公开(公告)号：EP0727691A1

公开(公告)日：1996-08-21

申请号：EP95400303.4

申请日：1995-02-14

Applicant: SAGEM S.A.

Inventor： Welzen, Theo

IPC: G02F1/139 ,  G02F1/1335

CPC classification number: G02F1/1393 ,  G02F1/13363 ,  G02F1/1362 ,  G02F2413/02

Abstract: In an active matrix liquid crystal display device the liquid crystal layer (10) has a non-twisted homogeneously aligned configuration while the liquid crystal cell is placed between two crossed polarizers (26,28) having their transmission direction at 45° with respect to the liquid crystal director at the cell-boundary. A negative birefringent retardation film (34,36) is positioned between the liquid crystal cell and one of the polyrizers in such a way that the optical axis of the retardation film is parallel to the liquid crystal boundary director while the absolute value of the retardation of the retardation film is equal to the effective retardation of the liquid crystal layer when no voltage is applied. In a preferred embodiment of the present invention, this one retardation film is replaced by two foils (34,36) of the same type which each have a retardation value which is equal to half the retardation value of the one film and which are placed on one side of the liquid crystal cell with their optical axis' parallel to the liquid crystal boundery-director.
To achieve a bright state at high voltage, the liquid crystal retardation is in the range 0.15-0.35 micron, and preferentially in the range 0.20-0.30 micron.

Abstract translation: 在有源矩阵型液晶显示装置的液晶层（10）具有非均匀扭曲对准构造而液晶单元在45℃具有它们的传输方向上的两个交叉的偏振器（26,28）之间放置相对于所述 在小区边界的液晶指向矢。 负双折射相位差电影（34,36）在寻求一种方式定位在所述液晶单元和所述polyrizers之一之间没有相位差的光轴薄膜平行于液晶边界导演同时的相位差的绝对值 当未施加电压时的延迟膜-等于液晶层的有效延迟。 在本发明的优选实施例，这一个相位差电影是由相同类型的每一个都具有相位差值的所有其等于所述一个膜的一半的延迟值，并且其两个箔（34,36）代替放置在 具有平行于液晶boundery导演及其光轴的液晶单元的一侧上。 在高电压实现明亮的状态下，液晶的延迟在上述范围内0:15至0:35微米，且优选范围为0:20至0:30微米。

公开(公告)号：EP0638834A3

公开(公告)日：1995-06-21

申请号：EP94401854.8

申请日：1994-08-12

Applicant: SAGEM S.A.

Inventor： Welzen, Theo

IPC: G02F1/139 ,  G02F1/1335

CPC classification number: G02F1/13363 ,  G02F1/1395 ,  G02F2202/40

Abstract: In a liquid-crystal display device having a pi-cell configuration between crossed polarizers and having a liquid-crystal retardation value such that it is possible to switch from a Bright state at low voltage to a Dark state at high voltage, the voltage for setting the Dark state can be lowered by making use of retardation films whose optical axes are parallel to the cell surfaces and perpendicular to the projection direction of the liquid-crystal director on the cell surfaces. Positioning of said films on both sides of the pi-cell in such a way that the total film retardation on the one side is equal to that on the other side results in angle-of-view-dependent transmission characteristics having better symmetry than in the case of the films being positioned on one side.

Abstract translation: 在正交偏振器之间具有π型晶体结构并具有液晶延迟值的液晶显示装置中，可以从低电压的明亮状态切换到高电压的黑暗状态， 通过使用光轴平行于单元表面且垂直于单元表面上的液晶导向器的投影方向的延迟膜，可以降低黑态。 将所述薄膜定位在pi单元的两侧，使得一侧上的总膜延迟等于另一侧上的总延迟导致视角相关透射特性具有比 电影放置在一侧的情况。

公开(公告)号：EP0638834A2

公开(公告)日：1995-02-15

申请号：EP94401854.8

申请日：1994-08-12

Applicant: SAGEM S.A.

Inventor： Welzen, Theo

IPC: G02F1/139 ,  G02F1/1335

CPC classification number: G02F1/13363 ,  G02F1/1395 ,  G02F2202/40

Abstract: In a liquid-crystal display device having a pi-cell configuration between crossed polarizers and having a liquid-crystal retardation value such that it is possible to switch from a Bright state at low voltage to a Dark state at high voltage, the voltage for setting the Dark state can be lowered by making use of retardation films whose optical axes are parallel to the cell surfaces and perpendicular to the projection direction of the liquid-crystal director on the cell surfaces. Positioning of said films on both sides of the pi-cell in such a way that the total film retardation on the one side is equal to that on the other side results in angle-of-view-dependent transmission characteristics having better symmetry than in the case of the films being positioned on one side.