JPS5862865A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To elevate a mass-productivity without dropping the working accuracy of a lead, by constituting a shape of a lead in the vicinityof an open hole for embedding a magnetic head for recording and reproducing a control signal of a gentle curve. CONSTITUTION:A lead 3 of the adjacent part of an open hole 6 in which a magnetic head for recording and reproducing a control signal is embedded is formed like a gentle curve 9, and working like the curve 9 is executed by a lead working cutting tool which is profile-guided by a cam. In the section (a)-(e) of the lead 3, a magnetic tape cannot be controlled, but linearity and working accuracy in the section (f)-(g) are elevated, therefore, no bad influence is exerted on stable running of the magnetic tape. Therefore, working of the lead is executed after the open hole 6 is made, without dropping the working accuracy of the lead, and accordingly, its mass-productivity is elevated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing device that improves the lead structure near a hole in which a magnetic head for recording and reproducing control signals is buried.

FIG. 1 shows a side view of a cylinder of a general magnetic recording/reproducing device, and the cylinder is a rotary cylinder 1 when only one video head 4 is shown.

It consists of a fixed cylinder 2 to which a chassis (not shown) is fixed. Reference numeral 3 denotes a lead of a guide stage of a magnetic tape 7 (see FIG. 2) provided on the fixed cylinder 2. A precise control head 5 that controls the running speed and phase of the magnetic tape 70 is connected to a hole 6 provided in the fixed cylinder 2.
Inside Vc is buried. FIG. 2 shows the pattern recorded on the magnetic tape 7 by the video head 4 and the control head 5. The pattern recorded by the control head 5 is (
(b). The maximum track width for recording control signals is about 0.5 square meters or less from the bottom edge of the magnetic tape.

In addition, due to the dimensional and shape constraints of the control head 5,
It is provided at a position to interrupt the six-hole lead 5 provided in the fixed cylinder 2.

The fixed cylinder 2 with the air hole 6 blocking the lead 6 in this way
In manufacturing, there are two methods: one is to drill the holes 6 after forming the leads, and the other is to form the holes 6 and then process the leads. The former requires five steps, including cylinder forging, lead machining, and hole machining, and is disadvantageous in terms of mass production and cost. Furthermore, if the lead processing is performed after drilling the latter hole, it is advantageous in terms of 1L cost, but the lead accuracy deteriorates.

The deterioration of read accuracy will be explained below.

The relationship between the lead machining tool 8 and the fixed cylinder 2 to be machined during lead machining will be explained with reference to FIG. 4, which shows details of the vicinity of the hole in a cross section taken along the line mV-IV in FIG. 6. (The lead machining tool 8 applied to the fixed cylinder 2 is cut by rotating the fixed cylinder 2 at a constant speed in the direction of the arrow (c). However, in this case, as shown in Fig. 4 (b), Since the lead machining tool 8 falls into the hole 6 provided in the rotary cylinder 2, it vibrates during cutting, and the machining accuracy of the K IJ-do 5 deteriorates as shown in Fig. 5. The cutting accuracy is dynamically unstable due to the vibration of the cutting tool 8, which not only seriously affects the machining surface accuracy, but also easily causes wear and damage to the lead processing tool 8.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a magnetic recording/reproducing device that can improve mass productivity without reducing the processing accuracy of cylinder leads.

The magnetic recording and reproducing apparatus of the present invention comprises a rotary cylinder provided with a video head and driven to rotate, and a fixed cylinder fixed to a chassis. A hole is provided in which a control head for recording and reproducing control signals for controlling the tape feed speed and phase of the tape is buried, and a lead is provided, and the shape of the lead near the hole is gently curved. It is formed by

Hereinafter, an embodiment of the magnetic recording/reproducing apparatus of the present invention will be described with reference to FIGS. 6 and 7, where the same parts as those of the conventional apparatus are denoted by the same reference numerals, and the explanation of the same parts will be omitted. FIG. 6 is an explanatory diagram of a curved lead in the vicinity of the hole 6, and FIG. 7 is a front view of the cylinder. The lead 3 near the hole 6 has a gentle curve 9
The curved shape 9 is processed by a cutting tool 8 for lead processing that is guided by a cam. The curved line 9 is indicated by a two-dot chain line, and includes arc α, C, and g sections of a circle with nine radii 1h, Rt, and Rs, and a b section that is a common tangent for each round of radii 1h and Rz.
It is formed by radius Rx' and section d, which is a common tangent for each round of Rs. Note that the f'i hole 6 is omitted in FIG. 6. Further, the nine portions indicated by dotted lines in FIG. 6 are conventional leads.

Although it is no longer possible to regulate the magnetic tape 7 in the leads 5Viα to e sections formed as described above, the direct MA processing accuracy in the 1st section and the V section is improved, and the magnetic tape 70 is stabilized. There are no adverse effects on driving.

In this way, in the magnetic recording/reproducing device of this embodiment, the lead shape in the vicinity of the hole is formed into a gentle curve.
Since the lead processing can be carried out after drilling the holes without reducing lead processing accuracy, mass productivity can be improved.

As described above, the magnetic recording/reproducing apparatus of the present invention has the effect of improving mass productivity without reducing the machining accuracy of cylinder leads.

[Brief explanation of drawings]

@Figure 1 is a front view of the cylinder of a general magnetic recording/reproducing device.
Fig. 2 is a diagram of the magnetic tape pattern in Fig. 1, Fig. 5 is a front view of a conventional cylinder, and Figs. Fig. 5 is an explanatory diagram of machining accuracy deterioration due to the machining state shown in Fig. 4, and No. ≠ is an explanatory diagram of the machining state of the vicinity of the hole in the embodiment of the magnetic recording/reproducing device of the present invention. The explanatory drawing, FIG. 7, is a front view of the cylinder provided with the lead shown in FIG. 6. 1... Rotating cylinder, 2... Fixed cylinder, 5
...Lead, 4...Video head, 5.
...Control head, 6.Blank hole, 7.Magnetic tape, 9.
...Curved. Oh l prisoner o 20 o 3I! ] No. 5 1 Tongue O 6/lR. O 7 prisoners] Low≦(2 2 λ /2 ”5

Claims (1)

[Claims] 1. A cylinder on which a magnetic tape is spirally mounted, consisting of a rotating cylinder equipped with a video head and driven to rotate, and a fixed cylinder fixed to a chassis, and a tape feeding speed and phase of the magnetic tape provided on the fixed cylinder. and a lead provided with a hole in which a control head for recording and reproducing control signals is embedded, wherein the shape of the lead near the hole is formed into a gentle 111 line shape. A magnetic recording/reproducing device characterized by: