JPH0227388Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a cassette loading device that removably loads a cassette containing a tape-shaped information recording medium wound between two reels onto a supply reel stand and a take-up reel stand of a playback device. The present invention relates to a device for correcting slack in a tape-shaped recording medium due to slight rotation of a reel of a cassette when the reel is fitted into a reel stand.

As shown in FIG. 6, a VTR cassette 1 is provided with an opening/closing lid 12 on the opening surface 11 on the tape drawer side, and is inserted into the cassette holder 21 of the playback device 2 shown in FIG. 4 and transferred to the reel stand 3, 3a side. The lid opens automatically on the way down, and closes automatically when the holder is on the way up due to the eject action.

When the cassette 1 is placed on the reel stands 3, 3a,
The shaft hole 14 of the reel 13 in the cassette is fitted onto the drive shaft 31 of the reel stand 3, 3a, but at this time, the shaft hole 14 and the drive shaft 31 are usually out of phase.

Normally, three protrusions 32 are formed at equal intervals on the outer circumference of the drive shaft 31, and six grooves 15 into which the protrusions can fit are formed at equal intervals in the shaft hole 14.
The protrusion 32 and the drive shaft 3 are connected at a pitch of 60 degrees on the reel 13.
1 becomes fittable.

Therefore, when the cassette is lowered onto the reel stand,
The reel 13 rotates within this range, and the shaft hole 14 and the drive shaft 31 fit together. The entry side of the protrusion 32 is a tapered guide surface (not shown), and even if the shaft hole 14 and the drive shaft 31 are out of phase, the reel will be guided by the guide surface and will rotate and follow the drive shaft 31. Fits in.

However, when the reel 13 rotates in a direction that pulls the tape, the tape becomes tense and there is no problem, but when the reel 13 rotates in a direction that loosens the tape, the tape bites out of the opening of the cassette. If the ejecting operation is performed in this state, there arises a problem that the tape 16 that has been bitten out is caught between the opening edge of the cassette and the lid 12, resulting in damage to the tape, as shown in FIG.

As an example of a means to solve this problem, conventionally, the drive shaft of the reel stand is arranged so as to be movable in the vertical direction, and is always urged upward by a spring. If the phase is out of sync, the shaft and hole will not fit, and the drive shaft will fall against the spring, causing the drive shaft to fit into the shaft hole when the reel stand rotates during loading operation. It has been adopted.

However, in the case of the above device, the structure is complicated, and the reel may rotate due to the impact of the reel hitting the drive shaft, causing the shaft hole and the drive shaft to fit, so it is difficult to reliably prevent the tape from loosening. I couldn't do it.

(Technical Problem to be Solved) The object of the present invention is to reliably prevent damage to the tape due to tape slack when loading a cassette.

(Structure) In order to solve the above technical problem, the present invention provides a playback device with a cassette switch that detects the loading of a cassette corresponding to the cassette loading position, and a take-up reel stand drive device that detects the cassette switch. A correction circuit was connected to the drive unit to operate the drive unit for a short period of time to wind up the tape in the cassette.

(Special effect) When loading a cassette, even if the reel rotates and the tape loosens due to a phase shift between the shaft hole of the cassette and the drive shaft of the reel stand, the reel stand automatically moves slightly in the winding direction after loading the cassette. Rotate to eliminate slack in the tape.

This prevents the tape from getting caught in the lid even if the cassette is removed without performing a play operation after being loaded.

In addition, since the tape loading mechanism also performs loading and unloading in conjunction with the rotation of the reel stand for absorbing tape slack, even if an external impact is received when releasing the reel brake when absorbing tape slack, new tape can be loaded and unloaded. The occurrence of slack is prevented.

The present invention will be specifically described below based on embodiments shown in the drawings.

Although the embodiment will be described with reference to a video tape recorder 2, the present invention is not limited thereto, and can be implemented as a playback device for a cassette in which a tape-shaped information recording medium is wound and housed between two reels.

As is well known, the video tape recorder 2 has a cassette holder 21 at one end of the main body, and a loading disk 22 and a cylinder 23 are located at the other end.
Below the cassette holder 21 is a supply reel stand 3.
A take-up reel stand 3a is also provided.

A reel motor 24 is located between both reels 3 and 3a.
and a transmission roller 2 that switchably transmits the rotation of the motor 24 to either one of the reel stands 3, 3a.
5 are deployed.

