JP2006267841A - Information reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information reproducing device which can be made low in profile and small in size. <P>SOLUTION: Light PL emitted by a semiconductor laser 3 passes through an opening 7, and is converted by a collimator lens 4a into parallel light, which is narrowed down into a linear converged beam by a cylindrical lens 5. The laser projection light PL while having its optical path bent by a reflecting prism 6 is stopped down into a linear converged beam, which is made incident on a core layer of a layer to be reproduced from a flank of a hologram memory medium 1. In the information reproducing device 100A, the incidence optical path from the semiconductor laser 3 to the cylindrical lens 5 is arranged on a detection optical path between the hologram memory medium 1 and a two-dimensional optical detector 2. Namely, the information reproducing device 100A has the incidence optical path and detection optical path arranged to be shared not only in terms of height positions, but also in three dimensions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an information reproducing apparatus, and more particularly to an information reproducing apparatus that reproduces information recorded by a hologram.

  Currently, information recording cards such as magnetic cards and IC (Integrated Circuit) cards are widely used as information recording media that are easy to carry. However, although magnetic cards are inexpensive, there is a high risk of information deterioration or counterfeiting due to external magnetization. An IC card is highly secure and difficult to counterfeit, but the cost per sheet is high, and the bit price is high as an information recording medium.

  As one of information recording media for overcoming such problems, a read-only multiplex hologram card is proposed in which planar single-mode optical waveguides including diffraction gratings for generating hologram images are stacked in multiple layers. Here, an information reproducing apparatus that reproduces information of a reproduction-only multiplex hologram card disclosed in Patent Documents 1 and 2 will be described as an example.

  FIG. 13 is a schematic diagram showing a configuration of an information reading apparatus 100X that reproduces information of a conventional reproduction-only multiplex hologram card 110X. The reproduction-only multiplex hologram card 110X has a periodic layer structure in which a clad layer and a core layer (including the core layer 104) are alternately stacked, and has an end face 103 cut at 45 degrees. In each core layer, a scattering factor (hologram) 105 is formed.

  Referring to FIG. 13, information reading apparatus 100 </ b> X condenses laser beam PL as a linear beam on end surface 103 of core layer 104 by cylindrical lens 102. The collected linear beam is scattered as diffracted light DF by the scattering factor 105 in the process of propagating through the core layer 104 as propagating light PW. As a result, hologram images 200a and 200b are generated.

  FIG. 14 is a schematic diagram showing a configuration of an information reproducing apparatus 100Y that reproduces information of a conventional reproduction-only multiplex hologram card 110Y. The reproduction-only multiplex hologram card 110 </ b> Y has a periodic layer structure in which a clad layer and a core layer are alternately stacked, and has a side surface 106. In each core layer, a scattering factor (hologram) is formed.

  Referring to FIG. 14, information reproducing apparatus 100Y condenses laser beam PL as a linear beam on side surface 106 by cylindrical lens 102. The condensed linear beam is scattered as diffracted light DF by a scattering factor in the process of propagating one of the core layers as traveling light PW. The diffracted light DF is emitted from the upper surface of the reproduction-only multiplex hologram card 110Y, and generates a hologram image Im on the image plane 200.

By reading the hologram image Im with a two-dimensional photodetector array (not shown) such as a CCD (Charge Coupled Device), information superimposed as a hologram on the core layer can be read. By moving the position of the cylindrical lens 102 up and down and condensing the linear light beam on another core layer, information recorded on the other core layer can be individually reproduced.
Japanese Patent Laid-Open No. 11-345419 JP 2001-52128 A

  However, in the information reading apparatus 100X shown in FIG. 13, the incident optical system including the cylindrical lens 102 is disposed on the upper surface of the reproduction-only multiplex hologram card 110X. For this reason, there is a problem that the entire reproducing optical system of the information reading apparatus 100X becomes thick and it is difficult to realize a thin information reading apparatus 100X.

