JP2015200770A - Head-up display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head-up display device that enables a user to visually recognize virtual images without giving discomfort to the user.SOLUTION: Videos are projected respectively to a first screen 20 and a second screen 21 from a projector 4 through a first projection lens 16 and a second projection lens 17, and the videos projected on the first screen 20 and second screen 21 are reflected on a windshield 6 of a vehicle 2 through a mirror 11 so as for a driver 7 of the vehicle to visually recognize the videos, and thereby creating virtual images of the videos that are visually recognized by the driver 7 of the vehicle. The second screen 21 is movable along a light path, and the distance between the mirror 11 and the second screen 21 along the light path of a light source is set with a state where the second screen 21 is located at a position at which the distance between the driver 7 of the vehicle and a second virtual image 8B becomes the shortest, as a reference.

Description

  The present invention relates to a head-up display device that generates various images that are 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, there is a head-up display device (hereinafter referred to as HUD).

  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. 2009-150947. It is possible to generate 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.

JP 2009-150947 A (page 8-10, FIG. 1)

  Here, in order to reduce the burden on the vehicle occupant during driving, it is important to appropriately set the position (more specifically, the distance from the occupant to the virtual image) where the virtual image is generated. 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. In view of this, the technique disclosed in Patent Document 1 proposes a technique for changing the imaging position, that is, the position for generating a virtual image, by configuring the position of the screen on which the image is projected so as to be movable along the optical path. .

  On the other hand, in order to make the virtual image generated in the HUD clearly visible to the user, the positional relationship between the screen and the concave mirror that reflects the image projected on the screen is important. Therefore, conventionally, the position of the concave mirror has been designed based on the position of the screen with respect to the optical path of the light source. However, since the position of the screen with respect to the optical path of the light source is not fixed in the technique of the above-mentioned Patent Document 1, it is a problem how to design the position of the concave mirror. And in the said patent document 1, the design of the position of the concave mirror which considered the movement of the screen was not performed.

  As a result, the user's visual aspect of the generated virtual image does not correspond to the distance from the occupant to the virtual image, and the user viewing the virtual image feels uncomfortable. For example, a virtual image that appears farther than a virtual image that appears closer to the user may appear clearer.

  The present invention has been made to solve the above-mentioned conventional problems, and by designing the position of the concave mirror in consideration of the movement of the screen, the virtual image can be visually recognized without making the user feel uncomfortable. It is an object of the present invention to provide a head-up display device that is made possible.

  In order to achieve the above object, a head-up display device (1) according to the present invention includes a screen (5), a projector (4) that projects an image generated on the screen based on light output from a light source, A virtual image generating means (11, 12) for generating a virtual image of the video by reflecting the video projected on the screen to a concave mirror (11) and allowing the user to visually recognize the video, and the screen along the optical path of the light source. A moving means (24) for moving within a predetermined movable range, and a distance from the user to the virtual image generated by the virtual image generating means by moving the screen along the optical path of the light source by the moving means. A virtual image position changing means (31) for changing the distance between the concave mirror and the screen along the optical path of the light source. Some concave mirror set distance, wherein the distance from the user within the movable range to said virtual image is set as a reference a state where there is the screen at the reference position is the most shortened position.

  According to the head-up display device of the present invention having the above-described configuration, the distance from the user to the virtual image can be adjusted by moving the screen, while the position of the concave mirror is designed in consideration of the movement of the screen, It is possible to make the virtual image visible without making the user feel uncomfortable. Specifically, the change in the distance from the user to the virtual image can correspond to the sharpness of the virtual image visually recognized by the user.

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 1st projection lens and 2nd projection lens with which a projector is provided. It is the figure which showed the movement aspect of the 2nd projection lens. It is the figure which each showed the 1st screen and the 2nd screen. It is the figure which showed the projection aspect of the image | video of the projector with respect to the 1st screen and the 2nd screen. It is the figure which showed the movement aspect to the front-back direction with respect to the optical path of a 2nd screen. It is the figure which each showed the virtual image produced | generated by the image | video projected on the 1st screen and the 2nd screen. It is the figure which showed the movement aspect to the crossing direction with respect to the optical path of a 1st screen and a 2nd screen. It is the figure which showed the projection aspect of the image | video of a projector at the time of moving a 1st screen and a 2nd screen to an up-down direction. It is the block diagram which showed the structure of HUD which concerns on this embodiment. A spot diagram in which when the second screen is located at the position where the generation distance from the vehicle occupant to the second virtual image is the shortest and the longest, respectively, the surface on which the image is projected on the second screen is an evaluation surface; It is the figure which showed the resolution map in comparison. It is a flowchart of the virtual image generation processing program which concerns on this embodiment. It is the figure which showed the position setting table. It is the figure shown about the movement control of a 2nd screen and a 2nd projection lens. It is the figure which showed an example of the virtual image visually recognizable from the passenger | crew of a vehicle.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment embodying a head-up display device according to the present invention will be described in detail with reference to the drawings.

