Patent ID: 7830475

Claim:
A liquid crystal display device, comprising: a first liquid crystal display panel and a second liquid crystal display panel located back to back, wherein: the first liquid crystal display panel includes a first substrate, a second substrate located opposite from the second liquid crystal display panel with respect to the first substrate, a first liquid crystal layer provided between the first substrate and the second substrate, and a first polarizing element located opposite from the first substrate with respect to the first liquid crystal layer; and the second liquid crystal display panel includes a third substrate, a fourth substrate located opposite from the first liquid crystal display panel with respect to the third substrate, a second liquid crystal layer provided between the third substrate and the fourth substrate, and a second polarizing element located opposite from the third substrate with respect to the second liquid crystal layer; the liquid crystal display device further comprising: a light source, provided to a side of the first substrate of the first liquid crystal display panel, and arranged to emit light toward a side surface of the first substrate; a third polarizing element provided between the first liquid crystal display panel and the second liquid crystal display panel; and a dimmer provided between the third substrate and the third polarizing element, the dimmer being switchable between a light reflective state and a light transmissive state; wherein the first substrate includes a light guide layer arranged to direct light, which is incident on the first substrate from the first light source and propagating inside the first substrate, toward the second liquid crystal display panel.