JPH07102789B2 - Reflective display device for vehicles - Google Patents

Description

The present invention relates to a vehicular display device for displaying driving information to a driver at the position of an instrument panel of a vehicle.

[Conventional technology]

Conventionally, a vehicle display device has been proposed in which a distant display is performed by utilizing a reflecting surface in order to increase the visual recognition speed of the display, for example, those shown in FIGS. 13 and 14.

The device of FIG. 13 is such that a display 23 such as a liquid crystal display or a fluorescent display tube is attached to the lower surface of the meter hood 22 of the instrument panel 21, and a half mirror 24 is arranged in the meter display portion of the instrument panel 21. By projecting the display image of the display unit 23 on the half mirror 24, this half mirror
The virtual image 25 displayed on the display unit 23 can be visually confirmed via 24.

As a result, the visually recognized virtual image 25 is located at a deep position behind the half mirror 24 by the distance between the half mirror 24 and the display unit 23, and the effect of a distant display is obtained.

Further, in the device shown in FIG. 14, a reflector 36 facing the half mirror 34 is provided in the meter hood 32 of the instrument panel 31.
And a display device 33 facing the reflection plate 36, and by projecting a display image of the display device 33 onto the half mirror 34 via the reflection plate 36, the display device 33 via the half mirror 34 and the reflection plate 36.
The virtual image 35 of the display is made visible.

As a result, the optical path length from the display device 33 to the half mirror 34 becomes long, and the effect of far distance display can be obtained, for example, as compared with the device shown in FIG.

It should be noted that 27 in FIG. 13 and 37 in FIG. 14 are other display devices that are seen to be superimposed on the virtual images 25 and 35 of the display, respectively.

[Problems to be Solved by the Invention]

However, the effect of far display is not sufficiently obtained in a device that reflects only once with a half mirror as in the device of FIG. 13 above. However, there is a problem in that the volume occupied by the optical path becomes large and the entire device becomes large when the number of optical paths is increased to increase the optical path length.

SUMMARY OF THE INVENTION It is an object of the present invention to increase the distance of far display in a reflective display device for a vehicle that uses a reflecting surface to perform far display while making the entire device compact.

[Means for Solving the Problems]

The reflective display device for a vehicle of the present invention made to solve the above problems is a display device, a reflective member having a spherical reflective surface facing the display surface side of the display device, the display device and the reflection. And a translucent reflector having a reflective surface for transmitting the display light from the display device, wherein the radial center point of the reflective surface of the reflective member is the viewpoint position on the driver's seat side. The optical axis of light transmitted through the reflector and incident on the reflective surface of the reflective member and light reflected by the reflective surface are coaxial or It is characterized in that the reflecting member is arranged such that it is paraxial and the reflected light from the reflecting surface of the reflecting member is reflected toward the driver's seat side from the reflecting surface of the reflector.

[Work]

In the vehicle reflective display device of the present invention, the display light from the display is transmitted through the reflector, the transmitted light is reflected by the reflecting member, and further reflected by the reflector to be visually recognized.

At this time, since the respective optical axes of the incident light and the reflected light in the reflecting member are coaxial or paraxial, the optical path of the incident light from the reflector to the reflecting member and the optical path of the reflected light from the reflecting member to the reflector. And occupy almost the same space.

Further, among the light rays incident on the reflecting member from the driver's seat side through the reflecting surface of the reflector, the light rays reflected by the reflecting surfaces of the reflecting member and the reflector toward the viewpoint position are reflected through the vicinity of the viewpoint position. Limited to the light rays that enter the body.

〔Example〕

FIG. 2 is a view showing a mounting state of the vehicle reflective display device according to the embodiment of the present invention.

In the figure, 1 is a light-emitting analog meter equipped with a backlight as will be described later, 2 is a prism as a reflector, and 3 is a slightly concave total reflection spherical mirror (reflection member). The light emitting analog meter 1, the prism 2 and the spherical mirror 3 constitute the display device of the embodiment and are housed in the instrument panel 4. In addition, 5 is a handle column, 6 is a handle,
7 is a windshield.

