Abstract: A sensor head has a multiplicity of linear image sensors in correspondence with different radial directions of light emitted from a pixel in a pixel line of an LCD panel. The linear image sensors extends in the direction of the axis of an imaginary semi-cylinder. The linear image sensors have light receiving faces that are angularly spaced apart on an imaginary semi-cylinder, with their light receiving faces having normals passing through the axis of the imaginary semi-cylinder. Interposed in the space between the LCD pixel and the linear image sensors is an optical system having a multiplicity of light paths associated with respective angular components of the radiation emitted from the pixel line. Each of the light paths receives a predetermined angular component of light and transmits the light thus reveived to a corresponding one of the linear image sensors.

Abstract: An apparatus is provided for measuring viewing angle characteristic of luminance and positional characteristic of a radiant object under measurement, by moving a condensing device and an imaging device relative to the object. The apparatus includes a first mechanism for moving the light receiving elements of the condensing device while keeping constant the solid angle subtended by the light receiving element at the radiant area. A second mechanism is provided for moving the imaging device in association with the condensing device, while maintaining thereon the image of the radiant area. A memory is provide. A circuit is provided for calculating viewing angle dependent and position dependent characteristics. A display device is provided for displaying radiance characteristic and distribution characteristic of the object and the result of evaluation of the calculated characteristic of luminance.