| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus constituted so that there is no limit to the number of writing times in a storage means and also life control information is updated and stored in the storage means even when a main power source is turned off. <P>SOLUTION: Voltage characteristic in the cases of turning off the main power sources of 24V and 5V while the image forming apparatus is operated in a printing operation mode is shown in the figure. When the main power source is turned off at time (ta), the voltage of the 24V power source drops as shown by the characteristic (C) and becomes 0V at time (tc). The voltage of the 5V power source starts dropping from time (tb) later than the time (ta) and becomes 0V at the time (tc) as shown by the characteristic (B). The time when the voltage of the 24V power source drops by 10% from rated voltage is time (tx) a little later than the time (ta) when the power source is turned off. Therefore, in the 5V power source, the time (tb-tx) exists until the time (tb) when the voltage drop is started. At such a time, the life control information is written in an FRAM. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
