JPH031743B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a helical scan type magnetic recording/reproducing device, and more particularly to a magnetic recording/reproducing device that can be miniaturized. PRIOR ART Currently, efforts are being made to make current home VTRs even more compact without changing the recording pattern on the magnetic tape. One of the ideas for miniaturizing VTRs is to wrap the magnetic tape around the guide drum at approximately 270 degrees, rather than the current approximately 180 degrees, and to install four video heads at 90 degree intervals.
There is an idea to reduce the diameter of the guide drum to 2/3 of the current diameter, thereby reducing the size of the guide drum and thereby reducing the size of the VTR. However, traditional magnetic tape is abbreviated to a guide drum.
The configuration in which the tape is wound over 270 degrees has a large number of tape guide poles arranged on the inlet and outlet sides of the tape running with respect to the guide drum, and the tape guide poles are arranged far away from the guide drum. Even if the guide drum itself is made smaller, a large number of guide poles are placed around it and separated from the guide drum, making it possible to downsize the device to accommodate the smaller diameter of the guide drum. There were some problems, such as not having one. Means for Solving the Problems It is an object of the present invention to provide a magnetic recording and reproducing device that solves the above problems, and has a structure in which a magnetic tape is spirally wound around a tape guide drum. In a magnetic recording/reproducing device, the inlet side of the tape guide drum in the running direction of the magnetic tape is inclined with respect to a direction perpendicular to the tape running direction, so that the magnetic tape is not moved toward the tape guide drum. A diagonal pole is provided to guide the magnetic tape to the peripheral surface, and on the exit side of the tape guide drum in the running direction of the magnetic tape, the pole is perpendicular to the tape running direction and is located away from the tape guide drum. orthogonal tape guide members that guide the tape to substantially reverse its running direction;
A second oblique pole is provided for guiding the magnetic tape guided by the orthogonal tape guide member so that it runs perpendicular to and parallel to the deck surface. Embodiment FIG. 1 is a plan view showing the state of the magnetic recording/reproducing apparatus according to the present invention in the recording/reproducing mode, FIG. 2 is a diagram schematically showing the apparatus of FIG. 4 and 4 are enlarged views of the tape path around the small tape guide drum and the guide pole as seen from the direction of the arrow in FIG. 2, respectively. In the magnetic recording/reproducing apparatus 1 shown in FIG.
is a small tape guide drum with a diameter of 2/3 of the current size,
3 are small tape cassettes arranged close to each other. Further, a group of tape guide poles is also arranged near the small tape guide drum 2.
As a result, the device 1 is significantly smaller in size than conventional devices. In addition, this device 1 has a structure in which a small tape guide drum 2 has four video heads arranged at 90 degree intervals, and a magnetic tape 4 is wound by tape guide poles over 180 degrees and approximately 270 degrees. In this case, the same track pattern as the present one is formed on the magnetic tape 4 by operating the video head by sequentially switching the angular range covering the tape attachment angle as one unit of operation, i.e. The system is designed to be compatible with current equipment. The small tape cassette 3 is smaller than the standard tape cassette, and consists of a cassette housing 7 having a supply reel 5 and a take-up reel 6, and a lid (not shown) on the front of the cassette housing 7. This small tape cassette 3 has a horizontally opened front lid that is slightly raised above the top surface of the small tape guide drum 2, with a portion of the lid covering the top surface of the small tape guide drum 2 in a plan view. , are arranged fairly close to the small tape guide drum 2. Furthermore, with the small tape cassette 3 attached, the capstan 8 is relatively fitted into the small tape cassette 3. During recording/reproduction, the magnetic tape 4 runs along the tape path shown in FIGS. 1 and 2. That is,
The magnetic tape 4 is pulled out from the supply reel 5, guided by two guide rollers 10 and 11 inside the cassette, and pulled out of the tape cassette 3, and is pulled out from the tape cassette 3 by a tension stud 12 and a tension pole for stabilizing the tape tension. 13. The tape is sequentially guided by a guide pole 14 that regulates the tape height, and then attached to the full-width erasing head 15 and the impedance roller 16 for reducing jitter, and the tape height adjustment guide roller 17 for compatibility adjustment.
will be guided to. Further, the magnetic tape 4 spirals approximately 270 degrees around the circumferential surface of the small tape guide drum 2 between an inclined pole 18 on the entrance side and a guide roller 19 on the exit side with respect to the guide drum 2 in the tape running direction. attached to the shape. While the magnetic tape 4 is running while attached to the small tape guide drum 2, the video head rotates approximately 270 degrees and the magnetic tape 4
One track is formed on the top with a standard track pattern, and video signals are recorded and reproduced. The magnetic tape 4 is wrapped around the guide roller 19 by 180 degrees, and the running direction is reversed, and the magnetic tape 4 is moved to the inclined pole 20.
