# US 6,297,864 B1 · Liquid crystal display > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,297,864 B1 - Document ID: US6297864B1 - Status: Granted - Kind: B1 - Application number: 09/485,393 - Filed: 2000-02-09 - Granted: 2001-10-02 - Earliest claimed: 1998-03-03 - Assignees: Citizen Watch Co., Ltd. - Inventors: Yasushi Kaneko; Masafumi Ide; Takashi Akiyama - Web page: https://patentgrep.com/patent/US6297864B1 ## CPC - G02F 1/13362: {providing polarized light, e.g. by converting a polarisation component into another one} - G02F 1/133536: {Reflective polarizers (G02F1/13362 takes precedence)} - G04G 9/0035: {constructional} - G02F 1/133533: {Colour selective polarisers (G02F1/1347 takes precedence)} - G02F 1/133543: {Cholesteric polarisers} - G02F 1/133621: {providing coloured light (G02F1/133617, G02F1/133533 take precedence)} - G02F 2201/08: light absorbing layer - G02F 2203/03: scattering - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - G04G: ELECTRONIC TIME-PIECES ## Abstract A single color liquid crystal display device is made up of a TN liquid crystal cell 7 with about 90° twisted nematic liquid crystals sealed in-between a pair of transparent substrates 1, 2 having respective transparent electrodes 3, 4, a first polarizing film 17 disposed on the visible side of the TN liquid crystal cell 7, and a second polarizing film 18, a retardation film 6 for circularly polarized light, a cholestric liquid crystal polymer sheet 10, a translucent light absorbing member 15 and a backlight 16 disposed successively on a side of the TN liquid crystal cell 7, opposite from the visible side thereof. With such a constitution, display is rendered visible even at night by lighting up the backlight 16, and colored display in a metallic tone can be indicated. ## Claims ### Claim 1 A liquid crystal display device comprising: a TN liquid crystal cell with about 90° twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes; a first polarizing film disposed on a visible side of the TN liquid crystal cell; and a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a translucent light absorbing member and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof. ### Claim 2 A liquid crystal display device comprising: an STN liquid crystal cell with 180° to 270° twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes; a retardation film disposed on a visible side of the STN liquid crystal cell; a first polarizing film disposed on an outer side of the retardation film; and a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a translucent light absorbing member and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof. ### Claim 3 (depends on 2) A liquid crystal display device according to claim 2, wherein the retardation film is a twisted retardation film. ### Claim 4 A liquid cell display device comprising: a TN liquid crystal cell with about 90° twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective electrodes; a first polarizing film disposed on a visible side of the TN liquid crystal cell; and a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof, wherein a face of said backlight, opposite to said cholestric liquid crystal polymer sheet, has a function of scattering polarized light. ### Claim 5 A liquid crystal display device comprising: an STN liquid crystal cell with 180° to 270° twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes; a retardation film disposed on a visible side of the STN liquid crystal cell; a first polarizing film disposed on an outer side of the retardation film; and a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof, wherein a face of said backlight, opposite to said cholestric liquid crystal polymer sheet, has a function of scattering polarized light. ### Claim 6 (depends on 5) A liquid crystal display device according to claim 5, wherein the retardation film is a twisted retardation film. ### Claim 7 A liquid crystal display device comprising: a TN liquid crystal cell with about 90° twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes; a first polarizing film disposed on a visible side of the TN liquid crystal cell; and a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film, a translucent light absorbing member and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof. ### Claim 8 A liquid crystal display device comprising: an STN liquid crystal cell with 180° to 270° twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes; a retardation film disposed on a visible side of the STN liquid crystal cell; a first polarizing film disposed on an outer side of the retardation film; and a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film, a translucent light absorbing member and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof. ### Claim 9 (depends on 8) A liquid crystal display device according to claim 8, wherein the retardation film is a twisted retardation film. ### Claim 10 A liquid crystal display comprising: a TN liquid crystal cell with about 90° twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes; a first polarizing film disposed on a visible side of the TN liquid crystal cell; and a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof, wherein a face of said backlight, opposite to said second polarizing film, has a function of scattering polarized light. ### Claim 11 A liquid crystal display device comprising: an STN liquid crystal cell with 180° and 270° twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes; a retardation film disposed on a visible side of the STN liquid crystal cell; a first polarizing film disposed on an outer side of the retardation film; and a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof, wherein a face of said backlight, opposite to said second polarizing film, has a function of scattering polarized light. ### Claim 12 (depends on 11) A liquid crystal display device according to claim 11, wherein the retardation film is a twisted retardation film. ### Claim 13 (depends on 1) A liquid crystal display device according to claim 1, wherein a luminescence center wavelength of the backlight is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 14 (depends on 4) A liquid crystal display device according to claim 4, wherein a luminescence center wavelength of the backlight is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 15 (depends on 7) A liquid crystal display device according to claim 7, wherein a luminescence center wavelength of the backlight is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 16 (depends on 10) A liquid crystal display device according to claim 10, wherein a luminescence center wavelength of the backlight is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 17 (depends on 1) A liquid crystal display device according to claim 1, wherein the backlight has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 18 (depends on 4) A liquid crystal display device according to claim 4, wherein the backlight has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 19 (depends on 7) A liquid crystal display device according to claim 7, wherein the backlight has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 20 (depends on 10) A liquid crystal display device according to claim 10, wherein the backlight has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet. ### Claim 21 (depends on 1) A liquid crystal display device according to claim 1, wherein the second polarizing film is a reflection-type polarizing film. ### Claim 22 (depends on 4) A liquid crystal display device according to claim 4, wherein the second polarizing film is a reflection-type polarizing film. ### Claim 23 (depends on 7) A liquid crystal display device according to claim 7, wherein the second polarizing film is a reflection-type polarizing film. ### Claim 24 (depends on 10) A liquid crystal display device according to claim 10, wherein the second polarizing film is a reflection-type polarizing film.