JP2676864B2 - Automotive hologram meter - Google Patents

Description

The present invention relates to a meter display device using a hologram,
In particular, the present invention relates 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 In an automobile or the like, a meter for displaying data relating to the running of the vehicle such as its speed and engine speed is attached, and the meter display is made two-dimensionally. However, a three-dimensional display instrument using a hologram for display was proposed for the purpose of increasing the quality of the instrument and shortening the time for visual inspection of the instrument during operation.
A patent application was filed on the 16th for an invention named "Vehicle warning display device using hologram" (Japanese Patent Application No. 62-13217).

Referring to the hologram meter according to this prior invention, its schematic structure 1 is shown in FIG. 10 (A), and a Lippmann hologram recording optical system for producing a hologram to be used is shown in FIG.
FIG. 10B shows the reproducing method, and FIG. 10C shows the reproducing method.

In FIG. 10 (A), 3 is a numeral scale hologram in which numerical scale information is recorded, 5 is a pointer hologram in which a pointer pattern is recorded, 7 is a reproduction illumination light source, 9 is a reproduced image, 11 is a drive section of the pointer hologram, Shown respectively. FIG. 10 (B) schematically shows the production of a corner hologram, 13 is a subject such as a numerical scale, 20 is a laser light source that illuminates the subject with reference light 15, 17 is object light from the subject, and 19 is a hologram dry plate. Are shown respectively. In FIG. 10C, 21-a and 21-b are reproduction illumination light sources and 23
Is a hologram produced by developing the dry plate recorded in FIG. 10 (B), and 25-a and 25-b are reproduced images by respective reproduction illumination light. That is, when the hologram produced in the state of FIG. 10 (B) is irradiated with reproduction illumination light from the same position as the laser of FIG. 10 (B), as shown by 21-a in FIG. 10 (C). , The reproduced image appears at the position 25-a which is exactly the same as the position of the subject at the time of hologram recording. However, when the reproducing irradiation light is illuminated from a position different from that, for example, a position such as 21-b, a reproduced image emerges at a position 25-b which is completely different from the position of the subject at the time of recording. Moreover, when these are irradiated at the same time, two reproduced images also emerge at the same time.

[Problems to be solved by the invention]

In the above laser hologram meter for a vehicle, the driver is dazzled by a plurality of reproduced images (hereinafter referred to as ghost images) generated by sunlight or other light sources other than the predetermined reproduction illumination light. The present invention provides a vehicle hologram meter capable of avoiding a plurality of such dazzles.

[Means for solving the problem]

The present invention is intended to solve the above-mentioned problems, and the invention according to claim 1 uses object light as light for reproducing a real image when reproducing a master hologram in which meter information is recorded. A divergence light from a divergence point or a convergent light that converges to a convergence point as a reference light, and a Lippmann hologram in which a reproduced image of the master hologram is re-recorded,
A reproducing light source that certifies from the lower side to the upper side of a predetermined mounting angle with respect to the normal line of the Lippmann hologram and on the front side of the Lippmann hologram, and is provided in front of the Lippmann hologram and the reproducing light source, and from the outside, A smoke plate having a predetermined transmittance to reduce external light incident on the surface of the Lippmann hologram, and the Lippmann hologram and the Lippmann hologram to observe reproduction meter information through a predetermined image of the master hologram reproduced from the Lippman hologram. A reproduction light source is arranged, the Lippmann hologram records the meter information in a first master hologram, records an information reproduction image of the first master hologram in a second master hologram, and reproduces the second master hologram. Object light is the light that reproduces the real image Then, the divergent light is made incident as a reference light from a divergence point in the opposite direction to re-record the information reproduction image of the second master hologram to produce a Lippmann hologram. To do.

According to a second aspect of the present invention, the Lippmann hologram according to the first aspect of the invention is recorded with meter information in a first master hologram, and thereafter, light for reproducing a real image when reproducing the first master hologram is incident as object light. Then, from the opposite direction, a reference light that converges to a converging point on the incident side of the object light is made incident, and the information reproduction image of the first master hologram is rerecorded and replaced with a Lippmann hologram produced. The technical means of doing is adopted.

[Action]

When a reproduction / divergence light source is installed at a point (position) equal to the divergence point or the convergence point of the reference light used when the reproduced image of the master hologram is recorded again on the Lippman hologram, and the Lippmann hologram is irradiated, re-recording is performed. A regular reproduction information image appears at a position equal to and a regular image of the master hologram is formed on the side opposite to this image. This reproduced information image can be observed only in the region between the straight lines connecting both ends of the Lippma hologram and both ends of the reproduced image of the master hologram. That is, the regular reproduced image of the recorded Lippmann hologram can be observed only through the regular image of the master hologram. Moreover, the reproduction light source is arranged so that the normal reproduction image of the Lippmann hologram can be observed through the normal image of the master hologram when referred to from below with respect to the normal line of the Lippman hologram. Further, the regular reproduced image of this Lippmann hologram is observed through a smoke plate having a predetermined transmittance in front of it.

〔The invention's effect〕

As described above, since the Lippmann hologram in which the meter information recorded in the master hologram is re-recorded is reproduced by the reproducing light source from below, this regular reproduced image is the corresponding regular master hologram image reproduced from the Lippmann hologram. The master hologram image that is observed only through the light source of sunlight or street light that is incident from above or from the rear direction is generated below the normal image, and thus is reproduced by such a light source. Since the observation of the ghost image is avoided, it is possible to obtain extremely practical visibility as a vehicle-mounted hologram meter.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the overall structure of a hologram meter for automobiles, and FIG. 2 shows a partial sectional view of the meter.

In FIG. 1, the regular image of the first master hologram
31 shows the relative positional relationship between the regular image 32 of the second master hologram and the image type Lippmann hologram 33. The regular image 31 of the first master hologram and the regular image 32 of the second master hologram are the positions reproduced from the Lippmann hologram 33 when illuminated from the position of the reproduction illumination light source 34, but are actually transparent. Therefore, the statue cannot be seen.

Here, almost all drivers (99
The positional relationship between the images 31 and 32 of the first and second master holograms will be described with respect to the 99% eye range (observation region) 39 in which both eyes (%) enter. From the highest point 39-1 of 99% eye range 39,
Optical paths L ₁ and L connecting the upper and lower ends of the Lippmann hologram 33
₂ and its extension pass through the area of the regular images 31 and 32 of the first and second master holograms, and the lowest point of the 99% eye range 3
The optical paths L ₃ and L ₄ connecting the upper and lower ends of the Lippmann hologram 33 from 9-2 and their extensions pass through the regions of the regular images 31 and 32 of the first and second master holograms. Like this, 9
Optical path L connecting the 9% eye range 39 to the Lippmann hologram
A region that is _{1 to} L ₄ and passes through the regions of the regular images 31 and 32 of the first and second master holograms becomes a regular image visible region 41,
In this area 41, a reproduced image of the scale recorded on the Lippmann hologram 33 can be visually recognized. In other words, when both eyes of the driver are located within the 99% eye range 39, the driver can certainly see the regular reproduced image from the Lippmann hologram 33.

Numerical scales such as a tachometer and a speedometer are recorded on the Lippmann hologram 33, and the reproduced light causes the reproduced image 39 to be three-dimensionally emerged on the reproducing surface behind it. This Lippmann hologram is attached to a position near the dial of a conventional meter. 34 is a Lippmann hologram
A white light bulb is used as a reproduction light source that irradiates 33 with reproduction irradiation light. The reproduction light source 34 illuminates the normal (H) of the Lippmann hologram from below the predetermined mounting angle to above and from the front side of the Lippmann hologram 33. This mounting angle is preferably in the range of greater than about 30 degrees, and is set to 45 degrees in this embodiment.

35 is a self-luminous display needle (light emitting pointer), which is shown in FIG.
As shown in FIG. 9, a needle-like or thin prismatic lightweight one is used. The light emission pointer 35 is located in a plane close to the reproduction surface 39-0 where the reproduction image 39 of the Lippmann hologram 33 is located, and is rotated and driven in this plane by the light emission pointer driving unit 36 such as a motor.

The light emitting pointer 35 is supplied with power from the vicinity of the shaft of the motor through a lead wire (not shown). For further simplification, the light emitting pointer 35 may be illuminated by a needle-shaped member whose surface is coated with a fluorescent paint and a reproduction light source 34.

As shown in FIGS. 8 and 9, the reproduced image 39 is
It is aesthetically preferable that the number 39-1 for meters and the scale 39-2 for meters are provided, and the similarity 39-1 is spatially located in front of the scale 39-2. Or, the number 39-1 is scaled 39-2.
The spatial positional relationship of may be reversed.

In FIGS. 1 and 2, 37 is a predetermined transmittance (about 20%)
A smoke plate made of the above material, for example, dark gray acrylic resin or the like is preferable. This smoke plate 37 is provided in front of the Lippmann hologram 33 and the reproduction light source 34, and is installed in the meter from the disturbance light 100 shown in FIG. 1, such as sunlight entering from the side of the vehicle or the rear window glass, a street light, and the like. It is provided to reduce the incidence on the surface of the Lippmann hologram 33. With this smoke plate 38, Lippmann hologram
33 It is possible to prevent the driver's face from being reflected on the surface.

Next, the principle of avoiding recording and reproduction of the Lippmann hologram 33 and observation of the ghost image will be described. Third
The figure shows the recording optical system for making the first mounter hologram,
FIG. 4 shows a recording optical system for producing the second master hologram, and FIG. 5 shows a recording optical system for producing the Lippmann hologram.

A method of manufacturing the first master hologram will be described with reference to FIG. The laser light oscillated from the recording laser 51 is
The beam splitter 52 splits the beam into two, one of which is a mirror 53-
The reference light P is made incident on the hologram dry plate 59 by 1,53-2, Lens 54-1 and the concave mirror 56. At this time, the reference light P is parallel light. The other light is the mirror 53-3,53-
Diffuser 58, subject 57 through 4,53-5, lenses 54-2, 55
The transmitted light is incident on the dry plate 59 as the object light Q. The object light P and the reference light Q interfere with each other near the dry plate 59, and the interference fringes are recorded on the dry plate. By developing this, a first master hologram is created. As the subject, a scale for meters and a three-dimensional representation of numbers are used.

Next, a method of manufacturing the second master hologram will be described with reference to FIG. Here, the first master hologram created by the recording optical system of FIG.
Set it to the 59 'position. A concave mirror 56 is used for this first master hologram, and reproduction light R is made incident from the direction completely opposite to the reference light P of FIG. The reproduction light R has a conjugate wave relationship with the reference light P shown in FIG. Then, the first master hologram 59 'causes a reproduced image 57' of a real image to appear at the same position as the position of the subject in FIG. Therefore, the hologram dry plate 60 is set, and the light that forms the real image is used as the object light Q, and the parallel reference light P is made incident from the same direction as the object light Q to cause interference fringes due to the interference between the object light Q and the reference light P. Is recorded on the hologram drying plate 60. This is developed and the second
A master hologram is created.

Next, referring to FIG. 5, a method of manufacturing a Lippmann hologram will be described. Here, the second master hologram made by the recording optical system of FIG.
Set to the 60 'position in the direction. The concave mirror 56 is used for this second master hologram, and the reproduction light R is made incident from the direction completely opposite to the reference light in FIG. The reproduction light R has a conjugate relationship with the reference light P of FIG. Then, the second master hologram 60 'causes the reproduced image 5 of the real image to be exactly at the same positions as the positions of the first master hologram and the subject in FIG.
9 ″, 57 ″ emerges. Therefore, hologram dry plate 61
Is set between the first master hologram 59 ″ and the subject 57 ″, the light that forms this real image is the object light Q, and the reference light that diverges from the divergence point 63 (lens 54-2) in the opposite direction P is made incident, and interference fringes due to the interference between the object light Q and the reference light P are recorded on the hologram dry plate 61. This is developed to produce a Lippmann hologram.

