JP2000228014A - Method and device for recording information of optical recording medium, method and device for reproducing information, and optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record and reproduce information on/from a recording medium at a high speed and with efficiency where information is recorded by forming three-dimensional recording marks. SOLUTION: This is a method/device for recording and reproducing information of an optical recording medium 6 which is arranged to record information on the optical recording medium 6 where plural marks 7 can be formed at predetermined positions including a beam waist of a light beam 1 and its surroundings by emitting the light beam 1. The marks 7 are formed on as if predetermined loci were plotted at recording mark positions in the recording medium by it that the beam waist position of the light beam is relatively moved. It does not matter what shape the optical recording medium 6 takes, disk-shape, hexahedral form, cylindrical form, truncated-cone-shape, or card-shape. Any recording and reproducing system can be used as far as it performs optical recording. As typical prescribed loci, a spiral form, a tree ring form, a rectangular spiral form, a sinusoidal form, a zigzag form, etc., can be mentioned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording method and apparatus for an optical recording medium, an information reproducing method and an apparatus, and an optical recording medium. The present invention relates to an information recording method and device, an information reproducing method and device, and an optical recording medium used in such an information recording and reproducing method and device, which are continuously recorded or reproduced in an arbitrary dimension in accordance with a predetermined rule.

In general, there is an optical recording disk as a medium on which large-capacity data such as a high-density image can be recorded. Conventionally, magneto-optical recording media, optical phase-change media, and the like have been developed as optical recording disks, but demands for increasing the amount of information recordable on optical recording disks are increasing. In order to increase the capacity of such optical recording disks, three-dimensional optical recording media have been proposed. This makes it possible to record information on an optical recording disc not only in the plane direction but also in the depth direction of the optical recording disk, in other words, to record information three-dimensionally by making the recording surface multilayer. It is. Although the optical recording disk is exemplified as the three-dimensional optical recording medium, the recording medium is not limited to the disk-shaped recording medium, but may be a card-shaped recording medium or a stick-shaped recording medium as long as it can record information in a plane direction and a depth direction. Even a recording medium is included in this three-dimensional optical recording medium.

The above-described magneto-optical recording medium and optical phase-change medium have low light transmittance and cannot realize a multi-layer structure of several tens to several hundred layers. However, the photo
An optical recording medium using a refractive material has several tens to one.
Attention has been paid to the possibility of realizing a multilayered three-dimensional optical recording disk of up to 00.

The first reports on three-dimensional optical recording media include JH Strickler, et al., Optical Letters, 16 (2
2), 1780 (1991). This report discloses a three-dimensional mark type optical memory using an inorganic photorefractive material. The photorefractive material is a material in which electric charges are spatially separated by irradiation of an electromagnetic wave, and a refractive index is changed by an electric field due to a spatial distribution of electric charges generated thereby. When such a material is applied to an optical memory, the intensity pattern of the electromagnetic wave is recorded as a change in the refractive index in the memory. According to the first report, it has been reported that a mark by the photorefractive effect was written in an optical memory three-dimensionally by irradiating two beams. At this time, surface information is recorded in multiple layers on the recording medium, and reproduction is performed using a phase-contrast microscope.
It is reported that information was reproduced layer by layer.

Further, Y. KAWATA et. Al., App1. Opt., 3
No. 4,4105 (1995) discloses a second report in which a mark based on the photorefractive effect is three-dimensionally written in an optical memory by irradiating one beam. In this second report, a phase contrast microscope is used for reproduction.

The method using a phase contrast microscope for reproducing recorded information as disclosed in the above two reports is suitable for a material having a small sectional area such as an inorganic crystal. It is not suitable for an optical recording medium having a large size. That is, if this reading method is applied to a large-area disk-type optical recording medium, the area that can be read by one shot is small, and batch processing is performed. This necessitates a long time for reproduction.

[0007] Also, consider a case where a recording / reproducing method performed on a conventional optical recording disk such as a compact disk is applied to a three-dimensional optical recording disk. In a conventional optical recording disk, information is recorded or reproduced by scanning a recording or reproducing light beam spirally in a plane direction of the disk. That is, while the optical recording disk is being rotated, the light source for recording or reproduction is irradiated by simultaneously moving the light source or the optical recording disk in the radial direction.

When this method is applied to a three-dimensional optical recording disk, a spiral recording / reproduction in the plane direction of the optical recording disk is performed.
It is possible to perform three-dimensional recording by performing reproduction on one layer and performing recording / reproduction on this one layer over multiple layers. However, the method of performing recording and reproduction for each layer over multiple layers has a problem that it takes a long time to reproduce information from all layers of the disc. For example, after the reproduction of the first layer is completed,
There is a problem that it takes a long time to start reproduction of the next layer.

That is, in order to end reproduction of the first layer and start reproduction of the second layer, information recorded on the second layer is written to any position in the depth direction of the optical recording disk. A process of detecting whether the In particular,
You can scan the lens that focuses the reproduction light up and down,
By moving the disk up and down, for example, changing the position where the beam is focused on the disk, measure the intensity of the reproduced light at that time, and determine the point where the intensity changed the most or the derivative of the intensity of the reproduced light. Detect points with large changes. Since the conventional reproducing method requires a process of detecting such a focal position in the depth direction, it is considered that the reproducing takes time.

[0010]

As described above, in this technical field, for example, in order to perform high-density recording on an optical recording disk, there is a strong demand for a three-dimensional optical recording medium capable of recording information in three-dimensional directions. At the same time, there is a strong demand for the development of an information recording / reproducing method, an information recording device, and an information reproducing device capable of recording / reproducing at high speed using this optical recording medium, but they have not been realized yet. If such an information recording / reproducing method is not provided, no matter how high-density the three-dimensional optical recording medium can record information, high-speed recording or high-speed recording that can withstand the implementation is required. This means that reproduction cannot be performed, and even if a high-performance recording medium is developed, it cannot be used effectively.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has an information recording / reproducing method capable of recording and reproducing information efficiently and at high speed on an optical recording medium capable of recording information at high density in a three-dimensional direction. In addition to providing a method, an information recording / reproducing method and apparatus for an optical recording medium and a three-dimensional recording medium capable of recording and reproducing information at high speed and with high efficiency using such an optical recording medium are provided. Aim.

[0012]

According to a first aspect of the present invention, there is provided a method for recording information on an optical recording medium, comprising the steps of: An information recording method for an optical recording medium in which information is recorded on an optical recording medium on which a plurality of marks can be formed at predetermined positions, wherein a predetermined locus is drawn by moving a beam waist of the light beam. The mark is formed as described above.

Further, the information recording apparatus for an optical recording medium according to the second basic configuration of the present invention provides an optical recording medium capable of recording a plurality of marks at predetermined positions including a beam waist of a light beam and its periphery. What is claimed is: 1. An information recording apparatus for an optical recording medium, wherein information is recorded by irradiating a light beam condensing part for forming said beam waist, and a movement for moving said beam waist so as to draw a predetermined locus. And a mechanism.

According to a third aspect of the present invention, there is provided a method for reproducing information from an optical recording medium, comprising: an optical recording medium capable of reproducing information recorded by a mark at a predetermined position including a beam waist of a light beam and a periphery thereof; An information reproducing method for an optical recording medium, in which information is reproduced by irradiating a medium with a light beam, wherein a beam waist of the light beam is moved in a three-dimensional direction so as to draw a predetermined locus, and the information is moved from the mark. It is characterized by reproduction.

Further, the information reproducing apparatus for an optical recording medium according to a fourth basic structure of the present invention irradiates the optical recording medium with a light beam so that a plurality of predetermined positions including a beam waist of the light beam and its periphery are provided. An information reproducing apparatus for an optical recording medium for reproducing information by reading out information as a mark, comprising: a light beam condensing section for forming a mark by moving a beam waist of the light beam; And a moving mechanism for sequentially moving the beam waist so as to draw.

In the information recording / reproducing method and apparatus for an optical recording medium according to the first to fourth basic constitutions, the recording medium is composed of an optical disk having a disk shape, and the mark is rotated by a rotating means. The optical disk may be formed so as to draw a predetermined trajectory by scanning the optical disk with the light beam and adjusting a beam waist of the light beam in a depth direction of the optical disk.

When the optical recording medium is composed of an optical disk as described above, the predetermined locus is such that the beam waist of the light beam is fixed to a predetermined position in the radial direction of the rotating optical disk, and the predetermined position of the beam waist is fixed. Is moved in the depth direction of the optical disc to form a mark on a spiral trajectory having the same distance from the center of the disc, and the beam waist position of the light beam is scanned in the radial direction so that the distance from the center position of the optical disc is reduced. The marks may be formed on equal spiral trajectories.

When the optical recording medium is composed of an optical disk as described above, the predetermined locus is such that the optical disk is rotated to scan the light beam in the radial direction of the optical disk, and the beam waist also extends in the depth direction. By moving the recording marks, recording marks may be sequentially formed on the spiral locus.

When the optical recording medium is constituted by an optical disk as described above, the distance L on the predetermined trajectory between two recording marks continuously recorded on the optical disk by the irradiation of the light beam, and the depth of the mark The difference d between the relative positions in the vertical direction may satisfy the relationship of “0 <d / L <2.5”.

In the information recording / reproducing method and apparatus for an optical recording medium according to the first to fourth basic constitutions, the recording medium comprises an optical recording rectangular parallelepiped having a rectangular parallelepiped shape including a block, a stick or a card. The mark may be formed so as to draw the predetermined trajectory by changing the relative position between the optical recording rectangular parallelepiped and the beam waist of the light beam in an arbitrary three-dimensional direction.

When the optical recording medium is constituted by an optical recording rectangular parallelepiped as described above, the optical recording rectangular parallelepiped has a block or stick shape, and the predetermined trajectory is a three-dimensional arbitrary shape including the depth direction of the optical recording rectangular parallelepiped. By moving the beam waist of the light beam in the direction, a sinusoidal curve may be drawn as the predetermined trajectory.

In the case where the optical recording medium is constituted by an optical recording rectangular parallelepiped as described above, the optical recording rectangular parallelepiped has a card shape, and the predetermined trajectory extends from the center of the card shape to any corner or any one of the corners. From the corner to the center, the beam waist of the light beam moves in the plane direction so as to trace the outer shape of the card, and the beam waist position is also sequentially moved in the depth direction, thereby forming the rectangular spiral as the predetermined locus. It may be configured to draw a shape.

In the case where the optical recording medium is constituted by an optical recording rectangular parallelepiped as described above, the distance L on the predetermined trajectory between two recording marks continuously recorded on the optical disk by irradiation of the light beam; And the difference d in the relative position in the depth direction may satisfy the relationship of “0 <d / L <2.5”.

An optical recording medium according to a fifth basic structure of the present invention is an optical recording medium in which a recording mark can be formed at an arbitrary position in three dimensions by using a light beam. The recording mark adjacent to the mark is recorded by moving the beam waist of the light beam to a position adjacent to the mark, and the recording mark is sequentially formed so that the position of the beam waist draws a predetermined locus having a predetermined rule. Thus, the information is recorded.

In the optical recording medium according to the fifth basic configuration, the optical recording medium is an optical disk having a disk shape or a cylindrical shape, and the optical beam is scanned in the radial direction of the optical disk while rotating the optical disk. At the same time, by adjusting the position of the beam waist of the light beam in the depth direction of the optical disc, information may be recorded so that marks are arranged on the predetermined locus.

In the optical recording medium according to the fifth basic configuration, the optical recording medium is formed of an optical recording rectangular parallelepiped having a rectangular parallelepiped shape including a block, a stick, or a card, and the optical recording rectangular parallelepiped and a beam waist of the light beam. By moving the relative position of the optical recording mark in an arbitrary three-dimensional direction, the optical recording mark is continuously formed three-dimensionally on the optical recording rectangular parallelepiped, and information is recorded so as to draw the predetermined locus. You may do it.

As described above, when the optical recording medium is composed of an optical disk or an optical recording rectangular parallelepiped, the distance L on the predetermined trajectory between two recording marks continuously recorded on the optical disk by the irradiation of the light beam. And the difference d between the relative positions of the marks in the depth direction are “0 <d / L <
2.5 ".

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an information recording method and apparatus for an optical recording medium, an information reproducing method and apparatus, and an optical recording medium according to the present invention will be described below in detail with reference to the accompanying drawings. First, the optical recording medium according to the present invention, whether formed in a disk shape or in a card shape, was formed in a rectangular core shape with a thickness greater than that of a card. Even if it is something,
It has a multi-layered recording layer ranging from 0 to several hundred layers, recording marks (pits for recording) are formed in a plane direction and a depth direction in accordance with a predetermined rule, and light physical properties are improved by light irradiation. Any shape can be used as long as the information can be recorded by the change.

The first embodiment of the present invention relates to an information recording apparatus provided with a mechanism for recording information by scanning a focused light beam on the surface of an optical recording disk. An information recording apparatus further comprising a mechanism for spirally scanning the inside of an optical recording disk.

A second embodiment of the present invention relates to an information reproducing apparatus provided with a mechanism for reproducing information by scanning a converged light beam on the surface of an optical recording disk. An information reproducing apparatus further comprising a mechanism for causing the optical recording disk to spirally scan within the optical recording disk.

According to a third embodiment of the present invention, in an optical recording disk on which recording marks are formed by irradiating a focused light beam and information is recorded, the positions where the recording marks are written are arranged in a spiral. The present invention relates to an optical recording disk characterized in that:

According to the information recording apparatus, the information reproducing apparatus, and the optical recording disk according to the first to third embodiments of the present invention, the positions (writing positions) where the recording marks are written in the optical recording disk are spirally arranged. Is done. Since such an optical recording disk has information written over three dimensions, high-density recording is possible. Beam direction 1
In order to prevent the depth of one recording mark written before and after from greatly changing the depth of one recording mark, the focus of the light beam in the depth direction when reproducing the next recording mark after reproducing one recording mark Recording marks can be reproduced continuously without changing the position. Further, by feeding back the change of the intensity or pattern of the reproduction light to the control of the focal position of the light beam, the reproduction can be continued continuously for a longer time.

Therefore, the time required for reproduction is shorter than that of a conventional optical recording disk in which recording mark writing positions are arranged in a plane and layers are stacked. That is, in the conventional method, after the reproduction of the first layer is completed, the lens for collecting the reproduction light is moved up and down to detect the recording mark position of the next layer, and the reproduction at that time is performed. A process of measuring the light intensity and detecting the point where the intensity changed the most or the point where the derivative of the reproduction light intensity changed greatly was necessary.In the present invention, however, this process became unnecessary, and the reproduction became unnecessary. Such time can be reduced.

In the present invention, the spiral shape is not a spiral shape but a three-dimensional one. Further, in the present invention, a state in which recording marks are adjacent in a certain three-dimensional direction means that when two adjacent marks among a plurality of recording marks are sequentially focused on, they are in a certain three-dimensional direction. This indicates a state in which the recording marks are arranged in a certain order, and not all of the plurality of recording marks are necessarily arranged in the same direction. Therefore, when observing the arrangement state of a large number of recording marks in a macroscopic manner, any arrangement can be used as long as it draws a continuous predetermined trajectory such as a spring-like, tornado-like, planar spiral-like, sine-wave-like, or zigzag-like. Shall be included.

Further, the optical recording medium according to the present invention may use any principle as long as the optical properties are modulated by light irradiation and the reproduction light is modulated. For example, a photorefractive medium in which an internal electric field is generated by light irradiation to change the refractive index, or a photopolymer medium in which a reaction between molecules or intramolecular by light irradiation to modulate the refractive index may be used. In particular, a photorefractive medium on which recorded information can be rewritten is desirable. Since the photorefractive material has a high light transmittance, an information amount corresponding to several tens to 100 layers can be recorded depending on the film thickness. Furthermore, if the medium is an organic photorefractive medium, it can be easily formed into a large-area optical recording disk. It is more preferable to use an organic photorefractive medium that can be written without applying an electric field.

The typical shape of the optical recording disk according to the present invention is a thin cylindrical shape, but the shape is not limited to this and may be a sphere, a rectangular parallelepiped, a cube, an elliptic plate,
Any of these may be used. Further, these shapes may be modified. For example, there is a cylindrical shape (a truncated cone shape) whose radius gradually increases. The optical recording medium according to the present invention needs to have a thickness at which information can be written in at least three dimensions.

The information recording method / apparatus or the information reproducing method / apparatus according to the present invention adopts a recording or reproducing method corresponding to the principle of an optical recording medium used for recording and reproducing information. Any thing may be used. Further, the information recording device or the information reproducing device according to the present invention may be an information recording / reproducing device capable of performing both information recording and reproducing.

FIG. 1 is a conceptual diagram showing an example of an information recording / reproducing apparatus and an optical recording disk according to the present invention. In the information recording / reproducing apparatus shown in FIG. 1, reference numeral 1 denotes a light beam for recording or reproducing, and reference numerals 2 and 3 denote lenses for condensing the light beam 1. Reference numeral 4 denotes an aperture, and reference numeral 5 denotes a photodetector for detecting a reproduction light. Reference numeral 6 denotes an optical recording disk, and reference numeral 7 denotes a recording mark recorded on the optical recording disk. Depending on the position of the photodetector and the aperture, the lens 3 may be constituted by elements other than the lens. Further, a disk rotating mechanism for rotating the optical recording disk 6 in the plane direction is provided (not shown).

Further, a lens moving mechanism for moving the lens 2 up and down (not shown) is provided. As the lens moving mechanism, a stepping motor or a piezo element can be used. In the present invention, for planar recording / reproduction on an optical recording rectangular medium, a mechanism for moving the relative position of the lens and the disk in the horizontal direction may be provided (not shown). As shown in the figure, when the recording medium is a disk, at least means for controlling the rotation of the disk, controlling the relative position between the disk and peripheral devices in the radial direction of the disk, and controlling the light beam condensing position are provided. Must have.

The light beam 1 emitted from the light source passes through the lens 2, passes through the optical recording disk 6, enters the lens 3 and the aperture 4 facing each other via the optical recording disk 6, and is detected by the photodetector 5. The light beam 1 is modulated by recording marks 7 recorded on an optical recording disk 6 and received by a photodetector 5.

In the information recording / reproducing apparatus shown in FIG. 1, the disk rotating mechanism and the lens moving mechanism are simultaneously operated so that the converged light beam 1 scans the optical recording disk 6 spirally.

The operation of the information recording / reproducing apparatus having the above configuration will be described. First, a method for recording information on an optical recording disk will be described.

When recording information on the optical recording disk 6,
The optical recording disk 6 is irradiated with a light beam 1 from a light source (not shown) located below, and the light beam 1 is condensed by a lens 2. At the writing position of the recording mark on the optical recording disk 6, the recording mark 7 is written near the focal point where the intensity of the condensed light beam becomes maximum (in FIG. 1, the state where the recording mark is formed is represented by a black circle. ing).

Further, when the optical recording disk 6 is rotated in the plane direction by the disk rotating mechanism, and at the same time the lens 2 for condensing the light beam 1 is raised by the lens moving mechanism, the focal position of the light spirals in the optical recording disk. Will be moved to. By irradiating the optical recording disk 6 with a pulsed light beam, an optical recording disk in which the recording marks 7 are spirally arranged can be obtained. That is, by moving the optical recording disk relatively in a direction that is not parallel to the rotation direction of the optical recording disk, the recording mark is written spirally.
At this time, the rotation of the optical disk 6 and the movement of the lens 3 are performed at a preset speed.

On the other hand, the following two reproduction methods are available. One is to condense reproducing light having a lower intensity or a different wavelength than the recording light on the optical recording disk. At this time, the focal point of the reproduction light is shifted slightly forward or backward from the focal position of the recording light on which the recording mark is recorded. Since the refractive index of the portion of the recording mark is different from the refractive index of the area where writing is not performed, only when the light for reproduction is irradiated so that the focal point of the light is at or near the recording mark,
The intensity pattern of the reproduction light changes. If a photodetector is installed so as to detect a part of the reproduction light transmitted through the optical recording disk, the presence or absence of a recording mark can be detected by a change in intensity or pattern size. At this time, if the focal position of the reproduction light matches the focal position of the recording light when the recording mark is recorded, the intensity distribution of the reproduction light does not change from that without the recording mark.

The other is a case where a reflective layer is provided on an optical recording disk. In the same manner as described above, light for reproduction is irradiated to the optical recording disk and reflected by the reflection layer, and light transmitted twice through the optical recording disk, that is, light returned from the optical recording disk, is detected by the photodetector as reproduction light. How to FIG. 1 shows the former method, while FIG. 5 described later shows the latter method.

In any case, since the intensity pattern of the reproduction light changes depending on the presence or absence of the recording mark, the presence or absence of the recording mark can be known by, for example, measuring the intensity of the central portion of the reproduction light. For example, when the optical recording disk is a photorefractive medium, the portion of the recording mark has a changed refractive index, so that the portion plays the role of a lens, and the reproduced light depends on the observation position (position in the beam direction of the detector). Has a dark or bright center. On the other hand, such a portion does not occur in a portion having no recording mark. Therefore, the presence or absence of a recording mark can be detected by detecting the intensity of the reproduction light, particularly at the central portion.

In FIG. 1, a light beam 1 for reproduction is applied to an optical recording disk 6 on which recording marks are arranged in a spiral, and light transmitted through the optical recording disk is detected by a photo detector 5 as reproduction light.

At the time of reproduction, the optical recording disk 6 is rotated in the surface direction at the same speed as the speed set in advance during recording. Thereby, after detecting the presence or absence of a recording mark at the first writing position, the next writing position is irradiated with light for reproduction. At this time, if the position of the lens 3 is not changed, the writing position and the position of the focal point of light slightly shift. However, since the writing positions are close to each other, even if the focus position is slightly shifted, the shift is slight and the intensity of the reproduction light changes, so that the presence or absence of the recording mark can be detected continuously.

When the reading of the recording mark continues and the deviation of the focal position from the position of the recording mark increases, the presence or absence of the recording mark cannot be detected. Therefore, it is necessary to provide a servo mechanism in the lens moving mechanism based on a change in the intensity of the reproduction light, and provide a mechanism for correcting the vertical movement of the lens 2 for condensing the light beam 1. As a result, the position of the focal point is corrected, and the information written at the write position of the spirally arranged recording marks can be successively and sequentially reproduced.

In the information recording apparatus or the information reproducing apparatus according to the present invention, the mechanism for causing the converged light beam to spirally scan the inside of the optical recording disk may be any mechanism having such an action. However, the present invention is not limited to the combination of the disk rotating mechanism and the lens moving mechanism described above.

FIGS. 2 and 3 show an example of the arrangement of recording marks on the optical recording disk according to the present invention. FIG. 6 shows a case where the recording marks are arranged in a cylindrical shape according to the recording format shown in FIG. The recording is performed so that the recording marks are arranged in a cylindrical shape by rotating the disk while moving the lens upward at a position where the distance from the normal center is equal. Next, the mark is recorded while moving the lens so that the distance from the center of the focus cylinder becomes shorter. Next, by moving the lens downward and rotating the disk, normal recording marks are arranged inside the arrangement of the already recorded marks. By repeating this method, marks arranged in a cylindrical shape are formed like annual rings.

FIG. 2 shows the optical recording disk 6 of FIG.
It is the figure seen from the direction of. In FIG. 2, the position where the recording mark 7 is formed is always kept constant from the center of the optical recording disk 6. By writing information in this manner, it is possible to write an address on the surface of the optical disk, which facilitates addressing, which is preferable. However, if the recording marks 7 are formed such that the upper and lower recording marks are arranged in rows, the error rate may increase if the interval between the upper and lower marks is narrow. Therefore, it is desirable to increase the interval or to form the recording marks positioned above and below so as not to overlap.

FIG. 3 is a view of the optical recording disk 6 used in FIG. Since the recording marks were formed while moving the lens 2 that condenses the light beam 1 while rotating the optical recording disk 6, the recording marks 7 were arranged in an oblique direction. FIG. 7 is a conceptual diagram of recording and reproduction on a stick-shaped recording medium. The monochromatic light condensed by the lens is guided to an arbitrary position on the optical recording medium by the mirror. The mirrors in the figure represent mirrors in a micromirror array, and the position of the array can be moved in any of the x, y, and z directions. The focus position of the light is controlled by the positions of the lens and the mirror array, the selection of the mirror to be driven in the mirror array, and the angle of the micro mirror. The relative positions of the mirror array, lens, and recording medium can be adjusted by changing any of them. For example, an apparatus having a means for controlling the position of the recording medium in the x and y directions, a means for moving the lens in the x and y directions, and a means for moving the mirror array in the x and y directions is used for recording marks at this time. Can be arranged in a sine wave shape or a zigzag shape.

The distance L in the plane direction and the relative difference d in the depth direction between two consecutive spirally arranged recording marks are “0”.
It is desirable to satisfy the relationship of <d / L <2.5. That is, one of the recording marks is defined as a, and the distance L from the recording mark b before or after the recording mark spirally recorded is L.
And the relative difference d in the depth direction (shown in FIG. 3) are “0 <d /
It is desirable to include a portion satisfying L <2.5. The portion that satisfies this condition can be read out continuously even if the focused beam is out of focus because it is within the defocusing allowable range, and the change in the intensity of the reproduction light is fed back to the position control of the lens 2. It becomes easy to do.

Between two consecutive recording marks, the distance L in the vertical direction from the longitudinal direction of the mark and the relative difference d in the direction parallel to the longitudinal direction have a relationship of “0 <d / L <2.5”. It is desirable to satisfy. When this condition is satisfied, even if the focused beam is out of focus, it can be read continuously because it is within the defocus allowable range.
It becomes easy to feed back the change in the intensity of the reproduction light to the position control of the lens. This can be understood as follows. Usually, a mark recorded as a refractive index modulation by optical recording has a three-dimensional elliptical rotator shape long in the propagation direction of recording light.

The region where the refractive index modulation occurs is, for example, 2.5 μm in the longitudinal direction, and the radius in the vertical direction is 3.0 μm.
It is assumed that the information is recorded as a mark of μm. If the recording marks are recorded spirally at the same depth, it is not necessary to control the position of the read light in the depth direction. Is possible. Next, consider the case where recording is performed while gradually changing the horizontal position of the mark. For example,
Assuming that the distance between adjacent marks in the vertical direction with respect to the longitudinal direction of the mark is 0.6 μm, the distance L from the center of the mark to the center is 1.2 μm. Since the size of the mark in the longitudinal direction is 2.5 μm, the relative difference d in the longitudinal direction of the mark is 2.5 μm or less at the maximum. Therefore, it is desirable that d / L <2.5.

FIG. 4 shows another example of the arrangement of the recording marks according to the present invention. As shown in FIG. 4, this is a method of laminating a plurality of layers on which recording marks are formed, and arranging the recording marks in a spiral at a connection portion between the layers. In FIG. 4, the optical recording disk 6 has a plurality of layers (layer 8, layer 9, layer 10, and layer 11) in which recording marks are arranged in a plane, and a portion between the layers, for example, The recording marks 7 are spirally arranged between the recording mark at the end of recording on the layer 9 and the recording mark at the beginning of recording on the layer 9. This array is formed by the following method.

That is, in the optical information recording / reproducing apparatus of FIG. 1, a mechanism for moving the light source or the disk in the radial direction of the optical recording disk 6 is further provided. Fix the lens 3,
When the optical recording disk 6 is rotated, the optical recording disk 6
By moving the optical recording disk 6 or the light source in the radial direction, a layer in which recording marks are arranged in a plane is formed. Next, while rotating the optical recording disk 6, the lens 3
Is raised, the light beam 6 scans spirally as in recording, and a portion where the recording marks are arranged spirally is formed.

When this arrangement is adopted, for example, layer 8 in FIG.
When the reproduction of the layer 9 is completed and the reproduction of the layer 9 is started, the movement of the position of the lens 2 is fed back by the change in the output of the reproduction light, and the mechanism for moving the focal position of the reproduction light beam is used. Continuous reading and high-density recording can be performed without going through the process of detecting recording marks in the direction.

On the other hand, in the information recording apparatus or the information reproducing apparatus according to the present invention, the number of light beams incident is not limited to one, but may be one.
Recording and reproduction may be performed by simultaneously inputting two or more light beams to one optical recording disk. Thus, recording and reproduction can be performed in parallel. For example, FIG. 5 shows a conceptual diagram of an information recording / reproducing apparatus for irradiating an optical recording disk with a plurality of light beams. In FIG. 5, reference numeral 12 denotes a light source of a light beam, and reference numeral 13 denotes a photodetector for detecting reproduction light. 14 is a half mirror, 15 is a light beam for recording or reproducing, and 16 is a lens for condensing the light beam on an optical recording disk. 17 is an optical recording disk, 18 is a reflective layer, and 19 is a recording mark recorded on the optical recording disk.

This information recording / reproducing apparatus is provided with a mechanism for rotating the optical recording disk 17 and moving the lens 16 up and down, thereby causing the light beam 12 to spirally scan and the recording / recording marks 19 to be spirally arranged. . Since a plurality of light sources are provided, a plurality of spiral recording mark arrays are formed. At the time of reproduction, by rotating the optical recording disk 17 and simultaneously moving the lens 16 up and down, the light beam 15 for reproduction is spirally scanned, and the transmitted light whose intensity pattern has changed according to the presence or absence of the recording mark is further reduced. The light is returned to the incident direction by the reflection layer 18. The light is detected by the photodetector 13 as reproduction light.

Next, a specific embodiment of the present invention will be described. Example 1 An unrecorded optical recording disk was manufactured by the following method.
As a recording material for the optical recording disk of the first embodiment, a photopolymer was used in which the molecules of the portion irradiated with the focused light beam were crosslinked, the molecular weight was increased, and the refractive index was increased.
This recording material is semi-permanently retained once the refractive index is modulated, and is difficult to restore. This photopolymer film was formed on a transparent substrate having a diameter of 12 cm to form an optical recording disk. Photopolymer film thickness is 2
mm.

Using an information recording / reproducing apparatus provided with a mechanism for moving the optical recording disk in the radial direction in addition to the information recording / reproducing apparatus as shown in FIG. 1, information is recorded on the unrecorded optical recording disk. Done.

First, the lens 2 is fixed, the optical recording disk 6 is rotated, and at the same time, the optical recording disk 6 is moved in the radial direction of the optical recording disk 6 to form a layer in which recording marks are arranged in a plane. And then the optical recording disk 6
When the lens 2 is raised while rotating the light beam, the light beam 6 scans spirally in the same manner as during recording, and a portion where the recording marks are arranged spirally is formed. At this time, a pulse wave turned on and off by a shutter or the like was used as the light beam. The recording marks of the obtained optical recording disc are arranged in a spiral pattern on a plane, and the recording marks are arranged in 80 layers, and the recording marks are spirally arranged between the layers. Met. The arrangement of the recording marks was as shown in FIG.

The reproduction of this optical recording disk was carried out by a similar apparatus using a semiconductor laser having a wavelength of 680 nm as a light source. First, the optical recording disk 6 was scanned with the reproducing light beam 1 on the optical recording disk 6 in the same manner as when recording.
The transmitted light from was detected by the photodetector 5 as reproduction light. At this time, a mechanism is provided to correct the vertical movement of the lens 2 for condensing the light beam 1 by applying a feed hack to the lens moving mechanism depending on the magnitude of the intensity change of the reproduction light. As a result, in the optical recording disk, a recording density of 10 ⁹ bits / cm ³ can be realized and 1.5 G
Successful reading at bps.

Comparative Example 1 An unrecorded optical recording disk similar to the optical recording disk used in Example 1 was recorded and reproduced using the information recording / reproducing apparatus shown in FIG. At the time of recording, an argon laser was used as a light source of the light beam. However, the optical recording disk 6
By rotating the optical recording disk 6 and moving the laser in the radial direction of the optical recording disk without rotating the lens 3 up and down at the same time as rotating the lens, the first layer is first recorded in a spiral on a plane. A layer in which marks were arranged was formed. In the next layer, the first layer is located at a depth sufficiently separated from the allowable defocus length so that the error rate is sufficiently small.
It was written in a spiral like the layer. 80
Layer wrote.

The arrangement of the recording marks of the obtained optical recording disk was such that 80 layers in which the recording marks were arranged spirally on a plane were formed.

The same device was used for reproduction of the optical recording disk, and a semiconductor laser having a wavelength of 680 nm was used as a light source, and the light beam 1 for reproduction was scanned on the optical recording disk 6 in the same manner as when recording. The transmitted light from the optical recording disk 6 was detected by the photodetector 5 as reproduction light. Upon reproduction, after the reproduction of the first layer is completed, a process of detecting in which position in the depth direction the second layer is written is necessary to start reproduction of the second layer.

Specifically, this detection method is to scan the lens focusing the reproduction light up and down, measure the reproduction light intensity at that time, and determine the point at which the intensity changes the most or the reproduction light intensity. This is to detect a point where the derivative of the intensity is large. The recording capacity was almost the same as that of the first embodiment, but the read speed was 2
Kbits / s.

Example 2 An unrecorded optical recording disk was manufactured by the following method. 200 molecular fullerene C ₇₀ showing the particulates and non-linear optical properties of the oxadiazole derivative and Bisuwaenoru A type polycarbonate and titanyl phthalocyanine as a recording material of an optical recording disc of the present embodiment in a weight ratio: 300:
What was mixed at a ratio of 10: 1 was used. The mixture was dissolved in toluene, cast on a quartz substrate, dried, and then heat-molded to produce a 200 μm thick film to obtain an optical recording disk.

The unrecorded optical recording disk is shown in FIG.
Recording and reproduction of information were performed using the same device as the device shown in FIG. For recording, a total of 2 × 10 7 recording marks were formed using an argon ion laser divided into a total of 20 beams.
²⁰ "pieces were formed in a spiral to obtain an optical recording disk. For reproduction, an array of 20 semiconductor lasers having a wavelength of 800 nm was used as a light source, and a light beam for reproduction was scanned on an optical recording disk in the same manner as when recording. Light reflected from the optical recording disk was detected as reproduction light by a photodetector.

At this time, a mechanism is provided to feed back to the lens moving mechanism according to the magnitude of the intensity change of the reproduction light, and to correct the vertical movement of the lens for condensing the light beam. During recording and playback, the position of the focal point focused by the racer is controlled by moving the lens up and down with a stepping motor or piezo element and rotating the optical recording disk, or moving the laser in the radial direction did. As a result, a recording density of 10 ¹³ bits / cm ³ was realized, and reading was successfully performed at 2 Gbps.

Comparative Example 2 Information was recorded and reproduced using the same optical recording disk used in Example 2. Only one argon ion laser was used for recording, and concentric recording marks were written only by rotating the optical recording disk and moving the light beam in the radial direction without raising or lowering the focal point. After writing one layer, the lens was moved up and down, and the next layer was similarly written concentrically.

An optical recording disk was obtained by forming a total of 2 × 10 ²⁰ recording marks. Wavelength 800 as light source for reproduction
Using a single semiconductor laser of nm, a light beam for reproduction was scanned on an optical recording disk in the same manner as when recording.
Light reflected from the optical recording disk was detected as reproduction light by a photodetector. As a result, the reading speed is 1 Mb
It / s.

Example 3 A cylindrical recording medium having a radius of 4 cm and a length of 4 cm as shown in FIG. 6 was prepared, and the same recording as in FIG. 6 was performed. First, the horizontal position of the lens was fixed at the position farthest from the center of the cylinder, and the lens was moved at a constant speed in the vertical direction.
When the laser pulse light was irradiated while rotating the optical disk, a recording mark was recorded while drawing a spring-like trajectory as shown in FIG.

When recording was performed from bottom to top, the lens was moved by 0.5 μm in the radial direction of the cylinder, and recording was performed by scanning the lens from top to bottom. When the recording was completed to the bottom, the lens was moved by 0.5 μm in the radial direction of the cylinder in the same manner as described above. Hereinafter, by repeating this operation, cylindrical recording was performed from a radius of 3.8 mm to 5 mm. FIG. 8 shows a block diagram of the device used at this time.
As a result, a readout speed of 10 ¹³ bit / cm ³ and 2 Gbps was achieved.

Example 4 A stick-shaped recording medium of 1 cm × 4 cm × 2 cm as shown in FIG. 7 was prepared, and the same recording as in FIG. 7 was performed. That is, while controlling the angle of the mirror and the position of the lens so that the recording marks are arranged in a sine wave shape, the marks are recorded in a line shape in the x direction of the recording medium, and then the positions are slightly shifted in phase. The information was recorded back to arrange the marks.

This operation is repeated to make a mark on the xz plane at an arbitrary position y1 in the y direction. Next, by moving the recording medium in the y direction, recording was similarly performed on the xz plane at the position y2. By repeating this operation, a recording mark was formed on the entire recording medium. FIG. 9 shows a block diagram of the apparatus used at this time. As a result, 10 ¹³ bits
/ Cm ³ and a read rate of 2 Gbps could be achieved.

[0080]

As described above in detail, according to the information recording method and apparatus of the optical recording medium, the information reproducing method and apparatus, and the optical recording medium according to the present invention, the light beam is projected at a predetermined position on the recording medium. When a record mark is formed by the beam waist and information is recorded, the relative position between the recording medium and the beam waist is moved so that the movement locus of the beam waist draws a predetermined locus. It is possible to provide an optical recording disk and an information recording / reproducing apparatus which can record information and record / reproduce this information at high speed.

[Brief description of the drawings]

FIG. 1 is an overhead view showing an information recording / reproducing apparatus and an optical recording disk according to the present invention.

FIG. 2 is a plan view of the optical recording disk of FIG. 1 as viewed from the direction of arrow A.

FIG. 3 is a front view of the optical recording disk of FIG. 1 viewed from the direction of arrow B;

FIG. 4 is an overhead view showing an example of the arrangement of recording marks according to the present invention.

FIG. 5 is an overhead view showing the information recording / reproducing apparatus and the optical recording disk of the present invention.

FIG. 6 is an overhead view and a plan view showing a cylindrical optical recording medium according to the present invention.

FIG. 7 is a bird's-eye view showing a rectangular optical recording medium according to the present invention and a bird's-eye view conceptually showing recording marks.

FIG. 8 is a block diagram showing a schematic configuration of a recording / reproducing apparatus according to the present invention.

FIG. 9 is a block diagram showing a schematic configuration of a recording / reproducing apparatus using a mirror array.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light beam 3 Lens 5 Photodetector 6 Optical recording medium 7 Mark 12 Light source 13 Photodetector 15 Light beam 16 Condensing lens

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Takayuki Tsukamoto, Inventor 1 Komukai Toshiba-cho, Yuki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Toshiba R & D Center (72) Inventor Yoshinori Motomiya, Yuki-ku, Kawasaki-shi, Kanagawa Komukai Toshiba-cho 1 Toshiba R & D Center (72) Inventor Kazunori Matsumoto 1 Komukai Toshiba-cho 1 Koyuki Mukai, Kawasaki-shi, Kanagawa Prefecture Toshiba R & D Center

Claims (5)

[Claims] An information recording apparatus for recording information on an optical recording medium on which a plurality of marks can be formed at predetermined positions including a beam waist of the light beam and its periphery by irradiating the light beam. A method of recording information on an optical recording medium, comprising forming the mark so as to draw a predetermined locus by moving a beam waist of the light beam. 2. An information recording apparatus for an optical recording medium, wherein information is recorded by irradiating a light beam onto a recording medium capable of recording a plurality of marks at a predetermined position including a beam waist of a light beam and a periphery thereof. An information recording apparatus for an optical recording medium, comprising: a light beam condensing unit for forming the beam waist; and a moving mechanism for moving the beam waist so as to draw a predetermined trajectory. . 3. Information reproduction of an optical recording medium for reproducing information by irradiating a light beam to an optical recording medium capable of reproducing information recorded by a mark at a predetermined position including a beam waist of a light beam and a periphery thereof. A method for reproducing information from an optical recording medium, comprising: moving a beam waist of the light beam in a three-dimensional direction so as to draw a predetermined locus, thereby reproducing the information from the mark. 4. The information of an optical recording medium for reproducing information by irradiating the optical recording medium with a light beam so as to read out information as a plurality of marks at predetermined positions including a beam waist of the light beam and its surroundings. A reproducing apparatus, comprising: a light beam focusing unit that forms a mark by moving a beam waist of the light beam; and a moving mechanism that sequentially moves the beam waist so as to draw a predetermined trajectory. An information reproducing apparatus for an optical recording medium, comprising: 5. An optical recording medium comprising a plurality of marks formed at arbitrary positions using a light beam, wherein the marks move along the beam waist so as to draw a predetermined trajectory. An optical recording medium on which information is recorded by being formed by moving a beam waist of the optical recording medium.