JP2004045628A - Solid image recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a solid image recorder which can produce high-quality solid image print. <P>SOLUTION: Increased output is especially contrived by multi-stage arrangement of multi-cavity lasers and arrayed collimate lenses by using a combining frequencies laser light source in a light source section 40 of an exposure processing part 36. In addition, since a fiber array light source and a bundle fiber light source with higher brightness can be constituted by using the combining frequencies laser light source, the solid image recorder is especially suitable for exposing film such as hologram film 38 with low sensitivity. Thus, laser light with high luminsnce and high power can be obtained like a line, high-definition interference hologram can be obtained even by the hologram film 38 with low sensitivity. In addition, exposure time can be shortened by using the line laser light with high luminance and high power and speed of image formation can be increased. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stereoscopic image recording apparatus that manufactures an interference hologram for reproducing a stereoscopic image.
[0002]
[Prior art]
Holography is a technique for recording and reproducing information on the amplitude and phase of light waves for reproducing a stereoscopic image on a medium. When the object is irradiated with coherent light such as laser light and the recording medium is irradiated with the reflected light (object light) from the object, the recording medium is simultaneously irradiated with another coherent light (reference light). Interference fringes are formed on the recording medium.
[0003]
A hologram is a light intensity distribution resulting from this interference recorded in a medium as a change in refractive index or absorptance. When the recording medium on which the hologram is recorded is irradiated with only the reference light, the hologram functions as a diffraction grating and the object light is reproduced. When an object having a three-dimensional structure is used as a subject, the reproduced image is a stereoscopic image with a natural stereoscopic effect. For this reason, holography is widely used as a technique for displaying a stereoscopic still image.
[0004]
However, holography has a problem that the photographing process is complicated, and a general person cannot easily obtain a desired three-dimensional image. For this reason, there has been a need for a mechanism for providing personally photographed images and personally created planar images as stereoscopic images. In addition, holography has a problem that it is difficult to obtain a full color image with high image quality and no sense of incongruity.
[0005]
For example, in the case of a Fresnel type hologram, an optical system for recording interference fringes is created by making object light and reference light incident on the photosensitive material from the same direction, and the hologram with the interference fringes recorded and developed is the same light as the captured reference light. When the illumination is performed, the reconstructed image (virtual image) appears at the position where the photographic object was placed. However, the reconstructed image cannot be obtained unless it is illuminated with the same light as the reference light that produced the hologram.
[0006]
By the way, an image reproduced by normal holography is a single color. For example, a color hologram capable of recording and reproducing a color image, as introduced in “Holography” written by Junpei Tsujiuchi (1997). Various studies have also been made and can be broadly classified into laser light reproduction holograms, white light reproduction holograms, and holographic stereograms.
[0007]
The method of Leith et al., Which first proposed a color hologram, is called a laser reproduction hologram. First, an object is illuminated with three colors of RGB laser light, and three holograms are photographed for each color of laser light. Next, when each of the three holograms is illuminated using the same color laser light as that used for photographing, the reproduced images of the three RGB colors appear at the same position and the color image is reproduced.
[0008]
However, there is a drawback that a so-called ghost image appears because each color laser beam is diffracted by each of the three holograms during reproduction. For this reason, a reconstructed image without a ghost image can be obtained by placing a Foucault grating in the reference optical system and recording so that the three holograms do not overlap at the time of photographing. The same optical system as the reference optical system is required, which is complicated.
[0009]
There are also white light reproduction holograms that can be photographed and reproduced using so-called white light such as sunlight and electric light in addition to laser light, and are roughly classified into three types: image holograms, rainbow holograms, and Lippmann holograms.
[0010]
Image hologram is a method that keeps the image of the object to be reproduced as far as possible from the hologram. Take an image with the object placed in the immediate vicinity of the hologram, or place an imaging system such as a lens between the object and the hologram. This is a method of placing an image of an object on the hologram and reducing the influence of dispersion during reproduction, and a white light reproduction hologram can be obtained by a simple method. If the aperture is small, the viewing zone is remarkably narrow, and if the object becomes large to some extent, the whole cannot be seen.
[0011]
Rainbow holograms are taken so that the spatial carrier of the hologram is in the horizontal direction. Three rainbow holograms are taken at the respective RGB wavelengths, and they are bonded to illuminate white light. Thus, the reproduced images from the three holograms appear overlapping at the same position, and the color image is reproduced. However, in the rainbow hologram, the position where an image with a correct color balance can be seen is determined, and there is a drawback that the color reproduction becomes worse if the eyes are moved from there.
[0012]
The Lippmann hologram is a color hologram in which interference fringes are written in each of the photosensitive layers provided corresponding to the three RGB colors of a photosensitive material having a thickness such as a silver halide photosensitive material. The fringe shape is almost parallel to the recording surface as in the so-called Lippmann color photograph. In addition, a three-dimensional image is observed by Bragg diffraction during reproduction, and the reproduced image from the photosensitive layer overlaps at the same position. The image is played back.
[0013]
Since such interference fringes have wavelength selectivity with respect to illumination light having a constant incident angle, the Lippmann hologram has an advantage that a color image can be reproduced with white light such as sunlight. Has a drawback that an image different from that at the time of photographing is reproduced.
[0014]
A color hologram can also be created using a stereogram, but a stereogram uses multiple two-dimensional photographic images to write intensity images that can be seen from various angles, up to the light phase control. Not.
[0015]
On the other hand, unlike ordinary holograms, a computer-generated hologram (Computer Generated Hologram: CGH) is used to calculate the structure of the hologram itself (the amplitude and phase distribution of the object light) using a computer. The hologram to be created. Here, a hologram synthesized from many ordinary photographs is called a holographic stereogram.
[0016]
Recently, a small device called a hologram printer that synthesizes a holographic stereogram from image data stored in a computer has been developed (M. Yamaguchi, N. Ohyama, T. Honda, “Holographic three-dimensional printer”). : New method, "Applied Optics 31, pp. 217-222 (1992), Nobuhiro Kihara, Akira Shirakura, Shigeyuki Baba," High-Speed Hologram Portrait Print System, "3D Image Conference '98, pp. 257-262 (1998) ).
[0017]
However, this hologram printer requires a complicated optical system for exposure using light interference, and has a drawback that high accuracy is required at the time of writing. That is, in order to improve the image quality and the viewing angle, the size of the pixel needs to be equivalent to the wavelength, and it is difficult to write such a minute spot with ordinary laser light. On the other hand, there is a method of displaying a stereoscopic image with an electron beam, but there are problems that the exposure apparatus becomes large and the gradation control is difficult.
[0018]
There is also a method of displaying a stereoscopic image from image data stored in a computer using a two-dimensional spatial light modulator. For example, there is a method of reproducing a stereoscopic image by controlling the amplitude and phase of transmitted light by changing the absorptance and refractive index for each fine cell using a liquid crystal spatial modulator.
