JPH0414659A - Rotary head assembly - Google Patents

Abstract

PURPOSE:To realize a device with high accuracy by selecting a rotary cylinder and a stator cylinder to be a prescribed shape so as to improve the linearity and the stability of a magnetic tape recording pattern. CONSTITUTION:The diameter of a stator cylinder 1 is set to be smaller than the diameter of a rotary cylinder 2, and the shape of the outer periphery of the stator cylinder 1 is formed noncircular so that the difference d1 of the diameter of the stator cylinder 1 and the diameter of the rotor cylinder 2 is maximum in the middle part at which a magnetic tape 4 is wound and a difference d2 between them gets smaller toward both winding ends, and the rotary cylinder 2 is formed tapered to have a smaller diameter opposite to the stator cylinder 1 and to have a larger diameter facing the other side. A force pressing a running magnetic tape onto a read position acts on a cylinder making recording and reproduction, the method is immune to the floating of the tape midposition, the tilt angle of a tape guide roller is kept to the ideal state, and no adverse influence is given onto the running of the tape at the outside of the tape guiding roller.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to video tapes and tapes that perform high-precision magnetic recording.
The present invention relates to a rotary head assembly that can be used in recorders (VTRs), digital audio tape recorders (DATs), and the like.

[Conventional technology]

4th Ga, b is a top view and a BB sectional view showing a conventional rotary head assembly of this type.

In FIG. 4, 1 is a fixed cylinder, 2 is a rotating cylinder mounted coaxially with this fixed cylinder l, 3 is a recording/reproducing head supported by this rotating cylinder 2, and d
I represents the difference in cylinder diameter at the center of the magnetic tape winding, and 6m represents the difference in cylinder diameter at both ends of the magnetic tape winding. Here, the outer peripheries of the fixed cylinder 1 and the rotary cylinder 2 are both circular and they are installed on the same axis, so the cylinder diameter difference d+ at the center of the magnetic tape winding is equal to the cylinder diameter difference crest at both ends of the magnetic tape winding. .

Next, FIG. 6 shows the running state of a magnetic tape on a conventional rotary head assembly. In FIG. 6, 4 is a magnetic tape, and 6 is a fixed cylinder for linearly supporting the magnetic tape 4. 7 is the magnetic tape 4.
A rotatable tape guide roller 8 for guiding the magnetic tape 4 is a tape guide 7 flange that provides vertical regulation for guiding the magnetic tape 4 .

Further, e is l1llll'! generated between the magnetic tape 4 and the lead 6 when the magnetic tape 4 is running. It stands for Jj and is called floating in the magnetic tape.

Note that FIG. 6 shows the recording trunk shift when recording is performed using a conventional rotary head assembly, and FIG. 7 shows a state in which a magnetic tape is wound around the conventional rotary head assembly.

As above & :! l! The operation of the rotary head assembly thus constructed will be explained. The magnetic tape 4 and the rotating cylinder 2 run and rotate in the directions of the arrows in FIG. 7, respectively. At this time, in order to improve recording and playback accuracy, conventionally the tape guide roller 7 was tilted to one side (toward the front in the figure), the height of the tape guide 7 lunge 8 was adjusted, or the rotating cylinder was By pressing the magnetic tape 4 against the lead 6 by making the diameter of the cylinder larger than that of the fixed cylinder, the linearity of the magnetic tape recording 7-inch turn can be improved.
Stability was sought. [Problems to be solved by the invention] However, in the method of tilting the tape guide roller to one side, the point of action is outside the recording/playback cylinder, so it is susceptible to floating in the tape. Furthermore, there are disadvantages such as the tape running direction regulating force caused by changes in the tape guide roller's inclination angle, which tends to adversely affect the tape running outside the tape guide roller. There were problems such as the tape bending in the width direction and the edges of the cylinder damaging the magnetic tape. This invention was made to improve the above-mentioned conventional drawbacks, and it has improved linearity and stability. [Means for solving the problem] A rotary head assembly according to the present invention supports a recording/reproducing head. A device that has a rotating cylinder and a fixed cylinder that rotatably supports the rotating cylinder and guides the running of the magnetic tape, in which the diameter of the rotating cylinder is larger than the diameter of the fixed cylinder, and the rotating cylinder is fixed to the rotating cylinder. The outer periphery of the fixed cylinder is formed into a non-circular shape so that the diameter difference between the cylinders is maximum at the center of the magnetic tape winding part on the rotating head assembly and decreases toward both winding ends, and the rotating cylinder is fixed. It is formed into a tapered shape with a small diameter on the side facing the cylinder and a large diameter on the opposite side.

[Effect]

Since the rotating head assembly of this invention has its point of action in the recording/reproducing cylinder, it is resistant to tape floating, and the tape guide roller can be maintained at an ideal angle of inclination, allowing the tape to run outside the tape guide roller. [Embodiment] Figures 1a and b are top views and cross-sectional views of the rotary head assembly according to the present invention, and Figure 2 shows the magnetic field on the rotary head assembly. FIG. 8 shows the recording trunk shift when recording with this rotary head assembly.

That is, the diameter of the fixed cylinder 1 is set smaller than the diameter of the rotating cylinder 2, and the diameter difference d1 between the fixed cylinder 1 and the rotating cylinder 2 is set at the center of the part where the magnetic tape 4 is wound.
becomes the maximum, and the diameter difference d increases as you move toward both ends of the winding.
The outer periphery of the fixed cylinder 1 is formed into a non-circular shape so that a is small, and the rotary cylinder is formed into a tapered shape with a small diameter on the side facing the fixed cylinder and a large diameter on the opposite side. In the rotating head assembly configured as described above, the force that presses the running magnetic tape against the leads is equal to the recording/recording force.
Since it acts on the cylinder part that performs playback, it is resistant to floating in the tape, and since the inclination angle of the tape card roller can be maintained in an ideal state, it does not adversely affect the running of the tape outside the tape guide roller.

Particularly, by forming the rotating cylinder into the above-mentioned tapered shape, as shown by arrow 0 in FIG. 2, the force for pressing the running tape becomes stronger at the entrance of the cylinder tape, so that it is effectively suppressed when the tape enters the cylinder. In addition, by making the fixed cylinder into a non-circular shape as described above, as shown by the arrow in Fig. 2, the running tape pressing force increases as it moves toward the center of the cylinder tape winding. It can be pressed without bouncing back.

Therefore, the magnetic tape runs linearly along the lead,
As shown in FIG. 8, there is no recording trunk shift. [Effects of the Invention] As described above, according to the present invention, the linearity and stability of the magnetic tape recording pattern are improved, and the highly accurate magnetic tape recording and reproducing apparatus can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows a rotary head assembly according to an embodiment of the present invention, & is a top view, bGz is a sectional view thereof, and FIG. 2 is a magnetic tape running state on the rotary head assembly according to the present invention. FIG. 8 shows the recording trunk shift when recording with the rotary head assembly according to the present invention. FIG. 4 shows a conventional rotary head assembly, in which a is a top view and b is a B-BWI side view, and FIG. 5 shows a magnetic tape running state on the conventional rotary head assembly.
FIG. 6 shows recording trunk displacement when recording is performed with a conventional rotary head assembly, and FIG. 7 shows a state in which a magnetic tape is wound around the conventional rotary head assembly. In the figure, 1 is a fixed cylinder, 2 is a rotating cylinder, 3 is a recording/reproducing head, and 4 is a magnetic tape. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] In a rotary head assembly for a magnetic recording/reproducing device, which has a rotating cylinder that supports a recording/reproducing head, and a fixed cylinder that rotatably supports the rotating cylinder and controls the running of a magnetic tape, the diameter of the rotating cylinder is The diameter is set to be larger than the diameter of the fixed cylinder, and the difference in diameter between the rotary cylinder and the fixed cylinder is maximum at the center of the part where the magnetic tape is wound, and becomes smaller toward both ends of the winding. A rotating head assembly characterized in that the fixed cylinder has a non-circular outer periphery, and the rotating cylinder has a tapered shape with a small diameter on the side facing the fixed cylinder and a large diameter on the opposite side. .