JPH02152038A - Cartridge type information recording medium - Google Patents

Abstract

PURPOSE:To improve the effect of preventing intrusion of dust, etc., from the outside and flawing and to enhance the stability at the time of rotation by completely hermetically closing the information recording medium with a cartridge and sealing liquid into the cartridge. CONSTITUTION:The flexible information recording medium 1 having a hole part at the center is completely hermetically held closed by the cartridge 12 having a central hole part and a window part 14 which is the route for incident (reflected) light from an optical head 13. The liquid 18 is sealed into the cartridge 12. The recording medium 11 starts rotating by the same principle as the operating principle a motor when current is passed in an outside multiple electromagnet coil 16 as a magnet 15 inserted in the central hole part is rotatably disposed. The rotation is slowly accelerated by the viscosity of the liquid 18 sealed in the recording medium 11 when the recording medium starts rotating. The influence by a change in the external environment is substantially prevented by the effect of the viscosity of the liquid 18 and the stable rotation is obtd. when the constant rotation is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a flexible information recording medium comprising a recording layer that allows information to be read, written and/or erased by a laser. .

More specifically, 1 Unreleased II relates to a cartridge-type information recording medium in which the flexible information recording medium is accommodated in a cartridge.

[Technical Background of the Invention 5; (] In recent years, a disc-shaped information recording medium that uses a high energy density beam such as a laser beam has been developed and put into practical use. This information recording medium is called an optical disk. It can be used as a video disc, an audio disc, a large capacity still image file, and a large capacity computer disk memory.

The basic structure of an optical disk is a disk-shaped transparent substrate made of plastic or the like, and a recording layer provided thereon that allows information to be read, written, and/or erased. The surface of the substrate on which the recording layer is provided is coated with an undercoat layer or an intermediate layer made of a polymeric material in order to improve the flatness of the substrate, improve the adhesion with the recording layer, and improve the sensitivity of the optical disc. Sometimes it is provided.

In recent years, a disk-shaped information recording medium (optical disk) has been developed in which a FA-able resin film is used as a substrate and two recording layers are formed. An information recording medium using such a flexible resin film is also rotated at high speed to write, read, or erase information in the same way as conventional video discs, audio discs, etc.

In particular, when rotating such flexible information recording media during recording and playback, it is difficult to achieve rotational stability and they are easily damaged. Cartridge type information recording media have been proposed.

When a conventional cartridge-type information recording medium is attached to a drive motor, it takes the form as shown in FIG.

FIG. 6 is an example of a schematic cross-sectional view of a flexible information recording medium 6 having a hole in the center.
1. A cartridge 62 that houses an information recording medium and has a hole in the center, an optical head 63 for recording and reproducing that is placed close to the bottom of the cartridge 62, and a cartridge that serves as a path for incident (reflected) light from the optical head. It consists of a window 64 provided at the bottom, a metal hub 65 provided on the inner peripheral side of the center of the information recording medium, and a motor 67 having a spindle 69 inserted into the metal hub 65 to rotate the metal hub 65. Ru.

The L arrangement portion 64 is a radially long elliptical open portion, and since there is a gap between the protruding portion of the metal hub 65 and the cartridge, air flow occurs between the protruding portions of the metal hub 65 and the cartridge. Further, the information recording medium is driven by using a motor 67 shown in FIG. 6 and inserting a metal hub 65 into a spindle 69.

By adopting such a cartridge-type configuration, when a flexible information recording medium is rotated during recording and playback, the amount of gas flowing through it is reduced, making it easier to control the rotation, thereby improving rotational stability. It becomes easier to secure. Furthermore, since the information recording medium is protected, scratches and the like are less likely to occur. Furthermore, since it becomes difficult for dust and the like to enter from the outside, it is possible to prevent dust and the like from adhering to the surface.

However, in the cartridge, as described above, the window 64 provided at the bottom of the cartridge, which serves as a path for incident (reflected) light from the optical head, is a radially long elliptical open part, allowing air to circulate. . In addition, in order to apply rotational force to the information recording medium, it is necessary to connect the rotary drive motor to the metal hub of the information recording medium, and for this purpose a 110M (usually for protruding the metal hub) is provided in the cartridge. . As described above, since the cartridge is not in a sealed state, dust and the like may intrude from the outside and adhere to the information recording medium, and rotational stability may also deteriorate due to significant changes in the environment. Furthermore, when the information recording medium starts or stops rotating.

The information recording medium may come into contact with the bottom surface inside the cartridge, which may cause scratches.

Therefore, in such a cartridge type information recording medium,
It cannot be said that it is sufficient in terms of durability and rotational stability.

[Object of the Invention] The present invention provides a novel cartridge-type information recording medium in which a flexible information recording medium is housed in a cartridge, and which is completely free from harmful bacteria. The purpose is to

Another object of the present invention is to provide a novel cartridge-type information recording medium in which a liquid is sealed in the cartridge and the cartridge is in a sealed state.

Furthermore, the present invention provides a cartridge-type information recording medium that has excellent stability during rotation of a flexible information recording medium, particularly stability at low speeds, and has an improved effect of preventing intrusion of dust and the like from the outside and preventing scratches. The purpose is to provide

[Summary of the Invention] The present invention provides information writing, reading, and/or information writing on a disk-shaped substrate made of a flexible resin film using light in a cartridge having a window made of a transparent material at least in the light incident part. A cartridge-type information recording medium containing a flexible information recording medium provided with an erasable and glossy recording layer, the cartridge being completely sealed. A cartridge-type information recording medium, characterized in that a liquid is sealed in the cartridge of the cartridge-type information recording medium.

Preferred embodiments of the cartridge type information recording medium of the present invention are as follows.

1) The above cartridge type information recording medium characterized in that the transparent material of the window is non-stretched plastic.

2) The absolute viscosity of the above liquid is 1O-2 to 25°C.
The above-mentioned cartridge type information recording medium is characterized in that it is in the range of 10 cps.

3) The cartridge type information recording medium, wherein the liquid is at least one selected from the group consisting of silicone oil, lower alcohol, liquid paraffin, lower paraffin hydrocarbon, lower olefin hydrocarbon, and water.

4) The cartridge-type information recording medium, wherein the information recording medium has a magnet in its center.

[Effects of the Invention] Since the cartridge-type information recording medium of the present invention is completely sealed and isolated from the outside world, it has a remarkable effect of preventing dust from entering from the outside and preventing scratches. The stability during rotation is also good.

When liquid is sealed in the cartridge of the above-mentioned cartridge-type information recording medium, in addition to the IF to prevent dust from entering from the outside and the effect of preventing scratches, it also improves the stability of the information recording medium during rotation, especially at low speeds. stability has been significantly improved.

[Detailed description of Emission 1] The cartridge type information recording medium of the present invention basically has 5
The information recording medium has a structure in which a recording layer on at least one surface of a substrate is provided on which information can be recorded by light, and the information recording medium is housed in a cartridge. The substrate needs to be made of a flexible resin film.

The information recording medium of the present invention includes a completely sealed cartridge-type information recording medium in which a flexible information recording medium is housed in a cartridge as described above, and a completely sealed cartridge-type information recording medium in which a liquid is sealed in the cartridge. It is an information recording medium in the breath.

In a conventional cartridge-type information recording medium, the window provided at the bottom of the cartridge, which serves as a path for incident (reflected) light from an optical head, is an elliptical open portion that is long in the radial direction.
Further, since a gap is required in the cartridge to connect the rotary drive motor and the metal hub of the information recording medium, the cartridge is of a non-sealed type. Such cartridge-type information recording media are susceptible to adhesion due to intrusion of dust and other substances from the outside, as well as a decrease in rotational stability due to significant changes in the environment.
Furthermore, there were problems such as damage caused by the information recording medium coming into contact with the inner wall of the cartridge when starting or stopping rotation. We have discovered that it is possible to prevent this, and have investigated how to do so.

As a result, in order to seal the cartridge, instead of fitting a conventional metal hub into the rotating shaft (spindle) of the motor, a magnet is inserted into the center of the information storage medium, and a motor or electromagnetic coil with a magnet is placed on the outside. IJI has found that it is possible to rotate the information recording medium in a sealed state by arranging the information recording medium. Also,
The window, which is an open part, is made of a material that transmits light at the oscillation wavelength of the laser used for recording and reproduction, such as glass or unstretched plastic, so that recording and reproduction can be performed in the same way as in the open state. It turned out that it was possible to seal the cartridge. As a result, a sealed cartridge-type information recording medium can be obtained, and such an information recording medium has excellent stability during rotation, and the cartridge has an improved effect of preventing dust from entering from the outside and preventing scratches. It is a type information recording medium. The gas inside these densely packed cartridges is generally air, but oxygen,
Other gases such as nitrogen, R2 (dioxide), etc. may also be enclosed.

