JPH0668908B2 - Digital signal recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal recording / reproducing apparatus which searches for data recorded on a tape at high speed by using a rotary head.

2. Description of the Related Art In recent years, digital recording / reproducing technology has been applied to a wide range of fields, and in particular, has made remarkable progress in the field of digital audio, and a rotary head type digital audio tape recorder (DAT) has come into practical use. Has arrived.

On the other hand, attempts to use the DAT as an auxiliary recording device for computers have become popular. In these devices, instead of digitized audio data, digital data supplied from a computer is sequentially recorded for each data block which is a preset fixed amount of data format, and the digital data is read by normal reproduction to read the data block. It is possible to record, reproduce, and save extremely large amount of data.
In the search operation, as in the case of audio applications, the program number for identifying the data block is read out from the sub data area at high speed and the recording position of the target data block is searched to find the head of the target data block. It is designed so that it can be put out.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional configuration, since the high-speed reproduction using the program number is searched, the target data block of the target data block is searched before the program number corresponding to the target data block is searched and stopped. Since the first frame has been moved too far and the first frame is searched by rewinding only the excess amount, it takes time to search, and when a discontinuous number is recorded in the program number, the target data It is impossible to determine whether the block exists in the forward direction or the reverse direction with respect to the moving direction of the tape, and it is necessary to rewind the tape and start the search from the beginning. Therefore, it takes time to search. Had a point.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above conventional problems and to provide a digital signal recording / reproducing apparatus which searches for the first frame of a target data block at high speed.

Means for Solving the Problems In order to solve the above problems, a digital signal recording / reproducing apparatus according to the present invention includes an absolute position information for identifying a frame unit based on a frame previously formed on a tape and a plurality of frames. Recording means for recording the data block identification information for identifying the formed data block in a predetermined specific area on a certain track, and a plus azimuth track and a minus azimuth track continuously or at normal speed or high speed, or Reproduction means for intermittent reproduction, first comparison means for comparing the data block identification information reproduced by the reproduction means with the target data block identification information of the target data block, and the first frame of the target data block , Or the absolute position information that targets a frame near the first frame above. The target data block by the second comparison means for comparing the information and the absolute position information reproduced by the reproduction means, and the comparison result of the first comparison means or the second comparison means. The search means, the storage means for storing search information in which the data block identification information reproduced by the reproduction means and the absolute position information corresponding to the data block identification information are paired, and the target data block identification information. Search from the search information stored in the storage means,
The second comparison means is provided with setting means for setting the absolute position information corresponding to the target data block identification information as the target absolute position information.

With the above-described structure, the present invention stores the pair of the data block identification information corresponding to each data block passing during the search of the target data block and the absolute position information corresponding to the head frame of the data block in the storage means. When the target data block is stored in the storage means, the search is performed based on the target absolute position information corresponding to the first frame of the target data block. The search can be executed without overshooting the first frame of the data block.

Embodiments Embodiments of the digital signal recording / reproducing apparatus of the present invention will be described below with reference to the drawings.

First, FIG. 1 shows the structure of a digital signal recording / reproducing apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a cassette half, 2 is a reel, 3 is a tape, 4
Is a cylinder, 5a and 5b are heads, 6 is a mechanism control unit for controlling the operation of the reel 2 and the cylinder 4, and 7 is a recording operation, which encodes a digital signal and supplies a recording signal to the heads 5a and 5b, and a reproducing operation. Is a signal processing unit that decodes the reproduced signals obtained from the heads 5a and 5b and outputs a digital signal. Reference numeral 8 supplies data block identification information, which is management information of the data block, to the signal processing unit 7 in the recording operation.
In the reproducing operation, the data block identification information recording / reproducing control section extracts the data block identification information from the signal processing section 7. Reference numeral 9 represents the absolute position information in the recording operation.
And an absolute position information recording / reproducing control unit for extracting the absolute position information from the signal processing unit 7 in the reproducing operation.
Is a search information storage unit for storing search information consisting of a pair of data block identification information and absolute position information corresponding to the first frame of the data block, and 11 is a communication unit for transmitting / receiving digital data to / from an external device. In the recording operation, 12 sends the data block identification information to the data block identification information recording / reproduction control section 8 or the absolute position information to the absolute position information recording / reproduction control section 9, and in the reproduction operation the data block identification information recording / reproduction control section. The data block identification information obtained in 8 and the absolute position information obtained in the absolute position information recording / reproducing control unit 9 are extracted, and the extracted data block identification information and the absolute position corresponding to the first frame of the extracted data block are extracted. The search information consisting of a pair of information is stored in the search information storage unit 10. In the search operation, the extracted absolute position information and the search information stored in the search information storage unit 10 correspond to the data block of the target data block. In the system control unit that compares the absolute position information to be transmitted, sends the tape speed information to the mechanism control unit 6, and retrieves the target data block. That.

The operation of the digital signal recording / reproducing apparatus of this embodiment constructed as described above will be described below. Prior to explanation, the tape format is shown in FIG. One frame consists of adjacent plus azimuth tracks and minus azimuth tracks, and each track has a main data area for recording digital data,
ATF (Automatic Track Fin) which is a sub-data area located on both sides of the sub-data area for recording auxiliary data and a track synchronization signal.
ding) area.

First, the recording operation will be described in detail. In the recording operation, the absolute position information and the data block identification information are recorded in the sub data area, and the user data given via the communication means is recorded in the main data area. First, the absolute position information is shown in FIG. 3 showing the frame arrangement of the tape.
Absolute position information of the 0th frame, which is a reference, is I0, n
Let In be the absolute position information of the th frame. The data block identification information is identification information of a data block formed by a plurality of frames in FIG.
And Next, in FIG. 1, the data block identification information recording / reproducing control unit 8 and the absolute position information recording / reproducing control unit 9 give an operation command to the mechanism control unit 6 via the system control unit 12 to drive the mechanism. , The data block identification information and the absolute position information are transferred to the signal processing unit 7,
The data is recorded in the sub data area for each frame via 5a and 5b.

Next, the reproducing operation will be described in detail. In FIG. 1, the absolute position information recording / reproduction control unit 9 and the data block identification information recording / reproduction control unit 8 give an operation command to the mechanism control unit 6 via the system control unit 12 to drive the mechanism and The absolute position information and the data block identification information in the data area are extracted through the heads 5a and 5b, and the signal processing unit 7 sends the absolute position information to the absolute position information recording / reproducing control unit 9 and the data block identification information. Information is input to the data block identification information recording / reproducing control unit 8.

Next, the search operation of a certain data block will be described in detail with reference to the flowchart of FIG. First, the system control unit 4 sets the mechanism to the high-speed reproduction operation, starts the search, and proceeds to the step. If the data block identification information of the data block to be retrieved exists in the retrieval information storage unit, the process proceeds to the step. Go to the step.

First, the case where the data block identification information of the data block to be searched does not exist in the search information storage unit will be described. In step, if the reproduced frame is the head frame of the data block, the process proceeds to step, and if it is not the head frame, the process of step is repeated again. Next, in the step, a pair of the reproduced data block identification information and the absolute position information corresponding to the data block identification information is stored in the search information storage unit 10. If the new data block matches the data block to be searched in the next step, the high-speed playback is stopped, the tape is rewound by the excessive amount, the data block to be searched is reached at the normal speed, and the search ends. To do.

Next, a case where the data block identification information of the data block to be searched is present in the search information storage unit will be described.
First, in step S, it is determined whether the position where the data block to be searched exists in the tape running direction is the forward direction or the backward direction, and high speed reproduction is started in the determined direction. Next, the process proceeds to step, and if the absolute position information corresponding to the data block to be searched does not match the reproduced absolute position information, the search ends. Also, if they do not match,
Proceed to the step, find the difference between the absolute position information corresponding to the data block to be searched and the reproduced absolute position information,
The speed control corresponding to the difference is performed. For example, when the difference is large, the reproduction is performed at high speed, and as the difference becomes smaller, the reproduction is decelerated toward the normal reproduction speed. In this way, steps are repeated, the deceleration is started from before the data block to be searched, the data block to be searched is reached by normal reproduction, and the search is ended.

