JPS59151345A - Information storage medium - Google Patents

Abstract

PURPOSE:To prevent the deformation and distortion of substrates by allowing spaces left among a reinforcing plate and the substrates to communicate with each other so as to make the temp., humidity and pressure of the air layer in one of the spaces equal to those of the air layer in the other of the spaces even when the temp. or humidity of only one of the substrates is increased. CONSTITUTION:Substrates 10, 10 are molded from plastics, glass or the like in about 1-2mm. thickness, and a metallic thin film of Te, Al or the like is formed on one side of each of the substrates as an information forming layer 11. A reinforcing plate 12 is molded from metal, glass, plastics, ceramics or the like in about 1-5mm. thickness, and the inside and outside diameters of the plate 12 are made almost equal to those of the substrates 10, 10. The substrates 10, 10 are placed on both sides of the plate 12 with inner and outer spacers 13, 14 in- between. The layers 11 face the plate 12, and spaces (a), (a) are left among the layers 11 and the plate 12. Plural through holes 15 are pierced in the plate 12 so as to allow the spaces (a), (a) to communicate with each other. The temp., humidity and pressure of the air layer in the upper space (a) are made equal to those of the air layer in the lower space (a) at all times.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention is used, for example, as an optical disc or a video disc. The present invention relates to an information storage medium from which information formed on an image can be read.

[Technical hell of inventions and their problems]

As this type of information storage medium, for example, one with a sandwich structure as shown in FIG. 1 is known. Name 1 in the figure is a reinforcing plate, and on both sides of this reinforcing plate 10, bases 3, 3 are provided facing each other with spacers 2, 2 in between. There is a space a between.

a are formed respectively. A light reflecting film 4 as an information forming layer is bonded to the inner surfaces of the substrates 3, 3, respectively.

However, in the past, when different temperatures or humidity were applied to the substrates 3°3 on both sides, the air layer B,
The temperature, temperature, and pressure in a are different on both sides, and the top and
Despite the lower symmetrical structure, as shown in FIG. 2, there was a problem in that the base plates 3, 3 were deformed or strained, causing them to break.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide an information storage medium whose base shape does not change due to the effects of temperature, humidity, or pressure. It is.

[Summary of the invention]

In the present invention, through holes are formed in the reinforcing plate, and spaces on both sides of the reinforcing plate are communicated with each other through the through holes.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on FIGS. 3 to 5. In the figure, 10.10 is the base, and these bases 10
．． 10 is made of plastic, glass, etc., with an outer diameter of approximately 300 m + III + 11 inner diameter of approximately 35 m, and a thickness of about 1 to 2 mm, with To on one side.

An information forming layer 11 made of a metal thin film such as At is formed. Further, J2 is a reinforcing plate, and this reinforcing plate 12 has approximately the same inner and outer diameters as the above-mentioned base plate 10.10, and a thickness of 1 to 5.
Light metal and glass.

Molded from plastic, ceramic, etc.

The bases 10, 10 are disposed on both sides of the reinforcing plate 12, spaced apart from each other and facing each other with inner and outer covers 13 and 14 interposed therebetween. Above base 10.1
The information forming layer 11 of No. 0 is opposed to the reinforcing plate 12, and spaces a and a are respectively formed between the two.

On the other hand, the reinforcing plate 12 is provided with a plurality of through holes 15, as shown in FIG. 5, and the spaces a, a are communicated with each other via these through holes 15.

However, if only one side of the information storage medium is exposed to temperature and humidity for a long period of time, such as during childcare, the reinforcing plate 1
2, the upper and lower spaces a, the temperature and humidity inside a,
The pressure changes and the base 10.10 tends to deform or strain, but at this time, air in the upper and lower spaces a, a flows through the through holes 15 of the reinforcing plate 12. Therefore, the temperature of the air layer in the upper and lower spaces a + a,
Humidity and pressure are the same, and the deformation and sagging of the base 10.10 will definitely be prevented. .

In the above embodiment, the outer spacer 14 is of a fixed type, but the outer spacer 14 is not limited to this.
As shown in the figure, the outer spacer 2 may be of a variable type. In this variable type, a through hole 15 is provided in the reinforcing plate 12 since it is necessary to further balance the vertical space ala. This is particularly effective.

〔Effect of the invention〕

As explained above, the present invention provides a through hole in the reinforcing plate and allows the spaces formed between the reinforcing plate and the base to communicate with each other. Even if temperature and humidity are applied to only one side of the board for a long time, the temperature, humidity, and pressure of the air layer in the space on both sides become equal, causing the board to deform or strain as in the past. The effect is that there is no risk.

[Brief explanation of the drawing]

3 is a plan view showing an information storage medium, FIG. 4 is a side sectional view thereof, FIG. 5 is a plan view showing a reinforcing plate, and FIG. 6 is a plan view showing an information storage medium. It is a side sectional view showing an example of this. 12... Reinforcement plate, 10.10... Base, 15...
Through hole. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] a reinforcing plate; a pair of bases which are provided on both sides of the reinforcing plate so that the surfaces thereof having the information forming layer are spaced apart and facing each other, each forming a space between the screen surfaces of the reinforcing plate; and the reinforcing plate. An information storage medium characterized in that it is provided with a through hole that is provided in a plate and allows the I- and both-arrangement spaces to communicate with each other.