JPH01105309A - Rotary head drum device - Google Patents

Abstract

PURPOSE:To improve a tape scanning and to drastically stabilize a head touch by vertically and rotatably providing a rotary drum in a tape scanning direction, and providing a tape guiding part to guide the lower edge of the tape on the upper edge of the fixed drum. CONSTITUTION:A rotary drum 7 of a rotary head drum 2 is vertically rotated for a chassis C, and vertically and freely-rotatably provided for the tape scanning direction. At the upper edge part of a fixed drum 3, a tape guiding part 3e to guide the lower edge of the tape is provided. Consequently, since the lower edge of a tape T is positioned by the guiding part 3e of the drum 3 without fail, the edge part of the tape lower edge does not make contact with other member or is not damaged. Thus, a stable air film is formed at the tape T and the external peripheral surface of the rotary drum 7, and the tape scanning is improved and the head touch is drastically stabilized.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to so-called parallel recording in which a plurality of parallel recording tracks are sequentially formed in the width direction of the tape by scanning a head in the running (longitudinal) direction of the tape. The present invention relates to a scanning type rotary head drum device.

[Summary of the Invention] The present invention is a parallel scanning rotary head drum device that scans a head in the running direction of a tape and sequentially records a plurality of parallel tracks in the width direction of the tape. A rotating head drum that stands perpendicular to the fixed drum is constructed of a fixed drum and a rotating drum that is housed within the fixed drum and projects upward from the fixed drum, and the rotating drum is mounted on the fixed drum side in the tape running direction. a tape guide portion is provided on the upper end side of the fixed drum to guide the lower edge of the tape running along the outer peripheral surface of the rotating drum; An opening extending along the axial direction of the rotating drum is provided on the outer peripheral surface of the rotating drum, and the head is provided to be able to reciprocate along the opening in parallel with the axis, thereby allowing the tape to be loaded diagonally onto the rotating head drum. By aligning the running direction of the tape with the scanning direction of the head without putting an unreasonable load on the tape, various functions during recording and playback can be further improved. This allows for even more stable running performance.

[Prior Art] Conventional VTRs employ a helical scan type rotary head drum device in which the head for recording (reproducing) video signals is arranged at an angle from the tape running direction, and the head is rotated to record diagonal patterns on the tape. is commonly used.

This helical scan type rotating head drum device is
For example, a rotary head drum tilted at a predetermined angle with respect to the shear of the VTR main body is rotatably supported. This rotary head drum is fixed to the chassis and is rotatably supported on the lower drum via a lower drum having a tape guide band as a tape guide section inclined on the outer circumferential surface, and a rotary shaft on the lower drum. A pair of video heads is arranged on the lower surface of the second drum between the two and the lower drums so as to protrude by a predetermined amount from the outer peripheral surface thereof.

Then, a loading mechanism consisting of a drawer guide, an inclined guide, etc. arranged around the rotating head drum,
A tape is helically wound around the outer peripheral surface of the rotary head drum from, for example, a tape cassette attached to the VTR main body, and a video head is scanned diagonally with respect to the tape to sequentially form diagonal tracks. ing.

[Problems to be Solved by the Invention] However, in the helical scan type rotary head drum device, high mounting accuracy is required to slant the rotary head drum to the chassis, and the tape must be run diagonally. Therefore, there is a drawback that an excessive load is applied to the tape when the tape is running. Furthermore, since the tape is run on a tape guide band formed diagonally on the outer circumferential surface of the rotating head drum, there are drawbacks such as the need for a large-scale mechanism to ensure stable tape running. Ta.

Therefore, the present invention provides a so-called parallel scan type rotary head drum device that solves the above-mentioned problems.

[Means for solving the problem] A rotary head drum that stands perpendicular to the running direction of the tape is composed of a fixed drum and a rotary drum that is housed within the fixed drum and projects upward from the fixed drum, This rotating drum is rotatably provided on the fixed drum side via a shaft supported perpendicularly to the tape running direction, and the rotating drum runs along the outer circumferential surface of the rotating drum at one end of the fixed drum. A tape guide portion is provided for guiding the lower end edge of the tape, and an opening is provided on the outer circumferential surface of the rotating drum that extends along the axial direction, and the head can be freely reciprocated along the opening in parallel to the axis. It is provided for.

[Operation] The tape running direction coincides with the head scanning direction, and a plurality of tracks are sequentially recorded in parallel in the width direction of the tape. When the tape runs, the lower edge of the tape is reliably guided by the tape guide portion of the fixed drum.

