Liquid-crystal display apparatus

• US 5,093,655 A
• Filed: 03/25/1991
• Issued: 03/03/1992
• Est. Priority Date: 10/16/1985
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Tanioka, Atsuyoshi, Katagishi, Tatsuo, Takesada, Hajime
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): HJERPE, RICHARD A
• Application Number:
  US07/675,052
• Time in Patent Office: 344 Days
• Field of Search: 340/765, 340/784, 340/811, 340/812, 340/813, 340/814, 340/789, 340/802, 340/805, 350/332, 350/333
• US Class Current: 345/96
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: H04N 3/127 using liquid crystals

Abstract

A liquid-crystal display apparatus visually compensates the flickers of the entire face of the liquid-crystal panel through reversing the polarity of the picture signals in adjacent columns to be applied to drive the liquid-crystal panel with a plurality of display picture-elements. The polarity is reversed for each of the display picture element, of at least one or more adjacent within at least the same row, and/or for at least one horizontal scanning period or more.

Claims

1. A liquid-crystal display apparatus comprising:

a liquid crystal panel including a plurality of display picture elements arranged in rows and columns and being arranged alternatively with one row of display picture elements to be selected for every odd field and a next row of display picture elements to be selected for every even field, and said liquid crystal panel being driven upon loading of a video signal to be held within each of the display picture elements for a period of two fields in one frame;

a control means for generating a control signal;

a first polarity reversing circuit connected with the control means for reversing polarity of the video signal at every two fields;

a second polarity reversing circuit connected with the first polarity reversing circuit for reversing a polarity of an output signal from the first polarity reversing circuit every time;

a first column drive means connected with the first polarity reversing circuit to load the video signal into odd numbered columns of the display picture elements;

a second column drive means connected with the second polarity reversing circuit to load the video signal into even numbered columns of the display picture elements;

a first row drive circuit connected to the control means to drive rows having been selected for a period of odd fields; and

a second row drive circuit connected to the control means to drive rows having been selected for a period of even fields,

wherein the video signal to be loaded into the display picture elements adjacent to each other in a row direction is mutually reversed in polarity at each row of the display picture elements, and the video signal to be loaded into the display picture elements adjacent to each other in a column direction is loaded at every two continued fields in a manner that the video signal is reversed in polarity at one field, but has a same polarity at a next field.

2. A liquid-crystal display apparatus comprising:

a liquid crystal panel including a plurality of display picture elements arranged in rows and columns and being arranged alternatively with one row of display picture elements to be selected for every odd field and a next row of display picture elements to be selected for every even field, and said liquid crystal panel being driven upon loading of a video signal to be held within each of the display picture elements for a period of two fields in one frame;

a control means for generating a control signal;

a first polarity reversing circuit connected with the control means for reversing polarity of the video signal at each line and at every two fields;

a second polarity reversing circuit connected with the first polarity reversing circuit for reversing a polarity of an output signal from the first polarity reversing circuit every time;

a first column drive means connected with the first polarity reversing circuit to load the video signal into odd numbered columns of the display picture elements;

a second column drive means connected with the second polarity reversing circuit to load the video signal into even numbered columns of the display picture elements;

a first row drive circuit connected to the control means to drive rows having been selected for a period of odd fields; and

a second row drive circuit connected to the control means to drive rows having been selected for a period of even fields,

wherein the video signal to be loaded into the display picture elements adjacent to each other in a row direction is mutually reversed in polarity at each row of the display picture elements, and the video signal to be loaded into the display picture elements adjacent to each other in a column direction is loaded at every two continued fields in a manner that the video signal is reversed in polarity at one field, but has a same polarity at a next field.