The mechanism control unit 6, the data block identification information recording / reproduction control unit 8, the absolute position information recording / reproduction control unit 9, and the system control unit 12 are independent control units. It may be configured by a computer and realized as software.

Further, although the absolute position information recording / reproducing control unit 9 of the present embodiment uses the absolute position information in frame units, the absolute position information may be in track units.

As described above, according to the present embodiment, a high-speed search can be realized for a data block whose search frequency is high.

Effects of the Invention As described above, the digital signal recording / reproducing apparatus of the present invention is
On a tape, absolute position information for identifying a frame unit based on a frame formed in advance and data block identification information for identifying a data block formed by a plurality of frames are specified in advance on a certain track. Recording means for recording in the area, reproducing means for reproducing the plus azimuth track and the minus azimuth track continuously or intermittently at normal speed or high speed, and data block identification information reproduced by the reproducing means. A first comparing means for comparing the target data block identification information of the target data block, the absolute position information targeting the head frame of the target data block or a frame near the head frame, and the reproduction. Second comparing means for comparing the absolute position information reproduced by the means, Or a search means for searching the target data block according to the comparison result of the second comparison means, data block identification information reproduced by the reproduction means, and absolute data corresponding to the data block identification information. Storage means for storing search information paired with position information, and the target data block identification information is searched from the search information stored in the storage means, and absolute position information corresponding to the target data block identification information. Is provided in the second comparison means as setting target absolute position information, it is easy to determine whether the target data block identification information is the forward direction or the reverse direction with respect to the tape running direction. Therefore, it is easy to search for the target absolute position information to be reached at the normal reproduction speed during high-speed reproduction. In addition, it is not necessary to record a huge amount of search information over the entire tape, the tape usage efficiency is high, and the memory of the device is small, so it is easy to implement at low cost, and the configuration is simple. There is a characteristic.

[Brief description of drawings]

FIG. 1 is a block diagram of a digital signal recording / reproducing apparatus, FIG. 2 is a block diagram of a tape format, FIG. 3 is a frame block diagram showing absolute position information on a tape in an embodiment of the present invention, and FIG. FIG. 5 is a frame configuration diagram showing the data block identification information on the tape in the embodiment of the present invention, and FIG. 5 is a flow chart showing the control procedure of the system control unit 12 in the embodiment of the present invention. 1 ... cassette half, 2 ... reel, 3 ... tape,
4 ... Cylinder, 5a, 5b ... Head, 6 ... Mechanism control section, 7 ... Signal processing section, 8 ... Data block identification information recording / reproducing control section, 9 ... Absolute position information recording / reproducing control section, 10 ...... Search information storage section, 11 …… Communication section, 12 …… System control section.

Claims (1)

[Claims] 1. An absolute position information for identifying a frame unit and a data block formed by a plurality of frames are identified on the basis of a frame composed of a plus azimuth track and a minus azimuth track which are previously formed on a tape. Recording means for recording the data block identification information in a predetermined specific area on a certain track,
At normal speed or high speed, plus azimuth track,
A reproducing means for reproducing a minus azimuth track continuously at a normal speed or intermittently at a high speed; a data block identification information reproduced by the reproducing means; and a target data block identification information of a target data block. One comparing means, and a second comparing means for comparing the absolute position information targeted for the head frame of the target data block or a frame near the head frame with the absolute position information reproduced by the reproducing means. , A search means for searching the target data block by the comparison result of the first comparison means or the second comparison means, and data block identification information and data block identification information reproduced by the reproduction means. A storage means for storing search information paired with corresponding absolute position information, and the target data block described above. Setting means for searching the identification information from the search information stored in the storage means, and setting absolute position information corresponding to the target data block identification information in the second comparing means as the target absolute position information. A digital signal recording / reproducing apparatus comprising: