JPH0561823U - Optical information recording medium - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an optical information recording medium capable of preventing the tracking deviation from occurring in the outer peripheral portion or the like when the recording medium is rotated at a high speed by improving the rigidity of a plastic substrate. .. [Structure] In an optical information recording medium made of a plastic resin substrate, a doughnut-shaped reinforcing plate made of a lightweight and high-rigidity material is joined and integrated on the side surface of the substrate opposite to the laser light incident side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of a disc-shaped optical information recording medium such as a compact disc or a laser disc.

[0002]

[Prior art]

 In recent years, optical discs for writing and reading information by laser light have been widely used as high-density recording media. A substrate of a disc-shaped optical information recording medium such as a compact disc (CD) or a laser disc (LD) is manufactured by molding a plastic material such as polycarbonate resin or acrylic resin with a stamper. Since this plastic substrate is made of low-rigidity polycarbonate resin, acrylic resin, etc., when recording and reproducing information with an optical pickup, the laser light will be deviated from tracking due to surface deflection and deformation of the substrate. There is a problem called. The occurrence of this tracking deviation becomes more noticeable as the disc rotates at a higher speed and as it approaches the outer periphery of the disc.

[0003]

[The purpose of the device]

 The present invention has been made in view of the above circumstances, and by improving the rigidity of the plastic substrate, it is possible to prevent the occurrence of tracking error in the outer peripheral portion or the like when the recording medium is rotated at high speed. The purpose is to provide a recording medium.

[0004]

[Device configuration]

 To achieve the above object, the present invention provides an optical information recording medium made of a plastic resin substrate, and a doughnut-shaped reinforcing plate made of a lightweight and high-rigidity material is integrally joined to the side of the substrate opposite to the laser light incident side, In an optical information recording medium made of a plastic resin substrate, a cylindrical ring made of a lightweight and high-rigidity material is integrally bonded to the outer peripheral surface of the substrate. A donut-shaped reinforcing plate made of a lightweight and high-rigidity material is joined and integrated on the side opposite to the light incident side, and a cylindrical ring made of a lightweight and highly-rigid material is joined and integrated on the outer peripheral surface of the substrate. ..

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments shown in the accompanying drawings. The optical information recording medium 1 of FIG. 1 has a structure in which a doughnut-shaped reinforcing plate 3 is joined and integrated on a resin substrate 2. Reference numeral 4 is a hub located at the center of the recording medium, and is a portion that is attracted and supported by a magnet provided on the spindle of the drive of the recording / reproducing apparatus.

The resin substrate 2 is made of a plastic material such as polycarbonate or acrylic, and has pre-pits and grooves formed by molding with a stamper, and then has a recording film, a protective film and a reflective film formed by a method such as sputtering. .. As the reinforcing plate 3, for example, a thin and high-strength titanium alloy, which is a lightweight and high-rigidity material, is used, and it is formed on the substrate surface (the film-forming side of the reflective film or the like) opposite to the incident side of the laser light L. Bonded with adhesive. In this case, an organic resin may be evenly applied between the reinforcing plate 3 and the reinforcing plate 3 in order to protect the thin film such as the reflective film.

As the titanium alloy, an alloy having a composition of Ti-6 wt% and Al-4 wt%, or Ti-10 wt%, V-2 wt%, Fe-3 wt, and Al alloy can be used. In any case, a lightweight and highly rigid material is preferable.

By thus joining and integrating a thin plate made of a lightweight and high-rigidity material on the resin substrate 2 to improve the mechanical strength of the resin substrate, the recording medium is rotated at a high speed and information is recorded by the optical pickup 5. It is possible to eliminate the problem that the laser beam deviates from tracking when recording and reproducing. It is possible to prevent such tracking deviation even in the outer peripheral portion of the recording medium.

Specifically, by joining the reinforcing plate, it is possible to improve the mechanical characteristics of the recording medium such as surface wobbling, surface wobbling acceleration, track wobbling, track wobbling acceleration, and tilt. In particular, it is effective in preventing the tracking deviation of the outer peripheral portion during high-speed rotation.

Next, FIG. 2 shows a second embodiment of the present invention, in which the same parts as those of the first embodiment are represented by the same reference numerals, and the duplicated description will be omitted. The structure is different in that the cylindrical ring 6 on the outer peripheral surface is joined with an adhesive. The cylindrical ring 6 is made of the same lightweight and highly rigid material as the reinforcing plate 3. At this time, the order of joining the substrate and the cylindrical ring 6 may be before or after the formation of the reflective film or the like. This embodiment also has the same effect as that of the first embodiment.

FIG. 3 shows a third embodiment of the present invention, which is a combination of the configurations of the first embodiment and the second embodiment. That is, in this embodiment, the reinforcing plate 3 is bonded to the substrate surface (film forming side) on the side opposite to the laser light L irradiation side, and the cylindrical ring 6 is bonded to the outer peripheral surface of the substrate 2. In the case of this embodiment, as in the case of each of the above-mentioned embodiments, a thin plate made of a lightweight and high-rigidity material is joined and integrated on the resin substrate 2 and the outer peripheral surface to improve the mechanical strength of the resin substrate, and thus the recording medium. It is possible to eliminate the problem that the substrate is deformed and the laser light is deviated from the tracking when the information is recorded and reproduced by the optical pickup 5 while rotating at high speed. It is possible to prevent such tracking deviation even in the outer peripheral portion of the recording medium. Moreover, since a lightweight reinforcing plate or the like is used, it is possible to prevent an increase in the total weight of the recording medium.

As the lightweight and high-rigidity material, besides titanium alloy, metal materials such as PH stainless steel and high-strength aluminum alloy, or fiber reinforced plastic with carbon fiber can be used. In addition, the strength can be improved even if two substrates are bonded together.

[0013]

As described above, according to the present invention, by improving the rigidity of the plastic substrate, it is possible to prevent the tracking error from occurring in the outer peripheral portion or the like when the recording medium is rotated at a high speed. You can

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a first embodiment of the present invention.

FIG. 2 is a structural explanatory view of a second embodiment of the present invention.

FIG. 3 is a structural explanatory view of a third embodiment of the present invention.

[Explanation of symbols]

1 optical information recording medium, 2 resin substrate, 3 reinforcing plate, 4
Hub, 5 optical pickups, 6 cylindrical ring.

Claims (3)

[Scope of utility model registration request] 1. An optical information recording medium comprising a plastic resin substrate, wherein a doughnut-shaped reinforcing plate made of a lightweight and high-rigidity material is joined and integrated on the side opposite to the laser light incident side of the substrate. Medium. 2. An optical information recording medium made of a plastic resin substrate, wherein a cylindrical ring made of a lightweight and high-rigidity material is joined and integrated on the outer peripheral surface of the substrate. 3. In an optical information recording medium made of a plastic resin substrate, a doughnut-shaped reinforcing plate made of a lightweight and high-rigidity material is joined and integrated on the side opposite to the laser beam incident side of the substrate, and at the outer peripheral surface of the substrate. An optical information recording medium characterized in that a cylindrical ring made of a lightweight and highly rigid material is integrally bonded.