Method and apparatus for optically counting discrete objects

• US 5,768,327 A
• Filed: 06/13/1996
• Issued: 06/16/1998
• Est. Priority Date: 06/13/1996
• Status: Expired due to Term

• Current Assignee: Kirby Lester LLC (Capsa Solutions LLC)
• Original Assignee: Kirby Lester LLC (Capsa Solutions LLC)
• Inventors: Pinto, Itzhak, Perozek, Barbara Lyn, Chessa, John Francis
• Primary Examiner(s): RUBIN, MARGARET R
• Application Number:
  US08/663,488
• Time in Patent Office: 733 Days
• Field of Search: 377/10, 377/11, 377/6, 377/7, 377/53
• US Class Current: 377/10
• CPC Class Codes: G01V 8/20 using multiple transmitters or receivers
• CPC Class Codes: G06M 1/00 Design features of general application
• CPC Class Codes: G06M 1/101 by electro-optical means

Abstract

An object counter includes a feeding funnel having a frustroconical section, the narrow end of which is coupled to a substantially vertical feeding channel having a substantially rectangular cross section. A pair of linear optical sensor arrays are arranged along adjacent orthogonal sides of the feeding channel and a corresponding pair of collimated light sources are arranged along the opposite adjacent sides of the feeding channel such that each sensor in each array receives light the corresponding light source. Objects which are placed in the feeding funnel fall into the feeding channel and cast shadows on sensors in the arrays as they pass through the feeding channel. Outputs from each of the two linear optical arrays are processed separately, preferably according to various conservative criteria, and two object counts are thereby obtained. The higher of the two conservative counts is accepted as the accurate count and is displayed on a numeric display. In another embodiment, four sensor arrays and light sources are provided. The third and fourth sensor arrays and corresponding light sources are located downstream of the first and second arrays. The outputs of each of the sensor arrays are processed separately and the highest conservative count is accepted as the accurate count and is displayed on a numeric display.

Claims

1. An apparatus for optically counting discrete objects, comprising:

a) a substantially vertical feeding channel having an upper end for receiving the objects;

b) first and second substantially collimated light sources arranged substantially orthogonally, substantially horizontally, and adjacent said feeding channel;

c) first and second photo-electric sensor arrays arranged substantially orthogonally, substantially horizontally, and adjacent said feeding channel such that light from said first light source is detected by said first sensor array and light from said second light source is detected by said second sensor array, each of said sensor arrays having an output;

d) processing means coupled to said outputs of said first and second sensor arrays for separately processing said outputs; and

e) numeric display means coupled to said processing means for displaying a total count of the objects, wherein

the objects which enter said feeding channel pass between said light sources and said sensor arrays to cast shadows on said sensor arrays,

said processing means detects said shadows on said sensor arrays by separately processing said outputs of said sensor arrays, determines separate counts of how many objects have cast shadows on each of said sensor arrays, consistently chooses the larger or smaller of said separate counts, and increments the numeric display by the amount of the chosen larger or smaller count.

2. An apparatus according to claim 1, wherein:

said processing means consistently chooses said larger separate count.

3. An apparatus according to claim 1, further comprising:

f) a feeding funnel having a substantially frustroconical section with a narrow end, said narrow end being coupled to said upper end of said feeding channel, wherein

a distance between said narrow end and said first and second sensor arrays is approximately eight inches.

4. An apparatus according to claim 1, wherein:

said feeding channel has a substantially rectangular cross-section.

5. An apparatus according to claim 3, wherein:

said feeding channel has first and second horizontal dimensions, and said objects have a longest dimension, wherein said first and second horizontal dimensions are at least two and one half times said longest dimension of said discrete objects.

6. An apparatus according to claim 5, wherein:

said first and second horizontal dimensions are each at least two and one-half inches.

7. An apparatus according to claim 1, further comprising:

f) third and fourth substantially collimated light sources arranged substantially orthogonally, substantially horizontally, and adjacent said feeding channel below said first and second light sources; and

g) third and fourth photo-electric sensor arrays arranged substantially orthogonally, substantially horizontally, and adjacent said feeding channel below said first and second sensor arrays such that light from said third light source is detected by said third sensor array and light from said fourth light source is detected by said fourth sensor array, each of said sensor arrays having an output, wherein

said processing means is coupled to said outputs of said third and fourth sensor arrays, and

said processing means separately processes said outputs of said first, second, third, and fourth sensor arrays, determines separate counts of how many objects have cast shadows on each of said sensor arrays, consistently chooses the largest or smallest of said separate counts and increments the numeric display by the amount of the chosen largest or smallest count.

8. An apparatus according to claim 7, wherein:

said processing means consistently chooses said largest separate count.

9. An apparatus according to claim 1, further comprising:

f) overspeed indication means coupled to said processor means for indicating an overspeed feeding condition, wherein

said processing means includes timer means for timing a period of time, means for determining a first number of how many times single ones of the objects are detected during said period of time, means for determining a second number how many times a group of at least two objects are detected during said period of time, means for taking a function of said first number and second number to provide a third number, and means for comparing said third number to a first preset threshold number,

said processing means activating said means for indicating an overspeed feeding condition based on a comparison of said means for comparing.

10. An apparatus according to claim 1, further comprising:

f) deflector means located below said first and second sensor arrays for preventing objects from bouncing back past said sensor arrays.

11. An apparatus according to claim 1, further comprising:

f) a variable delay feeding tube coupled to said upper end of said feeding channel and having at least two second feeding channels, each of said second feeding channels providing a different delay to the discrete objects traversing said second feeding channels.

12. An apparatus for optically counting discrete objects having a longest dimension, comprising:

a) a substantially vertical feeding channel having an upper end for receiving the objects, said feeding channel being at least six inches tall and a rectangular cross-section with first and second horizontal dimensions which are at least two and one half times said largest dimension of said discrete objects;

b) first and second substantially collimated light sources arranged substantially orthogonally. substantially horizontally, and adjacent said feeding channel;

c) first and second photo-electric sensor arrays arranged substantially orthogonally, substantially horizontally, and adjacent said feeding channel such that light from said first light source is detected by said first sensor array and light from said second light source is detected by said second sensor array. each of said sensor arrays having an output;

d) processing means coupled to said outputs of said first and second sensor arrays for processing said outputs;

e) numeric display means coupled to said processing means for displaying a total count of the objects; and

f) a variable delay feeding tube coupled to said upper end of said feeding channel and having at least two second feeding channels, each of said second feeding channels providing a different delay to the discrete objects traversing said second feeding channels.

13. A method of optically counting discrete objects comprising:

a) providing a substantially vertical feeding channel having an upper end for receiving the objects;

b) locating first and second substantially collimated light sources substantially orthogonally, substantially horizontally, and adjacent the feeding channel;

c) locating first and second photo-electric sensor arrays substantially orthogonally, substantially horizontally, and adjacent the feeding channel such that light from the first light source is detected by the first sensor array and light from the second light source is detected by the second sensor array, and the objects which enter the feeding channel pass between the light sources and the sensor arrays to cast shadows on the sensor arrays;

d) separately processing the outputs of the first and second sensor arrays to determine separate counts of how many objects have cast shadows on each of the sensor arrays;

e) consistently choosing the larger or smaller of the separate counts; and

f) incrementing a numeric display by the amount of the chosen larger or smaller count.

14. A method according to claim 13, wherein:

said larger of said separate counts is consistently chosen.

15. A method according to claim 13, further comprising:

g) locating third and fourth substantially collimated light sources substantially orthogonally, substantially horizontally, and adjacent the feeding channel below the first and second light sources;

h) locating third and fourth photo-electric sensor arrays substantially orthogonally, substantially horizontally, and adjacent the feeding channel below the first and second sensor arrays such that light from the third light source is detected by the third sensor array and light from the fourth light source is detected by the fourth sensor array, and the objects which enter the feeding channel pass between the light sources and the sensor arrays to cast shadows on the sensor arrays;

i) separately processing the outputs of the first, second, third, and fourth sensor arrays to determine four separate counts of how many objects have cast shadows on each of the sensor arrays;

j) consistently choosing the largest or smallest of the four separate counts; and

k) incrementing the numeric display by the amount of the chosen largest or smallest count.

16. A method according to claim 13, further comprising:

g) monitoring the rate of said incrementing according to the amount of the increment;

h) indicating a first overspeed feeding condition when the rate exceeds a first preset threshold.

17. A method according to claim 16, further comprising:

i) indicating a second overspeed feeding condition when the rate exceeds a second preset threshold.

18. A method according to claim 17, further comprising:

j) discontinuing counting when the rate exceeds a second preset threshold.