Picture display method using liquid crystal device

• US 6,573,882 B1
• Filed: 05/19/2000
• Issued: 06/03/2003
• Est. Priority Date: 05/20/1999
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Takabayashi, Hiroshi
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): ZAMANI, ALI A
• Application Number:
  US09/573,552
• Time in Patent Office: 1,110 Days
• Field of Search: 345/102, 345/88, 345/98, 345/202, 345/87, 345/100, 345/690, 345/691, 345/692, 345/693, 345/84, 349/61, 349/84, 349/68, 349/70, 315/119, 315/225, 315/307
• US Class Current: 345/102
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

A liquid crystal device is sequentially illuminated with three primary color lights in three primary color illumination steps including an off period (1) before, (2) before and after and (3) after the primary color light period, respectively. As a result, each primary color light illumination step includes a black picture display period corresponding to the off period, whereby motion picture blurring and color splitting can be suppressed without requiring a complicated circuit for generating new data for the black picture display.

Claims

1. A color picture display system using a liquid crystal display apparatus of the type including a light source capable of emitting three primary color lights of R (red), G (green) and B (blue) separately at arbitrary time, and a liquid crystal device for receiving and selectively switching the three primary color lights from the light source;

said system being operable to display a full-color motion picture in a succession of fields each including at least three sub-fields for emitting the color lights of R, G and B, respectively,

wherein an extinction period for turning off all the color lights is provided between each pair of successive sub-fields so as to provide the extinction period that is longer when placed between a successive pair of fields than when placed between a successive pair of sub-fields in one field period.

2. A color picture display system according to claim 1, wherein said at least three sub-fields for emitting the color lights of R, G and B have equal lengths of period, and the color lights of R, G and B are emitted for mutually equal lengths of period in the respective sub-fields.

3. A color picture display system according to claim 1, wherein the liquid crystal device comprises a matrix of pixels each comprising a liquid crystal, a capacitor for storing picture data, a first transistor for introducing the picture data to the capacitor, and a second transistor for transferring the picture data stored at the capacitor to the liquid crystal.

4. A liquid crystal display apparatus of the type including a light source capable of emitting three primary color lights of R(red), G(green) and B(blue) separately at arbitrary times, and a liquid crystal device for receiving and selectively switching the three primary color lights from the light source;

said apparatus being operable to display a full-color motion picture in a succession of fields each including at least three sub-fields for emitting the color lights of R, G and B, respectively,

wherein a period for displaying a black picture is provided between each pair of successive sub-fields such that the period for displaying the black picture is longer when placed between a successive pair of fields than when placed between a successive pair of sub-fields in one field period.