JP2732884B2 - Data recording method, data reproducing method, data recording / reproducing method, recording device, reproducing device, and recording / reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for transferring data via a buffer memory.

2. Description of the Related Art FIGS. 7 and 8 show a rotary head type digital audio tape recorder.
r; hereinafter, referred to as DAT) is an explanatory diagram showing an operation in a case where data transferred from an external device is directly recorded on the magnetic tape 1 by DAT using the data recorder of an external device such as a computer.

That is, when the magnetic tape T travels in the direction of arrow P in FIG. 7, the rotating head (not shown) of the DAT scans the magnetic tape T in a direction slightly inclined with respect to the width direction thereof, and the magnetic tape shown in FIG. Data is sequentially recorded on T from left to right. At this time, after the data transferred from the external device is recorded (the recording tracks of the data are indicated by reference numerals a1 and a2), a certain amount of dummy data different from the transfer data is recorded (the dummy data is recorded). (Recording tracks are indicated by reference numerals b1 to b4) The recording operation ends. That is, recording ends at point A on the magnetic tape T. Next, when recording new transfer data from the point A, the magnetic tape T is once run in the reverse direction, and the rotary head is returned to the position corresponding to the point B where the previous transfer data is recorded. After that, the magnetic tape T is caused to run again in the forward direction, and after the magnetic tape T reaches a certain running speed, the recording is restarted from the point when the rotary head approaches the point A.

By the way, since the recording speed and the reproduction speed of the DAT are fixed, for example, when the data transfer speed from the external device to the DAT is slower than the recording speed of the DAT, the DAT performs the above-described recording operation. Stopping and restarting are repeated many times as shown in FIG.

However, if the recording operation is stopped and restarted many times, not only can data not be recorded smoothly,
It takes a lot of time to record a certain amount of data, which is inefficient, and the magnetic tape T cannot use the magnetic tape T effectively because a large amount of gaps are present on the magnetic tape T where dummy data is interposed. The inefficiency described above also occurs when data is reproduced from the DAT and transferred to an external device.

Therefore, as one of measures to improve such a problem, the applicant of the present application firstly used a buffer memory to create a DAT.
It proposes a method to absorb the difference in data transfer speed between the device and the external device.

FIG. 5 and FIG. 6 are timing charts showing the write / read operation of the buffer memory by the above method.

FIG. 5 shows the operation of the buffer memory when data is transferred to the DAT from the computer having a higher data transfer rate than the DAT via the buffer memory.
In FIG. 5, the solid line shows a state in which the address at which data is written in the storage area of the buffer memory shifts with the elapse of time. It is written according to the repetition of returning to the address.

In FIG. 5, a broken line indicates a state where the address from which data is read in the storage area of the buffer memory shifts with the passage of time. It starts only after the time point T1 when the data is stored, and is written in the same address order as the writing. This read operation is performed in accordance with the recording speed of the DAT.
Since the data transfer speed to the memory is faster than the recording speed of the DAT, after the writing returns to the initial address again, the address at which the writing is performed approaches the address at which the reading is performed over time.

Therefore, when the address interval becomes less than a certain value,
The write operation is interrupted. Thereafter, when the address interval is opened to a certain value or more, the writing operation is restarted. In this way, the read operation is performed in the buffer memory so as to always follow the write operation.

On the other hand, FIG. 6 shows that a computer having a lower data transfer rate than a DAT
The operation of the buffer memory when the data is transferred to the buffer memory is shown in the same manner as in the previous case, the solid line shows the state where the address at which the data is written changes, and the broken line shows the state at which the address at which the data is read changes. Indicates the state of going.

In this case as well, the reading is started only at the time T2 when a certain amount of data x is accumulated in the buffer memory after the writing is started, but the writing speed and the reading speed in the buffer memory are the same as those in the previous case. As the time elapses, the address at which reading is performed approaches the address at which writing is performed. Therefore, when the address interval becomes equal to or less than a certain value, the read operation is interrupted. When the address interval becomes equal to or more than the certain value, the read operation is restarted.

As described above, in the buffer memory control method described above, since the read operation is performed so as to always follow the write operation, DATs having different data transfer speeds from each other are performed.
Data can be efficiently transferred between the computer and the computer using a buffer memory having a small storage capacity.

In FIGS. 5 and 6, the DAT
The operation when data is transferred to the DAT and recorded by DAT has been described, but the same applies to the case where data recorded on the DAT is read and transferred to a computer.

