JPH03214462A - Data reproducting method for disk device - Google Patents

Abstract

PURPOSE:To make the data transfer speed changeable and to enable the high speed data transfer by changing the rotation speed on a disk in accordance with an output requesting mode of a data and reproducing the data having a different transfer speed. CONSTITUTION:In the case of the disk device which is a device for receiving an original data, a changeover circuit 6 is changed to the side of a demodulation circuit 8 by an output requesting mode signal from the device, while the rotation speed of a spindle motor 2 is slowed down by a driving control circuit 10 with the output requesting mode signal in order to secure the time for data processing of demodulation and error correction, so that the original data is outputted. On the other hand, in the case of the device to be connected which has demodulation and error correction functions, the circuit 6 is changed to the side of a terminal 11, while the rotation speed of the motor is speeded up by the circuit 10 and a bit stream is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a data reproducing method for a disk device, and more particularly to a data reproducing method for a disk device that can realize a data transfer rate that corresponds to the data output request form. Regarding.

B. Summary of the Invention The first invention is to rotate a disk and, when reproducing data recorded on the disk, change the rotational speed of the disk according to the form of data output request, and transfer data at different transfer speeds. By performing reproduction, it is possible to reproduce data that is compatible with the functions of the device to which the data is sent. Further, the second invention provides a method for rotating a disk at a constant speed and reproducing data recorded on the disk.
By switching the number of times the playback head scans the same track between once and multiple times depending on the data output request format and playing back data at different transfer speeds, it adapts to the functions of the data destination device. This allows the data to be played back.

C. In conventional technology disk devices, such as optical disk devices, the spin F'
An optical disc is moved at a constant linear velocity (hereinafter referred to as CL) using a motor.
V: Constant Linear Velo
city) or constant angular velocity (hereinafter referred to as C A V
: Constant Angular Veloc
For example, in a so-called CDROM (Compact Disk - Read Only Memory), data is recorded as a Pinot train on a track. Data is reproduced by detecting changes in the intensity of reflected light depending on the presence or absence of the binoto. Furthermore, for example, magneto-optical disk devices use magneto-optical effects such as the Rikiichi effect to record or reproduce data.

In addition, the data recorded on the optical disk is different from the original data, and in order to correct data errors during data reproduction, error detection codes such as parity focus and error correction codes are added, for example, so-called 4/4 The data is recorded as a signal that has been subjected to modulation suitable for the recording medium, such as 15 modulation, and has a frame synchronization signal for synchronization, an address for data management, etc. added. In other words, in order to reproduce the original data from an optical disc, the reproduction signal reproduced by the optical head is binarized, and this binary
After detecting a frame same-month signal from the digitized data and pulling in synchronization, the binarized signal is demodulated, error correction is performed, and the original data is reproduced. This reproduced data is transferred to a device, such as a host computer, to which the optical disk device is connected using a predetermined interface.

By the way, the device to which the above optical disk device is connected includes:
As mentioned above, some devices receive data in the original data format that has been subjected to data processing such as demodulation and error correction, while others have demodulation and error correction functions and receive the binarized signal as is at high speed. There are also devices that can receive it. However, the data transfer speed when an optical disk device is connected to a device with such demodulation and error correction functions is limited by the rotational speed of the optical disk that ensures the time required to perform data processing such as error correction. Due to certain constraints imposed on the data transfer rate, it was the same as the data transfer rate when the data was processed. That is, even in data transfer that does not require data processing such as demodulation or error correction, a disk rotation speed that takes data processing into account is used, and as a result, it has not been possible to achieve a higher data transfer speed.

Furthermore, Japanese Patent Laid-Open No. 192012/1983 discloses a technique for changing the rotational speed of a disk in accordance with the data transfer speed during data recording in order to accommodate multimedia information. However, even in this technique, since data is transferred after performing data processing such as demodulation and error correction, it is not possible to avoid time constraints caused by data processing on the data transfer rate.

D. Problems to be Solved by the Invention The present invention has been made in view of the above circumstances, and it is possible to change the data transfer rate in accordance with the function of the device to which the optical disk device is connected, that is, the output request form. The purpose is to make it possible. In particular, it is an object of the present invention to enable high-speed data transfer to devices having data processing functions such as demodulation and error correction.

