JP6337720B2 - Virtual image display device - Google Patents

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, for example, the HUD installed on the vehicle as a moving body is located in front of the vehicle window (for example, the front window) as seen from the vehicle occupant as described in Japanese Patent Application Laid-Open No. 2011-73466. The driving information (for example, a mark indicating the vehicle ahead and a mark indicating the distance between the vehicles) can be generated as a virtual image superimposed on the foreground of the front visual field. As a result, the occupant can reduce the line-of-sight movement as much as possible when visually confirming the driving information, and can further reduce the burden during driving.

Japanese Patent Laying-Open No. 2011-73466 (page 3-4, FIG. 1)

  Here, in the virtual image display device described in Patent Document 1, a virtual image is generated at a position ahead of a predetermined distance set in advance by a user who visually recognizes the virtual image. Therefore, when the predetermined distance is set to a relatively long distance, an obstacle such as another vehicle often enters between the user and the position where the virtual image is generated. In that case, since it will be visually recognized from the user as if the virtual image was embedded in the obstacle, there was a problem that it was difficult for the user to visually recognize the virtual image.

  The present invention has been made to solve the above-described conventional problems, and even if an obstacle such as another vehicle enters between the user and the position where the virtual image is generated, the virtual image is appropriately displayed to the user. An object of the present invention is to provide a virtual image display device that can be visually recognized.

In order to achieve the above object, a virtual image display device according to the present invention includes a screen, a projector that projects an image on the screen, and a virtual image of the image by reflecting the image projected on the screen and allowing the user to visually recognize the image. A virtual image generating means including a concave mirror for generating the optical path length changing means for changing the optical path length between the screen and the concave mirror, and when detecting that an obstacle approaches the virtual image generation position, A virtual image position moving unit that moves a position where the virtual image is generated downward from the ground by changing a position at which the video is projected on the screen, and a position where the virtual image is generated by the virtual image position moving unit. After moving downward from the ground, the optical path length changing means changes the optical path length between the screen and the concave mirror. By, and having an a virtual image distance changing means for moving to the user side along a position where the virtual image is generated in the line-of-sight direction of the user.
The user's line-of-sight direction is the direction in which the user visually recognizes the virtual image, and corresponds to the length direction of a straight line connecting the user's position and the virtual image generation position.

  According to the virtual image display device according to the present invention having the above-described configuration, even when an obstacle such as another vehicle enters between the user and the position where the virtual image is generated, the position where the virtual image is generated is determined from the ground. Since the virtual image and the obstacle are configured not to overlap each other by being moved downward, it is possible for the user to appropriately recognize the virtual image. In addition, since the position where the virtual image is generated is moved to the user side after the position where the virtual image is generated is moved downward from the ground, the uncomfortable feeling that the virtual image is embedded in the ground is finally eliminated. It becomes possible to do.

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 projector which comprises HUD. It is the figure which showed the screen which comprises HUD. It is the figure which showed the movement aspect with respect to the optical path of a screen. It is the figure which showed the relationship between the optical path length between a screen and a mirror, and the production | generation distance of a virtual image. It is the figure which showed the change aspect of the production | generation distance of a virtual image. 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 visually recognizable from the passenger | crew of a vehicle. It is the figure which showed the obstacle interrupted ahead of the advancing direction of a vehicle. It is the figure which showed the relationship between the obstacle interrupted ahead of the advancing direction of a vehicle, and the position where a virtual image is produced | generated. It is the figure which showed the visual aspect of the virtual image and obstacle which can be visually recognized from the passenger | crew of a vehicle. It is the figure explaining the detail of the process which changes the production | generation position of a virtual image. It is the figure which showed the visual recognition aspect of the virtual image and obstacle which can be visually recognized from the passenger | crew of a vehicle after changing the production | generation position of a virtual image.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a virtual image generating device according to the invention will be described in detail with reference to the drawings with regard to an embodiment 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 6 in front of the driver's seat through the mirror and Fresnel lens provided in the HUD 1 as will be described later, and is made visible to the passenger 7 of the vehicle 2. ing. Note that the image projected on the screen 5 includes information related to the vehicle 2 and various information used for assisting the driving of the occupant 7. For example, a warning for an obstacle (another vehicle or a pedestrian), a guide route (scheduled travel route) set by the navigation device 48, guide information based on the guide route (such as an arrow indicating a right / left turn direction), the current vehicle speed, There are map images, traffic information, news, weather forecasts, times, connected smartphone screens, television programs, and the like.