, and as I will explain later,
The chassis 21 is positioned perpendicular to the deck 21 and at the same height as the tape height on the supply reel 5 side.
It is assumed that the tape path is parallel to . This magnetic tape 4
is guided by a height adjustment guide pole 22, attached to an audio control head 23, guided by a height adjustment guide pole 24, and driven by a pinch roller 25 and a capstan 8 to move the tape into the small tape cassette 3. , and after being guided by two guide rollers 26 and 27, it is taken up on the take-up reel 6. Here, the guide roller 19 is disposed at a position opposite to the small tape cassette 3 with respect to the guide drum 2. As a result, the magnetic tape 4
is the position approximately on the back side of the small tape cassette 3,
In other words, the tape is unattached to the small tape guide drum 2 at a position far away from the small tape cassette 3, and the length of the tape along the tape path from this tape attachment release position to the take-up reel is made long. I can do it. However, the small tape guide drum 2
Even if it is placed close to the small tape cassette 3,
The tape length L from the above-mentioned tape splicing release position to the control head can be set to a predetermined value (79.244 mm) without creating a tape path with a complicated shape to increase the tape length. The head arrangement is also compatible with standard equipment. The tape path around the small tape guide drum, the inclination directions and functions of the inclination poles 18 and 20 and the guide roller 19 will now be described with reference to FIGS. 3 and 4. Line 30 in each figure
is the center line (generating line) of the tape 4. In addition, the small tape guide drum 2 has a coordinate axis that is obtained by rotating the standard X-Y coordinate axis counterclockwise by an angle θ (=35°).
At X'- Y' , it is inclined at an angle of 10° and 20' in the -X' axis direction. Among the tape paths loaded as described above, the tape path 31A on the supply reel side from just before the inclined pole 18 is a tape path 31A in which the small cassette 3 is loaded parallel to the deck surface with the magnetic tape 4 perpendicular to the deck surface. The tape runs on the height plane (reference plane) S within the tape path. The inclined pole 18 functions to smoothly advance the tape of the tape path 31A into the lead of the small tape guide drum 2, and has a predetermined inclination angle, direction, and winding angle. The tape path 31B of the attached section of the circumferential surface of the guide drum from the inclined pole 18 on the drum entrance side to the gadolla 9 on the drum exit side gradually descends from the reference plane S as it progresses in the tape running direction, and reaches a point P. Then, the tape passes through the head rotating surface T of the drum 2, and then gradually descends. V ₈ is drum 2
The vector of the tape moving further away from the guide roller 19 is shown. V _B1 indicates a parallelism deviation component of the spectrum V _B with respect to the reference plane S. The guide roller 19 has its axis 19a perpendicular to the vector _VB , and is oriented in such a direction and angle as to allow the tape to be wound without being twisted. Here, the guide roller 19 is configured such that its axis 19a is perpendicular to the generatrix of the incoming and outgoing tape 4, and the surrounding roller portion rotates in the direction of the arrow as the tape travels. As a result, even if the wrapping angle around the guide roller 19 is as large as 180 degrees, as will be described later, the tape 4 passes through this portion without a substantial increase in tension. That is, the guide roller 19 functions to change the running direction of the tape 4 without increasing the tape running load. Also, the tape 4 is attached to this guide roller 19 at a length of 180 mm.
The vector of the tape path 31C that is wrapped around the tape and exits from the guide roller 19 toward the inclined pole 20.
