JPH10333081A - Head-up display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a head-up display device small and thin. SOLUTION: A hologram member 17 in which a hologram image as fixed information is recorded is arranged with close adhesion on the side of a projection light exit of a variable information projecting means composed of a liquid crystal panel 15 and a backlight 16. The display by the liquid crystal panel 15 is controlled by a controller 19, arbitrary information (image) is transmitted through the hologram member 17, reflected by a combiner 12 and projected on a visual point position 13. The hologram image recorded in the hologram member 17 is reproduced by the irradiation with a reproducing light beam of a reproducing light source 18 and introduced to the visual point position 13 through the combiner 12. A driver is enabled to visualize the fixed information and the variable information at the same time while visualizing a front scene, etc., through the combiner 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-up display device which enables a driver or the like to simultaneously visually recognize various information related to a vehicle or the like without leaving his / her gaze from the front.

[0002]

2. Description of the Related Art A head-up display device is a display device that enables a driver of a vehicle or the like to visually recognize instruments and other information while looking ahead through a windshield of a driver's cab.

A conventional head-up display device applied to a vehicle or the like is disclosed, for example, in Japanese Patent Application Laid-Open No. Hei 3-2277.
The one disclosed in Japanese Patent Publication No. 36 is known. This will be briefly described with reference to FIG.

This head-up display device includes a variable information projection unit and a fixed information projection unit. The variable information projection means has a first display 31 for displaying variable information such as a vehicle speed, and a first light source 32 for projecting the display by the first display 31. The fixed information projecting means has a second display 33 made of a pattern mask or the like on which fixed information such as a warning symbol is recorded, and a second light source 34 for projecting the display by the second display 33. .

[0005] Reference numeral 35 denotes a non-specular reflection type hologram mirror having a non-specular reflection property in which an incident angle of light and an emission angle of reflected light are different, and 36 denotes a Fresnel lens. 37 is a windshield. In the figure, the driver's viewpoint is located on the right side of the windshield 37.

[0006] The first display 31 by the illumination of the first light source 32
Is non-specularly reflected by the hologram mirror 35 and travels along the optical axis of the Fresnel lens 36,
The windshield 37 is reached. On the other hand, the fixed information projection light based on the second display 33 by the illumination of the second light source 34 is non-specularly reflected by the hologram mirror 35, travels along the optical axis of the Fresnel lens 36, and reaches the windshield 37.

As described above, the variable information projection light from the variable information projection means and the fixed information projection light from the fixed information projection means are superimposed on each other by the non-specular reflection type hologram mirror 35, so that the driver can visually recognize the front through the windshield 37. Meanwhile, the display by the variable information projection unit and the display by the fixed information projection unit can be visually recognized in a superimposed manner within the field of view of the windshield 37.

[0008]

However, according to the prior art described above, the display by the variable information projection means and the display by the fixed information projection means are projected on a windshield as a combiner via a hologram mirror. Requires a predetermined optical path length between the constituent means or members.

Also, the hologram mirror utilizes the property of non-specular reflection, which is the property that the angle of incidence of light on the hologram mirror and the angle of emission of light from the hologram mirror are different, so that two lights are superimposed. For this purpose, the incident angles of the two lights with respect to the hologram mirror must be made different from each other, so that it is necessary to dispose the variable information projecting means and the fixed information projecting means at a certain distance.

For this reason, there is a problem that the device becomes large in size and it is difficult to mount and use the device in a limited space, for example, on a dash panel of a vehicle.

The present invention has been made in view of such problems of the prior art, and has as its object to reduce the size of a head-up display device.

