JP3119683B2 - Rotary head device for magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device of a magnetic recording / reproducing apparatus for rotating a rotary head at a high speed for recording a high-band signal.

[0002]

2. Description of the Related Art In recent years, a broadcast video tape recorder for converting video and audio signals into digital signals for recording has been becoming mainstream from a broadcast video tape recorder for recording analog signals. Hereinafter, a video tape recorder that records with analog signals is called an analog VTR, and a video tape recorder that converts video and audio signals into digital signals and records them is called a digital VTR.

A digital VTR has a larger amount of information to record than an analog VTR, and the relative speed between the rotary head and the magnetic tape must be increased. Therefore, the rotation speed of the rotary head device is changed from 1800 rpm of the analog VTR to 5400 rpm.
Need to rotate faster. FIG. 4 shows a configuration employed in a digital VTR to improve the contact between the rotating head and the magnetic tape during high-speed rotation. Digital V
In the TR, a fixed lower drum 2 having a lead 1 for regulating a traveling height position of a magnetic tape wound on an outer peripheral surface, an upper drum 3 disposed above the lower drum 2, and a lower drum 2 A rotatable middle drum 5 including a rotatable middle drum 5 having a rotary head 4 disposed in the middle of the upper drum 3 and a connection support member 6 for fixing the lower drum 2 and the upper drum 3. It has become. Hereinafter, such a rotary head device will be referred to as a medium-rotation type rotary head device. The outer diameter of the upper drum 3 is larger than the outer diameter of the lower drum 2 so that the magnetic tape runs along the lead 1 and regulates the running height position of the magnetic tape. On the other hand, the outer peripheral surface of the upper drum 3 must have a certain amount of protrusion. In the middle rotary type rotary head device, the lower drum 2 is connected to the lower drum 2 by the connecting support member 6 so as not to rotate.
, The upper drum 3 and the lower drum 2 do not necessarily have to be coaxial, and the amount of protrusion of the outer peripheral surface of the upper drum 3 with respect to the outer peripheral surface of the lower drum 2 may not be constant. For this reason, in the medium-rotation type rotary head device, the upper drum 3 with respect to the outer peripheral surface of the lower drum 2 extends over a range of about 200 degrees from the magnetic tape winding start position to the winding end position.
May be set to a value at which the regulation of the traveling height position of the magnetic tape is optimal.

By the way, the upper drum 3 and the lower drum 2 of the conventional middle rotary type rotary head device are fixed by an upper drum fixing screw 7 and a lower drum fixing screw 8 via a connecting support member 6, as shown in FIG. I was The amount of protrusion of the outer peripheral surface of the upper drum 3 with respect to the outer peripheral surface of the lower drum 2 was set by sandwiching a metal foil 9 between the lower drum 2 and the connecting support member 6. Therefore, the adjustment of the protrusion amount of the outer peripheral surface of the upper drum 3 with respect to the outer peripheral surface of the lower drum 2 is performed in a state where the rotary head device is not mounted on the chassis, and the rotary head device is mounted on the chassis of the magnetic recording / reproducing device. Couldn't do that.

[0005]

In the conventional medium-rotation type rotary head device described above, the amount of protrusion of the outer peripheral surface of the upper drum 3 with respect to the outer peripheral surface of the lower drum 2 is restricted by the travel height position of the magnetic tape. It is set in advance by sandwiching a metal foil 9 between the lower drum 2 and the connecting support member 6 so that the value is assumed to be optimal, and the upper drum 3 and the lower drum 3 are connected via the connecting support device 6. The drum 1 was screwed. Therefore, after the rotating device is mounted on the chassis of the magnetic recording / reproducing device, the optimal control of the traveling height position of the magnetic tape due to the setting of the projection amount of the outer peripheral surface of the upper drum 3 with respect to the outer peripheral surface of the lower drum 2 is performed. If this is not the case, resetting of the amount of protrusion of the outer peripheral surface of the upper drum 3 with respect to the outer peripheral surface of the lower drum 2 must be performed by removing the rotary head device from the chassis of the magnetic recording / reproducing device, which is not easy. .

The present invention has been made to solve such a problem, and the amount of protrusion of the outer peripheral surface of the upper drum with respect to the outer peripheral surface of the lower drum without sandwiching a metal foil between the lower drum and the connecting support member. The purpose is to enable easy setting.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a fixed lower drum having a lead for restricting a running height position of a magnetic tape wound around an outer peripheral surface, and an upper portion of the lower drum. An upper drum, a rotatable middle drum having a head located between the lower drum and the upper drum, a connecting support member for fixing the lower drum and the upper drum, and the connecting support member And a worm having a structure in which the rotation torque is transmitted from one end thereof in the same direction as the rotation axis of the middle drum, and a worm wheel meshing with the worm is provided at one end, and the connection support member and the lower drum A fastening member for fastening and fixing, and an elastic member sandwiched between the connection supporting member and the lower drum,
A rotational torque is applied to the worm to deform the elastic member, thereby setting an amount of protrusion of the outer peripheral surface of the upper drum with respect to the outer peripheral surface of the lower drum.

