Range finding device

Patent metadata

Field	Value
Publication number	US-10528010-B2
Application number	US-201916395820-A
Country	US
Kind code	B2
Filing date	Apr 26, 2019
Priority date	Mar 19, 2018
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

A time-to-voltage converter (TVC) including a 555 timer integrated circuit (IC), and a charging circuit including a constant current source and a capacitor connected in series. The capacitor can be connected to a discharge pin of the 555 timer IC. The TVC can further include a trigger circuit and a reset circuit to receive a start signal and a stop signal, respectively, from an input line, and accordingly generate a trigger signal or a reset signal to trigger or reset the 555 timer IC. A switch can be configured to, under control of an output signal of the 555 timer IC, connect the input line with the reset circuit. A voltage across the capacitor when the 555 timer IC is reset indicates a time interval corresponding to the start and stop signals.

First claim

What is claimed is:

1. A range finding device, comprising:
a power supply;
a ground;
a light transmitter configured to transmit an optical pulse to a target;
a receiver configured to receive the optical pulse and a reflected pulse corresponding to the transmitted optical pulse, and generate a start signal and a stop signal corresponding to the optical pulse and the reflected pulse, respectively; and
a time-to-voltage converter (TVC) configured to receive the start and stop signals from the receiver at the input line, and generate digital bits indicating a flight time of the optical pulse between transmission of the optical pulse and reception of the reflective pulse, wherein the TVC comprises:
a 555 timer integrated circuit (IC);
a charging circuit including a constant current source and a first capacitor connected in series, the first capacitor being connected to a discharge pin and a threshold pin of the 555 timer IC;
a second capacitor connected to a control pin of the 555 timer IC configured to filter noise between the power supply and the ground;
a trigger circuit including an RC differentiator circuit and configured to,
receive a start signal from an input line, and
generate a trigger signal corresponding to a voltage transition in the start signal to trigger the 555 timer IC;

a reset circuit including an RC differentiator circuit and configured to,
receive a stop signal from the input line via an AND gate, and
generate a reset signal corresponding to the stop signal to reset the 555 timer IC; and

the AND gate with output of the 555 timer IC and the input line as input,
wherein a voltage across the first capacitor indicates a time interval corresponding to the start and stop signals.

2. The range finding device of claim 1 , further comprising:
a display device configured to receive the digital bits indicating the flight time of the optical pulse between transmission of the optical pulse and reception of the reflective pulse, and display a distance corresponding to the flight time of the optical pulse.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Abuelma'Atti Muhammad Taher

Classifications

• H03K4/08 Primary

  having sawtooth shape · CPC title

• H03M1/12

  Analogue/digital converters ({H03M1/001 – } H03M1/10 take precedence) · CPC title

• G04F10/005

  Time-to-digital converters [TDC] (analog-to-digital converters with intermediate conversion to time or phase H03M1/50, H03M1/60) · CPC title

• G04F10/10 Primary

  by measuring electric or magnetic quantities changing in proportion to time · CPC title