Driving method for display panels

• US 4,413,256 A
• Filed: 02/20/1981
• Issued: 11/01/1983
• Est. Priority Date: 02/21/1980
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ishii, Yutaka, Yasuda, Shuhei, Koyanagi, Katsubumi, Wada, Tomio
• Primary Examiner(s): TRAFTON, DAVID
• Application Number:
  US06/236,582
• Time in Patent Office: 984 Days
• Field of Search: 340/765, 340/784, 350/333
• US Class Current: 345/96
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/1375 using dynamic scattering
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/3622 using a passive matrix G09G3/3674 - G09G3/3696 take precedence
• CPC Class Codes: H04N 3/127 using liquid crystals

Abstract

A display device includes a combined dynamic scattering mode and twisted nematic mode cell structure including at least one first display electrode oriented in a first direction and a plurality of second display electrodes in a second direction. The plurality of second display electrodes oriented are supplied with a plurality of scanning signals of sequentially shifted phases with polarity inverted at a predetermined interval of time, whereas the first electrode is supplied with frame signals indicative of information to be displayed and having polarity inverted at the predetermined interval. In order to minimize variations in the threshold level of the display device, a plurality of pulse signals having a pulse width shorter than the pulse width of said scanning signals are added to the frame signals.

Claims

1. A display device comprising:

a dynamic scattering mode liquid crystal structure including at least one first display electrode oriented in a first direction and a plurality of second display electrodes oriented in a second direction;

means for supplying said plurality of second display electrodes with a plurality of scanning signals of sequentially shifted phases with polarity inverted at a predetermined interval of time;

means for supplying said first display electrode with frame signals indicative of information to be displayed and having polarity inverted at said predetermined interval; and

means for adding a plurality of pulse signals having a pulse width shorter than the pulse width of said scanning signals to said frame signals.

2. A display device as set forth in claim 1 wherein said dynamic scattering cell structure further comprises a polarizer and a detector with 90°

twisted alignment, thus forming a combined dynamic scattering mode and twisted nematic mode or DTN structure.