Victor Company of Japan, Limited

Toshikatsu Ichitou

Itsuo Takanashi

Takashi Yamamura

Hiromichi Tai

Hiroki Kitamura

Shintaro Nakagaki

Tsutou Asakura

Tetsuji Suzuki

Masato Furuya

Atsushi Nakano

Kazunori Namiki

Koubun Sakagami

A pulse-width modulation device for controlling shapes of dots printed out by a printer by regulating shapes of pulses of pulse-width modulation signals, which respectively represent gray levels of pixels of input image, according to code signals respectively indicating shapes of pulses of pulse-width modulation signals, each of which has a duration composed of time slots respectively corresponding to bits of image data representing a gray level of a pixel. The pulse-width modulation device is provided with a code converter for converting image data corresponding to each pixel of an input image into a predetermined code indicating a shape of a pulse of a corresponding pulse-width modulation signal and for outputting a code signal representing the predetermined code. The indicated shape of the pulse is formed by making the corresponding pulse modulation signal have a high level at a predetermined number of time slots thereof, which are serially counted from the time slot corresponding to the most significant bit of the image data or from the time slot corresponding to the least significant bit of the image data according to a gray level of each pixel. The pulse-width modulation device is further provided with a pulse generating circuit for receiving the code signal and for generating the pulse of the predetermined pulse-width modulation signal according to the code in response to a predetermined clock signal.

Pulse-width modulation device

An output apparatus for printing a proof sheet and making a planographic printing plate, comprising a printing image data generating means for producing the digital data of a plurality of different color images corresponding to a predetermined number of colors obtained by the color separation of the image data of an original to be printed; a proof sheet outputting means for sequentially forming a screened dot image of each color by using each color toner based on the printing image data derived from said printing image generating means; a planographic printing plate output means for forming a screened dot image of each color by using one recording medium for each color and the oil affinitive toner of each color based on the digital data of each color generated by said printing image data generating means. By providing further a means for compensating for the difference in characteristics between the printing of a proof sheet and the planographic printing (actual printing), one output apparatus can output both the data for printing a proof sheet and the data of the actual printing (the planographic printing).

Output device for proof and planograph using electrophotographic

A charge recording and reproducing device is constituted by a transfer device which transfers a film shaped recording medium from one to other side, a recording head adapted to form an electrostatic latent image from an image formed on the recording medium, an eraser for erasing the electrostatic latent image, a developing apparatus for developing the electrostatic latent image, and a reading device for reading the developed image.

Image pick-up apparatus

In a control system for an information recording laser beam, an intensity of a laser beam is varied in a predetermined variation pattern during each of sequential one-pixel periods. The laser beam is periodically activated and deactivated in synchronism with a change of the one-pixel periods. A duration of the activating the laser beam within each of the one-pixel periods is controlled in accordance with a density of each of pixels of an image to be recorded.

Control system for information recording laser beam

An electrophotography system for use in laser printers, printing machines and copying machines. The system includes a rototable drum having a photosensitive member which can take a first absorption spectrum state and a second absorption spectrum state, the variation from the first absorption spectrum state to the second absorption spectrum state being made by illuminating it with light whose intensity is above a predetermined threshold and whose wavelength is in a first predetermined wavelength region. Also included is an optical system including a light-emitting device for illumination of the photosensitive member so as to form thereon an electrostatic latent image, the optical system being arranged to directly illuminate the photosensitive member with light from the light-emitting device and further to illuminate it with reflected light from an original picture. The light-emitting device is arranged to emit light whose wavelength is in the first predetermined wavelength region and further light whose wavelength is in a second predetermined wavelength region. A control unit performs one selected from a laser-printing mode, a printing mode and a copying mode so as to form the corresponding electrostatic latent image on the photosensitive member by lights which are different in intensity and wavelength from each other.

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Kawasaki, Japan

Toshikatsu Ichitou