JPH0240585Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a cassette tape protection device for preventing the tape from loosening when a VTR is ejected in a mode after the cassette is loaded.

(b) Conventional example In a conventional VTR, when inserting a cassette into the cassette insertion slot and loading the cassette, if you accidentally load a cassette with loose tape from the beginning, or after loading a cassette with no loose tape. ,
If the tape becomes loose due to malfunction of the VTR when changing from fast forward or rewind mode to stop mode, or when changing from tape loading to tape unloading mode, if the tape is loosened due to a malfunction of the VTR, ejecting the cassette using eject mode will remove the slack. This sometimes caused the tape protruding from the cassette to become caught in the cassette lid, damaging the tape.

In order to prevent the above-mentioned damage to the tape, the reel is rotated when the cassette is ejected to prevent the tape from becoming loose.

However, in conventional VTRs, when ejecting, the reel is rotated in the direction in which the reel was rotating in each mode before ejecting to prevent the tape from loosening. If the reel always winds the tape in the unwinding direction, setting the eject mode will rotate the reel in the unwinding direction and prevent the tape from becoming slack, but when winding with the supply reel, especially in the leader tape section, When the eject mode is set, the reel rotates further in the unwinding direction to prevent the tape from loosening, which causes abnormal tension to be applied to the end of the leader tape, causing damage to the tape. .

When winding the tape with the take-up reel, if the eject mode was set in the leader tape section, the same drawback as described above occurred at the end of the leader tape.

Additionally, some VTRs have a limiter device installed in the reel drive section to prevent abnormal tension from being applied to the end of the leader tape, but this has the disadvantage of a complicated structure.

(c) Purpose of the invention The present invention is intended to eliminate the above-mentioned drawbacks, and aims to prevent damage to the tape by providing a tape position detecting means with a simple structure to eliminate slack in the tape.

(d) Structure of the invention The present invention includes a first reel stand, a second reel stand, and a reel drive motor for driving the first reel stand and the second reel stand in a VTR.
It is composed of a cassette lamp for detecting the attachment of a cassette, a tape end detecting means provided near the first reel stand for detecting the end of the tape, and a motor control circuit responsive to the tape end detecting means. .

(E) Embodiments The details of the present invention will be specifically explained by referring to illustrated embodiments.

In FIG. 1, the tape end detection means detects the light emitted by the cassette lamp, and the motor control circuit controls the rotational direction of the reel stand, and the take-up reel rotates in the direction A shown in the figure to eliminate tape slack. FIG. 2 is a functional block diagram of the cassette tape protection device of the present invention showing a state in which the cassette tape protection device is removed. FIG. 3 is a functional block diagram of the cassette tape protection device of the present invention, showing a state in which the supply reel rotates in direction C to remove slack in the tape.

In Figures 1 and 2, 1 is a magnetic tape, 2
a and 2b are leader tapes, 3 is a supply reel, 4 is a take-up reel, 5a and 5b are guide rollers, 6 is a cassette lamp, 7a and 7b are tape end detection means, 8 is a motor control circuit, and 9 is a reel drive 10 is a cassette tape protection device, and 13 is a power supply for the cassette lamp.

To explain the state shown in FIG. 1, a phototransistor 1 is located near the supply reel 3 and take-up reel 4.
1a, 11b, and resistors 12a , 12b .
When the tape end detecting means 7b provided on the side detects the light emitted from the cassette lamp 6 in a mode in which the magnetic tape 1 is being wound by the rotation of the take-up reel 4, the tape end detecting means 7b detects the light emitted from the cassette lamp 6, i.e., when the tape end detecting means 7b detects the light emitted from the cassette lamp 6 as shown in FIG. When the light emitted from the cassette lamp 6 is detected by the cassette lamp power source 13 through the transparent leader tape 2b at the end of the reel 3, the motor control circuit 8 responsive to the tape end detecting means 7b causes the reel stand to It has a function of controlling the drive motor 9 and stopping the rotation of the take-up reel stand (not shown) to put it in a stop mode. Further, in a mode in which the magnetic tape 1 is wound up by the rotation of the supply reel 3, the tape end detecting means 7a provided on the take-up reel 4 side detects a transparent leader tape 2a at the end portion on the take-up reel 4 side. When the light emitted from the cassette lamp 6 is detected through the cassette lamp 6, the rotation of the supply reel stand (not shown) is stopped in the same manner as described above.
In addition to the stop mode, the magnetic tape 1 and the leader tape 2a are also provided with a function of preventing and protecting the magnetic tape 1 and the leader tape 2a from loosening during ejection. 1st
In the figure, the supply reel 3 rotates in modes such as rewind and review, and the magnetic tape 1 is wound onto the supply reel 3 side, and the end of the tape is detected via the transparent leader tape 2a on the take-up reel 4 side. Means 7a
detects the light emitted by the cassette lamp 6, that is,
The figure shows a state in which all of the magnetic tape 1 is wound onto the supply reel 3 side and the eject mode is set. In this state, in order to prevent the magnetic tape 1 from becoming loose, the supply reel 3 is rotated and the leader tape 2a is Since abnormal tension may be applied to the tape end and damage it, the tape end detection means 7a is
When detecting the light emitted from the cassette lamp 6, the take-up reel 4 is moved in the direction A shown in the figure by the power of the reel stand driving motor 9 by the motor control circuit 8 which responds to the tape end detection means 7a. The magnetic tape 1 is rotated to move in the direction B, thereby preventing and protecting the magnetic tape 1 from loosening.