E. Means for Solving the Problems A data reproducing method for a disk device according to the first invention rotates a disk and, when reproducing data recorded on the disk, performs the above-mentioned method according to a data output request form. The above problem is solved by changing the rotational speed of the disk and reproducing data at different transfer speeds. Further, in the data reproducing method for a disk device according to the second invention, the disk is rotated at a constant speed, and when reproducing data recorded on the disk, the number of times the reproducing head scans the same track is controlled. The above problem is solved by switching between once and multiple times depending on the type of data output request, and reproducing data at different transfer speeds. F. The data reproducing method for a disk device according to the first aspect of the invention is such that when original data that has been subjected to data processing such as error correction is requested, the data reproduction method uses a disk rotation speed that secures the time necessary for data processing. The data is played back, the data is transferred using a predetermined data transfer rate, and when data before data processing is requested, the data is played back at a high disk rotation speed, and the data that has not been processed is Transfer at high speed. Further, in the data reproducing method of a disk device according to the second invention, when original data that has been subjected to data processing such as error correction is requested, the same track is scanned multiple times with the reproducing head, and the data processing is performed. Regenerate the data by securing the necessary time, transfer the data using the specified data transfer rate, and when the data before data processing is requested,
The data is reproduced by scanning the same track with the playback head - times, and the unprocessed data is transferred at high speed. G. Embodiment Hereinafter, an embodiment of a method for reproducing data on a disc device according to the present invention will be described with reference to the drawings. FIG. 1 is a bronc circuit diagram of a disk device to which the first invention is applied;
FIG. 2 is a block circuit diagram of a disk device to which the second invention is applied. In FIG. 1, a disk 1 is rotationally driven by a spindle motor 2 at a constant linear velocity, for example, under the control of a drive control circuit 1O, as will be described later. The disk l is, for example, a read-only so-called CD-ROM.
It is an optical disc such as 1, and on the tracks of the disc 1, error detection codes and error correction codes such as parity pits are added to the original data for error correction during data reproduction, and then the data is passed to the recording medium. A signal that has been modulated and has a frame synchronization signal and an address added thereto is recorded as a focus train.

The optical henode 3 is composed of, for example, optical components such as a laser diode, a collimator lens, an objective lens, a beam splitter, and a cylindrical lens, a photodetector divided into a predetermined arrangement, an RF amplifier in a matrix configuration, etc. The trunk of the disk I is irradiated with light, and changes in the intensity of reflected light due to the pits are detected, and a focus error signal is detected, for example, by a so-called astigmatism method, and a tracking error signal is detected, for example, by a so-called push-pull method. There is. These focus error signals and trunking error signals are used for focus servo control to maintain a constant distance between the objective lens of the optical head 3 and the recording surface of the disk L, and are sent from the optical head 3 to the optical head 3. This is used for tracking servo control to ensure that the laser beam accurately scans the trunk. The reproduction circuit 4 binarizes the reproduction signal from the optical head 3 and also reproduces the clock signal recorded on the disk l. The synchronization detection circuit 5 uses the clock signal and the binarized signal from the reproduction circuit 4 to detect a synchronization signal and pull in synchronization, and also removes, for example, a track address and generates an error detection code or an error correction code. is added to the data before demodulation (hereinafter referred to as a bit stream), and this pit stream is supplied to the switching circuit 6. The demodulation circuit 8 converts the pit stream supplied via the switching circuit 6 into, for example, EFM (Eight
o fourteen ) demodulate. Error correction circuit 9
For example, the so-called CIRC (Cross Interl
eave Reed Solo*on Cods) decoder etc.
g Code) is a decoder, which performs error correction on the demodulated data from the demodulation circuit 8 to form original data, and outputs the error-corrected original data via terminal l2 at a predetermined data transfer rate. output to another device. On the other hand, the stream from the switching circuit 6 is directly outputted to other devices via the terminal 11.

The drive circuit 110 controls the spindle motor 2 in order to control the rotational speed of the disk 1, as will be described later, in response to an output request form signal inputted through the terminal 13. Incidentally, the output request form signal is also used for switching control of the switching circuit 6. Next, we will explain the operation. If the device to which the disk device shown in FIG. 1 is connected does not have a demodulation or error correction function, that is, if it is a device that receives original data, the switching circuit 6 is activated by the output request form signal from the device. At the same time as switching to the demodulation circuit 8 side, the drive control circuit 10 lowers the rotational speed of the spindle motor 2 according to the output request form signal to output the original data so as to secure time for data processing for demodulation and error correction. It can be so. On the other hand, if the device connected to the disk device has a demodulation or error correction function, that is, if it is a device that directly receives the binoto stream, the switching circuit 6 is switched to the terminal 11 side by the output request form signal from the device. At the same time, the drive control circuit 10 switches the spindle motor 2 according to the output request form signal.
Increase the rotation speed of the machine to output a pit stream. As a result, it becomes possible to change the data transfer speed from the disk device 1 according to the output request form, that is, the function of the device to which the disk device is connected. As mentioned above, when the connected device has data processing functions such as demodulation and error correction, and the disk device does not need data processing such as error correction and can output the pit stream directly, the disk When outputting a bisoto stream with a high rotation speed, and outputting original data that has undergone data processing such as error correction, the rotation speed of the disk can be lowered to output the original data. It is possible to perform data transfer appropriate to the functions of the device. In other words, high-speed data transfer is possible depending on the functionality of the connected device. Next, the disk device shown in FIG. 2 will be explained. In FIG. 2, the disk 2l is connected to the spindle motor 22.
As will be explained later, it is rotated at a constant linear velocity. The disk 2l, like the disk l shown in FIG. 1, is a read-only optical disk such as a so-called CD-ROM, and on the tracks of the disk 2l, error detection codes and error correction codes are added to the original data. After being added, modulation suitable for the recording medium is applied, and the signal to which a frame synchronization signal and address are added is recorded as a binoto sequence. Like the optical hesode 3 shown in FIG. 1, the optical hesode 23 includes, for example, optical components such as a laser diode, a collimator lens, an objective lens, a beam splinter, and a cylindrical lens, a photodetector divided into predetermined arrangements,
It is composed of an RF amplifier with a matrix configuration, etc., and is designed to irradiate a laser beam onto the tracks of the disk 2l, detect changes in the intensity of light reflected by the pits, and detect focus error signals and tracking error signals. These focus error signals and tracking error signals are used for focus servo control and tracking servo control. Note that the optical head 23
As described later, the same trunk is operated once or multiple times (hereinafter referred to as N times) by a control signal from the drive control circuit 30.
Controlled to scan. Similar to the reproducing circuit 4 shown in FIG. 1, the reproducing circuit 24 binarizes the reproduced signal from the optical driver 23, and
The clock signal recorded on the disk 21 is reproduced.

Similar to the synchronization detection circuit 5 shown in FIG. 1, the synchronization detection circuit 25 receives the clock signal from the reproduction circuit 24 and 2(!
! The converted signal is used to detect a synchronization signal and pull in synchronization, and at the same time, the pit stream is supplied to the switching circuit 26. The track buffer 1 circuit 27 stores one track's worth of bitstream via the switching circuit 26, as will be described later. The demodulation circuit 28 performs the l track buffer times! For example, the pit stream stored in II 27 is demodulated using EFM.

The error correction circuit 29 is the error correction circuit 9 shown in FIG.
Similarly, it is an FCC decoder such as a CIRC decoder, which performs error correction on the demodulated data from the demodulation circuit 28, forms original data, and corrects errors via a terminal 32 at a predetermined data transfer rate. The corrected original data is output to another device.

On the other hand, the pit stream from the switching circuit 26 is directly output to other devices via the terminal 3l.

The drive circuit 30 controls the drive of the optical henode 23 so that it scans the same track once or N times in response to an output request form signal inputted through a terminal 33. The output request form signal is also used for switching control of the switching circuit 26. Next, we will explain the operation. The disk 2l is rotated by a spindle motor 22 at a constant linear velocity corresponding to the bit stream transfer rate. If the device to which the disk device shown in FIG. 2 is connected does not have a demodulation or error correction function, that is, if the device receives original data, an output request form signal from the device will cause the switching circuit to 26 is switched to the l track buffer circuit 27 side, and the drive control circuit 30 controls the number of times the optical head 23 scans the same trunk according to the output request form signal, and performs data processing such as demodulation and error correction.
Control is performed N times to ensure enough time to process data for the trunk. Then, while the optical head 23 scans the same track N times, one track's worth of bisoto streams is scanned N times.
The data is stored in the track buffer circuit 27. This l-track buffer circuit 27 performs demodulation and error correction on the recorded data and outputs the original data after error correction via the terminal 32. On the other hand, if the device connected to the disk device has a demodulation or error correction function, that is, if it is a device that directly receives the pit stream, the switching circuit 26 is switched to the terminal 31 side by the output request form signal from the device. At the same time, the drive control circuit 30 controls the number of times the optical disk 23 scans the same track only once. Each time the optical head 23 scans one trunk, it outputs a bit stream for one track through the terminal 3l. As a result, it is possible to change the data transfer rate from the disk device according to the output request form, that is, the function of the device to which the disk device is connected. Note that the bit stream for one trunk recorded in the one track hash circuit 27 is scanned N times on the same track, and the focused stream for N times is used to perform data processing such as majority voting, etc., to obtain an l track. It is also possible to set the data to minutes. As a result, it becomes possible to transfer data with a higher degree of trust.

As described above, when data processing such as error correction is required, the disk rotation speed is set high from the beginning, and when outputting the original data that has been subjected to data processing such as error correction, the optical head tracks the same track. Repeatedly scan multiple times, regenerate one trunk's worth of data during multiple scans,
After performing data processing such as error correction, the data is output, and when it is possible to directly output the pit stream, the optical head scans the same trunk only once, and scans one track each time it scans each track. By outputting a pit stream for each minute, it is possible to transfer data through the functions of the connected device. In other words, high-speed data transfer is possible depending on the functionality of the connected device. It should be noted that the present invention is not limited to the above-mentioned embodiments, and can of course be applied to, for example, a so-called write-once type optical disk device, a rewritable magneto-optical disk device, a magnetic disk device, etc. The present invention can also be applied to a disk device that rotates a disk at a constant angular velocity. Further, the output of the demodulation circuit 8 shown in FIG. 1 or the demodulation circuit 28 shown in FIG. 2 may be outputted depending on the output request form. That is, the bisoto stream, demodulated data, and original data after error correction may be selected and output. 11. Effects of the Invention As is clear from the above description, in the first invention, the angular velocity of the disk or the By changing the linear velocity, high-speed data transfer that is suitable for the functions of the data transfer destination device is possible. In addition, in the second invention, the disk is rotationally driven at a constant angular velocity or linear velocity using a disk rotation rate corresponding to the data transfer rate when directly outputting a binoto stream, and data for demodulation, error correction, etc. When the processed original data is requested, the original data is output by scanning the same track multiple times, and when the focus stream is directly transferred, one output is output each time the same trunk is scanned once. By outputting the binoto stream for the trunk, high-speed data transfer that passes through the functions of the data transfer destination device becomes possible.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of a disk device to which the first invention is applied, and FIG. 2 is a block circuit diagram of a disk device to which the second invention is applied. l, 2l...Disks 2, 22...Spindle motors 3, 23...Optical drives 6, 26...Switching circuit 10...Drive control circuit 30...Drive control circuit

Claims (2)

[Claims] (1) When a disk is driven to rotate and data recorded on the disk is played back, the rotational speed of the disk is changed depending on the form of data output request to reproduce data at different transfer speeds. Disk device data playback method featuring features. (2) When the disk is rotated at a constant speed and the data recorded on the disk is played back, the number of times the playback head scans the same track is determined to be once or multiple times depending on the data output request form. 1. A data reproducing method for a disk device, characterized in that data is reproduced at different transfer speeds by switching between the two.