JP2002523804A - Method and apparatus for producing hologram - Google Patents

Abstract

(57) Abstract: The present invention produces a hologram in which at least two light beams (L, R) in which a first light beam (L) is formed and modulated interfere with each other in a photosensitive layer (22). Method and apparatus. In a method aspect, the formation is performed while maintaining the length ratio of the rays to one another. On the surface of the device, a first optical system is provided for forming at least a first light beam (L), which advantageously comprises a pair of parabolic mirrors (18).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method for producing a hologram in which at least two light beams, on which a first light beam is formed and modulated, interfere with a photosensitive layer. The invention is also directed to an apparatus for performing the method.

[0002]

Problems to be solved by the prior art and the invention

The hologram is an interference fringe generated by superimposing a first light beam affected by the object and a reference light beam not affected by the object. In order for this interference fringe to be able to record information for all object points, all rays coming from these object points must simultaneously interfere with the reference ray bundle. Rays come from objects, even if the optical distances between the individual object points and the interference points are different, considering that the rays are not a series of formations but composed of multiple wave trains The above conditions are sharpened in the sense that the wave trains of all the rays must simultaneously overlap at the point of interference. When a wave train coming from an object point hits an interference point and the wave train of another object point is already separated from the interference point, the object point does not become a hologram. The connection of each wave train is called coherence, and the degree of connection is called coherence length.

In a classic hologram, object light is affected by the object itself. This results in a series of disadvantages. That is, the equipment used is large and optically unstable, lasers have high demands on energy and coherence length, and optical pretreatment of objects requires sufficient experience.

Therefore, two-dimensional images representing different viewing angles with respect to an object or an object point are generated, and these images are holographically converted into sub-holograms sequentially in different regions of the photosensitive layer by modulating the object light. It has been proposed to image. In this way, it is only necessary to always expose a small area, which requires relatively low laser energy. Two-dimensional images can be obtained photographically, for example by making stereoscopic images, or derived from computer-generated objects by calculating different viewing angles and outputting each as a matrix. Further, a combination of both variations is also possible. Holograms synthesized from sub-holograms can have vertical parallax. If not, the object can be viewed from the side but not from above or below. A known apparatus for producing a hologram (EP0814387A2, WO96 / 02)
873) a laser, a beam splitter for splitting the laser light into object light and reference light, a screen for displaying an image of the object, which can modulate the object light, an object light, And a lens system for forming a reference light that interferes with the light. The lens system has a limited acceptance angle, has spherical aberration and chromatic aberration, and affects the mutual length ratio of the object light beam. If the light receiving angle of the lens system is restricted, the hologram can be viewed only from the restricted viewing angle. If the lens system has spherical aberration, a distorted hologram will result. Chromatic aberrations may require a separate lens system for each color if quality requirements are high. Finally, the holographic formation of all object points can occur if, for example, the outer ray travels a longer distance than the inner ray, changing the ray-to-length ratio of the object ray bundle from the light source to the photosensitive layer. A correspondingly large coherence length must be selected so that all rays or their connected wave trains can simultaneously interfere so that an image can be obtained. However, a large coherence length cannot be realized without using an expensive laser.

It is an object of the present invention to provide a method and a device for producing holograms in the field, which supply excellent holograms at a lower cost.

[0006]

[Means for Solving the Problems]

This object is solved in terms of method by the features of claim 1. By forming the first beam bundle while maintaining the length ratio between the beams, a very short coherence length which can be in the order of the thickness of the photosensitive layer and which can be realized with inexpensive lasers In this case, if the optical distance of the reference light is equal to the optical distance of the object light, the modulation of the first light beam completely becomes a hologram. The formation while maintaining the length ratio is performed by at least one pair of parabolic mirrors, where the first parabolic mirror spreads the light beam and the second parabolic mirror focuses the light beam on the photosensitive layer. By doing so, a larger light receiving angle becomes possible and spherical aberration and chromatic aberration are eliminated, which leads to further improvement of the hologram quality and further lowering of the cost of the method for the reasons described above. Such an advantage is particularly effective when light beams for generating a combined hologram are sequentially focused on different regions of the photosensitive layer.

