Active matrix liquid crystal device with opposite substrate having black matrix with larger aperture than active substrate

• US 5,510,916 A
• Filed: 11/01/1993
• Issued: 04/23/1996
• Est. Priority Date: 10/30/1992
• Status: Expired due to Term

• Current Assignee: Gold Charm Limited (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Takahashi, Nobuo
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US08/143,738
• Time in Patent Office: 904 Days
• Field of Search: 359/58, 359/59, 359/87, 359/67
• US Class Current: 349/110
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode

Abstract

In an active matrix liquid crystal device assuming a light blocking condition when a voltage is applied, there are provided a main plate formed with a pixel electrode, wiring electrodes and a switching transistor, an opposing plate formed with an opposing electrode, and a liquid crystal material sandwiched between the main plate and the opposing plate, so that a transmission light is irradiated from the main plate side. A light blocking layer acting also as a storage capacitor electrode is provided on the main plate through an insulating layer under the wiring electrode, the switching device and a periphery of the pixel electrode. Thus, it is to prevent light leakage at a boundary of a pixel, and to simultaneously suppress and conceal an orientation abnormality of the liquid crystal occurring at a periphery of the pixel electrode.

Claims

1. An active matrix liquid crystal device comprising:

a transparent main plate having at least one transparent pixel electrode, one wiring electrode and one switching device, which are formed on an inside surface of said transparent main plate;

a transparent opposing plate having a transparent opposing electrode formed on an inside surface of said opposing plate; and

a liquid crystal material sandwiched between said inside surface of said main plate and said inside surface of said opposing plate, so that a transmission light is irradiated from the main plate side,

said main plate including a light blocking layer which is formed on said inside surface of said main plate and which is covered by an insulating layer on which said wiring electrode, said switching device and the entire periphery of said pixel electrode are formed, said light blocking layer acting as one electrode of a storage capacitor,

wherein said switching device is sensitive to light, and wherein said opposing plate has a light blocking layer 210 formed on said inside surface of said opposing plate at a position corresponding to said switching device of said main plate, said light blocking layer of said opposing plate having an area necessary to completely cover said switching device, and said light blocking layer provided on said main plate having a larger surface area per pixel than said light blocking layer provided on said opposing plate.

2. An active matrix liquid crystal device claimed in claim 1, wherein said light blocking layer of said opposing plate has a sufficient configuration and size capable of covering said switching device even if misalignment in plan view between said main plate and said opposing plate is large and said light blocking layer of said main plate has a sufficient configuration and size capable of ensuring that said light blocking layer of said opposing plate never becomes visible within a pixel aperture even if misalignment in plan view between said main plate and said opposing plate is large.

3. An active matrix liquid device comprising:

a transparent main plate having at least one transparent pixel electrode, one wiring electrode and one switching device, which are formed on an inside surface of said transparent main plate;

a transparent opposing plate having a transparent opposing electrode formed on an inside surface of said opposing plate; and

a liquid crystal material sandwiched between said inside surface of said main plate and said inside surface of said opposing plate, so that a transmission light is irradiated from the main plate side,

said main plate including a light blocking layer which is formed on said inside surface of said main plate and which is covered by an insulating layer on which said wiring electrode, said switching device and said pixel electrode are formed, said light blocking layer covering the entire periphery of said pixel electrode and acting as one electrode of a storage capacitor;

said switching device is sensitive to light, said opposing plate has a light blocking layer formed on said inside surface of said opposing plate at a position corresponding to said switching device of said main plate, said light blocking layer of said opposing plate has a sufficient configuration and size capable of covering said switching device even if misalignment in plan view between said main plate and said opposing plate is large, and said light blocking layer of said main plate has a sufficient configuration and size capable of ensuring that said light blocking layer of said opposing plate never becomes visible within a pixel aperture even if misalignment in plan view between said main plate and said opposing plate is large.