JP2019032362A - Head-up display device and navigation device - Google Patents

Abstract

To provide a head-up display device that can display a video with a depth feeling while inhibiting an increase in cost.SOLUTION: A head-up display device 100 displays a virtual image of a video projected by a video projection device 21, and comprises: a first mirror 23 that reflects a first video projected by the video projection device; one or more second mirrors 24, 25, 26 that superimpose the first video reflected by the first mirror on a second video projected by the video projection device; and fixing means 47 that fixes the second mirrors by using a space formed when a predetermined area of the second video is projected in a predetermined direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a head-up display device and a navigation device.

  2. Description of the Related Art A head-up display (HUD) device that projects information that supports driving of a vehicle driver or the like onto a reflection member of a window shield to form a virtual image in front of the driver is known. Since the virtual image is formed in front of the vehicle rather than the window shield, the driver who is looking far away can usually visually recognize the information for assisting driving with less line-of-sight movement than when viewing the display inside the vehicle.

  In such a head-up display device, a two-layer head-up display device has been devised in which the imaging position of a virtual image is made different between near and far (see, for example, Patent Document 1). FIG. 1 schematically shows a far virtual image 11 and a near virtual image 12 formed by a two-layer head-up display device. In FIG. 1A, the far virtual image 11 and the near virtual image 12 are shown for explanation, but in reality, the far virtual image 11 and the near virtual image 12 are only visible to the eyes.

  FIG. 1B shows an example of information for assisting driving displayed on the far virtual image 11 and the near virtual image 12. As an example, an icon 201 indicating a traveling lane is displayed on the far virtual image 11, an icon 202 indicating that the vehicle is following the near virtual image 12, a time 203 until a course change, and an incoming call notification 204 are displayed. Yes. As shown in FIG. 1 (b), since the head-up display device displays appropriate information in the distant and near areas, the user displays the information displayed in the distant virtual image 11 and the information displayed in the near virtual image 12. It becomes easy to grasp.

  Further, a head-up display device has been devised that increases the sense of depth by increasing the number of displayed virtual images (see, for example, Patent Document 2). Patent Document 2 discloses a vehicle display device that displays a lower virtual image below a front virtual image and displays an upper virtual image above the front virtual image. Since the lower virtual image and the upper virtual image give a depth feeling to the front virtual image, the appeal of information to the driver can be improved.

Japanese Utility Model Publication No. 7-5886 Japanese Patent Laid-Open No. 2006-68693

  However, the vehicle display device disclosed in Patent Document 2 has a problem in that the number of displays necessary for the number of virtual images is required, resulting in an increase in cost. That is, when the display is independent, the position of the display can be changed for each display, so that separate virtual images can be displayed above and below the front image. However, providing a plurality of displays increases the cost.

  In view of the above problems, an object of the present invention is to provide a head-up display device capable of displaying an image with a sense of depth while suppressing an increase in cost.

  The present invention is a head-up display device that displays a virtual image of a video projected by a video projection device, the first mirror reflecting a first video projected by the video projection device, and the first mirror comprising: One or more second mirrors that superimpose the reflected first image on the second image projected by the image projection device, and a predetermined area of the second image are projected in a predetermined direction. And fixing means for fixing the second mirror using a space formed at the time.

  A head-up display device capable of displaying an image with a sense of depth while suppressing an increase in cost can be provided.

It is an example of the figure which shows typically a distant virtual image and a near virtual image imaged with a 2 layer head-up display apparatus. It is an example of the figure explaining the general | schematic characteristic of a head-up display apparatus. It is a figure which shows an example of a distant virtual image and a near virtual image seen from a driver | operator's viewpoint. It is an example of the schematic block diagram of the head-up display apparatus mounted in the vehicle. It is an example of the figure explaining image formation of the virtual image by a convex lens. It is an example of the figure explaining the basic optical system of a head up display. It is a figure explaining the comparative example of a head-up display apparatus. It is an example of the figure explaining the schematic structure of a head-up display apparatus. It is an example of the figure explaining the schematic structure of a head-up display apparatus. It is an example of the figure explaining a non-drawing area | region. It is an example of the figure explaining the attachment structure of the 2nd mirror arrange | positioned so that it may superimpose on the image | video for near virtual images, or a 4th mirror. It is an example of the figure which shows the space which the non-drawing area | region of four corners can project on a concave mirror. It is an example of the figure explaining an eyebox. It is an example of the figure explaining a viewpoint position shift. It is a figure which shows an example of the near virtual image and the far virtual image superimposed on the real scene seen from the driver's seat. It is an example of the figure explaining AR image. It is an example of the figure explaining the perspective projection conversion to the projection surface of the projection image painted on the road surface.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

<Schematic features of the head-up display device>
FIG. 2 is an example of a diagram illustrating schematic features of the head-up display device of the present embodiment. The head-up display device of the present embodiment displays the near virtual image 12 and the far virtual image 11 in a superimposed manner with a single video projection device. As shown in FIG. 2, the distant virtual image 11 is displayed so as to overlap the approximate center of the near virtual image 12 from the viewpoint of the driver. The near virtual image 12 on which the far virtual image 11 is superimposed has non-drawing regions 31 at the center 31a and the four corners 31b. The non-drawing area 31 is an area that does not include information on brightness and darkness as well as information on characters and icons. Specifically, it can be said that the original image is a black pixel region or a region where no light is irradiated. For this reason, even if the far virtual image 11 and the near virtual image 12 are superimposed, the driver can visually recognize the far virtual image 11 satisfactorily.

