JPH0376084A - High speed search controller of rotary head type digital tape player - Google Patents

Abstract

PURPOSE:To shorten the search time by executing the search, based on a count value of a reel pulse count means and its target value, as for a start ID and a start ID in which a count value of a reel pulse is stored. CONSTITUTION:To a microcomputer 340, a reel pulse signal from an FG sensor 180 provided so as to output a pulse by synchronizing with a rotation of a reel 300 is inputted, and when each start ID signal recorded in a tape 16 is read out in the course of running of the tape 16, a count value in a reel pulse count means at that time is stored in accordance with the read-out start ID signal. In this state, based on comparison of the count value of the reel pulse count means and the count value stored in accordance with the target start ID signal, the target start ID signal is searched. In such a way, the target start ID signal can be searched in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rotary head type digital tape player, such as a rotary head type digital audio player (hereinafter referred to as R
-Abbreviated as DAT. This invention relates to a high-speed search control device.

[Conventional technology]

One of the features of the R-DAT that is not found in general cassette tape recorders is its high-speed search function. This fast-forwards (FF) or rewinds the tape at a speed of about 8 to 200 times the normal playback speed (RBW), reads the recorded subcode, uses it to search for the desired song, and searches for the beginning of the desired song. It is a function to find the position.

[Problem to be solved by the invention]

As mentioned above, the tape speed in high-speed search using this method is limited to about 200 times the normal playback speed, and at higher speeds the subcode information cannot be read accurately, making it difficult to find the target start ID. I couldn't.

Therefore, an object of the present invention is to send the tape at a higher speed than the conventional high-speed search and find the target start ID.
The aim is to make it possible to search for information, thereby further shortening the search time compared to conventional methods.

[Means to solve the problem]

FIG. 1 is a principle diagram of a high-speed search control device according to the present invention.

In the figure, the high-speed search control device of the present invention has tape 1
Start I to read out the start ID signal recorded in 6.
D signal reading means 20 and read start ID
A rotary head type digital device comprising a first search means 22 for searching for a target start ID signal based on a signal, and a reel pulse output means 18 for outputting a reel pulse synchronized with the rotation of a reel around which tape 16 is wound. A high-speed search control device for a tape player includes a reel pulse counting means 30 that counts the reel pulses with a polarity depending on the running direction of the tape, and each start I recorded on the tape while the tape is running.
When the D signal is read out, the count value in the reel pulse counting means 30 at that time is read out.
Reel pulse storage means 32 that stores in correspondence with the D signal
and a second search means 34 for searching for a target start ID signal based on a comparison between the count value of the reel pulse count means 30 and the count value stored corresponding to the target start ID signal. It is characterized by:

[For production]

Once the start ID and the reel pulse count value have been stored, the search is performed based only on the value counted by the reel pulse counting means 30 and its target value, so there is no need to read out the subcode, and the mechanism It becomes possible to feed the tape at a higher speed than before within the limits of target and tape strength.

In order to find an accurate position, it is sufficient to switch to the conventional search method a predetermined number of pulses before the target position.

〔Example〕

FIG. 2 is a diagram showing an example of an R-DAT to which the present invention is applied.

The tape 16, both ends of which are wound onto reels 300 and 302, is pressed against the side surface of the drum 12 by guide rollers 322 and 324 so as to contact the side surface of the drum 12 over a central angle of 90 degrees. The cylindrical drum 12 is mounted so that its axis is slightly inclined from a direction perpendicular to the feeding direction of the tape 16 in contact with the drum. The drum 12 includes an FG sensor 200 and a drum servo circuit 4.
04, a drive circuit 406, and a motor 312 to rotate at a constant speed. Therefore drum 1
Heads IOA and IO provided opposite to the sides of 2
B traces the tape 16 in a direction slightly inclined to the feeding direction of the tape 16 as the tape 16 is fed and the drum 12 rotates.

The signals picked up by the heads IOA and IOB are amplified by RF amplifiers 207 and 208, respectively, and one of them is selected by a switch 209 and sent to the equalizer 2.
03, where the waveform is equalized, converted into a digital signal by a comparator 204, and then sent to a demodulation circuit 2 using a PLL.
The digital signal recorded in 05 is reproduced.

This reproduced digital signal is guided to a signal processing circuit 206 for performing processing such as error correction and restoring various signals, and also to a relative speed detection circuit 220. Various methods of detecting relative speed in the relative speed detection circuit 220 have been put into practical use. For example, the PLL of the demodulation circuit 205
A method for detecting a frequency shift, a method for extracting a signal with a specific frequency such as an ATF pilot signal and detecting the frequency shift, and a method for detecting a time interval shift of a signal output at a specific interval such as a block synchronization signal. There are methods such as counting the number of beads in a bead-like envelope formed when the head crosses each recording track, and any of these methods may be used. Of these, FIG. 2 shows a method for detecting PLL frequency deviation, and the position of the relative speed detection circuit is different in other methods.

The output of the relative speed detection circuit 220 is a changeover switch 500,
It is supplied to motor 308 or motor 310 via driver 146 and changeover switch 342 as driving force for conventional high-speed search control.

On the other hand, among the signals restored in the signal processing circuit 206, the subcode signal is transmitted to the control microcomputer 34.
0. A reel pulse signal from an FG sensor 80 provided to output a pulse in synchronization with the rotation of the reel 300 is input to the microcomputer 340 . A switch 500 controlled by the microcomputer 340 is for switching between the conventional high-speed search control and the method according to the present invention.

FIG. 3 is a flowchart showing the processing of counting and storing reel pulses in the microcomputer 340.

A memory at a predetermined address within microcomputer 340 is used as a counter. When a tape is inserted (step a), this counter is reset to zero (step b). FF (fast forward) or PLAY
If (playing) (step C), all FG sensors 8
When the reel pulse falls from 0 (step d)
The counter is counted up (step e). R.E.
If W (rewinding) is in progress (step f), the counter is counted down at the rising edge of the !J pulse (step g) (step h).FF, PLAYSt
or when the start ID signal in the subcode is read during RIEW (step i), the counter value at that time is stored in memory in correspondence with the song number (step j)
. In either case, after performing other processing (step k), the process returns to step a.

Through the above processing, the count value of the reel pulse corresponding to each start ID signal as shown in FIG. 4, as an example, is stored in the memory for the start ID signals that have passed through the head even after the tape has been inserted. The arrow P in the figure represents the playback position when the tape is inserted.

FIG. 5 is a flowchart of processing performed by the microcomputer 340 to search for a location where a specific start ID is recorded. First, in step a), it is determined whether the count value corresponding to the start ID signal of the target song is stored. If it is stored, the next step is to switch the switch 500 (Fig. 2) to the Vo side. faster than the high-speed search processing, for example, the playback speed of 300
Rotate the skin reel twice as much (step b). During this time, the process of counting up or down the counter as explained in FIG. Continue rotating. This Y is a margin for transitioning to normal high-speed search processing before the target count value, and its sign is determined based on the running direction of the tape. For example, in the example shown in FIG. 4, from the position of arrow R to B represented by arrow Q
When searching for the beginning of a song, the tape is run in the REW direction, and when the counter value reaches 1500+100 counts, the process proceeds to step d. Then, the switch 500 is switched to the output side of the relative speed detection circuit 220, and the process shifts to normal high-speed search processing (step d).
), when the target start ID signal is found (step e), the search process ends. If the count value corresponding to the start ID of the target music piece is not stored in step a, the process starts from step d.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to search for a target start ID signal in a shorter time than in the conventional method.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle configuration of the present invention, Fig. 2 is a diagram showing an embodiment of the invention, Fig. 3 is a flowchart of reel pulse count processing, and Fig. 4 is an example of storing reel pulse count values. FIG. 5 is a flowchart of search processing according to the present invention. In the figure, 10A, IOB...head, 12...drum, 16
...Tape, 18...Reel pulse output means.

Claims (1)

[Claims] 1. Start ID signal reading means (20) for reading out the start ID signal recorded on the tape (16), and searching for a target start ID signal based on the read start ID signal. a first search means (22);
A high-speed search control device for a rotary head type digital tape player, comprising a reel pulse output means (18) that outputs a reel pulse synchronized with the rotation of a reel wound with a tape (16), according to the running direction of the tape. reel pulse counting means (30) for counting the reel pulses with a polarity of each start I recorded on the tape during running of the tape;
Reel pulse storage means (32) for storing the count value in the reel pulse counting means (30) at that time when the D signal is read out in correspondence with the read start ID signal; and the reel pulse counting means. (30) and a count value stored corresponding to the target start ID signal to search for the target start ID signal. A rotating head type digital tape player.