| 摘要 |
To reduce a pseudo contour which occurs when displaying by a time gray scale method. When gradation is expressed with an n bit, bits each of which is shown by a binary of the gray scales are divided into three bit groups, and one frame is divided into two subframe groups. Then, a (0<a<n) subframes corresponding to bits belonging to a first bit group are divided into three or more, each about half of which is arranged in each subframe group; b (0<b<n) subframes corresponding to bits belonging to a second bit group are divided into two, each one of which is arranged in each the subframe group; and c (0≦c<n and a+b+c=n) subframes corresponding to bits belonging to a third bit group are arranged in at least one of the subframe groups. And then, an overlapped time gray scale method is applied in each subframe group to express gradation. |
| 主权项 |
1. A driving method of a display device for expressing gradation by dividing one frame into a plurality of subframes, in the case where gradation is expressed with an n bit (here n is an integer), the display device comprising:
a pixel portion comprising pixels over a substrate, each of the pixels comprising a capacitor and a bottom-gate transistor comprising a compound semiconductor; a memory; and a circuit configured to output signals to the substrate by using signals stored in the memory, wherein the capacitor comprises a conductive layer and a semiconductor layer over the conductive layer with an insulating film between the conductive layer and the semiconductor layer, wherein a plurality of signals is input into each of the pixels by using the signals output from the circuit, and wherein the pixel portion is configured to display an image by expressing gray scales in accordance with the plurality of signals, the driving method comprising the steps of: classifying bits each of which is shown by a binary of gray scales into three kinds of bit groups, that is, a first bit group, a second bit group, and a third bit group; dividing the one frame into two subframe groups; dividing each of a (here, a is an integer satisfying 0<a<n) subframes corresponding to bits belonging to the first bit group into three or more, and arranging each about half of which in each of the two subframe groups of the one frame; dividing each of b (here, b is an integer satisfying 0<b<n) subframes corresponding to bits belonging to the second bit group into two, and arranging each one of which in each of the two subframe groups of the one frame; and arranging c (here, c is an integer satisfying 0<c<n and a+b+c=n) subframes corresponding to bits belonging to the third bit group in at least one of the two subframe groups of the one frame, wherein an appearance order of a plurality of subframes corresponding to bits belonging to the first bit group and a plurality of subframes corresponding to bits belonging to the second bit group is approximately the same between the two subframe groups of the one frame; and wherein as for a part or all of the plurality of subframes corresponding to bits belonging to the first bit group and the plurality of subframes corresponding to bits belonging to the second bit group, an overlapped time gray scale method is used in each of the two subframe groups of the one frame so that gradation is expressed. |
