JPH07182725A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To accurately cut CM by temporariy stopping an operation after a magnetic tape is rewound to the vicinity of a video recorded during the period from switching of the CM on a TV screen to the generation of a change in a voice pilot signal. CONSTITUTION:When a TV program is recorded, changes in luminance levels for every frame on 10 spots on a TV screen are detected by a screen switching detection microcomputer 18. Then, when there are 5 spots or more in which changes in luminance levels are 20% or more, the microcomputer 18 gives a screen switching signal to a system control microcomputer 14. When a specified change is generated in a voice pilot signal inputted from a tuner 22 to the microcomputer 14 after this screen switching signal is inputted, a magnetic tape is rewound by an amount equivalent to the period of time from inputting of the screen switching signal to the specified change in the voice pilot signal and psuedo reproducing time and an operation is temporarily stopped. Then, when a specified change is generated in the voice pilot signal again, the microcompuer 14 releases the temporary stop and starts recording again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a magnetic recording / reproducing apparatus capable of recording video signals and audio signals contained in television signals on a magnetic tape.

[0002]

2. Description of the Related Art When a television program is recorded by a video tape recorder, it is sometimes desired to pause the recording operation at the same time as the start of a commercial and then release the pause at the same time as the program restarts. Therefore, in the conventional video tape recorder (1), the pause and the pause release are automatically performed based on the broadcast audio signal. That is, in consideration of the fact that a normal television program is a monaural broadcast and a CM is a stereo broadcast, recording is temporarily stopped at the same time when a pilot signal included in a stereo audio signal is detected, and at the same time the pilot signal is no longer detected. The pause was canceled.

Further, in another conventional video tape recorder (2), the user corrects the program and the connecting portion of the program by the jog function.

[0004]

However, in the video tape recorder (1), the pilot signal is not always input at the same time as the CM transfer, and is input after 60 to 100 ms delay after the CM transfer. Because there is
During this time, there was a problem that the image of the CM was recorded.

In the video tape recorder (2),
There is a problem that the operation becomes complicated because it is necessary to display the playback screen and perform the jog operation at the time of pause. Therefore, a main object of the present invention is to provide a video tape recorder which can easily and accurately cut CM.

[0006]

A first aspect of the present invention is a magnetic recording / reproducing apparatus capable of recording a video signal included in a television signal and an audio signal in a stereo mode, a dual audio mode or the like on a magnetic tape. Detection means for detecting a change in at least one of the luminance level and the color level at a predetermined position of, and outputting a screen switching signal when the change is larger than a predetermined value, and an audio signal within a predetermined time after the input of the screen switching signal. When the mode changes, a control means for rewinding the magnetic tape and temporarily stopping the operation by the time from the screen switching signal being input until the mode is changed and the time required for the pseudo reproduction is provided. It is a magnetic recording / reproducing apparatus.

A second invention is a magnetic recording / reproducing apparatus capable of recording a video signal and an audio signal included in a television signal on a magnetic tape, and at least one of a luminance level and a color level at a predetermined position on a television screen. Is detected and outputs a screen switching signal when the change is larger than a predetermined value, and if there is a pause operation input within a predetermined time after the screen switching signal is input, the screen switching signal is input The magnetic recording / reproducing apparatus is provided with a control means for rewinding the magnetic tape for a time until a temporary stop operation is input and a time required for the pseudo reproduction to suspend the operation.

[0008]

According to the first aspect of the present invention, when a television program broadcast in, for example, a monaural audio mode is being recorded, a change in the luminance level at each of, for example, 10 points on the television screen, for example, for each frame, is changed by the screen. It is detected by the switching detection microcomputer. And for example 2
If there are, for example, five or more points where the brightness level has changed by 0% or more, the screen switching detection microcomputer determines that the screen has been switched and gives a screen switching signal to, for example, the system control microcomputer. For example, within 5 seconds after the screen switching signal is input, a signal in the stereo audio mode of CM, for example, is input to the system control microcomputer, and when the system control microcomputer detects the pilot signal included in this signal, the system control microcomputer The control microcomputer rewinds the magnetic tape for the time from the input of the screen switching signal to the detection of the pilot signal and the pseudo reproduction time required for the phase alignment of the magnetic tape,
Pause the operation.

According to the second invention, when the temporary stop key input signal is input to the system control microcomputer within, for example, 5 seconds after the screen switching signal is input, the system control microcomputer inputs the screen switching signal. After the magnetic tape is rewound for the time until the post-pause key input signal is input and the pseudo reproduction time, the operation is temporarily stopped.

[0010]

According to these inventions, since the operation is temporarily stopped after the magnetic tape is rewound for a predetermined time, the recording of CM can be cut easily and accurately. The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a magnetic recording / reproducing apparatus 10 of this embodiment includes a video block 12 to which a video signal is inputted. Then, under the control of the system control microcomputer 14, a predetermined recording signal is output from the video block 12 and given to the mechanism 16. The mechanism 16 records this recording signal on a magnetic tape (not shown) according to a control signal input from the system control microcomputer 14. The video block 12 also supplies a vertical synchronizing signal to the system control microcomputer 14 and a luminance signal, a vertical synchronizing signal and a horizontal synchronizing signal to the screen switching detection microcomputer 18.

The system control microcomputer 14 increments the frame counter 20 based on the vertical synchronizing signal. In addition, the screen switching detection microcomputer 18 takes in the brightness signals at a plurality of (for example, 10) points on the television screen by A / D conversion with reference to the vertical and horizontal synchronization signals, and outputs the level for each frame at each point. Detect changes. Then, when the points where the luminance signal level changes by α% or more are β% or more of all the points, it is determined that there is a change in the television screen, and a screen switching signal is output to the system control microcomputer 14. Note that α and β are set to 20 and 50, respectively.

The system control microcomputer 14 includes an operation unit 22.
When the control signal is output to the video block 12 and the mechanism 16 based on the key input signal from, but the video block 12 and the mechanism 16 are transited from the recording mode to the pause mode, and then transitioned from the pause mode to the recording mode. In particular, a control signal is output based on the screen switching signal, the vertical synchronizing signal, and the pilot signal provided from the tuner 24. The pilot signal here means a pilot signal included in the audio stereo broadcast and the audio multiplex broadcast.

Next, with reference to FIG. 2, the processing of the system control microcomputer 14 when the mode is changed from the recording mode to the pause mode and then returned to the recording mode will be described. First, if the mode is the recording mode in step S1, it is determined in step S3 whether a screen switching signal is input from the screen switching control microcomputer 18. If the screen switching signal is input, the frame counter 20 is reset in step S5 and the process proceeds to step S7. If the screen switching signal is not input, the process directly proceeds to step S7. Step S
In 7, it is judged whether or not the pilot signal has changed by a predetermined amount, and if there is no change, the process returns to step S3.
If there is a change, the process proceeds to step S9. Here, the predetermined change is a change from a state in which no pilot signal is detected to a state in which a pilot signal included in audio stereo broadcasting is detected (change from monaural audio mode to stereo audio mode), and multiplex audio broadcasting. It means a change from the state in which the included pilot signal is detected to the state in which the pilot signal included in the audio stereo broadcast is detected (change from the audio multiplex mode to the stereo audio mode).

In step S9, it is determined whether or not the frame counter value is 150 or less, and if "YES", the frame counter value and the X frame necessary for the pseudo reproduction (reproduction for adjusting the phase of the magnetic tape). Rewinding by the total amount, but if "NO", rewind only X frames in step S13. Then, in step S15, the mode is changed to the temporary stop mode. Then, step S1
If there is a predetermined change in the pilot signal in step 7, pseudo-playback is performed only for X frames in step S19, and then in step S21, the mode shifts to the recording mode, and the process ends. The predetermined change in step S17 means the opposite of step S7, that is, the change from the state in which the pilot signal included in the audio stereo signal is detected to the state in which it is not detected, and the pilot signal included in the audio stereo signal. It means a change from a detected state to a state in which a pilot signal included in audio multiplex broadcasting is detected.

When the TV program being recorded is a monaural broadcast or a voice multiplex broadcast such as a bilingual broadcast, and the CM is an audio stereo broadcast, the image is switched from the program to the CM and at the same time the screen switching detection microcomputer 18 to the system control microcomputer. A screen switching signal is given to 14 and then 60
After a lapse of milliseconds to 100 milliseconds, a tuner 24 gives a pilot signal for audio stereo broadcasting to the system control microcomputer 14. As a result, the magnetic tape is rewound from the point where the image is switched to the CM to the position before the X frame, and then transitions to the pause mode. After that, CM
When the pilot signal is no longer detected, the X-frame is pseudo-reproduced and the recording mode is entered. Note that the pilot signal is 60 even when the CM is switched to the program.
The video of several frames after the program is restarted is not recorded because it is not detected after a delay of 100 ms to 100 ms, but such a lack of video does not pose a problem when viewing the recorded content.

According to this embodiment, the magnetic tape is rewound for the time from the input of the screen switching signal to the system control microcomputer 14 to the change of the pilot signal and the time of X frames for the pseudo reproduction. After that, the CM is switched to the pause mode, so that the CM can be easily and accurately cut from the video and audio to be recorded.

In this embodiment, the change in the brightness level is detected and the operation is performed. However, it is needless to say that the operation can be appropriately performed even when the color level is detected. Further, in this embodiment, the change in the audio mode is detected and the operation is performed, but the operation can be performed even when the user pauses manually. In this case, the CM included in the stereo program can be easily and accurately operated. Can be cut into In this case, step S1 in FIG.
And S17 may be set as "Is there a pause operation?" And "Is there a pause release operation?", Respectively.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment in FIG.

[Explanation of symbols]

 10 ... Magnetic recording / reproducing device 14 ... System control microcomputer 18 ... Screen switching detection microcomputer 22 ... Tuner

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H04N 9/79

Claims (2)

[Claims] 1. A magnetic recording / reproducing apparatus capable of recording a video signal included in a television signal and an audio signal such as a stereo mode and a dual audio mode on a magnetic tape in a luminance level and a color level at a predetermined position on a television screen. Detecting at least one of the changes and outputting a screen switching signal when the change is larger than a predetermined value, and the screen when the mode of the audio signal changes within a predetermined time after the input of the screen switching signal. A magnetic recording / reproducing apparatus comprising: control means for rewinding the magnetic tape and temporarily suspending the operation for a period of time from the input of the switching signal to the change of the mode and a time required for the pseudo reproduction. . 2. A magnetic recording / reproducing apparatus capable of recording a video signal and an audio signal contained in a television signal on a magnetic tape, detecting a change in at least one of a luminance level and a color level at a predetermined position on a television screen, When the change is larger than a predetermined value, a detection unit that outputs a screen switching signal, and if there is a pause operation input within a predetermined time after inputting the screen switching signal, the screen switching signal is input and then the A magnetic recording / reproducing apparatus comprising: control means for rewinding the magnetic tape for a time until a temporary stop operation is input and for a time required for pseudo reproduction to suspend the operation.