  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, warnings for obstacles (other vehicles and pedestrians), guidance information set by the navigation device and guidance information based on the guidance route (such as arrows indicating the direction of turning left and right), current vehicle speed, guidance signs, map images, traffic information, There are news, weather forecast, time, screen of connected smartphone, TV program and so on.

  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.

  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 11, a Fresnel lens 12, a control circuit unit 13, and a CAN interface 14.

  Here, the projector 4 is a video projection device using an LED light source or a laser light source as a light source, and is a DLP projector, for example. As the projector 4, a liquid crystal projector, an LCOS projector, or a laser scanning projector may be used. When a laser scanning projector is used, a projection lens described later is not necessary. The projector 4 includes a projection lens 15 for projecting an image. In this embodiment, the projection lens 15 is composed of two projection lenses, a first projection lens 16 and a second projection lens 17, which are different from each other. Configure to project video. Here, FIG. 3 is a diagram showing the first projection lens 16 and the second projection lens 17 provided in the projector 4.

  As shown in FIG. 3, the first projection lens 16 and the second projection lens 17 have a divided shape obtained by dividing one circular lens in the vertical direction. Further, the second projection lens 17 below is configured to be movable in the front-rear direction along the optical path. On the other hand, the position of the first projection lens 16 is fixed. Specifically, by driving the lens drive motor 18 on the back side of the second projection lens 17, it is possible to move the second projection lens 17 in the front-rear direction along the optical path as shown in FIG. Become. In particular, in this embodiment, when the screen 5 is moved in the front-rear direction along the optical path as will be described later, the focal point of the image projected from the second projection lens 17 is made to coincide with the position of the screen 5 after the movement. In addition, the second projection lens 17 is also moved to follow.

  The lens drive motor 18 is a stepping motor. The HUD 1 can control the lens driving motor 18 based on the pulse signal transmitted from the control circuit unit 13 and appropriately position the second projection lens 17 with respect to the set position.

  The screen 5 is a projection medium onto which an image projected from the projector 4 is projected. For example, a Fresnel screen or a diffusion screen is used. In the present embodiment, the screen 5 includes two screens, a first screen 20 and a second screen 21. Here, FIG. 5 is a view showing the first screen 20 and the second screen 21.

  As shown in FIG. 5, the first screen 20 has a projection area 22 on which an image is projected upward, and is normally projected from the first projection lens 16 of the projector 4 as shown in FIG. Displayed. On the other hand, the second screen 21 has a projection area 23 on which an image is projected below. In a normal state, the image projected from the second projection lens 17 of the projector 4 is displayed as shown in FIG. Is done. That is, an image is projected from the projector 4 across the first screen 20 and the second screen 21. Further, as will be described later, in the present embodiment, the first screen 20 and the second screen 21 are configured to be movable in a direction that intersects the optical path integrally, and as a result, are projected from the first projection lens 16. A part of the image may be projected onto the second screen 21 or a part of the image projected from the second projection lens 17 may be projected onto the first screen 20 (see FIG. 10).

  Further, as shown in FIGS. 2 and 6, the first screen 20 and the second screen 21 are arranged side by side at predetermined intervals in the front-rear direction along the optical path so that the projection areas 22 and 23 do not overlap. Therefore, in the present embodiment, the virtual image 8 includes a virtual image of a video projected on the first screen 20 (hereinafter referred to as a first virtual image 8A) and a virtual image of a video projected on the second screen 21 (hereinafter referred to as a second virtual image 8B). It will be composed of.

  The second screen 21 is configured to be movable in the front-rear direction along the optical path. On the other hand, the position of the first screen 20 is fixed with respect to the front-rear direction. Specifically, the distance between the first screen 20 and the second screen 21 is changed as shown in FIG. 7 by driving the screen front / rear drive motor 24 on the back side of the second screen 21. The two screens 21 can be moved in the front-rear direction along the optical path. As a result, the position where the second virtual image 8B, which is the virtual image of the image projected on the second screen 21, is generated (specifically, the generation distance L2 that is the distance from the occupant 7 to the second virtual image 8B) is changed. Is possible. The generation distance L2 depends on the distance from the mirror 11 to the second screen 21. That is, the generation distance L <b> 2 is changed in length depending on the distance from the mirror 11 to the second screen 21. For example, the generation distance L2 increases as the distance from the mirror 11 to the second screen 21 increases, and the generation distance L2 decreases as the distance from the mirror 11 to the second screen 21 decreases.

