JP2002358788A - Optical memory element and its reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reproducing surely information (data) recoded in an optical memory element. SOLUTION: This element is optical memory element 10 constituted as a laminated body which comprises resin core layers 2A, 2B, resin clad layers 3A, 3B laminated on both surfaces of resin core layers and in which a plurality of optical waveguide members having ruggedness part in at least either of boundary of the resin core layer and the resin clad layer are laminated, and a plurality of optical waveguide members are constituted of optical waveguide members 323A for data of one or plurality and optical waveguide members 323B for element information recording information about optical memory elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical memory device and a method for reproducing the same, and more particularly, to a method suitable for manufacturing an optical memory device using an optical waveguide device.
The present invention relates to an optical memory device and a reproducing method thereof.

[0002]

2. Description of the Related Art In recent years, a technique has been proposed in which light is introduced into a planar (card-shaped) optical waveguide in which a pattern is cut in advance so as to generate predetermined scattered light, and an image is formed outside the optical waveguide surface. (IEEE Photon.Technol.Lett., Vol.9, p
p.958-960, JULY1997, etc.). That is, as schematically shown in FIG. 7, for example, a core (layer) 101 whose refractive index and film thickness are adjusted so as to function as an optical waveguide, and both sides (both sides) sandwiching the core layer 101 In the card-type slab-type optical waveguide device 100 including the (first and second) claddings (layers) 102 provided on the substrate, fine irregularities are present at the interface between the core layer 101 and the cladding layer 102. In this case, when light (laser light) is introduced into the core layer (optical waveguide) 101 via the lens 103, a part of the introduced light is scattered at the uneven portion, and the scattered light is
Come out through 2

Therefore, the scattering intensity and the phase of light that can form a specific image at a predetermined distance from the optical waveguide surface (optical waveguide 101) are calculated, and a fine uneven pattern corresponding to the calculation is previously formed in the core layer 101. In this case, a desired image can be formed outside the optical waveguide surface. That is, the core layer 101 functions as an information recording layer.

[0004] For example, the scattered light coming out of the optical waveguide surface is set at the above-mentioned predetermined distance to the CCD receiver 104.
To form a two-dimensional digital pattern (for example, a binary pattern of light and dark or a multi-valued pattern based on lightness (gray scale)) to generate a digital signal. A desired image processing can be performed on the formed image by a processing device (not shown).

[0005] For example, as schematically shown in FIG.
When a plurality of optical waveguides (recording layers) 101 are laminated by repeatedly laminating the cladding layer 102 and the core layer 101, light scattered by a certain optical waveguide 101 crosses another optical waveguide 101. However, since the refractive index difference between the core layer 101 and the cladding layer 102 is extremely small, the scattered light is hardly re-scattered by the unevenness formed on another optical waveguide 101, and the image formed is disturbed. There is no. Therefore, many images and patterns can be formed in proportion to the number of layers.

That is, the optical waveguide device 100 can be used as an optical memory element (a recording medium such as a ROM) having a capacity proportional to the number of layers. It is said that this optical memory element can theoretically have a capacity of about 1 gigabyte in one layer, and can be stacked up to about 100 layers. It is expected to be used as a large-capacity ROM that can sufficiently cope with recording and the like.

The above-mentioned fine concavo-convex pattern in the core layer 101 of the optical waveguide device 100 is formed, for example, by the following method. That is, first, as schematically shown in FIG. 9A, a photoresist is applied on a flat glass or the like serving as the (first) cladding layer 102, and exposure with light or an electron beam and the like are performed. By development, pits (concavo-convex pattern) corresponding to the image to be formed are formed on the glass (cladding layer 102).

Thereafter, the core layer 10 is formed on the uneven pattern.
Form one. As a result, the core layer 101 on which the concavo-convex pattern is formed is manufactured, and by further forming the second cladding layer 102 on the core layer 101, an optical waveguide device (optical memory element) for one layer is manufactured. . Then, in the same manner as described above, an uneven pattern is formed on the cladding layer 102 by exposure and development, and the core layer 101 is formed thereon.
Is formed repeatedly, as schematically shown in FIG. 9B, an optical memory element having a multilayer structure (hereinafter, referred to as “multi-layered optical memory element”).
A “multi-layer optical memory” 100a is manufactured.

However, in such a method using exposure and development, it takes a very long time and cost to fabricate the optical memory element 100 for one layer. Therefore, it is necessary to fabricate a large-capacity multilayer optical memory 100a. It takes enormous time and cost. For this reason, by making the core layer and the clad layer made of resin, the above-mentioned concave and convex pattern can be easily formed, and an optical memory element capable of holding a larger volume of information in a limited volume is easily and inexpensively manufactured. (Japanese Patent Application No. 11-1315).
12, Japanese Patent Application No. 11-131513).

[0010]

A drive (reproducing device) is used for reproducing data (information) recorded in the optical memory element. However, optical memory elements have various physical structures, and the reproduction conditions vary depending on the type of optical memory element. For this reason, if the drive cannot obtain the information necessary for reproducing such an optical memory element, the data recorded on the optical memory element cannot be reproduced.

For example, if only content data such as music data is recorded in the optical memory device, the drive may transmit information necessary for reproducing the optical memory device (for example, what physical structure the optical memory device has, How to set the reproduction condition of the optical memory element) cannot be obtained, and the optical memory element cannot be reproduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an optical memory element and a method for reproducing the same, which can reliably reproduce information (data) recorded in the optical memory element. Aim.