  FIG. 3 is a diagram illustrating the distant virtual image 11 and the near virtual image 12 viewed from the viewpoint of the driver, and explaining the non-drawing region 31. As described with reference to FIG. 2, the center 31 a and the four corners 31 b of the near virtual image 12 are the non-drawing regions 31, and the center 31 a is cut out, so that the far virtual image 11 has a sense of depth. Furthermore, in order to increase the sense of depth, the right drawing area 12r, the left drawing area 12l, the upper drawing area 12u, and the lower drawing area 12d of the near virtual image 12 are represented by perspective views. A perspective diagram is a diagram expressed in three dimensions using perspective. Also called perspective view. That is, a figure (a quadrilateral but more specifically a trapezoid) that becomes narrower as it approaches the far virtual image 11 is formed as a right drawing area 12r, a left drawing area 121, an upper drawing area 12u, and a lower drawing area 12d. Yes. Depth can be further enhanced by forming a translucent gradation that does not hinder the visibility of the actual scene.

  In the right drawing area 12r, the left drawing area 121, the upper drawing area 12u, and the lower drawing area 12d, it is possible to display information that supports driving suitable for each.

  A non-drawing region 31 at the center 31a exists around the far virtual image 11. Between the right drawing area 12r, the left drawing area 12l, the upper drawing area 12u, and the lower drawing area 12d of the near virtual image 12 is a non-drawing area 31 having four corners 31b. The non-drawing areas 31 at the center 31a and the four corners 31b also have an effect of enhancing the feeling of depth. Furthermore, the non-drawing area 31 at the center 31a is effective for ensuring the visibility with respect to a viewpoint blur in an eye box, which will be described later, and can also be used for distortion correction of the far virtual image 11.

  Further, the non-drawing region 31 at the four corners 31b between the right drawing region 12r, the left drawing region 121, the upper drawing region 12u, and the lower drawing region 12d of the near virtual image 12 is close to the far virtual image 11 as described later. This is an area where a fixed arm (an example of a fixing means) for fixing a mirror for realizing the superimposed display of the square virtual image 12 is installed. Therefore, the non-drawing area 31 at the four corners 31b not only enhances the sense of depth, but can also bring about an effect of making the fixed arm invisible.

<Schematic structure of head-up display device>
FIG. 4 shows a schematic configuration diagram of a head-up display device mounted on a vehicle. FIG. 4 shows a one-layer head-up display device for convenience of explanation. In the present embodiment, a head-up display device mounted on a vehicle will be described as an example. The display unit 20 of the head-up display device is embedded in the dashboard, and is projected on the upper surface of the display unit 20 from the exit window toward the window shield 13. The projected image is displayed as a virtual image 10 in front of the window shield 13. The driver 9 can visually recognize this virtual image. Therefore, the head-up display device is an embodiment of the display device. The driver 9 can visually check the information for assisting driving while keeping the line of sight on the vehicle or the road ahead (with little movement of the line of sight). Information for supporting driving will be described later.

<Optical system of head-up display>
The optical system of the head-up display will be described with reference to FIGS. FIG. 5 is an example of a diagram for explaining the formation of a virtual image by a convex lens, and FIG. 6 is an example of a diagram for explaining a basic optical system of a head-up display.

As shown in FIG. 5, when the object 52 is in front of the lens 51 with respect to the focal length f of the lens 51, the virtual image 10 can be seen from the viewpoint through the lens. The virtual image 10 does not actually exist there, and even if the screen is placed, an image of the object is not reflected. As is well known, when the distance from the lens 51 to the object 52 is a, the distance b to the virtual image 10 is f, and the focal length is f, these have the following relationship.
(1 / a)-(1 / b) = 1 / f
As understood from the distance b, the distance b from the lens 51 to the virtual image 10 increases as the distance a increases and the focal length f decreases. If the focal length f is constant, the distance b increases as the distance a increases, and a virtual image can be formed far away from the driver 9 (however, a virtual image can be obtained a <f). As the virtual image 10 is farther away, information that assists driving can be visually recognized with less line-of-sight movement for the driver 9 who is looking far away.

  Next, a virtual image by the concave mirror 27 will be described with reference to FIG. The image irradiated by the image projection device 21 onto the diffuser 22 is reflected and enlarged by the concave mirror 27 and then reflected by the combiner 17 of the window shield 13 in the direction of the driver's line of sight. At this time, it appears to the driver 9 that the image is enlarged and displayed far away through the combiner 17. This is because the concave mirror 27 functions in the same manner as the lens 51 described with reference to FIG. Due to the relationship between the focal length f of the concave mirror 27 and the distance L1 between the diffuser 22 (L1 <f), the front image of the vehicle becomes a virtual image 10 and does not actually exist in front of the combiner 17.

  The distance between the diffuser 22 and the concave mirror 27 is L1, the distance L2 between the concave mirror 27 and the combiner 17, and the distance between the virtual virtual image 10 ′ and the concave mirror 27 when the concave mirror 27 is a convex lens is L3. A distance L4 from 17 to the virtual image 10 is assumed. In correspondence with FIG. 5, the distance L1 corresponds to the distance a, and the distance L3 corresponds to the distance b. Therefore, it appears that a virtual image is formed at a distance L4 = L2 + L3 from the combiner 17.

