JP2019132990A - Head-up display device - Google Patents

Abstract

To provide a head-up display device that can easily prevent occurrence of disturbing light or virtual image distortion with no use of a masking material.SOLUTION: In a head-up display device 1 loaded in a vehicle, and displaying a virtual image forward a windshield, the head-up display device comprises: a picture image display device 2 that creates picture image light corresponding to the virtual image, and emit the picture image light; and reflection mirrors 4 and 5 that reflect the picture image light emitted from the picture image display device and project the reflected picture image light to the windshield. A reflection surface of the reflection mirror has a structure with a reflection film formed on a surface of a substrate, in which the structure is configured in such a manner that the reflection film is not formed in an invalid area 52 where the picture image light is not incident. Thus, disturbing light or virtual image distortion caused by reflection light from an area around an edge of the reflection mirror or a protrusion and a concavity part thereof can be easily prevented with no use of a masking material.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a head-up display device that is mounted on a vehicle or the like and displays various video information.

    In recent years, a head-up display device (hereinafter abbreviated as a HUD device) that displays various types of information on a windshield of a vehicle has been put into practical use as one of the technologies for displaying an image superimposed on a real space. For example, by providing information for a driver as video information to be displayed, driving operation of the vehicle can be supported.

  The basic configuration of the HUD device is that an image optically generated by an image display device is projected onto the windshield, the reflected image light enters the driver's eyes, and the driver visually recognizes the virtual image in front of the windshield. It is a configuration. The optical component for image projection includes a reflection mirror, but a surface reflection mirror in which a metal film is formed on the surface of a substrate material such as glass is used to increase the light reflectance.

  For example, Patent Document 1 describes a configuration in which a base layer (TiOx), an intermediate layer (AlOy), a reflective layer (Al), and a transparent protective layer are stacked as a light reflecting layer formed on the surface of glass. .

JP-A-6-51110

  In the HUD device, the image generated by the image display device is reflected by the reflection mirror and displayed as a virtual image. However, the light reflected near the edge of the reflection mirror becomes stray light and is surrounded by the virtual image. There is a problem of appearing as disturbing light. In particular, when the reflecting mirror is a plastic concave mirror, if there are protrusions (burrs) on the parting line of the molded product, a metal film is formed on the burrs, and the light reflected by these burrs becomes stray light, which interferes with the virtual image. It becomes. Alternatively, when sink marks (dents) occur in the peripheral portion of the reflection mirror in the plastic molding and cooling process, and a metal film is formed thereon, distortion and double images are generated in the virtual image reflected by the sink portions.

  To suppress the above-mentioned interference light and virtual image distortion, for example, cover the reflection mirror near the edge, parting line, and sink marks with a masking material to eliminate the generation of reflected light near the edge, parting line, and sink marks. It is possible. However, in that case, it is necessary to newly attach a masking material to the reflecting mirror, which increases the number of parts and the assembly process. Further, when the reflecting mirror is a concave mirror, the masking material must be processed along the concave shape, which increases the number of processing steps. In addition, although the round process which rounds the edge vicinity of a reflective mirror is also considered, the effect of stray light prevention was small by examination of this inventor.

  An object of the present invention is to provide a head-up display device that can easily prevent generation of interference light and virtual image distortion without using a masking material.

  The present invention relates to a head-up display device that is mounted on a vehicle and displays a virtual image in front of a windshield, a video display device that generates and emits video light corresponding to the virtual image, and the video display device that is emitted from the video display device. A reflecting mirror that reflects the image light and projects it onto the windshield, and the reflecting surface of the reflecting mirror has a structure in which a reflecting film is formed on the surface of the substrate, and the ineffective area where the image light does not enter In the structure, the reflective film is not formed.

  According to the present invention, it is possible to provide a head-up display device that can easily prevent generation of interference light and virtual image distortion without using a masking material.

