JPS6326812A - Head tape interface observing device - Google Patents

Abstract

PURPOSE:To improve the general-purpose application of a rotary drive system and to simplify the constitution by providing two prisms in horizontal and vertical drections reflecting light beams thrice between the upper part of axial center of an upper cylinder and ransparent head adhered to a base. CONSTITUTION:A transparent head 4 is made of an optical glass, a sapphitre, a ruby or a diamond or the like and a reflection preventing film made of MgF2 or the like is provided to a rear end face and sticked to the base 5. The base is provided with a groove for adhesive exclusion adhering the head 4. Light beams are made incident on a transparent head 4 from a stroboscope 15 via a vertical falling lighting microsope 14 and prisms 12, 13, then interference fringes are produced on a face of the head 4 toward the magnetic tape. The image is observed by a TV camera 16 via the prisms 13, 12 and the microscope 14. In this case, since the light beams are reflected while bypassing the axial center in the upper cylinder 12, a video tape recorder is used as a drive system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an observation device for optically measuring and analyzing the state of the head-tape interface in rotating head type magnetic recording of a VTR.

BACKGROUND OF THE INVENTION Recently, optical observation of Hendo tape interfaces has been widely used in fields such as magnetic recording. As an observation device for this head-tape interface, the 1985 IEICE Comprehensive National Conference Preliminary Collection ``Study on Spacing between Magnetic Heads and Tapes in Rotating Drums'' and the December 1985 Television Technical Report [ The configuration described in 8mm VTR Head/Tape Interface J is known.

A conventional video head-tape interface observation device will be described below with reference to FIG.

In FIG. 5, 101 is a lower cylinder fixed to a base 102, and 103 is an upper cylinder, which is connected at its outer peripheral portion to a rotating shaft 104 inserted through the lower cylinder 101, and is rotated together with the rotating shaft 104. 105 is the upper cylinder 10
The transparent head attached to the head 3 contacts the magnetic tape 106, which is formed in the same shape as the magnetic head and runs around the lower cylinder 101 and the upper cylinder 103. 107
108 is a vertical epi-illumination type microscope, which is installed above the center of the upper cylinder 103 and whose optical axis coincides with the axis of the upper cylinder 103; 109 is a stroboscope, and 1) 0 is a television camera.

Next, the operation of the above conventional example will be explained. Upper cylinder 1
The stroboscope 109 emits light in synchronization with the rotation of the stroboscope 03. When the magnetic tape 106 and the transparent head 105 are in contact with each other, when light is incident on the transparent head 105 from the stroboscope 109 via the vertical epi-illumination microscope 108 and the prism 107, the transparent head 105 and the magnetic tape 10
Interference fringes corresponding to the gap 6 are generated at the interface between the transparent head 105 and the magnetic tape 106. The interference fringes are the prism 107
, a television camera 1 via a vertical epi-illumination microscope 108
) entered 0 and observed by a monitor television.

Problems to be Solved by the Invention However, in the conventional configuration as described above, the upper cylinder 10
Since the prism 107 is arranged on the central axis of 3,
This becomes a hindrance, and the upper cylinder 1030 rotation drive system requires a special configuration different from that of commercially available VTR devices, resulting in a problem of lack of versatility.

The present invention solves the above-mentioned problems of the conventional example, and aims to provide a head-tape interface observation device that is capable of observing the head-tape interface using a commercially available VTR device. It is.

Means for solving the problems and technical means of the present invention for solving the above problems include a fixed lower cylinder and a rotating upper cylinder for running the magnetic tape, and a rotating upper cylinder for running the magnetic tape. A transparent head for observation of interference fringes is attached and comes into contact with the magnetic tape, and the light is folded between the upper cylinder's axis above and the transparent head, bypassing the axis in the upper cylinder and folding the light. With the above structure, the present invention uses a light folding system to reflect the image of interference fringes generated at the interface between the transparent head and the magnetic tape, so that the optical axis does not cross the axis in the upper cylinder. can be observed,
Since there is no obstruction to the axis of the upper cylinder, the upper cylinder equipped with a transparent head and light folding system can be easily constructed by converting and supporting a commercially available VTR device in which the rotating shaft passes through the upper cylinder. be able to.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

First, a first embodiment of the present invention will be described.

