JPH0792956B2 - Magnetic tape device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention records and reproduces a signal by pulling out a magnetic tape from a cassette and adjoining it to a rotating drum on which a rotating head is mounted and another fixed magnetic head. System magnetic tape device.

2. Description of the Related Art In general, a magnetic tape device capable of pulling out a magnetic tape from a cassette and performing a first-time indexing or a linear count in a fast winding (fast forward / rewind) mode has an opening provided on the outside of the cassette or on the cassette. A fixed magnetic head is installed on the magnetic head, and a magnetic tape is run alongside the magnetic head to record and reproduce control signals and position signals.

Further, in order to perform the first cueing or the linear count in the fast winding mode, the magnetic tape device must be in the recording / reproducing mode, and the magnetic tape must always run alongside the fixed magnetic head in the fast winding mode. For this reason,
It is necessary to form a tape path portion that is common in the reproducing mode and the fast winding mode, that is, a tape path portion in which the magnetic tape is attached to the fixed magnetic head.

By the way, generally, a video tape recorder (VTR) that pulls out a magnetic tape to the outside of the cassette and runs the tape.
The typical tape loading method in (2) is roughly classified into a U loading method and an M loading method. U as started in JP-A-55-160362
Although the loading method complicates the tape loading mechanism, the tape straightening distance is long and the tape wrap angle is small, and even when the magnetic tape is attached to the rotating magnetic head cylinder, it is fast wound with relatively small energy. Therefore, the tape pass in the recording / playback mode and the fast-winding mode can be the same, and therefore the first cue and the linear count in the fast-winding can be easily realized. However, there is a possibility that magnetic tape damage may occur due to high speed running in a complicated running system, and the rotary magnetic head is also easily worn.

On the other hand, in the M loading method, the tape loading mechanism is simplified, but the tape straightening distance is short, the winding angle of the tape around the post is large, and the magnetic tape is wound fast around the rotary magnetic head cylinder. Requires a lot of energy. Therefore, it is common to change the tape path between the recording / reproducing mode and the fast winding mode.

However, as described above, it is necessary to form a tape path that allows the magnetic tape to be attached to the fixed magnetic head in the recording / reproducing mode and the fast winding mode. Therefore, in the M loading type VHS format, At the time of winding, a recording position identification signal reproducing head as seen in JP-A-54-149609 is specially provided at the cassette opening,
Methods such as forming a tape path as shown in the figure have been taken.

A magnetic tape device having the conventional tape path forming means for cueing the tape in the M loading system will be described below with reference to the drawings.

In FIG. 6, a magnetic tape 2 is laid between the supply reel hub 4a and the take-up reel hub 5a in the cassette 1. The chassis 3 has a supply reel hub 4a and a take-up reel hub.
A pair of reel bases 4b and 5b that engage with 5a and rotate integrally are rotatably arranged. A pulley 6 which is driven in the forward and reverse directions by a reel motor (not shown) is arranged at substantially equal distances from both reel stands 4b and 5b. Therefore, when the idler 7 is brought into contact with the pulley 6, the idler 7 rolls on either the supply reel base 4b or the take-up reel base 5b according to the rotation direction of the pulley 6 to transmit the rotation. 2 winding operation is performed. In the fast-forward mode and the rewind mode, the pull-out post 17 'located at the cassette opening 21 is moved to the position shown by the solid line to attach the magnetic tape 2 to the fixed magnetic head 16 shown by the solid line in FIG. A traveling system capable of contact is formed, and the magnetic tape is caused to travel at a high speed by the reel driving mechanism as described above, and the fixed magnetic head 16 reads the necessary signal.

In the record / playback mode, the cassette opening 2
The magnetic tape 2 is pulled out by moving the pull-out posts 10, 11, 12, 13 located at 0, 21 to the positions shown by the alternate long and short dash line, and attached to the rotary drum 9 and the fixed magnetic head 16 by a predetermined angle, respectively. A tape path indicated by a chain line is formed. After that, the magnetic tape 2 is fed at a constant speed by the cooperation of the capstan 14 and the pinch roller 15, and is wound onto the take-up reel hub 5a by the reel drive mechanism. This is the configuration of a conventional tape device, which will be further described in connection with the present invention.