  Further, in the information reproducing apparatus 100Y shown in FIG. 14, the incident optical system including the cylindrical lens 102 is arranged adjacent to the side surface of the reproduction-only multiplex hologram card 110Y, and a two-dimensional photodetector array (not shown) is reproduced. The dedicated multiple hologram card 110Y is arranged with a certain distance on the upper surface. Therefore, in addition to the problem pointed out in FIG. 12, there is a problem that the entire projected area of the information reproducing apparatus 100Y, that is, the area occupied by the reproducing optical system viewed from the upper surface of the reproduction-only multiplex hologram card 110Y is increased.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an information reproducing apparatus that can be reduced in thickness and size.

  The present invention relates to an information reproducing apparatus for reproducing information on a recording medium in which a plurality of waveguide layers in which scattering factors are formed is laminated, the light source emitting light, and the light emitted from the light source One optical system is provided, and a photodetector that receives the diffracted light scattered by the scattering factor. The information reproducing apparatus three-dimensionally shares an incident optical path between the light source and the optical system and a detection optical path between the recording medium and the photodetector.

  Preferably, the light source and the optical system are arranged in a space at a height from the recording medium to the photodetector so that the incident optical path crosses the detection optical path.

  Preferably, the light source includes an opening that blocks a part of the light emitted from the light source. The optical system includes a collimating lens that collimates the light emitted from the light source, a condensing lens that condenses the collimated light on one of the waveguide layers, and a reflecting prism that changes the optical path of the collimated light.

  Preferably, the optical system includes a condensing lens that condenses light emitted from the light source onto one of the waveguide layers, and a reflection prism that changes an optical path of the light emitted from the light source in an incident direction to the waveguide layer. including.

  Preferably, the apparatus further includes a housing on which the light source and the optical system are mounted. In the photodetector, the width in one direction in the in-plane direction is narrower than the corresponding width of the recording medium, and the information reproducing apparatus integrally drives the housing and the photodetector in one direction.

  Preferably, the apparatus further includes a housing on which a photodetector having a smaller area than the recording medium is mounted. The information reproducing apparatus integrally drives the housing and the photodetector in the in-plane direction of the recording medium.

  According to another aspect of the present invention, there is provided an information reproducing apparatus for reproducing information on a recording medium in which a plurality of waveguide layers on which scattering factors are formed is laminated, and a light source that emits light and a light source that is emitted from the light source An optical system for entering light into one of the waveguide layers and a photodetector for receiving diffracted light scattered by the scattering factor are provided. An incident optical path between the light source and the optical system is disposed in the peripheral portion of the recording medium.

  Preferably, the optical system condenses the light emitted from the light source onto one of the waveguide layers, and the light emitted from the light source by reflecting the light emitted from the light source in two different directions. And a composite reflecting prism that converts the optical path of the light into the direction of incidence on the waveguide layer.

  Preferably, the scattering factor is a hologram.

  According to the present invention, the device can be made thinner and smaller.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
1 and 2 are a top view and a side view showing a reproducing optical system of an information reproducing apparatus 100A according to Embodiment 1 of the present invention. 1 and 2, the information reproducing apparatus 100A according to the first embodiment includes a two-dimensional photodetector 2, a semiconductor laser 3, a collimator lens 4a, a cylindrical lens 5, a reflecting prism 6, and an aperture 7. (Not shown in FIG. 1). The information reproducing device 100 </ b> A reproduces information recorded as a hologram in the waveguide of the laminated waveguide type hologram memory medium 1.

  The light PL emitted from the semiconductor laser 3 which is an example of the light source passes through the opening 7, is converted into parallel light by the collimator lens 4 a, and then is narrowed down to a linear condensed beam by the cylindrical lens 5. The opening 7 has an elliptical hole in accordance with the shape of the light PL emitted from the semiconductor laser 3. The laser emission light PL is focused to a linear condensed beam while the optical path is bent by the reflecting prism 6, and is incident on the core layer of the layer to be reproduced from the side surface of the hologram memory medium 1.

