JPH11219540A - Device and method for optical information recording, and device and method for optical information reproducing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record information in a higher density in an optical information recording medium for recording information by using a holography. SOLUTION: During recording, a laser light emitted from a laser coupler 20 is separated by a beam splitter 16, one light is passed through a space light modulator 15 to become an information light, and this information light is converged by an objective lens 13A, passed through a solid emersion lens 12A and projected to an optical information recording medium 1. The other light obtained as a result of the separation by the beam splitter 16 is passed through prisms 51 and 52, a convex lens 53, a concave lens 54 and a cylindrical lens 55 to become a recording reference light having a flat shape, passed through the solid emersion lens 12A and then projected to the optical information recording medium 1. The information light and the recording reference light intersect each other in an information recording layer 2, and in the information recording layer 2, a recording area composed of a volume hologram is formed in a layer shape.

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 and method for recording information on an optical information recording medium using holography, and to record information on an optical information recording medium using holography. And an optical information recording / reproducing apparatus and method for reproducing information from an optical information recording medium.

[0002]

2. Description of the Related Art In general, holographic recording in which information is recorded on a recording medium using holography is performed by superimposing light having image information and reference light inside a recording medium, and generating interference at that time. This is performed by writing stripes on a recording medium. When reproducing the recorded information, the recording medium is irradiated with reference light, whereby the image information is reproduced by diffraction due to interference fringes.

In recent years, volume holography, especially digital volume holography, has been developed in the practical range for ultra-high-density optical recording, and has attracted attention. Volume holography is a method of writing interference fringes three-dimensionally by actively utilizing the thickness direction of the recording medium. Increasing the thickness increases the diffraction efficiency, and using multiplex recording to increase the storage capacity. There is a feature that can be achieved. And
Digital volume holography is a computer-oriented holographic recording method that uses the same recording medium and recording method as volume holography, but limits image information to be recorded to binary digital patterns. In this digital volume holography, for example, 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, this digital pattern information is read out and decoded to return to the original image information for display. Thereby, even if the SN ratio (signal-to-noise ratio) is somewhat poor at the time of reproduction, the original information can be reproduced very faithfully by performing differential detection or encoding the binary data to correct errors. It becomes possible.

FIG. 26 is a perspective view showing a schematic configuration of a recording / reproducing system in conventional digital volume holography. This recording / reproducing system includes a spatial light modulator 10 for generating an information light 102 based on two-dimensional digital pattern information.
1, a lens 103 for condensing the information light 102 from the spatial light modulator 101 and irradiating the hologram recording medium 100 with the information light 102. Reference light irradiating means (not shown) for irradiating light 104, CCD (charge coupled device) array 107 for detecting reproduced two-dimensional digital pattern information, and reproduction light 105 emitted from hologram recording medium 100 And a lens 106 for condensing the light and irradiating the light onto the CCD array 107. For the hologram recording medium 100, a crystal such as LiNbO ₃ is used.

In the recording / reproducing system shown in FIG. 26, at the time of recording, information such as an original image to be recorded is digitized, and the 0 or 1 signal is further arranged two-dimensionally to generate two-dimensional digital pattern information. . One piece of two-dimensional digital pattern information is called page data. Here, it is assumed that page data # 1 to #n are multiplex-recorded on the same hologram recording medium 100. In this case, first, the spatial light modulator 101 selects transmission or light blocking for each pixel based on the page data # 1, whereby the spatially modulated information light 1 is selected.
02 is generated and irradiated on the hologram recording medium 100 via the lens 103. At the same time, the hologram recording medium 10
0, the reference light 1 from a direction θ1 substantially orthogonal to the information light 102.
04, and inside the hologram recording medium 100,
The interference fringes formed by the superposition of the information beam 102 and the reference beam 104 are recorded. In order to increase the diffraction efficiency, the reference light 104 is transformed into a flat beam by a cylindrical lens or the like, and the interference fringes are changed to the hologram recording medium 100.
To be recorded in the thickness direction. At the time of recording the next page data # 2, the reference light 104 is irradiated from the angle θ2 different from θ1, and the reference light 104 and the information light 1 are irradiated.
02 can be multiplex-recorded on the same hologram recording medium 100. Similarly, at the time of recording other page data # 3 to #n, information is multiplex-recorded by irradiating the reference beam 104 from different angles θ3 to θn. A hologram in which information is multiplex-recorded is called a stack. In the example shown in FIG. 26, the hologram recording medium 100 has a plurality of stacks (stack 1, stack 2,..., Stack m,...).

In order to reproduce any page data from the stack, the stack may be irradiated with the reference beam 104 having the same incident angle as when the page data was recorded. Then, the reference light 104 is selectively diffracted by an interference fringe corresponding to the page data, and a reproduction light 105 is generated. This reproduction light 105 is transmitted through a lens 106
, And the two-dimensional pattern of the reproduction light is detected by the CCD array 107. Then, the information such as the original image is reproduced by decoding the detected two-dimensional pattern of the reproduction light in a manner reverse to that at the time of recording.

[0007]

However, FIG.
In the conventional volume holography described with reference to FIG.
One unit of recording area (volume hologram) is formed in a block shape at a portion where 02 and the reference beam 104 overlap. Therefore, there is a problem that the recording area of one unit becomes relatively large, and it is difficult to perform high-density recording. In the conventional volume holography as described with reference to FIG. 26,
Information can be multiplex-recorded by changing the angle of the reference light. However, as the number of pieces of information to be multiplex-recorded increases, it becomes more difficult to separate each piece of information.

The present invention has been made in view of such a problem, and has as its object to record information at a higher density on an optical information recording medium on which information is recorded using holography. An object of the present invention is to provide an optical information recording apparatus and method and an optical information recording / reproducing apparatus and method.

[0009]

According to a first aspect of the present invention, there is provided an optical information recording apparatus, comprising: a recording light generating means for generating information light carrying information and a recording reference light; One of the information light and the recording reference light has a flat shape so that a recording area where information is recorded by an interference pattern due to interference with the recording reference light is formed in a layer shape, And a recording optical system for irradiating the information recording layer with the information light and the recording reference light so as to intersect with each other.

According to a seventh aspect of the present invention, there is provided an optical information recording apparatus, comprising: recording light generating means for generating information light carrying information and recording reference light; and interference between the information light and the recording reference light in the information recording layer. Recording light irradiating means for irradiating the information recording layer with the information light and the recording reference light so that an interference pattern is formed, and information is recorded in the information recording layer by the interference pattern, and Fixing a flat-shaped luminous flux for fixing information recorded by the interference pattern to the area where the interference pattern is formed in the information recording layer so that the recording area where the is fixed is formed in a layer shape. Fixing light irradiating means for irradiating the device with the application light so as to pass through a part of the area where the interference pattern is formed.

According to a twelfth aspect of the present invention, there is provided an optical information recording method, wherein an information beam carrying information and a recording reference beam are generated, and one of the information beam and the recording reference beam is made flat.
By irradiating the information recording layer with the information light and the recording reference light so as to intersect in the information recording layer, information is formed in the information recording layer by an interference pattern due to interference between the information light and the recording reference light. The recording area to be recorded is formed in layers.

In the optical information recording method according to the thirteenth aspect, an information light carrying information and a recording reference light are generated, and an interference pattern due to interference between the information light and the recording reference light is formed in the information recording layer. As described above, the information light and the recording-specific reference light are applied to the information recording layer, and flattened for fixing information recorded by the interference pattern to a region where the interference pattern is formed in the information recording layer. A recording beam in which information is recorded by the interference pattern and the information is fixed in the information recording layer by irradiating the fixing light of the luminous flux having a different shape so as to pass through a part of the region where the interference pattern is formed. In some cases, the regions are formed in layers.

An optical information recording / reproducing apparatus according to claim 14 is
A recording light generating means for generating an information light carrying information and a recording reference light, and a recording area in which information is recorded in an information recording layer by an interference pattern caused by interference between the information light and the recording reference light. One of the information light and the recording reference light has a flat shape so that the information light and the recording reference light are irradiated on the information recording layer so as to intersect in the information recording layer. A recording optical system for performing the recording operation, and irradiating the information recording layer with a reproduction reference light corresponding to the recording reference light at the time of recording, and reproducing the information generated from the information recording layer by irradiating the reproduction reference light. It comprises a reproducing optical system for collecting light and a detecting means for detecting the reproducing light collected by the reproducing optical system.

An optical information recording / reproducing apparatus according to claim 18 is
Recording light generating means for generating an information light carrying information and a recording reference light; and an information light and a recording medium such that an interference pattern is formed in the information recording layer by interference between the information light and the recording reference light. A recording light irradiating means for irradiating the information recording layer with reference light for use, and a recording area in which information is recorded by an interference pattern and the information is fixed is formed in a layer in the information recording layer. In a region where an interference pattern is formed in the information recording layer, fixing light of a flat light beam for fixing information recorded by the interference pattern is partially applied to the region where the interference pattern is formed. A fixing light irradiating unit for irradiating the recording medium with the reference light for reproduction corresponding to the reference light for recording at the time of recording and irradiating the reference light for reproduction with the information recording layer. Yo A reproducing optical system for collecting reproduction light generated from the information recording layer, in which a detecting means for detecting the collected reproduction light by the reproducing optical system.

The optical information recording / reproducing method according to claim 22 is
When recording information, an information light carrying information and a reference light for recording are generated, and one of the information light and the reference light for recording is formed into a flat shape, and the information light is crossed in the information recording layer. By irradiating the information recording layer with the reference light for recording, in the information recording layer, to form a layered recording area in which information is recorded by an interference pattern due to interference between the information light and the reference light for recording, At the time of reproducing information, the information recording layer is irradiated with the reproduction reference light corresponding to the recording reference light at the time of recording, and the reproduction light generated from the information recording layer by being irradiated with the reproduction reference light is collected. And
This is to detect the collected reproduction light.

The optical information recording / reproducing method according to claim 23,
At the time of information recording, an information light carrying information and a recording reference light are generated, and the information light and the recording reference light are formed such that an interference pattern between the information light and the recording reference light is formed in the information recording layer. The reference light is applied to the information recording layer, and fixing light of a flat light beam for fixing information recorded by the interference pattern is applied to an area where the interference pattern is formed in the information recording layer. By irradiating so as to pass through a part of the area where the interference pattern is formed, a recording area where the information is recorded by the interference pattern and the information is fixed is formed in the information recording layer in a layered manner. At the time of reproduction, the information recording layer is irradiated with a reproduction reference light corresponding to the recording reference light at the time of recording, and the reproduction light generated from the information recording layer by being irradiated with the reproduction reference light. Collected, and detects the collected reproduction light.

In the optical information recording apparatus according to the first aspect or the optical information recording method according to the twelfth aspect, one of the information light and the recording reference light has a flat shape and intersects in the information recording layer. The information light and the recording reference light are applied to the information recording layer so that a recording area in which information is recorded by an interference pattern due to interference between the information light and the recording reference light is formed in a layered manner. Formed.

In the optical information recording apparatus according to the seventh aspect or the optical information recording method according to the thirteenth aspect, the information is formed such that an interference pattern between the information light and the recording reference light is formed in the information recording layer. The information recording layer is irradiated with light and recording reference light, and a flat-shaped light flux for fixing information recorded by the interference pattern is formed in an area where the interference pattern is formed in the information recording layer. The fixing light is irradiated so as to pass through a part of the area where the interference pattern is formed, and a recording area where information is recorded by the interference pattern and the information is fixed is formed in a layer in the information recording layer. You.

In the optical information recording / reproducing apparatus according to the present invention or the optical information recording / reproducing method according to the present invention, at the time of recording information, one of the information light and the recording reference light has a flat shape. The information recording layer is irradiated with the information light and the recording reference light so as to intersect in the information recording layer, and information is formed in the information recording layer by an interference pattern due to interference between the information light and the recording reference light. A recording area to be recorded is formed in a layered manner, and when information is reproduced, the information recording layer is irradiated with reproduction reference light corresponding to the recording reference light at the time of recording, and reproduction light generated from the information recording layer is collected. And
Is detected.

In the optical information recording / reproducing apparatus according to the eighteenth aspect or the optical information recording / reproducing method according to the twenty-third aspect, when information is recorded, an interference pattern due to interference between the information light and the recording reference light is present in the information recording layer. The information light and the recording reference light are irradiated to the information recording layer so that the information recorded by the interference pattern is fixed to a region where the interference pattern is formed in the information recording layer so as to be formed. The fixing light of the flat light beam is irradiated so as to pass through a part of the area where the interference pattern is formed, and information is recorded and fixed by the interference pattern in the information recording layer. The recording area is formed in a layered manner, and when information is reproduced, the information recording layer is irradiated with reproduction reference light corresponding to the recording reference light at the time of recording, and reproduction light generated from the information recording layer is collected. It is, is detected.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, the configuration of the optical information recording medium according to the present embodiment will be described with reference to FIG. FIG.
FIG. 1 is an explanatory diagram showing a configuration of a pickup and an optical information recording medium in an optical information recording / reproducing apparatus according to a first embodiment of the present invention. Optical information recording medium 1 in the present embodiment
Using volume holography, information is recorded by an interference pattern due to interference between the information light carrying information and the recording reference light, and when the reproduction reference light is irradiated, the recorded information is , An information recording layer 2 for generating a reproduction light, a transparent substrate 3 provided on one side of the information recording layer 2, and a transparent substrate 3 provided on the other side of the information recording layer 2. It includes a positioning layer 4 and a transparent protective layer 5 provided outside the positioning layer 4. The entire optical information recording medium 1 is formed in a disk shape.

The information recording layer 2 is formed of a hologram material whose optical characteristics such as a refractive index, a dielectric constant, and a reflectivity change according to the intensity of light when the light is irradiated. As a hologram material, for example, Dupont
t) Photopolymers manufactured by the company
HRF-600 (product name) or the like is used.

The optical information recording medium 1 is provided with a plurality of address servo areas extending linearly in the radial direction at predetermined angular intervals. This address servo area corresponds to the positioning area in the present invention. In the optical information recording medium 1, a fan-shaped section between adjacent address / servo areas is a data area. On the surface of the positioning layer 4 on the protective layer 5 side in the address servo area, information for performing focus servo and tracking servo by a sampled servo method and address information are recorded in advance by emboss pits or the like. The focus servo can be performed based on light emitted from a pickup, which will be described later, and reflected by the reflective surface, with the boundary surface between the positioning layer 4 and the protective layer 5 as the reflective surface. For example, wobble pits can be used as information for performing the tracking servo.

Next, the configuration of the optical information recording / reproducing apparatus according to the present embodiment will be described with reference to FIG. In addition,
The optical information recording device according to the present embodiment is included in the optical information recording / reproducing device. This optical information recording / reproducing device 10
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 servo circuit 83 for controlling the spindle motor 82 so as to keep the rotation speed of the optical information recording medium 1 at a predetermined value. 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. A pickup 11 for detecting the reproduction light and reproducing the information recorded on the optical information recording medium 1; and a light input / output position of the pickup 11 can be moved in a radial direction of the optical information recording medium 1. And a driving device 84. Pickup 11
Is formed, for example, in an arm shape in which a light input / output unit rotates about a predetermined rotation axis. In this case, the driving device 84 is a device that rotates the pickup 11.

The optical information recording / reproducing device 10 further receives a focus error signal FE,
A detection circuit 85 for detecting the tracking error signal TE and the reproduction signal RF; and driving an actuator in the pickup 11 based on a focus error signal FE detected by the detection circuit 85 and a command from a controller described later. A focus servo circuit 86 for performing focus servo by moving the objective lens in the thickness direction of the optical information recording medium 1 and an actuator in the pickup 11 based on the tracking error signal TE detected by the detection circuit 85 to drive the objective lens Servo circuit 87 that moves the optical information recording medium 1 in the radial direction of the optical information recording medium 1 to perform tracking servo, and controls the driving device 84 based on the tracking error signal TE and a command from a controller described later to pick up the pickup 11
And a seek control circuit 88 for controlling a seek for moving the light input / output position in the radial direction of the optical information recording medium 1.

The optical information recording / reproducing apparatus 10 further decodes output data of a later-described CCD array in the pickup 11 to reproduce data recorded in a data area of the optical information recording medium 1, A signal processing circuit 89 that reproduces a basic clock and determines an address from a reproduction signal RF from the controller 10 and a controller 90 that controls the entire optical information recording / reproducing apparatus 10 are provided. The controller 90 receives the basic clock and address information output from the signal processing circuit 89 and controls the pickup 11, the spindle servo circuit 83, the seek control circuit 88, and the like. The spindle servo circuit 83 receives the basic clock output from the signal processing circuit 89.

Detection circuit 85, focus servo circuit 8
6, the tracking servo circuit 87 and the seek control circuit 88 correspond to the position control means in the present invention.

Next, referring to FIG.
Will be described. The pickup 11 is a solid immersion lens (hereinafter, referred to as SIL) 12A arranged to face the surface of the optical information recording medium 1 on the transparent substrate 3 side when the optical information recording medium 1 is fixed to the spindle 81. The objective lens 13A provided on the opposite side of the optical information recording medium 1 in the SIL 12A, and the surface of the optical information recording medium 1 on the protective layer 5 side when the optical information recording medium 1 is fixed to the spindle 81. SIL 12B arranged to face, and objective lens 13B provided on the opposite side of optical information recording medium 1 in SIL 12B
And In the present embodiment, the objective lens 13A
And the objective lens 13B are arranged such that their optical axes are on the same line, and these optical axes make an angle of 60 ° with the surface of the optical information recording medium 1.

The pickup 11 further includes the objective lens 1
An actuator 14A that can move 3A in the optical axis direction and the radial direction of the optical information recording medium 1 and an actuator 14B that can move the objective lens 13B in the optical axis direction and the radial direction of the optical information recording medium 1 are provided.

The pickup 11 further includes the objective lens 1
3A, a spatial light modulator 15, a beam splitter 16, a collimator lens 17, a laser coupler 20, and an optical information recording medium in the objective lens 13B, which are disposed in this order on the opposite side of the optical information recording medium 1 from the objective lens 13A side. 1 and a CCD array 19 provided on the opposite side.