The figure which shows the whole structure of a HUD apparatus (Example 1). The figure which shows typically the virtual image and stray light which are displayed on a windshield. The figure which shows the shape of a concave reflective mirror (countermeasures against stray light caused by edges). The figure which shows the shape of a concave reflective mirror (measures against the stray light caused by burrs). The figure which shows the modification of the concave surface reflective mirror of FIG. The figure which shows the structural example of a reflecting film. (Example 2) explaining the sink mark which generate | occur | produces in the peripheral part of a concave reflective mirror. The figure which shows the state at the time of film-forming of a reflecting film. FIG. 10 is a diagram illustrating a display example of a virtual image pattern as an effect of the second embodiment.

  Hereinafter, embodiments of a head-up display device (HUD device) according to the present invention will be described with reference to the drawings.

In the first embodiment, a countermeasure against stray light caused by an edge or burr of the concave reflecting mirror 5 in the HUD device will be described.
FIG. 1 is a diagram showing the overall configuration of the HUD device. The HUD device 1 is housed in a case 10 and is mounted inside a dashboard of a vehicle. The video display device 2 in the HUD device 1 includes a light source such as an LED and a video display element such as a liquid crystal panel, and generates a video to be displayed.

  Video light 8a (shown by a solid line) emitted from the video display device 2 is magnified by the lens 3, reflected by the two reflecting mirrors 4 and 5, and projected toward the windshield 6 (also referred to as a windshield) of the vehicle. Is done. The reflection direction of the first reflection mirror 4 is a flat reflection mirror, and the reflection direction of the second mirror 5 is variable by a mirror drive unit 5a. The two reflecting mirrors 4 and 5 have a structure in which a reflecting film (including an aluminum metal film) is formed on the surface of the substrate, but the planar reflecting mirror 4 has a reflecting film formed on a flat glass substrate. On the other hand, in the concave reflecting mirror 5, a reflecting film is formed on the surface of a plastic molded body that is injection-molded in a concave shape (including a free-form surface shape and an optical axis asymmetric shape). In this embodiment, the concave reflecting mirror 5 is described as a plastic molded body, but may be a glass molded body.

  The image light 8a emitted from the concave reflecting mirror 5 is reflected by the windshield 6, enters the driver's viewpoint 7, and forms an image on the retina, whereby the image can be visually recognized. At this time, the driver sees the virtual image 8 existing in front of the windshield 6.

  Here, the image display device 2 also emits ambient light 9a (indicated by a broken line) around the image light 8a. This ambient light 9a is reflected near the edges of the plane reflecting mirror 4 and the concave reflecting mirror 5, and is similarly projected onto the windshield 6. Although this ambient light 9a is white light without a video signal, it is not uniform white light because it is scattered near the edges of the reflecting mirrors 4 and 5, and becomes a streak-like bright line (or dark line) that is visible to the driver. Will be. Hereinafter, this bright line is referred to as “stray light”. When the stray light is generated, not only the quality of the display image of the HUD device 1 is deteriorated but also the interference light with respect to the virtual image 8 visually recognized by the driver. The ambient light 9a is self-luminous emitted from the video display device 2, but stray light is also generated when light (external light) incident from the outside of the HUD device 1 is reflected near the edge. .

  FIG. 2 is a diagram schematically showing a virtual image and stray light displayed on the windshield. On the windshield 6 viewed from the driver, for example, information on the road conditions ahead and the traveling speed is displayed as a virtual image 8. Around the virtual image 8, the stray light 9 by the ambient light 9a shown in FIG. That is, the light reflected in the vicinity of the edges of the reflection mirrors 4 and 5 in the ambient light 9 a appears as stray light 9 around the virtual image 8. In particular, for the concave reflecting mirror 5, since the plastic molded body has protrusions (burrs) along the mold dividing position (parting line), the light reflected in the vicinity of the burr appears as stray light 9 as well. To do.

  Here, the pattern of the stray light 9 is shown in a simplified manner, but various patterns are obtained depending on the edge shape of the reflection mirrors 4 and 5 and the shape of burrs. That is, depending on the sharpness of the edge and the size of the burr, the thickness and brightness of the stripe-like bright line and the number of bright lines are variously generated. Regarding the sharpness of the edge, in the study by the inventors of the present application, stray light is still generated even when a round process is performed to round the vicinity of the edge.

