초록 ▼

A light-reflection defect detection apparatus and method for sensing the presence of food products or other articles and detecting defects therein is described using pulsed light-emitting semiconductor devices, such as light-emitting diodes (LEDs). The LEDs emit at least three different wavelengths

A light-reflection defect detection apparatus and method for sensing the presence of food products or other articles and detecting defects therein is described using pulsed light-emitting semiconductor devices, such as light-emitting diodes (LEDs). The LEDs emit at least three different wavelengths of light including two of visible light (i.e., red and green light) and one of infrared light. Viewers each including photosensor, such as a photoelectric detector, are employed to sense the light reflected from the article and to produce sensor output signals which are sampled and stored before being transmitted to a digital computer for signal processing. The groups of LEDs are pulsed ON and OFF by a capacitor discharge pulse generator circuit which causes a substantially constant current to flow through the LEDs so that they emit light of uniform intensity. The defect detection apparatus and method is especially useful in detecting defects in elongated food products such as French-fry potato strips.

대표청구항 ▼

Defect detection apparatus for detecting defects in articles, comprising: optical sensor means for sensing articles and for scanning the articles to detect any defects therein; a plurality of light-emitting semiconductor devices including first devices which emit light of a first wavelength and seco

Defect detection apparatus for detecting defects in articles, comprising: optical sensor means for sensing articles and for scanning the articles to detect any defects therein; a plurality of light-emitting semiconductor devices including first devices which emit light of a first wavelength and second devices which emit light of a second wavelength different from said first wavelength, at least one of said wavelengths being visible light; pulser means for applying electrical pulses to control said semiconductor devices to actuate said first and second devices on and off, said pulses having an on/off duty cycle of much less than 50% so that each of said devices is pulsed off for a period many times greater than it is pulsed on; illumination means for directing the emitted light of said first and second wavelengths at said articles in projection fields wider than the sensed article to cause said light to be reflected from the exposed three dimensional surface of the sensed article and from any defects on said surface; and viewer means for receiving said reflected light and directing it to said optical sensor means which measure the amount of reflected light to detect defects in said articles.