Cross-type light guide

Abstract

With the width d of the incidence-side light guide portion of a first light guide and the width d of the incidence-side light guide portion of a second light guide, the width W1 of the emission-side light guide portion of the first light guide and the width W2 of the emission-side light guide portion of the second light guide are set to satisfy the relationship of d<W1=W2. In the first light guide, substantially all of the light that has been emitted from the incidence-side light guide portion and has been transmitted through the intersection can be captured by the emission-side light guide portion without being leaked out. In the second light guide, substantially all of the light that has been emitted from the incidence-side light guide portion and has been transmitted through the intersection can be captured by the emission-side light guide portion without being leaked out. Consequently, light loss can be reduced significantly.

Dependencies are inferred from the claim text.