  For example, when the second screen 21 is moved to the projector 4 side (the side where the distance to the mirror 11 is increased), the generation distance L2 is increased (that is, the second virtual image 8B is viewed farther from the passenger 7). It becomes like). On the other hand, when the second screen 21 is moved to the side opposite to the projector 4 (the side where the distance to the mirror 11 is shortened), the generation distance L2 is shortened (that is, the second virtual image 8B is visible closer to the occupant 7). Will come to be). Since the position of the first screen 20 is fixed in the front-rear direction, the position (specifically, from the occupant 7 to the first virtual image 8A, which is a virtual image of the image projected on the first screen 20). The generation distance L1) that is the distance to one virtual image 8A is fixed. That is, by changing the generation distance L2, the distance (| L2-L1 |) from the first virtual image 8A to the second virtual image 8B is changed.

  Therefore, if the first screen 20 and the second screen 21 are at the same distance from the mirror 11 along the optical path, the first virtual image 8A and the second virtual image 8B are generated at the same position in front of the vehicle 2. However, when the first screen 20 and the second screen 21 are at different distances from the mirror 11 along the optical path, the first virtual image 8A and the second virtual image 8B are at different positions as shown in FIG. Will be generated. Further, as shown in FIGS. 5 and 6, each screen is arranged so that the projection area 22 of the first screen 20 is positioned above the projection area 23 of the second screen 21, but the mirror 11. Thus, the image is inverted upside down, so that the second virtual image 8B is generated above the first virtual image 8A with reference to the direction intersecting the optical path.

  In the present embodiment, the first screen 20 and the second screen 21 are configured to be integrally movable in a direction crossing the optical path. Specifically, by driving a screen up / down drive motor 25 on the side surface of the first screen 20, the first screen 20, the second screen 21, and the screen front / rear drive motor 24 are integrated with each other as shown in FIG. It is possible to move in a direction that intersects (more specifically, a vertical direction that is the arrangement direction of the first screen 20 and the second screen 21). As a result, as shown in FIG. 10, the first projection mode in which the image from the projector 4 is projected on the first screen 20 and the second screen 21, and the image from the projector 4 on the first screen 20 only. The projection mode of the image on the screen 5 can be switched between the second projection mode to be projected.

  When the projection mode is the first projection mode, the HUD 1 basically has different types of video images (for example, the first projection lens 16 presents the current vehicle state) between the first projection lens 16 and the second projection lens 17. The vehicle speed image and the second projection lens 17 project guidance information and warning information image) on each screen. On the other hand, when the projection mode is the second projection mode, one video (for example, the first projection lens 16) that is basically a combination of the images projected by the first projection lens 16 and the second projection lens 17. Then, the image on the lower half of the television screen is projected on the first screen 20 and the image on the upper half of the television screen is projected on the second projection lens 17. As a result, in the second projection mode, it is possible to generate a larger-size image without a dividing line as a virtual image. Even in the second projection mode, the first projection lens 16 and the second projection lens 17 may be configured to project different types of images.

  Each of the screen front / rear drive motor 24 and the screen vertical drive motor 25 is a stepping motor. Then, the HUD 1 can control the screen front / rear drive motor 24 based on the pulse signal transmitted from the control circuit unit 13 and appropriately position the front / rear position of the second screen 21 with respect to the set position. The HUD 1 controls the screen vertical drive motor 25 based on the pulse signal transmitted from the control circuit unit 13 and appropriately positions the vertical positions of the first screen 20 and the second screen 21 with respect to the set position. Is possible.

  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, as shown in FIG. 2, the mirror (concave mirror) 11 reflects the image light from the screen 5, and makes the occupant 7 visually recognize the image on the screen 5 through the front window 6, so that a virtual image is displayed in front of the occupant 7. 8 (see FIG. 1) is a virtual image generating means. 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 first screen 20 and the second screen 21 is reflected by the reflecting mirror 10 and the mirror 11, the generated virtual image is projected on the first screen 20 and the second screen 21. The resulting image is an inverted image of the top, bottom, left and right. Further, in the HUD 1 according to the present embodiment, when designing the installation position of the mirror 11, the distance from the mirror 11 to the second screen 21 along the optical path of the light source of the projector 4 is designed to be a predetermined design value. To do. The predetermined design value is a position where the generation distance L2 from the vehicle occupant to the second virtual image 8B is the shortest (for example, when the generation distance L2 can be changed between 2.5 m to 20 m, the generation distance The position where the second screen 21 is at a position where L2 is 2.5 m is set as a reference. Details will be described later.

  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. 11 is a block diagram showing the configuration of the HUD 1 according to the present embodiment.

  As shown in FIG. 11, 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. 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 13 is connected to the projector 4, the lens drive motor 18, the screen front / rear drive motor 24, and the screen vertical drive motor 25.

