Patent ID: 7798660
Filing Date: 2010-09-21
Classification: G02B

Abstract:
1. A surface illumination apparatus, comprising: a light source; an end-surface light-guide portion which guides light emitted from the light source in a long-side direction thereof and generates emitted light in a short-side direction thereof; and a light guide plate which allows the emitted light to be incident upon an end-surface portion thereof and emits the incident light from one main-surface portion thereof, wherein: the end-surface light-guide portion includes a plurality of polarization control portions arranged in the long-side direction; the plurality of polarization control portions each have a half-wave plate and a polarizing prism; the end-surface light-guide portion emits the emitted light in the form of either of S-polarized light and P-polarized light, using the plurality of polarization control portions; the light guide plate emits, as output light, either of S-polarized light and P-polarized light from the one main-surface portion; the end-surface light-guide portion includes a light introduction portion upon which light emitted from the light source is incident, and a light distribution portion in which the plurality of polarization control portions are arranged in the long-side direction; and the light introduction portion has: a polarizing prism which transmits the P-polarized light of light emitted from the light source to guide the P-polarized light to the light distribution portion and reflects the S-polarized light thereof; a mirror which reflects the S-polarized light reflected by the polarizing prism; and a half-wave plate which converts the S-polarized light reflected by the mirror into P-polarized light and guides the P-polarized light to the light distribution portion.