Patent ID: 7719687

Claim:
A reflection characteristic measuring apparatus, comprising: a first light projecting/detecting unit having an illuminator and a light receiving section; a second light projecting/detecting unit having another illuminator and another light receiving section; said illuminators configured to illuminate a sample surface to be measured with light; said light receiving sections each adapted for receiving the light reflected on the sample surface illuminated by the light from the respective illuminator to output two-dimensional light receiving data, said light receiving sections being arranged axially symmetrically with each other with respect to a normal to the sample surface set in a predetermined position at a point on a measurement area; and a processor configured to derive a characteristic of the sample surface based on a weighted average obtained by applying a weighting factor to each of the light receiving data outputted from the light receiving sections based on an installation condition concerning the illuminator and the light receiving sections, and by averaging the light receiving data weighted with the weighting factors, wherein one of the first light projecting/detecting unit and the second light projecting/detecting unit includes: a light source; a lens element configured to guide first light outputted from the light source to the sample surface; a light receiving sensor having a two-dimensional light receiving surface; and a half mirror configured to transmit the first light from the light source of the one of the first light projecting/detecting unit and the second light projecting/detecting unit, and for reflecting second light outputted from a light source of the other one of the first light projecting/detecting unit and the second light projecting/detecting unit that has been reflected on the sample surface to the light receiving surface of the light receiving sensor.