  In order to suppress the stray light described above, it is conceivable to cover the vicinity of the edge of the reflecting mirror and the vicinity of the parting line with a masking material to eliminate the generation of the reflected light near the edge and the parting line. Possible masking materials include attaching a jig to the edge, sticking black flocked paper, or applying a low-reflection coating. However, there is a problem that it is necessary to newly attach a masking material, and in the case of a concave reflecting mirror, the masking material must be processed into a concave surface. Therefore, in this embodiment, the following measures are taken in order to easily suppress stray light. Hereinafter, when the reflection mirror is a concave reflection mirror, a countermeasure against stray light caused by an edge and a countermeasure against stray light caused by a burr will be described in detail.

  FIG. 3 is a diagram showing the shape of the concave reflecting mirror 5 in which countermeasures against stray light caused by edges are taken. (A) is the front view seen from the reflective surface side, (b) is a side view, (c) is a top view. The reflecting surface of the concave reflecting mirror 5 has a concave shape in the horizontal direction (H direction) and the vertical direction (V direction). A region surrounded by a dotted line on the reflection surface is an effective area 51 where the image light 8a is incident on the concave reflection mirror 5, and a reflection film is formed on the surface. The outside of the effective area 51 is an area where the image light 8a does not enter, and is referred to as an invalid area 52. The edges 50 of the concave reflecting mirror 5 are all included in the invalid area 52, but the stray light 9 is generated when the ambient light 9a other than the image light 8a is incident and reflected near the edge 50.

  Therefore, in this embodiment, in order to eliminate reflection in the vicinity of the edge 50 of the concave reflecting mirror 5, a structure in which no reflecting film is formed in the ineffective area 52 is adopted. Therefore, a jig that covers the ineffective area 52, for example, a masking jig for sputtering film formation, is used in the reflective film forming step. Thereby, since no reflection film is formed in the vicinity of the edge 50 of the concave reflecting mirror 5, even if the ambient light 9a is incident, the reflected light is not generated, and the generation of stray light can be suppressed.

  In this way, if the reflective film is not formed in the ineffective area 52 near the edge 50 of the concave reflecting mirror 5, it is not necessary to newly attach a masking material or the like in mounting the concave reflecting mirror 5 on the HUD device 1. Can easily prevent the occurrence of stray light.

  FIG. 4 is a diagram showing the shape of the concave reflecting mirror 5 in which a countermeasure against stray light due to burrs is taken. (A) is the perspective view seen from the reflective surface side, (b) is a partial enlarged view, (c) is a figure which shows the state at the time of film-forming of a reflecting film. The concave substrate of the concave reflecting mirror 5 is a plastic molded body by injection molding, but there are protrusions (burrs 53a) on the surface along the mold dividing position (parting line 53) when the molded body after injection molding is taken out. . In this example, as shown in (b), a parting line 53 (burr 53a) exists on the side surface of the concave reflecting mirror 5 substantially in parallel with the line of the edge 50. A reflection film is formed on the burr 53a, and when the ambient light 9a is incident on the burr 53a, the reflected light similarly becomes stray light. As a countermeasure, it may be possible to mechanically remove the burr 53a generated in the parting line 53, but a new fine processing is required.

  In this embodiment, therefore, the reflective film is formed using the masking jig 11 that covers the parting line 53 (burr 53a) when the reflective film of FIG. This eliminates the formation of a reflective film in the vicinity of the parting line 53, eliminates the reflected light from the burr 53a, and suppresses the generation of stray light. The shape of the masking jig 11 is preferably such that it covers both the edge 50 and the burr 53a at the same time, and a countermeasure against stray light caused by the edge and the burr can be realized at the same time.

  FIG. 5 is a diagram showing a modification of the shape of the concave reflecting mirror 5 of FIG. 4 as a countermeasure against stray light caused by burrs. At the time of film formation in FIG. 4C, there is a possibility that the particles of the target material go into the gap between the concave reflecting mirror 5 and the masking jig 11 and be formed on the parting line 53 (burr 53 a). As a countermeasure, a stepped portion (notch) 55 is formed from the edge 50 of the concave reflecting mirror 5 to the parting line 53 as shown in FIG. The shape of the stepped portion 55 is a shape that is cut into an L shape by about several millimeters according to the position of the parting line 53, the size of the burr 53a, and the design of the mold. The bottom surface and the wall surface of the step portion 55 may be inclined surfaces.

