JPH0664769B2 - Recording / playback device mode switching device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mode switching device for a recording / reproducing apparatus such as a VTR, which prevents the tape from being jammed due to the tape sticking to a rotating head drum.

2. Description of the Related Art In a conventional VTR, when a cassette holder having a cassette inserted therein is mounted on a mechanical deck, the tape is loaded, and after this loading is completed, the tape is in a stop mode in which the tape is still wound on a rotary head drum.

On the other hand, in order to prevent the tape from being displaced due to the repetition of loading and unloading, at this time, the supply reel stand is braked.

Problems to be Solved by the Invention However, when the drum adopts the upper drum rotation system, if the tape is stuck to the drum when the drum starts rotating, the braking torque of the main brake is not sufficient. The tape may be pulled out from the supply reel base by the drum motor, and the tape may be jammed.

Even if it is detected by a dew (DEW) sensor that detects dew condensation, it does not work if the tape is stuck and dried on the drum, so it is not very effective.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a mode switching device for a recording / reproducing apparatus, which prevents tape jamming that occurs when a tape is stuck to a rotating head drum.

Means for Solving the Problems The present invention relates to a mode switching device of a recording / reproducing device that winds a tape from a supply reel base to the take-up reel base via the outer peripheral edge of a rotary head drum. A brake, a switching unit that operates the hard brake to switch the supply reel base between a rotatable state and a non-rotatable state, and a detection unit that detects the rotational speed of the rotary head drum. When the recording / reproducing apparatus operates from the stop mode to the traveling mode, the switching means is switched based on the command of the detecting means detecting a predetermined rotation speed, and the hard brake makes the supply reel base rotatable. The present invention relates to a mode switching device of a recording / reproducing device that is operated as described above.

Action A hard brake that engages with the supply reel base gear to prevent rotation of the supply reel base is provided, and since this hard brake is also applied during the stop mode, when shifting from this stop mode to the tape running mode, If the tape sticks to the rotating head drum and this drum is rotated in the direction to pull the tape from the supply reel,
The tape is never pulled out of the supply reel stand.

At this time, the detection means detects the rotation speed of the rotary head drum, and the rotary head drum reaches a predetermined rotation speed, and it is confirmed that the tape is not stuck to the rotary head drum. When the rotary head drum is not at the predetermined rotation speed after the mode is first entered, the rotary head drum is stopped so that the tape is stuck to the rotary head drum because the tape is attached to the rotary head drum. But the tape does not jam.

Embodiment An embodiment in which the present invention is applied to an 8 mm VTR will be described below with reference to the drawings.

First, referring to FIG. 2, an outline of a drive device for a mode switching slider (hereinafter simply referred to as M slider) 1 which is the basis of the mode switching device will be described. A contact gear 3 of a rotary switch is rotatably attached to the take-up reel spindle 2, and the contact gear 3 is rotationally driven from a control motor 4 via a speed reducer 5. On the other hand, there is a slider drive gear 6 which is rotationally driven via the contact gear 3, and this slider drive gear 6 meshes with the rack 7 of the M slider 1. Therefore, the contact gear 3 rotates to a predetermined position according to the desired mode, and accordingly, the M slider 1 also slides in the direction of arrow a or b while being guided by the guide. And this M slider 1 is eject, loading / unloading, FF (fast winding) / REW (rewinding), stop, F
A desired position out of 6 positions (modes) of WD (playback) / REC (recording) and RVS (reverse) is reached and stopped. By this sliding, predetermined levers are moved to switch the desired mode.

In FIG. 2, reference numeral 9 is a rotary head drum, reference numeral 10 is a drum motor directly connected to the rotary head drum shaft, reference numeral 11 is a capsten, reference numeral 12 is a capstan motor directly connected to the capstan 11, and reference numeral 13 is a pinch. Roller, reference numeral 14 is a loading motor, reference numeral 1
Reference numeral 5 is a loaded magnetic tape, and reference numeral 16 is a supply reel spindle.

Next, referring to FIG. 1, a mode switching mechanism related to attachment / detachment of the hard brake and the main brake will be described.
First, a hard brake will be described. A hard brake lever 56 is rotatably attached to a fulcrum shaft 55 fixed at a predetermined position of a mechanical chassis. The hard brake lever 56 is counterclockwise mounted by a tension spring 57. It is urged to rotate. A claw 58 is provided at the tip of the hard brake lever 56, and the claw 58 is formed so as to be insertable into the teeth 60 of the rewinding gear 59 fixed to the supply reel stand attached to the supply reel stand shaft 16. Has been done. A pressed member 61 is projected on the hard brake lever 56 in a predetermined direction.
It engages with a cam 62 formed on the side end surface of the slider 1 in the longitudinal direction. When the pressed member 61 is in the recessed cam groove 63, the hard brake lever 56 becomes free and is biased by the tension spring 57 to rotate in the counterclockwise direction, and the claw 58 of the rewinding gear 59 is rotated. This will prevent the rotation of the supply reel base that enters the tooth 60 and is integral with the rewinding gear 59. On the other hand, when the pressed member 61 engages with and is pressed against the side end surface of the M slider 1 which is a part of the cam 62, the hard brake lever 56 rotates clockwise against the tension spring 57 and the pawl. The engagement between 58 and the tooth 60 is configured to be released.

