Vertical movement control device for a paper feed table device

摘要

Provided is a vertical movement control device for a paper feed table device which allows a favorable paper feeding action to be carried out at an appropriate paper feed pressure for all kinds of paper without involving any failure to properly lift the paper feed table or any occurrence of seizure of the electric motor, and eliminates any unduly long waiting period even when the required lift of the paper feed table is relatively great due to addition of new paper or removal of paper jamming. An upper limit sensor 19 detects if the upper surface of the paper stack on the paper feed table 1 has reached a prescribed height by the upward movement of the paper feed table 1. The motor 13 is driven in the upward direction in an intermittent manner until the upper limit sensor 19 has detected that the upper surface of the paper stack on the paper feed table 1 has reached the prescribed height, and the duration of the intermittent drive period of the electric motor 13 is gradually increased with the elapsing of time until the upper limit detecting sensor 19 has detected that the upper surface of the paper stack on the paper feed table 1 has been positioned at the prescribed height.