Liquid crystal display device, and method for assembling the same

A method for assembling a liquid crystal display device (100, 100') includes: a) assembling together a front frame (1, 1' , 1"), a liquid crystal panel (2, 2' , 2") and an optical plate unit (3, 3', 3") in a dust-free environment to form a first unit (200, 200', 200") in a manner that the liquid crystal panel (2, 2' , 2") closes an opening (14, 14', 14") in the front frame (1, 1', 1") and that a sealed state is established between the liquid crystal panel (2, 2', 2") and the optical plate unit (3, 3', 3"); b) assembling a circuit board (7, 7' , 7") to one side of a rear frame (4, 4', 4") without requirement of a dust-free environment to form a second unit (300, 300', 300"); c) assembling a light source (5, 5', 5") to one of the first and second units (200, 200', 200", and 300, 300', 300"); and d) interconnecting the first and second units (200, 200', 200", and 300, 300', 300") without requirement of a dust-free environment in a manner that the light source (5, 5', 5") is able to provide light to a light-entrance surface (33, 33', 33") of the optical plate unit (3, 3', 3").