Matsushita Electric Industrial Co., Ltd.

Tetsu Ogawa

Shingo Fujita

Hisanori Yamaguchi

Hiroaki Mizuno

Yoshio Iwai

Takayuki Hatanaka

Tomoaki Sekime

Seiichi Nagata

Masaki Nishinaka

Hiroshi Mizuno

Shoichi Ishihara

Koji Akiyama

Sadayoshi Hotta

Hiroshi Tsutsui

Yoshihiro Matsuo

Yoneharu Takubo

Hiroshi Tsutsu

Kazuhisa Morimoto

Ikunori Kobayashi

Shinji Hisamitsu

Yoshihiro Sakurai

Tomaoki Sekime

Deviation in phase difference of the light passing each of the red, green, and blue dots, i.e., 2&pgr;*(&agr;*d *&Dgr;n &plus;Re )/&lgr; , 2&pgr;*(&agr;*d *&Dgr;n &plus;Re )/&lgr; , and 2&pgr;*(&agr;*d *&Dgr;n &plus;Re )/&lgr; , are matched when thickness of a liquid crystal layer at red, green, and blue dots are d , d , and d ; wavelength of a visible light passing each dot is &lgr; , &lgr; , and &lgr; ; refractive index anisotropy of the liquid crystal layer in the visible light wavelengths &lgr; , &lgr; , and &lgr; is &Dgr;n , &Dgr;n , and &Dgr;n ; and retardations of a retardation plate are Re , Re , and Re . This enables the achievement of a reflective color LCD with high achromatic color during white display and high contrast display.

Retardation matching using the liquid crystal twist angle for different color dots within a pixel of a reflective color LCD

A reflection type liquid crystal display device having a wide viewing angle, and capable of assuring a light utilization factor at or above a certain value for bright display even when conditions of an external light are varied is provided. The reflection type liquid crystal display device comprises (a) a liquid crystal cell comprising an upper substrate, a lower substrate and a liquid crystal layer between the substrates, (b) a polarizing film provided in a side of the upper substrate in the liquid crystal cell, (c) light reflecting means provided in a side of the lower substrate in the liquid crystal cell; and (d) an optical member provided between the polarizing film and the liquid crystal cell, and having a retardation axis when it is viewed in the normal direction. An angle between an absorption axis of the polarizing film and the retardation axis of the optical member is within a range of about 88&deg; to about 92&deg; or about &minus;2&deg; to about &plus;2&deg; . A retardation value in relation to the normal direction of the optical member is within a range of about 50 nm to about 500 nm.

Reflection type liquid crystal display device

A reflection liquid crystal display device comprises an upper substrate; a transparent electrode formed into an electrode pattern on one side of the upper substrate; an alignment film formed on the transparent electrode; a lower substrate opposed to the upper substrate; a reflective metal electrode including Al-alloy electrodes formed into an electrode pattern and opposed to the upper substrate; a protective insulation film formed on the reflective metal electrode; an alignment film formed on the protective film; and liquid crystal filled between the upper substrate and the lower substrate. The protective insulation film has a volume resistivity of small than 1&times;10 &OHgr;-cm. The defects due to the charges stored in the protective insulation film are alleviated, and a uniform display is achieved.

Reflective liquid crystal display apparatus

A reflective liquid crystal display element including a liquid crystal cell filling between an upper transparent substrate and lower substrate with liquid crystal, a polarizing film disposed at the upper transparent substrate side of the liquid crystal cell, a birefringent film layer disposed between the polarizing film and liquid crystal, cell and light reflecting means disposed at the lower substrate side of the liquid crystal cell. The display element further includes an undulated layer, which is not formed in the connection terminal between the lower substrate side of the liquid crystal cell and the external circuit board. Preferably, the sectional shape of the transparent electrode in the connection terminal between the display area and external circuit is formed in three stair steps.