To explain the state shown in Fig. 2, the take-up reel 4 rotates depending on the mode such as playback, queue, or fast forward.
2 is a functional block diagram showing a state in which the magnetic tape 1 is wound onto the take-up reel 4 side, and the entire magnetic tape 1 is wound onto the take-up reel 4 side, resulting in an eject mode. FIG. In this case as well, if the take-up reel 4 is rotated to prevent the magnetic tape 1 from loosening as described above, abnormal tension will be applied to the end of the leader tape 2b, damaging it . When the light emitted from the lamp 6 cannot be detected, that is, when the magnetic tape is wound on the take-up reel 4, the motor control circuit 8, which responds to the tape end detection means 7a , controls the power of the reel stand driving motor 9. The supply reel 3 is rotated in the C direction shown in the figure, and the magnetic tape 1 is moved in the D direction, thereby preventing and protecting the magnetic tape 1 from loosening.

In addition, when the magnetic tape 1 is wound on the supply reel 3 and the take-up reel 4, as described above, since the magnetic tape 1 is wound on the take-up reel 4, the supply reel 3 is The magnetic tape 1 is rotated in the direction to prevent and protect the magnetic tape 1 from loosening.
As described above, in any case in which the magnetic tape is wound on the supply reel 3 and the take-up reel 4 in the eject mode, the magnetic tape 1 and the leader are It is possible to prevent the tapes 2a and 2b from becoming loose and to protect the magnetic tape 1 from being caught in a cassette lid (not shown).

In this embodiment, the function of preventing and protecting the magnetic tape 1 and leader tapes 2a and 2b from loosening during ejection is performed by the tape end detecting means 7a on the take-up reel 4 side, but the supply reel 3 Even if the tape end detecting means 7b on the side is used, it is possible to prevent and protect the magnetic tape 1 and the leader tapes 2a and 2b from loosening in the same way as described above.

(f) Effects of the invention According to the cassette tape protection device of the invention, even when the leader tape section is set to eject mode, the rotational direction of the reel is controlled in a predetermined direction, and abnormal tension is not applied to the leader tape. It protects the tape and prevents it from becoming loose, and even if the tape is loose inside the cassette, setting it to eject mode prevents the tape from becoming loose and allows you to safely remove the cassette. can get.

[Brief explanation of drawings]

In Fig. 1, the take-up reel rotates in the direction A shown in the figure.
FIG. 2 is a functional block diagram of the cassette tape protection device of the present invention showing a state in which the slack in the tape is removed. FIG. FIG. Explanation of main figure numbers, 1...Magnetic tape, 2a, 2
b... Leader tape, 3... Supply reel, 4...
Take-up reel, 6...cassette lamp, 7a , 7b
... Tape end detection means, 8 ... Motor control circuit, 9 ... Reel stand driving motor, 10 ... Cassette tape protection device.

Claims (1)

[Scope of utility model registration request] In a VTR, a first reel stand, a second reel stand, a reel drive motor for driving the first reel stand and the second reel stand, a cassette lamp for detecting attachment of a cassette, and and a pair of tape end detection means for detecting the end of the tape provided near the reel stand and the second reel stand, and a motor control circuit that responds to the tape end detection means, and is in eject mode. At times, the rotation of the tape reel is controlled depending on the winding state of the tape on the tape reel placed on the first reel stand and the second reel stand to prevent the tape from loosening. Cassette tape protection device.