Electro-optical apparatus having antiferrodielectric liquid crystal panel with normalization to prevent white brightening
First Claim
1. An electro-optical apparatus comprising:
- an antiferroelectric liquid crystal panel; and
processing means for performing a series of normalization processes as many times as necessary to provide uniform brightness, in a no voltage condition, of all pixels required to exhibit a uniform electro-optical performance in a normalized level that is set not lower than a minimum brightness level and not higher than a level approximately equal to an aging brightness level, wherein said minimum brightness level represents a saturation value of the brightness level, in a no voltage condition, obtained by successively applying to said liquid crystal panel for a period of time, a voltage that causes only liquid crystal molecules in an antiferroelectric state to make a transition to a ferroelectric state, and then terminating the applied voltage, and wherein said aging brightness level represents a saturation value of the brightness level, in a no voltage condition, obtained by applying alternately to said liquid crystal panel, a voltage for a period of time that causes liquid crystal molecules in the antiferroelectric state to make a transition to the ferroelectric state and a voltage for a period of time that causes liquid crystal molecules in the ferroelectric state to make a transition to the antiferroelectric state and then terminating the applied voltage.
2 Assignments
0 Petitions
Accused Products
Abstract
An antiferroelectric liquid crystal display apparatus free from burn-in and achieving high display quality is provided by providing means for preventing pixel brightness from varying between pixels continuously held in an ON (bright) state and pixels continuously held in an OFF (dark) state. Aging processing is performed to saturate the brightness level of pixels into a stable state and thereby prevent the occurrence of a white brightening phenomenon. For this purpose, the brightness at a no voltage condition (base brightness) is set to a normalized level for all pixels in the liquid crystal panel that are required to exhibit uniform display performance. Further, temperature variations in the liquid crystal panel are eliminated to stabilize the brightness level and thereby prevent the occurrence of a white darkening phenomenon. Means is also provided for repeatedly performing normalization processes automatically or manually.
-
Citations
23 Claims
-
1. An electro-optical apparatus comprising:
-
an antiferroelectric liquid crystal panel; and
processing means for performing a series of normalization processes as many times as necessary to provide uniform brightness, in a no voltage condition, of all pixels required to exhibit a uniform electro-optical performance in a normalized level that is set not lower than a minimum brightness level and not higher than a level approximately equal to an aging brightness level, wherein said minimum brightness level represents a saturation value of the brightness level, in a no voltage condition, obtained by successively applying to said liquid crystal panel for a period of time, a voltage that causes only liquid crystal molecules in an antiferroelectric state to make a transition to a ferroelectric state, and then terminating the applied voltage, and wherein said aging brightness level represents a saturation value of the brightness level, in a no voltage condition, obtained by applying alternately to said liquid crystal panel, a voltage for a period of time that causes liquid crystal molecules in the antiferroelectric state to make a transition to the ferroelectric state and a voltage for a period of time that causes liquid crystal molecules in the ferroelectric state to make a transition to the antiferroelectric state and then terminating the applied voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
Specification