At the time of shifting from the fast winding mode to the recording / reproducing mode, the drawer post 17 maintains the position of the solid line in FIG. 6 as it is. It is a stop mode in a practical magnetic tape device,
Many modes such as fast winding mode, recording / playback mode, pause mode, and reverse playback mode are set, and the movement of the mechanism during those mode transitions is minimized to try to simplify the structure of the mechanism. This is because. However, in this recording / reproducing mode, if the magnetic tape 2 is in contact with the pull-out post 17, the tape path length (so-called X value) from the tape separation point of the rotating drum 9 to the fixed magnetic head 16 changes, and the tape device It becomes a big problem in guaranteeing compatibility between them. Also, as shown in FIG. 6, the magnetic tape 2 pulled out by the pull-out post 17
Runs around the rotary drum 9 at a slight angle, but the rotary drum 9 is generally inclined with respect to the tape running surface, which affects the tape running. It is common to incline the drawer post 17 in order to stabilize the tape running. Therefore, the magnetic tape 2 is pulled out in the recording / playback mode.
If it is in contact with 17, the running of the tape becomes unstable. Therefore, conventionally, as shown in FIG. 6, the pull-out post 17 is positioned by selecting a position where it does not contact the magnetic tape 2 in the tape path in the recording / reproducing mode.

Further, FIG. 7 shows a conventional example found in JP-A-59-112460. The basic structure is exactly the same as that shown in FIG. 6, but a second drawing pin 18 is added at the time of early winding so that the magnetic tape 2 is not attached to the rotating drum 9.
Then, during recording / reproduction, the pull-out pins 17 and 18 are in the positions as shown by the dotted lines and do not move.

Problems to be Solved by the Invention However, in the structure as shown in FIG.
Although the position of 17 does not move during fast winding and during recording / playback, the fixed magnetic head 16 reliably detects the signal during fast winding and contacts the magnetic tape 2 in the tape path during recording / playback. You must not do it. In other words, the tape winding angle around the fixed magnetic head 16 during early winding is smaller than that during recording and playback, and the output of the fixed magnetic head 16 tends to become unstable. A delicate adjustment was required by providing a means for adjusting the corners. Further, with respect to a support member for the pull-out pin 17 (not shown), strict requirements are placed on its accuracy and strength.

In the configuration shown in Fig. 7, recording / recording from the fast winding mode
When the playback mode is entered, the pull-out pins 17 and 18 once return to the positions indicated by the dotted lines, and then the supply-side pull-out posts 10 and 11 and the winding-side pull-up posts 12 and 13 move the magnetic tape 2 to the positions indicated by the alternate long and short dash lines. Since the pull-out and recording / reproducing modes are formed, the magnetic tape 2 is separated from the fixed magnetic head 16 in the transition from the fast winding mode to the recording / reproducing mode, and at this time, the signal relating to the tape position cannot be detected. The tape position is not guaranteed when the recording / playback mode is entered, and only a low-grade magnetic tape device can be supported.

In view of the above problems, the present invention does not require adjustment of the pull-out post with a simple structure, enables reliable signal reproduction, and ensures that the tape does not separate from the fixed magnetic head even during mode transition. A magnetic tape device capable of detecting the position of a magnetic tape.

Means for Solving the Problems In order to solve the above problems, a magnetic tape device according to the present invention draws out a magnetic tape from a tape cassette and attaches the magnetic tape to a rotating drum and a fixed magnetic head over a predetermined angle. First to form one tape path
The tape path forming means and the position where the angle of attachment of the magnetic tape to the fixed magnetic head when the first tape path forming means is not operating is larger than the angle of attachment when forming the first tape path. Second tape path forming means for pulling out the magnetic tape from the cassette to form a second tape path, and moving to a position not contacting the magnetic tape when the first tape path forming means forms the first tape path. In addition, the second tape path forming means and the first tape path forming means are provided with interlocking means to operate the second tape path forming means in conjunction with the first tape path forming means. Is also configured.

Operation In the present invention, since the magnetic tape is attached to the fixed magnetic head only at a necessary and sufficient angle in each mode of the magnetic tape device according to the above-mentioned configuration, the adjustment of the pull-out post is not necessary and the feed-side pull-out is performed. First tape path forming means including a post and a take-up side drawing post;
By operating the second tape path forming means including the pull-out post in conjunction with each other, the position of the tape can be surely detected without separating the tape from the fixed magnetic head when the mode is changed.

Embodiment A magnetic tape device according to an embodiment of the present invention will be described below with reference to the drawings.

