Real time distance sensor

• US 5,015,868 A
• Filed: 11/29/1988
• Issued: 05/14/1991
• Est. Priority Date: 11/30/1987
• Status: Expired due to Fees

• Current Assignee: Goldstar Co., Ltd. (LG Corporation)
• Original Assignee: Goldstar Jewellery LLC
• Inventors: Park, Hong C.
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): Shami, Khaled
• Application Number:
  US07/277,268
• Time in Patent Office: 896 Days
• Field of Search: 250/201, 250/204, 250/561, 356/1, 356/4
• US Class Current: 250/559.08
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48

Abstract

A real time distance sensor for measuring distance by calculating the position of image of reflected laser beams with an extremely high-speed, includes a detection module containing a light receiving lens, an infrared ray filter, a CCD sensor, a lens system, and a laser; and a processing module containing a comparator, a differentiator, a pulse shaping circuit, a T flip-flop, a counter, a latch circuit, a ROM for calculation of distance, and power control and a D/A converter wherein the lens system contains cylindrical form for maintaining the intensity of laser beams with the travel of the beams.

Claims

1. A real time distance sensor, comprising:

laser means for producing a laser beam to be reflected off an object;

lens means for directing said laser beam onto said object;

CCD sensor means for detecting the reflected laser beam and for generating scanned signals according to a position of an image formed by the reflected laser beam;

pulse shaping means, operatively connected to said CCD sensor means, for producing digital pulse signals when said scanned signals are above a predetermined threshold level;

synchronous signals generating means for generating synchronous signals;

flip-flop means, operatively connected to said pulse shaping means and said synchronous signals generating means, for comparing said digital pulse signals with said synchronous signals and for generating a pulse signal representing the comparison;

counter means for producing count data representing a measuring of a time interval between pulses in said synchronous signals;

latch means, responsive to said pulse signal, for latching said count data; and

calculating means, responsive to the latched count, for calculating a distance of said object from the real time distance sensor.

2. The real time distance sensor as claimed in claim 1, wherein said lens means interacts with said laser beam to produce a laser beam having individual rays which form a fan shape, said individual rays forming ribs of said fan shape.

3. The real time distance sensor as claimed in claim 1, wherein said CCD sensor means comprises:

a receiving lens having an infra-red filter to receive the reflected laser beam, the reflected laser beam having a power level proportional to said distance cubed.

4. The real time distance sensor as claimed in claim 1, further comprising:

driving means, operatively connected to said laser means, for driving said laser beam at a certain power level in accordance with the calculated distance.

5. The real time distance sensor as claimed in claim 1, wherein said calculating means is a ROM.

6. The real time distance sensor as claimed in claim 1, wherein said pulse shaping means comprises:

comparing means for comparing said scanned signal to said predetermined threshold level and for producing a comparison signal;

differentiating means, operatively connected to said comparing means, for differentiating said comparison signal to produce a differentiated signal;

diode means, operatively connected to said differentiating means, for blocking negative pulses in said differentiated signal; and

means, operatively connected to said diode means, for converting a signal from said diode means into said digital pulse signal.

7. The real time distance sensor as claimed in claim 1, further comprising:

gate means, operatively connected to said pulse shaping means and said flip-flop means, for selectively transmitting said digital pulse signal to said flip-flop means in accordance with said pulse signal.

8. The real time distance sensor as claimed in claim 1, wherein said synchronous signals generating means comprises:

oscillating means for generating a signal having a predetermined frequency; and

pulse generating means, operatively connected to said oscillating means, for generating said synchronous signals in accordance to said signal;

said counter means utilizing said frequency of said signal to produce said count data.