JPH1195156A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of removing double images nearly completely over the entire part of display light. SOLUTION: One of the display devices is the display device constituted to polarize the display light from a display 2 to an S wave, to projecting this light to a transparent planar body 1 provided with an azimuth rotator on its rear surface or front surface and to reflect the light to an eye point EP on the front surface of the transparent planar body 1 or the azimuth rotator 3. The incident light rays of all the light rays reflected by the eye point EP on the transparent planar body 1 are partly azimuthally rotated to a P wave by the azimuth rotator 3 so that the exit angle emitted from the rear surface of the transparent planar body 1 or the rear surface of the azimuth rotator 3 attains a Brewster angle.

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 (hereinafter referred to as a HUD) for a vehicle which optically projects display light and superimposes a foreground in or near a forward visual field so as to be visually recognized by a driver or the like. Or a display device applicable to a show window of a building.

[0002]

2. Description of the Related Art Conventionally, as a HUD, a film or a film having a function of a half mirror has been formed or bonded on the surface of a single glass plate or the inside of a laminated glass. However, reflection on the front or back surface of the glass sheet is unavoidable, and there is a drawback that the image is double-viewed. In order to prevent this double image, a λ / 2 plate (optical rotation) Child layer)
(Japanese Unexamined Patent Publication No. 2-141720) has been proposed, and the present applicant has also proposed a method in which a transparent film having birefringence is adhered to a transparent plate-shaped body (Japanese Unexamined Patent Publication No. 2-294615). An optical rotator made of a liquid crystal polymer adhered (Japanese Patent Application Laid-Open No. 6-40271), an optical rotator combined with a translucent translucent reflective film and an antireflection film (Japanese Patent Application No. 7-98).
No. 878).

[0003]

However, Japanese Patent Application Laid-Open Nos. Hei 2-141720 and Hei 2-294615 describe above.
Invention described in JP-A-6-40271,
In both cases, the display information is incident on the transparent plate at a Brewster angle, but the central optical axis is designed to enter at the Brewster angle, but all the light outside the central axis is brewed. Since the light was not incident at the star angle, the external reflection angle was not an appropriate angle, and the double image could not be completely removed over the entire display light.

[0004] The present invention has been made in view of such a point, and an object of the present invention is to provide a display device capable of almost completely removing a double image over the entire display light.

[0005]

According to one aspect of the present invention, there is provided a display device, comprising: a display device that polarizes display light from a display device into an S-wave and projects the display light into an S-wave on a transparent plate provided with an optical rotator on the back surface, front surface, or inner surface. In the display device, the surface of the transparent plate or the optical rotator reflects light to an eye point, and a part of all light reflected on the eye point is incident on the transparent plate or the optical rotator. Is arranged so that the output angle that is rotated by the optical rotator into a P-wave and emitted from the back surface is the Brewster angle, and the display light is S
Since the wave enters the transparent plate or the optical rotator, the light is reflected on the surface of the transparent plate or the optical rotator, reaches the eye point, and the display light is visually recognized.

As an example in which a rotator is provided on the inner surface, a rotator may be provided between an interlayer having a laminated glass structure or between the interlayer and a transparent plate. On the other hand, some light not reflected by the surface is rotated by a rotator into a P wave,
Although the light exits outside but has a Brewster angle, no light is reflected on the back surface of the transparent plate or the back surface of the optical rotator and reflected on the eye point side, and the entire amount is emitted from the back surface to the outside.

Further, one of the display devices of the present invention is to project the display light from the display device into a transparent plate-like body provided with a rotator on the front surface, the back surface, or the inner surface, by polarizing the display light into a P-wave. In a display device in which the back surface of a transparent plate or a rotator reflects light to an eye point, the angle of incidence of incident light on the transparent plate or the rotator of all light reflected at the eye point is determined by Brewster. The display light is incident on a transparent plate or a rotator as a P wave at a Brewster angle, so there is no reflection on this surface, and the entire amount is a rotator. Then, the light is rotated into an S wave and reaches the back surface of the transparent plate or the back surface of the optical rotator (interface with air), but a part of the light is reflected and emitted from the transparent plate to reach the eye point.

