JPH04249494A - Broadcast system control circuit - Google Patents

Abstract

PURPOSE:To eliminate need for a time to switch a broadcast system by providing a discrimination result storage setting means to set a magnetic recording and reproducing device to the broadcast system discriminated at first after insertion till a cassette is loaded/ejected to the control circuit. CONSTITUTION:When a loading is finished, a capstan FG signal corresponding to the rotation of a capstan motor 9 is outputted to a count register 10 of a PAL/NTSC discrimination circuit 2 via an FG head 6 and an amplifier circuit T. The FG signal is integrated by the circuit 10 and outputted to a PAL/NTSC discrimination comparator circuit 11. The circuit 11 fetches an integration value for each input of a PBCTL signal and compares it with a prescribed setting value, then the signal recorded on a tape 4 is discriminated for the PAL system or the NTSC system and the result is outputted to a mode discrimination circuit 12. The circuit 12 outputs a discrimination signal to a servo control register 13, in which the signal is stored. Thus, the circuit 13 outputs a servo control signal corresponding to the PAL system or the NTSC system recorded on the tape to a servo circuit 14.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention applies to PAL system and NTSC system.
The present invention relates to a broadcast system control circuit for a magnetic recording/reproducing device that is capable of recording and reproducing color television signals of a plurality of different broadcast systems. The present invention relates to a broadcast system control circuit that determines the type of broadcast system of a color television signal recorded on a magnetic tape using a signal and controls a magnetic recording/reproducing device.

0002

[Prior Art] There are various types of color television signal broadcasting systems, such as the NTSC system used in Japan and the United States, and the PAL system used in the UK and Italy. The broadcasting method of
Not compatible. Therefore, in general, VTR (Video
A magnetic recording/reproducing device such as a Tape Recorder (Tape Recorder) is set to an operation mode that allows signal processing to be performed in accordance with the broadcasting system of each region.

However, a magnetic recording/reproducing apparatus that processes signals only for a specific broadcasting system cannot reproduce a magnetic tape recorded in a broadcasting system different from the set state, and its use is therefore limited. In particular, in recent years, the movement of people and goods has become more active due to the development of transportation methods, and magnetic tapes containing color television signals of different broadcasting systems are often played back. has become a big problem.

[0004] Therefore, in order to greatly expand the usable range of magnetic recording and reproducing devices, there are models that have an operation mode that can record and reproduce color television signals of a plurality of different broadcasting systems. When playing back on a playback device, the broadcasting method of the color television signal recorded on the magnetic tape is determined, and the operating mode of the magnetic recording and playback device is set to correspond to the determined broadcasting method. .

[0005] Normally, the above-mentioned determination and control during playback is performed as follows:
This is implemented by a broadcast system control circuit, and this broadcast system control circuit uses PBCT recorded on magnetic tape.
A signal input circuit that reproduces the L signal and the capstan FG signal, and a PAL discrimination signal and N signal based on the above two signals.
It has a PAL/NTSC discrimination circuit that outputs a TSC discrimination signal and a servo control circuit that controls a servo circuit using the discrimination signal from this PAL/NTSC discrimination circuit (Fig. 2
reference).

Conventionally, as shown in FIG. 3, the above-mentioned broadcast system control circuit determines whether or not a magnetic tape is being loaded (S11), and if loading is in progress, the PAL signal is output as YES. A mode initial setting signal is output to initialize the magnetic recording/reproducing apparatus to an operation mode compatible with the PAL system (S12).

On the other hand, if loading is not in progress, N
Determine whether loading is completed as O (S1
3) If loading has not been completed, select NO and initialize to the above PAL operation mode in S1.
2 is now executed. After that, when loading is completed, the data that is the result of the discrimination by the PAL/NTSC discrimination circuit is output as a discrimination signal as YES, and the operation mode corresponding to the broadcasting method of this discrimination signal is set. (S14).

[0008] As a result, the conventional broadcast system control circuit
Since the broadcast system of the color television signal recorded on the magnetic tape is determined and the magnetic recording/playback device is set to the operating mode that corresponds to the determined broadcast system, there is no need to check the broadcast system during playback. It is now possible to simplify the operation of the playback device.

[0009]

[Problems to be Solved by the Invention] However, in the conventional broadcast system control circuit described above, when the broadcast system of the color television signal recorded on the magnetic tape is the NTSC system, it always takes a long time to start playback. There is a problem.

