PRISMATIC LIGHT-GUIDE PLATE AND ILLUMINATION DEVICE THAT ENABLE THE PROVISION OF GOOD-QUALITY PLANAR LIGHT SOURCE

A prism light guide plate, a lighting apparatus, and an electronic device are provided to widely emit the light and to restrict the decrease of luminance due to interference of the emitted light through a black matrix although a relative position between the prism light guide plate and a liquid crystal panel is misaligned from an optimal position, by forming a diffusion unit on a light emitting surface of the prism light guide plate. A prism light guide plate is composed of a prism surface(3a) equipped with a plurality of prisms(P) for reflecting the light incident from a light incident end portion(3c); a light emitting surface(3b) for transmitting the incident light through total reflection and radiating the emitted light reflected from each prism; and a diffusion unit(30) installed in a region of the light emitting surface radiating the emitted light at high density, to widen the visual angle of the light by diffusing the emitted light.