Erasing device for liquid crystal display image and liquid crystal display device including the same

A reflective liquid crystal display device for displaying an image by reflecting incident light from an external source onto a liquid crystal display panel where the display device comprises:

• pixels on the display panel driven by active elements;
• an erasing device coupled to the display and activated when a power source of a main body is turned OFF, wherein the erasing device includes:
• power source OFF detecting means for detecting an OFF signal that turns OFF the power source of the main body of said liquid crystal display device;
• panel power maintaining means for supplying power to said liquid crystal display panel for a certain period when said power source OFF detecting means detects said OFF signal;
• and
• erasing means for, when said power source OFF detecting means detects said OFF signal, applying to all of the pixels in said liquid crystal display panel an ON-level voltage which is a saturation voltage of liquid crystal and subsequently applying an OFF-level voltage to said all pixels in said liquid crystal display panel using the power supplied by said panel power maintaining means.

A liquid crystal display device having a Guest-Host liquid crystal display panel comprising:

• pixels on the display panel driven by active elements;
• an erasing device coupled to the display and activated when a power source of a main body is turned OFF, wherein the erasing device includes:
• power source OFF detecting means for detecting an OFF signal that turns OFF the power source of the main body of said liquid crystal display device;
• panel power maintaining means for supplying power to said liquid crystal display panel for a certain period when said power source OFF detecting means detects said OFF signal;
• and
• erasing means for, when said power source OFF detecting means detects said OFF signal, applying to all pixels in said liquid crystal display panel an ON-level voltage which is a saturation voltage, and subsequently applying an OFF-level voltage to said all pixels, using the power supplied by said panel power maintaining means.

A method for erasing an image from a liquid crystal display panel in a liquid crystal display device having pixels driven by active elements comprising the steps of:

• a. detecting an OFF signal that turns OFF a power source of a main body of said liquid crystal display device;
• b. powering said liquid crystal display panel for a certain period after an OFF signal is detected;
• c. after the OFF signal is detected, applying the power to the liquid crystal panel to charge all pixels of the panel to an ON-level which is a saturation voltage level, and
• d. subsequently applying an OFF-level voltage to all pixels of said liquid crystal panel to erase any image left on the display from prior to step (a).