Reflective liquid crystal display element and image display device using the same

A reflection liquid crystal display device comprising only one polarization film, wherein the twist angle of a nematic liquid crystal ranges from 0&deg; to 90&deg;, the relationship between the difference between the indices of birefringence &Dgr;n , the thickness of the liquid crystal layer d , and the retardation of the phase plate R is expressed by &Dgr;n .d &equals;0.20 to 0.30 &mgr;m, R -&Dgr;n .d &equals;&minus;0.20 to &minus;0.05 &mgr;m; Defining the direction in which a nematic liquid crystal is twisted toward a lower substrate when viewed from above an upper substrate as positive and letting the direction of the major axis of the liquid crystal molecule the nearest to one of the upper and lower substrates be represented by &PHgr; , the direction of the phase lagging axis of the phase plate be represented &PHgr; , and the direction of the absorbing or transmitting axis of the polarization film be represented by &PHgr; , the relationship between the directions is expressed by &PHgr; -&PHgr; &equals;&minus;40&deg; to &minus;25&deg;, &PHgr; -&PHgr; &equals;&plus;50&deg; to &plus;80&deg; or &PHgr; -&PHgr; &equals;&plus;65&deg; to 105&deg;, &PHgr; -&PHgr; &equals;&minus;60&deg; to &minus;90&deg;. Therefore, bright white can be displayed and a nonchromatic high-contrast image can be also displayed.

Reflection liquid crystal display device

An electrode width of intermediate connection wiring which connects terminal electrode and common electrode is made narrower than an electrode width of terminal electrode at forming an electrode pattern on one of substrates configuring a liquid crystal display device. This enables the prevention of detrimental effect of cutting and polishing the periphery of a liquid crystal cell onto the terminal electrode. A laser irradiation process required for removing the common electrode is eliminated, and thus manufacturing cost may be reduced.

Liquid crystal display and manufacture therefore

In a reflective liquid crystal display device with a single polarizing film and two retardation films located in between the polarizing film and liquid crystal cell, the angle of twist of nematic liquid crystal is 45&deg;&tilde;90&deg;, the product of the birefringence of the liquid crystal and the thickness of the liquid crystal layer is 0.20 &mgr;m&tilde;0.30 &mgr;m, the retardation value of the retardation film on the polarizing film side is 0.13 &mgr;m&tilde;0.18 &mgr;m, the retardation value of the retardation film on the liquid crystal cell side is 0.13 &mgr;m&tilde;0.18 &mgr;m, and the Z coefficient of each of two retardation films is 0.3&tilde;1.0. This invention is featured by the following optical relations, that is, &Oslash; 75&deg;&tilde;195&deg;, &Oslash; &minus;&Oslash; , 105&deg;&tilde;115&deg;, and &Oslash; &minus;&Oslash; , 165&deg;&tilde;175&deg;, where &Oslash; , &Oslash; and &Oslash; are angles formed by the reference line and respectively the direction of the absorption axis of the polarizing film, the direction of the slow axis of the retardation film on the polarizing film side, and the direction of the slow axis of the retardation film on the liquid crystal cell side. With the foregoing construction, a high contrast display of bright achromatic white and achromatic black is achieved.

Reflection liquid crystal display element

A reflective liquid crystal display device of the present invention has the following construction. A transparent electrode is provided via color filter layer on a transparent substrate positioned at the upper side of the device. A metallic reflective electrode is provided on a substrate positioned at the lower side of the device. An alignment layer is provided on the transparent electrode and on the metallic reflective electrode respectively. The transparent substrate positioned at the upper side and the substrate positioned at the lower side are arranged parallel to each other with alignment films provided on the transparent electrode and on the metallic reflective electrode facing each other. A liquid crystal layer is provided between the alignment films. A scattering film is provided on a surface of the transparent substrate positioned at the upper side opposite to the surface where the transparent electrode is provided. A polymer film and a polarization film are provided in that sequential order on the scattering film. The present reflective liquid crystal display device can express a black and white display in achromatic color having bright white display and with high contrast, and has low visual angle dependency and excellent optical characteristics.

Reflective liquid crystal display device

A reflection-type liquid crystal display device comprises a liquid crystal cell, a polarizing film, a birefringent film, a scattering layer, and a light reflection means, in which a diffuse reflection factor &ldquo;R&rdquo; of the scattering layer is designed to be 7% or greater, but 110% or less when an incident angle of light is in the range of 25&deg; or greater and 45&deg; or smaller. Here the diffuse reflection factor &ldquo;R&rdquo; is defined by the formula of R&equals;R1/R2&times;100 (where R1 is a reflection factor irradiated at an incident angle of 0&deg;, and R2 is a reflection factor irradiated at an incident angle of 25&deg;). This structure is able to provide a reflection-type LCD which is bright in White display, capable of producing a high contrast, and reducing blur of an image.

Reflection liquid crystal display

Reflective LCD device with low visual angle dependency and high contrast

A reflective liquid crystal display device of the present invention has the following construction. Only one polarization film is needed. The twist angle of the nematic liquid crystal layer is set in the range of 0&deg; to 90&deg;. The product of the birefringence of the nematic liquid crystal layer &Dgr;n,and the thickness of the liquid crystal layer d,, &Dgr;n,&middot;d,, is in the range of 0.35 &mgr;m to 0.50 &mgr;m. The birefringence difference, &Dgr;R&equals;R,&minus;&Dgr;n,&middot;d,is in the range of &minus;0.20 &mgr;m to 0.00 &mgr;m. When a reflective liquid crystal display device is seen from a side of a substrate positioned at the upper side, the direction of the liquid crystal which is twisted to a side of a substrate positioned at the lower side is designated as the positive direction, &phgr;,represents an angle between the base line and the longer axis direction of the liquid crystal molecule which is positioned most closely to a first substrate, &phgr;,represents an angle between the base line and the retardation axis direction of the polymer film, &phgr;,represents an angle between the base line and the adsorption axis direction of the polarization film, &phgr;,&minus;&phgr;,is in the range of 70&deg; to 110&deg;and &phgr;,&minus;&phgr;,is in the range of &minus;90&deg; to &minus;60&deg;.

A reflector electrode is provided with hills and valleys thereon, and the reflector electrode is formed on an inside face of a transparent substrate having a transparent electrode and an opposite substrate. Light-scattering-liquid-crystal is provided with forward-scattering component and back-scattering component, so that scattering of reflected light from the reflector electrode is increased when the light-scattering-liquid-crystal is transparent. As a result, contrast is less dependent on a viewing angle, and a brighter quality display with higher color purity can be obtained.

A reflective liquid crystal display device employing only one sheet of polarizer film, the liquid crystal display device comprising: a liquid crystal cell comprising liquid crystal sealed between a pair of substrates, a polarizer film, two sheets of retardation film, a scattering film, and a specular reflector. The twisting angle of the liquid crystal is between 220.degree. and 260.degree.. The retardation .DELTA.nLC.multidot.dLC of the liquid crystal is between 700 nm and 1000 nm, and the retardation of the retardation films is .vertline.Rfilm(2)-Rfilm(1).vertline..ltoreq.200 nm. A specific angular relationship is established among the alignment of the liquid crystal molecules, the slow axis of the two sheets of retardation film, and the absorption axis of the polarizer. This configuration provides the reflective liquid crystal display device with a bright white display, an achromatic black and white display with high contrast, and less dependence on viewing angle.

A reflective liquid crystal display device comprising a polarizer, a retardation film, a front scattering film layer, and a liquid crystal cell having a mirror reflector, in which the front scattering film layer includes at least one film of which scattering angle range is asymmetrical to the normal direction of film. A plural front scattering films of which scattering angle range is asymmetrical to the film normal are laminated so that the projection direction onto the film surface in the central angle direction of the scattering angle range may be different. At least one of the scattering films for composing the scattering film layer is a front scattering film for scattering more strongly the transmission light from the second incident angle region not containing the film normal direction than the transmission light from the first incident angle region containing the film normal direction.

Reflective liquid crystal display device having front scattering films

A reflective liquid crystal display device comprises a substrate, a transparent substrate facing the substrate, and a liquid crystal layer sandwiched between the substrate and the transparent substrate, and further comprises first transparent electrodes, an electrically insulating separating layer and a reflective film formed in that order from the liquid crystal layer side at the inward-facing surface of the substrate, and also comprises a second transparent electrode included in the inward-facing surface of the transparent substrate. The electrically insulating separating layer physically and electrically separates the reflective film made of Al from the first transparent electrodes, so that durability against chemicals at processing and reliability are improved.

Growing community of inventors

Ishikawa, Japan

Tetsu Ogawa