JP2513271B2 - Light tape - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optical tape used as a recording medium in an optical recording / reproducing system.

[Outline of Invention]

According to the present invention, in an optical tape comprising a thin film base layer (hereinafter referred to as a base layer) and a recording layer, an antireflection layer having a light antireflection action and a friction reducing action is formed on the back surface of the base layer. The antireflection layer prevents the light passing through the base layer from being reflected to improve the recording / reproducing characteristics of the signal, and makes it possible to smooth the tape path and increase the tape running speed.

[Conventional technology]

In recent years, in an optical recording / reproducing system or the like, it is sensitive to light (laser light) as a recording medium capable of storing a larger amount of information with respect to an optical disk, an optical card, or the like used as a recording medium. Optical tape is also being developed.

Such an optical tape is, for example, as shown in FIG.
A recording layer formed by coating an organic material such as a senior dye on the surface of the base layer 1A formed of a material such as plastic.
A recording medium formed by forming 1B, in which the optical tape 1 is driven by a mechanism (not shown) such as a capstan and a pinch roller, like a magnetic tape in a magnetic recording device.
Done by Also, the optical tape 1 is a tape support base 2
By slidingly traveling, the distance from the objective lens 3A becomes constant during traveling, and an appropriate focus state is maintained.

When information is recorded on the optical tape, the optical tape 1 travels in the direction A in the figure, and the optical head unit 3 irradiates the recording film 2 with laser light while deflecting it in the direction B (recording track direction) in the figure. At this time, the recording layer 1B is destroyed by heat and scattered in the portion irradiated with the laser beam L, and the holes formed thereby remain as recording pits P, P ....

As described above, the recording information data supplied to the optical head is recorded as pits P, P ... On the optical tape 1.

Further, at the time of reproduction, a laser beam at a level lower than that at the time of recording (a level at which the recording film is not destroyed) is irradiated along the recording track, and pit information is detected by the difference in reflected light level of the irradiated laser light L.

In order to detect the difference in reflected light level by the pits P during reproduction, for example, the recording layer 1B of the optical tape is made of a material and a film thickness so as to have a high light reflectance, and the base layer
1A forms the optical tape 1 so that the transmission or absorption characteristics of laser light are enhanced.

In such an optical tape 1, the reproduction laser light L moves in the direction B (recording track direction) in the figure on a certain track on the optical tape in which the pits P are formed as shown in FIG. 4 (a). As shown in FIG. 4, since the laser light is not reflected at the pit P, the reflected light is detected by an optical detector or the like in an optical reproduction system (not shown) as shown in FIG. A signal having a waveform as shown in (b) can be obtained.

Then, by processing this signal, the information recorded on the optical tape is reproduced.

[Problems to be solved by the invention]

However, in the conventional base layer 1A of the optical tape 1, it is impossible to almost completely transmit or absorb the laser light L, and there are the following three problems.

1). As shown in FIG. 5 (a), the laser light reaching the base layer 1A, that is, the laser light applied to the recording pits, is partially reflected on the back surface of the base layer and is detected as reflected light. Therefore, there is a drawback that the S / N in the reproduced signal is deteriorated.

2). Since the optical tape 1 has flexibility unlike the optical disc, as described above, the tape traveling position is guided by the tape support base or the like to keep the positional relationship with the optical head constant and maintain an appropriate focus state. It is necessary to provide the tape support base 2.

However, if the tape support base 2 is provided for this reason, the laser light that has passed through the base layer 1 is also reflected by the tape support base 2 as shown in FIG. It becomes noise in the reproduced signal and is detected by the photodetector, degrading the S / N.

3). Further, when the optical tape 1 travels while sliding on the tape support base 2, the friction of the optical tape 1 and the tape support base 2 causes the consumption of the optical tape 1 to be severe, especially when the tape is run at high speed. There was a problem.

[Means for solving problems]

The present invention is intended to solve the above-mentioned problems by applying a coating treatment to the back surface of the base layer of the optical tape, that is, the surface of the base layer that is in contact with the tape support to form a light reflection preventing layer. Is.

[Action]

The coating treatment on the back surface of the base layer prevents the reflection of the laser light reaching the base layer by using a material that has a very low light reflectance and a friction-relieving effect. It is possible to prevent consumption of the optical tape due to sliding of the table.

〔Example〕

FIG. 1 shows an embodiment of the optical tape of the present invention, and shows a cross section of a portion of the optical tape 10 in which pits P are formed.

In the figure, the same reference numerals as those in FIG.
Is an antireflection layer formed on the back surface of the base layer 1A.

It is preferable that the antireflection layer 11 be coated with, for example, carbon, graphite or the like to have a high light absorptivity and a small friction coefficient when sliding on the tape support 2. .

In the optical tape 10 of the present invention, the laser light L applied to the recording layer 1B is reflected with a high reflectance, and a high level signal is obtained by detecting the reflected light, and the pit P, that is, the recording. Since the laser light L applied to the portion having no layer component is transmitted through the base layer 1A and is hardly reflected, a low-level reproduction signal with few noise components is detected.

That is, in the case of the conventional optical tape, as described above, the laser light L applied to the pit P portion is reflected by the back surface of the base layer 1A or the tape support base 2 and deteriorates the signal reproduction characteristic. However, in the case of the present invention, the base layer 1A
The laser light L that has passed through is absorbed by the antireflection layer 11, and the transmitted light of the light applied to the pit P is hardly detected.

Therefore, the noise component is suppressed in the detected signal, and the reproduction characteristic is greatly improved.

Further, the antireflection layer 11 can alleviate the sliding friction of the optical tape 10 with the tape support 2, and the friction of the optical tape 10 during traveling can be reduced at the same time.
High-speed running of the tape is also possible.

As shown in FIG. 2, the antireflection layer 11 of FIG. 1 is divided into two layers of an antireflection portion 11A and a friction reducing portion 11B, and the antireflection action and the friction reducing action are shared by the respective layers. It may be configured as follows.

〔The invention's effect〕

As described above, in the optical tape of the present invention, by forming the light reflection preventing layer having the light reflection preventing function and the sliding friction reducing function on the back surface of the base layer, the signal recording / reproducing characteristics are improved, and the optical tape The friction coefficient produced by sliding on the tape support is reduced, the durability of the optical tape is improved, and the high-speed running of the optical tape is sufficiently possible.

[Brief description of drawings]

1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view showing another embodiment of the present invention, FIG. 3 is a schematic view for explaining a recording / reproducing operation by an optical tape, FIG. FIG. 4 (a) is an explanatory view of the reproducing operation from the optical tape, and FIG.
FIG. 5A is a waveform diagram showing a signal obtained from the reproducing operation, and FIGS. 5A and 5B are explanatory diagrams of an improper reflection operation of the reproducing laser light. In the figure, 1A is a base layer, 1B is a recording layer, 2 is a tape support base,
10 is an optical tape, 11 is an antireflection layer, P is a pit, and L is a laser beam.

Claims (1)

(57) [Claims] 1. An optical tape, wherein a recording layer sensitive to light is formed on one surface of a base layer, and a light reflection preventing layer is formed on the other surface of the base layer.