초록 ▼

A pair of optical systems of the same characteristics are disposed spaced apart by a base line length in the direction perpendicular to an optical axis, to form a focal plane, on which a standard photosensor and a reference photosensor, each having a plurality of photosensor elements, are disposed.

A pair of optical systems of the same characteristics are disposed spaced apart by a base line length in the direction perpendicular to an optical axis, to form a focal plane, on which a standard photosensor and a reference photosensor, each having a plurality of photosensor elements, are disposed. An image of an object is focused onto the standard and reference photosensors, to generate a standard optical signal and a reference optical signal which are compared with each other, while changing the phase of the reference optical signal relative to the phase of the standard optical signal to calculate correlation factors. A distance to the object is detected from a phase having an extreme value of the calculated correlation factors. If the calculated correlation factors are asymmetrical relative to the extreme value, one correlation factor change by a unit phase shift before the extreme value is subtracted from the other correlation factor change by the unit phase shift after the extreme value. The subtraction result is divided by a constant. The division result is added to the correlation factors at sampling points adjacent the extreme value on the side of the other correlation factor change. The addition results are used as the corrected correlation factors, to perform an interpolation calculation to obtain a phase having an extreme value of the corrected correlation factors.

대표청구항 ▼

A distance detecting method comprising the steps of: disposing a pair of optical systems spaced apart by a base line length in the direction perpendicular to an optical axis; disposing a standard photosensor and a reference photosensor on a focal plane of said pair of optical systems, said standard

A distance detecting method comprising the steps of: disposing a pair of optical systems spaced apart by a base line length in the direction perpendicular to an optical axis; disposing a standard photosensor and a reference photosensor on a focal plane of said pair of optical systems, said standard and reference photosensors each having a plurality of photosensor elements; focusing an image of an object onto said standard and reference photosensors, comparing a standard optical signal that is output by said standard photosensor with a reference optical signal that is output by said reference photosensor while changing the phase of said reference optical signal relative to the phase of said standard optical signal, and calculating correlation factors; detecting a phase having an extreme value of said correlation factors, wherein correlation factors occur before and after said extreme value; calculating a first correlation factor change value representing a rate of change of said correlation factors occurring before said extreme value and a second correlation change value representing a rate of change of said correlation factors occurring after said extreme value; calculating a compensation value based on the rate of changes of the correlation factors occurring before and after said extreme value by comparing said first and second correlation factor change values; correcting at least one of said correlation factors in accordance with said compensation value and producing at least one corrected correlation factor; and performing an interpolation calculation based on at least one of said correlation factors and said at least one corrected correlation factor, and obtaining a phase having an extreme value based on a result of said interpolation calculation.