RU2000761C1 - Phase indicator for blind persons - Google Patents

Abstract

Use, for partial rehabilitation of the visually impaired disabled Summary of the invention: since the leading edge of the difference signal corresponds to the beginning of the measuring signal, and the falling edge is formed by the decay of the reference, time-stable signal, the difference signal is inversely proportional to the time distance to the obstacle. from objects lying in great depths from the nearest, representing a danger, or from objects. having an elongation along the axis of the radiation does not affect the measurement accuracy. The main unit of the device is a phase-to-frequency converter, which includes digital frequency dividers of the reference and measuring signals, a coincidence circuit (AND), a role-playing phase detector, a storage capacitor , a voltage controlled oscillator and a bit key device. 2 silt

Description

The invention relates to medical equipment and is intended for partial rehabilitation of the visually impaired.

A device is known - an ultrasonic locator for the blind, containing a series-connected electro-acoustic transducer, receiver, multivibrator, transmitter, indicator device. In this locator, the time domain scale measurement unit is made up of a trigger connected in series. C-link, threshold circuit and pulse shaper. The trigger input is connected to the output of the receiver, and the output of the threshold circuit is connected to the input of the multivibrator.

As a result of the wide directivity of the radiation, the device has a low resolution and is subject to the strong influence of acoustic noise.

Increased bulkiness creates inconvenience in its application.

The closest in technical essence device for detecting obstacles by the blind is also known, which contains a pulse generator, a current generator, a photoresistor, a power amplifier and an infrared optical emitter, which form the transmitting channel of the device, and a serial chain photodetector - logarithmic amplifier - electroacoustic transducer - receiving the channel. In this case, a peak detector is connected between the output of the logarithmic amplifier and the control inputs of the pulse generator and the current generator.

The photoresistor included in the transmitting channel adjusts the amplitude of the current pulses by changing the power of the optical signals in high light conditions when the sensitivity of the photodetector of the receiving channel is reduced

The main disadvantage of the known device is the practical impossibility of determining the distance to the obstacle by the tonality of acoustic vibrations, since the scattering and reflection of optical signals depends on the characteristics of the reflecting surface of objects.

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Thus, the operation of the device under conditions of a constant change in light contrasts, color, shadows and natural illumination causes a continuous change in the frequency of acoustic vibrations, causing a feeling of tension and comfort in a disabled person. devoid of sight.

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often distorting information about the remoteness of obstacles, about danger.

The technical result is the exclusion of the influence of the properties of the reflecting surface of objects on the accuracy of measurements.

This technical result is achieved in that in a device containing a strobe, generator, current generator, the output of which is connected to a probing infrared emitter. A photodetector, an optical signal conversion amplifier and an acoustic indicator, a carrier frequency generator, a pulse shaper, a local oscillator, a local oscillator, a signal mixer, a reference signal shaper, a phase to frequency converter, a phase shifter, a measuring signal shaper, a photodetector current to frequency converter, as well as a switch to two positions and two directions, and the output of the strobe generator is connected to the input of the pulse shaper, the first controlling m input of the phase-to-frequency converter controlling the input of the carrier frequency generator, controlling the input of the current generator and controlling the input of the local oscillator generator connected to the first output to the local oscillator emitter and the second to the first input of the reference channel signal mixer, the second input of which is connected to the output of the carrier frequency generator and the second input of the current generator, and the output through a serially connected driver of the reference signal is connected to the first signal input of the phase converter a frequency in which the second control input is connected to the output of the pulse shaper, and the output through the closed contact of the first group of switches is connected to an acoustic indicator, the closed contacts of the second group of switches are connected to the photodetector and the input of the amplifier connected to the output through the phase shifter and the measuring signal shaper connected to the second signal input of the phase-to-frequency converter.

In FIG. 1 is a structural diagram of a device; in FIG. 2 time diagrams of the voltages at the output of its main nodes.

The device consists of a gate generator 1. pulse generator 2, a phase-shift converter 3 to the frequency of the carrier frequency generator 4 of the local oscillator generator 5. signal mixer 6, the local oscillator 7, the photo-oscillator 8. current generator 9. probing and radiation 10

phase shifter 11. reference signal shaper 12, amplifier 13, measuring signal shaper 14, acoustic indicator 15. photodetector current transducer at a frequency of 1 b (light to frequency converter), switch 17,

In FIG. 2 there are the following notation:

I- strobe signal;

2- pulse generator output:

3- converted strobe signal:

4- output of the master oscillator:

5 - output of the local oscillator;

6- optical signal:

7- output of the driver of the reference signal:

9- differential phase shift signal;

10- charge of the storage capacitor;

II- output of the phase-to-frequency converter.

