Oki Electric Industry Co., Ltd.

Oki Data Corporation

Nippon Telegraph and Telephone Public Corporation

Minoru Teshima

Hiroshi Kikuchi

Mitsuru Kishimoto

Minoru Isobe

Hirokazu Andou

Tadasi Kodama

Akira Nagumo

Jiro Tanuma

Hideaki Ishimizu

Yoshihisa Aikoh

Noboru Ohishi

Kenji Sato

Hiroyoshi Kawasaki

Tatsuya Koyama

Norio Nakajima

Kiyoshi Ikeda

Noboru Oishi

Hisashi Tsukagoshi

Wataru Ohara

Mitsuo Iwama

Youichi Umezawa

Adjustment of correction data for the respective LEDs at the end of manufacture of a print head is performed by transferring provisional correction data from a manufacturing device to an LED driver, directly, i.e., without once being stored in a storage circuit in the print head, and measuring the amounts of light from the LEDs and varying the correction data, and repeating such an operation until the correction data is optimized. The optimized correction data as well as the strobe time data determined from the measured average power are written in the storage circuit . During use of the printer, the data stored in the storage circuit is used for correction of the data and determination of the strobe time.

Print head having non-volatile memory and means for transmitting correction and inherent data

A method is used for correcting amounts of light of light emitting elements. A first correction range is defined which has a median of maximum and minimum values of the amounts of light of the light emitting elements, and includes a predetermined number of first subdivided ranges. If the minimum amount of light is not within the first correction range, a second correction reference is produced which is smaller than the first correction reference by a predetermined fraction of the difference between the maximum and minimum values. Then, a second correction range is defined which includes the minimum amount of light, has the second correction reference in its middle, and includes a predetermined number of second subdivided ranges. The amounts of light are corrected by increasing the amount of light if the measured amount of light is smaller than the second correction reference and decreasing the amount of light if the measured amount of light is larger than the second correction reference, the amounts of light being increased or decreased by the correction value corresponding to the second subdivided range. The first correction range may be set to include the minimum and maximum values therein, and the first and second subdivided ranges may progressively widen as the first subdivided ranges becomes increasingly far away from the first correction reference.

Method of correcting the amounts of emitted light

A driving apparatus has driving circuits that supply driving energy to driven elements which form dots. The driving circuits are controlled by driving data indicating which driven elements are to be driven, and compensation data adjusting the amount of driving energy. The compensation data are stored in compensation memory circuits coupled to the driving circuits. A single data transfer means transfers the driving data to the driving circuits and the compensation data to the compensation memory circuits. If the driven elements are located on two or more different semiconductor chips, some of the compensation data preferably compensate for chip-to-chip differences, while other compensation data compensate for dot-to-dot differences within the same chip.

Driving apparatus with circuits for efficiently transferring and storing

An LED print head is for use in an LED printer. The LED print head has an LED circuit board on which a plurality of LED chips are mounted in line, and a lens assembly having rod lenses for focusing light emitted from the LED chips on a surface of a photosensitive drum in the LED printer. A first member or slider engages either the LED circuit board or the lens assembly and is adapted to displace stepwise to cause either the LED circuit board or the lens assembly to flex stepwise relative to the surface of the photosensitive drum. A second member or slider engages said first member to movably hold said first member. The LED circuit board or lens assembly is flexed so that a point on the photosensitive drum and the surface of the corresponding LED form a pair of conjugate points with respect to the corresponding rod lens.

Led print head and method of adjusting the focus thereof

Wire dot print head

In a wire dot print head having print wires extending through an opening of a guide nose, the guide nose comprises two halves. The print head may further comprise a wire guide which is fitted in the guide nose and through which the print wires extend, and the wire guide may be clamped by the two halves. In another embodiment, the half members have abutting surfaces provided with semi-circular grooves, which when the guide nose halves are assembled, form guide holes in which the print wires are slidably supported. The use of the two halves facilitates assembly of the print head and reduces noise.

Wire dot print head with a pair of guide nose halves

In a spring-charge wire-dot print head, a support part of a plate spring is clamped, at its outer periphery, between a protruding member disposed on the front surface of the outer periphery of a spacer and a protruding member disposed on the rear surface of the outer periphery of a yoke, and the support part of the plate spring is additionally supported, at the rear surface of its inner periphery, by a protruding member disposed on the front surface of the inner periphery of the spacer.

Wire-dot print head

A dot matrix print head has a temperature sensor for detecting the temperature of the print head itself. When the detected temperature exceeds a preset temperature, the temperature sensor produces and output signal for stopping or slowing down the dot matrix print head so that its temperature may be lowered. The temperature sensor is accommodated in a substantially central hole of a radial member mounted in a heat conductor body and having a plurality of circumferentially spaced heat conducting arms with their radially outer ends held intimately against the radially inner surfaces of driver or demagnetizing coils which actuate dot pins. The heat conducting arms can quickly and accurately conduct the heat from the coils to the temperature sensor.

Dot matrix print head

A dot print head includes a spring plate having a plurality of integral tongues arranged successively along one longitudinal side edge thereof, a plurality of armatures each fixedly attached at a part at least excluding the rear end thereof to the upper surface of a respective tongue of the spring plate with the rear end of each armature located on the side of the fixed longitudinal side portion of the spring plate with respect to the fixed point of primary vibration thereof caused by the tongue of the spring plate, and a plurality of styluses each fixed to the free end of a respective armature. A yoke member is fixedly attached to the upper surface of the fixed longitudinal side portion of the spring plate and has a plurality of recesses for loosely receiving the armatures therein, to exert the effect of a magnetic field on the corresponding armatures. A restrictor is located on the respective path of the respective rear end of each armature to limit the movement of the respective rear end of the armature. A driver drives the armatures and a guide guides the styluses. A fastener fastens the spring plate, the yoke, the restrictor, the driver and the guide to a base plate.

Dot print head with restrained rebound of armature

A connector housing has an insertion slot for receiving a companion base board, a plurality of grooves defined in a housing bottom in a direction normal to the insertion slot, and a plurality of pin attachment holes disposed between the insertion slot and the grooves. Contact pins are approximately L-shaped and pivotally held in the pin attachment holes, respectively, in the vicinity of central bent portions of the contact pins. When the connector housing is attached to a base board and the companion board is inserted in the insertion slot, ends of the contact pins are connected to a circuit pattern on the base board and opposite ends of the contact pins are connected to a circuit pattern on the companion board. The base and companion boards are therefore electrically connected to each other substantially perpendicularly to each other.

Connector for connecting boards

A printer head having a circular first yoke, a cylindrical permanent magnet fixed on the circular first yoke, a (n) number of electromagnets (n is an integer) positioned on a circle on the first yoke within the permanent magnet having predetermined angle intervals, a ring shaped second yoke fixed on the permanent magnet so that the upper surface of the second yoke is on the same plane as that of the upper surface of the electromagnets, a ring shaped spacer positioned on the second yoke, a disk shaped spring fixed on the spacer having a common outer ring and a (n) number of projections projected in the internal direction from the common outer ring, (n) number of armatures each fixed on each projection of the spring, (n) number of print needles each fixed to each armature so that a print needle is perpendicular to the plane of the spring, a circular yoke plate fixed on the spring having (n) number of radial slits for accepting the armatures and the width of each slit being narrower than the width of projection of the spring, a guide frame fixed on the yoke plate having a ring and a hollow cylindrical post positioned at the center of the ring, the post having a guide slit at the top of the guide frame for accepting the tops of the aligned print needles, a side hole at the side of the post at the extension of the guide slit being provided. And an oil felt being provided on the inner wall of the permanent magnet.

Printer head

A serial printer head is provided which comprises a sandwich structure (1,3,5) of a first circular yoke plate (1), a cylindrical magnet (3) and a ring shaped second yoke plate (5); a plurality of electromagnets (2,4) positioned on the first yoke plate (1) at predetermined angle intervals; an armature-print-needle assembly (7,8,9,10) having a circular resilient spring (7), a plurality of armatures (8) and a plurality of print needles (9) placed on the sandwich structure (1,3,5) so that the sandwich structure (1,3,5), electromagnets (2,4) and the armatures (8) provide first a substantially closed magnetic path; and an adjusting yoke (12) attached to the sandwich structure (1,3,5). The adjusting yoke (12) has the magnetic characteristics that the magnetic reluctance increases as the temperature increases. Although the flux generated by the permanent magnet (3) is changed due to the change of the temperature, that flux change is compensated for by the presence of the adjusting yoke (12).

Printer head for serial dot printer

A printer head for mosaic printing having a plurality of needles positioned on a straight line each being selectively driven towards a paper through an ink ribbon has been found. The printer head comprises of a cylindrical permanent magnet, a first yoke covering the bottom of the permanent magnet, a plurality of electromagnets each positioned on a circle on the first yoke with the predetermined angle intervals, a disk shaped spring having an outer ring and a plurality of projections towards the center of the disk, a plurality of armatures each attached to the related projection of the disk spring, a plurality of print needles each attached to the related projection of the disk spring so that each of the needles has the perpendicular component to the disk spring plane. A ring shaped spacer is positioned between the disk spring and the cylindrical permanent magnet, a second yoke for providing a magnetic flux path is positioned between the permanent magnet and each of the electromagnets, and a guideframe having a thin linear slit for arranging the top of said needles and covering the needles is provided.

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Tokyo, Japan

Minoru Teshima