Product ripeness discrimination system and method therefor with area measurement

• US 5,401,954 A
• Filed: 02/15/1994
• Issued: 03/28/1995
• Est. Priority Date: 10/30/1992
• Status: Expired due to Term

• Current Assignee: Key Technology, Inc. (Duravant LLC)
• Original Assignee: Oms-Optical Measuring Systems
• Inventors: Richert, Gerald R.
• Primary Examiner(s): Nelms, David C.
• Application Number:
  US08/196,314
• Time in Patent Office: 406 Days
• Field of Search: 250/208.1, 250/226, 250/223 R, 250/560, 356/405, 356/406, 356/407, 356/425, 209/582, 209/586, 209/580, 209/581
• US Class Current: 250/226
• CPC Class Codes: B07C 5/10 measured by light-responsive means sorting according to colour B07C5/342
• CPC Class Codes: G01B 11/024 by means of diode-array scanning

Abstract

A product discrimination system using a fiber optic sensing system and a line scan camera sensor for recalibration of the fiber optic system. A plurality of fiber optic sensing stations measure reflected light spectra of products conveyed past the stations. The line scan camera is positioned adjacent one of the fiber optic sensors at one of the stations. A standard object is positioned adjacent conveyor so as to also be viewed by the line scan camera. The line scan camera recalibrates itself based on the standard object and is compared with the adjacent fiber optic station to recalibrate results from the fiber optic system.

Claims

1. A method for measuring ripeness of a product unit, comprising

moving the product unit past a sensing station along a conveying path;

sensing the magnitude of selected reflected light spectra indicative of cross-sectional area from a selected area of the product unit, including receiving reflected light from the product unit, randomizing the received light, and sensing the magnitude of selected spectra of the randomized light as an output indicative of cross-sectional area;

measuring by accumulating pixel output indicative of cross-sectional area using a line scan camera the selected area of the product unit sensed by said step of sensing;

calculating the difference between the pixel output indicative of cross-sectional area of the selected area of the product unit as measured by the line scan camera and the output indicative of cross-sectional area of the selected area of the product unit as sensed by the sensing step;

comparing said difference with a standard.

2. The method of claim 1 for measuring ripeness of a product unit, said step of sensing and said step of measuring are substantially simultaneous.

3. The method of claim 1 for measuring ripeness of a product unit, said step of sensing including repeatedly sensing the magnitude of selected spectra in selected areas of the product unit extending across the conveying path to cover substantially contiguous areas of the product unit.

4. The method of claim 3 for measuring ripeness of a product unit, said step of sensing and said step of measuring both including looking at the entire cross-sectional area of the product unit.

5. The method of claim 1 for measuring ripeness of a product unit, wherein said step of receiving light from a selected area of the product unit, using one end of a randomly bundled fiber optic cable, wherein said step of randomizing uses transmission along the randomly bundled fiber optic cable and said step of sensing the magnitude uses diodes at another end of the randomly bundled fiber optic cable.

6. The method of claim 1 for measuring ripeness of a product unit, further comprising

having a selected standard object positioned adjacent the conveying path adjacent the line scan camera;

simultaneously with said step of measuring, receiving reflected light from the standard object adjacent the conveying path;

converting the reflected light into a measurement of width;

comparing the measured width of the standard object with the known width of the standard object;

calibrating the line scan camera based on the calculated difference.