US 6,407,847 · Granted 2002-06-18
The Smart Glass Patent That Lets Windows Dim Themselves
Imagine a window that gets darker or lighter at the flip of a switch—no blinds needed. This patent describes how to build that using special electrochromic material sandwiched between glass panes, with an airtight seal and insulating gas to keep everything stable and insulated.
The plain-English version
What it protects
The patent covers the design of an electrochromic window assembly with two glass substrates held parallel by a frame and spacer, an electrochromic device mounted inside the airtight chamber between them, and the ability to fill chambers with insulating gas like argon. What's protected here is specifically the structural arrangement that keeps the electrochromic material sealed and functional, plus the manufacturing methods for assembling these layered window units and the use of steel electrical bus clips around the device's perimeter.
Why it matters
Smart glass technology is valuable because it reduces energy costs by controlling heat and light without moving parts, blinds, or maintenance. Gentex's patent on the sealed assembly design and manufacturing approach gave them an early foothold in a market where electrochromic windows can improve building efficiency and user comfort. The airtight chamber and insulating gas design ensure the color-changing material stays stable and doesn't degrade quickly, making the technology practical for real buildings.
Real-world use
If you've seen a car's rearview mirror that darkens automatically or visited a modern office building where windows tint themselves throughout the day, you're likely looking at technology descended from this electrochromic assembly design.
Original USPTO abstract
An electrochromic window assembly is disclosed that includes a first substrate and a second substrate that is maintained in a parallel and spaced relation from the first substrate by means of a window frame and spacer. The window assembly further includes an electrochromic device mounted within the airtight chamber formed between the first and second substrates. Electrochromic device 22 may be mounted so as to provide an air chamber between first substrate 12, which is the external substrate, and electrochromic device 22. At least one of the chambers formed between substrates 12 and 14 and electrochromic device 22 may be filled with an insulating gas such as argon. Also disclosed are novel methods for manufacture of an electrochromic device for incorporation into such a window assembly. A novel electrochromic device is also disclosed having electrical bus clips secured about the entire periphery of the electrochromic device. Also disclosed is the use of steel bus clips for the electrochromic device.
Patent details
- Publication number
- US 6,407,847
- Filing date
- 2000-07-25
- Grant date
- 2002-06-18
- Assignee
- Gentex Corporation
- Inventor(s)
- POLL DAVID L., ASH KEVIN L., THEISTE DAVID A., GUARR THOMAS F., TONAR WILLIAM L.
- CPC class
- E06B9/264
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