Photoelectric Sensor

A photoelectric sensor comprising:

• a light emitting element which repeatedly generates detection light;
• a light receiving element which receives reflected light of the detection light and generates a light receiving signal indicating a light receiving amount;
• a binarization processing section which binarizes the light receiving signal from the light receiving element;
• a capturing control circuit which generates a capturing signal corresponding to light emitting timing of the light emitting element;
• a waveform capturing section which has a large number of storage elements, each of the storage elements storing the binarized light receiving signal in accordance with the capturing signal;
• a capturing signal distribution section which has a branch circuit for supplying the capturing signal to each of the storage element;
• a light receiving signal distribution section which has a branch circuit for supplying the binarized light receiving signal to each of the storage elements;
• a delay circuit which is provided in at least one of the capturing signal distribution section and the light receiving signal distribution section, and relatively delays timing of supply of the capturing signal and the binarized light receiving signal to each of the storage elements such that the binarized light receiving signal is stored into the waveform capturing section as waveform data indicating a temporal change;
• a waveform integration part which matches light emitting timing of the light receiving element to integrate two or more pieces of the waveform data and generates integrated waveform data;
• and
• a workpiece discrimination part which discriminates presence or absence of a workpiece based on the integrated waveform data.