JPH02139731A - Optical recording medium - Google Patents

Abstract

PURPOSE:To prevent deterioration of C/N even after repetitive recording/erasing of informations, to obtain stable tape traveling and to improve durability of the optical recording medium by providing a light-transmitting lubricant layer on the tape-type optical recording medium on the side to be irradiated with light. CONSTITUTION:The medium is composed of a 10-mum thick polyethylene base film, a protective layer 4 deposited thereon, and further successively a 600-Angstrom thick recording layer 5 comprising a phase shift type recording medium material such as AsTeGe alloy, a protective layer 4, and 100-Angstrom thick light-transmitting lubricating layer 3. Since the light-transmitting lubricant layer 3 is provided on the side irradiated with light of the tape-type recording medium, friction during tape traveling is reduced, which enables stable traveling of such long tapes and improves durability of tapes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording system that enables high-density recording, and particularly to a tape-shaped optical recording medium having a large capacity.

[Prior Art] Generally known types of optical recording systems include read-only type, write-once type, and rewritable type. The read-only type is widely used as a compact disc (CD) or laser vision (LV), the write-once type is widely used as a disk for computer data files, and the rewritable type is also used in some devices such as magneto-optical disks. has been done. Research is also being conducted on rewritable optical discs that utilize phase changes in the material of the recording medium, and development is progressing toward practical use.

The characteristics of the optical disk system are that the areal recording density is more than a little higher than that of magnetic recording, capable of 10"bits/crn", and that it is durable because recording and reproduction can be performed without contacting the recording layer of the recording medium. The point is that the properties are very good.

By the way, the development of higher image quality is currently progressing.
Media such as high-definition TVs are close to being put into practical use.

Furthermore, systems are being developed to faithfully record and reproduce the high quality video signals.

However, in systems using conventional magnetic recording, no further improvement in areal density recording can be expected technically, and recording high-quality video as is requires a large amount of tape.

Furthermore, even if a rewritable optical disk system with a partially high areal recording density is applied to this system, since the recording medium is disk-shaped, the recording capacity will be insufficient and the transfer rate will be low.

To solve this problem, an optical recording tape system was developed that records and reproduces information using a rewritable recording medium in the form of a tape. FIG. 3 is a schematic cross-sectional view of a conventional optical recording tape. In FIG. 3, 6 is a base film made of polyethylene, and on the base film 6 are a heat-resistant protective layer 4, a recording layer 5 made of a material for a phase change type recording medium such as an AsTeGe alloy, and a heat-resistant protective layer 4. They are stacked in order.

Further, 1 in FIG. 3 indicates a laser beam incident on these layers, and the laser beam 1 is focused by an objective lens 2 and irradiated onto a predetermined area on the recording layer 5.

An information recording/reproducing system using an optical recording tape with such a structure first involves winding the optical recording tape around a rotating drum incorporating an optical head, then running the tape at a constant speed, and optically recording the tape by helical scanning. Information is recorded and reproduced diagonally onto the tape, which dramatically increases recording capacity.

[Problem to be solved by the invention]

When using the optical recording tape system as described above, it is necessary to run a long tape at a constant speed with high precision. However, with an optical recording tape having a conventional structure as shown in FIG. 3, tension fluctuations are likely to occur in the system, resulting in guide deviation or tape squeal, making stable running difficult. Furthermore, since the tape-shaped recording medium comes into contact with the rotating drum, the non-contact characteristic of conventional optical discs for recording and reproduction is lost, so the durability of the tape has been a problem.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an optical recording medium that enables stable tape running when recording and reproducing information on a tape-shaped recording medium, and that also has improved durability. With the goal.

[Means to solve the problem]

Such an optical recording medium of the present invention is a tape-shaped optical recording medium in which information is recorded and reproduced by irradiation with light, and a light-transmissive lubricant layer is provided on the side of the optical recording medium that is irradiated with the light. It is characterized by having the following.

[Effect]

In the optical recording medium of the present invention, since a light-transmissive lubricant layer is provided on the side of the tape-shaped optical recording medium that is irradiated with light, friction during tape running is reduced and long tapes can be used. The tape can be run stably and the durability of the tape can be improved.

[Examples] Hereinafter, the present invention will be specifically explained based on drawings showing examples thereof. FIG. 1 is a cross-sectional structural diagram schematically showing such an optical recording medium according to the present invention, and in the figure, 7 indicates a base film made of polyethylene and having a thickness of 10 μm. A protective layer 4 is laminated on the base film 1, and the upper surface is made of AsTe.
6 thickness of phase change recording medium material such as Ge-based alloy.
A recording layer 5 having a thickness of 100 mm, a protective layer 4, and a lubricating layer 3 having a light transmittance of 100 mm thick are laminated in this order.

Note that the light transmittance of the lubricant layer 3 may be of a level that does not interfere with recording and reproducing information.

Further, in FIG. 1, 1 indicates a laser beam incident on these layers, and the laser beam 1 is focused by an objective lens 2 and irradiated onto a predetermined position on the recording layer 5 from the light-transmitting lubricant layer 3 side. .

The material of the protective layers 4, 4 is Z n S + S
t02.

Examples include inorganic materials such as A1zOi+ ZrO
A terminal heterocyclic-containing perfluoropolyether with a specific gravity (20°C) of 1 and 702 (Fombl manufactured by Mondigison)
inAM2001).

The optical recording medium having the structure described above is obtained by laminating the protective N4, the recording layer 5, and the protective layer 4 in this order on the upper surface of the base film 1 using a vacuum deposition method, and further applying the lubricating layer 3 on the upper surface. can get.

FIG. 2 is a cross-sectional structural diagram showing another embodiment of the optical recording medium according to the present invention, and in the figure, numeral 4 indicates a protective layer made of an inorganic material. On the upper surface of the protective layer 4 are a recording layer 5 with a thickness of 600 mm made of a phase change type recording material such as an AsTeGe alloy, and a protective layer 4.
, a base film 1 made of polyethylene with a thickness of 10 μm is laminated in this order, and a base film 1 with a thickness of 10 μm is laminated in this order.
0 optically transparent lubricant layers 3 are laminated. In addition, 1 in FIG. 2 is a laser beam that is incident on these layers, and the laser beam 1 is focused by an objective lens 2 and passes through a lubricating layer 3.
A predetermined position on the recording layer 5 is irradiated from the side of the base film 6 having the upper surface thereof.

The materials for the protective layers 4, 4 are ZnS and StO□.

Inorganic materials such as AlzOz+Zr0z may be mentioned, and the material of the lubricating layer 3 may include the above-mentioned Fomblin.
AM2001 (manufactured by Montegisson) is mentioned. In an optical recording medium having such a structure, a lubricating layer 3 is coated on the upper surface of a base film 6, and a protective layer 4, a recording layer 5, and a protective layer 4 are placed on the side facing the lubricating layer 3, sandwiching the base film 6. It is obtained by sequentially stacking layers using a vacuum evaporation method.

As shown in FIGS. 1 and 2, the transparent lubricant layer 3 is provided on the side of the optical recording medium that is irradiated with the laser beam 1.

Next, the results of a comparison between this example and the conventional example will be described in detail. As a conventional example, a conventional optical recording medium having a structure in which a protective layer 4, a recording layer 5, and a protective layer 4 were laminated in this order on the upper surface of a base film 1 as shown in FIG. 3 was formed.

Here, the material of the optical recording medium of the conventional example was the same as that of the above-mentioned present example, and the optical recording medium was tape-shaped in both this example and the conventional example.

First, the running durability and friction coefficient of the present example and the conventional example were measured, and the results are shown in Table 1. Running durability is measured by repeatedly running a tape-shaped optical recording medium with an optical recording tape system and determining the number of times it can run without running problems such as broken edges or stopping running.The coefficient of friction is S[l5304 It was determined from the frictional resistance when a tape-shaped optical recording medium was wound 180 degrees around a rotating ring with a diameter of 40 mm and a load of 20 g was applied.

