JPH02176421A - Vehicle mounted hologram meter - Google Patents

Abstract

PURPOSE:To obtain a vehicle mounted hologram meter which can avoid driver's dazzlement due to ghost images by providing a Lippmann hologram, a regenerated light source and a smoke light source, and arranging these parts at the specified positional relationship. CONSTITUTION:The numerical scale of each meter is recorded in a Lippmann hologram 33. A regenerated image 39 of said scale is displayed on the rear regenerating plane with the regenerated light. The hologram is attached to a position in front of the dial of a conventional meter. A regenerating light source 34 emits light from the lower side of a specified attaching angle to the upward direction with respect to the normal line H of the hologram 33 and from the front side of the hologram 33. A smoke plate 37 has a transmittance which reduces external light inputted on the surface of the hologram 33. The smoke plate 37 is provided in front of the light source 34. Reflection of driver's face and the like is prevented. In this arrangement, the regular regenerated image of the hologram 33 can be observed through the regular image of a master hologram when the light from the light source 34 is projected from the lower side with respect to the normal line H. Said regenerated image is observed through the smoke plate 37.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a meter display device using a hologram, and more particularly to a laser hologram meter using a Lippmann hologram in which a reproduced image of a master hologram is rerecorded.

[Conventional technology]

2. Description of the Related Art Automobiles and the like are equipped with meters that display data related to the running of the vehicle, such as its speed and engine speed, and the meter displays are two-dimensional. However, a three-dimensional display instrument using a display hologram was proposed for the purpose of upgrading the instrument and shortening the time required to view the instrument while driving, and on June 16, 1988, the applicant proposed ``Vehicle warning display device using hologram
A patent application was filed for the invention named
17).

Referring to the hologram meter according to this prior invention below,
Its schematic structure 1 is shown in FIG. 10 (A), and the Lippmann hologram recording optical system for producing the hologram used is shown in
CB), and the reproduction method is shown in FIG. 10(C).

In FIG. 10(A), 3 is a numerical scale hologram recording numerical scale information, 5 is a pointer hologram recording a pointer pattern, 7 is a reproduction illumination light source, 9 is a reproduced image, 11 is a drive unit for the pointer hologram, Each is shown below. Fig. 1O (B) shows a simulation of the production of each hologram, where 13 is an object such as a numerical scale, 20 is a laser light source that irradiates the object with reference light 15, 17 is object light from the object, and 19 is a hologram dry plate. are shown respectively. In FIG. 10(C), 21-a.

21-b is a reproduction illumination light source, 23 is a hologram prepared by developing the dry plate recorded in FIG. 10(B), and 25-a
, 25-b show reconstructed images by the respective reconstructed illumination lights. That is, when the hologram produced in the state shown in FIG. 10 (I3) is irradiated with reproduction illumination light from the same position as the laser in FIG. 10 (B), as shown at 21-a in FIG. 10 (C), , the reproduced image appears at exactly the same position 25-a as the position of the subject at the time of hologram recording. However,
If the reproduction illumination light is illuminated from a different position, such as the position 21-b, a reproduced image will appear at a position 25-b, which is completely different from the position of the subject during recording. Moreover, if these are irradiated at the same time, two reconstructed images will also appear at the same time.

(Problems to be Solved by the Invention) In the vehicle laser hologram meter described above, a plurality of reproduced images (hereinafter referred to as ghost images) generated by sunlight or other light sources other than the predetermined reproduced illumination light cause the driver to You will be dazzled. The present invention provides a hologram meter for a vehicle that can avoid such multiple dazzles.

[Means to solve the problem]

Therefore, the present invention provides the following features when reproducing a master hologram that records meter information:
The light that reproduces the real image is the object light, and from the opposite direction,
A Lippmann hologram in which a reproduced image of the master hologram is re-recorded using diverging light from a diverging point or converging light converging to a converging point as reference light; a reproduction light source that illuminates from the front side of the Lippmann hologram; and a smoke that is provided in front of the Lippmann hologram and the reproduction light source and has a predetermined transmittance to reduce external light that enters the surface of the Lippmann hologram from the outside. The reproduction meter information is observed through a predetermined image of a master hologram reproduced from the Lippmann hologram (the Lippmann hologram and the reproduction light source are arranged).

[Effect]

A reproducing divergent light source is installed at a point (position) equivalent to the divergent point or convergent point of the reference target used when rerecording the reproduced image of the master hologram to the Lippmann hologram, and when the Lippmann hologram is irradiated, the reproducing image is rerecorded. A regular reproduced information image appears at the same position as , and a regular image of the master hologram is formed on the opposite side of this image. This reproduced information image can only be observed within the area between the straight lines connecting both ends of the Lippmann hologram and both ends of the reproduced image of the master hologram. That is, the normal reproduced image of the re-recorded Lippmann hologram can only be observed through the normal image of the master hologram. Moreover, when the reproduction light source is illuminated from below with respect to the normal line of the Tubmann hologram, the reproduction light source is arranged so that the regular reproduction image of the Lippmann hologram can be observed through the regular image of the master hologram.

Further, the normal reproduced image of this Lippmann hologram is observed through a smoke plate with a predetermined transmittance in front of it.

〔Effect of the invention〕

As mentioned above, since the Lippmann hologram in which the meter information recorded in the master hologram is re-recorded is reproduced using a reproduction light source from below, this regular reproduced image is the corresponding regular master hologram reproduced from the Tubmann hologram. The master hologram image can only be observed through the image, and the master hologram image reproduced by light sources such as sunlight or street lights that enter from above or from the rear is generated below the regular image, so it is difficult to see the master hologram image being reproduced by such light sources. Since the observation of ghost images is avoided, extremely practical visibility can be obtained as a vehicle-mounted hologram meter.

〔Example〕

Embodiments of the present invention will be described based on the drawings. FIG. 1 shows the overall structure of a hologram meter for an automobile, and FIG. 2 shows a partial sectional view of the meter.

In FIG. 1, the regular image 3 of the first master hologram
1. The relative positional relationship between the regular image 32 of the second master hologram and the image type Lippmann hologram 33 is shown. Note that the regular image 31 of the first master hologram and the regular image 32 of the second master hologram are devices composed of a Lippmann hologram 33 when illuminated from the position of the reproduction illumination light tA34, but they are actually transparent. The statue is not visible.

Here, almost all drivers (99
%) for the 99% eye range (observation area) 39 that includes both eyes, the images 31 and 32 of the first and second master holograms
Explain the positional relationship. The optical path L, which connects the uppermost point 39-1 of the 99% eye range 39 to the upper and lower end points of the Lippmann hologram 33, and its extension line are the first and second
An optical path passes through the area of the regular images 31 and 32 of the mask hologram and connects the lowest point 39-2 of the 99% eye range to the upper and lower end points of the Lippmann hologram 33, respectively.

L4 and its extension pass within the area of the regular images 31, 32 of the first and second master holograms. Like this, 99
%The area where the optical path connecting the Lippmann hologram from the eye range 39 is -L, and which passes within the areas of the regular images 31 and 32 of the first and second master holograms, is the regular image visible range 4.
1, and the reproduced image of the scale recorded on the Lippmann hologram 33 can be visually recognized in this area 41. That is, 99%
When the driver's eyes are positioned within the eye range 39, the driver can reliably see the normal reproduced image from the Lippmann hologram 33.

The Lippmann hologram 33 has a numerical scale such as a tachometer or a speedometer recorded thereon, and is made to appear three-dimensionally as a reproduced image 39 on the reproduction surface behind it by the reproduction light. This Lippmann hologram is conventionally mounted in front of the dial of a meter. 34 is a reproduction light source that irradiates the Lippmann hologram 33 with reproduction irradiation light, and uses a white light bulb. The reproduction light source 34 illuminates the normal line (H) of the Lippmann hologram from below to above at a predetermined mounting angle and from the front side of the Lippmann hologram 33. This mounting angle is preferably greater than about 30 degrees, and in this embodiment is set at 45 degrees.

35 is a self-luminous display hand (luminous pointer);
As shown in FIG. 9, a lightweight needle-like or thin prismatic shape is used. The light emitting pointer 35 is a Lippmann hologram 33
It is located in a plane close to the reproduction surface 39-0 on which the reproduced image 39 is located, and is rotationally driven within this plane by a light emitting pointer driving section 36 such as a motor.

The light-emitting pointer 35 is supplied with power from near the shaft of the motor via a lead wire (not shown). For further simplification, the light-emitting pointer 35 may be a needle-like member whose surface is coated with fluorescent paint, and the light source 34 may be used for illumination.

Incidentally, as shown in FIGS. 8 and 9, the reproduced image 39 is
It is aesthetically preferable that the meter 39-1 is provided with a meter numeral 39-1 and a meter scale 39-2, and that the similar figure 39-1 is located spatially in front of the scale 392. Alternatively, the spatial positional relationship between the numbers 39-1 and the scale 39-2 may be reversed.

In Figures 1 and 2, 37 indicates a predetermined transmittance (approximately 20%).
), preferably dark gray acrylic resin. This smoke plate 37 is provided in front of the Lippmann hologram 33 and the reproduction light source 34,
This is provided to reduce the incidence of disturbance light 100 shown in FIG. 1, such as sunlight entering from the side or rear window glass of the vehicle, street lights, etc., on the surface of the Tubman hologram 33 in the meter. This smoke plate 38 prevents the driver's face from being reflected on the surface of the Lippmann hologram 33.

Next, the principle by which recording and reproduction of the Lippmann hologram 33 and observation of ghost images are avoided will be explained. Third
The figure shows the recording optical system for producing the first master hologram.
FIG. 4 shows a recording optical system for producing a second master hologram, and FIG. 5 shows a recording optical system for producing a Tubmann hologram.

Referring to FIG. 3, a method for manufacturing the first master hologram will be explained. The laser beam oscillated from the recording laser 51 is
Divide into two with beam brick 52, and attach one side to mirror 5.
3-1.53-2. The lens 54-1 and the concave mirror 56 make the reference light P enter the hologram dry plate 59. At this time, the reference light P is parallel light. The other light is mirror 53-3.53-4.53-5. The diffuser plate 58 and the subject 57 are irradiated through the lens 54-2°55, and the transmitted light enters the dry plate 59 as object light Q. The object beam P and the reference beam Q interfere with each other near the dry plate 59, and their interference fringes are recorded on the dry plate.

This is developed and processed to produce a first master hologram. The subject to be photographed is a meter scale and a three-dimensional representation of numbers.

Next, a method for producing the second master hologram will be explained with reference to FIG. Here, the first
5 in the same orientation and direction as when recording the master hologram.
Set it to the 9' position.

A concave mirror 56 is used on this first master hologram, and a reproduction light R is made incident on the first master hologram from a direction completely opposite to that of the reference light P shown in FIG. This reproduction light R has a conjugate wave relationship with the reference light P shown in FIG. Then, due to the first master hologram 59°, a real reconstructed image 57° appears at the same position as the subject in FIG.
The light that forms a real image is defined as the object light Q, and a parallel reference light P is incident from the same direction as the object light Q. Interference fringes due to interference between the object light Q and the reference light P are formed on a hologram drying plate 60.
to be recorded. This is developed and processed to create a second master hologram.

Next, referring to FIG. 5, a method for producing a Lippmann hologram will be explained. In this case, the second master hologram made with the recording optical system shown in FIG. 4 is set at a position of 60° in exactly the same direction as during recording. Using the concave surface m56, the reproduction light R is made to enter the second master hologram from a direction completely opposite to that of the reference light shown in FIG. This reproduction light R is the fourth
It has a conjugate relationship with the reference light P shown in the figure. Then, real reproduced images 59'' and 57'' emerge from the second master hologram 60' at exactly the same positions as the first master hologram and the subject in FIG. Therefore, the hologram dry plate 61 is attached to the first master hologram 59'' and the subject 5.
7'', and the light that forms this real image is defined as the object light Q, and the divergence point 63 (lens 54-2
), and these object beams Q
The interference fringes caused by the interference between
Record in 1. This is developed and processed to produce a Lippmann hologram.

