JPS60106019A - Rotary head device - Google Patents

Abstract

PURPOSE:To decrease the cylinder diameter of a rotary head device while maintaining the interchangeability with a conventional device, by selecting the specific value for the tape winding angle to the cylinder, the number of heads which are put on a rotor such as a rotary cylinder, a rotary disk, etc. and the angle set between double azimuth heads respectively. CONSTITUTION:The shown equation are satisfied, where the winding angle of a magnetic tape 12 is set at theta to a cylinder 5, the number of double azimuth heads which are put on a rotor is set at Hn, the angle between said azimuth heads is set at DELTA and (n) is defined as a natural number respectively. The cyrinder 5 of a diameter L holds three pairs of double azimuth heads with a distance of 120 deg. in terms of the angle at the circumference, that is, heads 6 and 7, 8 and 9, and 10 and 11. The diameter of the cylinder 5 can be reduced down to 3/4 compared with a conventional one without changing the conventional recording system since the winding angle of the tape 12 is set at 240 deg. to the cylinder 5. Therefore the miniaturization is attained for a rotary magnetic head while maintaining the interchangeability with a VTR using a conventional large cylinder.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a rotating head recording type video tape recorder (hereinafter referred to as VTR), and in particular, to a rotating head recording type video tape recorder (hereinafter referred to as VTR). The present invention relates to a rotary head device comprising a magnetic head.

[Technical background of the invention and its problems]

Conventionally, a rotary head device used in a two-head rotary cylinder type VTR is a rotary head device having a diameter of l and has heads l and head 2 mounted at a circumferential angle of 180 degrees as shown in Figure 1. /da1. Magnetic chips f4 are wound around the circumferential surface of the cylinder 3 at a predetermined angle at an angle of 180 degrees, and as the magnetic tape 4 moves, the cylinder (
Video signals are recorded and reproduced by rotating the rotary cylinder 3 and alternately helically scanning the magnetic tape 4 with the heads 1 and 2.

When downsizing a rotary head recording type VTR while maintaining a certain recording method, the size of the reel around which the magnetic tape is wound and the cassette case that stores the magnetic tape and reel must be adjusted. the size of,
Furthermore, the size of the cylinder diameter has become a bottleneck, making it difficult to downsize.

In recent years, VTRs have been developed in which the cassette case is made smaller without changing the cylinder diameter. However, there is a limit to the miniaturization of VTRs unless the cylinders are made smaller. Therefore, an important issue when downsizing VTRs is to downsize the cylinder while maintaining a certain recording method, that is, while maintaining compatibility with VTRs that have the original large cylinder diameter. There is.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above drawbacks, an object of the present invention is to provide a rotary head device with a smaller cylinder diameter while maintaining compatibility with conventional devices.

[Summary of the invention]

The present invention has a plurality of magnetic heads mounted at a predetermined angle on the outer periphery of a rotating body such as a rotating cylinder or a rotating disk, and a magnetic case wound around the circumferential surface of the cylinder at a predetermined angle is moved while In a rotary head device of a video tape recorder that records and reproduces signals, the winding angle of the magnetic tape with respect to the cylinder is θ, the number of double athomus heads mounted on the rotary body such as the rotary cylinder or rotary disk is Hn, and 2. The angle between the heavy azimuth heads is △ and n
By determining the diameter of the cylinder so as to satisfy the following relationships, where θ=120Σ(1+-) n=1 2'' Hn=6X2n-1 Hn Δ=360/-, when is a natural number, This aims to achieve the above objectives.

[Embodiments of the invention]

An embodiment of the rotary head device of the present invention will be described below with reference to the drawings. Before going into the description of the embodiment, we will explain the conditions for reducing the cylinder diameter while maintaining the prescribed recording method, that is, while maintaining compatibility with VTRs that use conventional large cylinders. I'll keep it. The conditions are expressed by the following three equations, where θ is the case winding angle with respect to the cylinder, Hn is the number of heads mounted on the rotating cylinder, and Δ is the double azimuth head (twin head) opening angle.

θ=120Σ(1+-) ・・・・・・・・・(1)
n = 1 2n-1 Hn = 6 * 2n' = (2) Δ = 360/- (3) However, n is a natural number.

When the various values are determined to satisfy the above three equations, the cylinder diameter has the following relationship, where L is the conventional two-head system and that of the 111 system.

FIG. 2 is a diagram showing an embodiment of the rotary head device of the present invention. In this example, n=1 in the above conditional expression, θ=240K, Hn=6, and Δ=120 degrees. The cylinder 5, which has a diameter of L, is equipped with a 3 m double azimuth head located at a distance of 120 degrees at a circumferential angle, that is,
It is equipped with heads 6.7, heads 8 and 9, and heads t, o, and ii.

Note that the head 6.8.10 and the head 7.9.11 each have the same azimuth angle. Furthermore, a double azomass head is one in which two heads with different gap anomalous angles are placed close to each other at a predetermined distance.The two heads may be placed on the same base, or the two heads may be joined together. You can also get it. The magnetic cases 12 are wound around the circumferential surface of the cylinder 5 at a predetermined angle at an angle of 240 degrees, and as the magnetic case 12 moves in the direction of the arrow in the figure, the cylinder (rotating cylinder) 5 rotates. By sequentially switching each head as shown below while rotating in the direction of the arrow in the figure, each head performs helical scanning over the magnetic case 4 to record and reproduce video signals. The switching order of each head during recording is head 6→
Head 11→Head 8→Head 7→Head 1o→Head 9→Head 6... Also, during playback, the order is switched in the same manner.

To perform special playback using the rotary head device of this embodiment, for example, to perform slow forwarding of the tape by driving the tape by noggles, or to pause the screen, the same azimuth head can be used as shown below. This can be done by sequentially switching as shown in FIG. That is, head 6 → head 10 → head 8 →
By switching in the order of head 6, etc., or head 7, head 11, head 9, head 7, etc., the above-mentioned special reproduction can be carried out smoothly.

According to this embodiment, since the winding angle of the magnetic tape 12 with respect to the cylinder 5 is 240 degrees, the diameter of the cylinder 5 is compared to that of the conventional one according to equation (4) without changing the conventional recording method. /4 in size. Therefore, by using the rotary head device of this embodiment, it is possible to easily downsize the device while maintaining compatibility with a conventional VTR using a large cylinder.

FIG. 3 is a diagram showing another embodiment of the rotary head device of the present invention. This example is shown in (1), (2), (
This shows the case where n = 2 in equation 3), the tenor winding angle θ - 300 degrees, the number of heads mounted on the cylinder Hn 2 12, and the angle between double azimuth heads △ = 60 degrees. . That is, the cylinder 13 has a circumferential angle of 60
Head 14°15 and head 16.17 at 1g apart
and head 18.19 and head 20.21 and head 22.
23 and heads 24 and 25 are arranged. In addition, head 14.16.

18.20.22.24 and head 15,17°19.2
1, 23, and 25 have the same anomalous angle, and the operation is the same as in the previous embodiment.

In this embodiment, the winding angle of the magnetic chip f2G with respect to the cylinder 13 is 300 degrees. Therefore, the diameter of the cylinder 13 is 31 degrees compared to the conventional recording method without changing the conventional recording method.
5, and has the same effect as the previous embodiment.

It goes without saying that the diameter of the cylinder can be similarly reduced for n==3 and later. Further, in each of the above-mentioned embodiments, a double azimuth head is mounted on a rotating cylinder, but the present application is not limited to this, and a double anomalous head is mounted on a rotating disk located between an upper and lower stationary cylinder. Needless to say, the present invention can also be applied to a rotary head device equipped with a rotary head device.

〔Effect of the invention〕

As described above, according to the rotating head device of the present invention, in order to maintain compatibility with conventional VTRs using large cylinders, the tape winding angle with respect to the cylinder, the rotating body such as the rotating cylinder or the rotating disk, etc. By selecting specific values for the number of heads to be mounted and the angle between the double anomalous heads9, it is possible to reduce the cylinder diameter while maintaining compatibility with conventional devices.

[Brief explanation of drawings]

Figure 1 shows an example of a conventional rotating head device, Figure 2 shows an example of a conventional rotating head device.
The figure shows one embodiment of the rotary head device of the present invention, and FIG. 3 is a diagram showing another embodiment of the rotary head device of the present invention. 5...Cylinder, 6 to 11...Head. Representative Patent Attorney Noriyuki Chika (1 person) Figure 1 Figure 2

Claims (1)

[Scope of Claims] A plurality of double 7-magnetic heads are mounted at a predetermined angle on the outer periphery of a rotating body, and the plurality of double 7-nomas magnetic heads are wound around a cylinder surface at a predetermined angle to move the magnetic head at a predetermined angle. In a rotary head device of a video tape recorder that records and reproduces video signals using a double azimuth magnetic head, the winding angle of the magnetic tape with respect to the cylinder is θ, and the number of 2M anomalous heads mounted on the rotating body is Hnl. Between the double azimuth heads When the angle is Δ and n is a natural number, the diameter of the cylinder is determined to satisfy the following relationships: θ=120Σ(1+-) n==1 2n I Hn=6X2n' Δ=360/- Features a rotating head device.