Sony Corporation

Sadao Maeyama

Kiyoshi Arai

Kiyotaka Dochi

Shigemichi Honda

Minoru Yamazaki

Masakuni Suzuki

Shohgo Fujito

Yoshio Kaneko

The present invention overcomes disadvantages including the occurrence of uneven printing, the need to provide a large-sized power supply, high cost and the deterioration of energy conversion efficiency resulting from the application of high current to the common resistance of a line head in a thermal printer for printing an image by the line head. Specifically, a gradation generating means ( ) for generating gradation data; a selection means ( ) for alternatively selecting each image data the number of which corresponds to the number of head elements of a head, and data of value 0 for the respective image data, and for switching selection as to which data is to be selected, the image data or the data of value 0, every time a value of the gradation data changes; and a comparison means ( ) for feeding signals each indicating a comparison result of comparing the data selected by the selection means ( ) with the gradation data, are provided at a line head controller ( ) of a thermal printer.

Head controller of thermal printer and thermal printer printing method

A video printing apparatus includes a trigger signal generator for generating a first trigger signal and a second trigger signal having a timing different from that of the first trigger signal, a first memory for storing an input video signal in response to the first trigger signal supplied thereto, a second memory for storing an input video signal in response to the second trigger signal supplied thereto, and a printing device for printing an image of a first color based on the video signal stored in the first memory and printing an image of a second color different from the first color based on the video signal stored in the second memory.

Color video printer

The color signals to be printed by a thermal color transfer printer are processed in order to provide gamma and temperature compensation for nonlinearities in the responses of the colored dyes used in the thermal printing ribbon and also to provide color compensation to correct for any overlap in the spectral response of these colored dyes. Color data signals are sampled and multiplexed to place the main or print color signal, which is determined by the color of the dye in position in front of the thermal head at that instant, in the center of a multiplexed, time-sharing arrangement with the non-print color signals arranged on either side. The multiplexed signal is digitized and used to address a read only memory containing compensation curves to provide both gamma compensation and color compensation, and the compensated signals are adjusted in gray scale magnitude before being pulse width modulated for driving the thermal head to produce the desired color, hard-copy print.

Circuit providing gamma, color and temperature compensation for thermal

Apparatus for thermally printing images, such as color images, on a print medium. The medium is moved repeatedly from a reference position through a printing region, as by rotating the medium on a platen. Thermal print elements are disposed at the print region and are selectively energizable to cause images, such as color images, to be printed. A movable web of thermally transferable material has a run interposed between the print medium and the thermal elements at the print region. In one embodiment, the web is provided with successive frames of respectively different colors of thermally transferable material arranged in repeated sequence. Energizing signals are supplied to the thermal elements representative of the image to be printed; and an image is printed in a color corresponding to the color frame then disposed at the printing region. Successive passes of the print medium are made in order to print images of the remaining colors in the sequence of frames on the web.

Growing community of inventors

Chiba, Japan

Sadao Maeyama