  Further, in the HUD 1 of the present embodiment, when the occupant 7 visually recognizes an image projected on the screen 5 by reflecting the front window 6, the occupant 7 is not at the position of the front window 6 but at the front of the front window 6. An image projected on the screen 5 at a distant position is configured to be visually recognized as a virtual image 8. The virtual image 8 that can be seen by the occupant 7 is an image projected on the screen 5, but the vertical direction is reversed because the image is projected through the mirror. In addition, the size is changed by using a Fresnel lens.

  Here, regarding the position where the virtual image 8 is generated, more specifically, the distance L from the occupant 7 to the virtual image 8 (hereinafter referred to as a generation distance) L, the shape and position of the mirror and Fresnel lens provided in the HUD 1, and the screen 5 with respect to the optical path It is possible to appropriately set the position depending on the position. In particular, in the present embodiment, the position of the screen 5 is configured to be movable in the front-rear direction along the optical path as will be described later. As a result, the generation distance L can be changed as appropriate. For example, the generation distance L can be changed between 2.5 m and 20 m.

  A front camera 17 is installed above the front bumper of the vehicle. The front camera 17 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 17, an obstacle such as another vehicle has entered between the position where the occupant 7 and the virtual image 8 are generated as described later. Detected. Note that a sensor such as a millimeter wave radar may be used in place of the front camera 17 as means for detecting the entry of an obstacle.

  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 basically includes a projector 4, a screen 5, a reflection mirror 10, a mirror (concave mirror) 11, a Fresnel lens 12, a control circuit unit 13, and a CAN interface 14. ing.

  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 15 inside. For example, in a laser scanning projector, the laser light output from the light source 15 is reflected by the MEMS mirror 16 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 on which an image projected from the projector 4 is projected. For example, a transmissive screen made of a diffusing plate such as ground glass or a microlens array is used. Here, FIG. 4 is a diagram showing the screen 5.

  As shown in FIG. 4, the screen 5 has a projection area 22 on which an image is projected, and an image projected from the projector 4 is displayed. In addition, the passenger | crew 7 will visually recognize the image | video projected by the projector 4 from the opposite side to a projection side. The screen 5 is configured to be movable in the front-rear direction along the optical path. Specifically, by driving the screen front / rear drive motor 24 on the back side of the screen 5, as shown in FIG. 5, the screen 5 can be moved in the front / rear direction along the optical path. As a result, the optical path length between the screen 5 and the mirror 11 is changed.

  In the HUD 1, the position at which the virtual image 8 of the image projected on the screen 5 is generated in the optical path length between the screen 5 and the mirror 11 (specifically, the generation distance L that is the distance from the occupant 7 to the virtual image 8). ) Will depend. Specifically, as shown in FIG. 6, when the screen 5 is moved to the side where the optical path length D between the screen 5 and the mirror 11 becomes shorter, the generation distance L becomes shorter (that is, closer to the passenger 7). The virtual image 8 is visually recognized). On the other hand, when the screen 5 is moved to the side where the optical path length D between the screen 5 and the mirror 11 becomes longer, the generation distance L becomes longer (that is, the virtual image 8 is viewed farther from the passenger 7. It becomes like). Therefore, by moving the screen 5 in the front-rear direction along the optical path, the length of the generation distance L, which is the distance from the occupant 7 to the virtual image 8, as shown in FIG. It becomes possible to change in ~ 20m).

  The screen front / rear drive motor 24 is a stepping motor. The HUD 1 controls the screen front / rear drive motor 24 based on the pulse signal transmitted from the control circuit unit 13, and can appropriately position the front / rear position of the screen 5 with respect to the set position.

  On the other hand, the reflecting mirror 10 is a reflecting plate that reflects an image projected from the projector 4 to change the optical path and projects it onto the screen 5 as shown in FIG.

  Further, the mirror 11 reflects the image light from the screen 5 as shown in FIG. 2, and causes the occupant 7 to visually recognize the image of the screen 5 through the front window 6. 1), and constitutes a virtual image generating means together with the reflecting mirror 10 and the front window 6. As the mirror 11, a spherical concave mirror, an aspheric concave mirror, or a free-form curved mirror for correcting distortion of a projected image is used. Since the image projected on the screen 5 is reflected by the mirror 11, the generated virtual image is an image that is vertically inverted from the image projected on the screen 5.