Next, we will discuss the reproduction of the Lippmann hologram produced through the three steps of FIGS. 3, 4, and 5 as described above in the sixth section.
This will be explained with a diagram. Reference numeral 34 indicates a geometrically uniform reproduction divergence point and reproduction light source corresponding to the divergence point 63 in FIG. 5, and white light like a miniature light bulb is used. Set the Tubmann hologram recorded in Figure 5 as shown in Figure 6, 34.
When the reproduction light R having a divergence point is irradiated, an image 31 of the second master hologram 59 recorded in FIG. 3 and used in FIG. 4, and an image 31 of the second master hologram 59 recorded in FIG. As the image 32 of the master hologram 60 is reproduced, a reproduced image 39 of the subject 57 in FIG. 3 emerges. Note that it is preferable that the reproduction light a34 be placed at a geometrically even position corresponding to the divergence point 63, but it may be placed in the vicinity of that position. The vicinity here refers to a range where no problem will occur due to the displayed reproduced image appearing distorted. The images 31 and 32 of the first and second master holograms and the reproduced image shown in FIG. 6 correspond to those shown in FIG. This reconstructed image 33 can be seen through the first master hologram image 31 and the second master hologram image 32 (observer 90), but the viewer 91 is at a position away from the first master hologram image 31. When viewed from above, this reconstructed image cannot be seen. This is a feature of the Lippmann hologram that is re-recorded from the master hologram mentioned above. That is, the re-recording of the master hologram or the Tubmann hologram has the effect of limiting the diffraction direction of the reproduced light to the direction of the image 31 of the first master hologram.

FIG. 7 illustrates the production of a Lippmann hologram by another method. Here, the first master hologram made with the recording optical system shown in FIG. 3 is set at a position of 59° in exactly the same direction and orientation as during recording. Using the concave mirror 56 of the first master hologram, the reproduction light R is made to enter from the direction completely opposite to the reference light P shown in FIG. This reproduction light R has a conjugate wave relationship with the reference light P shown in FIG. Then, the first
A reproduced image 57' appears at the same position as the subject in Figure 3 by the master hologram 59'.Therefore, a hologram dry plate 61 is set, and the light that forms this real image is designated as the object beam Q. A reference beam P converging on the convergence point 66 is made incident from the opposite direction, and is recorded on the hologram dry plate 61 by interference between the object beam Q and the reference beam P, thereby producing an image-type Lippmann hologram.

In other words, the same Lippmann hologram as the hologram of the first embodiment described above can be produced in the two steps shown in FIGS. 3 and 7. However, in the recording optical system of FIG. 7, in order to obtain convergent light that converges on the convergence point 66, the lens 65 needs to have a large diameter or a small F number (short focal length).

In particular, if you create an image-type Lippmann hologram with an area that can be used for an on-vehicle meter, the hologram dry plate 6
The area of 1 is at least 100ma + (vertical) x 200mm
(horizontal), and in this case, the lens 65 has an effective aperture of 8
00m and a focal length of about 400IIIm. However, such a large-diameter lens may pose technical constraints that cannot be ignored when producing an image hologram.

Therefore, when producing an image-type Lippmann hologram with an area large enough to be used as an on-vehicle meter, the three-step recording method according to the first embodiment is not subject to the technical limitations of the other embodiments. Lippmann holograms can be easily produced.

Next, with reference to FIG. 1, it will be explained how this image-type Lippmann hologram removes ghost images. Here, the reproduction light source 34 is a diverging light source that makes the reproduction image 39 appear at the normal position at the time of recording.

The imaging distance and imaging direction at this time can be found from the following equations.

・・・・・・・・・(2) Here, the subscripts t, C, O, and r represent the reconstructed image, the reconstructed light, the object light during recording of the Lippmann hologram, and the reference light, respectively, and R indicates their The distance from the hologram origin, θ is the angle measured from their H axis, and λ is the wavelength.

The disturbance light 100 at the position shown in FIG. 1 is the Lippmann hologram 3.
3, the ghost image visible range 42 is expressed by equation (1),
In (2), Rc=co, λC=λ0. From θC,
It can be seen that the image is reproduced at position 42 in FIG.

From this, compared to the normal image visible area 41, the ghost image visible area is located at a position where it cannot be seen from the normal driver's sitting position, that is, is far from the 99% eye range 39 when facing downward. Drivers cannot see ghost images.

FIGS. 8 and 9 show examples of display images of the meter display device.

