[54] OPTICAL DEVICE AND ELECTROLYTIC SOLUTION
[75] Inventors: Toru Udaka, Kanagawa; Hideharu Miyagaki, Chiba, both of Japan
[73] Assignee: Sony Corporation, Tokyo, Japan
[21] Appl. No.: 08/924,599
[22] Filed: Sep. 4, 1997
[30] Foreign Application Priority Data
Sep. 6, 1996 [JP] Japan P08-257866
Aug. 7, 1997 [JP] Japan P09-207980
[51] Int. CI.7 G02B 5/23; G02F 1/153
[52] U.S. CI 252/586; 252/582; 359/273;
359/275
[58] Field of Search 252/586, 582;
359/273, 275
[56] References Cited
U.S. PATENT DOCUMENTS
5,210.638 5/1993 Eid et al 359/265
5,215,684 6/1993 Okabayashi et al 252/582
5,274,493 12/1993 Couput et al 359/275
An optical device is provided as an optical filter including a pair of substrates at least one of which is transparent, at least one transparent electrode disposed on one side of the transparent substrate, at least one counter electrode, a spacer provided between a pair of the substrates at peripheries thereof, and an RED solution as a filtering material provided in a space between a pair of the substrates. The RED solution includes a silver salt and a mixed solvent, preferably DMSO and another solvent, for dissolving the silver salt. The transparent electrodes and the counter electrode are driven by applying a voltage thereto, and the silver salt is reversibly deposited and dissolved by controlling the voltage. The RED solution is brought to be colored and to be colorless, respectively, so that an amount of light passing through the device may be adjusted.
27 Claims, 7 Drawing Sheets
