SU1483257A1 - Light range finder - Google Patents

Abstract

The invention relates to devices for geodetic instrumentation and can be used to measure the distance to an object. The aim of the invention is to increase the sensitivity and accuracy of measurement. The device consists of a radiator 1, a two-junction coordinate-sensitive photodetector 3, a differentiating circuit 5, a synchronous amplifier 6, a detector 7, an interrupter 8, feedback from a master oscillator 10, a registration circuit 9. 3 il.

Description

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The invention relates to geodetic instrumentation devices and can be used to determine the distance to an object.

The purpose of the invention is to increase the sensitivity and accuracy of measurement by increasing the gain of the signal.

FIG. 1 shows the structural scheme of the proposed range finder; FIG. 2 - one of the variants of the block scaler; FIG. 3 - diagrams explaining the operation of the distance meter.

A light range finder consists of a semiconductor emitter 1 (infrared light emitting diode or laser) forming a narrow light beam, a coordinate-sensitive photodetector - scanstor 2, perceiving diffuse reflected radiation projected from object 3, a bias voltage source 4, a differentiating circuit (difcepi) 5, synchronous amplifier 6, detector 7, feedback chopper 8 (integral voltage switch), registration circuit 9 (voltmeter) and master oscillator 10 (generator, chain of frequency dividers and coincidence circuits performed on the logical elements).

The range finder works as follows

The master oscillator 10 generates pulses to start the emitter 1 (and the corresponding control gates for blocks 6–8). The bias voltage source 4 forms a linearly increasing co-ordinate voltage on the dividing bus of the scanner 2. The collector potential is set by the output of the feedback chopper 8. The emitter 1 forms a series of short light pulses. The light spot on the object, formed by the emitter 1, is projected onto the photosensitive area of the scanner 2, aligned with the dividing line. If the projected spot falls on the dividing bus sections with a potential greater than the collector potential, then the photocurrent entering the differential circuit 5 and the synchronous amplifier 6 will have a positive polarity (Fig. 3A). The synchronous amplifier 6 and the detector 7 will be made accordingly The amplification and detection of the signal in this case form a positive voltage at its output (Fig. 36). Feedback breaker 8 shifts this voltage by a time equal to the duration of the light pulse (Fig. Sv) and integrates it. Thus, the reservoir potential will increase until it is comparable with the potential of the illuminated 5

the probe beam of the photosensitive region (Fig. 3g), since in this case the total photocurrent tends to zero. At the same time, the differentiating circuit 5 pre-filters the input signal and differentiates the voltage Ux coming from the feedback chopper. Since the transient process in this voltage is shifted

If the voltage is behind (delayed), then the high-frequency voltage harmonics do not fall into the path of the synchronous amplifier during its active work (in Figs. Za and Fig. Sv). Thus, the gain path will not self-excite at

 any gain because the feedback is broken during active operation of the amplifier.

FIG. 2 shows one of the variants of the concept of a range finder,

0 working as follows. A signal is formed on the resistance R, the differential chain V (V, and 4) is made on the 1HR elements. The synchronous amplifier is made on OY A, and At with the appropriate framing and S11KCH chains. The key K is only open at the time of the luminescence of the radiator. The detector is made on the OY A3 and A4, the storage capacitance Cr and the key Kg, which is closed only during the luminescence time of the radiator. The feedback chopper is provided on the OY A and commanding capacitance C3 and the integrating key chain K3 opening for the luminescence time of the radiator.

Claims (1)

Invention Formula 5 Light rangefinder containing a single junction coordinate-sensitive photodetector, large-scale synchronous amplifier, detector, semiconductor emitter, registration circuit, Q that, in order to increase sensitivity and accuracy by increasing the signal gain, a feedback breaker, a differentiating circuit, a master oscillator, a coordinate-sensitive photodetector are made in it 5 two-junction coordinate-sensitive photodetector, the collector output of which is connected to the input of the differentiating circuit, the input of the registration circuit and the output of the feedback chopper, the output of the differentiating circuit is connected to the input of the synchronous amplifier, the output of the detector is connected to the input of the feedback chopper, which sets the generator with a semiconductor emitter, a synchronous amplifier, a detector and a feedback chopper.