Patent ID: 6115554
Filing Date: 2000-09-05
Classification: G02B

Abstract:
A distance measuring device for a camera comprising:a plurality of light-emitting elements for emitting a measuring light to an object;a plurality of light-receiving elements for receiving measuring light reflected by the object;an adding circuit for adding outputs of a selected plurality of contiguous light-receiving elements;an amplifying circuit for amplifying an output of the adding circuit;an integrating circuit for integrating an output of the amplifying circuit; andcalculating means for calculating a distance to the object based upon an output of the integrating circuit;wherein the calculating means includes means for performing a pre-measurement process including determining a combination comprising one of the light-emitting elements at which a maximum amplification gain is obtained and a first group of contiguous light-receiving elements at which a result of the addition is maximized in response to a light emitting and detecting operation, selecting a second group of light-receiving elements comprising the first group of light-receiving elements and one of a single and a plurality of the light-receiving elements contiguous to the first light-receiving element group from the determined light-emitting element and the determined first group of light-receiving elements, and dividing the second group of light-receiving elements into a plurality of subgroups, and for performing a distance measurement operation by measuring the distance to the object based on outputs from the respective divided subgroups.