Hitachi, Ltd.

Other

Tadashi Okada

Tatsuki Inuzuka

Takeshi Shibuya

Atsushi Onose

Eiji Yoshino

Masayuki Kanda

Akira Sasaki

Hitoshi Tamura

Toshiaki Nakamura

Nobuo Suzuki

Hiroyuki Tadokoro

Seiji Kageyama

Makoto Kitagawa

Takuya Shimakawa

Satoru Matsumoto

Junichi Kazama

Naoyuki Urata

Tatsunari Satoo

A personal computer has a print image developing means and a data compression means including a fixed rate compression. A color printer has a data extension means, a color correction means, a gamma correction means, a first halftoning means, an image area segmentation means, and a second halftoning means. The transmission time of a print image can be shortened necessarily to less than a constant time, and further, since an enormous memory for extension is unnecessary, a low cost printer can be provided.

Information print system and image processing apparatus

In a halftoning unit of a laser printer and the like, a high speed, high density and high gradations halftoning is realized by multi-value implementation by clustered dot concentrated dither halftoning (known as a sub-matrix method) and PWM distributing gradation among the plurality of halftone dots with a small memory and circuit. For this purpose, the value of the difference between an input gradation value n,and a threshold value n,, &Dgr;n&equals;n,&minus;n,, is shortened within a range of 0 to &Dgr;h and the lower s bit of &Dgr;h is removed by a round-down or round-up process. Meanwhile, a threshold array is generated from an extended threshold pattern obtained by combining threshold patterns of 2,whose threshold interval is &Dgr;h, i.e. &Dgr;Ah&times;K, &Dgr;h&times;K&plus;1, . . . , &Dgr;&times;K&plus;2,. Thereby, a halftone dot dither process in which the PWM gradation increases distributively among the 2,dots may be realized with a small scale memory and circuit.

Distributed PWM halftoning unit and printer

In a printing system including a plurality of terminal equipment, a plurality of printers which can be shared by the terminal equipment, one or more printer/spooler control servers each for receiving a print from the terminal equipment and for controlling the print by the printer, and a distributed printing management server, for various errors which occur in the printers, the contents of the errors are informed to the user and an error recovery process according to the error is realized. Thus, a use efficiency, performance, reliability, and serviceability as a printing system are improved.

Printing system

Growing community of inventors

Hadano, Japan

Tadashi Okada