Patents by Inventor Hsing-Jen Liu

Hsing-Jen Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5730054
    Abstract: An inking and coloring device for a printer has a pair of ink supply rollers, a pair of ink transfer rollers, a printing drum, a cam arm and a drive device. Each of the ink transfer rollers are movable between a first position in which the ink transfer rollers contact a respective ink supply roller and a second position for transferring ink to the printing drum. Each of the ink transfer rollers are connected to a respective cam roller operable by the cam arm. The drive device causes the cam arm to move in a reciprocal manner, thereby causing each cam roller to move a respective ink transfer roller between its first and second positions. The arrangement is such that when one ink transfer roller is in the first position, the other is in the second position and, vice versa. The printing drum is reciprocally movable between the ink transfer rollers simultaneously with the movement of the said cam arm.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: March 24, 1998
    Inventor: Hsing-Jen Liu