US 7,327,511 · Granted 2008-02-05
E Ink's Secret Formula for Better E-Readers and Digital Displays
E Ink figured out how to make electronic paper displays work better by tweaking the invisible stuff inside them. They discovered that if you match the clarity of the liquid holding the colored particles to the container walls, and protect the display from harmful light, the image looks sharper and lasts longer.
The plain-English version
What it protects
The claim covers multiple improvements to electrophoretic displays (the tech behind e-readers like Kindle). What's protected here is the specific approach of matching the refractive index of the suspending fluid to its surrounding material, planarizing capsule layers before adhesive application, concentrating electrophoretic particles in controlled areas, and using UV-absorbing transparent plates to shield the display layer from light damage. A competitor copying these exact methods would infringe.
Why it matters
E Ink dominates the e-reader and digital signage market, and this patent protects core manufacturing techniques that make their displays sharper, more durable, and longer-lasting. By controlling how light moves through the display and how particles are positioned, E Ink locked down innovations that directly improve product quality and shelf life. This kind of patent portfolio is what lets companies maintain market leadership in display technology.
Real-world use
Every time you read on a Kindle or look at a digital price tag in a store, you're seeing technology influenced by these display improvements. The sharper text and longer battery life come partly from these optical and structural refinements.
Original USPTO abstract
Various improvements in electrophoretic media and displays intended for use in light modulators are described. These improvements include index matching of the suspending fluid to a continuous phase surrounding the fluid, index matching of a capsule wall to a binder, planarization of a layer containing electrophoretic capsules before application of adhesive thereto, methods for concentrating electrophoretic particles into limited areas of sidewalls of electrophoretic capsules or microcells in the light-transmissive state of the display, and, in the case of light modulators comprising an electrophoretic layer sandwiched between two transparent plates, forming at least one of the plates so as to absorb electromagnetic radiation which adversely affects the electrophoretic layer.
Patent details
- Publication number
- US 7,327,511
- Filing date
- 2005-03-22
- Grant date
- 2008-02-05
- Assignee
- E Ink Corporation
- Inventor(s)
- WHITESIDES THOMAS H., MCCREARY MICHAEL M., PAOLINI, JR. RICHARD J.
- CPC class
- G02F1/167
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