Distance measuring equipment

A distance measuring equipment comprising:

• a first light emitting element for measurement;
• an optically shielded second light emitting element for use during a correction mode;
• timing means for generating a timing signal;
• light emission trigger signal generating means for receiving the timing signal from said timing means and for generating a trigger signal in response to said timing signal;
• driving means for receiving the trigger signal from said light emission trigger signal generating means to selectively drive said first and second light emitting elements to emit light;
• a light receiving element for receiving light emitted from said first light emitting element for measurement and reflected by a forward object during a measurement mode;
• adding means for conducting an adding operation on an output signal delivered from said light receiving element, said adding operation occurring a predetermined number of times during a period between reception of subsequent timing signals from said timing means, and for binarizing and normalizing an addition result of said adding operation;
• and
• distance calculating means for calculating a distance between said equipment and said forward object on the basis of a signal supplied from said adding means and the timing signal from said timing means,
• wherein said timing means drives said optically shielded light emitting element during said correction mode to emit light, and thereby generate a correction signal, and wherein said correction signal is utilized by said adding means to correct said output signal delivered from said light receiving element.