JPH01211287A - Manufacture of center positioning member for information recording medium - Google Patents

Abstract

PURPOSE:To easily secure the adhesive strength between the title member and a base, to lighten the member, and to suit the member for mass production by composing a hub of an inorganic substance thin plate and an organic substance base material and shaving one surface of the member at a side to be fixed to a substrate after forming the hub. CONSTITUTION:An imbedding plate 5 is manufactured by pressing using stainless copper, the plate 5 is loaded by inserting the center hole of the plate 5 into the center protruding portion of a lower die 36, and after that, an upper die 7 is made to adhere to the lower die 36. A resin 11 passes through a nozzle 10, fills a runner 12, passes through a gate 13, and fills the space (a hub shaped space) between the upper die 7 and the lower die 36. After the resin 11 fills the space between the dies 7 and 36, the resin 11 is cooled and solidified. Next, the resin 11 is removed with the tip part of the nozzle 10, an ejector pin 8 is raised, and an article, in which the imbedding plate 5 and a resin filling part 6 are unified, is taken out from the die 36. Next, the side of the article to be fixed to the substrate is shaved by making the center hole of a hub 2 into its reference.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a method that causes physical or chemical changes when irradiated with light to perform any or all of the processes such as recording, reproducing, and erasing information. The present invention relates to a method of manufacturing a center positioning member for an information recording medium.

(Prior art) In recent years, in the field of information recording, in addition to conventional magnetic recording, optical recording, in which information is recorded by causing a physical or chemical change by irradiating light, has been developed as a non-volatile recording. It is being researched and put into practical use. For example, for playback-only consumer use, home video discs, audio PCs, etc.
There are M disks, etc.

The advantages of this optical recording over other recording methods, such as magnetic recording, are: ◎ Since the distance between recording tracks can be as close as 1 to 2 square meters, high-density recording is possible.

◎ Easy maintenance and handling due to non-contact recording and playback.

◎ Low cost per l bit.

◎ Most recording media are disk-type, and access is much faster than other high-capacity recordings such as magnetic tape.

Therefore, it can be said that this is the preferred recording method in the future industrial society that will need to record large amounts of information.

This information recording medium has groups or pits on the substrate as a means for tracking the track, and therefore organic materials that are easy to mold are often used as the substrate material, but this material is resistant to the rotating shaft. Since the abrasion resistance is poor, it is necessary to provide a central positioning member (hereinafter abbreviated as a hub) 32 made of aluminum at the center of the substrate 1, as shown in FIG. FIG. 2 is a main cross-sectional view when a conventional information recording medium is installed in a recording/reproducing apparatus.
2 is magnetically attracted to support the rotating shaft 3 or the substrate l.

Therefore, the hub 32 needs to be made of a magnetic material. The manner in which the information recording medium is attached and detached is not directly related to the present invention and will therefore be omitted. And so far, regarding the hub, we have
There are proposals such as 3242 and JP-A-58-50636.

[Invention or problem to be solved]

However, the above-mentioned conventional technology has the following problems.

The hub is often in the shape of a metallic disk, and the fixation between the board and the hub is simple from the viewpoint of workability, such as by adhesion, and it is difficult to ensure sufficient adhesion between the board and the metal hub. It is extremely difficult. Also, it is desirable for the hub to be lightweight;
If the hub is a metal disk, the weight of the hub relative to the overall weight will have an effect.

And in order to increase the adhesive strength between the hub and the board,
Although it is a good method to change the shape of the hub from a disc with holes to a cylinder with stepped holes and insert the thinner cylindrical part into the center hole of the board and glue it together, it makes the shape of the hub complicated and makes the hub expensive. There are some drawbacks to it.

Therefore, the present invention aims to solve these problems.
The purpose is to provide a method for manufacturing a center positioning member for an information recording medium that can easily ensure adhesive strength with a substrate, is lightweight, and is suitable for mass production.

(Means for Solving the Problems) A method for manufacturing a center positioning member for an information recording medium according to the present invention includes: a disc-shaped transparent substrate having a recording guide groove; center positioning of a recording guide groove forming a part of the transparent substrate, which has a recording layer that undergoes any or all of the processes of recording, reproducing, and erasing information by causing physical or chemical changes; manufacturing a center positioning member for an information recording medium, the recording layer is formed on the opposite side of the center positioning member fixed to the transparent substrate, and the center positioning member is formed by integrating an inorganic substance and an organic substance. The method is characterized in that after the center positioning member is integrated from an inorganic material and an organic material, a surface of the center positioning member that is fixed to the transparent substrate is shaved.