As is clear from Table 1, the running durability of this example is more than 20 times that of the conventional example, and the friction coefficient is also lower than that of the conventional example. By providing the lubricating layer 3, the friction during tape running is reduced. It shows what you did.

Next, each of the present example and the conventional example was run using an optical recording tape system, and the C/N ratio was measured during the first run and after 10 repeated runs. The results obtained are shown in Table 2.

Note that the recording frequency in C/N ratio measurement is 5 MHz.

Table 2 As is clear from Table 2, the C/N ratio at the first run is the same as 55 dB in both this example and the conventional example, but the C/N ratio after 10 repeated runs is 55 dB in this example. While there was almost no difference after driving, the conventional example had a decrease of 10 dB. From this, the optical recording medium of this example has almost no noise even when information is repeatedly recorded and erased.
It can be seen that good recording and playback is possible at all times.

In this example, the optically transparent lubricant layer 3 is made of a perfluoropolyether containing a terminal heterocycle (Fo
For example, perfluoropolyether (Fomblin ZO3, Z15 or Z25 manufactured by Montegisson) was used.
), perfluoropolyether with terminal ethylol group (Fomblin ZDOL-2000 or ZDOL-4000, manufactured by Montegisson), perfluoropolyether with terminal carboxylmethyl group (Fomblin, manufactured by Montegisson)
blin ZDIEAL-2000 or ZDEAL-4
000), perfluorooctyl-di-2-ethylaminoamide (υ-325, manufactured by Ipposha Yushi Kogyo Co., Ltd.),
Methyl acrylate perfluorooctyl acrylate copolymer (manufactured by Ichisha Yushi Kogyo Co., Ltd. tlR-33
0), octadecyltriethoxysilane (TSL-8186 manufactured by Toshiba Silicone), methyltrimethoxysilane (TSL-8113 manufactured by Toshiba Silicone), hexamethyldisilazane (TSL-8 manufactured by Toshiba Silicone)
802) may be used instead.

〔effect〕

As detailed above, in the optical recording medium of the present invention, a light-transmitting lubricant layer is provided on the side of the tape-shaped optical recording medium that is irradiated with light, so even if information is repeatedly recorded and erased, C/N ratio does not decrease and noise does not increase. Further, the present invention has excellent effects such as stable tape running and improved durability of the optical recording medium.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional structural diagram schematically showing an optical recording medium according to the present invention, FIG. 2 is a cross-sectional structural diagram showing another embodiment of the optical recording medium according to the present invention, and FIG. 3 is a conventional optical recording medium. FIG. 3 is a cross-sectional structure diagram of the tape. l...Laser beam 2...Objective lens 3...Light-transmitting lubricant layer 4...Protective layer 5...Recording layer 6...
・Base film patent Applicant Sanyo Electric Co., Ltd. Agent Patent attorney Noboru Kono Diagram procedural amendment (voluntary) 1゜2゜3゜Indication of the case 1986 Patent application No. 293046 Name of the invention Optical recording medium Relationship with the case of the person making the amendment Patent Applicant Address: 2-18 Keihan Hondori, Moriguchi City Contact: Tokyo 837-6239 Patent Center Representative Yamazaki 4, Target of amendment/Details of the invention in the specification "Explanation" column. 5. Contents of amendment (1) ``1 specified -'' stated in page 3, line 13 of the specification is changed to 1.
Correct the position. (2) "1 thickness t 100 people" stated in page 5, line 19 and page 7, line 3 of the specification is corrected to "1 thickness 100 people."

Claims (1)

[Claims] 1. In a tape-shaped optical recording medium that records and reproduces information by irradiating light, a light-transmissive lubricant layer is provided on the side of the optical recording medium that is irradiated with the light. An optical recording medium characterized by: