JPS6028054A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the damage of a tape even in a sagged state in case the tape is set under a rapid traverse or rewinding mode at the time of application of a power supply by winding the sag of tape at a low speed, then transferring the operation to a stop mode. CONSTITUTION:A control circuit 11 starts its actuation as soon as a power supply is turned on. Then only a sensor 7 produces a detection signal, and a reel revolving signal for low speed is produced when a cam 1 is set in a rapid traverse mode. In this case, a take-up reel 14 is revolved at a low speed in the take- up direction of a tape 20. A sag part 20a is taken up by the reel 14. Then a supply reel 12 is pulled by the tape 20 and starts revolutions. Thus a frequency generating circuit 13 produces a signal FGS1, and the revolution of the reel 14 is stopped. Only a sensor 8 produces a detection signal to eliminate the tape sag through a similar process even in a rewind mode. Thus the damage of a tape is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing device, which determines whether it is in fast forward mode or rewind mode when the power is turned on, and generates a reel rotation control signal in these modes to operate the supply reel or take-up reel. It is an object of the present invention to provide a magnetic recording/reproducing device that prevents damage to the tape by rotating the tape at a low speed, without using a plunger, and winding up slack in the tape at a low speed.

In a general video tape recorder, if the power is cut off while operating in fast forward mode (or rewind mode),
Even after the reel motor stops and the reel on the side that is winding the tape stops, the reel on the side that is being wound continues to rotate due to inertia, leaving the tape in a slack state. After that, when the power is turned on again and the operation is started, the tape may become loose and the tape may come off the guide pole during the loading operation and the tape may be damaged. If the tape running direction is reversed from before the power is cut off, there are drawbacks such as creases in the tape. In order to avoid the above situation, conventionally a plunger was used to automatically brake the reel when the power was turned off.

However, the plunger generates heat, generates large operating noise, and requires a large-capacity capacitor for driving the plunger, and has disadvantages such as the difficulty of using the plunger in portable pull machines to save power.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings.

FIG. 1 shows an overall configuration diagram of the apparatus of the present invention. The mode determining means a determines whether the mode set when the power is turned on is a fast forward mode or a rewind mode among various modes. When it is determined that the mode is the fast forward mode or the rewind mode, the control signal generating means generates a reel rotation control signal for winding the tape at a low speed, and the reel motor 18 rotates in accordance with this reel rotation control signal. Take up the slack.

2A and 2B show a plan view and a side view of an embodiment of the mode detection mechanism used in the device of the present invention. In the same figure, 1
is a part of the cam body (hereinafter simply referred to as "cam") that moves the loading post, pinch roller, etc. and sets the mode by rotating as a whole.This cam 1
is fixed to the rotating shaft 2 and driven by a motor 19, which will be described later. This cam 1 is provided with through holes 38 to 3e, through holes 4a to 4e, and ribs 5.about.6 on the circumference centered on the shaft 2. 8 and the rib 5.degree. 6 by the leaf type switch 9.10, the exact rotational position of the cam 1 can be known.

Here, the radius (a) of the cam 1 shown by the broken line is in the eject mode when it is rotated to the arrow position, for example, and the radius 1b-
When each of 7h rotates to the arrow A position, short rewind mode, stop mode, fast forward mode 9 rewind mode, recording/playback mode, fast forward search mode, still playback mode, recording pause mode 9 rewind search mode, respectively. It corresponds to

FIG. 3 shows a block system diagram of an embodiment of the apparatus of the present invention. In the figure, detection signals from sensors 7 and 8 and switches 9 and 10 are supplied to a control circuit 11.

In addition, a signal FG with a frequency corresponding to 120 rotations of the supply reel is
A frequency generator 13 that generates S1, and a frequency generator 15 that generates a signal with a frequency corresponding to the rotation of the take-up reel 14.
Each signal is supplied to the control circuit 11 described above.

The control circuit 11 generates a reel rotation control signal and supplies it to the drive circuit 16 in response to various signals supplied thereto, and also generates a cam rotation control signal and supplies it to the drive circuit 17. The drive circuit 16 supplies a drive current to the reel motor 18 in accordance with the reel rotation control signal, and supplies the drive current to the reel motor 18 in response to the reel rotation control signal.
14. Further, the drive circuit 17 supplies a drive current to the motor 19 in accordance with the cam rotation control signal to rotate the cam body for mode setting.

Next, the operation of the control circuit 11 will be explained using the flowchart shown in FIG. The control circuit 11 executes the program shown in FIG. 4 when the power is turned on. First, in step 30, the detection signals of the sensor 7.8 and the switch 9.10 are checked, and if only the sensor 7 generates a detection signal and the cam 1 is in the fast forward mode position, the process moves to step 31; In this case, the process moves to step 32. In step 21, a low speed reel rotation control signal is generated. At this time, since the reel rotation mechanism (not shown) is set to fast-forward mode, the take-up reel 14 is driven to rotate at a low speed in the direction of winding the tape 20, and the slack portion of the tape 20 is
0a is wound onto the take-up reel 14. This step 31
In step 33, the frequency generator 13 generates the signal FG
The process continues until S1 occurs, that is, until the supply reel 12 is rotated by being pulled by the tape 20, and then the process moves to step 34.

In step 32, if only the sensor 8 generates a detection signal and is in rewind mode, the process moves to step 35; otherwise, the process moves to step 34. In step 35, a low speed reel rotation control signal is generated, whereby the supply reel 12 is driven to rotate in the direction in which the tape 20 is wound. This step 35 is continued until the tape 20 is pulled and the take-up wheel 14 rotates, and the signal FGS2 generated by the frequency generator 15 is detected in step 36.
After this, the process moves to step 34. In step 34, a cam rotation control signal is generated to rotate the cam 1 from the rotation position of the cam 1 when the power is turned on toward the stop mode rotation position, and the cam body is rotated by the drive of the motor 19. move. This step 34 is continued until the detection signals from the sensor 7.8 and the switch 9 are supplied in step 37 to enter the stop mode, at which point the program ends.

In this way, even if the tape is slack because it is set to fast forward mode or rewind mode when the power is turned on, this slack is taken up at a low speed and then the mode is switched to stop mode, so the tape will not move further than the guide ball. It won't come off or crease and damage the tape.

Note that the frequency generator 13 or 15 generates the signal FGS1 or F
, instead of rotating the take-up reel 14 or the supply reel 12 at low speed until GS2 occurs, they may be rotated at low speed for a predetermined period of time to wind up the slack portion 20a of the tape 20. Not limited. Further, the present invention may be applied to, for example, a tape recorder for recording and reproducing audio in addition to a video tape recorder.

Note that slits passing through the mode setting cam 1 may be provided at the positions of the ribs 5 and 6, and photosensors may be provided in place of the switches 9 and 10, and the slits may be detected by the photosensors. Moreover, instead of providing the rib 5.6 and the switch 9.10, a microswitch for detecting the loading post position in the unloading state and a microswitch for detecting the loading post position in the afterloading state are provided, and these microswitches Detection signals similar to switches 9 and 10 may be extracted, and the present invention is not limited to the above embodiment.

As described above, the magnetic recording and reproducing apparatus according to the present invention includes a mode determining means for determining whether the mode set when the power is turned on is fast forward mode or rewind mode, and fast forward mode or rewind mode. A control signal generating means generates a reel rotation control signal for winding the tape at a low speed when it is determined that the tape is wound at a low speed, and a reel motor rotates the supply reel or take-up reel in accordance with the reel rotation control signal. Or, even if the power is cut off during rewinding and the tape becomes slack, when the power is turned on again, this slack is taken up at a low speed, preventing damage to the tape, and since no plunger is used, there is no heat generation.
It has features such as low operation noise and power saving.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram of the device of the present invention, Figures 2 (A) and (B)
) are a plan view and a side view of an embodiment of the mode detection mechanism used in the device of the present invention, FIG. 3 is a block diagram of an embodiment of the device of the present invention, and FIG. 4 is a program of the control circuit shown in FIG. 1 is a flowchart of one embodiment. DESCRIPTION OF SYMBOLS 1... Cam, 7.8... Sensor, 9, 10... Switch, 11... Control circuit, 12... Supply reel,
13° 15... Frequency generator, 14... Take-up reel, 16° 17... Drive circuit, 18... Reel motor, 19... Motor, 20... Tape, 30-37...
...Step, a...Mode discrimination means, b...Control signal generation means. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] Mode determining means for determining whether the mode set at power-on is fast forward mode or rewind mode, and for winding the tape at a low speed when it is determined to be the fast forward mode or the rewind mode. 1. A magnetic recording and reproducing apparatus comprising: a control signal generating means for generating a reel rotation control signal; and a rotary motor for rotating a supply reel or a take-up reel in accordance with the reel rotation control signal.