Self-calibrating photoelectric control system

A method for operating a self-calibrating photoelectric control system comprising the steps of:

• utilizing a light source for emitting a light beam having an intensity;
• utilizing a photoelectric sensor for receiving light from said light source and for generating an output signal when said received light is equal to or greater than a light-state threshold of said photoelectric sensor;
• and
• automatically calibrating the sensitivity of said photoelectric control system after occurrence of at least one of a plurality of predetermined events during operation of said checkstand, said calibration circuit operative for performing a calibration process which adjusts the intensity of the light beam emitted by the light source such that said intensity is greater than said light-state threshold of said photoelectric sensor,
• wherein said calibration comprises:
• reducing the intensity of the light source such that said photoelectric sensor is in a dark-state mode;
• increasing the intensity of said light source until said photoelectric sensor transitions into a light-state mode so as to determine the intensity of the light source which causes said photoelectric sensor to transition from said dark-state mode to said light-state mode;
• and
• adjusting the intensity of said light source such that the intensity is greater than the intensity of the light source which causes said photoelectric sensor to transition from said dark-state mode to said light-state mode.

A self-calibrating photoelectric control system for use in a checkstand, said self-calibrating photoelectric control system comprising:

• a light source for emitting a light beam having an intensity;
• a photoelectric sensor for receiving light from said light source and for generating an output signal when said received light is equal to or greater than a light-state threshold of said photoelectric sensor, said photoelectric sensor having a variable light-state threshold;
• and
• a calibration circuit for automatically calibrating the sensitivity of said photoelectric control system after occurrence of at least one of a plurality of predetermined events during operation of said checkstand, said calibration circuit operative for performing a calibration process which adjusts the light-state threshold of the photoelectric sensor such that intensity of the light beam emitted by the light source is greater than said light-state threshold of said photoelectric sensor,
• wherein said calibration comprises:
• reducing the intensity of the light source such that said photoelectric sensor is in a dark-state mode;
• increasing the intensity of said light source until said photoelectric sensor transitions into a light-state mode so as to determine the intensity of the light source which causes said photoelectric sensor to transition from said dark-state mode to said light-state mode;
• and
• adjusting the intensity of said light source such that the intensity is greater than the intensity of the light source which causes said photoelectric sensor to transition from said dark-state mode to said light-state mode.

A self-calibrating photoelectric control system for use in a checkstand, said self-calibrating photoelectric control system comprising:

• a light source for emitting a light beam having an intensity;
• a photoelectric sensor for receiving light from said light source and for generating an output signal when said received light is equal to or greater than a light-state threshold of said photoelectric sensor, said photoelectric sensor comprising an amplifier having a variable gain;
• and
• a calibration circuit for automatically calibrating the sensitivity of said photoelectric control system after occurrence of at least one of a plurality of predetermined events during operation of said checkstand, said calibration circuit operative for performing a calibration process which adjusts the gain of said amplifier in said photoelectric sensor such that intensity of the light beam emitted by the light source is greater than said light-state threshold of said photoelectric sensor,
• wherein said calibration comprises:
• reducing the intensity of the light source such that said photoelectric sensor is in a dark-state mode;
• increasing the intensity of said light source until said photoelectric sensor transitions into a light-state mode so as to determine the intensity of the light source which causes said photoelectric sensor to transition from said dark-state mode to said light-state mode;
• and
• adjusting the intensity of said light source such that the intensity is greater than the intensity of the light source which causes said photoelectric sensor to transition from said dark-state mode to said light-state mode.