As will be described later in detail, the light-emitting analog meter 1
The display light of is transmitted through the prism 2, reflected by the spherical mirror 3, and further reflected by the reflection surface of the prism 2. When viewed from the vicinity of the driver's viewpoint 8, the display light is displayed at a position behind the prism 2 (in front of the vehicle). The virtual image X is visually recognized.

FIG. 1 is a view showing the display device of the above-mentioned embodiment. The prism 2 is arranged close to the dial 17 on the dial 17 side of the light emitting analog meter 1, and the light emitting analog meter of the prism 2 is provided. On the side opposite to 1, the spherical mirror 3 is arranged so as to face the dial 17 of the light-emitting analog meter 1 with a space provided between the prism 2 and the prism 2.

The dashed-dotted line in the figure represents a light ray that finally travels from the light-emitting analog meter 1 to the viewpoint position 8, and the description will be given based on this ray tracing. First on the incident side of prism 2
The light enters the surface 2a at a right angle, but when passing through the second surface 2b serving as the reflecting surface of the prism 2, the light is refracted along the optical axis A and enters the spherical mirror 3 at a substantially right angle.

On the other hand, the spherical mirror 3 satisfies the reflection condition and reflects the incident light ray along an optical axis B that makes a slight angle with the optical axis A,
The reflected light rays are directed to the second surface 2b. Further, the reflected ray is reflected by the second surface 2b and is directed to the viewpoint position 8 in the direction of the optical axis C. Here, the optical axis A and the optical axis B may be coaxial or paraxial, but since the optical axis A and the optical axis B are close to each other, the light beam passes between the second surface 2b of the prism 2 and the spherical mirror 3. I will make a round trip.

Therefore, the optical path length between them is the second surface 2b and the spherical mirror 3
The distance can be approximately doubled, and the optical path can be lengthened, while the space occupied by the optical path can be reduced to make the entire apparatus compact.

At this time, the virtual image visible from the viewpoint position 8 is the prism 2
The second surface 2b of the second surface 2b
The distance from the virtual image to the virtual image is larger than α + β + γ + δ, which is the sum of the distances between the members shown by (α, β, γ, δ) in the figure.

That is, the spherical mirror 3 is slightly concave, and the light emitting analog meter 1 is optically inserted inside the focal point F of the spherical mirror 3 as shown in FIG. The virtual image X is larger than the display size of the light emitting analog meter 1 and the second surface
It is visually recognized at a position deeper than the position separated from 2b by α + β + γ + δ.

As described above, since the display image is enlarged and displayed by the spherical mirror 3, the light emitting analog meter 1 can be downsized. Further, since the center of the sphere of the spherical mirror 3 is set so as to substantially coincide with the viewpoint position 8, as shown in FIG. 4, the spherical mirror 3 is moved from the viewpoint position 8 side to the spherical mirror 3 via the second surface 2b. Of the incident light rays, the spherical mirror 3 and the second surface
The ray reflected by 2b and traveling toward the viewpoint position 8 is the viewpoint position 8
To the second surface 2b from. However, since the driver's face is actually present at this viewpoint position 8, the driver does not see the external light incident on the spherical mirror 3 via the second surface 2b.

Therefore, the driver is not dazzled even when external light such as headlights of the following vehicle or sunlight at sunset enters the rear of the vehicle compartment.

Further, the optical positional relationship with the viewpoint position 8 can be easily set, for example, by adjusting the angle of the spherical mirror 3 while the light emitting analog meter 1 and the prism 2 are fixed to the instrument panel 4. You can

Next, the positional relationship between the viewpoint position 8 (direction of the optical axis C) and the prism 2 and the characteristics of the prism 2 will be described.

FIG. 3 is a diagram showing a state in which a virtual light ray 1 is made incident on the prism 2 from the viewpoint position 8 side, and the locus of this virtual light ray 1 is considered as the line of sight from the viewpoint position 8 geometrically. be able to.

With respect to the prism angle θ between the first surface 2a and the second surface 2b of the prism 2, the light ray 1 is refracted and enters the prism 2 from the second surface 2b of the prism 2, and this incident light ray 1 is the first light ray in the prism 2 The angle is set so that the surface 2a is totally reflected. That is,
The angle ψ in the figure is made larger than the critical angle of total reflection on the first surface 2a. When the first surface 2a is totally reflected as described above, the second surface 2b is also totally reflected as shown in FIG.

Therefore, when the second surface 2b of the prism 2 is desired from the direction of the light ray 1 (direction of the viewpoint position 8), the outside of the first surface 2a, that is, the light emitting analog meter 1 transmits the prism 2 from the second surface 2b. Can not be seen directly.

As described above, since the light emission type analog meter 1 is not seen through the prism 2 due to the total reflection, the prism 2 and the light emission type analog meter 1 can be brought as close as possible, and accordingly, the prism 2 and the spherical mirror 3 are required. The distance of the far display can be increased by increasing the interval of.

Moreover, when the second surface 2b is desired from the direction of the light ray 1 as described above, the surface of the third surface 2c is visually recognized through the second surface 2b and the first surface 2a in the prism 2. However, in the prism 2 of this embodiment, a black coating surface 2d is provided on the third surface 2c.
Is formed, and it actually looks dark, and the display image of the light-emitting analog meter 1 is displayed in the distance in the background of this dark color, and the contrast is enhanced.

Further, as described above with respect to the light ray 1 and the total reflection in the prism 2 in FIG. 3, the light incident on the prism 2 from the second surface 2b is transmitted through the first surface 2a and is applied to the light emitting analog meter 1. Since it does not occur, it is possible to prevent washout due to incidence of external light.

FIG. 6 is a partial cross-sectional view of the light emitting analog meter 1, FIG.
FIG. 8 is a partial front view of the same, and FIG. 8 is an exploded perspective view thereof.

In the figure, 11 is a meter internal unit that rotates a pointer shaft 11a according to an electric signal input from a circuit (not shown), and the internal structure thereof is a miniaturized version of a conventionally known analog meter. 12 is a case body disposed on the front surface of the meter internal unit 11 on the side of the pointer shaft 11a, 13 is a reflector that is housed in the case body 12 and has a cylindrical concave reflecting surface 13a directed toward the opening side of the case body 12, 14 Is a cold-cathode tube (discharge lamp) arranged along the focal point f of the reflector 13. The cold-cathode tube 14 is connected to an external power source through a lead wire (not shown) drawn from the socket 15 and the case body 12. Connected to form a high-power light source. In addition, reflector
Since 13 forms a concave mirror by the cylindrical concave reflecting surface 13a, the focal point f becomes linear as shown in FIG.

16 is a light diffusing plate arranged to cover the opening of the case body 12, 17 is a dial arranged in front of the light diffusing plate 16, and 18 is a disc-shaped pointer arranged in front of the dial 17. It is a plate, and the center of the pointer plate 18 is fixed to the tip of the pointer shaft 11a.

As shown in FIG. 7, the dial 17 has a black face surface 17a (hatched portion) formed on the transparent resin plate by a black printing process, etc., and the scale and numeral portion 17b are left out. The graduations and numerals and the circular portion overlapping the pointer plate 18 are made light transmissive. Further, the pointer plate 18 has a black face surface 18a (hatched portion) formed by a black printing process on a disk-shaped transparent resin plate, and since the black face surface 18a is not partially printed in the radial direction from the vicinity of the center, the pointer plate 18 has a light transmitting property. A slit 18b is formed, and this slit 18b serves as a pointer.

Note that the scale and numeral portions 17b and the slits 18b as described above can also be formed by punching using a light opaque member.

By the way, generally, in a car-mounted analog meter, in many cases, the scale is not formed on the entire circumference, but is generally formed in the range from 8:00 to 4:00 clockwise in the dial of the timepiece.

The scale of the dial 17 of this embodiment is also not formed on the entire circumference as shown in FIG. 7, and the center of the pointer plate 18 is a certain distance d below the center of the height H of the scale portion. It is set in a position that is offset. Further, as shown in FIG. 6, the height of the reflecting surface 13a of the reflector 13 is set so as to include the height H of the scale portion, and the center and the cold cathode tube
The position of 14 coincides with the approximate center P of the height H of the scale portion. And, in correspondence with the center of the pointer plate 18, dial 1
7, the light diffusion plate 16, the reflector 13 and the case body 12 are formed with small diameter shaft holes 17c, 16a, 13b, 12a, respectively, and the pointer shaft 11a has respective shaft holes 12a, 13b, 16a, 17c. It passes through and passes under the cold cathode tube 14 and is directed to the center of the pointer plate 18.

With the above configuration, the light from the cold cathode fluorescent lamp 14 is transmitted to the light diffusion plate 16
The light that is diffused by the reflector 13 and is directed toward the reflector 13 is reflected by the reflecting surface 13a into substantially parallel light, and the light diffuser 16
Spread by Then, uniform and bright light is emitted behind the dial 17 and the pointer plate 18 through the light diffusion plate 16, and only the scale, the numbers, and the slit 18b portion are illuminated, and the pointer plate 18 is displayed by the meter internal unit 11. When is rotated, the pointer (slit 18b) that emits light rotates to indicate the scale that emits light, and analog display is performed.

As described above, in the light-emitting analog meter 1 according to the above-described embodiment, the uniform and bright light is radiated to the back of the dial 17 and the pointer plate 18, so that the light amount of the display pattern such as scales, characters, and pointers is not uniform. It is a light emitting analog meter with high brightness and is suitable for the reflective display device according to the present invention.

In the light emitting analog meter 1 of the above embodiment, the dial 17
Although a slight clearance is provided between the pointer and the pointer plate 18, light leakage may occur from this clearance. However, when it is incorporated in the reflection type display device as described above, the light emission type analog meter 1 can be optically viewed from the front side and the contrast is enhanced by utilizing the reflection surface. , This light leak is almost invisible.

Incidentally, in order to further reduce the light leakage, for example, it may be as shown in FIG.

The light-emitting analog meter shown in the same figure is different from the configuration shown in FIG. 8 in that the dial plate and the pointer plate are changed, and the dial plate 17 'is arranged on the front face. On pointer plate 1
8'is arranged. In FIG. 9, the same parts as those in FIG. 8 are designated by the same reference numerals.

There is an opening 17 in the part of the dial 17 'facing the pointer plate 18'.
A c'is formed, and a black face surface 17a 'is formed around the c', as in FIG. In addition, the pointer plate 18 '
Like the pointer plate 18, the black face surface 18a 'has a slit 18b' formed therein.

Around the opening 17c ′ of the dial 17 ′, as shown in the cross section in FIG. 10, a step portion 17 is formed on the pointer plate 18 ′ side (light diffusion plate 16 side).
d'is formed, and the periphery of the pointer plate 18 'is loosely fitted in the step portion 17d' to set a certain clearance. Thereby, light leakage from the clearance between the dial 17 'and the pointer plate 18' can be reduced.

In the reflection type display device of the above embodiment, the spherical mirror 3 is used to enlarge the display and eliminate the dazzling due to the external light. The spherical mirror 3 is long in the direction perpendicular to the drawing in FIG. It is in the direction. Therefore, when the spherical mirror 3 is used as described above, the light emitting analog meter 1
Do not flatten the display surface (clock face 17) of
As shown in the drawings and FIG. 12, the curved shape (FIG. 11) or the polyhedral shape (FIG. 12) can reduce the deformation of the image by the spherical mirror 3.

In FIG. 11 (a), the dial 17 has a convex surface in accordance with the curvature of the spherical mirror 3, and the radius of curvature r of this convex surface is r.
_D, as shown in FIG. (B), the radius of curvature of the spherical mirror 3 r _M, the distance from the convex surface of the dial 17 until the spherical mirror 3 when is h, the r _D = r _M -h It is set. Under this condition, the spherical mirror 3
Although it is not possible to completely correct the aberration due to, it is possible to obtain a sufficient correction effect in practical use.

In FIG. 12 (a), the dial 17 is polyhedral in accordance with the radius of curvature of the spherical mirror 3 and is perpendicular to the radial direction of the spherical mirror 3 as shown in FIG. 12 (b). Face 17 ₁ , 17
It is composed of _two sides. In addition, graduations of different meters (for example, a speedometer and a tachometer) are formed on each of the planar portions 17 ₁ and 17 ₂ of the multifacet.

As described above, in the case of the multi-sided structure, the effect of correcting the aberration by the spherical mirror 3 is lower than that in FIG. 11, but practically, there is no problem and the dial etc. can be easily formed. it can. As shown in FIG. 1, since the dial 17 of the light-emitting analog meter 1 and the spherical mirror 3 face each other substantially in parallel, most of the deformation of the dial 17 due to the aberration at the vertical position is small. It does not occur and the display quality does not deteriorate in practical use.

Although the light emitting type analog meter is used in the above embodiment, it goes without saying that an indicator such as a fluorescent display tube or a liquid crystal display plate may be used.

〔The invention's effect〕

As described above, according to the reflective display device for a vehicle of the present invention, a display, a reflection member having a spherical reflection surface facing the display surface side of the display, the display and the reflection member And a translucent reflector having a reflective surface that transmits the display light from the display, and the radial center point of the reflective surface of the reflective member is preset as the viewpoint position on the driver's seat side. The optical axis of the light transmitted through the reflector and incident on the reflection surface of the reflection member and the light reflected by the reflection surface are coaxial or paraxial. And, since the reflection member is arranged so that the reflection light from the reflection surface of the reflection member is reflected toward the driver's seat side from the reflection surface of the reflection member, the reflection light from the reflection member to the reflection member The optical path and the optical path of the reflected light from the reflector to the reflector are almost the same. Now it occupies, it is possible to increase the distance of the far display while the entire apparatus compact. However, among the light rays that enter the reflecting member from the driver's seat side through the reflecting surface of the reflector, the rays reflected by the reflecting surfaces of the reflecting member and the reflector toward the viewpoint position pass through the vicinity of the viewpoint position. Since the light will be limited to the light rays that enter the reflector, the driver will be dazzled even if external light such as headlights of the following vehicle or sunlight at sunset enter from both sides of the driver. There is no.

[Brief description of drawings]

FIG. 1 is a diagram showing a vehicular reflection type display device according to an embodiment of the present invention, FIG. 2 is a diagram showing a mounting state of the vehicular reflection type display device according to the embodiment, and FIG. 3 is a view showing the function of a prism in the embodiment. FIG. 4 is a diagram illustrating the relationship between the spherical mirror and the viewpoint position in the embodiment, FIG. 5 is a diagram illustrating the positional relationship between the spherical mirror and the light emitting analog meter in the embodiment, and FIG. Partial sectional view of the light emitting analog meter in the example, FIG. 7 is a partial front view of the light emitting analog meter, FIG. 8 is an exploded perspective view of the light emitting analog meter, and FIG. 9 is a light emitting analog meter. FIG. 10 is a diagram showing another embodiment relating to a dial and a pointer plate, FIG. 10 is a sectional view of the same embodiment, FIG. 11 is a diagram showing an embodiment in which the surface shape of the dial is spherical, and FIG. 12 is a dial. Figure 13 shows an example in which the surface shape of the Figure 14 is a diagram showing an example of a conventional display device using a reflection plate. 1 ... Emitting analog meter, 2 ... Prism, 3 ...
… Spherical mirror.

Claims (3)

[Claims] 1. A display device, a reflecting member having a spherical reflecting surface facing the display surface side of the display device, a display member disposed between the display device and the reflecting member, and transmitting display light from the display device. And a translucent reflector having a reflecting surface for allowing the center point in the radial direction of the reflecting surface of the reflecting member to be optically coincident or substantially coincident with a position preset as a viewpoint position on the driver side. The optical axis of the light which is disposed and which is transmitted through the reflector and incident on the reflecting surface of the reflecting member and the light which is reflected by the reflecting surface are coaxial or paraxial, and the reflected light from the reflecting surface of the reflecting member The reflection type display device for a vehicle, wherein the reflection member is arranged so that the reflection member reflects toward the driver's seat side from the reflection surface of the reflector. 2. The reflector is a prism, the first surface of the two surfaces where the prisms meet is opposed to the display surface of the display, and the second surface is the reflective surface of the reflector. , The light reflected from the reflecting surface of the reflecting member is incident on the second surface from the direction in which the light is reflected by the second surface, so that the light is totally reflected by the first surface in the prism. 2. The angle between two surfaces is set, and the angle is set.
The reflective display device for a vehicle described. 3. The surface other than the two surfaces with which the prisms are associated is processed to have a dark color system.
The reflective display device for a vehicle described.