The spatial light modulator 15 has a large number of pixels arranged in a lattice, and each pixel has a light transmitting state (hereinafter also referred to as ON) and a light blocking state (hereinafter also referred to as OFF). By selecting (1) and (2), the light can be spatially modulated by the light intensity. As the spatial light modulator 15, for example, a liquid crystal display element can be used. The control of the spatial light modulator 15 is performed by a drive circuit (not shown) under the control of the controller 90 in FIG. In addition, CCD array 1
9 has a large number of pixels arranged in a grid.

The beam splitter 16 has a semi-reflective surface 16a whose normal direction is inclined by 45 ° with respect to the optical axis direction between the collimator lens 17 and the spatial light modulator 15. And the collimator lens 1
Part of the amount of light incident on the beam splitter 16 from the side 7 is transmitted through the semi-reflective surface 16a and enters the spatial light modulator 15, and part of the amount of light is reflected on the semi-reflective surface 16a. ing.

The pickup 11 is further disposed in the traveling direction of the light reflected by the semi-reflective surface 16a of the light incident on the beam splitter 16 from the collimator lens 17 side, and is a total reflection surface parallel to the semi-reflective surface 16a. A prism 51 having a total reflection surface 52a disposed in the traveling direction of light reflected by the total reflection surface 51a of the prism 51, and having a total reflection surface 52a orthogonal to the total reflection surface 51a; A convex lens 53, a concave lens 54, and a cylindrical lens 55 are provided in this order from the prism 52 side in the traveling direction of the reflected light. The light emitted from the cylindrical lens 55 has its center (optical axis)
Is irradiated on the information recording layer 2 so as to be orthogonal to the center (optical axis) of the light emitted from the objective lens 13A in the information recording layer 2. Therefore, the light emitted from the cylindrical lens 55 is applied to the optical information recording medium 1 so as to form an angle of 30 ° with the surface of the optical information recording medium 1.

In FIG. 1, reference numeral 57 indicates the rotation direction of the optical information recording medium 1, and reference numeral 58 indicates the pickup 1.
1 shows a seek direction.

In the pickup 11 shown in FIG. 1, the laser coupler 20 emits a laser beam, which is converted into a parallel light beam by the collimator lens 17, enters the beam splitter 16, and partially reflects the light amount. The light passes through the surface 16a, and a part of the light amount is reflected by the semi-reflective surface 16a. The light transmitted through the semi-reflective surface 16a passes through the spatial light modulator 15, is collected by the objective lens 13A, passes through the SIL 12A, and irradiates the optical information recording medium 1. The light converges on the interface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter.

On the other hand, the light reflected by the semi-reflective surface 16a is
The light is sequentially reflected by the total reflection surface 51a of the prism 51 and the total reflection surface 52a of the prism 52, and the convex lens 53 and the concave lens 54
, So that the diameter of the light beam is reduced. The light emitted from the concave lens 54 is transmitted to the cylindrical lens 5.
By 5, the light beam is converged only in the optical axis direction of the objective lens 13 </ b> A to be a flat light beam, passes through the SIL 12 </ b> A, and irradiates the optical information recording medium 1.

The light from the objective lens 13A and the light from the cylindrical lens 55 intersect in the information recording layer 2 so that the centers of the respective lights are orthogonal. Further, the light from the cylindrical lens 55 side is separated from the center of the light from the objective lens 13A side by the cylindrical lens 55.
It is designed to be thinnest on a straight line perpendicular to the plane of the drawing passing through a point where the centers of light from the sides intersect.

At the time of recording information, the light from the objective lens 13A side becomes the information light, and the light from the cylindrical lens 55 side becomes the recording reference light, and these information light and the recording reference light are stored in the information recording layer 2. A recording area 59 in which information is recorded is formed in a layered manner by an interference pattern due to interference with the recording medium. This recording area 59 has a cone,
It has a disk-like shape formed by slicing in the direction perpendicular to the central axis.

Light traveling from the optical information recording medium 1 toward the objective lens 13A sequentially passes through the objective lens 13A and the spatial light modulator 15, and a part of the light amount passes through the semi-reflective surface 16a of the beam splitter 16, and The light is condensed by the lens 17 and enters the laser coupler 20.

The light traveling from the optical information recording medium 1 toward the objective lens 13B is converted into a parallel light beam by the objective lens 13B and enters the CCD array 19.
At the time of reproducing information, the light from the cylindrical lens 55 side becomes the reference light for reproduction, and the reference light for reproduction is applied to the recording area 59 to generate the reproduction light from the recording area 59. Through the lens 13B, C
The light enters the CD array 19.

Here, referring to FIG. 2, SIL12A,
12B will be described in detail. First, SIL12A
The surface of the optical information recording medium 1 on the transparent substrate 3 side is formed flat. The surface of the SIL 12A opposite to the transparent substrate 3 has two spherical portions 12Aa and 12Ab. The spherical portion 12Aa is formed at a position where light from the objective lens 13A side is incident, and is formed in a spherical shape centering on a point 61 where light from the objective lens 13A side has the smallest diameter. The spherical portion 12Ab is formed at a position where light from the side of the cylindrical lens 55 is incident, and the center of the light from the side of the objective lens 13A and the cylindrical lens 5A.
It is formed in a spherical shape centered on a point 62 where the centers of light from the 5 side intersect. Also, the refractive index of SIL12A is
It is substantially equal to the refractive index of the transparent substrate 3.

The light from the objective lens 13A side is SIL1
The light is perpendicularly incident on the spherical portion 12Aa of 2A, travels without being refracted at the spherical portion 12Aa, and converges at the point 61 to have the smallest diameter. Cylindrical lens 5
The light from the fifth side is perpendicularly incident on the spherical portion 12Ab of the SIL 12A, travels without being refracted by the spherical portion 12Ab, and becomes thinnest on a straight line passing through the point 62 in a direction perpendicular to the paper surface. Converge.

In this embodiment, since the light from the objective lens 13A and the light from the cylindrical lens 55 are made to enter the optical information recording medium 1 from oblique directions, the SIL 12A is not provided. When these lights pass through the optical information recording medium 1, aberrations occur in these lights. In the present embodiment, since the SIL 12A is provided, the light from the objective lens 13A side and the light from the cylindrical lens 55 side are respectively perpendicularly incident on the SIL 12A, so that the aberration of these lights can be significantly reduced. Can be.

In the SIL 12B, the surface on the protective layer 5 side of the optical information recording medium 1 is formed flat. The surface of the SIL 12B opposite to the protective layer 5 is formed in a spherical shape centered on a point 61 where light from the objective lens 13A has the smallest diameter. The refractive index of the SIL 12B is substantially equal to the refractive index of the protective layer 5.

At the time of reproduction, reproduction light generated in the recording area 59 passes through the SIL 12B and enters the objective lens 13B. Therefore, in the present embodiment, the provision of the SIL 12B can significantly reduce the aberration of the reproduction light.

FIG. 3 is a sectional view showing an example of a support mechanism of the SILs 12A and 12B. In this example, the objective lens 1
3A is supported by the support member 91. On the SIL 12A side of the objective lens 13A, a correction lens 92 for correcting optical characteristics such as aberration is provided as necessary, and the correction lens 92 is also supported by a support member 91. A magnet 95 constituting a part of the actuator 14A is attached to the outer peripheral side of the support member 91. Around this magnet 95,
A coil 96 constituting a part of the actuator 14A is provided at a predetermined interval from the magnet 95. A slider 94 is attached to the optical information recording medium 1 side of the support member 91 via a suspension 93. The SIL 12A is supported by the slider 94. The slider 94 slides on the transparent substrate 3 of the optical information recording medium 1. The slider 94
Is provided with an opening 94a in a portion through which light from the objective lens 13A passes, and an opening 94b in a portion through which light from the cylindrical lens 55 passes.

On the other hand, the SIL 12B is supported by a slider 97. The slider 97 slides on the protective layer 5 of the optical information recording medium 1. Slider 97
Is attached to a support member 99 via a suspension 98. Although not shown, the objective lens 13B is attached to the support member 99. The support member 9
The configuration around 9 is similar to the configuration around the support member 91.

The support members 91 and 99 can be moved close to and away from the optical information recording medium 1 by a drive mechanism (not shown) so that the optical information recording medium 1 can be replaced.

FIG. 4 is a side view showing another example of the support mechanism of the SILs 12A and 12B. In this example, SIL12
A and 12B are supported by flying head type support members 61 and 62, respectively. Support member 61,
Numeral 62 floats so as to face the optical information recording medium 1 with a predetermined air gap opened as the optical information recording medium 1 rotates. Also in this example, the support members 61 and 62 can be moved toward and away from the optical information recording medium 1 by a drive mechanism (not shown) so that the optical information recording medium 1 can be replaced.

FIG. 6 is a perspective view showing the structure of the laser coupler 20 in FIG. 1, and FIG. 7 is a side view of the laser coupler 20. As shown in these figures, the laser coupler 20
Semiconductor substrate 2 on which photodetectors 25 and 26 are formed
1 and a prism 22 arranged on the semiconductor substrate 21 so as to cover the photodetectors 25 and 26 and bonded to the semiconductor substrate 21 at a position different from the position where the photodetectors 25 and 26 are formed on the semiconductor substrate 21. The semiconductor device includes a semiconductor element 23 arranged and bonded on a semiconductor substrate 21 and a semiconductor laser 24 bonded on the semiconductor element 23. The semiconductor laser 24 emits forward laser light in the horizontal direction toward the prism 22 and emits backward laser light in a direction opposite to the forward laser light. Semiconductor laser 2 of prism 22
On the side of the semiconductor laser 2, a slope is formed.
4 reflects part of the forward laser light from the semiconductor substrate 2
1 and a semi-reflective surface 22a that transmits a part of the return light from the optical information recording medium 1. The upper surface of the prism 22 is a total reflection surface 22b that totally reflects light passing through the prism 22, as shown in FIG. In the semiconductor element 23, a photodetector 27 that receives a backward laser beam from the semiconductor laser 24 is formed. The output signal of the photodetector 27 is used to automatically adjust the output of the semiconductor laser 24. Various amplifiers and other electronic components are built in the semiconductor substrate 21. The semiconductor element 23 has built-in electronic components such as an amplifier for driving the semiconductor laser 24.

The laser coupler 20 shown in FIGS. 6 and 7
1, a part of the forward laser light from the semiconductor laser 24 is reflected by the semi-reflective surface 22a of the prism 22, and is incident on the collimator lens 17 in FIG. A part of the return light from the optical information recording medium 1 collected by the collimator lens 17 passes through the semi-reflective surface 22a of the prism 22, and is guided into the prism 22,
It is directed to the photodetector 25. A semi-reflective film is formed on the photodetector 25, and a part of the light guided into the prism 22 passes through the semi-reflective film on the photodetector 25 and is incident on the photodetector 25, and the other part is a photodetector. The light is reflected by the semi-reflective film on the surface 25, further reflected by the total reflection surface 22 b of the prism 22, and incident on the photodetector 26.

Here, as shown in FIG.
The light guided into the light source 2 is once converged so as to have the smallest diameter in the middle of the optical path between the photodetectors 25 and 26. In a focused state where the light from the laser coupler 20 converges on the boundary between the positioning layer 4 and the protective layer 5 in the optical information recording medium 1 so as to have the smallest diameter, the diameter of the light incident on the photodetectors 25 and 26 Are equal to each other, and when they are out of the in-focus state, the diameters of the light incident on the photodetectors 25 and 26 are different. Since the changes in the diameter of the light incident on the photodetectors 25 and 26 are in opposite directions, a focus error signal can be obtained by detecting a signal corresponding to the change in the diameter of the light incident on the photodetectors 25 and 26. As shown in FIG. 6, the photodetectors 25,
Reference numeral 26 has a light receiving unit divided into three parts. A1, C1, and B light receiving sections in the photodetector 25
1. The light receiving units in the photodetector 26 are A2 and C
2, B2. C1 and C2 are A1 and B1 respectively.
And a light receiving portion at the center between A2 and B2. The dividing line between the light receiving sections is arranged so as to be parallel to the direction corresponding to the track direction in the optical information recording medium 1. Accordingly, a tracking error signal can be obtained by the push-pull method from the difference between the outputs between the light receiving units A1 and B1 and between the outputs between A2 and B2.

The output of the semiconductor laser 24 in the laser coupler 20 is controlled by a drive circuit (not shown) under the control of the controller 90 shown in FIG.

FIG. 8 shows a detection circuit 85 for detecting a focus error signal, a tracking error signal and a reproduction signal based on the outputs of the photodetectors 25 and 26.
FIG. 3 is a block diagram showing the configuration of FIG. This detection circuit 85
An adder 31 for adding the respective outputs of the light receiving sections A1 and B1 of the photodetector 25, a gain adjusting amplifier 32 for adjusting the gain of the output of the adder 31, and a gain for adjusting the gain of the output of the light receiving section C1 of the photodetector 25. Adjustment amplifier 33
And a subtractor 34 for calculating the difference between the output of the gain adjustment amplifier 32 and the output of the gain adjustment amplifier 33;
And a gain adjustment amplifier 36 for adjusting the gain of the output of the adder 35, a gain adjustment amplifier 37 for adjusting the gain of the output of the light receiving section C2 of the photodetector 26, and an output of the gain adjustment amplifier 36 and the gain adjustment amplifier 37. A subtractor 38 for calculating a difference between the output and a subtractor 39 for calculating a difference between an output of the subtractor 34 and an output of the subtractor 38 to generate a focus error signal FE.

The detection circuit 85 further includes a subtractor 40 for calculating the difference between the output of the light receiving section A1 of the photodetector 25 and the output of the light receiving section B1, and the light receiving section A of the photodetector 26.
Subtractor 4 for calculating the difference between the output of the light receiving section B2 and the output of the light receiving section B2
1 and a subtractor 4 that calculates the difference between the output of the subtractor 40 and the output of the subtractor 41 to generate the tracking error signal TE.
2 is provided. The detection circuit 85 further includes the adder 31
An adder 43 for adding the output of the light receiving unit C1 to the output of
An adder 44 that adds the output of the adder 35 and the output of the light receiving unit C2, and an adder 45 that adds the output of the adder 43 and the output of the adder 44 to generate a reproduction signal RF. .

In this embodiment, the reproduction signal RF
Is a signal obtained by reproducing information recorded in the address servo area of the optical information recording medium 1. The signal processing circuit 89 uses a PLL (phase synchronization loop) circuit to synchronize the phase of the basic clock with the phase of the reproduction signal RF.

Next, the operation of the optical information recording / reproducing apparatus according to the present embodiment will be described in order of servo, recording, and reproduction. The following description also serves as an explanation of the optical information recording method and the optical information recording / reproducing method according to the present embodiment. Note that the optical information recording medium 1 is controlled by the spindle motor 82 to be controlled so as to maintain a specified number of rotations in any of servo, recording, and reproduction.

First, the operation at the time of servo will be described.
At the time of servo, all the pixels of the spatial light modulator 15 are turned on. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. The controller 90 predicts the timing at which the output light of the objective lens 13A passes through the address servo area based on the basic clock reproduced from the reproduction signal RF, and outputs the output light of the objective lens 13A through the address servo area. During the passage, the above settings are used.

At the time of servo operation, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 17, enters the beam splitter 16, a part of the light amount passes through the semi-reflective surface 16a, and a part of the light amount Is a semi-reflective surface 1
6a. The light transmitted through the semi-reflective surface 16a passes through the spatial light modulator 15, is condensed by the objective lens 13A, passes through the SIL 12A, and irradiates the optical information recording medium 1. This light converges on the boundary surface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter, and is reflected at the boundary surface between the positioning layer 4 and the protective layer 5. The light is modulated by the pits and returns to the objective lens 13A side. This return light
The light is converted into a parallel light beam by the objective lens 13A,
, And enters the beam splitter 16, and a part of the light amount passes through the semi-reflective surface 16a. The return light transmitted through the semi-reflective surface 16a is collected by the collimator lens 17, enters the laser coupler 20, and is detected by the photodetectors 25 and 26. Then, based on the outputs of the photodetectors 25 and 26, the detection circuit 85 shown in FIG. 8 generates a focus error signal FE, a tracking error signal TE, and a reproduction signal RF. While the tracking servo is performed, reproduction of the basic clock and determination of the address are performed.

In the present embodiment, the actuators 14A and 14B are arranged so that the convergence position of the light passing through each of the objective lenses 13A and 13B (the position where the luminous flux has the smallest diameter) is the same as that of the positioning layer 4 and the protective layer 5. The focus servo circuit 86 is controlled so as to interlock so as to be on the boundary surface.

Next, the operation at the time of recording will be described. During recording, the spatial light modulator 15 is turned on or off for each pixel according to the information to be recorded. Laser coupler 2
The output of the outgoing light of 0 is pulsed to a high output for recording based on the basic clock reproduced from the reproduction signal RF. The controller 90 predicts the timing at which the output light of the objective lens 13A passes through the data area based on the basic clock reproduced from the reproduction signal RF.
Make the above settings. While the light emitted from the objective lens 13A passes through the data area, focus servo and tracking servo are not performed, and the objective lenses 13A and 13B are fixed.

At the time of recording, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 17 and is incident on the beam splitter 16. Is a semi-reflective surface 16
reflected at a. The light transmitted through the semi-reflective surface 16a passes through the spatial light modulator 15 and is spatially modulated according to the information to be recorded to become information light. This information light is transmitted through the objective lens 1
The light is condensed by 3A, passes through the SIL 12A, and irradiates the optical information recording medium 1. The information light is applied to the optical information recording medium 1 so that the center thereof forms an angle of 60 ° with the surface of the optical information recording medium 1.

On the other hand, the light reflected by the semi-reflective surface 16a is
The light becomes recording reference light, is sequentially reflected by the total reflection surface 51a of the prism 51 and the total reflection surface 52a of the prism 52, passes through the convex lens 53 and the concave lens 54 in order, and reduces the diameter of the light beam. 1
The optical information recording medium 1 is converged only in the optical axis direction of the optical information recording medium 3A and passes through the SIL 12A.
Is irradiated. The recording reference light is applied to the optical information recording medium 1 such that the center thereof forms an angle of 30 ° with the surface of the optical information recording medium 1.

The information light from the objective lens 13A and the recording reference light from the cylindrical lens 55 intersect in the information recording layer 2 such that the centers of the light are orthogonal. Then, at a portion where the information light and the recording reference light intersect,
When an interference pattern due to the interference of these lights is formed and the output of the emitted light from the laser coupler 20 becomes high,
An interference pattern by the information light and the recording reference light is volumetrically recorded in the information recording layer 2, and a recording region 59 composed of a transmission type (Fresnel type) volume hologram is formed in a layer. This recording area 59 has a disk shape.

FIG. 9 shows the information recording layer 2 of the optical information recording medium 1.
Is a conceptual representation of a recording area 59 formed on the recording medium. In this figure, reference numeral 63 indicates an address servo area, and reference numeral 64 indicates a data area. Reference numeral 65 indicates a track. In the example shown in FIG. 9, five recording areas 59 are formed at equal intervals in the data area 64 between two adjacent address / servo areas 63. Further, an emboss pit 66 is formed in the address servo area 63. In FIG. 9, the recording area 59 and the emboss pit 66 are considerably larger than actual.

FIG. 10 shows a recording area 59 in the information recording layer 2 of the optical information recording medium 1. In addition,
FIG. 2 shows a cross section of the information recording layer 2 along the radial direction of the optical information recording medium 1. As shown in this figure, a plurality of layered recording areas 59 are formed in the information recording layer 2 so as to be stacked. Each recording area 59 is formed such that its normal direction is inclined by 30 ° with respect to the normal direction of the information recording layer 2.

In this embodiment, the positions of the information light and the recording reference light with respect to the optical information recording medium 1 are adjusted so that a plurality of recording areas 59 are formed in the information recording layer 2 without overlapping each other. Take control.

Next, the operation at the time of reproduction will be described. At the time of reproduction, all the pixels of the spatial light modulator 15 are turned off. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. The controller 90 predicts the timing at which the output light of the objective lens 13A passes through the data area based on the basic clock reproduced from the reproduction signal RF. Make the above settings. While the light emitted from the objective lens 13A passes through the data area, focus servo and tracking servo are not performed.
3A and 13B are fixed.

At the time of reproduction, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 17, enters the beam splitter 16, a part of the light amount passes through the semi-reflective surface 16a, and a part of the light amount Is a semi-reflective surface 16
reflected at a. Light transmitted through the semi-reflective surface 16a is blocked by the spatial light modulator 15. On the other hand, the semi-reflective surface 16
The light reflected by a becomes the reference light for reproduction corresponding to the reference light for recording, is sequentially reflected by the total reflection surface 51a of the prism 51 and the total reflection surface 52a of the prism 52, and sequentially passes through the convex lens 53 and the concave lens 54. The diameter of the light beam is reduced, and the light beam is converged only in the optical axis direction of the objective lens 13A into a flat light beam by the cylindrical lens 55. The light beam passes through the SIL 12A and is irradiated onto the optical information recording medium 1.

When the recording area 59 in the information recording layer 2 is irradiated with reproduction reference light, reproduction light is generated from the recording area 59. This reproduction light is transmitted to the positioning layer 4 and the protective layer 5.
After converging so as to have the smallest diameter on the boundary surface with the light, the light is emitted from the protective layer 5 side to the outside of the optical information recording medium 1 while diffusing. This reproduction light passes through the SIL 12B, enters the CCD array 19 via the objective lens 13B. In this manner, on the CCD array 19, only the portion corresponding to the pixel that was turned on in the spatial light modulator 15 at the time of recording is illuminated brightly, and its two-dimensional pattern is detected by the CCD array 19, and information is reproduced. Will be

At the time of reproduction, the reference light for reproduction may be continuously applied to the optical information recording medium 1 or may be applied intermittently in synchronization with the timing at which the recording area 59 passes. You may. In this case, the timing of irradiating the reproduction reference light is determined by the laser coupler 20 during recording.
The timing is the same as the timing at which the output of the outgoing light is made high, and is determined based on the basic clock. in this way,
When the reproduction reference light is intermittently radiated, the SN ratio can be improved and the temperature rise of the optical information recording medium 1 can be suppressed as compared with the case of continuously irradiating the reproduction reference light.

When the two-dimensional pattern of the reproduction light is detected by the CCD array 19, the reproduction light and the CCD
Position the array 19 correctly or use the CCD array 1
It is necessary to recognize the reference position in the reproduction light pattern from the 9 detection data. In the present embodiment, the latter is adopted. Here, referring to FIG. 11 and FIG.
A method for recognizing the reference position in the pattern of the reproduction light from the detection data of the array 19 will be described. As shown in FIG. 11, the aperture of the pickup 11 is
The light is divided into a plurality of pixels 72 by the spatial light modulator 15. The pixel 72 is the minimum unit of the two-dimensional pattern data. In this embodiment, one pixel of digital data “0” or “1” is represented by two pixels, and one of two pixels corresponding to one-bit information is turned on and the other is turned off. If both pixels are on or both off, error data is generated. Expressing 1-bit digital data with two pixels as described above has advantages such as an increase in data detection accuracy by differential detection. FIG. 12A shows 2 bits corresponding to 1-bit digital data.
This represents a set 73 of pixels. The area where the set 73 exists is hereinafter referred to as a data area. In the present embodiment, the reference light information indicating the reference position in the reproduction light pattern is included in the information light by utilizing the fact that error data is generated when both pixels are on or both off. . That is, as shown in FIG.
Cross-shaped area 74 with a width of 2 pixels passing through the center of the aperture
In addition, the error data is intentionally arranged in a predetermined pattern. This error data pattern is hereinafter referred to as a tracking pixel pattern. This tracking pixel pattern becomes reference position information. In FIG. 12B, reference numeral 75 denotes an ON pixel, and reference numeral 76 denotes an OFF pixel. In addition, the area 77 of four pixels at the center is always turned off.

When the tracking pixel pattern and the pattern corresponding to the data to be recorded are combined, FIG.
A two-dimensional pattern as shown in FIG. In the present embodiment, among the regions other than the data region, the upper half in the figure is turned off and the lower half is turned on, and pixels in the data region that are in contact with the region other than the data region are other than the data region. It is turned on when the state opposite to the area, that is, the area other than the data area is off, and turned off when the area other than the data area is on. This allows
From the detection data of the CCD array 19, it is possible to detect the boundary of the data area more clearly.

At the time of recording, an interference pattern between the information light spatially modulated according to the two-dimensional pattern as shown in FIG. 13A and the recording reference light is recorded on the information recording layer 2.
As shown in FIG. 13B, the pattern of the reproduction light obtained at the time of reproduction has a lower contrast and a lower SN ratio than at the time of recording. At the time of reproduction, the pattern of the reproduction light as shown in FIG. 13B is detected by the CCD array 19 to determine the data. At this time, the tracking pixel pattern is recognized and the position is used as a reference position. Is determined.

FIG. 14A conceptually shows the contents of the data determined from the pattern of the reproduction light. In the figure, areas denoted by reference numerals such as A-1-1 represent 1-bit data. In the present embodiment, the data area is
By dividing the area into the cross-shaped area 74 in which the tracking pixel pattern is recorded, four areas 78A and 78 are formed.
B, 78C and 78D. And FIG.
As shown in (b), the diagonal areas 78A and 78C are combined to form a rectangular area, and similarly, the diagonal areas 78B and 78C are formed.
A rectangular area is formed by combining 78D, and an ECC table is formed by arranging two rectangular areas vertically. The ECC table is a data table formed by adding an error correction code (ECC) such as a CRC (cyclic redundancy check) code to data to be recorded. FIG. 14B shows an example of an ECC table of n rows and m columns, and other arrangements can be freely designed. The data array shown in FIG. 14A uses a part of the ECC table shown in FIG. 14B, and the data array shown in FIG.
Portions of the CC table that are not used in the data array shown in FIG. 14A have a constant value regardless of the data content. At the time of recording, E as shown in FIG.
The CC table is decomposed into four areas 78A, 78B, 78C and 78D as shown in FIG. 14A and recorded on the optical information recording medium 1, and at the time of reproduction, an array as shown in FIG. The data of FIG.
The ECC table as shown in FIG.
Data is reproduced by performing error correction based on the CC table.

The recognition of the reference position (tracking pixel pattern) and the error correction in the reproduction light pattern 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 of the present embodiment, the layered recording area 59 is formed in the information recording layer 2 of the optical information recording medium 1. This makes it possible to record information at a higher density than when a block-shaped recording area is formed in the information recording layer. Further, according to the present embodiment, since information can be recorded at high density without performing multiplex recording, it is possible to easily separate each information while realizing high density of information. become.

Further, according to the optical information recording / reproducing apparatus 10 of the present embodiment, the positions of the information light, the recording reference light, and the reproduction reference light are controlled using the information recorded on the positioning layer 3. As a result, the positioning of these lights can be performed with high accuracy, and as a result, the removability is good, the random access is easy, and the recording capacity and the transfer rate can be increased.

Further, according to the optical information recording / reproducing apparatus 10 according to the present embodiment, the information recording layer 2 is irradiated with the information light and the recording reference light such that their centers are orthogonal to each other. Therefore, the pitch of the interference fringes can be reduced, and higher density recording becomes possible.

According to the optical information recording / reproducing apparatus 10 of the present embodiment, the SIL 12A through which the information light, the recording reference light and the reproduction reference light pass, and the SIL 12A through which the reproduction light passes.
The provision of the IL 12B makes it possible to significantly reduce aberrations generated in the information light, the recording reference light, the reproduction reference light, and the reproduction light.

Further, according to the present embodiment, the reference position information indicating the reference position in the reproduction light pattern is included in the information light, so that the reproduction light pattern can be easily recognized.

Hereinafter, some modifications of the present embodiment will be described. First, in the above-described embodiment, an example has been given in which address information and the like are recorded in advance in the positioning layer 4 in the address servo area using embossed pits. And selectively irradiating the optical information recording medium with a high-power laser beam in a portion near one surface of the information recording layer 2 in the address servo area to select the refractive index of the portion. The format may be performed by recording address information or the like by dynamically changing the format.

Instead of recording address information and the like in the address servo area of the optical information recording medium 1 by emboss pits, a predetermined pattern is previously formed in the same manner as in the recording using holography in the data area. May be recorded as a hologram. FIG.
The optical information recording medium 1 in which a hologram 67 representing address information and the like is recorded in a servo area 63 is conceptually shown.

Thus, the address servo area 63
In the case where a hologram 67 representing address information or the like is recorded, the pickup 11 is set in the same state as during reproduction during servo operation, and the pattern of the reproduction light generated from the hologram 67 is detected by the CCD array 19. . In this case, the basic clock and address are
It can be obtained directly from the detection data of the array 19. The tracking error signal can be obtained from information on the position of the pattern of the reproduction light on the CCD array 19. Also,
The focus servo controls the objective lens 13 so that the contrast of the reproduction pattern on the CCD array 19 is maximized.
A and 13B can be driven. Also,
At the time of reproduction, the focus servo can be performed by driving the objective lenses 13A and 13B so that the contrast of the reproduction pattern on the CCD array 19 is maximized.

As described above, when address information and the like are recorded as hologram 67, hologram 67
Since it is necessary to quickly process the reproduction light from the CCD, a smart optical sensor in which a MOS type solid-state imaging device and a signal processing circuit are integrated on a single chip instead of the CCD array 19 (for example, the document “O plus”) E, 1996
September, No. 202, pages 93-99 ". )
May be used. Since this smart optical sensor has a high transfer rate and a high-speed calculation function, high-speed reproduction can be performed by using this smart optical sensor. For example, reproduction at a transfer rate of the order of G bits / second can be performed. Becomes possible.

Further, using an optical information recording medium on which a hologram 67 representing address information or the like is not recorded in advance, formatting is performed on the optical information recording medium to record the hologram 67 representing address information or the like. Is also good.

In the embodiment, as shown in FIG. 1, the information light emitting portion (objective lens 13A) and the recording reference light emitting portion (cylindrical lens 55) are arranged along the seek direction 58. However, as shown in FIG. 16, the information light emitting portion (objective lens 13A) and the recording reference light emitting portion (cylindrical lens 55) may be arranged along the track direction 68 as shown in FIG. Good. In this case,
In the cross section of the information recording layer 2 along the track direction 68, the recording area 59 is arranged as shown in FIG.

Further, in the embodiment, as shown in FIG. 1, the center of the information light is
An example of irradiating the optical information recording medium 1 with the information light and the recording reference light such that the recording light forms an angle of 30 ° and the center of the recording reference light forms an angle of 30 ° with the surface of the optical information recording medium 1. Although described above, the angle formed by the center of the information light and the center of the recording reference light with respect to the surface of the optical information recording medium 1 is not limited to the above example. FIG. 17 shows another example in which the center of the information beam forms an angle of 45 ° with respect to the surface of the optical information recording medium 1 and the center of the recording reference beam forms 90 ° with respect to the surface of the optical information recording medium 1. 2 shows a configuration of a pickup 70 that irradiates the optical information recording medium 1 with the information light and the recording reference light so as to form an angle. In the pickup 70 shown in this figure, the objective lens 13A and the objective lens 13B have their optical axes on the same line, and these optical axes make an angle of 45 ° with the surface of the optical information recording medium 1. Are arranged as follows.
In the pickup 70, the convex lens 53, the concave lens 54, and the cylindrical lens 55 are arranged such that their optical axes are perpendicular to the surface of the optical information recording medium 1. In the pickup 70, a mirror 71 is provided instead of the prisms 51 and 52 in FIG.
The light reflected on the semi-reflective surface 16 a of the beam splitter 16 is totally reflected by the mirror 71 and guided to the convex lens 53. Other configurations of the pickup 70 are the same as those of the pickup 11 shown in FIG.

When the pickup 70 shown in FIG. 17 is used, a layered recording area 59 is provided in the information recording layer 2.
Are formed perpendicular to the surface of the optical information recording medium 1.

Next, a second embodiment of the present invention will be described. The present embodiment is an example in which a reflection type hologram is formed. In this embodiment, the same optical information recording medium 1 as in the first embodiment is used.
The overall configuration of the optical information recording / reproducing apparatus according to the present embodiment is the same as that of FIG. 5 except that the configuration of the pickup is different.

FIG. 18 is an explanatory diagram showing the configuration of a pickup in the optical information recording / reproducing apparatus according to the present embodiment. Hereinafter, the same members as those in the pickup shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.
The pickup 111 according to the present embodiment includes an SIL 12A arranged so as to face the surface of the optical information recording medium 1 on the side of the transparent substrate 3 when the optical information recording medium 1 is fixed to the spindle 81, and the light in the SIL 12A. Objective lens 113A provided on the side opposite to information recording medium 1
And the SIL 12B disposed so as to face the surface of the optical information recording medium 1 on the protective layer 5 side when the optical information recording medium 1 is fixed to the spindle 81, and the optical information recording medium 1 in the SIL 12B is opposite to the SIL 12B. And an objective lens 113B provided on the side. In the present embodiment, the objective lens 113A and the objective lens 113B are arranged such that their optical axes are on the same line and that these optical axes make an angle of 60 ° with the surface of the optical information recording medium 1. Have been.

The pickup 111 further includes an actuator 114A capable of moving the objective lens 113A in the optical axis direction and the radial direction of the optical information recording medium 1, and an objective lens 1A.
13B is provided with an actuator 114B that is movable in the optical axis direction and the radial direction of the optical information recording medium 1.

The pickup 111 further includes a spatial light modulator 1 disposed on the opposite side of the objective lens 113B from the optical information recording medium 1 in order from the objective lens 113B side.
5, a beam splitter 116, a collimator lens 17, a laser coupler 20, and a CCD array 19 provided on the side of the objective lens 113A opposite to the optical information recording medium 1.

The beam splitter 116 has a semi-reflective surface 116a whose normal direction is inclined by 45 ° with respect to the optical axis direction between the collimator lens 17 and the spatial light modulator 15. A part of the light incident on the beam splitter 116 from the collimator lens 17 is transmitted through the semi-reflective surface 116a, and the spatial light modulator 1
5 and a part of the light amount is reflected by the semi-reflective surface 116a.

The pickup 111 is further disposed in the traveling direction of the light reflected by the semi-reflective surface 116a of the light incident on the beam splitter 116 from the collimator lens 17 side, and is a total reflection surface parallel to the semi-reflective surface 116a. A prism 121 having a total reflection surface 122a disposed in the traveling direction of light reflected by the total reflection surface 121a of the prism 121, and having a total reflection surface 122a orthogonal to the total reflection surface 121a; A convex lens 53, a concave lens 54, and a cylindrical lens 55 are sequentially provided from the prism 122 side in the traveling direction of the reflected light. The light emitted from the cylindrical lens 55 is applied to the information recording layer 2 such that the center (optical axis) of the light is orthogonal to the center (optical axis) of the light emitted from the objective lens 113B in the information recording layer 2. Irradiation is carried out. Therefore, the cylindrical lens 5
The light emitted from the optical information recording medium 1 is applied to the optical information recording medium 1 so as to form an angle of 30 ° with the surface of the optical information recording medium 1.

Pickup 111 in the present embodiment
Then, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 17, enters the beam splitter 116, and a part of the light amount is partially reflected by the semi-reflective surface 116.
a, and a part of the light amount is reflected by the semi-reflective surface 116a. The light transmitted through the semi-reflective surface 116a passes through the spatial light modulator 15, is collected by the objective lens 113B, passes through the SIL 12B, and irradiates the optical information recording medium 1. The light converges on the interface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter.

On the other hand, the light reflected by the semi-reflective surface 116a is
The light is sequentially reflected by the second total reflection surface 122a, sequentially passes through the convex lens 53 and the concave lens 54, and the diameter of the light beam is reduced. The light emitted from the concave lens 54 is converged by the cylindrical lens 55 only in the optical axis direction of the objective lens 113B to form a light beam having a flat shape.
The light passes through the spherical portion 12Ab of the IL 12A and is irradiated onto the optical information recording medium 1.

The light from the objective lens 113B and the light from the cylindrical lens 55 intersect in the information recording layer 2 so that the centers of the respective lights are orthogonal.
Further, the light from the cylindrical lens 55 side becomes the thinnest on a straight line in a direction perpendicular to the paper plane passing through a point where the center of the light from the objective lens 113B and the center of the light from the cylindrical lens 55 cross. ing.

At the time of recording information, the light from the objective lens 113B side becomes the information light, and the light from the cylindrical lens 55 side becomes the recording reference light. The recording area 123 in which information is recorded is formed in a layered manner by an interference pattern due to interference with the recording medium. The recording area 123 has a disk-like shape formed by slicing a cone in a direction perpendicular to the center axis, similarly to the recording area 59 in the first embodiment.