[0008] One of the display devices of the present invention is characterized in that the display light from the display device is polarized into a P-wave and projected on a transparent plate having a translucent reflection film provided on the back surface, and the transparent plate is formed. In a display device configured to reflect light to an eye point on the translucent reflective film surface on the back surface of the body, the Brewster angle is an incident angle of incident light on the transparent plate body of all light reflected at the eye point. The display light reflected at the eye point is incident on the transparent plate at a Brewster angle as a P-wave, so there is no reflection on this surface and the back surface is translucent. Since only the light reflected by the reflection film reaches the eye point, the double image is not visually recognized.

Further, one of the display devices of the present invention is characterized in that the display light from the display device is polarized into a P-wave and projected on a transparent plate having a translucent reflective film provided on the surface thereof, and In a display device in which light is reflected to an eye point on the surface of a body, part of all light reflected on the eye point and incident on the transparent plate is transmitted through the transparent plate and emitted from the back surface. The display light reflected to the eye point is reflected by the translucent reflective film on the surface to reach the eye point.

The light not reflected by the translucent reflection film passes through the transparent plate and reaches the back surface and exits into the air. However, since the exit angle is the Brewster angle, the entire amount passes through the air. Since there is no light reaching the eye point from this portion, the double image is not visually recognized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a transparent plate, inorganic glass such as plate glass or organic glass such as a transparent resin plate can be used. Not only a single plate but also two transparent plates can be used as an intermediate film. It can be applied to those having a structure combined with, such as a structure in which a sheet glass and a transparent resin plate are laminated, and can also be suitably used as a combiner for a head-up display for an automobile, especially as a separate combiner. However, it can also be used as a display device for architecture.

However, in any case, it is necessary to form a transparent plate on a curved surface so that all display light reaching the eye point enters at the Brewster angle or exits at the Brewster angle. In general, it is difficult to apply the present invention to windshields (laminated glass) for automobiles or window glasses for construction, but it is applicable if a curved surface satisfying the above conditions is obtained.

As the optical rotator, an optical rotator made of a liquid crystal polymer, a transparent film having birefringence, an optical rotator such as a λ / 2 plate, and the like can be used. The translucent reflection film is made of Al, A
Various films such as indium oxide and tin oxide can be employed in addition to metal thin films such as g, Au, and Cu.

As the display, various displays such as a CRT, a fluorescent display, and a liquid crystal display can be adopted. When a liquid crystal display is used, the direction of the polarizing plate of the liquid crystal display is changed to P-polarized light or P-polarized light. If the S-polarized light condition is set and the P-polarized light means or the S-polarized light means is used, there is no need to separately provide a polarizing means.

In order to project display light from a display onto a transparent plate-like body and to prevent light reflected to an eye point by reflection from the transparent plate-like body from forming a double image, a transparent plate-like body is formed. A method of obtaining the positional relationship between the curved surface, the transparent plate, and the display device will be described for the case of the head-up display for a vehicle in FIG.

Eye point E. P and the position of the display are fixed, and the eye point E.P. The direction in which the display light from P is viewed obliquely below the eye point can be determined to be, for example, R1, R2, or R3 in consideration of display magnification and display quality.

Then, the angle formed by R1 is 2θ which is twice the Brewster angle θ (56.2 ° in the case of glass), and the straight surface I1 passing on the display corresponding to R1 (R1 is the display light) Is determined.

Similarly, the angle formed by R2 is 2θ, and R2
The angle formed between I2 and R3 passing on the display corresponding to
And I3 passing on the display corresponding to R3 is determined.
Since the straight surfaces I1, I2, and I3 determined here represent the projection light of the display D, the light I
S1, which is the normal to the bisector of 1 and R1 and passes through the intersection of I1 and R1, is the reflection surface itself to be determined. Similarly, S2 and S3 are determined, and these are continuously calculated. The curved surface tied so as to become a gentle curved surface becomes the curved surface of the reflective surface described later, and in order to make such a curved surface, the transparent plate-like body is ground or pressed by using a mold, It can be made by known methods.

In the case of Embodiments 2 and 3 described below,
Since this is an example in which the incident angle from the display is incident at the Brewster angle, the incident surface (front surface) may be manufactured by such a method, and the back surface may be manufactured so as to be parallel to the front surface. Strictly speaking, the display light reaching the eye point is reflected on the back surface of the transparent plate, so the curved surface on the back should be made in consideration of the thickness of the transparent plate. If the thickness is up to about 2 mm, there is no practical problem even if it is made parallel to the surface.

In the first and fourth embodiments described later,
It is necessary to set the output angle, not the incident angle from the display light, to the Brewster angle. In this case, if the thickness is up to about 2 mm, the surface is formed by the above-described method in the same manner as in Examples 2 and 3. There is no practical problem if it is manufactured so that the back surface is made parallel to the front surface.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIGS. 1 to 4 are schematic views of main parts applied as separate HUDs for vehicles in Examples 1 to 4 of the present invention, respectively.

Example 1 A case will be described in which display light from a display device is polarized into an S-wave and projected on a transparent plate having a rotator provided on the back surface.

As shown in FIG. 1, an optical rotator 3 made of a liquid crystal polymer is provided on the back surface of a transparent plate 1 made of polymethyl methacrylate or the like, and the transparent plate 1 and a display 2 such as a liquid crystal display are assembled. The one that is connected and integrated with the frame only on both sides so as not to obstruct the view is arranged on the dashboard.

Although not shown, a polarizing plate for polarizing to S-wave is provided at the tip of the display. In such a device, the eye point E.I. When the display light reflected by P is projected from the display 2 to the transparent body 1 as an S wave at almost Brewster's angle, a part of the display light is reflected by the surface and the eye point E.P. At P, the display light is visually recognized.

On the other hand, the remaining light not reflected on the surface of the transparent plate enters the transparent plate, is rotated into a P wave by the optical rotator 3 and reaches the rear surface (interface with air), but is emitted. Is almost the Brewster angle θ, there is no light reflected from this interface to reach the eye point again from the transparent plate-like body, and the double image is not visually recognized.

In this case, if an optical rotator is provided on the front surface instead of the rear surface and the S wave is projected at a substantially Brewster angle, the S wave is reflected on the surface of the optical rotator and the eye point E.E. Remaining light that has reached P and is not reflected is rotated by a rotator into a P-wave and reaches the rear surface of the transparent plate-shaped body. There is no light from the transparent plate to the eye point, and no double image is visible.

In this case, a similar effect can be obtained by providing an optical rotator on the inner surface of the laminated glass structure (between the intermediate film or between the intermediate film and the transparent plate). Example 2 A case will be described in which display light from a display device is polarized into a P-wave and projected on a transparent plate-shaped body provided with an optical rotator on the surface.

As shown in FIG. 2, an optical rotator 3 such as a λ / 2 plate is provided on the surface of a transparent plate 1 such as polymethyl methacrylate, and the transparent plate 1 and a display 2 such as a liquid crystal display are provided. Are integrated on the dashboard by connecting only frames on both sides so as not to obstruct the view.

Although not shown, a polarizing plate for polarizing P-waves is provided at the tip of the display. In such an apparatus, the display light reflected on the eye point is converted from the display 2 to the transparent body 1 as a P wave by the Brewster angle θ.
When the light is projected, the light is incident at a Brewster angle as a P wave, so there is no reflection at this surface (interface with air), and the entire amount is turned into an S wave by the optical rotator 3 and enters the transparent plate 1. A part of the display light exits into the air on the back surface (interface with air) of the transparent plate 1, but the remaining display light travels in the transparent plate in the opposite direction, and is turned into a P wave by a rotator. Almost all the light reaches the surface (interface with air) and exits into the air. At P, the display light is visually recognized.

In this case, if a rotator is provided on the back surface instead of the front surface and the P wave is projected at the Brewster angle, there is no reflection on the surface of the transparent plate, and the entire amount enters the transparent plate. The rotator rotates the S-wave to reach the back surface, and a part of the display light is emitted. The remaining display light is again rotated by the rotator to P, and almost all of the light is emitted from the transparent plate-like member. Point E. At P, the display light is visually recognized.

In this case, a similar effect can be obtained by providing an optical rotator on the inner surface of the laminated glass structure (between the intermediate film or between the intermediate film and the transparent plate). Example 3 A case will be described in which display light from a display device is polarized into a P-wave and projected on a transparent plate-shaped body provided with a translucent reflective film on the back surface.

