Patent ID: 8385799

Claim:
A lubricating device comprising: a lubricant impregnation member configured to coat a surface of a target member with lubricant; a lubricant supply member configured to supply lubricant to the lubricant impregnation member; a subsidiary roller configured to feed the lubricant impregnation member out; a main roller configured to reel in the lubricant impregnation member fed out by the subsidiary roller; a drive motor configured to drive the main roller; an encoder disc provided at a rotational shaft of the subsidiary roller; an encoder sensor adjacent to the encoder disc and configured to detect a rotational state of the encoder disc; a controller unit configured to receive output from the encoder sensor and to calculate an outer diameter of the main roller and a portion of the lubricant impregnation member reeled by the main roller, based on a number of drive steps of the drive motor detected by the encoder sensor during a detection interval of the encoder disc, and to determine a drive velocity of the drive motor based on the calculated outer diameter.