JPS61156492A - Recording card for high density information - Google Patents

Abstract

PURPOSE:To record information at both faces by laminating high and low refraction factor layers so as to constitute a plane waveguide path and further laminating a diffusion layer and a recording one thereon. CONSTITUTION:On a substrate 1, a lower side clad layer 2, a core layer 3 and a defective part 4 are formed, and on the core layer 3 a transmittable upper side clad layer 5 is laminated. When an irradiated light beam condensed on the end face of the core layer 3 from the side of a card-like recording medium 11 is made incident, the light beam incident on the core layer 3 transfers heat inside the layer due to total reflection, and the light beam for reaching the defective part 4 of the core layer 3 passes through the upper side clad layer 5 and is diffused by a light diffusion layer 6. The distribution state of the defective part 4 of the core layer 3 and the thickness of the diffusion layer 6 are appropriately controlled, whereby a planal light source for making the entire recording area approximately uniform can be constituted. The light beam from said light source transmits a write bit 10, and therefore the presence or absence of the bit 10 can be read by any of a photodetecting means from the surface of the card. Thus information can be recorded at both faces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention 1] The present invention relates to a high-density information recording card in which information can be optically read from a recording layer on which information is written by changing light transmittance.

[Technical background of the invention and its problems] In recent years, laser discs, which write and read data using laser light, have been used as video discs and audio discs as a medium for recording high-density information, replacing conventional magnetic recording media. It is becoming widely used.

However, in the advanced information society expected in the future, financial institutions, medical institutions, and even large-scale stores will be required to verify customer identity (I.
D) When attempting to use a high-density information recording medium as a card, a shape similar to a conventional magnetic card would be preferable to a disk format from the viewpoint of portability and ease of handling.

An example of a recording medium that meets the above requirements is a large storage capacity card as described in Nikkei Computer, March 21, 1983 issue, pages 129-136. This card has an organic colloid (gelatin) layer containing highly concentrated silver particles formed on a substrate such as polyester, and when this layer is irradiated with laser light, it is melted into spots and recorded. It would be best to record on such a card-shaped recording medium in a column-stripe configuration as shown in FIGS. 8 and 9. In addition, a circular or arcuate recording method is also possible, but requires advanced technology to drive the card or read head.

On the other hand, when attempting to search for digital data in the Nth stripe of the Mth column from a column-stripe recording configuration as shown in FIGS. If you try to read each card individually, you must frequently drive the card or head left and right after #I, or use circular-to-linear scanning conversion such as a rotating polygon mirror, which speeds up search scanning and simplifies the reading device. It becomes a big obstacle for

Therefore, it is possible to perform parallel reading for each stripe using a line sensor, and there are several methods as shown in FIGS. 10 to 12.

FIG. 10 shows an imaging lens 22 and a half mirror 2 for a card 21 having a stripe' (band-shaped record 4) 21A.
3 to project the light from the linear light source 24 onto the stripe 2IA, and the reflected image of the stripe 21A is formed onto the line sensor 25 by the same imaging lens 22 and half mirror 23.

The disadvantages of the means shown in FIG. 10 are: (1) The illumination system and the continuous output system must be aligned accurately. ■ Signal strength changes due to blur are large.

■Dense @Difficult to read. etc.

In FIG. 11, an illumination lamp 26 illuminates the back side of a card 21 having a plurality of stripes 21A, and an imaging lens 22 forms a transmitted image of the stripes 21A onto a line sensor 25.

In FIG. 12(a), the illumination lamp 26 is used as in FIG. 11?
The card 21 having the S2 number stripes 21A is illuminated from the back side, the line sensor 25 is brought into close contact with the card 21, and the transmitted image of the stripes 21A is read.

In this case, the card 21 has a lower layer (underlayer) 21C formed on a transparent substrate 21B as shown in FIG.
1A, the stripe 21A has a pit 21E extending to the lower layer 21C, and the card surface has a transparent thin film. [210 is formed. Further, a light receiving array 25Δ is arranged in the line sensor 25.

