JPS58158037A - Recording disc of information - Google Patents

Abstract

PURPOSE:To improve high density recording, high speed recording and reproducing, etc. by irradiating laser light to a disc of polymer material which is stretched radially from a center to change the optical properties such as reflectivity, refractive index or the like thereof then reading out said change. CONSTITUTION:A pulse-like laser beam 7 is irradiated through a polarizer 8 to a polymer film disc 1 of PE, polystyrene or the like which is stretched radially from the center. The molecular orientation by the stretching is released in the part 9 where the laser beam is irradiated, and said release can be recorded as a change in reflectivity, refractive index or double refractive index. Said change is read out through an analyzer 10 by using the laser light which has the smaller light energy required for the recording so as not to release the molecular orientation by the stretching and the read out light is detected with a detector 11, whereby reproduction is accomplished.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] After irradiating a polymer material disk with laser light to change its optical properties such as reflective salt, refraction wheel, and birefringence, Regarding information recording discs that are read out by
:Relates to an information recording disk in which a polymer material disk extends radially from the center.

[Prior art and problems]

It is known that polymeric material sheets of the following types are polarized by the action of temperature and electric field (twofold) and have pyroelectricity and piezoelectricity, and that this polarization occurs only at locations where temperature and electric field act together; Alternatively, if an electric field in the opposite direction to the original polarization is applied to a local part of a polarized polymeric material sheet along with temperature, the polarization in that part will be erased or reversed. An information recording and reproducing method in which information signals are stored as locally different polarization distributions on the surface of a polymeric material sheet and reproduced and read as necessary has already been proposed in Japanese Patent Laid-Open No. 47-41722. The fact that the polarization signal has pyroelectricity and piezoelectricity has the advantage that not only the pyroelectric method but also the piezoelectric method can be used to reproduce the signal. However, in the case of reproduction using pyroelectricity, the piezoelectric effect caused by changes in the tension acting on the sheet may cause noise.

When a sheet of polymer material that can record information through polarization is polarized, the polarity of piezoelectricity is generated when tension is applied to the sheet, and the polarity of pyroelectricity is generated when this sheet is heated. are in opposite directions, and if heating and tension are applied at the same time, they may be completely canceled out.Furthermore, piezoelectricity of the same sign as the heating pyroelectricity generated by tension relaxation becomes a noise signal. For example, when polarizing a composite piezoelectric material made by combining lead phosphate or other ferroelectric inorganic compound powder with a thermoplastic resin as a molecular material, the polarity of the piezoelectricity caused by applying tension and the polarity of the pyroelectricity generated by heating are in the same direction. Therefore, polymer materials containing a large amount of stretchable electric powder often have the same polarity, but in this case, if the tension and heating occur simultaneously, piezoelectricity and pyroelectricity will interact with each other. cancel each other out.

The most common method for recording and reproducing information using a sheet-like recording material is a method in which a tape-like recording material is wound onto a reel and recorded or reproduced while being wound onto another reel. However, when running the tape while rewinding it, tension is always applied, and it varies greatly depending on the start and stop of running, changes in speed, etc. Furthermore, fluctuations in force also occur if the reel operation lacks even the slightest degree of smoothness, and the fluctuations in this case are often caused by repetitive vibrations.

If the piezoelectricity caused by this variation in tension has the same polarity as the pyroelectricity caused by the reproduction of information, it becomes a noise signal, and in the opposite case, the information is canceled out, resulting in an erroneous signal. Furthermore, even when information is reproduced piezoelectrically, the applied pressure must act perpendicularly to the sheet surface in order to see the difference in polarization between local areas on the surface, but fluctuations in the tension applied to the sheet If so, this tension variation results in noise in the piezoelectric signal. In addition to the above-mentioned points, an information recording memory that records locally different polarization distributions on a polymer material sheet and reads the recorded polarization signals by pyroelectrically or piezoelectrically reproduces them. The resolution continues to be
It has the disadvantage that it depends largely on the resolution of the image, making it unsuitable for high-density recording.

On the other hand, an information recording memory in which information is written by irradiating a polymeric material film that has been uniformly electretized in advance with a light beam is also described in Japanese Patent Publication No. 53-36298 and is well known as a high-density recording method. but,
In this case as well, a needle-like induction machine or an MO8 type semiconductor field effect device for detecting an externally appearing electric field is used for readout, and there are major restrictions on high-density recording and recording speed. In addition, when a disk is formed from a polymeric material film that is axially or biaxially stretched, it has optical anisotropy in the stretching direction.

β is a polymer film placed between the polarizer and analyzer.
] Every time the light is turned, the intensity of the light after passing through the analyzer varies.87
The temperature was significantly lowered.

[Purpose of the invention]

In the present invention, a laser beam is irradiated onto a polymer material disk that is elongated in a radiation direction from the center to change at least one optical property such as a reflection corridor, a refractive index, and a birefringence index, and then read out using a laser beam. To provide information recording discs for the purpose of: In particular, the present invention improves high-speed recording and reproduction, which are problems when conventional polymer film is used as a recording medium for discs, and also improves the intensity of light after passing through an analyzer as the disc rotates. It is something to improve. This book also provides an information recording disk that improves the deterioration of the film due to oxidation and corrosion, which is a problem when used as a recording medium for °C disks, by forming a metal thin film such as a cTe alloy or an organic thin film such as a color film on a substrate. , the purpose of which is to perform recording and reproduction optically.

[Summary of the invention]

The present invention involves irradiating a polymer material disk stretched radially from the center with laser light to change at least one optical property of reflectance, refraction driving, and birefringence, and then using laser light to It is an information recording disk characterized by being readable, and more specifically, polyethylene, polystyrene, polypropylene and other polyolefins, acrylic resins, polyvinyl chloride, polyvinyl acetate, polyvinyl ether, polyvinyl ketone, polyether, fluorine resin,
Stretched radially from a center made of at least one of polycarbonate, polyester, polyamide V, diene plastic, polyimide V, polysulfone, polyphenylene sulfide V, high acrylonitrile copolymer and derivatives thereof, and cellulose plastic. This information recording disc is characterized in that a film is irradiated with a laser beam to locally change the optical properties of the irradiated portion of the film, and this is read out optically. The filament-like polymer distribution is stretched radially from the center.

That is, information recording disks are provided by applying strong shearing stress radially from the center to increase the birefringence.

〔Effect of the invention〕

Information is written by irradiating a laser beam onto a disk made of a polymeric material that extends radially from the center.
The optical properties of the irradiated portion of the disk, such as reflection driving, refractive index, and birefringence, are locally changed. Since this change is read out using laser light, there is the advantage that by controlling the laser light, it is possible to reproduce fine patterns at high speed and with high density. Furthermore, compared to information recording disks using Te alloys or pigment thin films, there is no film removal oxidation or corrosion due to moisture, making folding extremely reliable. Furthermore, since the substrate itself also serves as a recording medium, it is possible to completely eliminate the complicated process of forming an alignment film on the substrate.

[Embodiments of the invention]

FIG. 1 shows polyethylene, polystyrene, polypropylene and other polyolefins, acrylic resins, polyvinyl chloride, and polyvinyl acetate, which are stretch-molded radially from the center according to the present invention.

At least polyvinyl ether, polyvinyl ketone, polyether, fluororesin, polycarbonate, polyester, polyamide V, diene plastic, Boliimi F1 polysulfone, polyphenylene sulfide V, high acrylonitrile copolymer, and derivatives thereof, cellulose plastic. 1 shows a polymeric film disk l with a central rotation hole 2 selected from 1. As shown in Figure 2, the method of stretching radially from the center is to stretch a polymer film formed in advance by the inflated method, T-shaped die method, calender roll method, solvent casting method, etc. into concentric circles. The polymer film is sandwiched between a concentric ring 3 and a concentric ring 4 having an inner diameter slightly larger than the outer diameter of the concentric ring 3, and the polymer film 5 is placed outside the ring 4. This is achieved by applying the weight 6 at a temperature near the melting point of . As shown in Figure 3, the polymer film disk 1 stretched radially from the center is irradiated with a pulsed laser beam 7 through a polarizer 8, whereby the molecules of the portion 9 irradiated with the laser beam are formed by stretching. Relaxation of the orientation occurs and can be recorded as changes in reflectance, refractive index, and birefringence, and the phase is determined by using a laser beam that does not cause relaxation of molecular orientation due to stretch molding, which is smaller than the optical energy required for recording. Reproduction can be performed by reading out the light through the analyzer 10 and receiving it with the detector 11 using at least one of diffraction and interference effects.

FIG. 4 (1 ml) is a schematic diagram in which a pattern corresponding to information is drawn with a distribution binding method that shows the relaxation of molecular orientation that occurs during stretch molding (BL is an enlarged view. Molecules in the laser irradiated area 12) The orientation is relaxed.

FIG. 5 shows the output signal reproduced in accordance with the present invention. Although an embodiment of transmission type recording and reproduction has been described here, the present invention is not limited to this, and in order to perform reflection type recording and reproduction, the incidence of the polymer material film 13 can be adjusted as shown in FIG. A metal reflective film 14 may be provided on the surface opposite to the optical path. In addition, as another method for radially oriented molecular orientation from the center, resin may be injected radially from a gate located at the center using an injection molding method, and is not limited to the method described in this example. .

[Brief explanation of drawings]

＠Figure 1 shows an example of the configuration of a polymer film disk used to implement the information recording disk of the present invention.
Figure 2 is a diagram showing an example of the configuration of a jig for forming a polymer film disk that is radially stretched upward from the center and has molecular orientation according to the present invention. Figure W&4 is a schematic diagram of an information recording memory formed according to the present invention, Figure 5 is a diagram showing reproduced signals, and Figure 6 is an implementation of an information arrangement disk used for reflective recording and reproduction. Polymer film used for
FIG. 2 is a diagram showing an example of a configuration of a disk. 1.5...Polymer film disk 3.4...Same name circular ring 6...Weight 7...Laser beam 8-
...Polarizer 9,12...Laser light irradiation unit 10...Analyzer 11...Detector agent Patent attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 51 ! Figure 6

Claims (1)

[Claims] (Li) A polymer material disk stretched radially from the center is irradiated with laser light to change and record at least one optical property of 1 reflection, refraction, and birefringence. rear,
An information recording disk characterized in that reading is performed using a laser beam with an energy that is sufficiently higher than the energy required for recording. (2) The information recording brass disk according to claim 1, wherein the polymeric material disk extending radially from the center is made of thermoplastic resin. (3) Polymer material disks stretched radially from the center are polyethylene, polystyrene, polypropylene and other polyolefins, acrylic resins, polyvinyl chloride, polyvinyl acetate, polyvinyl ether, polyvinyl ketone, polyether, fluororesin, polycarbonate. , polyester, polyamide V, diene plastic, polyimide V. Polysulfone, polyphenylene sulfide V. An information recording disk containing a high acrylonitrile coelectric composite and its derivatives.