[0012]

According to a first aspect of the present invention, there is provided a head-up display device comprising: a hologram member on which a hologram image as fixed information is recorded; and a surface of the hologram member. A reproducing light source that irradiates the reproducing light toward the hologram member; a variable information projecting unit that emits arbitrary variable information projecting light; a hologram image projection light reproduced by irradiating the hologram member with the reproducing light; and the variable information. A combiner having a semi-transmissive light that reflects the variable information projection light by the projection means and guides the variable information projection light to a viewpoint position, wherein the variable information projection light emitted by the variable information projection means passes through the hologram member and the hologram image The back surface of the hologram member is set so that the hologram member emits the variable information projection light of the variable information projection means so that the hologram member travels in a superimposed manner with the projection light. Characterized by being arranged so as to be in close contact with the surface.

The variable information projection light from the variable information projection means passes through the hologram member and reaches the combiner. On the other hand, a hologram image as fixed information recorded on the hologram member is reproduced by irradiation with reproduction light. The hologram image projection light travels in a superimposed manner with the variable information projection light to reach the combiner. Thus, the driver or the like can visually recognize the display by the variable information projection unit and the display by the reproduction of the hologram image in a superimposed manner within the field of view of the combiner while visually recognizing the scenery or the like ahead through the combiner.

Since the hologram member on which the hologram image is recorded is disposed in close contact with the variable information projection means,
A configuration in which the optical path length required between each component or member can be shortened as compared with the related art, and the variable information projection unit and the fixed information projection unit have to be arranged apart from each other as in the related art. In comparison, the size of the device can be reduced.

According to a second aspect of the present invention, in the head-up display device according to the first aspect, an incident direction of the reproduction light to the hologram member and a normal line of the hologram member are formed. The angle is set to be greater than the angle between the direction of incidence of the widest component of the variable information projection light of the variable information projection means on the hologram member and the normal line of the hologram member.

In the head-up display device according to the first aspect, the variable information projection light from the variable information projection means passes through the hologram member and reaches the combiner.
There is a possibility that the variable information projection light interferes with the hologram image recorded on the hologram member, thereby causing a new problem of adversely affecting the display. By setting the relationship with the spread angle of the variable information projection light by the means as described in claim 2, such a new problem can be prevented and good display can be realized.

According to a third aspect of the present invention, in the head-up display device according to the first aspect, a limiting member for limiting the spread angle of the variable information projection light of the variable information projecting means is provided with the hologram member. The variable information projection means is interposed between the variable information projection means.

The third aspect of the present invention is also to alleviate the new problem that the variable information projection light interferes with the hologram member and adversely affects the display. By restricting the divergence angle of the image by the restricting member, such a new problem is alleviated, and a better display can be realized.

According to a fourth aspect of the present invention, in the head-up display device according to the first aspect, the hologram image of the hologram member has a wavelength different from a wavelength range of the variable information projection light of the variable information projection means. It is characterized by recording with light in the region.

The fourth aspect of the present invention is also to alleviate the new problem that the variable information projection light interferes with the hologram member and adversely affects the display, and is used for recording a hologram image. By making the wavelength of the light different from the wavelength of the projection light of the variable information projection means, such a new problem is alleviated, and better display can be realized.

According to the head-up display device of the present invention, each constituent means or member can be intensively arranged in a small space, and the device can be made smaller than in the prior art. Since it is possible, there is an effect that a head-up display device suitable for being mounted and used in a limited space on a dash panel of a vehicle is provided.

According to the head-up display device of the present invention, in addition to the effect of the first aspect, the projection light of the variable information projecting means is applied to the hologram image of the hologram member. Interference is prevented or mitigated, display degradation can be prevented, and a head-up display device having excellent display performance is provided.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of one embodiment of the head-up display device of the present invention.

In FIG. 1, reference numeral 11 denotes a housing of the head-up display device, and a combiner 12 made of a semi-transmissive reflective member is attached to the upper surface of the housing 11 at an angle.

The inclination angle of the combiner 12 can be arbitrarily adjusted or changed. The combiner 12 can adopt a planar shape, and can also employ a hologram. Also, as the combiner 12,
It is also possible to change the image forming distance by adopting a curved surface. 13 is a driver's viewpoint position. A window 14 penetrating inward and outward is formed on the upper surface of the housing 11 on the viewpoint position 13 side with respect to the combiner 12.

