Contour detecting and dimension measuring apparatus

• US 4,192,613 A
• Filed: 08/24/1978
• Issued: 03/11/1980
• Est. Priority Date: 01/08/1976
• Status: Expired due to Term

• Current Assignee: Martin Hammar
• Original Assignee: Martin Hammar
• Inventors: Hammar, Martin
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Rosenberger, R. A.
• Application Number:
  US05/936,644
• Time in Patent Office: 565 Days
• Field of Search: 250/560, 250/571, 356/376, 356/379, 356/380, 356/384, 356/385, 356/386
• US Class Current: 356/639
• CPC Class Codes: G01B 11/105 using photoelectric detection means
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence

Abstract

Apparatus for detecting contours and measuring dimensions of an object employs a plurality of light transmitting means for transmitting a scan of an equal plurality of light rays, and also employs an equal plurality of light receiving means, each arranged to receive light from only a complementary one of the light transmitting means. The object is moved through the light rays such that the object prevents the light receiving means from receiving light shining on one side of the contours of the object. Counter means are employed for counting the number of light receiving means which receive light from corresponding light transmitting means. The light transmitting means and light receiving means are disposed in a configuration enabling a more sensitive detection of the contours yet avoiding the risk of "cross-talk" between adjacent light receivers.

Claims

1. Apparatus for detecting the contours of an object, comprising:

(a) a measuring station to and from which said object is moved;

(b) a plurality of light transmitting means at said station for providing a scan of an equal plurality of light rays;

(c) an equal plurality of light receiving means at said station each arranged to sequentially receive light from only a complementary one of said light transmitting means;

(d) each of said light transmitting and light receiving means having a predetermined physical dimension in a predetermined direction, said physical dimension restricting the minimum closeness between two light transmitting and light receiving means, respectively, to an edge-to-edge relationship;

(e) means for guiding said object through the paths of the light rays such that said light receiving means are prevented by said object from receiving light from those of the light rays that shine on one side of each of said contours;

(f) counter means for counting the number of said light receiving means which receive light from said complementary light transmitting means;

(g) said light transmitting means disposed in a predetermined configuration having a first and a second row of light transmitting means, the distance between the centers of two consecutive light transmitting means in each of the rows having a predetermined like value, the rows being arranged in parallel and staggered such that the center of each said light transmitting means in one of the rows is located at a predetermined distance from a point in said one row which point lies opposite to the center of a said light transmitting means in the other row, said predetermined distance being less than said predetermined value and less than said physical dimension;

(h) said light receiving means being disposed in a configuration corresponding to said predetermined configuration; and

(i) movable light source means being provided to sequentially activate a predetermined number of said light transmitting means alternately in each of said rows such that each of said rows emits a scan of light travelling in said predetermined direction, the scans of the different rows forming a composite scan wherein the distance between two consecutive light rays, as seen along said predetermined direction, is equal to said predetermined distance.

2. Apparatus according to claim 1, wherein said movable light source means are provided to sequentially activate said predetermined number of said light transmitting means such that each row emits two scans of light which are progressively travelling toward each other.

3. Apparatus according to claim 1, wherein each row of light transmitting means consists of the output ends of a predetermined number of stationary light transmitting optical fibers and each row of light receiving means consists of the input ends of a corresponding number of stationary light transmitting optical sound fibers, one of said movable light sources being provided for each row to sequentially project light on the input ends of the first fibers, and a movable light responsive means for each row being provided to sequentially sense each output end of the second fibers.

4. Apparatus according to claim 3, wherein the input ends of the first fibers are arranged to sequentially and in succession receive light from said light sources, a selected number of the output ends of the first fibers being arranged in the rows such that every second output ends of the selected number of output ends are provided to produce a first scan of light travelling in a first direction, the other output ends of the selected number of output ends being arranged in the rows to produce a second scan of light travelling in a direction opposite to the first direction.

5. Apparatus according to claim 4, wherein the light sources are arranged to sequentially move past the input ends of the first fibers in its corresponding row, the light sources being provided to emit light during a predetermined time interval each time it moves past each of said input ends of the first fibers, each light responsive means being arranged to move past the output ends of the second fibers in synchronism with corresponding light source, means being provided to trigger each light responsive means simultaneously with the emission of light from corresponding light source.

6. Apparatus according to claim 5, wherein said light responsive means are capable of producing an electric pulse to said counter means when the light responsive means is simultaneously triggered and receives light, said counter means being provided to count the number of said pulses during one cycle of light transmission to all the first fibers.

7. Apparatus according to claim 1, wherein the light transmitting means are placed in such relationship relative to the light receiving means that all light rays travel substantially above one another in a predetermined area between the light transmitting means and the light receiving means.