  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. Accordingly, the HUD 1 is configured to be able to project output screens of the navigation device 48, the AV device 49, and the like.

  Subsequently, when designing the HUD 1 according to the present embodiment, a method for designing the installation position of the mirror 11 will be described below. Here, the mirror 11 produces | generates the virtual image which can be visually recognized from the passenger | crew of a vehicle by reflecting the image | video projected on the 1st screen 20 or the 2nd screen 21 as mentioned above. In order to make the generated virtual image clearly visible to the user, the positional relationship between the first screen 20 or the second screen 21 and the mirror 11, more precisely, from the first screen 20 or the second screen 21. The distance to the mirror 11 along the optical path of the light source (hereinafter referred to as a concave mirror setting distance) is important. However, in the present embodiment, as described above, of the first screen 20 and the second screen 21, the second screen 21 is configured to be movable along the optical path of the light source (FIG. 7). Therefore, it is a problem to design the concave mirror setting distance based on the position where the second screen 21 is located. Therefore, in the present embodiment, the position where the generation distance L2 from the vehicle occupant to the second virtual image 8B is the shortest (for example, when the generation distance L2 can be changed between 2.5 m to 20 m, the generation distance L2 is 2). The setting distance of the concave mirror is designed with reference to the state in which the second screen 21 is at a position of 5 m).

  Specifically, when the second screen 21 is at a position where the generation distance L2 from the vehicle occupant to the second virtual image 8B is the shortest, the concave mirror setting distance is set so that the generated second virtual image 8B is the clearest. To design. Here, FIG. 12 shows the case where the second screen 21 is located at the position where the generation distance L2 from the vehicle occupant to the second virtual image 8B is the shortest (2.5 m) and the longest position (20 m), respectively. It is the figure which compared and showed the spot diagram which used the surface where the image | video is projected in 2 screens 21 as the evaluation surface, and the resolution map.

  The spot diagram shows the coordinate distribution of the passing light on the evaluation surface by tracing a large number of light from the point light source to the lens. FIG. 12 shows a spot diagram particularly when the pupil diameter is 7 mm. Basically, the smaller the spot diameter is, the clearer the virtual image is obtained from the image projected on the spot.

  Similarly, the resolving power map shown in the lower part of FIG. 12 is created based on the spot diagram, and shows how the spot diameter is distributed with respect to the screen. In the resolving power map, regions are divided based on the spot diameter. Specifically, an area of level 1 where the spot diameter satisfies the first reference value (for example, 0.25 mm) or less is an area where a particularly clear virtual image can be generated. “OK1”, which is defined as “OK1”, is an area where a relatively clear virtual image can be generated in an area of level 2 where the spot diameter is larger than the first reference value and satisfies the second reference value (eg, 0.35 mm) or less. An area of level 3 where the spot diameter is larger than the second reference value is defined as “gray”, which is an area where a blurred virtual image is generated.

  In the present embodiment, referring to the spot diagram when the second screen 21 is at the position where the generation distance L2 from the vehicle occupant to the second virtual image 8B is the shortest as shown in FIG. Set the concave mirror setting distance to be the smallest. In addition, as shown in FIG. 12, even within the same screen, the spot diameter varies greatly at the evaluation position. Specifically, the spot diameter is smaller in the center area, and the spot diameter is larger in the outer area. However, the range on the screen where the image is actually projected is limited to the vicinity of the center. Therefore, in the present embodiment, a range within a predetermined distance from the center of the screen (for example, a range in which the top, bottom, left, and right are respectively reduced to 2/3 or 1/2) is set as the evaluation area. The concave mirror setting distance is set so that the average value of the spot diameters of the spot diagrams becomes the smallest.

  As a result, when the second screen 21 is at a position where the generation distance L2 from the vehicle occupant to the second virtual image 8B is the shortest (hereinafter referred to as a reference position), the second virtual image 8B is configured to be the clearest. Is done. On the other hand, when the image is located at a position other than the reference position, the second virtual image 8B becomes unclear compared to the case where the image is located at the reference position. In particular, as the position of the second screen 21 moves away from the reference position, the position becomes unclear and the generation distance L2 from the vehicle occupant to the second virtual image 8B is the longest (for example, the generation distance L2 is between 2.5 m and 20 m). If it can be changed, the second virtual image 8B becomes the most unclear when there is the second screen 21 at a position where the generation distance L2 is 20 m.

  Here, when compared with the spot diagram when the generation distance L2 is 2.5 m and when the generation distance L2 is 20 m using FIG. 12, the spot diameter when the generation distance L2 is 20 m generally has a larger spot diameter. ing. Further, when the resolution maps are compared, in the case of the generation distance L2 of 20 m, the resolution map “OK1” that is the level 1 area is narrower, and conversely “grey” that is the level 3 area is wider. . That is, it can be seen that the second virtual image 8B generated at 20 m becomes blurred compared to the case where the generation distance L2 from the vehicle occupant to the second virtual image 8B is 2.5 m.

  As a result, it is possible to make the change in the distance from the vehicle occupant to the second virtual image 8B correspond to the sharpness of the second virtual image 8B visually recognized by the occupant. Specifically, the second virtual image 8B generated close to the occupant looks clearer to the vehicle occupant than the second virtual image 8B generated far away. In addition, the second virtual image 8B generated in the distance will be unclear from the vehicle occupant. Therefore, it will be similar to the actual appearance of the object, and the passenger will not feel uncomfortable.

  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 executed after the ACC of the vehicle is turned on, and a virtual image 8 that warns the other vehicle when another vehicle traveling in another lane in front of the traveling direction of the own vehicle interrupts. Is a program that generates In the following description, it is assumed that the image projection mode on the screen 5 is always in the first projection mode (FIG. 10).

  First, in step (hereinafter abbreviated as S) 1 in the virtual image generation processing program, the CPU 31 determines whether another vehicle traveling in another lane ahead of the traveling direction of the host vehicle has interrupted. Specifically, the distance sensor is always detected by a distance measuring sensor, and it is determined that the other vehicle has interrupted when the distance changes shorter by a predetermined amount or more at a time. Further, when the direction indicator information of the other vehicle traveling in the lane adjacent to the lane in which the host vehicle travels is acquired and it is detected that the direction indicator on the lane side in which the host vehicle travels is detected, It may be determined that an interrupt has been performed.

  And when it determines with the other vehicle which drive | works another lane ahead of the advancing direction of the own vehicle having interrupted (S1: YES), it transfers to S2. On the other hand, when it is determined that there is no interrupted vehicle (S1: NO), the virtual image generation processing program is terminated.

  In S <b> 2, the CPU 31 acquires a distance R from the own vehicle to another vehicle that has interrupted (hereinafter referred to as an interrupting vehicle) based on a detection result of a distance measuring sensor or the like. A configuration may be adopted in which the distance R is acquired using a captured image captured by the front camera instead of the distance measuring sensor.

  In S3, the CPU 31 determines whether or not the distance R acquired in S2 is 20 m or less. Note that the distance serving as the determination criterion of S3 is determined by the HUD1 standard, and specifically, is the longest generation distance L2 at which the second virtual image 8B can be generated by the HUD1. As described above, in the present embodiment, the second screen 21 is moved in the front-rear direction along the optical path to generate the second virtual image 8B that is a virtual image of the image projected on the second screen 21 (specifically, Can change the generation distance L2) that is the distance from the occupant 7 to the second virtual image 8B (see FIG. 8). When the second screen 21 is moved most toward the projector 4, the generation distance L2 is the longest. And when the longest generation distance L2 which can produce | generate the 2nd virtual image 8B by HUD1 is 20 m, the criterion of said S3 will be 20 m. On the other hand, when the longest generation distance L2 that can generate the second virtual image 8B by the HUD 1 is 30 m, the determination criterion in S3 is 30 m. In the following example, it is assumed that the longest generation distance L2 that can generate the second virtual image 8B by the HUD 1 is 20 m.

  And when it determines with the distance R acquired by said S2 being 20 m or less (S3: YES), it transfers to S4. On the other hand, when it is determined that the distance R acquired in S2 is longer than 20 m (S3: NO), the process proceeds to S5.

  In S4, the CPU 31 sets the generation distance L2 of the second virtual image 8B to the distance R acquired in S2. On the other hand, in S5, the CPU 31 sets the generation distance L2 of the second virtual image 8B to 20 m which is the maximum distance. Thereafter, the CPU 31 controls the position of the second screen 21 so that the second virtual image 8B is generated at a position away from the occupant 7 by the generation distance L2 set in S4 or S5 as described later.

  Subsequently, in S6, the CPU 31 reads the position setting table from the flash memory 34, and determines the position of the second screen 21 based on the generation distance L2 set in S4 or S5. Furthermore, in S7, the CPU 31 determines the position of the second projection lens 17 based on the position of the second screen 21 determined in S6. In the position setting table, as shown in FIG. 14, the position of the second screen 21 for generating the second virtual image 8B at the generation distance L2 is defined for each generation distance L2. Further, the position of the second projection lens 17 is defined in association with the position of the second screen 21.

  Here, the positions of the second screen 21 and the second projection lens 17 are configured to be movable along the optical path 52 of the light source 51 of the projector 4 as shown in FIG. Since the generation distance L2 depends on the distance from the mirror 11 to the second screen 21, the position of the second screen 21 is the generation distance in which the distance from the mirror 11 to the second screen 21 is set in S4 or S5. It is determined to be a distance corresponding to L2. On the other hand, the position of the second projection lens 17 is determined as a position where the image projected from the second projection lens 17 is focused on the second screen 21. In other words, if the second screen 21 moves along the optical path in a direction away from the mirror 11 (that is, a direction approaching the second projection lens 17) in order to increase the generation distance L2, the second projection lens 17 follows the optical path. Therefore, it moves in a direction approaching the second screen 21 which is the opposite direction. On the other hand, if the second screen 21 moves along the optical path in a direction approaching the mirror 11 (that is, a direction away from the second projection lens 17) in order to shorten the generation distance L2, the second projection lens 17 follows the optical path. Therefore, it moves in the direction away from the second screen 21 which is the opposite direction. That is, the position of the second screen 21 in the optical path 52 is first determined based on the generation distance L2 set in S4 or S5, and the second position in the optical path 52 is determined based on the determined position of the second screen 21. The position of the projection lens 17 is determined. In addition, the second projection lens 17 and the second screen 21 move in different directions along the optical path 52.

  As a result, for example, even when the second screen 21 is moved to the second projection lens 17 side in order to change the generation distance L2, the second projection lens 17 is also moved along with the movement of the second screen 21. By moving to the second screen 21 side, it is possible to maintain the state in which the projected image is focused on the second screen 21. As a result, a clear image can be projected even after the second screen 21 is moved.

  Subsequently, in S8, the CPU 31 determines the drive amount (number of pulses) of the screen front / rear drive motor 24 necessary to move the second screen 21 from the current position of the second screen 21 to the position determined in S6. To do. Similarly, the driving amount (number of pulses) of the lens driving motor 18 required to move the second projection lens 17 from the current position of the second projection lens 17 to the position determined in S7 is determined.

  Thereafter, in S9, the CPU 31 transmits a pulse signal for driving the screen front / rear drive motor 24 by the drive amount determined in S8 to the screen front / rear drive motor 24. Similarly, a pulse signal for driving the lens driving motor 18 by the driving amount determined in S8 is transmitted to the lens driving motor 18. The screen front / rear drive motor 24 and the lens drive motor 18 that have received the pulse signal drive based on the received pulse signal. As a result, the second screen 21 moves to the position determined in S6, and the second projection lens 17 moves to the position determined in S7.

  Next, in S10, the CPU 31 determines whether or not the movement of the second screen 21 and the second projection lens 17 is completed. Specifically, the movement of the second screen 21 and the second projection lens 17 is received when a signal indicating that the drive is completed is received from the screen front / rear drive motor 24 or the lens drive motor 18 that transmitted the pulse signal in S9. Is determined to be complete.

  And when it determines with the movement of the 2nd screen 21 and the 2nd projection lens 17 having been completed (S10: YES), it transfers to S11. On the other hand, when it is determined that the movement of the second screen 21 and the second projection lens 17 is not completed (S10: NO), the process waits until the movement is completed.

  In S <b> 11, the CPU 31 transmits a signal to the projector 4 and starts projecting an image by the projector 4. Here, the video projected by the projector 4 includes information related to the vehicle 2 and various types of information used for assisting the driving of the occupant 7. For example, warnings for obstacles (other vehicles and pedestrians), guidance information set by the navigation device and guidance information based on the guidance route (such as arrows indicating the direction of turning left and right), current vehicle speed, guidance signs, map images, traffic information, There are news, weather forecast, time, screen of connected smartphone, TV program and so on.

  In particular, in this embodiment, the image projected on the first screen 20 by the first projection lens 16 is an image of the current vehicle speed of the vehicle. The image projected onto the second screen 21 by the second projection lens 17 is a warning image for the interrupting vehicle. In the present embodiment, the second screen 21 is disposed below the first screen 20 as shown in FIG. Accordingly, as a result of reflection by the mirror 11, the second virtual image 8B that is a virtual image of the image projected on the second screen 21 is generated above the first virtual image 8A that is a virtual image of the image projected on the first screen 20. Will be.

  Therefore, as shown in FIG. 16, a numerical value indicating the current vehicle speed is generated as the first virtual image 8 </ b> A in the vicinity of the lower edge of the front window 6 and in front of the front window 6, and is visible to the passenger. Further, a frame surrounding the interrupting vehicle 60 is generated as the second virtual image 8B in the vicinity of the center of the front window 6 and in front of the front window 6, and is visible to the passenger. Here, since the position of the first screen 20 is fixed, the position where the first virtual image 8A is generated (specifically, the generation distance L1 which is the distance from the occupant 7 to the first virtual image 8A) is also fixed. The position is 2.5 m ahead of the occupant 7. The generation distance L1 may be other than 2.5 m. However, if the generation distance L1 is too long, the first virtual image 8A is embedded in the road surface, and therefore it is preferably about 2 m to 4 m.

