JPH01213885A - Digital magnetic reproducing device - Google Patents

Abstract

PURPOSE:To attain high speed program searching by driving a tape at high speed in correspondence to a distance between the present position and object position of the tape. CONSTITUTION:When a tape cassette 4 is mounted and the program searching is executed from the present position of the tape to the head of another program, time difference is computed by an MPU13 from the absolute time of the present position and the absolute time of an object place in a RAM14 and the distance of the tape up to the place is computed. The tape is traveled at speed to be higher than the readable speed of a recorded signal. At such a time, the respective rotational periods (frequencies) of the take-up reel 5 and the supply reel 6 of a tape driving system are monitored through rotation detectors 7 and 8. The MPU13 calculates the present tape position from the information of respective reel pulses and deceleration is executed in the vicinity of the object position. Then, the normal program searching can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a high-speed cueing device in a digital magnetic regenerator, particularly a DAT.

B0 Summary of the Invention The information recorded on the tape can be read even if the tape is run at a speed higher than the normal playback speed, and the number of revolutions on the take-up side and the supply side of the reel is In a digital magnetic regenerator comprising means for detecting.

When the TOC and absolute time are recorded on the tape, the beginning position of each program on the tape is memorized by reading the TOC, and this position information is used to read the signal at a speed faster than the signal reading speed. Run the tape and find the beginning.

One of the features of the C0 conventional technology DAT is that it is capable of high-speed cueing. There, for example, R-DAT
As shown in FIG. 4, an area called a subcode is reserved in addition to the audio signal on the signal track recorded obliquely on the tape 1. In the figure, A represents an audio signal area, and B represents a subcode area.

This subcode includes the absolute time on the tape, the relative time within each program (hereinafter referred to as program time), the program number, and the identification code indicating the beginning of the program (hereinafter referred to as start time in this specification). I
It is abbreviated as D. ), a content table (hereinafter abbreviated as TOC in this specification) in which table of contents information (absolute time at which each program starts, etc.) on the tape is recorded. As shown in Figure 5, when the tape is run at a higher speed than the normal tape running speed during playback, the head runs across the recording track, and the track direction component of the head trajectory By changing the rotational speed of the drum so that the relative speed of the head is the same as during normal running, it is possible to read the contents of some of the tracks that have the same azimuth as the head. Arrow 2 in FIG. 5(a) represents the trajectory of the head during rewinding, and arrow 3 in FIG. 5(b) represents the trajectory of the head during high-speed travel during fast forwarding. In this way, the time information, start ID, program number, and other information written in subcode area B on the tape are read while the tape is running at high speed, and when the tape reaches the target position on tape 1, the tape is read. A known method is to accurately cue a predetermined position by stopping high-speed running and returning to normal playback speed.

D0 Problems to be Solved by the Invention However, as the running speed of the tape increases, the length (number of bits of information) that can be read from one track becomes shorter, and the block structure of the recorded signal becomes shorter. Therefore, the maximum tape speed at which recorded contents can be read is approximately 200 times the normal speed, and if the tape is run at a speed higher than this, the cue information recorded on each track may not be read. comes out.

[Object of the Invention] An object of the present invention is to provide a device that runs the tape at a higher speed and enables even faster cueing, without using a method of cuing up while reading information recorded on the tape. It is to provide.

Means for Solving the E0 Problem In order to achieve the above object, the digital magnetic regenerator according to the present invention includes a storage device and, based on tape insertion, writes TOC information recorded on the tape to the storage device. a first calculating means for calculating a target position information value corresponding to a time difference to the target position during a cueing operation; and a second calculating means for calculating a value indicating the current tape position from a signal accompanying the rotation of each reel. The calculation means sets the tape to a first high-speed run during a cueing operation, and sets the tape to a second high-speed run from which tape recording information can be read based on the target position information and a value indicating the current tape position. The gist is to include a microcomputer including means for setting.

F0 action First, read the TOC information, and when you want to cue from the current tape position to the beginning of another program, calculate the time difference from the absolute time of the current position and the absolute time of the target location, and then The distance of the tape is calculated, and the tape is run to the target location at a speed higher than the limit that allows the recorded signals to be read.

G. EXAMPLES The present invention will be explained in more detail below using examples with reference to the drawings, but these are merely illustrative and various modifications and improvements can be made without going beyond the scope of the present invention. Of course it is possible.

FIG. 1 is a conceptual diagram showing the configuration of a digital magnetic reproducing device according to the present invention. In the figure, 4 is a DAT cassette, 5 is a pick-up reel, 6 is a supply reel, 7 is a pick-up rotation detector, and 8 is a supply rotation. detector, 9
is tape thickness identification switch, 10 is Prerecord
ed Tape (hereinafter referred to as pre-recorded tape).

), 11 is a pickup reel motor and servo, 12 is a supply reel motor and servo, 13 is a microcomputer, and 14 is a memory device (RAM).

FIG. 2 is a conceptual diagram showing the configuration of a signal processing system of a high-speed cueing device according to the present invention. In the figure, 15 is a tape, 16 is a drum, 17 is a head, 18 is an amplifier, 19 is a drum motor, and 20 is a drum. A servo, 21 represents a reproduction frequency detection device, and 22 represents a signal processing system. Signal processing system 2
2 is included in the microcomputer 13.

The operation of the above embodiment will be explained below.

As mentioned above, for example, in the subcode area of R-DAT, table of contents information on the tape called TOC and absolute time are recorded. When a cassette is inserted into the deck, this TOC information is first read and the absolute time at which each program on the tape starts is stored in the microcomputer.

By the way, there is a difference between a user tape recorded by the user and a pre-recorded tape that is sold with the source recorded in advance.On a pre-recorded tape, the TOC is written over the entire tape, whereas on a user tape The standard has been set to record at the beginning of the tape. Therefore, when a cassette is inserted, the microcomputer determines whether or not the cassette is a prerecorded tape by looking at an identification hole called an ID hole provided in the cassette. If it is a user tape and the current tape position is not at the beginning, it is rewound to the beginning, the TOC information recorded there is read, and its contents are stored.

From now on, when you want to cue to the beginning of another program from the current tape position, calculate the time difference from the absolute time of the current position and the absolute time of the destination location, and then calculate the distance on the tape to that point. calculate. The tape begins to run at high speed, and the speed may be greater than the limit at which the signals recorded on the tape can be read. At this time, the rotation period or frequency of each of the pick-up reel and the supply reel is monitored by rotation detection systems provided on the pick-up side and the supply side of the tape drive system.

Then, the approximate current tape position is calculated from the information of each reel pulse, and when the tape approaches the target location, the running of the tape is decelerated so that the information recorded on the tape can be read. After that, just as with normal cueing, start, move the tape to the correct position while reading the absolute time, program number, etc., and proceed to normal playback operations from the desired location to play the tape.

From the rotation period of the pickup side and the supply side,
Explain how to calculate tape position.

Each rotation period of the pick-up and supply is T.
t and T s are the radius of the tape on each reel (including the hub and tape), rt and rst, the hub diameter of the reel, rh + the running speed of the tape, V, and the thickness, t
, the length of the tape wound on each of the pick-up and supply reels is 1, and the total length of the l S+ tape is L. Among the above parameters, rh is determined by the standard, and information about t can be obtained from the identification hole of the cassette.

Here 2π　r,=vT.

That is, rs = vTs/2 π −−(3
)2 π rt = vTt, that is, rt = vTt/2tc --(4
) Substituting equations (3) and (4) into equations (1) and (2) and adding them, L = (1s+lt) ・・・・・・・・・・・・(6) Equation (6) Substituting into equations (3) and (4) to obtain (1) and (2), we get ・・・・・・・・・・・・(7) ・・・・・・・・・・・・(8) The current position of the tape can be known.

Although the length of the tape is undetermined, the formula (
6).

FIG. 3 is a flowchart showing the high-speed cueing operation described above.

As explained in detail about the H0 invention, according to the present invention, it is possible to search for the beginning without reading the information recorded on the tape, so it is possible to perform a high-speed search that is faster than searching while reading information. This is an advantage.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing the configuration of the high-speed cueing device according to the present invention, FIG. 2 is a conceptual diagram showing the configuration of the high-speed cueing device signal processing system according to the present invention, and FIG. 3 is the high-speed cueing operation described above. FIG. 4 is a track layout diagram, and FIG. 5 is a flowchart showing the
The figure shows the locus of the head during high-speed travel during rewinding and fast forwarding. 4...DAT cassette, 5...Tick-up reel, 6...Supply reel, 7...
... Tick-up rotation detector, 8 ... Supply rotation detector, 9 ... Tape thickness identification switch, 10 ... Preliminary recorded tape identification switch, 11...Tick-up reel motor and servo, 12...Supply reel motor and servo, 13...Microcomputer, 14
...Memory device (RAM), 15 tape, 16 ... drum, 17 ... head,
18...Amplifier, 19...Drum motor, 20...Drum servo, 21...
Reproduction frequency detection device, 22...signal processing system. Figure 2. Signal of U's signal C, 22 degrees, 1 concave/1 (b)

Claims (1)

[Claims] (a) a storage device; (b) means for writing TOC information recorded on a tape into the storage device based on tape insertion; (c) a time difference to a target position during a cue operation; (d) a second calculation means that calculates a value indicating the current tape position from a signal accompanying the rotation of each reel; and (e) during a cueing operation. A microcomputer includes means for setting the tape to a first high-speed running mode and, based on the target position information and a value indicating the current tape position, setting the tape to a second high-speed running mode from which tape recording information can be read. A digital magnetic reproducing device comprising: