JP2760336B2 - Liquid crystal display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to an electrode structure of a liquid crystal display device using a non-linear element. (Summary of the Invention) In the present invention, in an electrode structure of a liquid crystal display element using a non-linear element , a capacitance is provided by providing an electrode on a counter substrate between a signal application terminal of an electrode for applying a signal and a display portion. it is obtained by adding a is thereby those to prevent destruction of the non-linear element caused by static electricity applied from the manufacture in the outer. [0003] Conventionally, in a liquid crystal display device using a non-linear element, SID84 DIGEST 304-30.
7, pages 324 to 325, IEEE Trans. E
electron Dev. , ED-30, 532 (19
83) etc., but there is no particular reference to the structure of the signal electrode itself, and it was considered that the resistance of the signal electrode should be low as long as the display does not become uneven. Conventionally, in a liquid crystal display device using a non-linear element, a defect of a pixel due to an abnormality (defective) of the non-linear element has been a major cause of a reduction in yield and an increase in cost. The causes of the abnormalities of the non-linear element are not only those generated during the process, such as a defective shape of the element pattern, but also the non-linear element of the non-linear element due to static electricity applied to the electrode during manufacturing, especially when connecting to an external driver part. There were cases where the characteristics became abnormal. Therefore, the present invention is to solve such a problem, and an object of the present invention is to provide an inexpensive liquid crystal display device using a non-linear element. In the liquid crystal display device of the present invention, a liquid crystal is sealed between a pair of substrates, and one of the substrates has a signal electrode to which a signal is applied and a signal electrode. A two-terminal type non-linear element electrically connected to the substrate, and a signal supplied from the signal electrode via the non-linear element to form a pixel electrode arranged in a matrix. In a liquid crystal display element having a counter electrode facing the electrode of the pixel, the signal electrode is disposed between a pixel region in which the electrode of the pixel is arranged in a matrix and an input terminal of the signal electrode. A first capacitor electrode formed in the same layer as the signal electrode so as to be electrically connected to the first electrode; and the other substrate facing the first capacitor electrode via the liquid crystal. For the second capacitor formed separately from the electrode And an electrode. FIG. 1 is a perspective view of a non-linear element according to an embodiment of the present invention.
r) A description will be given based on a liquid crystal display element using a so-called MIM element having a three-layer structure of one metal (Metal).
In this embodiment, an MIM element made of tantalum-tantalum oxide-chromium is used. FIG. 1 is a schematic perspective view of a liquid crystal display device showing one embodiment of the liquid crystal display device of the present invention. A tantalum film 2 serving as a signal application terminal is formed on a transparent substrate 1 (tentatively referred to as an A substrate). The tantalum film 2 is covered with a tantalum oxide (perspective portion) except for a terminal portion. Reference numeral 3 denotes an MIM element which is abbreviated, and reference numeral 4 denotes a transparent electrode for forming a pixel. Wirings to which the MIM elements 3 of the tantalum film 2 shown by oblique lines in the figure are connected are signal electrodes. The transparent electrode 4 forms a pixel via a liquid crystal 7 between the transparent electrode 4 and a transparent electrode 6 of an opposing substrate 5 (to be referred to as a B substrate later). Reference numeral 8 denotes a spacer for providing a gap between the transparent substrates and enclosing the liquid crystal. Reference numeral 9 denotes a protection resistor provided between the input terminal and the pixel portion. Reference numeral 10 denotes a capacitor forming portion (first capacitor electrode) made of the tantalum film 2, and a capacitor forming electrode (second capacitor) of the opposing B substrate. Between the capacitor electrode 11 and the signal applying terminal 2 of the A substrate
It forms a protection capacitance against static electricity that enters from outside. The capacitance forming electrode 11 is formed separately from the transparent electrode 6 as shown. Reference numeral 12 denotes an electrode for forming a protection capacitor on the signal electrode of the B substrate. FIG. 2 is a schematic view of an electrode structure in a conventional example, and corresponds to portions 2, 3, and 4 in FIG. FIG. 3 is an enlarged view of a portion of the MIM element 3 in FIGS. 1 and 2, and 13 is a tantalum electrode covered with tantalum oxide, which will be a signal electrode. Reference numeral 14 denotes a chromium electrode pattern. FIG. 4 is a schematic view of a cross section taken along the dashed line 15 in FIG. 3, wherein 8 is a transparent substrate (A substrate), 16 is tantalum, 17 is tantalum oxide, and FIGS.
Electrodes are formed. FIG. 5 is an equivalent circuit diagram of the input terminal portion of the signal electrode shown in the embodiment of FIG. 1, wherein 18 is an input terminal, 19 is a protection resistor, 20 is a protection capacitor, and 21 is a resistance of the MIM element at both ends. Varies with voltage. 22 is the capacitance of the MIM element,
23 is a liquid crystal resistor, 24 is a liquid crystal capacitance, and 25 is an electrode of the opposing substrate. FIG. 6 is a schematic diagram of an electrode structure according to another embodiment of the present invention, in which a double CR circuit is formed. In an experiment on a liquid crystal display device using an MIM device according to one embodiment of the present invention, it was found that the conventional electrode shown in FIG.
%, The number of pixel defects increased, but no increase was observed at all by changing the electrode structure as shown in FIG. At this time, the resistance of the signal electrode from the input terminal to the first pixel is 2
00Ω to 2KΩ, and the protection capacitance was about 1.5 μF for one pixel in area. Also, when the charge stored in the 100 μF capacitor is discharged to the terminal and the number of pixel defects is increased, the pixel structure is increased by twice by changing the electrode structure of FIG. 2 from the electrode structure of FIG. 2 to the electrode structure of FIG. Did not. As described above, according to the present invention, in a liquid crystal display device using a non-linear element, a signal electrode is electrically connected between a pixel region and an input terminal of a signal electrode. By forming the formed electrode on the same layer as the signal electrode, a capacitance is formed via the liquid crystal layer between the non-linear element in the pixel area and the non-linear element due to static electricity entering from the terminal during manufacturing, especially during mounting. The device can be prevented from being destroyed. In addition, since it is possible to provide the capacitance electrode without increasing the number of new manufacturing processes and to use the conventional manufacturing process, it is possible to improve the yield without increasing the cost and to provide an inexpensive liquid crystal display device. Has an effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing one embodiment of a liquid crystal display device of the present invention. FIG. 2 is a schematic diagram of a conventional electrode structure. FIG. 3 is a schematic pattern diagram of an MIM element. FIG. 4 is a schematic sectional view of an MIM element. FIG. 5 is an equivalent circuit diagram of an electrode in the embodiment. FIG. 6 is a schematic diagram of an electrode shape according to another embodiment.

Claims (1)

(57) [Claims] A liquid crystal is sealed between a pair of substrates, and on one of the substrates, a signal electrode to which a signal is applied, a two-terminal non-linear element electrically connected to the signal electrode, and the non-linear element A liquid crystal display element in which a signal is supplied from the signal electrode via the first electrode and a pixel electrode arranged in a matrix is formed, and a counter electrode facing the pixel electrode is formed on the other substrate. A first electrode formed in the same layer as the signal electrode between a pixel region in which the electrode of the pixel is arranged in a matrix and an input terminal of the signal electrode so as to be electrically connected to the signal electrode; And a second capacitor electrode formed separately from the counter electrode on the other substrate facing the first capacitor electrode via the liquid crystal. Liquid crystal display element. 2. 20 between the first capacitor electrode and the input terminal.
2. The liquid crystal display device according to claim 1, wherein a resistor having a resistance value of 0 Ω to 2 KΩ is inserted.