US 12,462,767 B2
Method for driving electrophoretic display device
Craig Lin, Fremont, CA (US); and Xiaolong Zheng, Fremont, CA (US)
Assigned to E Ink Corporation, Billerica, MA (US)
Filed by E Ink Corporation, Billerica, MA (US)
Filed on Aug. 19, 2024, as Appl. No. 18/808,801.
Application 18/808,801 is a continuation of application No. 18/475,643, filed on Sep. 27, 2023, granted, now 12,094,429.
Application 18/475,643 is a continuation of application No. 18/191,592, filed on Mar. 28, 2023, granted, now 11,804,190, issued on Oct. 31, 2023.
Application 18/191,592 is a continuation of application No. 17/819,371, filed on Aug. 12, 2022, granted, now 11,640,803, issued on May 2, 2023.
Claims priority of provisional application 63/241,027, filed on Sep. 6, 2021.
Prior Publication US 2024/0412703 A1, Dec. 12, 2024
Int. Cl. G09G 3/34 (2006.01)
CPC G09G 3/344 (2013.01) [G09G 2310/0254 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method for driving an electrophoretic display comprising a layer of an electrophoretic medium having a viewing surface on one side thereof, and a second surface on the opposed side thereof, the electrophoretic display further comprising voltage control means for applying an electric field through the layer of electrophoretic medium, the electrophoretic medium comprising a fluid and first, second, third and fourth types of particles dispersed in the fluid, the first, second, third and fourth types of particles being respectively partially light-transmissive red, reflective yellow, reflective blue, and white, the first and third types of particles having charges of one polarity and the second and fourth types of particles having charges of the opposite polarity, the first type of particles having a greater zeta potential or electrophoretic mobility than the third type of particles, and the second type of particles having a greater zeta potential or electrophoretic mobility than the fourth type of particles,
the driving method comprising:
(i) providing a DC balancing pulse of a first driving voltage and a first polarity;
(ii) after step (i), applying a shaking pulse to achieve a mixed color state in which all four types of particles are randomly distributed in the fluid;
(iii) after step (ii), applying zero voltage for a first period of time;
(iv) after step (iii), applying a second driving voltage having a second period of time and having a same magnitude as the first driving voltage and an opposite polarity of the first polarity;
(v) after step (iv), applying zero voltage for a third period of time, the third period of time being longer than the second period of time; and
(vi) repeating steps (iv) and (v), thereby causing a process black color to be displayed at the viewing surface.