Liquid crystal display apparatus and method for driving the same

Abstract

There are disclosed methods for driving liquid crystal display apparatuses for certainly completing in a short time to performing a transition of liquid crystal molecules to a displayable alignment in liquid crystal display apparatuses such that an initial alignment of the liquid crystal molecules is different from the displayable alignment, typically an optically compensated bend mode liquid crystal display apparatus. A voltage is applied to a liquid crystal layer until display area in the liquid crystal layer is transformed to the displayable alignment. After the completion of the transition, a backlight is switched on to shift to a display-driving mode. In order to complete the transition in a short time, voltage pulse under the conditions (such as a frequency and a voltage value) determined in accordance with a temperature of a liquid crystal panel is applied to the liquid crystal layer.

1 - 44 . (canceled)  
   
   
       45 . A method for driving a crystal display apparatus, the method is for an optically compensated bend mode crystal display apparatus comprising: a liquid crystal panel including a pair of substrates, a liquid crystal layer sandwiched between said substrates, and a voltage-application unit for applying a voltage to said liquid crystal layer; said method including in advance of displaying an image the steps of: 
 measuring a temperature of said liquid crystal panel;    determining a condition of a voltage pulse for performing a transition of said liquid crystal layer to a bend alignment on the basis of the measured temperature; and    applying said voltage pulse to said liquid crystal layer according to the determined condition.    
   
   
       46 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein a frequency of said voltage pulse is determined on the basis of the measured temperature in the step of determining a condition of said voltage pulse.  
   
   
       47 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein a frequency of said voltage pulse is set to be higher at a high temperature than at a low temperature in the step of determining a condition of said voltage pulse.  
   
   
       48 . The method for driving a liquid crystal display apparatus in accordance with  claim 47 , wherein a frequency of said voltage pulse is set to be in a range of 2 to 5 Hz at said temperature of 20° C. or more; and a frequency of said voltage pulse is set to be in a range of 0.2 to 1 Hz at said temperature of 0° C. or less.  
   
   
       49 . The method for driving a liquid crystal display apparatus in accordance with  claim 47 , wherein a frequency of said voltage pulse is set to be in a range of 2.5 to 4 Hz at said temperature of 20° C. or more; and a frequency of said voltage pulse is set to be in a range of 0.4 to 0.6 Hz at said temperature of 0° C. or less.  
   
   
       50 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein a voltage value of said voltage pulse is determined on the basis of the measured temperature in the step of determining a condition of said voltage pulse.  
   
   
       51 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein a frequency and a voltage value of said voltage pulse are determined on the basis of the measured temperature in the step of determining a condition of said voltage pulse.  
   
   
       52 . The method for driving a liquid crystal display apparatus in accordance with  claim 50 , wherein a voltage value of said voltage pulse is set to be higher at a low temperature than at a high temperature in the step of determining a condition of said voltage pulse.  
   
   
       53 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein a pulsewidth of said voltage pulse is determined on the basis of the measured temperature in the step of determining a condition of said voltage pulse.  
   
   
       54 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein a condition of said voltage pulse varies continuously in accordance with a temperature of said liquid crystal panel.  
   
   
       55 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein a condition of said voltage pulse to be determined is set for each predetermined temperature range in the step of determining the condition of said voltage pulse.  
   
   
       56 . The method for driving a liquid crystal display apparatus in accordance with  claim 55 , wherein an operable temperature range is divided into said two temperature ranges.  
   
   
       57 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein an initial period in which a voltage value applied to said liquid crystal layer is approximately 0 V is set immediately before applying said voltage pulse between to said liquid crystal layer in said step of applying said voltage pulse.  
   
   
       58 . The method for driving a liquid crystal display apparatus in accordance with  claim 57 , wherein said initial period is set to be in a range of 0.2 to 5 seconds.  
   
   
       59 . The method for driving a liquid crystal display apparatus in accordance with  claim 57 , wherein a plurality of said voltage pulses are intermittently applied in said step of applying said voltage pulse; and at least one of said voltage pulses is accompanied with a period in which a voltage value applied to said liquid crystal layer is set to be approximately 0 V in an interval from said preceding voltage pulse thereto.  
   
   
       60 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein said voltage pulse is simultaneously applied at all pixels in said step of applying said voltage pulse.  
   
   
       61 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein said optically compensated bend mode liquid crystal display apparatus comprising a backlight for projecting light to said liquid crystal panel and said backlight is switched on after a completion of said transition of the liquid crystal layer to a bend alignment by applying said voltage pulse.  
   
   
       62 . The method for driving a liquid crystal display apparatus in accordance with  claim 45 , wherein said optically compensated bend mode liquid crystal display apparatus is an active matrix type liquid crystal display apparatus having a switching element at each pixel.  
   
   
       63 - 65 . (canceled)  
   
   
       66 . A liquid crystal display apparatus comprising: 
 a liquid crystal panel including a pair of substrates, a liquid crystal layer being sandwiched between said substrates and having an initial alignment of spray alignment and a displayable alignment of bend alignment, and a voltage application unit for applying a voltage to said liquid crystal layer;    a temperature-detecting unit for detecting a temperature of said liquid crystal panel; and    a pulse condition-determination unit for determining a condition of a voltage pulse to be applied by said voltage application unit for performing a transition of said liquid crystal layer to a bend alignment on the basis of a temperature of said liquid crystal panel detected by said temperature-detecting unit.    
   
   
       67 . The liquid crystal display apparatus in accordance with  claim 66 , wherein said condition is a pulse frequency selected from a range of 0.2 to 1 Hz.  
   
   
       68 . The liquid crystal display apparatus in accordance with  claim 66 , wherein said condition is a pulse frequency selected from a range of 0.4 to 0.6 Hz.  
   
   
       69 . An optically compensated bend mode liquid crystal display apparatus comprising: 
 a liquid crystal panel including a pair of substrates, a liquid crystal layer being sandwiched between said substrates and having an initial alignment of spray alignment and a displayable alignment of bend alignment and a voltage application unit for applying a voltage to said liquid crystal layer;    a temperature-measuring unit for measuring a temperature of said liquid crystal panel;    a pulse condition-determination unit for determining a condition of a voltage pulse for performing a transition of said liquid crystal layer to a bend alignment on the basis of the temperature measured by said temperature-measuring unit; and    a voltage pulse-application unit for applying a voltage pulse to said liquid crystal layer according to the condition determined by said pulse condition-determination unit.    
   
   
       70 . The liquid crystal display apparatus in accordance with  claim 69 , wherein said condition of a voltage pulse to be determined is at least one selected from the group consisting of a frequency, a voltage value and a pulsewidth of said voltage pulse.  
   
   
       71 - 73 . (canceled)