JPS61151792A - Optical information recording media - Google Patents

Abstract

PURPOSE:To prevent to decrease a memory capacity per unit area and to improve an AT accuracy by arranging alternately a tracking track and a clock track in the light card and providing an information recording area between tracks. CONSTITUTION:At a light card 1, clock tracks 21, 22, 23,... recorded by a clock signal and formed in an intermittent broken-line shape, and tracking tracks 31 and 32,... which are formed in a continuous line shape are alternately arranged at the equal interval beforehand, and between respective tracks, recording areas 41, 42, 43,... to record information are provided. When information is recorded, light spots S1-S3 are scanned in the (a) direction of an arrow, a clock signal and a tracking signal are detected and a recording bit 5 is recorded. At the time of reproduction, the light spots S1-S3 are irradiated on tracks 21,..., 31,..., the clock signal and the tracking signal are detected, a reflecting light S2 is detected and a track 251,... can be read.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical information recording medium, and more particularly to a card-shaped optical information recording medium provided with tracks for obtaining tracking signals and clock signals.

[Prior art]

2. Description of the Related Art Conventionally, various types of media such as disk-shaped, card-shaped, tape-shaped, etc. are known as media for recording information using light and ejecting the previously recorded information.

Among these, card-shaped optical recording media (hereinafter referred to as optical cards) are expected to be in great demand as small, lightweight, easily portable media with a large storage capacity.

By the way, the above-mentioned optical card generates an optically detectable recorded bit string (
Information is recorded as an information track). At this time, in order to accurately record information without causing problems such as crossing of information tracks, the irradiation position of the light beam must be adjusted to 7! ! It was necessary to perform control (auto tracking, hereinafter referred to as AT) in a direction perpendicular to the scanning direction. Furthermore, in order to correct variations in scanning speed, it was also necessary to obtain a clock signal. Therefore, Mr. Mizuide started working with Dr@xl@r Technology Corpo.
According to a technical disclosure received from RATLON), an optical card has been proposed in which a track for obtaining a tracking signal and a clock signal is formed in advance on the card. A first example of such an optical card is shown in FIG.

FIG. 3 is a schematic plan view of the optical card. Here, a clock signal is recorded in advance on the optical card 31, and a clock track 32 is formed in an intermittent broken line shape.
2-32m-324... are arranged at equal intervals. Recording areas 341, 34t-341, . . . for recording information are provided between the clock tracks.

FIG. 3 @) shows an enlarged view of the recording surface of the optical card 31. When recording information on this optical card, three beams are irradiated from the optical head, and each beam is ejected into a small slit.
, , S, , 8. The light is focused as

These spots are scanned in the direction of arrow a by the relative movement of the optical card and the optical head, and are scanned in the recording area 34 . The recording pit 35 is recorded by the center spot s2.
Information is recorded as follows. Further, the reflected light from either the spot S or S is guided to a detection means in the optical head, and a tracking signal is detected using a known method such as a so-called pushinable method. Based on this tracking signal, the positions of the spots s11s, Is, in the vertical direction (b direction) are moved integrally with the scanning direction, so that the spot S always traces accurately on the clock track 321. do. Therefore, the recording pit 35. are formed precisely along the clock track 321, thereby preventing the information tracks from crossing over. At the same time, a clock signal is reproduced from the reflected light from the spot S1 or S, and is used as a clock for the recording signal. Furthermore, information is reproduced in the same manner.

However, in general, in optical cards, the transfer speed of the card during recording or reproduction is slow, so the frequency of fluctuations in the tracking signal due to the discontinuity of the clock track is close to the servo band of the AT (which has the disadvantage of adversely affecting the AT). there were.

Therefore, a second example of an optical card that solves the above drawbacks is proposed in the above-mentioned technical disclosure. This is shown in FIG.

The fourth weakest country is a schematic plan view, and the optical card 41 has a recording area 44. , 44. ... and on one side is a clock track 42. , 42. , 42°...but,
Also on the other side is a tracking track 43* -43
@-4:%... are formed respectively. Here, the tracking tracks 431... have a continuous linear form.

FIG. 4 ω) shows an enlarged view of the recording surface of the optical card 41. In this optical card, three spots are basically scanned in the direction of the arrow a, similarly to the example shown in FIG. 3, and recording pits 45 are recorded by the spot S.

However, in this example, tracking track 4 at spot S
The tracking signal is violated by tracing 3s = 43... Further, the clock signal is obtained from spot 8 which is irradiated onto the clock tracks 42m-42m... Therefore, in this example, the tracking signal can be detected completely independently of the clock signal, and an accurate measurement T.
is possible.

However, the optical card 41 requires more area for the tracking track than the example shown in FIG. 3, and the recording capacity per area inevitably decreases.

