Electrochromic medium having a color stability

• US 6,407,847 B1
• Filed: 07/25/2000
• Issued: 06/18/2002
• Est. Priority Date: 07/25/2000
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Tonar, William L., Guarr, Thomas F., Poll, David L., Ash, Kevin L., Theiste, David A.
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/626,714
• Time in Patent Office: 693 Days
• Field of Search: 359/265, 359/267, 359/271, 359/273, 359/275, 359/270, 359/885, 252/583, 252/582, 252/586
• US Class Current: 359/275
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 3/66 Units comprising two or more parallel glass or like panes permanently secured together reforming and uniting glass sheets by fusing C03B23/00; joining glass to glass or to other materials C03C27/00; laminated glass B32B17/10
• CPC Class Codes: E06B 3/66366 specially adapted for units comprising more than two panes or for attaching intermediate sheets
• CPC Class Codes: E06B 3/6722 with adjustable passage of light
• CPC Class Codes: E06B 3/6775 Evacuating or filling the gap during assembly
• CPC Class Codes: E06B 9/264 Combinations of lamellar blinds with roller shutters, screen windows, windows, or double panes; Lamellar blinds with special devices
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/161 Gaskets; Spacers; Sealing of cells; Filling or closing of cells
• CPC Class Codes: G02F 2201/44 Arrangements combining different electro-active layers, e.g. electrochromic, liquid crystal or electroluminescent layers
• CPC Class Codes: Y10S 359/90 Methods

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.

Claims

1. A window comprising an electrochromic medium having a color stability Δ

E less than 5, measured in its minimum low transmission state after exposure to 700 hours in a weatherometer while cycling, each cycle consisting of application of sufficient potential for a sufficient time such that the window reaches its low transmission state for at least 210 hours.

2. The window of claim 1, wherein each cycle consists of applying a voltage of about 1.2V for 20 sec. and 0.0V for 40 sec.

3. The window of claim 1, wherein said electrochromic medium is dispersed in a cross-linked polymer matrix.

4. A window comprising an electrochromic medium having a color stability Δ

E less than 5, measured in its high transmission state after exposure to 700 hours in a weatherometer while cycling, each cycle consisting of application of sufficient potential for a sufficient time such that the window reaches its low transmission state for at least 210 hours.

5. The window of claim 4, wherein each cycle consists of applying a voltage of about 1.2V for 20 sec. and 0.0V for 40 sec.

6. The window of claim 4, wherein said electrochromic medium is dispersed in a cross-linked polymer matrix.

7. A window comprising an electrochromic medium having a color stability Δ

E less than 5, measured in its low transmission state after exposure to 700 hours in a weatherometer while cycling, and a color stability Δ

E less than 5, measured in its high transmission state after exposure to 700 hours in a weatherometer while cycling, wherein each cycle consists of application of sufficient potential for a sufficient time such that the window reaches its low transmission state for at least 210 hours.

8. The window of claim 7, wherein each cycle consists of applying a voltage of about 1.2V for 20 sec. and 0.0V for 40 sec.

9. The window of claim 7, wherein said electrochromic medium is dispersed in a cross-linked polymer matrix.