US 10,891,907 B2
Electrophoretic display including four particles with different charges and optical characteristics
Craig Lin, Fremont, CA (US); and Ming-Jen Chang, New Taipei (TW)
Assigned to E INK CALIFORNIA, LLC, Fremont, CA (US)
Filed by E Ink California, LLC, Fremont, CA (US)
Filed on Feb. 18, 2020, as Appl. No. 16/793,456.
Application 16/793,456 is a continuation of application No. 16/551,103, filed on Aug. 26, 2019, granted, now 10,586,499.
Application 16/551,103 is a continuation of application No. 16/181,946, filed on Nov. 6, 2018, granted, now 10,431,168, issued on Oct. 1, 2019.
Application 16/181,946 is a continuation of application No. 15/724,718, filed on Oct. 4, 2017, granted, now 10,147,366, issued on Dec. 4, 2018.
Application 15/724,718 is a continuation in part of application No. 14/939,666, filed on Nov. 12, 2015, granted, now 9,812,073, issued on Nov. 7, 2017.
Claims priority of provisional application 62/080,845, filed on Nov. 17, 2014.
Prior Publication US 2020/0184906 A1, Jun. 11, 2020
This patent is subject to a terminal disclaimer.
Int. Cl. G09G 3/34 (2006.01); G09G 3/20 (2006.01); G02F 1/167 (2019.01); G02F 1/1685 (2019.01); G02F 1/1675 (2019.01)
CPC G09G 3/344 (2013.01) [G02F 1/167 (2013.01); G02F 1/1685 (2019.01); G09G 3/2003 (2013.01); G02F 2001/1678 (2013.01); G02F 2203/34 (2013.01); G09G 2300/0452 (2013.01); G09G 2300/0473 (2013.01); G09G 2310/06 (2013.01); G09G 2310/067 (2013.01); G09G 2310/068 (2013.01); G09G 2310/08 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An electrophoretic display comprising a first surface on a viewing side, a second surface on a non-viewing side, and an electrophoretic fluid disposed between a first light-transmissive electrode and a second electrode, the electrophoretic fluid comprising:
a first type of particles, a second type of particles, a third type of particles, and a fourth type of particles, all of which are dispersed in a solvent, wherein
(a) the four types of pigment particles have different optical characteristics;
(b) the first type of particles and the third type of particles are positively charged, wherein the first type of particles have a greater magnitude of positive charge than the third particles, and wherein the magnitude of the positive charge of the third particle is less than 50% of the magnitude of the positive charge of the first particle; and
(c) the second type of particles and the fourth type of particles are negatively charged, wherein the second type of particles have a greater magnitude of negative charge than the fourth particles, and wherein the magnitude of the negative charge of the fourth particle is less than 50% of the magnitude of the negative charge of the second particle,
wherein a mixture of the optical characteristics of both the first type of particles and the second type of particles is visible at the first surface on the viewing side after:
a first driving voltage, having a first period of time, a first polarity, and a first amplitude, is applied between the first light-transmissive electrode and the second electrode,
a second driving voltage having a second period of time, a second polarity, and a second amplitude, is applied between the first light-transmissive electrode and the second electrode, wherein the first and second polarities are opposite from each other, the first amplitude is the same as the second amplitude, and the second period of time is shorter than the first period of time, and
a shaking pulse is applied.