  The light PL incident on the core layer is scattered as diffracted light DF by the hologram formed in the waveguide in the process of propagating through the core layer, as described with reference to FIGS. The diffracted light DF is emitted from the surface of the hologram memory medium 1 and generates a hologram image on the two-dimensional photodetector 2 arranged on the imaging plane. The two-dimensional photodetector 2 is, for example, a CCD or a CMOS (Complementary Metal-Oxide-Semiconductor).

  By reading the hologram image two-dimensionally, information superimposed as a hologram on the core layer can be read. Further, by moving the position of the cylindrical lens 5 up and down and condensing a linear light beam on another core layer, information recorded on the other core layer can be individually reproduced.

  Next, features of the information reproducing apparatus 100A according to Embodiment 1 will be described in detail.

  In the hologram memory medium 1, the reproduced image of information is formed by superimposing light diffracted by the hologram. Therefore, in order to obtain the necessary resolution in the reproduced image, it is necessary to separate the hologram memory medium 1 from the two-dimensional photodetector 2 by a certain distance. In other words, in the information reproducing apparatus 100A, a certain distance is necessarily required between the medium and the detector because of the reproduction principle, and the hologram image cannot be detected by bringing them into close contact with each other.

  Therefore, in the information reproducing apparatus 100A of the first embodiment, the space between the hologram memory medium 1 and the two-dimensional photodetector 2 (hereinafter also referred to as a detection optical path) is effectively used. Specifically, an optical system (hereinafter also referred to as an incident optical path) from the semiconductor laser 3 to the cylindrical lens 5 is disposed in the detection optical path. In the information reproducing apparatus 100A, the incident optical path and the detection optical path are arranged so as to be shared not only in the height position but also three-dimensionally.

  The diffracted light DF in the detection light path travels in a direction substantially perpendicular to the surface of the hologram memory medium 1, whereas the laser emission light PL in the incident light path travels in parallel to the surface of the hologram memory medium 1. Therefore, even if the diffracted light DF and the laser emission light PL cross (orthogonal) in the common space, no interference phenomenon occurs.

  Further, a corner cube type reflecting prism 6 is provided in the rear optical path of the cylindrical lens 5 that generates the linear condensed beam. Thereby, the traveling direction of the laser emission light PL can be accurately reversed, and the light can be efficiently incident on the side surface of the hologram memory medium 1.

  As described above, according to the first embodiment, the optical path of incident light is changed by an optical element such as a reflecting prism, and the incident optical path and the detection optical path are three-dimensionally shared. And miniaturization are possible.

[Embodiment 2]
In the information reproducing apparatus 100A of the first embodiment, the collimator lens 4a is disposed on the opposite side of the semiconductor laser 3 with the hologram memory medium 1 interposed therebetween, and the distance between the semiconductor laser 3 and the collimator lens 4a is increased. In this case, useless light (stray light) that does not enter the collimator lens 4a is generated in the light PL emitted from the semiconductor laser 3.

  The stray light can be incident directly on the two-dimensional photodetector 2 and become noise. The information reproducing apparatus 100A of Embodiment 1 blocks such stray light by providing an opening 7 at the exit of the semiconductor laser 3. In the second embodiment, an information reproducing apparatus having an optical arrangement that does not require the use of the opening 7 will be described.

  3 and 4 are a top view and a side view showing a reproducing optical system of an information reproducing apparatus 100B according to Embodiment 2 of the present invention. The information reproducing apparatus 100B of the second embodiment is different from the information reproducing apparatus 100A of the first embodiment only in that the collimator lens 4a is replaced with the collimator lens 4. Therefore, description of the same parts as those in Embodiment 1 will not be repeated here.

  As shown in FIGS. 3 and 4, the collimator lens 4 is arranged on the same side as the semiconductor laser 3 with respect to the hologram memory medium 1. As a result, stray light that does not enter the collimator lens 4 is not generated, so that it is not necessary to use the opening 7 unlike the information reproducing apparatus 100A of the first embodiment.

  As shown in FIG. 4, it is sufficient for the collimator lens 4 to collimate the laser emission light PL at least in the z direction. That is, as shown in FIG. 3, the laser emission light PL may not be completely collimated in the y direction. The collimator lens 4 functions as an NA (Numerical Aperture) conversion lens that converts the emission angle of the laser emission light PL in the y direction.

  As described above, according to the second embodiment, by disposing the collimator lens on the same side as the semiconductor laser, in addition to the effect of the first embodiment, the information reproducing apparatus is further increased by the amount of not using the opening 7. Can be reduced in size and cost.

[Embodiment 3]
5 to 7 are a top view, a side view, and a perspective view showing a reproducing optical system of an information reproducing apparatus 100C according to Embodiment 3 of the present invention. With reference to FIGS. 5 to 7, the information reproducing apparatus 100 </ b> C of Embodiment 3 includes a two-dimensional photodetector 2, a semiconductor laser 3, a collimator lens 4, a cylindrical lens 5, a reflecting prism 6, and a housing 10. And guide bearings 11a and 11b and guide shafts 12a and 12b, which reproduce information recorded on the hologram memory medium 1.

  In the information reproducing apparatus 100C of the third embodiment, the area of the two-dimensional photodetector 2 is smaller in the y direction than the hologram memory medium 1. The information reproducing apparatus 100C reproduces information recorded as a hologram in the waveguide of the hologram memory medium 1 by driving the two-dimensional photodetector 2 one-dimensionally in the y direction. Since the operation of generating the hologram image on the two-dimensional photodetector 2 by the light PL emitted from the semiconductor laser 3 is the same as that of the second embodiment, description thereof will not be repeated here.

  As shown in FIG. 7, the information reproducing apparatus 100 </ b> C has a semiconductor laser 3, a collimator lens 4, a cylindrical lens 5, and a reflecting prism 6 mounted on a housing 10. In the housing 10, the two-dimensional photodetector 2 is disposed above. The housing 10 is provided with guide bearings 11a and 11b and corresponding guide shafts 12a and 12b.

  The information reproducing apparatus 100C moves the housing 10 in the y direction via the two guide shafts 12a and 12b. The information reproducing apparatus 100C integrally drives the housing 10 on which the semiconductor laser 3, the collimator lens 4, the cylindrical lens 5, and the reflecting prism 6 are mounted, and the two-dimensional photodetector 2 in the y direction integrally.

  In the information reproducing apparatuses 100A and 100B according to the first and second embodiments, the light PL incident on the hologram memory medium 1 is incident on the entire width of the hologram memory medium 1 at a time. On the other hand, in the information reproducing apparatus 100C according to the third embodiment, the light PL that is incident on the hologram memory medium 1 is incident as a thin linear condensed beam having a width that is only a part of the hologram memory medium 1.

  The linear condensed beam is scattered as diffracted light DF by a hologram formed in the waveguide in the process of propagating through one of the core layers (see FIG. 6). The hologram image generated from the diffracted light DF is detected by the two-dimensional photodetector 2 having the minimum necessary width corresponding to the narrow linear condensed beam.

  As described above, since the width of the two-dimensional photodetector 2 in the y direction is the minimum necessary, the recording area once in the y direction of the hologram memory medium 1 is limited. For this reason, the information reproducing apparatus 100C can generate a different hologram image each time the two-dimensional photodetector 2 is moved in the y direction. That is, the information reproducing apparatus 100C is advantageous for the local multiplex recording of the hologram memory medium 1.

  Further, since the two-dimensional photodetector 2 of the information reproducing apparatus 100C has a minimum width in the y direction, a two-dimensional photodetector array (for example, CCD, CMOS) having a small area can be used. Thereby, the two-dimensional photodetector 2 can be reduced in size and weight. As a result, the cost of the information reproducing apparatus 100C can be reduced.

  In the information reproducing apparatus 100C of the third embodiment, as in the first and second embodiments, the entire optical system is arranged so that the incident optical path and the detection optical path cross each other so that both share a space. Accordingly, the information reproducing apparatus 100C can be disposed above (in the + y direction in FIGS. 5 to 7) with respect to the hologram memory medium 1. As a result, the information reproducing apparatus 100C can be thinned and the projection area can be reduced.

