JPH01199384A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To execute a high-speed access to use an absolute address by providing a means to regulate a tape traveling so that an absolute address unrecorded part cannot approach from a recording head between magnetic tape end edges in a magnetic tape forward direction traveling mode not to be accompanied with an absolute address recording means. CONSTITUTION:The title device is a magnetic recording and reproducing device to record and reproduce information of a video signal, a sound signal, etc., on a magnetic tape, and it has a tape transfer control means to regulate the tape traveling so that the absolute address unrecorded part cannot approach from the recording head between the magnetic tape start edges in the magnetic tape forward direction traveling mode not to be accompanied with the absolute address recording means. Consequently, at the time of recording a new program next, the unrecorded part of the signal cannot be generated between the recorded program and it. Thus, to the absolute address, a successive code without a break can be given all over the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applied to a magnetic recording and reproducing apparatus for recording and reproducing information such as video signals and audio signals on a magnetic tape.

2. Description of the Related Art A digital audio tape recorder (hereinafter referred to as DAT) is a high-quality audio signal recording and reproducing device.This DAT is equipped with a high-speed search function and uses the following 10 data.

1. Program number code 2. Time code for hours, minutes, and seconds 3. Start code indicating the start of a song A program number code indicates the number of multiple songs recorded on a tape, for example, as a continuous number. . The time code indicates the playing time of one song. The start code simply indicates your starting position.

The invention tries to solve I! subject All of these only indicate relative addresses.

Therefore, when searching for data for a certain purpose, when feeding the tape at high speed, 1. The rotating head must be able to accurately read the signal at all times, including at the start of the signal, which requires extremely complex and highly accurate control means, and there are also limitations on high-speed tape feeding speed due to signal processing. These problems can be solved if an absolute address can be assigned with the beginning of the tape as the starting point, but DAT
Conventional tape recorders, including the ``Tape Recorder'', can start recording from any position, so it is not possible to assign continuous absolute addresses because unrecorded portions may occur between programs.

Another possible method is to record absolute addresses on a blank tape, but this reduces tape productivity and increases costs.

Therefore, the present invention provides a means for recording absolute addresses as a continuously increasing code starting from the beginning of the tape using a tape recorder.

Means for Solving the Problems The present invention provides an absolute address recording means for recording an absolute address on a magnetic tape, a recording head for recording the absolute address, and a forward running mode of the magnetic tape that does not involve the absolute address recording means. A magnetic recording and reproducing apparatus characterized in that the magnetic recording and reproducing apparatus comprises tape transport control means for regulating tape running so that a portion where no absolute address is recorded cannot enter between the recording head and the starting edge of the magnetic tape.

Function: Plays back a tape on which an existing program has been recorded including absolute addresses, or in tape forward running mode that does not involve absolute address recording, such as tape fast forwarding, so that it is not possible to enter a part where no absolute address is recorded. By doing so, when recording a new program next time, it is possible to prevent unrecorded portions of the signal from occurring due to jumps with recorded programs. As a result, it becomes possible to assign continuous absolute addresses throughout the tape without interruption.

Embodiment An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a control circuit of the present invention. In this embodiment, a method of recording an absolute address on a linear track of a magnetic tape using cue rad 1 will be explained.
It is also possible to record on a helical track along with the video signal.

5.7 is a recording amplifier, and 6.8 is a reproducing amplifier. 11
is a start/end detection circuit that detects the start or end of the tape. 12 is a playback level detection circuit that detects whether an absolute address is recorded, and 13 is a playback level detection circuit that detects whether a video signal is recorded on a helical track. If recorded, P3, P4=H is output to the system control circuit 15, and if not recorded, L is output to the system control circuit 15.

14 is an absolute address generation circuit for recording an absolute address on a linear track. 15 is a system control circuit; 16 and 17 are reel control circuits and servo circuits which obtain execution mode information from the system control circuit 15 and control the reel motor, capstan motor, etc.

SWI is a changeover switch for recording and playing back video signals by video head 2, and when recording video signals, 3a-3 is used.
B is connected, and during playback, 3a to 3c are connected.

SW2 is a changeover switch for recording and reproducing the absolute address signal using the queue controller, and when recording an absolute address, switch 4a
-4b jump is connected, and 4a-4c are connected during playback.