That is, the conventional broadcast system control circuit initially sets the operation mode of the magnetic recording/reproducing device to the PAL system until loading is completed, and the color television signal recorded on the magnetic tape is If the broadcasting system is NTSC, it is necessary to change the setting from the initial PAL operating mode to the NTSC operating mode, so the time required to start playback is longer than the PAL operating mode.
This will take longer than the conventional method. When changing the operating mode from the PAL system to the NTSC system, the initial setting to the PAL system is performed every time the disc is loaded, so it always takes a long time to start playback.

Therefore, it is an object of the present invention to provide a broadcasting system control circuit that can shorten the time required to start playback by maintaining the determined operating mode of the broadcasting system after inserting a cassette. The purpose is

0012

[Means for Solving the Problems] In order to solve the above problems, the broadcasting system control circuit of the present invention provides a magnetic recording system capable of recording and reproducing color television signals of a plurality of different broadcasting systems, such as the PAL system and the NTSC system. A broadcasting system control circuit that is included in the recording/reproducing device and determines the broadcasting method of the color television signal recorded on the magnetic tape of the inserted cassette, and sets the magnetic recording/reproducing device to the determined broadcasting method. In the above, the broadcast system control circuit has a signal input circuit, a PAL/NTSC discrimination circuit, and a servo control circuit serving as discrimination result storage setting means, and the servo control circuit operates until the cassette is removed. The feature is that the magnetic recording/reproducing device is set to the first broadcasting method determined after insertion.

[0013]

[Operation] According to the above structure, the determination result storage setting means causes the magnetic recording and reproducing device to set the broadcasting method of the color television signal determined first after the insertion of the cassette until the cassette is removed. It has become. Therefore, when the magnetic recording and reproducing apparatus is started from a stopped state, the broadcasting system control circuit can immediately set it to the magnetic tape broadcasting system without determining the broadcasting system. This eliminates the need for the broadcasting system control circuit to distinguish between broadcasting systems once a cassette is inserted and played, and the time required for stabilizing the rotational speed of a capstan motor when switching broadcasting systems, for example. Since this eliminates the need for color television signals, it is possible to shorten the time required to start reproducing a color television signal.

[0014]

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

The broadcast system control circuit according to this embodiment is shown in FIG.
As shown in the figure, it has a signal input circuit 1, a PAL/NTSC discrimination circuit 2, and a servo control circuit 3, and the broadcasting system control circuit consisting of each of these circuits 1, 2, and 3 is capable of handling PAL or NTSC systems. A magnetic recording/reproducing device capable of recording and reproducing color television signals of a plurality of broadcasting systems such as the above is provided.

The above signal input circuit 1 has a magnetic head 5 for reproducing the PBCTL signal recorded on the magnetic tape 4, and this magnetic head 5 is connected to an amplifier circuit 8 for amplifying the above PBCTL signal. has been done. Further, the signal input circuit 1 is also provided with an amplifier circuit 7 that amplifies the signal, similar to the amplifier circuit 8 described above, and this amplifier circuit 7 includes a capstan FG head 6 that outputs a capstan FG signal. is connected. The capstan FG head 6 is configured to output a capstan FG signal from a capstan motor 9, and this capstan motor 9 is configured to determine the running speed and direction of the magnetic tape 4. It has become.

The amplifier circuit 7 to which the capstan FG signal is input from the capstan FG head 6 is a PAL
/NTSC discrimination circuit 2 is connected to the count register circuit 10, and the count register circuit 10 is connected to the PA
It is connected to the comparison circuit 11 for L/NTSC discrimination. The counting register circuit 10 integrates the capstan FG signals inputted through the amplifier circuit 7 and outputs the integrated value to the PAL/NTSC discrimination comparison circuit 11.

[0018] Furthermore, the PAL/
The NTSC discrimination comparison circuit 11 includes the magnetic head 5 described above.
An amplifier circuit 8 to which a PBCTL signal is input from is also connected, and when a PAL/NTSC discrimination comparison circuit 11 receives a PBCTL signal through the amplifier circuit 8,
The integrated value from the count register circuit 10 is taken in internally, while the count register circuit 1
The integrated value of 0 is cleared. and,
The PAL/NTSC discrimination comparison circuit 11 determines whether the color television signal recorded on the magnetic tape 4 is in the PAL format or in the NTSC format by comparing the integrated value, which is the input interval of the PBCTL signal, with a predetermined setting value. PAL discrimination signal or NTS which is a discrimination signal
A C discrimination signal is output.

