.[.Herein disclosed are a liquid crystal display device and a data processing device, which can have their frame portions reduced in area to reduce the size and weight by extracting the terminals of video signals to only one side of a liquid crystal display panel and by arranging a video signal line driving circuit substrate to be connected with the terminals, only at one side of the display panel..]. .Iadd.A liquid crystal display device includes a liquid crystal display panel, a light guide plate, a fluorescent tube, and a lamp reflector. First and second lamp cables of different length are connected to the fluorescent tube. One end of the fluorescent tube is inserted in a hole of a first rubber bush and a part of the one end of the fluorescent tube is connected to the first lamp cable in the hole of the first rubber bush and an other end of the fluorescent tube is inserted in a hole of a second rubber bush and a part of the other end of the fluorescent tube is connected to the second lamp cable in the hole of the second rubber bush. The first and second lamp cables are extracted from a same place of a mold case..Iaddend.