Optical scanner

• US 4,042,823 A
• Filed: 03/17/1976
• Issued: 08/16/1977
• Est. Priority Date: 03/17/1976
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Decker, Louise A., Langford, Gary O.
• Primary Examiner(s): Nelms, David C.
• Application Number:
  US05/667,806
• Time in Patent Office: 517 Days
• Field of Search: 350/6, 350/96 R, 350/96 B, 350/96 GN, 250/216, 250/227
• US Class Current: 250/227.26
• CPC Class Codes: G02B 2006/0098 for scanning
• CPC Class Codes: G02B 23/2476 Non-optical details, e.g. housings, mountings, supports
• CPC Class Codes: G02B 26/103 having movable or deformable optical fibres, light guides or waveguides as scanning elements light guides per se G02B6/00

Abstract

An optical scanner to inspect the surface of an object. A laser beam sourcemits a beam which is reduced in cross section, for mode matching, and caused to rotate by a series of lenses. A collimating lens focuses the rotating beam into a fiber optic cable. The beam, upon emergence from the cable, is reflected to the surface to be scanned by a reflecting cone. A detector, coupled to sensing devices, receives and interprets the surface reflections. The head portion of the cable is mounted in a crawler having a bellows at its mid-portion which enables the device to travel in a curved path, if necessary.

Claims

1. A scanner which comprises:

a. a laser beam source;

b. a relay lens to adjust the diameter of a beam emergent from said source to a predetermined dimension;

c. an inclined plate of transparent material, said plate located in the path of said beam to cause an emerging beam to be shifted a predetermined amount in a direction parallel to said beam;

d. rotation means to cause said plate to rotate about the point at which said beam impinges upon said plate;

e. optical transfer means located beyond said inclined plate to intercept and transmit said emerging beam; and

f. a reflecting cone located beyond said optical transfer means to deflect a beam emerging from said optical transfer means to the surrounding environment.

2. A scanner as described in claim 1 wherein said optical transfer means comprises:

a. a first mode matching lens to intercept said emerging beam and redirect it to the focal point of said mode matching lens;

b. an optic cable having the center of one end cross section located at the focus of said mode matching lens; and

c. a second mode matching lens having its focal point at the center of the other end cross section of said optic cable.

3. A scanner as described in claim 2 wherein said scanner additionally comprises a detector proximate to said reflecting cone to receive the reflection of said rotating emergent beam from said surrounding environment.

4. A scanner as described in claim 3 wherein said scanner additionally comprises a mechanical crawler attached to said detector, said second mode matching lens and said reflecting cone to advance said scanner.

5. A scanner as described in claim 4 wherein said optic cable is composed of Sel-foc material.

6. A scanner as described in claim 5 wherein said scanner additionally comprises:

a. said crawler having a rear cap and a head cap;

b. said rear cap having a hole therein of larger cross section than said optic cable and through which said cable passes;

c. said detector attached to said head cap;

d. said second mode matching lens mounted in said head cap;

e. a bellows mounted between said rear cap and said head cap enclosing a portion of said optic cable therein.

7. A scanner as described in claim 6 wherein said scanner also comprises:

a. a rear inner tube surrounding said rear cap;

b. a head inner tube surrounding said head cap;

c. a first air tube joined at one end to said rear inner tube;

d. a second air tube joined at one end to said head inner tube;

e. a third air tube joined at one end to said bellows; and

f. a logic valving and air pressure control device connected to the other end of said first, second and third air tubes to vary the air pressure within said rear head inner tubes and said bellows so that said crawler may advance at a predetermined rate.

8. A scanner as described in claim 7 wherein said detector is of the Schottky Barrier Silicon Photodiode type.