Comparative Study on Optical Devices for Lemon Fruit Counting

Abstract

This study was to compare the performance tested among optical devices for counting lemon fruits. Methodology was comprised of making up an electrical circuit to be capable of mounting 4 optical devices namely electric bulb with concaving lens (EL), laser emitting LED (LL), infrared emitting LED (reflectance type) (IL) and infrared emitting LED with fiber optic (IO). The aspect of the experiment was a) to determine the countability and counting accuracy, b) maximum clearance that a device could detect an object, and c) light dispersion. Result showed that i) the optical devices namely LL, IO, IL, and EL could detect (count) lemon fruits accurately without errors at the rate of 4.3, 4.07, 4.15 and 4.16 fruits/second respectively, ii) LL could detect an object further than other devices (more than 200 cm) on the condition that light source and receiver have to be aligned, iii) within a distance of 8 cm between light source and the object, LL has no light dispersion (angle of light dispersion, ϴ= 0). Laser beam was straight with 0.2 cm in diameter and symmetrical to the centre line of light source. EL, IL and IO gave ϴ= 4.3, 5.7 and 20.6 degrees respectively.