[Example] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1.5, 1 is a rotating head drum device used in a VTR. The rotary head drum 2 of this rotary head drum device 1 is provided in an upright position perpendicularly to the chassis C of the VTR main body. Specifically, this rotary head drum 2 includes a fixed drum 3 vertically fixed to the chassis C, and a cylindrical bearing part 3b vertically protruding from the center of the bottom part 3a of the fixed drum 3, and a pair of bearings. 4.5 through the shaft 6 fitted with the fixed drum 3
The rotary drum 7 is housed and rotatably supported within the peripheral wall 3c of the rotary drum 7.

A disk-shaped flange 8 is fastened and fixed to the upper end surface of the cylindrical bearing portion 7b protruding from the center of the bottom portion 7a of the rotating drum 7 with screws 9. A plate-shaped lid 10 is fastened and fixed with a plurality of screws 11 so as to overlap the flange 8.

A brushless motor 12 for rotating the shaft 6 is attached to the lower surface of the bottom 3a of the fixed drum 3. The stator of this brushless motor 12 includes a substantially cylindrical yoke I3 fixed to the lower surface of the bottom 3a of the fixed drum 3, and a space between the inner peripheral surface of the yoke I3 and the bearing part 3b of the fixed drum 3. A disc-shaped stator yoke 14 is arranged parallel to the bottom 3a of the stator yoke 14, a stator coil 15 is fixed to the lower surface of the stator yoke 14 in a predetermined phase so as to form an annular shape, and a lower end opening of the yoke 13 is arranged. It is composed of a stator cover 16 that closes.

The rotor of the brushless motor 12 includes a rotor boss 17 fitted to the lower end of the shaft 6, a disc-shaped rotor yoke 18 caulked and fixed to the rotor boss 17 so as to face the stator yoke 14, and The rotor magnet 19 includes a disc-shaped rotor magnet 19 fixed to the upper surface of the rotor yoke 18 so as to face the stator coil 15 with a predetermined clearance therebetween. The shaft 6 and the bearing portion 7b of the rotary drum 7 are fastened and fixed with screws 20 to prevent them from spinning idly, and the brushless motor 12
The rotational force can be reliably transmitted to the rotating drum 7 via the shaft 6.

On the lower side of the outer peripheral surface of the peripheral wall portion 7c of the rotating drum 7,
As shown in Fig. 1.4, the recess 7 is cut out in a stepped annular shape.
A vertically (axially) long rectangular opening 7e is formed at a position facing 180° from the lower end to the upper end of the peripheral wall 7c.

7e, respectively. A convex portion 3d formed in an annular manner protruding from the upper end side of the inner circumferential surface of the peripheral wall portion 3c of the fixed drum 3 is inserted into the recessed portion 7d of the rotating drum 7. The lower part is rotatably housed within the peripheral wall 3c of the fixed drum 3. Also,
The upper end surface 3e of the convex portion 3d serves as a tape guide portion that guides the lower end edge of the tape T running on the outer peripheral surface of the peripheral wall portion 7c of the rotary drum 7.

A carriage 21 as a head mounting member is disposed in one of the openings 7e via a lead screw (ball screw) 22 so as to be vertically movable. That is, the carriage 21
is a bearing portion 23 screwed into the lead screw 22 on one end side.
It is formed into a substantially T-shape by a flat part 21a that is fitted with the mounting flat part 21a, and a vertical upright part 21c that is vertically integrally formed on the other end side of this mounting flat part 21a and has a pair of head exposure holes 21b, 21b in the center. It is. A midway portion of the guide shaft 24 is fitted into the flat portion 21a of the carriage 21 so as to be parallel to the vertically erected lead screw 21. The upper and lower ends of the lead screw 21 are fitted with bearings 25a, 25 fitted to the flange 8 and the bottom 7a of the rotating drum 7.
The upper and lower parts of the guide shaft 24 are slidably supported by bushes 26a and 26b fitted to the flange 8 and the bottom 7a of the rotating drum 7.

Moreover, on the upper and lower surfaces of the flat part 21a of the carriage 21,
Recording (R
FC) head 29.29 is fixed. The pair of recording heads 29, 29 are inserted into the pair of head exposure holes 21b, 21b of the vertically erected portion 21c, and their respective tips protrude slightly outward from the outer surface of the vertically erected portion 21c. . The outer surface of this vertically standing portion 21c is a curved surface flush with the outer circumferential surface of the peripheral wall portion 7c of the rotating drum 7, and a stepped thin portion 21d is formed at the bottom thereof. be. This thin portion 21d is formed by the carriage 2
When the drum 1 is lowered, it enters into a convex portion 3d of the peripheral wall portion 3c of the fixed drum 3, as shown in FIG.

The upper end of the lead screw 22 is connected to a PM type stepping motor (
(pulse motor) 30.

That is, the stator of this PM type stepping motor 30 includes a disc-shaped stator cover 32 fixed to the upper surface of the lid IO with screws 3I, and a large number of pole teeth 33a along the inner peripheral surface. The stator yoke 33 is arranged in an annular manner and has an annular stator yoke 33 formed by winding two sets of windings 34 from the inner circumferential side to the outer circumferential side.

