Canon Kabushiki Kaisha

Sadatoshi Narazaki

Sohei Tanaka

For an ink jet recording apparatus that utilizes the STOP mode function of a CPU to reduce power consumption and a method for controlling the recording apparatus, many NMI interrupts occur due to chattering generated upon switching when the trigger for the restoration from the STOP mode is effectuated by use of the power switch, and the normal ON/OFF process for the power supply is disabled. For example, therefore, an ink jet recording apparatus, which is provided with a CPU having plural modes including a mode to reduce the power consumption by suspending the clock signal as an operational mode, and receives a signal from a power switching unit as an NMI interrupt signal for the execution of NMI interrupt process, is arranged to be provided with a controller for prohibiting the NMI interrupt until operation is completed by way of the status of the recording apparatus with respect to the NMI interrupt process to be executed by the input of the signal from the power switching unit.

Ink jet recording apparatus provided with interrupt control circuit and method for controlling recording apparatus

A device is provided for chopping a control signal of an initial excitation phase or a final excitation phase by a predetermined cycle during low speed rotation control of an excitation phase control signal (excitation control signal) of a stepping motor when acceleration control and deceleration control of the stepping motor are effected, thereby reducing an excessively great driving current created during low speed rotation of the stepping motor, particularly the initial retaining excitation period during acceleration control and the final retaining excitation period during deceleration.

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Chiba, Japan

Sadatoshi Narazaki