JPH0294149A - High-speed searching method for rotary head type digital tape recorder - Google Patents

Abstract

PURPOSE:To reduce the time required for searching a tape by making the tape moving means and aimed tape speed at the initial stage of searching selectable in accordance with the moving distance when the tape is searched from the leading edge by using continuously changing information. CONSTITUTION:After a tape is tightly stretched by controlling reels 6 and 7 to rotate in opposite directions in which the tape 15 is stretched by rotating a cylinder 2 and the tape 15 is brought into contact with heads 3 and 3', the address value Ap of the current position is read. Then the moving direction of the tape 15 is decided by comparing the address value Ap of the current position with the address value As of the position to be searched. Thereafter, the absolute value ¦Ap-As¦ of the difference between the address values Ap and As is calculated and the feeding quantity of the reels 6 and 7 or capstan 4 which are tape moving means and tape speed are decided depending upon the magnitude of the absolute value. Therefore, the time required for searching the tape can be reduced.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention records a PCM signal in a PCM area and also records subcode information such as time information in an independent subcode area on a track. The present invention relates to a rotary head type magnetic recording/reproducing device for reproducing subcode information.

(B) Conventional technology Conventionally, in a rotary head type digital audio tape recorder (hereinafter referred to as R-DAT), each track recorded by a rotary head has a PCM signal recorded thereon.
ATF that records signals for CM area and tracking control
The area and the subcode area for recording subcode information are formed separately, and each can be recorded and reproduced independently. Information such as a cue signal (start ID), track number (P-No), and absolute time from the beginning of the tape (A-time) is recorded in this subcode area, and each piece of information can be used to search. It is possible to do this. For example, regarding high-speed search using subcode information, P
-Unexamined Japanese Patent Publication No. 62-188084 as a search by No.
(Some are described in GllB27.1(1) etc.

(...) Problems to be Solved by the Invention In the R-D AT mentioned above, when searching for a target position using information that changes continuously from the beginning of the tape (A-Time, etc.), the distance from the current position to the target position is A search is performed according to a fixed procedure regardless of the distance. For example, with a 200x fast forward high-speed search, the target A-Tim
Since an overrun occurs, the target A-Time is detected again at 8x speed and the target position is searched. Since an overrun occurs, a search is performed to absorb the overrun, resulting in a problem that the time required for the search becomes long.

(d) Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, when performing a search, first, the head is rotated without moving the tape, the address value at the current position is read, and this value and By comparing the address value at the target position, the tape moving direction is determined, and at the same time, the tape moving means and target tape speed at the beginning of the search are determined depending on the magnitude of the difference between the two address values.

(f) Effect According to the above means, overruns do not occur during high-speed searching, the time required for searching is shortened, and the tape can be stopped at the target position.

(f) Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 3. In FIG. 1, (1) is the tape drive mechanism;
(2) is a rotary head cylinder equipped with magnetic heads (3) and (3)'' spaced apart by 80 degrees; (4) is a capstan;
(5) is a pinch roller, (6) is a supply side l-ru, (7)
is the take-up reel, (8), (9), (1 (1), (
11) is a tape guide post, (]2), (13), (
14) are cylinder (2) and capstan (4) respectively.
, an FG detector that detects the rotation of the supply and take-up reels (6) and (7), (15) is a magnetic tape, and (16) is a loading device for winding the magnetic tape (15) around the cylinder (2). It is a driving part and also has the role of pressing the pinch roller against the capstan and releasing it.

(17) is an input terminal for information signals such as audio signals;
) is a circuit that samples and holds the input analog signal, (19) is an A/D conversion circuit, (2 (1)
is the interleaving of digital signals and error correction code.
A digital signal processing circuit that performs addition, time axis compression, etc.
21) is a recording amplifier, (22) is a recording/playback switching circuit, (23) is a playback amplifier, (24) is an equalizer that shapes the waveform of the playback signal, (25) is a D/A conversion circuit,
(26) is a low-pass filter, (27) is an output terminal, (
28) is a serve system that controls the cylinder, capstan, and both reels, and (29) is a microcomputer that controls the system.