  The Fresnel lens 12 is a magnifying glass for generating a virtual image 8 by enlarging the image projected on the screen 5 as shown in FIG. And in HUD1 which concerns on this embodiment, the image | video projected on the screen 5 is further reflected on the front window 6 via the mirror 11 and the Fresnel lens 12, and is made to be visually recognized by the passenger | crew 7, so that the front of the front window 6 is visible. The image projected on the screen 5 at a distant position is enlarged and is visually recognized by the occupant as a virtual image 8 (see FIG. 1).

  The control circuit unit 13 is an electronic control unit that controls the entire HUD 1. Here, FIG. 8 is a block diagram showing the configuration of the HUD 1 according to the present embodiment.

  As shown in FIG. 8, the control circuit unit 13 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. 9) 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 13 is connected to the projector 4 and the screen front / rear drive motor 24, respectively, and performs drive control of the projector 4 and various motors.

  The CAN (controller area network) interface 14 is an interface for inputting / outputting data to / from CAN which is an in-vehicle network standard for performing multiplex communication between various on-vehicle devices installed in a vehicle and control devices for vehicle equipment. 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. 9 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 the ACC power supply of the vehicle is turned on and generates a virtual image 8 that is visually recognized by the vehicle occupant 7. Note that the program shown in the flowchart of FIG. 9 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 generation distance L of the virtual image 8 to the longest distance 20 m which is the reference distance. If the current position of the screen 5 is not arranged at a position where the generation distance L of the virtual image 8 is 20 m (a position where the optical path length between the screen 5 and the mirror 11 is the longest), the screen is driven back and forth. The motor 24 is driven to move the screen 5 to a position where the generation distance L of the virtual image 8 is 20 m. In the present embodiment, the reference distance of the generation distance L is 20 m, which is the longest distance, but may be other than 20 m (for example, 15 m or 10 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 7. For example, a warning for an obstacle (another vehicle or a pedestrian), a guidance route (planned 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), the current vehicle speed, a guidance sign , Map image, traffic information, news, weather forecast, time, connected smartphone screen, TV screen and so on. In particular, in the present embodiment, 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.

  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 virtual image 8 of an arrow indicating the direction is generated. Note that when an intersection to be turned left or right approaches in front of the traveling direction of the vehicle, a virtual image 8 of an arrow indicating a right / left turn is generated instead of an arrow indicating a straight traveling direction. As a result, a virtual image 8 of an arrow indicating the traveling direction of the vehicle is generated at a position ahead of the occupant 7 by a reference distance (20 m), and the occupant 7 may minimize the movement of the line of sight when viewing the virtual image 8. Is possible. In particular, when generating the virtual image 8 of the arrow indicating the right / left turn, it is desirable to generate the virtual image 8 corresponding to the position of the intersection that is the target of the right / left turn. That is, the distance from the occupant 7 to the intersection to be turned left and right is calculated, the calculated distance is set as the target generation distance, and the screen 5 is moved along the optical path of the projector 4 so that the generation distance L becomes the target generation distance. Configure to move. If the distance from the occupant 7 to the intersection to be turned left or right changes as the vehicle moves thereafter, the generation distance L is also changed accordingly. As a result, the occupant 7 can clearly identify the position of the intersection to be turned left or right. In the present embodiment, the virtual image 8 is generated so that the virtual image 8 indicated by an arrow is positioned on the ground, more specifically, the lower end of the virtual image 8 is positioned on the ground.

  Subsequently, in S <b> 3, the CPU 31 acquires a captured image captured by the front camera 17. 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 traveling direction of the vehicle, that is, an obstacle that approaches the generation position of the virtual image 8. Specifically, as shown in FIG. 10, the obstacle (two-wheeled vehicle in the example shown in FIG. 10) enters the lane 52 where the vehicle 2 travels beyond the lane line 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. For example, on a road without a lane marking 53, a straight line is set between the vehicle and the generation position of the virtual image 8, and the vehicle travels when an obstacle approaches within a predetermined distance (for example, 5 m) from the straight line. You may comprise so that it may determine with the obstacle which interrupted ahead.

  If 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 generation position of the virtual image 8 (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 generation position of the virtual image 8 (S4: NO), the image on the screen 5 The virtual image generation processing program is terminated while continuing the projection.

  In S5, the CPU 31 obtains the distance R from the vehicle to the obstacle that interrupted. Specifically, the image is acquired based on the image captured by the front camera 17 or the detection result of other sensors such as a distance measuring sensor installed in the vehicle.

  Next, in S <b> 6, the CPU 31 compares the distance R from the vehicle acquired in S <b> 5 to the interrupted obstacle with the currently set generation distance L, and the distance R is shorter than the generation distance L. Whether or not the position of the obstacle is between the generation position of the virtual image 8 and the occupant 7 is determined.

  If it is determined that the distance R is shorter than the generation distance L, that is, the position of the obstacle is between the generation position of the virtual image 8 and the occupant 7 (S6: YES), the obstacle is temporarily the virtual image 8 When moving in the direction, it is estimated that there is a possibility that an obstacle is visually recognized from the occupant 7 overlapping with the virtual image 8, and in particular, the virtual image 8 may be visually recognized as being embedded in the obstacle. Accordingly, the process proceeds to S7 in order to move the generation position of the virtual image 8.

  On the other hand, when it is determined that the distance R is equal to or longer than the generation distance L, that is, the position of the obstacle is not between the generation position of the virtual image 8 and the occupant 7 (S6: NO), the obstacle is temporarily a virtual image. Even if the vehicle moves in the direction 8, it is estimated that the occupant 7 can clearly see the obstacle without being overlapped with the virtual image 8. Therefore, the projection of the image on the screen 5 is continued without moving the generation position of the virtual image 8, and the process returns to S3.

  In S <b> 7, the CPU 31 obtains the moving direction and moving speed of the obstacle that is determined to have interrupted in the forward direction of the vehicle. Specifically, the image is acquired based on the image captured by the front camera 17 or the detection result of other sensors such as a distance measuring sensor installed in the vehicle.

  Next, in S8, the CPU 31 calculates a time T1 until the obstacle and the virtual image 8 overlap on the optical path based on the moving direction and moving speed of the obstacle acquired in S7. Note that overlapping on the optical path means that the obstacle 51 and the virtual image 8 are not obstructed on the straight line (optical path) from the occupant 7 to the virtual image 8 of the vehicle 2 regardless of the positional shift between the obstacle 51 and the virtual image 8 as shown in FIG. If at least a part of 51 is located, it is considered that they overlap. That is, as shown in FIG. 13, when the occupant 7 who visually recognizes the front in the traveling direction of the vehicle appears to overlap even part of the virtual image 8 and the obstacle 51, it overlaps on the optical path.

  Subsequently, in S9, the CPU 31 calculates a time T2 necessary for making the generation distance L shorter than the distance R to the obstacle, that is, for moving the generation position of the virtual image 8 to the occupant 7 side from the position of the obstacle. To do. Specifically, the moving time of the screen 5 necessary for changing the generation distance L to a distance shorter than the distance R (for example, R-1m) is calculated as T2. The HUD 1 is a position setting in which the position of the screen 5 for realizing the generation distance L is associated with each settable generation distance L (in this embodiment, in units of 0.5 m between 2.5 m and 20 m). The table is stored in advance in the flash memory 34 or the like, and the CPU 31 calculates T2 using the position setting table and the moving speed of the screen 5.

  After that, in S10, the CPU 31 determines the time T1 until the obstacle calculated in S8 and the virtual image 8 overlap on the optical path, and the generation position of the virtual image 8 calculated in S9 from the position of the obstacle. The time T2 required for moving to the side is compared, and it is determined whether T2 is equal to or less than T1. If T2 is equal to or less than T1, the position at which the virtual image 8 is generated by changing the optical path length between the screen 5 and the mirror 11 before the obstacle and the virtual image 8 overlap on the optical path. Can move to the occupant 7 side rather than the obstacle. On the other hand, when T2 is longer than T1, the position where the virtual image 8 is generated cannot move to the occupant 7 side of the obstacle before the obstacle and the virtual image 8 overlap on the optical path. .

  When it is determined that T2 is equal to or less than T1 (S10: YES), that is, before the obstacle and the virtual image 8 overlap on the optical path, the optical path length between the screen 5 and the mirror 11 is changed. Thus, when it is determined that the position where the virtual image 8 is generated can be moved to the occupant 7 side from the obstacle, the process proceeds to S12. On the other hand, when it is determined that T2 is longer than T1 (S10: NO), that is, before the obstacle and the virtual image 8 overlap on the optical path, the position where the virtual image 8 is generated is closer to the occupant 7 side than the obstacle. If it is determined that it is not possible to move to step S11, the process proceeds to step S11.

  In S <b> 11, the CPU 31 moves the position where the virtual image 8 is generated downward from the ground by changing the position where the image is projected onto the screen 5. Specifically, as shown in FIG. 14, the position of the image 55 projected on the screen 5 is moved upward. As a result, the position of the virtual image 8 generated based on the video 55 moves downward (on the ground side) in the vertical direction. Then, when the position where the virtual image 8 is generated moves downward from the ground as shown in FIG. 14, the obstacle 51 and the virtual image 8 overlap on the optical path even when the obstacle approaches the virtual image 8. There is nothing. That is, it becomes possible for the occupant 7 who visually recognizes the front in the traveling direction of the vehicle to visually recognize the virtual image 8 and the obstacle 51 without overlapping. In addition, the distance which moves the projection position of the image | video 55 in said S11 shall be the shortest distance from which an obstruction and the virtual image 8 do not overlap on an optical path.

  Next, in S12, the CPU 31 sets the generation distance L of the virtual image 8 to a distance R ′ shorter than the distance R to the obstacle. R ′ is shorter than the distance R to the obstacle, and when the generation distance L is set to R ′, the lower end of the virtual image 8 is above or above the ground (ie, the virtual image 8 is on the ground). Distance that is not embedded). The position of the virtual image 8 generated based on the projected image if the screen 5 is moved so as to shorten the generation distance L without changing the projection position of the image on the screen 5 due to the structure of the HUD 1. Will be higher.

  Subsequently, in S13, the CPU 31 changes the size of the video 55 projected onto the screen 5 to a size corresponding to the virtual image generation distance L (= R ′) newly set in S12. In general, humans look smaller as they look farther and look larger as they look closer. Since the generation distance L is changed to a shorter distance in S12, the video 55 is changed to a larger size in S13 as shown in FIG. As a result, since the virtual image 8 that is viewed at a close distance from the occupant 7 is viewed with a larger size, the size of the virtual image 8 that matches the human sense can be viewed. In the present embodiment, the size of the video 55 is changed before the screen 5 is moved. However, the image 55 may be changed at the same time as the screen 5 is moved, or after the movement of the screen 5 is finished. Also good.

  Thereafter, in S14, the CPU 31 drives the screen front / rear drive motor 24 to move the screen 5 to a position where the generation distance L of the virtual image 8 is the distance R ′ set in S12.

Details of the process of S14 will be described below.
First, the CPU 31 sets the target generation distance De, which is the target value of the generation distance L of the virtual image 8, to the distance R ′. Next, the CPU 31 reads the position setting table from the flash memory 34 and acquires the position (target movement position) of the screen 5 for generating the virtual image 8 at a position separated by the target generation distance De. The position setting table indicates the position of the screen 5 for generating the virtual image 8 at the generation distance L for each settable generation distance L (in this embodiment, 0.5 m unit between 2.5 m and 20 m). Is stipulated. Subsequently, the CPU 31 determines the drive amount (number of pulses) of the screen front-rear drive motor 24 necessary for moving the screen 5 to the target movement position. Thereafter, the CPU 31 transmits a pulse signal for driving the screen front / rear drive motor 24 by the determined drive amount to the screen front / rear drive motor 24. The screen front / rear drive motor 24 that has received the pulse signal drives based on the received pulse signal. As a result, the screen 5 moves to a target movement position where the virtual image 8 is generated at a position separated by the set target generation distance De.

  Then, when the screen 5 is moved to a position where the generation distance L of the virtual image 8 becomes the distance R ′ set in S12 by the above processing, the position at which the virtual image 8 is generated is the sight line direction of the occupant 7 (the progression of the vehicle). Direction) and moves to the occupant 7 side, and is located at a distance R ′ from the occupant 7 closer to the obstacle. As a result, even if the obstacle 51 approaches the virtual image 8 as shown in FIGS. 14 and 15, the occupant 7 can visually recognize the virtual image 8 and the obstacle 51 without overlapping. Further, since the virtual image 8 is not visually recognized as being embedded in the ground, and the size of the virtual image 8 is a size corresponding to the new generation distance L, the occupant 7 can visually recognize the virtual image 8 without a sense of incongruity. Is possible.

  When it is determined in S10 that T2 is equal to or less than T1 (S10: YES), that is, before the obstacle and the virtual image 8 overlap on the optical path, the optical path length between the screen 5 and the mirror 11 is reached. If it is determined that the position where the virtual image 8 is generated can be moved to the side of the occupant 7 rather than the obstacle, the generation position of the virtual image 8 does not move below the ground. In addition, it is possible to prevent the occupant 7 from seeing an obstacle overlapping the virtual image 8 only by shortening the generation distance L. Accordingly, the image size is changed and the screen 5 is moved in S12 to S14 without performing the processing of S11. In that case, the virtual image 8 is never seen as if it was embedded in the ground, and even if the obstacle approaches the virtual image 8, the occupant 7 gives the virtual image 8 as shown in FIG. Can be visually recognized without overlapping with the obstacle 51.

  As described above in detail, according to the HUD 1 according to the present embodiment, an image is projected from the projector 4 onto the screen 5, and the image projected onto the screen 5 is reflected on the front window 6 of the vehicle 2. 7, the virtual image of the image | video which the passenger | crew 7 of a vehicle visually recognizes is produced | generated. Further, when it is detected that the obstacle 51 is approaching the generation position of the virtual image 8, the position where the virtual image 8 is generated is changed below the ground by changing the position where the image is projected onto the screen 5. Move (S11). Then, after the position where the virtual image 8 is generated moves downward from the ground, the position where the virtual image 8 is generated moves to the occupant 7 side by changing the optical path length between the screen 5 and the mirror 11. Therefore, even if an obstacle such as another vehicle enters between the occupant 7 who visually recognizes the virtual image 8 and the position where the virtual image 8 is generated, the position where the virtual image 8 is generated is lower than the ground. The virtual image 8 and the obstacle are not overlapped with each other by moving the virtual image 8 to the occupant 7 appropriately. In addition, when the position where the virtual image 8 is generated is moved downward from the ground and then the position where the virtual image 8 is generated is moved toward the occupant 7 side, the virtual image 8 is visually perceived to be embedded in the ground. Can be finally eliminated.

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 6 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 6. In addition, the object to be reflected by the HUD 1 may be a visor (combiner) installed around the front window 6 instead of the front window 6 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 screen 5 is moved along the optical path to change the optical path length between the screen 5 and the mirror 11. However, the screen 5 is fixed and the mirror 11 is moved along the optical path. It is good also as a structure which changes the optical path length between the screen 5 and the mirror 11 by making it move.

  Further, in the present embodiment, the arrow that guides the traveling direction of the vehicle along the guidance route is generated as the virtual image 8, but the virtual image 8 other than the arrow that guides the traveling direction may be generated. For example, warnings for obstacles (other vehicles and pedestrians), traffic jam information, accident information, current vehicle speed, information signs, map images, traffic information, news, weather forecast, time, connected smartphone screens, TV screens, etc. It is good also as a structure produced | generated as the virtual image 8. FIG. In that case, the virtual image generation processing program (FIG. 9) can change the generation positions of the virtual images 8 so as not to overlap the obstacles.

  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 this embodiment, the screen is composed of one screen, but the number of screens may be two or more. When two or more screens are used, all the screens may be configured to be movable along the optical path, or only a part of the screens may be configured to be movable along the optical path.

  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 virtual image generating means including a screen, a projector that projects an image on the screen, a concave mirror that generates a virtual image of the image by reflecting the image projected on the screen and allowing a user to visually recognize the image, the screen, and the screen By changing the optical path length changing means for changing the optical path length between the concave mirror and the position at which the image is projected on the screen when it is detected that an obstacle approaches the virtual image generation position. A virtual image position moving means for moving the position where the virtual image is generated downward from the ground, and the optical path length changing means after the position where the virtual image is generated is moved downward from the ground by the virtual image position moving means. By changing the optical path length between the screen and the concave mirror, the position where the virtual image is generated is viewed by the user. It characterized by having a a virtual image distance changing means for moving to the user side along the direction.
According to the virtual image display device having the above configuration, even if an obstacle such as another vehicle enters between the user and the position where the virtual image is generated, the position where the virtual image is generated is moved downward from the ground. By doing so, the virtual image and the obstacle are configured not to overlap each other, so that the user can appropriately recognize the virtual image. In addition, since the position where the virtual image is generated is moved to the user side after the position where the virtual image is generated is moved downward from the ground, the uncomfortable feeling that the virtual image is embedded in the ground is finally eliminated. It becomes possible to do.

