SEED SENSOR WITH LIGHTPIPE PHOTODETECT ASSEMBLY

摘要

In one example embodiment, a seed sensor is disclosed adapted to fit a conventional mounting location in existing seed tubes that provides improved performance by providing a wide light source (more LEDS), a wide photodetector and a current profiling scheme for the LEDs that provides more light at the opposite ends of the LED array. A result of such an arrangement is to improve seed resolution and to reduce seed spatial variability within the seed tube.

主权项

1. A seed counting device for counting seeds passing through a longitudinal portion of a seed tube having a front, back and two side walls, the counting device comprising:
a sensor assembly adapted to be mounted on a front and back wall of the seed tube, said sensor assembly including an LED (light emitting diode) array disposed opposite a photodetector device adapted to receive light from the LED array, said photodetector device configured to generate signal pulses in response to interruptions in light received from the LED array, said LED array comprised of a plurality of LEDs that are disposed in a line that is substantially perpendicular to the longitudinal portion of the seed tube; and a controller configured to control a current driving each of said plurality of LEDs so as to generate a current profile for a selected LED array having a left leg, a center leg and a right leg, said controller further configured to change the current profile of the selected LED array so as to reduce optical intensity variability in the tube by increasing the drive current of a side wall LED of the right and left leg located adjacent to each tube side wall and increasing the drive current of a second LED of the right and left leg adjacent each of the side wall LEDs to a drive current value less than the drive current of the side wall LED so as to increase the optical intensity of the right and left legs at the side walls of the tube, wherein a center leg LED has a drive current value less than the drive current value of the second LED of the right and left legs, thereby improving spatial position detection of seed counting device of a seed passing through the seed tube and allow for adjustments to improve seed deposition accuracy.