Patent ID: 7663744
Filing Date: 2010-02-16
Classification: G01J

Abstract:
1. An integrating photometer for measuring a total flux of light generated from a light source to be measured, comprising: a hemispherical unit having a light diffuse reflection layer provided on an inner face of the hemispherical unit; a plate-shaped mirror provided so as to intersect at a substantial center of curvature of said hemispherical unit and to block an opening of said hemispherical unit; a light receiving unit measuring an illuminance at the inner face of said hemispherical unit; and a correcting light source generating a correcting flux of light, wherein said mirror includes: a first window, provided at a region including the substantial center of curvature of said hemispherical unit, said light source to be measured is attachable to said first window such that a flux of light generated from said light source to be measured is guided toward the inner face of said hemispherical unit; and a second window provided at a position spaced away from said first window by a predetermined distance, said correcting light source is provided so as to emit said correcting flux of light to the inner face of said hemispherical unit through said second window, said first window is configured such that a calibration mirror having a size equal to that of an opening region of said first window is attachable along an identical plane with a mirror face of said mirror, said integrating photometer further comprising a correcting coefficient calculating unit calculating a correcting coefficient resulted from light absorption by said light source to be measured, based on a first illuminance measured in a case where said light source to be measured in a non-light emitting state is attached to said first window and said correcting light source is in a light emitting state, and a second illuminance measured in a case where said calibration mirror is attached to said first window and said correcting light source is in the light emitting state.