(Embodiment) FIG. 1 is a sectional view of an information recording medium in an embodiment of the present invention, where l is a recording plate (substrate), 2 is a hub, and the hub 2 has a hook on its outer periphery. It is composed of an embedded plate 5 having a cylindrical shape and a resin filling part 6 integrated with the embedded plate 5.

The hub 2 was bonded to the recording plate 1 using an anaerobic adhesive. 3 is a rotating shaft that supports the recording plate l and the hub 2, 4 is a magnet for magnetically attracting the hub 2 as in the conventional example, and a1 stone 4 is a rotating shaft that supports the rotating shaft 3.
Fixed. In this manner, the information recording medium of the present invention is mounted on the rotating shaft 3 in the same manner as in the conventional example. Now, the production of the hub 2 will be explained below.

Figure 3 is a schematic diagram of the vertical injection molding machine used to manufacture the hub 2, and 36 is the lower mold.

The lower mold fi 36 is fixed to the mold fixing plate 16, 7 is the upper mold, the upper mold 7 is fixed to the movable mold fixing plate 17, and the upper mold 7 is attached to the movable side fixed plate along the guide shaft 14. It moves up and down as shown in 23 integrally with the plate 17.

Reference numeral 18 is a cylinder through which resin passes for injection molding, and the resin is stored in a material receiver 20 in the cylinder 1.
8, and 19 supplies the resin in the cylinder 18 to the mold 36.
．． There is a pressurizing mechanism section for injecting into the space between 7 and 7, and these components are each fixed or supported on the bed 15. Here, the vertical movement mechanism of the movable side fixed plate 17, the mold clamping mechanism, the pressurizing mechanism section 19. Further, the mechanisms and the like inside the cylinder 18 are omitted because they are not directly related to the purpose of the present invention.

FIGS. 4(a) and 4(b) are sectional views of main parts of a mold of an injection molding machine, and the manufacturing process of the hub 2 will be explained below.

In FIG. 4(a), the lower mold 36 has a protrusion at the center of the groove, into which the center hole of the embedded plate 5 is inserted. The embedded board 5 this time is magnetic stainless steel 5US43
It was manufactured by pressing using 0. After loading the embedded plate 5 into the lower mold 36, the upper mold 7 is brought into close contact with the lower mold 36. The resin 11 passes through the nozzle 10, fills the runner 12, passes through the gate 13, and forms the upper mold 7 and the lower mold fi36.
In the figure, 8 is the ejector bin for pushing out the product, and 9 is the ejector pin 8 for pushing out the product by filling the space (hub shape) created by the embedded plate 5.
It is a spring that keeps the product lowered so as not to contact the
Although not shown in the figure, the ejector bin 8 for pushing out items can be reciprocated by a reciprocating mechanism and a spring 9.

Now, the state in which the resin 11 is cooled and solidified after the resin 11 fills the space between the upper mold 7 and the lower mold 36 is shown in FIG. 4(b).
The upper mold 7 rises as shown at 22, and the resin 11 separates at the tip of the nozzle 10. After that, the product extrusion ejector pin 8 is raised as shown in 21, and the product in which the embedded plate 5 and the resin filling part 6 are integrated is separated and taken out from the lower mold 36, and the product is removed from the spool at the gate part. The resin-filled portion is separated by, for example, folding.

The hub 2 manufactured in this way may not be able to secure acceptable flatness on the side that is fixed to the substrate of the hub 2 due to shrinkage after molding, or the side that is fixed to the substrate of the hub 2 may not have the same flatness as the center hole of the hub 2. The verticality of the side to be fixed may be outside the permissible limits. For this reason, in the present invention, after molding the hub 2, a step is added to shave the side to be fixed to the substrate with reference to the center hole of the hub 2.

This situation is shown in FIG. 5, in which 40 is a collet chuck that guides and holds the center hole of the embedded plate 5 of the hub, 43 is a shaft for opening the collet chuck 40, and 44 The collet chuck is rotated by the shaft 42
45 is a bearing for the shaft 43, 47 is a spring for pushing out the shaft 43, and 46
is an electromagnet for drawing in the shaft 43, and 41 is an electromagnet for attracting the embedded plate 5 of the hub. First, in the step of fixing the hub to the rotating shaft, the electromagnet 46 is energized, the shaft 43 is retracted, the collet chuck 40 is narrowed, and the collet chuck 40 is inserted into the center hole of the embedded plate 5.