A PAL/NTSC circuit having the above-described counting register circuit 10 and PAL/NTSC discrimination comparison circuit 11
The NTSC discrimination circuit 2 is connected to a servo control circuit 3 which is discrimination result storage setting means. The servo control circuit 3 includes a mode discrimination circuit 12 and a servo control register circuit 13, and the mode discrimination circuit 12 includes the PAL/NTSC discrimination comparison circuit 11 of the PAL/NTSC discrimination circuit 2 described above. connected, PAL discrimination signal and NTS
A C discrimination signal is input.

The above-mentioned mode discrimination circuit 12 detects the above-mentioned PAL discrimination signal and N based on the mode discrimination routine described later.
A discrimination signal consisting of a TSC discrimination signal and a PAL mode initial setting signal are output. The above initial setting signal is designed to set the magnetic recording/reproducing device to the PAL operating mode, and is output when the cassette is first loaded after being inserted into the magnetic recording/reproducing device. There is.

The mode discrimination circuit 12 described above is connected to a servo control register circuit 13, and this servo control register circuit 13 uses the discrimination signal and initial setting signal inputted from the mode discrimination circuit 12 to detect the PAL system. or NTSC
It is designed to output a servo control signal compatible with the system. This servo control register circuit 13 is
It is connected to a servo circuit 14 that stably rotates the above-mentioned capstan motor 9, and this servo circuit 14 is
By controlling the rotational speed and the like according to the servo control signal, the magnetic recording/reproducing apparatus is set to the PAL system and NTSC system operation modes.

In the above configuration, the operation of the broadcast system control circuit will be explained based on the flowchart of FIG.

First, when a cassette containing the magnetic tape 4 is inserted into the magnetic recording/reproducing device and a play button (not shown) is pressed, the magnetic tape 4 is pulled out from the cassette and loading is started. At this time, the servo control circuit 3 executes the mode determination routine shown in FIG. 1, and determines whether or not the magnetic tape 4 is being loaded (S1).

[0024] If it is determined that loading is in progress in S1 above, S2 will be executed as YES.
It is determined whether the current loading is the first loading after inserting the cassette (S2). Since this loading is the first loading after inserting the cassette, S3 is executed as YES, and the PAL mode initial setting signal is output from the mode discrimination circuit 12 to the servo control register circuit 13. It turns out. As a result, the servo control register circuit 13 outputs a servo control signal compatible with the PAL system to the servo circuit 14 to rotate the capstan motor 9.
The magnetic recording/reproducing device is set to the PAL operating mode (S3).

[0025] Next, the loading is completed and the above PA
When playback is started in the L method operation mode, a PBCTL signal is output from the magnetic tape 4 via the magnetic head 5, and this PBCTL signal is amplified to a predetermined voltage level by the amplifier circuit 8. After that, PAL/NT
PAL/NTSC discrimination comparison circuit 11 of SC discrimination circuit 2
It will be output to.

When loading is completed, a capstan FG signal with a number of pulses corresponding to the rotation of the capstan motor 9 is input to the amplifier circuit 7 via the capstan FG head 6.
After the signal is amplified to a predetermined voltage level by the amplifier circuit 7, it is output to the counting register circuit 10 of the PAL/NTSC discrimination circuit 2.

The capstan FG signal inputted to the counting register circuit 10 is integrated by the counting register circuit 10, and this integrated value is
/NTSC determination comparison circuit 11. Then, the PAL/NTSC discrimination comparison circuit 11 to which this integrated value and the above-mentioned PBCTL signal are input,
By taking in the integrated value each time a TL signal is input and comparing it with a predetermined setting value, it is determined whether the color television signal recorded on the magnetic tape 4 is in the PAL system or the NTSC system, and the servo control circuit A PAL discrimination signal and an NTSC discrimination signal, which are discrimination signals, are output to the mode discrimination circuit 12 of No. 3.

At this time, the mode discriminating circuit 12 to which the above discriminating signal is input determines in S1 that loading is not in progress, and as a result of NO, S4 is executed, and it is determined whether or not loading has been completed. (S4
). Then, by determining that loading has been completed in S4, S5 is executed as YES, and the mode discrimination circuit 12 uses the discrimination signal input from the PAL/NTSC discrimination circuit 2 to the mode discrimination circuit 12 as a servo control. The signal is output to the control register circuit 13, and the data of the discrimination signal is stored in the register (S5).

As a result, the servo control register circuit 1
3 outputs a servo control signal compatible with the PAL system to the servo circuit 14 to rotate the capstan motor 9 when the color television signal recorded on the magnetic tape 4 is in the PAL format, The magnetic recording/reproducing device is operated in the operating mode of the system. On the other hand, if the color television signal is in the NTSC format, the NT
A servo control signal compatible with the SC system is output to the servo circuit 14 to rotate the capstan motor 9, and the magnetic recording/reproducing device, which is initially set to the PAL system operation mode, is
The operation mode will be changed to the SC method.

Next, when the magnetic recording/reproducing apparatus is brought to a halt, the capstan motor 9 is halted and the magnetic tape 4 is unloaded. At this time, the mode determination routine is continuously executed in the servo control circuit 3, and after it is determined that loading is not performed (S1), it is further determined that loading is not completed in S4 (S4), and the process ends with NO. will be done. As a result, the servo control register circuit 13
By maintaining the storage state of the register, the data of the first discrimination signal when the cassette is inserted is stored, and this data is stored when the cassette is removed from the magnetic recording/reproducing device and then inserted again. This will be maintained until S5 is executed.

Next, when the magnetic recording/reproducing apparatus resumes reproduction from the above-mentioned stopped state, it is determined in S1 that loading is in progress, and S2 is executed with a YES answer. Then, in this S2, it is determined that the current playback is not the first loading after inserting the cassette, and the mode determination routine is ended with a NO, and the servo control register circuit 13 registers the previously recorded register. A servo control signal corresponding to the data is output to the servo circuit 14 to rotate the capstan motor 9, thereby setting the operating mode of the magnetic recording/reproducing device.

As described above, the broadcast system control circuit of this embodiment holds the contents of the register of the servo control register circuit 13 at least until the cassette is removed, and when playing back from the stopped state, the broadcast system is changed. The operating mode of the capstan motor 9, etc. is immediately set using register data without any discrimination. Therefore, once the broadcast system is played back, this broadcast system control circuit does not require an operation to determine the broadcast system, and also eliminates the need for the time required for stabilizing the servo circuit 14 when switching the broadcast system. It has become possible to shorten the time required to start playing a television signal.

In this embodiment, the broadcast system control circuit is used to control the capstan motor 9; however, the present invention is not limited to this, and the settings may be changed when changing the broadcast system. It may also be used for setting and controlling other necessary circuit systems and mechanical systems.

[0034]

Effects of the Invention As described above, the broadcasting system control circuit of the present invention is provided in a magnetic recording and reproducing device capable of recording and reproducing color television signals of a plurality of different broadcasting systems, and is capable of recording and reproducing color television signals of a plurality of different broadcasting systems on a magnetic tape of an inserted cassette. The broadcasting system control circuit that determines the broadcasting system of the recorded color television signal and sets the magnetic recording/reproducing device to the determined broadcasting system is configured to perform the first determined broadcasting after insertion until the cassette is removed. This configuration is provided with determination result storage setting means for setting the magnetic recording/reproducing device to the system.

[0035] With this, when the magnetic recording/reproducing device is played back from a stopped state, the broadcasting method control circuit can immediately set the broadcasting method to the magnetic tape without having to use the determination result storage setting means to determine the broadcasting method. Therefore, there is no need to perform an operation to determine the broadcasting system, and there is no need to take the time to switch between broadcasting systems.This has the effect of shortening the time required to start playing a color television signal. play.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of a mode determination routine.

FIG. 2 is a block diagram of a broadcast system control circuit.

FIG. 3 is a flowchart of a conventional mode determination routine.

[Explanation of symbols]

1 Signal input circuit 2 PAL/NTSC discrimination circuit 3 Servo control circuit (discrimination result storage setting means) 4
Magnetic tape 5 Magnetic head 6 Capstan FG head 7 Amplifier circuit 8 Amplifier circuit 9 Capstan motor 10 Count register circuit 11 PAL/NTSC discrimination comparison circuit 12
Mode discrimination circuit 13 Servo control register circuit 14 Serpo circuit

Claims (1)

[Claims] 1. A magnetic recording and reproducing device capable of recording and reproducing color television signals of a plurality of different broadcasting systems is provided,
In the broadcast system control circuit, which determines the broadcast system of the color television signal recorded on the magnetic tape of the inserted cassette and sets the magnetic recording/reproducing device to the determined broadcast system, the cassette is inserted until it is removed. 1. A broadcasting system control circuit comprising a determination result storage setting means for setting a magnetic recording/reproducing device to a later first determined broadcasting system.