JPH0562425A - Cleaning cloth for optical disk - Google Patents

Abstract

PURPOSE:To inexpensively and easily provide the cleaning cloth which can remove the electrostatic charge on an optical disk surface. CONSTITUTION:A material exhibiting a work function within a + or -0.13eV range of the work function of the surface layer material on at least the recording surface side of the optical disk is used as the cleaning cloth for the optical disk for the purpose of wiping away the stains on the surface of the optical disk. The electrostatic change is hardly generated even by the contact friction of the surface of the optical disk and the cleaning cloth and the sticking of foreign matter, such as dust, to the surface layer is exceedingly prevented. The number of the times for the wiping operations by the cleaning cloth is drastically decreased as compared to heretofore and further, the foreign matter, such as dust, hardly sticks to the surface of the optical disk and, therefore, the generation of troubles at the time of recording and reproducing of the optical disk is exceedingly prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk cleaning cloth for wiping dirt off an optical disk.

[0002]

2. Description of the Related Art Currently, optical discs, which are widely used as recording media for music and images, perform writing and reproducing by laser irradiation, and therefore have an insulating property of high transmittance of laser light and low refractive index. It is generally protected by a surface layer formed of a flexible resin, but the optical disc and the optical disc are always accommodated by vibration, shock, etc. when taking out the optical disc from the drive device or when carrying the optical disc. Contact and friction occur with the cartridge.

For this reason, the surface layer may be charged and foreign matter such as dust may adhere to the surface of the optical disk, and if the recording surface side of the optical disk becomes dirty, recording and reproduction cannot be performed accurately. The problem occurs.
Therefore, conventionally, a cleaning cloth made of nylon, cotton, or the like is used to wipe off the surface of the optical disk to remove dirt.

However, conventionally, attention has been paid only to prevent the surface of the optical disk from being scratched, and the softness of the cleaning cloth has been given the highest priority. For this reason, the optical disc surface may become more charged due to contact friction when the optical disc surface is wiped with a cleaning cloth. However, this was a problem because it required wiping with a cleaning cloth.

A method of removing the charged state of the surface layer by ion-blowing the surface of the optical disk with an ionizer or applying a surfactant (cleaning liquid such as ethanol) is also conceivable. The method is very expensive for general users, and it is troublesome to handle, and the method using a surfactant is cheaper than the ionizer, but a cleaning solution is used every time the stain is wiped off. However, it is necessary to completely remove the cleaning liquid each time, which is troublesome.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a cleaning cloth which is inexpensive and can easily remove the electrostatic charge on the surface of an optical disk.

The inventors of the present invention have found that the potential difference caused by the contact friction between the optical disk and the cleaning cloth is triboelectric series (in the order of positive → negative, air → human hand → asbestos → rabbit hair → glass → mica → nylon → fur). → Lead → Silk → Aluminum → Paper → Cotton → Steel → Wood → Amber → Seal wax → Hard rubber → Nickel (copper) → Tin (silver) → Gold (platinum) → Sulfur → Acetate (rayon) → Polyester → Celluloid → Urethane → polyethylene → vinyl → silicon → Teflon), and because the arrangement of this triboelectric series is determined by the size of the work function of the substance, the potential difference caused by the contact friction is the work function. Paying attention to the fact that the larger the difference, the larger the difference between the work function values of the surface layer material of at least the recording surface side of the optical disc is ± 0. It has been found that the above object can be achieved by using a cleaning cloth characterized by using a material exhibiting a work function in the range of 13 eV.

[0008]

Embodiments of the present invention will be described in detail. As shown in FIG. 1, the optical disk used in the embodiment has an optical recording layer 2 and a surface layer 3 (about 10 μm thick) sequentially formed on one main surface of a substrate 1 (about 1.2 mm thick) made of polycarbonate and having a diameter of about 86 mm. The back surface layer 4 is formed by stacking layers on the other main surface of the substrate 1.

The optical recording layer 2 is a first dielectric layer of amorphous yttrium sialon (about 1100 Å thickness) and an amorphous Gd-Dy-Fe based magneto-optical recording layer (about 250 Å thickness), a second dielectric layer of amorphous yttrium sialon (about 300 Å thickness), and a reflective layer of aluminum (about 800 Å thickness) are sequentially laminated. Also,
The surface layer 3 is made of the material shown in Table 1, and the back surface layer 4 is made of the same material as the surface layer 3.

[0010]

[Table 1]

Next, the surface layer is cleaned with a cleaning cloth.
The results of examining the charged state of the surface layer and the attached state of ash by rubbing at a rate of 50 times / 30 seconds will be described. In addition, the measurement of the amount of electrification was performed at a temperature of about 22 ° C and a humidity of about 58% at a measurement distance of 10 mm using the Huggle Electronics MODEL2C.
I went there.

As shown in FIG. 2, in Table 1, the difference in work function between A1 to A4 of the comparative example and B1 to B4 of the example (work function of cleaning cloth-work function of surface layer, but absolute value) is shown. As for the relationship with the charge amount, it was found that the charge amount increased in a series function as the difference in work functions increased. In the figure, ◯ is the data of Examples B1 to B4, and × is the data of Comparative Examples A1 to A4. Here, the work function difference between the surface layer and the cleaning cloth is ±
For Examples B1 to B4 of 0.12 eV or less, the charge amount was 2 kV.
It can be seen that

On the other hand, when the relationship between the charge amount and the ash adhesion rate is examined, the relationship is as shown in FIG. Here, the ash adhesion rate is the ratio of the area where the ash adheres to the surface area of the sample when one main surface of the charged sample is brought closer to the ash of tobacco by a distance of about 10 mm. From the results shown in FIG. 3, it can be seen that if the charge amount is 2 kV or less, ash adhesion does not occur at all. That is, in FIG. 2, it can be seen that the work function difference between the surface layer and the cleaning cloth should be approximately ± 0.13 eV or less in order to reduce the charge amount to 2 kV or less.

In fact, when the above-mentioned ash adhesion state was examined in Examples B1 to B4, the ash adhesion rate was almost 0%, but in Comparative Example A2, ash adhered at a high rate of 16.6%. Therefore, by setting the difference in work function between the surface layer and the cleaning cloth within ± 0.13 eV, it can be expected that the conventional charging can be completely prevented. Further, particularly when the surface layer is made of polycarbonate or acrylic UV resin, the surface cloth is suppressed to a charge amount of about 1 kV or less by using polyethylene terephthalate or polyester having a work function similar to that of the surface layer as the cleaning cloth. be able to.

The combination of the materials of the surface layer and the cleaning cloth is not limited to the above-mentioned embodiment, and may be appropriately changed and implemented as long as the difference between them is within ± 0.13 eV. Further, although an optical disc having a magneto-optical recording layer and a back surface layer is shown as an example, the optical disc is not limited to this, and any optical disc having a surface layer as a protective layer of the recording layer may be used. It can be implemented by appropriately changing it regardless of the presence or absence of the back surface layer and its material.

[0016]

As described above in detail, according to the optical disk cleaning cloth of the present invention, the difference in work function between the surface layer of the optical disk and the cleaning cloth is within ± 0.13 eV, so that the surface of the optical disk and the cleaning cloth are cleaned. Charging is less likely to occur due to contact friction with a cloth, and foreign matter such as dust is prevented from adhering to the surface layer as much as possible, and the number of wiping operations with a cleaning cloth can be significantly reduced compared to the conventional case. Since foreign matter such as dust hardly adheres to the surface of the optical disc, problems can be prevented as much as possible during recording / reproduction of the optical disc.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical disc according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a work function difference and a charge amount.

FIG. 3 is a graph showing a relationship between a charge amount and an ash adhesion rate.

[Explanation of symbols]

 1 ... Substrate 2 ... Reflective layer 3 ... Front surface layer 4 ... Back surface layer

Claims (1)

[Claims] 1. A cleaning cloth for an optical disk for wiping off dirt on the surface of the optical disk, which shows a work function within a range of ± 0.13 eV with respect to the work function of the surface layer material of at least the recording surface side of the optical disk. A cleaning cloth for optical disks, which is made of a material.