[0008]

With the above arrangement, the value of the dial gauge changes when the rotary head device is mounted on the chassis of the magnetic recording / reproducing device without sandwiching the metal layer between the lower drum and the connecting support member. While watching, the amount of protrusion of the outer peripheral surface of the upper drum with respect to the outer peripheral surface of the lower drum can be easily set so that the regulation of the traveling height position of the magnetic tape is optimized.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, a rotary head device of a magnetic recording and reproducing apparatus according to the present invention comprises a lower drum 11 and an upper drum.
Rotation torque is applied to the worms 14a and 14b provided substantially parallel to the rotation axis of the middle drum 13 rotatably provided between the lower drum 11 and the worms 14a and 14b. By deforming the member 16, the projecting amount of the outer peripheral surface of the upper drum 12 with respect to the outer peripheral surface of the lower drum 11 can be set. For more information, see Screw 17
The thickness t1 of the connection support member 15 from the end face B at the fixed portion (A portion) of the connection support member 15 and the upper drum 12 by the screw 18 is the fixed portion (C
Thickness t2 of the connection support member 15 from the end face B
Larger than. The worms 14a and 14b are vertically rotatably supported by a worm support 19 of the connecting support member 15 in parallel with each other. A cross groove is formed at the upper end of each of the worms 14a, 14b so that it can be rotated by a driver or the like. The rotation of each of the worms 14a, 14b is transmitted to the worm wheels 20a, 20b that mesh with the worms 14a, 14b. The worm wheels 20a, 20b are integrally provided at the tip of the screw 18, and the rotation of the worm wheels 20a, 20b causes the screw 18 to rotate, so that the connecting support member 15 and the lower drum Tighten 11.
Reference numeral 21 denotes a lead provided on the lower drum 11 for regulating the traveling height position of the magnetic tape 22 wound on the outer peripheral surface, and reference numeral 23 denotes a head provided on the middle drum 13.

In the above configuration, the amount of protrusion of the outer peripheral surface of the upper drum 12 with respect to the outer peripheral surface of the lower drum 11 is set as follows. First, rotate one worm 14a,
When the screw 18 forming one end of the worm wheel 20a engaging with the worm 14a is tightened, the thickness t3 of one elastic member 16 is reduced. At this time, in FIG. 3, the upper drum and the outer drum with respect to the outer peripheral surface of the lower drum 11 at the magnetic tape winding end position (D portion) and the magnetic tape winding intermediate position (E position)
The protrusion amount of the outer peripheral surface of the upper drum 12 becomes larger with respect to the outer peripheral surface of the lower drum 11 at the magnetic tape winding start position (F portion). Warm 14
When a is rotated to loosen a screw 18 at one end, which forms a worm wheel 20a that meshes with the worm 14a, the thickness t3 of one elastic member 16 increases. At this time, FIG.
Thus, the amount of protrusion of the outer peripheral surface of the upper drum 12 with respect to the outer peripheral surface of the lower drum 11 in the portions D and E decreases, and the amount of protrusion of the outer peripheral surface of the upper drum 12 relative to the outer peripheral surface of the lower drum 11 in the portion F increases. In the same manner as above, the other worm 14b
Is rotated, and the screw 18 forming one end of the worm wheel 20b engaging with the worm 14b is tightened.
Upper drum with respect to the outer peripheral surface of the lower drum 11 in section E
The protrusion amount of the outer peripheral surface of the upper drum 12 with respect to the outer peripheral surface of the lower drum 11 at the portion D becomes smaller. By rotating the worm 14b, the worm 14a
Screw forming worm wheel 20a at one end
When the nut 18 is loosened, the amount of protrusion of the outer peripheral surface of the upper drum 12 with respect to the outer peripheral surface of the lower drum 11 in the portions F and E in FIG.
The protrusion amount of the outer peripheral surface of the twelve becomes large. A middle part (G part) of the lower drum 11 and a middle part (H part) of the upper drum 12 in FIG. 2 are applied with a dial gauge or the like, and the protrusion amount of the outer peripheral surface of the upper drum 12 with respect to the outer peripheral surface of the lower drum 11 is measured. By combining the above operations, the amount of protrusion of the outer peripheral surface of the upper drum 12 with respect to the outer peripheral surface of the lower drum 11 can be set.

[0011]

As described above, according to the present invention, it is not necessary to sandwich a metal foil between the lower drum and the connecting support member, but by adjusting the tightening torque of the screw for fixing the connecting support member and the lower drum. In addition, the amount of protrusion of the outer peripheral surface of the upper drum with respect to the outer peripheral surface of the lower drum can be easily set. By rotating the worm in the same direction as the rotation axis of the middle drum, the outer circumference of the upper drum with respect to the outer circumference of the lower drum in a state where the rotary head device is mounted on the chassis of the magnetic recording / reproducing device. The projection amount of the surface can be easily set.

[Brief description of the drawings]

FIG. 1 is a front view of a rotary head device of a magnetic recording and reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a partially cutaway side view of a rotary head device of the magnetic recording / reproducing apparatus.

FIG. 3 is a plan view of a rotary head device of the magnetic recording and reproducing device.

FIG. 4 is an external view of a middle-rotation type rotary head device in a conventional example.

[Explanation of symbols]

 11 Lower drum 12 Upper drum 13 Medium drum 14a Worm 14b Worm 15 Connecting support member 16 Elastic member 17 Screw 18 Screw 19 Warm support portion 20a Worm wheel 20b Worm wheel 21 Lead 22 Magnetic tape 23 Head

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 5/52-5/53 G11B 15/61

Claims (1)

(57) [Claims] 1. A fixed lower drum having a lead for regulating a running height position of a magnetic tape wound on an outer peripheral surface, an upper drum disposed above the lower drum, and a lower drum and an upper drum. A rotatable middle drum having a head disposed in the middle, a connecting support member for fixing the lower drum and the upper drum, and facing the same direction as the rotation axis of the middle drum provided on the connecting support member. A worm having a structure in which rotational torque is transmitted from one end thereof, a worm wheel meshing with the worm at one end, a fastening member for fastening and fixing the connection support member and the lower drum, An elastic member sandwiched between the drums is provided, and a rotational torque is applied to the worm to deform the elastic member, thereby setting an amount of protrusion of the outer peripheral surface of the upper drum with respect to the outer peripheral surface of the lower drum. A rotary head device for a magnetic recording and reproducing apparatus.