SU1446472A1 - Apparatus for measuring small gaps between two surfaces of which one in translucent - Google Patents

Abstract

This invention relates to instrumentation technology. The purpose of the invention is to enhance operational capabilities by providing a dynamic measurement of small gaps with relative movement of surfaces. An interferometer formed by light source 1, aperture diaphragm 2, a beam splitter 3, surfaces 4 and 5 controlled by it, and a line of photodetectors 6 measure the position of surface 5 relative to a rotating transparent surface (disk) 4, which simulates the rotation of a magnetic disk. The linear displacement sensor controls the electronic switch 9 so that the input of the multichannel registration unit 10 receives signals from the photodetectors of the ruler 6, which record the interfering rays from certain points of the surface 5. The multichannel registration unit 10 records the vibration parameters of the surface 5. 1 slug.

Description

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The invention relates to instrumentation technology and can be used to measure the gap between a magnetic disk and a magnetic head.

The purpose of the invention is to expand the operational capabilities by providing a dynamic measurement of small gaps with the relative movement of two surfaces.

The drawing shows the block diagram of the device.

The device contains an optically coupled light source 1 and a slit diaphragm 2, a beam splitter 3 dividing the luminous flux into the reference and working light beams. A beam splitter 3 with a controlled surface 4 (for example, with a magnetic head and a disk) and a transparent surface forms an interferometer. The device (Also contains a photoelectric sensor, made in the form of a line of 6 photodetectors, a linear displacement sensor 7 connected in series, a converter 8 analogue-code and an electronic switch 9, a multichannel recording unit 10, the inputs of which are connected to the corresponding outputs of the electronic switch 9, whose inputs are connected to each of the photodetectors of the ruler 6, installed along the reference light beam. The slit aperture 2 is designed to form a light mark on the transparent surface 4 (e.g. disk) along the direction of movement of surface 5 (e.g. magnetic head).

The device works as follows.

When the transparent surface 4 rotates at a certain speed, due to aerodynamic forces arising, the spring-loaded surface 5 moves relative to the transparent surface 4. When the surface 5 radially moves, additional changes in the gap occur due to its oscillations relative to the axis of suspension. The luminous flux emitted by the light source 1 with the wavelength D through the slit aperture 2 is directed into the measured gap between the surfaces in the form of a light line oriented in the radial direction of the transparent disk 4, through which the surface 5 moves.

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The interfering beams of these two surfaces are guided by the beam splitter 3 to the line 6 of photodetectors (the number of photodetectors is determined by the radius of the disk). The signals from the photodetectors through the electronic switch 7 are sent to the multichannel registration unit 10, the movement of the surface 5 is detected by a linear displacement sensor, which produces an analog signal, which through the converter 8 analogue-code controls the electronic switch 9. In the initial position of the surface 5 the electronic switch 9 provides for the inclusion of, for example, three photodetectors. The first photodetector registers the interference pattern from the first beam, the second photodetector from the second and the third photodetector from the third beam. As a result, at their outputs, we obtain 3 instantaneous values of the gap between the surfaces. When the surface 5 is moved one step, at the output of the linear displacement sensor 7, we obtain a voltage change, while the electronic switch 9 ensures that the first, and the second, third and fourth photo detectors are turned off. At the input of the multichannel registration unit 10, we again have three gap values.

With consistent surface movement, there is a continuous change in the instantaneous values of the gaps. By changing this ratio, the surface 5 is judged upon its radial movement relative to the rotating transparent surface 4. To automatically interpret the instantaneous change in the ratio of three signals, the multichannel registration unit 10 can be performed in a computer input, which performs signal processing according to the appropriate algorithm and em registration measurement result.

The proposed device can be used in computing to register instantaneous values of the gap during the radial movement of the magnetic head relative to the rotating disk.

Claims (1)

Invention Formula Device for measuring small gaps between left surfaces U46472 one of which is transparent, containing the relative movement of a two optically coupled source of light surfaces, is a series connection and a beam splitter designed with a linear transmission sensor for dividing the luminous flux of the nanometer, an analog converter is the reference code and working light beams, and an electronic A switch, a photoelectric sensor unit, and a registration unit are made multi-cubic, and a different photoelectric sensor is made in order to expand installation possibilities by dynamic measurement of the noise measured during the reference light beam – liver, the output of each of the photoelectric array during relative displacement of the receiver is connected to the corresponding two surfaces, it is equipped with a device-input of the electronic switch assigned in the course of the light flux of which is connected with a corresponding slit diaphragm, intended by 5 inlets of the multichannel block, to form a light mark of registration, a transparent surface for example avle