Since the reel drive mechanism in this embodiment is the same as the conventional example described in FIGS. 6 and 7, description thereof will be omitted. Further, the same components are given the same reference numerals. FIG. 1 is a plan view of a magnetic tape device according to an embodiment of the present invention in a stop mode and a fast winding mode. The supply-side pull-out posts 10 and 11 and the take-up-side pull-out posts 12 and 13 are provided with a feed-side slider 22 that is movable by being guided by guide grooves 24 formed in the chassis 3, respectively.
It is erected on the winding side slider 23. Numeral 25 is a recording / reproducing mode, and is positioned when the pull-out posts 10, 11, 12, 13 pull out the magnetic tape 2 from the inside of the cassette 1 and move it to the position indicated by the alternate long and short dash line where it can be attached to the rotating drum 9 by a predetermined angle. It is a stopper that does. The pull-out pin 17 is an arm rotatably supported by a shaft set up on the chassis 3.
It is planted on 26. The arm 26 is biased counterclockwise by a spring 27 when the tape 2 is pulled out as shown in FIG. Further, the arm 26 has a gear portion 28 and a protrusion portion 29.
Are formed. A cam gear 30 rotatably supported by a shaft 31 erected in the rear surface direction of the chassis 3 has a gear portion on the outer periphery and is rotationally driven by a motor (not shown). A grooved cam (A) 32 having a cam diagram shown in FIG. 5 is arranged on one end surface of the cam gear 30. A cam follower 34 is planted at one end of a fan-shaped arm 33 that is rotatably supported by a shaft that is planted on the surface of the chassis 3, and engages with a groove cam (A) 32 through a hole 35 formed in the chassis 3. I am fit. Further, at the other end of the fan-shaped arm 33, a gear portion 36 that can mesh with a gear portion 28 provided on the arm 26, and a pressing cam 37 that can abut the protrusion portion 29 also provided on the arm 26 are formed. .

FIG. 2 shows a state in which the cassette 1 is mounted at a predetermined position on the chassis 3 of the magnetic tape device by a known method. The drawer posts 10, 11, 12, 13 and the drawer pin 17 have the cassette openings 20, 21. It is located inside.

FIG. 3 shows the state of each element when the tape is running in the magnetic tape device in the recording / playback mode. By the method described below, the magnetic tape 2 forms a fixed magnetic head 16 and a first tape path contacting the rotary drum 2 at a predetermined angle by the pull-out posts 10, 11, 12, 13 included in the first tape pull-out means. At the same time, the magnetic tape 2 is fed at a constant speed by the cooperation of the capstan 14 and the pinch roller 15, and the magnetic tape 2 is wound around the take-up reel hub 5a by the reel drive mechanism described above. At this time, the drawer pin 17 is rotated in the counterclockwise direction from the position in the fast winding mode or the stop mode in FIG. 1 by the rotation of the grooved cam (A) 32 provided in the cam gear 30 to rotate the arm 26 counterclockwise. It moves into the inside 21 and is completely separated from the magnetic tape 2.

FIG. 4 is a rear view of the apparatus at the time when the cassette 1 of FIG. 2 is completely attached to a predetermined position of the magnetic tape apparatus, and the construction of the first tape path forming means will be described with reference to this figure.
Reference numerals 39 and 40 denote loading gears meshing with each other, and are rotatably supported by shafts set up on the rear surface side of the chassis 3. Reference numeral 42 denotes a loading first arm that rotates integrally with the supply side loading gear 39, and one end of a loading second arm 43 is rotatably supported at the end thereof. A hole is formed in the other end of the second loading arm 43, and the second loading arm 43 is rotatably engaged with a pin 46 that is erected on the chassis rear surface side of the supply slider 22. Similarly, 44 is a loading third arm which rotates integrally with the winding side loading gear 40, and a loading fourth arm 45 is provided at the end thereof.
Has one end rotatably supported. A hole is formed in the other end of the loading fourth arm 45, and the pin 47 is rotatably engaged with the pin 47 set on the rear surface of the chassis of the winding-side slider 23.

Further, a small gear 41 formed integrally with the winding-side loading gear 40 meshes with a transmission gear 48 rotatably supported by a shaft erected on the rear surface of the chassis 3. A groove 49 is bored in the transmission gear 48, and the transmission gear 48 engages with a pressing pin erected at one end of an L-shaped lever 50. The lever 50 is rotatably supported by a shaft set up on the rear surface of the chassis 3,
A cam follower 52 is planted at the other end. The cam follower 52 is engaged with the grooved cam (B) 53 provided on the other end surface of the cam gear 30, and the rotation of the cam gear 30 causes the lever 50 to rotate in accordance with the cam curve shown in FIG. 1 tape forming means is operated.

