Lead sense system for component insertion machine

• US 4,799,268 A
• Filed: 11/12/1985
• Issued: 01/17/1989
• Est. Priority Date: 11/12/1985
• Status: Expired due to Fees

• Current Assignee: Emhart Inc.
• Original Assignee: USM Corporation
• Inventors: McLean, Jean A., Duncan, Robert J.
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): Couso, Jose L.
• Application Number:
  US06/797,322
• Time in Patent Office: 1,162 Days
• Field of Search: 250/561, 250/562, 356/375, 356/380, 356/398, 364/468, 364/478, 364/490, 358/101, 358/106, 358/107, 382/1, 382/8, 382/10, 382/53, 382/34, 382/48, 382/51, 382/52, 29/33 M, 29/739, 29/720, 29/721, 29/741
• US Class Current: 382/146
• CPC Class Codes: H05K 13/0473 Cutting and clinching the terminal ends of the leads after they are fitted on a circuit board
• CPC Class Codes: H05K 13/0815 Controlling of component placement on the substrate during or after manufacturing

Abstract

A system is disclosed for verifying the proper insertion of the leads of an electrical component. The system includes a camera mounted within a component insertion machine. The camera image is stored within the system and analyzed for the absence of any leads that should have been inserted.

Claims

1. A machine for inserting electronic components, such as dip components, having a pair of rows of parallel leads, running from one end of a component to the other end and defining the sides of the component, into holes of a printed circuit board comprising:

means for inserting the parallel leads of a component into holes of the printed circuit board so that the leads extend beyond the bottom surface of the printed circuit board,

camera means,

means for mounting said camera means on one side of the leads at an angle to the rows of parallel leads selected so that said camera means will see the leads of one row spaced from the leads of the other row,

means for making each of the leads extending beyond the bottom surface of the printed circuit board appear dark to said camera means with the rest of the image seen by the camera appearing light including

light source means and

means for mounting said light source means at the opposite side of the leads to direct light toward the bottom surface of the printed circuit board proximate the leads so that it will reflect towards said camera means thereby presenting to said camera means a pattern of dark spots corresponding to the leads extending beyond the printed circuit board, and

means for comparing the pattern of dark spots seen by said camera means with the pattern which the camera would see if all the leads were present in the inserted component and stopping said machine if the patterns do not match.

2. A machine according to claim 1 wherein said mounting means mounts said camera means at an angle to the bottom surface of the printed circuit board selected so that said camera means will see one row of the leads above and spaced from the other row of leads.

3. A machine according to claim 2 wherein said mounting means mounts said camera means at an angle of about 25°

to the bottom surface of the printed circuit board.

4. A machine according to claim 2 further comprising means for supporting the bottom surface of the printed circuit board, said supporting means being selectively configured not to block the path of light from said light source means to the bottom surface of the printed circuit board and reflected therefrom to said camera means.

5. A machine according to claim 4 further comprising means for displacing said supporting means between an elevated support position and a lowered position.

6. A system for verifying the proper insertion of a row of leads of an electronic component such as a DIP into a printed circuit board prior to securing the leads to the board comprising:

means for backlighting the row of inserted leads of an inserted component so that the inserted leads will appear dark from the front thereof,

camera means including a plurality of photosensitive binary elements arranged in horizontal rows to define a two-dimensional array, such elements having a one value when the image sensed is dark and having a zero value when the image sensed is light,

means for mounting said camera means in front of the row of inserted leads and at a distance therefrom selected so that each backlit lead, which will occupy an area at least six photosensitive elements wide by about fifteen photosensitive elements high, will be located within a discrete window of photosensitive elements defined by about fifteen consecutive horizontally spaced rows of such photosensitive elements each row having about fifteen photosensitive elements,

means for determining whether about any two consecutive photosensitive elements in each of about ten consecutive rows within each of said windows have said one value, and

means for indicating that all leads are present in the event said determining means so determines.

7. A system according to claim 6 wherein the electronic component has two rows of leads and said mounting means comprises means for mounting said camera means so that each of the leads of the two rows of leads will be located within a discrete window of photosensitive elements.

8. A system according to claim 7 wherein said mounting means comprises means for mounting said camera means at about a 25°

angle with the bottom surface of the printed circuit board through which the leads have been inserted.

9. A system according to claim 8 wherein said determining means comprises:

means for summing the one value of each of said photosensitive elements in a row within a window.

10. A system according to claim 9 wherein said determining means further comprises means for successively applying two bit masks to the values of photosensitive elements of a row within a window.

11. A system according to claim 10 further comprising:

means for displaying the image seen by said camera means, and

means for outlining said discrete windows on said displaying means so that the proper location of said discrete windows can be confirmed.