JPS63146248A - Optical information recording method and its optical information recording medium - Google Patents

Abstract

PURPOSE:To accurately write and read information with use of a comparatively inexpensive device by having a preliminary process where flat bits are formed previously at the periodical positions and then a recording process where the prescribed one of these bits is covered and providing the information volume to the positions of remaining bits of the flat bits. CONSTITUTION:The flat bits 11 are formed previously at the periodical positions in a preliminary process and then the prescribed one of those bits is covered with a flat cover member 21 in a recording process. Then the information value is secured by a fact whether the bit 11 is covered or not. In other words, the covered bit 11 has no bit and the uncovered bit 11 has a bit respectively in terms of an optical reading mode. Then it is possible to secure the margin of positional accuracy in a covering process as long as some margin is secured for the size the member 21 in the information recording process and the covering process. Therefore both the size and the shape of an information bit can be stabilized despite the deterioration of accuracy of a writing device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording method and an optical information recording medium used therein.

[Conventional technology]

In recent years, optical information recording methods that can perform high-density information recording have become widespread, and optical disks, optical cards, and the like are currently being actively used as optical information recording media used in this method. Such optical information recording methods generally employ write-once recording methods. That is,
A thermally destructible metal thin film or organic material thin film is uniformly formed on the entire surface of the recording substrate, and this thin film is partially thermally destroyed to form concave minute bits. The information bit “01” depends on the presence or absence of
It expresses 2. A focused laser beam or an electric heating element (thermal recording head) is used to form the micro pits.

[Problem that the invention seeks to solve]

As mentioned above, conventional optical information recording methods write information by forming minute pits on a thin film using heat, but in order to read the information recorded in this way with high accuracy, It is necessary to keep the size and shape of the micro pits constant. If there are variations in the size of the micro pits, the read signal level will fluctuate, and if there are variations in the shape, the noise level on the read signal will increase.
In either case, accurate reading becomes impossible and becomes a factor that reduces the reliability of reading. For this reason, conventionally, expensive devices that can write and read information with high precision have been required.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an optical information recording method that allows accurate writing and reading of information using a relatively inexpensive device, and an optical information recording medium used in the method.

[Means for solving problems]

The present invention provides an optical information recording method for forming optically readable information bits on an information recording medium, in which optically readable information bits are formed on an information recording medium at predetermined periodic positions on a recording substrate. An optical information recording medium in which a plurality of flat bits made of different materials are formed is prepared, some of the flat bits are selected based on the information to be recorded from among the plurality of flat bits, and a recording substrate is prepared. Information is recorded by concealing only the selected flat bits using a flat concealing member made of a material that has approximately the same reflectance as , and accurate information can be written and read using a relatively inexpensive device. This is how it was done.

[For production]

In conventional optical information recording methods, concave bits are formed on a recording medium, and the amount of information is provided at the position where the concave bits are formed. In contrast, in the method according to the present invention, a preliminary step is performed in advance in which flat bits are formed at periodic positions, and then a recording step is performed in which predetermined ones of the flat bits are concealed by a flat concealing member. The amount of information is determined by whether or not the flat bits are hidden. That is, in terms of optical reading, the hidden flat bits are absent, and the unhidden flat bits are present. Furthermore, the unconcealed flat bit always has a predetermined size and shape determined by the conditions in the preliminary stage. Therefore, accurate reading is possible even using a relatively inexpensive reading device. Further, in the information recording step, that is, the concealment step, it is sufficient that a flat concealing member having at least the same size as the flat bit can be formed on the flat bit. Therefore, if the size of the flat concealing member is allowed to have some margin (although it cannot be made so large that it may conceal part of the adjacent flat bit), the positional accuracy in the concealment process can be increased. This makes it possible to stabilize the size and shape of the information bits even if the accuracy of the writing device is lowered compared to conventional methods. That is, according to the present invention, it is possible to write and read information using a relatively inexpensive device.

〔Example〕

The present invention will be described below based on illustrated embodiments. FIG. 1 is a partial perspective view of an optical information recording medium according to a first embodiment of the present invention. This optical information recording medium is composed of a recording substrate 10 and a plurality of flat bits 11.

The recording substrate 10 serves as the base of an optical information recording medium, and in this embodiment, a credit card-sized white vinyl chloride sheet is used. Further, in this embodiment, the flat bits 11 are circular printing black ink layers having a diameter of 50 μm, and are formed at predetermined periodic positions (1/200 inch pitch) on the recording substrate 10.

This optical information recording medium can be easily produced by printing a circular pattern with black printing ink on a white vinyl chloride sheet and drying it.

Now, in order to record information on such an optical information recording medium, the following writing process was performed.

First, a thermal transfer printing film 20 as shown in the upper part of FIG. 1 is prepared. A flat concealing member 21 is disposed on this thermal transfer printing film 20.

The arrangement pattern of the flat concealing member 21 is similar to that of the recording substrate 10.
This corresponds to the periodic arrangement pattern of the plate-like dots 11 above. In this embodiment, a polyester film with a thickness of 4 μm is used as the thermal transfer printing film 20, and a wax containing white pigment is used as the flat concealing member 21. Here, the reason why the flat concealing member 21 is white is because the recording substrate 10 is white. The material of the flat concealing member 21 is determined based on the recording substrate 10, and in short, it is sufficient to use a material that has almost the same reflectance as the recording substrate 10 so that the flat bit 11 can be hidden. . Further, the shape and size of the flat concealing member 21 are also determined based on the shape and size of the flat plate 11. In this embodiment, the flat bit 1
Since 1 is circular, the flat concealing member 21 is also circular,
Moreover, in order to ensure reliable concealment, the latter is made slightly larger than the former to provide some margin.

Such a thermal transfer printing film 20 is attached to the recording substrate 10.
The flat bit 11 to be concealed is selected based on the information to be recorded, and the flat concealing member 21 corresponding to the selected flat bit 11 is placed in close contact with the top so that their patterns match. The head performs thermal transfer onto the recording substrate 10 side.

That is, the flat hiding member 21 is transferred onto the selected flat bit 11, and the flat bit 11 is hidden. FIG. 2 shows the state of the optical information recording medium after such concealment by thermal transfer. Black flat bit 11 where the hatched part remained unhidden
The part without hatching is a white plate-shaped concealing member 21 which has been thermally transferred. The thermally transferred portion of the planar concealing member 21 has almost the same reflectance as the recording substrate 10, and therefore, when optically read, there is no information bit. In this way, the presence or absence of information bits can be set to “0°” and “
1”, it is possible to record any information.

The advantage of the above recording process is that position control during thermal transfer is relatively easy. That is, if a slight margin is allowed in the size of the flat concealing member 21, reliable concealment can be achieved even if there is some positional variation. Therefore, as the writing device, an inexpensive device with a relatively large positional control tolerance can be used. In FIG. 2, the size and shape of the remaining flat bit 11 are always constant regardless of the accuracy of this writing device, and accurate reading can be performed. Although the flat bit 11 has a circular shape when viewed from above in the above-described embodiment, it can also have a shape such as an ellipse, a square, a rectangle, or a rhombus.

Incidentally, in order to protect the flat plate-like dot 11 and the flat-plate concealing member 21 from external environments such as friction, it is preferable to further form a transparent protective layer on the upper surface of the structure shown in FIG.

Further, in the above-mentioned embodiments, a method of concealing using a thermal transfer printing film has been described, but it goes without saying that other concealing means may be used. For example, an impact printing ribbon containing white ink is prepared, this impact printing ribbon is placed on the recording substrate 10, and an impact head is used to eject ink from the impact printing ribbon. Bit 11 can also be hidden.

〔Effect of the invention〕

As described above, in the optical information recording method according to the present invention,
A preliminary step of forming flat bits at periodic positions is performed in advance, and then a recording step is performed to hide predetermined ones of the flat bits, so that the remaining positions of the flat bits have an amount of information. As a result, even if the accuracy of the writing device is reduced compared to conventional methods, the size and shape of the information bit can be stabilized, making accurate reading possible, and making it possible to write and write information with a relatively inexpensive device. Reading becomes possible.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a partial perspective view of an embodiment of the optical information recording medium and concealing means according to the present invention, and FIG. 2 is a partial perspective view of the optical information recording medium shown in FIG. FIG. 2 is a partial perspective view of a recording medium showing a state recorded by a method according to an embodiment. 10... Recording substrate, 11... Flat bit, 20
...Thermal transfer printing film, 21...Flat-shaped concealing member.

Claims (1)

[Scope of Claims] 1. An optical information recording method for forming optically readable information bits on an information recording medium, the method comprising: forming optically readable information bits at predetermined periodic positions on the information recording medium; a preliminary step of forming a plurality of flat bits made of materials with different reflectances from the recording medium; selecting some flat bits from among the plurality of flat bits based on information to be recorded; 1. An optical information recording method comprising the step of concealing only selected flat bits with a flat concealing member made of a material having substantially the same reflectance as that of an information recording medium. 2. The optical information recording method according to claim 1, wherein the flat bits are formed on the information recording medium by printing. 3. Prepare a thermal transfer printing film in which a plurality of flat hiding members are arranged at periodic positions, place this thermal transfer printing film on an information recording medium, and use a thermal head to convert the flat hiding members into a flat sheet. 3. The optical information recording method according to claim 1, wherein the concealment is carried out by thermal transfer onto the bit. 4. The optical information recording method according to claim 3, wherein the flat concealing member is made of wax containing pigment. 5. Prepare a ribbon for impact printing containing ink, place this ribbon for impact printing on an information recording medium, use an impact head to eject ink from the ribbon for impact printing, and form a flat cover made of this ink. 3. The optical information recording method according to claim 1, wherein the concealment is performed by forming the member on a flat bit. 6. An optical information recording medium for forming optically readable information bits, which is made of a material having a different reflectance from that of the recording substrate at predetermined periodic positions on the recording substrate. An optical information recording medium characterized by forming a plurality of flat bits. 7. Flat bits can be circular, oval, square, rectangular,
Claim 6, characterized in that it is or diamond-shaped.
The optical information recording medium described in Section 1. 8. The optical information recording medium according to claim 6 or 7, wherein the flat bit is made of printing ink. 9. The optical information recording medium according to any one of claims 6 to 8, wherein the flat hiding member is made of wax containing pigment.