JPH04335238A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a disturbance of a reproducing sound in a mode changing part by changing a standard mode to a long time mode at the time when the level of a sound signal becomes lower than a prescribed value. CONSTITUTION:During video recording with a timer, a video recording residual time 100 from a timer circuit 1 and a tape residual amt. time 200 from a tape residual amt. measuring part 3 are inputted, and when it is decided that the tape is short, the time for changing the standard mode to the long time mode is calculated by a video recording mode changeover program 21. On the other hand, the sound signal level 400 is inputted from a sound level detecting circuit 5 to the program 21. Then, when the time for changing the video recording mode has come, and when the sound level 400 is more than the prescribed value, no changeover is made by a system microcomputer 2, and when it becomes below the prescribed value, the speed is dropped to the long time mode. Consequently, at the changing time, only the sound less than the prescribed value is inputted, so that the disturbance of the sound can be prevented.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus having a function of switching the tape recording mode from a standard recording mode to a long-time recording mode when the remaining capacity of the tape becomes insufficient during timer recording.

0002

[Prior Art] Conventionally, this type of magnetic recording/reproducing device (hereinafter referred to as V
(sometimes referred to as TR), during timer recording, if there is not enough remaining tape for the recording time set in standard recording mode and it is not possible to record the entire time in standard recording mode, you can switch to recording mode from the middle. Some devices have a function of switching to a long-time recording mode and recording the entire timer-selected recording time on the tape.

FIG. 4 is a block diagram illustrating the functions of a conventional magnetic recording/reproducing apparatus of this type. During recording, the timer circuit 1 measures the remaining time 100 of the set recording time and notifies the recording mode switching program 21 of the system microcomputer 2 of this time. On the other hand, the tape remaining amount measuring section 3 measures the remaining amount of the tape that can be recorded based on the tape reel rotation speed (not shown), and calculates this amount as the tape remaining amount time 2.
00 to the recording mode switching program 21 of the system microcomputer 2. The recording mode switching program 21 calculates the time to switch the recording mode of the device from the standard recording mode to the long recording mode based on the timer recording remaining time and tape remaining time, and
When that time arrives, a recording mode switching signal 300 is output to the servo circuit 4 to switch the device from the standard recording mode to the long-term recording mode. As a result, when the recording time set in the timer circuit 1 has elapsed, the recording of a television program or the like is performed so that the remaining amount of tape becomes almost zero.

However, when the level of the audio signal being recorded is high, if the recording mode is changed from the standard recording mode to the long recording mode as described above, the playback mode changes to standard playback at the point where the recording mode is changed during playback. Since the mode is switched to the long playback mode, the tape speed changes at this point, and at this moment, there is a drawback that the sound played from the tape is momentarily disturbed. Furthermore, if the level of the video signal being recorded is high at the point where the recording mode is changed, there is a drawback that the reproduced video signal is similarly momentarily disturbed at the point where the mode is changed during playback.

[0005]

[Problem to be Solved by the Invention] A VTR having a function of changing the recording mode from the standard recording mode to the long recording mode when the remaining tape capacity runs out during recording as described above.
, if the recorded audio level is high or the recorded video signal level is high at the time when the recording mode is changed from standard recording mode to long-time recording mode, when playing back the tape, the playback mode changes from standard playback mode to long-time recording mode. There is a drawback that the reproduced audio or video signal is momentarily disturbed at the moment the mode is switched to the long-term reproduction mode.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks. Even if a tape including a portion where the recording mode has changed from the standard recording mode to the long-term recording mode during recording is played back, the portion where the recording mode has changed is always displayed. It is an object of the present invention to provide a magnetic recording and reproducing device that can prevent the reproduced audio and video from being disturbed. [Structure of the invention]

[0007]

[Means for Solving the Problems] The present invention provides that when the remaining capacity of the tape becomes insufficient when recording is continued in the current recording mode,
In a magnetic recording/playback device that reduces the tape speed during recording and automatically switches the recording mode to continue recording,
an audio level detection means for detecting the level of the recorded audio signal during the recording; and if the level of the audio signal detected by the audio level detection means is not below a predetermined value, the point at which the recording mode is switched during the recording is determined. The recording mode is not switched even when the recording mode is reached, and the recording mode is then controlled to be switched when the level of the audio signal becomes equal to or lower than a predetermined value.

