摘要:
A thickness of a form document loaded in a pin feed tractor is measured to appropriately adjust a gap between a platen and a print head. A projection formed on a pressing block is linearly moved toward and away from the form document supported on a tractor cover. The pressing block is moved by a stepping motor, and an amount of rotations of the stepping motor is detected to measure the movement of the projection. A first amount of rotations is detected under a condition where the form document is not loaded and subsequently a second amount of rotations is detected under a condition where the form document is loaded. The thickness of the form document is computed based on a difference between the first amount of rotations and the second amount of rotations to eliminate influence of resilient deformation of the tractor cover.
摘要:
In a dot-line printer, a hammer bank carrying a plurality of dot printing hammers reciprocally moved along a printingline. Each of the printing hammers is made up of a leaf spring, one end of which is fixedly secured to the hammer bank and to another end of which a printing pin is attached. According to the invention, the plurality of dot printing hammers are separated into an odd-number group and an even-number group, in which the printing hammers in each of the odd-number and even-number groups are further separated into a predetermined number of sub-groups. The printing hammers in the odd-number group are arranged in the upper side of the printing line so that the printing pins extend downwardly and the printing hammers in the even-number group are arranged in the lower side of the printing line so that the printing pins extend upwardly. The printing pins in each of the sub groups of the odd-number group are positioned along a straight line inclined by a predetermined angle with respect to the printing line and the printing pins of the printing hammers in each of the sub groups of the even-number group are positioned along another straight line parallel to the aforementioned straight line. In order to facilitate fabrication of the printing hammers, the printing hammers in each of the sub groups are formed integrally to be in a comb-like shape.
摘要:
A dot line printer with a paper feed time controlling capability includes a hammer bank accommodating a plurality of print hammers, a shuttle mechanism for shuttling the hammer bank back and forth along a print line, and a sheet feeding mechanism for feeding a sheet of paper in a direction perpendicular to the direction in which the hammer bank shuttles. When a first predetermined amount of a line space feeding is to be carried out after completion of one line printing, a hammer bank reversing time is prolonged. When more than the first predetermined amount of the line space feeding but less than a second predetermined amount of line space feeding is to be carried out, it is carried out during an extended period of time including both the hammer bank reversing time and the subsequent hammer bank scanning time without prolonging the hammer bank reversing time. Further, when the amount of the interline space feed is more than the second predetermined amount, it is taken place during a prolonged hammer bank reversing time and also the subsequent hammer bank scanning time.
摘要:
A dot line printer having ink ribbon guides for stabilizing running performance of an ink ribbon. A dot line printer includes a hammer bank, a shuttle mechanism, a platen and ink ribbon guides. The hammer bank has print hammers for forming a plurality of dot impressions. The shuttle mechanism has one side positioned adjacent to one end of the hammer bank for reciprocally moving the hammer bank. The platen is adapted for bearing dot impression force, and a part of the ink ribbon is positioned at an ink ribbon path extending along the platen. The ribbon guides have a first guide positioned adjacent to another end of the hammer bank, and a second guide positioned adjacent to another side of the shuttle mechanism. The ink ribbon guides guide travel of the ink ribbon at the ink ribbon path. The ribbon guides further include a third ink ribbon guide positioned between the hammer bank and the shuttle mechanism for further guiding travel of the ink ribbon at the ink ribbon path.
摘要:
A shuttle printer carries out printing on a printing paper when a hammer bank shuttles back and fourth. At the beginning of the hammer bank reversal at the right or left end in the hammer bank shuttling path, a braking force is exerted to a shuttle motor which drives the hammer bank and an acceleration force is exerted to the shuttle motor immediately after the hammer bank turns around. In order to set a reversing duration of the hammer bank at constant, the braking force and the acceleration force exerting durations are prolonged from a predetermined minimum to a value when the hammer bank reversing duration is shortened to an extent as desired, whereby a printing paper can be fed a predetermined amount within the hammer bank reversing duration as desired.
摘要:
A dot-line printer has a hammer bank carrying a plurality of printing hammers arranged in groups, each group having a predetermined number of printing hammers displaced from one another by predetermined numbers of dot-lines in the direction of paper feed. A shuttle mechanism causes the hammer bank to undergo reciprocating shuttle movements with a reversing period between successive shuttle movements. A character line, covering a predetermined number of dot-lines, is printed over a plurality of shuttle movements, a paper feed mechanism causing the paper to move a predetermined number of dot-lines in the reversing period between shuttle movements. A number of blank dot-lines separate a printed character line from the beginning of the first dot-line of the next character line to be printed. A control mechanism sets the reversing period between successive shuttle movements to be longer than the paper feed time to move the paper to the first dot-line to be printed after the preceding character line has been printed and causes the paper feed to the first dot-line of the next character line to be printed to occur entirely in the reversing period.