The device operates as follows. With the arrival of the signal of the strobe generator 1, the pulse generator generates a short signal along its leading edge, which is fed to the control input of the phase shift to frequency converter 3. The converter capacitor is discharged with this signal. The signal of the strobe generator 1. supplied to the second control input of the converter 3 disables the built-in voltage-controlled oscillator (VCO). There is no generation at the output of the converter. With the arrival of the strobe signal to the carrier frequency generator 4 and the local oscillator 5, a pulse sequence is generated at their outputs, which is supplied to the corresponding inputs of the mixer 6. The output of which is a sequence of signals of the converted (difference) frequency. The oscillator of the local oscillator 7 generates a sequence of optical signals arriving at the input of the photodetector 8. At the same time, the current generator 9 generates a voltage with a gentle front and a fall and a flat peak, whose signal is close in duration to the signal of the strobe generator. Exposure to

Claims (1)

SUMMARY OF THE INVENTION A PHASE INDICATOR for BLINDING, comprising a strobe generator, a current generator, to the output of which a probing infrared optical emitter is connected, a photodetector, an converted optical signal amplifier and an acoustic indicator, characterized in that a carrier oscillator is introduced therein the signal frequency of the carrier frequency generator 4, this voltage is converted to the current pump pulses of the probe emitter 10. The difference signal from the output of mixer 6 passes to the input of the reference signal 12 and then to the signal input of the phase-shift converter to frequency 3 in the form of a sequence of rectangular signals of logical levels. The optical signal reflected from the obstacle is received by the photodetector 8. As a result of the simultaneous action of the reflected signals and the signals of the local oscillator emitter in the selective circuit of the optical signal receiver, a difference measuring signal is supplied to the input of the amplifier 13, and then through the phase shifter 12. the measuring signal shaper 14 passes to the input of the phase-shift converter to frequency 3, having logic levels. The reference and measuring signals are processed by the built-in phase detector (matching circuit I), a difference signal from the output of which the storage capacitor is charged. With the end of the strobe (pulse), the previously blocked generator is switched on, controlled by voltage, and a low-frequency square wave signal is generated at its output, which is proportional to the difference signal and converted by the acoustic indicator into sound vibrations. When working in the passive mode (using natural light), the power from the described nodes is turned off and fed to the photodetector current transducer at frequency 16. The photodetector 8, which is still in photodiode mode, is switched to the input of this converter, and the output of the converter is connected to the input of the acoustic indicator , Switching is carried out using switch 17. (56) UK patent N 1284026. CL. A 61 F9 / 08. 1972. USSR copyright certificate No. 1289484, cl. A 61 F 9/08, 1986. frequencies, a pulse shaper a local oscillator generator, a local oscillator, a signal mixer, a reference signal shaper, a phase-to-frequency converter, a phase shifter, a measuring signal shaper, a photodetector current converter into frequency, and a two-way switch and two positions, besides the output of the generator, it is connected by r, “by the pulse shaper, by controlling the input of the Phase-to-frequency converter, controlling the input of the carrier frequency generator, controlling the input of the eye generator and controlling the input of the local oscillator connected the first output to the local oscillator emitter, and the second to the input of the signal mixer, the second input of which is connected to the output of the carrier frequency generator and the second input of the current generator, and the output through a sequentially connected driver shaper A large signal is connected to the first signal input of the phase shift to frequency converter, the second control 5 8 whose input is connected to the output of the pulse shaper, and the output through the closed contact of the first group of switches is connected to an acoustic indicator, the closed contacts of the second group of switches are connected to the photodetector and the input of the amplifier connected by the output through the phase shifter and the shaper of the measuring signal to the second signal input of the phase converter frequency shift, open contact of the second group of the switch is connected to the input of the current transducer photodetector It is connected to the frequency, and the open contact of its first group is connected to the output of this converter. FIG. 1. Ljl f l i O 4 iJ L G l ./ fit Fig 2.