JPH0411924B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording method for optically recording digital or video information on a rotating recording disk.

[Conventional technology]

2. Description of the Related Art Techniques for optically recording and reproducing information on a disk-shaped information recording medium, such as an optical video disk, are conventionally known. One of the features of disc-shaped recording media is that when reading information, the required information can be accessed at high speed. In this case, information tracks are usually arranged in a spiral shape on a disk, and each track is given an address indicating the position of the track.

[Problem to be solved by the invention]

In FIG. 1, on track 2 on disk 1, address 3 and data 4 are recorded every round. When reproducing information, the address of the track requested from the outside is given, and the reproduction head is accessed so as to optically detect a track that matches this address. For example, when recording information such as video information, where the information is separated by one track rotation, the addresses can be recorded on the same radius on the disk by aligning the positions in the gaps between the data. When recording continuous information such as information that does not have a break every time a track goes around, data may be recorded in an overlapping manner at a fixed address position on the disk.

To avoid this, for example, it is possible to count the number of data from the address position, stop the data once the track has gone around the track, record the next address, and then continue recording the data. If there is rotational unevenness (so-called jitter), overlapping recording will still occur.

The present invention solves the above problems and provides an optical information recording method that can prevent overlapping recording and accurately record information.

[Means to solve the problem]

In the recording method of the present invention, an index mark having a reflectance different from that of the surrounding area is provided on the inner or outer periphery of the recording disk, and each rotation is performed using an index pulse that is optically detected from the mark. This method is characterized by controlling the recording start position of the track.

[Effect]

According to the present invention, since the recording start position of each track is controlled by the index pulse detected every rotation from the index mark provided in the shape of a recording disk, overlapping recording is prevented and information is recorded correctly. can do.

〔Example〕

An embodiment of the present invention will be described below using one data format. An example of the recording disk used in FIG. 2 is shown. On the disk 1, an information track 2 and an index mark 5 indicating a reference position on the disk surface are formed on the inner or outer circumference of the disk. The index mark 5 is formed by pasting a metal piece of 1 to 2 mm, making the reflectance different from the other surface by metal vapor deposition, or making a hole. The index mark 5 is read as shown in FIG. That is, in the figure, a minute index mark with high reflectance is formed on a disk with low reflectance. A diffused beam of light emitted from a light emitting element (for example, a small lamp, a light emitting diode, a diode laser) 6 is condensed by a condensing lens 8 to a disk 2.
The reflected light beam is focused by the lens 9 and focused on the light receiving element 7 . When the index mark 5 is placed on the disk, the reflectance of that portion is high, so the output of the light receiving element increases and the index mark is detected.
The lens and the light emitting/receiving element may be placed several mm to cm from the disk. Note that the signal detected each time the disk rotates is called an index pulse.

In FIG. 2, the information track 2 has an address section 21, a data section 22, and an EOF section 23 in one data format, an address is added to each data, and recording is continued in a continuous spiral manner. The recording method of the present invention will be explained in detail using the time chart shown in FIG. Based on the index pulse (shown in Figure 4a) generated every rotation, a gap of 20 is set to prevent signal overlap.
(shown in Figure 4b), then track address 210
The address part 21 (shown in Figure 4c) containing the information address 211 in the same track is recorded, followed by the data part 22 (shown in Figure 4d), and at the end of the data part 22, the data part 21 is recorded. An EOF section 23 indicating the end is recorded. Then, when recording the next data, the address section 21, data section 22,
The EOF portion 23 (shown in FIG. 4e) is recorded. Next, the case where an index pulse arrives will be explained. When an index pulse comes while recording the address section 21 or the data section 22, the address section 21 records all the contents, and the data section 22 records only 1.
Stop recording when you have finished recording the data,
Continue gap 20. After the gap 20, the address section 21 is recorded again, and the remaining portion of the data begins to be recorded. If the index pulse comes while recording the EOF section 23, the EOF section 23
After recording ends, end recording. Therefore, gap 2
The period of 0 is selected to be larger than the period of the address section 21, one data section of the data section, and the EOF section 23. For example, 4 bytes of address part, 1 data 2
If the EOF part is 3 bytes, the gap 20 should be 4 bytes or more. Note that if the gap section 20 is left blank, tracking becomes impossible, so a pulse train that is not considered as data is recorded.

Next, consider playback. The current position of the head is n
If the track address and desired address are the m track address and the l information address, first, the optical head (consisting of a light source and lens system) moves while reading the address section 21 after the gap 20 and moves to the m track using the random access mechanism. The address is accessed, and since the information track of the address section after the gap is address 0, the l-th address section is read out while searching m tracks, and then the data section 22 is read out. Considering the case where information is interrupted during recording due to an index pulse and the information that has started recording again is read out, the address field, data field, and EOF
Since the data section is in one data format, the address information once read is stored until the EOF section arrives, and even if the address section comes in the middle of the data section,
Since it has a process of continuing to store data until the EOF section is reached, there is no interference due to index pulses, and even if a gap 20 is provided, it can be reproduced as continuous data.

〔Effect of the invention〕

As described above, by using a recording disk on which index marks are provided on the inner or outer periphery and having a reflectance different from that of the surrounding area, each By controlling the recording start position of the track, information in the address section and data section can be correctly recorded while preventing overlapping recording.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a recording disk for explaining the present invention, FIG. 2 is a diagram showing an example of a recording disk used in the present invention, and FIG. 3 is a diagram illustrating an example of a recording disk used in the present invention. FIG. 4 is a diagram showing an index mark detection method for explanation, and is a diagram showing an example of an information recording method according to the present invention.

Claims (1)

[Claims] 1 An optical information recording method for recording data on a track of a disc-shaped recording medium in an optically readable form, which comprises a disc-shaped recording medium provided with an index mark indicating a reference position on the surface of the recording medium. using the index pulse detected from the mark every rotation of the recording medium as a reference,
An optical information recording method characterized in that recording is started on the track, the recording is ended based on the index pulse, and a gap area where no data is recorded is provided within one revolution of the track.