As a result of further research into improving the rotational stability of the cartridge-type information recording medium, it was found that the rotational stability could be significantly improved by sealing a liquid in the cartridge. That is, when the inside of the cartridge is liquid, the viscosity inside the cartridge is higher than when it is air. Therefore, when the information recording medium starts rotating, it takes a little longer to stabilize the rotation due to the viscosity of this liquid than in the case of air, but once the rotation is stabilized, the external environment The shadow caused by the change! In particular, even when rotating at low speed, the information recording medium floats smoothly and stable rotation is obtained.

The method of rotating the information recording medium of the present invention described above includes mounting a magnet at the center of the information recording medium, disposing a motor having a magnet outside, and rotating the S-5 or N-N of both magnets.
This method utilizes the repulsion of S-N and the attraction of S-N to rotate the information recording medium along with the rotation of the motor. Alternatively, an electromagnetic coil may be placed externally to rotate the information recording medium using the same operating principle as a motor. Furthermore, examples include a combination of a MiW wave motor and an ultrasonic oscillator, and a combination of an aluminum plate and a multipolar electromagnet.

The above-mentioned liquid may be any liquid as long as it does not attack the cartridge or information recording medium, etc., but a liquid whose absolute viscosity is in the range of 10-2 to 10 cps at 25°C has particularly good rotational stability at low speeds. It is preferable to improve the performance.

Next, the shapes of the cartridge and information recording medium of the cartridge-type information recording medium of the present invention, and the driving method thereof will be explained with reference to the attached FIGS. 1, 2, 3, 4, and 5. explain in detail.

FIG. 1 is an example of a cross-sectional schematic diagram of a cartridge-type information recording medium in which both the information recording medium of the present invention inserted into a drive coil and the cartridge have a hole in the center. a flexible information recording medium 11 having a hole in the center for accommodating the information recording medium; a cartridge 12 having a hole in the center for accommodating the information recording medium; A window 14 provided at the bottom of the cartridge serves as a path for incident (reflected) light. It is composed of a magnet 15 inserted into the center hole of the information recording medium and an external multipolar electromagnetic coil (driving coil) 16 placed close to the hole to rotate the magnet 15. . A liquid 18 is sealed inside the cartridge.

Instead of the multi-pole magnet coil 16, the magnet 15 can be rotated by rotating a motor having a magnet at the top, for example.

FIG. 2 is an example of a plan view of a cartridge-type information recording medium of the present invention inserted into the drive coil shown in FIG. 1. FIG. Information recording medium 1
1. A cartridge 12 having a hole in the center that accommodates an information recording medium, a window 14 provided at the bottom of the cartridge that serves as a path for incident (reflected) light from the optical head, and a cartridge that is inserted into the center hole of the information recording medium. The attached magnet 15 and this magnet 1
It is composed of a multipolar electromagnetic coil (driving coil) 16 arranged close to the hole in order to rotate the motor.

In FIGS. 1 and 2, when a current is applied to an external multi-polar electromagnetic coil (driving coil) 16, a magnet 15 inserted into the central hole of the information recording medium 11 becomes rotatable. Because of this arrangement, it starts rotating based on the same operating principle as a motor. This can be thought of as a motor consisting of a magnet and a multipolar electromagnetic coil. When the information recording medium starts to rotate, the viscosity of the liquid 18 accelerates the rotation more slowly than in the case of air, and reaches a certain rotation speed. - Once stabilized, due to the viscosity of the liquid, it is less susceptible to changes in the external environment and stable rotation can be obtained. Particularly in the case of a flexible information recording medium, even when rotating at a low speed, it floats smoothly and stable rotation can be obtained.

FIG. 3 is an example of a schematic cross-sectional view of a cartridge type information recording medium in which only the information recording medium of the present invention, which is mounted on the upper part of the drive motor, has a hole in the center.

