Liquid crystal display device

• Main Author: KOYAMA, HITOSHI
• Format: Patent
• Language: English
• Published: 21.02.2006
• Edition: 7
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

This invention provides a liquid crystal display device of a dual pass-through and reflection type, in which the contrast of the displayed image of reflection mode using external light is improved so as to improve the quality of the display device. In the dual mode type liquid crystal display device having a pass-through portion (12) and a reflection portion (13) in one pixel, the width (L1) of the black matrix (4a) corresponding with the two side portions of the pass-through portion (12) is set larger than the width (L2) of the black matrix (4b) corresponding with the two side portions of the reflection portion (13). With this arrangement, light leaking from the step (12a) of the two sides of the pass-through portion (12) is avoided, and light reflected from the planar portion (12b) is prevented from mixing with the light reflected from the reflection portion (13), to enable a high quality display with a pleasant view of image without glare. As a result of evaluation of the contrast ratio, the contrast ratio is 74 with the reflection mode while it is 194 with the pass-through mode. In either case of the reflection mode or the pass-through mode a high contrast display is obtained.