  In order to reduce the movement of the driver's line of sight, L2 or L3 may be increased. The distance L2 is often determined by the structure of the vehicle, and it is often difficult to increase the distance L2. In order to increase the distance L3, it is necessary to decrease the focal length f of the concave mirror 27 or increase the distance L1 as described in FIG. As a method for increasing the distance L1, the head-up display device employs a method in which an image is folded by several mirrors to increase the distance.

<Structural example of head-up display device of this embodiment>
<< Head-up display device in which near and far virtual images do not overlap >>
FIG. 7 is a diagram illustrating a comparative example for comparison with the head-up display device 100 of the present embodiment. The head-up display device 100 in FIG. 7 is a two-layer head-up display device, but the near virtual image 12 and the far virtual image 11 do not overlap.

  The head-up display device 100 includes a combiner 17 formed on the display unit 20 and the window shield 13. The display unit 20 further includes a video projection device 21, a diffuser 22, a first mirror 23 (an example of a first mirror), a second mirror 24 (an example of a second mirror), and a concave mirror 27. Details of these will be described with reference to FIG.

  The video projector 21 projects a video image formed as the far virtual image 11 and a video image formed as the near virtual image 12 onto the diffuser 22. The far virtual image is reflected by the first mirror 23 toward the second mirror 24 and reflected by the second mirror 24 toward the concave mirror 27. On the other hand, the near virtual image video reaches the concave mirror 27 directly from the diffuser 22.

  The concave mirror 27 reflects the far virtual image and the near virtual image toward the combiner 17. The far virtual image 11 and the near virtual image 12 can be seen from the viewpoint of the driver. Because of the first mirror 23 and the second mirror 24, the far virtual image 11 has a longer optical path length to the concave mirror 27 than the near virtual image, so the far virtual image 11 is more driver than the near virtual image 12. It forms an image far away as seen from the top.

<< Head-up display device 1 with near and far virtual images superimposed >>
FIG. 8 is an example of a diagram illustrating a schematic structure of the head-up display device 100 of the present embodiment. That is, the head-up display device 100 of FIG. 8 is a two-layer head-up display device in which the near virtual image 12 and the far virtual image 11 are superimposed. As a difference from FIG. 7, the second mirror 24 is superimposed on the near virtual image 43. Thereby, the far virtual image 11 superimposed on the near virtual image 12 is obtained.

  The video projection device 21 generates a video projected as a virtual image based on information for assisting driving acquired from a vehicle-side unit mounted on the vehicle. Specifically, an AR image that looks as if a mark indicating the traveling direction is drawn on the road surface is generated. AR stands for “Augmented Reality” and is called augmented reality. In this case, the video projection device 21 generates an AR image by arranging some projection image (referred to as an object) in the three-dimensional coordinate system and performing perspective projection conversion on the projection image corresponding to the driver's field of view. . Alternatively, information such as the vehicle speed may be simply generated without displaying the AR.

  The video projection device 21 has a function of projecting video. Projection methods include LCD (Liquid Crystal Display), DLP (Digital Light Processing), and laser projector. In the present embodiment, the projection method is not limited.

  The diffuser 22 has a role of expanding the image (light) projected by the image projection device 21. Microlenses are formed on the surface of the diffuser 22 on the image projection device 21 side without any gaps. Since the microlens can reduce the distance between the object images as compared with a normal lens, it is easy to earn the distance L1. The angle at which the image spreads is determined from the size of the microlens, the focal length of each lens, and the like.

  A first mirror 23 and a second mirror 24 are disposed on the back surface (image projection direction) of the diffuser 22 as viewed from the image projection device 21. The first mirror 23 is disposed above the second mirror 24 in the vertical direction. The second mirror 24 is arranged directly below the first mirror 23 and in the center of the near virtual image 43. Although the areas of the first mirror 23 and the second mirror 24 in FIG. 8 are the same, either one may be larger.

  The first mirror 23 is arranged in the projection range of the far virtual image 42 because the far virtual image 42 is turned back toward the second mirror 24. That is, it overlaps with the diffuser 22. The second mirror 24 is arranged in the projection range of the near virtual image 43 in order to superimpose the far virtual image 42 on the near virtual image 43. That is, it overlaps with the diffuser 22.

  How much the first mirror 23 overlaps with the diffuser 22 is adjusted according to the image design policy. That is, if it is desired to increase the information for supporting the driving displayed as the near virtual image 12, the overlapping area of the first mirror 23 and the diffuser 22 is reduced. In order to increase the information for supporting driving displayed as the distant virtual image 11, the overlapping area of the first mirror 23 and the diffuser 22 is increased. However, since the near virtual image 12 is displayed so as to surround the far virtual image 11, the overlapping area of the first mirror 23 and the diffuser 22 is less than half that of the diffuser 22. In order to fully express the sense of depth, it is preferably less than 1/3.

  The first mirror 23 and the second mirror 24 are arranged in parallel to each other, and the first mirror 23 and the second mirror 24 superimpose the far virtual image 42 from the diffuser 22 on the near virtual image 43. Reflected toward the concave mirror 27 in parallel with the near virtual image 43.

  As described above, the concave mirror 27 serves as a lens for enlarging and reflecting the image toward the combiner 17 and forming a virtual image. An image 42 for a far virtual image reaches the concave mirror 27 so as to be superimposed on a video 43 for a near virtual image. The image reflected by the concave mirror 27 passes through the emission unit 18 of the display unit 20 and reaches the combiner 17. The size, angle, and position of the concave mirror 27 are designed so that the entire image reaches the combiner 17.

  The combiner 17 has two functions. One is a function of reflecting an image reflected by the concave mirror 27 toward the driver (function of a reflecting member). The other is a function (transmission function) that secures the field of view obtained by the driver 9 via the combiner 17. Since the beam splitter is formed on the surface of the combiner 17 on the driver side, at least a part of the incident image is reflected toward the driver 9. Further, at least a part of the external light is transmitted and reaches the eyes of the driver 9. As a result, the driver 9 can view both the virtual image and the real scene at the same time.

  Since the outer surface of the combiner 17 has substantially the same curvature as the inner surface, it does not have a lens effect on the light transmitted through the combiner 17 and the actual scene is not distorted.

  As is clear from FIG. 8, the former is longer in the optical path length from the diffuser 22 to the first mirror 23, the second mirror 24, and the concave mirror 27 and the optical path length from the diffuser 22 to the concave mirror 27. . Therefore, the near virtual image 12 forms an image closer to the driver 9 than the far virtual image 11, and the far virtual image 11 forms an image farther than the near virtual image 12 as viewed from the driver 9.

  According to the configuration as shown in FIG. 8, the near virtual image 12 and the far virtual image 11 can be superimposed with one second mirror 24. That is, since the number of mirrors is small, an increase in cost can be suppressed. On the other hand, the distance of the distant virtual image 42 cannot be obtained much.

  By the way, there is a possibility that the edges 41 of the first mirror 23 and the second mirror 24 can be seen when the driver moves his / her line of sight in an eye box described later. However, when the edges of the first mirror 23 and the second mirror 24 are not mirror-coated, they do not become an optical path (passage), and therefore only appear black.

  On the other hand, although the phenomenon of the floating of the edge 41 does not occur, an image cannot pass through the edge 41, so there is an area that cannot be drawn. However, by securing a non-drawing area at the center 31a of the near virtual image 43 larger than the far virtual image 42, an area that cannot be drawn can be made inconspicuous.

  Further, when the eyes are moved in the eye box, the distant virtual image 11 cannot be seen at the center, but this is also solved by providing the non-drawing region 31 at the center 31a.

  Further, when the second mirror 24 is arranged, it is necessary that an attachment part (hereinafter referred to as a fixed arm) other than the mirror main body is arranged so as not to block the optical path of the near virtual image 43. This structure will be described with reference to FIG.

<< Head-up display device 2 with near and far virtual images superimposed >>
FIG. 9 is an example of a diagram illustrating a schematic structure of the head-up display device 100 of the present embodiment. In the description of FIG. 9, differences from FIG. 8 are mainly described.

  In FIG. 9, the first mirror 23, the second mirror 24 (an example of the first reflection part), the third mirror 25 (an example of the second reflection part), and the fourth mirror 26 (an example of the third reflection part). The image 42 for the far virtual image is reflected. The arrangement of the first mirror 23 and the second mirror 24 is the same as in FIG. The third mirror 25 reflects the far virtual image 42 reflected by the second mirror 24 upward in the vertical direction. The fourth mirror 26 is disposed directly above the third mirror 25 and in the center of the near virtual image 43. That is, the fourth mirror 26 is arranged in the projection range of the near virtual image 43 in order to superimpose the far virtual image 42 on the near virtual image 43. That is, it overlaps with the diffuser 22.

  The areas of the first mirror 23, the second mirror 24, the third mirror 25, and the fourth mirror 26 are the same, but are not necessarily the same. The fourth mirror 26 superimposes the far virtual image 42 with the near virtual image 43 and reflects it toward the concave mirror 27 in parallel with the near virtual image 43.

  According to the configuration of FIG. 9, the far virtual image 42 projected by the diffuser 22 is sequentially reflected by the first mirror 23, the second mirror 24, the third mirror 25, and the fourth mirror 26 to the concave mirror 27. Led. Accordingly, the optical path length of the far virtual image 42 can be made longer than that in the configuration of FIG. Since the number of parts increases by the amount of the third mirror 25 and the fourth mirror 26, there is a possibility that the cost is slightly increased. However, since the difference in the distance between the near virtual image 12 and the far virtual image 11 can be increased, It is possible to increase the sense of depth compared to the configuration of FIG.

  Note that when the fourth mirror 26 is disposed, the fixed arm other than the mirror body needs to be disposed so as not to block the optical path of the near virtual image 43, which is the same as the configuration of FIG. The arrangement method of the fixed arm is the same as that in FIG. 8, and will be described with reference to FIG.

