Optical device having reverse mode holographic PDLC and front light guide

An optical device comprising a light transmissive plate-shaped light guide for guiding light incident from an end surface, an optical control layer provided on a lower surface of said plate-shaped light guide through a transparent electrode provided as a first electrode, and a second electrode which is an electrode provided on a lower surface of said optical control layer for making mirror reflection of light,

• wherein said optical control layer is selected from the group consisting of liquid crystal particles dispersed in a polymer resin area, a polymer dispersed liquid crystal comprising polymer resin particles dispersed in a liquid crystal, and a polymer dispersed liquid crystal in which a respective polymer resin area and a liquid crystal area are continuous,
• wherein said liquid crystal has a structure periodically distributed in the form of a diffraction grating, and
• wherein said optical control layer is made of a reverse mode holographic polymer dispersed liquid crystal which is constructed by dispersing a low molecular-weight liquid crystal in a liquid crystalline polymer, and changes in diffraction ability by an electric field applied by said first electrode and said second electrode so that said optical control layer becomes a uniform birefringent thin film in the absence of any applied electric field, while said optical control layer becomes said diffraction grating for functioning as a hologram when an electric field is applied.

A display apparatus comprising an optical device and a illumination means for applying light to said optical device,

• wherein said optical device has an end surface for incident light from said illumination means, a light transmissive plate-shaped light guide for guiding incident light, an optical control layer provided on a lower surface of said plate-shaped light guide through a transparent electrode provided as a first electrode, and a reflection plate made of a light transmissive plate provided on a lower surface of said optical control layer through a transparent electrode provided as a second electrode,
• wherein said optical control layer is selected from the group consisting of liquid crystal particles dispersed in a polymer resin area, a polymer dispersed liquid crystal comprising polymer resin particles dispersed in a liquid crystal, and a polymer dispersed liquid crystal in which a respective polymer resin area and a liquid crystal area are continuous,
• wherein said liquid crystal has a structure periodically distributed in the form of a diffraction grating, and
• wherein said optical control layer is made of a reverse mode holographic polymer dispersed liquid crystal which is constructed by dispersing a low molecular-weight liquid crystal in a liquid crystalline polymer, and changes in diffraction ability by an electric field applied by said first electrode and said second electrode so that said optical control layer becomes a uniform birefringent thin film in the absence of any applied electric field, while said optical control layer becomes said diffraction grating for functioning as a hologram when an electric field is applied.

A display apparatus comprising an optical device and a illumination means for applying light to said optical device,

• said optical device has an end surface for incident light from said illumination means, a light transmissive plate-shaped light guide for guiding incident light, an optical control layer provided on a lower surface of said plate-shaped light guide through a transparent electrode provided as a first electrode, and a second electrode provided as an electrode on a lower surface of said optical control layer for making mirror reflection of light,
• wherein said optical control layer is selected from the group consisting of liquid crystal particles dispersed in a polymer resin area, a polymer dispersed liquid crystal comprising polymer resin particles dispersed in a liquid crystal, and a polymer dispersed liquid crystal in which a respective polymer resin area and a liquid crystal area are continuous,
• wherein said liquid crystal has a structure periodically distributed in the form of a diffraction grating, and
• wherein said optical control layer is made of a reverse mode holographic polymer dispersed liquid crystal which is constructed by dispersing a low molecular-weight liquid crystal in a liquid crystalline polymer, and changes in diffraction ability by an electric field applied by said first electrode and said second electrode so that said optical control layer becomes a uniform birefringent thin film in the absence of any applied electric field, while said optical control layer becomes said diffraction grating for functioning as a hologram when an electric field is applied.

An optical device comprising a light transmissive plate-shaped light guide for guiding light incident from an end surface, an optical control layer provided on a lower surface of said light guide through a transparent electrode provided as a first electrode, and a reflection film provided on a lower surface of said optical control layer through a transparent electrode provided as a second electrode,

• wherein said optical control layer is selected from the group consisting of liquid crystal particles dispersed in a polymer resin area, a polymer dispersed liquid crystal comprising polymer resin particles dispersed in a liquid crystal, and a polymer dispersed liquid crystal in which a respective polymer resin area and a liquid crystal area are continuous,
• wherein said liquid crystal has a structure periodically distributed in the form of a diffraction grating, and
• wherein said optical control layer is made of a reverse mode holographic polymer dispersed liquid crystal which is constructed by dispersing a low molecular-weight liquid crystal in a liquid crystalline polymer, and changes in scattering degree or diffraction efficiency field applied by said first electrode and said second electrode so that said optical control layer becomes a uniform birefringent thin film in the absence of any applied electric field, while said optical control layer becomes said diffraction grating for functioning as a hologram when an electric field is applied.

A display apparatus comprising an optical device and a illumination means for applying light to said optical device,

• said optical device having an end surface for incident light from said illumination means, a light transmissive plate-shaped light guide for guiding incident light, an optical control layer provided on a lower surface of said plate-shaped light guide through a transparent electrode provided as a first electrode, a reflection film provided on a lower surface of said optical control layer through a transparent electrode provided as a second electrode, and a substrate provided on a lower surface of said reflection film,
• wherein said optical control layer is selected from the group consisting of liquid crystal particles dispersed in a polymer resin area, a polymer dispersed liquid crystal comprising polymer resin particles dispersed in a liquid crystal, and a polymer dispersed liquid crystal in which a respective polymer resin area and a liquid crystal area are continuous,
• wherein said liquid crystal has a structure periodically distributed in the form of diffraction grating, and
• wherein said optical control layer is made of a reverse mode holographic polymer dispersed liquid crystal which is constructed by dispersing a low molecular-weight liquid crystal in a liquid crystalline polymer, and changes in scattering degree or diffraction efficiency by an electric field applied by said first electrode and said second electrode so that said optical control layer becomes a uniform birefringent thin film in the absence of any applied electric field, while said optical control layer becomes said diffraction grating for functioning as a hologram when an electric field is applied.