Oki Electric Industry Co., Ltd.

Oki Data Corporation

Hideaki Ishimizu

Jiro Tanuma

Chihiro Komori

Hiroshi Kikuchi

Tadashi Kasai

Mitsuru Kishimoto

Toshiyuki Asaka

Naoji Akutsu

Hiroshi Sakaino

Takao Uchida

Hirokazu Andou

Yoichi Umezawa

Masayuki Ishikawa

Noboru Ooishi

Minoru Teshima

Takanori Mimura

Akira Hagiwara

Hiroyoshi Kawasaki

Takao Mizutani

Shigeru Tsunoda

Masahiko Shimosugi

Toshiro Suemune

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.

Image forming apparatus for normal and thick print media

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. The surface of the meniscus is subjected to fine vibration prior to either a printing operation or an ejection test. When the ejection test is performed, the controller determines the drive voltage by adding a first correction voltage to a drive voltage required for a printing operation. When the surface of meniscus is subjected to fine vibration, the controller determines the drive voltage by adding a second correction voltage to the drive voltage.

Apparatus for driving a printhead and method of driving the printhead

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.

Wire dot print head with print wires fixed to tip portions of armatures

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.

Method of adjusting a head gap for a wire dot impact printer

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. Each of the printing elements is driven for printing either at a reference timing which occurs once a standard printing cycle having a standard period, at a timing 1/4 of the standard period past said reference timing, at a timing half the standard period past said reference timing, or at a timing 3/4 of the standard period past said reference timing.

Dot print head and method of control over printing therewith

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.

Print gap setting in an impact printer

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.

Printed substrate for mounting high-power semiconductor chip thereon and

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.

Self-adjusting controller for dot impact printer

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.

Carriage speed control based on average dot density

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.

Solenoid actuator

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.

Card type integrated circuit and respective 8/16-bit card connector

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.

Method of and device for printer control

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.

Wire-dot print head driving apparatus having sensing coils

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. Furthermore, by basing the time over which reduced-character-printing is performed on the length of time that the alarm temperature was exceeded. It is possible to set the reduced-character-printing time to an appropriate length such that the print head does not overheat and throughout is not excessively impaired.

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Tokyo, Japan

Hideaki Ishimizu