JPH01286120A - Optical head device - Google Patents

Abstract

PURPOSE:To prevent the reflection of a laser beam passing the base layer of an optical tape which produces a noise by applying a reflection preventing processing on the optical tape contact plane of an optical tape travel supporting part. CONSTITUTION:A reflection preventing layer 10 is formed on the contact plane with the optical tape 1 of the optical tape travel supporting part 2A. By providing the layer 10 on the supporting part 2A in such way, the component of the laser beam irradiating a pit P passing the base layer 1B is absorbed in the layer 10, and is reflected on a sliding plane between the supporting part 2A and the tape 1, and passes the layer 1B again, then, the component detected as reflected light scarcely exists. Therefore, a signal reproducing characteristic can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical head device in an optical recording/reproducing system using an optical tape as a recording medium.

[Summary of the invention]

The present invention provides an optical head device equipped with an optical tape running support part either integrally or separately, in which a light reflection prevention treatment is applied to the optical tape contacting surface of the optical tape running support part, and the optical tape running support part allows laser beams to be emitted from the optical tape running support part. This prevents reflection of light and improves recording and reproducing characteristics.

[Conventional technology]

First, the operation of an optical recording/reproducing system using an optical tape as a medium will be explained.

FIG. 2 is a schematic diagram showing a signal recording operation on an optical tape, where l is an optical tape consisting of a recording layer IA and a thin film base layer IB (hereinafter simply referred to as the base layer), 2 is an optical tape that houses an objective lens 3, It is a housing that constitutes an optical head device together with the objective lens 3, and is integrally provided with an optical tape running support section (hereinafter simply referred to as a support section) 2A, which guides the running of the optical tape I. Although the running mechanism of the optical tape 1 is not shown, it is run at a constant speed using a capstan, pinch rollers, etc., similar to the magnetic tape in a magnetic recording device.

When recording, the optical tape 1 travels in the direction A, and the laser light emitted from the laser source passes through various optical systems and reaches the objective lens 3, and is deflected in the direction B while passing through the recording layer IA of the optical tape 1. The recording track is formed in a direction substantially perpendicular to the longitudinal direction of the tape.

The recording layer IA is formed by coating an organic material such as a cyanine dye on the paste layer IB, and has a high light reflectance when irradiated with a low-level laser beam (reproduction laser beam), and a high-level Depending on the laser beam (recording laser beam), it has the characteristic of being easily destroyed. Therefore, in the area irradiated with the recording laser beam, the recording layer components are destroyed by the heat, and the holes formed there become pits P, in which a signal is recorded.

The recorded signal is reproduced based on the difference in the level of reflected light between the pit portion and the portion where no pits are formed.

In other words, since the base layer IB is made of a material that has high light absorption or transmission properties, in the area where the pit is formed, that is, the area where the recording layer IA has disappeared, the reproduction laser beam is directly transmitted to the base layer. The reproduction laser beam reaches IB and is mostly transmitted or absorbed, so almost no reflected light is generated. , reflected by the recording layer IA. Therefore, by detecting the difference in the level of reflected light using an optical detector (not shown) or the like, pit information, that is, the presence or absence of pits, can be detected and a reproduction signal can be generated.

By the way, when performing recording and reproduction on the optical tape 1 in this manner, the support section 2A that guides the running position of the optical tape 1 is required, as described above.

In other words, since the optical tape 1 is flexible unlike an optical disk or the like, unless the support portion 2A is provided, the distance to the objective lens 3 will not be determined and proper focus will not be maintained.

[Problem that the invention seeks to solve]

However, by providing the support portion 2A in this manner, the following problems occur.

FIG. 3 shows a cross section of the optical tape 1 and the support portion 2A. As shown in FIG. Therefore, the reflected light reflected by the support part 2A becomes noise in the reproduced signal, causing the problem that pit information cannot be detected accurately. Ta.

[Means for solving problems]

The present invention has been made in view of these problems, and includes applying anti-reflection treatment to the optical tape contacting surface of the support portion.

[Effect]

Since the surface of the support part (optical tape contact surface) is anti-reflection treated, it is possible to prevent the laser light that has passed through the base layer from being reflected on the support part and the optical tape sliding surface, and the reflected light is It can be made to a minute level.

〔Example〕

FIG. 1 shows an embodiment of the present invention, and the same reference numerals as in FIG. 2 indicate the same parts.

IO is an antireflection layer formed on the contact surface of the support portion 2A with the optical tape 1, and is coated with carbon, graphite, or the like.

In this way, by providing the antireflection layer 1o on the support portion 2A, the laser beam irradiated onto the base layer I
The component that has passed through B is absorbed by the antireflection layer IO, is reflected on the sliding surface of the support portion 2A and the optical tape 1, and almost no component that passes through the base layer again is detected as reflected light.

Therefore, the noise component in the reflected light detected by an optical detector or the like (not shown) is reduced to a small amount, and the signal reproduction characteristics are greatly improved.

Further, by coating with carbon, graphite, etc. in this manner, the coefficient of friction between the optical tape 1 and the support portion 2A can also be reduced.

The optical tape can also run smoothly.

〔Effect of the invention〕

As explained above, in the optical head device of the present invention, by applying an anti-reflection treatment to the sliding surface of the optical tape running support section against the optical tape and forming an anti-reflection layer, the optical head device that causes noise can be removed. Since the reflection of the laser beam that has passed through the base layer can be suppressed, there is an effect that the signal recording and reproducing characteristics are improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an explanatory view of optical tape recording, and FIG. 3 is a sectional view showing a conventional example. In the figure, l is an optical tape, IA is a recording layer, IB is a thin film base layer, 2 is a housing, 2A is an optical tape running support part, 10
indicates an antireflection layer. 1st F! ! J Figure 3

Claims (1)

[Claims] In an optical recording/reproducing system using an optical tape as a recording medium, in an optical head device equipped with an optical tape running support part, a part or all of the optical tape contacting surface of the optical tape running support part is subjected to anti-reflection treatment. An optical head device characterized by: