	US 7,495,821 B2
	Display device and method of preparing particles for use in image display of a display device
Hiroyuki Yamakita, Osaka (Japan); Toshiyasu Oue, Nara (Japan); Naohide Wakita, Suita (Japan); and Mariko Kawaguri, Moriguchi (Japan)
Assigned to Matsushita Electric Industrial Co., Ltd., Osaka (Japan)
Filed on Oct. 29, 2003, as Appl. No. 10/695,669.
Claims priority of application No. 2002-314005 (JP), filed on Oct. 29, 2002; application No. 2002-314453 (JP), filed on Oct. 29, 2002; application No. 2002-318194 (JP), filed on Oct. 31, 2002; and application No. 2003-031218 (JP), filed on Feb. 07, 2003.
Prior Publication US 2004/0150325 A1, Aug. 05, 2004
Int. Cl. G02B 26/00 (2006.01)

U.S. Cl. 359—296 [359/290; 359/295]

12 Claims

3. A display device comprising:

a pair of substrates disposed opposite to each other, at least one of which is transparent;

a plurality of particles having an electrostatic property contained in a gaseous phase provided between the pair of substrates;

first and second electrodes provided for each of pixels arranged in a matrix for driving the particles; and

a voltage applying portion for applying voltage to the first and second electrodes in accordance with an image signal, wherein:

the particles each comprise a parent particle as a core, a first coating layer coating an entire surface of the parent particle and comprising a material having a higher softening point than that of the parent particle, a second coating layer coating an entire surface of the first coating layer and comprising the same material as that of the parent particle or a material having a lower softening point than that of the parent particle, and plural child particles fixed to the second coating layer in a manner to cover a substantially entire surface of the second coating layer; and

when voltage is applied to the first and second electrodes by the voltage applying portion, the particles are caused to travel between the first and second electrodes in accordance with the voltage applied so as to display an image corresponding to the image signal.