Further, the rotor of the PM type stepping motor 30 includes a rotor yoke 35 having a bottomed cylindrical shape rotatably housed inside the stator yoke 33, and a rotor yoke 35 spaced apart from a large number of pole teeth 33a of the stator yoke 33 by a predetermined clearance. It consists of a large number of rotor magnets 36° fixed at equal intervals on the outer peripheral surface of the rotor. The upper end of the lead screw 22 is fitted into the annular boss 35b protruding from the center of the bottom 35a of the rotor yoke 35, and the boss 35b and the upper end of the lead screw 22 are connected to the screw 37. It is fastened and fixed. Further, the upper end of the guide shaft 24 of the carriage 21 is locked to the lower surface of the bottom portion 35a of the rotor yoke 35, so that the carriage 2
Stopper 38 for positioning the upper limit stroke position of 1
are fixed with screws 39. These PM type stepping motors 30 and lead screws 22 are used to
A drive mechanism 40 is configured to reciprocate the carriage 21 in the vertical direction so as to step-feed the tape T by a distance in the width direction corresponding to at least the recording area of the tape T.

A playback (PB) head 4I is disposed in the other opening 7e so as to be movable downward by a carriage (head mounting member) 42 and a drive mechanism 43.

The structures of the carriage 42 and drive mechanism 43 are exactly the same as those of the carriage 21 and drive mechanism 40 of the recording head 29, and therefore their explanation will be omitted.

Between the -1- side of the bottom 3a of the fixed drum 3 and the lower side of the bottom 7a of the rotary drum 7, a recording signal is supplied to the recording head 29 during recording, and a reproducing head 4 during reproduction is provided.
A rotary transformer 45 is interposed for extracting the reproduced signal to 1. This rotary transformer 45 includes a rotary transformer stator 4 attached to the fixed side of the bottom portion 3a of the fixed drum 3.
6, and a rotating transformer rotor 47 attached to the rotating side of the bottom 7a of the rotating drum 7.

Also, one end of the shaft 6 is in contact with a plurality of brushes 48, and the recording head 29. A rod-shaped slip ring 49 is connected to supply current to the reproducing head 41 and the like.

When the tape cassette 50 is installed at a predetermined position inside the VTR body using this rotary head drum device 1,
As shown in FIG. 5, the tape T of the tape cassette 50 is
are loaded onto the outer peripheral surface of the rotating drum 7 by two sets of left and right drawer guides 51 and 52 driven by a loading drive mechanism (not shown). Furthermore, the fifth
In the figure, 53 is a capstan shaft, 54 is a pinch roller, and 55 is a capstan shaft.
56 is a guide moved by a tension arm (not shown), and 56 is a guide roller.

Recording head 2 of the rotary head drum device 1 of the above embodiment
A tape format (tape pattern), which is the pattern of the recording tracks on the tape T surface obtained as a result of the scanning by 9 and its dimensional relationship, is shown in FIG. 7 in a simplified manner. The track (1) located at the lower stage of this tape format is recorded by the recording head 29, which scans parallel to the lower edge of the tape T loaded on the outer peripheral surface of the rotary head drum 2 by the rotation of the rotary drum 7. is recorded, for example, during half a rotation. When this recording is completed, the stepping motor 30 rotates the lead screw 22 in the direction of the arrow in FIG. +333mm) and recording of track (2) is started. The starting point of this track (2) changes its position to the right in FIG. 7 by a length S because the tape T moves to the left in FIG. 7 at the tape speed ■. In this way,
Tracks are sequentially recorded toward the upper edge of the tape T parallel to the edge, and when reaching the first limit, as shown in FIG.
The upper end of the guide shaft 24 of the carriage 21 comes into contact with the stopper 38 of the rotor yoke 35, and the upper limit position of the recording head 29 is determined, so that the uppermost track is recorded.

When this uppermost track is recorded, the stepping motor 30 is reversed, the carriage 21 is lowered via the lead screw 22, and the recording head 29 is stepped downward by 1/2 step (for example, 0.0666 mm) and is already New tracks are recorded between recorded tracks.

Thereafter, the recording head 29 is moved downward one step to record up to track (N). By repeating the above steps, recording tracks are sequentially formed on the tape T without wasting any space.

Note that, assuming that the rotational speed of the rotary drum 7 is R, the number of racks is N, and the gap between adjacent tracks in the longitudinal direction is G, the tape speed V is expressed as V=R(L+G)/N. Further, during reproduction by head scanning of the reproduction head 41, tracking control is performed at the same time as repeating the sequence control.

