JPH05151715A - Information recording disk - Google Patents

Abstract

PURPOSE:To eliminate one rotation waiting time of a disk and to enable continuous recording and reproducing of an information by providing a switching region corresponding to the switching time of recording and reproducing frequencies at the recording region boundary where recording and reproducing frequencies are different. CONSTITUTION:An information recording disk is divided into a spiral shaped information track 101 and sectors 102 and 103 are provided. The disk has a so-called MCAV system format in which recording and reproducing frequencies are step wise switched to gradually become higher from the inner to the the outer peripheries. The recording and reproducing frequencies are switched corresponding to the recording regions by switching the clocks of a synthesizer. The sector 102 is the last sector of a recording and reproducing frequency A, the sector 103 is the top sector of the next recording and reproducing frequency B1 and the recording and reproducing frequency is switched at the boundary between the sectors 102 and 103. A switching region 105 is provided in this boundary region so that the length of the region is set in accordance with the switching time of the recording and the reproducing frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording disk such as an optical disk and a magneto-optical disk, and more particularly to an information recording disk divided into a plurality of recording areas having different recording / reproducing frequencies.

[0002]

2. Description of the Related Art Conventionally, in an optical disc having a spiral information recording track (hereinafter referred to as a track), the recording / reproducing frequency is increased stepwise from the inner circumference to the outer circumference of the disk in order to increase the storage capacity. Therefore, a recording format has been proposed in which the mark length (information density) is substantially constant regardless of the inner and outer circumferences. Such a system is generally called MCAV. FIG. 3 is an enlarged view showing a switching portion of the recording / reproducing frequency of the MCAV recording format. In the figure, 501 to 5
Reference numeral 03 denotes an information recording sector (hereinafter referred to as a sector), and a boundary between the sectors 501 and 502 is a recording / reproducing frequency switching boundary. In addition, at the end of each sector, in order to absorb the fluctuation in rotation during disk rotation,
A buffer unit 504 for a disk rotation fluctuation margin is provided.

FIG. 4 is a block diagram showing an information signal processing system of the above-mentioned optical disk recording / reproducing apparatus. In FIG. 4, the information sequence converted into an electric signal by the detection means 303 at the time of reproducing information is digitized by the binarization circuit 305, and the data separator 307 and the sector mark (S).
M) Input to the sync signal detection circuit 306 for detection. In order to detect the SM sync signal, the controller 319 issues an instruction signal 3 for specifying the recording / reproducing frequency in advance.
18 is output to the synthesizer 309. Therefore, the synthesizer 309 outputs a clock 311 for synchronization.
Is output to the synchronization signal detection circuit 306. Further, the clock 311 output from the synthesizer 309 is input to the data separator 307, and the sync data 313 and the sync clock 314 are input from the digitized information string.
Is extracted.

[0004]

By the way, in the above-mentioned conventional example, it is necessary to switch the recording / reproducing frequency when the reproducing operation shifts from the sector 502 to the sector 503. Explain. First, immediately after the end of reproduction of the sector 502, the controller 319 outputs a frequency switching instruction signal 318 to the synthesizer 309. This time is t _c . As a result, the recording / reproducing frequency A before the instruction transits to B1 by switching the clock 311 of the synthesizer 309. As a result, in the data separator 307, the binarized signal is newly synchronized with the changed clock 311. However, the PL of the data separator 307
The time (t ₁ -t _c ) until the synchronization signal 313 locked to L is stably extracted is generally longer than the time required for the recording / reproducing head to pass through the buffer section 504 for the disk rotation margin, and thus the above-mentioned Sector 502 and Sector 503
Cannot be played continuously. Therefore, when continuously playing back recording areas with different recording and playback frequencies,
There is a problem in that the waiting time for one rotation of the disk is added as an overhead and the reproduction time becomes long. Also,
There was a similar problem when recording.

The present invention has been made in order to solve such a problem, and an object thereof is to wait for one rotation of a disk when continuously recording and reproducing recording areas having different recording and reproducing frequencies. An object of the present invention is to provide an information recording disk capable of continuously recording and reproducing information without requiring.

[0006]

DISCLOSURE OF THE INVENTION It is an object of the present invention to record information having a different recording / reproducing frequency on an information recording disk in which information tracks are spirally provided and the recording / reproducing frequency is switched in a plurality of steps according to the recording area. This is achieved by an information recording disk characterized in that a frequency switching area according to the switching time of the recording / reproducing frequency is provided at the boundary of the areas.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing an embodiment of an information recording disc of the present invention. In FIG. 1, 101 is a spiral information track provided on the information recording disk, and 102 and 103 are sectors provided by dividing the information track 101. The information recording disc is
It is formatted in a so-called MCAV system in which the recording / reproducing frequency is switched so as to sequentially increase from the inner circumference to the outer circumference in a plurality of steps. The recording / reproducing frequency can be switched corresponding to the recording area by switching the clock 311 of the synthesizer 309 as described in FIG. In the example of FIG. 1, the last sector, sector 103 of the sector 102 recording frequency A is a first sector of the next recording frequency B _1, the sector 102 and 1
The recording / reproducing frequency is switched at the boundary of 03. In the present embodiment, a switching area 105 whose length is set according to the switching time of the recording / reproducing frequency is provided in this boundary area. The switching area 105 will be described later in detail. Reference numeral 106 in the figure is an arrow indicating the rotation direction of the information recording disk.

FIG. 2A shows the sector 103, and FIG. 2B.
FIG. 3 is a diagram showing in detail the format of each sector 102. In the figure, 203 indicates S, which is the start position of the sector.
M, 204 is ID fields, 205 is Sync fields, 20
6 is Data and Reync fields, 207 is a buffer section (Buffer
fields). The buffer section 207 is provided to absorb the rotation fluctuation when the information recording disk rotates, as described above. 105 is the sector 102 and 10
The switching area 105 is a switching area for the recording / reproducing frequency provided between No. 3 and No. 3, and the switching area 105 is set as follows. First, it is assumed that the last sector of the recording area of the recording / reproducing frequency A described in FIG. 5 is the sector 102, and the recording / reproducing frequency is switched to B ₁ over the next sector 103. In this case, the switching area 105 is regarded as a circular arc centered on the center O of the disk, its central angle is θ, and the time required for the recording / reproducing head to pass through the switching area 105 is T _b . Further, the time required for one rotation of the disc is T, the central angle corresponding to a region required as a rotation fluctuation margin of the disc (region as a buffer portion) is θ _W , and the recording / reproducing frequency A is B as described with reference to FIG. Move to ₁ ,
The time required for stable recording and reproduction is t ₁ -t _c . Based on these conditions, the setting condition of the switching region 105 capable of stably switching the recording / reproducing frequency is set so as to satisfy the following formula.

Θ ≧ θ _W + 2π (t ₁ −t _c ) / T

[0010]

As described above, according to the present invention, a switching area corresponding to the switching time of the recording / reproducing frequency is provided at the boundary of the recording areas having different recording / reproducing frequencies, so that the overhead of waiting for one rotation is required. Without
There is an effect that continuous recording / reproduction can be performed and the recording / reproduction time can be significantly shortened compared to the conventional case. Further, in the case where the recording area is subdivided in order to increase the capacity efficiency, the change point of the recording / reproducing frequency is increased, so that the effect is further increased.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an information recording disc of the present invention.

FIG. 2 is a diagram showing a sector format of the embodiment of FIG.

FIG. 3 is a diagram showing a conventional information recording disk.

FIG. 4 is a block diagram showing an information signal processing system of an MCAV type optical disc recording / reproducing apparatus.

FIG. 5 is a characteristic diagram showing a frequency response when the recording / reproducing frequency is switched.

[Explanation of symbols]

 101 information track 102, 103 sector 105 switching area 207 buffer section

Claims (1)

[Claims] 1. In an information recording disk in which information tracks are spirally provided and the recording / reproducing frequency is switched in a plurality of steps according to the recording area, the recording / reproducing frequency is switched at the boundary of the recording areas having different recording / reproducing frequencies. An information recording disk having a frequency switching area according to time.