Another configuration of the present invention is that if recording continues in the current recording mode, the remaining capacity of the tape becomes insufficient.
In a magnetic recording/playback device that reduces the tape speed during recording and automatically switches the recording mode to continue recording,
The video level detection means detects the level of the video signal during recording, and if the level of the video signal detected by the video level detection means is not below a predetermined value, a time has come to switch the recording mode during the recording. and control means for controlling the recording mode to be switched without switching the recording mode even when the level of the video signal becomes equal to or lower than a predetermined value.

[0009]

In the magnetic recording and reproducing apparatus of the present invention, the audio level detecting means detects the level of the recorded audio signal during recording. If the level of the audio signal detected by the audio level detecting means is not below a predetermined value, the control means does not switch the recording mode even if the time comes to switch the recording mode during the recording, and thereafter controls the recording mode of the audio signal. Control is performed to switch the recording mode when the level becomes below a predetermined value.

As another feature of the present invention, the video level detection means detects the level of the video signal during recording. If the level of the video signal detected by the video level detection means is not below a predetermined value, the control means does not switch the recording mode even when the time comes to switch the recording mode during the recording, and thereafter controls the video signal. Control is performed to switch the recording mode when the level becomes below a predetermined value.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, in which the same parts as those of the conventional example are given the same reference numerals. FIG. 1 is a block diagram showing an embodiment of the magnetic recording/reproducing apparatus of the present invention. 1 is a timer circuit that measures the remaining recording time when recording is started by timer reservation; 2 is a system microcomputer that controls mode switching of the apparatus; and has a recording mode switching program 21. 3 is a tape remaining amount measuring unit that measures the remaining amount of tape that can be recorded based on the number of rotations of the tape reel, etc.; 4 is a servo circuit that maintains the tape running speed at a predetermined speed depending on the standard mode/long time mode; 5 is an audio level detection circuit that detects the level of an audio signal during recording.

Here, the audio level detection circuit 5 constitutes an audio level detection means, and the recording mode switching program 21 constitutes a control means.

Next, the operation of this embodiment will be explained. During recording, timer circuit 1 indicates the remaining time of the reserved recording time 10.
0 to the recording mode switching program 21 of the system microcomputer 2. During recording, the remaining tape amount measuring section 3 calculates the remaining amount of the tape from the number of rotations of the tape reel and calculates the remaining amount of time 2.
00, and use this as the recording mode switching program 21.
Let me know. The recording mode switching program 21 uses the remaining recording time 100 inputted from the timer circuit 1 and the remaining tape amount time 200 inputted from the remaining tape amount measuring section 3.If recording continues in the standard mode, the remaining tape amount will be If it is determined that the remaining recording time is insufficient, the remaining recording time is 100.
The time at which the recording mode is to be switched from the standard recording mode to the long recording mode is calculated from the remaining tape time 200 and the arrival of this time is waited.

On the other hand, the audio level detection circuit 5 detects the level 400 of the audio signal being recorded and outputs it to the recording mode switching program 21. The recording mode switching program 21 executes the program when the calculated recording mode switching time comes.
Audio signal level 4 input from audio level detection circuit 5
00 is above a predetermined value, the switching of the recording mode is temporarily postponed, and then the recording mode is switched from the standard recording mode to the long-term recording mode at the first time when the audio signal level 400 falls below the predetermined value. A switching signal 300 is output to the servo circuit 4. As a result, the servo circuit 4 reduces the tape running speed from the standard speed to the long-term speed, and sets the mode of the apparatus to the long-term recording mode.

According to this embodiment, when the recording mode switching program 21 of the system microcomputer 2 switches the recording mode from the standard mode to the long-time mode,
When the level 400 of the recorded audio signal detected by the audio level detection circuit 5 is above a predetermined value, switching of the recording mode is postponed, and after that, when the level of the audio signal becomes below a predetermined value, the recording is started. In order to perform control to switch the mode from standard recording mode to long-term recording mode, when playing back this tape, when playing back the part where the recording mode has been switched, there is no audio signal in this switching part, or Since only audio signals of a predetermined level or lower are included, it is possible to prevent the reproduced audio from being disturbed at the mode switching portion.

FIG. 2 is a block diagram showing another embodiment of the present invention. In this example, in addition to the configuration of the previous example, a video level detection circuit 6 is further provided, the brightness level of the video signal being recorded is detected by this circuit, and the detection signal 500 is inputted to the gate circuit 7. Since the audio signal level 400 detected by the audio level detection circuit 5 is also input to the other input of this gate circuit 7, the gate circuit 7 takes the AND condition of these two detection signals and sends the result to the system microcomputer. It outputs to the recording switching program 21 of No. 2. Here, the gate circuit 7 has an audio signal level of 400
A high-level signal is output to the recording mode switching program 21 only when both the brightness signal level 500 and the brightness signal level 500 are low level. Therefore, the recording mode switching program 21 controls the gate circuit 7 when the recording mode switching time arrives.
When the signal input from the gate circuit 7 is at a low level, the switching is temporarily suspended, and then, when the signal output from the gate circuit 7 becomes a high level, the recording mode is changed from the long-time recording mode to the standard recording mode. Perform switching control. Here, the video level detection circuit 6 constitutes video level detection means.

According to this embodiment, the recording mode during recording is switched only when the level of the recorded audio is below a predetermined value and the level of the recorded video signal is below a predetermined value. Since neither audio signal nor video signal is included or the level thereof is low, it is possible to prevent disturbances in the reproduced video signal and the reproduced audio signal in this portion.

FIG. 3 is a block diagram showing still another embodiment of the present invention. In this example, a video level detection circuit 6 is provided in place of the audio level detection circuit shown in FIG. is being entered. Therefore, if the level of the video signal is above a predetermined value at the time of switching the recording mode, the recording mode switching program 21 temporarily suspends the switching, and then when the level of the video signal becomes below the predetermined value. Signal 30 to switch recording mode with
Control is performed to output 0 to the servo circuit 4.

According to this embodiment, even if a portion where the recording mode is switched is played back, the level of the video signal recorded in this portion is low or non-existent, so that there is no disturbance in the played video signal when the portion is played back. can be prevented.

[0020]

As described above, according to the magnetic recording and reproducing apparatus of the present invention, even if a tape including a portion in which the recording mode has been changed from the standard recording mode to the long recording mode during recording is played back, the recorded It is possible to prevent the playback audio and playback video from being disturbed at the portion where the mode changes.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording/reproducing apparatus of the present invention.

FIG. 2 is a block diagram showing another embodiment of the invention.

FIG. 3 is a block diagram showing still another embodiment of the present invention.

FIG. 4 is a block diagram showing an example of a conventional magnetic recording/reproducing device.

[Explanation of symbols]

1...Timer circuit 2...System microcomputer 3...Tape remaining amount measuring section 4...Servo circuit 5...Audio level detection circuit 6...Video level detection circuit 7...Gate circuit

Claims (2)

[Claims] 1. A magnetic recording/playback device which, when recording continues in the current recording mode and there is not enough remaining tape, reduces the tape speed during recording and automatically switches the recording mode to continue recording. An audio level detection means detects the level of the recorded audio signal during recording, and if the level of the audio signal detected by this audio level detection means is not below a predetermined value, a time has come to switch the recording mode during the recording. 1. A magnetic recording and reproducing apparatus, characterized in that the magnetic recording and reproducing apparatus is provided with a control means for controlling the recording mode to be switched without switching the recording mode even when the level of the audio signal becomes equal to or lower than a predetermined value. 2. A magnetic recording and reproducing apparatus that reduces the tape speed during recording and automatically switches the recording mode to continue recording when there is insufficient remaining capacity on the tape if recording is continued in the current recording mode. A video level detection means detects the level of the video signal during recording, and if the level of the video signal detected by this video level detection means is not below a predetermined value, the time has come to switch the recording mode during the recording. 1. A magnetic recording and reproducing apparatus, characterized in that the magnetic recording and reproducing apparatus is characterized in that the magnetic recording and reproducing apparatus is provided with a control means that performs control to switch the recording mode without switching the recording mode even when the level of the video signal becomes equal to or lower than a predetermined value.