Abstract: A paper loading system for use in a printer has a platen and a paper bail mounted with two rollers. A carriage having a projection is provided to move parallelly to the platen. At the free end of the projection, a photodetector is provided to detect an edge of a loaded paper so as to memorize the opposite ends of the loaded paper. When the paper bail is in a pressing position at which rollers are holding the paper on a path of advance of the paper, no engagement is accomplished between the projection and the rollers. But when the paper bail is in a releasing position at which rollers are separated from the path to release the paper, the projection may come into contact with rollers to change the position of rollers. Using the memorized data, the movements of the carriage and the paper bail are controlled to locate the rollers at the opposite side rims of the loaded paper.

Abstract: In an ink liquid supply system for an ink jet system printer, an ink liquid reservoir, an air trap, a pump, an air chamber and an electromagnetic cross valve are made of resin blocks. Conduit means associated with the above-mentioned elements are formed in said resin blocks, whereby the elements are communicated with each other when the resin blocks are fixed to each other.

Abstract: A plate shaped slim electrode is mounted on a carriage which supports an ink issuing unit and a charging tunnel, and is driven to travel in the lateral direction. A cylinder shaped rotary deflection electrode is rotatably mounted on the body of an ink jet system printer in a direction parallel to the travelling direction of the carriage. In a preferred form, a slit opening is formed in the center of the plate shaped slim electrode. The plate shaped slim electrode is maintained at the ground potential, whereas the rotary deflection electrode is connected to a high voltage source to establish a high voltage electric field between the plate shaped slim electrode and the rotary deflection electrode.

Abstract: A pair of rotary deflection electrodes are provided to confront with each other in an ink jet system printer in order to deflect charged ink droplets emitted from a nozzle as they pass through a high voltage electric field established therebetween. Cleaners are installed close to the rotary deflection electrodes at the position where the electric field established between the rotary deflection electrodes will not be disturbed by the cleaners in order to sweep the rotary deflection electrodes as they rotate.