JPS6310507B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an apparatus for recording and reproducing signals using a disk-shaped recording medium (hereinafter referred to as a disk).

[Prior art and its problems]

Various information recording and reproducing devices using conventional disks (e.g. magnetic disk devices, optical disk devices)
is constant angular velocity (Cnstant Angular Vel
The city (abbreviated as CAV) rotates the disk to record and play back information.

When the disk rotation is CAV, the positional relationship in the track direction of information recorded by dividing it into sectors based on the rotation reference position is that the recording start position of each sector is aligned in the radial direction of the disk, so the sector during playback Detection of the starting position can be easily performed.

However, because the disk rotates in CAV mode, the relative speed between the recording and reproducing heads at the outer and inner peripheries of the disk changes, making it impossible to record and reproduce signals of the same quality on the inner and outer peripheries. .

On the other hand, for signals where the information to be recorded is continuous, such as television signals and audio signals, the disk is rotated at a constant linear velocity (CLV) to increase the storage capacity of the information. There is also the ivy method. However, if the disk rotation is CLV in an information recording/playback device that records and plays back information in sector units, the recording start position of each sector will be different for each track, and it will take time to search for the desired sector during playback. It had

[Purpose of the invention]

The present invention was made in view of the above points, and records information in a certain number of bits (hereinafter referred to as sectors).
However, in an information recording/reproducing device using a disk that records/reproduces data by dividing it into sectors (including accompanying data bits such as address information), the number of sectors recorded in one rotation of the disk is an integer number.
Information recording that improves recording capacity by controlling the rotation in stages so that the linear velocity of the rotating disk is approximately constant with respect to the recording/playback head, and also allows easy and reliable rotation control and sector detection during playback.・The purpose is to provide playback equipment.

[Summary of the invention]

The present invention has the advantage that the recording start positions of each sector are aligned in the radial direction of the disk within a certain number of tracks, and it is possible to increase the recording capacity of the entire disk, which is a characteristic of constant linear velocity recording. It provides a specific means of rotation control, in which the rotational speed is changed in units of a fixed number of tracks, and the rotation of the disk is controlled to a nearly constant linear velocity, and within a unit of a fixed number of tracks, the disc is recorded at a constant angular velocity in one revolution. The rotation of the disk is controlled so that the number of sectors that are rotated becomes an integral number. Further, by forming a non-recording area in each sector and counting the number of non-recording areas existing within one track during reproduction, the rotation of the disk can also be controlled.

〔Effect of the invention〕

According to the present invention, when a disk of information recorded as concentric recording tracks is viewed macroscopically,
Since CLV recording is used, the physical length of each sector is approximately constant across the entire disk, increasing recording capacity. Furthermore, within a predetermined number of tracks where the amount of movement of the recording/reproducing head 16 is small,
CAV recording makes access easy.
In other words, all relationships such as the rotational speed of the disk, the number of sectors included in a track, and the starting position of each sector are in one-to-one correspondence with the track position, so when a track position is specified, the Since the number of sectors and the starting position of each sector can be known, it is easy to detect sectors during recording and reproduction. Furthermore, by associating the disk rotation control system, the information signal system, and the information signal system, when a track position is specified, the rotation speed of the disk in the said track can be determined, so that the disk can be moved to the specified track. At the same time as the recording/reproducing head is moved, it is possible to control the rotation so that the rotation speed of the disk in the specified track is reached, and the time required for rotation control that occurs during CLV control can be apparently shortened. Even when the recording/reproducing head 16 is moved randomly to record/reproduce information, an increase in access time can be prevented.

Furthermore, according to the present invention, by adding a non-recording area immediately before a sector, it is possible not only to easily detect the start position of each sector without depending on changes in the rotational speed of the disk, but also to make it possible to easily detect the start position of each sector without depending on changes in the rotation speed of the disk. By counting the number of non-recording areas existing in the disc, it is possible to control the rotation of the disc even at any recording/reproducing head position on the disc radius, and access can be performed easily and at high speed. Also, by comparing the counted number of non-recording areas with the number of sectors that should be included in one rotation of the designated access track, the discrepancy between the designated access sector position and the actual access position of the recording/playback head is detected. , can be corrected. This is particularly effective when the disk substrate is made of a material such as acrylic resin that expands and contracts depending on temperature and humidity, or when there is eccentricity due to disk replacement.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an information recording/reproducing apparatus according to the present invention.

