MOTION DETECTION APPARATUS AND METHOD APPLIED TO LIQUID CRYSTAL DISPLAY DEVICE

1 . A motion detection apparatus, comprising:

a storage unit for storing a first frame image at a first time;

a difference calculation unit electrically connected to said storage unit for receiving said first frame image and a second frame image received at a second time so as to calculate a difference value of each pixel between said first frame image and said second frame image; and

a threshold unit electrically connected to said difference calculation unit for determining an adjustment value and a variance between said first frame image and said second frame image according to the result of said difference value of each pixel between said first frame image and said second frame image.

2 . The motion detection apparatus, as recited in claim 1 , wherein if the average of the sum of difference values of each pixel between said first frame image and said second frame image is less than or equal to a critical value, said second frame image is identified as a static image and if the average of the sum of difference values of each pixel between said first frame image and said second frame image is greater than said critical value, said second frame image is considered variable and thereby identified as a motion image.

3 . The motion detection apparatus, as recited in claim 1 , wherein if the average of the sum of difference values of each pixel between said first frame image and said second frame image is less than or equal to a critical value, said second frame image is identified as a static image and thus a driving circuit is actuated to keep a backlight module on to supply light to a liquid crystal panel steadily.

4 . The motion detection apparatus, as recited in claim 1 , wherein if the average of the sum of difference values of each pixel between said first frame image and said second frame image is greater than said critical value, said second frame image is considered variable and thereby identified as a motion image and thus a driving circuit is actuated to enable a backlight module to supply light to a liquid crystal panel by the scan backlight technique.

5 . The motion detection apparatus, as recited in claim 1 , wherein said storage unit is a buffer.

6 . The motion detection apparatus, as recited in claim 1 , wherein said difference calculation unit is a subtractor.

7 . The motion detection apparatus, as recited in claim 1 , wherein said adjustment value is an overdrive value.

8 . The motion detection apparatus, as recited in claim 1 , wherein said motion detection apparatus is applied to a liquid crystal display device.

9 . A motion detection method, comprising the steps of:

storing a first frame image in a storage unit at a first time;

receiving said first frame image and a second frame image which is received at a second time;

calculating a difference value of each pixel between said first frame image and said second frame image; and

determining a adjustment value and a variance between said first frame image and said second frame image according to the result of said difference value of each pixel between said first frame image and said second frame image.

10 . The motion detection method, as recited in claim 9 , wherein if the average of the sum of difference values of each pixel between said first frame image and said second frame image is less than or equal to a critical value, said second frame image is identified as a static image and if the average of the sum of difference values of each pixel between said first frame image and said second frame image is greater than said critical value, said second frame image is considered variable and thereby identified as a motion image.

11 . The motion detection method, as recited in claim 9 , wherein said motion detection method is applied to a liquid crystal display device.

12 . The motion detection method, as recited in claim 11 , wherein if the average of the sum of difference values of each pixel between said first frame image and said second frame image is less than or equal to a critical value, said second frame image is identified as a static image and thus a driving circuit is actuated to keep a backlight module on to supply light to a liquid crystal panel steadily.

13 . The motion detection method, as recited in claim 11 , wherein if the average of the sum of difference values of each pixel between said first frame image and said second frame image is greater than said critical value, said second frame image is considered variable and thereby identified as a motion image and thus a driving circuit is actuated to enable a backlight module to supply light to a liquid crystal panel by the scan backlight technique.

14 . A motion detection method applied to a liquid crystal display device, comprising the steps of:

storing a first frame image in a frame buffer at a first time;

storing gradually a second frame image in a first line buffer at a second time;

retrieving gradually said first frame image from said frame buffer and then storing gradually said retrieved first frame image in a second line buffer;

calculating a difference value of each pixel between said first frame image which is stored in said second line buffer and said second frame image which is stored in said first line buffer;

generating a gain according to the information of said second frame image which is stored in said first line buffer;

multiply said gain by the difference value of each pixel between said first frame image and said second frame image;

calculating a modified overdrive value by means of multiply said gain by the average of the sum of difference values of each pixel;

determining variation in gray scale values between said first frame image and said second frame image based on said modified overdrive value.

15 . The motion detection method, as recited in claim 14 , wherein said gain is figured out, on the basis of a block of n*n pixels, by subtracting the minimum gray scale value of said block from the maximum gray scale value of said block.

16 . The motion detection method, as recited in claim 14 , wherein said gain is figured out by multiplying a block of n*n pixels of said second frame image by a filter value specified for said block of n*n pixels.

17 . The motion detection method, as recited in claim 14 , wherein if the average of the sum of the products of said gain and a difference value of each pixel between said first frame image and said second frame image is less than or equal to a critical value, said second frame image is identified as a static image and thus a driving circuit is actuated to keep a backlight module on to supply light to a liquid crystal panel steadily.

18 . The motion detection method, as recited in claim 14 , wherein if the average of the sum of the products of said gain and a difference value of each pixel between said first frame image and said second frame image is greater than a critical value, said second frame image is considered variable and thereby identified as a motion image and thus a driving circuit is actuated to enable a backlight module to supply light to a liquid crystal panel by the scan backlight technique.

19 . The motion detection method, as recited in claim 17 , wherein if the average of the sum of the products of said gain and a difference value of each pixel between said first frame image and said second frame image is greater than said critical value, said second frame image is considered variable and thereby identified as a motion image and thus a driving circuit is actuated to enable said backlight module to supply light to said liquid crystal panel by the scan backlight technique.