FIG. 3 shows a flexible information recording medium 3 having a hole in the center.
1. A cartridge 32 that houses the information recording medium and has a shaft 39 in the center, an optical head 33 for recording and reproduction disposed close to the bottom thereof, and a bottom portion of the cartridge that serves as a path for incident (reflected) light from the optical head. A window 34 provided in the information recording medium, a magnet 35 inserted into the central hole of the information recording medium, and a magnet 36 at the top of a rotating shaft placed close to the concentric circle of the magnet 35 to rotate the magnet 35. motor with 3
Consists of 7. There is liquid 3 in the cartridge.
8 is included.

Instead of the motor 37 having the magnet 36 on top,
For example, a multipolar magnet coil can also be used.

In FIG. 3, as the motor 37 rotates, the magnet 36 at the top also rotates, and due to the attraction and repulsion between the magnet 36 and the magnet 35 provided in the central hole of the information recording medium 11, the information recording medium 31 is rotated. Rotates around 39. As mentioned in Figure 1, when the information recording medium starts rotating,
Due to the viscosity of the liquid 18, the rotation is accelerated more slowly than in the case of air, and a constant rotation speed is reached, resulting in stable rotation.

FIG. 4 is an example of a schematic cross-sectional view of a cartridge-type information recording medium without a hole in the center according to the present invention, which is mounted on the upper part of a drive motor.

FIG. 4 shows a flexible information recording medium 41 in which a magnet 45 having four parts in the center is inserted into a central hole. A cartridge 42 having protrusions 49a and 49b in the center that complement the recessed portion, a recording/reproducing light beam 43 disposed close to the bottom thereof, and serving as a path for incident (reflected) light from the optical head. A window 44 provided at the bottom of the cartridge, a magnet 45 inserted in the center of the information recording medium, and a magnet 46 at the top of a rotating shaft placed close to the concentric circle of the magnet to rotate the magnet 45. It is composed of a motor 47 having a. A liquid 48 is sealed within the cartridge.

1 instead of the motor 47 with the magnet 46 at the top
For example, a multipolar magnet coil can also be used.

The rotation in FIG. 4 is performed in the same manner as in FIG. 3 except that the axis of rotation is a protrusion.

FIG. 5 is an example of a schematic cross-sectional view of a cartridge-type information recording medium having no hole in the center according to the present invention, which is attached to the upper part of the driving coil.

FIG. 5 shows a magnet 55 having four parts in the center, and a flexible information recording medium 5 having the magnet 55 protruding from the center.
1. A cartridge 52 having protrusions 59a and 59b in the center that fit into the recesses, an optical head 53 for recording and reproducing disposed close to the cartridge 52, and a path for incident (reflected) light from the optical head. A window 54 provided at the bottom of the cartridge, and a magnet 5 provided at the center of the information recording medium.
5 and a multipolar electromagnetic coil (
It is composed of 4R (driving coil) 56. A liquid 58 is sealed within the cartridge.

Instead of the multi-pole magnet coil 56, the magnet 55 can be rotated by rotating a motor having a magnet at the top, for example.

It consists of a motor 57 having a magnet 46 at the top arranged to rotate this magnet 45. A liquid 58 is sealed within the cartridge.

Instead of the multi-polar magnetic coil 57 having the magnet 56 at the top, a motor, for example, can also be used.

The rotation in FIG. 5 is performed in the same way as in FIG.

Note that the above theory 11JJ describes some of the embodiments of the information recording medium of the present invention, and is not limited to the above.For example, the cartridge may not be filled with liquid, and the shape of the cartridge may be changed. A combination of four parts in the center and a convex part in the center of the information recording medium may be used.Furthermore, the shape of the cartridge and magnet may be other than those mentioned above as long as they can rotate.Also, the rotational force in each figure is It may be provided by a motor or an electromagnetic coil, and instead of a combination of a magnet and a motor, an ultrasonic motor and an ultrasonic oscillator may be combined, and the window and optical head may be provided. The position may be on the upper side of the information recording medium or on the lower side as described above.

As the resin film (resin substrate), recording layer, undercoat layer, etc. constituting the information recording medium of the present invention, any known materials can be used as desired, except for the characteristic structure of the final IJI. These will be briefly explained below. Materials for the disc-shaped resin film used in the present invention include acrylic resin, vinyl chloride resin, polystyrene resin, polyamide resin, polyolefin resin (e.g., polypropylene, polyethylene ), polycarbonate, polyester resins (eg, polyethylene terephthalate), and thermoplastic resins such as polyvinylidene chloride. Preferred are polyolefin resins, polycarbonate resins, and polyester resins.

The surface of the substrate on which the recording layer is provided has improved flatness,
An undercoat layer (and/or intermediate layer) may be provided for the purpose of improving adhesive strength and preventing deterioration of the recording layer.
and/or intermediate layer), for example, polymeric substances such as polymethyl methacrylate, acrylic acid-methacrylic acid copolymer, nitrocellulose, polyethylene, kt1 hydrogenated oligoolefin polypropylene, polycarbonate; UV-curable resins such as silane coupling agents; organic substances such as silane coupling agents; and inorganic substances such as inorganic oxides (ZnS, 5i02, A-203, etc.) and inorganic fluorides (MgF2). Using the above materials, for example, a layer made of UV curable resin may be provided as an undercoat layer, and an inorganic oxide layer may be further provided thereon as an intermediate layer, or the above materials may be combined to form a single layer. More than one layer can be provided as appropriate.

In the present invention, the recording layer formed on the information recording medium is of a type (write-once type or DRAW) that can be written only once by forming bits, etc.
After Write type), and a type that allows repeated recording and erasing by utilizing phase change or changes in the direction of magnetization in the case of magneto-optical recording (erasable f-type, that is, E-DRAW [ Erasable
e-Direct Read After Write
There is 5).

Examples of materials used for the DRAW type recording layer include T.
e, Zn, In, Sn, Zr, AU.

Metals such as Ti, Cu, Ge, Au, Pt: Bi, As,
Metalloids such as Sb; semiconductors such as Si; and alloys thereof or combinations thereof can be mentioned. Compounds such as sulfides, oxides, borides, silicon compounds, carbides, and nitrides of these metals, semimetals, or semiconductors; and mixtures of these compounds and metals can also be used in the recording layer. The recording layer may further contain various known metals, semimetals, or compounds thereof as recording layer materials.

Alternatively, the recording layer may be made of a dye such as a cyanine dye.

The recording layer may be a single layer or a multilayer, and the thickness of the recording layer is generally from 100 to 50 mm in terms of optical density required for optical information recording.
In the range of 500X, preferably 150~xoooz
is within the range of

Further, when the recording layer is of the E-DRAW type, a recording layer made of the following material, which is a substance capable of causing a phase change due to temperature, is provided. At this time, a light-absorbing substance may be dispersed and contained if necessary.

Examples of the phase change include a change between a crystalline state and an amorphous state, a change between a compatible state and a phase-separated state, and the like.

Examples of substances that can cause a state change between a crystalline state and an amorphous state include 5b2Se, Te01 (0<x<2),
S b+oo-x Tex (40<x<60)
, As-Te-Ge-based, 5n-Te-3e-based, and other metal and semimetal compounds. For example, 5b2Se is relatively in a crystalline state at room temperature and has high reflectance and low transmittance, but becomes amorphous at high temperatures, resulting in lower reflectance and higher transmittance. Conversely, Tea is in an amorphous state at room temperature and becomes crystalline at high temperatures. In addition, known metals, semimetals, and compounds thereof that undergo a state change between a crystalline state and an amorphous state can be used.

Furthermore, a typical example of a substance that can undergo a state change between a compatible state and a phase-separated state is a polymer blend consisting of a mixture of two or more types of polymers. However, a combination of a polymer and a monomer may also show similar behavior, and such compositions may also result in the final IJ
In No. 1, it is included in the polymer blend.

As the material used for the recording layer (perpendicular magnetization film) of magneto-optical recording, GdFeCo, TbFeCo, etc. can be used.

If the recording layer is made of a metal or the like, or if the substance that can cause a phase change is an inorganic substance such as the metal,
It can be formed on the substrate by vapor deposition, sputtering, or ion blasting on the substrate surface. The recording layer may be a single layer or a hair scrap, but its layer thickness is generally 100 to 15 mm in terms of the optical density required for optical information recording.
It is in the range of 00 or more, preferably in the range of 150 to too0 or more.

In addition, when the recording layer is an organic compound such as a dye or the above-mentioned polymer blend, a coating solution is prepared by dissolving the substance and, if necessary, a light-absorbing substance in an appropriate solvent, and this coating solution is coated with a spin code method. It can be formed on a substrate by applying it to the surface of the substrate by a coating method such as a roll coating method and then drying it.