As shown in FIG. 1, the light emission color of the light emitting pointer 350 is red, and the three-dimensional scale 39-2 is an image reproduced from the hologram 33.
, if the reproduced color of the number 39-1 is green, these overlapping parts 39-A are colored in accordance with the intensity ratio of red and green (for example, yellow).
It can be seen as Therefore, this light emitting pointer 3
By changing the shape of the overlapping portion of 5, the numeral 39-1, and the scale 39-2, various display designs can be created. Also, the 9th
As shown in the figure, the respective distances l7, 2□, 2. Needless to say, can be arbitrarily set as a subject during recording.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram showing an automotive hologram meter according to an embodiment of the present invention, Fig. 2 is a partial sectional view of the hologram meter shown in Fig. 1, and Figs. 3 to 5 are recording optical systems for producing Lippmann holograms. FIG. 3 shows the first embodiment of the
FIG. 4 shows a recording optical system for producing a master hologram, FIG. 4 shows a recording optical system for producing a second master hologram, FIG. 5 shows a reproduction optical system for an image type Lippmann hologram, and FIG. FIG. 7 shows a reproduction optical system for an image-type Lippmann hologram, and FIG. 8 shows another example of a recording optical system for producing a Tubmann hologram.
FIG. 9 is a diagram showing a reproduced image of the numbers and scale of a hologram meter, and FIGS. 10 (A) to (C) are conceptual diagrams of a structural example of a conventional hologram meter, a recording optical system, and a reproducing optical system, respectively. 31... Image of first master hologram, 32... Image of second master hologram, 33... Lippmann hologram for numerical scale, 34... Reproducing light source, 35... Light emitting pointer, 36... Light emitting pointer drive unit, 37°3
8... Smoke board, 39... Reproduction image. Representative Patent Attorney Takashi Okabe Figure 6

Claims (1)

[Claims] (1) When reproducing a master hologram that records meter information, the light that reproduces the real image is used as object light, and from the opposite direction, diverging light from a diverging point or converging light converging to a converging point A Lippmann hologram in which a reproduced image of the master hologram is re-recorded using light as a reference beam; and reproduction in which illumination is performed from below to above at a predetermined mounting angle with respect to the normal line of the Lippmann hologram, and from the front side of the Lippmann hologram. a light source; and a smoke plate provided in front of the Lippmann hologram and the reproduction light source and having a predetermined transmittance to reduce external light incident on the surface of the Lippmann hologram from the outside, and a master reproduced from the Lippmann hologram. A vehicle-mounted hologram meter, characterized in that the Lippmann hologram and a reproduction light source are arranged to observe reproduction meter information through a predetermined image of the hologram. (2) The vehicle-mounted hologram meter according to claim 1, wherein the mounting angle of the reproduction light source is greater than about 30 degrees. (3) The vehicle-mounted hologram meter according to claim 1, wherein the reproduction light source is provided near a position geometrically equivalent to the divergence point or convergence point during recording of the Lippmann hologram. (4) The vehicle-mounted hologram meter includes a needle-like self-luminous display needle portion located in a plane close to a spatial reproduction surface where reproduced meter information reproduced from the Lippmann hologram is located, and the display needle portion. The vehicle-mounted hologram meter according to claim 1, which is an analog type meter comprising a drive unit that rotates the hologram meter within the plane. (5) The vehicle-mounted hologram meter according to claim 3, wherein the reproduced meter information includes a meter number and a meter scale, and the meter number is located spatially in front of the meter scale. (6) The Lippmann hologram stores meter information as the first
recording on a master hologram, recording an information reproduction image of the first master hologram on a second master hologram,
When reproducing the second master hologram, a light for reproducing a real image is made incident as an object beam, and a diverging light is made incident as a reference beam from a divergence point in the opposite direction, thereby re-recording the information reproduction image of the second master hologram. 2. The vehicle-mounted hologram meter according to claim 1, wherein a Lippmann hologram is produced by: (8) The Lippmann hologram stores meter information as the first
After recording on the master hologram, a light for reproducing a real image during reproduction of the first master hologram is incident as an object beam, and a reference beam is incident from the opposite direction to a convergence point on the incident side of the object beam. 2. The vehicle-mounted hologram meter according to claim 1, wherein a Lippmann hologram is produced by re-recording the information reproduction image of the first master hologram.