Abstract: A fixing means for an electrophotographic copier includes a first roller and a second roller which are compressed against each other and serve to fix toner images on an image transferring medium passed therebetween. A control means is programmed to operate the rollers such that the heating of the second roller is continued for a predetermined length of time or until the surface temperature of the second roller reaches a certain predetermined temperature level after the surface temperature of the first roller reaches another predetermined temperature level such that the second roller is prevented from cooling down suddenly after the fixing operation is started. In another aspect of the present invention, the size of the image transferring medium passed between the rollers is detected and the heaters for the rollers are controlled accordingly such that temperature variations on the roller surfaces can be reduced and hence the roller lifetimes can be improved.

Abstract: An automatic document feeder including an automatic sheet winding device and an exposure device. The automatic sheet winding device includes a rotary drum and a sheet clamping device for clamping the original sheet wound around a circumferential face of the rotary drum such that a sheet clamping region and an exposure region on the circumferential face of the rotary drum are circumferentially spaced from each other.

Abstract: An ink liquid supply system for an ink jet system printer includes an ink liquid reservoir for containing ink liquid therein, and a compact size plunger pump for supplying the ink liquid to a nozzle. The compact size plunger pump integrally includes three pressure chambers defined by coaxially connected pistons. The pistons are driven to reciprocate by a plunger associated with an electro-magnetic solenoid. The first pressure chamber functions to introduce the ink liquid from the ink liquid reservoir and develop the ink liquid toward the nozzle. The third pressure chamber functions to introduce an ink liquid collected by a beam gutter of the ink jet system printer for returning the ink liquid to the ink liquid reservoir. The second pressure chamber functions as a damper for decelerating the shift movement of the pistons and plunger, thereby reducing the shock which will be created when the plunger is attracted by the electromagnetic solenoid.

Abstract: An ink liquid supply system for an ink jet system printer includes a constant flow rate pump and a pressure accumulator for removing a pressure pulsation or ripple created by the constant flow rate pump. In order to stabilize the constant flow rate operation and to shorten the preparation period of the system when the system operation is started, a temperature compensation or sensitive system is provided for varying the ink liquid pressure within the pressure accumulator. The temperature compensation system includes a bimetal element for varying the pressure to be applied to a resilient member included in the pressure accumulator. The pressure adjusting operation is continuously conducted even when the ink jet system printer does not operate.

Abstract: An ink jet system printer includes a nozzle for emitting an ink liquid under a predetermined pressure, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in accordance with an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and a charging tunnel for charging the ink droplets in accordance with print information. A charge condition detection unit is provided for monitoring the charge condition of the ink droplets, the output signal of the charge condition detection unit being indicative of a droplet formation condition. When the output signal of the charge condition detection unit indicates the occurrence of satellite ink droplets in addition to the normal ink droplets, the voltage level of the excitation signal, which is applied to the electrode-mechanical transducer, is varied to eliminate the occurrence of the satellite ink droplets.

Abstract: The present invention is directed to an ink jet system printer comprises a carriage carrying a nozzle for discharging ink droplets towards a recording medium in response to an ink supply device, deflection means for selectively deflecting the ink droplets for recording purposes, and a beam gutter for collecting an amount of the ink droplets which are not contributive to the recording purposes. A pump means is connected to the beam gutter for feeding the amount of the ink droplets back to the ink supply device. In a specific form of the present invention, the pump is combined with a ink supply pump for supplying the nozzle with ink, the ink supply pump being part of the ink supply device.

Abstract: An ink liquid supply system for an ink jet system printer comprising an ink liquid reservoir for containing ink liquid therein, and a constant flow rate pump for supplying the ink liquid to a nozzle. The constant flow rate pump comprises a first chamber for introducing an ink liquid collected by a beam gutter of the ink jet system printer and for returning the ink liquid to the ink liquid reservoir. The constant flow rate pump further comprises a second chamber for introducing the ink liquid from the ink liquid reservoir and for developing the ink liquid to the nozzle. The first and second chambers include a coaxial piston disposed therein for varying the pressure created in the first and second chambers.

Abstract: The present invention is directed to an ink supply device for use in an ink jet printer having a constant flow rate pump for ink supply. Preferably, the ink supply pressure at an ink ejection nozzle is sensed and as a result of this ink and an ink solvent are alternatively fed, thus supplying ink of a fixed viscosity to the ink ejection nozzle.

Abstract: An ink liquid concentration controller is provided in an ink liquid supply system for an ink jet system printer to ensure a stable printing operation. The ink liquid concentration controller functions to maintain the concentration of the ink liquid at a constant value by supplying a volatile dilution to the ink liquid introduced into the ink liquid concentration controller.

Abstract: A vertical tabulation control for a high speed printer comprises a presettable memory, such as a random access memory (RAM), for storing vertical tabulation addresses, a counter for counting the number of line feed operations, a comparator for developing a continuous line feed termination command when the contents of the counter reach the preset vertical tabulation address, and a rechargeable battery means which is charged when the printer is activated through a power switch. The rechargeable battery supplies the presettable memory and the counter with a necessary voltage for maintaining their contents when the power supply through the power switch is terminated.

Abstract: An electronic tabulator for use in non-impact printers and similar data terminal printout apparatus includes a random access memory (RAM) having a capability of storing the maximum of printing carriage positions to be tabulated at random order in response to TAB preset instructions, which in one preferred form may be implemented with MOS integrated circuit technology. While the carriage is moved in incremental steps along a given path in the course of the printing operation, address signals representative of the instantaneous positions of the carriage are developed from a carriage address counter. If there is evaluated an equivalence between the address signal and the preset signal of the memory, the memory produces its output which is in turn applied to the carriage bearing a printing member to indicate that the printing operation should be effected at that position.