Backlight unit

A backlight unit disposed between a first liquid crystal panel and a second liquid crystal panel, which are arranged parallel to each other, to illuminate both the first and second liquid crystal panels, said backlight unit comprising:

• a light source;
• a light guide plate disposed parallel to the first and second liquid crystal panels to receive light emitted from said light source and emit light for illuminating said first and second liquid crystal panels;
• an annular frame surrounding a peripheral edge of said light guide plate, said frame having a first end surface on a side thereof closer to said first liquid crystal panel and a second end surface on a side thereof closer to said second liquid crystal panel;
• a shielding-reflecting sheet disposed between said second liquid crystal panel and said light guide plate to shield and reflect light emitted from said light guide plate, said shielding-reflecting sheet being fixed to the second end surface of said frame to form, in cooperation with said frame, a casing that houses said light source and said light guide plate, and said shielding-reflecting sheet having an opening through which light emitted from said light guide plate passes toward said second liquid crystal panel;
• and
• a prism sheet disposed between said shielding-reflecting sheet and said second liquid crystal panel at a position corresponding to the opening of said shielding-reflecting sheet, said prism sheet being stretched across said opening;
• wherein respective surfaces of said shielding-reflecting sheet and said second liquid crystal panel that face said light guide plate have respective reflectances that are set so that light emitted from said light guide plate toward said second liquid crystal panel is reflected back to said light guide plate uniformly across said light guide plate by said surfaces of said shielding-reflecting sheet and said second liquid crystal panel.