Abstract: An image-forming apparatus includes a developing roller and a developing blade. The developing blade applies toner to the developing roller to form a thin layer of toner on the developing roller. The image-forming apparatus performs a printing operation that includes a paper-feeding period and a developing period following the paper-feeding period. The developing roller rotates relative to the developing blade at a first speed during the paper-feeding period and then at a lower second speed than during the developing period, thereby eliminating chance of white lines of occurring in a printed image. The developing roller may be rotated at a constant speed in each printing operation until the circumferential surface of the developing roller has traveled over a certain cumulative distance. When the surface has traveled over the first distance, the developing roller may be rotated at an increased speed over a certain distance.

Abstract: An image-forming apparatus includes a developing roller and a developing blade. The developing blade applies toner to the developing roller to form a thin layer of toner on the developing roller. The image-forming apparatus performs a printing operation that includes a paper-feeding period and a developing period following the paper-feeding period. The developing roller rotates relative to the developing blade at a first speed during the paper-feeding period and then at a lower second speed than during the developing period, thereby eliminating chance of white lines of occurring in a printed image. The developing roller may be rotated at a constant speed in each printing operation until the circumferential surface of the developing roller has traveled over a certain cumulative distance. When the surface has traveled over the first distance, the developing roller may be rotated at an increased speed over a certain distance.

Abstract: An apparatus for driving a printhead has a timer, a power supply, and a controller. The power supply applies a drive voltage to the printhead to eject ink drops from the printhead. The timer counts an elapsed time during which the printhead does not eject ink drops. The controller performs an ejection test where the drive voltage drives the printhead a plurality of times to eject a plurality of ink drops. The controller drives the power supply to increase the drive voltage in accordance with a length of the elapsed time. The ejection test is performed at a predetermined length of the elapsed time, the drive voltage and the predetermined length of the elapsed time are selected in accordance with a decrease in an ejection speed of the ink drops. The controller controls the drive voltage such that the surface of meniscus of ink in the orifice is subjected to fine vibration before the ink drop is ejected.

Abstract: Resiliency of a flat spring 7 corresponding to an end print wire 12 is set to be greater than that corresponding to a central print wire 12 by varying width of an effective spring portion 7b of a flat spring piece 7A to which an armature 13 is attached depending on positions of corresponding tips of the print wires 12. Distance between a magnet yoke 5 and a core 15 provided between the flat spring 7 and a permanent magnet 4 at a position corresponding to a central print wire 12 side is set to be smaller than that at a position corresponding to an end print wire 12 side by varying it depending on positions of corresponding tips of the print wires 12.

Abstract: According to a method of adjusting a head gap, a wire dot head is set to a predetermined position of a reference head gap; a printing pattern for detecting printing time is printed by a plurality of pins; reference printing times of respective pins are detected. Next, a test printing is performed with test printing dots previously selected from printing data, and printing time of the test printing is detected. Then, the thickness of the printing media is calculated based on the reference printing time and the printing time of the test printing. At that time, a rule of thumb in which the difference of the printing time corresponds to the difference of the head gap, is used. Then, a shift amount of the wire dot head is calculated for setting the head gap to an optimum value according to the thickness of the printing media, and gap shifting mechanism shifts the wire dot head by the shift amount. This leads to highly accurate detection of the head gap and improves printing quality thereof.

Abstract: In a dot print head of an impact type moved in a direction of spacing movement relative to a printing medium, and having a plurality of printing elements each having a printing wire arranged substantially in an elongated circle centered at a line parallel with the direction in which the printing elements are driven, and which is provided with a wire guide having guide elements for the respective printing wires for guiding tips of the printing wires to predetermined positions on said printing medium, the guide elements are divided into at least four rows each extending in the direction orthogonal to said direction of the spacing movement and orthogonal to the direction in which the printing wires extend, and distances between said rows are multiples of 1/240 inches.

Abstract: An impact printer having a print head, the print head having a movable armature, a printing wire fixed to the armature, and sensor for detecting movement of the armature. The position of the armature is monitored based on an output of the sensor. A home sensor detects whether the print head is at a home position. A paper end sensor detect whether a printing medium is between the platen and the print head. A gap motor means adjusts a gap between the printing wire and the platen. A gap controller is responsive to detection signals output by said home sensor and said paper end sensor, for controlling the print head to swing the armature so as to cause the tip of said printing wire to strike the platen, determining a time of impact of the tip with the platen based on the monitored position of the armature, performing a comparison of the time of impact with a predetermined impact time, and outputting a drive signal to the gap motor for adjusting the gap according to a result of the comparison.

Abstract: A printed chip-on-board substrate is for mounting a high-power semiconductor chip. As a construction for efficiently releasing or dissipating heat to be generated in the semiconductor chip, the printed substrate has a printed interconnected substrate and a metal plate bonded on a back side of the substrate. The printed interconnected substrate is constructed by forming an interconnected layer on a surface of the substrate. At a mount area where the semiconductor chip is to be mounted, an opening is formed reaching the metal plate. The metal plate covers the opening on the side of the back side and is formed with a thickness capable of providing rigidity sufficient to support thereon at least the semiconductor chip to be mounted.

