Liquid crystal display device and a method for driving the same

• US 7,692,621 B2
• Filed: 08/26/2002
• Issued: 04/06/2010
• Est. Priority Date: 08/28/2001
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Song, Jang-Kun
• Primary Examiner(s): Patel; Nitin
• Application Number:
  US10/488,067
• Publication Number:
  US 20040183773A1
• Time in Patent Office: 2,780 Days
• Field of Search: 345 84-102, 345/103, 345/204, 345/211, 345/212, 315/200, 315/224, 315/225, 315/169.1, 315/169.3, 362/30, 362/246, 362/800
• US Class Current: 345/102
• 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 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 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

Disclosed are a liquid crystal display device and a method for driving the same. After all the gate lines included in each effective display region divided into several regions, are turned on, a light is supplied to a liquid crystal after all the liquid crystals are completely arranged, but the light is not applied to a portion of the effective display regions until all the liquid crystals are completely arranged. The process is repeatedly performed concerning each effective display region. Thus, the poor quality of display image such as image spreading phenomenon of the moving image can be prevented. Also, the light supply time can greatly increase, thereby accomplishing an image display with a high brightness.

Claims

1. A liquid crystal display device comprising:

a liquid crystal display panel including a liquid crystal interposed between two substrates, and a plurality of gate lines; and

a backlight assembly having i) a signal synchronism part for detecting a gate line to which a gate driving signal is applied and generating an inverter control signal, ii) an inverter for receiving the inverter control signal to generate a lamp driving signal, and iii) at least two lamps parallel disposed under the liquid crystal display panel to be turned on or off in response to the lamp driving signal,

wherein the inverter control signal generated from the signal synchronism part is a signal for turning off a portion of the lamps to stop supplying light to the liquid crystal corresponding to the gate line to which the gate driving signal is applied during a predetermined period of arranging the liquid crystal, after the gate driving signal is applied to the corresponding gate line,

wherein the backlight assembly supplies the liquid crystal display panel with light continuously during one frame.

2. The liquid crystal device of claim 1, wherein the predetermined period starts when the gate driving signal is applied to the corresponding gate line, and ends when the arrangement of the liquid crystal corresponding to the gate line to which the gate driving signal is applied is completed.

3. The liquid crystal display device of claim 1, wherein the gate lines of the liquid crystal display panel are divided into a plurality of groups corresponding to positions of the lamps, the gate lines of each group are turned on sequentially, and a lamp corresponding to a group including the gate line to which the gate driving signal is applied is turned off in response to the inverter control signal during the predetermined period after a last gate line of the corresponding group is turned on.

4. The liquid crystal display device of claim 3, wherein the lamp corresponding to each group is continuously turned on during one frame after the predetermined period.

5. The liquid crystal display device of claim 3, wherein the predetermined period starts when the gate driving signal is applied to the last gate line of the corresponding group, and ends when an arrangement of the liquid crystal corresponding to the last gate line of the corresponding group is completed.

6. The liquid crystal display device of claim 1, wherein the turned off lamp is continuously turned on during one frame after the predetermined period.

7. A method for driving a liquid crystal display device comprising the steps of:

i) applying an electric field to a liquid crystal included in a first region of a liquid crystal display panel to arrange the liquid crystal, the liquid crystal display panel being divided into a plurality of regions, each region comprising a plurality of gate lines, wherein a gate-on voltage is applied to the gate lines sequentially from a first gate line to a last gate line in each region;

ii) stopping supplying a light to the liquid crystal included in the first region during a predetermined period of arranging the liquid crystal included in the first region, upon application of the gate-on voltage to the last gate line in the first region;

iii) supplying the light to the liquid crystal included in the first region after the predetermined period of arranging the liquid crystal included in the first region; and

iv) repeating the steps ii) and iii) concerning liquid crystals included in other regions of the liquid crystal display panel,

wherein the light is continuously supplied to the liquid crystal display panel during one frame.

8. A liquid crystal display device, comprising:

a liquid crystal display panel including a liquid crystal interposed between two substrates, and a plurality of gate lines; and

a backlight assembly having i) a signal synchronism part for detecting a gate line to which a gate driving signal is applied and generating an inverter control signal, ii) an inverter for receiving the inverter control signal to generate a lamp driving signal, and iii) at least two lamps parallel disposed under the liquid crystal display panel to be turned on or off in response to the lamp driving signal,

wherein the gate lines are divided into a plurality of groups corresponding to positions of the lamps, the gate lines of each group are turned on sequentially, and a lamp corresponding to each group is turned off in response to the inverter control signal during a predetermined period of arranging the liquid crystal after a last gate line of each group is turned on,

wherein the backlight assembly supplies the liquid crystal display panel with light continuously during one frame.

9. The liquid crystal display device of claim 8, wherein the predetermined period starts when the gate driving signal is applied to a last gate line of the corresponding group, and ends when an arrangement of the liquid crystal corresponding to the last gate line of the corresponding group is completed.

10. The liquid crystal display device of claim 8, wherein the lamp is turned on at the end of the predetermined period and remains on until the signal synchronism part detects the next application of the gate driving signal to the last gate line of the corresponding group.

11. The liquid crystal display device of claim 8, wherein the lamp corresponding to each group is continuously turned on during one frame after the predetermined period.