In this way, the tape T can be run on the outer peripheral surface of the rotating drum 7 in a direction perpendicular to its axial direction, and the tape path system can be constructed on the same plane, so the tape guide of the loading mechanism can be made into a roller. In addition to this, the running direction of the tape T and the scanning direction of the head 29.41 can be made to coincide with each other without applying an excessive load to the tape T during recording or reproduction. Therefore, unlike the conventional helical scan type rotary head drum device, there is no need for an inclined guide to guide the tape diagonally to the outer circumferential surface of the rotary head drum, and the tape path during tape loading and unloading is improved. It is easier to consider normalization. For this reason, the tape T has a biased tape tension distribution, so the tape is protected and loaded.

It is possible to increase the speed of tape feeding during unloading, and it is also possible to greatly simplify the structure of the loading mechanism and the like. Further, the lower edge of the tape T running on the outer circumferential surface of the rotating drum 7 is reliably positioned by the upper end surface 3e of the fixed drum 3 serving as a tape guide, so that the lower edge portion of the tape T is No contact with or damage to components.

Furthermore, since the running direction of the tape and the scanning direction of the head can be matched, data processing can be performed without the RF (output signal from the head) becoming a so-called solo pan ball, which occurs with the helical scan method. Noise-free images can be reproduced at any speed.

In addition, the brushless morph 1 provided on the fixed drum 3 side
A drive mechanism 40.43 is attached to the rotating drum 7 rotated by 2.
The recording head 29 and the reproducing head 41 are provided which move up and down, and the thin part 21d of the carriage 21 enters into the peripheral wall 3c of the fixed drum 3 from the upper end surface 3e of the fixed drum 3. A uniform air film can be created between the surface and the tape T running on this outer peripheral surface, and the lower edge of the tape T is reliably guided by the upper end surface 3e of the fixed drum 3, further stabilizing the tape running performance. can be done. For this reason, each head 29
．． 41 from the outer peripheral surface of the rotating drum 7 can be kept as small as possible, and this small amount of protrusion (
For example, with a thickness of 8 μm), it is possible to ensure a sufficient contact of the tape T.

Therefore, the life of the head is extended and the tape is protected.

It is possible to significantly reduce sliding noise.

The stepping motor 30 that serves as the drive source for the drive mechanism 40.43 is flat and thin, and is housed in the upper part of the rotating drum 7, so the rotating drum 7 can be made compact and the rotating head can be The overall size and weight of the drum device 1 can be further reduced.

Further, since all tracks in the width direction of the tape T can be accessed by the head drive mechanism 40, 43, reproduction can be performed even when the tape T is stopped and not running. Therefore, it is possible to compensate for a transient delay in tape speed when changing the playback speed such as in jog mode playback.

According to the above embodiments, a rotary head drum device used in a VTR has been described; however, the present invention is not limited to these, and may also be applied to, for example, a rotary head drum device used in a digital audio tape deck (DAT deck). Of course, it can be applied.

[Effects of the Invention As described above, the rotary head drum device of the present invention employs a parallel scan method in which the scanning direction of the head coincides with the running direction of the tape, so that the tape can be placed diagonally on the rotary head drum. There is no need to load the tape, there is no undue load on the tape, and various functions during recording and playback can be further improved. Further, since the rotating drum is rotatably housed within the fixed drum, and the tape guide section is provided on the upper end side of the fixed drum, a stable air film can be formed between the tape and the outer peripheral surface of the rotating drum. The running performance of the tape and the head touch on the tape can be further stabilized.

[Brief explanation of the drawing]

1 is a sectional view taken along the line B-B in FIG. 3 showing an embodiment of the rotating head drum device of the present invention, FIG. 2 is an exploded perspective view of the main parts, FIG. 3 is a plan view of the same, and FIG. Figure 4 shows A shown in Figure 1.
5 is a schematic plan view of a VTR using a rotating head drum device; FIG. 6 is an enlarged sectional view showing a state in which the head is lowered along the axial direction of the outer peripheral surface of the rotating head drum; FIG. 7 is an explanatory diagram of the tape format by the same device. l... Rotating head drum device, 2... Rotating head drum, 3e... Upper end surface (tape guide part), 6... Shaft, 7e... Opening, 29.41... Head, T. ·tape.

Claims (1)

[Claims] A rotating head drum that stands perpendicular to the running direction of the tape is composed of a fixed drum and a rotating drum that is housed within the fixed drum and projects upward from the fixed drum, and the rotating drum is placed on the fixed drum side and A tape guide section is rotatably provided via a shaft supported perpendicularly to the tape running direction, and is provided on the upper end side of the fixed drum to guide the lower edge of the tape running along the outer peripheral surface of the rotating drum. A rotary head drum device comprising: an opening extending along the axial direction on the outer peripheral surface of the rotary drum; and a head movable back and forth along the opening in parallel with the axis. .