1 to 3 show a first embodiment of the present invention, FIG. 1 is an overall sectional view, FIG. 2 is a perspective view of a transparent head and a substrate, and FIG. 3 is a DI-]1 of FIG. 2. ) is a sectional view taken in the direction of arrows.

In Fig. 1, 1 is a lower cylinder fixed to a base (not shown), 2 is an upper cylinder, and a hole 2a formed in the central axial direction is fitted into a rotating shaft 3 inserted through the lower cylinder 1. and are held so that they can rotate together. Reference numeral 4 denotes a transparent head for observation of interference fringes. This transparent head 4 is attached to the upper cylinder 2 by a substrate 5, and comes into contact with the magnetic tape 6 that runs around the lower cylinder 1 and the upper cylinder 2. The transparent head 4 is made of optical glass, sapphire, or The curvature and dimensions of the surface in contact with the magnetic tape 6 are formed in the same shape as the magnetic head using either ruby or diamond, and an anti-reflection film made of MgF2 or the like is provided on the rear end surface to prevent light transmission. It is designed to improve efficiency. As shown in FIGS. 2 and 3, the substrate 5 has bifurcated mounting pieces 8 integrally provided on both sides of the base of the support piece 7, and the base side of the transparent head 4 is adhered onto the support piece 7 with adhesive. There is. A groove 9 is formed in the supporting piece 7 along the width direction of the transparent head 4 at the rear end of the transparent head 4, and when the two are bonded, excess adhesive is discharged into the groove 9, and the transparent head 4 is Adhesive is attached to the rear end surface to prevent light from passing through. A mounting hole 10 is formed in the mounting piece 8, and by using this mounting hole IO, the substrate 5 supporting the transparent head 4 can be mounted to the upper cylinder 2 with screws (not shown). 1) is a light folding system, which consists of two prisms 12 and 1 in the horizontal and vertical directions.
It is composed of 3. One horizontal prism 1
One end of the prism 2 is formed vertically, and the other vertical side surface of the prism 13 is adhered to this vertical surface with an optical adhesive (for example, balsam) or optically connected with a certain gap. The prism 13 is inserted into a hole 2b formed on the outer periphery of the upper cylinder 2 parallel to the axis, the prism 12 is placed on the upper cylinder 2, and these prisms 12 and 13 are fixed to the upper cylinder 2 by appropriate means. held in a relationship. The reflective surface 12a at one end of the prism 12 can return the light at a right angle at the axis of the upper cylinder 2, the reflective surface 13a at one end of the prism 13 can return the light at a right angle, and the other end of the prism 13 can return the light at a right angle. The light can be reflected at right angles by the reflective surface 13b. That is, the light can be folded back by detouring the axis within the upper cylinder 2 between the upper part of the axis of the upper cylinder 2 and the transparent head 4. 14 is a vertical epi-illumination type microscope provided above the center of the upper cylinder 2 and whose optical axis coincides with the axis of the upper cylinder 2; 15 is a stroboscope; and 16 is a television camera.

Note that 17 is a magnetic head attached to the upper cylinder 2 by a substrate 18, and the characteristics of the magnetic tape 6 can be obtained by this magnetic head 17. Since this magnetic head 17 is not directly related to the observation device of the present invention, it may be omitted.

Next, the operation of the above embodiment will be explained. Upper cylinder 2
The stroboscope 15 emits light in synchronization with the 0 rotation. When the magnetic tape 6 and the transparent head 4 are in contact with each other, when light is incident on the transparent head 4 from the stroboscope 15 via the vertical epi-illumination microscope 14 and the prisms 12 and 13,
Light is reflected before and after the contact surface between the transparent head t and the magnetic tape 6, and interference fringes are generated on the surface of the transparent head 4 on the magnetic tape 6 side. An image of the interference fringes is formed on a television camera 16 via a prism 13.12 and a vertical epi-illumination microscope 1.1, and can be observed on a single monitor television. At this time, the light is turned back so as to bypass the axis inside the upper cylinder 2, so there is no obstruction to the axis inside the upper cylinder 2, and the upper cylinder 2 with the transparent head 4 and prisms 12 and 13 attached can be made commercially available. It can be used by being attached to the rotating shaft 3 of a VTR device. Further, since the prisms 12 and 13 constituting the light folding system 1) fold the light only three times, there are few reflection points and light loss can be reduced. Therefore, it is possible to know the actual state of contact between the magnetic tape and the head, understand the relationship between tape characteristics (mechanical characteristics such as Young's modulus) and output, and contribute to the improvement of rotary head magnetic recording technology.

Next, a second embodiment of the present invention will be described. FIG. 4 shows a second embodiment of the present invention, and is a side view of a light folding system.

In this embodiment, one horizontal prism 220
Reflective surfaces 22a and 22b are formed at both ends, and a reflective surface 23a is formed at the lower end of the other vertical prism n to optically connect them.Other configurations are the same as in the first embodiment. Note that the light folding system 1) may be constructed of one prism that folds the light three times as in each of the above embodiments.

Effects of the Invention As described above, according to the present invention, a light folding system is provided between the upper part of the axis of the upper cylinder and the transparent hen nozzle to bypass the axis in the upper cylinder and return the light. , there is no interference with the axis in the upper cylinder, a commercially available VTR device can be used as the rotational drive system of the upper cylinder, and the configuration is simple.

[Brief explanation of drawings]

1 to 3 show a head-tape interface observation device according to a first embodiment of the present invention, in which FIG. 1 is an overall sectional view, FIG. 2 is a perspective view of a transparent head and a substrate, and FIG. 3 is a perspective view of a transparent head and a substrate. 2 is a sectional view taken in the direction of arrow 1), FIG. 4 is a side view of the light folding system, and FIG. 5 is a sectional view of a conventional head-tape interface observation device. Yes, 1...Lower cylinder, 2...Upper cylinder, 3...
Rotating shaft, 4... Transparent head, 5... Substrate, 6...
Magnetic tape, 1)・Light folding system, 12.13...
Prism, ]4... Vertical epi-illumination microscope, 15...
・Stroboscope, 16...TV camera. Name of agent Patent attorney Toshio Nakao and 1 other figure 2

Claims (6)

[Claims] (1) A fixed lower cylinder and a rotating upper cylinder for running the magnetic tape, a transparent head for observing interference fringes attached to the upper cylinder and in contact with the magnetic tape, and an axis of the upper cylinder. A head characterized in that it is equipped with a light folding system for folding light around the axis in the upper cylinder between the center above the center and the transparent head.
Tape interface observation device. (2) The transparent head is attached to the upper cylinder by a substrate, the transparent head is adhered to the substrate with adhesive, and the substrate has a groove for discharging the adhesive located at the rear end of the transparent head. A head-tape interface observation device according to claim 1. (3) The head according to claim 1, wherein the light folding system is composed of two prisms in the horizontal and vertical directions, and the light is folded three times between the upper cylinder axis and the transparent head. Tape interface observation device. (4) The head according to claim 1, wherein the light folding system is composed of one prism having a horizontal part and a vertical part, and the light is folded three times between the upper cylinder axis and the transparent head. - Tape interface observation equipment. (5) The transparent head is made of optical glass, sapphire, ruby,
2. The head-tape interface observation device according to claim 1, wherein the head-tape interface observation device is formed of any material selected from diamond into a shape similar to that of a magnetic head. (6) The head-tape interface observation device according to claim 1, wherein the transparent head has an antireflection film on the rear end surface.