JPS60107737A - Data reader and data reading method - Google Patents

Abstract

PURPOSE:To read out optically an optical recording medium which has put an unreadable flaw on a protective layer by steeping the optical recording medium into a liquid having a refractive index roughly equal to a refractive index of its protective layer, and reading information recorded in the medium through the liquid. CONSTITUTION:A laser card 8 in which a flaw 10 which cannot be read out optically in a usual state is put on a protective layer 4 is inserted into a vessel 13 filled with a transparent liquid 14. As for the liquid 14, a solution which does not invade a substrate of the laser card 8 and a protective layer 4, etc., and also has a refractive index equal or roughly equal to that of the protective layer 4 is selected. The surface of the laser card 8 inserted into the liquid 14 becomes the same as a state that a protective layer whose refractive index is equal is formed virtually because the liquid having a refractive index which is the same as that of the protective layer 4 or similar to it goes into the flaw put on the protective layer 4. In this state, an unreadable bit formed on a crust 3 under the flawed protective layer is read out by irradiating a laser light in a read optical system 11. In this regard, as for the medium, instead of the liquid, a medium of a gas, etc. having a refractive index which is the same as that of the protective layer or roughly equal to it can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to a data reading device and a data reading method from an optical information recording medium, particularly when the protective layer of the information recording medium is damaged. The present invention relates to a data reading device and a data reading method convenient for reading data.

(2) Background of technology Recently, as in digital audio discs (DAD) and video discs (VD), laser beams are used to form a focus (four parts) on a recording layer formed on a substrate. Optical recording media that detect high-density recorded information by using a semiconductor laser or the like to detect the difference in reflectance between pits and lands during readout are widely used, and are widely used in external storage devices for electronic computers. Optical recording media are also beginning to be used in place of magnetic memory such as floppy disks and hard disks.

The substrate of such an optical recording medium is a synthetic resin, glass, or the like, and the recording layer is made of Al, Ph, or Au.

A reflective metal film such as Cr, semimetal such as Te, Bi, Se, or an oxide thereof is used, or 5e-Te-A
Vapor-deposited thin films of chalcogen compounds such as S, Te-As, etc. are also used, but it is customary to cover the protective film after forming the focus to protect the recording layer.

Also known is a laser card in which a recording layer is formed using the above-mentioned laser to form a carbon fiber.

The laser car 1, bank card or tally car 1
1.1 The storage capacity of the punk card, which is used for conventional automatic bank cash withdrawals, etc., has a storage capacity of several hundred bits, compared to the magnetic strip type memory card used for automatic cash withdrawal, etc. It is said that 5 million bits of data can be stored on the upper stripe, and 40 million bits of information can be recorded on both sides of the cart.

This type of laser car F has a protective layer formed on it like the above-mentioned I) AD and video disk, but due to the nature of the cart, the protective layer cannot be made as thick as 0.5 to 2 m like DAD. Since it can only take about 11 TI per 0.1 stroke, there is a problem that optical reading becomes impossible if the protective layer is scratched or dust is attached.

(3) Problems with the Prior Art A schematic side sectional view of the case where the above-mentioned optical recording medium is used in a laser car F is shown in FIG. In the figure, reference numeral 1 denotes a substrate made of polyester or the like, and a lower layer N2 of 3 to 10 microns is formed on the substrate. The lower layer is made of, for example, an organic colloid and is used as a thermal insulator during laser irradiation,
A crust 3 (with a thickness of approximately 0.1 micron) is placed on the lower layer 2 (
This crust is used as a recording layer and has a reflectance of about 40%. A transparent protective layer 4 with a thickness of about 0.1 nm is formed on the second part of the crust, and a laser card having a thickness of, for example, 175 μm is formed as a whole. When the crust 3 is irradiated with the laser 6, a pit I-5 is formed and can be used as recorded information. Marinox, which uses such an organic substance as a recording layer, dissolves at about 200°C, so it is possible to record and read data using a semiconductor laser or the like. However.

The laser spot diameter during recording is 5 μm or more compared to DAD etc.
Since the protective layer 4 has a large thickness of 8 μrn and is relatively thick, it has the disadvantage that it is easily affected by dust 7 and scratches deposited on the surface of the protective layer. In particular, if the laser car 1 has a scratched surface, it may become impossible to read the data on the card. This is particularly problematic if the unreadable data is not stored in the memory of the host computer. For this reason, it is possible to form a thin protective layer on the car 1 itself that will not cause any scratches, but such a high-quality transparent protective layer has not yet been found.

(4) Purpose of the Invention In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide a data reading device and a data reading method that are capable of reading data even if the protective layer is damaged.

(5) Structure of the Invention According to the present invention, the above object is to form a protective layer on the surface of an optical recording medium on which information is recorded and read using light;
A liquid having a refractive index substantially equal to the refractive index of the protective layer is immersed in a container, and the optical recording medium is immersed in the liquid, and the reading means records information on the optical recording medium through the liquid. This is achieved by providing a data reading device characterized in that it captures information from JJt.

(6) Examples of the invention An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a plan view of a laser card which is an optical recording medium of the present invention, and FIG. 3 is a side sectional view schematically showing the 8-in section of FIG.

In FIG. 2, the laser card 8, for example, 5
1,000,000 pits are formed and recorded using optical recording means, and used as a memory exclusively for reading data.

Tin 1 is added to the protective layer 4 on the stripe 9 of the laser card 8.
When 0 is added, as shown in FIG. 3, the ratio between the focused laser spot diameter φ2 formed in class 1 and the laser card +=¥φ1 on the surface of the protective layer 4 becomes extremely small. This means that the protective layer 4 is thin.

The laser spot (this is because the flea is large, and the flaw 10 greatly affects the reading operation, making it impossible to read the laser spot).

Therefore, it is necessary to transfer the data of the scratched part recorded on this stripe 9 to a new laser card, or to re-record the data of the scratched part in the empty part of the scratched radar card. To do this, of course, data must be read from the scratched laser card.

A data output device for optically reading out data from such a scratched laser card using a laser semiconductor or the like will be described in detail with reference to FIGS. 4 and 5.

FIG. 4 is a side sectional view showing one embodiment of the data successive device of the present invention, and FIG. 5 is a side sectional view showing another embodiment of the data reading device of the present invention. In Figures 4 and 5, 'ζ1~
4 shows various layers similar to those shown in FIG. 1 constituting a laser card 8, and the laser card is assumed to have scratches 10 on the protective layer 4 which are not optically readable under normal conditions.

The scratched laser card 8 described above is inserted into a container 13 filled with a transparent liquid 14. As the liquid 14, a solution is selected that does not soak the substrate of the laser card 8, the protective layer 4, etc., and is equal to or approximately equal to the refractive index of the protective N4. If the protective layer 4 is made of synthetic resin with a refractive index of about 1.5, xylene or the like can be selected, for example. In the case not shown in FIG. 4, the protective layer 4 of the laser card 8 is immersed toward the upper side of the container 13, and in the case of FIG. 5, the protective layer 4 is immersed toward the lower side of the container 13. The surface of the laser card 8 inserted into the liquid 14 is protected by the liquid having the same or similar refractive index as the protective layer 4 entering into the scratches made on the protective layer 4 and having an apparently equal refractive index. It is the same as when a layer is formed.

In this state in FIG. 4, the optical system 1 reads from the top of the container 13.
The unreadable focus formed on the crust 3 under the protective layer with scratches 41 is read out by irradiating the laser beam 1, and the read signal from the reading optical system 11 is converted into an electric signal, and a new one is sent to the transfer device 12. You can recreate a laser card.

In the case shown in FIG. 5, the bottom of the container 13 is made of an optically transparent material, or a lens or the like is fitted to bring the protective layer 4 of the laser card 8 into close contact with the bottom of the container.
In order to make the surface of the protective layer 40 isometrically uniform as the solution 14 enters the 0 part, and to perform reading by irradiating the laser beam from the bottom of the container, the influence of fluctuations on the liquid surface is removed compared to FIG. 4. It becomes possible to do so.

In the above embodiments, an example in which a liquid was used as the medium was explained, but it is clear that a medium such as a gas having the same or substantially the same refractive index as that of the protective layer may also be used.

(7) Effects of the Invention Since the present invention is constructed as described above, it has a feature that it is possible to optically read out an optical recording medium in which the protective layer has unreadable scratches.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view of a conventional optical recording medium, FIG. 2 is a plan view of the optical recording medium of the present invention used in a laser card, and FIG. 3 is a schematic side view of a conventional optical recording medium. A cross-section cutaway view,
FIG. 4 is a sectional side view of one embodiment of the data reading device of the invention, and FIG. 5 is a sectional side view of another embodiment of the data reading device of the invention. 1... Substrate, 2... Lower layer, 3... Crust,
4...Protective layer, 5...Bit, 6...Laser light. 7...Dust, 8...Laser card. 9... Striped area, lO... Scratch. 11... Reading optical system, 12... Transfer device, 13
...container, 14...liquid. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 IiI Tan 1

Claims (2)

[Claims] (1) A protective layer is formed on the surface of an optical recording medium that records and reads information using light, and a liquid having a refractive index approximately equal to that of the protective layer is immersed in a container. A data reading device characterized in that the optical recording medium is immersed in the liquid and the information recorded on the optical recording medium is read through the liquid by a ζ reading means. (2) When reading information from an optical recording medium on which information is recorded using light, the protective layer of the optical recording medium is brought into contact with a medium whose refractive index is approximately equal to the refractive index of the protective layer of the optical recording medium. A data reading method characterized in that the above information is read by