Light source position detection and positioning system

The invention relates to a light source position automatic detection positioning system which is composed of a CCD fruit size measure apparatus, a control module, a management setting module, a stepping motor, a multistage gear transmission device, a screw positioner, a slide-changing resistor type position sensor, a light source fixing device and a switch power supply on a production line where a spectrum technology is used for performing nondestructive tests on the internal quality of fruits, the influence generated on the spectrum quality due to distance difference of surface light source and fruit to be detected can be overcome when the spectrum technology is used for on-line detection of the internal quality of the fruits, thereby the measure error can be reduced and the prediction accuracy can be enhanced.