[0019]
According to this method, a phase conjugate image does not appear, and ghost images due to other wavelengths can be prevented by spatially separating RGB, which is the three primary colors of light, compared to the case where a reproduced image is obtained by diffraction by interference fringes. In addition, it has an advantage that high diffraction efficiency can be obtained (a bright image can be reproduced).
[0020]
However, with the current technology, the liquid crystal pixels of the spatial modulator are as large as about 100 μm and it is difficult to increase the area, so that it is difficult to display a stereoscopic image that can withstand viewing. Another disadvantage is that the cost is high for the purpose of enjoying still images.
[0021]
By the way, when reproducing a hologram, in order to apply light emitted from a parallel light beam or a point light source at a distant position to the hologram, a considerably wide space is required in front of or behind the hologram, and further, the position of the illumination device and the light source It is necessary to keep the relationship correct.
[0022]
For this reason, when using a hologram for a display, a compact reproduction illumination device is used to illuminate from the end face of the hologram (so-called edge-lit hologram), but a large incident angle close to 90 °. In the case of using reference light and reproduction illumination light having the above, there is a drawback that the resolution of the reproduction image is lower than that of a normal hologram.
[0023]
On the other hand, it is known that the density of the photographic film changes depending on the exposure amount, as well as relief formation and refractive index change due to expansion / contraction. Using this, the amplitude of the object light calculated by the computer is known. There is a method of recording the distribution and phase distribution on a photographic film.
[0024]
This technique is called kinoform, and records the amplitude distribution on the red photosensitive layer and the phase distribution on the blue photosensitive layer and the green photosensitive layer using, for example, a reversal color film. By reproducing the reversal color film after recording with a red laser (HeNe laser), it is possible to reproduce a parallax character image (DC Chu, JR Fienup, JW Goodman, “ Multiemulsion on-axis computer generated hologram, "Applied Optics 12, pp. 1386-1388 (1973)). However, even if a reversal color film is used, the obtained image is a monochromatic image.
[0025]
Further, the conventional holographic photosensitive material has low sensitivity, for example, about 30 mJ / cm for the DuPont Omnidex holographic photosensitive material. ² Even a photosensitive material for silver salt holography is up to 30 μJ / cm ² It is lower than ordinary photographic light-sensitive materials. In order to compensate for this low sensitivity, it is better that the light intensity of the laser as the light source is high, but speaking of high power lasers so far, it is a solid-state laser equipped with a large gas laser or amplifier, which is a device Since the size of the device is large, the cost is high, and a large amount of heat is generated. However, if micro-vibration occurs during the exposure of the hologram, there is a drawback that the diffraction efficiency of the hologram is lowered, and vibration due to the fan becomes a big problem.
[0026]
As described above, the conventional holographic method cannot obtain a stereoscopic image in which a high-quality color image is reproduced.
[0027]
[Problems to be solved by the invention]
In consideration of the above facts, an object of the present invention is to obtain a stereoscopic image recording apparatus capable of producing a high-quality stereoscopic image print.
[0028]
[Means for Solving the Problems]
According to the first aspect of the present invention, in order to record interference fringes, a small amount of stereoscopic image data is recorded on a stereoscopic image recording film having at least one photosensitive layer provided corresponding to the wavelength of one or more recording light sources. A three-dimensional image recording apparatus for producing an interference hologram by recording amplitude information and phase information for each region, and a laser including a fiber light source that emits laser light emitted from a plurality of semiconductor lasers from a single fiber The apparatus, a plurality of pixel portions arranged two-dimensionally on a substrate, a spatial light modulation element that modulates laser light emitted from the laser device, and a light modulation state for each pixel portion, the stereoscopic image data And control means for irradiating the stereoscopic image recording film with laser light, which is controlled according to amplitude information and phase information for each small area.
[0029]
According to the first aspect of the present invention, the laser device includes a fiber light source that emits laser light emitted from a plurality of semiconductor lasers from a single fiber. As a result, high-power and high-intensity laser light can be obtained, so that a high-quality interference hologram can be obtained even with a low-sensitivity stereoscopic image recording film.
[0030]
In addition, by using a semiconductor laser, the stereoscopic image recording apparatus can be downsized as compared with the case of using a gas laser or a solid-state laser. Furthermore, since a low-cost semiconductor laser can be used as compared with a gas laser and a solid-state laser, the cost can be reduced.
[0031]
In addition, by using a semiconductor laser, the temperature increase rate of the laser device can be suppressed as compared with a gas laser and a solid-state laser. If the temperature rise rate of the laser device is large, a fan for cooling the laser device needs to be installed and the generated heat needs to be reduced. However, if a minute vibration occurs during the exposure of the hologram, the diffraction efficiency of the hologram decreases. The vibration caused by the fan becomes a big problem. For this reason, it is not necessary to provide a fan for cooling the laser device by suppressing the temperature rise rate of the laser device. Therefore, the diffraction efficiency of the hologram does not fall.
[0032]
In the second aspect of the present invention, a plurality of fiber light sources are provided, and the light emitting points at the emission ends of the plurality of fiber light sources are arranged in an array or a bundle. As a result, high-power and high-intensity laser light can be obtained in a line shape, so that the exposure time can be shortened and the image formation speed can be increased.
[0033]
In the invention described in claim 3, the interference hologram is any of a Lippmann type, a Fresnel type, an image type, a relief type, and a holographic stereogram type.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Next, the stereoscopic image recording apparatus according to this embodiment will be described.
[0035]
In this stereoscopic image recording apparatus (hereinafter referred to as “stereoscopic image printer”), a holographic stereogram type is used, and a one-step holographic stereogram with only horizontal parallax (HPO) is adopted, and a parallax image is also obtained. Combined with a shooting device.
[0036]
The HPO type one-step holographic stereogram is designed to obtain a three-dimensional image from a plurality of two-dimensional images, and is composed of a number of slit-shaped holograms (element holograms). The image displayed on the liquid crystal panel is projected in the non-parallax direction (up and down direction) and condensed and recorded in the parallax direction (left and right direction). Such element hologram exposure is performed over the entire surface.
[0037]
As a result, although the image recorded on each element hologram is a two-dimensional image, the image exposed to each element hologram has appropriate visual field information, so that the overall lateral parallax can be reduced. A stereoscopic image can be obtained.
[0038]
Next, the configuration of the stereoscopic image printer will be described with reference to the block diagram shown in FIG. The stereoscopic image printer 10 is roughly composed of a parallax image capturing camera unit 12, an image processing unit 14, and a hologram printer unit 16, and each is controlled by a DOS / V personal computer 18.
[0039]
The parallax image capturing camera unit 12 includes a CCD camera 20 that captures a subject and captures a parallax image by the NTSC method, and an image displayed on the liquid crystal panel 22 provided in the hologram printer unit 16 is a computer graphic or It is generated by image processing based on a parallax original image obtained from a real image.
[0040]
Here, a real image is used as the original parallax image, and this real parallax original image can be obtained by moving the CCD camera 20 around the subject. This image processing is a method called Slice and Dice, in which the parallax original image is divided into slits in the parallax direction and reconstructed between different parallax original images.
[0041]
Accordingly, there is an effect of correcting the distortion peculiar to the holographic stereogram having only the lateral parallax and reducing blur by bringing a stereoscopic image of the subject onto the hologram.
[0042]
Specifically, as shown in FIG. 2, a rail (not shown) is provided so as to be parallel to the subject 24, the CCD camera 20 is set on this rail, and the CCD 22 (or camera film) is provided. And the subject 24 are parallel to each other. Further, a stepping motor (not shown) is disposed on the rail, and the CCD camera 20 moves along the rail by driving the stepping motor.
[0043]
The CCD 28 arranged in the CCD camera 20 can be moved in the direction of the arrow in the CCD camera 20 by a stepping motor (not shown). Since the photographing lens 30 is fixed to the CCD camera 20, the area to be photographed is moved by making the CCD 28 movable with respect to the CCD camera 20.
[0044]
The stepping motor for moving the CCD camera 20 and the stepping motor for moving the CCD 28 are synchronized so that the center of the subject 24 is always at the center of the CCD 28 even if the CCD camera 20 moves.
[0045]
In this manner, by arranging the CCD 22 (or camera film) and the subject 24 in parallel, it is not necessary to correct so-called keystone distortion when performing slice and dice image processing, thereby saving image processing power. be able to.
[0046]
For example, if the camera film or CCD surface is arranged in an arc shape around the subject so that the distance between the subject and the camera film or CCD surface is constant, keystone distortion will occur and non-correction will occur. It is necessary to perform enlargement / reduction with respect to the parallax direction, and additional image processing power is required.
[0047]
On the other hand, as shown in FIG. 1, the hardware of the DOS / V personal computer 18 has a 256 Mbyte memory, and can record a parallax original image taken by the CCD camera 20 via the RAM 15 in real time.
[0048]
The image processing unit 14 is provided with a look-up table (LUT) 32, which downloads the parallax original image recorded in the DOS / V personal computer 18, performs slice and die image processing, and then performs a hologram printer. An image is transmitted to the liquid crystal panel 22 provided in the unit 16.
[0049]
Here, the hologram printer unit 16 will be described.
[0050]
The hologram printer unit 16 is provided with a hologram printer 34. The hologram printer 34 can fully automatically perform from shooting to printout of a hologram and can withstand use in a general office environment. Further, the hologram film 38 (see FIG. 3A) is made into a cartridge.
[0051]
Further, a small air surface plate (not shown) is disposed in the hologram printer 34, and an optical system of an exposure processing unit 36 (see FIG. 3A) is disposed on the air surface plate. ing. The exposure processing unit 36 is covered with a completely light-shielding cover to protect the hologram film 38 from external light. With these measures, the hologram printer 34 can be operated without any problem even in a normal office environment.
[0052]
Next, the optical system of the exposure processing unit 36 disposed in the hologram printer 34 will be described.
[0053]
3A and 3B show an optical system of the exposure processing unit 36, FIG. 3A shows a plan view of the optical system, and FIG. 3B shows a side view of the optical system. 3A, the hologram film 38 is sent from the back of the drawing to the front side.
[0054]
As shown in FIG. 3A, the exposure processing unit 36 includes a light source unit 40 (described later) that emits a laser beam having a predetermined wavelength. ₁ A shutter 42 is disposed on the optical axis.
[0055]
The shutter 42 is controlled by the DOS / V personal computer 18 (see FIG. 1), and is closed when the hologram film 38 is not exposed, and is opened when the hologram film 38 is exposed.
[0056]
Here, the on / off state of the laser beam is switched using the shutter 42. However, in the case of a semiconductor laser, the shutter 42 may be used by modulating the current and driving the pulse.
[0057]
On the other hand, the laser beam that has passed through the shutter 42 is transmitted to the object beam L by the beam splitter 44. ₃ And reference light L ₂ The object light L ₃ Is modulated by the liquid crystal panel 22. This liquid crystal panel 22 uses a 510,000-pixel TFT black and white liquid crystal panel, and the object light L that has passed through the liquid crystal panel 22. ₃ Is condensed on the hologram film 38 in the parallax direction and projected in the non-parallax direction.
[0058]
This point will be described in detail below. First, as shown in FIG. 3A, an optical system in the non-parallax direction will be described. In order to ensure a non-parallax direction, that is, a viewing angle in the vertical direction when observing, the object light L is close to the hologram film 38 only in the non-parallax direction. ₃ A one-dimensional diffusing plate 46 (see FIG. 4A) is disposed.
[0059]
The one-dimensional diffuser plate 46 is used to give the holographic stereogram a vertical viewing angle. That is, the one-dimensional diffusion plate 46 allows the object light L ₃ Are diffused in the vertical direction, i.e., in the major axis direction of the created element hologram, so that the created holographic stereogram has a viewing angle in the vertical direction.
[0060]
For this reason, with respect to the non-parallax direction, if the liquid crystal image is not projected, the image is blurred in the vertical direction. Therefore, enlargement projection is performed on the one-dimensional diffusion plate 46 using the spherical lenses 48 and 50.
[0061]
Next, the optical system in the parallax direction shown in FIG. 3B will be described. With respect to the parallax direction, the liquid crystal image is condensed on one surface of the hologram film 38 by the cylindrical lens 52 as shown in the side view, thereby giving information in the angular direction.
[0062]
The condensing angle of the condensing cylindrical lens 52 is 57 °, and a one-dimensional diffusion element in the parallax direction is arranged on the liquid crystal panel 22 in order to improve the diffraction efficiency by making the light amount distribution on the hologram film 38 uniform. doing.
[0063]
As a result, the condensing point on the hologram film 38 has a spread, but if the condensing point spreads outside the element hologram, the diffraction efficiency decreases due to crosstalk with the adjacent element hologram. Therefore, the light leaking out of the element hologram is cut by arranging the slit 54 at the condensing point by the spherical lens 48. Here, the slit width can be determined from the element hologram width and the focal lengths of the cylindrical lens 52 and the spherical lens 50.
[0064]
On the other hand, as shown in FIG. 3A, the laser beam branched by the beam splitter 44 is the reference light L. ₂ After being expanded only in the non-parallax direction, the collimated cylindrical lens 56 makes a parallel beam, which is reflected by the total reflection mirror 58 and projected onto one surface of the hologram film 38.
[0065]
As a result, the reference light L ₂ And object light L ₃ And the interference fringes generated by this interference are recorded on the hologram film 38 as a change in refractive index.
[0066]
Here, the light source unit 40 constituting the optical system of the exposure processing unit 36 will be described.
[0067]
As shown in FIG. 5A, the light source unit 40 is configured by a fiber array light source 66, and includes a plurality of (for example, six) laser modules 64. Each laser module 64 includes a multimode optical fiber 80. Are connected at one end.
[0068]
An optical fiber 81 having the same core diameter as that of the multimode optical fiber 80 and a cladding diameter smaller than the multimode optical fiber 80 is coupled to the other end of the multimode optical fiber 80. As shown in FIG. A laser emission portion 82 is configured by arranging the emission end portions (light emission points) of the optical fiber 81 in one row (so-called array shape) along the main scanning direction orthogonal to the sub-scanning direction. As shown in FIG. 5D, the light emitting points can be arranged in two rows (so-called bundle shape) along the main scanning direction.
[0069]
As shown in FIG. 5B, the emission end of the optical fiber 81 is sandwiched and fixed between two support plates 65 having a flat surface. Further, a transparent protective plate 63 such as glass is disposed on the light emitting side of the optical fiber 81 in order to protect the end face of the optical fiber 81.
[0070]
The protective plate 63 may be disposed in close contact with the end surface of the optical fiber 81 or may be disposed so that the end surface of the optical fiber 81 is sealed. The exit end portion of the optical fiber 81 has a high light density and is likely to collect dust and easily deteriorate. However, the protective plate 63 can prevent dust from adhering to the end face and delay the deterioration.
[0071]
In this example, in order to arrange the emission ends of the optical fibers 81 with a small cladding diameter in a row without any gap, the multimode optical fiber 80 is placed between two adjacent multimode optical fibers 80 at a portion with a large cladding diameter. Two exit ends of the optical fiber 81 coupled to the two multi-mode optical fibers 80 adjacent to each other at the portion where the clad diameter is large are the exit ends of the optical fiber 81 coupled to the stacked multi-mode optical fiber 80. Are arranged so as to be sandwiched between them.
[0072]
For example, as shown in FIG. 6, an optical fiber 81 having a length of 1 to 30 cm and having a small cladding diameter is coaxially connected to the tip of the multimode optical fiber 80 having a large cladding diameter on the laser light emission side. Can be obtained by linking them together.
[0073]
The two optical fibers 80 and 81 are fused and joined so that the incident end face of the optical fiber 81 and the outgoing end face of the multimode optical fiber 80 are aligned with the central axes of both optical fibers. Here, the diameter of the core 81 a of the optical fiber 81 is the same as the diameter of the core 80 a of the multimode optical fiber 80.
[0074]
Also, a short optical fiber in which an optical fiber having a short cladding diameter and a large cladding diameter is fused with an optical fiber having a small cladding diameter may be coupled to the output end of the multimode optical fiber 80 via a ferrule or an optical connector. Good.
[0075]
By detachably coupling using a connector or the like, the tip portion can be easily replaced when an optical fiber having a small cladding diameter is broken, and the cost required for exposure head maintenance can be reduced. Hereinafter, the optical fiber 81 may be referred to as an emission end portion of the multimode optical fiber 80.
[0076]
The multimode optical fiber 80 and the optical fiber 81 may be any of a step index type optical fiber, a graded index type optical fiber, and a composite type optical fiber. For example, a step index type optical fiber manufactured by Mitsubishi Cable Industries, Ltd. can be used.
[0077]
In the present embodiment, the multimode optical fiber 80 and the optical fiber 81 are step index optical fibers, and the multimode optical fiber 80 has a cladding diameter = 125 μm, a core diameter = 25 μm, NA = 0.2, an incident end face. The coating transmittance is 99.5% or more, and the optical fiber 81 has a cladding diameter = 60 μm, a core diameter = 25 μm, and NA = 0.2.
[0078]
Here, with laser light in the infrared region, propagation loss increases as the cladding diameter of the optical fiber is reduced. For this reason, a suitable cladding diameter is determined according to the wavelength band of the laser beam.
[0079]
However, the shorter the wavelength, the smaller the propagation loss. In the case of laser light having a wavelength of 405 nm emitted from a GaN-based semiconductor laser, the cladding thickness {(cladding diameter−core diameter) / 2} is set to infrared light in the wavelength band of 800 nm. The propagation loss hardly increases even if it is about ½ of the case of propagating infrared light and about ¼ of the case of propagating infrared light in the 1.5 μm wavelength band for communication. Therefore, the cladding diameter can be reduced to 60 μm.
[0080]
However, the cladding diameter of the optical fiber 81 is not limited to 60 μm. The clad diameter of an optical fiber used in a conventional fiber light source is 125 μm, but the depth of focus becomes deeper as the clad diameter becomes smaller. Therefore, the clad diameter of a multimode optical fiber is preferably 80 μm or less, more preferably 60 μm or less. Preferably, it is 40 μm or less. On the other hand, since the core diameter needs to be at least 3 to 4 μm, the cladding diameter of the optical fiber 81 is preferably 10 μm or more.
[0081]
On the other hand, the laser module 64 is configured by a combined laser light source (fiber light source) shown in FIG. This combined laser light source is composed of a plurality of (for example, seven) chip-like lateral multimode or single mode GaN-based semiconductor lasers LD1, LD2, LD3, LD4, LD5, LD6, which are arranged and fixed on the heat block 84. And LD7, collimator lenses 85, 86, 87, 88, 89, 90, and 91 provided corresponding to each of the GaN-based semiconductor lasers LD1 to LD7, one condenser lens 92, and one multi-lens. A mode optical fiber 80.
[0082]
The number of semiconductor lasers is not limited to seven. For example, as many as 20 semiconductor laser beams can be incident on a multimode optical fiber having a cladding diameter = 60 μm, a core diameter = 50 μm, and NA = 0.2. In addition, the number of optical fibers can be further reduced.
[0083]
The GaN-based semiconductor lasers LD1 to LD7 all have the same oscillation wavelength (for example, 405 nm), and the maximum output is also all the same (for example, 100 mW for the multimode laser and 30 mW for the single mode laser). As the GaN-based semiconductor lasers LD1 to LD7, lasers having an oscillation wavelength other than the above 405 nm in a wavelength range of 350 nm to 450 nm may be used.
[0084]
As shown in FIGS. 8 and 9, the above combined laser light source is housed in a box-shaped package 94 having an upper opening together with other optical elements. The package 94 includes a package lid 95 created so as to close the opening thereof. After the degassing process, a sealing gas is introduced and the opening of the package 94 is closed by the package lid 95, whereby the package 94 and the package lid are disposed. The combined laser light source is hermetically sealed in a closed space (sealed space) formed by the reference numeral 95.
[0085]
A base plate 96 is fixed to the bottom surface of the package 94, and the heat block 84, the condensing lens holder 45 that holds the condensing lens 92, and the multimode optical fiber 80 are disposed on the top surface of the base plate 96. A fiber holder 98 that holds the incident end is attached. The exit end of the multimode optical fiber 80 is drawn out of the package 94 through an opening formed in the wall surface of the package 94.
[0086]
A collimator lens holder 44 is attached to the side surface of the heat block 84, and the collimator lenses 85 to 91 are held. An opening is formed in the lateral wall surface of the package 94, and a wiring 47 for supplying a driving current to the GaN-based semiconductor lasers LD1 to LD7 is drawn out of the package 94 through the opening.
[0087]
In FIG. 9, in order to avoid complication of the figure, only the GaN semiconductor laser LD7 is numbered among the plurality of GaN semiconductor lasers, and only the collimator lens 91 is numbered among the plurality of collimator lenses. doing.
[0088]
FIG. 10 shows the front shape of the attachment part of the collimator lenses 85-91. Each of the collimator lenses 85 to 91 is formed in a shape in which a region including the optical axis of a circular lens having an aspherical surface is cut out in a parallel plane. This elongated collimator lens can be formed, for example, by molding resin or optical glass. The collimator lenses 85 to 91 are closely arranged in the arrangement direction of the light emitting points so that the length direction is orthogonal to the arrangement direction of the light emitting points of the GaN-based semiconductor lasers LD1 to LD7 (left and right direction in FIG. 10).
[0089]
On the other hand, each of the GaN-based semiconductor lasers LD1 to LD7 includes an active layer having a light emission width of 2 μm, and each of the laser beams B1 in a state in which the divergence angles in a direction parallel to and perpendicular to the active layer are, for example A laser emitting ~ B7 (see FIG. 7) is used. These GaN-based semiconductor lasers LD1 to LD7 are arranged so that the light emitting points are arranged in a line in a direction parallel to the active layer.
[0090]
Therefore, in the laser beams B1 to B7 emitted from the respective light emitting points, the direction in which the divergence angle is large coincides with the length direction and the divergence angle is small with respect to the elongated collimator lenses 85 to 91 as described above. Incident light is incident in a state where the direction coincides with the width direction (direction perpendicular to the length direction).
[0091]
That is, the collimator lenses 85 to 91 each have a width of 1.1 mm and a length of 4.6 mm, and the beam diameters of the laser beams B1 to B7 incident thereon are 0.9 mm and 2, respectively. 6 mm. Each of the collimator lenses 85 to 91 has a focal length f. ₁ = 3 mm, NA = 0.6, and lens arrangement pitch = 1.25 mm.
[0092]
On the other hand, as shown in FIG. 8, the condensing lens 92 is obtained by cutting an area including the optical axis of a circular lens having an aspherical surface into an elongated plane in a parallel plane, and arranging the collimating lenses 85 to 91 in the horizontal direction. It is long and short in the direction perpendicular to it. The condenser lens 92 has a focal length f. ₂ = 23 mm, NA = 0.2. The condensing lens 92 is also formed, for example, by molding resin or optical glass.
[0093]
In the above embodiment, an example using a fiber array light source including a plurality of combined laser light sources has been described, but the laser light source is not limited to a fiber array light source in which the combined laser light sources are arrayed. For example, a fiber array light source obtained by arraying fiber light sources including one optical fiber that emits laser light incident from a single semiconductor laser having one light emitting point can be used.
[0094]
As a light source having a plurality of light emitting points, for example, as shown in FIG. 11, a laser array in which a plurality of (for example, seven) chip-shaped semiconductor lasers LD1 to LD7 are arranged on a heat block 100 is used. Can be used. A chip-shaped multicavity laser 110 in which a plurality of (for example, five) light emitting points 110a shown in FIG. 12A is arranged in a predetermined direction is known.
[0095]
Since this multi-cavity laser 110 can arrange the light emitting points with high positional accuracy as compared with the case where chip-shaped semiconductor lasers are arranged, it is easy to multiplex laser beams emitted from the respective light emitting points. However, as the number of light emitting points increases, the multicavity laser 110 is likely to be bent at the time of laser manufacturing. Therefore, the number of light emitting points 110a is preferably 5 or less.
[0096]
In the light source unit 40 constituting the optical system of the exposure processing unit of the stereoscopic image printer of the present invention, a plurality of multi-cavity lasers 110 are disposed on the heat block 100 as shown in FIG. Can be used as the light source. The multi-cavity laser array is arranged in the same direction as the arrangement direction of the light emitting points 110a of each chip.
[0097]
The combined laser light source is not limited to one that combines laser beams emitted from a plurality of chip-shaped semiconductor lasers. For example, as shown in FIG. 13, a combined laser light source including a chip-shaped multicavity laser 110 having a plurality of (for example, three) emission points 110a can be used.
[0098]
This combined laser light source is configured to include a multi-cavity laser 110, one multi-mode optical fiber 130, and a condensing lens 120. The multi-cavity laser 110 can be composed of, for example, a GaN-based laser diode having an oscillation wavelength of 405 nm.
[0099]
In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 110 a of the multicavity laser 110 is collected by the condenser lens 120 and enters the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.
[0100]
A plurality of light emitting points 110 a of the multicavity laser 110 are arranged in parallel within a width substantially equal to the core diameter of the multimode optical fiber 130, and a focal point substantially equal to the core diameter of the multimode optical fiber 130 is formed as the condenser lens 120. By using a convex lens of a distance or a rod lens that collimates the outgoing beam from the multi-cavity laser 110 only in a plane perpendicular to the active layer, the coupling efficiency of the laser beam B to the multi-mode optical fiber 130 can be increased. it can.
[0101]
Further, as shown in FIG. 14, a multi-cavity laser 110 having a plurality of (for example, three) emission points is used, and a plurality of (for example, nine) multi-cavity lasers 110 are equally spaced from each other on the heat block 111. A combined laser light source including the laser array 140 arranged in (1) can be used. The plurality of multi-cavity lasers 110 are arranged and fixed in the same direction as the arrangement direction of the light emitting points 110a of each chip.
[0102]
This combined laser light source includes a laser array 140, a plurality of lens arrays 114 arranged corresponding to each multi-capability laser 110, and a single lens arranged between the laser array 140 and the plurality of lens arrays 114. A rod lens 113, one multimode optical fiber 130, and a condenser lens 120 are provided. The lens array 114 includes a plurality of microlenses corresponding to the emission points of the multi-capability laser 110.
[0103]
In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 110a of the plurality of multi-cavity lasers 110 is collected in a predetermined direction by the rod lens 113, and then each microlens of the lens array 114. It becomes parallel light. The collimated laser beam L is condensed by the condenser lens 120 and enters the core 130a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.
[0104]
Still another example of the combined laser light source will be described. In this combined laser light source, as shown in FIGS. 15A and 15B, a heat block 182 having an L-shaped cross section in the optical axis direction is mounted on a substantially rectangular heat block 180, and two heats are provided. A storage space is formed between the blocks.
[0105]
On the upper surface of the L-shaped heat block 182, a plurality of (for example, two) multi-cavity lasers 110 in which a plurality of light emitting points (for example, five) are arranged in an array form light emitting points 110a of each chip. Are arranged at regular intervals in the same direction as the arrangement direction.
[0106]
A concave portion is formed in the substantially rectangular heat block 180, and a plurality of (for example, two) light emitting points (for example, five) are arranged in an array on the upper surface of the space side of the heat block 180. The multi-cavity laser 110 is arranged such that its emission point is located on the same vertical plane as the emission point of the laser chip arranged on the upper surface of the heat block 182.
[0107]
On the laser beam emission side of the multi-cavity laser 110, a collimator lens array 184 in which collimator lenses are arranged corresponding to the light emission points 110a of the respective chips is arranged. In this collimating lens array 184, the length direction of each collimating lens coincides with the direction in which the divergence angle of the laser beam is large (fast axis direction), and the width direction of each collimating lens is the direction in which the divergence angle is small (slow axis direction) Are arranged to match.
[0108]
Thus, by collimating and integrating the collimating lenses, the space utilization efficiency of the laser light can be improved, the output of the combined laser light source can be increased, and the number of parts can be reduced and the cost can be reduced. .
[0109]
Further, on the laser light emitting side of the collimating lens array 184, there is one multimode optical fiber 130 and a condensing lens 120 that condenses and couples the laser light to the incident end of the multimode optical fiber 130. Has been placed.
[0110]
In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 110a of the plurality of multicavity lasers 110 arranged on the heat blocks 180 and 182 is collimated by the collimating lens array 184 and collected. The light is condensed by the optical lens 120 and is incident on the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.
[0111]
It should be noted that a laser module in which each of the above combined laser light sources is housed in a casing and the emission end portion of the multimode optical fiber 130 is pulled out from the casing can be configured.
[0112]
In the above embodiment, another optical fiber having the same core diameter as the multimode optical fiber and a cladding diameter smaller than the multimode optical fiber is coupled to the output end of the multimode optical fiber of the combined laser light source. However, for example, a multimode optical fiber having a cladding diameter of 125 μm, 80 μm, 60 μm, or the like can be used without coupling another optical fiber to the output end. Good.
[0113]
Here, the light sources that can be used in the present invention can be summarized as follows.
[0114]
(1) A laser array in which a plurality of semiconductor lasers (for example, GaN-based semiconductor lasers) are arranged in an array.
[0115]
(2) A multi-cavity laser (for example, a GaN-based multi-cavity laser) having a plurality of light emitting points on one chip.
[0116]
(3) A plurality of semiconductor lasers (for example, a GaN-based semiconductor laser), one optical fiber, and laser light emitted from each of the plurality of semiconductor lasers are condensed, and the condensed beam is applied to the incident end of the optical fiber. And a condensing optical system to be coupled.
[0117]
(4) A plurality of multi-cavity lasers (for example, a GaN-based multi-cavity laser), one optical fiber, and laser light emitted from each of a plurality of light emitting points of the plurality of multi-cavity lasers are condensed and condensed. And a condensing optical system for coupling a beam to an incident end of the optical fiber.
[0118]
(5) A multicavity laser (for example, a GaN-based multicavity laser) having a plurality of light emission points, a single optical fiber, and laser light emitted from each of the plurality of light emission points is condensed, and a condensed beam And a condensing optical system that couples the optical fiber to the incident end of the optical fiber.
[0119]
(6) A fiber array light source that includes a plurality of the combined laser light sources, and each of the light emitting points at the output ends of the optical fibers of the combined laser light sources is arranged in an array, or a fiber bundle that is arranged in a bundle light source.
[0120]
(7) A single semiconductor laser (for example, a GaN-based semiconductor laser), one optical fiber, and laser light emitted from the single semiconductor laser are condensed, and a condensed beam is incident on the optical fiber. A fiber array light source including a plurality of fiber light sources each having a condensing optical system coupled to an end, and a fiber array light source in which each of light emitting points at an output end of the optical fiber of the plurality of fiber light sources is arranged in an array, or a bundle Arrayed fiber bundle light source.
[0121]
Next, the operation of the image stereoscopic printer according to the embodiment of the present invention will be described.
[0122]
By using a combined laser light source for the light source unit 40 of the exposure processing unit 36 shown in FIGS. 3A and 3B, particularly high output is achieved by multistage arrangement of multicavity lasers and an array of collimating lenses. be able to. Moreover, since a higher-intensity fiber array light source or bundle fiber light source can be formed by using a combined laser light source, it is particularly suitable for exposing a film with low sensitivity such as the hologram film 38.
[0123]
In this way, since high-power and high-luminance laser light is obtained in a line shape, a high-quality interference hologram can be obtained even with the hologram film 38 having low sensitivity. Further, by using a high-power and high-brightness line-shaped laser beam, the exposure time can be shortened, and the speed of image formation can be increased.
[0124]
Furthermore, the spatial coherence of the laser light is good by using the combined laser light source. That is, since it is close to a point light source, there is little wavefront distortion when using the magnifying optical system. Further, since the laser light emission end is close to a point light source, the focal length can be increased, and the tolerance of the exposure head 70 (see FIG. 4B) can be increased.
[0125]
Further, by using a semiconductor laser for the light source unit 40, the stereoscopic image printer 10 can be downsized as compared with the case of using a gas laser or a solid-state laser. Furthermore, since a low-cost semiconductor laser can be used as compared with a gas laser and a solid-state laser, the cost can be reduced.
[0126]
Furthermore, as shown in FIG. 5A, by using the laser emission portion 82 as the emission end of the optical fiber 81, variation in the beam emission position for each laser module 64 can be reduced, and the light source portion 40 ( The replacement is easy at the time of failure shown in FIG.
[0127]
Further, as shown in FIGS. 5A to 5D, each of the light emitting points 81 at the emission ends of the plurality of multimode optical fibers 80 is arranged in an array or a bundle so as to achieve high power and high luminance. By obtaining the laser light, the temperature increase rate of the light source unit 40 can be suppressed as compared with the case of obtaining high-power and high-intensity laser light with one light source.
[0128]
When the temperature rise rate of the light source unit 40 is large, it is necessary to dispose a cooling fan and reduce the generated heat. However, if a minute vibration occurs during exposure of the hologram, the diffraction efficiency of the hologram is reduced. There are drawbacks, and the vibration caused by the fan is a big problem. For this reason, it is not necessary to use a cooling fan by suppressing the temperature rise rate of the light source unit 40. Therefore, the diffraction efficiency of the hologram does not fall.
[0129]
Next, the exposure head provided in the exposure processing unit will be described.
[0130]
In conventional holographic stereogram exposure, in order to avoid the influence of vibration, a hologram film 202 such as a photopolymer pasted on a glass plate 200 (or a hologram dry plate) is usually used as shown in FIG. The hologram was fixed on the pulse stage 204 and recorded.
[0131]
However, in this method, the inertia of the pulse stage 204, the glass plate 200, etc. is large, and as a result, it is necessary to take a relatively long vibration damping time after moving the pulse stage 204. Moreover, it is disadvantageous in automation that the hologram film 202 needs to be stuck on the glass plate 200.
[0132]
Therefore, as shown in FIG. 4B, an exposure head 70 capable of exposing the hologram film 38 as it is is used. The exposure head 70 can intermittently feed the hologram film 38 under the control of the DOS / V personal computer 18 (see FIG. 1), and the hologram set in the exposure head 70 in a predetermined state. Every time one image is recorded on the film 38 as one element hologram, the hologram film 38 is intermittently fed by one element hologram based on a control signal from the DOS / V personal computer 18.
[0133]
As a result, an image based on the image data processed by the image processing unit 14 (see FIG. 1) is sequentially recorded as an element hologram on the hologram film 38 so as to be continuous in the lateral direction.
[0134]
The exposure head 70 is detachably provided with a film cartridge 72 in which a hologram film 38 is loaded. The hologram film 38 loaded in the film cartridge 72 is for feeding provided at a predetermined distance. It is conveyed by rollers 73 and 74.
[0135]
Pinch rollers 73A and 74A are disposed opposite to the feed rollers 73 and 74, respectively, and the hologram film 38 is sandwiched between the feed rollers 73 and 74 and the pinch rollers 73A and 74A. It is held between the feeding roller 74 and substantially perpendicular to the optical axis of the object light.
[0136]
Further, the feeding roller 73 and the feeding roller 74 are urged in directions away from each other by a torsion coil spring (not shown). As a result, a predetermined tension is applied to the hologram film 38 stretched between the feeding roller 73 and the feeding roller 74, and as a result, the position of the hologram film 38 is stabilized, and the hologram film 38 is The generated vibration is suppressed. Such tension may be applied by a pinch roller method, a sprocket feed method, or the like.
[0137]
Further, the feeding rollers 73 and 74 can be freely rotated by a stepping motor (not shown), and a control signal supplied from the DOS / V personal computer 18 (see FIG. 1) when creating a holographic stereogram. Based on the above, the image is rotated by a predetermined angle corresponding to one element hologram at the end of exposure for one image. Thus, the hologram film 38 is fed from the feeding roller 73 side to the feeding roller 74 side by one element hologram every time exposure of one image is completed.
[0138]
Further, between the feeding roller 73 and the feeding roller 74, an optical component 61 that is integrally bonded in a state where the one-dimensional diffusion plate 46 and the louver film 60 are curved corresponds to the incident position of the object light. Are arranged as follows. The optical component 61 is held so as to be movable toward and away from the hologram film 38 by an optical component driving mechanism (not shown).
[0139]
Here, the louver film 60 is an optical component having a fine bowl-shaped grating, and prevents the reference light transmitted through the hologram film 38 from being reflected by the one-dimensional diffusion plate 46 and entering the hologram film 38 again. Is for.
[0140]
On the other hand, the optical component driving mechanism that moves the optical component 61 is driven based on a control signal supplied from the DOS / V personal computer 18 before the exposure operation starts, and moves the optical component 61 so as to contact the hologram film 38. .
[0141]
As a result, the optical component 61 is pressed against the hologram film 38 loaded between the feeding roller 73 and the feeding roller 74. In this way, by pressing the optical component 61 against the hologram film 38, minute vibrations of the hologram film 38 can be suppressed, and as a result, a holographic stereogram having excellent diffraction efficiency and a bright reproduced image can be created. It becomes possible.
[0142]
By the way, the exposure head 70 generates a tension by a spring for the hologram film 38 pulled out from the film cartridge 72 through two pinch rollers 73A and 74A, and presses the hologram film 38 against the louver film 60, thereby improving vibration resistance. It is increasing.
[0143]
As a result, in this exposure head 70, as compared with the conventional exposure head 206 (see FIG. 4A), the vibration amplitude during travel of the hologram film 38 becomes 1/20, and the vibration attenuation time is 0.15. Seconds and 1/10 of the conventional one.
[0144]
As a result, the recording cycle per element hologram could be reduced to 0.5 seconds. Specifically, the film running and the accompanying vibration attenuation waiting time are about 0.25 seconds or less, and during that time, the image processing unit 14 performs Slice and Dice image processing in parallel.
[0145]
Also, the hologram exposure time is about 0.25 seconds, and it takes 147 seconds in total to expose 295 all element holograms, and the entire process can be completed within 3 minutes even when shooting for 7.5 seconds. It becomes.
[0146]
Next, a method for creating a holographic stereogram by the stereoscopic image printer according to the embodiment of the present invention will be described.
[0147]
As shown in FIG. 1, first, an original parallax image captured by the CCD camera 20 is temporarily stored in the RAM 15 in real time as image data digitally converted by the Data Converter 17.
[0148]
On the other hand, as shown in FIGS. 1 and 4, the optical film of the exposure head 70 of the hologram printer 34 is transferred from the DOS / V personal computer 18 with the hologram film 38 loaded between the feeding roller 73 and the feeding roller 74. A control signal is sent to the component drive mechanism, the optical component drive mechanism is driven, and the optical component 61 is pressed against the hologram film 38 with a predetermined pressure.
[0149]
Then, the parallax original image temporarily stored in the RAM 15 is transmitted by the DOS / V personal computer 18 as an exposure image by the VGA and transmitted to the liquid crystal panel 22 provided in the hologram printer unit 16.
[0150]
As a result, an exposure image based on the image data is displayed on the liquid crystal panel 22, and a control signal is sent from the DOS / V personal computer 18 to the shutter 42 shown in FIG. 3A to open the shutter 42 for a predetermined time. The hologram film 38 is exposed.
[0151]
At this time, the laser light L that has passed through the shutter 42 emitted from the light source unit 40. ₁ Of these, the light L reflected by the half mirror 33 ₂ Enters the hologram film 38 as reference light.
[0152]
On the other hand, the light L transmitted through the half mirror 33 ₃ Becomes projection light on which an image displayed on the liquid crystal panel 22 is projected, and the projection light is incident on the hologram film 38 as object light. As a result, the exposure image displayed on the liquid crystal panel 22 is recorded on the hologram film 38 as a strip-shaped element hologram.
[0153]
When the recording of one image on the hologram film 38 is completed, a control signal is then sent from the DOS / V personal computer 18 to the exposure head 70 (see FIG. 4), and the hologram film 38 is sent by one element hologram.
[0154]
The above operation is repeated by sequentially changing the exposure image displayed on the liquid crystal panel 22 in the order of the parallax image sequence. Thereby, the exposure image based on the image data processed by the image processing unit 14 is sequentially recorded on the hologram film 38 as a strip-shaped element hologram.
[0155]
As described above, in the stereoscopic image printer 10, a plurality of exposure images based on the image data processed by the image processing unit 14 are sequentially displayed on the liquid crystal panel 22, and the shutter 42 is opened for each image. The images are sequentially recorded on the hologram film 38 as strip-shaped element holograms.
[0156]
At this time, since the hologram film 38 is sent by one element hologram for each image, the element holograms are continuously arranged in the horizontal direction. Thereby, a plurality of images including the parallax information in the horizontal direction are recorded on the hologram film 38 as a plurality of element holograms continuous in the horizontal direction.
[0157]
On the other hand, an ultraviolet lamp (not shown) is arranged on the downstream side of the feeding roller 74 along the traveling direction of the hologram film 38, and the hologram film 38 sent by the feeding roller 74 is arranged. Irradiate ultraviolet rays. Thereby, the polymerization of the monomer M of the hologram recording layer of the hologram film 38 is completed.
[0158]
As described above, the hologram film 38 in which the polymerization of the monomer M of the hologram recording layer of the hologram film 38 is completed is heated by a heat roller (not shown) arranged on the downstream side of the ultraviolet lamp, and the refractive index modulation of the hologram film 38 is performed. The recorded image is fixed on the hologram film 38 by increasing the degree.
[0159]
Then, the hologram film 38 on which the recorded image is fixed is cut off by a cutter (not shown), thereby forming an independent holographic stereogram.
[0160]
In the above-described embodiment, the holographic stereogram having the parallax information in the lateral direction by recording a plurality of strip-shaped element holograms on one hologram film 38 is described as an example. The present invention has horizontal and vertical parallax information by recording a holographic stereogram having vertical parallax information and a plurality of dot-shaped element holograms on a recording medium such as one hologram film. Needless to say, the present invention can also be applied to a holographic stereogram.
[0161]
In the above-described embodiment, a monochromatic holographic stereogram has been described as an example. However, the present invention can be applied to a color holographic stereogram in exactly the same manner. When a color holographic stereogram is created, for example, three lights that are the three primary colors of light may be used as recording light.
[0162]
Furthermore, although the liquid crystal panel has been described as the optical modulator, the present invention is not limited to this, and for example, a digital micromirror device (so-called DMD) may be used.
[0163]
In addition to displaying a three-dimensional image, the three-dimensional image print can be used as an optical modulator in optical information communication, and can also be used as a phase wavefront distortion compensation film for light using only a phase modulation layer. .
[0164]
Furthermore, conventional monochromatic CGH (Computer Generated Hologram) such as kinoform, HOE (Holographic Optical Element), and holographic memory can be recorded using the same fiber combined light source and DMD as in this embodiment. . Also, conventional hologram images (Lippmann type, Fresnel type, image type, relief type, holographic stereogram) can be recorded by causing the two light velocities from the optical fiber to interfere.
[0165]
【The invention's effect】
Since the present invention has the above-described configuration, a high-power and high-brightness laser beam can be obtained, and thus a high-quality interference hologram can be obtained even with a low-sensitivity stereoscopic image recording film. Further, by using a high-power and high-brightness line-shaped laser beam, the exposure time can be shortened, and the speed of image formation can be increased.
[0166]
In addition, by using a semiconductor laser, the stereoscopic image recording apparatus can be downsized as compared with the case of using a gas laser or a solid-state laser. Furthermore, since a low-cost semiconductor laser can be used as compared with a gas laser and a solid-state laser, the cost can be reduced. In addition, since the temperature increase rate of the laser device can be suppressed by using the semiconductor laser as compared with the gas laser and the solid-state laser, it is not necessary to provide a fan for cooling the laser device. Therefore, the diffraction efficiency of the hologram does not fall.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a stereoscopic image printer according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating a parallax image capturing method that constitutes the stereoscopic image printer according to the embodiment of the present invention.
3A is a plan view and FIG. 3B is a side view showing an optical system of a stereoscopic image printer according to an embodiment of the present invention.
4A is a side view showing a conventional example of an exposure head of a stereoscopic image printer, and FIG. 4B is a side view of the exposure head of the stereoscopic image printer according to the embodiment of the present invention.
FIGS. 5A and 5B are diagrams showing a fiber array light source that constitutes an exposure head provided in the stereoscopic image printer according to the embodiment of the present invention, FIG. 5A is a perspective view showing the configuration of the fiber array light source, and FIG. (A) The elements on larger scale, (C) And (D) is the top view which shows the arrangement of the luminous point in the laser emission section.
FIG. 6 is a diagram showing a configuration of a multimode optical fiber provided in a fiber array light source.
FIG. 7 is a plan view showing a configuration of a combined laser light source.
FIG. 8 is a plan view showing a configuration of a laser module.
9 is a front view showing the configuration of the laser module shown in FIG. 8. FIG.
10 is a partial side view showing the configuration of the laser module shown in FIG. 8. FIG.
FIG. 11 is a perspective view showing a configuration of a laser array.
12A is a perspective view showing a configuration of a multi-cavity laser, and FIG. 12B is a perspective view of a multi-cavity laser array in which the multi-cavity lasers shown in FIG.
FIG. 13 is a plan view showing another configuration of the combined laser light source.
FIG. 14 is a plan view showing another configuration of the combined laser light source.
15A is a plan view showing another configuration of the combined laser light source, and FIG. 15B is a cross-sectional view taken along the optical axis of FIG.
[Explanation of symbols]
10 Stereoscopic image printer (stereoscopic image recording device)
18 DOS / V PC (control means)
22 Liquid crystal panel (spatial light modulator)
40 Light source (laser device)
66 Fiber array light source (laser device)
84 Heat block (laser device)
100 Heat block (Laser device)
110 Multicavity laser (laser device)
140 Laser array (laser device)
180 Heat block (laser device)
182 Heat block (laser device)

Claims (3)

In order to record interference fringes, amplitude information and phase information for each small area of stereoscopic image data are recorded on a stereoscopic image recording film having at least one photosensitive layer provided corresponding to the wavelength of one or more recording light sources. A stereoscopic image recording apparatus for recording and manufacturing an interference hologram,
A laser device including a fiber light source that emits laser light emitted from a plurality of semiconductor lasers from a single fiber;
A spatial light modulation element in which a large number of pixel portions are two-dimensionally arranged on a substrate and modulates laser light emitted from the laser device;
Control means for controlling the light modulation state for each pixel unit according to amplitude information and phase information for each small region of the stereoscopic image data, and irradiating the stereoscopic image recording film with laser light;
A stereoscopic image recording apparatus comprising: The stereoscopic image recording apparatus according to claim 1, wherein a plurality of the fiber light sources are provided, and light emitting points at emission ends of the plurality of fiber light sources are arranged in an array or a bundle. The stereoscopic image recording apparatus according to claim 1, wherein the interference hologram is any one of a Lippmann type, a Fresnel type, an image type, a relief type, and a holographic stereogram type.

Images