JP2003178460A - Optical information recording device and optical information reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information recording device and a reproducing device which can record and reproduce a large quantity of information to and from an optical information recording medium at high density by hologram recording. <P>SOLUTION: Information light carrying and supporting the two-dimensional pattern information corresponding to data and reference light for recording modulated by phase modulation patterns are arranged on the hologram optical information recording medium in such a manner that the optical axes are aligned to the same line and the generated interference patterns are recorded. Parity data based on the two-dimensional pattern information is also recorded in a prescribed region. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording apparatus for recording information on an optical information recording medium by utilizing holography, and an optical information reproducing apparatus for reproducing information on the optical information recording medium for utilizing holography. ..

[0002]

2. Description of the Related Art Holographic recording in which information is recorded on a recording medium by using holography generally causes light having image information and reference light to overlap each other inside the recording medium, resulting in interference caused at that time. This is done by writing stripes on the recording medium. At the time of reproducing the recorded information, by irradiating the recording medium with the reference light, the image information is reproduced by the diffraction due to the interference fringes.

In recent years, volume holography, particularly digital volume holography, has been developed in the practical range and has attracted attention for ultra-high density optical recording. Volume holography is a method in which interference fringes are three-dimensionally written by positively utilizing the thickness direction of a recording medium. Increasing the thickness enhances diffraction efficiency, and multiple recording increases the recording capacity. The feature is that it can be achieved. And
The digital volume holography is a computer-oriented holographic recording method in which the image information to be recorded is limited to a binarized digital pattern while using the same recording medium and recording method as the volume holography. In this digital volume holography, image information such as an analog picture is once digitized, developed into two-dimensional digital pattern information, and recorded as image information. At the time of reproduction, the digital pattern information is read and decoded to restore the original image information for display. As a result, even if the SN ratio (signal-to-noise ratio) is a little bad at the time of reproduction, the original information can be reproduced extremely faithfully by performing differential detection or coding the binary data and performing error correction. It will be possible.

FIG. 75 is a perspective view showing a schematic structure of a recording / reproducing system in the conventional digital volume holography. This recording / reproducing system includes a spatial light modulator 10 for generating information light 102 based on two-dimensional digital pattern information.
1, a lens 103 that collects the information light 102 from the spatial light modulator 101 and irradiates the hologram recording medium 100, and refers to the hologram recording medium 100 from a direction substantially orthogonal to the information light 102. Reference light irradiation means (not shown) for irradiating light 104, CCD (charge coupled device) array 107 for detecting reproduced two-dimensional digital pattern information, and reproduced light 105 emitted from hologram recording medium 100. And a lens 106 for condensing and irradiating the light on the CCD array 107. Crystals such as LiNbO ₃ are used for the hologram recording medium 100.

In the recording / reproducing system shown in FIG. 75, at the time of recording, information such as an original image to be recorded is digitized and the 0 or 1 signal is further two-dimensionally arranged to generate two-dimensional digital pattern information. . One piece of two-dimensional digital pattern information is called page data. Here, it is assumed that the page data # 1 to #n are multiplexed and recorded on the same hologram recording medium 100. In this case, first, the spatial light modulator 101 selects transmission or light shielding for each pixel based on the page data # 1, so that the spatially modulated information light 1 is transmitted.
02 is generated and irradiated onto the hologram recording medium 100 via the lens 103. At the same time, the hologram recording medium 10
0 from the direction θ1 substantially orthogonal to the information light 102 to the reference light 1
04, and inside the hologram recording medium 100,
An interference fringe formed by superposition of the information light 102 and the reference light 104 is recorded. In order to improve the diffraction efficiency, the reference light 104 is transformed into a flat beam by a cylindrical lens or the like, and interference fringes are generated in the hologram recording medium 100.
Be recorded over the thickness direction. At the time of recording the next page data # 2, the reference light 104 is emitted from an angle θ2 different from θ1, and the reference light 104 and the information light 1 are emitted.
Information can be multiplexed and recorded on the same hologram recording medium 100 by superimposing 02 and 02. Similarly, when recording the other page data # 3 to #n, the reference light 104 is emitted from different angles θ3 to θn to multiplex record information. A hologram in which information is multiplexed and recorded in this way is called a stack. In the example shown in FIG. 75, the hologram recording medium 100 has a plurality of stacks (stack 1, stack 2, ..., Stack m, ...).

To reproduce arbitrary page data from the stack, the stack may be irradiated with the reference light 104 having the same incident angle as when the page data was recorded. Then, the reference light 104 is selectively diffracted by the interference fringe corresponding to the page data, and the reproduction light 105 is generated. This reproduction light 105 is reflected by the lens 106.
The two-dimensional pattern of the reproduction light is incident on the CCD array 107 through the CCD array 107 and is detected by the CCD array 107. Then, the detected two-dimensional pattern of the reproduction light is decoded in reverse to that at the time of recording to reproduce the information such as the original image.

[0007]

In the configuration shown in FIG. 75, information can be multiplex-recorded on the same hologram recording medium 100. However, in order to record information at an extremely high density, the hologram recording medium 100 must be recorded with the same information. Positioning of the information light 102 and the reference light 104 becomes important. However, in the configuration shown in FIG. 75, the hologram recording medium 10
Since 0 itself has no information for positioning, the information light 102 and the reference light 10 for the hologram recording medium 100 are
The positioning of No. 4 can only be performed mechanically, and positioning with high accuracy is difficult. Therefore, the removability (the ease of moving the hologram recording medium from one recording / reproducing device to another recording / reproducing device to perform the same recording / reproducing) is poor, and random access is difficult and high-density recording is difficult. There is a problem that is. Further, in the configuration shown in FIG. 75, the optical axes of the information light 102, the reference light 104, and the reproduction light 105 are arranged at positions spatially different from each other, so that the optical system for recording or reproduction becomes large. There is a problem of doing.

The present invention has been made in view of the above problems, and an object thereof is an optical information recording apparatus for recording information on an optical information recording medium using holography, and an optical information recording medium using holography. An optical information reproducing apparatus for reproducing information from an optical information recording medium, recording a large amount of information on an optical information recording medium with high density, and reproducing information from the optical information recording medium on which a large amount of information is recorded with high density. An object of the present invention is to provide an optical information recording device and an optical information reproducing device that enable the above.

[0009]

The optical information recording apparatus of the present invention is an apparatus for recording information on an optical information recording medium having an information recording layer on which information is recorded by utilizing holography. The information light generating means for generating a plurality of information lights carrying a plurality of two-dimensional pattern information and the phase modulating means for spatially modulating the phase of the light are included, and the phase of the light is spatially modulated by the phase modulating means. Recording reference light generating means for generating a plurality of recording reference lights modulated by a plurality of different phase modulation patterns for each of a plurality of two-dimensional pattern information, and a plurality of information lights and a plurality of recording references. The information recording layer is irradiated with light so that the respective optical axes are arranged on the same line, and a plurality of information beams and a plurality of recording reference beams interfere with each other in the same recording area of the information recording layer. Depending on the interference pattern The two-dimensional pattern information is obtained and a recording means for multiplexing recording.

In the optical information recording apparatus of the present invention, a plurality of information lights carrying a plurality of two-dimensional pattern information and a plurality of recording reference lights modulated by a plurality of different phase modulation patterns for each of the plurality of two-dimensional pattern information. Due to the plurality of interference patterns due to the interference with the plurality of two-dimensional pattern information, a plurality of two-dimensional pattern information is recorded in the same recording area in the information recording layer of the optical information recording medium.

In the optical information recording apparatus of the present invention, the recording means further comprises: adjacent recording areas of the plurality of recording areas are displaced in a predetermined direction on the optical information recording medium, and some of them overlap each other. As described above, a plurality of pieces of two-dimensional pattern information may be recorded in a multiplexed manner.

In the optical information recording device of the present invention,
The recording means may record the same information in a plurality of recording areas in the information recording layer.

The optical information recording apparatus of the present invention further comprises:
The optical information recording medium is provided with a two-dimensional pattern information generating unit that divides information to be recorded into a plurality of data and generates a plurality of two-dimensional pattern information corresponding to each data, and the recording unit generates the two-dimensional pattern information. The plurality of two-dimensional pattern information generated by the means may be multiplex-recorded over a plurality of recording areas in a predetermined order. In this case, the optical information recording device further includes parity data generating means for generating parity data based on the plurality of two-dimensional pattern information generated by the two-dimensional pattern information generating means, and the recording means has a plurality of two-dimensional pattern information. When recording the pattern information on the information recording layer, the parity data may be recorded on the information recording layer based on a predetermined rule by an interference pattern due to the interference of the information light based on the parity data and the recording reference light.

In the optical information recording apparatus of the present invention,
The parity data generating means may generate a plurality of parity data corresponding to the plurality of two-dimensional pattern information, and the recording means may collectively record the plurality of parity data in a predetermined area in the information recording layer.

In the optical information recording apparatus of the present invention,
The parity data generating means generates a plurality of parity data corresponding to the plurality of two-dimensional pattern information, and the recording means includes at least one parity data in each recording area in which the two-dimensional pattern information is recorded. Alternatively, multiple pieces of parity data may be multiplex-recorded over multiple recording areas.

In the optical information reproducing apparatus of the present invention, the phase of light is spatially modulated by a plurality of information lights carrying a plurality of two-dimensional pattern information and a plurality of phase modulation patterns different for each of the plurality of two-dimensional pattern information. From an optical information recording medium provided with an information recording layer in which a plurality of two-dimensional pattern information is multiplex-recorded in the same recording area by a plurality of interference patterns due to interference with a plurality of recording reference beams, using holography, An apparatus for reproducing a plurality of two-dimensional pattern information, including phase modulation means for spatially modulating the phase of light,
The phase modulation means spatially modulates the phase of light to generate a plurality of reproduction reference light modulated by a plurality of phase modulation patterns, and a plurality of reproduction reference light information. While irradiating the same recording area in the recording layer, and a reproducing means for collecting and detecting a plurality of reproducing light generated from the information recording layer by being irradiated with a plurality of reproducing reference light, the reproducing means, Irradiation of the reproduction reference light and collection of the reproduction light are performed so that the optical axis of the reproduction reference light and the optical axis of the reproduction light are arranged on the same line.

In the optical information reproducing apparatus of the present invention, a plurality of reproducing reference lights modulated by a plurality of phase modulation patterns are applied to the same recording area in the information recording layer to generate a plurality of reproducing signals from the information recording layer. Light is collected and detected. As a result, a plurality of pieces of two-dimensional pattern information that are multiplex-recorded in the same recording area are reproduced.

In the optical information reproducing apparatus of the present invention, in the optical information recording medium, adjacent recording areas of the plurality of recording areas are displaced in a predetermined direction in the optical information recording medium, and some of them overlap each other. As described above, a plurality of two-dimensional pattern information may be recorded in multiplex.

In the optical information reproducing apparatus of the present invention,
The optical information recording medium may have the same information recorded in a plurality of recording areas in the information recording layer.

Further, in the optical information reproducing apparatus of the present invention,
The optical information recording medium includes a plurality of data corresponding to a plurality of data generated by dividing information to be recorded on the optical information recording medium.
The dimension pattern information may be multiple-recorded in a predetermined order over a plurality of recording areas. in this case,
In the optical information recording medium, parity data generated based on a plurality of two-dimensional pattern information is recorded based on a predetermined rule by an interference pattern due to interference between the information light and the recording reference light based on the parity data. It may be recorded in a layer.

In the optical information reproducing apparatus of the present invention,
The optical information recording medium may be one in which a plurality of parity data corresponding to a plurality of two-dimensional pattern information are collectively recorded in a predetermined area in the information recording layer.

Further, in the optical information reproducing apparatus of the present invention,
In the optical information recording medium, a plurality of parity data corresponding to a plurality of two-dimensional pattern information is multiplexed over a plurality of recording areas so that each recording area in which the two-dimensional pattern information is recorded includes at least one parity data. It may be recorded.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The first embodiment of the present invention is an example in which multiple recording by phase encoding (phase encoding) multiplexing is possible. FIG. 1 is an explanatory diagram showing a configuration of a pickup device (hereinafter, simply referred to as a pickup) in an optical information recording / reproducing apparatus according to the present embodiment and an optical information recording medium according to the present embodiment, and FIG.
FIG. 1 is a block diagram showing an overall configuration of an optical information recording / reproducing device according to this embodiment. The optical information recording / reproducing device is
It includes an optical information recording device and an optical information reproducing device.

First, the structure of the optical information recording medium in the present embodiment will be described with reference to FIG. The optical information recording medium 1 includes a hologram layer 3 as an information recording layer on which information is recorded by using volume holography, and a reflective film 5 on one surface of a disk-shaped transparent substrate 2 formed of polycarbonate or the like. , And the protective layer 4 are laminated in this order. Hologram layer 3 and protective layer 4
Address / servo areas 6 as a plurality of positioning areas extending linearly in the radial direction are provided at a predetermined angular interval on the boundary surface between and, and a fan-shaped section between adjacent address / servo areas 6 is a data area 7. It has become. In the address / servo area 6, information for performing focus servo and tracking servo by the sampled servo method and address information are recorded in advance by embossed pits or the like. The focus servo can be performed by using the reflective surface of the reflective film 5. For example, wobble pits can be used as the information for performing the tracking servo. The transparent substrate 2 is, for example, 0.6 m
The thickness of the hologram layer 3 is 10 μm or less.
The appropriate thickness is set as described above. The hologram layer 3 is formed of a hologram material whose optical characteristics such as a refractive index, a dielectric constant, and a reflectance change according to the intensity of light when the light is irradiated. The hologram material is, for example, a photopolymer (photopopo) manufactured by Dupont.
Polymers) HRF-600 (product name) or the like is used. The reflective film 5 is made of, for example, aluminum.

Next, the configuration of the optical information recording / reproducing apparatus according to the present embodiment will be described with reference to FIG. The optical information recording / reproducing apparatus 10 includes a spindle 81 to which the optical information recording medium 1 is attached, a spindle motor 82 for rotating the spindle 81, and a spindle motor for keeping the number of rotations of the optical information recording medium 1 at a predetermined value. And a spindle servo circuit 83 for controlling 82. The optical information recording / reproducing apparatus 10 further irradiates the optical information recording medium 1 with information light and recording reference light to record information, and irradiates the optical information recording medium 1 with reproduction reference light. Then
A pickup 11 for detecting reproduction light and reproducing information recorded on the optical information recording medium 1, and a drive device 84 for moving the pickup 11 in the radial direction of the optical information recording medium 1 are provided. ing.

The optical information recording / reproducing apparatus 10 further uses the focus error signal FE,
Based on the detection circuit 85 for detecting the tracking error signal TE and the reproduction signal RF, and the focus error signal FE detected by the detection circuit 85, the actuator in the pickup 11 is driven to move the objective lens to the optical information recording medium. 1, a focus servo circuit 86 for performing focus servo by moving in the thickness direction of 1, and a detection circuit 8
A tracking servo circuit 87 for driving the actuator in the pickup 11 based on the tracking error signal TE detected by 5 to move the objective lens in the radial direction of the optical information recording medium 1 to perform tracking servo.
And a slide servo circuit 88 for performing a slide servo for controlling the drive device 84 based on the tracking error signal TE and a command from a controller described later to move the pickup 11 in the radial direction of the optical information recording medium 1. .

The optical information recording / reproducing apparatus 10 further decodes output data of a CCD array, which will be described later, in the pickup 11 to reproduce the data recorded in the data area 7 of the optical information recording medium 1 and a detecting circuit. A signal processing circuit 89 for reproducing a basic clock and determining an address from a reproduction signal RF from 85, and an optical information recording / reproducing device 10.
A controller 90 for controlling the entire controller and an operation unit 91 for giving various instructions to the controller 90. The controller 90 inputs the basic clock and address information output from the signal processing circuit 89, and controls the pickup 11, the spindle servo circuit 83, the slide servo circuit 88, and the like. The spindle servo circuit 83 inputs the basic clock output from the signal processing circuit 89. The controller 90 is a CPU (central processing unit), R
It has an OM (Read Only Memory) and a RAM (Random Access Memory), and the CPU realizes the function of the controller 90 by executing the program stored in the ROM using the RAM as a work area. It has become.

Next, the structure of the pickup 11 in the present embodiment will be described with reference to FIG. The pickup 11 includes an objective lens 12 that faces the transparent substrate 2 side of the optical information recording medium 1 when the optical information recording medium 1 is fixed to the spindle 81, and the objective lens 12 in the thickness direction of the optical information recording medium 1. Further, an actuator 13 that is movable in the radial direction, and a two-divided optical rotation plate 14 and a prism block 15 that are sequentially arranged from the objective lens 12 side are provided on the opposite side of the objective lens 12 from the optical information recording medium 1. The two-part optical rotation plate 14 has an optical rotation plate 14L arranged on the left side of the optical axis in FIG. 1 and an optical rotation plate 14R arranged on the right side of the optical axis in FIG. The optical rotation plate 14L rotates the polarization direction by + 45 °,
R rotates the polarization direction by -45 °.
The prism block 15 has a semi-reflective surface 15a and a reflective surface 15b, which are sequentially arranged from the side of the two-part optical rotation plate 14. The semi-reflective surface 15a and the reflective surface 15b are both arranged such that their normal directions are inclined 45 ° with respect to the optical axis direction of the objective lens 12 and are parallel to each other.

The pickup 11 further includes a prism block 19 arranged laterally of the prism block 15. The prism block 19 is arranged at a position corresponding to the semi-reflective surface 15a of the prism block 15, and is parallel to the semi-reflective surface 15a, and a reflective surface 15b.
And has a semi-reflective surface 19b which is arranged at a position corresponding to and is parallel to the reflective surface 15b.

The pickup 11 further includes, between the prism block 15 and the prism block 19, convex lenses 16 and phase spatial light sequentially arranged from the prism block 15 side at positions corresponding to the semi-reflective surface 15a and the reflective surface 19a. A modulator 17 and a spatial light modulator 18 disposed between the prism block 15 and the prism block 19 at positions corresponding to the reflecting surface 15b and the semi-reflecting surface 19b are provided.

The phase spatial light modulator 17 has a large number of pixels arranged in a grid pattern, and the phase of light can be spatially modulated by selecting the phase of outgoing light for each pixel. It is like this. A liquid crystal element can be used as the phase spatial light modulator 17.

The spatial light modulator 18 has a large number of pixels arranged in a lattice pattern, and spatially modulates the light according to the light intensity by selecting a light transmission state or a light blocking state for each pixel. Then, information light carrying information can be generated. A liquid crystal element can be used as the spatial light modulator 18. Spatial light modulator 18
Constitutes the information light generating means in the present invention.

The pickup 11 further receives the return light from the optical information recording medium 1 after passing through the spatial light modulator 18.
The prism block 19 is provided with a CCD array 20 as a detecting means arranged in a direction of being reflected by the semi-reflective surface 19b.

The pickup 11 further includes a beam splitter 23, a collimator lens 24, and a light source device 25, which are arranged in order from the prism block 19 side, on the side of the prism block 19 opposite to the spatial light modulator 18. There is. The normal direction of the beam splitter 23 is 45 ° with respect to the optical axis direction of the collimator lens 24.
It has a tilted semi-reflective surface 23a. Light source device 25
Emits coherent linearly polarized light. For example, a semiconductor laser can be used.

The pickup 11 further includes a light source device 25.
A photodetector 26 arranged in a direction in which light from the side is reflected by the semi-reflective surface 23a of the beam splitter 23;
On the opposite side of the beam splitter 23 from the photodetector 26, a convex lens 27, a cylindrical lens 28, and a four-division photodetector 29, which are sequentially arranged from the beam splitter 23 side, are provided. The photodetector 26 receives light from the light source device 25, and its output is used to automatically adjust the output of the light source device 25. The four-division photo detector 29 is shown in FIG.
As shown in FIG. 5, the optical information recording medium 1 has four light receiving portions 29a to 29d divided by a dividing line 30a parallel to the direction corresponding to the track direction and a dividing line 30b perpendicular to the direction. There is. The cylindrical lens 28 is arranged such that the central axis of its cylindrical surface forms an angle of 45 ° with the dividing lines 30a and 30b of the four-divided photodetector 29.

