Process and device for producing a hologram, hologram and illumination device for a vehicle

Abstract

A process is provided for producing a hologram that can be applied in particular to a curved carrier, characterized by the process steps of bending a flat, photosensitive recording material and projecting the hologram into the curved recording material.

Claims

1. A process for producing a hologram, the process comprising the following process steps: bending a flat, photosensitive recording material by moving at least one roller or at least one sphere in at least two directions; and projecting the hologram onto a curved recording material.

2. The process in accordance with claim 1, wherein the hologram produced acts as a master hologram for production of replica holograms, or in that the hologram produced is a replica hologram.

3. A device for producing a hologram, the device comprising: a light source for generating a laser beam; a holder for a flat, photosensitive recording material; at least one roller or at least one sphere positioned and located directly adjacent or indirectly adjacent to the photosensitive recording material, the at least one roller or the at least one sphere being moveable in at least two directions to bend the photosensitive recording material; and wherein the hologram is projected onto the photosensitive recording material with the light originating from the light source.

4. A process for producing a hologram using the device in accordance with claim 3, the method comprising the steps of: bending of a flat, photosensitive recording material; and projecting the hologram onto a curved recording material.

5. The device in accordance with claim 3, wherein the device comprises at least one substrate to which the recording material is applied; and wherein when the recording material is in a state of being applied to the at least one substrate, the hologram is projected onto the recording material.

6. The device in accordance with claim 5, wherein the at least one substrate is bendable such that the substrate is bent together with the recording material, or the substrate is curved, wherein the device further comprises a plurality of substrates curved in different ways.

7. The device in accordance with claim 3, wherein the device produces replica holograms, wherein a master hologram is applied to a first side of a substrate, and wherein the photosensitive recording material is applied to a second side of the substrate.

8. The device in accordance with claim 7, wherein the light source is a scanning laser light with which a linear or punctiform intensity distribution is scanned over the master hologram, or as a laser light source for producing a flat illumination of the master hologram, or as a laser light source for producing laser pulses.

9. The device in accordance with claim 3, wherein the device comprises a moveable lens for shaping the light originating from the light source.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

(2) FIG. 1 is a schematic side view of a detail of a first embodiment of an inventive device.

(3) FIG. 2 is a schematic side view of a detail of a second embodiment of an inventive device.

(4) FIG. 3 is a schematic side view of a detail of a third embodiment of an inventive device.

(5) FIG. 4 is a schematic side view of a detail of a fourth embodiment of an inventive device.

(6) FIG. 5 is a schematic side view of a master hologram produced with a device according to FIG. 4.

(7) FIG. 6 is a schematic side view of a detail of a fifth embodiment of an inventive device.

(8) FIG. 7 is a perspective view of a detail of a sixth embodiment of an inventive device.

(9) FIG. 8 is a perspective view of a detail of a seventh embodiment of an inventive device.

(10) FIG. 9 is a schematic side view of a detail of a device for producing a hologram according to the current state of technology.

DETAILED DESCRIPTION OF THE DRAWINGS

(11) In the figures, identical components and components with identical functions have been given the same reference numbers.

(12) FIG. 9 shows the production of a master hologram with a process according to current state of technology in which a photosensitive recording material 1 is illuminated by means of reference beams 2, some of which impinge from different directions. In this way, it is possible to optimize the master hologram produced or a replica hologram produced with the aid of the master hologram for application to a curved substrate.

(13) In order to replicate the master hologram produced using a process according to FIG. 9, it can be illuminated by reference beams some of which impinging from different directions as shown in FIG. 9, where a photosensitive recording material serving to inscribe the replica hologram is arranged parallel to the master hologram. In this context, both the master hologram and the recording material for the replica hologram are of a flat design.

(14) As an alternative to this, an inventive device or an inventive process can achieve an illumination of the master hologram 10 and the recording material 11 without some reference beams 12 impinging from different directions (see FIG. 1). All of the reference beams 12 shown in this first sample embodiment run parallel to each other or parallel to the vertical in FIG. 1. In this respect, the master hologram 10 is, for example, connected, specifically laminated, to the photosensitive recording material 11 for the replica hologram via a flexible substrate 13.

(15) The substrate 13 acts as a flexible and transparent carrier substrate that simplifies positioning the master hologram 10 taking the form of a film and the recording material 11 taking the form of a film relative to each other.

(16) As an alternative, there is also the possibility of the master hologram 10 and the recording material 11 making direct contact with each other, which makes it possible to dispense with the substrate 13 between the two.

(17) The substrate 13 with the master hologram 10 and the recording material 11 is guided over at least one roller 14, which gives rise to a curvature 15 of the substrate 13 and the master hologram 10 or, as the case may be, the recording material 11. The roller 14 can be moved upwards and downwards in FIG. 1 as well as to the right and left (see for example the arrows 16, 17 in FIG. 1), which makes it possible to change the shape and size of the curvature 15. In FIG. 1, the roller 14 makes contact on the lower side of the recording material 11. It can, however, also make contact on the upper side of the master hologram 10.

(18) By deforming the substrate 13 by means of the at least one roller 14, it is possible to reconstruct virtually any geometry of the hologram or of an intended carrier. This means that, in contrast to the current state of technology, changing the reference angle according to FIG. 9 is achieved through the curvature 15 of the master hologram 10 or the recording material 11 instead of reference beams at different angles. To make it possible to reconstruct the variation in the reference angles in the replication process and to nevertheless make it possible to use a flat wave for the illumination, the master hologram 10 and the recording material 11 are curved in such a way that the illumination of the curved master hologram 10 or the curved recording material 11 corresponds to an illumination with variable reference angles.

(19) In the second sample embodiment that can be seen from FIG. 2 several rollers 14 are provided for instead of one roller. This makes it possible to generate more complex geometries of the substrate 13 using the master hologram 10 and the recording material 11.

(20) In the sample embodiment shown, a roller 14 makes contact at the lower side of the recording material 11, whereas two rollers 14 make contact on the upper side of the master hologram 10. It is entirely possible to provide for fewer or more than three rollers 14 and/or another arrangement or distribution of the rollers.

(21) The embodiment according to FIG. 2 schematically indicates optical means 18 in addition that comprise at least two lenses 19 and 20. One or both of the lenses 19, 20 shown can be movable in the direction of propagation of the reference beam 12 (see the arrow 21). This makes it possible to implement wide reference angle or divergence angle corrections or also a variable illumination.

(22) Instead of the rollers 14, the third sample embodiment shown in FIG. 3 provides for a plurality of spheres 22 that are arranged both on the upper sides and on the lower side of the substrate 13 with the master hologram 10 and the recording material 11. The spheres 22 can be movable in three directions vertical to each other. This makes it possible to use a suitable height adjustment of the individual spheres 22 to produce a three-dimensional shape of the substrate 13 with the master hologram 10 and the recording material 11 or, as the case may be, the replica hologram surface.

(23) Both the spheres 22 and the rollers 14 can also serve to press the master hologram 10 and/or the recording material 11 to the substrate 13.

(24) FIG. 4 shows an arrangement comparable to FIG. 1. In this sample embodiment, however, corresponding illumination of a photosensitive recording material 11 applied to a substrate 13 produces a master hologram. In this respect, the contour or the curvature 15 of the recording material 11 can correspond to the contour of a carrier or a sheet to which, for example, the hologram is to be applied in an illumination device for a vehicle, in particular a headlamp for a vehicle.

(25) With a corresponding number of rollers 14 or spheres 22, it is possible to reproduce in this respect the contour or curvature 15 of the carrier comparatively well.

(26) FIG. 5 shows schematically a master hologram 10 produced in this manner featuring a corresponding curvature 15. In the following replication for mass production of a large number of replica holograms, the master hologram 10 produced in such a manner is used, for example, in a device depicted in FIG. 7 to copy the holographic information of the master hologram into new recording materials in each case.

(27) The device according to FIG. 7 comprises a holder 23 for the master hologram 10 and a feed for the recording material 11. In this context, the recording material 11 can take the form of a film that can be wound off a roll. The device further comprises an illumination device featuring a light source and optical means for shaping the light originating from the light source. In this context, the light source can take the form of a scanning laser light source with which a linear or punctiform intensity distribution can be scanned over the master hologram or take the form of a laser light source for producing a flat illumination of the master hologram or, in the case of diverging reference angles, the form of a laser light source for producing laser pulses.

(28) The holder 23 for the master hologram 10 and the recording material 11 to be illuminated for the first time for creating the replica hologram must be designed in such a way that a defined distance between the master hologram 10 and the new recording material 11 is maintained to each other. In this context, it is possible to use a glass sheet with a defined thickness acting as substrate 13 onto one side of which, the upper side for example, the master hologram 10 has been laminated and onto the other side of which, for example the lower side, the recording material has been laminated. This is shown as an example in FIG. 6.

(29) In the current state of technology, flat, planar glass sheets are always used as substrate or carrier. In the embodiment according to FIG. 8, it is indicated that the holder 23 of the device for replication purposes is designed in such a way that curved and bent geometries can be specified as substrate or carrier. In this context, it is possible, for example, to use bendable, flexible glass sheets as a substrate 13 that are held in a shaping holder 23. FIG. 8 further indicates that a conventional holder with a flat, planar sheet acting as a substrate 13 can be replaced in the device for replication purposes with the bendable substrate 13.

(30) Instead of a bendable glass sheet, a rigid, curved glass sheet can also be used as substrate 13, especially when the thickness of the flexible glass sheet is not sufficient for the defined distance between the master hologram 10 and the new recording material 11. The bending or curving of glass sheets is known, for example, from curved windows, vehicle screens or curved displays and televisions.

(31) In this context, several, specifically any number of holders with glass panes with different curves acting as substrate 13 may be provided for in order to facilitate common production on a corresponding replication device for different geometries and projects. The necessary variability in the mechanics, in particular the guides for contact rollers in order to laminate the recording material onto the curved glass sheet is to be provided for in order to be able to use the different geometrical holders and glass sheets.

LIST OF REFERENCE NUMBERS

(32) 1 photosensitive recording material 2 Reference beam 10 Master hologram 11 photosensitive recording material 12 Reference beam 13 Substrate 13 Substrate according to the current state of technology 14 Roller 15 Curvature 16, 17 Arrows to indicate the movability of the roller 18 Optical means 19, 20 Lens 21 Arrow to indicate the movability of the lens 22 Sphere 23 Holder