# US 7,609,435 B2 · Display medium, display device, and displaying method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,435 B2 - Document ID: US7609435B2 - Status: Granted - Kind: B2 - Application number: 11/448,578 - Filed: 2006-06-07 - Published: 2007-06-07 - Granted: 2009-10-27 - Earliest claimed: 2005-12-06 - Assignees: Fuji Xerox Co., Ltd. - Inventors: Hiroaki Moriyama; Yasuo Yamamoto; Jun Kawahara; Masaaki Abe - Web page: https://patentgrep.com/patent/US7609435B2 ## CPC - G09G 3/34: by control of light from an independent source - G02F 1/167: by electrophoresis - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - 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 ## Abstract A display medium including a light-modulating layer containing charged mobile particles assuming a color at a lightness corresponding to the dispersion state of the charged mobile particles and first particles with lower mobility than the charged mobile particles. The first particles assume a color at a lightness that is outside a lightness range that the charged mobile particles can exhibit. ## Claims ### Claim 1 A display medium comprising a light-modulating layer containing charged mobile particles assuming a color exhibiting a brightness that corresponds to the dispersion state of the charged mobile particles, and also containing first particles with lower mobility than the charged mobile particles, the first particles assuming a color exhibiting a brightness that is outside a brightness range that the charged mobile particles can exhibit, wherein a mobility of the charged mobile particles is higher by at least 1×10−6 cm2/Vs than the mobility of the first particles. ### Claim 2 (depends on 1) The display medium of claim 1, wherein the first particles are black particles. ### Claim 3 A display medium comprising a light-modulating layer containing charged mobile particles assuming a color exhibiting a brightness that corresponds to the dispersion state of the charged mobile particles, and also containing first particles with lower mobility than the charged mobile particles, the first particles assuming a color exhibiting a brightness that is outside a brightness range that the charged mobile particles can exhibit, wherein the first particles assume a color exhibiting a lower brightness than the brightness range that the charged mobile particles can exhibit, and the light-modulating layer further contains second particles with lower mobility than the first particles, the second particles assuming a color exhibiting a higher brightness than the brightness range that the charged mobile particles can exhibit. ### Claim 4 (depends on 3) The display medium according to claim 3, wherein the mobility of the first particles is higher by at least 1×10−6 cm2/Vs than the mobility of the second particles. ### Claim 5 (depends on 3) The display medium according to claim 3, wherein the second particles have a larger volume average particle diameter than the charged mobile particles and the first particles. ### Claim 6 (depends on 3) The display medium according to claim 3, wherein the second particles are white particles. ### Claim 7 A display medium comprising a light-modulating layer containing charged mobile particles assuming a color exhibiting a brightness that corresponds to the dispersion state of the charged mobile particles, and also containing first particles with lower mobility than the charged mobile particles, the first particles assuming a color exhibiting a brightness that is outside a brightness range that the charged mobile particles can exhibit, wherein the charged mobile particles are colloidal metal particles having color strength due to surface plasmon resonance. ### Claim 8 (depends on 7) The display medium according to claim 7, wherein the colloidal metal particles are gold or silver particles. ### Claim 9 A display device comprising a light-modulating layer and an electric field-generating unit that generates an electric field in the light-modulating layer, the light-modulating layer containing charged mobile particles assuming a color exhibiting a brightness corresponding to the dispersion state of the charged mobile particles, and also containing first particles with lower mobility than the charged mobile particles, and the first particles assuming a color exhibiting a brightness that is outside the brightness range that the charged mobile particles can exhibit, wherein the mobility of the charged mobile particles is higher by at least 1×10−6 cm2/Vs than the mobility of the first particles. ### Claim 10 (depends on 9) The display device of claim 9, wherein the first particles are black particles. ### Claim 11 A display device comprising a light-modulating layer and an electric field-generating unit that generates an electric field in the light-modulating layer, the light-modulating layer containing charged mobile particles assuming a color exhibiting a brightness corresponding to the dispersion state of the charged mobile particles, and also containing first particles with lower mobility than the charged mobile particles, and the first particles assuming a color exhibiting a brightness that is outside the brightness range that the charged mobile particles can exhibit, wherein the first particles assume a color exhibiting a lower brightness than the brightness range that the charged mobile particles can exhibit, and the light-modulating layer further contains second particles with lower mobility than the first particles, and the second particles assume a color exhibiting a higher brightness than the brightness range that the charged mobile particles can exhibit. ### Claim 12 (depends on 11) The display device according to claim 11, wherein the mobility of the first particles is higher by at least 1×10−6 cm2/Vs than the mobility of the second particles. ### Claim 13 (depends on 11) The display device according to claim 11, wherein the second particles have a larger volume average particle diameter than the charged mobile particles and the first particles. ### Claim 14 (depends on 11) The display device according to claim 11, wherein the second particles are white particles. ### Claim 15 A display device comprising a light-modulating layer and an electric field-generating unit that generates an electric field in the light-modulating layer, the light-modulating layer containing charged mobile particles assuming a color exhibiting a brightness corresponding to the dispersion state of the charged mobile particles, and also containing first particles with lower mobility than the charged mobile particles, and the first particles assuming a color exhibiting a brightness that is outside the brightness range that the charged mobile particles can exhibit, wherein the charged mobile particles are colloidal metal particles having color strength due to surface plasmon resonance. ### Claim 16 (depends on 15) The display device according to claim 15, wherein the colloidal metal particles are gold or silver particles. ### Claim 17 A displaying method comprising: dispersing charged mobile particles, first particles, and second particles in a light-modulating layer, wherein the charged mobile particles assume a color corresponding to the dispersion state of the charged mobile particles, the first particles have lower mobility than the charged mobile particles and have a lower brightness than the brightness range that the charged mobile particles can exhibit, and the second particles have lower mobility than the first particles and assume a color exhibiting a higher brightness than the brightness range that the charged mobile particles can exhibit; and moving the charged mobile particles, the first particles, and the second particles in a predetermined display direction in the light-modulating layer.