The phase spatial light modulator 17, the spatial light modulator 18 and the light source device 25 in the pickup 11 are controlled by the controller 90 shown in FIG. The controller 90 uses the phase spatial light modulator 1
7 holds information on a plurality of modulation patterns for spatially modulating the phase of light. In addition, the operation unit 91
Is capable of selecting an arbitrary modulation pattern from a plurality of modulation patterns. Then, the controller 90 gives the information of the modulation pattern selected by itself or the modulation pattern selected by the operation section 91 to the phase spatial light modulator 17, and the phase spatial light modulator 17 gives it from the controller 90. The phase of the light is spatially modulated by the corresponding modulation pattern according to the information of the modulation pattern.

Further, each semi-reflective surface 1 in the pickup 11
The reflectances of 5a and 19b are appropriately set, for example, so that the intensities of the information light and the recording reference light incident on the optical information recording medium 1 are equal.

FIG. 3 is a block diagram showing the structure of a detection circuit 85 for detecting the focus error signal FE, the tracking error signal TE and the reproduction signal RF based on the output of the four-division photo detector 29. The detection circuit 85 includes an adder 31 that adds the outputs of the light receiving sections 29a and 29d on the diagonal of the four-division photo detector 29, and 4
Diagonal photodetectors 29b, 29 of the split photodetector 29
an adder 32 for adding the respective outputs of c, a subtracter 33 for calculating the difference between the output of the adder 31 and the output of the adder 32, and generating a focus error signal FE by the astigmatic method.
An adder 34 that adds the respective outputs of the light receiving portions 29a and 29b adjacent to each other along the track direction of the four-divided photodetector 29 and the respective outputs of the light receiving portions 29c and 29d that are adjacent to each other along the track direction of the four-divided photodetector 29 are added together. Adder 35, a subtractor 36 that calculates the difference between the output of the adder 34 and the output of the adder 35, and generates a tracking error signal TE by the push-pull method, and the output of the adder 34 and the adder 35. And an output of the adder 37 to generate a reproduction signal RF. In the present embodiment, the reproduction signal RF is a signal obtained by reproducing the information recorded in the address / servo area 6 of the optical information recording medium 1.

Next, the operation of the optical information recording / reproducing apparatus according to the present embodiment will be described in order for servo operation, recording operation and reproduction operation. It should be noted that the optical information recording medium 1 is controlled by the spindle motor 82 to be maintained at a prescribed number of revolutions during servo, recording, and reproduction.

First, the operation during servo will be described with reference to FIG. At the time of servo, all the pixels of the spatial light modulator 18 are set to the transmissive state. The output of the light emitted from the light source device 25 is set to a low output for reproduction. The controller 90 predicts the timing at which the light emitted from the objective lens 12 passes through the address / servo area 6 based on the basic clock reproduced from the reproduction signal RF, and the objective lens 12
The above setting is made while the emitted light of (1) passes through the address / servo area 6.

The light emitted from the light source device 25 is collimated by the collimator lens 24, is incident on the beam splitter 23, and part of the light amount is transmitted and part is reflected by the semi-reflecting surface 23a. The light reflected by the semi-reflective surface 23 a is received by the photo detector 26. The light transmitted through the semi-reflective surface 23a is incident on the prism block 19, and a part of the light amount is transmitted through the semi-reflective surface 19b. The light transmitted through the semi-reflective surface 19b passes through the spatial light modulator 18, is reflected by the reflective surface 15b of the prism block 15, a part of the light amount is transmitted through the semi-reflective surface 15a, and is further divided into two rotatory plates 14.
Then, the information recording medium 1 is irradiated with light so that it is condensed by the objective lens 12 and converged on the boundary surface between the hologram layer 3 and the protective layer 4 in the optical information recording medium 1.
This light is reflected by the reflective film 5 of the optical information recording medium 1, at which time it is modulated by the embossed pits in the address servo area 6 and returns to the objective lens 12 side.

The return light from the optical information recording medium 1 is collimated by the objective lens 12, passes through the two-divided optical rotation plate 14 again, and is incident on the prism block 15. Through. The return light transmitted through the semi-reflective surface 15a is reflected by the reflective surface 15a, and the spatial light modulator 18
Through the semi-reflective surface 19b of the prism block 19. The return light transmitted through the semi-reflective surface 19b is incident on the beam splitter 23, a part of the light amount thereof is reflected by the semi-reflective surface 23a, passes through the convex lens 27 and the cylindrical lens 28 in order, and is then detected by the four-division photo detector 29. It The detection circuit 85 shown in FIG. 3 generates the focus error signal FE, the tracking error signal TE, and the reproduction signal RF based on the output of the 4-division photo detector 29,
Based on these signals, focus servo and tracking servo are performed, and the basic clock is reproduced and the address is determined.

In the above servo setting,
The pickup 11 has a structure of a pickup for recording and reproducing on a normal optical disk such as a CD (compact disk), a DVD (digital video disk or a digital versatile disk), and an HS (hyper storage disk). Will be similar to. Therefore, the optical information recording / reproducing apparatus 10 according to the present embodiment can be configured to have compatibility with a normal optical disk device.

Here, A-polarized light and B-polarized light used in the following description are defined as follows. That is, as shown in FIG. 10, A-polarized light is S-polarized light of −45 ° or P-polarized light is + 45 ° linearly polarized light, and B-polarized light is S-polarized light of + 45 ° or P-polarized light of −45 °. Linearly polarized light with the polarization direction rotated. The polarization directions of the A-polarized light and the B-polarized light are orthogonal to each other. The S-polarized light is linearly polarized light whose polarization direction is perpendicular to the plane of incidence (the paper surface of FIG. 1), and the P-polarized light is linearly polarized light whose polarization direction is parallel to the plane of incidence.

Next, the operation during recording will be described. FIG. 6 is an explanatory diagram showing the state of the pickup 11 during recording. At the time of recording, the spatial light modulator 18 selects a transmission state (hereinafter, also referred to as ON) and a blocking state (hereinafter, also referred to as OFF) for each pixel in accordance with the information to be recorded, and determines the passing light. It is spatially modulated to generate information light. In the present embodiment, two pixels represent 1-bit information, and one of two pixels corresponding to 1-bit information is always turned on and the other is turned off.

Further, the phase spatial light modulator 17 applies to the passing light, for each pixel, in accordance with a predetermined modulation pattern.
Phase difference 0 (rad) or π (ra
By selectively imparting d), the phase of the light is spatially modulated, and the recording reference light in which the phase of the light is spatially modulated is generated. The controller 90 provides the phase spatial light modulator 17 with information on the modulation pattern selected by itself or the modulation pattern selected by the operation unit 91 according to a predetermined condition.
The phase of the passing light is spatially modulated according to the information of the modulation pattern given by 0.

The output of the light emitted from the light source device 25 is pulsed to a high output for recording. The controller 90
Predicts the timing at which the light emitted from the objective lens 12 passes through the data area 7 on the basis of the basic clock reproduced from the reproduction signal RF. While the light emitted from the objective lens 12 passes through the data area 7, Set as. While the light emitted from the objective lens 12 passes through the data area 7, the focus servo and the tracking servo are not performed, and the objective lens 12 is fixed. In the following description, the light source device 25 emits P-polarized light.

As shown in FIG. 6, the P-polarized light emitted from the light source device 25 is made into a parallel light flux by the collimator lens 24, is incident on the beam splitter 23, and a part of the light amount is on the semi-reflective surface 23a. Transparent, prism block 1
It is incident on 9. The light incident on the prism block 19 is
Part of the light amount is transmitted through the semi-reflective surface 19b, and part of the light amount is reflected by the semi-reflective surface 19b. The light transmitted through the semi-reflective surface 19b passes through the spatial light modulator 18, and at that time, the light is spatially modulated according to the information to be recorded and becomes information light. This information light is reflected by the reflecting surface 15b of the prism block 15, and a part of the light amount thereof passes through the semi-reflecting surface 15a and passes through the two-divided optical rotation plate 14. Here, the light passing through the optical rotation plate 14L of the two-part optical rotation plate 14 has its polarization direction rotated by + 45 ° to become A-polarized light, and the light passing through the optical rotation plate 14R has its polarization direction rotated by −45 °. It becomes B-polarized light. The information light that has passed through the two-division optical rotation plate 14 is condensed by the objective lens 12 and converges on the boundary surface between the hologram layer 3 and the protective layer 4 in the optical information recording medium 1, that is, on the reflection film 5. The optical information recording medium 1 is irradiated.

On the other hand, the semi-reflective surface 1 of the prism block 19
The light reflected by 9b is reflected by the reflecting surface 19a, passes through the phase spatial light modulator 17, and at that time, the phase of the light is spatially modulated according to a predetermined modulation pattern, and the recording reference light is recorded. Becomes The recording reference light becomes light that passes through the convex lens 16 and converges. A part of the light amount of the recording reference light is reflected by the semi-reflective surface 15 a of the prism block 15 and passes through the two-divided optical rotation plate 14. Where here 2
The light passing through the optical rotation plate 14L of the split optical rotation plate 14 has its polarization direction rotated by + 45 ° and becomes A-polarized light.
The light passing through R has its polarization direction rotated by −45 ° and becomes B-polarized light. The recording reference light that has passed through the two-divided optical rotation plate 14 is condensed by the objective lens 12 and is applied to the optical information recording medium 1. After converging to
It passes through the hologram layer 3 while diverging.

7 and 8 are explanatory views showing the state of light during recording. In these figures, the symbol indicated by reference numeral 61 indicates P-polarized light, the symbol indicated by reference numeral 63 indicates A-polarized light, and the symbol indicated by reference numeral 64 indicates B-polarized light.

As shown in FIG. 7, the information light 51L that has passed through the optical rotation plate 14L of the two-divided optical rotation plate 14 becomes A-polarized light, which is irradiated onto the optical information recording medium 1 through the objective lens 12 to generate a hologram. It passes through the layer 3, converges to have the smallest diameter on the reflective film 5, is reflected by the reflective film 5, and passes through the hologram 3 again. Further, the recording reference light 52L that has passed through the optical rotator 14L of the two-divided optical rotator 14 becomes A-polarized light, which is irradiated onto the information recording medium 1 through the objective lens 12 to form the hologram layer 3 and the protective layer 4. After converging to have the smallest diameter on the front side of the boundary surface, it passes through the hologram layer 3 while diverging. Then, in the hologram layer 3, the A-polarized information light 51L reflected by the reflective film 5 and the A-polarized recording reference light 52L traveling toward the reflective film 5 side.
Interfere with each other to form an interference pattern, and when the output of the light emitted from the light source device 20 becomes high, the interference pattern is volumetrically recorded in the hologram layer 3.

Further, as shown in FIG. 8, the information light 51R that has passed through the optical rotation plate 14R of the two-division optical rotation plate 14 becomes B-polarized light, which is irradiated onto the information recording medium 1 via the objective lens 12, The light passes through the hologram layer 3, converges to have the smallest diameter on the reflection film 5, is reflected by the reflection film 5, and then passes through the hologram 3 again. The recording reference light 52R that has passed through the optical rotation plate 14R of the two-division optical rotation plate 14 is
The light becomes B-polarized light, is irradiated onto the information recording medium 1 through the objective lens 12, and is converged so as to have the smallest diameter on the front side of the boundary surface between the hologram layer 3 and the protective layer 4.
It passes through the hologram layer 3 while diverging. In the hologram layer 3, the B-polarized information light 51R reflected by the reflective film 5 and the B-polarized recording reference light 52R traveling toward the reflective film 5 interfere with each other to form an interference pattern.
When the output of the emitted light of 0 becomes high, the interference pattern is recorded volumetrically in the hologram layer 3.

As shown in FIGS. 7 and 8, in the present embodiment, the information light and the recording reference light are arranged such that the optical axis of the information light and the optical axis of the recording reference light are arranged on the same line. And are irradiated to the hologram layer 3 from the same surface side.

In the present embodiment, by performing the recording operation a plurality of times by changing the modulation pattern of the reference beam for recording at the same location of the hologram layer 3, the phase encoding multiplexing is performed.
It is possible to record multiple information at the same location on the hologram layer 3.

In this way, in this embodiment, a reflection type (Lippmann type) hologram is formed in the hologram layer 3. The A-polarized information light 51L and the B-polarized recording reference light 52R do not interfere with each other because their polarization directions are orthogonal to each other. Similarly, the B-polarized information light 51R and the A-polarized recording reference light 52L are , The polarization directions are orthogonal, so there is no interference.
As described above, in the present embodiment, it is possible to prevent the generation of extra interference fringes and prevent the deterioration of the SN (signal to noise) ratio.

Further, in the present embodiment, as described above, the information light is irradiated so as to converge so as to have the smallest diameter on the boundary surface between the hologram layer 3 and the protective layer 4 in the optical information recording medium 1. Is reflected by the reflection film 5 of the information recording medium 1 and returns to the objective lens 12 side. This return light is incident on the four-division photodetector 29 in the same manner as during servo. Therefore, in the present embodiment, it is possible to perform the focus servo even at the time of recording by using the light incident on the four-division photo detector 29. It should be noted that the recording reference light is converged so as to have the smallest diameter on the front side of the boundary surface between the hologram layer 3 and the protective layer 4 in the optical information recording medium 1 and becomes divergent light, so that it is reflected by the information recording medium 1. Even if the light is reflected by the film 5 and returns to the objective lens 12 side, no image is formed on the four-division photodetector 29.

In this embodiment, by moving the convex lens 16 back and forth and changing its magnification, a region in which one interference pattern of the information light and the reference light is recorded in the hologram layer 3 (volumetrically). It is possible to arbitrarily determine the size of the hologram.

Next, the operation during reproduction will be described with reference to FIG. During reproduction, all pixels of the spatial light modulator 18 are turned on. Further, the controller 90 gives the information of the modulation pattern of the recording reference light at the time of recording the information to be reproduced to the phase spatial light modulator 17, and the phase spatial light modulator 17 gives the information of the modulation pattern given by the controller 90. According to the information, the phase of the passing light is spatially modulated to generate the reproduction reference light in which the phase of the light is spatially modulated.

The output of the light emitted from the light source device 25 is set to a low output for reproduction. The controller 90 predicts the timing at which the light emitted from the objective lens 12 passes through the data area 7 based on the basic clock reproduced from the reproduction signal RF, and the light emitted from the objective lens 12 passes through the data area 7. In the meantime, set as above. While the light emitted from the objective lens 12 passes through the data area 7, the focus servo and the tracking servo are not performed.
Is fixed.

As shown in FIG. 9, the P-polarized light emitted from the light source device 25 is made into a parallel light flux by the collimator lens 24, is incident on the beam splitter 23, and a part of the light amount is on the semi-reflecting surface 23a. Transparent, prism block 1
It is incident on 9. The light incident on the prism block 19 is
A part of the light amount is reflected by the semi-reflective surface 19b, and the reflected light is reflected by the reflective surface 19a, and the phase spatial light modulator 1
7. At that time, according to a predetermined modulation pattern,
The phase of the light is spatially modulated and becomes the reproduction reference light.
This reproduction reference light becomes light that passes through the convex lens 16 and converges. A part of the light amount of the reproduction reference light is reflected by the semi-reflective surface 15 a of the prism block 15 and passes through the two-part optical rotation plate 14. Here, the two-divided optical rotation plate 14
The light passing through the optical rotation plate 14L has its polarization direction rotated by + 45 ° and becomes A-polarized light, and the light passing through the optical rotation plate 14R has its polarization direction rotated by −45 ° and becomes B-polarized light.
The reproduction reference light that has passed through the two-divided optical rotation plate 14 is condensed by the objective lens 12 and is applied to the optical information recording medium 1, and once has the smallest diameter before the boundary surface between the hologram layer 3 and the protective layer 4. After converging so as to become, the light passes through the hologram layer 3 while diverging.

FIGS. 10 and 11 are explanatory views showing the state of light during reproduction. In these figures,
The symbol indicated by reference numeral 61 represents P-polarized light, the symbol indicated by reference numeral 62 represents S-polarized light, the symbol indicated by reference numeral 63 represents A-polarized light, and the symbol indicated by reference numeral 64 represents B-polarized light.

As shown in FIG. 10, the two-part optical rotation plate 14 is used.
The reproduction reference light 53L that has passed through the optical rotatory plate 14L becomes A-polarized light, irradiates the optical information recording medium 1 through the objective lens 12, and is closer to the front side than the boundary surface between the hologram layer 3 and the protective layer 4. Then, after converging to have the smallest diameter, the light passes through the hologram layer 3 while diverging. As a result, the reproduction light 54L corresponding to the information light 51L at the time of recording is generated from the hologram layer 3. The reproduction light 54L travels toward the objective lens 12 side, is converted into a parallel light flux by the objective lens 12, passes through the two-split optical plate 14 again, and becomes S-polarized light.

Further, as shown in FIG. 11, the reproduction reference light 53R that has passed through the optical rotation plate 14R of the two-division optical rotation plate 14.
Becomes B-polarized light, is irradiated onto the optical information recording medium 1 through the objective lens 12, and is converged so as to have the smallest diameter on the front side of the boundary surface between the hologram layer 3 and the protective layer 4. It passes through the hologram layer 3 while diverging. As a result, from the hologram layer 3, the information beam 51R at the time of recording is obtained.
The reproduction light 54R corresponding to This reproduction light 54R
Goes to the objective lens 12 side, is converted into a parallel light flux by the objective lens 12, passes through the two-division optical rotation plate 14 again, and becomes S-polarized light.

The reproduction light that has passed through the two-divided optical rotation plate 14 is incident on the prism block 15, and a part of the amount of light is transmitted through the semi-reflective surface 15a. The reproduction light transmitted through the semi-reflective surface 15a is reflected by the reflective surface 15a, passes through the spatial light modulator 18, and a part of the light amount is partially reflected by the semi-reflective surface 19 of the prism block 19.
The light is reflected by b, enters the CCD array 20, and is detected by the CCD array 20. An on / off pattern formed by the spatial light modulator 18 during recording is imaged on the CCD array 20, and information is reproduced by detecting this pattern.

When a plurality of pieces of information are recorded in the hologram layer 3 by changing the modulation pattern of the recording reference light, the same modulation pattern as the reproduction reference light of the plurality of pieces of information is recorded. Only the information corresponding to the recording reference light of is reproduced.

As shown in FIGS. 10 and 11, in the present embodiment, the irradiation of the reproducing reference light is performed so that the optical axis of the reproducing reference light and the optical axis of the reproducing light are arranged on the same line. The reproduction light is collected from the same surface side of the hologram layer 3.

Further, in the present embodiment, a part of the reproduction light is incident on the four-division photodetector 29, like the return light at the time of servo. Therefore, in the present embodiment,
It is possible to perform focus servo during reproduction by using the light incident on the four-division photo detector 29. The reproducing reference light converges to have the smallest diameter on the front side of the boundary surface between the hologram layer 3 and the protective layer 4 in the optical information recording medium 1 and becomes divergent light. Even if the light is reflected by the reflective film 5 and returns to the objective lens 12 side, no image is formed on the four-division photodetector 29.

By the way, when the two-dimensional pattern of the reproduction light is detected by the CCD array 20, the reproduction light and the CCD are detected.
Accurately position array 20 or CCD array 2
It is necessary to recognize the reference position in the pattern of the reproduction light from the detection data of 0. In this embodiment, the latter is adopted. Here, referring to FIGS. 12 and 13, the CCD
A method of recognizing the reference position in the reproduction light pattern from the detection data of the array 20 will be described. 12
As shown in (a), the aperture in the pickup 11 is divided by the two-part optical rotation plate 14 into two regions 71L and 71R that are symmetrical about the optical axis. Further, as shown in FIG. 12B, the aperture is divided into a plurality of pixels 72 by the spatial light modulator 18.
The pixel 72 is the minimum unit of the two-dimensional pattern data. In the present embodiment, two pixels represent 1-bit digital data “0” or “1”, and one of the two pixels corresponding to 1-bit information is turned on and the other is turned off. If two pixels are both on or off, error data will result. As described above, expressing 1-bit digital data with two pixels has an advantage that the detection accuracy of data can be improved by differential detection. FIG.
(A) shows a set 73 of two pixels corresponding to 1-bit digital data. The area in which this set 73 exists will be referred to as a data area hereinafter. In this embodiment, 2
When the pixels are both on or off, error data is used, and the reference position information indicating the reference position in the pattern of the reproduction light is included in the information light. That is, as shown in FIG. 13B, a cross-shaped region 74 composed of a portion having a width of 2 pixels parallel to the dividing line of the two-part optical rotation plate 14 and a portion having a width of 2 pixels perpendicular to the dividing line.
In addition, the error data is intentionally arranged in a predetermined pattern. Hereinafter, the pattern of this error data is referred to as a tracking pixel pattern. This tracking pixel pattern serves as reference position information. In FIG. 13B, reference numeral 75 represents an ON pixel, and reference numeral 76 represents an OFF pixel. Further, the 4-pixel area 77 in the central portion is always turned off.

When the tracking pixel pattern and the pattern corresponding to the data to be recorded are combined, FIG.
The two-dimensional pattern as shown in FIG. In the present embodiment, among the areas other than the data area, the upper half in the figure is turned off and the lower half is turned on. It is turned on when the state opposite to the area, that is, when the area other than the data area is off, and when the area other than the data area is on. This allows
From the detection data of the CCD array 20, it becomes possible to more clearly detect the boundary portion of the data area.

At the time of recording, an interference pattern of the information light spatially modulated according to the two-dimensional pattern as shown in FIG. 14A and the recording reference light is recorded on the hologram layer 3. The pattern of the reproduction light obtained during reproduction is shown in FIG.
As shown in (b), the contrast is lower and the SN ratio is worse than when recording. CC during playback
The D array 20 detects the reproduction light pattern as shown in FIG. 14B and discriminates the data. At that time, the tracking pixel pattern is recognized and the data is discriminated using the position as the reference position. .

FIG. 15A conceptually shows the contents of data discriminated from the reproduction light pattern. In the figure, areas marked with symbols such as A-1-1 represent 1-bit data. In this embodiment, the data area is
By dividing the area 74 in the cross shape in which the tracking pixel pattern is recorded, four areas 78A, 78
It is divided into B, 78C and 78D. And in FIG.
As shown in (b), diagonal areas 78A and 78C are combined to form a rectangular area, and diagonal areas 78B and 78C are also formed.
78D is combined to form a rectangular area, and two rectangular areas are arranged above and below to form an ECC table. The ECC table is a table of data formed by adding an error correction code (ECC) such as a CRC (cyclic redundancy check) code to the data to be recorded. Note that FIG. 15B shows an example of an ECC table of n rows and m columns, and other arrays can be freely designed. Further, the data array shown in FIG. 15 (a) uses a part of the ECC table shown in FIG. 15 (b), and E shown in FIG. 15 (b).
A part of the CC table that is not used in the data array shown in FIG. 15A has a constant value regardless of the content of the data. At the time of recording, E as shown in FIG.
The CC table is decomposed into four areas 78A, 78B, 78C, 78D as shown in FIG. 15A and recorded on the optical information recording medium 1, and at the time of reproduction, an array as shown in FIG. 15 is detected and rearranged, and the data in FIG.
This ECC table is reproduced by reproducing the ECC table as shown in (b).
Data is reproduced by performing error correction based on the CC table.

Recognition of the reference position (tracking pixel pattern) in the reproduced light pattern and error correction as described above are performed by the signal processing circuit 89 in FIG.

As described above, according to the optical information recording / reproducing apparatus 10 in the present embodiment, the optical information at the time of recording can be recorded on the optical information recording medium 1 by the phase encoding multiplex while the information can be multiplexed. Irradiation of the recording reference light and the information light onto the information recording medium 1 and irradiation of the recording reference light onto the optical information recording medium 1 during reproduction and collection of the reproducing light are all performed on the same surface side with respect to the optical information recording medium 1. Since it is performed on the same axis, the optical system for recording or reproducing can be made smaller than that of the conventional holographic recording method, and the stray light as in the case of the conventional holographic recording method can be used. Problem does not occur. Further, according to the present embodiment, the optical system for recording and reproducing can be configured in the form of the pickup 11 similar to that of a normal optical disc device. Therefore, the optical information recording medium 1
Can be easily accessed at random.

Further, according to the present embodiment, the information for performing the focus servo and the tracking servo is recorded on the optical information recording medium 1, and the focus servo and the tracking servo can be performed by using this information. Therefore, it is possible to accurately position the light for recording or reproduction, and as a result, it is possible to increase the recording density, the recording capacity, and the transfer rate while improving the removable property and facilitating the random access. . Particularly, in the recording of this embodiment, it is possible to dramatically increase the recording density, the recording capacity, and the transfer rate in combination with the fact that the information can be recorded in multiplex by the phase encoding multiplex. For example, when a series of information is multiplexed and recorded at the same location of the hologram layer 3 while changing the modulation pattern of the recording reference light, it is possible to record and reproduce the information at an extremely high speed. .

Further, according to the present embodiment, the information recorded on the optical information recording medium 1 must use the reproduction reference light having the same modulation pattern as the modulation pattern of the recording reference light at the time of recording the information. If you can't play it,
Copy protection and confidentiality can be easily achieved. Further, according to the present embodiment, the optical information recording medium 1
In addition, various kinds of information (for example, various kinds of software) having different modulation patterns of the reference light are recorded, and the optical information recording medium 1 itself is provided to the user at a relatively low cost, and each optical information recording medium 1 can be provided in accordance with the user's request. It is possible to realize a service in which the information of the modulation pattern of the reference light that makes it possible to reproduce the type of information is individually provided as key information for a fee.

Further, according to the optical information recording / reproducing apparatus 10 in the present embodiment, since the reference position information indicating the reference position in the pattern of the reproducing light is included in the information light, the pattern of the reproducing light is recorded. Easy to recognize.

Further, according to the optical information recording / reproducing apparatus 10 in the present embodiment, the information recorded by the embossed pits is recorded on the recording medium by setting the pickup 11 in the servo state shown in FIG. Since reproduction is possible, compatibility with the conventional optical disk device can be provided.

In addition, according to the optical information recording / reproducing apparatus 10 in the present embodiment, each of the information multiplexed and recorded on the optical information recording medium 1 is associated with the modulation pattern of the phase of the different reference light. Therefore, the optical information recording medium 1 on which information is recorded
Is extremely difficult to duplicate. Therefore, illegal copying can be prevented.

Further, in the optical information recording medium 1 in the present embodiment, the hologram layer 3 on which information is recorded by using holography and the layer on which information such as an address is recorded by embossed pits are separated from each other. When an attempt is made to copy the optical information recording medium 1 on which information is recorded, these two
Since the two layers must correspond to each other, duplication is difficult also from this point, and illegal duplication can be prevented.

Next explained is an optical information recording / reproducing apparatus according to the second embodiment of the invention. In this embodiment,
This is an example in which it is possible to perform multiplex recording by using both phase encoding multiplexing and hole burning type wavelength multiplexing. The overall configuration of the optical information recording / reproducing apparatus according to the present embodiment is shown in FIG.
Optical information recording / reproducing apparatus 1 according to the first embodiment shown in FIG.
The configuration of 0 is substantially the same.

First, the hole burning type wavelength division multiplexing will be briefly described. The hole burning is a phenomenon in which the light absorption rate changes at the wavelength position of incident light in the light absorption spectrum, and is also called photochemical hole burning. Hereinafter, a material that causes hole burning, that is, a material that causes a change in the light absorption rate at the wavelength position of incident light in the light absorption spectrum is referred to as a hole burning material. Hole burning materials are generally amorphous,
This is a material in which a light absorption center (called guest) material such as a dye is dispersed in a medium (called host) having an irregular structure. This hole-burning material has a broad light absorption spectrum due to superposition of the light absorption spectra of many guests at extremely low temperatures. When such hole-burning material is irradiated with light having a specific wavelength (however, a wavelength within the light absorption band of the hole-burning material) such as laser light, only the guest having the resonance spectrum corresponding to the wavelength is exposed to the photochemical reaction. Therefore, in the light absorption spectrum of the hole burning material, the light absorption rate is reduced at the wavelength position of the irradiated light.

FIG. 16 shows a state in which the light absorptance of the hole-burning material is reduced at a plurality of wavelength positions by irradiation with light of a plurality of wavelengths. In the hole-burning material, a portion whose light absorption rate is reduced by irradiation with light is called a hole. Since this hole is extremely small, it becomes possible to multiplex record multiple information on the hole burning material by changing the wavelength.
Such a multiple recording method is called hole burning type wavelength multiplexing. Since holes have a size of about 10 ⁻² nm, it is considered that a hole burning material can provide a multiplicity of about 10 ³ to 10 ⁴ . For a detailed explanation of hole burning, see, for example, "Corona Publishing," Basics of Optical Memory, "pages 104-133, 1990.
Or, it is described in the above-mentioned document "New research on real-time recording / reproduction of wavelength-multiplexed hologram using PHB".

In the present embodiment, the hole burning type wavelength division multiplexing described above is utilized to
A plurality of holograms can be formed by changing the wavelength. Therefore, in the optical information recording medium 1 used in the optical information recording / reproducing apparatus according to the present embodiment, the hologram layer 3
Are formed of the hole burning material described above.

Further, in this embodiment, the light source device 25 in the pickup 11 is assumed to be capable of selectively emitting coherent light of a plurality of wavelengths within the light absorption band of the hole burning material forming the hologram layer 3. There is. As such a light source device 25, a wavelength tunable laser device having a dye laser and a wavelength selection element (prism, diffraction grating, etc.) for selecting the wavelength of the emitted light of this dye laser, or the laser and the emitted light of this laser A wavelength tunable laser device or the like having a wavelength conversion element using a nonlinear optical element for converting a wavelength can be used.

In this embodiment, the operation section 91 can select the modulation pattern of the reference light from a plurality of modulation patterns as in the first embodiment, and
The wavelength of the light emitted from the light source device 25 can be selected from a plurality of selectable wavelengths. Then, the controller 90 provides the light source device 25 with information on the wavelength selected by itself or the wavelength selected by the operation unit 91 according to a predetermined condition, and the light source device 25 responds according to the wavelength information provided by the controller 90. It emits light of a wavelength.

The other structure of the optical information recording / reproducing apparatus in this example is the same as that in the first embodiment.

In the optical information recording / reproducing apparatus according to this embodiment,
At the time of recording, the wavelength of the light emitted from the light source device 25 is selected from a plurality of selectable wavelengths. As a result, the information light and the recording reference light of the selected wavelength are generated. In the present embodiment, multiple recording can be performed by hole burning type wavelength multiplexing by changing the wavelengths of the information light and the recording reference light at the same location of the hologram layer 3 and performing a plurality of recording operations.

Further, in the optical information recording / reproducing apparatus according to the present embodiment, the recording pattern is changed a plurality of times by changing the modulation pattern of the recording reference light at a certain wavelength at the same position of the hologram layer 3, and further Similarly, by changing the modulation pattern of the reference beam for recording at a wavelength of, and performing the recording operation a plurality of times, it is possible to perform multiplex recording by using both phase-encoding multiplexing and hole-burning wavelength multiplexing. In this case, assuming that the multiplicity of the phase-coded multiplexing is N and the multiplicity of the hole burning type wavelength multiplexing is M, a multiplicity of N × M is obtained. Therefore, according to the present embodiment, it is possible to further increase the recording density, recording capacity and transfer rate as compared with the first embodiment.

Further, according to this embodiment, the information recorded on the optical information recording medium 1 must use the reproduction reference light having the same wavelength as that of the information light and the recording reference light at the time of recording the information. For example, since the data cannot be reproduced, copy protection and confidentiality can be easily realized as in the first embodiment. Furthermore, when multiple recording is performed using both phase-encoding multiplexing and hole-burning wavelength multiplexing, the same wavelength as that of the information light and the recording reference light at the time of recording the information, and the recording reference Since reproduction can be performed only by using the reproduction reference light having the same modulation pattern as the light modulation pattern, it is possible to more strongly realize copy protection and confidentiality protection.

Further, according to the present embodiment, various kinds of information having different wavelengths of the information light and the recording reference light or the modulation patterns of the reference light are recorded on the optical information recording medium 1, and the optical information is recorded. The recording medium 1 itself is provided to the user at a relatively low cost, and according to the user's request, the wavelength of the reference light and the information of the modulation pattern that can reproduce each type of information are individually provided as key information for a fee. Such services can be realized.

Other operations and effects in this embodiment are the same as those in the first embodiment.

Next explained is an optical information recording / reproducing apparatus according to the third embodiment of the invention. The overall configuration of the optical information recording / reproducing apparatus according to the present embodiment is substantially the same as the configuration of the optical information recording / reproducing apparatus 10 according to the first embodiment shown in FIG. However, the structure of the pickup is different from that of the first embodiment.

FIG. 17 is an explanatory view showing the structure of the pickup in the present embodiment, and FIG. 18 is a plan view showing the structure of the optical unit including the respective elements constituting the pickup.

Pickup 111 in the present embodiment
Is a light source device 112 that emits coherent linearly polarized laser light, a collimator lens 113 and a neutral density filter (neutral dens filter) that are sequentially arranged from the light source device 112 side in the traveling direction of the light emitted from the light source device 112.
ity filter; hereinafter referred to as ND filter. ) 114, an optical element 115 for optical rotation, a polarization beam splitter 116, a phase spatial light modulator 117, a beam splitter 118, and a photodetector 119. Light source device 112
Emits linearly polarized light of S polarization or P polarization. The collimator lens 113 is used as the light source device 1.
The emitted light of 12 is collimated and emitted. The ND filter 114 has a characteristic that makes the intensity distribution of the light emitted from the collimator lens 113 uniform. The optical element 115 for optical rotation rotates the light emitted from the ND filter 114 and emits light containing an S-polarized component and a P-polarized component. As the optical element 115 for optical rotation, for example, a ½ wavelength plate or an optical rotation plate is used. The polarization beam splitter 116 is an optical element 1 for optical rotation.
It has a polarization beam splitter surface 116a that reflects the S-polarized component and transmits the P-polarized component of the 15 emitted lights. The phase spatial light modulator 117 is the same as the phase spatial light modulator 17 in the first embodiment. The beam splitter 118 has a beam splitter surface 118a. The beam splitter surface 118a transmits, for example, 20% of the P-polarized component and reflects 80% thereof. The photo detector 119 monitors the light amount of the reference light, and automatically adjusts the light amount of the reference light (auto power control).
trol; hereinafter referred to as APC. ) Is used to do. In this photo detector 119, the light receiving portion may be divided into a plurality of regions so that the intensity distribution of the reference light can be adjusted.

The pickup 111 further includes the light source device 1.
A polarization beam splitter 120, a two-divided optical rotation plate 121, and a rising mirror 122, which are sequentially arranged from the beam splitter 118 side, are provided in a direction in which the light from 12 is reflected by the beam splitter surface 118a of the beam splitter 118 and travels. . The polarization beam splitter 120 is
It has a polarization beam splitter surface 120a that reflects the S-polarized component and transmits the P-polarized component of the incident light.
The two-divided optical rotation plate 121 has an optical rotation plate 121R arranged on the right side of the optical axis in FIG. 17 and an optical rotation plate 121L arranged on the left side of the optical axis. Optical rotation plate 121
R and 121L are the same as the optical rotation plates 14R and 14L of the two-division optical rotation plate 14 in the first embodiment, and the optical rotation plate 121R rotates the polarization direction by −45 ° and the optical rotation plate 1 is rotated.
21L rotates the polarization direction by + 45 °. The rising mirror 122 is tilted at 45 ° with respect to the optical axis of the light from the two-part optical rotation plate 121, and reflects the light from the two-part optical rotation plate 121 in a direction orthogonal to the paper surface of FIG. It has a reflective surface.

When the optical information recording medium 1 is fixed to the spindle 81, the pickup 111 is further arranged in the direction in which the light from the two-divided optical rotation plate 121 is reflected by the reflection surface of the rising mirror 122 and travels. In addition, the optical information recording medium 1
Objective lens 123 facing the transparent substrate 2 side, and an actuator 124 capable of moving the objective lens 123 in the thickness direction and the track direction of the optical information recording medium 1 (see FIG. 1).
8)) and.

The pickup 111 further includes the light source device 1.
In the direction in which the light from 12 is reflected by the polarization beam splitter surface 116a of the polarization beam splitter 116 and travels,
Spatial light modulator 125, convex lens 126, and beam splitter 1 arranged in order from the polarization beam splitter 116 side.
27 and a photo detector 128. The spatial light modulator 125 is similar to the spatial light modulator 18 in the first embodiment. The convex lens 126 has a function of converging the information light on the front side of the recording reference light in the optical information recording medium 1 to form an interference region between the recording reference light and the information light. By adjusting the position of the convex lens 126, the size of the interference region between the recording reference light and the information light can be adjusted. The beam splitter 127 has a beam splitter surface 127a. This beam splitter surface 127a is, for example, S
The polarized component is transmitted by 20% and reflected by 80%. The photo detector 128 is used to monitor the light amount of the information light and perform APC of the information light. In this photo detector 128, the light receiving portion may be divided into a plurality of regions so that the intensity distribution of the information light can be adjusted. Light that enters the beam splitter 127 from the convex lens 126 side and is reflected by the beam splitter surface 127 a enters the polarization beam splitter 120.

The pickup 111 further includes a convex lens 129, a cylindrical lens 130, and a four-division photo detector 131, which are arranged in this order from the beam splitter 127 side, on the side of the beam splitter 127 opposite to the polarization beam splitter 120. The four-division photo detector 131 is the same as the four-division photo detector 131 in the first embodiment.
It is similar to the split photodetector 29. The cylindrical lens 28 is arranged such that the central axis of its cylindrical surface forms 45 ° with respect to the dividing line of the four-divided photodetector 131.

The pickup 111 further includes an image forming lens 132 and a CCD array 133, which are arranged in order from the beam splitter 118 side, on the side of the beam splitter 118 opposite to the polarizing beam splitter 120.

The pickup 111 further includes a collimator lens 134 and a fixing light source device 135, which are arranged in order from the polarization beam splitter 116 side on the side of the polarization beam splitter 116 opposite to the spatial light modulator 125.
Is equipped with. The fixing light source device 135 emits light for fixing the information recorded on the hologram layer 3 of the optical information recording medium 1, for example, ultraviolet light having a wavelength of 266 nm. As such a fixing light source device 135, a laser light source, a light source device that wavelength-converts the light emitted from the laser light source through a nonlinear optical medium, and emits the light is used. The collimator lens 134 is a fixing light source device 135.
The emitted light is converted into a parallel light flux. Further, in this embodiment, the fixing light source device 135 emits S-polarized light.

As shown in FIG. 18, the optical unit 14
0 includes an optical unit body 141. Note that FIG. 18 shows only the bottom surface portion of the optical unit body 141. The optical unit body 141 includes the collimator lens 113, the ND filter 114, the optical element 115 for optical rotation, the polarization beam splitter 116, the phase spatial light modulator 117, the beam splitter 118, the polarization beam splitter 120, and the two-divided optical rotation plate 121. Launch mirror 1
22, spatial light modulator 125, convex lens 126, beam splitter 127, convex lens 129, cylindrical lens 130, imaging lens 132 and collimator lens 1
34 is attached.

FIG. 18 shows an optical element 115 for optical rotation as 1
An example using a / 2 wavelength plate is shown. Further, in this example, in the optical unit main body 141, the optical element 1 for optical rotation is provided.
In order to adjust the ratio between the S-polarized component and the P-polarized component in the outgoing light of 15, the motor 142 and the motor 142 are adjusted.
A gear 143 is provided for transmitting the rotation of the output shaft to the optical element 115 for optical rotation.

FIG. 19 shows an example of an optical element 115 for optical rotation using an optical rotating plate. The optical element 115 for optical rotation in this example has two wedge-shaped optical rotation plates 115a and 115b facing each other. These optical plates 11
At least one of 5a and 115b is displaced in the direction of the arrow in the drawing by a driving device (not shown), and
As shown in (a) and (b), the optical rotation plates 115a and 11
The total thickness of the optical rotatory plates 115a and 115b at the portion where 5b overlaps is changed. This allows
The rotation angle of the light passing through the optical rotation plates 115a and 115b changes, and as a result, the ratio of the S polarization component and the P polarization component in the emitted light of the optical element 115 for optical rotation changes. As shown in FIG. 19A, the optical rotation plate 1
When the total thickness of 15a and 115b is large, the optical rotation angle becomes large, and as shown in FIG.
When the total thickness of 15a and 115b is small, the optical rotation angle becomes small.

The actuator 124 is attached to the upper surface of the optical unit body 141. Light source device 112
Is integrated with a drive circuit 145 that drives the light source device 112, and together with the drive circuit 145, the unit main body 14
1 is attached to the side surface. Photo detector 11
9 is integrated with the APC circuit 146, and is attached to the side surface of the unit body 141 together with the APC circuit 146. The APC circuit 146 includes the photo detector 11
The output of 9 is amplified and the signal APC _ref used for APC of the reference light is generated. The photodetector 128 is integrated with the APC circuit 147, and is attached to the side surface of the unit main body 141 together with the APC circuit 147. The APC circuit 147 is configured to amplify the output of the photodetector 119 and generate a signal APC _obj used for APC of the information light. A signal AP from each APC circuit 146, 147 is provided on the side surface of the unit body 141 near the motor 142.
The drive circuit 1 that drives the motor 142 by comparing C _ref and APC _{obj so} that the ratio of the S-polarized component and the P-polarized component in the emitted light of the optical element 115 for optical rotation is in an optimum state.
48 is attached.

The four-division photo detector 131 is integrated with the detection circuit 85 (see FIG. 2), and is attached to the side surface of the unit body 141 together with the detection circuit 85. The CCD array 133 is integrated with a signal processing circuit 149 that drives the CCD array 133 and processes output signals of the CCD array 133, and is attached to the side surface of the unit body 141 together with the signal processing circuit 149. The fixing light source device 135 is the fixing light source device 13.
It is integrated with a drive circuit 150 for driving the motor 5, and is attached to the side surface of the unit main body 141 together with the drive circuit 150. An input / output port 151 for inputting / outputting various signals between a circuit inside the optical unit 140 and the outside of the optical unit 140 is further attached to a side surface of the unit main body 141. An optical fiber flexible cable 152 including an optical fiber that transmits a signal using light is connected to the input / output port 151, for example.

Although not shown, the optical unit body 1
A drive circuit that drives the phase spatial light modulator 117 and a drive circuit that drives the spatial light modulator 125 are attached to the upper surface of 41.

In FIG. 20, the light source device 112 is used as light of a plurality of wavelength bands in red (hereinafter, referred to as R), green (hereinafter, referred to as R).
Write G. ) And blue (hereinafter, referred to as B) laser lights of three colors can be emitted, and the CCD array 133
3 also shows an example of the configuration of the pickup 111 in the case where the lights of three colors of R, G, and B can be detected.

The light source device 112 in the example shown in FIG.
Includes a color combining prism 161. The color combining prism 161 includes an R light incident portion 162R and a G light incident portion 16R.
The 2G, B light incident part 162B is provided. Each incident part 16
Correction filters 163R, 163G, and 163B are provided in 2R, 162G, and 162B, respectively. The light source device 112 further includes semiconductor lasers (hereinafter, referred to as LD) 164R, 1 that emit R light, G light, and B light, respectively.
64G, 164B and LDs 164R, 164G, 16
The light emitted from 4B is converted into a parallel light flux, and each incident portion 162
It is provided with collimator lenses 165R, 165G and 165B which are made incident on R, 162G and 162B. Each LD
R light emitted from 164R, 164G, 164B, G
The light and the B light are collimator lenses 165R, 165G, 1
After passing through 65B and the correction filters 163R, 163G, and 163B, they enter the color combining prism 161, are combined by the color combining prism 161, and enter the ND filter 114. Note that in the example shown in FIG.
The collimator lens 113 in FIG. 17 is not provided.

CCD array 1 in the example shown in FIG.
33 includes a color separation prism 171. The color separation prism 171 includes an R light emitting portion 172R, a G light emitting portion 172G, and a B light emitting portion 172B. Correction filters 173R, 173G, and 173B are provided in the respective emission units 172R, 172G, and 172B.
The CCD array 133 is further provided with each emitting unit 17
2R, 172G, 172B is arranged at a position facing
CCD 174 for capturing R light image, G light image, and B light image
R, 174G, 174B. Imaging lens 1
The light from the 32 side is R by the color separation prism 171.
It is decomposed into light, G light, and B light, and these R light, G light, and B light are
Correction filters 173R, 173G, 173B, respectively
After that, the light enters the CCDs 174R, 174G, and 174B.

21 to 23, the slide feeding mechanism of the optical unit 140 according to the present embodiment will be described. FIG. 21 is a plan view showing the slide feeding mechanism, FIG. 22 is a partially cutaway side view showing the slide feeding mechanism in a stationary state, and FIG. 23 is a view showing the slide feeding mechanism when the optical unit is slightly displaced. It is a partial cutaway side view.

The slide feeding mechanism is the optical unit 140.
Shafts 1 arranged in parallel along the moving direction of the
81A and 181B, and two shafts 181A and 181B are provided for each shaft 181A and 181B.
A bearing 182 that is movable along the path, a leaf spring 183 that elastically connects each bearing 182 and the optical unit 140,
A linear motor 184 for moving the optical unit 140 along the shafts 181A and 181B is provided.

The linear motor 184 is the optical unit 14
Coil 185 connected to the lower end of 0, and two frame-shaped yokes 186A arranged along the moving direction of the optical unit 140 so that a part of the coil 185 penetrates the coil 185.
186B and a magnet 187 fixed to the inner peripheral portions of the yokes 186A and 186B so as to face the coil 185.
A, 187B.

Here, the operation of the slide feed mechanism will be described. When the linear motor 184 is operated, the optical unit 140 is displaced. When this displacement is very small,
As shown in FIG. 23, the bearing 182 is not displaced, and the leaf spring 183 between the bearing 182 and the optical unit 140 is deformed. When the displacement of the optical unit 140 exceeds a predetermined range, the bearing 182 also moves following the optical unit 140. According to such a slide feed mechanism, the bearing 182 does not displace when the displacement of the optical unit 140 is minute, and therefore wear due to sliding of the bearing 182 can be prevented. As a result, it is possible to drive the optical unit 140 by the linear motor 184 and perform tracking servo while ensuring the durability and reliability of the slide feed mechanism. The seek is also performed by the slide feed mechanism.

The actuator 124 includes the objective lens 12
3, a columnar actuator body 182 that holds 3 and is rotatable about an axis 181 is provided. The actuator body 182 has two holes 1 parallel to the shaft 181.
83 is formed. A focusing coil 184 is provided on the outer peripheral portion of the actuator body 182. Further, an in-field access coil (not shown) is provided on a part of the outer circumference of the focusing coil 184. The actuator 124 further includes a magnet 185 inserted through each hole 183 and a magnet (not shown) arranged so as to face the in-field access coil. The objective lens 123 is the actuator 12
4 in a stationary state, the center of the objective lens 123 and the axis 1
The line connecting 81 and 81 is arranged so as to face the track direction.

Next, with reference to FIGS. 24 to 27, a method of positioning (servo) the reference light and the information light with respect to the data area of the optical information recording medium 1 in the present embodiment will be described. The actuator 124 in the present embodiment can move the objective lens 123 in the thickness direction and the track direction of the optical information recording medium 1.

24A to 24C, the objective lens 123 is moved to the optical information recording medium 1 by the actuator 124.
The operation of moving in the track direction is shown.
In the stationary state, the actuator 124 is in the state shown in (b). The actuator 124 energizes a field-of-view access coil (not shown), so that (b)
It changes from the state shown to the state shown in (a) or (c). In this way, the objective lens 123
The operation of moving the optical disc in the track direction of the optical information recording medium 1 is called in-field access in the present embodiment.

FIG. 25 shows the moving direction of the seek of the objective lens 123 and the access direction within the visual field. In FIG. 25, reference numeral 191 indicates the objective lens 123.
The reference numeral 192 represents the movement direction of the objective lens 123 within the visual field. Further, reference numeral 193 represents the locus of the center of the objective lens 123 when the movement by seek and the access in the visual field are used together. For access within the visual field, the center of the objective lens 123 can be moved by, for example, about 2 mm.

In the present embodiment, the reference light and the information light are positioned (servo) in the data area of the optical information recording medium 1 by using the access within the visual field. FIG. 26 shows
It is an explanatory view for explaining this positioning. In the optical information recording medium 1 in the present embodiment, as shown in FIG. 26A, the groove 201 is formed for each track in the address / servo area 6, but in the data area 7, Groove 201 is not formed. Also,
A pit string 202 is used at the end of the address / servo area 6 for reproducing a clock and indicates which of the two ends of the data area 7 is adjacent to the end (referred to as polarity in the present embodiment). Are formed.

In FIG. 26B, reference numeral 203 represents the locus of the center of the objective lens 123 during recording or reproduction. In the present embodiment, when the information is multiplexed and recorded in the data area 7 by phase-encoding multiplexing, or when the information multiplexed and recorded in the data area 7 is reproduced,
Without stopping the center of the objective lens 123 in the data area 7, as shown in FIG.
The center of the objective lens 123 is moved using the in-field access so as to reciprocate within a section including a part of the servo area 6. Then, the clock is reproduced using the pit train 202 and the polarity is determined, and the focus servo and the tracking servo are performed using the groove 201 in the section 204 in the address servo area 6.
Section 20 including data area 7 between sections 204 and 204
Within 5, the tracking servo is not performed and the state at the time of passing the section 204 is maintained. The folding position in the movement of the center of the objective lens 123 is determined to be a constant position based on the reproduced clock. Further, the position where the information is multiplexed and recorded in the data area 7 is also determined so as to be a fixed position based on the reproduced clock. In FIG. 26B, reference numeral 206 represents a gate signal indicating the timing of recording or reproduction. With this gate signal, when high (H) level,
Indicates that it is the timing of recording or reproduction.
In order to multiplex-record information at a fixed location in the data area 7, for example, the output of the light source device 112 may be selectively set to a high output for recording when the gate signal is at a high level. Further, in order to reproduce the information multiplexed and recorded at a certain place in the data area 7, for example, when the gate signal is at a high level, light is selectively emitted from the light source device 112, or the CCD array is used. When 133 has an electronic shutter function, an image may be captured by using the electronic shutter function when the gate signal is at a high level.

By performing the positioning of the reference light and the information light by the method as described above, recording or reproduction is performed at the same location of the optical information recording medium 1 even when recording or reproduction is performed for a relatively long time. It is possible to prevent the position from shifting. Further, even if the optical information recording medium 1 is rotating, by performing access within the visual field so as to follow the rotation of the optical information recording medium 1, recording is performed in the same situation as when the optical information recording medium 1 is stationary. It is possible to perform recording and reproducing at the same location of the optical information recording medium 1 for a relatively long time. Further, if the technique of positioning the reference light and the information light using the in-field access as described above is used, the disc-shaped optical information recording medium 1
However, the reference light and the information light can be easily positioned even when an optical information recording medium of other form such as a card is used.

FIG. 27 shows an example of the locus of the center of the objective lens 123 when a plurality of locations on the optical information recording medium 1 are accessed by using both seek movement and in-field access. In this figure, the vertical straight line represents seek, the horizontal straight line represents movement to another location in the track direction, and the portion that reciprocates within a short section performs recording or reproduction. It represents the part that is.

Next, an example of a cartridge for housing the optical information recording medium 1 will be described with reference to FIGS. 28 and 29. 28 is a plan view of the cartridge, FIG.
FIG. 6 is a plan view of the cartridge with a shutter opened. The cartridge 211 in this example has a window portion 212 that exposes a part of the optical information recording medium 1 housed inside.
And a shutter 213 that opens and closes the window 212. The shutter 213 is biased in the direction to close the window 212, and normally closes the window 212 as shown in FIG. 28. However, when the cartridge 211 is attached to the optical information recording / reproducing apparatus. As shown in FIG. 29, the optical information recording / reproducing apparatus moves the window portion 212 in the opening direction.

Next, referring to FIGS. 30 to 34, 1
An example of the arrangement of the optical unit 140 in the case where a plurality of pickups 111 are provided in the optical information recording / reproducing device of the table will be described.

FIG. 30 shows an example in which two optical units 140A and 140B are arranged so as to face one surface of the optical information recording medium 1. The optical unit 140A is shown in FIG.
The same form as the optical unit 140 shown in FIG.
Say type. )belongs to. On the other hand, the optical unit 1
40B has a form (hereinafter referred to as B type) which is plane-symmetric with respect to the optical unit 140 shown in FIG. Two
The two optical units 140A and 140B are arranged at positions facing the optical information recording medium 1 exposed through the window 212 of the cartridge 211. In addition, each optical unit 140
The slide feed mechanisms A and 140B are arranged such that the center of the objective lens 123 of each optical unit 140A and 140B moves along a line passing through the center of the optical information recording medium 1.

FIG. 31 shows an example in which two optical units are arranged so as to face each surface of the optical information recording medium 1, and a total of four optical units are provided. Figure 32
31 is a sectional view taken along the line AA ′ of FIG. 31, and FIG. 33 is a sectional view of FIG.
It is a B-B 'line sectional view. In this example, the optical information recording medium 1
So as to face one surface (back surface in FIG. 31) of
The two optical units 140A and 140B are arranged so that the two optical units 140C and 140D are arranged so as to face the other surface (the surface in FIG. 31) of the optical information recording medium 1.
Are arranged. The optical unit 140C is an A type, and the optical unit 140D is a B type.

Arrangement of the optical units 140A, 140B and the slide feed mechanism thereof, and the optical units 140C,
The conditions for arranging the 140D and its slide feed mechanism are shown in FIG.
This is as explained using 0. In order to effectively use the four optical units 140A, 140B, 140C, 140D, it is necessary to use an optical information recording medium 1 capable of recording and reproducing information from both sides.

FIG. 34 shows the optical information recording medium 1 facing each surface.
Place 8 optical units each as
An example in which 16 optical units are provided is shown. This example
Then, one surface of the optical information recording medium 1 (shown in FIG.
8 optical units 140 facing each other)₁~
140₈On the other side of the optical information recording medium 1 (Fig.
8 optical units so that the
140₉~ 140 ₁₆Are arranged. Optical Uni
140₁, 140_Three, 140₅, 140₇, 140
_Ten, 140₁₂, 140₁₄, 140₁₆Is A type
Is. Optical unit 140_Two, 140_Four, 140₆，
140₈, 140₉, 140₁₁, 140 ₁₃, 140
₁₅Is of the B type. Slide of each optical unit
The feed mechanism is the objective lens of each optical unit.
The center of 123 is along the line passing through the center of the optical information recording medium 1.
It is arranged so that it moves. 16 optics
To use the unit effectively, put it in the cartridge.
Optical information that can be recorded and reproduced from both sides without fail
It is necessary to use the recording medium 1.

By the way, in the system including the optical information recording / reproducing apparatus and the optical information recording medium 1 according to the present embodiment,
It is possible to record an extremely large amount of information in the optical information recording medium 1, and such a system is suitable for the purpose of recording a huge amount of continuous information. However, in a system used for such an application, if the information cannot be reproduced while recording a huge amount of continuous information, the system becomes very difficult to use.

Therefore, for example, as shown in FIGS. 30 to 34, by providing a plurality of pickups 111 in one optical information recording / reproducing apparatus, recording and reproducing of information using one optical information recording medium 1. It is possible to perform simultaneous recording and reproducing by a plurality of pickups 111 at the same time, and it is possible to improve the recording and reproducing performances. Can be configured. In addition, a plurality of pickups 1 can be provided in one optical information recording / reproducing device.
By providing 11, the performance can be dramatically improved when searching for desired information from a large amount of information, as compared with the case where only one pickup 111 is provided.

Next, with reference to FIGS. 35 to 46, an example of a specific structure of the optical information recording medium 1 in the present embodiment will be described.

Optical information recording medium 1 in the present embodiment
Has a first information layer (hologram layer) in which information is recorded by holography, and a second information layer in which servo information and address information are recorded by embossed pits or the like. Then, it is necessary to form the interference region between the recording reference light and the information light in the first information layer to some extent while converging the reference light so as to have the smallest diameter in the second information layer. Therefore, in the present embodiment, a gap having a certain size is formed between the first information layer and the second information layer. As a result, the reference light is converged so as to have the smallest diameter in the second information layer, and the information recorded in the second information layer can be reproduced, while the recording reference light and the information are recorded in the first information layer. It is possible to form the light interference region in a sufficient size.
The optical information recording medium 1 in the present embodiment can be classified into an air gap type and a transparent substrate gap type depending on the method of forming the gap.

35 to 37 show an air gap type optical information recording medium 1, FIG. 35 is a half sectional view of the optical information recording medium 1, and FIG. 36 is an exploded half of the optical information recording medium 1. FIG. 37 is a perspective view, and FIG. 37 is a perspective view of a half of the optical information recording medium 1. The optical information recording medium 1 includes a reflective substrate 221 having one surface serving as a reflective surface, a transparent substrate 222 arranged to face the reflective surface of the reflective substrate 221, a reflective substrate 221, and a transparent substrate 222. And the outer peripheral spacer 223 and the inner peripheral spacer 2 that separate the
24 and a hologram layer 225 bonded to the surface of the transparent substrate 222 on the side of the reflective substrate 221. Between the reflection surface of the reflection substrate 221 and the hologram layer 225,
An air gap having a predetermined thickness is formed. The hologram layer 225 becomes the first information layer. A pre-groove is formed on the reflection surface of the reflection substrate 221, and this reflection surface serves as the second information layer.

38 to 40 show a transparent substrate gap type optical information recording medium 1, FIG. 38 is a sectional view of half of the optical information recording medium 1, and FIG. 39 is half of the optical information recording medium 1. FIG. 40 is an exploded perspective view, and FIG. 40 is a perspective view of a half of the optical information recording medium 1. The optical information recording medium 1 includes a transparent substrate 231 and a hologram layer 23 that serves as a first information layer.
2. A transparent substrate 233 is laminated in this order. On the surface of the transparent substrate 231 opposite to the hologram layer 232, a pre-groove is formed and a reflective film 234 is provided. This transparent substrate 23
The surface opposite to the hologram layer 232 in 1 is the second
Information layer. This second information layer and hologram layer 23
A gap having a predetermined thickness is formed between the two and the transparent substrate 231. The transparent substrate 233 is the transparent substrate 2
It is thinner than 31.

The optical information recording medium 1 in this embodiment can be classified into a single-sided type and a double-sided type.

41 to 43 show a single-sided type optical information recording medium 1. FIG. 41 is a sectional view of the optical information recording medium 1 having a thickness of 1.2 mm, and FIG. FIG. 4 is a sectional view of a 6 mm type optical information recording medium 1.
FIG. 3 is an explanatory diagram showing how to irradiate the single-sided optical information recording medium 1 with the recording reference light and the information light. The optical information recording medium 1 shown in FIG. 41 and FIG.
It has the structure shown in. However, the optical information recording medium 1 shown in FIG. 41 has the transparent substrate 231 and the hologram layer 23.
2 and the transparent substrate 233 have a total thickness of 1.2 mm, and the optical information recording medium 1 shown in FIG. 42 has a total thickness of the transparent substrate 231, the hologram layer 232, and the transparent substrate 233 of 0.6 mm. Has become.

The recording reference light 241 emitted from the objective lens 123 to the optical information recording medium 1 is converged so as to have the smallest diameter on the surface where the pre-groove is formed, and the optical reference medium 241 is irradiated from the objective lens 123. Information light 24 emitted to the
2 converges so as to have the smallest diameter on the front side of the hologram layer 232. As a result, in the hologram layer 232, an interference region 243 is formed by the recording reference light 241 and the information light 242.

41 and 42 show the transparent substrate gap type single-sided optical information recording medium 1, the air gap type single-sided optical information recording medium 1 may be constructed. In this case, the transparent substrate 22
2. The total thickness of the hologram layer 225 and the air gap is 1.2 mm or 0.6 mm.

44 to 46 show a double-sided type optical information recording medium 1, FIG. 44 is a sectional view of the transparent substrate gap type optical information recording medium 1, and FIG. 45 is an air gap type optical information recording medium. 46 is a cross-sectional view of the medium 1, and FIG. 46 is an explanatory diagram showing how to irradiate the double-sided optical information recording medium 1 with the recording reference light and the information light. The optical information recording medium 1 shown in FIG. 44 is the single-sided type 2 shown in FIG.
The optical information recording medium has a structure in which reflective films 234 are attached to each other. The optical information recording medium 1 shown in FIG. 45 has a structure in which two single-sided optical information recording media shown in FIG. In the optical information recording medium 1 shown in FIG. 45, the total thickness of the transparent substrate 222 on one side, the hologram layer 225 and the air gap is 0.6 mm.

The recording reference light 241 emitted from the objective lens 123 to the optical information recording medium 1 is converged so as to have the smallest diameter on the surface on which the pregroove is formed, and the optical reference medium 241 is supplied from the objective lens 123. Information light 24 emitted to the
No. 2 converges so that the diameter is the smallest on the front side of the hologram layers 232 and 225. As a result, the hologram layer 2
32 and 225, recording reference light 241 and information light 2
An interference area 243 is formed by

By the way, the optical information recording / reproducing apparatus of the present embodiment is also capable of recording / reproducing information using a conventional optical disc. For example, as shown in FIG. 47, when using a single-sided type optical disc 251 in which a pre-groove is formed on one surface of a transparent substrate 252 and a reflective film 253 is provided, as shown in FIG.
The light emitted from the objective lens 123 to the optical disc 251 is converged so as to have the smallest diameter on the surface of the optical disc 251, on which the pre-groove is formed, that is, the information layer. In the optical disc 251 shown in FIG. 47, the transparent substrate 252 has a thickness of 1.2 mm, for example. As the optical disc having the structure shown in FIG. 47,
CD, CD-ROM, CD-R (Write Once
Once) CD), MD (mini disk), and the like.

Further, as shown in FIG. 49, 2 in which a pre-groove is formed and a reflection film 263 is provided on one surface 2
When a double-sided type optical disc 261 having a structure in which a plurality of transparent substrates 262 are attached to each other with reflection films 263, as shown in FIG. At the surface where the pre-groove is formed, that is, the information layer is converged so as to have the smallest diameter. Incidentally, in the optical disc 261 shown in FIG. 49, the transparent substrate 262 on one side is
Has a thickness of, for example, 0.6 mm. As the optical disc having the structure as shown in FIG. 50, there are DVD, DVD-RO.
There are M, DVD-RAM, MO (magneto-optical) disks and the like.

In the optical information recording medium 1 according to the present embodiment, the second information layer is the information layer in the conventional optical disc as shown in FIGS. 47 and 49, for example, and the contents of the information to be recorded. The same form can be included. In this case, the information recorded on the second information layer can be reproduced by setting the pickup 111 in the servo state. Further, since information for servo and address information are also recorded in the information layer of the conventional optical disc, the second optical layer has the same form as the information layer of the conventional optical disc. Servo information and address information recorded in the information layer can be used as they are for positioning the information light for recording and reproduction, the recording reference light and the reproduction reference light in the hologram layer. Becomes Also, the second information layer (information layer in the conventional optical disc)
In addition, by recording directory information, directory management information, etc. of information recorded in the first information layer (hologram layer), high-speed search becomes possible, and the second information layer has a wide application range.

Next, before explaining the operation of the optical information recording / reproducing apparatus according to the present embodiment, FIGS.
The principle of phase-coded multiplexing will be described with reference to.
FIG. 51 is a perspective view showing a schematic configuration of a general recording / reproducing system that performs phase-encoding multiplexing. This recording / playback system is 2
Spatial light modulator 301 for generating information light 302 based on three-dimensional digital pattern information, and spatial light modulator 301
The information light 302 from the light is condensed to form the hologram recording medium 3
00 to generate a reference beam 305 whose phase is spatially modulated.
A phase spatial light modulator 304 that irradiates the hologram recording medium 300 from a direction substantially orthogonal to the information light 302,
The CCD array 308 for detecting the reproduced two-dimensional digital pattern information and the reproduction light 306 emitted from the hologram recording medium 300 are condensed and the CCD array 30.
8 and a lens 307 for irradiating the light on the upper surface.

In the recording / reproducing system shown in FIG. 51, at the time of recording, information such as an original image to be recorded is digitized, and the signal of 0 or 1 is further two-dimensionally arranged and two-dimensional digital pattern information (hereinafter, Page data) is generated.
Here, it is assumed that the page data # 1 to #n are multiplexed and recorded on the same hologram recording medium 300. Also, two-dimensional digital pattern information (hereinafter referred to as phase data) for phase modulation, which is different for each page data # 1 to #n.
1 to #n are generated. First, when the page data # 1 is recorded, the spatial light modulator 30 is based on the page data # 1.
1, the spatially modulated information light 302 is generated, and the hologram recording medium 300 is irradiated with the information light 302 via the lens 303. At the same time, based on the phase data # 1, the phase spatial light modulator 304 generates the reference light 305 whose phase is spatially modulated and irradiates the hologram recording medium 300. As a result, on the hologram recording medium 300, interference fringes formed by superposition of the information beam 302 and the reference beam 305 are recorded. Similarly, page data #
When recording 2 to #n, page data # 2 to # 2 respectively
The spatial light modulator 301 generates the spatially modulated information light 302 based on #n, and outputs the phase data # 2 to
Based on #n, the phase spatial light modulator 304 generates the reference light 305 whose phase is spatially modulated, and irradiates the hologram recording medium 300 with the information light 302 and the reference light 305. In this way, a plurality of pieces of information are multiply recorded at the same location on the hologram recording medium 300. A hologram in which information is multiplexed and recorded in this way is called a stack. In the example shown in FIG. 51, the hologram recording medium 300 has a plurality of stacks (stack 1, stack 2, ..., Stack m, ...).

To reproduce arbitrary page data from the stack, the reference beam 305 whose phase is spatially modulated based on the same phase data as when the page data was recorded.
To the stack. Then,
The reference light 305 is selectively diffracted by the interference fringes corresponding to the phase data and page data, and the reproduction light 306 is generated. This reproduction light 306 is reflected by the lens 307.
The two-dimensional pattern of the reproduction light is incident on the CCD array 308 through the CCD array 308 and is detected by the CCD array 308. Then, the detected two-dimensional pattern of the reproduction light is decoded in reverse to that at the time of recording to reproduce the information such as the original image.

FIG. 52 shows how interference fringes are formed on the hologram recording medium 300 due to the interference of the information light 302 and the reference light 305. In FIG. 52,
(A) is an information beam 302 based on page data # 1
₁ and the reference beam 305 ₁ based on the phase data # 1 interfere with each other to form an interference fringe 309 ₁ . Similarly, (b), the page data # between the information light 302 ₂ based on 2, the reference light 305 ₂ based on the phase data # 2
Interference by, shows how the interference fringes 309 ₂ is formed of, (c), the information light 302 based on the page data # 3
_3, by the interference of the reference light 305 ₃ based on the phase data # 3, shows how the interference fringes 309 ₃ is formed.

Next, the operation of the optical information recording / reproducing apparatus according to this embodiment will be described in order for servo operation, recording operation, and reproduction operation.

First, the operation during servo will be described with reference to FIGS. 53 and 54. FIG. 53 is an explanatory diagram showing the state of the pickup 111 during servo. During the servo, all the pixels of the spatial light modulator 125 are turned off. The phase spatial light modulator 117 is set so that all the lights passing through each pixel have the same phase. The output of the light emitted from the light source device 112 is set to a low output for reproduction. The controller 90 predicts the timing at which the light emitted from the objective lens 123 passes through the address / servo area 6 on the basis of the basic clock reproduced from the reproduction signal RF, and the light emitted from the objective lens 123 is detected at the address / servo area. While passing 6, the above setting is made.

The light emitted from the light source device 112 is made into a parallel light flux by the collimator lens 113, passes through the ND filter 114 and the optical element 115 for optical rotation in order, and enters the polarization beam splitter 116. The S-polarized component of the light that has entered the polarization beam splitter 116 is reflected by the polarization beam splitter surface 116 a and blocked by the spatial light modulator 125. Polarization beam splitter 11
The P-polarized light component of the light that has entered 6 is transmitted through the polarization beam splitter surface 116 a, passes through the phase spatial light modulator 117, and is incident on the beam splitter 118. A part of the light that has entered the beam splitter 118 is reflected by the beam splitter surface 118a, and the polarized beam splitter 12
The light passes through 0 and enters the two-part optical rotation plate 121. Here, the light that has passed through the optical rotation plate 121R of the two-part optical rotation plate 121 becomes B-polarized light, and the light that has passed through the optical rotation plate 121L becomes A-polarized light. The light passing through the two-division optical rotation plate 121 is reflected by the rising mirror 122, condensed by the objective lens 123, and converged on the pre-groove on the inner side of the hologram layer in the optical information recording medium 1. Then, the information recording medium 1 is irradiated. This light is reflected on the pre-groove, at which time it is modulated by the pits formed on the pre-groove and returns to the objective lens 123 side. The raising mirror 122 is omitted in FIG.

The return light from the information recording medium 1 is made into a parallel light flux by the objective lens 123, passes through the two-division optical rotation plate 121, and becomes S-polarized light. This return light is reflected by the polarization beam splitter surface 120a of the polarization beam splitter 120, enters the beam splitter 127, partially passes through the beam splitter surface 127a, and passes through the convex lens 129 and the cylindrical lens 130 in this order. It is detected by the four-division photo detector 131. And
Based on the output of the 4-division photo detector 131,
The focus error signal FE, the tracking error signal TE and the reproduction signal RF are generated by the detection circuit 85, and the focus servo and the tracking servo are performed based on these signals, and the reproduction of the basic clock and the determination of the address are performed. ..

A part of the light incident on the beam splitter 118 enters the photodetector 119, and the signal APC _ref is generated by the APC circuit 146 based on the output signal of the photodetector 119. Then, based on this signal APC _ref , the optical information recording medium 1
The APC is performed so that the light amount of the light radiated on is constant. Specifically, the drive circuit 148 drives the motor 142 and adjusts the optical element 115 for optical rotation so that the signal APC _ref becomes equal to a predetermined value. Alternatively, during servo, the optical element 115 for optical rotation may be set so that the light that has passed through the optical element 115 for optical rotation has only the P-polarized component, and the output of the light source device 112 may be adjusted to perform APC. . When the light receiving portion of the photodetector 119 is divided into a plurality of regions and the phase spatial light modulator 117 is also capable of adjusting the amount of transmitted light, the phase is determined based on the output signal of each light receiving portion of the photodetector 119. The amount of transmitted light for each pixel in the spatial light modulator 117 may be adjusted so that the intensity distribution of the light with which the optical information recording medium 1 is irradiated becomes uniform.

In the servo setting,
The structure of the pickup 111 is similar to that of a recording / playback pickup for a normal optical disc. Therefore, the optical information recording / reproducing apparatus according to the present embodiment can also record / reproduce by using an ordinary optical disk.

FIG. 54 is an explanatory diagram showing the state of light in the vicinity of the optical disc when recording or reproducing is performed using an ordinary optical disc by the optical information recording / reproducing apparatus according to the present embodiment. In this figure, a double-sided type optical disc 261 is taken as an example of a normal optical disc. In this optical disc 261, a pre-groove 265 is formed on the surface of the transparent substrate 262 on the side of the reflection film 263, and light from the objective lens 123 side is irradiated onto the optical disc 261 so as to converge on the pre-groove 265. It is modulated by the pits formed on the pre-groove 265 and returns to the objective lens 123 side.

Next, the operation during recording will be described with reference to FIGS. 55 to 57. FIG. 55 is an explanatory diagram showing the state of the pickup 111 during recording, and FIGS. 56 and 57 are explanatory diagrams showing the state of light near the optical information recording medium 1 during recording. In the following,
As shown in FIG. 56, the case where an air gap type medium is used as the optical information recording medium 1 will be described as an example.

At the time of recording, the spatial light modulator 125 selects a transmission state (hereinafter, also referred to as ON) and a blocking state (hereinafter, also referred to as OFF) for each pixel according to the information to be recorded, and passes through. Information light is generated by spatially modulating the incident light. The phase spatial light modulator 117 is
According to a predetermined modulation pattern, a phase difference of 0 (rad) or π (rad) is selectively given to each pixel with respect to a predetermined phase as a reference to spatially modulate the phase of the light and A recording reference light whose phase is spatially modulated is generated.

In the present embodiment, as already described,
When the information is multiplexed and recorded in the data area 7 by phase encoding, the center of the objective lens 123 is the data area 7.
The center of the objective lens 123 is moved by using the access in the visual field so as to reciprocate within a section including a part of the address servo area 6 on both sides thereof. Objective lens 12
When the center of 3 reaches a predetermined position in the data area 7, the output of the light source device 112 is selectively set to a high output for recording.

The light emitted from the light source device 112 is made into a parallel light flux by the collimator lens 113, passes through the ND filter 114 and the optical element 115 for optical rotation in order, and enters the polarization beam splitter 116. The P-polarized light component of the light incident on the polarization beam splitter 116 passes through the polarization beam splitter surface 116a and the phase spatial light modulator 117, at which time the phase of the light is spatially modulated and recorded. For reference light. The recording reference light enters the beam splitter 118. Beam splitter 11
A part of the recording reference light incident on the beam No. 8 is reflected by the beam splitter surface 118 a, passes through the polarization beam splitter 120, and is incident on the two-part optical rotation plate 121. Where 2
The recording reference light that has passed through the optical rotation plate 121R of the split optical rotation plate 121 becomes B-polarized light, and the recording reference light that has passed through the optical rotation plate 121L becomes A-polarized light. The recording reference light that has passed through the two-part optical rotation plate 121 is reflected by the rising mirror 122,
The optical information recording medium 1 is condensed by the objective lens 123 and is irradiated onto the optical information recording medium 1 so that the optical information recording medium 1 converges on the inner side of the hologram layer 225. The raising mirror 122 is omitted in FIG. 55.

On the other hand, the S-polarized component of the light incident on the polarization beam splitter 116 is reflected by the polarization beam splitter surface 116a, passes through the spatial light modulator 125, and at that time, spatially according to the information to be recorded. Is modulated to
It becomes information light. This information light is transmitted to the beam splitter 127.
Incident on. A part of the information light incident on the beam splitter 127 is reflected by the beam splitter surface 127 a, and the beam splitter surface 120 of the polarization beam splitter 120 is reflected.
It is reflected by a and enters the two-part optical rotation plate 121. Here, the information light that has passed through the optical rotation plate 121R of the two-divided optical rotation plate 121 becomes A-polarized light, and the information light that has passed through the optical rotation plate 121L becomes B-polarized light. The information light that has passed through the two-split optical rotation plate 121 is reflected by the rising mirror 122 and the objective lens 1
The optical information recording medium 1 is irradiated with light so that the light is condensed by 23 and converges once on the front side of the hologram layer 225 in the optical information recording medium 1 and passes through the hologram layer 225 while diffusing.

As a result, as shown in FIG. 56, in the hologram layer 225, the recording reference light 311 and the information light 3 are recorded.
An interference region 313 is formed by 12. The interference area 313 has a barrel shape. As shown in FIG. 55, by adjusting the position 310 of the convex lens 126, the convergent position of the information light can be adjusted, whereby the interference region 3
The size of 13 can be adjusted.

As shown in FIG. 57, the hologram layer 22
In FIG. 5, the A-polarized recording reference light 311A that has passed through the optical rotation plate 121L of the two-division optical rotation plate 121 and the two-division optical rotation plate 1
Information light 312 of A polarization that has passed through the optical rotation plate 121R of No. 21
A reference light 311B for recording B polarized light that has passed through the optical rotation plate 121R of the two-division optical rotation plate 121 due to interference with A and information light 3 for B polarization that has passed the optical rotation plate 121L of the two-division optical rotation plate 121.
12B and these interference patterns are recorded volumetrically in the hologram layer 225.

By changing the modulation pattern of the phase of the recording reference light for each information to be recorded, it is possible to multiple-record a plurality of information at the same location on the hologram layer 225.

By the way, as shown in FIG. 55, a part of the recording reference light that has entered the beam splitter 118 enters the photodetector 119, and the APC circuit 146 outputs the signal APC based on the output signal of the photodetector 119. _ref is generated. A part of the information light that has entered the beam splitter 127 enters the photodetector 128, and the APC circuit 147 outputs a signal APC based on the output signal of the photodetector 128.
_obj is generated. Then, these signals APC _{r ef,} A
Based on PC _obj , APC is performed so that the ratio of the intensity of the reference light for recording and the intensity of information light with which the optical information recording medium 1 is irradiated becomes an optimum value. Specifically, the drive circuit 148 compares the signals APC _ref and APC _obj , drives the motor 142, and adjusts the optical element 115 for optical rotation so that they have a desired ratio. The light receiving portion of the photodetector 119 is divided into a plurality of regions, and the phase spatial light modulator 11
In the case where the amount of transmitted light is also adjustable, reference numeral 7 indicates the output signal of each photodetector of the photodetector 119.
The amount of transmitted light for each pixel in the phase spatial light modulator 117 may be adjusted so that the intensity distribution of the recording reference light with which the optical information recording medium 1 is irradiated becomes uniform. Similarly, when the light receiving portion of the photodetector 128 is divided into a plurality of regions and the spatial light modulator 125 is also capable of adjusting the amount of transmitted light, the photodetector 1
The amount of transmitted light for each pixel in the spatial light modulator 125 is adjusted based on the output signal of each light receiving unit 28 so that the intensity distribution of the information light with which the optical information recording medium 1 is irradiated becomes uniform. You may do it.

In this embodiment, the signal AP
Based on the sum of C _ref and APC _obj , APC is performed so that the total intensity of the recording reference light and the information light has an optimum value. As a method of controlling the total intensity of the recording reference light and the information light, the peak value of the output of the light source device 112 is controlled, the emission pulse width in the case of emitting light in a pulsed manner, and the intensity of the emitted light with respect to time. Profile control etc.

Next, with reference to FIGS. 58 and 59, the operation at the time of fixing will be described. 58 is an explanatory view showing the state of the pickup 111 at the time of fixing, and FIG. 59 is
FIG. 4 is an explanatory diagram showing a state of light near the optical information recording medium 1 at the time of fixing. At the time of fixing, the spatial light modulator 125
All pixels are turned off. Phase spatial light modulator 117
Are set so that all the light passing through each pixel has the same phase. No light is emitted from the light source device 112, and fixing S-polarized ultraviolet light is emitted from the fixing light source device 135.

The light emitted from the fixing light source device 135 is collimated by the collimator lens 134,
The light enters the polarization beam splitter 116, is reflected by the polarization beam splitter surface 116 a, and enters the phase spatial light modulator 117.
And enters the beam splitter 118. A part of the light incident on the beam splitter 118 is reflected by the beam splitter surface 118a, and the polarized beam splitter 1
After passing through 20, the light enters the two-part optical rotation plate 121. Here, the light that has passed through the optical rotation plate 121R of the two-part optical rotation plate 121 becomes B-polarized light, and the light that has passed through the optical rotation plate 121L becomes A-polarized light. The light that has passed through the two-divided optical rotation plate 121 is reflected by the rising mirror 122 and condensed by the objective lens 123, and the hologram layer 2 in the optical information recording medium 1 is reflected.
The information recording medium 1 is irradiated so as to converge on the pre-groove on the back side of 25. Then, this light fixes the interference pattern formed in the interference region 313 in the hologram layer 225. The raising mirror 122 is omitted in FIG.

The positioning (servo) of the fixing light with respect to the optical information recording medium 1 can be performed in the same manner as the positioning of the recording reference light and the information light during recording.

A part of the fixing light that has entered the beam splitter 118 enters the photodetector 119, and the APC circuit 146 generates the signal APC _ref based on the output signal of the photodetector 119. Then, based on this signal APC _ref , APC is performed so that the light amount of the fixing light with which the optical information recording medium 1 is irradiated becomes constant. Specifically, the signal APC _ref
Fixing light source device 135 so that is equal to a predetermined value.
Adjust the output of. The light receiving portion of the photodetector 119 is divided into a plurality of regions, and the phase spatial light modulator 117
When the amount of transmitted light is adjustable, the amount of transmitted light of each pixel in the phase spatial light modulator 117 is adjusted based on the output signal of each light receiving unit of the photodetector 119, and the optical information recording medium 1 It may be adjusted so that the intensity distribution of the fixing light irradiated on the sheet becomes uniform.

Next, the operation during reproduction will be described with reference to FIGS. 60 to 62. FIG. 60 is an explanatory diagram showing the state of the pickup 111 during reproduction, and FIGS. 61 and 62 are explanatory diagrams showing the state of light near the optical information recording medium 1 during reproduction.

At the time of reproduction, all the pixels of the spatial light modulator 125 are turned off. The phase spatial light modulator 117 has a phase difference of 0 (rad) or π with respect to passing light according to a predetermined modulation pattern for each pixel with reference to a predetermined phase.
By selectively giving (rad), the phase of the light is spatially modulated, and the reproduction reference light in which the phase of the light is spatially modulated is generated. Here, in this embodiment, the phase modulation pattern of the phase of the reproduction reference light is the phase spatial light modulator 11.
7 is a point-symmetrical pattern with the phase modulation pattern of the recording reference light at the time of recording the information to be reproduced.

The light emitted from the light source device 112 is made into a parallel light flux by the collimator lens 113, passes through the ND filter 114 and the optical element 115 for optical rotation in this order, and enters the polarization beam splitter 116. The S-polarized component of the light that has entered the polarization beam splitter 116 is reflected by the polarization beam splitter surface 116 a and blocked by the spatial light modulator 125. Polarization beam splitter 11
The P-polarized light component of the light incident on the beam No. 6 passes through the polarization beam splitter surface 116a and passes through the phase spatial light modulator 117. At this time, the phase of the light is spatially modulated, and the reproduction reference light. Becomes The reproduction reference light enters the beam splitter 118. A part of the reproduction reference light that has entered the beam splitter 118 is part of the beam splitter surface 118a.
Is reflected by, passes through the polarization beam splitter 120,
It is incident on the two-part optical rotation plate 121. Here, the reproduction reference light that has passed through the optical rotation plate 121R of the two-divided optical rotation plate 121 becomes B polarized light, and the reproduction reference light that has passed through the optical rotation plate 121L is A
It becomes polarized light. The reproduction reference light that has passed through the two-split optical rotation plate 121 is reflected by the rising mirror 122, condensed by the objective lens 123, and converged on the inner side of the hologram layer 225 in the optical information recording medium 1. , The optical information recording medium 1 is irradiated. The raising mirror 122 is omitted in FIG.

The positioning (servo) of the reproducing reference light with respect to the optical information recording medium 1 can be performed in the same manner as the positioning of the recording reference light and the information light during recording.

As shown in FIG. 62, the two-divided optical rotation plate 12
Reference light 3 for reproduction of B-polarized light that has passed through the optical rotation plate 121R of No. 1
15B passes through the hologram layer 225, is reflected by the reflection surface at the convergent position on the back side of the hologram layer 225, and passes through the hologram layer 225 again. At this time, the reproduction-specific reference light 315B after being reflected by the reflection surface passes through a portion of the interference region 313 irradiated with the recording-specific reference light 311A during recording, and has the same modulation pattern as the recording-specific reference light 311A. It has become light. Therefore, this reproduction reference beam 31
5B, reproduction light 316B corresponding to the information light 312A at the time of recording is generated from the interference area 313. The reproduction light 316B travels toward the objective lens 123 side.

Similarly, the optical rotation plate 12 of the two-part optical rotation plate 121.
The A-polarized reproduction reference light 315A that has passed 1 L passes through the hologram layer 225, is reflected by the reflecting surface at the convergent position on the back side of the hologram layer 225, and passes through the hologram layer 225 again. At this time, the reproduction reference light 315A after being reflected by the reflection surface passes through a portion of the interference region 313 irradiated with the recording reference light 311B at the time of recording, and has the same modulation pattern as that of the recording reference light 311B. It has become light. Therefore, with this reproduction reference beam 315A,
The reproduction light 316A corresponding to the information light 312B at the time of recording is generated from the interference area 313. This reproduction light 316
A advances toward the objective lens 123 side.

The B-polarized reproduction light 316B is the objective lens 1
After passing 23, the optical rotation plate 121 of the two-part optical rotation plate 121
It passes through R and becomes P-polarized light. A-polarized reproduction light 31
6A passes through the objective lens 123, and then passes through the optical rotation plate 121L of the two-division optical rotation plate 121 to become P-polarized light. The reproduction light that has passed through the two-part optical rotation plate 121 enters the polarization beam splitter 120, passes through the polarization beam splitter surface 120a, and enters the beam splitter 118. Part of the reproduction light that has entered the beam splitter 118 passes through the beam splitter surface 118 a, passes through the imaging lens 132, and enters the CCD array 133. As shown in FIG. 60, by adjusting the position of the image forming lens 132, the image forming state of the reproduction light on the CCD array 133 can be adjusted.

An on / off pattern formed by the spatial light modulator 125 during recording is imaged on the CCD array 133, and information is reproduced by detecting this pattern. When a plurality of pieces of information are recorded in the hologram layer 225 by changing the modulation pattern of the recording reference light, a modulation pattern that is point-symmetrical to the reproduction reference light modulation pattern among the plurality of information is recorded. Only the information corresponding to the recording reference light is reproduced.

A part of the reproduction reference light that has entered the beam splitter 118 enters the photodetector 119, and the signal APC _ref is generated by the APC circuit 146 based on the output signal of the photodetector 119. Then, based on the signal APC _{r ef,} APC is performed such that the light amount of the reference light for reproduction to be irradiated to the optical information recording medium 1 is constant. Specifically, the signal APC
_The drive circuit 148 drives the motor 142 and adjusts the optical element 115 for optical rotation so that _ref becomes equal to a predetermined value. Alternatively, at the time of reproduction, the optical element 115 for optical rotation may be set so that the light passing through the optical element 115 for optical rotation has only the P-polarized component, and the output of the light source device 112 may be adjusted to perform APC. . Photo detector 11
When the light receiving unit 9 is divided into a plurality of regions and the phase spatial light modulator 117 is also capable of adjusting the amount of transmitted light, the phase space is calculated based on the output signal of each light receiving unit of the photodetector 119. The amount of transmitted light for each pixel in the optical modulator 117 may be adjusted so that the intensity distribution of the reproduction reference light with which the optical information recording medium 1 is irradiated becomes uniform.

Further, in the present embodiment, the light source device 1
As 12, an element capable of emitting laser light of three colors of R, G, B is used, and as the CCD array 133, an element capable of detecting light of three colors of R, G, B is also used. Medium 1
By using the one having three hologram layers whose optical characteristics are changed only by the light of each color of R, G, B, the same modulation pattern of the reference light for recording is used, and the same optical information recording medium 1 is used. It is possible to record three types of information at a location, and it is possible to multiple-record more information. Examples of the recording medium having three hologram layers as described above include H manufactured by DuPont.
There is RF-700X059-20 (trade name).

As described above, the three colors of R, G, and B light are used.
In the case of performing multiple recording of the information to be recorded, the optical information recording medium 1
For the same location, information for each color of R, G, B is time-divided.
Record information. At that time, information for each color of R, G, B
The modulation pattern of the light is changed, but the modulation pattern of the reference light for recording is changed.
I won't change. Here, each pixel of the information light of each color is 2
When carrying value information, ie whether each pixel is light or dark
When expressed, information based on R, G, and B color lights
By performing multiple recording of, for example, R is MSB (the highest
Bit) and B as LSB (least significant bit)
Per 8 (= 2 ^Three) It is possible to record value information.
It The spatial light modulator 125 adjusts the amount of transmitted light in three or more steps.
Each pixel of the information light of each color is n (n is 3 or more)
(Integer) When carrying information of gradation, three colors of R, G, B
By performing multiple recording of information by light,
n^ThreeIt becomes possible to record value information.

Various methods can be used to reproduce the information when the information is recorded in multiplex by the light of three colors of R, G and B. That is, the reference light for reproduction is set to R,
If one of G and B light is used, only the information recorded using the light of the same color as the reproduction reference light is reproduced. When the reproduction reference light is light of any two colors of R, G, and B, only two types of information recorded using the same two colors of light as the reproduction reference light are reproduced. . The two types of information are separated by the CCD array 133 into information for each color. Further, when the reproduction reference light is the light of three colors of R, G, and B, all three types of information recorded by using the light of three colors are reproduced. The CCD array 133 separates these three types of information into information for each color. In addition,
When the optical information recording medium 1 has a layer for each color of R, G, B, multiple recording is performed by phase encoding multiplexing on each layer for each color. This produces an effect that a reproduced image of a pattern for each color of R, G, and B can be obtained for each modulation pattern of the phase of the reference light.

Next, referring to FIGS. 63 and 64, a direct read after write (Direct Rrad After Writ) included in the optical information recording / reproducing apparatus in this embodiment will be described.
e; hereinafter referred to as DRAW. ) Function and write power control (Write Power Control;
Hereinafter referred to as WPC. ) Describes the function.

First, the DRAW function will be described.
The DRAW function is a function of reproducing the recorded information immediately after recording the information. With this function, it is possible to verify the recorded information immediately after recording the information.

The principle of the DRAW function in this embodiment will be described below with reference to FIGS. 55 and 57. First, in the present embodiment, when the DRAW function is used, the modulation pattern of the recording reference light is a point-symmetric pattern with respect to the center of the phase spatial light modulator 117. At the time of recording, in the hologram layer 225, the A-polarized recording reference light 311A that has passed through the optical rotation plate 121L of the two-division optical rotation plate 121 and the optical rotation plate 121R of the two-division optical rotation plate 121.
The reference light 311B for recording of the B-polarized light which has passed through the optical rotation plate 121R of the two-divided optical rotation plate 121 and the optical rotation plate 12 of the two-divided optical rotation plate 121 interfere with the information light 312A of the A-polarized light which has passed through
The B-polarized information beam 312B passing through 1L interferes with each other, and these interference patterns are recorded volumetrically in the hologram layer 225.

As described above, when the interference pattern starts to be recorded in the hologram layer 225, the A-polarized recording reference light 311A that has passed through the optical rotation plate 121L of the two-division optical rotation plate 121.
The light reflected by the reflection surface at the convergent position on the back side of the hologram layer 225 causes reproduction light of A polarization to be generated from the portion where the interference pattern is recorded by the recording reference light 311B. This reproduction light travels to the objective lens 123 side,
After passing through the objective lens 123, it passes through the optical rotation plate 121L of the two-divided optical rotation plate 121 to become P-polarized light. Similarly, B that has passed through the optical rotation plate 121R of the two-divided optical rotation plate 121
The polarized recording reference light 311B is reflected by the reflection surface at the converging position on the back side of the hologram layer 225, and the B-polarized reproduction light is generated from the position where the interference pattern is recorded by the recording reference light 311A. . This reproduction light travels to the objective lens 123 side, passes through the objective lens 123, and then passes through the optical rotation plate 121R of the two-part optical rotation plate 121 to become P-polarized light. The reproduction light that has passed through the two-part optical rotation plate 121 enters the polarization beam splitter 120, passes through the polarization beam splitter surface 120a, and enters the beam splitter 118. A part of the reproduction light that has entered the beam splitter 118 passes through the beam splitter surface 118 a, passes through the imaging lens 132, and then the CCD array 13
It is incident on 3 and is detected. In this way, it is possible to reproduce the recorded information immediately after recording the information.

In FIG. 63, reference numeral 321 shows one example of the relationship between the output time of the CCD array 133 and the elapsed time after the start of recording information at one location on the optical information recording medium 1. As described above, the output level of the CCD array 133 gradually increases according to the degree of recording of the interference pattern on the optical information recording medium 1 after the recording of information is started, reaches the maximum value at a certain time, and thereafter,
It gets smaller and smaller. It can be said that the higher the output level of the CCD array 133, the higher the diffraction efficiency due to the recorded interference pattern (hereinafter referred to as the recording pattern). Therefore, at the time of recording, when the output level of the CCD array 133 reaches the output level corresponding to the desired diffraction efficiency, the recording is stopped, so that the recording pattern of the desired diffraction efficiency can be formed.

In this embodiment, it is preferable that the optical information recording medium 1 is provided with a test area as appropriate in order to form a recording pattern having a desired diffraction efficiency by using the DRAW function as described above. The test area is the data area 7
Similarly to, is an area in which information can be recorded by holography. Then, preferably, the controller 90 performs the following operation when recording the information. That is, the controller 90 performs an operation of recording predetermined test data in the test area in advance and detects the output level profile of the CCD array 133 as shown in FIG. At this time, it is preferable to change the output of the light source device 112 or the ratio of the light amounts of the reference light for recording and the information light so as to record the test data and output the output level of the CCD array 133 at a plurality of locations in the test area. A profile detection operation is performed, and for example, reference numeral 321 in FIG.
As indicated by reference numerals 323 to 323, a plurality of profiles are detected, the optimum profile is selected from them, and the actual information recording operation is performed under the conditions corresponding to the selected profiles.

Further, the controller 90, based on the detected profile or the selected profile,
The output level corresponding to the desired diffraction efficiency or the time from the start of recording when the output level is obtained is obtained. The controller 90 monitors the output level of the CCD array 133 during the actual recording of information, and stops recording when the output level reaches the output level corresponding to the desired diffraction efficiency obtained in advance. Alternatively, the controller 90
In actual recording of information, when the elapsed time after the start of recording reaches the time from the start of recording at which an output level corresponding to the desired diffraction efficiency obtained in advance is obtained, recording is stopped. By such an operation, it becomes possible to form a recording pattern with a desired diffraction efficiency on the optical information recording medium 1.

As described above, in the present embodiment,
The DRAW function can be used to verify the recorded information. FIG. 64 shows a circuit configuration necessary for performing this collation in the optical information recording / reproducing apparatus according to the present embodiment. As shown in this figure, the optical information recording / reproducing apparatus is provided with information to be recorded by the controller 90, and this information is sent to the spatial light modulator (S in FIG. 64).
It is written as LM. ) Encoder 331 that encodes the modulation pattern data of 125 and CCD array 13
3 output data from the controller 90 to the encoder 3
A decoder 322 for decoding the data into the format given to 31;
A comparison unit 333 that compares the data given to 31 with the data obtained by the decoder 322 and sends the information of the comparison result to the controller 90. Comparison unit 333
As the information of the comparison result, for example, the degree of coincidence of two data to be compared or the information of the error rate (error rate) is sent to the controller 90. For example, when the information of the comparison result sent from the comparison unit 333 is within the range where the error of the data can be repaired, the controller 90
The recording operation is continued, and if the information of the comparison result is out of the range where the error of the data can be repaired, the recording operation is stopped.

As described above, according to the optical information recording / reproducing apparatus in the present embodiment, since it has the DRAW function, there are variations in the sensitivity of the optical information recording medium 1, changes in the external environmental temperature, Even if there is a disturbance such as fluctuation of the output of the light source device 112, the recording operation can be performed in the optimum recording state.

Further, according to the present embodiment, since it has a function of collating the recorded information at the same time as recording the information, it is possible to perform high-speed recording while maintaining high reliability. This function is particularly useful when recording information at a high transfer rate. It is not preferable to reproduce the information in the state where the information is not fixed, because it has the same effect as overwriting and deteriorates the quality of the recorded information. With the collating function in the above form, since the confirmation of the recorded information is completed during the recording operation, no problem occurs.

Next, the WPC function at the time of multiple recording will be described. When a plurality of pieces of information are multiplex-recorded at the same location of the optical information recording medium 1 by changing the modulation pattern of the recording reference light, the diffraction efficiency of the recording pattern recorded first is gradually increased by the recording performed thereafter. descend. The WPC function in the present embodiment is a function of controlling the recording reference light and the information light at the time of recording so that substantially the same diffraction efficiency can be obtained in each recording pattern for each information to be recorded at the time of the multiple recording. is there.

Here, the diffraction efficiency of the recording pattern includes the intensity of the recording reference light and the information light, the irradiation time of the recording reference light and the information light, the intensity ratio of the recording reference light and the information light, and the recording reference light. The modulation pattern and the total number of times of recording are performed on the same portion of the optical information recording medium 1, and the number of times of recording is dependent on the parameters. Therefore, the WPC function may control at least one of these parameters. For easy control, the intensity and irradiation time of the recording reference light and the information light may be controlled. When controlling the intensities of the recording reference beam and the information beam, the intensities are decreased as the recording is performed later. When the irradiation time of the recording reference light and the information light is controlled, the irradiation time is shortened for later recording.

In the WPC function of this embodiment, the CCD array 1 as shown in FIG.
1 to m based on 33 output level profiles
(M is an integer of 2 or more) Controls the recording reference light and the information light during the second recording. FIG. 63 shows an example of the irradiation time in the case of controlling the irradiation time of the recording reference light and the information light. That is, in the example shown in FIG. 63, recording is performed 5 times at the same location on the optical information recording medium 1, and T ₁ , T ₂ , T ₃ , T ₄ , and T ₅ are respectively
1st recording, 2nd recording, 3rd recording, 4
The irradiation time of the reference light for recording and the information light at the time of the fifth recording is shown.

As described above, according to the present embodiment, it is possible to make the diffraction efficiencies of the respective recording patterns for each of the multiplex-recorded information substantially equal.

By the way, according to the optical information recording / reproducing apparatus in the present embodiment, it becomes possible to record a large amount of information on the optical information recording medium 1 at high density. This means that if a part of the information cannot be reproduced due to a defect or the like in the optical information recording medium 1 after the recording of the information, the amount of information lost due to the defect also increases. In the present embodiment, in order to prevent such loss of information and improve reliability, as described below, RAID (Redundant Arra)
It is possible to record information by applying ys of Inexpensive Disks) technology.

The RAID technique is a technique for increasing the reliability of recording by recording data with redundancy using a plurality of hard disk devices. RA
IDs are classified into five, RAID-1 to RAID-5. In the following explanation, among these, representative R
AID-1, RAID-3 and RAID-5 will be described as an example. RAID-1 is a method of writing the same content in two hard disk devices, and is also called mirroring. RAID-3 is a method in which input data is divided into a predetermined length and recorded in a plurality of hard disk devices, and parity data is generated and written in another hard disk device. In RAID-5, the unit (block) of data division is increased to record one divided data as a data block in one hard disk device, and the parity data for the data blocks corresponding to each other in each hard disk device is parity block. Is recorded in another hard disk device and the parity block is distributed to all hard disk devices.

An information recording method (hereinafter referred to as a distributed recording method) to which the RAID technique according to the present embodiment is applied.
Is for recording information by replacing the hard disk device in the above description of RAID with the interference area 313 in the optical information recording medium 1.

