. In this embodiment, the “panel display position” is a position where the generation distance L of the first virtual image 9A is 3 m. However, if the distance is shorter than the distance R, it may be other than 3 m (for example, 2.5 m or 5 m). good.

  Next, in S <b> 8, the CPU 31 transmits a signal to the projector 4, and in particular changes the content of the image projected onto the transmissive screen 5 </ b> A. Specifically, from a video for generating a virtual image for guidance by superimposing on the surrounding environment and causing the occupant 8 to visually recognize, a virtual image for guiding is generated by causing the occupant 8 to visually recognize without superimposing on the surrounding environment. Switch to the video to do. Specifically, the arrow indicating the traveling direction of the vehicle changes from the shape of the arrow superimposed on the road surface to the shape of the arrow indicating the direction.

  As a result, as shown in FIG. 17, even when the obstacle 51 approaches the first virtual image 9A, the position where the first virtual image 9A is generated is a position 3 m away from the tip of the host vehicle. The object 51 and the first virtual image 9A do not overlap on the optical path. If the obstacle 51 subsequently moves from the front in the vehicle traveling direction, the positions of the first mirror 11 and the second mirror 12 are returned to the reference position, and the content of the projected image is also returned to the content of S2. It is desirable to configure. In S8, the content of the image projected on the transmission screen 5A is changed from the arrow indicating the traveling direction of the vehicle to the map information around the vehicle and the guidance information based on the guidance route set by the navigation device 48 or the guidance route. It may be configured to be changed.

  As described above in detail, according to the HUD 1 according to the present embodiment, the screen for displaying the image projected from the projector 4 is configured by the transmissive screen 5A and the reflective screen 5B, and the transmissive screen 5A and the reflective screen are displayed. The image projected on the mold screen 5 </ b> B is reflected on the concave mirror 6 and the front window 7 of the vehicle 2 so as to be visually recognized by the vehicle occupant 8, thereby generating a virtual image of the image visually recognized by the vehicle occupant 8. Further, the HUD 1 is configured to overlap a part of the first optical path that is the optical path of the light source transmitted by the transmissive screen 5A and the second optical path that is the optical path of the light source reflected by the reflective screen 5B. . As a result, it is possible to simultaneously generate a plurality of virtual images at positions where the distance from the occupant 8 is different. On the other hand, even when a plurality of screens are used, problems such as dividing a virtual image can be solved without the area corresponding to the gap between the screens being visually recognized as dark. As a result, it is possible to generate an appropriate virtual image that does not make the user feel uncomfortable.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the present embodiment, the virtual image is generated in front of the front window 7 of the vehicle 2 by the HUD 1, but the virtual image may be generated in front of a window other than the front window 7. In addition, the object to be reflected by the HUD 1 may be a visor (combiner) installed around the front window 7 instead of the front window 7 itself.

  In the present embodiment, the HUD 1 is installed on the vehicle 2. However, the HUD 1 may be installed on a moving body other than the vehicle 2. For example, it can be installed on a ship or an aircraft. Moreover, you may install in the ride type attraction installed in an amusement facility. In that case, a virtual image can be generated around the ride so that the rider can visually recognize the virtual image.

  In this embodiment, the transmissive screen 5A and the reflective screen 5B are integrally formed. However, the transmissive screen 5A and the reflective screen 5B are not necessarily integrated. In addition, if the projector 4 is a laser projector, an image can be appropriately displayed even if the distance from the projector differs for each screen.

  In this embodiment, different images are displayed on the transmissive screen 5A and the reflective screen 5B, respectively, but an image straddling the transmissive screen 5A and the reflective screen 5B may be displayed. In this embodiment, since the virtual image is not divided by the gap between the screens, it is possible to appropriately generate a virtual image having a larger size.

  In the present embodiment, the first mirror 11 and the second mirror 12 are moved integrally along the optical path to change the optical path length X1 of the first optical path 22 connecting the transmission screen 5A to the concave mirror 6. However, the first mirror 11 and the second mirror 12 may be fixed, and the optical path length X1 may be changed by moving the screen 5 and the concave mirror 6 along the optical path. In addition, the first mirror 11 and the second mirror 12 may be configured to be driven by different driving sources as long as the first mirror 11 and the second mirror 12 are configured to move together.

  In this embodiment, a laser scanning projector that does not require a projection lens is used, but a projector other than the laser scanning projector (for example, a DLP projector, a liquid crystal projector, or an LCOS projector) may be used.

  In the present embodiment, the CPU 31 of the HUD 1 is configured to execute each step of the virtual image generation processing program (FIG. 13). However, an in-vehicle device (for example, the navigation device 48) other than the HUD 1 or an ECU that controls the vehicle is one. It is good also as a structure which performs a part or all process.

  Moreover, although the embodiment which actualized the virtual image display device according to the present invention has been described above, the virtual image display device can also have the following configuration, and in that case, the following effects can be obtained.

For example, the first configuration is as follows.
A projector (4) that projects an image generated based on light output from the light source (18), and a first image that is a part of the image projected from the projector by transmitting light from the light source. A transmissive screen (5A) for displaying, a reflective screen (5B) for displaying a second image that is part of the image projected from the projector by reflecting the light of the light source, and the transmissive screen A virtual image (9A, 9B) of the first video and the second video is generated by reflecting the displayed first video and the second video displayed on the reflective screen to allow the user to visually recognize the first video and the second video displayed on the reflective screen. A projection mirror (6), a first optical path (22) that is an optical path of the light source transmitted by the transmissive screen, and a reflective screen. A portion of the second optical path is an optical path of the reflected light source (23) to overlap.
According to the virtual image display device having the above-described configuration, a plurality of virtual images are simultaneously generated at different distances from the user by using two screens of a transmissive screen and a reflective screen as a video display surface for displaying video. It becomes possible to do. On the other hand, by overlapping the optical path of the light source transmitted by the transmissive screen and the optical path of the light source reflected by the reflective screen, even when a plurality of screens are used, It is possible to solve problems such as the virtual image being divided without the area corresponding to the gap being visually recognized dark. As a result, it is possible to generate an appropriate virtual image that does not make the user feel uncomfortable.

The second configuration is as follows.
The optical path length of the first optical path (22) connecting the transmissive screen (5A) to the projection mirror (6) and the second optical path (23) connecting the reflective screen (5B) to the projection mirror. Is a different distance from the optical path length.
According to the virtual image display device having the above-described configuration, it is possible to simultaneously generate a virtual image based on the image projected on the transmission screen and a virtual image based on the image projected on the reflection type screen at different positions from the user. Become.

The third configuration is as follows.
The transmissive screen (5A) and the reflective screen (5B) are constituted by one continuous surface.
According to the virtual image display device having the above-described configuration, it is possible to further reduce the size and simplify the device even when a plurality of screens are used by integrally configuring a plurality of screens.

The fourth configuration is as follows.
The first video and the second video are different videos.
According to the virtual image display device having the above-described configuration, it is possible to simultaneously generate virtual images based on different videos at positions at different distances from the user.

The fifth configuration is as follows.
The first optical path (22) that is disposed between the transmission screen (5A) and the projection mirror (6) along the first optical path (22) and is incident in the first direction from the transmission screen. And reflecting mirrors (11, 12) that go to the projection mirror (6) and change to a second direction that is parallel to and opposite to the first direction.
According to the virtual image display device having the above-described configuration, the light path of the light source that has passed through the transmissive screen is folded back by the reflection mirror, whereby the light path of the light source that has passed through the transmissive screen and the light path of the light source that has reflected from the reflective screen are It is possible to make the optical path directions the same in the same direction.

The sixth configuration is as follows.
The first optical path (22) from the reflecting mirror (11, 12) to the projection mirror (6) and the second optical path from the reflective screen (5B) to the projection mirror (6) A part of (23) is overlapped.
According to the virtual image display device having the above configuration, the light path of the light source that has passed through the transmissive screen is folded back by the reflection mirror, whereby the light path of the light source that has passed through the transmissive screen after the turn and the light source that has reflected the reflective screen are reflected. It is possible to appropriately overlap the optical path.

The seventh configuration is as follows.
A moving mechanism (24) for moving the reflecting mirror (11, 12) along the first direction;
According to the virtual image display device having the above configuration, the optical path length from the transmissive screen to the projection mirror is changed by displacing the position of the reflecting mirror, and is generated based on the image displayed on the transmissive screen from the user. The distance to the virtual image can be arbitrarily changed.

The eighth configuration is as follows.
A generation distance determining means (31) for determining a generation distance that is a distance from the user to the virtual image (9A) of the first video, and a position corresponding to the generation distance determined by the generation distance determination means. Mirror position determining means (31) for determining the position of the reflecting mirror for generating a virtual image of one image, and the position determined by the mirror position determining means by controlling the moving mechanism (24) The reflecting mirror (11, 12) is moved to the position.
According to the virtual image display device having the above configuration, it is possible to generate a virtual image at an arbitrarily set position by controlling the position of the reflection mirror, that is, the optical path length from the transmission screen to the projection mirror.

DESCRIPTION OF SYMBOLS 1 Head-up display apparatus 2 Vehicle 3 Dashboard 4 Projector 5 Screen 5A Transmission type screen 5B Reflective type screen 6 Concave mirror 7 Front window 8 Crew 9 Virtual image 10 Front camera 11 First mirror 12 Second mirror 22 First optical path 23 Second optical path 24 mirror drive motor 31 CPU
32 RAM
33 ROM
34 Flash memory

Claims (8)

A projector that projects an image generated based on light output from a light source;
A transmissive screen that displays a first image that is part of an image projected from the projector by transmitting light from the light source;
A reflective screen that displays a second image that is part of the image projected from the projector by reflecting light from the light source;
The first image displayed on the transmissive screen and the second image displayed on the reflective screen are respectively reflected and made visible to the user to generate virtual images of the first image and the second image. A projection mirror,
A virtual image display device that overlaps a part of a first optical path that is an optical path of the light source transmitted by the transmissive screen and a second optical path that is an optical path of the light source that is reflected by the reflective screen.   The optical path length of the first optical path connecting the transmission screen to the projection mirror and the optical path length of the second optical path connecting the reflection screen to the projection mirror are different distances. Virtual image display device.   The virtual image display device according to claim 1, wherein the transmissive screen and the reflective screen are configured by one continuous surface.   The virtual image display device according to claim 1, wherein the first video and the second video are different videos.   The first optical path that is disposed between the transmission screen and the projection mirror along the first optical path and is incident in the first direction from the transmission screen is directed to the projection mirror and the first direction. The virtual image display device according to claim 1, further comprising a reflection mirror that changes in a second direction that is parallel and opposite.   The virtual image display device according to claim 5, wherein a part of the first optical path between the reflection mirror and the projection mirror overlaps with the second optical path between the reflection screen and the projection mirror.   The virtual image display device according to claim 5, further comprising a moving mechanism that moves the reflecting mirror along the first direction. Generation distance determining means for determining a generation distance that is a distance from the user to the virtual image of the first video;
Mirror position determining means for determining a position of the reflecting mirror for generating a virtual image of the first image at a position corresponding to the generation distance determined by the generation distance determining means;
The virtual image display device according to claim 7, wherein the moving mirror is controlled to move the reflecting mirror to a position determined by the mirror position determining unit.

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