  FIG. 5C shows an example of the masking jig 11 used at the time of film formation, and the step portion 12 (projection portion) is provided in accordance with the shape of the step portion 55 (notch) provided on the concave reflecting mirror 5. Thereby, it is possible to prevent the target material particles from wrapping around and to reliably prevent the reflective film from being formed on the parting line 53 (burr 53a).

FIG. 6 is a diagram illustrating a configuration example of the reflective film in the present embodiment. On the plastic substrate, the base layer (Nb or Si), the first layer (Al, main reflection layer), the second layer (SiO ₂ ), and the third layer (NbOx) are laminated in this order to increase the reflection of Al. It is a film. A sputtering apparatus was used as the film forming apparatus, and a metal material was used as the masking jig 11. The material shown here is an example and can be appropriately changed according to the application.

Further, the second layer (SiO ₂ ) and the third layer (NbOx) are transparent protective films, which may cause stray light even if they are formed on the edge 50 of the concave reflecting mirror 5 or the parting line 53 (burr 53a). Must not. Therefore, the second layer and the third layer may be formed without the masking jig 11.

  In the first embodiment, since the reflecting film is not formed on the ineffective area 52 (edge 50 or burr 53a) of the concave reflecting mirror 5, a masking material or the like is newly added in mounting the concave reflecting mirror 5 on the HUD device 1. Therefore, it is possible to easily prevent generation of interference light.

  The embodiment described above is the case of the concave reflecting mirror 5 in which the reflecting film is formed on the plastic molded body, but can also be applied to the case of the flat reflecting mirror 4 in which the reflecting film is formed on the glass substrate. In that case, it is needless to say that the countermeasure against stray light caused by the edge is similarly effective.

  In the first embodiment, countermeasures against stray light caused by edges and burrs of the concave reflecting mirror 5 have been described. In the second embodiment, countermeasures against virtual image distortion caused by “sink marks” generated in the peripheral portion of the concave reflecting mirror 5 will be described. . The “sink” is a dent (dent) on the surface that is generated when the plastic molding is cooled and contracted.

  FIG. 7 is a diagram for explaining sink marks generated in the peripheral portion of the concave reflecting mirror 5. Here, the shape of the plastic molded body before forming the reflective film is shown, (a) is a perspective view seen from the reflective surface side, (b) is a partially enlarged view, and (c) is an end sectional view. (B) As shown in (c), in the peripheral part of the concave reflecting mirror 5, the height of the reflecting surface is indented from the design value over the range of a predetermined width from the edge 50 to the inside. Hereinafter, this portion is referred to as “sink portion 61”. This is because a temperature difference occurs between the central part and the peripheral part of the mirror during the process of cooling the plastic molded body. In this example, sink marks 61 are generated in the periphery of each side of the reflecting surface. In particular, as shown in (c), the rear surface side of the mirror has a rib structure 62 in order to maintain a concave shape, and the amount of sink marks (the width and depth of the sink part 61 is generated because cooling is slow in the vicinity thereof. ) Will grow.

  When a reflection film is formed on the reflection surface side of the plastic molded body in which such a sink part 61 exists, distortion and a double image are generated in the projected virtual image 8 by the light reflected by the reflection film of the sink part 61. . Therefore, in this embodiment, a structure in which the reflective film is not formed on the sink part 61 prevents the distortion of the virtual image and the generation of the double image.

  FIG. 8 is a diagram illustrating a state when the reflective film is formed. The reflective film is formed using the masking jig 21 that covers the sink portion 61 as in FIG. This eliminates the formation of a reflective film on the sink part 61 and suppresses the occurrence of virtual image distortion and double image due to the reflected light from the sink part 61.

  FIG. 9 is a diagram illustrating a display example of a virtual image pattern as an effect of the present embodiment. For comparison, (a) shows the case of using a conventional mirror having a sink part, and (b) shows the case of using the mirror of this embodiment. Here, a grid pattern is used as a virtual image test pattern.

  In the case of the conventional product mirror shown in (a), distortion and a double image (reference numeral 71) are generated in the display pattern in the lower side area 70 of the screen. This is because the sink portion 61 exists in the corresponding lower side region of the concave reflecting mirror 5 and the reflected light at that portion is disturbed.

  On the other hand, in the mirror of this embodiment shown in FIG. 8B, the reflection film is not formed on the sink portion 61 by the masking film formation as shown in FIG. 8, and as a result, distortion is generated in the lower side region 70 of the screen. The displayed display pattern 71 disappears, and virtual image distortion and double image generation can be prevented. In this example, a 1-mesh width pattern is not displayed in the lower side area.

  In other words, if the definitions of the effective area 51 and the invalid area 52 in FIG. 3 are used, the lower side area 70 where the sink part exists in the concave reflecting mirror 5 is set as the invalid area 52, while the effective area 51 is the sink part. Is set not to exist. The ineffective area 52 is not formed with a reflective film, and the incident range of the image light 8 a is adjusted to be excluded from the ineffective area 52. The reason why the reflective film is not formed in the invalid area 52 is that it is not preferable to leave the reflective film since the ambient light 9a other than the image light 8a may enter the invalid area 52.

  Thus, also in Example 2, since it was set as the structure which does not form a reflecting film in the invalid area 52 (sink part 61) of the concave reflective mirror 5, in mounting to the HUD apparatus 1 of the concave reflective mirror 5, masking material etc. are used. It is not necessary to attach a new one, and it is possible to easily prevent generation of virtual image distortion and double image.

  Needless to say, by appropriately combining the configurations of the first and second embodiments, it is possible to suppress the occurrence of interference light and virtual image distortion caused by edges, parting lines (burrs), and sink marks of the concave reflecting mirror. .

1: Head-up display (HUD) device,
2: Video display device,
3: Lens,
4: Plane reflection mirror,
5: concave reflecting mirror,
6: Windshield,
8: Virtual image,
8a: image light,
9: stray light,
9a: ambient light,
11, 21: Masking jig,
12: Stepped part,
50: Edge,
51: Effective area
52: Invalid area,
53: Parting line
53a: Bali,
55: Stepped portion,
61: sink part,
70: Screen bottom area,
71: Virtual image distortion and double image.

Claims (7)

In a head-up display device that is mounted on a vehicle and displays a virtual image in front of the windshield,
A video display device for generating and emitting video light corresponding to the virtual image;
A reflection mirror that reflects the image light emitted from the image display device and projects the image light onto the windshield, and
The reflection surface of the reflection mirror has a structure in which a reflection film is formed on a surface of a substrate, and the reflection film is not formed in an ineffective area where the image light is not incident. Display device. The head-up display device according to claim 1,
The head-up display device, wherein the invalid area includes an edge of a reflecting surface of the reflecting mirror. The head-up display device according to claim 2,
The reflecting mirror is a concave reflecting mirror in which the reflecting film is formed on a concave substrate which is a plastic molded body, and the reflecting film is not formed in the vicinity of a parting line of the plastic molded body. A head-up display device characterized by that. The head-up display device according to claim 3,
When the concave reflecting mirror has the parting line on the side surface of the reflecting surface,
A head-up display device, wherein a step portion is formed from an edge of the reflecting surface to the parting line. The head-up display device according to claim 1,
The reflecting mirror is a concave reflecting mirror in which the reflecting film is formed on a concave substrate which is a plastic molded body, and the reflecting film is not formed in the vicinity of the sink part of the plastic molded body. A head-up display device. The head-up display device according to claim 3,
A head-up display device having a structure in which the reflective film is not formed in the vicinity of a sink part of the plastic molded body. In a head-up display device that is mounted on a vehicle and displays a virtual image in front of the windshield,
A video display device for generating and emitting video light corresponding to the virtual image;
A reflection mirror that reflects the image light emitted from the image display device and projects the image light onto the windshield, and
The reflection mirror is a concave reflection mirror in which a reflection film is formed on the surface of a concave substrate that is a plastic molded body,
While setting the vicinity of the sink part of the plastic molding is an invalid area where the image light does not enter,
A head-up display device having a structure in which the reflective film is not formed in the invalid area.

Images