  And in the example shown in FIG. 16, although it is set as the structure which displays the image | video of the present vehicle speed as the 1st virtual image 8A, other information, for example, a guidance sign, a map image, traffic information, news, a weather forecast, time, connected It is good also as a structure which displays also the image | video of the information which does not need to displace the distance from vehicles, such as a smart phone screen and a television program. Then, when the generation distance L1 is fixed to an appropriate distance (for example, 2.5 m), the interruption vehicle 60 approaches the host vehicle as shown in FIG. 16, and the position where the second virtual image 8B is generated is displaced. Even so, it is possible to prevent the generation of an unnatural virtual image that is embedded in the road surface. Furthermore, the vehicle occupant can reduce the line-of-sight movement as much as possible when visually recognizing the first virtual image 8A, and can further reduce the burden during driving.

  On the other hand, as shown in FIG. 16, the position where the second virtual image 8B is generated is the position ahead of the generation distance L2 set in S4 or S5 from the vehicle (that is, the position of the interrupting vehicle 60). Therefore, the occupant can reduce the movement of the line of sight as much as possible when visually recognizing the second virtual image 8B, and can further reduce the burden during driving. Further, as described above, the closer the second virtual image 8B is to the vehicle occupant side, the clearer the second virtual image 8B is seen from the vehicle occupant, which is similar to how an actual object is viewed, and makes the vehicle feel uncomfortable. There is nothing.

  Thereafter, in S12, the CPU 31 determines whether or not the elapsed time t from the start of projection of the video by the projector 4 in S11 is equal to or longer than a predetermined time Y (for example, 5 seconds). The predetermined time Y can be changed as appropriate depending on the content of the projected image.

  If it is determined that the elapsed time t from the start of the projection of the video by the projector 4 is equal to or longer than the predetermined time Y (S12: YES), the projection of the video by the projector 4 is terminated (S13). Note that only the projection by the second projection lens 17 may be terminated and the projection by the first projection lens 16 may be continued.

  On the other hand, when it is determined that the elapsed time t from the start of video projection by the projector 4 is less than the predetermined time Y (S12: NO), the process proceeds to S14.

  In S14, the CPU 31 obtains again the distance R from the host vehicle to the interrupting vehicle.

  Next, in S15, the CPU 31 determines whether or not the difference between the generation distance L2 set in S4 or S5 and the distance R acquired in S14 is a predetermined distance X (for example, 2 m) or more. The predetermined distance X can be changed as appropriate depending on the content of the projected image.

  If it is determined that the difference between the generation distance L2 set in S4 or S5 and the distance R acquired in S14 is equal to or greater than the predetermined distance X (S15: YES), the process proceeds to S3. . Thereafter, the generation distance L2 is newly set based on the newly acquired distance R (S4, S5), and the second screen 21 is moved. As a result, even if the distance from the own vehicle to the interrupting vehicle has changed greatly, the second virtual image 8B can be generated at the position of the interrupting vehicle after the change.

  On the other hand, when it is determined that the difference between the generation distance L2 set in S4 or S5 and the distance R acquired in S14 is less than the predetermined distance X (S15: NO), the process proceeds to S12. Continue projecting the current video.

  As described above in detail, according to the HUD 1 according to the present embodiment, the projector 4 projects images on the first screen 20 and the second screen 21 via the first projection lens 16 and the second projection lens 17, respectively. The image projected on the first screen 20 and the second screen 21 is reflected on the front window 6 of the vehicle 2 via the mirror 11 and made visible to the vehicle occupant 7 so that the vehicle occupant 7 can visually recognize the image. Generate a virtual image of The second screen 21 is movable along the optical path, and the distance from the mirror 11 to the second screen 21 along the optical path of the light source is the position where the distance from the vehicle occupant 7 to the second virtual image 8B is the shortest. Therefore, the distance from the vehicle occupant 7 to the second virtual image 8B can be adjusted by moving the second screen 21, while the second screen 21 By designing the position of the concave mirror in consideration of movement, it is possible to make the virtual image visible without making the vehicle occupant feel uncomfortable. Specifically, the change in the distance from the occupant 7 to the virtual image can correspond to the sharpness of the virtual image visually recognized by the occupant 7.

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 movable range of the second screen is set so that the generation distance L2 is displaced between 2.5 m and 20 m, but the lower limit and the upper limit of the generation distance L2 can be changed as appropriate. It is.

  In this embodiment, a range within a predetermined distance from the center of the screen (for example, a range in which the top, bottom, left, and right are reduced to 2/3 or 1/2 of the entire screen, respectively) is set as the evaluation area. Although the concave mirror setting distance is set so that the average value of the spot diameters of the spot diagram is minimized, the evaluation area may be other than a range within a predetermined distance from the center of the screen. For example, when images are frequently projected near the lower left of the screen, the lower left part obtained by dividing the screen into four may be used as the evaluation area. Further, the entire area of the screen may be set as the evaluation area.

  In the present embodiment, only the second screen 21 is configured to be movable in the front-rear direction along the optical path. However, the first screen 20 may be configured to be movable. Similarly, the first projection lens 16 may be configured to be movable. In that case, the generation distance L1 of the first virtual image 8A can be changed. When the first screen 20 is configured to be movable, the position of the mirror 11 may be designed based on the first screen 20. That is, when the first screen 20 is at a position where the generation distance L1 from the vehicle occupant to the first virtual image 8A is the shortest, the concave mirror setting distance is designed so that the generated first virtual image 8A is the clearest. May be.

  In this embodiment, the screen is composed of two screens, a first screen 20 and a second screen 21, and the lens of the projector 4 is composed of two lenses, a first projection lens 16 and a second projection lens 17. However, the number of screens and lenses may be only one pair or three or more pairs. Further, as the light source of the projector 4, a lamp or a laser may be used in addition to the LED. Further, only the second screen 21 may be configured to be movable in the front-rear direction along the optical path, and the position of the second projection lens 17 may be fixed.

  Moreover, although the embodiment which actualized the head-up display device according to the present invention has been described above, the head-up 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.
The concave mirror setting distance is set so that the virtual image generated by the virtual image generating means becomes clearest when the screen is at the reference position within the movable range.
According to the head-up display device having the above-described configuration, a virtual image generated near the user appears more clearly to the user than a virtual image generated far away. In addition, the virtual image generated far away will appear unclear to the user. Therefore, it is similar to the actual appearance of the object, and the user does not feel uncomfortable.

The second configuration is as follows.
The concave mirror setting distance is set so that the spot diameter of the spot diagram having the screen on which the image is projected as the evaluation surface is the smallest when the screen is at the reference position within the movable range.
According to the head-up display device having the above configuration, it is possible to appropriately set the concave mirror setting distance so that the virtual image generated when the screen is at the reference position is the clearest by using the spot diagram. Become.

The third configuration is as follows.
When the image is projected on the screen and the range within the specified distance from the center of the screen is set as the evaluation area, and the screen is at the reference position within the movable range, the spot diameter of the spot diagram in the evaluation area The concave mirror setting distance is set so that the average value of the minimum is the smallest.
According to the head-up display device having the above configuration, even when there is a variation in spot diameter in the screen, the average of the spot diameter in the vicinity of the center of the screen where the frequency of projecting the image is particularly high is used. It is possible to appropriately set the concave mirror setting distance so that the virtual image generated when the screen is at the position is the clearest.

DESCRIPTION OF SYMBOLS 1 Head up display apparatus 2 Vehicle 3 Dashboard 4 Projector 5 Screen 6 Front window 7 Crew 8 Virtual image 16 1st projection lens 17 2nd projection lens 18 Lens drive motor 20 1st screen 21 2nd screen 24 Screen front and rear drive motor 25 screen Vertical drive motor 31 CPU
32 RAM
33 ROM
34 Flash memory 51 Light source 52 Optical path

Claims (4)

Screen,
A projector that projects an image generated based on light output from a light source onto the screen;
Virtual image generating means for generating a virtual image of the video by reflecting the video projected on the screen to a concave mirror and allowing the user to visually recognize the video,
Moving means for moving the screen within a predetermined movable range along the optical path of the light source;
Virtual image position changing means for changing the distance from the user to the virtual image generated by the virtual image generating means by moving the screen along the optical path of the light source by the moving means,
A state in which the screen is located at a reference position where the distance from the concave mirror to the screen along the optical path of the light source is the shortest distance from the user to the virtual image within the movable range. The head-up display device is characterized in that it is set with reference to the above.   2. The concave mirror setting distance is set so that the virtual image generated by the virtual image generating means becomes clearest when the screen is at the reference position in the movable range. Head up display device.   Setting the concave mirror setting distance so that the spot diameter of the spot diagram with the screen as the evaluation surface is the smallest when the screen is at the reference position within the movable range. The head-up display device according to claim 1, wherein: The surface on which the image is projected on the screen, and a range within a predetermined distance from the center of the screen is set as an evaluation area,
4. The concave mirror setting distance is set so that an average value of spot diameters of spot diagrams in the evaluation area is minimized when the screen is at the reference position in the movable range. The head-up display device described in 1.

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