SU1402979A1 - Device for automatic readout of indications off the scales of tested instruments - Google Patents

Abstract

The invention relates to a measurement technique and can be used for automatic calibration of measuring instruments. The device contains a movable mirror 2, an optical system 3, an actuator 5 and an opto-electronic converter (OED) 4, including photodiodes and a differential amplifier. When moving the pointer of the instrument to be scanned 1 along the scale, the tracking system of the reading device continuously combines the image of the pointer 1 with the optical center of the OEP 4. Due to the large slope of the characteristic, the combination is performed with very high accuracy. The use of OEP 4 has made it possible to significantly simplify the design of the optical system. 3 il.

Description

figure 1

The invention relates to a measurement technique and can be used for automatic calibration of measuring instruments.

The aim of the invention is to improve read accuracy to simplify the design.

Figure 1 shows the functional (heme of the proposed automatic device in figure 2 - the location of the photodiodes relative to the plane of reading and the zones of their optical sensitivities; figure 3 shows the principle of the optical-electronic converter;

1 The functional diagram shows an overlay device 1, a movable mirror of 2 each, an optical system 3, an optoelectronic converter (OED) 4j

the actuator 5, in this case; the Moving mirror 2 is mechanically connected with the output of the actuator 5 and optically with the adjustable device 1 and the optical system 3, the output of which is connected via an optical 1 electronic converter 4 to the executive mechanism 5; the first

; photodiode (PD1) 6, the second photodiode

(PD2) 7s zone 8 of the optical sensitivity of PD 1, zone 9 of the optical; sensitivity of PD2, plane 10:: reads the image of the pointer 11 of the device I,

1 According to the principle of operation, the optoelectronic converter is differential-I. The schematic diagram (fig. 3) shows the first 6 and second 7 photodiodes and the differential amplifier 12, made on a standard -circuit of type K140UD17A.

The device works as follows.

In the initial state, the mirror 2 (Fig. 1) is installed in such a way that the part of the scale with marks and the indicator of the instrument being turned on, set at the zero point of the scale, are projected with the ASSISTANCE of the movable mirror

2 and the optical system 3 in the plane 10 of reading the opto-electronic converter 4 {FIG. 1). If the image of the pointer 11 (Fig. 2) in the readout plane 10 (Fig. 2) is shifted relative to the optical center of the OEP 4 /, then the output of its error signal forms, which is fed to the actuator 5, Perform the rotary mechanism 5

Thus, when moving the pointer of the instrument being scanned along the scale, the tracking system of the reader continuously aligns the image of the pointer with the optical center of the OEP. Due to the large steepness of the characteristic, the combination is produced with very high accuracy.

The use of differential opto-electronic converters has significantly simplified the design of the optical system, since the devices can practically work at a transmission coefficient of one. In addition, the design is simplified due to the absence of additional nodes in it, the task of which is to increase the accuracy of reference

Thus, the use of a differential OEP in an automatic reading device made it possible to significantly simplify the design, increase the accuracy of reading, and increase the reliability of the device. The greater slope of the system makes it possible to reduce the calibration time of the instrument.

Due to the use of differential EIA, the accuracy of the calculation increased, labor productivity increased. The designs have become safer and cheaper.

Claims (1)

Claim 1 Device for automatic read the readings from the scales of the instruments being scanned, containing a movable mirror mechanically connected with the operating mechanism, as well as having optical connections with the instrument being tested and the optical system, the output of which is connected through an optical-electronic converter, to an actuator different By the fact that, in order to increase the reading accuracy and simplify the design, the optoelectronic converter of the device is made on two photodiodes with intersecting zones of optical sensitivity, which ikul rny to reading plane, wherein the output of the first photodiode is connected to the noninverting input, and the second - to the inverting input di4) differential amplifier, whose output is the output of the optoelectronic transducer. tm /////// t 8ff 0tt2.2 fig.Z