Liquid crystal display device, image display device, illumination device and emitter used therefor, driving method of liquid crystal display device, driving method of illumination device, and driving method of emitter

• US 20110134154A1
• Filed: 01/31/2011
• Published: 06/09/2011
• Est. Priority Date: 06/15/2000
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Jinda, Akihito, Shiomi, Makoto, Miyachi, Koichi
• Application Number:
  US12/929,523
• Publication Number:
  US 20110134154A1
• Time in Patent Office: Days
• US Class Current: 345/690
• 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 2310/066 Waveforms comprising a gently increasing or decreasing portion, e.g. ramp
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• 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 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines

Abstract

The cold cathode tube for illuminating pixels with light which is in accordance with an output signal has luminance which gradually increases at a rise and gradually decreases at a fall per one frame time. The cold cathode tube contains a fluorescent material of only one of three primary colors of light, and has a certain OFF period or dimming period per one frame time. Between a diffusing plate and a reflecting plate are provided partition walls for parting emitting areas, so that the illumination light of one cold cathode tube does not reach the display elements to be illuminated by the other cold cathode tubes. The emission of each display element is changed per one frame time between a normal ON state and a dim state. The cold cathode tube has two or more OFF periods within one frame time, and luminance of the cold cathode tube is changed per one frame period. As a result, it is possible to suppress shortening of life of emitters in an illuminating section, and to relieve lowering of luminance of the emitters, and also to obtain a desirable display quality even in a fast-moving image.

Claims

1-153. -153. (canceled)

154. A liquid crystal display device comprising:

an emitter having a period of emitting light at a first luminance level and a period of emitting light at a second luminance level within a vertical period, said first luminance level and said second luminance level being different from each other and brighter than an OFF state.

157. The liquid crystal display device of claim 154, comprising one of a cold cathode tube, a light-emitting diode element, an electroluminescence element, a hot cathode tube, a mercury lamp, a halogen lamp, and a laser.

155. A driving method of a liquid crystal display device comprising an emitter, the method comprising a first driving signal and a second driving signal being input into an emitter at different timings within a vertical period, so that luminance of the emitter becomes different when the emitter receives the first driving signal and when the emitter receives the second driving signal, and the luminance by the first driving signal and the luminance by the second driving signal are brighter than an OFF state.

156. A liquid crystal display device comprising:

an illumination device for illuminating pixels of the liquid crystal display device;

an emitter for emitting light which is in accordance with a driving signal, luminance of said emitter being periodically changed; and

emission control means for controlling the driving signal so that one period includes two or more separate periods of reduced luminance.