JP3603371B2 - Rotating head drum device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a rotary head drum device suitable for application to a digital VTR or the like that performs high-density recording and reproduction.
[0002]
[Prior art]
The high-density recording of a VTR includes short-wavelength recording and narrowing of the track, and the narrowing of the track is governed by the linearity accuracy of the recording pattern. The main factor that hinders the linearity is the processing accuracy of the lead of the fixed drum (provided on the outer peripheral portion to guide the tape diagonally) with respect to the rotation locus of the head on the rotating drum.
[0003]
Therefore, a method has been adopted in which, after assembling the rotary head drum device, the lead portion is modified based on the rotation axis.
[0004]
However, in a digital VTR, the rotating trajectory of the head slightly changes from a static state to rotate the rotating drum at a high speed. Therefore, there is a limit to the linearity accuracy that can be secured only by mechanical accuracy.
[0005]
Further, a method has been proposed in which the head is mounted on an actuator such as a piezoelectric element, and the absolute height of the rotating head is controlled. However, although the case where the recording pattern is traced at the time of reproduction is realized, maintaining the linearity with high accuracy at the time of recording is not realized.
[0006]
As a method of adjusting the linearity, there is a technique disclosed in Japanese Patent Application Laid-Open No. 2-126458. According to this method, when a pair of heads having different azimuth angles reproduce a signal, linearity is evaluated and adjusted using an azimuth time difference caused by a track shift. This method is characterized in that the linearity measurement accuracy is high, and the linearity is displayed on a display in real time, and the linearity can be evaluated.
[0007]
[Problems to be solved by the invention]
As described above, there is a limit to the linearity accuracy that can be secured only by mechanical accuracy. In addition, the lead portion of the fixed drum is partially worn at the edge of the tape due to the tape running, and the linearity of the recording pattern is deteriorated after long use.
[0008]
SUMMARY OF THE INVENTION The present invention solves the above-described problems, and improves linearity accuracy that could not be achieved only with mechanical accuracy, and extends the life of a rotary head drum device by correcting linearity accuracy that deteriorates due to lead wear. It is an object of the present invention to provide a rotary head drum device that can realize the above.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an adjustment bearing that supports one end of a rotating shaft, a shaft adjustment member that applies side pressure to the adjustment bearing, and a shaft adjustment member interposed between the adjustment bearing and the shaft adjustment member. It is provided with a shaft hanging adjusting means composed of an elastic member.
[0010]
[Action]
While the master tape for linearity adjustment is running and the signal is reproduced by the head, the running post is adjusted so that the tape follows the lead of the fixed drum. If the linearity accuracy cannot be obtained as a result of this adjustment, adjust the axial adjustment member in an arbitrary direction while checking the deviation of the linearity, and search for a position where the linearity accuracy falls within the predetermined accuracy. Fix the shaft adjustment member. With the above operation, it is possible to obtain linearity accuracy that cannot be achieved by ordinary adjustment.
[0011]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a sectional view of a rotary head drum device according to a first embodiment of the present invention, and FIG. 2 is a top view thereof.
[0013]
1 and 2, the rotating drum 22 to which the head 10 is attached is attached to a disk 24 fixed to a rotating shaft 20. The rotating shaft 20 is supported by a ball bearing 26 and a bearing 64 of a fixed drum 60, and a preload is applied to the ball bearing 26 by a preload boss 28.
[0014]
The status part 66 of the motor is attached to the lower end of the fixed drum 60, and the rotor part 68 is attached to the preload boss 28.
[0015]
Leads 62 are formed on the outer periphery of the fixed drum 60, and guide the magnetic tape 80 by being wound diagonally and approximately 180 degrees. The upper fixed drum 70 is fixed above the rotating drum 22 by a connecting block 72. A rotary transformer 74 for transmitting a signal is attached to the disk 24 and the fixed drum 60.
[0016]
The above is the same as that of a generally known rotary head drum device.
In this embodiment, an adjusting bearing 30 is further mounted on the disk 24 concentrically with the rotating shaft 20 at the upper end of the rotating shaft 20. The adjustment bearing 30 includes a rotating part 32, a ball bearing 34, and a fixed part 36. Although not shown, a stopper is provided to prevent the fixed portion 36 from rotating together when the rotation side of the adjustment bearing 30 rotates. On the other hand, the vertical adjustment member 40 is attached to the upper fixed drum 70 by an adjustment screw 38 so as to be adjustable in an arbitrary direction. A ring-shaped elastic member 50 is attached to the outer periphery of the fixed portion 36 of the adjustment bearing 30, and is in contact with the inner periphery of the shaft hanging adjustment member 40. The elastic member 50 is made of a hollow rubber material and has the function of a compression spring.
[0017]
The adjustment bearing 30, the shaft hanging adjustment member 40, and the elastic member 50 constitute shaft hanging adjusting means.
[0018]
One configuration example of the rotary head 10 will be described in detail. In FIG. 3, the recording head 12 includes a recording head 12 attached to a head base 16 and a reproducing head 14 attached to a piezoelectric actuator 18. The recording head 12 is composed of a pair of heads 12A and 12B whose azimuth angles are opposite to each other, and the reproducing head 14 is similarly composed of 14A and 14B, so that recording and reproduction can be performed by two heads at the same time.
[0019]
The above is the configuration of the first embodiment, and the operation will be described below. The master tape for linearity adjustment is run, and while the signal is being reproduced by the recording head 12, the running adjustment, that is, the linearity adjustment is performed. At this time, as described in the background art, it is more convenient to use a linearity adjustment method using an azimuth time difference caused by a track shift.
