| 摘要 |
A liquid crystal display (LCD) controller includes a plurality of segment/key source control circuits connected with an LCD panel and a key matrix through a plurality of segment/key source terminals, to periodically output a signal for one frame which contains a display output period and a key source output period. The plurality of segment/key source control circuits output to the plurality of segment/key source terminals during the display output period, segment signals having display drive voltages indicating a maximum value, a minimum value, and intermediate values between the maximum value and the minimum value. The plurality of segment/key source control circuits output first key scan pulse signals varying between the maximum value and the minimum value to the plurality of segment/key source terminals during the key source output period in a key scan state when the key matrix has been operated, and then, second key scan pulse signals obtained by inverting the first key scan pulse signals to the corresponding segment/key source terminal. |