However, in the case of the buffer memory control method described above, even if the writing speed to the buffer memory is faster than the reading speed as shown in FIG. Even if the writing speed to the buffer memory is lower than the reading speed, the reading operation always starts at the time points T1 and T2 when a certain amount of data x is accumulated after the start of the writing operation. There was a problem that an inefficient situation would occur.

That is, as shown in FIG. 5, when the writing speed, that is, the data transfer speed on the computer side is high, the operation of reading data from the buffer memory, that is, the recording operation of DAT is started, and then the operation from the computer is started immediately. The data transfer is interrupted, and the system is put into a transfer waiting state. On the other hand, when the writing speed is low as shown in FIG. 6, the recording operation is immediately interrupted after the DAT recording operation is started. Meanwhile, DAT
On the side, as described above, a considerable amount of time is required for completing the stop of the operation (the time required for the operation is indicated by reference numeral t1 in FIG. 6) and resuming the operation (the time required for the operation is indicated by reference numeral t2 in FIG. 6). It will cost. In such prior art,
This also occurs when data reproduced by the DAT is transferred to the computer via a buffer memory.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and an apparatus capable of efficiently transferring data via a buffer memory.

Means for Solving the Problems To achieve the above object, the present invention provides a data recording method for temporarily storing data transferred from an external device in a buffer memory and then recording the data on a recording medium of a recording device. When data is transferred from the device and the data transfer speed of the external device is faster than the data processing speed of the recording device, the data is recorded from the buffer memory when the buffer memory reaches x1. When data reading to the device starts and the data transfer speed of the external device is slower than the data processing speed of the recording device, when the buffer memory reaches x2, which is larger than x1 To start reading data from the buffer memory to the recording device.

Further, the present invention provides a data reproducing method for temporarily storing data reproduced from a recording medium of a reproducing device in a buffer memory and then transferring the data to an external device. When the data processing speed of the external device is faster than the data transfer speed,
When the buffer memory reaches the data storage amount y1, data reading from the buffer memory to the external device starts, and when the data processing speed of the external device is slower than the data transfer speed of the playback device, When the buffer memory reaches a data storage amount y2 smaller than the data storage amount y1, data reading from the buffer memory to the external device side is started.

Further, according to the present invention, the data transferred from the external device is temporarily stored in a buffer memory and then recorded on a recording medium of the recording / reproducing device, and the data reproduced from the recording medium of the recording / reproducing device is temporarily stored in the buffer memory. In the data recording / reproducing method of transferring data to an external device after storing the data, when data is transferred from the external device, when the data transfer speed of the external device is faster than the data processing speed of the recording / reproducing device, When reading of data from the buffer memory to the recording / reproducing device starts when the buffer memory reaches the data accumulation amount x1, and the data transfer speed of the external device is slower than the data processing speed of the recording / reproducing device. When the buffer memory reaches the data storage amount x2 larger than the data storage amount x1, the data from the buffer memory to the recording / reproducing device is When data transfer to an external device is started while reading data from the external device, when the data processing speed of the external device is faster than the data transfer speed of the recording / reproducing device, the buffer memory has reached the data storage amount y1. At this point, data reading from the buffer memory to the external device side is started, and when the data processing speed of the external device side is lower than the data transfer speed of the recording / reproducing device side, the buffer memory exceeds the data storage amount y1. Low data storage
At time y2, data reading from the buffer memory to the external device is started.

Further, the present invention provides a recording apparatus for recording data transferred from an external device on a recording medium, wherein a buffer memory for temporarily storing data when performing data transfer with the external device; When data is transferred from the device and the data transfer speed of the external device is faster than the data processing speed of the recording device, the data is recorded from the buffer memory when the buffer memory reaches x1. When data reading from the medium is started and the data transfer rate on the external device is slower than the data processing rate on the recording device, and the buffer memory reaches x2, which is larger than x1 And control means for starting reading data from the buffer memory to the recording medium.

Further, the present invention provides a reproducing apparatus for transferring data recorded on a recording medium to an external device, wherein a buffer memory for temporarily storing data when performing data transfer with the external device; When transferring data to the device, if the data processing speed of the external device is faster than the data transfer speed of the playback device, when the buffer memory reaches the data storage amount y1, the data is transferred from the buffer memory to the external device. When the data processing speed on the external device side is slower than the data transfer speed on the playback device side, when the buffer memory reaches the data storage amount y2 smaller than the data storage amount y1, Control means for starting to read data from the buffer memory to the external device.

