Transmissivity measuring apparatus for a color separation prism

An apparatus for measuring color transmissivities of a color separation prism which receives a measurement light on an incident path, the incident path defining an incident axis, the prism emitting one of three color lights on a corresponding one of three exit axes, each exit axis defining a line in a different direction, the apparatus comprising:

• a light source for generating a reference light and a measurement light;
• photomeasuring means for measuring an intensity of one of three color lights emitted by the prism entering the photomeasuring means on an entrance path, the entrance path displaced laterally from the incident axis;
• a reference optical system for guiding the reference light to the photomeasuring means;
• an incident optical system for guiding the measurement light to the color separation prism on the incident path;
• a first movable mirror movable to one of four first positions, each first position located along one of the incident axis and the three exit axes, the first movable mirror reflecting the light on the respective axis to a second movable mirror;
• and
• the second movable mirror placed on the entrance path of the photomeasuring means and movable to one of four second positions to reflect the light from the first movable mirror to the photomeasurement means.

An adapter attachable to a spectrophotometer for measuring color transmissivities of a color separation prism which receives a measurement light on an incident path, the incident path defining an incident axis, the prism emitting one of three color lights on a corresponding one of three exit axes, each exit axis defining a line in a different direction, the spectrophotometer having a light source for generating a reference light and the measurement light, the adapter comprising:

• extracting optical means located in the spectrophotometer for guiding reference light and measurement light from the spectrophotometer;
• photomeasuring means for measuring an intensity of light entering the photomeasuring means on an entrance path, the entrance path being displaced laterally from the incident axis;
• a reference optical system for guiding the reference light to the photomeasuring means;
• an incident optical system for guiding the measurement light to the color separation prism on the incident path;
• a first movable mirror movable to one of four first positions, each first position located along one of the incident axis and the three exit axes, the first movable mirror reflecting the light on the respective axis to a second movable mirror;
• and
• the second movable mirror placed on the entrance path of the photomeasuring means and movable to one of four second positions to reflect the light from the first movable mirror to the photomeasuring means.