Next, the reproduction of the Lippmann hologram produced through the three steps of FIGS. 3, 4, and 5 as described above will be described with reference to FIG. Reference numeral 34 denotes 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 bulb is used. The Lippmann hologram recorded in FIG. 5 is set as shown in 33 of FIG. 6, and when the reproduction light R having a divergence point 34 is referred to, it is recorded in FIG.
Image 31, 4th of the second master hologram 59 used in the figure
The image 32 of the second master hologram 60 recorded in FIG. 5 and used in FIG. 5 is reproduced, and the object 57 in FIG.
A reconstructed image 39 of is emerged. It should be noted that the reproduction light source 34 is preferably in a geometrically uniform position corresponding to the divergence point 63, but may be in the vicinity of that position. The vicinity here does not cause a problem because the display reproduction image looks distorted. Say the range. The images 31 and 32 and the reproduced images of the first and second master holograms shown in FIG. 6 correspond to those in FIG. This reproduced image 33 is
It can be seen through the image 31 of the first master hologram and the image 32 of the second master hologram (observer 90), but when viewed from a position deviated from the image 31 of the first master hologram like the observer 91, this reproduction The statue cannot be seen. This is a characteristic of the Lippmann hologram obtained by re-recording the above-mentioned master hologram. In other words, the Lippmann hologram that re-records the master hologram is
There is an effect of limiting the diffraction direction of the reproduction 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 produced by the recording optical system of FIG. 3 is set at the position 59 ′ in the same direction and direction as when recording. Using the concave mirror 56 of the first master hologram, the reproduction light R is made incident from the direction completely opposite to the reference light P of FIG. This reproduction light R is the third
Since the first reference hologram P has a conjugate wave relationship with the reference light P in the figure, the first master hologram 59 'causes the reproduced image 57' to appear at the same position as the position of the subject in FIG. Therefore, the hologram dry plate 61 is set, the light that forms this real image is used as the object light Q, and the reference light P that focuses on the convergence point 66 is incident from the opposite direction, and the object light Q and the reference light P By recording on the hologram dry plate 61 by interference, an image type Lippmann hologram is produced.

That is, the same Lippmann hologram as the hologram of the first embodiment described above can be produced in the two steps of FIGS. 3 and 7. However, in the recording optical system of FIG. 7, in order to obtain convergent light that converges to the converging point 66, the lens 65 needs to have a large aperture or a small F number (short focal length). In particular, when an image-type Lippmann hologram with an area that can be used for an on-vehicle meter is manufactured, the hologram dry plate 61 has an area of at least 100 mm (length) x 200 mm.
(Horizontal), in which case the lens 65 has an effective aperture of 800 m
m, focal length of about 400 mm is required. However,
Such a large-diameter lens may be a non-negligible technical constraint in producing an image hologram.

Therefore, when making an image type Lippmann hologram with an area that can be used as a vehicle-mounted meter,
The three-step recording method according to the embodiment can easily produce a Lippmann hologram without being subjected to the technical restrictions as in the other embodiments.

Next, how the image type Lippmann hologram removes a ghost image will be described with reference to FIG. Here, the reproduction light source 34 is a divergent light source that makes the reproduction image 39 stand out at a regular position during recording.

Now, the image forming distance and the image forming direction at this time can be understood from the following expressions.

Here, the subscripts i, c, o, and r are the reproduced image, the reproduced light, and
Object light and reference light at the time of recording a Lippmann hologram are represented, R is a distance from the hologram origin, θ is an angle measured with respect to their H axis, and λ is a wavelength.

The disturbance light 100 at the position shown in FIG.
Incident on the ghost image visible region 42,
From (2), it can be seen from Rc = ∞, λc = λo, θc that reproduction is performed at the position 42 in FIG. From this, when the ghost image visible range is downward compared to the normal image visible range 41,
Since it is far from the position where it can not be seen from the normal driver's sitting posture, that is, 99% eye range 39,
The driver cannot see the ghost image.