Further, the present invention provides a recording / reproducing apparatus for recording data transferred from an external device on a recording medium and transferring the data recorded on the recording medium to the external device, wherein data transfer with the external device is performed. A buffer memory for temporarily storing data when performing data transfer, and a buffer memory for transferring data from an external device when the data transfer speed of the external device is faster than the data processing speed of the recording / reproducing device. -When the memory reaches the data storage amount x1, data reading from the buffer memory to the recording medium starts, and when the data transfer speed of the external device is slower than the data processing speed of the recording / reproducing device, the buffer is used. -When the memory reaches the data storage amount x2 which is larger than the data storage amount x1, the data reading from the buffer memory to the recording medium is started while the external device When transferring data to the external device, the data processing speed on the external device side is faster than the data transfer speed on the recording / reproducing device side, and when the buffer memory reaches the data storage amount y1, the data is transferred from the buffer memory to the external device side. When reading data to the buffer device starts and the data processing speed on the external device side is slower than the data transfer speed on the recording / reproducing device side, the buffer memory reaches the data storage amount y2 smaller than the data storage amount y1 And control means for starting reading of data from the buffer memory to the external device.

According to the present invention, when data is transferred from the external device to the recording device, the buffer memory stores the data storage amount x1 under the condition that the data transfer speed of the external device is faster than the data processing speed of the recording device. At this time, the reading of data from the buffer memory to the recording device is started, so that it takes much time for the address to be written in the buffer memory to catch up with the address to be read, and the external The opportunity of interrupting the data transfer operation of the device is reduced.

On the other hand, under the condition that the data transfer speed on the external device side is slower than the data processing speed on the recording device side, when the buffer memory reaches the data accumulation amount x2 which is larger than the data accumulation amount x1, the recording device Since the reading of data into the buffer memory is started, it takes much time for the address to be read in the buffer memory to catch up with the address to be written, and the chance of interrupting the recording operation of the recording device is reduced.

In the same manner, when data is transferred from the playback device to the external device, the chance of interrupting the operation of the external device or the playback device is reduced.

Embodiment FIG. 1 is a block diagram of one embodiment of the present invention.

In the data recording / reproducing apparatus, data transfer between a rotary head type DAT 1 as a recording / reproducing apparatus and a computer 2 as an external device using the DAT 1 as a data recorder is performed via a buffer memory 3. 1, an interface 4 for exchanging data with the computer 2 is provided on the DAT1 side in FIG. 1, and this interface 4 is composed of a control circuit 5 for controlling the entire DAT1 and the buffer memory described above. 3 and is connected to.

Further, a signal processing circuit 6 for performing various signal processing on input data is connected to the next stage of the buffer memory 3. The signal processing circuit 6 and the rotary drum 7 are connected via an amplifier 8. Data output from the signal processing circuit 6 is amplified by the amplifier 8 and supplied to the rotary drum 7 as data to be recorded. The reproduction data output from the drum 7 is amplified by the amplifier 8 and input to the signal processing circuit 6.

A rotating head (not shown) is provided on the rotating drum 7.
By scanning the magnetic tape 9 on which the rotating head runs, data is recorded on the magnetic tape 9 or data recorded on the magnetic tape 9 is reproduced. First
In the figure, a capstan 10 is a member for running the magnetic tape 9, and a capstan driving device 11 is a device for driving the capstan 10.

FIG. 2 is a schematic diagram schematically showing a storage area of the buffer memory. FIGS. 3 and 4 show operations in the buffer memory 3 when data sent from the computer 2 is recorded by the DAT1. FIG. Referring to FIGS. 2 to 4, the recording operation of the DAT1 is performed when the data transfer speed of the computer 2 is higher than the data processing speed of the DAT1 and when the data transfer speed of the computer 2 is lower. The case will be described below.

When the data transfer rate of the computer 2 is high Data sent from the computer 2 is sequentially written to the buffer memory 3 via the interface 4. The solid line in FIG. 3 shows a state in which the address to which the data is being written in the buffer memory 3 changes at this time, and the vertical axis shows the address and the horizontal axis shows the time axis.

By this write operation, the amount of data stored in the buffer memory 3 is indicated by a symbol x1 in FIG.
Is set to be smaller than the accumulated data amount x in the case of the data transfer shown in FIGS. 5 and 6) when the buffer memory 3 is controlled from the time T10 by the control of the control circuit 5. Reading of the data written so far is started in the same address order as in the case of writing.

The dashed line in FIG. 3 indicates a state in which the address at which reading is performed in the buffer memory 3 shifts at this time, and is performed in the same address order as writing. This reading operation is performed in accordance with the recording speed of DAT1.
Since the data transfer speed is faster than the recording speed of DAT1, after writing returns to the initial address again, the address at which writing is performed approaches the address at which reading is performed over time.

However, in this case, when the amount x1 of accumulated data in the buffer memory 3 is smaller than that in the case shown in FIG.
Since the reading is started at T10, the fifth address is required before the address where the writing is performed catches up with the address where the reading is performed.
It takes more time than in the case of the figure, and cannot catch up with the address where reading is performed even at the end of writing. Therefore, in this case, the write operation is not interrupted halfway. That is, it is possible to prevent the transfer of data from the computer 2 to the DAT 1 from being in a standby state on the way.

The data read from the buffer memory 3 is processed in the signal processing circuit 6, amplified by the amplifier 8, sent to the rotating head of the rotating drum 7, and recorded on the magnetic tape 9 by the rotating head. At the start of recording data on the magnetic tape 9, the control circuit 5 controls the capstan 10 via the capstan driving device 11, whereby the capstan 10 runs the magnetic tape 9 once in the reverse direction by a certain amount. After that, the magnetic tape 9 is run in the forward direction, and when the rotary head comes to a position on the magnetic tape 9 where data is to be recorded, the data read from the buffer memory 3 is recorded.

When there is no more data to be read from the buffer memory 3, dummy data is finally recorded on the magnetic tape 9 by a command from the control circuit 5, thereby ending a series of recording operations.

In the case where the data transfer speed on the computer 2 side is low, the solid line in FIG. 4 also indicates the transition state of the address when the data sent from the computer 2 via the interface 4 is written in the buffer memory 3 at this time. In this case, the amount of data accumulated in the buffer memory 3 by the write operation is indicated by the symbol x2 in FIG.
(The accumulated data amount x2 is set to be larger than the accumulated data amount x in the case of the data transfer shown in FIGS. 5 and 6). The reading operation is started from time T20 when the value reaches.

The broken line in FIG. 4 also shows the state where the address to be read is shifted in the buffer memory 3 at this time, and is performed in the same address order as the write. In this case, the magnitude relationship between the writing speed and the reading speed in the buffer memory 3 is opposite to that in the previous case.
As time elapses immediately after the start of the read operation, the address at which the reading is performed approaches the address at which the writing is performed.

However, in this case, the accumulated data amount x2 in the buffer memory 3 is larger than that shown in FIG. 6 (x2>
x> x1) Since reading is started at time T20, it takes more time than in the case of FIG. 6 until the address to be read catches up with the address to be written, and reading is performed even at the end of writing. The address cannot keep up with the address to be written. Therefore, in this case, the reading operation is not interrupted halfway. That is, it is possible to avoid a situation where the recording operation of the DAT1 is stopped halfway and restarted, and the time required for stopping and restarting the recording operation can be omitted.

In the above embodiment, the case where the data sent from the computer 2 is recorded by the DAT 1 has been described.
The same applies to the case where data reproduced by DAT1 is transferred to the computer 2. In this case, if the data transfer speed of the computer 2 is lower than the reproduction operation speed of the DAT 1, that is, if the read operation in the buffer memory 3 is slower than the write operation, the buffer memory The point at which the amount of data y1 stored in 3 is relatively small is selected. Conversely, when the data transfer speed of the computer 2 is higher than the reproduction operation speed of the DAT1, the time point at which the data amount y2 stored in the buffer memory 3 is relatively large (y2> y1) as the start time of the read operation Is selected.

Effect of the Invention As described above, according to the present invention, the buffer and the data transfer rate of the external device and the recording / reproducing device are changed according to the magnitude relationship.
Since the amount of stored data, which is a guide at the time of reading data from the memory, is switched and set, the chances of interrupting the recording / reproducing operation of the recording / reproducing device or interrupting the data transfer operation of the external device are reduced. Data transfer can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of the present invention, FIG. 2 is a schematic diagram schematically showing a storage area of a buffer memory 3 provided in a DAT 1, and FIGS. FIGS. 5 and 6 are timing charts showing the write / read operation of the buffer memory 3 in the case of the proposed buffer memory control method, respectively. 7 and 8 are explanatory views showing a recording operation in the DAT in the case where data is transferred from an external device to the DAT without using a buffer memory in the prior art. 1 ... DAT, 2 ... Computer, 3 ... Buffer memory, 4 ... Interface, 7 ... Rotating drum, 9 ...
…Magnetic tape

