JPH10207329A - Production of hologram - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a hologram in which line widths are continuously changed or changed for each line in an extremely short time. SOLUTION: A master hologram 2 to be operated as a diffraction grating is overlapped on a non-exposed photosensitive material 1 while recording a scatter board, a laser beam 8 is made incident on this overlapped upper surface by an optical system composed of plural lenses 4 and 5, mirror, two galvano scanners 6 and 7. The laser beam is focused on the photosensitive material coated plane of photosensitive material. By changing the quantity of exposure due to the laser beam, the hologram in which line widths are continuously changed or changed for each line is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a master hologram and an unexposed photosensitive material are superimposed on an image formed by a computer or an image input to the computer by a scanner or the like without using a spatial light modulator or shutter. ,
By the device which performs direct exposure by the laser beam which passed through the optical path consisting of a mirror and a galvanometer scanner,
The present invention relates to a method for producing a hologram which can be exposed in a very short time, is hardly affected by vibration, and can produce a hologram image having an extremely fine line width.

[0002]

2. Description of the Related Art Hitherto, as one method of producing a hologram, there has been proposed a method of automatically producing a three-dimensional image hologram using a computer. This method
JP-A-63-131167, JP-A-2-2596
No. 84, Japanese Unexamined Patent Application Publication No. 2-259885, Japanese Unexamined Patent Application Publication No.
These are well known in JP-A-35171, JP-A-6-59613, JP-A-6-59614 and the like. However, for example, JP-A-5-35171 discloses that
“A photosensitive material is placed on an XY stage, and a laser beam is incident on the XY stage while sequentially moving the XY stage to a corresponding position according to image data.” Also, JP-A-6-59613 discloses that "On the master hologram, each cell arranges a spatial light modulator corresponding to each of the element holograms, controls the intensity of transmitted light at the corresponding position by the spatial light modulator according to parallax image data, These methods not only take a long time to produce a hologram, but also cannot produce a stable hologram, as described in "Producing a transmission hologram by irradiating a laser beam from the surface of a light modulation element." The problem has been improved, but not completely solved.

[0003]

As described above, in the conventional method for producing a hologram, it takes a long time to produce a hologram, and a stable hologram cannot be produced. Further, in the conventional hologram manufacturing method, since a hologram is manufactured using dots as pixels, it is difficult to manufacture a hologram having a continuously changing line width or a hologram having a line width changed for each line.

[0004]

In order to achieve the above object, a master hologram recording a diffusion plate and acting as a diffraction grating is superimposed on an unexposed photosensitive material, and a plurality of lenses are provided on the superimposed upper surface. And, a mirror, a laser beam is made incident by an optical system composed of two galvanometer scanners, and the incident laser beam is split into diffracted light and transmitted light on a master hologram surface,
In a method for producing a hologram using a hologram producing apparatus, wherein interference fringes are recorded on a surface of the unexposed photosensitive material, the laser beam is focused on a photosensitive surface of the photosensitive material, and is exposed by the laser beam. This is a method for producing a hologram in which a hologram having a line width that is continuously changed by changing the amount or a hologram in which the line width is changed is produced.

In the hologram producing apparatus, the direction of the interference fringes is recorded differently by reversing the overlapping of the unexposed photosensitive material and the master hologram, and the laser beam is irradiated on the photosensitive surface of the photosensitive material. This is a method for producing a hologram in which a hologram having a different line width or a hologram having a changed line width is continuously produced by focusing and changing the exposure amount by a laser beam.

Further, in the hologram producing apparatus, a plurality of master holograms having different diffraction directions are used for one unexposed photosensitive material to produce a hologram that diffracts in multiple directions. Is a method of producing a hologram in which a hologram having a different line width or a hologram having a changed line width is continuously produced by focusing on a photosensitive surface of a photosensitive material and changing an exposure amount by a laser beam.

Further, there is provided a hologram producing method for producing a hologram for recording an interference fringe at an arbitrary position without using a shutter by controlling a galvanometer scanner in the hologram producing apparatus.

Further, in the hologram manufacturing apparatus, a change in scanning speed of a laser beam by a galvanometer scanner, control of a power supply current of a laser, insertion of a polarizing film into an optical system, insertion of a micromirror into the optical system,
This is a method for producing a hologram in which a hologram is produced by inserting a mechanical aperture device into an optical system or inserting an LCD into an optical system to change the amount of exposure by a laser beam.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a laser beam is focused on a photosensitive surface of a photosensitive material by an interference fringe recording apparatus shown in FIG. Different holograms or holograms with different line widths were produced.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, a method for manufacturing a transmission hologram will be described.