SW3 is a switch for checking the absolute address, and when the absolute address is not recorded, 9a-9c are connected and P
2=L is output to the system control circuit 15.

SW4 is a switch for switching the absolute address recording/reproducing means between operation and non-operation, and is a manual switch that can be operated by the user. When selecting the conventional recording/reproducing means in which the absolute address recording/reproducing means is inactive, the jumps 10a-1b are connected and P1=L is output to the system control circuit 15.

2 to 6 are partial flowcharts of the microcomputer in the system control circuit 15. FIG. The flowchart of the absolute address check subroutine shown in FIG. 2 will be explained. Connect 9a-9brW1 of SW3 and set output signal P2 to H. SW4 output signal PI is H
(The oven is located between 10a and 10b as shown in FIG. 1). If P1=L, this subroutine ends because the user does not want an absolute address. When P1=H (in the case of absolute address recording mode), execute REW mode for 1 second, then PL for 0.5 seconds.
The AY mode is executed to obtain the absolute address output detection signal P3. If P3=L (absolute address is not recorded), enters REW mode and switches this mode to start/end detection circuit 1.
The process continues until the beginning of the tape is detected by 1 or P3=H (absolute address is detected). If the beginning of the tape is detected with P3=L, it means that no absolute address has been recorded, so exit the REW mode with the entire tape wound around the supply reel, and exit from this subroutine with P2=L. . If P3=H, it means that an absolute address exists, and the final absolute address is set in a part of the memory of the absolute address generation signal circuit, and the subroutine is ended.

This absolute address check subroutine performs the following three functions: 1, checking 2 whether or not an absolute address is recorded, 3 reading the final absolute address information, and locating the beginning of the last absolute address recording position.

FIG. 3 is a flowchart of the tape fast forward mode.

First, execute the absolute address check subroutine shown in Figure 2,
Next, the FF mode subroutine is executed. The FF mode subroutine is the same as the conventional FF mode, in which the reel control circuit 16 and servo circuit 17 rotate the reel motor at high speed. Next, the output signal P1 of SW4 is determined, and P1=L (absolute address non-operation mode).
If so, the FF mode continues through the key scan table subroutine and tape start end determination.

The key scan table subroutine is one that obtains various operation mode instruction key information input manually into the system control circuit 15 and moves a pointer to a predetermined subroutine according to the instructions.

When the tape start end is detected during execution of the FF mode, tape running is stopped as in the conventional case, and the process moves to the key scan table subroutine.

When P1=H (absolute address operation mode), the absolute address is read and the P3 signal is determined. When P3=H (absolute address can be read), the FF mode continues to be executed in the same way as when P1=L. If P3=L (absolute address cannot be read), FF mode is immediately stopped and REW mode is continued until P3=H. When the start end is detected in the state of P3=L, the REW mode is stopped and the subroutine is ended.

When P3=H, the REW mode continues for 0.5 seconds, then stops, and the subroutine ends.

According to this tape fast forward subroutine, in the 11 absolute address recording operation mode, tape fast forwarding operates only within the absolute address recording range, and beyond that range, entry into areas where no absolute addresses are recorded is prohibited.

2. In the absolute address recording non-operation mode, the tape can be sent to any position regardless of the presence or absence of an absolute address, as in the past.

It has the above two functions.

Next, the absolute address recording subroutine for recording only absolute addresses will be explained with reference to FIG. First, if P1=L (absolute address non-operation mode), this subroutine is ended. When P1=H (absolute address operation mode), after the absolute address check subroutine, P2=H and the recording mode (2
) continues in parallel with the key scan table subroutine and the tape start/end detection determination by the tape start/end detection circuit. Recording mode (2) is SW2 4a.
-4b is connected and the absolute address generation circuit 14 records an absolute address signal on the tape.

According to this subroutine, it is possible to record an absolute address on a tape on which only a video signal has already been recorded or on a tape on which nothing has been recorded at all. FIG. 5 shows a video signal recording mode subroutine for recording the video signal as well as the absolute address. This subroutine is basically the same as the subroutine shown in FIG. In the recording mode (1) subroutine performed with P1=H (absolute address operation mode), switch 3a-3b of SWI to SW2.
Connect the 4a-4b leaps. As a result, the video signal is recorded through the video head 2, and the absolute address signal is recorded from the absolute address generation circuit 12 onto the tape through the cue head l. On the other hand, when P1=L (absolute address non-operation mode), SW
Connect between 3a and 3b of I and send the video signal to video head 2.
The subroutine for recording mode (3) for recording on tape is executed.

According to this video signal recording mode subroutine, by selecting SW4 whether or not to record an absolute address, either video signal recording with absolute address recording or recording of only the video signal is executed according to the instruction. . When recording absolute addresses, continuous address signals can be newly recorded from the last recording position using the absolute address check subroutine.

Finally, a method for executing the absolute address check subroutine shown in FIG. 2 not in each of the modes described above, but when a tape cassette is loaded into a VTR will be explained with reference to FIG. First, when a tape cassette is installed in a VTR, a motor for drawing out the tape winds the tape at a predetermined angle around a cylinder, and then the motor is stopped. (
Tape loading) In this state, the program immediately jumps to the absolute address check subroutine and performs an absolute address check. Then move the pointer to the key scan table.

According to this, since the absolute address check is performed immediately upon loading the tape cassette, it is not necessary to perform the absolute address check every time in each mode.

An example of a high-speed access method using this absolute address will be described with reference to FIG. If P1=L, this subroutine ends because the absolute address cannot be used. Perform an absolute address check and input the target absolute address (M) into the absolute address memory. (Calculation of absolute address) Then, the required number of reel rotations (N) is determined from the difference and input into the counter memory. (Reel count check) Next, the take-up or supply reel is driven by the number of revolutions to feed the tape at high speed. (Tape transfer mode (1)) When the counter memory and the number of rotations N match, it is then checked whether the P3 signal is H at that position. The tape transport mode (2) in which the tape is transported at a low speed is continued until the P3 signal and the value of the absolute address memory match. If this value matches, the subroutine ends.

Effects of the Invention According to the magnetic recording/reproducing apparatus of the present invention, the following effects can be obtained.

(1) Absolute addresses that can be expressed as numbers that continuously increase or decrease starting from the beginning of the tape can be recorded, allowing high-speed access using absolute addresses.

(2) When absolute addresses are used, unlike DAT, it is not necessary to constantly read the address signal to send the tape to the target position, making it possible to achieve high speeds that exceed the speed limits imposed by signal processing.

(3) If you know the final absolute address value, you can know the recording time, so it is possible to add functions that were not possible in the past, such as not accepting reservations that exceed the remaining time when making program reservations.

(4) In running modes such as FF and PLAY that do not involve recording of absolute addresses, the vehicle does not enter an area where no absolute addresses are recorded, making it easy to locate the beginning of the next record.

Furthermore, there is no need to worry about troubles such as overlapping recording due to discrepancies.

(5) Since only absolute addresses can be recorded even on tapes on which video signals have already been recorded, new functions using absolute addresses can be used.

(6) Since the user can select whether or not to use absolute addresses, there is compatibility with conventional recording and reproducing methods.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the control circuit of the magnetic recording/reproducing apparatus of the present invention, Fig. 2 is a flowchart of the absolute address check subroutine, Fig. 3 is a flowchart of the tape-fast forward mode, and Fig. 4 is the absolute address recording mode. 5 is a flowchart of the video signal recording mode, FIG. 6 is a flowchart when loading a cassette, and FIG. 7 is a flowchart during high-speed access. SWI...Video signal recording/reproduction switching SW, SW2...
・Absolute address recording re-switching sw, swa...Absolute address check SW, SW4...Absolute address operation switching SW,
15. System control circuit. Name of agent: Patent attorney Toshio Nakao 1 person No. 1 rA 1 A Figure 2 Figure 3 Figure 411! J Figure 5 Figure 6

Claims (1)

[Claims] an absolute address recording means for recording an absolute address on a magnetic tape;
In the magnetic tape forward running mode without the recording head for recording the absolute address and the absolute address recording means, tape running is restricted so that a portion where no absolute address is recorded cannot enter between the recording head and the end of the magnetic tape. What is claimed is: 1. A magnetic recording and reproducing apparatus comprising: a tape transport control means for controlling the tape transport;