[0020]
It is the same operation as in the related art that the traveling posts 76 and 78 are adjusted so that the magnetic tape 80 travels along the leads 62 of the fixed drum 60, and further fine adjustment is performed while viewing the display for linearity adjustment.
[0021]
FIG. 4 shows an example of display display. The horizontal axis indicates the position from the 0-degree position on the entrance side to the 180-degree position on the exit side of the tape, and the vertical axis indicates the deviation in linearity.
[0022]
If the predetermined linearity still cannot be obtained by the above adjustment, the following operation is performed.
[0023]
While looking at the display such as "undulation" and "tilt" indicating linearity, fine adjustment is made to the axis adjustment member 40 in an arbitrary direction, and a position where the linearity display falls within a predetermined value is searched. The adjustment screw 38 of 40 is fixed.
[0024]
When the tape is run for a long time, the lead edge of the fixed drum is worn by the tape edge. It is a general tendency that linearity deteriorates. When such a phenomenon occurs, a lateral pressure is applied in a direction parallel to a tangent line at a 30-degree position, that is, in a direction from a position at 120 degrees to a position at 300 degrees, thereby correcting linearity deterioration caused by wear of the lead. You can do it. Therefore, if the linearity is readjusted by the shaft adjusting member 40 every time the periodic inspection is performed, the life of the fixed drum can be extended.
[0025]
As described above, according to the present embodiment, the vertical adjustment means including the adjustment bearing 30, the vertical adjustment member 40, and the elastic member 50 achieves high precision that cannot be realized only by adjusting the traveling posts 76 and 78. Can be obtained. Further, deterioration of linearity due to wear of the lead 62 can be easily adjusted.
[0026]
In addition, as shown in FIG. 5, a plurality of cut-and-raised leaf springs 52 may be provided on the circumference to form the elastic member 50, and the circumferential portion may be used as the axial adjustment member 40. The same purpose as that of the first embodiment can be achieved.
[0027]
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a sectional view of the rotary head drum device of the present embodiment, and FIG. 7 is a top view thereof. This second embodiment is different from the first embodiment in that the elastic member is a coil spring, and the axial suspension adjusting means is formed.
[0028]
6 and 7, a spring hook 42 is provided at one end of the fixing portion 36 of the adjustment bearing 30. On the other hand, the shaft hanging adjustment member 40 is provided with a plurality of spring hooks 44 on the circumference. Since the fixing portion 36 of the adjustment bearing 30 is rotatable, one end of the coil spring 54 is attached to the spring hook 42, and the other end is attached to the spring hook 44 in the direction in which the side pressure is desired to be displaced. This allows fine adjustment of linearity.
[0029]
As described above, according to the present embodiment, as in the first embodiment, high-precision adjusting means including the adjusting bearing 30, the axial adjusting member 40, and the coil spring 54 as an elastic member provides high accuracy. The linearity can be obtained, and the deterioration of the linearity due to the wear of the lead 62 can be easily readjusted.
[0030]
【The invention's effect】
As is clear from the above description, according to the rotary head drum device of the present invention, an adjustment bearing that supports one end of the rotating shaft, a shaft adjustment member that applies a side pressure to the adjustment bearing, an adjustment bearing and the shaft suspension The perpendicularity of the rotation axis can be finely adjusted in any direction by the vertical adjustment means consisting of the elastic member interposed between the adjustment member and the linearity accuracy of the recording pattern, which could not be achieved only by mechanical accuracy. Can be easily realized. In addition, the shaft hanging adjustment means has a simple configuration and has high practical value.
[0031]
Further, it is possible to correct deterioration of linearity accuracy due to wear of the lead of the fixed drum, which is effective for extending the life of the rotary head drum device.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a rotary head drum device according to a first embodiment of the present invention; FIG. 2 is a top view of the rotary head drum device according to the embodiment; FIG. FIG. 4 is a characteristic view showing an example of a display for displaying the linearity of a recording pattern in real time. FIG. 5 is a sectional view of a rotary head drum device according to another embodiment of the present invention. FIG. 7 is a sectional view of a rotary head drum device according to a second embodiment of the invention. FIG. 7 is a top view of the rotary head drum device according to the second embodiment.
Reference Signs List 10 Head 20 Rotary shaft 22 Rotary drum 24 Disk 30 Adjustment bearing 40 Axis adjustment member 50 Elastic member 52 Leaf spring 54 Coil spring 60 Fixed drum 62 Lead 64 Bearing 70 Upper fixed drum 72 Connection block 76, 78 Travel post 80 Tape

Claims (2)

A fixed drum that guides the tape by winding it diagonally,
A rotating drum that attaches a head and rotates around a rotation axis,
A rotary head drum device comprising a bearing for supporting the rotary drum,
A first spring hook is provided at one end of the rotatable fixing portion, and an adjustment bearing for supporting one end of the rotating shaft;
A plurality of second spring hooks are provided, and an axial adjustment member for applying a side pressure to the adjustment bearing;
Yes other end one end attached to over the first spring and a shaft vertical adjustment means comprising a resilient member attached to any one of direction of the plurality of second Banekake which you wish to apply lateral pressure And
It said plurality of second Banekake the rotary head drum apparatus that provided on the circumference of the shaft vertical adjustment member. The rotary head drum device according to claim 1, wherein the elastic member comprises a coil spring .

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