Embodiment 1 FIG. 1 is a schematic view of a hologram producing apparatus for producing a hologram of the present invention. First,
A master hologram (2) having a diffusion plate recorded thereon is superimposed on the photosensitive material (1) of FIG. 1, and a plurality of lenses (4), (5)
Then, using a mirror (not shown) and two galvanometer scanners (6) and (7), exposure is performed by scanning a laser beam by a driver of another galvanometer scanner (not shown). The galvanometer scanner used here can scan a laser beam in a one-dimensional space by vibrating a mirror attached to a shaft in a rotating direction. Further, by using two galvanometer scanners arranged at right angles, a laser beam can be scanned in a two-dimensional space.

FIG. 2 is an explanatory view schematically showing a state in which a laser beam is incident on the master hologram. The distance between the master hologram (10) and the photosensitive material (9) is large. It is for explanation and is actually in close contact. The incident laser beam (1
1) is transmitted light (1) by the master hologram (10).
2) and diffracted light (13). The laser beams are superimposed immediately below the master hologram (10) (14), and interference fringes can be recorded by placing a photosensitive material there. As a result, a copy of the master hologram is formed. Here, the laser beam is focused by the lenses (4) and (5) on the photosensitive material coated surface of the photosensitive material (9), so that a fine image having a spot diameter width at the focal position is obtained. A line is created. In this hologram production apparatus, the hologram (15) in which the line width of one object line continuously changes as shown in FIG. 1
6) and (17) can be manufactured.

Embodiment 2 Next, a method for producing a hologram by changing the exposure amount of a laser beam will be described in detail.
In the present embodiment, the positions in the optical system of the elements that change the respective exposure amounts are merely examples, and similar effects can be obtained in other parts.

First, as shown in FIG. 1, the light amount of a laser beam is made constant, and a galvanometer scanner (6) is used.
The scanning speed of (7) is changed. Since the cross section of the laser beam changes its light amount in a Gaussian distribution, the light amount is the highest at the center and decreases toward the outside. Therefore, when the scanning speed of the galvanometer scanner is fast,
Only the vicinity of the center of the laser beam is exposed.
When the scanning speed of the galvanometer scanner is low, the outside of the laser beam is also exposed at an appropriate exposure amount. By changing the scanning speed of this galvanometer scanner for each object, it is possible to produce holograms of objects with different line widths, and by changing the scanning speed of the galvanometer scanner during exposure of the object, A hologram in which the line width changes continuously in one image can be produced.

As another method, as shown in FIG. 1, the scanning speed of the galvanometer scanner is kept constant, and the amount of the laser beam is changed by controlling the power supply current (3) of the laser. Since the cross section of the laser beam changes its light amount in a Gaussian distribution, the light amount is the highest at the center and decreases toward the outside. Therefore, when the total amount of light is small, only the vicinity of the center of the laser beam is exposed. When the total amount of light is large, the outside of the laser beam is also exposed to a proper exposure amount. If the power supply current of this laser is changed for each object, holograms with different line widths can be produced, and if the power supply current of the laser is changed during the exposure of the object, one image can be produced. A hologram in which the line width changes continuously in the line can be produced.

As another method, as shown in FIG. 4, after the light amount of a laser beam and the scanning speed of a galvanometer scanner are kept constant, a polarizing film (2
1) is inserted and rotated to change the amount of light. Since the cross section of the laser beam changes its light amount in a Gaussian distribution, the light amount is the highest at the center and decreases toward the outside.
Therefore, when the amount of light is small due to the polarizing film, only the vicinity of the center of the laser beam is exposed. When the amount of light is large due to the polarizing film, the outside of the laser beam is also exposed at an appropriate exposure amount. By changing the change in light amount due to the rotation of this polarizing film for each image line,
Holograms with different line widths can be produced,
In addition, if the change in the amount of light due to the rotation of the polarizing film is changed during the exposure of the object, a hologram in which the line width changes continuously in one object can be produced.