In terms of a device, the above-mentioned problem is solved by the features of claim 7. First
Includes at least one first parabolic mirror instead of a lens, which allows a larger light acceptance angle by focusing the first light beam onto the photosensitive layer. At the same time, spherical aberration and chromatic aberration disappear.

If the first optical system includes a second parabolic mirror and the parabolic mirror can generate a first ray bundle from a light source located at its focal point, this ray bundle Since all light rays travel the same optical distance from the light source to the photosensitive layer, the coherence length can be substantially limited to the thickness of the photosensitive layer. One advantageous light source is the exit of an optical fiber through which the light of a laser, especially a pulsed diode laser, passes. There is a beam deflecting element between the two parabolic mirrors, so that if the beam deflection is advantageously 90 degrees, the light source can be located on a different plane from the photosensitive layer.

[0009] There is a light modulation between the light source and the adjacent first or second parabolic mirror, or between these parabolic mirrors, or between the first parabolic mirror and the photosensitive layer. The light modulator is advantageously configured as a flat screen with controllable light transmission,
For example, it is configured as a liquid crystal display. However, in some cases, it is sufficient to make the optical modulator interchangeable as a diamond scope.

[0010] In order to ensure a sufficiently wide exposure of the photosensitive layer, a light scattering member may be arranged between the first parabolic mirror and the light modulator or between the light modulator and the photosensitive layer. .

A parabolic mirror is an off-axis parabolic mirror having the same parabolic segment.

A second optical system, which may include a lens system instead of a parabolic mirror system, is provided to form a second light bundle. If the second optical system is assigned to each side of the photosensitive layer, the present apparatus can be easily set for producing a transmission hologram and for producing a reflection hologram. The setting described above is simplified if a switching device is provided, by means of which the second light beam can be guided to one of the two surfaces of the photosensitive layer.

If the device and the photosensitive layer are displaceable relative to each other, it is possible, in particular, to sequentially expose different areas of the photosensitive layer, each representing a sub-hologram. Finally, it is intended to assign the same device to each of the colors red, green and blue and to move these colors together relative to the photosensitive layer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

Next, the present invention will be described in detail with reference to embodiments. The accompanying schematic drawings show an apparatus according to the invention.

The exit 6 of the optical waveguide 8 is located at the focal point 2 of the parabolic mirror 4, and coherent light of a laser, not shown, which is a pulse laser diode, passes through the optical waveguide. A focal ray 10 extends between the parabolic mirror 4 and its focal point 2. A plane mirror 14 is arranged in the optical path of the guide beam 12, which is also located in the optical path of the guide beam 16 of the parabolic mirror 18. Guiding rays 12 and 16
Are perpendicular to each other. The inclination of each of these guided rays with respect to the plane mirror 14 is 4
5 degrees. At the focal point 20 of the parabolic mirror 18 having the same parabolic segment as the parabolic mirror 4, there is a photosensitive layer 22 protected on both sides by apertures 24 and 26. A focal ray 32 extends between the parabolic mirror 18 and its focal point 20. In the optical path, a liquid crystal display 34 is arranged on the parabolic mirror side and a diffuser 36 is arranged on the layer side in parallel with the guide light 16. The optical paths outlined above are defined as areas L1 to L4 when the laser light is turned on.
Pass through the object light beam L including. Since this optical path must interfere with the reference beam bundle R to produce the hologram, there are collimator lenses 38 and 40 on both sides of the photosensitive layer, the optical axes 42 and 44 of which are Extending through focal point 20, focal points 46 and 48 of these collimator lenses are located at exits 50 and 52 of light guides 54 and 56.

The mode of action is as follows:

The exit 6 of the optical waveguide 8 acts as a point-like light source, which emits a light cone L 1 whose intensity distribution is rotationally symmetric, which follows the focal ray 10 and which is a parabolic mirror 4. Is reflected as a parallel beam L2 having a non-uniform intensity distribution, which follows the stimulating ray 12. Then, this expanded beam L2
Is guided by a plane mirror 14 deflecting 90 degrees as a beam L3 along a stimulating ray 16 to a parabolic mirror 18, which converts the beam into a beam L3.
As 4, the light is focused toward the photosensitive layer 22 along the focal ray 32, and the non-uniform intensity distribution is eliminated again.

As can be easily understood by following the transition of the light beams of the beams L1 to L4 from the exit 6 of the optical waveguide 8 to the focal point 20 located on the photosensitive layer 22, all the light beams of the beams L1 to L4 are easily understood. Have traveled an equal distance and are simultaneously in focus 20. Therefore, the required length of the connected wave train, that is, the coherence length is almost determined only by the thickness of the photosensitive layer, so that a very inexpensive laser can be used. Since only a plane mirror and a parabolic mirror are used to form the beams L1 to L4, no spherical aberration occurs, which is particularly important for a system having a large receiving angle and a short focal length. Since no chromatic aberration is expected, the focus will be at the same point for any color.

All of these are favorable prerequisites for modulating the expanded beams L1 to L4 with object properties. This modulation is performed when the beam L4 passes through the liquid crystal display 34 as an intensity modulator, and the parabolic mirror 18 to be used is used.
Depending on the geometric dimensions of the light cone L4, which depends on the parameters of
Is exposed from various directions at an intensity set according to the modulation. If the diffraction at the individual pixels of the liquid crystal display 34 is not enough to fully illuminate the preset area of the photosensitive layer 22, the beam L4 will pass through the diffuser 36 further after modulation and be diffracted. The diffused light is distributed by the diffuser over a preset area.

When a further parallel reference beam R is applied to this area, interference fringes are generated, and the interference fringes are emitted as a sub-hologram from an object point related to the sub-hologram and pass through the sub-hologram as a real image or a virtual image. It represents all light in the spatial direction set by L4, or represents a memory block of a holographic memory organized in a block. When the collimator lens 38 directs the reference beam R to the side of the photosensitive layer 22 that is irradiated by the object beam L4, a transmission sub-hologram occurs. When the reference beam R is emitted from the collimator lens 40 arranged on the opposite side of the photosensitive layer 22, a reflection hologram occurs. For this purpose, the reference beam R is switchably split into two optical paths and connected according to the desired hologram type.

Exposure of different areas of the photosensitive layer 22 sequentially in the manner described above results in a hologram synthesized from a number of sub-holograms, which can be further developed or fixed. For successive exposures, the photosensitive layer 22 may be movable stepwise in a first direction x and other devices may be stepwise movable in a second direction y perpendicular thereto. In order to produce a color hologram, one device is assigned to each of the red, green, and blue colors, and each region is sequentially exposed to each color. In this case, all devices may be integrated into a print head that is movable with respect to the photosensitive layer 22.

Still another configuration of the present invention includes, for example, focusing the beam L4 on a focal line, disposing an optical modulator in the optical path of the beam L1, L2 or L3, or a light scattering member in the optical path of the beam L3. Or by changing the deflection angle.

The compact structure of two parabolic mirrors and one plane mirror as a whole provides the best focus, a large acceptance angle, a variable angle between injected and outgoing light, and a light source. With equal optical distance from to the focal point.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an apparatus for producing a hologram according to the present invention.

[Explanation of symbols]

 2, 20 focus 4 parabolic mirror 8 optical fiber 14 beam polarizing member 18 parabolic mirror 22 photosensitive layer 34 light modulator 38, 40 lens

[Procedure amendment] Submission of translation of Article 34 Amendment of the Patent Cooperation Treaty [Date of submission] August 29, 2000 (2000.8.29) [Procedure amendment 1] [Document name to be amended] Description [Amendment] Item name] Claims [Correction method] Change [Content of amendment] [Claims] [Procedure amendment 2] [Document name to be amended] Description [Item name to be amended] Detailed description of the invention [Correction method] Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-emitting device in which at least two light beams that are formed and modulated by a first light beam interfere with each other in a photosensitive layer. A method of making a matching hologram. The invention is also directed to an apparatus for performing the method. 2. Description of the Related Art A hologram is an interference fringe generated by superimposing a first light beam affected by an object and a reference light beam not affected by an object. is there. In order for this interference fringe to be able to record information for all object points, all rays coming from these object points must simultaneously interfere with the reference ray bundle. Rays come from objects, even if the optical distances between the individual object points and the interference points are different, considering that the rays are not a series of formations but composed of multiple wave trains The above conditions are sharpened in the sense that the wave trains of all the rays must simultaneously overlap at the point of interference. When a wave train coming from an object point hits an interference point and the wave train of another object point is already separated from the interference point, the object point does not become a hologram. The connection of each wave train is called coherence, and the degree of connection is called coherence length. In a classic hologram, object light is affected by the object itself. This results in a series of disadvantages. That is, the equipment used is large and optically unstable, lasers have high demands on energy and coherence length, and optical pretreatment of objects requires sufficient experience. Therefore, two-dimensional images representing different viewing angles with respect to an object or an object point are generated, and these images are holographically converted into sub-holograms sequentially in different regions of the photosensitive layer by modulating the object light. It has been proposed to image. In this way, it is only necessary to always expose a small area, which requires relatively low laser energy. Two-dimensional images can be obtained photographically, for example by making stereoscopic images, or derived from computer-generated objects by calculating different viewing angles and outputting each as a matrix. Further, a combination of both variations is also possible. Holograms synthesized from sub-holograms can have vertical parallax. If not, the object can be viewed from the side but not from above or below. A known apparatus for producing a hologram (European Patent Application No. 0814387, International Patent Application Publication No. 96/02873) includes a laser, a beam splitter for splitting a laser light into object light and reference light, It includes a screen for displaying an image of the object, by which the object light can be modulated, and a lens system for forming reference light that interferes with the object light. The lens system has a limited acceptance angle, has spherical aberration and chromatic aberration, and affects the mutual length ratio of the object light beam. If the light receiving angle of the lens system is restricted, the hologram can be viewed only from the restricted viewing angle. If the lens system has spherical aberration, a distorted hologram will result. Chromatic aberrations may require a separate lens system for each color if quality requirements are high. Finally, the holographic formation of all object points can occur if, for example, the outer ray travels a longer distance than the inner ray, changing the ray-to-length ratio of the object ray bundle from the light source to the photosensitive layer. A correspondingly large coherence length must be selected so that all rays or their connected wave trains can simultaneously interfere so that an image can be obtained. However, a large coherence length cannot be realized without using an expensive laser. [0005] European patent application device for producing a hologram to the 0,849,649 Patent publication is serial
In this device, two light beams interfere with each other in the photosensitive layer in the same manner. one
There is an off-axis parabolic mirror in the optical path of the other ray bundle, and this off-axis parabolic mirror has a parallel beam.
Beam, which ultimately causes the object (in this case, the diffuser plate) to
Is illuminated. In this case, the parabolic mirror is used to make it parallel.
However, this is not necessary with the optical arrangement applied here.
Absent. Because the parallel light is eventually turned into divergent light by the diffuser
This is because it is a photographic material. Yet another disadvantage of this optical arrangement is that parabolic mirrors
Must have at least the same size as the diffuser to be illuminated
It is a point. However, an off-axis parabolic mirror of the size described in
It is relatively difficult and expensive. It is an object of the present invention to provide a method and a device for producing a hologram in the field, which supplies an excellent hologram at a lower cost. This problem is solved in terms of method by the features of claim 1. By forming the first beam bundle while maintaining the length ratio between the beams, a very short coherence length which can be in the order of the thickness of the photosensitive layer and which can be realized with inexpensive lasers In this case, if the optical distance of the reference light is equal to the optical distance of the object light, the modulation of the first light beam completely becomes a hologram. The formation while maintaining the length ratio is performed by at least one pair of parabolic mirrors, where the first parabolic mirror spreads the light beam and the second parabolic mirror focuses the light beam on the photosensitive layer. By doing so, a larger light receiving angle becomes possible and spherical aberration and chromatic aberration are eliminated, which leads to further improvement of the hologram quality and further lowering of the cost of the method for the reasons described above. Such an advantage is particularly effective when light beams for generating a combined hologram are sequentially focused on different regions of the photosensitive layer. [0008] In terms of equipment, the above-mentioned problem is solved by the features of claim 7. First
Includes at least one first parabolic mirror instead of a lens, which allows a larger light acceptance angle by focusing the first light beam onto the photosensitive layer. At the same time, spherical aberration and chromatic aberration disappear. If the first optical system includes a second parabolic mirror and the parabolic mirror can generate a first ray bundle from a light source located at its focal point, this ray bundle Since all light rays travel the same optical distance from the light source to the photosensitive layer, the coherence length can be substantially limited to the thickness of the photosensitive layer. One advantageous light source is the exit of an optical fiber through which the light of a laser, especially a pulsed diode laser, passes. There is a beam deflecting element between the two parabolic mirrors, so that if the beam deflection is advantageously 90 degrees, the light source can be located on a different plane from the photosensitive layer. Light modulation between the light source and the adjacent first or second parabolic mirror, or between these parabolic mirrors, or between the first parabolic mirror and the photosensitive layer The light modulator is advantageously configured as a flat screen with controllable light transmission,
For example, it is configured as a liquid crystal display. However, in some cases, it is sufficient to make the optical modulator interchangeable as a diamond scope. [0011] To ensure a sufficiently wide exposure of the photosensitive layer, a light scattering member may be arranged between the first parabolic mirror and the light modulator or between the light modulator and the photosensitive layer. . A parabolic mirror is an off-axis parabolic mirror having the same parabolic segment. In order to form the second light beam, a second optical system is provided which may include a lens system instead of a parabolic mirror system. If the second optical system is assigned to each side of the photosensitive layer, the present apparatus can be easily set for producing a transmission hologram and for producing a reflection hologram. The setting described above is simplified if a switching device is provided, by means of which the second light beam can be guided to one of the two surfaces of the photosensitive layer. If the device and the photosensitive layer are displaceable relative to each other, it is possible, in particular, to sequentially expose different areas of the photosensitive layer, each representing a sub-hologram. Finally, it is intended to assign the same device to each of the colors red, green and blue and to move these colors together relative to the photosensitive layer. Next, the present invention will be described in detail with reference to embodiments. The accompanying schematic drawings show an apparatus according to the invention. The exit 6 of the optical waveguide 8 is located at the focal point 2 of the parabolic mirror 4, and coherent light of a laser (not shown), which is a pulse laser diode, passes through the optical waveguide. A focal ray 10 extends between the parabolic mirror 4 and its focal point 2. A plane mirror 14 is arranged in the optical path of the guide beam 12, which is also located in the optical path of the guide beam 16 of the parabolic mirror 18. Guiding rays 12 and 16
Are perpendicular to each other. The inclination of each of these guided rays with respect to the plane mirror 14 is 4
5 degrees. At the focal point 20 of the parabolic mirror 18 having the same parabolic segment as the parabolic mirror 4, there is a photosensitive layer 22 protected on both sides by apertures 24 and 26. A focal ray 32 extends between the parabolic mirror 18 and its focal point 20. In the optical path, a liquid crystal display 34 is arranged on the parabolic mirror side and a diffuser 36 is arranged on the layer side in parallel with the guide light 16. The optical paths outlined above are defined as areas L1 to L4 when the laser light is turned on.
Pass through the object light beam L including. Since this optical path must interfere with the reference beam bundle R to produce the hologram, there are collimator lenses 38 and 40 on both sides of the photosensitive layer, the optical axes 42 and 44 of which are Extending through focal point 20, focal points 46 and 48 of these collimator lenses are located at exits 50 and 52 of light guides 54 and 56. The mode of operation is as follows: The outlet 6 of the light guide 8 acts as a point-like light source, which emits a light cone L 1 whose intensity distribution is rotationally symmetric, Following the focal ray 10 and reflected by the parabolic mirror 4 as a parallel beam L2 having a non-uniform intensity distribution in cross section, this beam follows the guiding ray 12. Then, this expanded beam L2
Is guided by a plane mirror 14 deflecting 90 degrees as a beam L3 along a stimulating ray 16 to a parabolic mirror 18, which converts the beam into a beam L3.
As 4, the light is focused toward the photosensitive layer 22 along the focal ray 32, and the non-uniform intensity distribution is eliminated again. As can be easily understood by following the transition of the light beams of the beams L1 to L4 from the exit 6 of the optical waveguide 8 to the focal point 20 located on the photosensitive layer 22, all the light beams of the beams L1 to L4 are easily understood. Have traveled an equal distance and are simultaneously in focus 20. Therefore, the required length of the connected wave train, that is, the coherence length is almost determined only by the thickness of the photosensitive layer, so that a very inexpensive laser can be used. Since only a plane mirror and a parabolic mirror are used to form the beams L1 to L4, no spherical aberration occurs, which is particularly important for a system having a large receiving angle and a short focal length. Since no chromatic aberration is expected, the focus will be at the same point for any color. All of these are favorable prerequisites for modulating the expanded beams L1 to L4 with object properties. This modulation is performed when the beam L4 passes through the liquid crystal display 34 as an intensity modulator, and the parabolic mirror 18 to be used is used.
Depending on the geometric dimensions of the light cone L4, which depends on the parameters of
Is exposed from various directions at an intensity set according to the modulation. If the diffraction at the individual pixels of the liquid crystal display 34 is not enough to fully illuminate the preset area of the photosensitive layer 22, the beam L4 will pass through the diffuser 36 further after modulation and be diffracted. The diffused light is distributed by the diffuser over a preset area. When a parallel reference beam R is applied to this region, an interference fringe is generated. This interference fringe is a beam emitted from an object point related to the sub-hologram and penetrating the sub-hologram as a real image or a virtual image. It represents all light in the spatial direction set by L4, or represents a memory block of a holographic memory organized in a block. When the collimator lens 38 directs the reference beam R to the side of the photosensitive layer 22 that is irradiated by the object beam L4, a transmission sub-hologram occurs. When the reference beam R is emitted from the collimator lens 40 arranged on the opposite side of the photosensitive layer 22, a reflection hologram occurs. For this purpose, the reference beam R is switchably split into two optical paths and connected according to the desired hologram type. Exposure of different areas of the photosensitive layer 22 sequentially in the manner described above results in a hologram synthesized from a number of sub-holograms, which can be further developed or fixed. For successive exposures, the photosensitive layer 22 may be movable stepwise in a first direction x and other devices may be stepwise movable in a second direction y perpendicular thereto. In order to produce a color hologram, one device is assigned to each of the red, green, and blue colors, and each region is sequentially exposed to each color. In this case, all devices may be integrated into a print head that is movable with respect to the photosensitive layer 22. Still another configuration of the present invention includes, for example, focusing the beam L4 on a focal line, disposing an optical modulator in the optical path of the beam L1, L2 or L3, or a light scattering member in the optical path of the beam L3. Or by changing the deflection angle. The compact structure of two parabolic mirrors and one plane mirror as a whole provides the best focus, a large acceptance angle, a variable angle between injected and outgoing light, and a light source. With equal optical distance from to the focal point.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY , CA, CH, CN, CU, CZ, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE , KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZWF terms (reference) 2K008 BB00 BB04 FF01 FF07 HH06 HH18 HH21 HH23 HH26

Claims (31)

[Claims] At least a first light beam (L) is formed and modulated 2
In a method of making a hologram, wherein two light beams (L, R) interfere with each other in a photosensitive layer (22), the formation of the first light beam (L) is performed by determining the length of each light beam of the light beam (L). Is performed while maintaining exactly the same. 2. The method according to claim 1, wherein the shaping is performed by at least one pair of emitting mirrors. 3. A first light beam bundle (L) is expanded by a first parabolic mirror (4) and focused on a photosensitive layer (22) by a second parabolic mirror (18). Item 3. The method according to Item 2. 4. The method according to claim 3, wherein the first light bundle is focused at a focal point or a focal line. 5. The method according to claim 3, wherein the first light flux (L) is sequentially focused on different areas of the photosensitive layer (22). 6. The method according to claim 5, wherein the exposed and developed areas represent sub-holograms. 7. Two light beams (L, R) that interfere with each other in the photosensitive layer (22);
Producing a hologram, particularly for performing the method according to any one of claims 1 to 6, comprising at least one first optical system forming at least a first light beam (L). Apparatus, wherein the first optical system includes at least one first parabolic mirror (18). 8. A first light beam (L) is applied by a first parabolic mirror (18) to a photosensitive layer (L).
Apparatus according to claim 7, wherein the apparatus can be focused on (22). 9. The device according to claim 8, wherein the first light bundle is focusable at a focal point or a focal line. 10. A light source whose first optical system includes a second parabolic mirror (4) by which a first ray bundle (L) is located at its focal point (2). The device according to any one of claims 7 to 10, wherein the device can be generated from: 11. An optical fiber according to claim 11, wherein the light source is an outlet of an optical fiber through which the laser beam passes.
11. The device of claim 10, wherein 12. The device according to claim 11, wherein the light of the pulse laser passes through the optical fiber. 13. A beam deflecting member (1) between both parabolic mirrors (4, 18).
13. The device according to claim 10, wherein (4) is arranged. 14. The apparatus of claim 13, wherein said beam deflection is 90 degrees. 15. Between the light source (6) and an adjacent first parabolic mirror (18) or a second parabolic mirror (4), or between these parabolic mirrors. Or an optical modulator (34) is arranged between the first parabolic mirror (18) and the photosensitive layer (22),
Apparatus according to any one of claims 10 to 14. 16. The device according to claim 15, wherein the light modulator is a flat screen with areas of different light transmission. 17. The apparatus of claim 16, wherein the light modulator is replaceable. 18. The method according to claim 16, wherein the light transmittance is controllable.
8. The apparatus according to claim 7, wherein 19. The device according to claim 18, wherein the light modulator is a liquid crystal display. 20. A light scattering member (36) is arranged between the first parabolic mirror (18) and the light modulator (34) or between the light modulator and the photosensitive layer (22). Apparatus according to any one of claims 15 to 19. 21. Apparatus according to claim 7, wherein the parabolic mirror is an off-axis parabolic mirror. 22. Parabolic mirrors (18, 4) having the same parabolic segment,
Apparatus according to any one of claims 7 to 21. 23. At least one second optical system is provided, with which a second light beam (R) can be formed.
The device according to any one of the preceding claims. 24. The second optical system comprising at least one lens (38, 40).
24. The device of claim 23, comprising: 25. Apparatus according to claim 23 or claim 24, wherein a second optical system is assigned to each side of the photosensitive layer (22). 26. A switching device is provided, wherein the second switching device is provided.
Layer (22) which is selectively irradiated from the first light beam (L) with the light beam (R)
26. The device according to claim 23, wherein the device can be guided to the side of the vehicle or to the side opposite thereto.
The device according to any one of the preceding claims. 27. Different areas of the photosensitive layer (22) can be sequentially exposed.
The device according to any one of claims 7 to 26. 28. The apparatus according to claim 27, wherein the exposed and developed areas represent sub-holograms. 29. A device member (4) for performing at least forming, deflecting and modulating.
29. Apparatus according to any one of claims 7 to 28, wherein the photosensitive layer (22) is movable relative to one another. 30. A device member for forming, deflecting and modulating (4, 14, 1)
8, 34, 36, 38, 40) are movable in a first direction (y), and the photosensitive layer (22) is movable.
3) is movable in a second direction (x) perpendicular to the first direction (y).
An apparatus according to claim 9. 31. A member for forming, deflecting, and modulating (4, 14, 1)
31. Apparatus according to any one of claims 7 to 30, wherein (8, 34, 36, 38, 40) are provided for each of the colors red, green and blue.