Display control method and apparatus for liquid crystal display device

Claim 2

A display control apparatus for liquid crystal display device, in which a ferroelectric liquid crystal (9) is interposed between a plurality of scanning electrodes (L) and signal electrodes (S) which are arranged in a direction intersecting each other, intersecting are as of the scanning electrodes (L) and signal electrodes (S) are formed into picture elements (A), a selective voltage (VCA) for rewriting the picture elements on the electrode is applied to one scanning electrode among the plural scanning electrodes, a non-selective voltage (VCB) for not rewriting the picture elements on the electrodes is applied to the remaining scanning electrodes, and a signal voltage (VSC, VSD, VSG) corresponding to data to be displayed by the picture elements on the scanning electrode to which the selective voltage (VCA) is applied, is applied to the signal electrodes (S), comprising; control means (22) which performs the partial rewriting operation, whereby when displayed by the picture elements (A) of the liquid crystal display device (20), it is detected for every scanning electrode (L) whether there is change in data, the selective voltage (VCA) is applied to the scanning electrodes where there is the change, and the signal voltage (VSC, VSD, VSG) is applied to the signal electrodes responsive to whether the picture elements on the selected scanning electrode are changed from a bright display state to a dark display state, or from the dark display state to the bright display state, or the bright and dark display states are not changed, and the transcribing operation, whereby the display state of all picture elements (A) of the liquid crystal display device (20) is rewritten at the rate of one scanning electrode for every plural adjoining scanning electrodes, and an interlaced scanning for rewriting all of the picture elements in plural fields is conducted at a fixed period, said control means (22) securing the time for rewriting the picture elements on the scanning electrode by the partial rewriting operation, whenever the picture elements on (A) a fixed number of scanning electrodes are transcribed by the transcribing operation, for a fixed number of scanning electrodes in advance.

Claim 3

A display control apparatus for the liquid crystal display device in accordance with claim 2, wherein said control means (22) includes, a memory (26) for display which stores data to be displayed next for one picture screen, a memory (28) for discrimination which stores discrimination data indicating whether there is the change in data of the display memory (26) for every scanning electrode (L) in the lump, and a holding memory (28) which stores the display state of the picture elements (A) displayed on the liquid crystal display device (20) for one picture screen, in case the picture elements (A) of the liquid crystal display device (20) are rewritten by the interlaced scanning, data of the holding memory (28) is used as the data to be displayed by the picture elements on the scanning electrode to which the selective voltage (VCA) is applied, and in case the scanning electrode, whose data to be displayed by the picture elements (A) of the liquid crystal display device (20) has changed, is rewritten, the data obtained from data of the display memory (26) and the holding memory (28) is used as data to be displayed by the picture elements on the scanning electrode to which the selective voltage (VCA) is applied, and at the same time, data of the display memory (26) is stored in the holding memory (25).

Claim 4

A display control apparatus for the liquid crystal display device in accordance with claim 3 wherein the control means (22) will not store data to be displayed next in the display memory (26), unless all of the data, which are data of the display memory (26) previously stored and differ from the data of the display memory (26) stored even before, are stored in the holding memory (28).