JP2001325730A - Data recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reproducible data recording medium by surely separating data recorded in plural plane optical waveguide type recording layers having a periodic light scattering factor. SOLUTION: In an optical card 11 which is formed by laminating plural plane optical waveguide type recording layers having the periodic light scattering factor, incident light 13 becomes propagation light 14 which propagates only the specified layer by providing, in respective recording layers L1, L2, L3, a light incident part wherein rugged lines composing the periodic light scattering factor are formed at such a pitch interval that the directions of incident light which is diffracted in the direction coinciding with the optical waveguide layer respectively become different directions every recording layer, scattered light 15 from a data recording area provided in the specified layer reaches a detector 12, and only the data is reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording medium comprising a plurality of planar optical waveguide type recording layers having periodic light scattering factors.

[0002]

2. Description of the Related Art In recent years, demands for compact and easy-to-carry and large-capacity memories such as mobile computing have been rapidly increasing. As one method of realizing a large-capacity memory at low cost, a planar optical waveguide type multiplex optical memory in which data is embedded (recorded) in a planar optical waveguide as a periodic light scattering factor and the optical waveguides are stacked has been proposed. (See, for example, JP-A-11-345419).

FIG. 1 shows an example of a conventional data recording medium of this type together with information reproduction. The data recording medium 1 includes a plurality of core layers and cladding layers alternately stacked or a plurality of layers each having a core layer sandwiched between cladding layers. ) Is obtained by multiplying the planar optical waveguide type recording layer held in step (1).

In each recording layer, data is recorded at a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, which is periodically formed on the optical waveguide layer near the interface between the optical waveguide layer and the holding layer or on the holding layer. Is recorded as a periodic light scattering factor composed of a large number of lines having an uneven shape having

[0005] Data is reproduced by the light 3 emitted from the light source 2.
To the target incident position 4 of the recording layer, and an image 5 generated by scattering the light propagating through the recording layer due to the periodic light scattering factor is picked up by the image pickup device 6.

[0006]

As described above, a data recording medium using a planar optical waveguide type recording layer can be increased in capacity and is promising in the future. There is a problem that it must be separated and reproduced.

SUMMARY OF THE INVENTION It is an object of the present invention to reliably separate and reproduce data recorded in each recording layer in a data recording medium comprising a plurality of planar optical waveguide type recording layers having periodic light scattering factors. To provide a simple data recording medium.

[0008]

In order to solve the above-mentioned problems, the present invention comprises an optical waveguide layer and holding layers above and below the optical waveguide layer, and scatters light generated when data is transmitted to the optical waveguide layer. A data recording medium comprising a plurality of stacked planar optical waveguide recording layers having a periodic light scattering factor for recording reproducibly as an image according to the invention, wherein the periodic light scattering factor is the optical waveguide layer and the holding layer. In the data recording medium, which is formed in the optical waveguide layer or the holding layer in the vicinity of the interface, and is a large number of lines having a concave and convex shape having a repetition pitch of about the wavelength of light propagating in the optical waveguide layer, In each recording layer, a line having an uneven shape constituting a periodic light scattering factor is formed at a pitch interval such that directions of incident light diffracted in a direction coinciding with the optical waveguide layer are different directions for each recording layer. Light entrance , Characterized by providing a periodic optical length of the irregular shape of the lines constituting the scattering factor or the phase or the data recording area for recording data both.

According to the above construction, the lines of the concave and convex shapes at the light incident portions of the plurality of stacked recording layers are such that the directions of the incident light diffracted in the direction coinciding with the optical waveguide layer are different for each recording layer. Therefore, the direction of the incident light diffracted in the direction corresponding to the optical waveguide layer at the light incident portion of each recording layer differs for each recording layer. Therefore, the incident light diffracted in the direction corresponding to the optical waveguide layer at the light incident portion of the desired recording layer is not diffracted in the direction coincident with the optical waveguide layer at the light incident portion of the other recording layer. The light propagates only through the desired recording layer to reach the data recording area, and thus, it becomes possible to reproduce only the data recorded in the desired recording layer. To reproduce data recorded on another recording layer, the direction (angle) of incident light
Can be changed by selecting a recording layer in which the direction of the incident light diffracted at the light incident portion coincides with the optical waveguide layer.

