IMAGE DISPLAY DEVICE

PROBLEM TO BE SOLVED: To avoid that new image data is displayed on a screen after image data before update. SOLUTION: It is decided that the position of a scanning line S is between a position A and a position B, namely, at a first image update position (S3) after detecting the current position of the scanning line S (S2) by a scanning line position detection means, the front stage image data is updated, outputted and stored from a data storage part to a memory by a data update control means (S4). After that, it is decided that the position of the scanning line S is between a position C and a position D, namely, at a second image update position (S7) after detecting the current position of the scanning line S (S6) and the rear stage image data is updated, outputted and stored from the data storage part to the memory by the data update control means (S8). Next, in accordance with switching of a scanning means from the bottom end to the top end of the screen, the updated front stage image data and rear stage image data are sequentially read from the memory and displayed on an image display means in response to the scanning. COPYRIGHT: (C)2005,JPO&NCIPI