As shown in FIG. 3, a film made of Al or the like is provided as a translucent reflective film 4 on the back surface of a transparent plate 1 made of polymethyl methacrylate or the like, and the transparent plate 1 and a display such as a liquid crystal display are provided. 2 is arranged on a dashboard.

Although not shown, a polarizing plate for polarizing P-waves is provided at the tip of the display. In such an apparatus, when the display light reflected on the eye point is projected from the display 2 onto the transparent transparent body 1 as a P wave at a Brewster angle, it is incident on the transparent body 1 at a Brewster angle. Reflection at the interface with air)
All of the light enters the transparent plate 1 and a part of the display light is emitted into the air on the back surface (interface with air) of the translucent reflective film 4, but the remaining display light is reversed in the transparent plate. Then, almost all of the light reaches the surface (interface with air) of the transparent plate-like body 1 and exits into the air. At P, the display light is visually recognized.

Example 4 An example of a case in which display light from a display device is polarized into a P-wave and projected on a transparent plate having a translucent reflection film provided on the surface will be described.

As shown in FIG. 4, a film made of Al or the like is provided as a translucent reflective film 4 on the surface of a transparent plate 1 made of polymethyl methacrylate or the like, and the transparent plate 1 and a display such as a liquid crystal display are provided. 2 is arranged on a dashboard.

Although not shown, a polarizing plate for polarizing P-waves is provided at the tip of the display. In such a device, when the display light reflected at the eye point is projected from the display 2 to the transparent plate 1 as a P wave at a substantially Brewster's angle, even if the display light is incident at a Brewster's angle as a P wave, Is provided with a translucent reflective film 4,
Part of the display light is reflected by this surface (the interface with the air) to form an eye point E.E. It reaches P and is visually recognized.

The display light, which is not reflected and enters the transparent plate through the semi-transparent reflective film, reaches the rear surface of the transparent plate. There is no light reflected and traveling backward through the transparent plate, and the entire amount is emitted into the air, so that the double image is not visually recognized.

[0038]

According to the display device of the present invention, not only a part of the display light but also the entire display light can be visually recognized so that a double image does not occur.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part applied as a separately provided HUD for a vehicle in a first embodiment.

FIG. 2 is a schematic diagram of a main part applied as a separately provided HUD for a vehicle in a second embodiment.

FIG. 3 is a schematic view of a main part applied as a separately mounted HUD for a vehicle in a third embodiment.

FIG. 4 is a schematic view of a main part applied as a separately mounted HUD for a vehicle in a fourth embodiment.

FIG. 5 is a schematic view of a main part for obtaining a curved surface of a transparent plate and a relationship between the transparent plate and the display.

[Explanation of symbols]

 1 transparent plate 2 display 3 optical rotator 4 translucent reflective film P eye point

Claims (4)

[Claims] 1. A display device according to claim 1, wherein the display light from the display device is polarized and projected as S-waves on a transparent plate provided with a rotator on the back surface, the front surface, or the inner surface. In the display device configured to reflect light to the eye point, a part of the incident light on the transparent plate body of all the light reflected by the eye point is turned into a P wave by the optical rotator to form a transparent plate. A display device, wherein an emission angle emitted from the back surface or the back surface of the optical rotator is set to be the Brewster angle. 2. A display device according to claim 1, wherein the display light from the display device is polarized as a P wave and projected onto a transparent plate having a rotator provided on the front surface, the back surface, or the inner surface. In a display device that reflects light to the eye point, the incident angle of light incident on the transparent plate or the optical rotator of all light reflected on the eye point is set to be the Brewster angle. Display device. 3. The display light from a display device is polarized and projected as P-waves on a transparent plate having a translucent reflective film provided on a back surface, and the display light is reflected by the translucent reflective film on the back surface of the transparent plate. A display device configured to reflect light to an eye point, wherein the incident angle of light incident on the transparent plate body of all light reflected at the eye point is set to a Brewster angle. . 4. A display device, wherein display light from a display device is polarized and projected as P-waves on a transparent plate having a translucent reflective film provided on a surface thereof, and reflected to an eye point on the surface of the transparent plate. In the display device described above, a part of the light incident on the transparent plate-like body of all the light reflected on the eye point is transmitted through the transparent plate-like body, and the emission angle emitted from the back surface becomes the Brewster angle. A display device, comprising: