Abstract: A channel wafer has a plurality of nozzle flow channels and a common ink reservoir. Pits communicating with the ink reservoir from above heating elements are formed in a polyimide layer on a heater wafer. Each of the pits has a throttled portion in the rear of the heating element and the terminal of a nozzle flow channel is situated on the throttled portion so as to form the minimum sectional area portion of the flow channel. Stable ink discharge characteristics are attained by means of the flow channel resistance of the minimum sectional area portion and bubble pressure is prevented from being relieved toward the ink reservoir. The pressure propagated to the ink reservoir is made to attenuate internally, so that no crosstalk is produced.

Abstract: A drying device capable of keeping substantially constant the temperature of a moving recording sheet and evenly drying it without increasing radiation heat. Though the surface temperature of a recording sheet is lower on the upstream in the drying region and the temperature of outside air blown into the drying region is lower, the temperature of the recording sheet moved in the drying region is kept substantially constant by making the output of the upstream halogen lamp larger than that of the downstream halogen lamp. Even if the airflow velocity in the drying region is different, the radiation heat amount is adjusted according to the velocity to keep substantially constant the temperature of the recording sheet moved in the drying region. Thus, the recording sheet can be evenly dried and even if a jam of the recording sheet occurs in the drying region, there is no possibility of scorching, fuming or the like.

Abstract: An ink jet printer which causes ink to fly to a recording medium to form an image, comprising: plural nozzles functioning as ink ejection ports; plural individual flow paths which are disposed with respectively corresponding to the nozzles, the individual flow paths respectively having driving elements which eject internal ink through the nozzles; a common liquid chamber which communicates with the individual flow paths, the common liquid chamber having an opening portion through which ink is supplied into the chamber; an ink supply path which has a sectional area smaller than a sectional area of the opening portion of the common liquid chamber, the ink supply path being connected to the opening portion to guide ink to the common liquid chamber; and an ink supply source for supplying ink through the ink supply path.

Abstract: A thermal ink-jet head of the present invention is so designed as to improve operating frequency by surely trapping foreign substances and reducing the influence of a cross stroke. In the thermal ink-jet head of the present invention, a channel wafer is provided with a nozzle channel, a coupling flow channel, and an ink reservoir. A protective layer and a polyamide layer are formed on a heater wafer. The polyamide layer is provided with pits extending from a heating element up to the coupling flow channel and a bypass pit for coupling the ink reservoir and the coupling flow channel. Foreign substances are trapped at the entry port of the bypass pit and the entry port of the coupling flow channel. The pit controls the growth of the bubble by eating away the front end of the heating element and reducing its rear end.

Abstract: Ink-jet recording apparatus to reduce the change of the pressure of ink in the inside of ink discharge nozzles in an ink-jet recording apparatus as well as to improve the efficiency of use of ink. In the condition where an ink tank is used in an ink-jet recording apparatus, an ink joint provided in the lower end portion of the ink tank communicates with ink discharge nozzles of a head tip. Upon reception of air pressure from above, ink kept by a porous ink keeper stored in the inside of the ink tank is permitted to be supplied to the head tip. The ink tank is formed so that the internal volume of the ink tank increases in order from the lower portion to the upper portion. Accordingly, when the initial residual quantity of ink is relatively large, the change of the pressure (negative pressure) of ink in the inside of the head tip as caused by consumption of ink can be reduced.

Abstract: A method of forming servo information in a magnetic disk apparatus of a sector servo system. Servo information is recorded in advance at the beginning of each of the sectors, and includes a DC erase signal, a track address signal and a burst signal. The track address signal indicates on which track of the magnetic disk the sector is located, and is formed by expressing the track address in Gray code and interleaving a dummy code into the Gray code. Servo information is recorded using an NRZI system or an RLL coding method. Servo information in which the dummy code is interleaved is decoded after the dummy code is removed at the time of demodulation.