JPS5914152A - Information storage medium - Google Patents

Abstract

PURPOSE:To prevent completely the deterioration of an information producing film which is due to moisture, by having linkage via an electric path between a space formed between two substrates and the outside and providing a moistureproof filter at the electric path. CONSTITUTION:An information producing film 2 is formed on a single side of a substrate 1, and a substrate 6 is adhered to the surface of the film 2 via ring- shaped inside and outside spacers 3 and 4. Thus a space part 5 is formed. A vent hole 7 is drilled to the substrate 6 to reach the part 5 via a cut part 3a formed at the outer fringe part of the spacer 3. At the same time, a cap 8 is attached at the outside of the substrate 6 and at the position corresponding to the part 3a. The part 5 is connected to the outside via an electric path consisting of the part 3a, the hole 7, a depressed part 8a and a through hole 9 of the cap 8. An absorbing filter 11 is put into the part 8a, and a dustproof filter 12 is fitted to the hole 7. Thus the intrusion of moisture or dust into the part 5 are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an information storage medium that can be applied, for example, as an original disc, a video disc, and a compact disc for DAD.

[Technical background of the invention and its problems]

In recent years, original disk memory has become capable of high-density recording, non-contact recording and playback, high-speed random access, excellent long-term storage, easy recording method, additional recording possible, and Due to its low cost and other features, it is widely used for recording/playback or for playback only. Applications for playback-only types include home video discs, commercial video discs, and audio P.
There are commercial discs, etc., and recording/reproducing type applications include document files, video files, computer general-purpose memory, etc.

On the other hand, as one of the information storage media used in this type of information processing device, a recording film or a light reflecting film is formed on one side.
There is an air-sander-chip type in which two plastic substrates are laminated in such a way that the information forming films are located inside each other and a space is formed between the mutually facing surfaces of each information forming film. exist.

However, since it is necessary to irradiate the information forming film (and the laser source) through the substrate, the substrate cannot be made very thick, and the elasticity of the plastic substrate itself is not very strong. Air or inert gas has the problem of bending or waviness due to changes in the external environment such as expansion and contraction due to temperature changes or pressure differences with the outside air.If these bends or waviness are large, information processing is difficult. Inability to eliminate defocus in the device not only leads to a decline in information processing accuracy, but also serious fS problems such as the information storage medium and optical head coming into contact with each other due to severe lifting, making information processing impossible. be.

Therefore, a conventional device has been developed in which a vent hole for air circulation is formed in the substrate to eliminate the pressure difference between the internal space and the outside of the substrate, and the vent hole is covered with a dustproof filter.

However, although this can prevent the bending and waviness of the board caused by the pressure difference between the internal space and the outside of the board, the ventilation hole is simply covered with a dustproof filter to prevent dirt and dust. There is a problem that moisture inside the space may enter the space.When moisture enters the space, deterioration such as oxidation and wet corrosion of the information forming film formed from metals or semimetals is accelerated, and the information forming film is damaged. There was a problem in that one of the purposes of the existence of this type of information storage medium, which is long-term storage of information, was lost.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to prevent bending and waviness of the substrate caused by the pressure difference between the internal space and the outside of the substrate, and to prevent early deterioration of the information forming film due to moisture intrusion. It is an object of the present invention to provide a highly reliable information storage medium that can reliably prevent such problems and perform stable information processing over a long period of time.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention communicates the space formed between two substrates with the outside via a ventilation system path, and eliminates the pressure difference between the two. A moisture-proof filter is provided to prevent moisture from entering the space, thereby preventing early deterioration of the information forming film due to moisture.

[Embodiments of the invention]

The present invention will be described below with reference to an embodiment shown in FIGS. 1 and 2. In the figure, reference numeral 1 denotes a first substrate made of a plastic plate having an outer diameter of about 300 mm, an inner diameter of about 35 mm, and a thickness of about 1 to 2 layers. On one side of this first substrate I, there is an information forming film 2 made of a recording film or a light reflecting film T.
eB1. It is formed as a ring by depositing a chalcogenide such as Se, a metalloid, or a metal.

On the side of the first substrate 1 on which the information forming film is formed, inner spacers 3 of a ring shape with a thickness of about 1 to 4 mm are arranged concentrically.
A second substrate 6 is superimposed and bonded so that a space 5 is formed between the information forming film 2 and the surface of the information forming film 2 via the outer spacer 4.

The second substrate 6 has the same inner and outer diameters as the first substrate 1, but has greater rigidity than the first substrate 1.
This serves as a reinforcing plate to prevent the board 1 from bending or waviness. The second substrate 6 as a reinforcing plate is made of a metal plate or a plastic plate. In the case of stainless steel, the number is about 1.5 to 5.

Further, a ventilation hole 7 is formed in the second substrate 6. This ventilation hole 7 communicates with the space 5 via a notch 3a formed in the outer peripheral edge of the inner spacer 3.

Further, at a position corresponding to the outer side of the second substrate 6 and the inner spacer 3, a hole is provided with the concave portion 8a facing the second substrate 6 side, and a well-known fixing means (not shown) such as screwing is provided. A cap 8 is removably attached. The opening end of the ventilation hole 7 faces the inside of the recess 8a, and the space 5 is divided into the notch Ja, the ventilation hole 7, and the recess 8a.
, and a ventilation system path IO consisting of a through hole 9 formed in the cap 8 (through which the substrate 1 .
It is made so that no pressure difference occurs between the space 5, which is formed between 6 and 5, and the outside.

Further, the midway portion of the ventilation system path 10 that communicates the space 5 with the outside, that is, the concave portion 8a of the cap 8, is filled with a hygroscopic filter 1 made of a hygroscopic substance such as silica gel (trade name). The ventilation hole 7i is filled with a dust filter 12 to prevent dirt and dust from entering.

Therefore, since the space 5 formed between the substrates 1 and 6 communicates with the outside through the ventilation system path 10, there is no pressure difference between the space and the outside, which is caused by the pressure difference. Bending and waviness of the substrates 1 and 6 can be reliably prevented. In addition, moisture that has entered the ventilation system path 10 is absorbed by the hygroscopic filter 11 packed in the middle of the ventilation path 10 and easily enters the space 5, thereby preventing the promotion of oxidation of the information forming film 2 due to moisture. That will happen. Fine dirt and dust that should pass through the hygroscopic filter 11 is captured by the dustproof filter 12 provided in the latter stage, and is transferred to the space 5.
This prevents the intrusion into the information forming film 2, thereby reliably preventing any adverse effects caused by the adhesion of these onto the information forming film 2.

Further, the cap 8 of the hygroscopic filter II is removed and replaced as appropriate.

In the above-described embodiment, the filters 11 and 12 are used to prevent moisture, dirt, and dust from entering the space 5. The same purpose can also be achieved by partitioning the space with a moisture-proof elastic film I3 made of a moisture-proof material such as polyethylene or polystyrene film.

In other words, the expansion and contraction of the air in the space 5 may be absorbed by a modified version of the moisture-proof stretchable membrane 13, thereby eliminating the pressure difference between the inside and outside of the space 5.

Further, the elastic film 13 may be used to prevent moisture, dirt, and debris from entering the space 5.

In the explanation of FIG. 3, the same parts as those of the above-mentioned embodiment are given the same reference numerals and the explanation will be omitted.

〔Effect of the invention〕

As explained below, the present invention communicates the space formed between two substrates with the outside through a ventilation system path, eliminates the pressure difference between the two, and creates a space in the ventilation system path. A moisture-proof filter is installed to prevent moisture from entering the
It is possible to reliably prevent the bending and waviness of the substrate caused by the pressure difference between the internal space and the outside of the substrate, as well as the early deterioration of the information forming film due to the infiltration of moisture, resulting in stable information processing over a long period of time. .

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway schematic plan view of an embodiment of the present invention, FIG. 2 is a schematic vertical side view, and FIG. 3 is a schematic longitudinal side view of another embodiment of the present invention. It is. DESCRIPTION OF SYMBOLS 1... First substrate, 2... Information forming film consisting of a recording film or a light reflection film, 3... Inner spacer, 4...
outer spacer, 5... space section, 6... second substrate,
7... Ventilation hole, 10... Ventilation system path, 11... Hygroscopic filter. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) A first substrate having an information forming film formed on one side thereof is superposed and integrated with the first substrate so that a space is formed between the surface of the information forming film of the first substrate. In the information storage medium ζ comprising a second substrate ζ, a ventilation path is formed to communicate the space with the outside
An information storage medium characterized by being provided with a moisture-proof filter that prevents moisture from entering the space from the outside of the ventilation system. (2) The information storage medium according to claim 1, which uses a moisture-proof elastic film as a moisture-proof filter. (3) The information storage medium according to claim 1, which uses a moisture-absorbing filter made of a hygroscopic substance as the moisture-proof filter.