  As described above, according to the third embodiment, the housing 10 and the two-dimensional photodetector 2 are integrally driven one-dimensionally, so that the two-dimensional photodetector 2 is added to the effect of the first embodiment. This is advantageous for the local multiplex recording of the hologram memory medium 1.

[Embodiment 4]
8 and 9 are a top view and a side view showing a reproducing optical system of an information reproducing apparatus 100D according to Embodiment 4 of the present invention. 8 and 9, the information reproducing apparatus 100D according to the fourth embodiment includes a two-dimensional photodetector 2, a semiconductor laser 3, a collimator lens 4, a cylindrical lens 5, a housing 10, and a guide bearing 11a. 11b, guide shafts 12a and 12b, an optical path conversion mirror 14, and a composite reflection prism 15, and reproduces information recorded in the hologram memory medium 1.

  The information reproducing apparatus 100D of the fourth embodiment differs from the information reproducing apparatus 100C of the third embodiment in that the semiconductor laser 3, the collimator lens 4, and the optical path conversion mirror 14 are fixed in the incident optical system. Hereinafter, in the fourth embodiment, the semiconductor laser 3, the collimator lens 4, and the optical path conversion mirror 14 are referred to as a fixed optical unit.

  The light PL emitted from the semiconductor laser 3 is converted into parallel light by the collimator lens 4, and then the optical path is converted from the x direction to the y direction by the optical path conversion mirror 14. The light whose path has been converted is narrowed down to a linear condensed beam by the cylindrical lens 5. The laser emission light PL is focused to a linear condensed beam while the optical path is bent by the composite reflecting prism 15, and is incident on the core layer of the layer to be reproduced from the side surface of the hologram memory medium 1.

  Since the operation of generating the hologram image on the two-dimensional photodetector 2 by the light PL incident on the core layer is the same as that of the second embodiment, the description will not be repeated here. Hereinafter, in the fourth embodiment, the cylindrical lens 5 and the composite reflecting prism 15 are referred to as a movable optical unit.

  FIG. 10 is a diagram showing an example of a specific configuration of the composite reflecting prism 15 in the information reproducing apparatus 100D of FIGS. Referring to FIG. 10, the composite reflecting prism 15 includes a first reflecting portion 15a and a second reflecting portion 15b. The laser emission light PL that has traveled from the y direction is narrowed down to a linear condensed beam by the cylindrical lens 5. The laser emission light PL is narrowed down to a linear condensed beam while the optical path is bent by the composite reflecting prism 15.

  The composite reflecting prism 15 first converts the laser emission light PL incident from the y direction into the z direction at the first reflecting portion 15a, and then converts it into the x direction at the second reflecting portion 15b. Thus, even when the end surface of the core layer of the hologram memory medium 1 is completely different from the direction of the laser emission light PL as shown in FIGS. 8 and 9, the laser emission light PL can be accurately incident on the core layer. Become.

  In the information reproducing apparatus 100C of Embodiment 3, the incident optical path and the detection optical path are shared by arranging the semiconductor laser 3, the collimator lens 4, the cylindrical lens 5 and the like in the detection optical path. On the other hand, in the information reproducing apparatus 100D according to the fourth embodiment, the fixed optical unit is arranged in the peripheral part of the hologram memory medium 1. As a result, the information reproducing apparatus 100D can increase the degree of freedom of the optical path in the fixed optical unit, and can reduce the size and weight of the movable optical unit and increase the moving speed associated therewith.

  In the information reproducing apparatus 100 </ b> D, the incident optical path from the semiconductor laser 3 to the cylindrical lens 5 is arranged at a height between the hologram memory medium 1 and the two-dimensional photodetector 2. Thereby, the information reproducing apparatus 100D according to the fourth embodiment can effectively utilize the detection optical path between the hologram memory medium 1 and the two-dimensional photodetector 2 as in the first to third embodiments. As a result, the apparatus can be thinned.

  As described above, according to the fourth embodiment, by disposing the fixed optical unit in the peripheral portion of the hologram memory medium 1, in addition to the effects in the first embodiment, the degree of freedom of the optical path in the fixed optical unit is increased. In addition, the movable optical unit can be reduced in size and weight and the moving speed can be increased.

