公开(公告)号：JPH07110666A

公开(公告)日：1995-04-25

申请号：JP24464693

申请日：1993-09-30

Applicant: IBM

Inventor： KUSANO MASAKAZU ,  OIE MASAKI ,  KANZAKI EISUKE

IPC: G02F1/133 ,  G06T5/00 ,  G09G3/20 ,  G09G3/36

Abstract: PURPOSE: To more precisely express an image expressed by image data even when a display is provided with a small number of expressable gradations. CONSTITUTION: In conversion at the time of converting image data expressing the density of one dot by 4-bit dot data to plural frames of data expressing the density of one dot by three bits and executing frame modulation for successively displaying the plural frames to LCD, high-order three bits of dot data are extracted to make data of one dot of each frame. When the lowest-order bit of dot data is 1 and the highest-order bit is 0, 1 is adde to a part of data in each corresponding frame and when the lowest-order bit of dot data is 0 and the highest-order bit is 1, 1 is subtracted from a part of data in each corresponding frame. Thereby, the total value (apparent density) of data in the plural converted frames always varies with the variation of dot data.