Methods and apparatus for driving electro-optic displays

• US 9,269,311 B2
• Filed: 11/25/2013
• Issued: 02/23/2016
• Est. Priority Date: 11/20/2001
• Status: Expired due to Fees

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Inventors: Amundson, Karl Raymond
• Primary Examiner(s): SHERMAN, STEPHEN G
• Application Number:
  US14/089,610
• Publication Number:
  US 20140085350A1
• Time in Patent Office: 820 Days
• Field of Search: 345/107
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2310/068 Application of pulses of alternating polarity prior to the drive pulse in electrophoretic displays
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T

Abstract

Waveforms for driving electro-optic displays, especially bistable electro-optic displays, are modified by one or more of insertion of at least one balanced pulse pair into a base waveform; excision of at least one balanced pulse pair from the base waveform; and insertion of at least one period of zero voltage into the base waveform. Such modifications permit fine control of gray levels.

Claims

1. A method for driving an electro-optic display having a plurality of pixels, each of which is capable of achieving at least two different gray levels, the method comprising:

storing a base waveform defining a sequence of voltages to be applied to a pixel during a specific transition by the pixel between gray levels;

storing a multiplication factor, n, that is a natural number greater than one; and

effecting said specific transition by applying to said pixel a driving waveform-corresponding to n base waveforms.

2. The method of claim 1, wherein the multiplication factor is temperature-dependent.

3. The method of claim 1, wherein the base waveform comprises a set of bits, and the driving waveform comprises n sets of bits.

4. The method of claim 1 wherein the driving waveform is n times longer in time than the base waveform.