Inside the housing 11, variable information display means having a liquid crystal panel 15 for displaying variable information and a backlight 16 for illumination arranged in close contact with the back side of the liquid crystal panel 15 are provided. It is mounted so that it faces the combiner 12 through the window 14 of the body 11.

As the variable information display means, instead of the liquid crystal panel 15 and the backlight 16, a plasma display, a self-luminous fluorescent display tube, or any other device capable of displaying arbitrary information is used. Can be.

A plate-like hologram member 17 in which a hologram image as fixed information is recorded in close contact with the surface of the liquid crystal panel 15 (the side opposite to the backlight 16) of the variable information display means. ing.

The hologram member 17 is provided inside the housing 11.
To irradiate the reproduction light at a predetermined angle from the oblique direction,
A reproduction light source 18 is attached, and a hologram image recorded on the hologram member 17 is reproduced by reproduction light from the reproduction light source 18. The light source for reproduction 18 is configured to be able to irradiate light close to a point light source by condensing and emitting light from a halogen bulb or an LED using a reflector or the like.

Display by the liquid crystal panel 15 of the variable information display means, lighting of the backlight 16 and lighting of the reproduction light source 18 are controlled by the controller 19.

The hologram image recorded on the hologram member 17 is, for example, information (image) for notifying the driver of the position of the end of the vehicle, and is recorded in advance according to the principle of holography.

This will be described briefly with reference to FIG. The laser beam 20 is split into two beams by the half mirror 21, and one of the laser beams reflected by the half mirror 21 is guided to the hologram member (photographic plate or film) 17 as the reference beam 24 via the mirror 22 and the lens 23.

The other laser beam transmitted through the half mirror 21 irradiates an object 27 to be recorded via a mirror 25 and a lens 26, and a reflected light (object light) 28 reflected and scattered on the surface of the object 27 is used as a hologram member. Lead to 17. On the hologram member 17, fine interference fringes having an interval of about several micrometers are formed and recorded by interference between the reference beam 24 and the object beam 28. By developing this, a hologram member 17 on which a predetermined hologram image is recorded is obtained.

In reproducing the hologram image, when the hologram member 17 is illuminated with the reproduction light having the same wavefront as the original reference light 24, the interference fringes function as a diffraction grating and are formed by diffraction on the hologram member 17. The wavefront of the new light becomes the same as the wavefront of the original object light 28, and the observer can see a three-dimensional reconstructed image of the object in a form floating in space.

The position of the object (image) recorded on the hologram member 17 is set so that the image can be seen at a predetermined position when the driver 13 visually recognizes the hologram image via the combiner 12. Have been.

The angle of incidence of the reproduction light from the reproduction light source 18 on the hologram member 17 (the angle between the incident direction of the reproduction light and the normal to the hologram member 17) and the hologram of the reproduced object light (hologram image projection light) The exit angle from the member 17 (the exit direction of the hologram image projection light and the hologram member 17
Is set as shown in FIG. 3.

That is, the reproduction light from the reproduction light source 18 is incident on the hologram member 17 at an incident angle φin, and the reproduced object light is emitted toward the combiner 12 at an emission angle φout. Angle φin and emission angle φ
out is set to a different angle. The reason why the incident angle φin and the emission angle φout are set to different angles is to prevent light from the reproduction light source 18 from directly entering the driver's field of view.

The reproduced hologram image projection light is reflected by the combiner 12 and guided to the driver's viewpoint 13. In this way, the driver can visually recognize an image indicating the end of the vehicle as fixed information forward through the combiner 12.

On the other hand, the display of variable information by the variable information display means is performed as follows. This will be described with reference to FIG. First, based on a control signal corresponding to information (image) to be displayed from the controller 19, the liquid crystal panel 1
5 is displayed. Note that this display is a reverse display (display in which light passes through the information portion and light does not pass through the background portion) so that the driver can see it correctly.

The illumination light from the backlight 16 is incident on the liquid crystal panel 15 from the back side, and the light transmitted through the liquid crystal panel 15 further transmits through the hologram member 17, and this transmitted light is directed to the combiner 12 as variable information projection light. Irradiated.

Since the controller 19 controls the display on the liquid crystal panel 15 based on the state of the vehicle, navigation information, and other arbitrary information, various displays are possible.

The variable information projection light is reflected by the combiner 12 and guided to the driver's viewpoint 13. In this way, the driver can move forward through the combiner 12,
Various information (images) as variable information can be visually recognized.

With such a configuration, the variable information projection light from the variable information projection means passes through the hologram member 17 on which the hologram image is recorded, so that interference between the variable information projection light and the hologram image occurs. However, there is a new problem that the image may be deteriorated.

In this embodiment, the following measures are taken. That is, as shown in FIG. 5, the emitted light (variable information projection light) from the liquid crystal panel 15 is emitted with a spread, so that the traveling direction of the component with the widest spread angle of the emitted light and the hologram member 17 Assuming that the angle between the normal and the normal is β, the angle between the reproduction light source 18 and the hologram member 17 is larger than the angle βin between the traveling direction of the reproduction light from the reproduction light source 18 and the normal to the hologram member 17. The positional relationship of the member 17 is set.

By adopting such an angle condition, the light emitted from the liquid crystal panel 15 is prevented from being incident at an angle which is the same as or close to the incident angle of the reproduced light for reproducing the hologram image. The interference at 17 is reduced, and the deterioration of the displayed image can be reduced.

For example, when the spread angle of the light emitted from the liquid crystal panel 15 is 20 degrees (β = 10 degrees), the incident angle φin of the reproduction light from the reproduction light source 18 to the hologram member 17 is set to 50 degrees. It is good to set to.

As a countermeasure other than changing the incident angle φin of the reproduction light from the reproduction light source 18 to the hologram member 17, the liquid crystal panel 15 having a narrow spread angle of the output light is used. Of the hologram member 17 can be reduced.

Alternatively, as shown in FIG. 6, a fine louver 29 serving as a restricting member for restricting the spread angle of the light emitted from the liquid crystal panel 15 to be smaller than the original spread angle is provided with the liquid crystal panel 15. By interposing between the hologram members 17, the interference of the light emitted from the liquid crystal panel 15 at the hologram member 17 can be reduced. Note that, as the restricting member, instead of the louver 29, a light-shielding plate, a polarizing plate, a microlens, or any other member that can restrict the output angle can be used.

Further, instead of, or in addition to, the method or means for reducing the interference of the light emitted from the liquid crystal panel 15 at the hologram member 17, the projection light of the backlight 16 of the variable information projection means is used. By making the wavelength range different from the wavelength range of the reproduction light by the reproduction light source 18 (that is, the wavelength range of the reference light at the time of recording), interference of the light emitted from the liquid crystal panel 15 on the hologram member 17 is reduced. Can be.

According to the above-described embodiment of the present invention, the hologram member 17 on which a hologram image as fixed information is recorded is disposed in close contact with the surface of the liquid crystal panel 15 of the variable information display means. The variable information projection light is transmitted through the hologram member 17 and guided to the combiner 12, while the hologram image recorded on the hologram member 17 is reproduced by the reproduction light source 18 by the hologram member 17.
The hologram image projection light is reproduced by irradiating it from the surface side (the opposite side to the liquid crystal panel 15) of the liquid crystal panel 15 and the reproduced hologram image projection light is guided to the combiner 12.

Therefore, the head-up display device can be configured to be very small and thin, and for example, a head-up display device of a type used by mounting it on a dash panel of an automobile can be realized. Become.

Further, as described above, due to the new problem of image deterioration due to interference with the hologram member caused by transmission of the variable information projection light by the variable information projection means through the hologram member 17, sufficient consideration is given. Also, the displayed image is good.