According to the present invention, there is provided a periodic light comprising a light guide layer and a holding layer above and below the light guide layer, wherein data is reproducibly recorded as an image by scattered light generated when light is propagated through the light guide layer. A data recording medium comprising a stack of a plurality of planar optical waveguide recording layers having scattering factors, wherein the periodic light scattering factors are caused by the optical waveguide layer or the optical waveguide layer near the interface between the optical waveguide layer and the holding layer. In a data recording medium that is formed in a holding layer periodically, and is a number of lines having a concave-convex shape having a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, a periodic light scattering factor is applied to each recording layer. A light incident portion formed at a pitch interval such that a direction of incident light diffracted in a direction coinciding with the optical waveguide layer is different from each other for each recording layer; Irregularities that make up the factor Length shaped for line or and the phase, or both, characterized in that a recording data recording area data and the pitch as the same as the light incident portion of the same recording layer.

According to the above-mentioned structure, the pitch interval between the uneven lines constituting the periodic light scattering factor in the data recording area;
Since the pitch interval of the uneven lines constituting the periodic light scattering factor at the light incident portion is the same, the pitch interval of the uneven lines constituting the periodic light scattering factor must be one type for each recording layer. And the productivity is improved.

According to the present invention, there is provided a periodic light for recording data reproducibly as an image formed by scattered light generated when light is propagated through the optical waveguide layer, comprising an optical waveguide layer and upper and lower holding layers. A data recording medium comprising a stack of a plurality of planar optical waveguide recording layers having scattering factors, wherein the periodic light scattering factors are caused by the optical waveguide layer or the optical waveguide layer near the interface between the optical waveguide layer and the holding layer. In a data recording medium that is formed in a holding layer periodically, and is a number of lines having a concave-convex shape having a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, a periodic light scattering factor is applied to each recording layer. A light incident portion formed at a position where the direction of incident light diffracted in a direction coinciding with the optical waveguide layer is different from each other for each recording layer, and a periodic light scattering factor. The length of the irregular shaped line that constitutes Alternatively, characterized in that a phase or the data recording area for recording data both.

According to the above construction, the lines of the concave and convex shapes of the light incident portions of the plurality of stacked recording layers are such that the directions of the incident light diffracted in the direction coinciding with the optical waveguide layer are different for each recording layer. Therefore, the position of the incident light diffracted in the direction corresponding to the optical waveguide layer at the light incident portion of each recording layer differs for each recording layer. Therefore, the incident light diffracted in the direction corresponding to the optical waveguide layer at the light incident portion of the desired recording layer is not diffracted in the direction coincident with the optical waveguide layer at the light incident portion of the other recording layer. The light propagates only through the desired recording layer to reach the data recording area, and thus, it becomes possible to reproduce only the data recorded in the desired recording layer. In order to reproduce data recorded on another recording layer, by changing the position of the incident light, by selecting a recording layer in which the direction of the incident light diffracted at the light incident part matches the optical waveguide layer. It is possible.

According to the present invention, there is provided a periodic light comprising an optical waveguide layer and a holding layer above and below the optical waveguide layer, the data being reproducibly recorded as an image by scattered light generated when the light is propagated through the optical waveguide layer. A data recording medium comprising a stack of a plurality of planar optical waveguide recording layers having scattering factors, wherein the periodic light scattering factors are caused by the optical waveguide layer or the optical waveguide layer near the interface between the optical waveguide layer and the holding layer. In a data recording medium that is formed in a holding layer periodically, and is a number of lines having a concave-convex shape having a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, a periodic light scattering factor is applied to each recording layer. Lines of the concavo-convex shape to be formed are provided with light incident portions formed at an angle of arrangement such that incident light diffracted in a direction coinciding with the optical waveguide layer is propagated in different directions for each recording layer. Light incident on recording layer By on the extension line of the propagation direction of the incident light, characterized in that a periodic optical length of the irregular shape of the lines constituting the scattering factor or the phase or the data recording area for recording data both.

According to the above-mentioned structure, the lines having the uneven shape at the light incident portion of each of the plurality of stacked recording layers cause the incident light diffracted in the direction coinciding with the optical waveguide layer to propagate in different directions for each recording layer. The incident light diffracted in the direction coincident with the optical waveguide layer at the light incident portion of each recording layer propagates in a different direction for each recording layer, and the incident light To the data recording area provided on the extension of the propagation direction of the data. Therefore, data recorded on all recording layers is reproduced. However, since the propagation direction of incident light differs for each recording layer and the position of the data recording area differs for each recording layer, the data depends on the position of the detector. From which the recording layer can be extracted.

[0016]

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

FIG. 2 shows a first embodiment of the present invention. In the figure, reference numeral 11 denotes an optical card (data recording medium);
Is a detector, 13 is incident light used for reproduction, 14 is propagation light propagating through the recording layer L2, 15 is scattered light, 16 is transmitted light,
17 is a diffracted light from the recording layer L1, and 18 is a diffracted light from the recording layer L3.

Hereinafter, the operation of the present embodiment will be described.

The optical card 11 is a large-capacity read-only memory using a multilayer hologram. In addition to being able to be mass-produced by a transfer type or the like, it is intended to accumulate a large amount of data in multiple layers, and in detail, similarly to the conventional example, a plurality of core layers and clad layers are alternately laminated, or By stacking a plurality of layers in which a core layer is sandwiched between cladding layers, a planar optical waveguide type recording layer in which the upper and lower portions of the core layer (optical waveguide layer) are held by cladding layers (holding layers) is multilayered. FIG. 2 shows an example in which the recording layers L1, L2, and L3 are stacked, but it goes without saying that the number of layers may be larger.

In each of the recording layers, the lines of the uneven shape constituting the periodic light scattering factor are such that the directions of the incident light diffracted in a direction coinciding with the optical waveguide layer are different for each recording layer. A light incident portion formed with such a pitch interval, and a data recording area in which data is recorded with the length and / or phase of the uneven line constituting the periodic light scattering factor are provided. Reproduction is performed by accurately guiding light to the data recording area of each recording layer.

The periodic light scattering factor is caused by a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, which is periodically formed on the optical waveguide layer near the interface between the optical waveguide layer and the holding layer or on the holding layer. And a large number of irregularly shaped lines having

A method of reproducing data on a card will be described with reference to FIG.

When the incident light 13 is incident on the light incident portion of the optical card 11 at an angle θ0, diffracted light is generated in the direction of the angle θ2 = 90 ° due to the uneven line (pattern) recorded on the recording layer L2. The diffracted light propagates as the propagating light 14 in the optical waveguide layer in the recording layer L2. When the propagating light 14 comes to a data recording area in which data is recorded in the length and / or phase of the pattern, the light is scattered by this pattern and scattered light 15 is generated. The scattered light 15 is transmitted to the detector 12
The data can be reproduced by detecting with. It is preferable that the detector 12 use a two-dimensional sensor array such as a CCD or a CMOS sensor.

FIG. 2B shows how diffracted light is generated by the light incident portion of each recording layer with respect to the incident light 13.

When the incident light 13 enters at an angle θ0, the angle θ1 of the diffracted light 17 from the light incident portion of the recording layer L1 of the optical card 11 is as follows.

In the pattern recorded on the light incident portion of the recording layer L1 of the optical card 11, if the pitch interval (basic period) of the pattern is d1, sin (θ1) −sin (θ0) = a · λ / d1 Is required. Here, λ is the wavelength of light in the optical card, and is a value obtained by dividing the wavelength in air by the refractive index n of the optical card. Since n is around 1.5, the wavelength in the optical card is about 0.67 times that in air. Here, a represents the order of the diffracted light to be used, and here, the + 1st-order diffracted light, that is, a
= + 1.

Similarly, when the incident light 13 is incident at an angle θ0, the diffracted light from the light incident portion of the recording layer L2 of the optical card 11 propagates as the propagation light 14 in the optical waveguide layer in the recording layer L2. The angle θ2 is set to 90 degrees, and has the following relationship.

In the pattern recorded on the light incident portion of the recording layer L2 of the optical card 11, the basic period of the pattern is d2
Then, sin (θ2) −sin (θ0) = a · λ / d2 is obtained.

Similarly, when the incident light 13 is incident at an angle θ0, the angle θ3 of the diffracted light 18 from the light incident portion of the recording layer L3 of the optical card 11 is as follows.

In the pattern recorded on the light incident portion of the recording layer L3 of the optical card 11, the basic period of the pattern is d3
Then, sin (θ3) −sin (θ0) = a · λ / d3 is obtained.

As described above, the direction of the diffracted light can be changed by changing the basic period of the pattern recorded on the light incident portion of each recording layer. Here, an example in which the + 1st-order diffracted light is used has been described. However, a -1st-order diffracted light (a = −1) may be used, and a higher-order diffracted light (a = + 2, +3) may be used.
... or a = -2, -3, ...).

FIG. 3 shows an example of a data recording area of each recording layer together with the detection of scattered light (reproduced data). FIG. 3A shows data reproduction from the recording layer L2. (B) shows a plan view.

When the propagating light 14 propagates through the recording layer L2 from the light incident portion and reaches the data recording area, scattered light 15 is generated by the pattern recorded in the data recording area of the recording layer L2 of the optical card 11, The data can be reproduced by capturing the scattered light 15 by the detector 12. In order to read a pattern recorded in the data recording area of the recording layer L1, the incident angle of light incident on the light incident portion is changed so that diffracted light propagates through the optical waveguide layer in the recording layer L1. Similarly, in order to read a pattern recorded in the data recording area of the recording layer L3, the incident angle of the light incident on the light incident portion is changed so that the diffracted light propagates through the optical waveguide layer in the recording layer L3. To Thus, by adjusting the angle of the incident light, the propagation of light can be controlled, and the data recorded in each layer can be separately detected.

FIG. 4 shows a specific example of the pattern of the light incident portion of each recording layer, here, an example in which the basic period of the above-mentioned pattern is changed, wherein 111 is the pattern of the recording layer L1, and 112 is the recording layer. L2 pattern, 113 is the recording layer L
This is the third pattern. The pattern formed on the light incident part is
It is preferable that the protective layer (cladding layer) surrounding the optical waveguide layer (core layer) has a lower refractive index than that of the optical waveguide layer (core layer), and is formed by making the interface between the core layer and the cladding layer uneven. Thus, by changing the basic period, the recording layer through which the light propagates changes depending on the angle of the incident light, and the data in each layer can be separated and reproduced.

FIGS. 5A and 5B show another example of the pattern of the data recording area of each recording layer together with data reproduction. FIG. 5A shows data reproduction from the recording layer L2, and FIG. This shows how data is reproduced from the recording layer L3.

In the pattern of the data recording area, the refractive index of the protective layer (cladding layer) surrounding the optical waveguide layer (core layer) is set low, and the interface between the core layer and the cladding layer is made uneven. It is a good example to form by forming. In FIG. 3, the basic period of the pattern of the data recording area of each layer is all the same, but in FIG. 5, the basic period of the pattern of the data recording area of each layer is the same as the basic period of the pattern of the light incident portion of each layer. I have. This way,
The basic period of the pattern formed on each recording layer can be unified into one, which facilitates manufacturing.

However, the scattered light from the data recording area (1
Since the direction of (5, 19) changes according to the basic period of the pattern, it is a good example to change the recording position of the data recording area according to the basic period of the pattern. Further, the position of the detector 12 may be changed for each recording layer, that is, for each basic period of the pattern.

FIG. 6 shows a second embodiment of the present invention. Here, a light incident portion of each recording layer of an optical card is shown. In the first embodiment, the example in which the basic period of the pattern of the light incident portion recorded on each layer is changed has been described. In the present embodiment, the example in which the position of the pattern of the light incident portion recorded on each layer is changed. Show.

FIG. 6A shows a pattern 21 of the first layer formed at the center of the light incident portion, and FIG. 6B shows a pattern 22 of the second layer formed on the left side of the light incident portion. 6 (c) shows a pattern 23 of the third layer formed on the right side of the light incident portion.

As described above, when the position of the light incident portion changes, the angle of the incident light changes (provided that the position of the light source of the incident light is assumed to be constant), whereby the recording layer through which the light propagates can be selected. Here, an example in which the light incident portion is swung right and left is shown, but it is also a good example to shake the light incident portion up and down with respect to the paper surface. Although the example in which the basic period of the pattern is the same is shown, it is also a good example to form the light incident portion by changing both the position and the basic period of the pattern. Combining both allows for more layers to be selected.

FIG. 7 shows a third embodiment of the present invention, in which each recording layer of an optical card is shown. In the first and second embodiments, the recording layer through which light propagates is selected. In this embodiment, an example in which the direction in which light propagates is selected to select each recording layer. Is shown.

FIG. 7A shows the pattern 31 of the first layer including the pattern 31a of the light incident part and the pattern 31b of the data recording area, and FIG. 7B shows the pattern 32a of the light incident part.
FIG. 7C shows a pattern 32 of the light incident portion, and a pattern 32 of the second layer including the pattern 32b of the data recording area.
3A shows a pattern 33 of a third layer composed of a and a pattern 33b of a data recording area.

The pattern 32a of the light incident portion of the second layer is formed so that light propagates horizontally on the paper surface, and the light incident on the pattern 32a propagates horizontally on the paper surface, and the pattern of the data recording area is formed. The light is scattered by 32b and comes out. The light is detected by a detector (not shown) arranged at the front or the back of the paper to reproduce data.