Then, when the electromagnet 46 is de-energized, the shaft 43 is pushed out, the collet chuck 40 is pushed and expanded, and the collet chuck 40 holds the center hole of the embedded plate 5. Then, as an aid to holding the hub, the electromagnet 41 is energized to attract the embedded plate 5 of the hub, and after holding the hub on the rotating shaft, the hub is rotated as shown by arrow 48, and the cutting tool 49 is moved as shown by arrow 5.
Move it as shown and scrape the side of the hub that will be fixed to the board. After the hub has been shaved in this manner, the hub is removed from the rotating shaft 42 by performing the reverse procedure for mounting the hub on the rotating shaft 42.

In this way, the hub 2 is manufactured efficiently.

The present invention is characterized in that the hub is made of two types of materials, and the thin plate 5 is made of two types of materials.

Magnetic metals such as steel and stainless steel are applicable, and the material of the base material 6 includes vinyl chloride resin, methyl methacrylic resin, epoxy resin, melamine resin, ABS resin, A
S resin, silicone resin, fluorine-containing resin, polyolefin resin, polyacetal, polyimide, polyamide, polyester, polyamideimide, polyphenylene oxide, polysulfone, polyurethane, voluria, polystyrene, modified polystyrene, cellulose acetate, chlorinated polyether, polycarbonate, Polymer materials made by copolymerizing or mixing a single resin or two or more resins such as polyethylene, polyethylene terephthalate, polypropylene, vinylidene chloride resin, phenol resin, polyurethane, and silicone resin can be applied, and in this example, The hub may be manufactured by using an injection molding machine, or by other methods such as compression molding, transfer molding, extrusion molding, etc.

(Effects of the Invention) As described above, according to the present invention, the hub has a structure composed of a thin plate made of an inorganic material and a base material made of an organic material, and after the hub is molded, the surface of the hub that is fixed to the substrate is By cutting, the hub can be easily manufactured at low cost. In addition, it is easy to firmly bond the thin plate and the base material by the mechanical throwing effect depending on the shape of the thin plate, and when the recording plate (substrate) is made of an organic material, When bonding the board, van der
Because the adhesive strength between the hub and the recording plate can be easily secured through interactions such as Waalska, Coulomb force, intermolecular entanglement, and covalent bonds, various types of adhesives, such as hot-melt adhesives, can be used.

Anaerobic type, radiation curing type, thermosetting type, etc. can be applied, and the workability of bonding the hub and recording plate is greatly improved. In other words, the present invention makes it possible to mass-produce inexpensive hubs, and easily realizes highly reliable adhesion in joining the hub and the recording plate.

[Brief explanation of the drawing]

FIG. 1 is a main sectional view of an information recording medium showing an embodiment of the present invention. FIG. 2 is a main sectional view showing a conventional information recording medium. FIG. 3 is a schematic diagram of a vertical injection molding machine for manufacturing a hub according to an embodiment of the present invention. FIGS. 4(a) and 4(b) are sectional views of main parts showing the process of forming the hub. FIG. 5 is a cross-sectional view of the main part showing the cutting process of the hub. l... Recording plate (substrate) 2... Center positioning member (hub) 3... Rotating shaft 4... Magnet 5... Embedded plate 6... Resin filling part 7... Upper mold ″ lO...Nozzle 1.1...Resin 13...Gate 36...Lower mold 40...Collet chuck 43...Shaft 47...Spring 49 Fist/bite or above Applicant Seiko Epson Hajime Co., Ltd. / Zuken 2 Zumutsu 3m 'f, 4 75 (a an

Claims (4)

[Claims] (1) A disc-shaped transparent substrate equipped with a recording guide groove, which is formed on the transparent substrate and undergoes a physical or chemical change when irradiated with light, allowing information to be recorded, reproduced, erased, etc. or a recording layer that undergoes all the processes, and at least a center positioning member for a recording guide groove forming a part of the transparent substrate, and the recording layer has a center positioning member fixed to the transparent substrate. In a method for manufacturing a center positioning member for an information recording medium, which is formed on the opposite side of the inorganic substance and is formed by integrating an inorganic substance and an organic substance, after the center positioning member is integrated from an inorganic substance and an organic substance, the center positioning member is A method for manufacturing a center positioning member for an information recording medium, the method comprising: cutting a surface fixed to the transparent substrate. (2) The center of the information recording medium according to item 1, wherein the information recording medium is a combination of the transparent substrate on which the recording layer is formed on one side and the transparent substrate on which the recording layer is not formed. A method for manufacturing a positioning member. (3) The information recording medium is a combination of two transparent substrates each having the recording layer formed on one side.
A method for manufacturing a center positioning member for an information recording medium as described in 1. (4) The information recording medium has only one transparent substrate with the recording layer formed on one side.
A method for manufacturing a center positioning member for an information recording medium as described in 1.