Spatial scanning means for a photometer

In combination with a radiant energy measuring meter having a measuring aperture, the provision of:

• an optical scanning system comprising
• laterally and longitudinally spaced first and second lens means;
• a pair of prisms between said first and second lens means for folding the optical axes of both lens means along a coincident laterally extending optical axis portion between said prisms;
• one of said lens means being a collimating lens whereby collimated light is transmitted along said optical axis portion between said prisms,
• and means for mounting said one of said lens means and its associated prism for movement relative to the lateral optical axis portion.

An optical scanning means for enabling the measurement of selected area portions of luminance displays by a radiant energy measuring meter, comprising

• a collimating lens adapted to be focused on a radiant energy display and to collimate radiant energy beams received therefrom;
• an energy reflecting member associated with said collimating lens;
• said energy reflecting member transmitting the received collimated radiant energy beams along a folded path;
• a second energy reflecting member receiving and reflecting said collimated radiant energy beams;
• a telescopic lens for receiving the collimated radiant energy beams from said second reflecting member and for focusing and imaging said beams at a measuring aperture;
• and means for moving said collimating lens and said first mentioned reflecting member along an optical axis portion between said energy reflecting members for scanning the luminance display.