It is preferable that a tracking guide layer is provided on the recording layer, especially in order to improve tracking performance during recording. A photographic halogenated emulsion is used as a material for forming the tracking guide layer. Servo marks and the like are formed on the tracking guide layer to perform tracking control.

Further, if desired, an adhesion layer made of a silane coupling agent or the like may be provided in order to improve the adhesion between the recording layer and the protective layer.

ZnS, 5i02, MgF2.5n02'8 is placed on the tracking guide layer or between the recording layer and the tracking guide layer for the purpose of physically and chemically protecting the recording layer.
cy) A protective layer made of an inorganic material or an organic material such as a UV curable resin may be provided.

In addition, silicon dioxide, tin oxide, magnesium fluoride, etc. may be added to the substrate side of the recording layer, on both sides of the recording layer, or on the surface opposite to the substrate, in order to improve the scratch resistance, moisture resistance, and prevention of deformation and deterioration of the recording layer. A thin film made of an inorganic substance such as zinc sulfide or the like may also be provided.

In addition, on the surface of the recording layer on the substrate side or on the opposite side to the substrate, a light beam made of metals such as An, Cr, and Ni is coated for the purpose of improving the S/N ratio during information reproduction and improving the sensitivity during recording. A reflective layer may also be provided.

The material for the cartridge used in the present invention is not particularly limited, but moldable resins are preferred because they are advantageous in manufacturing. Examples of such materials include acrylic resins, vinyl chloride resins, and polystyrene resins. based resin,
Examples include thermoplastic resins such as polyamide resins, polyolefin resins, polycarbonates, polyester resins, and polyvinylidene chloride.

The window material provided in the cartridge is preferably a material that transmits the oscillation wavelength of the laser used for recording and reproduction, etc. For example, glass; and unstretched films such as polycarbonate, polymethyl methacrylate, polyolefin, and triacetyl cellulose. Or a board.

Examples of the liquid sealed in the cartridge include silicone oil, lower alcohol, liquid paraffin, lower paraffin hydrocarbon, lower olefin hydrocarbon, and wood.

Next, Examples and Comparative Examples of the present invention will be described. However, the following items do not limit the present invention.

[Example 11 On a strip-shaped (web-shaped) polyethylene terephthalate film (75Q9XH, manufactured by Bunshishi ■) with a thickness of 7571 m,
As an undercoat layer, UV curing resin (307
0: manufactured by Three Pond Co., Ltd.) was applied using a roll. On top of that, a layer of zinc sulfide is applied to a layer thickness of 7 mm using electron beam evaporation.
00X. Furthermore, a reversible non-solid phase change was caused by laser irradiation, and an S b 52T e as layer having a thickness of 700 mm was formed as an erasable and rewritable recording layer by a binary simultaneous vapor deposition method. Then, a layer of zinc sulfide was formed on this recording layer by electron beam evaporation to a thickness of 1500 mm.

Next, as a waterproof layer, a UV curing resin (3070: manufactured by Three Pond Co., Ltd.) was coated with acrylic acid to a thickness of 0.5 gm.
Using a roll, apply a photographic halogenated emulsion (mainly containing gelatin and silver bromide) to a dry layer thickness of 17 mm. Then, a tracking guide layer having servo marks was formed by performing pattern exposure, development and fixing for 9trjL. Furthermore, a UV curable resin (3070: manufactured by Three Pond Co., Ltd.) was applied as a protective layer onto the tracking guide layer to a thickness of 0.5 gm using a roll.

The information recording disk film wound up into a roll obtained above was punched out into a disk shape having an outer diameter of 586 mm and an inner diameter of 25 mm to produce an information recording medium.

A method for manufacturing a cartridge type information recording medium will be described below with reference to FIG. 4.

A ceramic magnet 45 having four parts at the center of the front and back surfaces was inserted into the inner peripheral side of the central hole of the obtained information recording medium. This information recording medium is connected to a window portion 4 made of non-stretched polycarbonate that serves as a path for incident (reflected) light from the optical head.
4 is provided at the bottom of the ABS cartridge 42 (a rectangular parallelepiped whose knee side is a square plane with an outer dimension of 94 mm and an inner dimension of 90 mm, and a height of an outer dimension of 3 mm and an inner dimension of 0.27 mm). The ceramic protrusions 49a and 49b provided inside the center of the cartridge were arranged and assembled so that the four parts of the ceramic magnet 45 were fitted into each other. Then, methanol was sealed in the cartridge to produce a cartridge type information recording medium.