<Attachment structure of second mirror 24 and fourth mirror 26>
FIG. 10 is an example of a diagram illustrating the non-drawing area 31. The diffuser 22 projects a near virtual image 43 (an example of a second image) and a far virtual image 42 (an example of a first image) constructed in one image. If the near virtual image 43 can have the same shape as the first mirror 23, it is ideal because the near virtual image 12 having the maximum size can be projected in the design of the head-up display device 100. However, since the image is distorted by the concave mirror 27 and the combiner 17, the image whose distortion has been corrected in advance is projected so that this distortion is eliminated when the near virtual image 12 is formed. Since the image whose distortion has been corrected is not the same rectangle as the first mirror 23, the near virtual image 43 has a non-drawing area 32 for distortion correction. Therefore, the area 35 where the information is actually drawn is a part of the near virtual image 43 (smaller than the size of the first mirror 23).

  The near virtual image 43 has the non-drawing region 31 at the center 31a and the four corners 31b as described above. The near virtual image 43 is divided into an upper drawing area 12u, a left drawing area 121, a right drawing area 12r, and a lower drawing area 12d. Each region is represented by a perspective view to produce a perspective. The non-drawing area 31 at the center 31a and the four corners 31b is a remaining area obtained by subtracting the perspective drawing of the upper drawing area 12u, the left drawing area 121, the right drawing area 12r, and the lower drawing area 12d from the near virtual image 43. It is.

  In consideration of the design of the user interface, the upper drawing area 12u, the left drawing area 121, the right drawing area 12r, and the lower drawing area 12d are determined, and the non-drawing areas 31 at the center 31a and the four corners 31b are determined in advance. It has been. However, the non-drawing region 31 is determined in consideration of the space where the fixed arm attaches the second mirror 24. In any case, the non-drawing area 31 is determined in advance.

  The far virtual image 42 is overlapped with the center 31 a of the near virtual image 43 together with the non-drawing area 32. Therefore, the area 35 where the information of the far virtual image 42 is drawn and the non-drawing area 32 are superimposed on the non-drawing area 31 at the center 31a of the near virtual image 43. Accordingly, a part of the non-drawing area 31 at the center 31 a becomes the non-drawing area 32.

  The second mirror 24 or the fourth mirror 26 is attached using the non-drawing regions 31 at the four corners 31b of the near virtual image 43. That is, the fixed arm fixes the second mirror 24 or the fourth mirror 26 so as not to overlap the non-drawing region 31 at the four corners 31b.

  The non-drawing region 31 at the center 31a (the non-drawing region 32 around the far virtual image 42) is not limited to the non-drawing region 31 at the four corners 31b.

  FIG. 11 is an example of a diagram illustrating a mounting structure of the second mirror 24 or the fourth mirror 26 arranged so as to overlap with the near virtual image 43. Although the attachment structure of the second mirror 24 is described in FIG. 11, the same concept applies to the fourth mirror 26.

  On the concave mirror 27, a near virtual image 43 and a far virtual image 42 are superimposed and projected. The diffuser 22 projects the near virtual image 43 toward the second mirror 24. The positions of the near virtual image 43 corresponding to the four vertices 44 of the second mirror 24 are the center 31a and the four corners 31b. This is the intersection 45.

  Further, the range of the four corners 31b from the intersection 45 corresponding to the four vertices 44 of the second mirror 24 to the vertex 46 of the near virtual image 43 is a non-drawing region 31 for providing a sense of depth. The fixed arm 47 uses the space formed by projecting the non-drawing regions 31 at the four corners 31b of the near virtual image 43 in the direction of the concave mirror 27 (an example of a predetermined direction), so that the second mirror 24 is surrounded by the surrounding wall surface. 49. Note that not all of the four fixing arms 47 need to be fixed to the wall surface 49, and at least one or more may be fixed to the wall surface 49.

  FIG. 12 is an example of a diagram showing a space 48 formed by projecting the non-drawing region 31 at the four corners 31 b onto the concave mirror 27. As shown in FIG. 12, the fixed arm 47 is disposed in a space 48 formed by the non-drawing region 31 at the four corners 31b. The same applies to the fixing arm 47 other than that illustrated.

  By using the non-drawing area 31 of the projected image in this way, the fixed arm of the second mirror 24 is prevented from casting a shadow on the near virtual image 12 even when the second mirror 24 is superimposed on the diffuser 22. it can.

<Viewpoint misalignment>
As described with reference to FIG. 3, the virtual image is displayed so that the far virtual image 11 is surrounded by the near virtual images 12 in the vertical and horizontal directions. Since the near virtual image 12 is formed in front of the driver as viewed from the driver, the near virtual image 12 may block the far virtual image 11 depending on the position of the driver's eyes. However, in the present embodiment, the non-drawing region 32 for distortion correction (around the center 31a after being superimposed with the near virtual image 43) is provided around the far virtual image 42, so the near virtual image There is almost no possibility that 12 will block the distant virtual image 11.

  First, the eye box will be described with reference to FIG. FIG. 13 is an example for explaining an eye box. For convenience of explanation, FIG. 13 shows a one-layer head-up display device. Since the physique of the driver 9 and the posture when seated in the driver's seat are not necessarily the same depending on the driver 9, the eye position of the driver 9 also changes. For this reason, in the head-up display device, a constant region centered on the position of the eyes of a typical driver 9 is assumed. The optical system of the head-up display is designed so that the virtual image can be visually recognized as long as the eyes of the driver 9 are in this region. The fixed area (viewing area) set in this way is referred to as an eye box 19.

  In FIG. 13, the angle of the concave mirror 27 (image reflection direction by the combiner 17) and the like are designed so that the light reflected by the concave mirror 27 can be reflected by the combiner 17 covering the eye box 19.

