Liquid crystal display device

#This application is based upon and claims the benefit of priority from Japanese Patent Applications No. 2007-210078 filed on Aug. 10, 2007; and No. 2008-048673 filed on Feb. 28, 2008, the entire contents of which are incorporated herein by reference.

#1. Field of the Invention

#The present invention relates to a liquid crystal display device, particularly to a liquid crystal display device in which a protrusion to serve as a spacer is formed on a substrate.

#FIG. 1 is a schematic cross-sectional view of a liquid crystal display device according to a first embodiment.

#FIG. 2 is a plan view schematically showing a configuration on an array substrate in the liquid crystal display device.

#FIG. 3 is a plan view schematically showing a configuration on an opposite substrate in the liquid crystal display device.

#As shown in FIG. 1, a liquid crystal display device according to a first embodiment includes an array substrate 100, an opposite substrate 200, a liquid crystal layer 300 and spacers 103. The opposite substrate 200 is disposed opposite the array substrate 100, and the liquid crystal layer 300 is sandwiched by these substrates. The spacers 103 are disposed on the array substrate 100 so as to keep a gap between the substrates constant. On both outer sides of the two substrates 100 and 200, polarizing plates (not shown) are disposed. On the back side of the array substrate 100, a backlight (not shown) is disposed. The liquid crystal display device is a transmissive liquid crystal display device which displays images by using illumination light from the backlight as a light source.

#The two substrates 100 and 200 are bonded together by a one drop fill method in the following steps. Firstly, a continuous line of an adhesive agent 400 is disposed on one of the substrates so as to surround a display region. Then, a predetermined amount of a liquid crystal is dropped into the region surrounded by the adhesive agent 400. Then, the two substrates are bonded together under vacuum. Thereafter, the pressure is increased from vacuum to normal atmospheric pressure, so that a pressure difference between a region surrounded by the substrates and an inner wall of the adhesive agent 400 and its outside region flattens the adhesive agent 400. The two substrates are supported by the spacers 103, and thus a predetermined cell gap 500 is formed between the substrates.

#In the array substrate 100, an insulating layer (not shown) is formed on a glass substrate 101, and transparent pixel electrodes 102 are formed on the insulating layer. The pixel electrodes 102 are arranged in a matrix. As shown in a plan view of FIG. 2, multiple signal lines 106 and multiple scanning lines 105 are disposed in a manner that each signal line 106 crosses the scanning lines 105. On the intersections of these lines, the pixel electrodes 102 and TFTs 107 are disposed, respectively. Moreover, storage capacitor lines 108 are disposed parallel to the scanning lines 105. On the storage capacitor lines 108, the spacers 103 are disposed. The spacers 103, which are protrusions formed by photolithography, are columns made of a transparent resin and having the same height. As TFTs 107, TFTs each including a semiconductor layer made of amorphous silicon (a-Si) is used. Drain terminals of the TFTs 107 are connected to the signal lines 106, source terminals of the TFTs 107 are connected to the pixel electrodes 102, and gate terminals of the TFTs 107 are connected to the scanning lines 105.