As another method, as shown in FIG. 5, after the light amount of a laser beam and the scanning speed of a galvanometer scanner are kept constant, a micro mirror (3
1) is inserted and controlled to change the laser beam diameter. By changing the change of the laser beam diameter under the control of the micromirror for each object, it is possible to produce holograms of objects having different line widths. , A hologram in which the line width changes continuously in one image line can be produced.

As another method, as shown in FIG. 6, after the light amount of the laser beam and the scanning speed of the galvanometer scanner are kept constant, a mechanical diaphragm device (4
0) is inserted and controlled to change the laser beam diameter.
By changing the change of the laser beam diameter by the control of the mechanical aperture device for each object line, it is possible to produce holograms of objects having different line widths, and to control the laser beam diameter by the control of the mechanical aperture device. If the change is changed during image exposure, a hologram in which the line width changes continuously for each image can be produced.

As another method, as shown in FIG. 6, after the light amount of the laser beam and the scanning speed of the galvanometer scanner are fixed, an LCD (41) is inserted into the optical system to control the laser beam diameter. Change. This LC
By changing the change of the laser beam diameter under control of D for each object, it is possible to produce holograms of objects having different line widths. , It is possible to produce a hologram in which the line width changes continuously for each image line.

In the method of producing a hologram by controlling both the laser beam and the galvanometer scanner, the light amount of the laser beam and the scanning speed of the galvanometer scanner are kept constant. Even if the scanning speed is changed, it can be manufactured similarly.

(Embodiment 3) In the optical system with a change in the exposure amount in the above embodiment, as shown in FIG. 7, master holograms (48), (49), and (50) having different diffraction directions.
As shown in FIG. 8, different patterns A, B,
By exposing C, 3 is applied to one photosensitive material (52).
A hologram diffracted in the direction is recorded. As shown in FIG. 9, the recorded photosensitive material (64) is
The visible pattern differs depending on the position of 3).

In this way, by exposing holograms having different patterns to the master holograms having different diffraction directions, holograms whose patterns change depending on the observation direction can be manufactured. By using this method, it is possible to produce a hologram that changes the pattern, makes the pattern move, or makes the two-dimensional pattern stereoscopically viewed.

The method of producing a hologram that diffracts in three directions shown in FIGS. 7, 8 and 9 is merely an example, and it is possible to produce a hologram that diffracts in multiple directions by using a plurality of master holograms. Can be.

(Embodiment 4) In the optical system having a change in the exposure amount in the above embodiment, a laser beam is emitted by a computer (not shown) in which two galvanometer scanners are connected to another galvanometer scanner driver (not shown). By performing exposure by scanning in a two-dimensional space, a hologram of a two-dimensional image composed of objects having different line widths or an object whose line width continuously changes in one image is formed. Can be made.

Although the method of manufacturing a transmission hologram has been described above, the method of manufacturing a reflection hologram can be obtained by reversing the relationship between the master hologram and the photosensitive material and performing the same manufacturing method as in the above embodiment.

[0026]

As described in detail above, according to the present invention,
A master hologram is superimposed on the photosensitive material, a plurality of lenses, a mirror, and two galvanometer scanners are used to focus on the photosensitive material-coated surface of the photosensitive material, and the galvanometer is driven by another galvanometer scanner driver (not shown). Since the exposure method in which the meter scanner is scanned is used, a hologram of an object constituted by a fine object having a fine width and a width change can be manufactured in a very short time against an external influence such as vibration.

[Brief description of the drawings]

FIG. 1 Interference fringe recording device

FIG. 2 is a diagram showing a state when a laser beam is incident on a master hologram in an embodiment of the present invention.

FIG. 3 shows a hologram in which the line width of one object line continuously changes and a hologram of an object line having a different line width.

FIG. 4 is a diagram in which a polarizing filter is inserted into the optical system of the interference fringe recording device.

FIG. 5 shows a micromirror inserted into the optical system of the interference fringe recording device.

FIG. 6 is a diagram in which a mechanical diaphragm device or an LCD is inserted into the optical system of the interference fringe recording device.

FIG. 7 shows a state in which master holograms having different diffraction directions are observed.

FIG. 8 shows a method of recording different patterns on one photosensitive material by using master holograms having different diffraction directions.

FIG. 9 is a diagram showing a state in which holograms produced by master holograms having different diffraction directions are observed.

[Explanation of symbols]

1, 9, 18, 27, 36, 52 ... photosensitive material 2, 10, 19, 28, 37, 53 ... master hologram 3, 20, 29, 38, 54 ... laser light source 4, 5, 22, 23, 30, 32, 39, 42, 55, 56 ... Lens 6, 7, 24, 25, 33, 34, 43, 44, 57, 58 ... Galvanometer scanner 8, 11, 26, 35, 45, 51 ・ ・ ・ Laser beam 12 ・ ・ ・ Transmitted light 13 ・ ・ ・ Diffraction light 14 ・ ・ ・ Interference fringes 15 ・ ・ ・ Continuously different holograms 16, 17 ・ ・ ・ Change the line width Hologram 21 ... Polarization filter 31 ... Micro mirror 40 ... Mechanical aperture device 41 ... LCD 46 ... Reference light 47, 63 ... Observer 48, 49, 50, 59, 60, 61: Master hologram produced with limited diffraction direction 62: Reference beam 64: Hologram in which different patterns are recorded using master holograms 59, 60, 61

Claims (11)

[Claims] 1. A master hologram recording a diffusion plate and acting as a diffraction grating is superimposed on an unexposed photosensitive material, and a plurality of lenses, mirrors,
A laser beam is made incident by an optical system composed of two galvanometer scanners, and the incident laser beam is split into diffracted light and transmitted light on a master hologram surface, and interferes with the surface of the unexposed photosensitive material. In a hologram manufacturing method using a hologram manufacturing apparatus, which records fringes, the laser beam is focused on a photosensitive surface of a photosensitive material, and a continuous line is formed by changing an exposure amount by the laser beam. A method for producing a hologram, comprising producing holograms having different widths. 2. A master hologram recording a diffusion plate and acting as a diffraction grating is superimposed on an unexposed photosensitive material, and a plurality of lenses, a mirror,
A laser beam is made incident by an optical system composed of two galvanometer scanners, and the incident laser beam is split into diffracted light and transmitted light on a master hologram surface, and interferes with the surface of the unexposed photosensitive material. In a hologram manufacturing method using a hologram manufacturing apparatus characterized in that fringes are recorded, the laser beam is focused on a photosensitive surface of a photosensitive material, and a line width is changed by changing an exposure amount by the laser beam. A method for producing a hologram, characterized by producing a hologram that has been made to fall. 3. A method for producing a hologram, wherein the method of superposing an unexposed photosensitive material and a master hologram is reversed so that interference fringes are recorded in different directions, and a laser beam is applied to the photosensitive material. 3. The hologram manufacturing method according to claim 1, wherein the hologram is manufactured by focusing on a photosensitive surface and changing an exposure amount by a laser beam. 4. In the hologram producing apparatus, 1
By using a plurality of master holograms with different diffraction directions for one unexposed photosensitive material, a laser beam is focused on the photosensitive surface of the photosensitive material by producing a hologram that diffracts in multiple directions. 3. The method of manufacturing a hologram according to claim 1, wherein the hologram is manufactured by changing an exposure amount of the hologram. 5. The hologram producing apparatus according to claim 1, wherein the interference fringes are recorded at an arbitrary position without using a shutter by controlling a galvanometer scanner by a computer. 5. The method for producing a hologram according to 4. 6. The hologram producing apparatus according to claim 1, wherein an exposure amount by the laser beam is changed by changing a scanning speed of the laser beam by the galvanometer scanner.
Or the method for producing a hologram according to 4. 7. The hologram manufacturing apparatus according to claim 1, wherein the hologram manufacturing apparatus changes a light exposure amount by a laser beam by controlling a power supply current of a laser. Method. 8. The hologram producing apparatus according to claim 1, wherein the amount of exposure by a laser beam is changed by inserting a polarizing film into an optical system in the apparatus for producing a hologram. Production method. 9. The hologram manufacturing apparatus according to claim 1, wherein an exposure amount by a laser beam is changed by inserting a micromirror into an optical system in the hologram manufacturing apparatus. Production method. 10. The apparatus for producing a hologram,
5. The hologram manufacturing method according to claim 1, wherein an exposure amount by a laser beam is changed by inserting a mechanical aperture device into an optical system. 11. The apparatus for producing a hologram,
5. The method for producing a hologram according to claim 1, wherein the amount of exposure by a laser beam is changed by inserting an LCD into an optical system.