JPH0521484Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a display device for a vehicle to allow a following vehicle to recognize the presence of the own vehicle, information to be transmitted, etc. while the vehicle is driving or parked.

[Conventional technology]

BACKGROUND ART Conventionally, brake lamps, high-mounted stop lamps, and reflectors installed near bumpers have been used as means for making those following the vehicle aware of the presence of the own vehicle while driving.

[Problem that the invention attempts to solve]

However, brake lights and reflectors have the disadvantage that they are difficult to notice because their display is low and out of the center of the rear driver's field of vision.High-mounted brake lights and reflectors, whose installation is legal in the United States, impede rear visibility. They had the disadvantage of being narrow, and they also made it impossible to recognize the proximity of following vehicles.

Also, there was no adequate means to indicate the presence of a vehicle to nearby vehicles while parked.

The present invention was developed in consideration of these points, and does not obstruct the rear view of the driver in front.
It can be displayed in the center of the rear driver's field of vision, and
It is an object of the present invention to provide a novel display device that allows nearby vehicles to recognize the presence of a vehicle even when the vehicle is parked.

[Means for solving problems]

The vehicle display device of the present invention is equipped with a reflective hologram on which display information such as characters and figures is recorded on the rear, front, and side windows of the vehicle. It is characterized by being regenerated by the light of a headlight.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

Fig. 1 is a schematic diagram for explaining the operation of the present invention, Fig. 2 is a diagram showing the optical system when producing a reflection hologram, and Fig. 3 is a diagram showing the reflection hologram produced by the optical system in Fig. 2. FIG. 3 is a front view of the main parts attached to the rear window glass of the vehicle.

FIGS. 1 and 3 show an example in which a reflection hologram 1 on which display information is recorded by a method described later is provided on a rear window glass 2 of an automobile to display a warning to a following vehicle 3.

(Production of hologram) Photosensitive material 5 such as dichromate gelatin dye-sensitized with methylene green on polyester film 4
For example, the hologram original plate 6 is coated with 15μ of
is held in a shape that matches the rear window glass 2 for an automobile, and is filtered and exposed using an optical system as shown in FIG.

A red laser beam with a wavelength of 647 nm is oscillated from a krypton laser oscillator 7, and is split into two by a beam splitter 8. One side is transmitted as a plane wave through a reflecting mirror 9, a reflecting mirror 10, a convex lens 11, and a convex lens 12, and the other is a plane wave through a reflecting mirror 13. , convex lens 14, convex lens 15,
Masking board 16 with the word STOP cut out
are irradiated onto the photosensitive material 5 as a plane wave through the rays, thereby recording interference fringes in the shape of STOP. Next, the reflecting mirror 10, the convex lens 11, and the convex lens 12 are arranged as shown by two-dot chain lines, and the angle of the laser beam is changed to record interference fringes in a superimposed manner. Thereafter, a phenomenon treatment is performed to obtain a reflection hologram 1.

The reflection hologram 1 thus obtained is adhered to the rear window glass 2 of an automobile using a transparent adhesive such as epoxy or acrylic, using the photosensitive material 5 as an adhesive surface.

[Effect]

In Fig. 1, when the following vehicle 3 approaches and the distance between the vehicles becomes about 50 m, the reflective type will be reflected in the path of arrows A to C due to sunlight during the day, and the path of arrows B to C due to the light of the headlights at night. The display information recorded on the hologram 1, ie, the presence of the red letters STOP, is visually recognized by the following vehicle 3. As the inter-vehicle distance becomes even shorter, this displayed information will be recognized more clearly, and it will serve as a warning to the following vehicle that the vehicle is approaching the vehicle ahead.

Moreover, in the daytime, a reproduced image of display information is formed by the optical path A'→C' that is conjugate to sunlight A and reflected light C, but there is no light source indoors, and indoor light incident from outside can be considered as the light source. However, since it is scattered light and the contrast between indoor and outdoor brightness is extremely large, the information displayed on reflective hologram 1 is not actually visible to the driver of the vehicle in front, and the hologram is located at the rear of the vehicle. To ensure sufficient rearward visibility even when installed on the entire surface of a window glass. At night, since there is no light source inside the vehicle, the driver of the vehicle in front will not have his or her view obstructed by the displayed information.

In addition, the reflection characteristics of holograms are very sharp, and light other than wavelengths λ ₁ , λ ₂ , λ ₃ during exposure and wavelengths in the vicinity (±10 nm) are transmitted without being reflected. Holograms formed using light sources on the long wavelength side, such as yellow, have high visibility even if the diffraction efficiency is lowered, so by lowering the reflectance and increasing the transmittance, the number of laser light sources during exposure and its Daytime external light transmittance can be adjusted by appropriately combining wavelengths.

Even when parking at night, the STOP display information is recognized by the light from the headlights of an approaching vehicle, giving a warning of proximity and preventing collisions.

Although the preferred embodiments have been described above, the present invention is not limited to these embodiments and can be applied in various ways.

In addition to recognizing the presence of a vehicle and giving a warning, the present invention also includes a hologram recording information to be transmitted, such as advertising information, not only on the rear window glass, but also on the side window glass, front window glass, etc. It is also possible to have it recognized not only by following vehicles, but also by vehicles traveling alongside and oncoming vehicles. In this case, it is more effective to use a color hologram that reflects in a plurality of wavelength ranges, preferably three primary colors, in addition to a hologram that reflects in a single wavelength range. It is also preferable to display the information three-dimensionally by forming an image on or near the hologram surface.

How to place a hologram on window glass:
In addition to the methods described in the examples, holograms dislike moisture, so when using laminated glass such as front window glass, it is preferable to seal the hologram between two interlayer films. A protective film may be provided depending on the situation. Further, in laminated glass, it may be provided between the plate glass and the interlayer film, and in this case, the protective film may be omitted. Furthermore, it may be made detachable so that the displayed information to be transmitted can be changed.

[Effect of idea]

The vehicle display device of the present invention can be used not only during the daytime, but also at night, and regardless of whether the vehicle is running or parked, it can communicate the presence of the vehicle or the information that it wants to convey to the following vehicles, etc. externally. It is something that can be recognized without obstructing the field of view.

Further, by appropriately selecting a laser light source during hologram exposure, the external light transmittance during daytime can be adjusted.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram for explaining the operation of the present invention, Fig. 2 is a diagram showing the optical system when producing a reflection hologram, and Fig. 3 is a diagram showing the reflection hologram produced by the optical system in Fig. 2. FIG. 3 is a front view of the main parts attached to the rear window glass of the vehicle. 1... Reflective hologram, 2... Rear window glass.

Claims (1)

[Scope of utility model registration request] A display for a vehicle, characterized in that a reflective hologram on which display information is recorded is provided on a vehicle window glass, and the hologram is reproduced by sunlight and light from headlights of other vehicles. vessel.