Claims (6)

(57) [Claims] In a data recording method for temporarily storing data transferred from an external device in a buffer memory and then recording the data on a recording medium of the recording device, when the data is transferred from the external device, the recording device side When the data transfer speed of the external device is faster than the data processing speed of the
Data reading from the buffer memory to the recording device is started when the value becomes x1, and when the data transfer speed of the external device is slower than the data processing speed of the recording device, the buffer memory stores the data accumulation amount x1. 2x more data storage
A data recording method which starts reading data from the buffer memory to the recording device at the point of time when the data recording operation is completed. 2. A data reproducing method for temporarily storing data reproduced from a recording medium of a reproducing apparatus in a buffer memory and then transferring the data to an external device. When the data processing speed of the external device is faster than the transfer speed, when the buffer memory reaches the data storage amount y1, data reading from the buffer memory to the external device is started, and the data of the reproducing device is started. When the data processing speed of the external device is slower than the transfer speed, data reading from the buffer memory to the external device starts when the buffer memory reaches a data storage amount y2 smaller than the data storage amount y1. A data reproducing method. 3. A method for temporarily storing data transferred from an external device in a buffer memory and then recording the data on a recording medium of the recording and reproducing apparatus, and temporarily storing data reproduced from the recording medium of the recording and reproducing apparatus in the buffer memory. When data is transferred from an external device and the data transfer speed of the external device is faster than the data processing speed of the recording / reproducing device, the data is transferred to an external device. -When the memory reaches the data storage amount x1, data reading from the buffer memory to the recording / reproducing device starts, and when the data transfer speed of the external device is slower than the data processing speed of the recording / reproducing device, When the buffer memory reaches the data storage amount x2 larger than the data storage amount x1, the data transfer from the buffer memory to the recording / reproducing device When reading is started and data is transferred to the external device, when the data processing speed on the external device side is faster than the data transfer speed on the recording / reproducing device side, when the buffer memory reaches the data storage amount y1 Starts reading data from the buffer memory to the external device side, and when the data processing speed on the external device side is slower than the data transfer speed on the recording / reproducing device side, the buffer memory is smaller than the data storage amount y1 A data recording / reproducing method, which starts reading data from the buffer memory to the external device when the data storage amount reaches y2. 4. A recording device for recording data transferred from an external device on a recording medium, comprising: a buffer memory for temporarily storing data when data is transferred to and from the external device; When data is transferred from the external device and the data transfer speed of the external device is faster than the data processing speed of the recording device, the buffer memory
Data reading from the buffer memory to the recording medium starts at x1 and when the data transfer speed of the external device is slower than the data processing speed of the recording device, the buffer memory stores the data storage amount x1. 2x more data storage
Control means for starting reading of data from the buffer memory to the recording medium at the time when the condition is satisfied. 5. A reproducing apparatus for transferring data recorded on a recording medium to an external device, comprising: a buffer memory for temporarily storing data when data is transferred to and from the external device; When the data processing speed of the external device is faster than the data transfer speed of the playback device, the data is transferred from the buffer memory to the external device when the buffer memory reaches the data storage amount y1. When the data transfer speed of the external device is slower than the data transfer speed of the playback device, the buffer memory becomes smaller when the data storage amount y2 becomes smaller than the data storage amount y1. A reproducing device, comprising: a control unit that starts reading data from the memory to the external device side. 6. A recording / reproducing apparatus for recording data transferred from an external device on a recording medium and transferring the data recorded on the recording medium to the external device, wherein data transfer with the external device is performed. A buffer memory for temporarily storing data when the data is transferred from an external device, and when the data transfer speed of the external device is faster than the data processing speed of the recording / reproducing device, the buffer memory is used. Data reading from the buffer memory to the recording medium is started when the memory reaches the data storage amount x1, and when the data transfer speed on the external device side is slower than the data processing speed on the recording / reproducing device side, the buffer memory When the memory reaches x2, which is larger than x1, the data reading from the buffer memory to the recording medium starts, while the external device When transferring data, when the data processing speed on the external device side is faster than the data transfer speed on the recording / reproducing device side, when the buffer memory reaches the data storage amount y1, the data is transferred from the buffer memory to the external device side. When the data processing speed on the external device side is slower than the data transfer speed on the recording / reproducing device side, when the buffer memory reaches the data storage amount y2 smaller than the data storage amount y1, Control means for starting reading of data from the buffer memory to the external device side.