Next, the reel stand main brake will be described with reference to FIG. A brake release arm (hereinafter simply referred to as B release arm) 19 that rotates around the guide pin 18 is provided on the upper portion of the M slider 1, and the tip end portion of the B release arm 19 is located at a predetermined position. Is fixed with a pin 20 protruding toward the M slider 1.

Further, between the B release arm 19 and the M slider 1, a brake release slider (hereinafter referred to as a backward movement guide in the direction of arrow c and a backward movement in the direction of arrow d) is guided by pins 21 and 22 fixed to a chassis or the like. A B release slider) 23 is provided. The sliding directions c and d of the B releasing slider 23 are set at right angles to the sliding directions a and b of the M slider 1, and the B releasing slider 23 is moved by the tension spring 24 to form an arrow d. Biased in the direction, pin 2
1, 22 also serve as a stopper in the direction of arrow d. The B release slider 23 and the B release arm 19 are connected to each other by a tension spring 25,
The pin 20 of the B release arm 19 is inserted through the rectangular through hole 26 formed at a predetermined position. In a normal state, the pin 20 is stretched by the tension spring 25 and abuts on the inner end surface 26a of the through hole 26 in the arrow c direction. When the B release slider 23 returns to its return position when the FF / REW mode is switched to the stop mode, the B release arm 19 rotates about the pin 18 in the direction of arrow f by a predetermined amount. It has a sufficient length in the sliding direction to move.

On the other hand, a pair of reel stand main brakes 28, 29 are provided at predetermined positions. Each of these main brakes 28, 29 includes a brake lever 32, 33 rotatable about a fulcrum shaft 30, 31, and a respective pin 34.
A brake shoe lever 37 having a brake shoe 36 biased in the braking direction by a torsion spring 35 around
And the brake levers 32 and 33 are tension springs 38.
Are connected to each other by. When the B release slider 23 slides in the direction of arrow c, the pressing portions 39, 40 are pushed.
The brake is released by being pushed by and the backward movement in the direction of arrow d is urged by the torsion spring 35 to brake the reel base.

A solenoid plunger 42 is provided at a predetermined position. When the plunger 42 is turned on, the plunger 42 is sucked and the lock lever 43 attached thereto is rotated counterclockwise about the fulcrum shaft 31, and the engaging claw 44 thereof is engaged with the engaging portion 45 of the B release slider 23. Engage. When the plunger 42 is turned off, the lock lever 43 is rotated backward by the urging force of the tension spring 24 in the clockwise direction to release the lock.

On the other hand, as shown in FIG. 1, at a predetermined position of the M slider 1, a taper surface 48 inclined from the upper side to the lower side in the direction of the arrow a and an M slider 1 continuing from the taper surface 48.
And a horizontal plane 49 parallel to the sliding direction of the FWD / RE
A C cam 50 is provided so as to project, and the pin 20 of the B release arm 19 can be brought into contact with the cam 50. Reference numeral 51 is provided at a position substantially symmetrical to the cam 50 about the stop mode position of the M slider 1.
FF / REW forming a figure eight shape with the cam 50
It is a cam for use and has tapered surfaces 52 and 53 on the left and right.

Next, the operation of the mode switching mechanism configured as above will be described. In the state where the cassette holder is ejected, the M slider 1 stands by at the loading / unloading mode position shown in FIG. That is, the pressed member 61 of the hard brake lever 56 is rotated counterclockwise in the recessed cam groove 63 of the M slider 1, and the pawl 58 thereof has the teeth 6 of the rewinding gear 59 of the supply reel base.
It engages with 0 to prevent the supply reel base from rotating. See B
The release slider 23 is moved forward in the direction of arrow c by a mechanism (not shown), and is held in the forward movement position by the plunger 42 which has been turned on via the lock lever 43. It has been canceled.

When the cassette holder in which the cassette is inserted is mounted, this mounting is detected and the tape loading device starts to move to load the tape. When this tape loading is completed, the M slider 1 slides in the direction of the arrow b, reaches the stop mode position shown in FIG. 1 and stops, and enters the standby state. At this time, the plunger 42 is turned off, the B release slider 23 moves back, and the main brakes 28 and 29 are applied to the reel stand. Further, the hard brake 56 is temporarily released in the FF / REW mode position on the way, but is returned again and the brake is in the hardened state in the stop mode position.