FIG. 65 is an explanatory diagram showing an example of the distributed recording method according to the present embodiment. In this example, the information to be recorded on the optical information recording medium 1 is a series of data DATA.
1, DATA2, DATA3, ..., and the same data DATA1, DATA2, DATA3 ,.
It is recorded in 3e. In addition, each interference area 313a-31
In 3e, a plurality of data are multiplexed and recorded by phase encoding and multiplexing. This recording method is RAID-1
It corresponds to. According to this recording method, even if the data cannot be reproduced in any of the plurality of interference areas 313a to 313e, the data can be reproduced from the other interference areas.

FIG. 66 is an explanatory diagram showing another example of the distributed recording method according to the present embodiment. In this example, the information to be recorded on the optical information recording medium 1 is a series of data DATA.
1, DATA2, DATA3, ..., DATA12, the data is divided into a plurality of interference regions 31.
3a to 313d, the plurality of interference areas 31
Parity data for the data recorded in 3a to 313d is generated, and this parity data is used as the interference area 313e.
It is recorded in. More specifically, in this recording method, the data DATA1 to DATA4 are recorded in the interference areas 313a to 313d, respectively, and the data DATA
Parity data PARITY for 1 to DATA4
(1-4) is recorded in the interference area 313e, and the data DA
TA5 to DATA8 are interference regions 313a to 313, respectively.
13d, the parity data PARITY (5-8) for the data DATA5 to DATA8 is recorded in the interference area 313e, and the data DATA9 to DATA12.
Are recorded in the interference areas 313a to 313d, respectively,
Parity data PARITY (9-12) for the data DATA9 to DATA12 is recorded in the interference area 313e. In each of the interference areas 313a to 313e, a plurality of data are multiplexed and recorded by phase encoding and multiplexing. This recording method corresponds to RAID-3. According to this recording method, the plurality of interference regions 31
Even if the data cannot be reproduced in any of 3a to 313d, the data can be restored using the parity data recorded in the interference area 313e.

FIG. 67 is an explanatory diagram showing still another example of the distributed recording method according to the present embodiment. In this example, the information to be recorded on the optical information recording medium 1 is a series of data DA.
TA1, DATA2, DATA3, ..., DATA12, this data is divided and recorded in four interference areas of the plurality of interference areas 313a to 313e, and parity data for the recorded data is generated. , This parity data is converted into a plurality of interference areas 313a.
.. are recorded in the remaining interference area of 313e. In addition, in this method, the interference area in which the parity data is recorded is sequentially changed. More specifically, in this recording method, the data DATA1 to DATA4 are recorded in the interference areas 313a to 313d, respectively, and the data D
Parity data PARI for ATA1 to DATA4
TY (1-4) is recorded in the interference area 313e, and the data DATA5 to DATA8 are respectively recorded in the interference area 313a.
To 313c and 313e, data DATA5 to
Parity data PARITY for DATA8 (5-
8) is recorded in the interference area 313d, and data DATA9
~ DATA12 are interference regions 313a and 313, respectively.
b, 313d, 313e, data DATA9
~ Parity data PARITY for DATA12
(9-12) is recorded in the interference area 313c. In addition,
In each of the interference areas 313a to 313e, a plurality of data are multiplexed and recorded by phase encoding and multiplexing. This recording method corresponds to RAID-5. According to this recording method, even if the data cannot be reproduced in any of the plurality of interference areas in which the data is recorded, the data can be restored using the parity data.

For example, the distributed recording method as shown in FIGS. 65 to 67 is performed under the control of the controller 90 as the control means.

FIG. 68 shows an example of the arrangement of a plurality of interference areas used in the above distributed recording method. In this example, the interference areas used in the distributed recording method are a plurality of adjacent interference areas 313 in one track. In this case, it is preferable that the plurality of interference areas 313 used in the distributed recording method are interference areas within a range accessible within the visual field. This is because each interference area 313 can be accessed at high speed.

FIG. 69 shows another example of the arrangement of a plurality of interference areas used in the above distributed recording method.
In this example, the plurality of interference areas used in the distributed recording method are two-dimensionally adjacent to each other in the radial direction 331 and the track direction 332 of the optical information recording medium 1.
I am trying. In this case, it is preferable that, of the plurality of interference areas used in the distributed recording method, the plurality of interference areas 313 adjacent to each other in the track direction 332 are interference areas within a range in which access within the visual field is possible. It is track direction 3
This is because each interference area 313 adjacent to 32 can be accessed at high speed.

In the distributed recording method according to this embodiment, a series of data is recorded in a plurality of adjacent interference areas 313.
The plurality of interfering areas 31 located at different positions without being recorded in
Alternatively, the data may be dispersed in 3 and recorded.

Up to this point, the distributed recording method in the case of multiple-recording a plurality of data in one interference area 313 by phase-encoding multiplexing has been described. However, in the case of multiple-recording a plurality of data by another method. Also, the distributed recording method can be realized. As an example,
Referring to FIG. 70, shift multiplexing (shift
A distributed recording method in the case of multiple recording of a plurality of data using a method called "multiplexing" will be described.
The shift multiplexing means, as shown in FIG. 70, a plurality of interference regions 313 with respect to the optical information recording medium 1.
Are formed so that they are slightly shifted from each other in the horizontal direction and partially overlap each other, and a plurality of pieces of information are multiplexed and recorded. Note that FIG. 70 shows an example in which a plurality of interference areas 313 used in the distributed recording method are two-dimensionally arranged, but a plurality of interference areas 313 used in the distributed recording method are shown.
May be arranged adjacent to each other in the same track.
Further, in FIG. 70, the arrow indicated by reference numeral 334 represents the recording order. In the distributed recording method using multiplexing, data or parity data divided from a series of data is distributed and recorded in a plurality of interference areas 313.

The distributed recording method can also be realized when multiple recording of a plurality of data is performed by using both phase encoding multiplexing and shift multiplexing. FIG. 71 shows that in the track direction 332 of the information recording medium 1, interference regions 313 that multiplex-record information by phase-encoding multiplexing are formed without overlapping each other, and in the radial direction 331 of the information recording medium 1, the shift multiplex is performed. An example is shown in which the adjacent interference regions 313 are formed so as to be slightly offset from each other in the horizontal direction and partially overlap each other by using the kixing. The interference areas 313 in this example are the interference areas 313a in FIGS. 65 to 67, respectively.
~ 313e are treated the same.

Next, with reference to FIG. 72 and FIG. 73, as an application example of the optical information recording / reproducing apparatus according to the present embodiment,
A juke device using the optical information recording / reproducing device according to the present embodiment will be described. The juke device is
A large-capacity information recording / reproducing apparatus having an autochanger mechanism for exchanging a recording medium.

FIG. 72 is a perspective view showing the external appearance of the juke device, and FIG. 73 is a block diagram showing the circuit configuration of the juke device. This juke device comprises a front panel block 401 provided on the entire surface of the juke device and a robotics block 402 constituting the inside of the juke device.
, A rear panel block 403 provided on the back side of the juke device, a first disk array 404 provided inside the juke device and having a plurality of optical information recording / reproducing devices connected thereto, and a plurality of optical information recording devices. A second disk array 405 to which a reproducing device is connected, and a power supply block 40 that supplies predetermined power to each part of the juke device.
6 and.

The front panel block 401 includes a front door 407 which is opened and closed when the disk arrays 404 and 405 are exchanged, and a front panel 408.

On the front panel 408, a keypad 409 having various operation keys, a display 410 for displaying, for example, an operation mode, and a front door 40 are provided.
Functional switch 4 to specify opening / closing of 7
11, an optical information recording medium 1 for inserting and ejecting the optical information recording medium 1, and an optical information recording medium for transferring and ejecting the optical information recording medium 1 inserted through the mail slot 412 to a mail box (not shown). A transfer motor 413 that transfers 1 from the mail box to the mail slot 412 and a full sensor 414 that detects that the number of optical information recording media 1 inserted in the juke device has reached a specified number are provided.

The front door 407 includes the front door 4
A door sensor 415 for detecting the open / closed state of 07, a door lock solenoid 416 for controlling the opening / closing of the front door 407, and an interlock switch 417 for controlling the opening / closing of the front door 407 according to the operation of the functional switch 411 are provided. ing.

The robotics block 402 is provided inside the lower magazine 421 capable of accommodating, for example, 10 optical information recording media 1, and on the upper surface of the lower magazine 421. Further, it has an upper magazine 422 capable of accommodating, for example, 10 optical information recording media 1, and a controller block 423 for controlling the entire juke device.

The robotics block 402 is a grip operation motor 424 for controlling the grip operation of a manipulator (not shown) for moving the optical information recording medium 1 inserted in the juke device to a predetermined position, and a controller block 423. The grip operation motor controller 425 that controls the rotation speed and the rotation direction of the grip operation motor 424 according to the control of 1. and the rotation speed and the rotation direction of the grip operation motor 424 are detected. And a grip operation encoder 426 to be supplied. In addition, the robotics block 402 includes a rotation operation motor 427 for controlling rotation of the manipulator in a clockwise direction, a counterclockwise direction, or a left-right direction, and a rotation speed of the rotation operation motor 427 according to control of the controller block 423. It has a rotation operation motor controller 428 that controls the rotation direction, and a rotation operation encoder 429 that detects the rotation speed and rotation direction of the rotation operation motor 427 and supplies this detection data to the controller block 423. In addition, the robotics block 402
A vertical movement motor 430 for controlling the vertical movement of the manipulator, and a vertical movement motor controller 431 for controlling the rotation speed and the rotation direction of the vertical movement motor 430 according to the control of the controller block 423.
And the number of rotations and the direction of rotation of the vertical movement motor 430 are detected, and the detected data is detected by the controller block 423.
And an up-and-down movement encoder 432 for supplying to.

The robotics block 402 also includes a transfer motor controller 433 for controlling the rotation speed and rotation direction of the transfer motor 413 for inserting and ejecting the optical information recording medium 1 via the mail slot 412.
And a clear pass sensor 434 and a clear pass emitter 420.

The rear panel block 403 is an RS232C connector terminal 4 which is an input / output terminal for serial transmission.
35, a connector terminal 436 for UPS (Uninterruptible Power System), and a first SCSI (Small Computer System Interfac) which is an input / output terminal for parallel transmission.
e) connector terminal 437 and a second SCSI connector terminal 438 which is also an input / output terminal for parallel transmission.
And an AC (alternating current) power supply connector terminal 439 connected to a commercial power supply.

The RS232C connector terminal 435 and the UPS connector terminal 436 are connected to the controller block 423, respectively. The controller block 423 converts serial data supplied via the RS232C connector terminal 435 into parallel data and supplies the parallel data to the disk arrays 404 and 405.
The parallel data from each disk array 404, 405 is converted into serial data and supplied to the RS232C connector terminal 435.

Further, each SCSI connector terminal 437,
The reference numeral 438 is connected to the controller block 423 and the disk arrays 404 and 405. Each disk array 404, 405 has a SCSI connector terminal 4
Data is directly transferred via the devices 37, 438, and the controller block 423 uses the respective disk arrays 404,
The parallel data from 405 is converted into serial data and supplied to the RS232C connector terminal 435.

The AC power supply connector terminal 439 is connected to the power supply block 406. The power supply block 406 is + 5V, + 12V, based on the commercial power source taken through the AC power connector terminal 439.
Each power of + 24V and -24V is formed and supplied to each other block.

The manipulator (not shown) is a carriage having a gripper for performing operations such as picking up the optical information recording mediums 1 transferred to the mail box via the mail slot 412 one by one, and a carriage holding portion for holding the carriage. And a drive unit for controlling the carriage up / down, left / right, front / back, and rotation. Inside the juke device, a substantially rectangular shape is formed on the bottom surface,
From the four corners of the rectangular shape to the upper surface of the juke device, four columns are erected so as to be perpendicular to the bottom surface. The carriage holding unit holds the carriage rotatably to the left, right, front, rear, and rotatably. ing.

The carriage driving section generates a driving force for controlling the movement of such a manipulator up and down along the support column, a driving force for controlling the left, right, front and rear, and rotation of the manipulator. A driving force for picking up the optical information recording medium 1 is generated.

As shown in FIG. 72, the front door 40
7, one end of which is supported in a cantilever manner by a hinge 450 so that it can be opened and closed. It can be installed. Each magazine 421,
The optical information recording medium 1 has a box shape in which ten optical information recording media 1 each housed in a cartridge are stacked in parallel with the bottom surface of the juke device. The magazines 421 and 422 are inserted from the back side (the side opposite to the front side where the front door 407 is provided when the magazines 421 and 422 are mounted on the juke device).
The user can mount the optical information recording medium 1 on each magazine 4
21 and 422 can be taken out and stored manually, and the magazines 421 and 422 accommodating the optical information recording medium 1 can be mounted in the juke device at once. Further, by inserting the optical information recording medium 1 through the mail slot 412, the inserted optical information recording medium 1 is transferred to the mailbox, and the optical information recording medium 1 transferred to the mailbox is transferred to the manipulator. The magazines 421 and 422 are mounted. As a result, the optical information recording medium 1 can be automatically attached to each magazine 421, 422.

The first and second disk arrays 404,
Each of the reference numerals 405 includes a RAID controller and a drive array configured by connecting first to fifth optical information recording / reproducing devices.

Each optical information recording / reproducing apparatus has a disc insertion / ejection port, and the optical information recording medium 1 is inserted into each optical information recording / reproduction device or each optical information recording / reproduction via this disc insertion / ejection port. It is designed to be discharged from the device. Further, the RAID controller is connected to the controller block 423, and under the control of the controller block 423, each optical information recording / reproducing apparatus is controlled in accordance with the recording system of RAID1, RAID3, or RAID5. In addition, RAID1,
Each of the RAID 3 and RAID 5 recording methods is selected by operating a keypad 409 provided on the front panel 408.

In this juke device, the disk array 4
04 and 405, data recording is performed by the recording method of RAID1, RAID3, or RAID5. In order to record data in this way, it is necessary to mount the optical information recording medium 1 on the juke device in advance. Optical information recording medium 1 for juke device
There are the following two methods of mounting.

In the first mounting method, as shown in FIG. 72, the front door 407 is opened, the lower magazine 421 and the upper magazine 422 are taken out, and optical information recording is manually performed on these magazines 421 and 422. This is a method of mounting the medium 1.

The second mounting method is a method of mounting the optical information recording media 1 one by one via the mail slot 412 shown in FIG. When the optical information recording medium 1 is mounted in the mail slot 412, the controller block 423
Detects this and drives and controls the transfer motor 413,
The optical information recording medium 1 is transferred to the mailbox. When the optical information recording medium 1 is transferred to the mailbox, the controller block 423 drives and controls the vertical movement motor 430 to control the movement of the manipulator in the direction in which the mailbox is provided, and also for grip operation. The motor 424 is drive-controlled to control the movement of the optical information recording medium 1 picked up by the gripper provided in the manipulator to the vacant disc storage portions of the magazines 421 and 422. Then, the grip operation motor 4
The optical information recording medium 1 picked up by the gripper is released in the disc housing portion by controlling the driving of the optical disc 24. The controller block 423 controls each part to repeat such a series of mounting operations every time the optical information recording medium 1 is inserted through the mail slot 412.

As described above, when the optical information recording medium 1 is mounted on each magazine 421, 422 by the first mounting method or the second mounting method, the controller block 423.
Controls the manipulator to transfer the optical information recording medium 1 stored in the lower magazine 421 or the upper magazine 422 to the first disk array 404 or the second disk array 405. Each disk array 404,
Each of the magazines 405 can be loaded with five optical information recording media 1, and each magazine 42 can be loaded by a manipulator.
Of the total 20 optical information recording media 1 accommodated in 1 and 422, 5 of them will be mounted on the first disk array 404 and the other 5 will be mounted on the second disk array 405.

The user, when recording data,
By operating the keypad 409, RAID1,
A desired recording method is selected from the RAID 3 or RAID 5 recording methods, and the keypad 409 is operated to specify the start of data recording. Disk arrays 404, 40
5, RS232C connector terminal 435 or the
Data to be recorded is supplied via the first and second SCSI connector terminals 437 and 438. When the start of data recording is designated, the controller block 423 performs data recording according to the selected recording method via the RAID controller provided in each disk array 404, 405. It controls each disk array 404, 405.

In this juke device, the hard disk device in the RAID using the conventional hard disk device is replaced with an optical information recording / reproducing device provided in each of the disk arrays 404 and 405, and RAID
Data is recorded according to a recording method selected from the recording methods of 1, RAID 3 and RAID 5. In this juke device, the data interface is not limited to the ones mentioned in the above description.

By the way, in the optical information recording / reproducing apparatus according to the present embodiment, it is possible to easily realize copy protection and confidentiality protection, as in the first embodiment. Further, the optical information recording medium 1 in which various kinds of information (for example, various kinds of software) having different modulation patterns of the reference light are recorded is provided to the user, and each kind of information can be reproduced according to the user's request. It is possible to realize an information distribution service in which information on light modulation patterns is individually provided as key information for a fee.

Further, the phase modulation pattern of the reference light, which serves as key information for extracting the predetermined information from the optical information recording medium 1, may be created based on the unique information of the individual who is the user. Personal information includes a personal identification number, a fingerprint, a voiceprint, an iris pattern, and the like.

FIG. 74 shows a main part of the optical information recording / reproducing apparatus according to the present embodiment when the modulation pattern of the phase of the reference light is created based on the unique information of the individual as described above. An example of the configuration is shown. In this example, the optical information recording / reproducing apparatus modulates the phase of the reference light based on the personal information input unit 501 for inputting the unique information of the individual such as a fingerprint and the information input from the personal information input unit 501. When a pattern is created and information is recorded or reproduced, the phase space modulator 117 is provided with information on the created modulation pattern as necessary, and the phase space modulator 1
A phase modulation pattern encoder 502 for driving 17,
The card 504 in which the information of the modulation pattern created by the phase modulation pattern encoder 502 is recorded is issued, and when the card 504 is mounted, the information of the modulation pattern recorded in the card 504 is changed to the phase modulation pattern. Issuing a card to send to the encoder 502
And an input unit 503.

In the example shown in FIG. 74, when the user records information on the optical information recording medium 1 using the optical information recording / reproducing apparatus according to the present embodiment, the user inputs it to the personal information input section 501. When inputting individual peculiar information such as a fingerprint, the phase modulation pattern encoder 502, the personal information input unit 50
1 creates a modulation pattern of the phase of the reference light on the basis of the information inputted from the phase spatial light modulator 1 at the time of recording the information.
Give the information of the created modulation pattern to 17,
The phase spatial modulator 117 is driven. As a result, information is recorded on the optical information recording medium 1 in association with the phase modulation pattern of the reference light created based on the unique information of the individual who is the user. Further, the phase modulation pattern encoder 502 sends information on the created modulation pattern to the card issuing / input unit 503, and the card issuing / input unit 503.
Issues the card 504 in which the information of the transmitted modulation pattern is recorded.

In order for the user to reproduce the information recorded as described above from the optical information recording medium 1, whether the user inputs the unique information of the individual to the personal information input section 501 as in the recording. , Card 504 to card issuing / input unit 503
Attach to.

When the unique information of the individual is input to the personal information input unit 501, the phase modulation pattern encoder 502 modulates the phase of the reference light based on the information input from the personal information input unit 501. When a pattern is created and the information is reproduced, the information of the created modulation pattern is given to the phase spatial modulator 117 to generate the phase spatial modulator 117.
To drive. At this time, if the light phase modulation pattern during recording matches the reference light phase modulation pattern during reproduction, desired information is reproduced. Note that even if the unique information of the same individual is input to the personal information input unit 501, in order to prevent the phase modulation pattern encoder 502 from creating different modulation patterns during recording and during reproduction, Even if the information input from the information input unit 501 differs to some extent, the same modulation pattern may be created in the phase modulation pattern encoder 502.

On the other hand, when the card 504 is attached to the card issuing / input unit 503, the card issuing / input unit 503
Sends the information of the modulation pattern recorded on the card 504 to the phase modulation pattern encoder 502, and the phase modulation pattern encoder 502 gives the sent information of the modulation pattern to the phase space modulator 117 to send the phase space. Drive the modulator 117. As a result, desired information is reproduced.