[Embodiment 5]
11 and 12 are a top view and a side view showing a reproducing optical system of an information reproducing apparatus 100E according to Embodiment 5 of the present invention. 11 and 12, an information reproducing apparatus 100E according to the fifth embodiment includes a two-dimensional photodetector 2, a semiconductor laser 3, a collimator lens 4, a cylindrical lens 5, a reflecting prism 6, and a housing 10. And guide bearings 11a, 11b and guide shafts 12a, 12b, 13 for reproducing information recorded on the hologram memory medium 1.

  In the information reproducing apparatus 100E according to the fifth embodiment, the area of the two-dimensional photodetector 2 is smaller in the x direction and the y direction than the hologram memory medium 1. For this reason, the information reproducing apparatus 100E can use, as the two-dimensional photodetector 2, various small and inexpensive CCDs and CMOSs that are generally commercially available.

  Further, since the widths of the two-dimensional photodetector 2 in the x direction and the y direction are the minimum necessary, the recording area of the hologram memory medium 1 in the x direction and the y direction is limited. For this reason, the information reproducing apparatus 100E can generate different hologram images each time the two-dimensional photodetector 2 is moved in the x direction and the y direction. That is, the information reproducing apparatus 100E is advantageous for the local multiplex recording of the hologram memory medium 1.

  The information reproducing apparatus 100E reproduces information recorded as a hologram in the waveguide of the hologram memory medium 1 by driving the two-dimensional photodetector 2 two-dimensionally in the x direction and the y direction. Specifically, the information reproducing apparatus 100E moves the two-dimensional photodetector 2 in the y direction as the first stage, and then sequentially moves the two-dimensional photodetector 2 in the x direction as the second stage. Since the operation of generating the hologram image on the two-dimensional photodetector 2 by the light PL emitted from the semiconductor laser 3 is the same as that of the second embodiment, description thereof will not be repeated here.

  As shown in FIG. 11, the housing 10 can be driven in the y direction through the guide bearings 11a and 11b and the corresponding guide shafts 12a and 12b, as in the third embodiment. In addition, since the housing 10 of the fifth embodiment is provided on the guide shaft 13 in the x direction, it can be driven not only in the y direction but also in the x direction. The information reproducing apparatus 100E integrally drives the two-dimensional photodetector 2 and the housing 10.

  As in the third embodiment, the information reproducing apparatus 100E according to the fifth embodiment arranges the entire optical system so that the incident optical path and the detection optical path cross each other so that both share a space. As a result, the information reproducing apparatus 100E can be disposed above (in the + y direction in FIGS. 11 and 12) the hologram memory medium 1. As a result, the information reproducing apparatus 100E can be thinned and the projection area can be reduced.

  As described above, according to the fifth embodiment, the two-dimensional photodetector 2 and the housing 10 are integrally two-dimensionally driven, so that the two-dimensional photodetector 2 is added to the effect of the third embodiment. Can be further reduced, and it is further advantageous for the local multiplex recording of the hologram memory medium 1.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

