JPS62239344A - optical information recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an optical information recording medium, and particularly to an optical information recording medium suitable for application to a card-shaped medium.

[Prior Art] Conventionally, various types of media such as discs, cards, and tapes have been known as media for recording information using light and reading recorded information. (hereinafter referred to as "card") is expected to be in great demand as a small, portable, large storage capacity medium that is convenient to carry.

FIG. 8 is a schematic plan view of such an optical card.
is an optical card, 103 is a tracking track, and 107 is a track number.

The optical card described above is an optically detectable recording pit row (information track) by scanning the card with a light beam that is modulated according to recorded information and focused on a minute spot.
Information is recorded as .

At this time, in order to accurately record and reproduce information without causing problems such as crossing of information tracks, the irradiation position of the light beam is controlled in a direction perpendicular to the scanning direction (auto tracking, hereinafter referred to as AT). There is a need to. Further, in order to stably irradiate a minute spot despite the bending of the optical card and mechanical errors, it is necessary to perform control (autofocusing, hereinafter referred to as AF) in a direction perpendicular to the optical card.

do. Initially, the light beam is at a home position outside the recording area. Next, the light beam moves in the direction shown in the figure, finds a track to be recorded or reproduced, scans this track in the F direction, and records or reproduces. Here, as a means for detecting whether the track is a target track or not, conventionally, as explained in FIG.
The track number 107 recorded in advance on the extension line (hereinafter referred to as preformat) is read, and the contents are inspected to determine whether or not it is the target track. Furthermore, by inquiring the track number and management information, it can be determined whether the track has already been recorded or not, and it is possible to prevent so-called override, in which additional information is accidentally written on a recorded track.

However, in such conventional optical cards,
The tracking track, which should not be interrupted, becomes partially missing due to the track number, which causes a disturbance to the control circuit system of the AT, which is undesirable in terms of control. Furthermore, since the track addresses are formed in advance, there is a problem in that if there is a defect such as a pinhole at the position where the track number is formed, malfunctions may occur.

[Summary of the Invention] An object of the present invention is to provide an optical information recording medium that eliminates the drawbacks of the prior art described above, allows reliable confirmation of a reference position with a simple configuration, and avoids overriding. .

The above-mentioned object of the present invention is to have tracking tracks arranged at regular intervals and a recording section provided between the tracking tracks and on which information is recorded by irradiation of a light beam, and at least one of the recording sections. This is achieved by an optical information recording medium provided with an optically detectable mark indicating a reference position.

[Example] FIG. 1 is a schematic plan view of an optical card to which the present invention can be applied. In the figure, an optical card 1 includes a substrate made of plastic or the like, and a recording layer 2 of a silver salt type, dye type, chalcogen type, etc. on which information can be recorded optically. Further, on this recording layer 2, tracking tracks 3+, 32+3s, which are formed in advance in a continuous linear shape, are formed in advance.
*34+3 g, .

...3n-1+3・-3, 3・-2・ 3・-1・
3. are arranged parallel to each other at equal intervals. A recording section for recording information between each track is provided. That is, the optical card 1 has a recording section located between each tracking track. Further, optically detectable reference position marks 51.5□ (hereinafter referred to as G marks) are formed at two locations on the recording section. Further, a medium identification pattern 6 is formed in the recording section where the G mark 52 is provided.

FIG. 3 is a diagram illustrating the configuration of an embodiment of an optical information recording and reproducing apparatus for recording and reproducing information on an optical card according to the present invention. A beam emitted from a light source 11 such as a semiconductor laser is collimated by a collimator lens 12, and is converted into three beams 14 by a diffraction grating 13 onto an optical card 1 as shown in FIG. 6, forming beam spots Sl, S2, . s,
form. Here, the optical card 1 is moved in the direction of arrow R by a driving means (not shown), and is scanned by the beam spot in the direction in which the tracking track extends. Beam spot Sl.

S2. The reflected light from S3 passes through the objective lens again, is reflected by the beam splitter 15, and is sent to the condenser lens system 16.
are projected onto photodetectors 17, 18, and 19, respectively.

The condensing lens system 16 is an astigmatism system, and is an example arranged so that autofocusing can be performed using a well-known astigmatism method. These photodetectors are configured in the arrangement shown in FIG. In Figure 3,
20 is a prism for converting the cross-sectional distribution of the collimated light beam emitted from the semiconductor laser from an ellipse to a circular shape, and 21 is a mirror that guides the light beam to the objective lens 14.

The photodetector 18 has a light-receiving surface divided into four parts as shown by A, B, C, and D in FIG. -ffrI
The operation when recording a bird report of 10 meters and 9 meters or more will be explained with reference to FIG. 4. First, when recording information on the recording section 10, spots Sl, s2. S3 is applied to the tracking track 35, recording section 10, and tracking track 34, respectively. These spots are scanned in the direction of arrow F by the movement of the optical card 1 as described above. The reflected light from spot S1 enters the aforementioned photodetector 17, and the reflected light from spot S3 enters photodetector 19,
Tracking signals are detected from these output signals.

That is, spots S1 and S3 are tracking track 3S.
, 34, a difference occurs in the intensity of light incident on the photodetectors 17 and 19, and a tracking signal is obtained by comparing the signals from these light receiving surfaces.

Based on this tracking signal, the spots s, , S2,
33 are integrally moved in a direction perpendicular to the scanning direction (direction b) to perform AT. Then, the recording section 10 has a spot S.
2, the recording pits 9 are accurately recorded along the tracking track 34.3S. The recorded pits are indicated by broken lines in FIG.

