Liquid Crystal Display Device Having A Plurality of First and Second Scanning Lines and a Plurality of First and Second Video Lines

• US 20120026214A1
• Filed: 10/11/2011
• Published: 02/02/2012
• Est. Priority Date: 09/05/2007
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Japan Display Incorporated
• Inventors: Oke, Ryutaro, Ono, Kikuo, Mori, Ikuko, Baba, Masashi, Sato, Yuya
• Granted Patent: US 8,482,513 B2
• 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 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• 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 3/3666 with the matrix divided into sections

Abstract

A liquid crystal display device includes a liquid crystal display panel having first and second scanning lines, first and second video lines, a first scanning line driving circuit, a second scanning line driving circuit, at least one first video line driving circuit, at least one second video line driving circuit, a backlight having a number of light sources, and a light controlling circuit for controlling the turning on and off of the backlight. The first scanning lines are divided into M groups where M is an integer of 2 or more (M≧2), the second scanning lines are divided into N groups where N is an integer of 2 or more (N≧2), the region of the backlight which corresponds to the first scanning lines is divided into M regions, and the region which corresponds to the second scanning lines is divided into N regions.

Claims

1. (canceled)

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4. (canceled)

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9. (canceled)

10. A liquid crystal display device, comprising:

a liquid crystal display panel having a number of first scanning lines, a number of second scanning lines, a number of first video lines which cross said number of first scanning lines, and a number of second video lines which cross said number of second scanning lines;

a first scanning line driving circuit for supplying a scanning voltage to said number of first scanning lines;

a second scanning line driving circuit for supplying a scanning voltage to said number of second scanning lines;

at least one first video line driving circuit for supplying a video voltage to said number of first video lines; and

at least one second video line driving circuit for supplying a video voltage to said number of second video lines, said first video line driving circuit an said second video line driving circuit are provided along two sides of said liquid crystal display panel which face each other;

a backlight having a number of light sources; and

a light controlling circuit for controlling the turning on and off of said backlight;

wherein said number of first scanning lines are divided into M groups where M is an integer of 2 or more (M≧

2), said number of second scanning lines are divided into N groups where N is an integer of 2 or more (N≧

2), the region of said backlight which corresponds to said number of first scanning lines is divided into M regions and the region which corresponds to said number of second scanning lines is divided into N regions, and said light controlling circuit turns off a jth region of said backlight (1≦

j≦

M) when said first scanning line driving circuit is supplying a selective scanning voltage to the first scanning lines within a jth group of said number of first scanning lines, turns on the jth region of said backlight when no selective scanning voltage is supplied to the first scanning lines within the jth group, turns off a kth region of said backlight (1≦

k≦

N) when at least one of said second scanning line driving circuits supplies a selective scanning voltage to the second scanning lines within a kth group of said number of second scanning lines, and turns on the kth region of said backlight when no selective scanning voltage is supplied to the second scanning lines within the kth group.

11. The liquid crystal display device according to claim 10, wherein said liquid crystal display panel has each of said number of first video lines and said number of second video lines is provided in such a manner as to be cut out between said number of first scanning lines and said number of second scanning lines.

12. The liquid crystal display device according to claim 10, wherein when the direction from said first video line driving circuit toward said second video line driving circuit is a first scanning direction and the direction from said second video line driving circuit toward said first video line driving circuit is a second scanning direction, the direction in which a selective scanning voltage is supplied from said first scanning line driving circuit to each scanning line of said number of first scanning lines in sequence is said first scanning direction, and the direction in which a selective scanning voltage is supplied from said second scanning line driving circuit to each scanning line of said number of second scanning lines in sequence is said second scanning direction

13. The liquid crystal display device according to claim 12, wherein said light controlling circuit makes the period during which the Mth region from among the M regions of said backlight and the first region from among the N regions which are adjacent to the Mth region are turned on shorter than the time during which the remaining regions are turned on.

14. The liquid crystal display device according to claim 10, wherein the jth region and the kth region of said backlight have at least one cold cathode fluorescent tube, and said light controlling circuit controls the turning on and off of said cold cathode fluorescent tube in the jth region and the kth region of said backlight.

15. The liquid crystal display device according to claim 10, wherein the jth region and the kth region of said backlight have at least one light emitting diode, and said light controlling circuit controls the turning on and off of said light emitting diode in the jth region and the kth region of said backlight.