JPS63195835A - Recording method for information on recording material - Google Patents

Abstract

PURPOSE:To attain recording with high density as compared with an ordinary digital recording method by changing the quantity of energy to be applied and recording information in a recording material. CONSTITUTION:When energy such as light is applied to plural points of the recording material, the plural points are changed and digital recording is executed on the plane of the recording material in accordance with the array of the plural points. When the capacity of energy applied to the plural points is changed, respective points are changed continuously or in stages and analog or digital information corresponding to the change is recorded. Thereby, information is three-dimensionally recorded in the recording material, and recording density can be improved as compared to an ordinary digital method.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an information recording method on a recording material that records information at a higher density than a normal digital method.

(Prior art) Conventionally, as a method for recording information on recording materials, heat is applied to a low tellurium oxide (TeOx) to cause a phase transition from amorphous to crystalline or vice versa, or as in magneto-optical recording. A digital recording method is known in which digital information represented by a logical value rOJ or "1" is recorded on the recording material by irradiating a magnetic material with light to reverse its magnetization direction.

(Problems to be Solved by the Invention) However, according to the conventional recording method described above, unless the writing ability improves, the distance between recording bits will not become narrower, and there is a limit to the conventional high density.

(Means for Solving the Problems) An object of the present invention is to provide a method for recording information on a recording material that can perform higher density recording than conventional digital recording methods. , an information recording method in which digital information is recorded on a recording material by applying energy such as light to a plurality of points on the recording material. It is characterized by giving continuous or stepwise changes to each of these and recording analog or digital information.

(Function) When energy such as light is applied to a plurality of points on the recording material, the plurality of points change, and digital recording is performed on the plane of the recording material depending on the arrangement of the plurality of points. By changing the amount of energy applied to each of the plurality of points, each point changes continuously or stepwise, and analog or digital information corresponding to the change is recorded. Therefore, recording is performed on the recording material three-dimensionally, and the recording density is greater than in the normal digital method.

(Example) Next, the present invention will be explained in detail.

As a recording material used in carrying out the present invention, by changing the magnitude of energy such as light or heat, the point where energy is applied cumulatively (that is, continuously or stepwise) changes the light transmittance, etc. For example, phosphorus, which was previously proposed by the applicant, is used (see Japanese Patent Application No. 32765/1983).
.

Now, we are using a recording material that can change, for example, in five stages by changing the amount of energy, and with this,
For example, a case will be explained in which 1, 2, 10, 128 are respectively recorded as quinary codes.

As shown by the circle in Fig. 1 (A), for 1, energy such as light of size 1 is applied to the weight position of 5 on the recording material as shown by the height of the rectangle in Fig. 1 (B). The light transmittance changes depending on its size. Similarly, for 2, energy of magnitude 2 is applied to the weight position 5 of the recording material, for 10, energy of magnitude 2 is applied to the weight position 5 of the recording material, and for 128, energy of magnitude 2 is applied to the weight position 5 of the recording material. Energy of magnitude 1 is applied to the weight position, and energy of magnitude 3 is applied to the weight position of 5, causing a change in the light transmittance or the like in accordance with the magnitude of the energy at each position.

In this way, as with the normal digital method, a planar (two-dimensional) digital method is recorded on the recording material, and in addition, there is another dimension that can be thought of as the thickness direction.
Recording is done in two dimensions.

As a method for reproducing the information recorded on the recording material as described above, various methods are used that can distinguish and reproduce changes in the recording material corresponding to the recorded information.

The recording method of the present invention will be described in detail regarding the case where phosphorus is used as the recording material.

Phosphorus is formed into a thin film (3,000 to 50,000 layers) on the substrate by any known means such as vacuum deposition or sputtering. The base material is, for example, a visible-end transparent material such as a plastic sheet such as Mylar film, a plastic plate such as acrylic or polycarbonate, a glass plate, or a synthetic resin sheet or film such as polymethyl methacrylate resin, on which information can be written. , a material that does not completely absorb laser light used for reproduction, erasing, etc., and does not deform when irradiated with light is used.

Examples of phosphorus include red phosphorus such as red phosphorus and purple phosphorus, white phosphorus or supercooled liquid phosphorus, and white phosphorus that is generally a mixture thereof.

When recording information on white phosphorus or supercooled liquid phosphorus formed in a thin film on a base material, irradiation with ultraviolet rays of 200 nm or less, heating to a temperature of 250° C. or more and less than 570° C., or a combination thereof is used.

When using ultraviolet rays, change the irradiation time when the wavelength is the same, change the wavelength when the irradiation time is constant, or do both at the same time; when using ultraviolet rays, change the heating time when using the same thermal energy, When the time is constant, the heating temperature is changed, or both are performed simultaneously, and by changing the amount of ultraviolet irradiation or heating, white phosphorus or supercooled liquid phosphorus is converted into red phosphorus continuously or stepwise. , information is recorded continuously or in stages.

The transition from white phosphorus or supercooled liquid phosphorus to red phosphorus due to ultraviolet irradiation or heating proceeds from the light irradiation surface or heating surface in the irradiation direction or heating direction, and the light transmission of the recording material changes depending on the amount of ultraviolet irradiation or heating. rate changes.

FIG. 2 shows the respective light transmittance curves when five types of information are recorded on the recording material. In the figure, (a) shows the light transmittance curve when no recording is performed, that is, when white phosphorus or supercooled liquid phosphorus is used, and (b) shows the light transmittance curve when recording is performed and red phosphorus is used.