Next, the function of the G mark will be explained. Figure 2 is G of Figure 1.
This is an enlarged view of the part where the mark 52 is provided. The mark 52 is actually formed in the shape of an interrupted broken line as shown in FIG.

Initially, the light spot S1 is at the home position 4, and when this light spot S+ is moved in the D direction by a driving means (not shown), the detection signal level of the reflected light of the spot S1 changes as shown in FIG. . That is, the spot S1 moves in the D direction, and the tracking track 3n
The first change appears when it crosses 3n+1%3
It changes every time it crosses n-2 and G mark 52. At this time, if the moving speed of the spot is constant, 3n-2 and 52
and the time between 3n and 3n-1%3n-1 and 31-2
Since it is clearly different from the time between, it is possible to determine whether the G mark 52 has been crossed by using a time measuring circuit (not shown) to measure the change time of the signal. Next, when the light spot S1 comes to the top of the tracking track 3°-5, as shown in FIG. 4, the light spot S3 is on the tracking track 3°-2. stop.

Next, in this state, card 1 is sent in the F direction to point p, and then in the backward direction to point 9. Light spot S at this time
The change in the signal level obtained from the + reflected light is shown in Figure 6.When the card is sent to point P, the signal level is LOW, the card feeding direction is reversed, and the time when the signal is HIGH while passing through the G mark 52 is measured. If so, it is determined that it is a G mark, and if there is no change in the signal by the time the 9th point is reached, the current track is determined to be the reference track. By arranging the preformatted G mark at a predetermined location on the card 1 as described above, it becomes possible to reliably identify the reference track without arranging a track number on the tracking track. Then, based on this reference track, add 11 ml + 6 sets of subbolts in the direction of the arrow in Figure 1. Information is recorded one after another in the recording section. And another G mark 5. When detected, that recording section is determined to be the final track, and recording ends.

That is, in this embodiment, the recording area 8 is formed on the medium surface;
It is divided into non-recording areas 71.7 and 7□, and their boundaries are marked with G marks 5. ．． 52. Tracking track 3n+3n-1r3 provided in the non-recording area 72
n-2 is not used for recording information, but is simply used as a guard track. For example, when the recording section closest to the Baume position is set as the reference track, the light spot is moved in the first tracking direction, and when the light spot crosses the tracking track that first appears, the control circuit of the AT (not shown) rapidly As the vehicle tries to follow the track, the optical pickup (ie, the optical spot) also moves rapidly and greatly. As a result, overshoot or the like may cause a malfunction in which the track follows the next track. Therefore, in this embodiment, at least two or more tracking tracks are provided outside the recording section where the G mark 5□ is provided, and these are used to reliably draw the G mark 52 into the tracking track. This starts detection.

Similarly, the tracking track 3. provided in the non-recording area 71. ．． 32.33 is also used as a guard track. That is, when accessing the track, G mark 5. due to trouble. When the spot goes past the final track without being detected, one of these guard tracks pulls the spot in to prevent the spot from jumping out from the surface of the medium. G like this
It is desirable that at least two or more tracking tracks are also formed outside the mark 5□.

The intermittent pattern of the G mark shown in Figure 2 is sometimes preferable because the detection signal clearly appears when the spot crosses it, but the same effect can be obtained by using the G mark as a partial band-like pattern. It will be done.

In addition, the G mark is shown in Figure 1, 5. ．． As shown in 54, by providing the track on the q side as well, the area sandwiched between HIGH signals for a certain period of time between p and 9 is determined to be the reference track, making it less susceptible to scratches and dust. A reliable reference position can be detected.

When the present invention is applied to an optical card as in the above embodiment, the width W1 of the tracking track shown in FIG.
．． It is desirable that the thickness is 5 μm or more. The reason for this will be explained below.

Optical information recording media usually have a transparent protective layer on the recording layer on which the beam spot is imaged. The light beam diameter on the surface of this protective layer is larger than the spot diameter on the recording layer. Therefore, even if there is dust on the surface of the protective layer,
Even if dust or the like is attached, the influence on signal detection will be small. Based on this principle, optical disks and the like have a track width of about 1 to 2 μm to achieve high density. However, in optical cards,
From the viewpoint of standardizing the size with general credit cards, etc., the card thickness is limited to about 8+1111.

Therefore, the thickness of the transparent protective layer is also 1/3 that of the optical digital screen.
The width of the tracking track must be approximately 1/2.5, but considering the engraving of dust, etc., the width of the tracking track needs to be 2.5 μm or more. For the same reason, it is desirable that the interval between the tracking tracks, that is, the width W1 of the recording section, is also 2.5 μm or more.

In addition to the embodiments described above, the present invention can be applied in various ways. For example, the medium shape is not limited to a card shape, but can also be applied to a tape shape.

[Effects of the Invention] As explained above, the present invention provides a mark indicating the reference position on a part of the recording section, so the reference position can be reliably confirmed with a simple configuration, and overriding can be avoided. It has become possible.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the optical information recording medium of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is an example of the recording/reproducing device of the medium shown in FIG. Figure 4 is a perspective view showing the plane of the medium showing the recording pattern.
Each figure shows the waveform of a detection signal, and FIGS. 8 and 9 are plan views showing examples of conventional optical information recording media. DESCRIPTION OF SYMBOLS 1... Optical card, 2... Recording layer, 31-311
...Tracking track, 4...Home position, 5, ~54...G mark, 6...Pattern for medium type identification.

Claims (1)

[Claims] (1) Tracking tracks arranged at regular intervals,
a recording section provided between the tracking tracks and on which information is recorded by irradiation with a light beam; an optical Information recording medium.