JPH0424482Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fade device for a magnetic recording/reproducing device.

Conventionally, there have been magnetic recording and playback devices that have a tape editing function that allows fade-out at any position, but since the fade start and end positions are manually operated, it is necessary to rely on the indicated value of the tape counter recorded in advance. I had to.

The present invention has been conceived in view of the above, and an object of the present invention is to provide a fade device for a magnetic recording/playback device that accurately and automatically fades playback of any section on a magnetic tape.

The present invention will be explained below with reference to examples.

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

In FIG. 1, 1 is a microcomputer. The microcomputer 1 includes a detection mechanism 2 that detects the rotation of the tape reel stand of the magnetic green tone reproduction device.
The count value of tape counter 3, which is counted in response to the output _of
is stored (count value N) at the time of closing, and compared with the count value A before a predetermined count value,
A counter instruction value storage memory 1a that sends an output when the counted value is from N-A to N, and a counter instruction value storage memory 1a that outputs an output when the count value is from N-A to N, and the counter instruction value storage memory 1 when the automatic fade command switch SW ₂ and the recording mode signal are input.
Comparator 1b that sends an output when there is an output from a
and a drive circuit 1c for controlling the volume adjustment mechanism 4 with the output from the comparator 1b. The erase current control circuit 4 includes a transistor Q1 that is turned on by receiving a control signal from the comparator 1b of the microcomputer 1, and a transistor _{Q1 .}
a constant current source I ₁ connected to the collector of to charge the capacitor C ₁ during the on-period of the transistor Q ₁ ;
a buffer amplifier A ₁ that inputs the potential of the capacitor C ₁ and supplies a power supply voltage to the bias oscillator B;
Transistor Q A transistor controlled by the collector voltage of ₁ to control the operation of bias oscillator B
It consists of Q ₂ . In this embodiment, the ground point of the bias oscillator B is configured to be grounded via the transistor _Q2 . Note that 5 is an erase head.

In this embodiment configured as described above, when the counter instruction value storage command switch SW ₁ is closed at the tape position where the fade is desired while monitoring the tape in the constant speed playback mode, the microcomputer 1 stores the counter instruction value. memory 1
a stores the count value N of the tape counter 3 when the switch SW ₁ is closed. Then rewind the magnetic tape and turn the automatic fade signal command switch SW _2.
Close it and switch back to constant speed playback mode. During this constant speed playback, as shown in the flowchart shown in Fig. 2, the magnetic tape position changes from the count value N to before the predetermined count value A, that is, the count value of the tape counter 3 becomes (N-A). At this time, the memory 1a for storing the counter instruction value of the microcomputer 1 sends an output to the comparator 1b, and since the automatic fade command switch SW ₂ is closed and the recording mode signal is input, the comparator 1b
outputs a control signal (L level) to the erase current control circuit 4. As shown in FIG. 3, this control signal turns on the transistor _Q1 , and the collector potential of the transistor _Q1 reaches the voltage of the power supply Vcc. The constant current source I ₁ is activated by the rise in the collector potential of the transistor Q ₁ , and the capacitor C ₁ is charged with a constant current by the output of the constant current source I ₁ , and the potential of the capacitor C ₁ increases sequentially. The potential of capacitor _C1 is applied as a voltage to bias oscillator B via buffer amplifier _A1 . At the same time, due to the rise in the collector potential of transistor _Q1 , the transistor
_Q2 is turned on, and bias oscillator B oscillates according to the output voltage of buffer amplifier _A1 .
Therefore, the bias oscillation output increases sequentially and fades are performed sequentially on the magnetic tape. on the other hand,
When the constant speed winding of the magnetic tape progresses and the count value of the tape counter 3 matches the count value N stored in the counter instruction value storage memory 1a of the microcomputer 1, the microcomputer 1 is driven. The circuit 1c stops outputting the control signal. Therefore, the power supply voltage applied to the bias oscillator B disappears, and the grounding of the bias oscillator B is cut off, thereby completing the fade operation.

As explained above, according to the present invention, since a pre-recorded tape can be automatically faded at any position, accurate tape editing is possible. That is, in the case of the present invention, when recording FM broadcasts, etc., the method is to apply a fade by increasing the erasing current rather than attenuating the recorded signal, so it is not necessarily necessary to apply a fade while recording. Without,
Since fades can be performed calmly during playback at a later date, this has the effect of allowing accurate tape editing.

Furthermore, since the fade time is constant,
Settings can be made to minimize dropouts, etc. that are harmful to the audibility, in accordance with the mechanical conditions of the magnetic recording/playback device, and anyone can easily and accurately perform fades for a certain amount of time without requiring any skill. It has the following effects.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention;
3 and 3 are a flowchart and a waveform diagram for explaining the operation of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Microcomputer, 2... Reel stand rotation detection mechanism, 3... Tape counter, 4... Erase current control circuit, _I1 ... Constant current source, B... Bias oscillator.

Claims (1)

[Scope of Claim for Utility Model Registration] A means for setting a fade completion position during playback by a magnetic recording and reproducing device; and a storage means for storing a count value of a tape counter when the fade completion position is set by the setting means. , A fixed value is subtracted from the counted value of the tape counter stored in this storage means, and when rewinding is performed and the tape is played back again, the tape counter calculates the stored value from the counted value obtained as a result of this subtraction. A fade device for a magnetic recording/playback device, comprising: erasing current control means for controlling a recording erasing current supplied to an erasing head to gradually increase during a period of counting up to a counted value.