US 6,556,192 B2 · Apparatus and method for preventing a white-screen error in a liquid crystal display device

Abstract

A system and method for preventing a white-screen error in a liquid crystal display (LCD) device operates by detecting an output voltage signal from a DC/DC converter and reducing a time delay between the output voltage signal and a data signal for the LCD gradually by a fixed value until a timing problem between the output voltage signal and the data signal is overcome. A software reset is executed when the time interval between the output voltage signal and the data signal is too great, causing the output voltage signal to shut down before the data signal is turned on. The process is repeated until the timing is proper such that the output voltage signal is detected to remain when the data signal is output. If the time delay is reduced to a predetermined threshold, then it is determined that a malfunction has occurred, and an alert is provided to a user.

Claims32

Dependent claims

A driving portion of a liquid crystal display device, comprising:

a data-line driving circuit;
a gate-line driving circuit;
an interface outputting data signals;
a liquid crystal display controller receiving the data signals and outputting display data signals to the data-line driving circuit and timing signals to the gate-line driving circuit;
a DC/DC converter supplying a plurality of output power source voltages to the gate-line driving circuit and the data-line driving circuit;
a voltage detector detecting a voltage level of one of the output power source voltages supplied by the DC/DC converter and outputting a feedback signal;
and
an interface controller receiving the feedback signal from the voltage detector, outputting enable signals to the interface and to the DC/DC converter, and outputting a control signal to advance the data signals when the detected voltage level of the one output power source voltage is less than 90% of a preset voltage level.

5 more elements

In a liquid crystal display device including:

a data-line driving circuit,
a gate-line driving circuit,
an interface controller outputting control signals according to a preset program,
an interface receiving video signals and converting said video signals to data signals according to a preset resolution and display size,
a liquid crystal display controller receiving the data signals from the interface and outputting display data signals to the data-line driving circuit and a timing signal to the gate-line driving circuit,
a DC/DC converter receiving a power source voltage and converting the power source voltage into a plurality of output power source voltages, and
a liquid crystal display panel receiving the display data signals from the data-line driving circuit and displaying images according to a signal from the gate-line driving circuit, a method of preventing a white-screen error, comprising:
(a) transmitting enable signals from the interface controller to the DC/DC converter and the interface;
(b) outputting the data signals from the interface after a timing offset N from a time of transmitting the enable signals;
(c) determining whether the timing offset N is less than a first constant a, the first constant a being preset corresponding to a time period indicating a hardware malfunction;
(d) when the timing offset N is greater than the first constant α, determining whether the output power source voltage supplied from the DC/DC converter is normal;
(e) decreasing the timing offset by a second constant β when the output power source voltage is abnormal;
and
(f) repeating steps (a) through (e) until the output power source is determined to be normal.

11 more elements

Dependencies are inferred from the claim text.

Apparatus and method for preventing a white-screen error in a liquid crystal display device

Life of this patent

Apparatus and method for preventing a white-screen error in a liquid crystal display device

Life of this patent

Abstract

Claims32