The second configuration is as follows.
When it is detected that the obstacle approaches the generation position of the virtual image, before the obstacle and the virtual image overlap on the optical path, the optical path length changing unit causes the screen and the concave mirror to A movement determining unit that determines whether or not the position where the virtual image is generated can be moved to the user side from the obstacle by changing the optical path length of When it is determined that the position where the virtual image is generated cannot be moved to the user side with respect to the obstacle before the obstacle and the virtual image overlap on the optical path, The generation position of the virtual image is moved by the virtual image position moving unit and the virtual image distance changing unit, and the virtual image is moved by the movement determination unit before the obstacle and the virtual image overlap on the optical path. When it is determined that the position formed can be moved to the user side from the obstacle, the virtual image distance change is performed without moving the virtual image generation position by the virtual image position moving means. The moving position of the virtual image is only moved by the means.
According to the virtual image display device having the above configuration, the virtual image and the obstacle are overlapped by changing the optical path length between the screen and the concave mirror without moving the position where the virtual image is generated below the ground. If the image can be viewed without being changed, the projection position of the image on the screen is not changed. Therefore, it is possible to change the generation position of the virtual image so that the virtual image is never visually recognized as being embedded in the ground, and the virtual image and the obstacle are not overlapped. Therefore, it becomes possible to make a user visually recognize a virtual image more appropriately.

The third configuration is as follows.
The virtual image position moving unit is configured to change a position at which the video is projected onto the screen when the position of the obstacle is between the virtual image generation position and the user.
According to the virtual image display device having the above-described configuration, when it is predicted that the virtual image and the obstacle overlap from the user and the virtual image is predicted to be viewed as if embedded in the obstacle, the virtual image is Since the generated position is moved downward from the ground, the virtual image can be appropriately viewed by the user even when the obstacle approaches the virtual image generation position.

The fourth configuration is as follows.
Mounted on a vehicle, the virtual image generation means generates the virtual image to be visually recognized occupant of the vehicle ahead in the traveling direction of the vehicle, the lane before Symbol obstacle beyond the division line of the traveling lane of the vehicle When the vehicle enters the position, it is detected that the obstacle has approached the generation position of the virtual image .
According to the virtual image display device having the above-described configuration, it is possible to accurately predict whether or not a virtual image and an obstacle are visually recognized by a user who is a vehicle occupant from the movement of the obstacle. It becomes .

The fifth configuration is as follows.
The virtual image is an image that guides traveling along the planned traveling route of the vehicle, and the virtual image generating means generates the virtual image on the ground in front of the traveling direction of the vehicle.
According to the virtual image display device having the above configuration, when generating a virtual image that guides traveling along the planned traveling route of the vehicle, the virtual image is appropriately recognized by the user without overlapping the virtual image and the obstacle. Is possible. Therefore, it is possible to appropriately perform the travel guidance along the planned travel route using the virtual image.

The sixth configuration is as follows.
After the position at which the virtual image is generated by the virtual image position moving unit moves below the ground, the size of the image projected on the screen is changed to the generation position of the virtual image after the moving by the virtual image distance changing unit. It is characterized by having a size changing means for changing to a size according to the above.
According to the virtual image display device having the above configuration, when the virtual image generation position is moved to the user side, the virtual image is generated with a size corresponding to the virtual image generation position after the movement. Even if it is a case where it moves, a user can visually recognize a virtual image without a sense of incongruity.

The seventh configuration is as follows.
The size changing means is after the position where the virtual image is generated by the virtual image position moving means is moved downward from the ground and before the position where the virtual image is generated by the virtual image distance changing means is moved. The size of the video is changed.
According to the virtual image display device having the above configuration, when moving the generation position of the virtual image to the user side, the size of the virtual image is changed in advance so that the size corresponds to the generation position of the virtual image after the movement. After changing the generation position, the user can visually recognize the virtual image without a sense of incongruity.

