JPH08221900A - Digital data recorder - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a device that can handle data of any rate and can efficiently use a medium regardless of the number of channels and the rate of input data. A digital data recording apparatus comprises an input means capable of inputting a plurality of types of digital data having different rates, a conveying means for conveying a recording medium, and the conveying means for conveying the digital data from the input means at a predetermined rate. A recording means for recording on a recording medium conveyed by the recording medium, and a control means for controlling the conveying means to intermittently drive the recording medium according to a ratio of the rate of the input data to the predetermined rate. Has been done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital data recording device, and more particularly to a device capable of recording a plurality of types of digital data having different data rates.

[0002]

2. Description of the Related Art Conventionally, in an apparatus for recording digital data on a recording medium such as a magnetic tape, a recordable data rate (per unit time is determined by a track length formed on the tape and a shortest recording wavelength. In general, the amount of information to be transmitted) and the data rate of a signal to be recorded (input data rate) are set to be substantially equal to each other, and data is recorded while the medium is continuously run.

Further, in the 6-channel (hereinafter referred to as ch) PCM recording format in the 8 mm VTR, one track is divided into a plurality of areas, and audio signals of a plurality of channels having a relatively low data rate are recorded in each area in units of ch. The method of doing has been put to practical use.

[0004]

By the way, with recent improvements in image compression technology and development of so-called multimedia technology, an apparatus capable of recording digital signals of all data rates has been demanded. If you want to record data, use multiple
It is indispensable to efficiently record the input data of h in conformity with the rate.

However, in the method of area-dividing the inside of a track such as the above-mentioned 6-channel PCM, the continuously recordable time with one tape is constant regardless of the input data rate, and the above-mentioned demand cannot be satisfied.

In addition, when the number of input data channels or the data rate changes, there may be areas that are not used, and there is a problem that the efficiency of use of the medium decreases.

In view of the above problems, it is an object of the present invention to provide a device which can handle data of any rate and can efficiently use a medium regardless of the number of input data channels and the rate.

[0008]

SUMMARY OF THE INVENTION In order to solve the conventional problems and achieve the above object, the present invention conveys a recording medium and an input means capable of inputting a plurality of types of digital data having different rates. And a recording means for recording the digital data from the input means on a recording medium conveyed by the conveying means at a predetermined rate, and the recording means according to the ratio of the input data rate and the predetermined rate. And a control means for controlling the conveying means to intermittently drive the recording medium.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a digital VT which is an embodiment of the present invention.
FIG. 3 is a block diagram showing a main configuration of an R recording system.

In FIG. 1, 101 to 103 are input terminals for inputting digital image data of 2.5 Mbps, 2.5 Mbps, and 5 Mbps, respectively, and each digital data is a memory control circuit with a clock corresponding to the rate of each data. It is written in the memories 104 to 106 by 113. Each of the memories 104 to 106 has a two-bank configuration, and each bank has a capacity of one frame. Therefore, in each memory, while one bank is writing data, the other bank is reading data. The memory control circuit 113 has a clock generation circuit that generates a clock according to the rate of each input data, and generates a clock of each rate that is phase-synchronized with the input data. The memory control circuit 113 is controlled by the control circuit 117.

The image data read from the memories 104 to 106 is supplied to the format circuit 108 via the switch 107, converted into a format suitable for recording, and output to the ID adding circuit 109. The image data stored in the memories 104 to 106 is read at a clock adjusted to a recording rate of 25 Mpbs, which will be described later. That is, these memories convert to a rate according to the recording rate.

The ID adding circuit 109 adds ID data such as the type of data to the formatted image data and outputs it to the modulating circuit 110. The modulation circuit 110 is I
The interleaved NRZI modulation for suppressing the DC component is applied to the data from the D addition circuit 109, and
Modulation for superimposing a reproduction tracking pilot signal is performed and output to the amplifier 111. The amplifier 111 amplifies the modulated data to a predetermined level and rotates the rotary head 112.
And the head 112 outputs the digital data to the cassette 2.
It is recorded on the tape 201 in 00. At this time, the same data as the ID data added by the ID adding circuit 109 is also recorded in the memory 202 provided in the cassette 200.

Further, the drum servo circuit 115 and the capstan servo circuit 116 respectively control the control unit 117 to control the rotational speed / phase of a rotary drum (not shown) and the operation of transporting the tape 201 by the capstan.

In this embodiment, the data rate of the input data is 2.5 Mbps, 2.5 Mbps, 5 Mbps,
A recording data rate (hereinafter, a normal data rate) when the tape 201 is continuously run to record data is set to 25.
Hereinafter, the operation at the time of recording will be described as Mbps.