Other configurations, operations and effects in this embodiment are the same as those in the first embodiment.

The present invention is not limited to the above-mentioned embodiments. For example, in the above-mentioned embodiments, address information and the like are recorded in advance in the address / servo area 6 of the optical information recording medium 1 by embossed pits. However, without providing embossed pits in advance, a portion of the hologram layer 3 near the protective layer 4 in the address / servo area 6 is selectively irradiated with a high-power laser beam to refract that portion. You may make it format by recording address information etc. by changing a rate selectively.

As the element for detecting the information recorded on the hologram layer 3, a MOS array is used instead of the CCD array.
Optical sensor in which a solid-state image sensor and a signal processing circuit are integrated on one chip (for example, refer to the document “O plus”).
E, September 1996, No. 202, pp. 93-99 ". ) May be used. Since this smart optical sensor has a large transfer rate and a high-speed arithmetic function, high-speed reproduction is possible by using this smart optical sensor, for example, reproduction is performed at a transfer rate on the order of G bits / second. Is possible.

Further, in particular, when a smart optical sensor is used as an element for detecting the information recorded on the hologram layer 3, the address information or the like is embossed in the address / servo area 6 of the optical information recording medium 1. Instead of recording, address information of a predetermined pattern is recorded in advance by the same method as recording using holography in the data area 7, and the pickup is set in the same state as in reproduction during servo, Address information and the like may be detected by a smart optical sensor. In this case, the basic clock and address can be obtained directly from the detection data of the smart light sensor. The tracking error signal can be obtained from information on the position of the reproduction pattern on the smart optical sensor. The focus servo can be performed by driving the objective lens 12 so that the contrast of the reproduction pattern on the smart optical sensor is maximized. Also, during reproduction, focus servo can be performed by driving the objective lens so that the contrast of the reproduction pattern on the smart optical sensor is maximized.

Further, in each of the embodiments, the information on the modulation pattern of the reference light and the information on the wavelength may be given to the controller 90 from an external host device.

[0241]

As described above, according to the optical information recording apparatus of any one of claims 1 to 7, a plurality of two-dimensional pattern information is recorded in the same recording area of the information recording layer of the optical information recording medium. Since multiple recording can be performed, it is possible to record a large amount of information on the optical information recording medium with high density.

Further, in the optical information recording apparatus according to the second aspect, the recording means is such that adjacent recording areas of the plurality of recording areas are displaced in a predetermined direction on the optical information recording medium, and a part of them is adjacent to each other. A plurality of pieces of two-dimensional pattern information are recorded in multiplex so as to overlap each other. Therefore, according to the present invention, it is possible to record a larger amount of information on the optical information recording medium with higher density.

Further, in the optical information recording apparatus according to the third aspect, the recording means records the same information in a plurality of recording areas in the information recording layer. Therefore, according to the present invention, even if the information cannot be reproduced in any of the recording areas, the information can be reproduced from the other recording areas.

Further, in the optical information recording apparatus according to any one of claims 5 to 7, the information to be recorded on the optical information recording medium is divided into a plurality of data, and a plurality of two-dimensional patterns corresponding to the respective data are obtained. Information is multiple-recorded in a predetermined order over a plurality of recording areas, parity data is generated based on a plurality of two-dimensional pattern information, and the parity data is recorded in an information recording layer based on a predetermined rule. To do.
Therefore, according to the present invention, even if the information cannot be reproduced in any of the recording areas, it is possible to restore the information by using the parity data.

Further, according to the optical information reproducing apparatus of any one of claims 8 to 14, a plurality of two data recorded in the same recording area of the information recording layer of the optical information recording medium are multiplexed.
Since the dimensional pattern information can be reproduced, it is possible to reproduce the information from the optical information recording medium in which a large amount of information is recorded at high density.

In the optical information reproducing apparatus according to the ninth aspect, in the optical information recording medium, adjacent recording areas of the plurality of recording areas are displaced in a predetermined direction in the optical information recording medium, and A plurality of pieces of two-dimensional pattern information are recorded in multiplex so that the parts overlap each other.
Therefore, according to the present invention, it is possible to reproduce information from an optical information recording medium in which a larger amount of information is recorded with higher density.

Further, in the optical information reproducing apparatus according to the tenth aspect, the optical information recording medium has the same information recorded in a plurality of recording areas in the information recording layer. Therefore, according to the present invention, even if the information cannot be reproduced in any of the recording areas, the information can be reproduced from the other recording areas.

Further, in the optical information reproducing apparatus according to any one of claims 12 to 14, the optical information recording medium corresponds to a plurality of data generated by dividing information to be recorded on the optical information recording medium. A plurality of pieces of two-dimensional pattern information are multiplexed and recorded in a plurality of recording areas in a predetermined order. In the optical information recording medium, the parity data generated based on the plurality of two-dimensional pattern information is further based on a predetermined rule by the interference pattern due to the interference between the information light and the recording reference light based on the parity data. It is recorded on the information recording layer. Therefore, according to the present invention, even if the information cannot be reproduced in any of the recording areas, it is possible to restore the information by using the parity data.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a pickup and an optical information recording medium in an optical information recording / reproducing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an overall configuration of an optical information recording / reproducing apparatus according to the first embodiment of the present invention.

3 is a block diagram showing a configuration of a detection circuit in FIG.

FIG. 4 is an explanatory diagram showing a state of the pickup shown in FIG. 1 during a servo operation.

FIG. 5 is an explanatory diagram for explaining polarized light used in the first embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a state of the pickup shown in FIG. 1 during recording.

FIG. 7 is an explanatory diagram showing a state of light in the pickup in the state shown in FIG.

FIG. 8 is an explanatory diagram showing a state of light in the pickup in the state shown in FIG.

9 is an explanatory diagram showing a state during reproduction of the pickup shown in FIG. 1. FIG.

FIG. 10 is an explanatory diagram showing a state of light in the pickup in the state shown in FIG.

FIG. 11 is an explanatory diagram showing a state of light in the pickup in the state shown in FIG.

12 is an explanatory diagram for explaining a method of recognizing a reference position in a pattern of reproduction light from the detection data of the CCD array in FIG.

13 is an explanatory diagram for explaining a method of recognizing a reference position in a pattern of reproduction light from the detection data of the CCD array in FIG.

FIG. 14 is an explanatory diagram showing a pattern of information light and a pattern of reproduction light in the pickup shown in FIG.

15 is an explanatory diagram showing the content of data determined from the pattern of the reproduction light detected by the pickup shown in FIG. 1 and an ECC table corresponding to this data.

FIG. 16 is a characteristic diagram showing a state in which the light absorption spectrum of the hole-burning material is reduced in light absorption rate at a plurality of wavelength positions by irradiation with light having a plurality of wavelengths.

FIG. 17 is an explanatory diagram showing a configuration of a pickup according to a third embodiment of the present invention.

FIG. 18 is a plan view showing a configuration of an optical unit including each element that constitutes a pickup according to the third embodiment of the present invention.

19 is an explanatory diagram showing an example of an optical element for optical rotation in FIG.

FIG. 20 is an explanatory diagram showing a configuration of a pickup that can use laser light of three colors in the third embodiment of the present invention.

21 is a plan view showing a slide feeding mechanism of the optical unit shown in FIG.

22 is a partially cutaway side view showing the slide feeding mechanism shown in FIG. 21 in a stationary state.

FIG. 23 is a diagram when the optical unit is slightly displaced.
FIG. 3 is a side view with a part cut away showing the slide feeding mechanism shown in FIG.

FIG. 24 is an explanatory diagram showing the operation of the actuator shown in FIG. 21.

25 is an explanatory diagram showing a moving direction by seek of the objective lens and an in-field access direction in the pickup shown in FIG.

FIG. 26 is an explanatory diagram for explaining positioning of reference light and information light according to the third embodiment of the present invention.

FIG. 27 is an explanatory diagram showing an example of the locus of the center of the objective lens when a plurality of positions in the optical information recording medium are accessed by using both movement by seek and access in the visual field in the third embodiment of the invention. is there.

FIG. 28 is a plan view showing a cartridge accommodating the optical information recording medium according to the third embodiment of the invention.

FIG. 29 is a plan view of the cartridge shown in FIG. 28 with the shutter opened.

FIG. 30 is a plan view showing an example in which two optical units are arranged so as to face one surface of an optical information recording medium in the third embodiment of the invention.

FIG. 31 is a plan view showing an example in which four optical units are provided in the third embodiment of the invention.

32 is a cross-sectional view taken along the line AA ′ of FIG.

33 is a cross-sectional view taken along the line BB ′ of FIG.

FIG. 34 is a plan view showing an example in which 16 optical units are provided in the third embodiment of the invention.

FIG. 35 is a half cross-sectional view of an air gap type optical information recording medium according to the third embodiment of the present invention.

FIG. 36 is an exploded perspective view of a half of an air gap type optical information recording medium according to a third embodiment of the present invention.

FIG. 37 is a half perspective view of an air gap type optical information recording medium according to the third embodiment of the present invention.

FIG. 38 is a half cross-sectional view of the transparent substrate gap type optical information recording medium according to the third embodiment of the present invention.

FIG. 39 is an exploded perspective view of half of a transparent substrate gap type optical information recording medium according to the third embodiment of the present invention.

FIG. 40 is a half perspective view of a transparent substrate gap type optical information recording medium according to a third embodiment of the present invention.

FIG. 41 is a cross-sectional view of a single-sided type optical information recording medium having a thickness of 1.2 mm in the third embodiment of the present invention.

FIG. 42 is a sectional view of a single-sided type optical information recording medium having a thickness of 0.6 mm in the third embodiment of the present invention.

43 is an explanatory diagram showing a method of irradiating the single-sided type optical information recording medium shown in FIG. 41 or FIG. 42 with recording reference light and information light.

FIG. 44 is a cross-sectional view of a double-sided transparent substrate gap type optical information recording medium according to the third embodiment of the present invention.

FIG. 45 is a cross-sectional view of a double-sided air gap type optical information recording medium according to the third embodiment of the present invention.

FIG. 46 is an explanatory diagram showing a method of irradiating the double-sided optical information recording medium shown in FIG. 44 or 45 with recording reference light and information light.

FIG. 47 is an explanatory diagram showing a single-sided optical disc.

FIG. 48 is an explanatory diagram showing a case where the optical disc shown in FIG. 47 is used in the optical information recording / reproducing apparatus in the third embodiment of the present invention.

FIG. 49 is an explanatory diagram showing a double-sided type optical disc.

50 is an explanatory diagram showing a case where the optical disc shown in FIG. 49 is used in the optical information recording / reproducing apparatus according to the third embodiment of the present invention. FIG.

FIG. 51 is a perspective view showing a schematic configuration of a general recording / reproducing system that performs phase-encoding multiplexing.

FIG. 52 is an explanatory diagram showing how interference fringes are formed on a hologram recording medium due to interference between information light and reference light.

FIG. 53 is an explanatory diagram showing a state of a pickup during servo according to the third embodiment of the invention.

FIG. 54 is an explanatory diagram showing a state of light in the vicinity of the optical disc when recording or reproducing is performed using an ordinary optical disc by the optical information recording / reproducing device according to the third embodiment of the present invention.

FIG. 55 is an explanatory diagram showing a state of a pickup during recording according to the third embodiment of the present invention.

FIG. 56 is an explanatory diagram showing a state of light near the optical information recording medium at the time of recording in the third embodiment of the present invention.

FIG. 57 is an explanatory diagram showing a state of light near the optical information recording medium at the time of recording in the third embodiment of the present invention.

FIG. 58 is an explanatory diagram showing a state of a pickup at the time of fixing in the third embodiment of the invention.

FIG. 59 is an explanatory diagram showing a state of light in the vicinity of the optical information recording medium at the time of fixing in the third embodiment of the invention.

FIG. 60 is an explanatory diagram showing a state of a pickup during reproduction according to the third embodiment of the present invention.

FIG. 61 is an explanatory diagram showing a state of light in the vicinity of the optical information recording medium during reproduction according to the third embodiment of the present invention.

FIG. 62 is an explanatory diagram showing a state of light in the vicinity of the optical information recording medium during reproduction in the third embodiment of the present invention.

[Fig. 63] Fig. 63 is an explanatory diagram for describing a direct read-after-write function and a write power control function at the time of multiplex recording, which the optical information recording / reproducing apparatus according to the third embodiment of the present invention has. .

FIG. 64 is a block diagram showing a circuit configuration necessary for collation in the optical information recording / reproducing apparatus according to the third embodiment of the present invention.

FIG. 65 is an explanatory diagram showing an example of a distributed recording method according to a third embodiment of the present invention.

FIG. 66 is an explanatory diagram showing another example of the distributed recording method according to the third embodiment of the invention.

FIG. 67 is an explanatory diagram showing still another example of the distributed recording method according to the third embodiment of the present invention.

FIG. 68 is an explanatory diagram showing an example of an arrangement of a plurality of interference areas used in the distributed recording method according to the third embodiment of the present invention.

FIG. 69 is an explanatory diagram showing another example of an arrangement of a plurality of interference areas used in the distributed recording method in the third embodiment of the present invention.

[Fig. 70] Fig. 70 is an explanatory diagram for describing a distributed recording method when multiple recording of a plurality of data is performed by using shift multiplexing in the third embodiment of the present invention.

[Fig. 71] Fig. 71 is an explanatory diagram for describing a distributed recording method in the case of multiple recording of a plurality of data by using both phase encoding multiplexing and shift multiplexing in the third embodiment of the present invention.

FIG. 72 is a perspective view showing the outer appearance of a juke device as an application example of the optical information recording / reproducing device according to the third embodiment of the present invention.

73 is a block diagram showing a circuit configuration of the juke device shown in FIG. 72. FIG.

FIG. 74 is an example of a configuration of a main part of the optical information recording / reproducing apparatus according to the third embodiment of the present invention, in which a phase modulation pattern of reference light is created based on individual information unique to an individual; It is a block diagram showing.

FIG. 75 is a perspective view showing a schematic configuration of a recording / reproducing system in conventional digital volume holography.

[Explanation of symbols]

1 ... Optical information recording medium, 2 ... Transparent substrate, 3 ... Hologram layer, 4 ... Protective layer, 5 ... Reflective film, 6 ... Address / servo area, 7 ... Data area, 10 ... Optical information recording / reproducing device,
11 ... Pickup, 12 ... Objective lens, 14 ... 2 division optical rotation plate, 17 ... Phase spatial light modulator, 18 ... Spatial light modulator, 20 ... CCD array, 25 ... Light source device.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2K008 AA04 BB03 CC03 DD02 DD03                       EE04 FF17 GG01                 5D090 AA01 BB16 CC01 CC04 DD01                       DD05 FF08 FF11 FF43 KK12                       KK15 LL02                 5D119 AA22 BA01 BB20 DA01 DA05                       EB12 EC11 EC13 EC33 EC43                       JA30 JA58

Claims (14)

[Claims] 1. An optical information recording apparatus for recording information on an optical information recording medium having an information recording layer on which information is recorded by using holography, which carries a plurality of two-dimensional pattern information. A plurality of information light generating means for generating a plurality of information lights and a phase modulating means for spatially modulating the phase of the light, and the phase of the light is spatially modulated by the phase modulating means, and the plurality of two-dimensional Recording reference light generation means for generating a plurality of recording reference light modulated by a plurality of different phase modulation patterns for each pattern information, the plurality of information light and the plurality of recording reference light, respectively optical axis Is radiated to the information recording layer so that they are arranged on the same line, in the same recording area in the information recording layer,
An optical information recording apparatus comprising: a recording unit that multiplex-records the plurality of two-dimensional pattern information by a plurality of interference patterns due to the interference of the plurality of information lights and the plurality of recording reference lights. 2. The recording means is further arranged such that adjacent recording areas of the plurality of recording areas are displaced in a predetermined direction in the optical information recording medium, and a part of them overlap each other. 2. The optical information recording apparatus according to claim 1, wherein the two-dimensional pattern information is recorded in multiplex. 3. The optical information recording apparatus according to claim 1, wherein the recording means records the same information in a plurality of recording areas in the information recording layer. 4. A two-dimensional pattern information generating means for dividing the information to be recorded on the optical information recording medium into a plurality of data and generating a plurality of two-dimensional pattern information corresponding to each data, 2. The optical recording medium according to claim 1, wherein the recording means multiplex-records the plurality of two-dimensional pattern information generated by the two-dimensional pattern information generating means in a predetermined order over a plurality of recording areas. Information recording device. 5. A parity data generating means for generating parity data based on the plurality of two-dimensional pattern information generated by the two-dimensional pattern information generating means, wherein the recording means includes the plurality of two-dimensional pattern information. When recording pattern information on the information recording layer, the parity data is recorded on the information recording layer based on a predetermined rule by an interference pattern due to interference between the information light based on the parity data and the recording reference light. The optical information recording device according to claim 4, wherein 6. The parity data generating means generates a plurality of parity data corresponding to the plurality of two-dimensional pattern information, and the recording means stores the plurality of parity data in a predetermined area in the information recording layer. 6. The optical information recording apparatus according to claim 5, wherein the optical information recording apparatus collectively records the information. 7. The parity data generating means generates a plurality of parity data corresponding to the plurality of two-dimensional pattern information, and the recording means at least in each recording area in which the two-dimensional pattern information is recorded. 6. The optical information recording apparatus according to claim 5, wherein the plurality of parity data are multiplexed and recorded over the plurality of recording areas so that one piece of the parity data is included. 8. A plurality of recording references in which the phases of light are spatially modulated by a plurality of information lights carrying a plurality of two-dimensional pattern information and a plurality of phase modulation patterns different for each of the plurality of two-dimensional pattern information. From an optical information recording medium provided with an information recording layer in which the plurality of two-dimensional pattern information is multiplex-recorded in the same recording area by a plurality of interference patterns due to interference with light, using holography An optical information reproducing apparatus for reproducing pattern information, comprising phase modulating means for spatially modulating the phase of light, the phase modulating means spatially modulating the phase of the light, Reproducing reference light generating means for generating a plurality of reproducing reference light modulated by a modulation pattern, and irradiating the same recording area in the information recording layer with the plurality of reproducing reference light, And a reproducing unit that collects and detects a plurality of reproducing lights generated from the information recording layer by being irradiated with a plurality of reproducing reference lights, the reproducing unit having an optical axis of the reproducing reference light. An optical information reproducing apparatus, wherein irradiation of the reproduction reference light and collection of the reproduction light are performed such that the optical axis of the reproduction light is arranged on the same line. 9. The optical information recording medium according to claim 1, wherein adjacent recording areas among the plurality of recording areas are displaced in a predetermined direction in the optical information recording medium, and some of them overlap each other. 9. The optical information reproducing apparatus according to claim 8, wherein the two-dimensional pattern information is recorded in multiplex. 10. The optical information reproducing apparatus according to claim 8, wherein the optical information recording medium has the same information recorded in a plurality of recording areas in the information recording layer. 11. The optical information recording medium includes a plurality of two-dimensional pattern information corresponding to a plurality of data generated by dividing information to be recorded on the optical information recording medium, in a predetermined order. 9. The optical information reproducing apparatus according to claim 8, wherein the optical information reproducing apparatus is one in which multiple recording is performed over a recording area. 12. The optical information recording medium comprises the plurality of optical discs.
Parity data generated based on the dimension pattern information is recorded in the information recording layer based on a predetermined rule by an interference pattern due to interference between the information light and the recording reference light based on the parity data. The optical information reproducing device according to claim 11, wherein 13. The optical information recording medium comprises the plurality of optical discs.
13. The optical information reproducing apparatus according to claim 12, wherein a plurality of pieces of parity data corresponding to the dimensional pattern information are collectively recorded in a predetermined area of the information recording layer. 14. The optical information recording medium comprises a plurality of parity data corresponding to the plurality of two-dimensional pattern information so that each recording area in which the two-dimensional pattern information is recorded includes at least one piece of the parity data. 13. The optical information reproducing apparatus according to claim 12, wherein is recorded multiplex over the plurality of recording areas.