OPTICAL CONTOUR DEVICE AND METHOD

• US 3,625,618 A
• Filed: 10/23/1969
• Issued: 12/07/1971
• Est. Priority Date: 10/23/1969
• Status: Expired due to Term

• Current Assignee: Edward Evenden Bickel
• Original Assignee: Edward Evenden Bickel
• Inventors: Bickel, Edward Evenden
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Rothenberg, J.
• Application Number:
  US04/868,815
• Time in Patent Office: 775 Days
• Field of Search: 356/120,164,165,166,167,168,209,210,212,162 350/285
• US Class Current: 356/606
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object
• CPC Class Codes: G03B 15/00 Special procedures for taking photographs; Apparatus therefor

Abstract

A method and apparatus for optically measuring the contour of a surface in a given plane. A plane is generated by a narrow beam of light of low divergence, preferably the beam of light is generated by a laser, and the intersection of such a scan plane with the surface contour establishes points of intersection. Following intersection, the light rays are scattered and optically transferred to a conjugate image plane for observation, recording, comparison or measurement.

Claims

1. The method of obtaining a viewable surface contour of a test object, comprising the steps of emitting a laser beam which is a high-intensity narrow beam of light of low divergence, generating a sectioning plane by converting said narrow beam into a plurality of light rays, impinging said sectioning plane onto the surface contour of said test object to effect points of intersection, positioning light sensitive viewable means including photographic recording means remote from and substantially optically perpendicular to the sectioning plane of light, and receiving intersection light rays, scattered from intersection points of said sectioning plane and said test object, as a contour trace in an image plane in said light-sensitive viewable photographic recording means to obtain a permanent record of said surface contour.

2. The method which includes the steps of claim 1 above, and which further includes impinging said sectioning plane of light and scattering said intersection rays at a plurality of contouring stations along a predetermined length of said contour surface to obtain a corresponding plurality of viewable contour line traces sufficient to obtain a desired contoured profile of the test object.

3. The method which includes the steps of claim 2 above, and which further includes providing a preselected magnification relationship between the sectioning plane and the image plane to obtain a desired scaling of the contour traces of the test object.

4. The method which includes the steps of claim 1 above, and which further includes projecting light through a master line template of the contoured surface of the test object onto the light-sensitive viewable means to form a master template trace thereon, and superimposing said projected master line template trace onto said image plane to ascertain any departures from the contour line trace of the test object.

5. The method which includes the steps of claim 1 above, and which further includes superimposing a calibrated orthogonal grid chart on the light-sensitive viewable means, and measuring the coordinates of the contour trace of the test object on said light-sensitive recording means.

6. An apparatus for scanning and viewing a projected surface contour of a test object, including means to emit a laser beam which is a high-intensity, narrow beam of light of low divergence, means to convert said high-intensity beam of light into a sectioning plane characterized by a plurality of light rays, means to impinge said sectioning plane of light on said contoured surface, a light-sensitive image sensor positioned substantially optically perpendicular to said sectioning plane to receive scattered light rays from the line of intersection of said sectioning plane and said surface contour as a trace on an image plane in said image sensor, a master line template, and means to project a contour trace from said template onto said light-sensitive image sensor to thereby compare the surface contour trace with the template contour trace on said image sensor.

7. An apparatus which includes the features of claim 6 above, and which further includes a calibrated orthogonal grid chart associated with said light sensitive image sensor, said chart permitting evaluation of the surface contour by measurement of the contour trace.

8. An apparatus which includes the features of claim 6 above, and which further includes a relay lens system interposed between the sectioning plane of light and the image sensor, said relay lens system picking up the light from said intersection and transferring said intersection light rays as an intersection to the light-sensitive image sensor.

9. An apparatus which includes the features of claim 8 above, and which further includes means associated with said relay lens system to selectively magnify said intersection image on the light-sensitive image sensor to attain desired scaling of the surface contour.

10. An apparatus which includes the features of claim 6 above, wherein said light-sensitive image sensor is a permanent photographic record.

11. An apparatus which includes the features of claim 6 above, and which further includes a pivotably mounted and vertically adjustable housing positioned relative to said test object, said housing including optical means to selectively expand said laser beam to obtain said sectioning plane, a relay lens system to transfer the scattered light from the line of intersection to the image sensor, a calibrated chart mounted at said image sensor, means to adjustAbly receive said master template trace corresponding to the desired contour surfaces of the test object, and, means to desirably scale the contour trace and the master template trace relative to said calibrated chart to measure any departures of the contour trace from said master template trace.