The pattern 31a of the light incident portion of the first layer is formed at the lower right with respect to the plane of the paper, and the incident light propagates to the lower right of the plane of the paper. Therefore, the position of the light incident portion is the second position.
Even if it is the same as the layer, the data of the pattern 31b in the data recording area of the first layer can be detected by changing the position of the detector downward. Similarly, the pattern 33a of the light incident portion of the third layer is formed to rise to the right with respect to the plane of the paper, and the incident light propagates in the upper right direction of the plane of the paper. Therefore, even if the position of the light incident portion is the same as the first layer and the second layer, the data of the pattern 33b in the data recording area of the third layer can be detected by changing the position of the detector upward.

As described above, by changing the pattern inclination (array angle) for each layer, it is possible to change the position of the data recording area even if the position of the light incident portion is the same. The formed data can be selectively reproduced.

When the embodiments described above are used in combination, higher density card recording can be realized.

The uneven line forming the periodic light scattering factor also has a lower refractive index of the holding layer (cladding layer) surrounding the optical waveguide layer (core layer) than the core layer and the cladding layer. Although it has been shown that the core is formed by providing irregularities at the interface with the core, another ion may be implanted into the core or an optical irregularity may be formed by applying distortion.

[0048]

As described above, according to the present invention,
The uneven line of the light incident part of each of the plurality of stacked recording layers is
Since the direction of the incident light diffracted in the direction coinciding with the optical waveguide layer is formed with a pitch interval such that the direction is different for each recording layer, the light incident portion of each recording layer coincides with the optical waveguide layer. The direction of the incident light diffracted in the direction differs for each recording layer. Therefore, the incident light diffracted in the direction corresponding to the optical waveguide layer at the light incident portion of the desired recording layer is not diffracted in the direction coincident with the optical waveguide layer at the light incident portion of the other recording layer. The light propagates only through the desired recording layer to reach the data recording area, and thus, it becomes possible to reproduce only the data recorded in the desired recording layer.
Therefore, the recorded information can be separately reproduced only by recording the data at a high density and changing the direction (angle) of the incident light.

Further, according to the present invention, the pitch interval between the irregularly shaped lines constituting the periodic light scattering factor in the data recording area and the pitch between the irregularly shaped lines constituting the periodic light scattering factor in the light incident portion. Since the intervals are set to be the same, the pitch interval of the uneven lines constituting the periodic light scattering factor can be made one type for each recording layer, and the productivity is improved.

Further, according to the present invention, the direction of the incident light diffracted in the direction coinciding with the optical waveguide layer for each of the recording layers is different for each recording layer. Since it is formed at a position that is in a different direction, the position of the incident light diffracted in a direction coincident with the optical waveguide layer at the light incident portion of each recording layer differs for each recording layer. Therefore, the incident light diffracted in the direction corresponding to the optical waveguide layer at the light incident portion of the desired recording layer is not diffracted in the direction coincident with the optical waveguide layer at the light incident portion of the other recording layer. The light propagates only through the desired recording layer to reach the data recording area, and thus, it becomes possible to reproduce only the data recorded in the desired recording layer. Therefore, the recorded information can be separately reproduced only by recording the data at a high density and changing the position of the incident light.

Further, according to the present invention, the uneven lines of the light incident portion of each of the plurality of recording layers are arranged such that the incident light diffracted in the direction coinciding with the optical waveguide layer has a different direction for each recording layer. The incident light diffracted in a direction coincident with the optical waveguide layer at the light incident portion of each recording layer is propagated in a different direction for each recording layer because the light is formed at an angle of the array that is propagated to the recording layer. The light reaches a data recording area provided on an extension of the propagation direction of the incident light. Therefore, data recorded on all recording layers is reproduced. However, since the propagation direction of incident light differs for each recording layer and the position of the data recording area differs for each recording layer, the data depends on the position of the detector. From which the recording layer can be extracted. Therefore, the recorded information can be separately reproduced only by recording the data at a high density and changing the position of the detector.

According to these inventions, the light incident portion and the data recording area can be formed by the same process, and the light incident position with respect to the data can be formed accurately.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a conventional data recording medium.

FIG. 2 is a configuration diagram showing a first embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating an example of a data recording area according to the first embodiment;

FIG. 4 is a configuration diagram showing a specific example of a pattern of a light incident portion in the first embodiment.

FIG. 5 is a configuration diagram showing another example of the data recording area according to the first embodiment;

FIG. 6 is a configuration diagram showing a second embodiment of the present invention.

FIG. 7 is a configuration diagram showing a third embodiment of the present invention.