Curve (0) as the amount of ultraviolet irradiation or heating increases and the transition from white phosphorus or supercooled liquid phosphorus to red phosphorus progresses.
(1) (2) (3) As shown in (b), the light transmittance changes and shows five types of transmittance for the same reproduction light. The transmittance curve (
0) Between the maximum transmittance (90%) and minimum transmittance (0%) of the recording material on which the information is recorded when four types of information shown in (1) (2) (3) are recorded. 4
Record the case where the transmittance curve (0) falls within the transmittance range of 67.5% to 90% for reproduction light of a predetermined wavelength when divided equally into the same four stages as the type of energy. Below rOJ Similarly, the transmittance curve (1
), the record is "1", and the transmittance curve (2) in the range of 22-45% is "2", and the record is "2", and 0-45%.
The record for the transmittance curve (3) that falls within the range of 22% is
3'', four types of recording are performed at one point.

In the case of dividing the transmittance into four, four types of numbers can be recorded as they are without being converted, so they can be recorded in quaternary numbers. In the case of 10 divisions, there are 10 types of recording from 0 to 9, and decimal numbers can be recorded as they are without conversion. If the transmittance classification is further subdivided, it becomes possible to record the same number of types as the number of subdivisions at one point. If the transmittance is divided continuously, analog recording can be made at one point.

If the change division at one point on the recording material is divided into four, four types of signals (0, 1, 2, 3) can be recorded at one point on the recording material, so at two points (0, 0), (0,1), (i
, o), and (1, 1), the recording density is doubled compared to the usual digital force sense. Furthermore, the transmittance change section at one point on the recording material is further subdivided. That is, the recording density becomes higher by a multiple of the exponent than the normal digital method.

As a recording device, a time modulation type optical or thermal recording method, a wavelength modulation type optical recording method, a heat modulation type recording method, or a combination of these methods are used. It is preferable to use an apparatus that converts the information to be recorded into a time-series electrical signal and scans the recording material with a laser beam whose intensity is modulated according to the signal.

As a reproducing device, one that changes the wavelength when the transmittance is kept constant or one that changes the transmittance for light of a certain wavelength is used, but from the point of view of the simplicity of the device, it is possible to It is preferable to use an apparatus that reads and reproduces changes in recording by changes in transmitted light that passes through the recording material.

In addition, if the part or □ where white phosphorus or supercooled liquid phosphorus is converted to red phosphorus due to the recording operation is heated to a temperature of 580°C or higher and then rapidly cooled from there, nothing will be recorded. can be converted back to white phosphorus or supercooled liquid phosphorus corresponding to . Therefore, rewriting is possible.

Next, an embodiment of a method for recording information on a recording material made of phosphorus will be described.

As the recording material made of phosphorus, one manufactured as follows is used. In other words, 6N as a raw material for phosphorus
Using high-purity (99.9% or more) red phosphorus, it was placed in a tungsten board and placed on a glass plate rotated at a speed of 120 rpm in an exhausted atmosphere of 1 G' Torr or more for 2 to 10 people/min. 4,500 deposited films were obtained at a deposition rate of . During this vapor deposition, ultraviolet rays are irradiated from the outside, and the white phosphorus or supercooled liquid phosphorus cooled on the glass plate is converted from a gas by the ultraviolet rays to red phosphorus, thereby obtaining a red phosphorus vapor deposited film.

After forming a transparent protective film on the red phosphorus vapor deposited film, this was kept in a 300°C furnace for 2 hours and thermally relaxed to form a uniform red phosphorus film.
A uniform vapor deposition film of white phosphorus or supercooled liquid phosphorus was obtained by applying an energy density of more than ca to transform it into transparent liquid phosphorus and rapidly cooling it.

501+1J/(
Hg (, 120 mJ/m and 250,111 J/c
Recording is performed with an energy density of A, and the reproduction light is 0.8
Light of approximately W and 400M was used. The respective transmittances at this time were 70%, 30%, and 0%.

1.When erasing recorded records, apply an energy density of 300 mJ/ca or higher to at least the recorded area, and if this operation is stopped, the area will be instantly cooled to room temperature due to the film thickness. Return to the initial state where nothing is recorded (white phosphorus or supercooled liquid phosphorus).

Place the recorded items in a furnace at a temperature of 600℃ or higher and 650℃ or lower.
Records can be similarly erased by holding for a minute and then performing rapid cooling.

(Effects of the Invention) As explained above, according to the present invention, a change is made by applying energy to a plurality of points on a recording material, and digital information is transferred to the recording material from the changed arrangement of the plurality of points. At the same time as recording, continuous or stepwise changes are applied to each of the plurality of points to record analog or digital information, so the recording density is improved compared to conventional digital recording methods. have an effect.

[Brief explanation of the drawing]

FIGS. 1(A) and (B) are diagrams for explaining one example of the recording method of the present invention, and FIG. 2 is a diagram showing a light transmittance curve when phosphorus is used as the recording material. . (a)...Light transmittance curve when not recording (0) (
1) (2) (3) (b)...Light transmittance curves recorded at various 1-energy suspensions Showa era, August 5th

Claims (1)

[Claims] 1. In an information recording method in which digital information is recorded on a recording material by applying energy such as light to change a plurality of points on the recording material, by changing the amount of energy applied. 1. A method for recording information on a recording material, characterized in that analog or digital information is recorded by continuously or stepwise changing each of the plurality of points on the recording material. 2. The recording material according to claim 1, characterized in that the recording material is phosphorus and is changed from white phosphorus or supercooled liquid phosphorus to red phosphorus by applying at least one of heat and light. Information recording method.