Non-contact digital contour generator

• US 4,089,608 A
• Filed: 10/21/1976
• Issued: 05/16/1978
• Est. Priority Date: 10/21/1976
• Status: Expired due to Term

• Current Assignee: Howard W. Hoadley
• Original Assignee: Howard W. Hoadley
• Inventors: Hoadley, Howard W.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Rosenberger, R. A.
• Application Number:
  US05/734,600
• Time in Patent Office: 572 Days
• Field of Search: 356/156, 356/167, 356/1, 356/2, 358/101, 358/106, 358/107
• US Class Current: 356/601
• CPC Class Codes: G01B 11/005 coordinate measuring machines
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object

Abstract

A non-contact digital contour generator is provided for generating the X, Y and Z coordinates of the complex contoured surface of a three-dimensional model. The generator includes an illuminator digitally movable along the Z axis for providing contour lines about the model at successive levels or planes thereof. A camera having its optical axis disposed perpendicular to the Z planes is also digitally movable along the Z axis and provides for focussing the images of the contour lines on the model onto the X-Y image plane of the camera. Located within the camera so as to lie in the image plane thereof are scanning means including photosensitive means operable to digitally scan the image plane and thereby provide X and Y coordinates of the images of the contour lines which together with the Z coordinates of the illuminator define the surface of the model.

Claims

1. A non-contact digital contour generator for generating the X, Y and Z coordinates of the surface of a three-dimensional model comprising:

an adjustably mounted light source for successively providing contour lines about said model at different levels thereof, the movement of said light source being measured to provide a first of said coordinates;

a camera having an object plane and an image plane, said camera having its optical axis disposed perpendicular to the plane of the contour line and adjustably mounted such that its object plane is maintained in the plane of the contour line as the latter is changed to a different level so as to focus the image of the contour line on said image plane; and

scanning means including photosensitive means located in the image plane of said camera for scanning the successive images of the contour lines focussed thereon to provide the second and third of said coordinates.

2. A non-contact digital contour generator for generating coordinates of the contoured surface of a three-dimensional model comprising:

a light source having a beam disposed perpendicular to a first axis for forming a contour line on the surface of said model;

means for moving said light source and defining the coordinates of the plane of said contour line along said first axis;

an objective lens having an object plane and an image plane, said objective lens having its optical axis disposed perpendicular to the plane of the contour line formed about the surface of said model and having its object plane lying in the plane of said contour line so as to focus the image of the contour line on its image plane; and

scanning means including photosensitive elements disposed in the image plane for scanning the image of the contour line focussed thereon to define the coordinates thereof along second and third axes perpendicular to each other and to said first axis.

3. Apparatus for generating the X, Y and Z coordinates of the surface of a complex-shaped three-dimensional model comprising:

an illuminator means movable relative to said model along one coordinate direction to form contour lines at imcremental planes along the height of the model and operable to provide coordinates of the planes of said contour lines along said one coordinate direction;

a camera means having an object plane and an image plane and disposed with its optical axis aligned with said one coordinate direction and movable therealong with the illuminator means such that the object plane of the camera means remains coincident with the incremental planes of said contour lines formed on said model and provides for focussing said contour lines onto the image plane of the camera means; and

scanning means including photosensitive means located in the image plane of said camera means for scanning the successive images of the contour lines focussed thereon to provide coordinates thereof along the other two coordinate directions.

4. Apparatus in accordance with claim 3 wherein said illuminator means includes a laser beam rotatable about the model and reflector means incrementally movable along said one coordinate direction for reflecting said laser beam onto the periphery of the model to form said contour lines thereon at incremental planes.

5. Apparatus in accordance with claim 3 wherein said illuminator means includes means for forming a thin sheet of light disposed in planes perpendicular to said one coordinate direction.

6. Apparatus in accordance with claim 3 wherein said illuminator means includes a rotatable angular reflector that provides for sweeping a light beam to define a plane disposed perpendicular to said one coordinate direction.

7. Apparatus in accordance with claim 3 wherein said photosensitive means includes a linear array of photodiodes oriented in one of the coordinate directions of the image plane, and said scanning means includes means for moving said linear array along the other of the coordinate directions of said image plane.

8. Apparatus in accordance with claim 3 wherein said photosensitive means comprises a two-dimensional matrix array of photodiodes.

9. Apparatus for generating the X, Y and Z coordinates of the surface of a complex shaped three-dimensional model comprising:

an illuminator means incrementally movable relative to said model along the Z axis to provide contour lines at different planes along the height of the model, said illuminator means providing Z coordinates of the planes of said contour lines;

a camera having an optical axis disposed perpendicular to the planes of the contour lines formed on said model, said camera having an object plane and an image plane lying in the X-Y coordinate plane, and positioned and maintained with its object plane coincident at all times with the plane of said contour line, whereby the images of the contour lines on the model are focussed on the X-Y image plane of the camera;

a linear array of photodiodes lying in and oriented in the Y axis of said X-Y image plane and incrementally movable along the axis thereof, said camera providing X coordinates of the incremental position of said linear array; and

means for scanning said linear array of photodiodes at each incremental position along the X axis of the image plane to provide Y coordinates of the contour line imaged thereon which together with the X coordinates and the Z coordinates define the shape of the model at each of the planes along the height of the model.

10. Apparatus for generating X, Y and Z coordinates corresponding to points on the surface of a complex-shaped three-dimensional model comprising:

an illuminator movable in a Z coordinate direction and providing an intense light beam directed at said model to provide a contour line of light about the periphery thereof;

digital means for incrementally advancing said illuminator in the Z coordinate direction and providing a Z coordinate corresponding to the location of the plane of the contour line of light;

a camera having an X-Y image plane disposed parallel to the plane of said contour line of light, said camera having a linear array of photodiodes disposed in the Y coordinate direction of said X-Y image plane;

digital means for incrementally advancing said linear array in the X coordinate direction of said X-Y image plane and providing X coordinates corresponding to the location thereof; and

electronic means for scanning said linear array of photodiodes at each X incremental position of said linear array and providing Y coordinates corresponding to which ones of the photodiodes are activated by the image of the contour line.

11. A method of reproducing a three-dimensional model having complex curved surfaces comprising:

directing an illuminator incrementally movable along a Z axis to form contour lines of light about the periphery of the model and providing the Z coordinates of the planes of said contour lines;

providing an objective lens having an optical axis disposed perpendicular to the planes of the contour lines of light;

positioning and maintaining the object plane of said objective lens in the planes of the contour lines of light;

focussing the contour lines of light on the model by use of the objective lens as reduced images on an X-Y image plane;

positioning a two-dimensional matrix array of photosensitive elements in said X-Y image plane;

serially scanning said photosensitive elements in said two-dimensional matrix array and providing the X and Y coordinates of the images of said contour lines of light on said model;

feeding said X, Y and Z coordinates into a general purpose computer, and

modifying said X, Y and Z coordinates to provide a numerical control tape to control a machine tool to reproduce the model.