[Explanation of symbols]

11: optical card, 12: detector, 13: incident light, 14:
Propagation light, 15, 19: scattered light from recording layers L2, L3,
16: transmitted light, 17, 18: diffracted light from the recording layers L1, L3, 21, 22, 23: patterns of the light incident portions of the first, second, and third layers, 31, 32, 33: first, first Patterns of second and third layers, 111, 112, 113: recording layers L1, L
2, L3 light incident part pattern.

Continued on the front page (72) Inventor Akinori Furuya 2-3-1 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Inventor Masahiro Ueno 2-3-1 Otemachi, Chiyoda-ku, Tokyo Within Nippon Telegraph and Telephone Corporation (72) Inventor Manabu Yamamoto 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-term within Nippon Telegraph and Telephone Corporation (reference) 2H049 AA03 AA07 AA25 AA40 AA56 AA61 AA62 AA66 5D090 AA03 BB12 BB18 CC01 CC04 DD03 DD05 KK06 KK09 KK11 LL05

Claims (4)

[Claims] 1. A periodic light scattering factor comprising an optical waveguide layer and upper and lower holding layers and recording data reproducibly as an image by scattered light generated when light propagates through the optical waveguide layer. A data recording medium comprising a plurality of planar optical waveguide type recording layers stacked, wherein the periodic light scattering factor has a periodicity in the optical waveguide layer or the holding layer near the interface between the optical waveguide layer and the holding layer. A data recording medium, which is a multiplicity of irregularly shaped lines having a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, formed on a recording medium, wherein each recording layer has a concave and convex shape that constitutes a periodic light scattering factor. And a light incident portion formed at a pitch interval such that the direction of incident light diffracted in a direction coincident with the optical waveguide layer is different for each recording layer, and constitutes a periodic light scattering factor. The length of the uneven line And a data recording area in which data is recorded in phase or both. 2. A periodic light scattering factor comprising an optical waveguide layer and upper and lower holding layers and recording data reproducibly as an image by scattered light generated when the light propagates through the optical waveguide layer. A data recording medium comprising a plurality of planar optical waveguide type recording layers stacked, wherein the periodic light scattering factor has a periodicity in the optical waveguide layer or the holding layer near the interface between the optical waveguide layer and the holding layer. A data recording medium, which is a multiplicity of irregularly shaped lines having a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, formed on a recording medium, wherein each recording layer has a concave and convex shape that constitutes a periodic light scattering factor. And a light incident portion formed at a pitch interval such that the direction of incident light diffracted in a direction coincident with the optical waveguide layer is different for each recording layer, and constitutes a periodic light scattering factor. The length of the uneven line And a data recording area in which data is recorded in the same or similar phase as the light incident portion of the same recording layer. 3. A periodic light scattering factor, comprising an optical waveguide layer and upper and lower holding layers, for recording data reproducibly as an image by scattered light generated when the light propagates through the optical waveguide layer. A data recording medium comprising a plurality of planar optical waveguide type recording layers stacked, wherein the periodic light scattering factor has a periodicity in the optical waveguide layer or the holding layer near the interface between the optical waveguide layer and the holding layer. A data recording medium, which is a multiplicity of irregularly shaped lines having a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, formed on a recording medium, wherein each recording layer has a concave and convex shape that constitutes a periodic light scattering factor. The light incident portion is formed so that the direction of the incident light diffracted in the direction coinciding with the optical waveguide layer is different from each other for each recording layer, and the irregularities forming the periodic light scattering factor The length or phase of the shape line Or a data recording area for recording data in both of them. 4. A periodic light scattering factor comprising an optical waveguide layer and upper and lower holding layers, and recording data reproducibly as an image by scattered light generated when the light propagates through the optical waveguide layer. A data recording medium comprising a plurality of planar optical waveguide type recording layers stacked, wherein the periodic light scattering factor has a periodicity in the optical waveguide layer or the holding layer near the interface between the optical waveguide layer and the holding layer. In a data recording medium, which is formed in a plurality of lines of irregular shape having a repetition pitch of about the wavelength of light propagating through the optical waveguide layer, each recording layer has an irregular shape that constitutes a periodic light scattering factor. The light incident portion is formed with an angle of arrangement such that the incident light diffracted in the direction coinciding with the optical waveguide layer propagates in different directions for each recording layer. Of the incident light On the extension of the transportable direction, a data recording medium, characterized in that a periodic optical length of the irregular shape of the lines constituting the scattering factor or the phase or the data recording area for recording data both.