Ink pump control system

An ink pump control system that is driven by a stepping motor and can feed the maximum required amount of ink by causing said stepping motor to rotate at a revolution speed r.sub.0 under a printing condition involving the maximum revolution speed and the maximum printing element ratio, characterized in that said ink pump control system comprises

• a pulse generating section for generating pulses to cause the stepping motor to rotate,
• an arithmetic section for calculating, based on data on printing speed for a printing operation and data on printing element ratio of said printing operation, a hypothetical revolution speed r.sub.2 of said stepping motor required for feeding ink for said printing operation, time T.sub.2 required for said stepping motor to accomplish an angular displacement by a predetermined angle .alpha. at said hypothetical revolution speed r.sub.2, and a time difference .DELTA.t=T.sub.2 -T.sub.1 by subtracting from said time T.sub.2 time T.sub.1 required for said stepping motor to accomplish an angular displacement by a predetermined angle .alpha. at a predetermined revolution speed r.sub.1 higher than said revolution speed r.sub.0 required for feeding the maximum required amount of ink,
• a predetermined pulse output section for outputting pulses necessary for causing said stepping motor to accomplish an angular displacement by a predetermined angle a based on pulses generated by said pulse generating section and said time difference .DELTA.t obtained by said arithmetic section, and subsequently suspending the outputting of pulses equal to said time difference .DELTA.t, and
• an excitation signal output section for outputting excitation signals in accordance with outputs from said predetermined pulse output section to operate said stepping motor via a motor driver,
• a comparator section for comparing data on printing speed for said printing operation and data on printing element ratio inputted to said arithmetic section with predetermined conditions for printing speed and printing element ratio under which ink feed is not needed, and outputting a signal when at least any one of both data agrees with said conditions under which ink feed is not needed, and
• a power feed suspending section for suspending power feed to said motor driver based on said signal outputted by said comparator section
• so that said ink pump is controlled by the intermittent high-speed rotation of said stepping motor.