The disk 1 is rotationally driven by a DC motor 2. Rotary motor connected to the shaft of DC motor 2
An encoder 3 is provided. linear motor 4
moves the recording/reproducing head 16 to the track position specified by the track specifying section 6 in response to a signal from the access control section 7. On the other hand, the track position signal designated by the track designation section 6 is also input to the data converter 8, converted into the number of sectors to be recorded at the designated track position, and inputted to the rotation control section 9. The rotation control unit 9 divides the frequency of the signal from the oscillator 10, compares the phase with the rotation signal obtained from the rotary encoder 3, and controls the rotation of the DC motor 3 so that the phase difference becomes zero. The signal from the oscillator 10 is also applied to the sector control section 12, and the information input/output section 1 is output at the sector position specified by the sector specification section 11.
Controls the transmission and reception of signals in step 3 on a sector-by-sector basis. A rotation reference signal detected by the detector 5 from a rotation reference position mark 101 provided on the disk is also input to the sector control section 12, and a sector counter constituting the sector control section 12 is reset. The information input/output section 13 transmits and receives signals to and from the disk 1 according to the recording/reproducing operation specified by the operation specifying section 14. During a recording operation, a blank signal is applied to the recording/reproducing head 16 through the recording signal processing section 15, and a fixed number of bits is added to the disk 1 from a non-recording area formed by a blank signal indicating the start of a sector, as will be described later. Data is recorded in units of sectors, each consisting of a bit recording area. Also, during playback operation, the signal recorded on disk 1 is transferred to the recording/playback head 6.
It passes through the read and reproduced signal processing section 17 and is read into the information input/output section 13 sector by sector. Furthermore, the reproduction signal processing section 7 detects the number of sectors existing in one rotation of the recording track from the information signal and the rotation reference signal, and inputs this signal to the rotation control section 9.
Normal rotation control is performed at any position of the recording/reproducing head 16, and information can be reproduced.

Here, track designation part 6, sector designation part 1
1. Data is set in the operation specifying section 14 by a signal from a control section (not shown). Similarly, the transmission and reception of signals to be recorded and read signals to the information input/output section 13 are not shown because they are not directly related to the present invention.

In the information recording and reproducing apparatus configured as described above, the second
FIG. 3 shows a reproduction signal processing section for information from a disk.

Information is recorded on the disk 1 by the information input/output section 1.
The information data transferred from 3 and stored in the write data buffer 202 in sector units consisting of a fixed number of bits, and a blank signal having a length corresponding to a fixed number of bits generated by the blank generation circuit 201 are used as a blank signal. This is done by providing the information data to the write control 203 in order.

On the other hand, when reproducing information from disk 1,
Through the read control circuit 213, an electric signal corresponding to the intensity of reflection (or transmission) from the disk 1, which is modulated depending on the presence or absence of a bit, is extracted. From this signal, the blank detection circuit 211 detects the blank signal, and starts the sector. Perform position detection.
Then, the detected blank signal is transferred to the sector control unit, and the read control circuit 213 demodulates the information data in the same manner as in the past, and the information data is transferred sector by sector to the information input/output unit 13 via the read data buffer 212. do. Further, the blank counter 214 counts the number of blanks, that is, the number of sectors, existing in one circumference of the concentric recording track from the detected blank signal and the rotation reference signal detected by the rotation reference mark 101 by the detector 5, is transferred to the rotation control section 9.

Note that, as shown in FIG. 4, for example, the non-recording area 2
21 is a non-bit part 231, and its length is
L _B is bit 23 depending on the information in the sector.
2 and the inter-bit length l _{p '} . As an example, if the maximum value of l _p is 2 μm, it is sufficient for L _B to be about 100 to 200 μm, that is, about 50 to 100 bits in terms of the number of bits.

Next, in the information recording and reproducing apparatus configured as described above, the disk is moved to CLV while keeping the number of sectors recorded in one rotation of the disk to an integral number.
Fig. 5 shows a control system for controlling the rotation.

The data recording speed is determined by the oscillation frequency f _p of the oscillator 10.
If the wavelength of 1 bit on the disk is _dp , then the linear velocity V of the disk is expressed by the following equation.

V=f _p・d _p ...(1) When the position of the recording/playback head on the disk is the distance L _R from the center of the disk, the rotation speed R to satisfy V in equation (1) is given by the following equation. expressed.

R=V/2πL _R (2) On the other hand, in the rotation control system shown in FIG. 2, the rotation speed R of the disk is expressed by the following equation.

R=f _p /N _p・N _R・N _i ...(3) N _p is the frequency division number of the fixed frequency divider 18, N _R is the number of pulses per disk rotation of the rotary encoder 3, and N _i is This is the frequency division number of the variable frequency divider 19.

From formulas (1), (2), and (3), the variable frequency division number N _i is expressed by the following formula, N _i =L _R /d _p・(2π/N _p・N _R ) ……(4) By changing the variable frequency division number N _i in accordance with the change in the position of the recording/reproducing head on the disk (distance L _R from the center of the disk), the rotation of the disk can be controlled to CLV.

Also, let the variable frequency division number N _i be an integer, and the slight L _R
When N _i is constant, the rotational speed of the disk does not change as shown in equation (3), and CAV
Equation (4) is satisfied as a controlled change in wavelength d _p on a 1-bit disk.

As mentioned above, the number of bits recorded in one revolution of the rotationally controlled disk is (N _p × N _R ×
N _i ), and if each constant is determined so that the number of bits constituting one sector is equal to (N _p ×N _{R )} , then the variable frequency division number _N equals the number. By providing the data converter 8 with a conversion table of the variable frequency division number N _i (sector number) that satisfies equation (4) for the track number designated by the track designation section 6,
When a track number is input, the number of sectors recorded on that track is known, and the number of sectors becomes the frequency division number N _i set in the variable frequency divider 19.

Further, during reproduction, the number of sectors existing in one track, which is set in the blank counter 214, is set in the variable frequency divider 19 by the method described above, so that the recording/reproducing head can read the disc-shaped recording medium. Normal rotation control can be performed in any of the above cases.

Next, when the rotation control system is configured as described above, FIG. 6 shows a sector control section for transmitting and receiving signals on a sector-by-sector basis. Oscillator 1
The oscillation frequency f _p of 0 is divided by a fixed frequency divider 24 equal to the number of bits constituting one sector (N _p ×N _R ), and the divided output signal is counted by a sector counter 25 . Fixed frequency divider 24 and sector counter 25
is the rotation reference mark 10 provided on the disk 1.
1 is detected by the detector 5 and is cleared by the rotation reference position signal generated every rotation. A comparator 26 compares the sector number designated by the sector designation section 11 and the output of the sector counter 25, and when they match, outputs a sector coincidence signal to the information input/output section 13. Furthermore, when reproducing information, a similar method can be obtained by switching a switch to replace the output signal of the fixed frequency divider 24 with the blank signal detected and generated by the blank detection circuit 211 and counting it with the sector counter 25. Information input section 1 by method
It is possible to output a sector match signal to 3.

FIG. 7 shows an example of the form of information recorded as concentric recording trajectories on a disk by the information recording/reproducing apparatus according to the present invention.

Since the first sector is recorded from a fixed position determined by the rotation reference position mark 101, the first
The starting position of the sector is the same rotational position regardless of the radial position of the disk 1. In the example shown in FIG. 7a, the starting positions of the first sectors 110 are lined up on a line connecting the rotation reference position mark 101 and the center of the disk 1. In the example shown in FIG. In the figure, 111 is the second sector, 1
12 is the third sector, 113 is the {n+(m-
2)} sector, 114 is the {n+(m-1)} sector, 115 is the (n+m)th sector, 116
indicates the n-th sector, and 117 indicates the (n+1)-th sector. When recording is performed by moving the recording/reproducing head 16 randomly in the radial direction of the disk 1, the number of sectors recorded in one round of the concentric recording trajectory changes by a predetermined number of tracks, but the number of sectors recorded in one round of the said trajectory changes. The number of sectors is always an integer number.
Furthermore, the sector length L ₁ at the outermost periphery and the sector length L _o at the innermost periphery are approximately constant, and each sector is a non-recorded area formed by the blank signal, as shown in FIG. It consists of an area 221 and a pit recording area 222 consisting of a fixed number of bits.

It is clear that the present invention can be similarly implemented regardless of whether the recording medium is optical or magneto-optical, as long as the recording medium is disk-shaped.

In the embodiment, information is recorded on a disc-shaped recording medium as concentric recording trajectories, but it is clear that the same can be realized even if the recording trajectories are rectilinear.

Further, the frequency division number of the variable frequency division number 19 of the rotation control unit 9 may be determined by calculation so as to satisfy the equation (4).

Furthermore, it is clear that the non-recording area can be similarly realized even if it is provided in the form of continuous pits.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the information recording and reproducing apparatus of the present invention, FIGS. 2 and 3 are block diagrams showing one embodiment of the recording signal processing section and the reproduction signal processing section, respectively. The figure is a diagram showing a specific example of a method for forming a non-recording area of a sector. Further, FIGS. 5 and 6 are block diagrams showing one embodiment of the rotation control section and the sector control section, respectively.
FIG. 7 is a diagram showing an example of recording on a disc recorded according to the present invention. 1... Disc, 2... DC motor, 3... Rotary encoder, 4... Linear motor, 5...
... Rotation reference position mark detector, 6 ... Track designation section, 7 ... Access control section, 8 ... Data converter, 9 ... Rotation control section, 10 ... Oscillator, 1
DESCRIPTION OF SYMBOLS 1... Sector designation section, 12... Sector control section, 13... Information input/output section, 14... Operation specification section, 15... Recording signal processing section, 16... Recording/playback head, 17... Playback signal processing section.

Claims (1)

[Claims] 1. A disc-shaped recording medium comprising concentric or spiral tracks made up of a plurality of information units, and each of these information units is provided with an area for physically distinguishing each information unit. In an information recording and reproducing apparatus that uses a disk-shaped recording medium and moves a head randomly in the radial direction of the disk-shaped recording medium to reproduce information recorded in predetermined information units, a driving means for rotationally driving the disk-shaped recording medium. means for reading out a track signal indicating the position of the head on the disk-shaped recording medium rotationally driven by this means; means for detecting the area for distinguishing each information unit of the disk-shaped recording medium; means for counting the number of regions detected by this means; and calculating a control signal for controlling the driving means using a signal indicating the number of regions counted by this means and the track signal as variables. means for rotating the disc-shaped recording medium at a predetermined rotational speed based on the control signal calculated by the means;
means for controlling the driving means, wherein the relative speed between the head and the disc-shaped recording medium is controlled to be substantially constant;
An information reproducing apparatus characterized in that information recorded in predetermined information units by the head is reproduced.