Hitachi, Ltd.

Syoichi Ito

Katsufumi Takagishi

Takahiro Yamada

Toshio Tsubaki

Yuichi Horiuchi

Yoshio Kawamata

Mithuo Suzuki

Ken-ichi Akahori

In a printer system wherein one or a plurality of host computers use in common a single printer such as an expensive photo printer for electronic publishings of desktop publishings such as word processors, character format data of characters to be printed out is stored beforehand as character pattern data at a printer controller of the printer system. The host computer either stores minimum necessary character pattern data for monitor display or control, or stores no character pattern data. The character pattern data necessary for monitor display or control are used by transferring them from the printer controller to the host computer.

Printer system and operating method therefor

A photo printer system comprises a magnetic storage for storing a print data sent from a host computer, a bit map memory for storing a print dot data, and a printer engine for printing the contents of the bit map memory. The system includes a program which operates on the magnetic storage to serve as an external storage for the host computer and on the bit map memory to serve as a cache memory in response to a data read/write command issued by the host computer, and a CPU which controls the execution of the program. At least in a non-print process mode, the system forms a data path so that the host computer can access to the bit map memory and magnetic storage so as to have a bidirectional data read/write operation. In another mode, the system forms a data path so that image data picked up with an image scanner is saved directly in the bit map memory and the image data is sent to the host computer by request.

Photo printer having a host computer assist function and method of

A photo printer such as a laser printer incorporates a bit map memory having a large memory capacity. When the printer is connected to a host computer, a dot pattern corresponding to a bit pattern formed in accordance with the contents of the bit map memory is printed on a sheet in a normal mode. If a special command is transmitted from the host computer to the printer, a data file used by the host computer is temporarily stored in the bit map memory. If another special command is transmitted from the host computer, the data file stored in the bit map memory is transmitted to the host computer. That is, the bit map memory in the printer is used as the memory for temporarily storing the files of the host computer.

Method of controlling photo printer and apparatus therefor

A video signal generating circuit comprises a buffer memory for storing character codes and control data for control of vertical character positions, a character pattern memory having a plurality of stored character patterns which are selected by the output of the buffer memory, and a control circuit for successively reading the character codes and control data from the buffer memory and the character patterns from the character pattern memory. The value of a logical operation of raster data generated by the control circuit and the control data is used as raster data or an effective raster scan signal for the character pattern memory.

Video signal generating circuit

An ink jet printer provides a nozzle for ejecting droplets of inflammable ink towards a recording surface and a charging electrode for imparting a charge to the droplets in accordance with information to be printed. Deflecting electrodes are positioned between the charging electrode and the recording surface. A deflecting source supplies the deflecting plates with a predetermined deflecting voltage. A resistor is connected between one of the deflecting plates and the deflecting source.

Ink jet printer using inflammable ink

An ink jet printer uses a detector circuit for detecting the relation between the generation of an ink droplet and the phase of a charging signal on the basis of an output signal of a sensor against which the ink droplets charged by a phase detecting signal collide. A phase shift circuit is provided for matching the generation of the ink droplet and the phase of the charging signal on the basis of an output signal of the detector circuit, and an inhibit circuit is used for inhibiting the phase shift circuit from operating for a predetermined period after the phase shift circuit has operated.

Phase control for ink jet printer

An ink jet recording apparatus including a device for charging ink particles to enable detection of disorder in the recording, a device for detecting the thus charged ink particles at a predetermined position and for producing an output in accordance therewith. A device is provided for detecting the output for a predetermined period of time or the number of times an output is provided per a predetermined unit time as an indication of a disorder in the recording. The disorder in the recording or the anticipation of a disorder in the recording is indicated by energizing a light or according to the condition of the recording, stopping the recording operation.

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Ibaraki, Japan

Syoichi Ito