The loading disc 22 is connected to a loading motor 27 via a transmission gear 26.

A cassette switch 28 is provided on the downward path of the cassette holder 21 or at an arbitrary position to detect when the cassette 1 is loaded onto the reel stands 3, 3a.

The feature of the present invention is that the reel motor 2 is activated by detecting the loading of the cassette 1 by the cassette switch 28.
4 in the tape winding direction instantaneously or for a short period of time.

Figure 1 shows one embodiment of the present invention.
B ₁ is input to the power supply circuit 5 via the power switch 50 and diode 51, and the drive voltage B ₂ is input to the control circuit 4 of the reel motor 24.

The input end of the monostable multivibrator 40 is connected to the cassette switch 28, and the output end Q of the monostable multivibrator 40 is connected to the bases of two transistors TR ₁ and TR ₄ of a line for forward rotation of the reel motor 24 in the control circuit 4.

Therefore, when a cassette is loaded after turning on the power switch 50, the cassette switch 28 closes at the loading position, changes the input terminal potential of the monostable multivibrator 40, and output terminal Q remains open for a short period of time (approximately 1 second). Output two transistors TR ₁ ,
TR ₄ is excited, and a circuit for forward rotation of the reel motor 24 is formed.

Since the same output current is input to the power supply circuit 5 via the diode 52 and outputs the drive voltage _B2 , the reel motor 24 rotates forward in the tape winding direction for a short period of time. Therefore, even if there is slack in the tape when loading the cassette, the slack can be eliminated by rotation of the motor.

For reversing the reel motor 24, two further transistors TR ₃ and TR ₂ are arranged in the control circuit 4 in the motor reversing circuit. The reverse rotation signal is output from the computer built in the device to terminal C of control circuit 4.
, two transistors TR ₃ ,
By exciting TR ₂ , a reversing circuit for the reel motor 24 is formed, and current is passed through the reel motor 24 in the opposite direction to reverse the motor 24, thereby performing unloading.

FIG. 2 shows another embodiment of the present invention, in which the input end of a monostable multivibrator 40 is connected to the cassette switch 28 as in the first embodiment, and the Q output end is connected to the control circuit 6 of the loading motor 27. S of R-S flip-flop 8 via capacitor 7
Connected to the input end. Therefore, when loading a cassette, turning on the cassette switch 28 turns on the transistor of the input line of the loading motor 27.
TR ₅ and TR ₈ are excited and the loading motor 27
rotates forward for a short period of time (several hundred milliseconds) and performs a loading operation on the tape for only a short period of time.

After a time delay caused by the capacitor 7, the input signal enters the R-S flip-flop 8, and the transistor of the reverse circuit of the loading motor control circuit 6
TR ₇ and TR ₆ are excited to reverse the loading motor 27 and perform the unloading operation for a short time.

At the same time, a signal voltage is input to the input terminal A of the reel motor control circuit 4 via the diode 41, exciting the transistors TR ₁ and TR ₄ , causing the reel motor 24 to rotate in the normal direction as in the first embodiment, and winding the tape. This is what we do.

When the dog on the loading ring 22 contacts the unloading end switch 29 and inputs a signal to the R input terminal of the R-S flip-flop 8, the loading motor 27 stops and the reel motor 24 finishes winding the tape. It is possible to tighten the tape and eliminate the slack.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of the tape correction device, Figure 2 is a circuit diagram of another embodiment, Figure 3 is a timing chart of the same as above, Figure 4 is an explanatory diagram of the regenerating device, and Figure 5 is the back of the cassette. FIG. 6 is a perspective view of the cassette. 1...Cassette, 2...Playback device, 24...Reel motor, 27...Loading motor, 4...
Reel motor control circuit, 6...Loading motor control circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] A cassette loading device that removably loads a cassette containing a tape-shaped information recording medium wound between two reels onto a supply reel stand and a take-up reel stand of a playback device. Therefore, the playback equipment is equipped with a cassette switch that detects the loading of a cassette in accordance with the cassette loading position, and the drive device of the take-up reel stand is equipped with a drive device and a tape loading device that operate in conjunction with the detection of the cassette switch. A tape correction device when loading a cassette is connected to a correction circuit that drives a loading mechanism for a short period of time to wind up a tape from a cassette. The device according to claim 1, wherein the correction circuit is a monostable multivibrator whose input side is connected to a cassette switch and whose output side is connected to a drive device.