| 摘要 |
Provided is an edge-light illumination apparatus having high straight-down lighting intensity and the capability of eliminating emission-surface lighting irregularities that are apparent when viewed diagonally. An edge-light illumination apparatus (1) in which a light-emitting unit (3a, 3b) is installed on the incident-end face of a light-guide plate (2), wherein a recess (6) formed on the bottom surface (2c) of the light-guide plate (2) has an inner-side first inclined surface (6a) and a second inclined surface (6b) continuous with the first inclined surface (6a) and opening to the outer side. The recess (6) describes a stepped V-shape having an apex angle (?1) formed by facing first inclined surfaces (6a) set within 95-110°, and an apparent apex angle (?2) formed by facing second inclined surfaces (6b) set within 60-75°. The ratio of the inclined side length of the second inclined side (6b') to the total inclined side length is set at 40-65%, where one side of the first inclined surface (6a) is a first inclined side (6a'), one side of the second inclined surface (6b) is a second inclined side (6b'), and the total length of the continuous first inclined side (6a') and second inclined side (6b') is defined as the total inclined side length. |
