[54] SEQUENTIAL COLOR DISPLAY DEVICE
[75] Inventor: Harumi Yuyama, Yamanashi-ken, Japan
[73] Assignee: Citizen Electronics Co., Ltd.,
Fujiyoshida, Japan
[21] Appl. No.: 08/835,515
[22] Filed: Apr. 8, 1997
[30] Foreign Application Priority Data
Aug. 2, 1996 [JP] Japan 8-219140
[51] Int. CI.7 G02F 1/136; G02F 1/1335
[52] U.S. CI 349/62; 349/50; 359/142;
340/825.22; 235/380; 368/10 [58] Field of Search 349/62, 50; 359/142
[56] References Cited
U.S. PATENT DOCUMENTS
4,816,855 3/1989 Kitaura et al 354/415
Red, green and blue light sources, and a shutter are provided. Photosensors are provided for detecting the luminance ol each ol the light sources. A controller is provided for sequentially operating each ol the light sources, the shutter, and the photosensor in synchronism with each other at regular intervals. A luminance control circuit is provided for comparing a luminance detected by the photosensor with a relerence value and for controlling the luminance ol each ol the light sources based on the comparison so as to keep a color balance ol the light emitted Irom the color display device.
12 Claims, 13 Drawing Sheets
