JPH08238956A - Head-up display device - Google Patents

Abstract

PURPOSE: To reduce the number of part items so as to save space by disposing a transmission type aberration correcting hologram base, functioning as the dust protective cover of a head up display unit, at the case opening part of the display unit. CONSTITUTION: A head up display unit 2 is provided with a case 21 formed in such a way as to be able to shield light. A display 22 for emitting display light Lo, and a diaphragm 23 disposed in front of the display 22 so as to limit the optical path of the display light Lo are disposed inside the case 21, and a transmission type aberration correcting hologram base 25 is disposed at the opening part of the case 21. The aberration correcting hologram base 25 is provided with a transmission type aberration correcting hologram 26 for correcting the chromatic aberration of a display hologram 6, by a means of insertion, adhesion, or the like, and the aberration correcting hologram base 25 displays the function of a dust protective cover for preventing dirt, dust, and the like from entering the inside of the case 21 in addition to the original function as a hologram base.

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.

[0002]

2. Description of the Related Art A head having a head-up display unit for emitting display light and a display hologram for displaying a virtual image by diffracting (reflecting) the display light emitted from the head-up display unit. In the up-display device, there is known a head-up display device in which a dustproof cover is provided in an opening of the case in order to prevent dust and the like from entering the inside of the case of the head-up display unit. (See JP 62-103230 A).

[0003]

However, a head-up display unit having a dust-proof cover as described above has a reflection-type aberration correction hologram for correcting chromatic aberration of a display hologram (for example, JP-A-63-19422).
(See Japanese Patent Laid-Open No. 2), since the dust-proof cover and the reflection-type aberration correction hologram are separate bodies, the number of parts is large,
In addition, there is a problem that a large installation space is required.

An object of the present invention is to solve the above problems and to provide a head-up display device capable of reducing the number of parts and saving space.

[0005]

According to a first aspect of the present invention, there is provided a head, wherein a transmission-type aberration correction hologram substrate which functions as a dustproof cover of the head-up display unit is arranged in an opening of a case of the head-up display unit. Adopt up-display device.

According to a second aspect, the display hologram is provided,
Further, the entrance / exit angle difference ψ of the transmissive aberration correction hologram provided on the transmissive aberration correction hologram substrate is sufficiently larger than the entrance / exit angle difference | θ−φ | of the display hologram. The head-up display device according to claim 1 is adopted.

According to a third aspect of the present invention, the head-up display unit has a light-shielding portion that does not leak surface-reflected light on the incident surface of the transmission type aberration correction hologram substrate to the outside. The head-up display device of is adopted.

[0008]

According to the head-up display device of the first aspect, a transmission type aberration correction hologram is used, and the substrate of this transmission type aberration correction hologram has a function as a dust-proof cover of the head-up display unit. Since it is provided, the number of parts can be reduced and the installation space can be reduced.

According to the head-up display device of the second aspect, as will be described later in detail, the entrance / exit angle difference ψ of the transmission type aberration correction hologram is compared with the entrance / exit angle difference | θ−φ | of the display hologram. By setting the value to a sufficiently large value, the display light transmitted straight through the transmission type aberration correction hologram without being diffracted is reflected by the combiner substrate of the display hologram (for example, the windshield glass of an automobile) and the observer. It is possible to prevent a problem that the noise enters the visual field of the.

According to the head-up display device of the third aspect, the display light surface-reflected on the incident surface of the transmission type aberration correction hologram substrate is blocked by the light blocking portion and does not leak to the outside, so that the leaked light is visible to the observer. It is possible to prevent the trouble of entering.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a head-up display device according to an embodiment.

In FIG. 1, a head-up display unit 2 that emits the display light L ₀ is arranged on an appropriate mounting portion, for example, a dashboard 1 of an automobile, and another appropriate mounting portion (display hologram). Combiner substrate) of, for example, an automobile windshield glass 3,
Display light L ₀ from the head-up display unit 2
A display hologram 6 for diffracting (reflecting) and displaying a display image 5 as a virtual image is enclosed or attached in front of the observer 4.

The head-up display unit 2 is
The case 21 is formed so as to be shielded from light. Case 21
Inside of a display device 22 for emitting display light L _0, is placed in front of the display 22, a stop 23 for limiting the optical path of the display light L ₀ is provided, located in front of the diaphragm 23 A transmission aberration correction hologram substrate 25 is arranged in the opening 24 of the case 21. Aberration correction hologram substrate 25
Is provided with a transmission type aberration correction hologram 26 for correcting the chromatic aberration of the display hologram 6 by means such as encapsulation or attachment. The aberration correction hologram substrate 25 has a case 21 in addition to its original function as a hologram substrate. It functions as a dustproof cover that prevents dust and dirt from entering the inside of the.

Next, the diffraction characteristics of the aberration correction hologram 26 will be described with reference to FIG.
The input / output angle difference ψ of the display hologram 6 is sufficiently larger than the input / output angle difference | θ−φ | of the display hologram 6, that is,
It is set to satisfy the inequality ψ >> | θ−φ |.

The reason is that in the aberration correction hologram 26,
Display light L transmitted straight through without diffracting the center position₁ 
Among them, the surface is reflected by the windshield glass 3.
There is something, but this display light L₁ Windshield Gala
The incident angle ψ + φ to the space 3 satisfies the formula ψ + φ <θ
When the display light L₁ Reflected light L₁₁Is the desired display light L ₀ 
The rays are almost parallel or downward with
It becomes easy to get in as noise. Therefore, ψ + φ >> θ,
That is, if ψ >> | θ-φ | is set, the reflected light L₁₁But
The observer 4 is no longer in the viewing zone 7.

Regarding the display light L ₂ which passes straight through the edge portion of the aberration correction hologram 26, the display light L _{1 is also used.}
Like the above, it may be reflected by the windshield glass 3 and enter the viewing area 7 as noise, but this display light L ₂
The reflected light L ₂₂ to not enter the viewing zone 7, the display light L ₂
Angle of incidence (φ-α) + φ on the windshield glass 3
Is (ψ-α) + φ >> θ, that is, ψ >> | θ−φ | +
It may be set to α. Therefore, the aberration correction hologram 26
The reflected light of the display light that passes straight through the
Strictly speaking, it is necessary to satisfy the condition of ψ >> | θ−φ | + α in order to prevent noise from entering into, but if the condition of ψ >> | θ−φ | is satisfied. Therefore, it can be said that the above-mentioned problems due to reflected light can be sufficiently prevented.

Further, the display light L _c incident on the central portion of the aberration correction hologram 26 and the display light L _e incident on the end portions thereof have a difference Δψ in the entrance / exit angle difference ψ of the aberration correction hologram 26.
However, this angular difference Δψ can be made sufficiently small by the diaphragm 23, and the aberration correction hologram 2
It is possible to prevent the reflected light of the display light L _e transmitted through the end portions of 6 from entering the viewing area 7 of the observer 4 as noise.

The display light L ₀ emitted from the display 22 is also used.
Of the light, the light L ₃ (FIG. 1) that is surface-reflected on the incident surface of the aberration correction hologram substrate 25 leaks to the outside of the case 21 because the case 21 constitutes a light-shielding portion, and the visual field 7 of the observer 4 is detected. It never enters into as noise.

As described above, according to the above-described embodiment, the transmission type aberration correction hologram 26 is used, and the substrate 25 of this transmission type aberration correction hologram 26 is used.
In addition, since the head-up display unit 2 is provided with a function as a dustproof cover, the number of parts can be reduced and the installation space can be reduced.

Further, the entrance / exit angle difference ψ of the aberration correction hologram 26 is converted into the entrance / exit angle difference | θ−φ of the display hologram 6.
Since it is set to a value sufficiently larger than |, the display lights L ₁ and L _{2 which} have been transmitted straight through the aberration correction hologram 26 without being diffracted are reflected by the windshield glass 3 and fall into the viewing area 7 of the observer 4. It is possible to prevent the trouble of entering. Further, the display light L ₃ surface-reflected on the incident surface of the aberration correction hologram substrate 25 is blocked by the case 21 forming the light blocking portion and does not leak to the outside. can do.

The diaphragm 23 does not necessarily have to be specially provided, and the case 21 itself may have a function as a diaphragm. Also, the aberration correction hologram substrate 2
Reference numeral 5 is not limited to a flat surface, but may be a surface having a curvature, and may further be provided with an antireflection film or the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a head-up display device according to an embodiment.

FIG. 2 is an explanatory diagram for explaining a diffraction characteristic of a transmission type aberration correction hologram.

[Explanation of symbols]

2 Head-up display unit 21 Case (also used as a light shielding part) 24 Opening 25 Transmissive aberration correction hologram substrate (also used as dust cover) 26 Transmissive aberration correction hologram 6 Display hologram

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display area G02F 1/1335 G02F 1/1335 G03B 21/00 G03B 21/00 D (72) Inventor Yasugi Hagisato 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd.

Claims (3)

[Claims] 1. A head-up display device, wherein a transmission-type aberration correction hologram substrate that functions as a dust-proof cover of the head-up display unit is arranged in an opening of a case of the head-up display unit. 2. An entrance / exit angle difference ψ of the transmission aberration correction hologram having a display hologram and provided on the transmission aberration correction hologram substrate is defined as an entrance / exit angle difference | θ− of the display hologram. The head-up display device according to claim 1, wherein the head-up display device is sufficiently larger than φ |. 3. The head-up display unit according to claim 1, wherein the head-up display unit has a light-shielding portion that does not leak surface-reflected light on the incident surface of the transmission-type aberration correction hologram substrate to the outside. Display device.