Next, in the stop mode shown in FIG. 1, FWD / RE
When the C button is pressed, the rotating head drum 9 starts to rotate in the direction of drawing the tape from the supply reel by the drum motor (reference numeral 10 in FIG. 2) with the hard brake 56 applied. When it is confirmed by the speed detector that the number of rotations of the rotary head drum has risen to about 70%, the desired FWD / REC mode is set, and the control motor 4 in FIG. 2 starts rotating in the required direction. The contact gear 3 of the rotary switch and the slider drive gear 6 also rotate in the required directions, and the M slider 1 slides in the direction of arrow b in FIG. Then, the pressed member 61 of the hard brake lever 56 comes into contact with and is pressed by the side end surface of the M slider 1 which is a part of the cam 62, and the hard brake lever 56 rotates clockwise and the pawl 58 and the teeth. The engagement with 60 is released. At the same time, since the tapered surface 48 of the cam 50 contacts the pin 20, the pin 20 is pushed down along the tapered surface 48, and the B release arm 19 accordingly rotates about the guide pin 18 in the direction of arrow e. Therefore, in the B release slider 23, the inner end surface 26a of the through hole 26 is pushed by the pin 20 and slides in the direction of arrow c, and the main brakes 28, 2
9 is released. Then, when the pin 20 eventually engages with the horizontal surface 49 of the cam 50 and the relative position of the pin 20 with respect to the cam 50 reaches the FWD / REC mode position, the M slider 1 stops. Then, a reel base driving device (not shown) moves, and the winding gear of the winding reel base shaft 2 is rotationally driven to enter the FWD / REC mode.

On the other hand, the tape is attached to the rotating head drum 9,
When the rotation of the drum does not rise, the rotation of the drum is stopped, and the M slider 1 slides in the direction of arrow a to the loading / unloading mode position to unload the tape. When the tape unloading is completed, the M slider 1 further moves to the eject mode position to eject the cassette holder, and then reverses to return to the loading / unloading mode position for standby.

The same is true when the FF / REW button is pressed in the stop mode. First, the rise of the rotational speed of the rotary head drum 9 is detected with the hard brake 56 engaged. And when it is detected that it has risen to about 70%, FF / R
When it shifts to EW mode and does not stand up, it is ejected through unloading. When shifting to the FF / REW mode, the M slider 1 slides in the direction of arrow a, and the cam 51 moves the B release slider 23 in the direction of arrow c.

As described above, according to the present invention, the hard brake that engages with the supply reel base gear to prevent the rotation of the supply reel base is provided, and the hard brake is applied even in the stop mode. Therefore, when the tape is stuck to the rotating head drum when the tape is moved from the stop mode to the running mode of the tape, even if the drum is rotated in the direction of pulling the tape from the supply reel, the tape is not drawn from the supply reel. Absent.

Then, at this time, the rise of the rotation speed of the rotating head drum is detected by the detecting means, and it is confirmed that the tape is not stuck to the drum after rising to a predetermined rotation speed, and then the desired mode is started, When it does not rise, the rotary head drum is stopped and the unloading and eject modes are set. Therefore, even if the tape is attached to the rotating head drum, the tape does not jam and the mode is automatically changed to the next mode, which is convenient for handling.

Therefore, according to the present invention, a recording / reproducing apparatus with high reliability and good operability can be provided.

[Brief description of drawings]

FIG. 1 shows an embodiment in which the present invention is applied to an 8 mm VTR, and FIG. 1 is a plan view of a mode switching mechanism related to attachment / detachment of a hard brake and a main brake, showing a state in a stop mode, 2 is a schematic plan view of a VTR having a tape loaded, FIG. 3 is a view showing a state of the brake shown in FIG. 1 in a loading / unloading mode, and FIG. 4 is a hard brake shown in FIG. 4 is a diagram showing a state in FWD / REC mode of FIG. In the reference numerals used in the drawings, 1 ... Mode switching slider 2 ... Take-up reel spindle 9 ... Rotating head drum 15 ... Magnetic tape 16 ... Supply reel spindle 56 ... Hard brake lever 58 ... ... Claw 59 ... Rewinding gear (supply reel base gear) 60 ... Tooth 61 ... Pressed member 62 ... Cam.

Claims (1)

[Claims] In a mode switching device of a recording / reproducing apparatus for winding a tape from a supply reel stand to a take-up reel stand via an outer peripheral edge of a rotary head drum, a hard brake for preventing the supply reel stand from rotating, The recording / reproducing apparatus is provided with a switching means for operating the brake to switch the supply reel base between a rotatable state and a non-rotatable state, and a detecting means for detecting the rotational speed of the rotary head drum. When the mode is changed to the running mode, the switching means is switched based on a command from the detecting means detecting a predetermined rotation speed, and the hard brake is operated so as to make the supply reel base rotatable. Recording / playback device mode switching device.