Font control for electro-optic displays and related apparatus and methods

• US 9,928,810 B2
• Filed: 01/29/2016
• Issued: 03/27/2018
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Harrington, Demetrious Mark, Bouchard, Alain, Aprea, Matthew J., Crounse, Kenneth R.
• Primary Examiner(s): Dharia, Prabodh M
• Application Number:
  US15/010,980
• Publication Number:
  US 20160314766A1
• Time in Patent Office: 788 Days
• Field of Search: 345690-692, 345468, 345207, 345156, 345467, 382159, 382161, 382182, 715810, 348 43
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• 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 3/3446 with more than two electrodes controlling the modulating element
• CPC Class Codes: G09G 5/22 characterised by the display of characters or indicia using display control signals derived from coded signals representing the characters or indicia, e.g. with a character-code memory
• CPC Class Codes: G09G 5/227 Resolution modifying circuits, e.g. variable screen formats, resolution change between memory contents and display screen
• CPC Class Codes: G09G 5/28 for enhancement of character form, e.g. smoothing

Abstract

Methods are described for sequentially rendering fonts at multiple bit depths while reducing differences in visual appearance between the fonts rendered at different bit depths. The same hinting may be used for rendering the font at two different bit depths. Methods for reducing artifacts including edge artifacts also are described, including the use of font masks for updating electro-optic displays.

Claims

1. A method for driving an electro-optic display, the method comprising:

displaying a glyph on a display at a first time, wherein the glyph includes a font using a font hint, wherein at the first time, the glyph is presented at a first bit depth; and

displaying the same glyph at a second time on the display at a second bit depth, wherein the glyph presented at the second time includes the same font hint,

wherein the first bit depth has fewer bits than the second bit depth, and wherein the time needed to display the glyph in the first bit depth is shorter than the time needed to display the glyph in the second bit depth.

2. The method of claim 1, wherein the first bit depth is 1-bit.

3. The method of claim 1, wherein the font hint is specific to the second bit depth.