Printing apparatus and method for improving quality of printing image
AssigneeBenq Corporation
InventorsBen-Chuan Du, Yung-Li Li
Life of this patent
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Abstract
The present invention is related to an apparatus and a method for improving the quality of printing. The reference timings are adjusted by random values to decrease the cyclic unevenness of images associated with the conventional technique. The random values may be generated by the apparatus itself or may be received from an external device, such as a personal computer. The distance between two adjacent dots changes, and the unevenness of images is scattered to provide a higher quality of printing.
Claims23
A printing apparatus comprising:
- a print head for scanning over a printing medium in a predetermined direction, said print head comprising a printing element set comprising M printing elements for selectively forming dot images on said printing medium, wherein M is a positive integer;
- a timing device for, in response to a reference timing sequence and a random value series, generating N sets of driving timing sequences, said random value series including N random values, each of the N sets of driving timing sequences being obtained by shifting said reference timing sequence with corresponding one of N random values, wherein N is a positive integer;
- and
- a driving device for, in response to said N sets of driving timing sequences, forming said dot images, wherein each set of driving timing sequences sequentially drives the M printing elements to provide random distances in the predetermined direction between centers of consecutive dot images formed by the printing element set of the printing head.
A print method for forming dot images on a printing medium using a print head to scan over said printing medium in a predetermined direction, said print head comprising a printing element set comprising M printing elements wherein M is a positive integer, said method comprising the steps of:
- generating a reference timing sequence;
- generating N sets of driving timing sequences by shifting said reference timing sequence with a random value series including N random values, wherein N is a positive integer;
- and
- driving said printing element set in response to said N sets of driving timing sequences to form said dot images, wherein distances between centers of consecutive dot images formed by the printing element set of the printing head are random in the predetermined direction.
A printing apparatus comprising:
- a print head for scanning over a printing medium in a predetermined direction, the print head comprising at least one printing element;
- a timing device for generating a driving timing sequence by shifting a reference timing sequence with a random value;
- and
- a driving device for, in response to said driving timing sequence, driving said printing element to form an image by printing dots on said printing medium;
- wherein, with the shifting of said reference timing sequence, a cyclic unevenness of said image is scattered and random distances in the predetermined direction between centers of consecutive dots printed by the at least one printing element of the printing head is provided.
A print method for forming an image on a printing medium using a print head to scan over said printing medium in a predetermined direction, said print head comprising at least one printing element, said method comprising:
- generating a reference timing sequence;
- generating a driving timing sequence by shifting said reference timing sequence with a random value;
- and
- driving said printing element with said driving timing sequence to form said image on said printing medium, wherein distances between centers of consecutive dot images formed by the at least one printing element of the printing head are random in the predetermined direction.
Dependencies are inferred from the claim text.