JPH0510320Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a rotary head type digital audio tape recorder generally referred to as R-DAT. The present invention relates to a high-speed information retrieval device that performs high-speed retrieval of information using program numbers recorded such that they increase from the beginning to the end.

[Technical background of the invention and its problems]

In conventional devices of this type, the program number (hereinafter abbreviated as PNo) of the current position of the magnetic tape
and select this PNo and the specified search destination.
PNo., and based on the comparison result, a high-speed search operation in the FWD or REV direction is started, and the above comparison is performed during this high-speed search operation, and when both PNos match, a precision cueing operation is started, and the specified When the starting point of the specified PNo is detected, the search operation ends. If the beginning or end of the tape is reached during the high-speed search operation, the high-speed search operation is interrupted.

By the way, with R-DAT, if there is an unrecorded part of the RF signal between multiple information programs recorded on the magnetic tape, the
PNo may not be read.

In R-DAT, this includes PNo.
In order to read the SUBCODE during high-speed search running, the relative speed when the rotary head traces the track pattern recorded on the magnetic tape is set to be the same as during steady running, for example during playback, regardless of the running speed of the magnetic tape. This is because a servo that controls the rotation speed of the rotating drum, a so-called drum servo, is applied. The reference signal for this drum servo is obtained from the reproduced RF signal, and if the RF signal enters an unrecorded part during high-speed search,
The drum servo comes off. again in this state
Even if it enters the RF signal recording section, it is impossible to read the SUBCODE immediately because it takes time for the drum servo to relock. As a result, when performing a high-speed search, the
PNo is almost impossible to read.

As described above, conventional devices have a fatal drawback in that they may not be able to search for the PNo recorded on the magnetic tape.

[Purpose of invention]

The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional ones, and aims to provide a high-speed information retrieval device that dramatically improves the probability of reading PNo.

〔overview〕

The high-speed information retrieval device according to the present invention, which was developed to achieve the above purpose, currently uses PNo. and purpose.
A high-speed search operation is performed in the FWD or REV direction by comparing the PNos, and during the search operation, the target PNo.
When it is determined that the search has been skipped, the search operation is performed in the opposite direction again.
We are trying to improve the probability of reading PNo.

〔Example〕

An embodiment of the high-speed information retrieval device according to the present invention will be described below with reference to the drawings.

In the figure, 1 is a magnetic tape on which a plurality of information programs and PNos corresponding to each information program are recorded, 2 is a rotating drum, 3a and 3b are heads for reading the information programs and PNos from the magnetic tape 1, and 4 is a capstan. , 5 is a pinch roller, 6 is a tape end detection means, 7 is a tape start end detection means, and 8 is a mechanism section.

9 is a head amplifier for amplifying the output of magnetic heads 3a and 3b to an appropriate level; 10 is a head amplifier;
PNo reproducing means for reproducing a PNo; 11 is a current PNo holding means for retaining the PNo at the current position reproduced by the PNo reproducing means 10; 12 is for inputting a search destination PNo and inputting an instruction to start a search operation, etc. 13 is the operating means 12 for performing the operation.
14 is the current PNo holding means 1 for the purpose of holding the search destination PNo inputted by
1 and purpose PNo comparison means for comparing the sizes of the contents held in the PNo holding means 13; 15 is a control means for controlling the mechanism section 8 by the outputs of the operation means 12, the PNo comparison means 14, etc., and performing a search operation; be.

In the above configuration, the PNo is reproduced by the PNo reproducing means 10, and this is the current PNo holding means 1.
1 and when the search destination PNo is specified by the operation means 12, the search destination PNo.
The PNo is held in the target PNo holding means 13. Furthermore, when the start of the search operation is instructed by the operation means 12, the control means 15 causes the mechanism section 8 to perform high-speed operation in the FWD or REV direction based on the output of the PNo comparison means 14, that is, the result of comparing the current PNo and the target PNo. Performs control to start the search operation.

During the high-speed search operation, the control means 15 monitors the output of the PNo comparison means 14, and if the contents of the current PNo holding means 11 and the target PNo holding means 13 match, the control means 15 controls the mechanism section 8 to perform a precise cueing operation. start. When the starting point of the target PNo is detected by the precision cueing operation, the search operation is completed.

During high-speed search operation, if it is determined that the target PNo has been skipped, that is, during FWD search, when the current PNo becomes larger than the target PNo, the REV
During the search, when the current PNo becomes smaller than the target PNo, the search is reversed and a re-search operation is started from the opposite direction. During this re-search operation, if it is determined that the target PNo has been skipped again, the search operation is interrupted.

Furthermore, if the beginning or end of the tape is reached during the high-speed search operation, the high-speed search operation is interrupted.

In order to carry out the above operations, the control means 15 performs the work shown in the flowchart of FIG. 2 according to a predetermined program.

That is, the control means 15 starts execution of the flowchart according to the program in response to the search start operation in the operation means 12, and executes the first step.
At S1, the re-search flag is set to 0.
After that, proceed to step S2, and PNo comparison means 14
With the output of , the current PNo and the target PNo are the current PNo
<Objective PNo, Current PNo> Objective PNo, Current PNo=
Determine which relationship the target PNo is in.

Based on the judgment in step S2, the current PNo < purpose
If the result is PNo, the process advances to step S3, where a control signal is generated to cause the mechanism section 8 to start a high-speed search operation in the FWD direction. Thereafter, the process proceeds to step S4, where it is determined whether the current PNo=target PNo, and if the determination is NO, the process proceeds to step S5. In step S5, it is determined based on the output of the PNo comparison means 14 whether the current PNo>target PNo. Determine whether it has been reached. Steps S4 to S6 above
The determination of these steps is repeated until one of the determinations becomes YES.

Now, if the determination in step S4 is YES, that is, if the target PNo has been searched, the process advances to step S7, where a precise cueing operation is started, and upon completion of this operation, the execution of the program is ended. . On the other hand, the judgment in step S5 is
If YES, that is, if it is determined that the target PNo has been skipped by the search operation, the process advances to step S8, where it is determined whether the re-search flag is 1 or not. If the determination in step S8 is NO, the process advances to step S9, where the re-search flag is set to 1, and then the process proceeds to step S10.
Proceed to. If the determination in step S6 is YES, it is assumed that there is no record of the target PNo, and the process proceeds to step S11, where the search operation is interrupted and then
Stop program execution.

In step S10 above, the mechanism section 8 is
A control signal is generated to start a high-speed search operation in the direction, and the process then proceeds to step S12, where the current
Determine whether PNo=target PNo. Step S12
If the determination is NO, the process advances to step S13. In step S13, it is determined based on the output of the PNo comparison means 14 whether or not the current PNo<target PNo. Determine whether or not. Above steps
Until one of S12 to S13 becomes YES,
The determination of these steps is repeated.

Now, if the determination in step S12 is YES, that is, if the target PNo is searched, the process proceeds to step S7, and the mechanism section 8 is caused to perform a precision cueing operation. On the other hand, when the determination at step S13 is YES, that is, when it is determined that the target PNo has been skipped, the process advances to step S15, where it is determined whether the re-search flag is 1 or not. Since the re-search flag is set to 1 in step S9 as described above, the determination in step S15 is YES, and the process then proceeds to step S11, where the search operation is interrupted. Also, step S14
Even when the determination is YES, the process advances to step S11 and the search operation is interrupted here.

In other words, when you search in one direction and determine that you have skipped over the target PNo, search again in the opposite direction, and this research will also lead to the target PNo.
When PNo cannot be searched, the search operation is interrupted there.

The above operation is performed when the positional relationship between the current PNo and the target PNo at the start of the search is current PNo < target PNo, but when current PNo > target PNo,
After the determination in step S2, the process proceeds to step S10, where the mechanism section 8 starts a high-speed search operation in the REV direction. After that, the judgment in steps S12 to S14 is YES.
Steps S12 to S14 are repeated until step S12 becomes YES, and the process proceeds to step S7, where a precision cueing operation is performed. When the determination in step S13 is YES, it is determined in step S15 whether or not the re-search flag is 1, and the determination is made.
If NO, the re-search flag is set to 1 in step S16, and then the process proceeds to step S3.

Thereafter, steps S4 to S6 are repeatedly executed until the judgment in any one of steps S4 to S6 becomes YES, and when the judgment in step S4 is YES, the process proceeds to step S7, and when the judgment in step S5 is YES, the process proceeds to step S8. After that, proceed to step S11. After executing step S11, execution of the program is stopped.

Note that although the above-described embodiment does not particularly specify the method of detecting the tape start end and tape end, various methods are conceivable for this purpose. One method is to detect the leader tape section, and the other method is to detect the leader tape section.
Lead-in area (PNo=BB) or lead-out area (PNo=BB) in DAT format
EE) are recorded, these are detected. In the latter method, the PNo of each area
It becomes possible to interrupt the search operation more quickly at the time of detection, and unnecessary operations can be eliminated.

〔effect〕

As explained above, according to the present invention, if it is determined that the target PNo has been skipped during a high-speed search operation, the search operation is performed again from the opposite direction, which reduces the probability of reading the program number. It is now possible to improve dramatically.

In particular, it is extremely effective in searching for the target program number immediately after the RF signal has not been recorded.

It is also effective when it is difficult to read the program number due to tape damage or the like.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a high-speed information retrieval device according to the present invention, and FIG. 2 is a flowchart showing the operation of the control means in FIG. 1. DESCRIPTION OF SYMBOLS 1... Magnetic tape, 8... Mechanism part, 10... Program number reproducing means, 11... Current program number holding means, 12... Operating means, 13
...Objective program number holding means, 14...
Program number comparison means, 15... control means.

Claims (1)

[Claims for Utility Model Registration] A magnet for a rotary head type digital audio tape recorder, in which a plurality of information programs and a program number unique to each information program and increasing toward the end of the tape are recorded at the starting point of each information program. A program number reproducing means for reproducing the program number at the current position from the tape; a current program number holding means for retaining the program number at the current position reproduced by the program number reproducing means; and a program number at the search destination and the start of the search operation. an operating means for inputting an instruction; a target program number holding means for holding the program number of the search destination inputted by the operating means; and a content of the current program number holding means and a content of the target program number holding means. Comparing means for comparing program numbers; and control means for controlling a mechanism based on the outputs of the operating means and the program number comparing means; In response to the input of the start instruction, the mechanical unit is instructed to perform FWD or FWD based on the output of the program number comparison means.
When a high-speed search operation in the REV direction is started and it is determined that the target program number has been skipped during the high-speed search operation, the search direction of the mechanism is reversed and the search operation is performed again from the opposite direction from when the search operation was started. A high-speed information retrieval device characterized by: