Patent ID: 8325406

Claim:
A planar lighting apparatus, comprising: a laser light source for emitting a laser light; a light guide plate having an incident surface on which the laser light is to be incident and a principal surface from which the laser light, which is incident on the incident surface, is emitted; a scanning unit for scanning the incident surface of the light guide plate with the laser light emitted from the laser light source; and a controller for controlling the laser light source, wherein the controller controls a light quantity of the laser light scanning the incident surface of the light guide plate, such that an ongoing light emitted from the principal surface forms a specified luminance distribution in a scanning direction of the laser light by the scanning unit, wherein the scanning unit includes a polygon mirror having a plurality of mirror surfaces and includes a driver for drivingly rotating the polygon mirror, wherein the incident surface of the light guide plate includes a plurality of incident surfaces formed in rows, so as to form a plurality of rows of the incident surfaces arranged in a direction orthogonal to the scanning direction of the scanning unit, wherein each mirror surface of the plurality of mirror surfaces of the polygon mirror is formed to scan, with the laser light, one respective row of the plurality of rows of the incident surfaces, wherein all rows of the plurality of rows of the incident surfaces are scanned by the laser light reflected by all respective mirror surfaces of the plurality of mirror surfaces of the polygon mirror, wherein the principal surface of the light guide plate is divided into a plurality of rows of emission regions arranged in the direction orthogonal to the scanning direction of the scanning unit in conformity with respective rows of the incident surfaces of the plurality of rows of the incident surfaces, wherein each emission region of the plurality of rows of the emission regions is formed to emit the laser light incident on a corresponding incident surface of the plurality of rows of the incident surfaces, and wherein the controller two-dimensionally controls a luminance adjustment on the principal surface of the light guide plate by adjusting the quantity of the laser light incident on the light guide plate for respective rows of the plurality of rows of the incident surfaces.