The information recording medium is driven by a motor 47 shown in FIG.
The test was carried out by passing a current through the electromagnetic coil without using it.

[Comparative Example 1] As shown in FIG. 6, a metal hub 65 was inserted into the hole of the same information recording medium as in Example 1, and this information recording medium was
The dimensions were the same as in Example 1, but it was assembled into a conventional non-sealed cartridge 62.

The information recording medium was driven by using a motor 67 shown in FIG. 6 and inserting a metal hub 65 into a spindle 69.

[Method for evaluating information recording media] l) Scratch susceptibility of the disc. 25m
The information recording medium was vibrated in the lateral direction as shown in FIGS. This was done on 50 information recording media, and the number of information recording media with scratches was counted.

2) Number of defects on the disk due to external dust The number of defects on the medium was measured as follows before and after the disk was left in an environment where 100,000 particles of Kanto loam layer powder were present per sentence.

The disk was rotated at 90 rpm, the optical head was focused on the disk, and the portions where the amount of reflected light decreased by 20% or more were counted for each lOO track.

3) Low-speed stability of the disk While changing the number of rotations of the disk, the vertical movement of the disk was measured using an optical distance sensor.

The above test results 1) and 2) are shown in Table 1, and 3) is shown in FIG.

Table 1 Ease of scratching of disks due to external dust Number of defects on disks (number of scratched disks) Before deformation After release 21 Example 1 0 disks 10 f 110 pieces Comparative example 1 1
5 pieces 9 pieces 270 pieces Figure 7 shows the relationship between Example 1 (dotted line) and Comparative Example 1 (solid line), with the rotational speed of the disk on the horizontal axis and the rotational movement of the disk at that rotational speed on the vertical axis. It shows the relationship between

From Table 1, the information recording medium according to the present invention is superior in both the ease with which the disk is scratched and the ease with which external dust adheres.
This shows the effect of the closed cartridge type of the present invention.

Furthermore, FIG. 7 shows the stability of the information recording medium of the present invention at low speed rotation, and compared to Example 14, vertical fluctuations are small even at low speeds of 11,000 rpm or less, but in the case of Comparative Example 1, the stability is lower than 11,000 rpm. -L fluctuations are large at low speeds, especially at 400 rpm or less.

From the above examples, it is clear that the information recording medium of the present invention has excellent durability and rotational stability.

[Brief explanation of the drawing]

FIG. 1 is an example of a cross-sectional schematic diagram of a cartridge-type information recording medium in which the information recording medium of the present invention inserted into a drive coil and the cartridge both have a hole in the center. FIG. 3 is an example of a plan view of the cartridge-type information recording medium of the present invention inserted into the drive coil shown in the figure, in which only the information recording medium of the present invention attached to the upper part of the drive motor is centered. 1 is an example of a schematic cross-sectional view of a cartridge-type information recording medium having a hole. FIG. 4 is an example of a schematic cross-sectional view of a cartridge-type information recording medium having no hole in the center according to the present invention, which is mounted on the upper part of the drive motor. FIG. 5 is an example of a schematic cross-sectional view of a cartridge-type information recording medium having no hole in the center according to the present invention, which is attached to the upper part of the drive coil. FIG. 6 is an example of a schematic cross-sectional view of a conventional cartridge-type information recording medium inserted into a drive motor. FIG. 7 is a graph showing the relationship between the number of rotations of the disk and the vertical movement of the disk at that number of rotations. Magnet (motor 2): 36, 46.66 motor:
37, 47.67 Flexible information recording medium: 11° 51° Cartridge: 12, 32.4 Optical held: 13, 33, 43° Window: 14, 34, 44.54 Magnet (for information recording medium) center) 31.41°1.52,62 53.63. 64: 15,35°, 55, 65 Patent applicant Fuji Photo Film Co., Ltd. Agent Patent attorney Yasushi Yanagawa TL magnet coil: 16,56

Claims (1)

[Claims] 1. Information can be written, read, and/or erased by light on a disc-shaped substrate made of a flexible resin film in a cartridge having a window made of a transparent material at least in the light incident part. 1. A cartridge-type information recording medium containing a flexible information recording medium provided with a recording layer, the cartridge being completely sealed. 2. The cartridge type information recording medium according to claim 1, wherein a liquid is sealed in the cartridge.