Canon Finetech Inc.

Copyer Co., Ltd.

Michitaka Fukuda

Yuichi Sugiyama

Koji Terasawa

Shingo Takada

Hideyuki Kitajima

Yutaka Takata

A method and system for serial communication capable of increasing the speed of the transmission of serial data are provided. A block mode is employed if transmission of serial data having a specific length is required, and under which data to be transmitted are divided into plural blocks, and firstly transmitted is block information that notifies which blocks out of the entire blocks will be transmitted, and then transmitted are the data included in the blocks notified by the block information. The burst mode is a mode under which the block information which is currently transmitted is compared with the block information which was previously transmitted, and, if the two are the same, transmission of the data is introduced, while the block information being omitted. The system attached mode information notifying the mode through which data will be transmitted, to the data to be transmitted.

Method of synchronous serial communication and system for synchronous serial communication

An image forming device capable of detecting the presence/absence of ink as well as whether an ink tank is mounted. A detachable ink tank on a carriage includes a prism C, and a reflective optical sensor detects the presence/absence of ink depending on the difference in refractive index between the two states, that is, filled with ink and empty. A reflector lever movable in response to the ink tank being mounted or not, is provided on the bottom of an ink tank holder The reflector lever has one end fixed on a lower part of the ink tank and the other end that is a free end consisting of a triangular reflector D. The reflector lever is normally urged upward by a resilient member A, and it will not direct the reflection toward the sensor in the absence of the ink tank whereas it is deformed in the presence/absence of the ink tank to direct the reflection toward the sensor As a result, the presence/absence of the ink tank is detected.

Image forming device

An ink-jet type forming device comprising a suction fan ( ) for sucking from below a platen ( ), a print medium ( ) that is being conveyed on the platen ( ), and a variable controller for variably controlling the suction force of the suction fan ( ) under a predetermined condition. The variable controller that, in each scanning of a head, recognizes presence and absence of the head within a printing region ranging from the printing start position to the printing end position and that controls the suction fan such that the suction force is lower when the head is outside the printing region than when it is within the printing region, as the predetermined condition. Alternatively, it includes a detector that recognizes the kind of a print medium that has been set and that controls the suction force of the suction fan according to the recognized kind of print medium, as the predetermined condition. Adjustment of the suction force of the suction fan lowers the load on a conveyance motor and generally reduces power consumption and noise.

Ink-jet type image forming device

An ink-jet image forming device such that the test pattern detecting accuracy is improved with a single photodetector. A binarizing circuit ( ) which binarizes the output of a sensor for a test pattern includes a peak hold circuit ( ) which follows slow change in the sensor output, a voltage dividing circuit ( ) which divides the held output, and a comparator ( ) which converts the sensor output into a bi-level signal by using the output of the circuit ( ) as a threshold.

Ink-jet image forming device

In order to reduce the number of signal lines of the cable between the controller and the carriage and to allow the print timing of each head to be adjusted in increments smaller than one pixel, the signal lines include a line for carrying serial print data to be supplied to a plurality of print heads in a predetermined order, a line for carrying a clock signal corresponding to individual bits of the data, lines for carrying signal HDSEL&lsqb;1 . . . 0&rsqb; indicating which print head corresponds to which print data included in the serial print data, and lines for driving the heads. When data is transferred over this cable, one slice section is divided into a plurality of sections, the slice section corresponding to a time slot required to transfer a unit of print data corresponding to a plurality of dot printing elements of the plurality of heads, each divided section is further divided into a number of subsections the number of which is equal to the number of the print heads. The transfer of the print data of each print head is started independently of the print data of other print heads, beginning with its arbitrary subsection.

Growing community of inventors

Tokyo, Japan

Michitaka Fukuda