[Summary of the invention]

An object of the present invention is to solve the drawbacks of the prior art and provide an optical information recording medium that enables accurate AT without reducing the recording capacity per area.

The above objects of the present invention are achieved by alternately arranging tracking tracks for obtaining tracking signals and clock tracks for obtaining clock signals.

〔Example〕

FIG. 1 shows an embodiment of an optical card according to the present invention, in which the figure shows a schematic plan view of the card (the figure shows an enlarged view of the recording surface of the card). Nine clock tracks 21 m 21 # 21 . . . are recorded and formed in an intermittent broken line shape, and tracking tracks 3, , 3, . . . are formed in a continuous line shape.
are arranged alternately at equal intervals. And a recording area of 41 m for recording information on each track held 4.
l 4. ...is provided. That is, the optical card l
has a recording area all between the clock track and the tracking track.

When recording information on the optical card 1, first, as shown in (B), the spots s, ps, and a 88 are respectively placed on the clock track 21 by Sl and the tracking track 3 by ps.
Irradiate so that it is above 1. Spots 8 to S1 are scanned in the direction of arrow a by relative movement of the optical head that forms these spots and the optical card. Here, a tracking signal is detected from the reflected light of the spot S5 using a well-known method such as a clock signal. Based on this tracking signal, Spora) Sls s* 6 s
, are integrally moved in the direction perpendicular to the scanning direction (b direction),
AT is performed. As a result, the recording bit 5 is accurately recorded in the recording area 4□ along the tracking track 3m by the spot Ss. Next, recording area 4
．． When recording information on the spot, set the spot to 81' * 8
j s 8m', regenerate the clock signal from the clock track 28 by S', and
While performing AT by obtaining a tracking signal from the tracking track 3, 3. ' to record information. By switching operations like this, it is possible to record information in all recording areas. Here recording areas 41 and 4
The recording may be performed using different optical heads, or may be performed using the same optical head.

Reproduction of the information recorded as described above is also performed in the same manner as during recording. On the recording surface of the optical card, clock tracks 2□, 2. . . and tracking tracks 38 . . . , information tracks 25z, 25m . . . consisting of recording pit rows are formed. First, information track 25! When reading out the information, irradiate the three spots as shown in
A clock signal is reproduced from 81, and information is reproduced by detecting reflected light from the S warehouse while performing AT using a tracking signal from S. Next, when reading the information on the information track 25, move the spot to 81'a.
Irradiate as shown in k'
Perform playback. By switching the operation like this,
Information recorded in any area of the optical card can be reproduced. As shown in ζO, the optical head for reading information may be the same as the head used for recording, or a different optical head may be used. Furthermore, when reproducing recorded information, the clock can be extracted from the signal itself recorded on the information track (so-called self-clock), and it is not always necessary to reproduce the clock signal from the clock track. Therefore, various reproduction methods can be considered in addition to the example shown in FIG.

The present invention is not limited to the optical card having the amount of reflection shown in the embodiment.

It can also be applied to devices with a transmission amount in which information is recorded and reproduced by detecting light transmitted through an optical card. The tracking track and the clock track are formed in advance in the form of, for example, a change in reflectance, absorption spectrum, or phase change due to unevenness in the case of reflection amount. Transmission No.
Similarly, changes in transmittance, refractive index, and absorption spectrum,
D! J-convex formation etc. can be used. Furthermore, these tracks may have internal microstructures such as folded gratings. In addition, recording pits when recording information may be written by spot light irradiation based on the Ix principle similar to tracking tracks or a-track tracks on the recording surface, or they may be formed in a form different from these. You may do so.

According to the present invention, no matter in which recording area information is recorded, the tracking signal can be detected by the tracking track on either side of the recording area.
Accurate AT that is not affected by clock signals compared to the example in the figure
It is possible to do this. 9. Since it has a recording area on each track, it has a larger recording capacity per unit area than the example shown in FIG.

〔Effect of the invention〕

As explained above, the present invention arranges tracking tracks and clock tracks alternately in an optical card, and provides a recording area for each track, without reducing the recording capacity per unit area. , A.T.
This has the effect of improving the accuracy of.

[Brief explanation of drawings]

1(4) and (B) are diagrams each explaining an embodiment of the optical card based on the present invention, and FIG. 2 is an enlarged view of the recording surface of the optical card shown in FIG. Figure 3 (4)
, (B) and FIGS. 4(4) and 4(B) are diagrams illustrating examples of conventional optical cards, respectively. l...optical card, 2. , 2. , 2□...Clock track sat #a,...Tracking track 541m42*4s...Recording area, s, s s
, t s, *3. / # S's SS'”'
Spot〇

Claims (1)

[Claims] (1) A card-shaped optical device in which tracking tracks for obtaining tracking signals and clock tracks for obtaining clock signals are arranged alternately, and a recording area for recording information between each track. information recording medium.