Seiko Epson Corporation

Michio Maruyama

Susumu Shiohara

Kazunori Chihara

Sunao Murata

Tetsuya Suzuki

Noriyoshi Chiba

Hiroyasu Ogata

Kazuyuki Onuma

A host sends each page of image data to a page printer in band units and the page printer writes the received each band data into a reception buffer in DRAM by DMA and transfers the band data from the reception buffer to an image formation section made up of members. The host gets an available buffer capacity from the printer just before transmitting each band data, and transmits the band data only when the printer can receive the band data. In the printer, a CPU permits transfer DMA to be started after reception data as much as the data amount calculated based on the data reception speed and the transfer rate is stored in the buffer to prevent an underrun error from occurring. If an underrun error occurs, the CPU sets an error flag, and sends the error flag to the host just before the host starts transmitting each band data. When receiving the error flag, the host drops image resolution and resends the page data with the resolution dropped.

Page printer and page print system

An image processing apparatus which is adapted for image processing for reading/writing a large amount of data from/into an RAM and which has a high processing speed. A DRAM bus to which an SDRAM unit is connected is connected to a CPU bus through a bus driver so that a CPU can read/write data from/into the SDRAM unit directly to perform synchronous input/output processing between the CPU and the SDRAM unit. Thus, high speed data transfer can be performed, and the driving capability of the RAM bus is heightened by the bus driver so that the capacity of the SDRAM unit can be made large. Consequently, data can be transferred to a large capacity of SDRAM which can store a large amount of data necessary for image processing to make it possible to provide a printer which is both high in processing speed and has a high data capacity.

Image processing apparatus, information processing apparatus and printer

In the case where the free area of a memory in a printer is insufficient when one-page's image data from a host computer are converted into intermediate codes so as to be stored into the memory, the intermediate codes are converted into real image data, that is, bit map data, and the real image data are compressed and stored into the memory. If compressibility is insufficient in spite of the compression of the real image data, the real image data are converted into data of a data format higher in compressibility and then the converted data are compressed. A plurality of data formats different in compressibility are prepared so that an optimum data format is selected. Further, when the number of times of compression carried out to the one-page's image data or the time required for compression is larger than a threshold, a user is informed of this fact and given a proposal to extend the memory.

Apparatus and method for storing image data into memory

A memory device for a page printer utilizing a one port random access memory in connection with a central processing unit to process print data is provided. A first memory circuit is provided to receive head address data from the CPU. A second memory circuit receives tail address data from the CPU. The first memory circuit and second circuit store these input values. A first comparator compares the head address data stored in the first memory circuit with address data produced by the CPU, while a second comparator compares the tail address data stored in the second memory circuit with address data produced by the CPU. The memory is divided into a first region defined by the head address and the tail address and an other region. A memory control circuit receives the outputs from the second comparator and the first comparator and accesses one of the first region or the other region in response to the outputs of the comparators.

Growing community of inventors

Nagano, Japan

Michio Maruyama