[0013]

An optical memory device according to the present invention comprises a resin core layer and a resin clad layer laminated on both sides of the resin core layer. An optical memory element configured as a laminated body formed by laminating a plurality of optical waveguide members each having an uneven portion on at least one of the interfaces with the resin clad layer, wherein the plurality of optical waveguide members include one or more data optical waveguides. It is characterized by comprising a wave member and an element information optical waveguide member for recording information on the optical memory element.

Preferably, the resin core layer of the element information optical waveguide member is thicker than the resin core layer of the data optical waveguide member. In addition, it is preferable that the maximum brightness of the reproduced image from the optical waveguide member for element information be higher than the maximum luminance of the reproduced image from the optical waveguide member for data.

Here, the "maximum luminance" refers to the luminance of a portion set to have the highest luminance when the reproduced image is set to have a plurality of gradations. further,
It is preferable that the refractive index of the resin core layer of the optical waveguide member for element information is larger than the refractive index of the resin core layer of the optical waveguide member for data. Further, it is preferable that the refractive index of the resin clad layer of the element information optical waveguide member is smaller than the refractive index of the resin clad layer of the data optical waveguide member.

Further, it is preferable that the height of the device information unevenness portion of the device information optical waveguide member is higher than the height of the data unevenness portion of the data optical waveguide member. Further, it is preferable that the optical waveguide member for element information is provided on the outermost side of the laminate. Furthermore, it is preferable that the element information optical waveguide member is configured to output a servo pattern that can be used for adjusting the irradiation state of the incident light (claim 8).

Further, it is preferable that the element information optical waveguide member is configured to record information relating to the physical structure of the optical memory element. Further, it is preferable that the element information optical waveguide member is configured to record information relating to a reproduction condition of the optical memory element.
0). In addition, it is preferable that the element information concave and convex portion of the element information optical waveguide member be configured to have only intensity information.

According to a twelfth aspect of the present invention, there is provided a method of reproducing an optical memory element according to the tenth aspect, wherein information on a reproduction condition of the optical memory element from the element information optical waveguide member is reproduced. The reproducing condition is set based on the information on the reproducing condition of the optical memory element, and the data optical waveguide member is reproduced.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical memory device (optical memory, multilayer optical memory) and a reproducing method thereof according to an embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 6, the basic configuration of the optical memory device [laminated (planar) optical memory device; laminated waveguide hologram device, MWH device] according to the present embodiment is as shown in FIG. It is configured as a laminate in which a plurality of optical waveguide members 323 each composed of a core layer 2 and a resin clad layer 3 are laminated. Here, it is assumed that the resin film 4 is also attached.

Here, the optical waveguide member 323 comprises a resin core layer 2 and a resin clad layer 3 laminated on both sides of the resin core layer 2. At least one of the interfaces with the layer 3 has an uneven portion (information uneven portion) 5. Hereinafter, such an optical memory device 1
The method for manufacturing the laminate constituting No. 0 will be described.

First, as shown in FIG. 5 (A), a predetermined concave / convex pattern (concavo-convex shape; pit) corresponding to an image (information) to be formed on the surface is stamped on a stamper 1. A core material (liquid core resin) 2 'is applied to a thickness. In the present embodiment, the core material 2 ′ is made of an ultraviolet-curable resin agent that is cured by irradiating ultraviolet light (UV light). And completely cured to form a resin core layer 2 '.

Next, after the core material 2 'is completely cured as described above, as shown in FIG. 5B, an ultraviolet curable resin material having a smaller refractive index than the core layer 2' is further formed thereon. (A liquid clad resin) 3a 'is applied and cured by ultraviolet irradiation to form a resin clad layer 3a' having a lower refractive index than the core layer 2 '. Then, FIG.
As shown in (C), the same clad material 3b 'as the clad material 3a' is applied on the clad layer 3a ', and a resin film (resin film member) 4 serving as a support is formed on the clad material 3b', for example. Adhesion (lamination) is performed while applying pressure using a roller or the like. That is, the resin film 4 is laminated on the clad layer 3a 'via the clad material 3b'.

In this state, if the clad material 3b 'is cured by irradiating ultraviolet rays, the clad layer 3b' made of the same material as the clad layer 3a 'is formed and the resin film 4 is bonded. Here, the cladding layers 3a ', 3
Since b 'is made of the same clad material, it functions as one clad layer 3'. Then, as shown in FIG. 5 (D), a member 2'3'4 comprising the core layer 2 ', the cladding layers 3' (3a ', 3b') and the resin film 4 is integrally formed from the stamper 1. Peel (separate).

Next, as shown in FIG. 5E, a core layer 2 "and a clad layer 3a" are similarly coated on a stamper 1 "on which a desired concavo-convex pattern of the next layer is engraved, and irradiated with ultraviolet rays. After that, as shown in FIG. 5F, the clad material 3 is formed on the clad layer 3a ″.
The same clad material 3b "as that of a" is applied, and the members 2'3'4 are adhered thereon. After the clad material 3b ″ is cured by ultraviolet irradiation, as shown in FIG.
From the stamper 1 ″, the above-mentioned core layer 2 ″ and cladding layer 3 ″
(3a ", 3b") and the members 2'3'4 are integrally peeled off.

By repeating the above process, a resin clad layer 3 and a resin core layer 2 are formed on at least one surface of a resin film 4 as a support (substrate) as shown in FIG. An optical memory element 1 as a laminate in which two or more clad / core members each having an uneven portion 5 at an interface between a resin clad layer 3 and a resin core layer 2 are laminated.
0 is formed.

Here, as shown in FIG.
Since the core member is fragile, the resin film 4
Two or more clad / core members are laminated on top,
Further, two resin films 4 are bonded by bonding the resin film 4.
The structure is sandwiched between. This is the optical memory device 1
0 is because the effect of protection between the two resin films 4 is higher when the resin film 4 is manufactured (in particular, when the optical memory element 10 is cut). Note that the structure does not have to be sandwiched between the resin films. For example, the resin film may be attached to only one surface, or the resin film may not be attached.

As described above, since the two supports are made of two resin films 4, the optical memory element 10 can be reliably protected, and the resin film 4 has an appropriate flexibility. Is also preferable from the viewpoint of handling during production. The two supports need not necessarily be made of the same material, but may be made of different materials.

Here, the resin core layer 2 and the resin clad layers 3 laminated on both sides of the resin core layer 2 are used.
And a plurality of slab-type optical waveguide devices (optical waveguide members) 323 provided with an uneven portion 5 on at least one of the interfaces between the resin core layer 2 and the resin clad layer 3. It can also be seen as forming a body.

In this case, the plurality of optical waveguide members 3
Reference numeral 23 also serves as one clad layer between two adjacent optical waveguide members. Therefore, when five clad layers and core layers are laminated, for example, clad layer / core layer / cladding layer / core layer / cladding layer, two optical waveguide members 323 are laminated to form an optical memory as a laminate. Element 1
0 has been formed.

In this embodiment, the adjacent cladding layer is commonly used as one layer. However, the present invention is not limited to this, and a three-layer laminate (cladding layer / core layer / cladding layer) (optical waveguide) may be used. The member 323 may have a basic configuration, and a plurality of optical waveguide members 323 may be laminated with or without a support such as the resin film 4 interposed therebetween. Further, the optical waveguide members can be laminated with an adhesive. Here, as the adhesive, for example, a clad material that functions as a clad layer after curing can be used.

Further, the curl of the laminate may be suppressed by laminating a clad / core member or providing another resin layer on the back side of the resin film 4 as a support in the same manner. it can. In the above description, any resin may be used as the core material 2 as long as it is a liquid at the time of application and can be cured thereafter. Examples thereof include a photo-curable resin such as a resin and a thermosetting resin. However, when the transfer is performed by the stamper as described above, it is preferable to use a photocurable resin, for example, an acrylic resin, an epoxy resin, or a thiol resin.

The clad material 3 may be any material (resin) that is transparent and has a refractive index slightly smaller than that of the core material 2. However, it is convenient to apply the clad material 3 made of various resins. The clad material 3 made of a photocurable resin, a thermosetting resin, or the like has excellent adhesiveness to the resin film 4 and is suitable. The method of applying the core material 2 and the clad material 3 includes:
For example, there are a spin coating method, a blade coating method, a gravure coating method, a die coating method and the like, and any coating method may be used as long as the coating film thickness and the uniformity are satisfied.

Here, it is preferable that the thickness of the laminated body formed by laminating the optical waveguide members 323 is about 0.3 mm or more in order to obtain strength. More preferably, it is about 0.5 mm or more. However, optical memory (information recording medium) such as optical card
In consideration of the portability as described above, it is preferable that the thickness be about 5 mm or less. More preferably, it is about 3 mm or less. In the present embodiment, as the support, various materials such as resin and metal are used as long as they can function as a support for holding the laminate (optical memory element 10). If you need flexibility, such as doing
It is preferable to use a resin support. Various types of curable resins may be cured after being applied, or the resin may be dissolved in a solvent and applied and dried to form a resin support. This is preferable in terms of productivity and workability.

Specifically, the resin film 4 is made of polycarbonate, amorphous polyolefin such as ARTON (manufactured by JSR Corporation), PET (polyethylene terephthalate), P
It is preferable to use a thermoplastic resin film having excellent optical properties such as EN (polyethylene naphthalate) (PEN is further excellent in heat resistance) (particularly, PET or PE described above).
N is preferable because it is easy to obtain a film having a uniform thickness), and it is preferable that any of these is made to have a thickness of, for example, 100 μm or less by a method such as hot stretching or solvent casting.

In general, in the manufacturing process of the resin film 4, an optically scattering material such as inorganic particles is mixed into the film. If scattering of light by scatterers in the film becomes a problem when reading signals,
If the clad / core member is laminated only on one side of the film, it is preferable to use a light-shielding film as the film or to provide a light-shielding film between the film and the clad / core member. Accordingly, it is possible to prevent light from propagating into the resin film or interference of scattered light within the film with the signal light.

In this case, it is more preferable to make the support itself light-shielding, since the size of the optical memory element 10 can be reduced and the manufacturing process can be simplified. Here, examples of the light-shielding film and the light-shielding film include a PET film produced by kneading carbon into a resin or adding a dye. The light-shielding film or the wavelength region in which the light-shielding film acts is sufficient if the wavelength of the introduced light (incident light, reproduction light) used for reproduction can be shielded, and it is not necessary to shield the entire visible light region. Absent. Regarding the light-shielding performance, it is sufficient that 90% or more of the light can be blocked in the film thickness direction, but it is more preferable that 99% or more of the light can be blocked.

The thickness of the core layer 2 and the cladding layer 3 may be any thickness that allows the core layer 2 and the cladding layer 3 to function as an optical waveguide. In the wavelength region, the core layer 2 is approximately 0.5 to
It is considered to be about 3.0 μm. In this case, the thickness of the cladding layer 3 is not particularly limited, but is preferably 100 μm or less in consideration of reducing the overall thickness. If the lower limit is stipulated, it will be 0.1 μm or more.

It is preferable that the clad layer 3 is formed in two layers as described above because the film thickness is stable, but it may be formed as one layer. In the above description, the resin film 4
Although a method using a single-wafer film has been described as an example, implementation using a continuous film is also possible. By combining processes such as coating the core and clad material on the film with a die coater, microgravure, bar coater, etc., and curing the core and clad material while pressing the stamper, the clad / core member is formed on the support. Can be manufactured. Further, by using a roll stamper processed into a form that can be wound up into a roll as the stamper, it is possible to improve the productivity of the transfer process from the stamper.

The optical memory device 10 constructed as described above
For example, when light is introduced into the core layer 2 as an optical waveguide through the incident end face, the introduced light is propagated while being scattered at the uneven portion of the interface. The scattered light at this time propagates (transmits) in the vertical direction (intersecting direction) with respect to the introduced light, and is finally emitted to the outside from both sides of the optical memory element, and an image corresponding to the uneven pattern is formed. An image will be formed.

As described above, according to this embodiment, both the laminated core layer 2 and clad layer 3 are made of resin,
In addition, since the curable resin that can be cured by light, heat, or the like is used for the core layer (core material) 2 on which the unevenness is formed, it is not necessary to use the photoresist exposure and development processing as in the related art. By the transfer from the stamper, it is possible to easily form the uneven portion 5 having a desired shape at the interface between the core layer 2 and the clad layer 3.

The thickness of the cladding layer 3 is, for example, 10 μm.
By setting it to about m, the film thickness of the element can be suppressed to about 1 mm even when 100 layers are stacked, and a practical optical memory element 10 having a multilayer structure can be manufactured. Accordingly, mass production of the optical memory element 10 having a multilayer structure becomes possible, and the optical memory element 10 can be provided more easily (in a shorter time) and at lower cost than before.

By the way, such an optical memory element 10 is reproduced using a drive (reproducing apparatus). There are various physical structures of the optical memory element, and the reproducing condition depends on the type of the optical memory element. Therefore, if the drive cannot obtain the information necessary for reproducing such an optical memory element, the data recorded on the optical memory element cannot be reproduced.

For example, if only content data such as music data is recorded in the optical memory device, the drive stores information necessary for reproducing the optical memory device (for example, information on physical structure, information on reproduction conditions, etc.). Cannot be obtained, and the optical memory element cannot be reproduced. For this reason, in addition to content data such as music data, for example, information necessary for reproduction of the optical memory element 10 (for example, information on a physical structure, information on a reproduction condition, etc.) must be recorded in the optical memory element 10. .

Various methods can be considered for recording information necessary for reproduction of the optical memory element 10.
In particular, information necessary for reproduction of the optical memory element 10 (for example, information on a physical structure, information on a reproduction condition, etc.)
When the optical memory element 10 is reproduced, the important information is read (reproduced) first, so that it is not misread.
It must be able to read reliably.

Therefore, in the present embodiment, as shown in FIG. 1, the optical memory element 10 is used to store one or a plurality of data optical waveguide members (data) for recording desired data (information, for example, content data such as music data). Layer, information optical waveguide member, information layer) 323A and at least one media information optical waveguide member (element information optical waveguide member, media information layer, element information layer) 323B for recording information on the optical memory element 10. It is configured as having. In FIG. 1, reference numeral 13 denotes a CCD receiver.

Here, information necessary for reproduction of the optical memory element (for example, information relating to the physical structure, information relating to reproduction conditions, etc.) is recorded as irregularities (diffraction gratings) on the optical waveguide member. There is an advantage that important information is not accidentally erased.
Here, the information on the optical memory element 10 is information (element identification information, media identification information) necessary for reproduction of the optical memory element 10, such as information on a physical structure and information on reproduction conditions. All of this information is first read (reproduced) when the optical memory element 10 is reproduced.
Information.

Among them, as the information on the physical structure of the optical memory element (medium) 10, for example, the following information is recorded. ROM, RAM, or partially RA
M or storage capacity of 50 GB or 100 GB Whether or not five layers of 20 layers are stacked (2
0 layers × 5) or four layers of 25 layers (2
5 layers × 4) [that is, at what intervals the bases (supports) are provided; if 20 layers × 5, 25
If the layer × 4, the interlayer distance changes once for every 25 layers.] The thickness of the cladding layer (this changes how many μm servo should be applied) and the optical memory element (medium For example, the following information is recorded as the information on the 10 reproduction conditions. The information partially overlaps with the information on the physical structure described above. Focal length [distance between optical memory element 10 and CCD receiver 13; this determines how far the CCD receiver 13 is located. This is because the position at which the reproduced image is focused (imaging point) is determined by the concave / convex portions 5 recorded on the optical waveguide member 323 of the optical memory element 10. Incident light intensity (reproducing light intensity, incident light power, reproducing light power) Recording light intensity (when optical memory element 10 is RAM) Shutter speed, exposure time,
Exposure time Other information about the optical memory element 10 also includes a media number (media ID, media unique information).

As shown in FIG. 1, the optical memory element 10 has an uneven portion provided at the interface between the resin core layer 2 (2A, 2B) and the resin clad layer 3 (3A, 3B). 5 (5A, 5B), an incident end face (incident light introduction end face) for guiding incident light (reproducing light) for reading information to the resin core layers 2A, 2B of the optical waveguide members 323A, 323B.
11 is formed.

Here, the end face of each optical memory element 10 cut out to a desired size at 90 degrees (the angle formed with the surface of the optical waveguide member is 90 degrees) is defined as an incident end face (90-degree incident end face) 11. . The incident light is applied to the resin core layer 2.
The incident end face 11 for guiding to A and 2B is not limited to this, and various types can be considered. For example, one end face of the optical memory element 10 is cut at 45 degrees (an angle made with the surface of the optical waveguide member is 45 degrees), and a reflection film is formed as necessary to form a mirror end face (inclined end face, micro mirror). Alternatively, this mirror end face may be used as the incident end face (45 ° incident end face). In this case, light is incident on the 45 ° incident end face from a direction perpendicular to the surface of the optical memory element 10 and is reflected by the 45 ° incident end face to guide the incident light to the resin core layers 2A and 2B. Will be.

When the optical memory element 10 is reproduced, the drive first operates the optical waveguide member 323 for media information.
The reproduction condition of the optical memory element 10 is set based on the information on the reproduction condition of the optical memory element 10 obtained by reproducing B, and then the data optical waveguide member 323A is reproduced (the reproduction method of the optical memory element). ). Hereinafter, a specific configuration of the optical waveguide member 323B for media information of the optical memory device 10 according to the present embodiment will be described.

First, in the present embodiment, the media information optical waveguide member 323B is laminated on the outermost side of the optical memory element 10. That is, as shown in FIG. 1, the optical waveguide member for media information 323B is provided on the uppermost layer or below the lowermost layer of the optical waveguide member for data 323A. For this reason, the optical waveguide member for media information 323B is also referred to as an outermost optical waveguide member.

This is to suppress crosstalk when reproducing information recorded on the data optical waveguide member 323A. In particular, in the present embodiment, as described later, the media information optical waveguide member 323B is configured so that the reproduction pattern becomes bright, so that it does not affect the reproduction of the other data optical waveguide member 323A. It is necessary.

In this embodiment, the optical memory device 10
B is scattered by the data concavo-convex portion 5A and the media information concavo-convex portion (element information concavo-convex portion) 5B, and reads a reproduced image formed by scattered light emitted from one side to the outside to read the data concavo-convex portion. It may be configured as a single-sided optical memory element for reproducing the information of the portion 5A or the media information uneven portion 5B, or may be scattered by the data uneven portion 5A or the media information uneven portion 5B, and may be scattered from both sides to the outside. An optical memory element for double-sided reproduction that reads a reproduced image formed by the emitted scattered light and reproduces information in the data uneven portion 5A and the media information uneven portion 5B may be used.

In this embodiment, as shown in FIG. 1, the thickness of the resin core layer 2B of the optical waveguide member 323B for media information is larger than the thickness of the resin core layer 2A of the optical waveguide member 323A for data. It is thick. This makes it easy to make incident light incident on the resin core layer 2B of the optical waveguide member 323B for media information (that is, it is possible to make coupling easy).

The media information optical waveguide member 323B
Can be increased at the media information uneven portion 5B, and as a result, the output from the media information optical waveguide member 323B increases (the luminance of the scattered light increases), and the reproduction pattern becomes bright. For this reason, the optical memory element 10
Thus, it is possible to reliably read a reproduction pattern including important information that needs to be reproduced first at the time of reproduction.

As described above, when the resin core layer 2B is made thicker, a multi-mode is obtained. The multi-mode is more easily optically coupled (coupling) than the single mode, and
The scattered light is easily emitted to the outside, and as a result, the reproduction pattern is also bright, so that the media identification information recorded on the media information optical waveguide member 323B can be reliably read. Also, servo (initial alignment)
In this case, only the mechanical servo is sufficient, and the reproduction pattern can be read easily and quickly.

In particular, the optical waveguide member 323B for media information
The thickness of the resin core layer 2B is determined by the data optical waveguide member 32.
The thickness is preferably 1.1 times or more (more preferably, 2 times or more) the thickness of the resin core layer 2A of 3A. On the other hand, in consideration of increasing the storage capacity while reducing the thickness (film thickness) of the entire optical memory element 10, the thickness of the resin core layer 2B of the optical waveguide member for media information 323B is preferably 100 μm or less. .

As described above, since the media information optical waveguide member 323B is multimode in this embodiment, the media information irregularities (grating, diffraction grating, grating) of the media information optical waveguide member 323B are used. The pattern 5B is, as shown in FIG.
It is configured as a grating having only intensity information (without phase information).

In this case, the media information optical waveguide member 32
The scattered light scattered by the unevenness portion 5B for media information of 3B does not form an image outside the optical memory element 10 (that is, it does not become a hologram image). Therefore, even if the mere scattered light is read by the CCD receiver 13, the reproduction pattern 15 [output from the media information concave / convex portion 5B (media information layer output)] read by the CCD receiver 13 is shown in FIG. As shown in (B), the image is blurred (although each component of the reproduction pattern 15 is blurred and circular instead of being square), but the reproduction recorded on the optical waveguide member 323B for media information is performed. There is no problem in reproducing the pattern 15.

In particular, in this case, if information is recorded at a high density, it cannot be read by the CCD receiver 13, so that it is difficult to record a large amount of information. There is no problem because it is good. On the other hand, the data optical waveguide member 3
The data uneven portion 5A of 23A is formed as having the intensity information and the phase information, and the data optical waveguide member 323A is formed.
A hologram image (reproduced image, reproduced pattern) is formed by the scattered light scattered by the data uneven portion 5A, and the hologram image is read by the CCD receiver 13 to read the data (data) recorded on the data optical waveguide member 323A. Information). Here, the output (data layer output) from the data optical waveguide member 323A read by the CCD receiver 13 is a reproduced image 14 as shown in FIG. 3, for example.

In the present embodiment, since the resin-made core layer 2B of the media information optical waveguide member 323B is thickened so as to be multi-mode, the media information unevenness portion of the media information optical waveguide member 323B is used. 5B is configured to have only intensity information, but is not limited to this. The thickness of the resin core layer 2B of the optical waveguide member for media information 323B is reduced to a single mode, and The media information uneven portion 5B of the optical waveguide member 323B may be configured to have intensity information and phase information.

In this case, the media information optical waveguide member 32
The reproduced pattern is formed as a hologram image (reproduced image, output image, reproduced pattern) by the scattered light scattered by the media information uneven portion 5B of 3B and emitted to the outside. For example, the output (media information layer output) from the media optical waveguide member 323B read by the CCD receiver 13 is a clear reproduction pattern 15 without blur, as shown in FIG. A clear reproduction pattern 15) is obtained.

Here, there are various types of multi-modes from a mode close to a single mode to a complete multi-mode, and as the mode becomes single, the degree to which phase information is not used gradually increases. An image close to the single mode is slightly more blurred than the reproduced image in the single mode, but in a complete multi mode, it is merely scattered light, and the entire image is blurred and no image is formed.

In the present embodiment, since the media identification information is important information to be read first when reproducing the optical memory element 10, the media information unevenness of the media information optical waveguide member 323B is not misread. Part 5
B is formed so that the reproduction pattern from the optical waveguide member for media information 323B is brighter (higher luminance) than the reproduced image from the optical waveguide member for data 323A.

Specifically, the optical waveguide member 3 for media information
The unevenness portion 5B for media information 23B is formed so that the luminance of the reproduction pattern from the optical waveguide member 323B for media information is higher than the maximum luminance of the reproduced image from the optical waveguide member 323A for data. That is, in the present embodiment, the data concavo-convex portion 5A of the data optical waveguide member 323A is a set of pixels in which a data pattern of an image to be formed is a pixel having a square of several microns as a basic pixel. The media information unevenness portion 5B of the media information optical waveguide member 323B is formed by setting the luminance for each image so that the reproduced image is displayed at a predetermined gradation (a plurality of gradations). The brightness is set to be higher than the highest brightness (the brightness of the portion set to have the highest brightness) among the brightnesses set for forming the data uneven portion 5A of the optical waveguide member 323A. .

For example, when the reproduced image from the data concave and convex portion 5A of the data optical waveguide member 323A is represented by four gradations, the luminance of the reproduced pattern is set to the brightest part among the four levels ( The media information concave / convex portion 5B of the media information optical waveguide member 323B is formed so as to have a higher brightness than the brightness of a portion set to have the highest brightness.

The media information optical waveguide member 323B
In the case where the reproduction pattern from the media information is represented by a predetermined gradation (a plurality of gradations), the highest luminance of the reproduction pattern from the media information optical waveguide member 323B (the luminance of the portion set to have the highest luminance). ) Is the optical waveguide member 323 for data.
The media information concave / convex portion 5B of the media information optical waveguide member 323B is formed so as to be higher than the highest luminance of the reproduced image from A.

Preferably, the optical waveguide member 3 for media information
The luminance (maximum luminance) of the reproduced pattern from 23B is the highest luminance of the reproduced image from the data optical waveguide member 323A.
It should be at least 1 times (more preferably at least 1.2 times). Unless this difference is made, the reproduction pattern by the media information optical waveguide member 323B cannot be said to be bright, and it is difficult to read the media identification information easily and reliably. However, it is preferable to set it to three times or less. This is because if the brightness is too high, crosstalk increases when reproducing the other data optical waveguide member 323A.

When the media information concave / convex portion 5B of the media information optical waveguide member 323B is configured as described above,
The evaluation of the optical memory device 10 including the media information optical waveguide member 323B can be performed, for example, as follows. In other words, only the luminance (maximum luminance) of the portion set to have the highest luminance of the reproduced image from the data uneven portion 5A of the data optical waveguide member 323A represented by the predetermined gradation is picked up. Find the average brightness of
The average luminance of the reproduced image is compared with the luminance of the reproduced pattern (maximum luminance) to determine whether the luminance of the reproduced pattern (maximum luminance) is higher than the average luminance of the reproduced image. The element 10 can be evaluated.

In this case, since the evaluation is performed using the average luminance of the portion set so that the luminance of the reproduced image is the highest, the maximum luminance of the reproduced image is not affected by the noise in the reproduced image. (Brightness of the part where the brightness of the reproduced image is set to be the highest) and the luminance of the reproduced pattern (the highest luminance)
Thus, the optical memory element 10 can be evaluated.

Specifically, the optical waveguide member 3 for media information
The refractive index of the core 2B of the 23B is the optical waveguide member 323 for data.
The optical waveguide member 323B for media information is configured to have a refractive index larger than the refractive index of the core 2A of A. This allows
The scattering of the incident light (guided light) at the media information uneven portion 5B of the media information optical waveguide member 323B can be increased, and as a result, the output from the media information optical waveguide member 323B increases (scattered light Brightness).

In particular, the optical waveguide member 323B for media information
The refractive index of the core 2B is preferably 0.001 or more larger than the refractive index of the core 2A of the data optical waveguide member 323A. On the other hand, if the brightness is too high, the crosstalk during reproduction of the data optical waveguide member 323A increases, so that the media information optical waveguide member 323B.
The difference between the refractive index of the core 2B and the refractive index of the core 2A of the data optical waveguide member 323A is preferably 0.1 or less.

Conversely, the optical waveguide member 3 for media information
The optical waveguide member 323B for media information may be configured such that the refractive index of the cladding 3B of 23B is smaller than the refractive index of the cladding 3A of the optical waveguide member 323A for data. This makes it possible to increase the scattering of the incident light on the media information concave / convex portion 5B of the media information optical waveguide member 323B, and as a result, the media information optical waveguide member 32
The output from 3B can be increased (the brightness of the scattered light can be increased). In this case, between the media information optical waveguide member 323B and the data optical waveguide member 323A,
Two clad layers having different refractive indices are laminated.

In particular, the optical waveguide member 323B for media information
The refractive index of the core 2B is preferably 0.001 or more larger than the refractive index of the core 2A of the data optical waveguide member 323A. On the other hand, if the brightness is too high, the crosstalk during reproduction of the data optical waveguide member 323A increases, so that the media information optical waveguide member 323B.
The difference between the refractive index of the core 2B and the refractive index of the core 2A of the data optical waveguide member 323A is preferably 0.1 or less.

As described above, the media information optical waveguide member 3
If the difference in the refractive index between the core 2B and the cladding 3B of the 23B is made larger than the difference in the refractive index between the core 2A and the cladding 3A of the data optical waveguide member 323A, the media information optical waveguide member 323B. The scattering of the incident light at the media information uneven portion 5B can be increased, and as a result, the output from the media information optical waveguide member 323B can be increased (the scattered light brightness can be increased).

Incidentally, the optical waveguide member 323B for media information is used.
When the difference in the refractive index between the core 2B and the clad 3B is increased, if the thickness of the resin core layer 2B is the same, multi-mode is likely to occur. On the other hand, when the single mode is desired, the core 2 of the optical waveguide member 323B for media information is used.
It is necessary to increase the difference in the refractive index between B and the cladding 3B, and at the same time, to reduce the thickness of the resin core layer 2B. Generally, when the thickness of the resin core layer 2B is 2 μm or less, a single mode is obtained. For example, by setting the thickness of the optical waveguide member for media information 323B to about 1.4 μm, the waveguide mode can be made a single mode.

In this embodiment, as shown in FIG. 1, the height of the media information uneven portion 5B of the media information optical waveguide member 323B is set to be greater than the height of the data uneven portion 5A of the data optical waveguide member 323A. Is also higher. This makes it possible to increase the scattering of the media information optical waveguide member 323B at the media information unevenness portion 5B, and as a result, the output from the media information optical waveguide member 323B is increased (the brightness of the scattered light is increased). can do.

The media information optical waveguide member 323B
In order to change the height of the uneven portion 5B for media information, the pit depth of the stamper may be changed. In particular, the height of the media information uneven portion 5B of the media information optical waveguide member 323B is determined by the data uneven portion 5B of the data optical waveguide member 323A.
The height of A is preferably 1.1 times or more (more preferably 1.2 times or more). On the other hand, if the brightness is too high, crosstalk in reproducing the other data optical waveguide member 323A will increase. Therefore, the height of the media information concave / convex portion 5B of the media information optical waveguide member 323B will be reduced. Uneven part 5A for data of optical waveguide member 323A for data
Is preferably not more than three times the height of

When reproducing the optical memory element 10, incident light (reproducing light) incident on the optical memory element 10 is used.
(For example, depth of focus, irradiation position, irradiation angle, inclination of incident light, etc.) must be adjusted to align the incident light with the optical memory element 10. Here, since the optical waveguide member for media information 323B according to the present embodiment is configured as described above, it can be used for servo (can be used for adjusting the irradiation state of incident light, and can be used for alignment of incident light. By recording servo information (servo pattern) together, it can also be used as a servo optical waveguide member (servo layer).

That is, as described above, the optical waveguide member 323B for media information according to the present embodiment has the resin core layer 2B of the optical waveguide member 323A for data. Thicker than
The luminance of the reproduction pattern (output pattern, reproduction image, output image) from the media information optical waveguide member 323B is higher than the maximum luminance of the reproduction image from the data optical waveguide member 323A. The refractive index of the resin core layer 2B is larger than the refractive index of the resin core layer 2A of the data optical waveguide member 323A, and the refractive index of the resin clad layer 3B of the media information optical waveguide member 323B is the data optical waveguide member 323B. Resin clad layer 3 of wave member 323A
The height of the media information uneven portion 5B of the media information optical waveguide member 323B that is smaller than the refractive index of A is higher than the height of the data uneven portion 5A of the data optical waveguide member 323A. The member 323B is configured so as to satisfy the condition that the member 323B is provided on the outermost side of the laminate, and the member that meets these conditions is suitable for aligning incident light. If the servo information (servo pattern) is also recorded on the information optical waveguide member 323B and the servo pattern can be output, the media information optical waveguide member 323B can function as the servo optical waveguide member. It is.

According to this, since the medium identification information and the servo pattern are recorded on one layer, the thickness of the entire optical memory element 10 is smaller than when the medium identification information and the servo pattern are recorded on separate layers. Can be made thinner. Further, the medium identification information and the servo pattern are recorded on one layer, and the layer on which the medium identification information or the servo pattern is recorded is redirected to the data layer on which data is recorded. The storage capacity can be increased while preventing the data from becoming thick.

The media information optical waveguide member 323B
Apart from this, a servo layer (servo optical waveguide member) may be provided. In this case, when reproducing the optical memory element 10, first, the optical waveguide member 323B for media information is reproduced, then the servo layer is reproduced, and then the optical waveguide member 323A for data may be reproduced. Alternatively, the servo layer may be reproduced first, the optical waveguide member 323B for media information may be reproduced next, and then the optical waveguide member 323A for data may be reproduced.

Therefore, according to the optical memory device and the reproducing method of the present embodiment, the media information optical waveguide member 323B is provided, and the optical memory device 1
0 (for example, information relating to the physical structure of the optical memory element 10, information relating to the reproduction conditions of the optical memory element 10, etc.) are recorded.
There is an advantage that the information recorded in the information can be reliably reproduced.

In particular, the optical waveguide member 323B for media information
Since the thickness of the core layer 2B is large, it is easy to make incident light incident (coupling is easy), and information about the optical memory element 10 recorded in the media information optical waveguide member 323B can be easily and There is also an advantage that reading can be performed reliably. The media information concave / convex portion 5B of the media information optical waveguide member 323B is configured such that the reproduction pattern from the media information optical waveguide member 323B is brighter (has a higher brightness) than the reproduced image from the data optical waveguide member 323A. Furthermore, since the optical memory device 10 is formed so as to satisfy various conditions, there is an advantage that important media identification information which is read first when the optical memory element 10 is reproduced can be surely reproduced without being erroneously read.

In the above-described embodiment, the optical waveguide member 323B for media information is configured so as to satisfy various conditions in order to optimize the optical waveguide member 323B. You can also.

[0086]

According to the optical memory device and the reproducing method of the present invention as set forth in claims 1 to 12, the device information optical waveguide member is provided, and information about the optical memory device is recorded on the optical waveguide member. There is an advantage that information recorded in the optical memory element can be reliably reproduced.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an overall configuration of an optical memory device according to one embodiment of the present invention.

FIG. 2A is a schematic diagram showing a grating pattern of a media information optical waveguide member of an optical memory device according to an embodiment of the present invention, and FIG. It is a figure showing a reproduction pattern (media information layer output).

FIG. 3 is a diagram showing a reproduced image (data layer output) from a data optical waveguide member of the optical memory element according to the embodiment of the present invention.

FIG. 4 is a diagram showing another example of a reproduction pattern (media information layer output) from the media information optical waveguide member of the optical memory element according to the embodiment of the present invention.

FIGS. 5A to 5G are schematic cross-sectional views for explaining a method of manufacturing a laminated body constituting the optical memory element according to one embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view for explaining an example of a laminated structure of a laminated body constituting the optical memory element according to one embodiment of the present invention.

FIG. 7 is a schematic perspective view for explaining the operation principle of a conventional optical memory element.

FIG. 8 is a schematic perspective view for explaining the operation principle of a conventional optical memory element.

FIGS. 9A and 9B are schematic perspective views for explaining the operation principle of a conventional optical memory element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stamper 2, 2A, 2B Core layer 3, 3A, 3B Cladding layer 4 Resin film (support) 5 Uneven part 5A Uneven part for data 5B Uneven part for media information (uneven part for element information) 10 Optical memory element 11 Incident end face Reference Signs List 13 CCD receiver 14 Reconstructed image 15 Reconstructed pattern 323 Optical waveguide member 323A Optical waveguide member for data (data layer) 323B Optical waveguide member for media information (optical waveguide member for element information, media information layer, element information layer)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H047 KA04 KA11 KA15 KB08 LA03 PA02 PA28 QA05 RA04 TA00 5B003 AA09 AB01 AC00

Claims (12)

[Claims] 1. A resin core layer comprising: a resin core layer; and a resin clad layer laminated on both surfaces of the resin core layer, and at least one of interfaces between the resin core layer and the resin clad layer has an uneven portion. An optical memory device configured as a laminated body formed by laminating a plurality of optical waveguide members having: a plurality of optical waveguide members, one or a plurality of data optical waveguide members, and an element for recording information related to the optical memory device. Characterized by comprising an optical waveguide member for information,
Optical memory device. 2. The optical memory element according to claim 1, wherein a resin core layer of the optical waveguide member for element information is thicker than a resin core layer of the optical waveguide member for data. 3. The apparatus according to claim 1, wherein a maximum brightness of a reproduced image from the element information optical waveguide member is higher than a maximum brightness of a reproduced image from the data optical waveguide member. Item 3. The optical memory device according to item 1 or 2. 4. The optical waveguide member for element information, wherein a refractive index of the resin core layer is larger than a refractive index of the resin core layer of the optical waveguide member for data.
The optical memory device according to any one of the above items. 5. The optical waveguide member for element information according to claim 1, wherein the refractive index of the resin clad layer is smaller than the refractive index of the resin clad layer of the optical waveguide member for data. The optical memory device according to any one of the above items. 6. The device information optical waveguide member according to claim 1, wherein a height of the device information unevenness portion is higher than a height of the data unevenness portion of the data optical waveguide member.
The optical memory device according to any one of the above items. 7. The device information optical waveguide member is provided on the outermost side of the laminate.
7. The optical memory device according to any one of items 1 to 6. 8. The device information optical waveguide member according to claim 1, wherein the device information optical waveguide member is configured to output a servo pattern that can be used for adjusting an irradiation state of incident light. An optical memory device according to item 1. 9. The optical memory device according to claim 1, wherein the element information optical waveguide records information on a physical structure of the optical memory device. 10. The optical memory element according to claim 1, wherein the element information optical waveguide records information on a reproduction condition of the optical memory element. 11. The optical memory according to claim 1, wherein the concave / convex portion for element information of the optical waveguide member for element information is configured to have only intensity information. element. 12. The reproducing method of an optical memory device according to claim 10, wherein information on a reproducing condition of the optical memory device from the optical waveguide for element information is reproduced, and based on information on a reproducing condition of the optical memory device. A method for reproducing an optical memory device, comprising setting reproduction conditions and reproducing the data optical waveguide member.