公开(公告)号：EP0997767A2

公开(公告)日：2000-05-03

申请号：EP99114347.0

申请日：1999-07-21

申请人： Hewlett-Packard Company

发明人： Robrish, Peter R. ,  Weber, Andreas

IPC分类号： G02F1/1335

CPC分类号： G02F1/13362 ,  G02F1/13471 ,  G02F1/141 ,  G02F2001/133638 ,  G02F2203/02 ,  G09G3/2014 ,  G09G3/3629 ,  G09G2310/0235

摘要： A ferroelectric liquid crystal-based light valve [100] comprising a light input [106], a light output [108], a polarizing beam splitter [119], a reflective spatial light modulator [25] and a switchable half-wave plate [102]. Light polarized parallel to a first direction is received through the light input. Light from the light input and reflected by the spatial light modulator is output from the light output. The reflective spatial light modulator is structured as a quarter-wave plate and has a principal axis that switches through an angle φ. The polarizing beam splitter has orthogonal directions of maximum transmissivity and maximum reflectivity, one of which is parallel to the first direction. The polarizing beam splitter is located and aligned relative to the light input, the light output, and the spatial light modulator to transmit or reflect the light from the light input towards the spatial light modulator, and to reflect or transmit, respectively, towards the light output the light reflected by the spatial light modulator and having a direction of polarization substantially orthogonal to the first direction. The switchable half-wave plate is located between the beam splitter and the spatial light modulator, is structured as a half-wave plate and has a principal axis that switches through an angle θ, substantially equal to φ/2. The switchable half-wave plate inverts the sense of the light valve during the balance period of each display period to enable the light valve to generate a positive image, and therefore be illuminated, during the balance period in addition to during the illumination period.

摘要翻译： 一种铁电基于液晶的光阀[100]，其包括一个光输入[106]，光输出[108]，偏振分束器[119]，反射型空间光调制器[25]和一个可切换的半波片[ 102]。 通过光输入接收平行于第一方向偏振的光。 来自光输入并由空间光调制器反射的光从光输出端输出。 反射型空间光调制器被构造为四分之一波片并且具有切换角度φ的主轴。 偏振分束器具有最大透射率和最大反射率的正交方向，其中一个平行于第一方向。 偏振分束器相对于光输入，光输出和空间光调制器定位和对准，以将来自光输入的光透射或反射到空间光调制器，并且分别向光反射或透射 输出由空间光调制器反射并且具有基本上正交于第一方向的偏振方向的光。 可切换半波片位于分束器和空间光调制器之间，被构造为半波片并且具有切换角度θ的主轴，该角度θ基本等于φ/ 2。 可切换半波片在每个显示周期的平衡周期期间反转光阀的方向，以使得光阀能够在平衡周期期间除了在照明周期期间之外还产生正像，并且因此被照亮。

公开(公告)号：EP0997767A3

公开(公告)日：2000-10-18

申请号：EP99114347.0

申请日：1999-07-21

申请人： Hewlett-Packard Company

发明人： Robrish, Peter R. ,  Weber, Andreas

IPC分类号： G02F1/1335 ,  G02F1/141 ,  G02F1/1347

CPC分类号： G02F1/13362 ,  G02F1/13471 ,  G02F1/141 ,  G02F2001/133638 ,  G02F2203/02 ,  G09G3/2014 ,  G09G3/3629 ,  G09G2310/0235

摘要： A ferroelectric liquid crystal-based light valve [100] comprising a light input [106], a light output [108], a polarizing beam splitter [119], a reflective spatial light modulator [25] and a switchable half-wave plate [102]. Light polarized parallel to a first direction is received through the light input. Light from the light input and reflected by the spatial light modulator is output from the light output. The reflective spatial light modulator is structured as a quarter-wave plate and has a principal axis that switches through an angle ϕ. The polarizing beam splitter has orthogonal directions of maximum transmissivity and maximum reflectivity, one of which is parallel to the first direction. The polarizing beam splitter is located and aligned relative to the light input, the light output, and the spatial light modulator to transmit or reflect the light from the light input towards the spatial light modulator, and to reflect or transmit, respectively, towards the light output the light reflected by the spatial light modulator and having a direction of polarization substantially orthogonal to the first direction. The switchable half-wave plate is located between the beam splitter and the spatial light modulator, is structured as a half-wave plate and has a principal axis that switches through an angle θ, substantially equal to ϕ/2. The switchable half-wave plate inverts the sense of the light valve during the balance period of each display period to enable the light valve to generate a positive image, and therefore be illuminated, during the balance period in addition to during the illumination period.