Abstract: A controller for a dot impact printer has capacitance sensors for sensing the motion of the dot wires in the print head, and a non-volatile, rewritable memory for storing self-adjustment data relating to dot-wire characteristics. A processor controls the driving of the dot wires according to the self-adjustment data stored in the memory. At certain times, the processor causes the dot wires to be driven in a test sequence and updates the self-adjustment data in the memory according to the resulting sensor output. Print quality is thereby maintained for the full guaranteed life of the print head.

Abstract: Printing control includes determining printing dot density of print data to be supplied to a printing head, averaging the printing dot density during a predetermined period of time based on the printing dot density determined, selecting a printing speed in response to the average value of printing dot density, and controlling printing to print at the selected printing speed.

Abstract: A print head has a solenoid driving means which employs a filler mixed with a lubricating oil to fix an exciting coil to the core. The filler prevents the layer winding from being shorted due to corrosion of the exciting coil and prevents mechanical abrasion of the armature by supplying lubricating oil during extended operation.

Abstract: A printed chip-on-board substrate is for mounting a high-power semiconductor chip. As a construction for efficiently releasing or dissipating heat to be generated in the semiconductor chip, the printed substrate has a printed interconnected substrate and a metal plate bonded on a back side of the substrate. The printed interconnected substrate is constructed by forming an interconnected layer on a surface of the substrate. At a mount area where the semiconductor chip is to be mounted, an opening is formed reaching the metal plate. The metal plate covers the opening on the side of the back side and is formed with a thickness capable of providing rigidity sufficient to support thereon at least the semiconductor chip to be mounted.

Abstract: A card type integrated circuit device is provided with a terminal arrangement for adapting the device to both 8 bit and 16 bit external systems. The arrangement includes a central terminal array wherein terminals for carrying signals common to both 8 bit and 16 bit systems are disposed, and an end terminal array wherein terminals for carrying signals exclusive to a 16 bit system are disposed.

Abstract: In a printer in which a print head and a print medium are moved relative to each other in a spacing direction and in a line-feed direction, the position of the print head in the spacing direction is detected, and the stoppage of the print head during a spacing operation is detected, and the stop position in the spacing direction is stored. When the print head stops, reverse line-feed is performed by a first amount. The spacing operation is then performed in the same direction as before the carriage stopped. A forward line-feed is then performed by the first amount, and then the spacing operation is performed in the opposite direction. If the print head stops again at the same stop positon, an error indication is made. If the print head does not so stop, the spacing operation is continued.

Abstract: In a driving apparatus for a wire-dot print head having electromagnets for driving print wires, each electromagnet comprising a core and a coil, sensing coils are provided in association with the respective electromagnets and provided to interlink the magnetic flux passing through the core of the associated electromagnet, a magnetic flux detecting circuit is connected to the sensing coils for detecting the magnetic flux passing through the core, and a control and drive circuit is responsive to the detected magnetic flux for deciding the termination of the energization of the drive coil.

Abstract: A wire dot printer has a thermistor that detects the temperature of a print head and a counter that starts counting when the detection temperature exceeds an alarm temperature. The printer can be controlled by switching over between normal-printing and reduced-character-printing in which a reduced number of print wires is used. When the detection temperature exceeds the alarm temperature, the printer will first stop and then control the print head in such a way as to reduce the temperature. Once the temperature drops back down below the alarm temperature, the printer will perform reduced-character-printing for a definite period of time based on the length of time from when the temperature exceeded the alarm temperature to when the temperature dropped back down below the alarm temperature. By increasing the length of time in which reduced-character-printing is carried out, the amount of heat given off by the print head decreases.

Abstract: In a dot matrix print head drive method for controlling head drive signals for driving dot pins in accordance with print pattern signals, a correction factor is set specifically to each dot pin; and the length of time for which the print pattern signals are to remain in effects is varied according to the correction factor, to correct the drive time for each dot pin.

Abstract: In a dot-matrix printer including a wire-dot print head having print wires which print dots by impact on a printing medium, and a sensor for sensing the position of the print wires and generating signals indicating the position of the print wires, a parameter is set to determine a printing force with which each of the print wires impacts the printing medium. A control and driving circuit drives the print wire responsive to the signals from the sensors and the set parameter. The combination of the feature of setting a parameter for controlling the printing force and the feature of detecting the position of the print wire enables the control over printing force with a high reproducibility. So printing with an optimum printing force is ensured.

Abstract: A wire-dot impact printer includes a wire-dot print head having a plurality of print wires disposed therein. Each of the plurality of print wires has a distal end, and each is displaced in response to a drive signal so as to strike a printing medium with the distal end. A displacement detecting device is provided for detecting a displacement resulting from the drive signal of each of the plurality of print wires and for outputting a corresponding displacement detection signal. A control unit, which controls the overall printing operation of the impact printer, varies the print repetitive cycle of each of the plurality of print wires in accordance with the displacement detection signal outputted by the displacement detecting unit.

Abstract: A driving apparatus for a wire-dot print head in a wire-dot impact printer has a sensor mounted in the print head to detect the motion of the print wires, enabling each print wire to be driven for the optimum time for each dot. Beneficial results include improved print quality, reduced power consumption and operating temperature, and faster printing.