Patent ID: 8345181

Claim:
A light emitting device comprising: a backlight unit that supplies light; and a hold pedestal that hold rotatably the backlight unit; wherein a plurality of linear light sources in the backlight unit include a first linear light source and a second linear light source that are so disposed as to intersect each other; an angle measurement type light-emission control portion, which detects a rotation angle of the backlight unit to the hold pedestal; and in accordance with the rotation angle, controls light emission of the linear light source, is included; a surface of the backlight unit that faces the hold pedestal is a rotation surface and a surface of the hold pedestal that faces the rotation surface is a hold surface; the angle measurement type light-emission control portion includes a first detection portion and a second detection portion which have a relationship in which one of the first and second detection portions detects the other of the first and second detection portions; disposes the first detection portion on the rotation surface and disposes the second detection portion on the hold surface; and detects the rotation angle by detecting the other of the first and second detection portions by using the one of the first and second detection portions; and the angle measurement type light-emission control portion, on measuring a first angle range which is a rotation angle in a predetermined range corresponding to the hold pedestal, makes the first linear light source emit light; on the other hand, on measuring a second angle range which is a rotation angle in a predetermined range corresponding to the hold pedestal, makes the second linear light source emit light.