FIG. 5 shows a grooved cam (A) formed on both end surfaces of the cam gear 30.
32 is a cam diagram of the groove cam (B) 53, and the vertical axis shows the stroke of both cams 32 and 53. In the present embodiment, the positive stroke direction is the direction in which the distance from the rotation center to both cams 32, 53 increases. The horizontal axis represents the rotation angle of the cam gear 30, and the counterclockwise direction in FIG. 1 is shown as the positive direction. Set the rotation angle corresponding to each mode and the stroke of both cams 32, 53 according to this rotation angle, and set both cam followers 34, 52.
By operating the drawer post 10,11,12,13
And the second tape forming means including the pull-out pin 17 are operated.

Next, the operation of the magnetic tape device configured as described above will be described. As shown in FIG. 2, when the cassette 1 is mounted at a predetermined position, a mounting completion switch (not shown) operates and a motor (not shown) rotates to rotate the cam gear.
Fig. 2 Rotate 30 counterclockwise. By the rotation of the cam gear 30, as shown in FIG. 5, the stroke of the groove cam (B) 53 does not change, but the stroke of the groove cam (A) 32 first changes in the positive direction. As a result, the fan-shaped arm 33 integrated with the cam follower 34 rotates counterclockwise, and the arm 26 rotates clockwise due to the engagement of the gear portions 28 and 36, and the pull-out pin
17 starts to pull out the magnetic tape 2 from the cassette 1. When the cam gear 30 continues to rotate and the fan-shaped arm 33 further rotates, the engagement of the pressing cam 37 and the projection 29 starts from the meshing of the gear portions 28 and 36, and the arm 26 is largely rotated clockwise. Thus, when the cam gear 30 rotates and rotates to the rotation angle corresponding to the stop mode as shown in FIG. 5, the switch operates, the motor stops, and the second tape path shown in FIG. 1 is completed. At this time, the pull-out pin 17 is the magnetic tape 2
Is pulled out from the cassette 1 and stably attached to the fixed magnetic head 16 at an attachment angle larger than the attachment angle in the recording / reproducing mode shown by the alternate long and short dash line in FIG. The arm 26 stably holds the state shown in FIG. 1 by the counterclockwise biasing force of the spring 27 and the contact between the protrusion 29 and the pressing cam 37.
Next, when you press the fast-wind button, a switch (not shown) operates,
The tape path is the same as in FIG. 1 by the reel drive mechanism,
The magnetic tape 2 runs at high speed. The tape running is usually more unstable during high-speed running than during recording / playback, but since the pull-out pin 17 makes a large contact with the fixed magnetic head 16, the fixed magnetic head 16 can detect signals stably. . At this time, the magnetic tape 2 is attached to the rotating drum 9 although it has a small angle. However, by rotating the rotary drum 9 at this time, tape running becomes more stable,
Further, the wear of the rotary magnetic head and the rotary drum does not pose any problem because the tape tension can be set lower than in the normal recording / reproducing mode.

Next, when the record or play button is pressed from the stop mode, the switch is operated, the motor starts rotating, and the cam gear 30 rotates counterclockwise in FIG. Even if the cam gear 30 rotates, the stroke of the groove cam (A) 32 does not change from the stop mode, so the pull-out pin 17 holds the position shown in FIG. 1 for a while, but the stroke of the groove cam (B) 53 does not change. It begins to change in the positive direction. As a result, the lever 50 on which the cam follower 52 is erected rotates clockwise in FIG. 4, the transmission gear 48 engaged with the pressing pin 51 is counterclockwise, and the winding side loading gear 40 is clockwise. Then, the supply side loading gear 39 rotates counterclockwise. The loading first arm 42 and the loading second arm 43 guide the supply side slider 22, and the loading third arm 44 and the loading fourth arm 45 guide the winding side slider 23 together in the guide groove 24 toward the stopper 25. Press and move. Drawer post 10,11,1
2, 13 are moved from the state shown in FIG. 1 to further pull out the magnetic tape 2 and bring it into contact with the rotary cylinder 9. Then, when the cam gear 30 continues to rotate and the stroke of the grooved cam (B) 53 disappears and becomes horizontal as shown in FIG. 5, the pull-out posts 10, 11, 12, 13 are respectively stoppers. When it was pressed and fixed to 25 and the position was decided,
In this vicinity, the stroke of the groove cam (A) 32 starts to change in the negative direction. That is, the fan-shaped arm 33 rotates clockwise and the arm 26 rotates counterclockwise, and the drawer post moves from the position shown in FIG. 1 to the position shown in FIG. But,
The angle of attachment of the magnetic tape 2 to the fixed magnetic head 16 at this time is because the pull-out posts 12 and 13 have already moved to a predetermined position that defines the first tape path or in the vicinity thereof. Even if the pull-out pin 17 is moved, the magnetic tape 2 is not separated from the fixed magnetic head 16. Then, the cam gear 30 rotates, the stroke of the grooved cam (A) 32 becomes the same as that when the cassette is mounted, and when it rotates for a while, the switch operates, the motor stops and the recording or reproducing mode is set.