First, the rotary head type digital VTR in this embodiment is a two-head type and records / reproduces a digital image signal of 30 frames / sec.

When recording normal image data, one frame of image data is recorded on 10 tracks, and the recording format is completed by one frame.

Therefore, the amount of data that can be recorded in one frame during normal recording is 25 Mbit / 10≈0.83 Mbi.
The amount of data that can be recorded per track is 0.83 Mbit / 10 = 83 Kbit.

The operation of recording data at a rate different from the normal rate as described above on such a VTR will be described.

In this case, the operator first instructs the intermittent recording mode using the operation unit 114. And terminals 101 to
The digital image data input from 103 is the control circuit 11
The memory control circuit 113, which has received the instruction from the memory controller 7, writes the data in the memories 104 to 106 in accordance with the input data rate. On the other hand, from the memories 104 to 106, information such as the data rate of the input data and the storage status in the memory is sent to the control circuit 117.

The control circuit 117 calculates the total rate of these three input data, and determines the intermittent running recording mode in response to an instruction from the operation unit 114.
By controlling the capstan servo circuit 116, the tape transport operation according to the intermittent recording mode is performed.

After the intermittent recording mode is determined, the control circuit 117 controls the memories 104 to 10 while the tape 201 is running.
6, the data is sequentially read out in 1-frame units at a clock according to the recording data rate as described above, converted into data of a format suitable for recording as described above, and then the tape 201 in 1-frame (10 tracks) units. To record.

FIG. 2 is a diagram showing a track pattern formed on the tape 201 in such an intermittent recording mode.

In FIG. 2, 1 is a portion where data from the memory 104 is recorded on 10 tracks, 2 is a portion where data from the memory 105 is recorded on 10 tracks, and 3 is from the memory 106. Data is recorded in 10 tracks.

As shown in the figure, since the data stored in the memory 106 has a data rate twice that of the data in the memories 104 and 105, the number of tracks required is twice that of other data.

The intermittent recording operation will be described with reference to the timing chart of FIG.

FIG. 3 is a timing chart showing the data recording timing in the intermittent recording mode described above.

As described above, the normal recording data rate 25
Since the data rate from the terminals 101 and 102 is 2.5 Mbps with respect to Mbps, the normal rate is 1
It can be seen that it is / 10. Also, since the data rate from the terminal 103 is 5 Mbps, it can be seen that it is ⅕ of the normal rate.

The control circuit 117 calculates the ratio of the total rate of the three input data and the normal rate from the ratio of these data rates. That is, the total of the three input data is 1/10 + 1/10 + 1/5 = 4/10, and the tape 201 is run for only 4 frame periods out of 10 frame periods when recording at the normal rate, and the data 1, 2,
Data is recorded in the order of 3 and 3 in units of one frame.

After recording for four frame periods, the tape running and recording operations are stopped to prepare for recording the next data.

As described above, the memories 104 to 106 have two memories.
Since it has a bank structure, subsequent data is sequentially written in the memory which is not read in each memory.

Next, the operation of reproducing the data recorded in this way will be described.

FIG. 4 is a block diagram showing the structure of the reproducing system of the digital VTR in this embodiment. The same parts as in FIG.

In FIG. 4, when the reproduction of data is instructed by the operation unit 114, the control circuit 117 controls the drum servo circuit 115 to rotate the head 112 and controls the capstan servo circuit 116 to control the tape 2.
01 is continuously conveyed at the normal reproduction speed.

3 recorded on the tape 201 as described above
The data of the type is reproduced by the head 112 and the amplifier 1
After being amplified by 18, the demodulation circuit 119 demodulates the original data. At this time, the demodulation circuit detects the pilot signal component superimposed during recording, and the tracking control circuit (not shown) controls tracking.

In the data demodulated by the demodulation circuit 119, the ID data added at the time of recording is detected by the ID detection circuit 120, and the control unit 117 controls the processing of the reproduction processing circuit 121 using this ID data.

The reproduction processing circuit 121 is the ID detection circuit 120.
The data via the switch is subjected to a process reverse to that at the time of recording to be converted into data in a format suitable for output, and the data is sequentially output from the terminals 123 to 125 via the switch 122.

The control circuit 117 can also read the ID data from the memory 202 in the cassette 200, record data other than the data added to the record data in the memory 202, and reproduce this data at the time of reproduction. It is also possible to use. As described above, the data recorded in the memory 202 may be the data rate of the recorded data.

As described above, in the present embodiment, when the input data is recorded at the predetermined recording rate, the intermittent recording is performed at a ratio according to the ratio of the recording rate and the input rate, so that the tape is wasted. It is possible to efficiently record data at any rate without changing the setting.

Further, even when data of a plurality of channels having different rates are input, each data can be effectively recorded.

In the above embodiment, the amount of data recorded on each track was constant, but it can be changed according to the recording situation.

For example, FIG. 5 is a diagram showing a state in which the data amount of the first and tenth tracks in 10 tracks of one frame is changed.

That is, the data recorded on the first and tenth tracks are intermediate track numbers 2-9.
It is less than the data recorded in. This is because head trace misalignment may occur in the case of intermittent recording, and by reducing the amount of data on the track at the end of each frame in this way, data already recorded by the data recorded later is already recorded. The possibility of deleting existing data is reduced.

In order to record in this way, the data arrangement can be realized by reducing the data amount of the data recorded in the track numbers 1 and 10 when the data is previously formatted by the format circuit 108.

In the above-described embodiment, the case where three types of data are input in parallel and recorded has been described. However, when one data is input, it depends on the ratio between the input data rate and the recording rate. It goes without saying that the same effect can be obtained by performing intermittent recording at a different rate.

In the above-described embodiment, a plurality of types of data having different data rates are input from the outside. However, a compression circuit using a well-known technique such as DCT is provided inside the apparatus, and an image input from the outside is provided. The information amount of the signal may be internally compressed to generate data of different rates.

[0047]

As is apparent from the above description, the present invention records data while intermittently driving it at a rate according to the ratio of the input data rate to the recording data rate, so that for any rate of data. However, it is possible to efficiently record data at any rate without wasting the medium.

Further, in another invention of the present application, when a plurality of data having different rates are input in parallel and recorded, the data are recorded on the track at a ratio according to the ratio of the rates of the respective data, so that different rates are recorded. It is possible to effectively record the data without wasting the medium even when the data is input in parallel and recorded.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a recording system of a digital VTR as an embodiment of the present invention.

FIG. 2 is a diagram showing a state of data recorded by the apparatus of FIG.

FIG. 3 is a timing chart for explaining a recording operation of the apparatus of FIG.

FIG. 4 is a diagram showing a configuration of a reproduction system of a digital VTR as an embodiment of the present invention.

FIG. 5 is a diagram showing another recording example in the embodiment of the present invention.

[Explanation of symbols]

 113 memory control circuit 114 operation unit 117 control circuit 200 cassette

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Claims (8)

[Claims] 1. Input means capable of inputting a plurality of types of digital data having different rates, conveying means for conveying a recording medium, and digital data from the input means is conveyed by the conveying means at a predetermined rate. A digital data recording apparatus comprising: a recording unit that records on a recording medium; and a control unit that controls the conveying unit to intermittently drive the recording medium according to a ratio of the input data rate and the predetermined rate. 2. The digital data recording apparatus according to claim 1, wherein the predetermined data rate is higher than the rate of the input data. 3. The digital data is image data, and the recording means records the image data in a unit of a plurality of tracks per frame, and sets the data amount of a track at an end of each unit track to a data amount of other tracks. The digital data recording device according to claim 1, wherein the number is smaller than the above. 4. An additional data generation unit for generating additional data indicating a type of the input data, wherein the recording unit records the input data and the additional data on the recording medium. 1. The digital data recording device according to 1. 5. A memory device in which the recording medium and a memory other than the recording medium are integrally provided with means for recording and reproducing the additional data with respect to the memory. The described digital data recording device. 6. The memory for storing the digital data in the recording means, and the memory for writing the input data at a clock corresponding to the rate of the input data and reading the data from the memory at a clock corresponding to the predetermined rate. The digital data recording apparatus according to claim 1, further comprising a control unit. 7. Input means for inputting a plurality of types of digital image data having different rates in parallel, a memory for storing the input image data, and the input image data for the input image data at a clock according to the rate of the input data. Memory control means for writing to the memory and reading image data from the memory at a clock according to a predetermined rate, and recording means for recording the digital image data read from the memory on a plurality of tracks on a tape-shaped recording medium. A transport means for transporting the tape-shaped recording medium, and a control means for controlling the transport means for intermittently driving the tape-shaped recording medium according to a ratio of the rate of the input image data to the predetermined rate. The recording means adjusts the plurality of types of digital data from the input means according to the ratio of the mutual data rates. A digital data recording device which records on the same number of tracks. 8. Input means capable of inputting a plurality of types of digital data having different rates, and intermittently driving the recording medium, while digital data from the input means is being driven at a predetermined rate during the running of the recording medium. A digital data recording apparatus, comprising: a recording unit that records the data on the recording medium;