Furthermore, since both the hologram image (fixed information) projection light and the variable information projection light are guided to the driver by the combiner 12, for example, the curvature is appropriately selected using a curved shape combiner. This makes it possible to easily change the presentation distance (display position) of the display image.

FIG. 7 is a diagram showing a schematic configuration of another embodiment of the head-up display device of the present invention. Components that are substantially the same as those of the embodiment shown in FIG. 1 are denoted by the same reference numerals, and only different portions will be described.

In the above embodiment, the hologram member 17
Light source 18 for reproduction so that the reproduction light to
Is housed inside the housing 11, but in this embodiment, the reproduction light source 18 is connected to the housing 1 via the light source support member 30.
1 outside.

The light source support member 30 is rotatably attached to the housing 11 so that the light source support member 30 can be positioned at an arbitrary angle, and the reproducing light source 18 is positioned from the upper end of the combiner 12 so as not to hinder the driver's view. Are also arranged on the upper side.

The variable information display means comprising the liquid crystal panel 15 and the backlight 16 and the hologram member 17 closely attached thereto are arranged so as to be directed upward from the above-described embodiment.

The reproduction light from the reproduction light source 18 is irradiated obliquely downward, and the hologram image projection light reflected by the hologram member 17 is reflected by the combiner 12 to reach the driver's viewpoint 13. The variable information projection light from the variable information display means is transmitted through the hologram member 17 and
2, the variable information projection light together with the hologram image projection light is reflected by the combiner 12 and guided to the driver's viewpoint position 13.

By adopting such a configuration, the reproducing light source 18 and the optical path of the reproducing light from the reproducing light source 18 to the hologram member 17 are formed inside the casing 11 as compared with the configuration of the above-described embodiment. The size of the device can be reduced by the amount not provided.

The embodiments described above are described for facilitating the understanding of the present invention, but are not described for limiting the present invention. Therefore,
Each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram for explaining the principle of holography.

FIG. 3 is a diagram showing incident and exit angle conditions of a reproduction light with respect to a hologram member according to an embodiment of the present invention.

FIG. 4 is a diagram showing a state in which projection light is emitted by a variable information projection unit according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a relationship between a condition of an incident angle of a reproduction light to a hologram member and a spread angle of light projected by a variable information projection unit according to an embodiment of the present invention.

FIG. 6 is a diagram showing a configuration for limiting a spread angle of projection light by a variable information projection unit according to an embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of another embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Housing 12 ... Combiner 13 ... Driver's viewpoint position 15 ... Liquid crystal panel 16 ... Backlight 17 ... Hologram member 18 ... Reproduction light source 19 ... Controller

Claims (4)

[Claims] 1. A hologram member on which a hologram image as fixed information is recorded, a reproduction light source for irradiating reproduction light toward a surface of the hologram member, and a variable information projection means for emitting arbitrary variable information projection light And a combiner having a light semi-transmissive property that reflects the hologram image projection light reproduced by irradiating the hologram member with the reproduction light and the variable information projection light by the variable information projection unit and guides the variable information projection light to a viewpoint position. The hologram member is mounted on the back surface of the hologram member so that the variable information projection light emitted by the variable information projection unit passes through the hologram member and travels in a superimposed manner with the hologram image projection light. A head-up display device arranged so as to be in close contact with the emission surface of the variable information projection light. 2. The hologram member, wherein the angle between the incident direction of the reproduction light to the hologram member and the normal line of the hologram member is the hologram member having the widest component of the spread angle of the variable information projection light of the variable information projection means. 2. The head-up display device according to claim 1, wherein an angle between an incident direction to the hologram member and a normal line of the hologram member is set to be larger. 3. The variable information projection means according to claim 1, wherein a limiting member for limiting the spread angle of the variable information projection light of said variable information projection means is interposed between said hologram member and said variable information projection means. Head-up display device. 4. The head-up display device according to claim 1, wherein the hologram image of the hologram member is recorded with light in a wavelength range different from the wavelength range of the variable information projection light of the variable information projection means.