JPH04370574A - Recording system and recording disk - Google Patents

Abstract

PURPOSE:To provide a recording system capable of recording a video signal with high density and also capable of accessing with high speed at the time of reproduction. CONSTITUTION:This system is provided with a buffer memory 7 compressing time-axially the video signal to 1/N and a head 4 recording the video signal which is time-axially compressed to 1/N of the buffer memory 7, in a recording disk 1. The position of this head on the radius of recording disk 1 is divided into plural areas A, B, C, and when the position of the head 4 on the radius exists within each area A, B, C, N is set equally for each, and also when the position of the head 4 on the radius exists in the area distant from the center of recording disk 1, N is set larger as compared with the case when the position of the head 4 on the radius exists in the area near the center of recording disk 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method for recording information signals and a recording disk on which information signals are recorded.

0002

2. Description of the Related Art Conventionally, information signals are recorded at a constant speed over the entire surface of a recording disk that is rotated at a constant linear velocity.

0003

[Problem to be Solved by the Invention] It is preferable to record information signals at a constant speed over the entire surface of a recording disk that is rotated at a constant linear velocity because it increases the recording density of the recording disk. On the other hand, when reproducing information signals recorded on a recording disk, it is necessary to change the rotational speed of the recording disk depending on the radial position of the reproducing head, which makes high-speed access difficult. There was a drawback.

[0004] In view of the above, the present invention aims to propose a recording system and a recording disk that can record information signals at high density and nearly uniform density, as well as enable high-speed access during reproduction.

[0005]

[Means and operations for solving the problems] The recording method according to the first invention includes a compression means 7 for compressing the time axis of an information signal to 1/N, and a time axis compression means 7 for compressing the time axis to 1/N from the compression means 7. The radial position of the head 4 on the recording disk 1 is divided into a plurality of areas A, B, and C, and the radial position of the head 4 is divided into a plurality of areas A, B, and C. is in each area A, B, C, N
are set equal and the radial position of the head 4 is within an area far from the center of the recording disk 1,
N is set larger than when the radial position of the head 4 is within an area close to the center of the recording disk 1. Note that N is a positive integer or a value obtained by adding a positive decimal to a positive integer.

In the recording disk according to the second aspect of the present invention, a recording track is divided into a plurality of areas A, B, and C according to the size of the radius on a recording disk 1 that is rotated at a constant number of rotations, and each area is divided into two areas. Information signals are recorded on the recording tracks in areas A, B, and C at the same speed, and
Information signals are recorded on each recording track in an area consisting of recording tracks having a large radius at a higher speed than in each recording track in an area consisting of recording tracks having a small radius.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a recording/reproducing apparatus according to an embodiment of the present invention, which will be explained below. Reference numeral 1 denotes a recording disk, here a magneto-optical disk, which is rotated by a motor 3 via a spindle 2 at a constant rotational speed. As shown in FIG. 2, the disk 1 is divided into areas A, B, and C according to the radius of the recording track, which is small, medium, or large. Reference numeral 4 denotes an optical head (optical pickup) for recording and reproducing, and although not shown, it is configured to be able to move on the radius of the disk 1.

Next, the recording system will be explained. The video signal is supplied to the A/D converter 6 through the input terminal 5 for A/D conversion, and the resulting digital video signal is stored in a buffer memory having a storage capacity of 3 frames under the control of the microcomputer 12. 7, as shown in FIG. 3A1, the reference frequency F
0, and as shown in FIG. is supplied to the head 4 moving from the inside to the outside within the area A, and the disk 1 is supplied so that one frame (1F) of the digital video signal corresponds to one track.
The data is sequentially and continuously recorded on each track in area A of .

The video signal is supplied to the A/D converter 6 through the input terminal 5 for A/D conversion, and the obtained digital video signal is stored in the buffer memory 7 under the control of the microcomputer 12 as shown in FIG. 3B1. As shown, the reference frequency F0
3B.
As shown in FIG. 2, the time axis is compressed to 1/2 by continuously reading out the clock signal R-CK having a frequency 2F0 which is twice the reference frequency F0 from the PLL 11 controlled by the microcomputer 12. is supplied to the head 4, which moves from inside to outside within area B, on the radius of
Recording is performed sequentially and continuously on each track in area B of the disk 1 so that 1F×2) corresponds to one track.

The video signal is supplied to the A/D converter 6 through the input terminal 5 for A/D conversion, and the obtained digital video signal is stored in the buffer memory 7 under the control of the microcomputer 12 as shown in FIG. 3C1. As shown, the reference frequency F0
3C.
As shown in FIG. 2, by continuously reading out the clock signal R-CK with a frequency 3F0, which is three times the reference frequency F0, from the PLL 11 controlled by the microcomputer 12, the time axis is compressed to 1/3. The head 4 moves from the inside to the outside within the area C on a radius of Record sequentially and continuously on each track. In addition, the number of each track, the number of frames (or number of sectors) of the digital video signal in that track, and the time axis compression ratio 1
/N is recorded (stored) in the directory track of the disk 1 and the memory of the microcomputer 12,
The data is used during playback.

Next, the reproduction system will be explained. Recording disc 1
Under the control of the microcomputer 12, the reproduced digital video signal for one frame (1F) per track in the area A from the head 4 moving from the inside to the outside in the area A on the radius of A clock signal W-CK of a reference frequency F0 synchronized with a reproduced digital video signal from a PLL 11 controlled by a microcomputer 12 is continuously written into a buffer memory 8 having a storage capacity for a frame, and the clock signal W-CK is used as a reference. After continuous reading with a clock signal of frequency F0, D
/A converter 9 and outputs an analog video signal to output terminal 10.

The reproduction digital video signal for two frames (1F x 2) per track in area B from the head 4 moving from the inside to the outside in area B on the radius of recording disk 1 is processed by a microcomputer. A clock signal W-CK having a frequency twice the reference frequency F0 (2F0) is supplied to the buffer memory 8 under the control of the microcomputer 12 and synchronized with the reproduced digital video signal from the PLL 11 controlled by the microcomputer 12. The data is written continuously and read out continuously using a clock signal of the reference frequency F0 to expand the time axis by a factor of two, and then is supplied to the D/A converter 9 and an analog video signal is output to the output terminal 10. do.

The reproduction digital video signal for three frames (1F x 3) per track in area C from the head 4 moving from the inside to the outside in area A on the radius of recording disk 1 is processed by a microcomputer. A clock signal W-CK having a frequency (3F0) three times the reference frequency F0 is supplied to the buffer memory 8 under the control of the microcomputer 12 and synchronized with the reproduced digital video signal from the PLL 11 controlled by the microcomputer 12. Continuously write the reference frequency F0 as shown in Figure 3A2.
By reading out continuously using the clock signal of 3
After expanding the time axis by a factor of two, the signal is supplied to the D/A converter 9, and an analog video signal is output to the output terminal 10.

In the above description, a digital video signal of a moving image is recorded on and reproduced from the recording disk 1, but a digital video signal of a still image can also be recorded on and reproduced from the recording disk 1. In this case, by specifying the recording track number and sector number of the recording disk 1 during playback, the specified recording track number and sector number can be accessed at high speed, and the still image recorded thereon can be accessed at high speed. can play back digital video signals.

In the above embodiment, the recording disk 1
In the above, the case where the recording track is divided into three areas according to the size of the radius has been described, but the number of divisions is arbitrary. Further, the number of frames of the digital video signal recorded on one track of the recording disk 1 is not limited to an integer, and may be a fraction below the decimal point. Furthermore, the information signal recorded on the recording disc 1 may be not only a video signal but also other information signals such as an audio signal. Further, the information signal is not limited to a digital information signal, but may be an analog information signal, an FM modulated analog information signal (digital information signal), or the like. Furthermore,
The recording disk 1 is not limited to a magneto-optical disk, but may be an optical disk, a magnetic disk, a capacitance type recording disk, or the like.

[0016]

According to the present invention described above, information signals can be recorded at high density and at nearly uniform density, and since the number of rotations of the recording disk is constant, high-speed access during reproduction is possible. It is possible to obtain a recording disk and a recording method that allows easy control of a motor that rotates the recording disk.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a recording/reproducing device according to an embodiment of the present invention.

[Figure 2] Explanatory diagram of recording on a recording disc

[Figure 3] Explanatory diagram of signal processing

[Explanation of symbols]

1 Recording disc 3 Motor 4 Optical head (optical pickup) 7 Buffer memory 8 Buffer memory 12 Microcomputer A Area B Area C Area

Claims (2)

[Claims] 1. Compression means for compressing the time axis of an information signal to 1/N, and a head for recording the information signal from the compression means compressed in the time axis to 1/N on a recording disk, the head When the radial position of the recording disk is divided into a plurality of regions, and the radial position of the head is within each region, the N is set equal to each other, and
When the radial position of the head is in an area far from the center of the recording disk, the N is set to be larger than when the radial position of the head is in an area close to the center of the recording disk. A recording method characterized by being set to . 2. In a recording disk that is rotated at a constant rotation speed, a recording track is divided into a plurality of areas according to the size of the radius, and information signals are recorded on the recording track in each area at the same speed. In addition, an information signal is recorded on each recording track of the area consisting of recording tracks with a large radius at a higher speed than in each recording track of the area consisting of recording tracks with a small radius. disk.