The eighth configuration is as follows.
The optical path length changing means changes the optical path length between the screen and the concave mirror by moving the screen along the optical path.
According to the virtual image display device having the above configuration, the distance from the user to the position where the virtual image is generated can be changed with a simple configuration and control.

The ninth configuration is as follows.
The virtual image distance changing means moves the position where the virtual image is generated to a position closer to the user than the obstacle and the lower end of the virtual image is on the ground or above the ground.
According to the virtual image display device having the above-described configuration, it is possible to eliminate the uncomfortable feeling that the virtual image is visually recognized as being embedded in the ground by moving the generation position of the virtual image to the user side.

DESCRIPTION OF SYMBOLS 1 Head up display apparatus 2 Vehicle 3 Dashboard 4 Projector 5 Screen 6 Front window 7 Crew 8 Virtual image 17 Front camera 24 Screen front-rear drive motor 31 CPU
32 RAM
33 ROM
34 Flash memory 51 Obstacle 55 Video

Claims (9)

Screen,
A projector that projects an image on the screen;
Virtual image generation means including a concave mirror that generates a virtual image of the image by reflecting the image projected on the screen and allowing the user to visually recognize the image;
An optical path length changing means for changing an optical path length between the screen and the concave mirror;
When it is detected that an obstacle approaches the generation position of the virtual image, the position at which the virtual image is generated is moved downward from the ground by changing the position at which the image is projected onto the screen. A virtual image position moving means;
The virtual image is generated by changing the optical path length between the screen and the concave mirror by the optical path length changing means after the position where the virtual image is generated by the virtual image position moving means is moved downward from the ground. And a virtual image distance changing means for moving the position to the user side along the line of sight of the user. When it is detected that the obstacle approaches the generation position of the virtual image, before the obstacle and the virtual image overlap on the optical path, the optical path length changing unit causes the screen and the concave mirror to A movement determination means for determining whether the position where the virtual image is generated can be moved to the user side rather than the obstacle by changing the optical path length of
The movement determining means determines that the position where the virtual image is generated cannot be moved to the user side relative to the obstacle before the obstacle and the virtual image overlap on the optical path. In this case, the generation position of the virtual image is moved by the virtual image position moving unit and the virtual image distance changing unit,
It has been determined by the movement determination means that the position where the virtual image is generated can be moved to the user side rather than the obstacle before the obstacle and the virtual image overlap on the optical path. 2. The virtual image according to claim 1, wherein only the virtual image generation position is moved by the virtual image distance changing unit without moving the virtual image generation position by the virtual image position moving unit. Display device.   The virtual image position moving means changes the position at which the video is projected on the screen when the position of the obstacle is between the virtual image generation position and the user. Or the virtual image display apparatus of Claim 2. Mounted on the vehicle,
The virtual image generating means generates the virtual image that is visually recognized by an occupant of the vehicle in the forward direction of the vehicle,
If the previous SL obstacle enters the lane beyond the division line of the traveling lane of the vehicle, according to claim 1 wherein the said obstacle, characterized by detecting and approached the generation position of the virtual image Item 4. The virtual image display device according to any one of Items 3 to 4. The virtual image is an image that guides the traveling along the planned traveling route of the vehicle,
The virtual image display device according to claim 4, wherein the virtual image generation unit generates the virtual image on the ground ahead in the traveling direction of the vehicle.   After the position at which the virtual image is generated by the virtual image position moving unit moves below the ground, the size of the image projected on the screen is changed to the generation position of the virtual image after the moving by the virtual image distance changing unit. The virtual image display device according to claim 1, further comprising a size changing unit that changes the size according to the size.   The size changing means is after the position where the virtual image is generated by the virtual image position moving means is moved downward from the ground and before the position where the virtual image is generated by the virtual image distance changing means is moved. The virtual image display device according to claim 6, wherein a size of the video is changed.   The optical path length changing unit changes the optical path length between the screen and the concave mirror by moving the screen along the optical path. Virtual image display device.   The virtual image distance changing means moves a position where the virtual image is generated to a position closer to the user than the obstacle and a lower end of the virtual image is on the ground or above the ground. The virtual image display device according to claim 1.

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