Patent 7551283 was granted and assigned to Yokogawa Electric on June, 2009 by the United States Patent and Trademark Office.
An orientation meter for measuring an orientation of a measuring object, the orientation meter including: a plurality of light emitting elements for irradiating light to the measuring object; a light receiving element for receiving reflected light being reflected by the measuring object; and a gain adjusting light emitting element arranged at a vicinity of the light receiving element, wherein the plurality of light emitting elements is arranged around the light receiving element, and the orientation of the measuring object is measured based on a signal from the light receiving element.