V _c is the parallelism deviation component V _C1 of the above vector V _B
The parallelism deviation component V _B1 is an inverted vector and has the same absolute value. Further, the twisting component of the tape path 31C does not change from the twisting component of the tape path 31B, and becomes equal to this. The tape path 31C moves straight for a predetermined distance and gradually recovers its height. The inclined pole 20 is disposed at a position where the tape 4 has been restored to the height of the reference plane S, and is inclined at a predetermined angle in a predetermined direction, so that the tape path 31 on the take-up reel side than the inclined pole 20 is
Similarly to the tape path 31A, D is a tape path along the reference plane S with both the twist component and the parallelism deviation component being zero. Here, the magnetic tape 4 is wound spirally around the circumferential surface of the guide drum 2, and the tape vector V _B on the exit side of the guide drum 2 is equal to the tape vector V' on the entrance side. . tape pass 3
The vector V _C of 1C is a vector in the opposite direction to the vector V _B , which means that the vector V' is also a vector in the opposite direction. Also, tape pass 3
The vectors V _A and V _D of 1A and 31D are vectors in opposite directions. For this purpose, an inclined pole 18 which changes the vector V _A into a vector V _B and a vector V _C into a vector V _D
The absolute value (β ) of the inclination direction and the inclination angle of the inclination pole 20 with respect to the aforementioned
8 and 29 can be made into common parts. This is convenient for assembly and manufacturing of the device 1. Note that in the above embodiment, the guide roller 1
Although the wrapping angle of the tape with respect to 9 is 180 degrees, it is needless to say that it is not limited to this angle. Effects As described above, the magnetic recording and reproducing apparatus according to the present invention has the following features. To wind the magnetic tape onto the tape guide drum over an angular range that greatly exceeds 180 degrees, a total of three tape guide members, one on the drum entrance side and two on the drum exit side, are used. This can be done by arranging it at a position close to the tape guide drum. Therefore, when the diameter of the tape guide drum is reduced by winding the magnetic tape approximately 270 degrees, the tape guide members can also be gathered near the periphery of the tape guide drum in accordance with the reduction in the diameter of the tape guide drum. Therefore, it is possible to realize an ultra-compact device that is compatible with current standard devices. Since the tape running direction is configured to be changed by 180 degrees at the point of the orthogonal tape guide member on the exit side of the tape guide drum, the diagonal pole on the inlet side of the tape guide drum and the next stage of the orthogonal tape guide member are The oblique poles can be made to have the same inclination angle, and the parts of both oblique poles can be made common, which is advantageous in manufacturing and assembling the device.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the state of the magnetic recording and reproducing apparatus according to the present invention in recording and reproducing mode, FIG. 2 is a diagram schematically showing the apparatus of FIG. FIG. 4 is an enlarged view of the tape paths around the small tape guide drums together with the guide poles as seen from the direction of the arrow in FIG. 2. FIG. DESCRIPTION OF SYMBOLS 1... Magnetic recording/reproducing device, 2... Small tape guide drum, 3... Small tape cassette, 4... Magnetic tape, 5... Supply reel, 6... Take-up reel, 8... Capstan, 15... Full width erasing head, 16... Impedance roller , 18, 20... inclined pole, 19
...Guide roller, 21...Deck, 23...Audio control head, 25...Pinch roller,
28, 29...Pole base, 30...Tape center line (generating line), 31A, 31B, 31C, 31D...
tape pass.

Claims (1)

[Scope of Claims] 1. In a magnetic recording and reproducing device in which a magnetic tape is spirally wound around a tape guide drum, in the running direction of the magnetic tape, on the inlet side with respect to the tape guide drum, the tape running direction is A diagonal pole is provided that is inclined with respect to a direction perpendicular to the tape guide drum and guides the magnetic tape to the circumferential surface of the tape guide drum, and is located on the exit side with respect to the tape guide drum in the running direction of the magnetic tape. an orthogonal tape guide member that is orthogonal to the tape running direction and that guides the magnetic tape away from the tape guide drum so that its running direction is substantially reversed; and a second oblique pole for guiding the magnetic tape so that it runs perpendicular to and parallel to the deck surface. 2. The orthogonal tape guide member and the diagonal pole on the outlet side with respect to the tape guide drum are such that the running direction of the magnetic tape is at the orthogonal tape guide member.
2. The magnetic recording/reproducing device according to claim 1, wherein the magnetic recording/reproducing device is arranged so as to be converted by 180 degrees.