  Although FIG. 13 illustrates a one-layer head-up display device, the same applies to a two-layer head-up display device, in which light reflected by each of the first mirror 23 and the second mirror 24 is operated. The eye box 19 is formed by being reflected by the combiner 17 toward the eyes of the person 9.

  FIG. 14 is an example of a diagram for explaining viewpoint position deviation. FIG. 14A shows a side view for explaining the non-drawing region 31, and FIG. 14B shows a viewpoint position (center position of both eyes) in the eye box. FIG. 14C schematically shows the relative positions of the near virtual image 12 and the far virtual image 11 viewed from the driver. As shown in FIG. 14A, the near virtual image 12 is displayed above and below, and the far virtual image 11 is displayed therebetween. The near virtual images 12 on the left and right as viewed from the driver are omitted. The near virtual image 12 is displayed in front of the far virtual image 11.

  The viewpoint position of the driver can take any of a to e in FIG. When the viewpoint position is at a in the eye box, the far virtual image 11 appears at the center of the near virtual image 12 as indicated by c-1 in FIG. When the viewpoint position is at b in the eye box, the distant virtual image 11 appears closer to the upper side of the near virtual image 12 as indicated by c-2 in FIG. When the viewpoint position is at c in the eye box, the far virtual image 11 appears closer to the lower side of the near virtual image 12 as indicated by c-3 in FIG. When the viewpoint position is at d in the eye box, the far virtual image 11 appears closer to the right side of the near virtual image 12 as indicated by c-4 in FIG. When the viewpoint position is at e in the eye box, the far virtual image 11 appears closer to the left side of the near virtual image 12 as indicated by c-5 in FIG.

  However, since the non-drawing area 32 for correcting the distortion (around the center 31a after the superimposition) is provided around the far virtual image 42, the near virtual image 12 is the far virtual image 11 in the eyebox range. Is not interrupted or the visibility is not hindered.

<Display example of information to support driving>
An example of information for supporting driving displayed as the near virtual image 12 and the far virtual image 11 will be described with reference to FIG. FIG. 15 shows an example of the near virtual image 12 and the far virtual image 11 superimposed on the real scene viewed from the driver's seat. The near virtual image 12 and the far virtual image 11 can be displayed in an AR display superimposed on the real scene.

  First, the head-up display device 100 may be provided integrally with the navigation device, or may be provided only by the head-up display device 100. The navigation device is a device that performs various driving assistance. For example, the position of the host vehicle is detected by a GNSS (Global Navigation Satellite System) and the position of the host vehicle is displayed on a road map. In addition, the route to the destination is displayed on the road map, or the driver is guided to the destination by guiding the traveling direction before the route is changed.

  In the distant virtual image 11, a follow-up running mark 301 representing a preceding vehicle on which the host vehicle is following up and a destination mark 302 are displayed. When traveling following the vehicle, the vehicle detects the preceding vehicle with a radar or a stereo camera, and therefore detects the distance and direction with reference to the vehicle. The height of the road surface is known. Therefore, the video projection device 21 can display the following traveling mark 301 on the road surface behind the preceding vehicle.

  When the destination is set in the navigation device, the vehicle position and the coordinates of the destination (latitude, longitude, altitude) are detected. Therefore, the direction of the destination as seen from the vehicle position is also known. The video projector 21 can display the destination mark 302 so as to surround the destination. The POI mark may be displayed not only at the destination mark 302 but also at a POI (Point Of Interest) location. For example, a place where the driver stopped in the past, a facility determined from the driver's preference, a gas station, and the like.

  In the upper drawing area 12u of the near virtual image 12, for example, the traveling direction 303 of the host vehicle, the distance 304 to the destination, the guidance direction 305, and the like are displayed. That is, information that complements the information displayed in the far virtual image 11 is displayed. In this way, detailed information up to the destination can be displayed in the upper drawing area 12u of the near virtual image 12 without hindering the visibility of the far virtual image 11 that the driver often sees for driving. In addition, the traveling direction of the host vehicle indicates the direction from east, west, south, and north. The distance to the destination may be a road distance or a straight distance. The guidance direction is a direction in which the host vehicle travels when the next course is changed. The distance to the destination is preferably displayed directly above the destination mark 302 of the far virtual image 11. By doing so, the driver can grasp the relationship between the far virtual image 11 and the near virtual image 12. Further, since the guidance direction is displayed in the upper drawing area 12u of the near virtual image 12, the guidance direction can be guided without impairing the driver's visibility.

  Some warning is displayed on the left and right side surfaces (left drawing area 12l, right drawing area 12r). As an example, a warning frame 306 regarding the detected obstacle is displayed in the left drawing area 12 l of the near virtual image 12. FIG. 15 shows an example in which a pedestrian 307 is detected. Since the host vehicle detects an obstacle with a stereo camera or a radar, the distance and direction to the obstacle are known. The video projector 21 displays a quadrilateral surrounding the pedestrian 307 as a warning frame 306. The warning frame 306 is narrower in the distance and wider in the near direction so as to express a sense of perspective, so that the relative direction from the viewpoint of the driver can be easily understood.

  As an example, a rear approaching vehicle mark 308 is displayed in the right drawing area 12 r of the near virtual image 12. The vehicle approaching vehicle mark 308 is a warning that a vehicle has been detected on the right rear side of the host vehicle. A backward approaching vehicle mark 308 is displayed on the road surface on the right side when viewed from the host vehicle.

  In the lower drawing area 12d of the near virtual image 12, an area close to the dashboard displays a vehicle speed 310, an enlarged intersection map 311 and the like (infotainment area), and an area close to the road includes a traveling lane 312 and the like. Is displayed. Infotainment is a coined word that combines information (information) and entertainment (entertainment).

  A translucent gradation is displayed in the upper drawing area 12u, the left drawing area 121, the right drawing area 12r, and the lower drawing area 12d of the near virtual image 12. This gradation is lighter in the distance and deeper in the distance. Further, the upper drawing area 12u, the left drawing area 12l, the right drawing area 12r, and the lower drawing area 12d of the near virtual image 12 are drawn by perspective views that give a sense of perspective. As a result, the sense of depth can be increased.

  When there is no content to be displayed in the upper drawing area 12u, the left drawing area 12l, the right drawing area 12r, and the lower drawing area 12d of the near virtual image 12, these virtual images may be completely transparent images. Alternatively, it may be translucent when there is no content to be displayed. The gradation and frame lines of the upper drawing area 12u, the left drawing area 12l, the right drawing area 12r, and the lower drawing area 12d of the near virtual image 12 are displayed only when there is content to be displayed. Alternatively, a gradation and a frame line may be displayed when there is no content to be displayed.

  Further, the upper drawing area 12u, the left drawing area 12l, the right drawing area 12r, and the lower drawing area 12d of the near virtual image 12 are always displayed as a set of four, thereby providing a sense of depth. However, only any one or more may be displayed.

  As described above, the distant virtual image 11 is superimposed on the center of the near virtual image 12, thereby providing a video with a sense of depth. Moreover, the near virtual image 12 can be divided into four, and information for supporting appropriate driving can be displayed with a sense of depth.

  These display examples in FIG. 15 are merely examples, and what content is displayed in the upper drawing area 12u, the left drawing area 12l, the right drawing area 12r, and the lower drawing area 12d of the near virtual image 12 is appropriately determined. Is set. It is further preferable that the driver can arbitrarily set the driver.

<About creation of AR image>
FIG. 16 is an example of a diagram illustrating an AR image. FIG. 16A is an assumption diagram when the projected image 53 is painted on the road surface in front of the vehicle 6. Assuming that such a projection image 53 is actually painted on the road surface, the driver 9 sees a smaller right-pointing triangle (lane movement guidance projection image) as it goes farther. As an example, the vehicle width direction of the vehicle is the x axis, the vertical direction is the y axis, and the traveling direction is the z axis. One coordinate of the apex of the triangle is (x ₁ , y ₁ , z ₁ ).

FIG. 16B is a side view of the lane movement guide and the vehicle 6 similarly painted on the road surface. If a predetermined origin (for example, the center of the vehicle) moving with the vehicle 6 is taken, the height y1 to the road surface is known. Further, it has been experimentally determined how much forward the projected image 53 of the lane movement guidance is effective for assisting driving. Therefore, the distance z ₁ to forward the setting value. It has been experimentally determined how far in the vehicle width direction from the center of the vehicle 6 that the projection image 53 of the lane movement guidance is effective in assisting driving. Accordingly, the distance x ₁ in the vehicle width direction is set value. From the above, (x ₁ , y ₁ , z ₁ ) is known.

FIG. 17 is an example for explaining perspective projection conversion of the projection image 53 painted on the road surface onto the projection surface 54. The video projection device 21 performs perspective projection conversion of the projection image, and the projection plane 54 needs to be set for the perspective projection conversion. The projection plane 54 is a two-dimensional plane on which the projection image 53 is projected. The projection surface 54 represents the field of view of the driver 9. When the head-up display device 100 displays an AR image, the driver looks forward through the combiner, and thus a substantially vertical plane near the combiner 17 is set as the projection plane 54. Therefore, the center coordinates (x ₀ , y ₀ , z ₀ ) of the projection plane 54 are calculated in the above x, y, z coordinate system depending on where the projection plane 54 is set. The size of the projection surface 54 is also appropriately determined from the sizes of the eye box 19 and the combiner 17.

The video projection device 21 performs perspective projection conversion on the projection plane 54. If the coordinates of the projection image 53 projected on the projection surface 54 are x ₂ , y ₂ , and z ₂ , the projective transformation of the homogeneous coordinate system can be expressed as follows.

By performing this conversion for each pixel of the projection image, the video projection device 21 can create an AR image. The coordinates of the projection plane 54 can be obtained by dividing x ₂ and y ₂ by the fourth component on the left side.

  Therefore, if not only the road surface but also the three-dimensional coordinates of the pedestrian or the preceding vehicle described in FIG. 15 are known, an AR image can be appropriately created.

<Summary>
As described above, the head-up display device according to the present embodiment is a two-layer head-up display device, in which an area that is not drawn is provided at the center of the near virtual image 43, and the user interface has a high perspective. Can be realized. Compared with the conventional two-layer head-up display device, a sense of reality can be obtained, and a wide variety of user interfaces can be made by using the difference in depth between the near virtual image and the far virtual image. In particular, the degree of freedom of AR expression is increased.