11 and 12 are of the transmissive type, which solves the disadvantage of reflection in Fig. 10, but the common disadvantage of the transmissive type is that the substrate of the card 21 must be made of a transparent material. Things that must not happen. ■ Records such as memos cannot be written on the back side. ■Double-sided recording is not possible. etc.

[Object of the Invention] In view of the above-mentioned points, the object of the present invention is to provide a simple illumination system that does not require high alignment precision in the illumination system and readout system as in the case of a reflection type, and to provide a simple illumination system as in the case of a transmission type.
A high-density information recording card that does not suffer from dirt or writing on the back of the medium, enables double-sided recording, and can also be read by attaching a reading sensor to the card if the first protective layer on the surface of the medium is thin enough. Our goal is to provide the following.

[Summary of the Invention] The present invention provides a low refractive index layer formed of a substance with a relatively low refractive index, and a low refractive index layer formed on this layer with a substance with a relatively high refractive index of 8, which causes defects on the surface. A planar waveguide is constructed by laminating a high refractive index layer and a low refractive index layer made of substantially the same material as the low refractive index layer, and furthermore, a planar waveguide is formed by laminating a high refractive index layer made of a material substantially the same as that of the low refractive index layer, and further thereon, A card-shaped recording medium is constructed by laminating a scattering layer that scatters the reflected light and a recording layer on which information is written by changing the light transmittance. The light enters the defective portion and is guided to the recording layer through the scattering layer so that it can be read as an optical signal.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail based on the drawings.

FIG. 1 is a sectional view showing a first embodiment of a density information recording card according to the present invention.

In this figure, reference numeral 1 denotes a substrate, on which a lower cladding layer 2 is deposited, and a core layer (waveguide layer) 3 responsible for light propagation is further formed thereon.

A defective portion 4 is formed on the upper surface of the core layer 3 in the drawing, and a translucent upper cladding layer 5 is laminated on the core layer 3 . In this case, the lower cladding layer 2 and the upper cladding layer 5
is composed of a layer with a low refractive index for light, and the core layer 3 is composed of a layer with a high refractive index.

A light scattering layer 6 is provided on the upper surface of the upper cladding layer 5. A translucent underlayer 7 made of gelatin or the like is laminated on the scattering layer 6, and an opaque layer 8 that can be written by a laser is further formed thereon. This opaque layer 8 is composed of a tellurium oxide layer or a gelatin layer with silver particles, and back-filling bits 10 covering a part of the underlayer 7 are formed by laser writing. Note that a protective film 9 is coated on the upper surface of the card-shaped recording medium 11 subjected to V41 as described above.

In the above configuration, when the end face of the core F43 is irradiated with focused illumination light from the side surface of the card-shaped recording medium 11, the light incident on the core layer 3 propagates within the layer due to total reflection. core!
i! The light beam reaching the defective portion 4 of 3 passes through the upper cladding layer 5 and is scattered in the light scattering diagram 6. Defect portion 4 of core layer 3
By appropriately controlling the distribution state of the light and the thickness of the scattering layer 6, it is possible to construct a planar light source that provides approximately uniform brightness over the entire recording area. Therefore, by transmitting light from this light source through the included bit 10, the presence or absence of the bit 10 can be read from the card surface by any means capable of detecting light. Note that when the density of the defective portions 4 is distributed to be constant over the entire recording area, if the illumination light is incident only from one side of the card, the brightness will be sloped. Therefore, in this case, it is preferable that the illumination light enters from both the left and right sides of the card 11 in the drawing. Note that the illumination light source for irradiating light onto the recording medium 11 may be an illumination lamp or may be one using a light emitting element.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

In the first embodiment, the illumination light is focused and irradiated onto the end surface of the core layer 3, but if the relative position of the illumination optical system and the card 11 moves, the light m incident on the core layer 3 will change. To avoid this risk, in this embodiment, the illumination light is made into parallel light by the collimator lens 12 and is incident on the end face of the core layer 3, while the end face of the card 11 is configured to have a curvature.

If the end surface of the card 11 is replaced, the reason why the core layer 3 surface is given curvature is that when illuminating with parallel light, the propagation mode in the core layer 3 decreases (ideally becomes a single mode), and the core defect 4
This is to prevent uniform light scattering from occurring due to the formation of the curvature, and it is possible to focus the incident light within the core layer 3 and cause multimode propagation.

Above 1. In both of the second embodiments, illumination light is guided from the side surface of the card to the core layer 3, but generally when handling the card, fingers often come into contact with the end surface of the card, and dirt is relatively likely to adhere thereto. In addition, since the If force applied to the card edge when inserted into the II and stored is larger than that applied to the flat surface,
There is a high possibility that the side of the card will be damaged. The following embodiment takes this point into consideration.

FIG. 3 is a sectional view showing a third embodiment of the present invention, and FIG. 4 is a plan view thereof.

In FIG. 3, the side surface of the card 11 is cut and polished at an angle of approximately 45°, and an anti-gA film 13 is formed on the polished surface. The left side of the reflective film 13 in the figure is protected by a mold 14 and also maintained. ! A light shielding film 15 and an illumination window 16 are provided on the upper surface of the film 9 to prevent light other than the illumination light source from entering. In this case, as shown in Figure 4, card 1
1, there is a stripe-shaped opaque W! at almost the center position. 18 is formed, and illumination windows 16 are formed in a thin shape substantially parallel to the opaque layer 8 near both ends of the card surface.

Further, a light shielding layer 1115 is formed on the card surface excluding the opaque layer 8 and the illumination window 16.

In such a configuration, illumination light is transmitted from the surface of the card 11 through a condensing lens (not shown) to the protective film 9. The light passes through the upper cladding 5, is focused on the reflected NtA 13 on the end face of the core layer 3, is reflected, and propagates within the core layer 3. Thereafter, an optical signal is emitted from the card surface in the same manner as in FIG.

FIG. 5 is a sectional view showing a fourth embodiment of the present invention.

In the third embodiment, the illumination light is focused light as in the first embodiment, and in that case, there is a drawback that the tolerance for vertical movement and horizontal positional deviation of the card 11 is small. Then, the illumination light is made to enter as parallel light through the collimator lens 12. In this case, the portion including the end face of the core layer 3 is given a curvature and the reflective film 1 is applied to that portion.
By forming the core layer 3, multimode propagation is caused in the core layer 3 based on the same reason as explained in the second embodiment.

In addition, 3rd. In the fourth embodiment, the left side of the reflective film 13 in the figure is protected by the mold 14, but the reflective film 13 may be exposed without being molded. Furthermore, a light shielding film 15 and an illumination window 16 are provided on the upper surface of the protective film 9 to prevent light from sources other than the illumination light source from entering, but the light shielding film 15 is not always necessary and may be It is also possible that the form is not. Also, although not shown, scattering! 2
It is also possible to provide a configuration in which a reflective film is provided around i6 to prevent illumination light from leaking from the scattering layer 6.

FIG. 6 is a cross-sectional view showing a fifth embodiment of the present invention, and FIG. 7 is a perspective view showing a schematic structure of the carrier shown in FIG. 6.

In each of the first to fourth embodiments, the illumination light source is card 1.
However, in this embodiment, a light emitting diode array 17 is arranged along the end face of the core layer 3 and fixed to the upper part of the core layer 1 by a mold 14. The Ti m terminal of the light emitting diode array 17 is connected to the electrode 1 provided on the front and back surfaces of the card 11 via a lead.
8.19 is connected. In this card 11, simply by connecting an external power source to the electrodes 18 and 19 exposed on the card surface, the entire recording surface is almost uniformly restarted from inside the card, and the presence or absence of an interpolated bit can be detected. Therefore, card 1
1 is read by a card reader, for example, the card 11 is transferred to a carrier 20 (
It is sufficient if the electrodes 18 and 19 are automatically supplied with power when inserted into the device (see FIG. 7). As shown in FIG. 7, the carrier 20 is provided with card holding parts 22.23 at both ends of the bottom plate part 21 so that the card 11 can be inserted and held. can be inserted. The space between the card holders 22 and 23 is open, and a reading sensor (not shown) is disposed above the opening. Card holding section 22 (23) and bottom plate section 21 opposite thereto
As shown in FIG. 6, leaf spring-like electrodes 24 and 25 are provided on each of the electrodes 24 and 25, and these electrodes 24 and 25 are connected to a power source (not shown).

In the above configuration, when the card 11 is inserted and held in the carrier 20 disposed in the insertion slot of the card reader,
The electrodes 18 and 19 of the card 11 come into contact with the leaf spring electrodes 24 and 25 of the carrier 20, power is supplied from the power source to the light emitting diode array 17, and illumination light enters the core layer 3 from the diode array 17. be done. Note that when the card 11 is inserted into the carrier 20 (in the direction of arrow A), the card 11 is held at a predetermined position within the carrier by a positioning mechanism (not shown), and in this state, the carrier 20 itself is inserted in the direction of arrow B. The information recorded on the card 11 is read by the reading sensor.In this case, the carrier 20 may be fixed and the reading sensor may be moved.

In order to record on both sides of a card, cards with the same configuration may be bonded back to back with substrates 1, or the core layer 3 may be used as a common substrate and the upper clad layer, rli turbo layer, etc. A laminated structure may be used.

[Effect of the Invention 1] As described above, according to the present invention, when information is optically read out from a recording medium on which information is written by partially changing the transmittance, the illumination system can be extremely simplified; Close reading using a reading sensor is also possible. or,
Double-sided recording is also possible without being affected by dirt on the back side of the medium. Furthermore, compared to reflective illumination and reading systems, there is no strong requirement for alignment between the illumination system and the reading system.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of a high-density information recording card according to the invention, FIG. 2 is a sectional view showing a second embodiment of the invention, and FIG. 3 is a sectional view showing a third embodiment of the invention. Sectional view showing 4th
The figure is a plan view of FIG. 3, FIG. 5 is a sectional view showing the fourth embodiment of the present invention, FIG. 6 is a sectional view showing the fifth embodiment of the present invention, and FIG. 7 is a sectional view of FIG. FIGS. 8 and 9 are plan views showing the card recording format, FIG. 10 is an explanatory diagram showing the conventional reflective type, and FIGS. 11 and 12 are the conventional transmissive type. It is an explanatory diagram showing a method. 1... Substrate 2... Lower cladding layer 3
... Core layer 4 ... Defect portion 5 ... Upper cladding layer 6 ... Scattering layer 7 ... Underlayer 8 ... Opaque layer 10 ... Writing bit 11 ... Card-shaped recording medium Agent Patent Attorney Susumu Ito - 4Qln (%J - 瓢f-rnP-u) nK＞N -○ gu(%I -

Claims (5)

[Claims] (1) A planar guide in which a low refractive index film, a high refractive index film having a defective portion on the surface, and a low refractive index film are laminated in this order, and light is incident from the end face of the high refractive index film and guided from the defective portion. A waveguide, a scattering layer that is laminated on the light guide side of the planar waveguide and scatters light, and a recording layer that is laminated on the scattering layer and in which information is written by partially changing the light transmittance. A high-density information recording card characterized by comprising: (2) The high-density information recording card according to claim 1, wherein at least a portion of the high refractive index film on the end face of the planar waveguide is given a curvature in the thickness direction of the film. (3) At least the high refractive index film portion of the end face of the planar waveguide is sloped in the thickness direction of the film, and a reflective film is added to this sloped portion.
High-density information recording card as described in section. (4) A high refractive index film according to claim 1, characterized in that at least a high refractive index film portion of the end face of the planar waveguide is given a curvature in the thickness direction of the film, and a reflective film is added to this curvature portion. Density information recording card. (5) A high-density information recording card according to claim 1, characterized in that light emitting diodes are arranged and fixed close to at least a high refractive index film portion of the end face of the planar waveguide.