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

As shown in FIG. 1, if the emission color of the emission pointer 35 is red, the solid scale 39-2 which is an image reproduced from the hologram 33, and the reproduction color of the numeral 39-1 are green, these overlapping portions 39 are formed. −
A can be seen as a color (for example, yellow) according to the intensity ratio of red and green. Therefore, this luminous pointer 35 and the number 39
-1, various display designs can be produced by changing the shape of the overlapping portion of the scale 39-2. Also, three-dimensional scale as shown in Fig. 9
39-2, numeral 39-1, light emitting pointer 35, hologram 39-
It goes without saying that the respective distances l ₁ , l ₂ , l ₃ from 0 (33) can be arbitrarily set as the subject at the time of recording.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an automobile hologram meter according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the hologram meter of FIG. 1, and FIGS. 3 to 5 are recording optical systems for producing a Lippmann hologram. FIG. 3 shows the first embodiment of FIG.
FIG. 4 shows a recording optical system for producing a master hologram, FIG. 4 shows a recording optical system for producing the second master hologram, FIG. 5 shows a reproducing optical system for an image type Lippmann hologram, and FIG. FIG. 7 shows a reproduction optical system for an image type Lippmann hologram, FIG. 7 shows another embodiment of a recording optical system for producing a Lippmann hologram, and FIG.
The figures of the hologram meter and the reproduced image of the scale of FIG. 9 are shown, and FIGS. 10A to 10C are conceptual diagrams of a conventional hologram meter structure example, 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 numeral scale, 34 …… Reconstruction light source, 35 …… Emission pointer, 36 …… Emission pointer drive unit, 37 , 38 …… Smoke plate, 39 …… Reproduced image.

Claims (2)

(57) [Claims] 1. When reproducing a master hologram in which meter information is recorded, light for reproducing a real image is used as object light, and divergent light from a divergent point or convergent light converged to a divergent point from the opposite direction to the reference light. As a Lippmann hologram re-recording a reproduced image of the master hologram, a reproduction light source that proves from the lower side to the upper side of a predetermined mounting angle with respect to the normal line of the Lippmann hologram, and on the front side of the Lippmann hologram, The Lippmann hologram and the reproduction light source, and a smoke plate having a predetermined transmittance for reducing external light incident on the surface of the Lippmann hologram from the outside, and a predetermined master hologram reproduced from the Lippmann hologram. To observe reproduction meter information through the image of And the reproduction light source, the Lippmann hologram records the meter information in a first master hologram, records an information reproduction image of the first master hologram in a second master hologram, and records the second master hologram in the second master hologram. At the time of reproduction, light for reproducing a real image is made incident as object light, and divergent light is made incident as reference light from a divergence point in the opposite direction to re-record the information reproduced image of the second master hologram to produce a Lippmann hologram. In-vehicle hologram meter. 2. When reproducing a master hologram in which meter information is recorded, light for reproducing a real image is used as object light, and divergent light from a divergent point or convergent light converged to a divergent point from the opposite direction to the reference light. As a Lippmann hologram re-recording a reproduced image of the master hologram, a reproduction light source that proves from the lower side to the upper side of a predetermined mounting angle with respect to the normal line of the Lippmann hologram, and on the front side of the Lippmann hologram, The Lippmann hologram and a reproduction light source, and a smoke plate having a predetermined transmittance to reduce external light incident on the surface of the Lippmann hologram from the outside, and a predetermined master hologram reproduced from the Lippmann hologram. To observe reproduction meter information through the image of And the reproduction light source, the Lippmann hologram records meter information in a first master hologram, and then makes a light that reproduces a real image at the time of reproduction of the first master hologram incident as object light, and a direction opposite to this. From the above, an on-vehicle hologram meter is produced by making reference light converged at a converging point on the incident side of object light to re-record the information reproduction image of the first master hologram to produce a Lippmann hologram.