From the optical information recording medium 1 to the objective lens 113B
The light traveling toward the side is reflected by the objective lens 113B and the spatial light modulator 1
5 in order, and a part of the light amount
Is transmitted through the semi-reflective surface 116a, is condensed by the collimator lens 17, and is incident on the laser coupler 20.

From the optical information recording medium 1 to the objective lens 113A
The light traveling toward the side passes through the spherical portion 12Aa of the SIL 12A, is converted into a parallel light beam by the objective lens 113A, and is
The light enters the CD array 19. When information is reproduced, the light from the cylindrical lens 55 side becomes the reference light for reproduction, and the reference light for reproduction is applied to the recording area 123 to generate the reproduction light from the recording area 123. After passing through lens 113A, CC
The light enters the D array 19.

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

First, the operation at the time of servo will be described.
At the time of servo, all the pixels of the spatial light modulator 15 are turned on. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. The controller 90 predicts the timing at which the output light of the objective lens 113B passes through the address servo area based on the basic clock reproduced from the reproduction signal RF, and outputs the output light of the objective lens 113B through the address servo area. During the passage, the above settings are used.

At the time of servo, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 17, enters the beam splitter 116, a part of the light amount passes through the semi-reflective surface 116a, and a part of the light amount Is reflected by the semi-reflective surface 116a. The light transmitted through the semi-reflective surface 116a passes through the spatial light modulator 15 and passes through the objective lens 113B.
And is passed through the SIL 12B to irradiate the optical information recording medium 1. This light converges on the boundary surface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter, and is reflected at the boundary surface between the positioning layer 4 and the protective layer 5. The light is modulated by the pits and returns to the objective lens 113B side. This return light is converted into a parallel light beam by the objective lens 113B, passes through the spatial light modulator 15, enters the beam splitter 116, and a part of the light amount passes through the semi-reflective surface 116a. The return light transmitted through the semi-reflective surface 116a is collected by the collimator lens 17, enters the laser coupler 20, and is detected by the photodetectors 25 and 26.
Then, based on the outputs of the photodetectors 25 and 26, the detection circuit 85 shown in FIG. 8 generates a focus error signal FE, a tracking error signal TE, and a reproduction signal RF. While the tracking servo is performed, reproduction of the basic clock and determination of the address are performed.

In this embodiment, the actuators 114A and 114B are connected to the objective lenses 113A and 113B, respectively.
The focus servo circuit 86 controls the convergence position of the light passing through B (the position where the luminous flux has the smallest diameter) so as to be on the boundary surface between the positioning layer 4 and the protective layer 5. Has become.

Next, the operation at the time of recording will be described. During recording, the spatial light modulator 15 is turned on or off for each pixel according to the information to be recorded. Laser coupler 2
The output of the outgoing light of 0 is pulsed to a high output for recording based on the basic clock reproduced from the reproduction signal RF. The controller 90 predicts the timing at which the light emitted from the objective lens 113B passes through the data area based on the basic clock reproduced from the reproduction signal RF.
The above setting is made while the light emitted from the objective lens 113B passes through the data area. While the light emitted from the objective lens 113B passes through the data area, focus servo and tracking servo are not performed, and the objective lens 113A,
113B is fixed.

At the time of recording, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 17, enters the beam splitter 116, a part of the light amount passes through the semi-reflective surface 116a, and a part of the light amount Is reflected by the semi-reflective surface 116a. The light transmitted through the semi-reflective surface 116a passes through the spatial light modulator 15 and is spatially modulated according to the information to be recorded to become information light. This information light is condensed by the objective lens 113B, passes through the SIL 12B, and irradiates the optical information recording medium 1. The center of the information light is 60 ° with respect to the surface of the optical information recording medium 1.
The optical information recording medium 1 is irradiated so as to form an angle of.

On the other hand, the light reflected by the semi-reflective surface 116a becomes reference light for recording, and
21a and the total reflection surface 122a of the prism 122 sequentially reflect, pass through the convex lens 53 and the concave lens 54 in order, and reduce the diameter of the light beam.
The light is converged only in the optical axis direction of the objective lens 113B to form a flat light beam, and the spherical portion 12A of the SIL 12A is formed.
b, and irradiates the optical information recording medium 1. In addition,
The optical recording medium 1 is formed such that the center of the recording reference light forms an angle of 30 ° with the surface of the optical information recording medium 1.
Is irradiated.

The information light from the objective lens 113B and the recording reference light from the cylindrical lens 55 intersect in the information recording layer 2 so that the centers of the light beams are orthogonal. Then, at a portion where the information light and the recording reference light intersect, an interference pattern due to interference of these lights is formed,
When the output of the light emitted from the laser coupler 20 becomes high, an interference pattern by the information light and the recording reference light is volumetrically recorded in the information recording layer 2, and a reflection type (Lipman type) volume hologram is formed. Is formed in a layered form. The recording area 123 has a disk shape.

In the present embodiment, the positions of the information light and the recording reference light with respect to the optical information recording medium 1 are adjusted so that a plurality of recording areas 123 are formed in the information recording layer 2 without overlapping each other. Take control. The state of the recording area 123 in the information recording layer 2 of the optical information recording medium 1 is the same as that of the recording area 59 in the first embodiment shown in FIGS.

Next, the operation at the time of reproduction will be described. At the time of reproduction, all the pixels of the spatial light modulator 15 are turned off. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. Note that the controller 90 predicts the timing at which the output light of the objective lens 113B passes through the data area based on the basic clock reproduced from the reproduction signal RF. Make the above settings. Objective lens 11
While the outgoing light of 3B passes through the data area, focus servo and tracking servo are not performed, and the objective lenses 113A and 113B are fixed.

At the time of reproduction, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 17, enters the beam splitter 116, a part of the light amount passes through the semi-reflective surface 116a, and a part of the light amount Is reflected by the semi-reflective surface 116a. Light transmitted through the semi-reflective surface 116a is blocked by the spatial light modulator 15. On the other hand, the light reflected by the semi-reflective surface 116a becomes the reference light for reproduction corresponding to the reference light for recording, and becomes the total reflection surface 12 of the prism 121.
1a and the total reflection surface 122a of the prism 122 sequentially reflect, pass through the convex lens 53 and the concave lens 54 in order to reduce the diameter of the light beam, and are converged by the cylindrical lens 55 only in the optical axis direction of the objective lens 113B to be flat. SIL 12A spherical portion 12Ab
And irradiates the optical information recording medium 1.

When the recording area 123 in the information recording layer 2 is irradiated with reproduction reference light, reproduction light is generated from the recording area 123. The reproduction light is emitted from the transparent substrate 3 side to the outside of the optical information recording medium 1 while diffusing. This reproduction light passes through the spherical portion 12Aa of the SIL 12A, and enters the CCD array 19 via the objective lens 113A. In this way, on the CCD array 19, only the portion corresponding to the pixel that was turned on in the spatial light modulator 15 at the time of recording is illuminated brightly, and the two-dimensional pattern is
The information is detected by the D array 19 and the information is reproduced.

Other configurations, operations and effects of the present embodiment are the same as those of the first embodiment.

Next, a third embodiment of the present invention will be described. The overall configuration of the optical information recording / reproducing apparatus according to the present embodiment is the same as that of FIG. 5 except that the configuration of the pickup is different. The structure of the optical information recording medium 1 according to the present embodiment is the same as that of the first embodiment, but the information recording layer 2 changes its refractive index by irradiation with two lights having different wavelengths. A material formed of a material is used.

FIGS. 19 and 20 are explanatory diagrams showing the structure of the pickup in the optical information recording / reproducing apparatus according to the present embodiment. Hereinafter, the same members as those in the pickup shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. Pickup 211 in the present embodiment
Is opposite to the SIL 12A arranged so as to face the surface of the optical information recording medium 1 on the side of the transparent substrate 3 when the optical information recording medium 1 is fixed to the spindle 81, and opposite to the optical information recording medium 1 in the SIL 12A. And an SIL 12B disposed so as to face the surface of the optical information recording medium 1 on the side of the protective layer 5 when the optical information recording medium 1 is fixed to the spindle 81,
2B is provided with an objective lens 212B provided on the side opposite to the optical information recording medium 1 in 2B. In the present embodiment, the objective lens 212A and the objective lens 212B are arranged such that their optical axes are on the same line, and these optical axes make an angle of 60 ° with the surface of the optical information recording medium 1. Have been.

The pickup 211 further includes an actuator 213A capable of moving the objective lens 212A in the optical axis direction and the radial direction of the optical information recording medium 1, and an objective lens 212A.
12B is provided with an actuator 213B that is movable in the optical axis direction and the radial direction of the optical information recording medium 1.

The pickup 211 is further provided on the opposite side of the objective lens 212A from the optical information recording medium 1 with the two-part optical rotation plate 21 arranged in order from the objective lens 212A side.
4A, prism blocks 222 and 223, spatial light modulator 216, collimator lens 217, and laser coupler 2
0 is provided. A convex lens 224 is provided between the prism blocks 222 and 223.

The pickup 211 is further provided on the opposite side of the objective lens 212B with respect to the optical information recording medium 1 from the two-part optical rotation plate 21 arranged in order from the objective lens 212B side.
4C, prism blocks 215 and 216 and a CCD array 219B. Prism block 225,
226, a half-wave plate 227 and a convex lens 228
Are arranged. A CCD array 219A is provided on the side of the prism block 226.

The two-split optical rotation plates 214A and 214C are arranged at the upper part of the optical axis in FIGS. 19 and 20, and at the lower part of the optical axis in FIGS. 19 and 20, respectively. Optical rotation plate 2
14AL and 214CL. Each optical rotation plate 214
Each of AR, 214CR, 214AL, and 214CL is configured by sealing liquid crystal between, for example, two transparent electrode substrates. When no voltage is applied between the two transparent electrode substrates (hereinafter, referred to as “off”), the optical rotation plate 214AR rotates the polarization direction of the incident light by −45 ° and applies a voltage between the two transparent electrode substrates. (Hereinafter referred to as ON), the polarization direction of the incident light is not rotated. When the optical rotation plate 214AL is turned off, the polarization direction of the incident light is +
When turned on by 45 ° and turned on, the polarization direction of the incident light is not rotated. When the optical rotation plate 214CR is turned off, the polarization direction of the incident light is rotated by + 45 °, and when turned on, the polarization direction of the incident light is not rotated. When the optical rotation plate 214CL is turned off, the polarization direction of the incident light is rotated by -45 °, and when turned on, the polarization direction of the incident light is not rotated.

The prism block 223 has a polarization beam splitter surface 223a whose normal direction is inclined by 45 ° with respect to the optical axis direction between the two-segment optical rotation plate 214A and the spatial light modulator 216; Optical modulator 216
Is disposed in a direction in which light from the side is reflected by the polarization beam splitter surface 223a, and the polarization beam splitter surface 223a
And a reflection surface 223b that is parallel to.

The normal direction of the prism block 222 is inclined by 45 ° with respect to the optical axis direction between the two-segment optical rotation plate 214A and the spatial light modulator 216. A polarizing beam splitter surface 222a disposed at an angle of 90 ° with respect to the reflecting surface 223 of the prism block 223;
b, and a reflecting surface 222b parallel to the polarizing beam splitter surface 222a. The convex lens 224 includes a reflecting surface 223b of the prism block 223 and a reflecting surface 222b of the prism block 222.
And is located between.

The spatial light modulator 216 has a large number of pixels arranged in a grid pattern, and spatially modulates light according to the difference in polarization direction by selecting the polarization direction of emitted light for each pixel. You can do it. Specifically, the spatial light modulator 216 has, for example, the same configuration as that of a liquid crystal display element utilizing the optical rotation of liquid crystal except for a polarizing plate. Here, when turned off, the spatial light modulator 216 rotates the polarization direction by + 90 ° for each pixel, and does not rotate the polarization direction when turned on.
As the liquid crystal in the spatial light modulator 216, for example, a ferroelectric liquid crystal having a high response speed (on the order of microsecond) can be used. This enables high-speed recording, for example, recording information for one page in a few microseconds or less.

The prism block 225 has a polarizing beam splitter surface 225a whose normal direction is inclined by 45 ° with respect to the optical axis direction of the objective lens 212B and the split optical rotation plate 214C, and a split optical rotation plate 214.
The light from the C side is disposed in a direction in which the light is reflected by the polarization beam splitter surface 225a.
a and a reflection surface 225b parallel to a.

The prism block 226 has its normal direction inclined by 45 ° with respect to the optical axis direction of the objective lens 212B and the split optical rotation plate 214C, and 90 ° with respect to the polarization beam splitter surface 225a of the prism block 225. The polarizing beam splitter surface 226a disposed at an angle and the reflecting surface 225 of the prism block 225.
b, and a reflection surface 226b parallel to the polarization beam splitter surface 226a. The half-wave plate 227 includes a prism block 225.
Is disposed between the polarization beam splitter surface 225a of the prism block 226 and the polarization beam splitter surface 225a of the prism block 226. The convex lens 228 is
5 and the reflecting surface 226b of the prism block 226.

Each of the CCD arrays 219A and 219B has a large number of pixels arranged in a lattice. C
The CD array 219A is arranged in a direction in which light that has passed through the half-wave plate 227 is reflected by the polarization beam splitter surface 226a of the prism block 226, and the CCD array 219B has light that has passed through the convex lens 228. Are arranged in a direction in which the light is reflected by the reflection surface 226b and further reflected by the polarization beam splitter surface 226a.

The pickup 211 further includes a light source 231 that emits fixing light, and a collimator lens 232, a convex lens 53, and a concave lens that are sequentially arranged on the optical path of the fixing light emitted from the light source 231 from the light source 231 side. 54 and a cylindrical lens 55. The light emitted from the cylindrical lens 55 has its center (optical axis) in the information recording layer 2 within the objective lens 212A.
The information recording layer 2 is irradiated so as to be orthogonal to the center (optical axis) of the emitted light. Therefore, the light emitted from the cylindrical lens 55 is applied to the optical information recording medium 1 so as to form an angle of 30 ° with the surface of the optical information recording medium 1.

In the pickup 211 shown in FIGS. 19 and 20, the laser coupler 20 emits S-polarized (linearly polarized light whose polarization direction is perpendicular to the incident surface (the paper surface in FIG. 19)), and this laser light Is the collimator lens 21
7, a parallel light flux passes through the spatial light modulator 216 and is incident on the polarization beam splitter surface 223a of the prism block 223. Here, the light that has passed through the pixel off of the spatial light modulator 216 becomes P-polarized light (linearly polarized light whose polarization direction is parallel to the plane of incidence), transmits through the polarization beam splitter surface 223a, and passes through the prism block 22.
2, the light passes through the polarizing beam splitter surface 222a, passes through the split optical rotation plate 214A, and passes through the objective lens 212.
By A, the light is converged to have the smallest diameter in the optical information recording medium 1, passes through the spherical portion 21Aa of the SIL 12A, and is irradiated onto the optical information recording medium 1.
On the other hand, the light that has passed through the ON pixels of the spatial light modulator 216 remains S-polarized, and the polarization beam splitter surface 22
3a, further reflected by the reflecting surface 223b, and condensed by the convex lens 224.
22, the light is sequentially reflected by the reflection surface 222b and the polarization beam splitter surface 222a, passes through the split optical rotation plate 214A, and is passed through the objective lens 212A.
The light is converged so as to have the smallest diameter at a position on the near side of the light that has passed through the pixel off of the spatial light modulator 216, passes through the spherical portion 12Aa of the SIL 12A, and irradiates the optical information recording medium 1. It has become so.

From the optical information recording medium 1 to the objective lens 212A
The return light to the side is the objective lens 212A, the two-part optical rotation plate 2
14A, and is incident on the polarization beam splitter surface 222a of the prism block 222. The P-polarized light of the return light passes through the polarization beam splitter surface 222a, and further passes through the prism block 2.
The light passes through the polarization beam splitter surface 223a, passes through the spatial light modulator 216, is condensed by the collimator lens 217, and enters the laser coupler 20.

The optical information recording medium 1 uses the objective lens 212B
The reproduction light emitted to the side passes through the objective lens 212B and the two-segment optical rotation plate 214C in order, and passes through the prism block 225.
Is incident on the polarization beam splitter surface 225a. The P-polarized light of the reproduced light passes through the polarization beam splitter surface 225a and is a half-wave plate 2
27, the polarization direction is rotated by 90 ° to become S-polarized light, which is reflected by the polarization beam splitter surface 226a of the prism block 226 and enters the CCD array 219A. On the other hand, the S-polarized light of the reproduction light is reflected by the polarization beam splitter surface 225a, further reflected by the reflection surface 225b, and condensed by the convex lens 228 to form a parallel light beam.
6, the light is sequentially reflected by the reflection surface 226b and the polarization beam splitter surface 226a, and is incident on the CCD array 219B.

As a material for forming the information recording layer 2 in the present embodiment, for example, US Pat. No. 5,268,8
No. 62, a plastic material (PMMA) doped with a two-wavelength photosensitive photochromic substance can be used. This material has, for example, a wavelength of 53
When 2 nm light and 1064 nm wavelength light are irradiated simultaneously, they first change to spiropyran and then to the stable molecular form of merocyanine (m
erocyanine), and the refractive index changes.

Hereinafter, the case where the above-mentioned plastic material is used as a material for forming the information recording layer 2 will be described as an example. In this case, for example, the information light and the recording reference light, that is, the light emitted from the laser coupler 20 is set to light having a wavelength of 532 nm, and the fixing light emitted from the light source 231 is set to light having a wavelength of 1064 nm. In addition, wavelength 10
As the light of 64 nm, for example, neodymium yag (N
d: YAG) The fundamental wave of a laser can be used. As the light having a wavelength of 532 nm, for example, a second harmonic obtained by obtaining a fundamental wave of a neodymium-Yag laser through a nonlinear optical medium can be used. In the case of using this second harmonic, the semiconductor laser 24 in the laser coupler 20 is used. Instead, a light source device that generates the second harmonic is used.

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

First, the operation at the time of servo will be described.
At the time of servo, all the pixels of the spatial light modulator 216 are turned off, and the optical rotation plates 214 of the two-part optical rotation plates 214A and 214C are turned off.
AR, 214AL, 214CR, 214CL are all turned on. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. The light source 231 does not emit fixing light. Note that the controller 90 controls the reproduction signal R
Based on the basic clock reproduced from F, the timing at which the light emitted from the objective lens 212A passes through the address servo area is predicted. I do.

At the time of servo, the S-polarized laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 217 and enters the spatial light modulator 216. Here, since all the pixels of the spatial light modulator 216 are turned off, the light after passing through the spatial light modulator 216 is
The polarization direction is rotated by + 90 ° to become P-polarized light. The P-polarized light passes through the polarization beam splitter surface 223a of the prism block 223 and the polarization beam splitter surface 222a of the prism block 222 in this order, and is split into two optical rotation plates 21.
4A. Here, since the optical rotation plates 214AR and 214AL of the two-part optical rotation plate 214A are both turned on, the light passes through the two-part optical rotation plate 214A without any influence. The light that has passed through the two-segment optical rotation plate 214A is condensed by the objective lens 212A, converged to have the smallest diameter on the boundary surface between the positioning layer 4 and the protective layer 5 in the information recording medium 1, and is converged on the information recording medium. 1 is irradiated. This light is reflected on the boundary surface between the positioning layer 4 and the protective layer 5 in the information recording medium 1, and at this time, is modulated by the emboss pits in the address servo area and returns to the objective lens 212A side. This return light is converted into a parallel light beam by the objective lens 212A, and is not affected by the light.
After passing through the split optical rotation plate 214A, the prism block 222
Of the prism block 223 and the polarization beam splitter surface 223a of the prism block 223, pass through the spatial light modulator 216, and have a polarization direction of +90.
After being rotated by an angle, it is converted into S-polarized light again, enters the laser coupler 20, and is detected by the photodetectors 25 and 26. Then, based on the outputs of the photodetectors 25 and 26, the detection circuit 85 detects the focus error signal FE, the tracking error signal TE, and the reproduction signal R.
F is generated, and based on these signals, focus servo and tracking servo are performed, and the reproduction of the basic clock and the determination of the address are performed.

In the present embodiment, the actuator 213
A and 213B are controlled by the focus servo circuit 86 so as to be linked, and the objective lenses 212A and 212B
The convergence position (the position where the light beam has the smallest diameter) of each light passing through moves while maintaining a predetermined positional relationship. When recording or reproducing information on or from the information recording layer 2, the light from the objective lens 212 </ b> A has the smallest diameter on the interface between the positioning layer 4 and the protective layer 5 in the information recording medium 1. Focus servo is performed such that the divergent light having the smallest diameter on the surface of the transparent substrate 3 is converted into a parallel luminous flux.

Next, the operation at the time of recording will be described. During recording, the spatial light modulator 216 selects ON (0 °) or OFF (+ 90 °) for each pixel according to the information to be recorded. In the present embodiment, 1-bit information is expressed by two pixels. In this case, one of the two pixels corresponding to one bit of information is always turned on and the other is turned off. Each of the optical rotation plates 214AR and 214AR of the two split optical rotation plates 214A and 214C.
14AL, 214CR and 214CL are all turned off. The output of the light emitted from the laser coupler 20 is pulsed to a high output for recording. Further, the light source 231 emits the fixing light intermittently at the timing when the output of the light emitted from the laser coupler 20 becomes high. Note that the controller 90 predicts the timing at which the light emitted from the objective lens 212A passes through the data area based on the basic clock reproduced from the reproduction signal RF.
The above settings are made while the outgoing light passes through the data area. While the light emitted from the objective lens 212A passes through the data area, focus servo and tracking servo are not performed, and the objective lenses 212A and 212B are fixed.

Here, A-polarized light and B-polarized light used in the following description are defined as follows. In the present embodiment, as shown in FIG. 21, the A-polarized light is a linearly-polarized light obtained by rotating the S-polarized light by −45 ° or the P-polarized light by + 45 °, and the B-polarized light is viewed from the objective lens 212A side. Is S-polarized light as +45 degrees or P-polarized light as -45 degrees as viewed from the objective lens 212A side. The polarization directions of the A polarized light and the B polarized light are orthogonal to each other.

At the time of recording, the S-polarized laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 217 and enters the spatial light modulator 216.
Here, the light passing through the turned-on pixel of the spatial light modulator 216 remains S-polarized without rotating the polarization direction, and the light passing through the turned-off pixel has a polarization direction of + 90 °. Rotated to P-polarized light.

The P-polarized light from the spatial light modulator 216 is
Polarizing beam splitter surface 22 of prism block 223
3a and the polarized beam splitter surface 222a of the prism block 222 are sequentially transmitted, and are incident on the split optical rotation plate 214A. Here, the optical rotation plate 214 of the two-part optical rotation plate 214A
Since both AR and 214AL are turned off, the light that has passed through the optical rotation plate 214AR has its polarization direction rotated by −45 ° to become B-polarized light, and the light that has passed through the optical rotation plate 214AL has its polarization direction rotated by + 45 °. Then, the light becomes A-polarized light. This light converges on the interface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter.

S-polarized light from the spatial light modulator 216 is
Polarizing beam splitter surface 22 of prism block 223
3a, further reflected by the reflecting surface 223b, and condensed by the convex lens 224, then enter the prism block 222, where the reflecting surface 222b and the polarizing beam splitter surface 22
The light is sequentially reflected by 2a and enters the two-part optical rotation plate 214A. Here, the optical rotation plate 214A of the two-part optical rotation plate 214A
Since both R and 214AL are turned off, the optical rotation plate 2
The light that has passed through 14AR has its polarization direction rotated by −45 ° to become A-polarized light, and the light that has passed through optical rotation plate 14AL has its polarization direction rotated by + 45 ° and becomes B-polarized light. This light converges on the surface of the transparent substrate 3 so as to have the smallest diameter.

In the information recording layer 2, the B-polarized light from the optical rotation plate 214AR and the B-polarized light from the optical rotation plate 214AL interfere with each other, and the A-polarized light from the optical rotation plate 214AR and the optical rotation plate 2
A-polarized light from 14AL interferes with laser coupler 2
When the output of the 0 outgoing light becomes high, an interference pattern by these lights is volumetrically recorded in the information recording layer 2, and a transmission type (Fresnel type) volume hologram is formed. The A-polarized light and the B-polarized light do not interfere with each other because their polarization directions are orthogonal to each other. As described above, in the present embodiment, the light beam is divided into two, and the polarization directions of the light in the respective regions are made orthogonal to each other.
A decrease in the N ratio can be prevented.

In this embodiment, the light converging so as to have the smallest diameter on the back side of the information recording layer 2 and the light converging so as to have the smallest diameter on the front side of the information recording layer 2 are mutually different. They have complementary patterns, and can be regarded as information light carrying information to be recorded on the information recording layer 2. When the light converging so as to have the smallest diameter on the back side of the information recording layer 2 is viewed as information light, the light converging so as to have the smallest diameter on the front side of the information recording layer 2 is the recording reference light. Conversely, when the light converging so as to have the smallest diameter on the front side of the information recording layer 2 is regarded as the information light, the light converging so as to have the smallest diameter on the back side of the information recording layer 2 is recorded. Reference light.

The fixing light emitted from the light source 231 is converted into a parallel light beam by the collimator lens 232, and then passes through the convex lens 53 and the concave lens 54 in order to reduce the diameter of the light beam. Are converged only in the optical axis direction of the optical information recording medium 1, and pass through the spherical portion 12Ab of the SIL 12A to irradiate the optical information recording medium 1. It should be noted that the fixing light has a center at 30 degrees with respect to the surface of the optical information recording medium 1.
The optical information recording medium 1 is irradiated so as to form an angle of °. The fixing light passes through a part of the area where the interference pattern is formed in the information recording layer 2, and as a result, the information of the part where the fixing light has passed is fixed, the information is recorded by the interference pattern, and The recording area 259 to which the information is fixed is formed in a layer. The fixing of information is specifically performed as follows. That is, for example, when a fixing light having a wavelength of 1064 nm is irradiated on a region in the information recording layer 2 where an interference pattern is formed by interference between the information light having a wavelength of 532 nm and the reference light for recording, the information recording layer 2 is irradiated. In the above, the molecular form partially changes according to the interference pattern, and as a result, a refractive index distribution according to the interference pattern occurs, and the information is fixed.

Next, the operation at the time of reproduction will be described. At the time of reproduction, the spatial light modulator 216 selects a state in which all pixels are off (+ 90 °) and a state in which all pixels are on (0 °) as necessary. Also, the two-part optical rotation plates 214A, 21
4C optical rotation plates 214AR, 214AL, 214CR,
214CL are all turned off. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. The light source 231 does not emit fixing light. The controller 9
0 predicts the timing at which the output light of the objective lens 212A passes through the data area based on the basic clock reproduced from the reproduction signal RF, and performs the above setting while the output light of the objective lens 212A passes through the data area. And While the light emitted from the objective lens 212A passes through the data area, focus servo and tracking servo are not performed, and the objective lenses 212A and 212B are fixed.

When all the pixels of the spatial light modulator 216 are off, the S-polarized laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 217, and the polarization direction is changed by the spatial light modulator 216. +90
Rotated by ° to become P-polarized light. The P-polarized light from the spatial light modulator 216 sequentially passes through the polarization beam splitter surface 223a of the prism block 223 and the polarization beam splitter surface 222a of the prism block 222, and enters the two-rotation optical rotation plate 214A. Here, since the optical rotation plates 214AR and 214AL of the two-part optical rotation plate 214A are both turned off, the light passing through the optical rotation plate 214AR has a polarization direction of-.
Light that has been rotated by 45 ° to become B-polarized light and passed through the optical rotation plate 214AL has its polarization direction rotated by + 45 ° to become A-polarized light. This light converges on the interface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter.

From the recording area 259 in the information recording layer 2, a reproduction light is generated when the light converging so as to have the smallest diameter on the inner side of the information recording layer 2 is regarded as the recording reference light.
The reproduction light in this case is divergent light having the smallest diameter on the front side of the information recording layer 2. More specifically, in the upper half area of the recording area 259, the B from the optical rotation plate 214AR
Polarized light is applied, and during recording, the two-part optical rotation plate 2
Irradiated from the 14A optical rotation plate 214AL, the information recording layer 2
The reproduction light corresponding to the light having the smallest diameter is generated on the front side of. This reproduction light is B-polarized light, and the objective lens 2
The light is condensed by 12B and becomes a parallel light flux, and the two-part optical rotation plate
The light passes through the 4C optical rotation plate 214CR and becomes P-polarized light.
Similarly, in the lower half area of the recording area 259, the optical rotation plate 2
The A-polarized light from 14AL is irradiated, and is irradiated from the optical rotation plate 214AR of the two-part optical rotation plate 214A at the time of recording, and reproduction light corresponding to the light having the smallest diameter on the front side of the information recording layer 2 is generated. . This reproduction light is A-polarized light, and is converged by the objective lens 212B to become a parallel light flux.
After passing through the optical rotation plate 214CL of the two-divided optical rotation plate 214C, P
It becomes polarized light. The P-polarized reproduction light passes through the polarization beam splitter surface 225 a of the prism block 225, and has a polarization direction of 90 ° by the half-wave plate 227.
The light is rotated to be S-polarized light, and the prism block 226 is rotated.
Reflected by the polarization beam splitter surface 226a of the
An image is formed on the D array 229A. In this way CCD
On the array 219A, only the portion corresponding to the pixel that was turned on in the spatial light modulator 216 at the time of recording is illuminated brightly, and its two-dimensional pattern is detected by the CCD array 219A, and information is reproduced.

On the other hand, when all the pixels of the spatial light modulator 216 are on, the S
The polarized laser light is converted into a parallel light beam by the collimator lens 17, and the polarization direction is not rotated by the spatial light modulator 216, and remains as S-polarized light. The S-polarized light from the spatial light modulator 216 is reflected by the polarization beam splitter surface 223a of the prism block 223, and further reflected by the reflection surface 223.
b, is incident on the prism block 222, is sequentially reflected on the reflection surface 222b and the polarization beam splitter surface 222a, and is incident on the two-divided optical rotation plate 214A. Where 2
Since the optical rotation plates 214AR and 214AL of the split optical rotation plate 214A are both turned off, the light that has passed through the optical rotation plate 214AR has its polarization direction rotated by −45 °, becomes A-polarized light, and the light that has passed through the optical rotation plate 214AL. , Polarization direction is +4
Rotated by 5 °, it becomes B polarized light. This light is transmitted through the transparent substrate 3
Converges to the smallest diameter on the surface of.

From the recording area 259 in the information recording layer 2, reproduction light is generated when the light converging so as to have the smallest diameter in front of the information recording layer 2 is regarded as the recording reference light. The reproduction light in this case is divergent light having the smallest diameter on the inner side of the information recording layer 2. More specifically, the upper half area of the recording area 259 is irradiated with B-polarized light from the optical rotation plate 214AL, and is irradiated from the optical rotation plate 214AR of the two-part optical rotation plate 214A during recording. Reproduction light corresponding to the light having the smallest diameter on the back side is generated. This reproduction light is B-polarized light, and the objective lens 2
The light flux is condensed at 12B and slightly diffused, passes through the optical rotation plate 214CL of the two-part optical rotation plate 214C, and becomes S-polarized light. Similarly, in the lower half area of the recording area 259,
A-polarized light is emitted from the optical rotation plate 214AR, and is emitted from the optical rotation plate 214AL of the two-divided optical rotation plate 214A at the time of recording, and reproduction light corresponding to light having the smallest diameter on the back side of the information recording layer 2 is generated. Is done. This reproduction light is A-polarized light, and becomes a light flux which is condensed by the objective lens 212B and slightly diffuses, and becomes a light rotatory plate 214C of the two-divided optical rotator 214C.
The light passes through R and becomes S-polarized light. The S-polarized reproduction light is reflected by the polarization beam splitter surface 225a of the prism block 225, further reflected by the reflection surface 225b, and condensed by the convex lens 228 to form a parallel light beam. The light is sequentially reflected by the beam splitter surface 226a and forms an image on the CCD array 229B. In this manner, on the CCD array 229B, only the portion corresponding to the pixel that was turned off in the spatial light modulator 216 at the time of recording is illuminated brightly, and its two-dimensional pattern is detected by the CCD array 229B, and information is reproduced. Will be

In this embodiment, information may be reproduced by the CCD array 219A with all the pixels of the spatial light modulator 216 turned off, or the CCD may be set with all the pixels of the spatial light modulator 216 turned on. The reproduction of information may be performed by the array 219B. Furthermore, in the present embodiment, the spatial light modulator 21
6 is turned off and all the pixels of the spatial light modulator 216 are switched on to irradiate two types of reproduction reference light in a time-division manner.
For example, half of all 16 pixels are turned off and half of the pixels are turned on, and two types of reference light for reproduction are irradiated at the same time.
It is also possible to reproduce information by using both of 19A and 219B. In this case, two reproduction lights obtained by the CCD arrays 219A and 219B for one unit of the recording area 259 have complementary patterns.
By obtaining the difference between the two reproduction lights, information can be reproduced by so-called differential detection. When the information is reproduced by the differential detection as described above, specifically, the signal processing circuit 89 in FIG.
The output signals 19A and 219B are corrected to match the size, position and signal level of each pattern detected by the CCD arrays 219A and 219B, and the difference between the corrected signals is calculated to obtain information. Reproduce.

According to the optical information recording / reproducing apparatus according to the present embodiment, information can be recorded and fixed on the optical information recording medium 1 at any time, and the optical information recording medium 1 can be written on once. (Type) recording medium.

In this embodiment, when the information recording layer 2 on which information is recorded by the interference pattern is irradiated with, for example, light having a wavelength of 1064 nm, merocyanine emits fluorescence having a wavelength of 532 nm. Thus, by observing the fluorescence, an interference pattern can be observed, and the presence or absence of the interference pattern can be confirmed.

Other configurations, operations, and effects of the present embodiment are the same as those of the first embodiment.

Next, a fourth embodiment of the present invention will be described. The overall configuration of the optical information recording / reproducing apparatus according to the present embodiment is the same as that of FIG. 5 except that the configuration of the pickup is different. In the optical information recording medium 1 according to the present embodiment, similarly to the third embodiment, the information recording layer 2 is formed of a material whose refractive index changes by irradiation with two lights having different wavelengths. Use something.

FIGS. 22 and 23 are explanatory views showing the structure of the pickup in the optical information recording / reproducing apparatus according to the present embodiment. 1 and 19 and FIG.
The same members as those of the pickup shown in FIG. 0 are denoted by the same reference numerals, and detailed description thereof will be omitted. The pickup 311 according to the present embodiment has the same S as that of the third embodiment.
IL12A, 12B, objective lenses 212A, 212B,
An actuator 213A, an actuator 213B, and a two-part optical rotation plate 214A are provided. Further, the pickup 311 includes a two-part optical rotation plate 214B instead of the two-part optical rotation plate 214C in the third embodiment. The pickup 311 includes a light source 231, a collimator lens 232, a convex lens 53, a concave lens 54, and a cylindrical lens 55 similar to those of the third embodiment.

The pickup 311 is further mounted on the opposite side of the optical information recording medium 1 in the two-part optical rotation plate 214A.
The prism block 315A, the spatial light modulator 216, the collimator lens 217, the laser coupler 20, and the prism block 3 arranged in this order from the split optical rotation plate 214A side.
Convex lens 318A and CC disposed on the side of 15A
A D array 219A is provided.

The pickup 311 further moves the two-part optical rotation plate 214 B on the opposite side to the optical information recording medium 1.
A prism block 315B, a convex lens 318B, and a CCD array 2 arranged in this order from the split optical rotation plate 214B side.
19B.

The two-part optical rotation plate 214B is different from the optical rotation plate 214BR arranged in the upper part of the optical axis in FIG.
3, the optical rotation plate 214B disposed in the lower part of the optical axis
L. Each optical rotation plate 214BR, 214BL
Are formed by sealing liquid crystal between two transparent electrode substrates, for example. The optical rotation plate 214BR rotates the polarization direction of incident light to be turned off by -45 °, and does not rotate the polarization direction of incident light when turned on. On the other hand, when the optical rotation plate 214BL is turned off, the polarization direction of the incident light is rotated by + 45 °, and when it is turned on, the polarization direction of the incident light is not rotated.

The prism block 315A has a normal direction between the two-divided optical rotation plate 214A and the spatial light modulator 216 between the two-divided optical rotation plate 214A and the spatial light modulator 216.
Between the polarization beam splitter surface 315Aa and the polarization beam splitter surface 315A, which is disposed at an angle of 45 ° with respect to the optical axis direction.
and a reflecting surface 315Ab parallel to the polarizing beam splitter surface 315Aa.

The prism block 315B is disposed between the two-rotation optical rotation plate 214B and the convex lens 318B, and the polarizing beam splitter surface 31 of the prism block 315A is provided.
5Aa, a polarizing beam splitter surface 315Ba arranged in parallel with the light receiving surface 315Ab of the prism block 315A, and a reflecting surface 315 perpendicular to the polarizing beam splitter surface 315Ba.
Bb.

The reflecting surfaces 315Ab and 315Bb of the prism blocks 315A and 315B are disposed on the sides of the optical information recording medium 1, and the reflecting surfaces 315Ab and 315B
The light traveling toward 15Bb passes through the side of the optical information recording medium 1. The optical path of the light from the reflecting surface 315Ab to the reflecting surface 315Bb is arranged so as not to overlap the optical path of the fixing light.

In the pickup 311, the laser coupler 20 emits S-polarized laser light, which is converted into a parallel light beam by the collimator lens 217.
After passing through the spatial light modulator 216, the prism block 315
A is incident on the polarization beam splitter surface 315Aa. Here, the light passing through the pixel off of the spatial light modulator 216 becomes P-polarized light, passes through the polarizing beam splitter surface 315Aa, passes through the split optical rotation plate 214A, and is condensed by the objective lens 212A. The information recording medium 1 is irradiated. On the other hand, light that has passed through the ON pixel of the spatial light modulator 216 remains S-polarized light, is reflected by the polarization beam splitter surface 315Aa, is further reflected by the reflection surface 315Ab, is incident on the prism block 315B, and is reflected by the reflection surface. 315Bb, reflected in order by the polarizing beam splitter surface 315Ba,
After passing through 14B, the light is condensed by the objective lens 212B and irradiated onto the optical information recording medium 1.

The optical information recording medium 1 to the objective lens 212A
The light traveling toward the side is emitted from the objective lens 212A and the two-part optical rotation plate 2
The light sequentially passes through 14A and is incident on the polarization beam splitter surface 315Aa of the prism block 315A. The S-polarized light of this light is reflected by the polarization beam splitter surface 315Aa, collected by the convex lens 318A, and incident on the CCD array 219A. On the other hand, from the optical information recording medium 1 to the objective lens 212A
The P-polarized light of the light traveling to the side passes through the polarization beam splitter surface 315Aa, passes through the spatial light modulator 216, is condensed by the collimator lens 217, and enters the laser coupler 20. ing.

From the optical information recording medium 1 to the objective lens 212B
The light traveling to the side is divided by the objective lens 212B and the two-part optical rotation plate 2
14B, and sequentially enters the polarization beam splitter surface 315Ba of the prism block 315B. The S-polarized light of this light is reflected by the polarizing beam splitter surface 315Ba, and the P-polarized light is transmitted by the polarizing beam splitter surface 315Ba to form a convex lens 318.
The light is condensed by B and enters the CCD array 219B.

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

First, the operation at the time of servo will be described.
At the time of servo operation, all the pixels of the spatial light modulator 216 are turned off, and the optical rotation plates 214 of the two-part optical rotation plates 214A and 214B are turned off.
AR, 214AL, 214BR, 214BL are all turned on. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. The light source 231 does not emit fixing light. Note that the controller 90 controls the reproduction signal R
Based on the basic clock reproduced from F, the timing at which the light emitted from the objective lens 212A passes through the address servo area is predicted. I do.

At the time of servo operation, the S-polarized laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 217 and enters the spatial light modulator 216. Here, since all the pixels of the spatial light modulator 216 are turned off, the light after passing through the spatial light modulator 216 is
The polarization direction is rotated by + 90 ° to become P-polarized light. This P-polarized light passes through the polarizing beam splitter surface 315Aa of the prism block 315A and passes through the two-part optical rotation plate 214A.
Incident on. Here, the optical rotation plate 2 of the two-part optical rotation plate 214A
Since both 14AR and 214AL are turned on, the light passes through the split optical rotation plate 214A without any influence. The light that has passed through the split optical rotation plate 214A is condensed by the objective lens 212A, is converged so as to have the smallest diameter on the boundary surface between the positioning layer 4 and the protective layer 5, and is irradiated on the information recording medium 1. . This light is reflected on the boundary surface between the positioning layer 4 and the protective layer 5, and is modulated by emboss pits in the address servo area and returns to the objective lens 212A side. This return light is converted into a parallel light beam by the objective lens 212A, passes through the two-part optical rotation plate 214A without any influence, and is returned to the prism block 31.
5A through the polarizing beam splitter surface 315Aa,
After passing through the spatial light modulator 216, the polarization direction is rotated by + 90 ° and converted into S-polarized light again, is incident on the laser coupler 20, and is detected by the photodetectors 25 and 26.
Then, based on the outputs of the photo detectors 25 and 26, the focus error signal F is detected by the detection circuit 85.
E, a tracking error signal TE and a reproduction signal RF are generated. Based on these signals, focus servo and tracking servo are performed, and reproduction of a basic clock and determination of an address are performed.

Next, the operation at the time of recording will be described. During recording, the spatial light modulator 216 selects ON (0 °) or OFF (+ 90 °) for each pixel according to the information to be recorded. The optical rotation plates 214AR, 214AL, 214BR, and 214BL of the two-part optical rotation plates 214A and 214B are
All are turned off. The output of the light emitted from the laser coupler 20 is pulsed to a high output for recording. Light source 2
Reference numeral 31 intermittently emits fixing light at a timing when the output light of the laser coupler 20 becomes high. Note that the controller 90 controls the objective lens 212A, 212 based on the basic clock reproduced from the reproduction signal RF.
The timing at which the emitted light of 212B passes through the data area is predicted, and the above settings are made while the emitted lights of the objective lenses 212A and 212B pass through the data area. While the light emitted from the objective lenses 212A and 212B passes through the data area, focus servo and tracking servo are not performed, and the objective lenses 212A and 212B are fixed.

At the time of recording, the S-polarized laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 217 and enters the spatial light modulator 216.
Here, the light passing through the turned-on pixel of the spatial light modulator 216 remains S-polarized without rotating the polarization direction, and the light passing through the turned-off pixel has a polarization direction of + 90 °. Rotated to P-polarized light.

The P-polarized light from the spatial light modulator 216 is
Polarizing beam splitter surface 3 of prism block 315A
The light passes through 15Aa and is incident on the split optical rotation plate 214A. Here, the optical rotation plate 214A of the two-part optical rotation plate 214A
Since both R and 214AL are turned off, the optical rotation plate 2
The light that has passed through 14AR has its polarization direction rotated by −45 °, becomes B-polarized light, and the light that has passed through optical rotation plate 214AL is
The polarization direction is rotated by + 45 ° to become A-polarized light. This light converges on the interface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter.

The S-polarized light from the spatial light modulator 216 is
Polarizing beam splitter surface 3 of prism block 315A
15Aa, and further reflected by the reflecting surface 315Ab, enters the prism block 315B, and is reflected by the reflecting surface 315B.
Bb is sequentially reflected by the polarization beam splitter surface 315Ba, and is incident on the split optical rotation plate 214B. Here, since the optical rotation plates 214BR and 214BL of the two-part optical rotation plate 214B are both turned off, the light passing through the optical rotation plate 214BR is rotated by -45 ° to become B-polarized light, and the optical rotation plate 14BL is turned off. The transmitted light has its polarization direction rotated by + 45 ° and becomes A-polarized light. This light converges on the surface of the transparent substrate 3 so as to have the smallest diameter.

In the information recording layer 2, the B-polarized light from the optical rotation plate 214AR and the B-polarized light from the optical rotation plate 214BR interfere, and the A-polarized light from the optical rotation plate 214AL and the optically polarized light
The interference pattern with the A-polarized light from the 14BL forms an interference pattern, and the fixing light passes through a part of the area where the interference pattern is formed in the information recording layer 2, and as a result, the fixing light A recording area 260 where the information of the passed portion is fixed, the information is recorded by the interference pattern, and the information is fixed.
Are formed in layers. In the present embodiment, the recording area 26
0 is a reflection type (Lipman type) volume hologram.

In this embodiment, the light from the two-part optical rotation plate 214A and the light from the two-part optical rotation plate 214B applied to the information recording layer 2 from opposite directions have complementary patterns. Each of them can be regarded as an information light carrying information to be recorded on the information recording layer 2.
When the light from the split optical rotation plate 214A is viewed as the information light, the light from the split optical rotation plate 214B becomes the reference light for recording, and conversely, when the light from the split optical rotation plate 214B is viewed as the information light. The light from the two-divided optical rotation plate 214A becomes the recording reference light.

Next, the operation at the time of reproduction will be described. At the time of reproduction, the spatial light modulator 216 selects a state in which all pixels are off (+ 90 °) and a state in which all pixels are on (0 °) as necessary. Also, the two-part optical rotation plates 214A, 21
4B optical rotation plates 214AR, 214AL, 214BR,
214BL are all turned off. The output of the light emitted from the laser coupler 20 is set to a low output for reproduction. Note that the controller 90 predicts the timing at which the light emitted from the objective lens 212A passes through the data area based on the basic clock reproduced from the reproduction signal RF.
While the emitted lights of 2A and 212B pass through the data area,
Make the above settings. While the light emitted from the objective lenses 212A and 212B passes through the data area, focus servo and tracking servo are not performed, and the objective lens 21
2A and 212B are fixed.

When all the pixels of the spatial light modulator 216 are off, the S-polarized laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 217, and the polarization direction is changed by the spatial light modulator 216. +90
Rotated by ° to become P-polarized light. The P-polarized light from the spatial light modulator 216 passes through the polarization beam splitter surface 315Aa of the prism block 315A, and is split into two optical rotation plates 21.
4A. Here, since the optical rotation plates 214AR and 214AL of the two-part optical rotation plate 214A are both turned off, the light passing through the optical rotation plate 214AR has a polarization direction of -4.
The light that has been rotated by 5 ° to become B-polarized light and passed through the optical rotation plate 214AL has its polarization direction rotated by + 45 ° to become A-polarized light. This light converges on the interface between the positioning layer 4 and the protective layer 5 so as to have the smallest diameter.

From the recording area 260 in the information recording layer 2, the reproduction light when the light converging so as to have the smallest diameter on the back side of the information recording layer 2 when viewed from the objective lens 212 A is regarded as the recording reference light. Generated. The reproduction light in this case is divergent light having the smallest diameter on the front side of the information recording layer 2. More specifically, in the upper half area of the recording area 260, B-polarized light from the optical rotation plate 214AR is irradiated,
At the time of recording, the optical rotation plate 214B of the split optical rotation plate 214B
Reproduction light corresponding to the light emitted from R is generated. This reproduction light is B-polarized light, is condensed by the objective lens 212A, passes through the optical rotation plate 214AL of the two-part optical rotation plate 214A, and becomes S-polarized light. Similarly, in the lower half area of the recording area 260, A-polarized light is irradiated from the optical rotation plate 214AL, and reproduction light corresponding to light emitted from the optical rotation plate 214BL of the two-divided optical rotation plate 214B is recorded. Generated. This reproduction light is A-polarized light, is condensed by the objective lens 212A, passes through the optical rotation plate 214AR of the two-part optical rotation plate 214A, and becomes S-polarized light. These S
The polarized reproduction light is reflected by the polarization beam splitter surface 315Aa of the prism block 315A, and is reflected by the convex lens 318.
The light is condensed by A and forms an image on the CCD array 219A.
In this way, on the CCD array 219A, only the portion corresponding to the pixel that was turned on in the spatial light modulator 216 during recording is illuminated brightly, and the two-dimensional pattern is
The information is detected by the CD array 219A and the information is reproduced.

On the other hand, when all the pixels of the spatial light modulator 216 are in the ON state, the S
The polarized laser light is converted into a parallel light beam by the collimator lens 217, and the polarization direction is not rotated by the spatial light modulator 216, and remains as S-polarized light. Spatial light modulator 216
Is reflected by the polarization beam splitter surface 315Aa of the prism block 315A, further reflected by the reflection surface 315Ab, enters the prism block 315B, and is reflected by the reflection surface 315Bb and the polarization beam splitter surface 31.
The light is sequentially reflected at 5Ba, and is incident on the split optical rotation plate 214B. Here, the optical rotation plate 214B of the two-part optical rotation plate 214B
Since both R and 214BL are turned off, the optical rotation plate 2
The light that has passed through 14BR has its polarization direction rotated by −45 ° to become B-polarized light, and the light that has passed through the optical rotation plate 214BL is
The polarization direction is rotated by + 45 ° to become A-polarized light. Light from the two-part optical rotation plate 214B converges on the surface of the transparent substrate 3 so as to have the smallest diameter.

From the recording area 260 in the information recording layer 2, reproduction light is generated when the light from the two-part optical rotation plate 214B is regarded as reproduction reference light. To elaborate,
In the upper half area of the recording area 260, the optical rotation plate 214BR
, And the reproduction light corresponding to the light irradiated from the optical rotation plate 214AR of the two-part optical rotation plate 214A during recording is generated. This reproduction light is B-polarized light, is condensed by the objective lens 212B, passes through the optical rotation plate 214BL of the two-part optical rotation plate 214B, and becomes P-polarized light. Similarly, in the lower half area of the recording area 260, the A-polarized light from the optical rotation plate 214BL is irradiated, and the reproduction light corresponding to the light emitted from the optical rotation plate 214AL of the two-part optical rotation plate 214A during recording is emitted. Generated. This reproduction light is A-polarized light, is condensed by the objective lens 212B, passes through the optical rotation plate 214BR of the two-part optical rotation plate 214B, and becomes P-polarized light. The P-polarized reproduction light is applied to the polarization beam splitter surface 315 of the prism block 315B.
The light passes through Ba and is condensed by the convex lens 318B.
An image is formed on the D array 219B. In this way CCD
On the array 219B, only the portion corresponding to the pixel that was turned off in the spatial light modulator 216 at the time of recording is illuminated brightly, and its two-dimensional pattern is detected by the CCD array 219B to reproduce information.

In this embodiment, as in the third embodiment, information reproduction may be performed with all pixels of the spatial light modulator 216 turned off, or all pixels of the spatial light modulator 216 may be reproduced. May be turned on to reproduce information.

The other structures, operations, and effects of the present embodiment are the same as those of the third embodiment.

In the third and fourth embodiments, ultraviolet light may be used as fixing light. In this case, a photopolymer is used for the information recording layer 2. Recording and fixing of information in the information recording layer 2 proceed as follows. That is, the photopolymer constituting the information recording layer 2 is obtained by dispersing a photopolymerizable monomer in a binder polymer. When an interference pattern is formed in the information recording layer 2, polymerization of the photopolymerizable monomer proceeds in a bright portion of the interference pattern, a concentration gradient of the monomer occurs, and the monomer diffuses from a portion where polymerization has not progressed to a portion where the polymerization has progressed. I do. As a result, a polymer portion where polymerization has progressed, and a portion where the amount of the binder polymer is increased due to the decrease of the monomer are generated, and a refractive index distribution is generated, and information is recorded by the refractive index distribution. Irradiation with ultraviolet light in this state completes the polymerization of unreacted monomers and fixes the recording.

Next, a fifth embodiment of the present invention will be described. The overall configuration of the optical information recording / reproducing apparatus according to the present embodiment is the same as that of FIG. 5 except that the configuration of the pickup is different.

FIG. 24 is an explanatory diagram showing the configuration of a pickup in the optical information recording / reproducing apparatus according to the present embodiment. Hereinafter, the same members as those in the pickup shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.
The optical information recording medium 401 used in the optical information recording / reproducing apparatus according to the present embodiment has a configuration in which transparent protective layers 402, 402 are provided on both sides of the information recording layer 2.

Pickup 411 in the present embodiment
Is an objective lens 412 arranged to face one surface of the optical information recording medium 401 when the optical information recording medium 401 is fixed to the spindle 81;
01, a mirror 418 disposed at a position facing the objective lens 412, and a spatial light modulator 413 disposed on the side of the objective lens 412 opposite to the optical information recording medium 401 in order from the objective lens 412 side. , A beam splitter 414 and a CCD array 19. The pickup 411 further includes a collimator lens 415 and a laser coupler 20 disposed on a side of the beam splitter 414.

The objective lens 412 is disposed so that its optical axis forms an angle of 60 ° with the surface of the optical information recording medium 401. The beam splitter 414 has a semi-reflective surface 414 a whose normal direction is inclined by 45 ° with respect to the optical axis direction of the objective lens 412. Then, a part of the amount of light that enters the beam splitter 414 from the laser coupler 20 side is reflected by the semi-reflective surface 414a and enters the spatial light modulator 413, and a part of the amount of light passes through the semi-reflective surface 414a. It has become.

The spatial light modulator 413 has a large number of pixels arranged in a lattice, and spatially modulates light according to light intensity by selecting a light transmitting state or a light blocking state for each pixel. You can do it.

The pickup 411 further has a total reflection surface 416a that is arranged in the traveling direction of light that enters the beam splitter 414 from the laser coupler 20 side and passes through the semi-reflection surface 414a, and is parallel to the semi-reflection surface 1414a. A prism 416 and a total reflection surface 416a are disposed in the traveling direction of light reflected by the total reflection surface 416a of the prism 416.
Prism 417 having a total reflection surface 417a orthogonal to
And a convex lens 53, a concave lens 54, and a cylindrical lens 55, which are arranged in this order from the prism 417 side in the traveling direction of the light reflected by the total reflection surface 417a. The light emitted from the cylindrical lens 55 is applied to the information recording layer 2 such that the center (optical axis) of the light is orthogonal to the center (optical axis) of the light emitted from the objective lens 412 in the information recording layer 2. Irradiation is carried out. Therefore, the light emitted from the cylindrical lens 55 is applied to the optical information recording medium 401 so as to form an angle of 30 ° with the surface of the optical information recording medium 401. Further, the cylindrical lens 55
The emitted light is thinnest in the information recording layer 2.

Pickup 411 in the present embodiment
Then, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415, enters the beam splitter 414, and a part of the light amount is partially reflected by the semi-reflective surface 41.
4a, a part of the light amount is transmitted through the semi-reflective surface 414a. The light reflected by the semi-reflective surface 414 a passes through the spatial light modulator 413 and
And irradiates the optical information recording medium 401. The light converges on the surface of the mirror 418 so as to have the smallest diameter.

On the other hand, the light transmitted through the semi-reflective surface 414a is
The light is sequentially reflected by the total reflection surface 416a of the prism 416 and the total reflection surface 417a of the prism 417, passes through the convex lens 53 and the concave lens 54 in order, and the diameter of the light beam is reduced. The light emitted from the concave lens 54 is converged by the cylindrical lens 55 only in the optical axis direction of the objective lens 412 to form a light beam having a flat shape, and is applied to the optical information recording medium 401. The light from the objective lens 412 and the light from the cylindrical lens 55 intersect in the information recording layer 2 such that the centers of the respective lights are orthogonal.

At the time of recording information, the light from the objective lens 412 side becomes the information light, the light from the cylindrical lens 55 side becomes the recording reference light, and these information light and the recording reference light are stored in the information recording layer 2. The recording area 420 in which information is recorded is formed in a layered manner by an interference pattern due to interference with the recording medium. In the present embodiment, as shown in FIG.
Of the light from the side, the left half portion in the figure and the flat light from the cylindrical lens 55 side intersect. Therefore, the shape of the recording area 420 formed in the information recording layer 2 is a semicircular plate shape.

From the optical information recording medium 401 to the objective lens 41
The light traveling toward the second side is transmitted to the objective lens 412 and the spatial light modulator 4.
13 in order, and a part of the light amount is changed to a beam splitter 41.
4 through the semi-reflective surface 414 a and enters the CCD array 19.

Next, the operation of the optical information recording / reproducing apparatus according to the present embodiment will be described. In the optical information recording / reproducing apparatus according to the present embodiment, both a transmission hologram and a reflection hologram can be formed on the information recording layer 2 of the optical information recording medium 401.

First, a case where a transmission type hologram is formed on the information recording layer 2 will be described. In this case, at the time of recording, the right half area 4 of the spatial light modulator 413 in the drawing is shown.
In 13R, all the pixels are in the cutoff state, and the left half region 4
In 13L, a transmission state and a blocking state are selected for each pixel according to information to be recorded. In addition, the output of the light emitted from the laser coupler 20 is pulsed to a high output for recording.

The laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light amount is reflected by the semi-reflective surface 414a, and a part of the light amount is reflected by the semi-reflective surface 414a.
Through. The light reflected by the semi-reflective surface 414a enters the spatial light modulator 413, and from the left half region 413L,
Light modulated according to information to be recorded is emitted. This light is used as information light. This information light is condensed by the objective lens 412 and is applied to the optical information recording medium 401.

On the other hand, the light transmitted through the semi-reflective surface 414a is
The light is reflected by the total reflection surface 416a of the prism 416 and the total reflection surface 417a of the prism 417 in order, passes through the convex lens 53, the concave lens 54, and the cylindrical lens 55 in order, and becomes a flat-shaped light flux, and irradiates the optical information recording medium 401. Is done. This light is used as recording reference light.

The information light from the objective lens 412 and the recording reference light from the cylindrical lens 55 intersect in the information recording layer 2 so that the centers of the respective lights are orthogonal. Then, at a portion where the information light and the recording reference light intersect,
When an interference pattern due to the interference of these lights is formed and the output of the emitted light from the laser coupler 20 becomes high,
An interference pattern by the information light and the recording reference light is volumetrically recorded in the information recording layer 2, and a recording region 420 formed of a transmission type volume hologram is formed in a layered manner.

At the time of reproduction, in the right half area 413R of the spatial light modulator 413, all the pixels are in the transmitting state, and in the left half area 413L, all the pixels are in the blocking state. The output of the light emitted from the laser coupler 20 is set to a low output for recording.

The laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light amount is reflected by the semi-reflective surface 414a, and a part of the light amount is reflected by the semi-reflective surface 414a.
Through. The light transmitted through the semi-reflective surface 414a is sequentially reflected on the total reflection surface 416a of the prism 416 and the total reflection surface 417a of the prism 417, and the convex lens 53 and the concave lens 5 are reflected.
4 and the cylindrical lens 55 in order, and is made into a light beam having a flat shape, and is irradiated on the optical information recording medium 401. This light is used as reference light for reproduction. When this recording reference light is applied to the recording area 420 in the information recording layer 2, the recording area 420 generates reproduction light corresponding to the information light at the time of recording. The reproduced light travels to the mirror 418 side while converging, converges on the mirror 418 so as to have the smallest diameter, is reflected by the mirror 418, travels to the objective lens 412 side while diffusing, and travels to the objective lens 412.
Are converted into parallel light beams, pass through the right half region 413R of the spatial light modulator 413, a part of the light amount passes through the semi-reflection surface 414a of the beam splitter 414, and the CCD array 1
9 is incident. Then, information is reproduced by detecting the two-dimensional pattern of the reproduction light by the CCD array 19.

At the time of reproduction, the laser beam emitted from the laser coupler 20 passes through the right half area 413R of the spatial light modulator 413 and irradiates the optical information recording medium 401. Reflected by the objective lens 4
After passing through 12, the light is blocked in the left half region 413L of the spatial light modulator 413.

Next, a case where a reflection hologram is formed on the information recording layer 2 in the present embodiment will be described. In this case, at the time of recording, in the left half area 413L of the spatial light modulator 413, all the pixels are in the cutoff state, and in the right half area 413R, the transmission state and the cutoff state are selected for each pixel according to the information to be recorded. I do. In addition, the output of the light emitted from the laser coupler 20 is pulsed to a high output for recording.

The laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light amount is reflected by the semi-reflective surface 414a, and a part of the light amount is reflected by the semi-reflective surface 414a.
Through. The light reflected by the semi-reflective surface 414a enters the spatial light modulator 413, and from the right half region 413R,
Light modulated according to information to be recorded is emitted. This light is condensed by the objective lens 412, irradiates the optical information recording medium 401, passes through the optical information recording medium 401, converges on the mirror 418 so as to have the smallest diameter, and is reflected by the mirror 418. The light enters the optical information recording medium 401 again while being diffused. This light is used as information light.

On the other hand, the light transmitted through the semi-reflective surface 414a is
The light is reflected by the total reflection surface 416a of the prism 416 and the total reflection surface 417a of the prism 417 in order, passes through the convex lens 53, the concave lens 54, and the cylindrical lens 55 in order, and becomes a flat-shaped light flux, and irradiates the optical information recording medium 401. Is done. This light is used as recording reference light.

The information light from the mirror 418 and the recording reference light from the cylindrical lens 55 intersect in the information recording layer 2 such that the centers of the lights are orthogonal. And
An interference pattern due to the interference of these light beams is formed at a portion where the information light and the recording reference light intersect. When the output light of the laser coupler 20 becomes high, the information light and the recording reference light are output. An interference pattern due to light is volumetrically recorded in the information recording layer 2, and a recording area 420 formed of a reflective volume hologram is formed in a layered manner.

At the time of reproduction, all the pixels are in the transmission state in the left half area 413L of the spatial light modulator 413, and all the pixels are in the cutoff state in the right half area 413R. The output of the light emitted from the laser coupler 20 is set to a low output for recording.

The laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light amount is reflected by the semi-reflective surface 414a, and a part of the light amount is reflected by the semi-reflective surface 414a.
Through. The light transmitted through the semi-reflective surface 414a is sequentially reflected on the total reflection surface 416a of the prism 416 and the total reflection surface 417a of the prism 417, and the convex lens 53 and the concave lens 5 are reflected.
4 and the cylindrical lens 55 in order, and is made into a light beam having a flat shape, and is irradiated on the optical information recording medium 401. This light is used as reference light for reproduction. When this recording reference light is applied to the recording area 420 in the information recording layer 2, the recording area 420 generates reproduction light corresponding to the information light at the time of recording. The reproduced light travels to the objective lens 412 side while being diffused, is converted into a parallel light beam by the objective lens 412, and is formed in the left half area 413 of the spatial light modulator 413.
L, a part of the light amount passes through the semi-reflective surface 414 a of the beam splitter 414 and enters the CCD array 19. Then, information is reproduced by detecting the two-dimensional pattern of the reproduction light by the CCD array 19.

At the time of reproduction, the laser light emitted from the laser coupler 20 passes through the left half area 413L of the spatial light modulator 413 and irradiates the optical information recording medium 401. Reflected by the objective lens 4
After passing through 12, the light is blocked in the right half region 413R of the spatial light modulator 413.

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

Next, a sixth embodiment of the present invention will be described. The overall configuration of the optical information recording / reproducing apparatus according to the present embodiment is the same as that of FIG. 5 except that the configuration of the pickup is different.

FIG. 25 is an explanatory diagram showing a configuration of a pickup in the optical information recording / reproducing apparatus according to the present embodiment. Hereinafter, the same members as those in the pickup shown in FIG. 24 are denoted by the same reference numerals, and detailed description thereof will be omitted. The optical information recording medium 501 used in the optical information recording / reproducing apparatus according to the present embodiment has a transparent substrate 502 on one side of the information recording layer 2 and a transparent protective layer 50 on the other side.
3 is provided. The outer surface of the transparent substrate 502 is a reflection surface 504.

[0211] Pickup 511 in the present embodiment
Are an objective lens 412 disposed so as to face one surface of the optical information recording medium 501 when the optical information recording medium 501 is fixed to the spindle 81;
On the side opposite to the optical information recording medium 501, a spatial light modulator 413, a beam splitter 414, and a CCD array 19 are sequentially provided from the objective lens 412 side. The pickup 511 further includes a collimator lens 415 and a laser coupler 20 disposed on a side of the beam splitter 414. In the present embodiment, the objective lens 412 has an optical axis whose optical axis is
It is arranged so as to be perpendicular to the plane No. 01.

The pickup 411 further includes a mirror 512 disposed in the traveling direction of light that enters the beam splitter 414 from the laser coupler 20 side and passes through the semi-reflective surface 414a, and a light reflected by the mirror 512. A convex lens 53 arranged in the traveling direction from the mirror 512 side,
A concave lens 54 and a cylindrical lens 55 are provided. In the present embodiment, the cylindrical lens 55
The light emitted from the optical information recording medium 501 is irradiated onto the optical information recording medium 501 so that the center (optical axis) forms an angle of 45 ° with the surface of the optical information recording medium 501. At the point of intersection with the light from the objective lens 412 side. The light emitted from the cylindrical lens 55 is the thinnest in the information recording layer 2.

[0213] Pickup 511 in the present embodiment
Then, the laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415, enters the beam splitter 414, and a part of the light amount is partially reflected by the semi-reflective surface 41.
4a, a part of the light amount is transmitted through the semi-reflective surface 414a. The light reflected by the semi-reflective surface 414 a passes through the spatial light modulator 413 and
And the light is irradiated onto the optical information recording medium 501. The light converges on the reflection surface 504 of the information recording medium 501 so as to have the smallest diameter.

On the other hand, the light transmitted through the semi-reflective surface 414a is
Reflected by the mirror 512, the convex lens 53 and the concave lens 54
, So that the diameter of the light beam is reduced. The light emitted from the concave lens 54 is transmitted to the cylindrical lens 5.
5, a light beam having a flat shape is formed.
01 in the information recording layer 2 and the objective lens 412
It intersects with light from the side.

At the time of recording information, the light from the objective lens 412 side becomes the information light, the light from the cylindrical lens 55 side becomes the recording reference light, and these information light and the recording reference light are stored in the information recording layer 2. A recording area 520 in which information is recorded is formed in a layered manner by an interference pattern due to interference with the recording medium. In the present embodiment, as shown in FIG. 25, in the information recording layer 2, the objective lens 412
Of the light from the side, the right half portion in the figure and the flat light from the cylindrical lens 55 side intersect. Therefore, the shape of the recording area 420 formed in the information recording layer 2 is a semicircular plate shape.

From the optical information recording medium 501 to the objective lens 41
The light traveling toward the second side is transmitted to the objective lens 412 and the spatial light modulator 4.
13 in order, and a part of the light amount
4 through the semi-reflective surface 414 a and enters the CCD array 19.

Next, the operation of the optical information recording / reproducing apparatus according to the present embodiment will be described. In the optical information recording / reproducing apparatus according to the present embodiment, it is possible to form both a transmission hologram and a reflection hologram on the information recording layer 2 of the optical information recording medium 501.

First, a case where a transmission type hologram is formed on the information recording layer 2 will be described. In this case, at the time of recording, the left half area 4 of the spatial light modulator 413 in the drawing is shown.
In 13L, all the pixels are in the cutoff state, and the right half region 4
In 13R, a transmission state and a blocking state are selected for each pixel according to information to be recorded. In addition, the output of the light emitted from the laser coupler 20 is pulsed to a high output for recording.

The laser beam emitted from the laser coupler 20 is converted into a parallel beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light quantity is reflected by the semi-reflective surface 414a, and a part of the light quantity is reflected by the semi-reflective
Through. The light reflected by the semi-reflective surface 414a enters the spatial light modulator 413, and from the right half region 413R,
Light modulated according to information to be recorded is emitted. This light is used as information light. This information light is condensed by the objective lens 412 and is applied to the optical information recording medium 501.

On the other hand, the light transmitted through the semi-reflective surface 414a is
Reflected by mirror 512, convex lens 53, concave lens 54
Then, the light beam passes through the cylindrical lens 55 in order and becomes a flat-shaped light beam, and is irradiated on the optical information recording medium 501. This light is used as recording reference light.

The information light from the objective lens 412 and the recording reference light from the cylindrical lens 55 intersect in the information recording layer 2. Then, an interference pattern due to the interference of these light beams is formed at the intersection of the information light beam and the recording reference light beam. The interference pattern by the reference light for use is volumetrically recorded in the information recording layer 2, and a recording region 520 formed of a transmission type volume hologram is formed in a layered manner.

At the time of reproduction, in the right half area 413R of the spatial light modulator 413, all pixels are in a cutoff state, and in the left half area 413L, all pixels are in a transmissive state. The output of the light emitted from the laser coupler 20 is set to a low output for recording.

The laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light amount is reflected by the semi-reflective surface 414a, and a part of the light amount is reflected by the semi-reflective surface 414a.
Through. The light transmitted through the semi-reflective surface 414 a is reflected by the mirror 512, passes through the convex lens 53, the concave lens 54, and the cylindrical lens 55 in order, becomes a light beam having a flat shape, and is irradiated on the optical information recording medium 501. This light is used as reference light for reproduction. When the recording reference area 520 in the information recording layer 2 is irradiated with the reproduction reference light, the recording area 5
From 20, reproduction light corresponding to the information light at the time of recording is generated. The reproduced light travels to the reflecting surface 504 side while converging, converges to have the smallest diameter on the reflecting surface 504, is reflected by the reflecting surface 504, travels to the objective lens 412 side while diffusing, and The light beam is converted into a parallel light beam by the lens 412, and the left half region 4 of the spatial light modulator 413
13L, and a part of the light amount passes through the beam splitter 414.
And enters the CCD array 19 through the semi-reflective surface 414a. Then, information is reproduced by detecting the two-dimensional pattern of the reproduction light by the CCD array 19.

During reproduction, the laser light emitted from the laser coupler 20 passes through the left half area 413L of the spatial light modulator 413 and irradiates the optical information recording medium 501. 504, reflected by objective lens 4
After passing through 12, the light is blocked in the right half region 413R of the spatial light modulator 413.

Next, a case where a reflection hologram is formed on the information recording layer 2 in the present embodiment will be described. In this case, at the time of recording, in the right half area 413R of the spatial light modulator 413, all the pixels are in the cutoff state, and in the left half area 413L, the transmission state and the cutoff state are selected for each pixel according to the information to be recorded. I do. In addition, the output of the light emitted from the laser coupler 20 is pulsed to a high output for recording.

The laser light emitted from the laser coupler 20 is converted into a parallel light beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light quantity is reflected by the semi-reflective surface 414a, and a part of the light quantity is reflected by the semi-reflective
Through. The light reflected by the semi-reflective surface 414a enters the spatial light modulator 413, and from the left half region 413L,
Light modulated according to information to be recorded is emitted. This light is condensed by the objective lens 412, irradiates the optical information recording medium 501, passes through the information recording layer 2, converges on the reflecting surface 504 so as to have the smallest diameter, and is reflected by the reflecting surface 504. While diffusing into the information recording layer 2 again. This light is used as information light.

On the other hand, the light transmitted through the semi-reflective surface 414a is
Reflected by mirror 512, convex lens 53, concave lens 54
Then, the light beam passes through the cylindrical lens 55 in order and becomes a flat-shaped light beam, and is irradiated on the optical information recording medium 501. This light is used as recording reference light.

The information light from the reflection surface 504 and the recording reference light from the cylindrical lens 55 side
Cross within. Then, an interference pattern due to the interference of these light beams is formed at the intersection of the information light beam and the recording reference light beam. The interference pattern by the reference light for use is volumetrically recorded in the information recording layer 2, and the recording region 520 formed of a reflection type volume hologram is formed in a layered manner.

At the time of reproduction, in the right half area 413R of the spatial light modulator 413, all the pixels are in the transmitting state, and in the left half area 413L, all the pixels are in the blocking state. The output of the light emitted from the laser coupler 20 is set to a low output for recording.

[0230] The laser beam emitted from the laser coupler 20 is converted into a parallel beam by the collimator lens 415.
The light enters the beam splitter 414, a part of the light amount is reflected by the semi-reflective surface 414a, and a part of the light amount is reflected by the semi-reflective surface 414a.
Through. The light transmitted through the semi-reflective surface 414 a is reflected by the mirror 512, passes through the convex lens 53, the concave lens 54, and the cylindrical lens 55 in order, becomes a light beam having a flat shape, and is irradiated on the optical information recording medium 501. This light is used as reference light for reproduction. When the recording reference area 520 in the information recording layer 2 is irradiated with the reproduction reference light, the recording area 5
From 20, reproduction light corresponding to the information light at the time of recording is generated. The reproduction light is diffused while the objective lens 41
The beam proceeds to the second side, is converted into a parallel light beam by the objective lens 412, passes through the right half region 413R of the spatial light modulator 413, and a part of the light amount is
The light passes through 14 a and enters the CCD array 19. Then, information is reproduced by detecting the two-dimensional pattern of the reproduction light by the CCD array 19.

At the time of reproduction, the laser beam emitted from the laser coupler 20 passes through the right half region 413R of the spatial light modulator 413 and irradiates the optical information recording medium 501. 504, reflected by objective lens 4
After passing through 12, the light is blocked in the left half region 413L of the spatial light modulator 413.

Other structures, operations, and effects of the present embodiment are the same as those of the fifth embodiment.

The present invention is not limited to the above embodiments. For example, in each embodiment, a plurality of recording areas are formed in the information recording layer 2 without overlapping each other. Multiple recording may be performed such that adjacent recording areas partially overlap each other within a range where information for each recording area can be separated.

In the case where the light beam is modulated in accordance with the information to be recorded, in each of the embodiments, the light beam is modulated by a difference in polarization or light intensity. However, the light beam may be modulated by a phase difference or the like. Good.

In each of the first, second, fifth, and sixth embodiments, the light flux of the recording reference light of the information light and the recording reference light has a flat shape. The light beam may have a flat shape.

The form of the optical information recording medium is not limited to a disk, but may be a card, a tape, or the like.

[0237]

As described above, claims 1 to 6
According to the optical information recording device described in any one of the above or the optical information recording method according to the twelfth aspect, one of the information light and the reference light for recording has a flat shape and intersects in the information recording layer. The information recording layer is irradiated with the information light and the recording reference light as described above to form a recording area in the information recording layer where information is recorded by an interference pattern due to interference between the information light and the recording reference light. Since it is formed, it is possible to record information at a higher density on an optical information recording medium on which information is recorded using holography.

According to the optical information recording device of the present invention, an optical information recording medium having a positioning area for recording information for positioning the information light and the recording reference light is used. Since the positions of the information light and the recording reference light with respect to the optical information recording medium are controlled using the information recorded in the positioning area, it is possible to further accurately position the light for recording. It works.

According to the optical information recording apparatus of the present invention, the recording optical system has a solid immersion lens disposed to face the optical information recording medium and through which the information light and the recording reference light pass. So,
There is an effect that aberrations of the information light and the recording reference light can be reduced.

According to the optical information recording device of the present invention or the optical information recording method of the present invention, an interference pattern in the information recording layer due to interference between the information light and the recording reference light. The information recording layer is irradiated with the information light and the recording reference light so that the information recorded by the interference pattern is fixed in a region where the interference pattern is formed in the information recording layer so that The fixing light of a flat light beam is irradiated so as to pass through a part of the area where the interference pattern is formed, so that the information is recorded by the interference pattern and the information is fixed in the information recording layer. The recording area is formed in a layered manner, so that information can be recorded at a higher density on an optical information recording medium on which information is recorded using holography, and the optical information can be recorded. An effect that information to the recording medium can be recorded to and fixing at any time.

According to the optical information recording apparatus of the ninth aspect, an optical information recording medium having a positioning area for recording information for positioning the information light and the recording reference light is used. Since the positions of the information light and the recording reference light with respect to the optical information recording medium are controlled using the information recorded in the positioning area, it is possible to further accurately position the light for recording. It works.

According to the optical information recording apparatus of the eleventh aspect, the recording optical system has the solid immersion lens arranged to face the optical information recording medium and through which the information light and the recording reference light pass. With such a configuration, it is possible to further reduce the aberration of the information light and the recording reference light.

According to the optical information recording / reproducing apparatus described in any one of claims 14 to 17, or the optical information recording / reproducing method described in claim 22, when recording information, one of the information light and the recording reference light is used. The information light and the recording reference light are irradiated on the information recording layer so as to intersect in the information recording layer so as to intersect in the information recording layer. A recording area in which information is recorded by an interference pattern due to interference is formed in layers, and at the time of reproducing information, the information recording layer is irradiated with reproduction reference light corresponding to the recording reference light at the time of recording. Since the reproducing light generated from the optical information recording medium is collected and detected, information is recorded at a higher density on an optical information recording medium on which information is recorded using holography, and the optical information recording medium is recorded. Information recorded in An effect that earnestly can be reproduced.

According to the optical information recording / reproducing apparatus of the present invention, a positioning area in which information for positioning the information light, the recording reference light and the reproduction reference light is recorded as the optical information recording medium. Using the information provided, the information recorded in the positioning area is used to control the positions of the information light, the recording reference light, and the reproduction reference light with respect to the optical information recording medium. The effect is that the positioning of the light can be accurately performed.

According to the optical information recording / reproducing apparatus of the present invention, the recording optical system includes a solid immersion lens arranged to face the optical information recording medium and through which the information light and the recording reference light pass. Since the reproducing optical system has a solid immersion lens disposed so as to face the optical information recording medium and through which the reproducing light passes, the aberration of the information light, the recording reference light, and the reproducing light is further reduced. This has the effect of being able to reduce.

According to the optical information recording / reproducing apparatus described in any one of claims 18 to 21 or the optical information recording / reproducing method described in claim 23, at the time of recording information, the information light and the recording reference are recorded in the information recording layer. The information recording layer is irradiated with the information light and the recording reference light so that an interference pattern due to interference with light is formed. The fixing light of a flat light beam for fixing the information to be recorded is irradiated so as to pass through a part of the area where the interference pattern is formed, and the information is formed in the information recording layer by the interference pattern. A recording area in which the recorded and information is fixed is formed in a layered form, and at the time of reproducing the information, the information recording layer is irradiated with a reproduction reference light corresponding to the recording reference light at the time of recording. Since the generated reproduction light is collected and detected, it is possible to record information at a higher density on an optical information recording medium on which information is recorded using holography, Information can be recorded and fixed on the optical information recording medium at any time,
There is an effect that information recorded on the optical information recording medium can be appropriately reproduced.

According to the optical information recording / reproducing apparatus of the twentieth aspect, the optical information recording medium has a positioning area in which information for positioning the information light, the recording reference light, and the reproduction reference light is recorded. Using the information provided, the information recorded in the positioning area is used to control the positions of the information light, the recording reference light, and the reproduction reference light with respect to the optical information recording medium. The effect is that the positioning of the light can be accurately performed.

According to the optical information recording / reproducing apparatus of the present invention, the recording optical system includes a solid immersion lens arranged to face the optical information recording medium and through which the information light and the recording reference light pass. Since the reproducing optical system has a solid immersion lens disposed so as to face the optical information recording medium and through which the reproducing light passes, the aberration of the information light, the recording reference light, and the reproducing light is further reduced. This has the effect of being able to reduce.

[Brief description of the 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 apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for describing SIL in FIG. 1 in detail;

FIG. 3 is a sectional view showing an example of a support mechanism of the SIL in FIG. 1;

FIG. 4 is a side view showing another example of the support mechanism of the SIL in FIG. 1;

FIG. 5 is a block diagram showing an overall configuration of the optical information recording / reproducing apparatus according to the first embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of the laser coupler in FIG. 1;

FIG. 7 is a side view of the laser coupler in FIG.

8 is a block diagram illustrating a configuration of a detection circuit in FIG.

FIG. 9 is an explanatory diagram showing a recording area formed on an information recording layer of the optical information recording medium according to the first embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a recording area formed on an information recording layer of the optical information recording medium according to the first embodiment of the present invention.

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

FIG. 12 is an explanatory diagram for describing a method of recognizing a reference position in a reproduction light pattern from detection data of the CCD array in FIG. 1;

13 is an explanatory diagram showing a pattern of information light and a pattern of reproduction light in the pickup shown in FIG. 1;

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

FIG. 15 is an explanatory view conceptually showing an optical information recording medium in which a hologram representing address information and the like is recorded in an address servo area.

FIG. 16 is an explanatory diagram showing a configuration of a pickup according to a modification of the first embodiment of the present invention.

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

FIG. 18 is an explanatory diagram showing a configuration of a pickup in an optical information recording / reproducing device according to a second embodiment of the present invention.

FIG. 19 is an explanatory diagram showing a configuration of a pickup in an optical information recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 20 is an explanatory diagram showing a configuration of a pickup in an optical information recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 21 is an explanatory diagram for explaining polarized light used in the third embodiment of the present invention.

FIG. 22 is an explanatory diagram showing a configuration of a pickup in an optical information recording / reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 23 is an explanatory diagram showing a configuration of a pickup in an optical information recording / reproducing device according to a fourth embodiment of the present invention.

FIG. 24 is an explanatory diagram showing a configuration of a pickup in an optical information recording / reproducing apparatus according to a fifth embodiment of the present invention.

FIG. 25 is an explanatory diagram showing a configuration of a pickup in an optical information recording / reproducing device according to a sixth embodiment of the present invention.

FIG. 26 is a perspective view showing a schematic configuration of a recording / reproducing system in conventional digital volume holography.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical information recording medium, 2 ... Information recording layer, 3 ... Positioning layer, 10 ... Optical information recording / reproducing apparatus, 11 ... Pickup,
12A, 12B: SIL, 13A, 13B: Objective lens, 14A, 14B: Actuator, 15: Spatial light modulator, 19: CCD array, 20: Laser coupler.

Claims (23)

[Claims] 1. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern caused by interference between an information light carrying information and a recording reference light. An optical information recording apparatus for generating information light carrying information and a recording reference light, and recording light generating means for generating information light and recording reference light in the information recording layer by interference between the information light and the recording reference light. One of the information light and the recording reference light has a flat shape so that the recording area where information is recorded by the interference pattern is formed in a layered shape, and the information light and the information light are arranged to intersect in the information recording layer. An optical information recording apparatus, comprising: a recording optical system for irradiating a recording reference beam to an information recording layer. 2. The optical information recording apparatus according to claim 1, further comprising a position control means for controlling positions of the information light and the recording reference light with respect to the optical information recording medium. 3. An optical information recording medium having a positioning area in which information for positioning an information light and a recording reference light is recorded, wherein the position control means comprises:
3. The optical information recording apparatus according to claim 2, wherein the positions of the information light and the recording reference light with respect to the optical information recording medium are controlled using the information recorded in the positioning area. 4. The information processing apparatus according to claim 1, wherein the position control means includes:
3. The optical information recording apparatus according to claim 2, wherein the positions of the information light and the recording reference light with respect to the optical information recording medium are controlled so that a plurality of recording areas are formed without overlapping each other. 5. The optical information according to claim 1, wherein the recording optical system irradiates the information recording layer with the information light and the recording reference light such that their centers are orthogonal to each other. Recording device. 6. The optical information according to claim 1, wherein the recording optical system includes a solid immersion lens arranged to face the optical information recording medium and through which information light and recording reference light pass. Recording device. 7. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern due to interference between an information light carrying information and a recording reference light. An optical information recording apparatus for generating an information light carrying information and a recording reference light; and interference due to interference between the information light and the recording reference light in the information recording layer. Recording light irradiating means for irradiating the information recording layer with information light and recording reference light so that a pattern is formed; information is recorded in the information recording layer by the interference pattern; A flat area for fixing the information recorded by the interference pattern to the area where the interference pattern is formed in the information recording layer so that the recording area where the is fixed is formed in a layer shape. An optical information recording apparatus comprising: fixing light irradiating means for irradiating fixing light of a shape light beam so as to pass through a part of an area in which an interference pattern is formed. 8. The optical information recording apparatus according to claim 7, further comprising position control means for controlling positions of the information light and the recording reference light with respect to the optical information recording medium. 9. An optical information recording medium having a positioning area in which information for positioning an information light and a recording reference light is recorded, wherein the position control means comprises:
9. The optical information recording apparatus according to claim 8, wherein the positions of the information light and the recording reference light with respect to the optical information recording medium are controlled using information recorded in the positioning area. 10. The position control means controls a position of an information light and a recording reference light with respect to an optical information recording medium such that a plurality of recording areas are formed without overlapping each other in an information recording layer. The optical information recording apparatus according to claim 8, wherein: 11. The optical information according to claim 7, wherein the recording optical system has a solid immersion lens arranged to face the optical information recording medium and through which the information light and the recording reference light pass. Recording device. 12. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern caused by interference between an information light carrying information and a recording reference light. An information light carrying information and a recording reference light, wherein one of the information light and the recording reference light has a flat shape, and is formed in the information recording layer. By irradiating the information recording layer with information light and recording reference light so as to intersect,
An optical information recording method, wherein a recording area in which information is recorded in an information recording layer by an interference pattern due to interference between an information light and a recording reference light is formed in a layered manner. 13. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern caused by interference between an information light carrying information and a recording reference light. An optical information recording method for generating an information light carrying information and a reference light for recording, wherein an interference pattern due to interference between the information light and the reference light for recording is formed in the information recording layer. Irradiating the information recording layer with the information light and the recording reference light, and fixing the information recorded by the interference pattern to a region where the interference pattern is formed in the information recording layer. By irradiating the fixing light of the shape light beam so as to pass through a part of the area where the interference pattern is formed, information is recorded in the information recording layer by the interference pattern and the information is recorded. An optical information recording method comprising forming a fixed recording area in a layered manner. 14. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern due to interference between an information light carrying information and a recording reference light. And an optical information recording / reproducing apparatus for reproducing information from an optical information recording medium, comprising: an information light carrying information and a recording light generating means for generating a recording reference light; and One of the information light and the recording reference light has a flat shape so that a recording area where information is recorded by an interference pattern due to interference between the information light and the recording reference light is formed in a layered manner, A recording optical system for irradiating the information recording layer with the information light and the recording reference light so as to intersect within the information recording layer; and a reproduction reference corresponding to the recording reference light during recording on the information recording layer. Illuminate the light A reproduction optical system for collecting the reproduction light generated from the information recording layer by irradiating the reproduction reference light, and a detecting means for detecting the reproduction light collected by the reproduction optical system. An optical information recording / reproducing device comprising: 15. An information beam for the optical information recording medium,
15. The optical information recording / reproducing apparatus according to claim 14, further comprising position control means for controlling positions of the recording reference light and the reproduction reference light. 16. An optical information recording medium comprising: an information light;
A device having a positioning area in which information for positioning of the recording reference light and the reproduction reference light is recorded is used, and the position control means uses the information recorded in the positioning region to record an optical information recording medium. 16. The optical information recording / reproducing apparatus according to claim 15, wherein the positions of the information light, the recording reference light, and the reproduction reference light with respect to the position are controlled. 17. The recording optical system has a solid immersion lens disposed to face an optical information recording medium and through which information light and recording reference light pass, and wherein the reproduction optical system is an optical information recording medium. 15. The optical information recording / reproducing apparatus according to claim 14, further comprising a solid immersion lens disposed so as to face the lens and through which reproduction light passes. 18. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern caused by interference between information-bearing information and recording reference light. And an optical information recording / reproducing apparatus for reproducing information from an optical information recording medium, comprising: an information light carrying information and a recording light generating means for generating a recording reference light; and Recording light irradiating means for irradiating the information recording layer with the information light and the recording reference light so that an interference pattern due to interference between the information light and the recording reference light is formed; In the information recording layer, an interference pattern is formed on an area on which the interference pattern is formed so that a recording area on which information is recorded and the information is fixed is formed in a layered manner. Fixing light irradiating means for irradiating fixing light of a flat light beam for fixing information to be recorded by the sensor so as to pass through a part of the area where the interference pattern is formed; and information recording. A layer is irradiated with a reproduction reference light corresponding to the recording reference light at the time of recording, and a reproduction optical system for collecting reproduction light generated from the information recording layer by being irradiated with the reproduction reference light. An optical information recording / reproducing apparatus, comprising: a detecting unit configured to detect reproduction light collected by the reproducing optical system. 19. An information beam for the optical information recording medium,
19. The optical information recording / reproducing apparatus according to claim 18, further comprising position control means for controlling positions of the recording reference light and the reproduction reference light. 20. An optical information recording medium comprising: information light;
A device having a positioning area in which information for positioning of the recording reference light and the reproduction reference light is recorded is used, and the position control means uses the information recorded in the positioning region to record an optical information recording medium. 20. The optical information recording / reproducing apparatus according to claim 19, wherein the positions of the information light, the recording reference light, and the reproduction reference light with respect to are controlled. 21. The recording optical system has a solid immersion lens arranged to face an optical information recording medium and through which information light and recording reference light pass, and wherein the reproduction optical system is an optical information recording medium. 19. The optical information recording / reproducing apparatus according to claim 18, further comprising a solid immersion lens disposed so as to face the recording medium and through which reproduction light passes. 22. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern caused by interference between an information light carrying information and a recording reference light. An optical information recording / reproducing method for reproducing information from an optical information recording medium, comprising: generating an information light carrying information and a recording reference light when recording information; One of the light beams is formed into a flat shape, and the information recording layer is irradiated with the information light and the recording reference light so as to intersect in the information recording layer. A recording area in which information is recorded in an interference pattern due to interference with the reference light for recording is formed in layers, and when information is reproduced, the information recording layer is irradiated with reproduction reference light corresponding to the recording reference light for recording. Together, the optical information recording and reproducing method characterized by collecting and reproducing light for reproduction reference light is generated from the information recording layer by being irradiated to detect the collected reproduction light. 23. Using holography, information is recorded on an optical information recording medium having an information recording layer on which information is recorded by an interference pattern due to interference between an information light carrying information and a recording reference light. And an optical information recording / reproducing method for reproducing information from an optical information recording medium, wherein, when recording information, an information light carrying information and a recording reference light are generated, and the information light is recorded in the information recording layer. The information light and the reference light for recording are irradiated on the information recording layer so that an interference pattern due to interference between the light and the recording reference light is formed. By irradiating fixing light of a flat light beam for fixing information recorded by the interference pattern so as to pass through a part of the area where the interference pattern is formed, information is obtained. In the recording layer, a recording area in which information is recorded by an interference pattern and the information is fixed is formed in a layer shape. When information is reproduced, the information recording layer has a reproduction reference light corresponding to the recording reference light at the time of recording. An optical information recording / reproducing method, comprising: irradiating the information recording layer with a reference light for reproduction, collecting reproduction light generated from the information recording layer, and detecting the collected reproduction light.