Patent · US Expired

Flat panel device and display driver with on/off power controller used to prevent damage to the LCD

USRE39236E1 · kind E1 · reissue

4Cited by
20References
2Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 11, 2001
Grant dateAug 15, 2006
Priority date
Expiry dateMay 11, 2021

Classification

  • Technology area (CPC —)General

Abstract

Signal management control units 471-47n of respective scan drivers LSI in an LCD module are cascade-connected and each have the same construction. A detected signal of the signal management control unit 47J is a data signal latch clock LP applied to a terminal CKB1. A detected signal of the signal management control unit 472 is a frame start signal SP applied to a terminal CKB2. A detected signal of the signal management control unit 47n is an AC-transforming clock FR applied to a terminal CKBn. The signal management control unit 471 includes a signal stop detection circuit 48 serving as a signal detection means for detecting a stop of the detected signal and a sequence processing circuit 51 consisting of a signal delay circuit 49 and a logic circuit 50. When stopping oscillations of, e. g., the frame start signal SP, outputs T1-Tn of the circuit 51 change to an L level. Hence, a display-off signal DF of the LCD module assumes the L level. A liquid crystal panel is forcibly set in a display-off mode. As a result, even if the frame start signal SP is stopped due to some cause, a liquid crystal application voltage is set down to zero. It is, therefore, possible to avoid a liquid crys…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.