It is the top view which showed the reproduction | regeneration optical system of 100 A of information reproduction apparatuses by Embodiment 1 of this invention. It is the side view which showed the reproduction | regeneration optical system of 100 A of information reproduction apparatuses by Embodiment 1 of this invention. It is the top view which showed the reproduction | regeneration optical system of the information reproduction apparatus 100B by Embodiment 2 of this invention. It is the side view which showed the reproduction | regeneration optical system of the information reproduction apparatus 100B by Embodiment 2 of this invention. It is the top view which showed the reproduction | regeneration optical system of 100 C of information reproduction apparatuses by Embodiment 3 of this invention. It is the side view which showed the reproduction | regeneration optical system of 100 C of information reproduction apparatuses by Embodiment 3 of this invention. It is the perspective view which showed the reproduction | regeneration optical system of 100 C of information reproduction apparatuses by Embodiment 3 of this invention. It is the top view which showed the reproduction | regeneration optical system of information reproduction | regeneration apparatus 100D by Embodiment 4 of this invention. It is the side view which showed the reproduction | regeneration optical system of information reproduction apparatus 100D by Embodiment 4 of this invention. It is the figure which showed an example of the specific structure of the composite reflective prism 15 in the information reproduction apparatus 100D of FIG. It is the top view which showed the reproduction | regeneration optical system of the information reproduction apparatus 100E by Embodiment 5 of this invention. It is the side view which showed the reproduction | regeneration optical system of the information reproduction apparatus 100E by Embodiment 5 of this invention. It is the schematic which showed the structure of the information read-out apparatus 100X which reproduces | regenerates the information of the conventional reproduction | regeneration only multiple hologram card 110X. It is the schematic which showed the structure of the information reproducing | regenerating apparatus 100Y which reproduces | regenerates the information of the conventional reproduction | regeneration only multiple hologram card | curd 110Y.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Hologram memory medium, 2 Two-dimensional photodetector, 3 Semiconductor laser, 4, 4a Collimator lens, 5 Cylindrical lens, 6 Reflection prism, 7 Aperture, 10 Housing, 11a, 11b Guide bearing, 12a, 12b, 13 Guide shaft, 14 optical path conversion mirror, 15 compound reflecting prism, 100A to 100E, 100Y information reproducing device, 100X information reading device, 102 cylindrical lens, 103 end surface, 104 core layer, 105 scattering factor, 106 side surface, 110X, 110Y reproduction-only multiple hologram card , 200 Imaging plane, 200a, 200b Hologram image.

Claims (9)

An information reproducing apparatus for reproducing information of a recording medium in which a plurality of waveguide layers in which scattering factors are formed are laminated,
A light source that emits light;
An optical system for entering light emitted from the light source into one of the waveguide layers;
A photodetector for receiving the diffracted light scattered by the scattering factor,
An information reproducing apparatus that three-dimensionally shares an incident optical path between the light source and the optical system and a detection optical path between the recording medium and the photodetector.   The information reproducing apparatus according to claim 1, wherein the light source and the optical system are disposed in a space at a height from the recording medium to the photodetector so that the incident optical path crosses the detection optical path. The light source includes an opening that blocks a part of the light emitted from the light source,
The optical system is
A collimating lens that collimates the light emitted from the light source;
A condensing lens for condensing the parallel light on one of the waveguide layers;
The information reproducing apparatus according to claim 1, further comprising a reflecting prism that changes an optical path of the parallel light. The optical system is
A condensing lens that condenses the light emitted from the light source onto one of the waveguide layers;
The information reproducing apparatus according to claim 1, further comprising a reflecting prism that changes an optical path of light emitted from the light source in a direction of incidence on the waveguide layer. A housing in which the light source and the optical system are mounted;
In the photodetector, the width in one direction in the in-plane direction is narrower than the corresponding width of the recording medium,
The information reproducing apparatus according to claim 1, wherein the information reproducing apparatus integrally drives the housing and the photodetector in the one direction. Further comprising a housing on which the photodetector having a smaller area than the recording medium is mounted;
The information reproducing apparatus according to claim 1, wherein the information reproducing apparatus integrally drives the housing and the photodetector in an in-plane direction of the recording medium. An information reproducing apparatus for reproducing information of a recording medium in which a plurality of waveguide layers in which scattering factors are formed are laminated,
A light source that emits light;
An optical system for entering light emitted from the light source into one of the waveguide layers;
A photodetector for receiving the diffracted light scattered by the scattering factor,
An information reproducing apparatus, wherein an incident optical path between the light source and the optical system is disposed in a peripheral portion of the recording medium. The optical system is
A condenser lens that condenses the light emitted from the light source onto one of the waveguide layers;
The composite reflecting prism which converts the optical path of the light radiate | emitted from the said light source into the incident direction to the said waveguide layer by reflecting the light radiate | emitted from the said light source in two different directions. Information playback device.   The information reproducing apparatus according to claim 1, wherein the scattering factor is a hologram.

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