In addition, in the R-DAT having the above configuration, each track recorded on the tape has a PCM area (P) for recording input signals and a subcode area (Ss) for recording subcode information, as shown in FIG. (Se), and ATF areas (Ts) and (Te) for recording signals for tracking are formed by dividing the area. This subcode area can contain subcode information such as a cue signal (S-ID), track number (P-NO), and absolute time from the beginning of the tape (A-time). This information can also be read during high-speed searches.

Next, we will explain the operation when the target search position is given by information that changes continuously from the tape start recorded in the subcode area, such as absolute time (A-time) from the tape start, that is, an address. do.

First, the microcomputer (29) that controls the system receives an instruction to search for the target position (address value As) (step 3 (1)) and reads the address value Ap at the current position (step 31). That is, , rotate the cylinder (2) (step 32), and rotate the reel (6),
(7) in the direction in which the tape (15) is stretched by i-1''.
control to rotate in the opposite direction (step 33)
By removing the slack in the tape, remove the tape (15).
After setting the address to (3) (3)'', read the address value Ap of the current position (step 3, 1).
. Compare the magnitude of the address Ap of the current position read in this way and the address As of the given search position 1 (
Step 36) determines the tape moving direction (Step 37) or (Step 38) (Step 35). Next, the absolute fii of the difference between address values Ap and As
Calculate l A p A s 1 (Step 7, Step 39)
).

This tape moving means (6), (7) or capstan (4) at the beginning of the search depends on the size of (iM).
) feed and target tape speed (±200200x00
(step 4)
o, 45) However, to explain it specifically, first,
Compare the value of IAp-AsI and a2 (step 4)
1), if IAp-As>a2, select high-speed search by reel feeding (step 42) as the movement means, 1A
If pAs1≦a2, a low-speed search using capstan feeding (step 43) is selected as the moving means. If high-speed search by reel feeding (step 42) is selected, then compare the size of 1Ap-Asl and a3, and select 1Ap-Asl.
If p-Asl > a 3, the target tape speed is set to 200 times the normal playback speed (step 47), and 1Ap-Asl≦
For a3, increase the target tape speed by 100 times (step 1
8) and start tape movement (step 52).
.

On the other hand, if low-speed search by capstan feeding is selected (step 43), the loading drive unit (16) presses the pinch roller (5) onto the capstan (4) (step 44), and then 1Ap-Asl and al. If l Ap-As l > a 1, set the target tape speed to 10 times, and if IAp-As≦a1, set the target tape speed to 3 times. Step 50.51) The movement is started (step 52).

Note that the value a1. used for the comparison used in steps 46, 48, and 49. The relationship between a2 and a3 is a3>a2>al>0. Also, Figure 2 shows the target tape speed and tape moving means at the distance between the current position 1 (Ap) and the target position. For example, when searching for the position indicated by the arrow x, start the search by feeding the reel at 1100x speed. That's what I do.

(g) Effects of the Invention In the present invention, when performing a search using information that changes continuously from the beginning of the tape, the tape moving means and target tape speed at the beginning of the search can be selected according to the moving distance. This is extremely beneficial as it can significantly shorten the time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a rotary head type digital tape recorder of the present invention, FIGS. 2 and 3 are schematic diagrams of a tape and a flowchart for explaining the present invention in detail, and FIG. The figure shows the tape format of R-1) AT. area, (SsXSe) subcode area, (15)...
・Tape, (4) ・Capstan (tape moving means),
(6), (7)... Reel (tape moving means).

Claims (1)

[Claims] (1) A PCM area in which digital information is recorded on each track of the tape that is helically scanned by a rotating head, a tracking area in which information for tracking control is recorded, and a subcode area in which subcode information is recorded. In a rotary head type digital tape recorder that is formed by dividing the tape, when performing a high-speed search using address information that changes continuously from the beginning of the tape recorded in the subcode area, the address of the current position is searched immediately before the tape is driven. The value is read and compared with the address value of the specified search position to determine the direction of tape movement, and also to determine the tape movement means at the beginning of the search and the tape speed by the means according to the difference between the two address values. High-speed search method for rotating head type digital tape recorders.