Oki Electric Industry Co., Ltd.

Oki Data Corporation

Oki Electric Co., Ltd.

Minoru Mizutani

Kuniharu Hayashi

Shyoichi Watanabe

Masanori Maekawa

Norihisa Isaka

Hiroshi Kikuchi

Yoshiharu Momiyama

Kiyoshi Matsuda

Sinichi Ootani

Toshiyuki Sato

Takashi Itaya

Makoto Yabuki

Takeshi Asaba

Koji Aida

Toshiaki Saito

Eisaku Mutou

Yoshihisa Fukurohata

Naoki Chiba

Shoichi Watanabe

An image forming apparatus includes a plurality of removable developing units each of which has an image carrier whose width is narrower than a width of a printable area of the printing paper, and a driving unit for driving the plurality of the removable developing units. The plurality of the removable developing units are disposed in different rows parallel to a main scanning direction such that one end of an image producing area of an image carrier of a first developing unit coincides with one end of an image producing area of an image carrier of a second developing unit adjoining to the first developing unit. The image forming apparatus further includes a control unit for supplying printing data to the plurality of the removable developing units in timings shifted form row to row.

Image forming apparatus

In a serial printer a pinion and a rack for lateral movement of a carriage, a dislodging member with edges proximate to the rack is provided to remove any chads or other foreign matters that may be attached to the rack, as they approach the pinion with the lateral movement of the carriage. The chads or other foreign matters are prevented from being caught between the pinion and the rack, and noises and increase in the torque due to the rolling in is prevented.

Rack and pinion cleaning mechanism in a serial printer

Toner cartridge

Image drum cartridge

A multicolor ink ribbon for use with a dot impact printer includes at least three layers. The layers include an ink layer composed of at least one colored ink ribbon having a first surface which forms a printing surface of the multicolor ink ribbon, an intermediate barrier layer having a first surface which covers a second surface of the ink layer, for preventing ink penetration from the ink layer therethrough, and a protective layer having a first surface which covers a second surface of the intermediate barrier layer and having a second surface which forms a printing head surface of the multicolor ribbon. The intermediate barrier layer prevents ink penetration from the ink layer into the protective layer, and the protective layer protects the intermediate barrier layer from physical deterioration due to impact from a printing head during use.

Multicolor ink ribbon having barrier and protective layers

A cassette holder assembly includes a first cassette holder for detachably attaching a first ink ribbon cassette at a position that the ink ribbon is supplied to a printing face of a print head, and a second cassette holder detachably mounted on the first cassette holder when the first ink ribbon cassette is detached from the first cassette holder and provided with a ribbon shifting mechanism for shifting the ink ribbon of a second ink ribbon cassette with respect to the printing face of the print head. In accordance, the cassette holders can be replaced easily by an operator, and the printer can be used effectively.

Cassette holder assembly

A main frame (22) of a printer comprises a horizontal bottom plate (23e) and walls (23a to 23d) to form a box-shaped enclosure defining an inner space (23f). At least one of the walls is offset from the respective edge (104a to 104c) of the bottom plate to form an outer space (106) above the bottom plate (23e). A platen (8) and a carriage (10) are positioned in the inner space (23f) and fixed to the walls (23b, 23c) of the main frame (22). A controller board (3) and a power unit (4) are positioned in the outer space (106). An upper cover (13) has a top plate (13e) and walls (13a to 13d). The controller board (3) and the power unit (4) are positioned between the walls (13a to 13d) of the upper cover ( 13) and the walls (23a to 23d) of the main frame (23). The main frame (22) is formed by integral molding, and provides rigidity required for holding the platen (8) and the carriage (10), while collision or interference between the platen and the carriage (which move mechanically) and the controller board and the power unit is prevented.

Printer including integral one-piece main frame

Ink ribbon cassette

A permanent magnet type stepping motor comprising first and second stator assemblies arranged coaxially about a longitudinal axis. Each assembly includes first and second ring-shaped stators made of magnetic material. The first ring-shaped stator has a central portion with an opening therein, an annular yoke surrounding the periphery of the central portion and a plurality of pole pieces distributed about the circumference of the opening and extending toward a plane transverse to the axis. The second ring-shaped stator has a central portion with an opening therein, an annular substantially planar yoke surrounding the periphery of the central portion and a plurality of pole pieces distributed about the circumference of the opening and extending away from the transverse plane so as to interleave with the pole pieces of the first stator. The central portion of the second stator protrudes from the plane of the yoke in a direction away from the transverse plane. A coil is interposed between the first and second ring-shaped stators and surrounds the pole pieces. The first and second stator assemblies are arranged with respect to the transverse plane so that the second ring-shaped stator of the first stator assembly is adjacent the second ring-shaped stator of the second stator assembly at the transverse plane thereby forming a gap between the protruding central portions of the second stators of the first and second stator assemblies. A permanent magnet having N and S poles distributed alternately about the outer circumference thereof is rotatably supported within the openings in the central portions of the first and second stators of the first and second stator assemblies.

Permanent magnet type stepping motor

A sheet guide mechanism, for use with a printer having a printing head on a carriage that is mounted on a carriage shaft for movement in a printing direction which is transverse to a feeding direction of a printing sheet supported by a platen, includes a sheet guide movably mounted on the carriage shaft. The sheet guide moves in the printing direction along with the printing head. The sheet guide can move in unison with the printing head without interfering with the printing operation.

Sheet guide mechanism for a printer

A reinking color ribbon cassette for a printer is described. The cassette has plural, independent ink ribbons of different colors - such as the primary colors and a black color - and a ribbon feeder for driving only the ink ribbon of a selected color to perform printing through the ink ribbon of the selected color. The ink ribbons can be used repeatedly by feeding their corresponding inks by a color ink feeder. The color ink feeder is constructed of ink tanks, in which inks of the different colors are contained respectively, and ink feeding members. These plural ink ribbons, color ink feeder and ribbon feeder are enclosed within a cassette casing constructed of a lower cover and an upper cover.

Reinking color ribbon cassette and ink ribbon selection mechanism

An ink ribbon cartridge has an ink ribbon and a ribbon casing accommodating the ink ribbon therein and defining in a part thereof an ink ribbon exposure opening. A film defining a printing opening therethrough is fixed at lengthwise opposite ends thereof on the ribbon casing by two supports, respectively, while covering the exposure opening. At least one of the two supports is movable along the length of the film.

Ink ribbon cartridge

Sheet stacker having sheet-feed function

A pin platen mechanism includes coiled springs mounted in respective retaining holes formed in a sprocket wheel for biasing respective sprocket pins to the outside at all times. A cam groove in a cam member has freely fitted therein projections of the sprocket pins. A wider part of the cam groove enables the pins to be withdrawn inwardly only when necessary.

Growing community of inventors

Tokyo, Japan

Minoru Mizutani