  In addition, it can be expected that expression with a high sense of reality is effective in maintaining a sense of depth and balance in the driver's field of vision. By dividing the near virtual image into a plurality of areas, it is possible to display appropriate information for each area and to interpolate information between the plurality of areas.

  Further, in order to project the far virtual image to the center of the near virtual image, the second mirror 24 or the fourth mirror 26 is fixed, but the non-drawing area 31 at the four corners 31b can be projected in the direction of the concave mirror 27. The fixed arm 47 can be attached by using the space. Therefore, it can be realized only by arranging the mirror without greatly changing the mechanism of the conventional two-layer head-up display device, and the increase in size and cost of the head-up display device can be suppressed.

<Other application examples>
The best mode for carrying out the present invention has been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention. And substitutions can be added.

  For example, in this embodiment, the four corners of the near virtual image 43 are set as the non-drawing area 31, but the non-drawing area 31 may be provided anywhere in the near virtual image 43. That is, it is only necessary to obtain a space in which the fixed arm can be fixed by the non-drawing region 31. However, since the near virtual image 43 is an image for displaying information for supporting driving, the visibility of the information for supporting driving may be considered.

  Moreover, the fixed arm may fix the second mirror 24 by using only a part of the four corners 31b instead of using all the four corners 31b.

  Further, the head-up display device need not be embedded in the dashboard, and may be disposed on the dashboard. Or you may be attached to the ceiling and may be attached to the sun visor. The head-up display device may be detachable from the vehicle.

  In addition, it is preferable that the entire far virtual image 42 is superimposed on the near virtual image 43, but only a part may be superimposed. In addition, superimposition is performed so that only one side of the near virtual image 43 and the far virtual image 42 are in common, or the near virtual image 43 and the far virtual image 42 are overlapped. May be superimposed so that only the two sides are common, or may be superimposed so that only the three sides of the near virtual image 43 and the far virtual image 42 are common.

  Further, the right drawing area 12r, the left drawing area 12l, the upper drawing area 12u, and the lower drawing area 12d of the near virtual image 12 of the near virtual image 43 are not limited to quadrilaterals, but are angles that express perspective. The figure may be rounded. Moreover, the figure by which the corner was cut may be sufficient.

  Moreover, although this embodiment demonstrated that the information which assists driving | running | working was displayed on the far virtual image 11 and the near virtual image 12, various information can be displayed on the far virtual image 11 and the near virtual image 12. FIG. For example, the arrival of a call / mail may be displayed with characters or icons, or the contents of the mail may be displayed. Further, when a notice (news or the like) is received from a server or the like, the content may be displayed.

  In FIG. 9, the near virtual image and the far virtual image are superimposed while increasing the optical path length by the second mirror 24 to the fourth mirror 26. However, if the number of mirrors is further increased, the optical path length is increased, and the near virtual image and the far virtual image are obtained. Can be superimposed.

  Moreover, although the head-up display device 100 has been described as being mounted on the vehicle 6 in the present embodiment, it may be mounted on a moving body other than the vehicle 6. For example, it can be mounted on an airplane, a train, a ship, a motorcycle, or a wheelchair.

11: Distant virtual image 12: Near virtual image 20: Display unit 21: Video projection device 22: Diffuser 23: First mirror 24: Second mirror 25: Third mirror 26: Fourth mirror 27: Concave mirror 31, 32: Non Drawing area 47: Fixed arm 100: Head-up display device

Claims (10)

A head-up display device that displays a virtual image of a video projected by a video projection device,
A first mirror that reflects a first image projected by the image projection device;
One or more second mirrors that superimpose the first image reflected by the first mirror on a second image projected by the image projection device;
Fixing means for fixing the second mirror using a space formed when a predetermined region of the second image is projected in a predetermined direction;
A head-up display device comprising:   The head-up display device according to claim 1, wherein the predetermined area of the second video is an area not including information of the second video.   The head-up display device according to claim 1, wherein the predetermined region of the second image is a region where light is not projected because the region is a region where black pixels are formed. The second video has a figure in which perspective is expressed on the right side, the upper side, the left side, or the lower side of the superimposed first video,
The predetermined region is a region of remaining four corners obtained by subtracting the graphic in which perspective is expressed from the second image. Head up display device.   The fixing means is disposed in the space formed by each of the four corners, and at least one of the fixing means fixes an apex of the second mirror to a wall surface of the head-up display device. Item 5. The head-up display device according to Item 4.   The second mirror is arranged so as to overlap the second video, and the second video is superimposed on the first video reflected by the first mirror. The head-up display device according to claim 1, wherein the head-up display device reflects light in a projected direction. The second mirror includes a first reflecting portion that reflects the first image reflected by the first mirror;
A second reflecting portion for reflecting the first image reflected by the first reflecting portion;
The first image is arranged so as to overlap with the second image, and the first image reflected by the second reflection unit is superimposed on the second image and reflected in the direction in which the second image is projected. Three reflective parts;
The head-up display device according to claim 1, comprising:   The head-up display device according to claim 1, wherein a non-drawing area in which no information is included in the first video is formed around the first video. .   The head-up display device according to claim 4, wherein the video projection device displays driving support information inside the graphic. The head-up display device according to any one of claims 1 to 9,
A navigation device for guiding a vehicle on which the head-up display device is mounted to a destination.