The transition operation from the recording / reproducing mode to the stop mode or the fast winding mode is only the reverse operation to the above-mentioned operation, and therefore its explanation is omitted.

In the present embodiment, the position of the pull-out pin 17 in the recording / reproducing mode is the same as that when the cassette is mounted, but it may be in any position so long as it does not contact the magnetic tape 2, and the cam curve of the groove cam (A) 32 is It can be changed easily. Also,
Although the pull-out posts 10, 11, 12, 13 and the pull-out pin 17 are interlocked with each other by the groove cam (A) 32 and the groove cam (B) 53 provided on the cam gear 30, other structures such as levers are adopted. However, it is obvious that it can be easily realized.

EFFECTS OF THE INVENTION As described above, the first tape path forming means including the drawing post for forming the first tape path by drawing the magnetic tape from the cassette onto the rotary drum and the fixed magnetic head and contacting the same at a predetermined angle. When the first tape path forming means is not in operation, the magnetic tape is pulled out from the cassette at a position where the angle of attachment of the magnetic tape to the fixed magnetic head is larger than the angle of attachment when forming the first tape path. A second tape path forming unit including a pull-out pin that forms a tape path and moves to a position where it does not contact the magnetic tape when the first tape path forming unit forms the first tape path is provided, and the cam gear is provided. A groove cam is provided to serve as an interlocking unit between the second tape path forming unit and the first tape path forming unit, and the second tape path forming unit serves as the first tape path forming unit. Since the second tape path forming unit does not need a position and angle adjusting unit, the structure can be simplified by configuring the second tape path forming unit to operate in conjunction with each other. The stability of signal detection by the fixed magnetic head is greatly improved during early winding, and the magnetic tape is separated from the fixed magnetic head even if there is a change between the first tape path and the second tape path due to mode transition. It is possible to detect the position of the magnetic tape without fail, which is extremely advantageous in practical use.

[Brief description of drawings]

FIG. 1 is a plan view of a magnetic tape device according to an embodiment of the present invention in a stop mode or a fast winding mode, FIG. 2 is a plan view of the same embodiment when a cassette is mounted, and FIG. 4 is a plan view of the reproducing mode, FIG. 4 is a rear view of the same embodiment, FIG. 5 is a cam line diagram of the grooved cam of the same embodiment, and FIG. 6 is a plan view of a magnetic tape device of the first conventional example. FIG. 7 is a plan view of the magnetic tape device according to the second conventional example. 10,11,12,13 …… Drawer post, 16 …… Fixed magnetic head, 17 …… Drawer pin, 30 …… Cam gear, 33 …… Fan arm, 53 …… Groove cam (B).

Continuation of the front page (56) Reference JP 59-112460 (JP, A) JP 59-188868 (JP, A) JP 59-113567 (JP, A) Actual development 55-141368 (JP , U)

Claims (2)

[Claims] 1. A tape cassette containing a pair of reel hubs around which a magnetic tape is wound, a rotary drum on which a rotary magnetic head is mounted outside the tape cassette, a fixed magnetic head, and the tape cassette. First tape path forming means for drawing out the magnetic tape and forming a first tape path for abutting the magnetic tape on the rotary drum and the fixed magnetic head at a predetermined angle, and the first tape path forming means. When the first tape pass is formed, it moves to a position where it does not contact the magnetic tape,
Further, when the first tape path forming means is not in operation, the second tape path is formed such that the angle of attachment of the magnetic tape to the fixed magnetic head is larger than the angle of attachment when forming the first tape path. A magnetic tape device comprising: a second tape path forming unit that operates and a linking unit that links the operation of the second tape path forming unit with the operation of the first tape path forming unit. 2. The magnetic tape device according to claim 1, wherein the interlocking means is an integrally formed cam.