Sharp Kabushiki Kaisha Corporation

Toshio Urakawa

Takao Tagawa

Masahiko Aiba

Fumikazu Nagano

Shigeru Fujimura

Hideki Goto

Kounosuke Mino

Fumio Sato

The invention avoids an increase in the number of parts and components which form an apparatus for forming an image, and hence, prevents a main body of the image forming apparatus from completed in a large size. To this end, the image forming apparatus comprises yellow, magenta, cyan and black photosensitive drums 7Y, 7M, 7C and 7B, chargers 8Y, 8M, 8C and 8B which respectively charges the photosensitive drums 7Y, 7M, 7C and 7B which correspond to the respective colors, laser diodes 11Y, 11M, 11C and 11B which generate laser beams representing the respective colors in accordance with image signals, the laser beams exposing the respective photosensitive drums 7Y, 7M, 7C and 7B so that electrostatic latent images are formed on the photosensitive drums 7Y, 7M, 7C and 7B which correspond to the respective colors, developing members 31Y, 31M, 31C and 31B corresponding to the respective colors for supplying developing agents, a polygon mirror 13 for scanning the laser beams representing the respective colors emitted from the laser diodes 11Y, 11M, 11C and 11B, and a reflection mirror 15 for reflecting the laser beams which are indicative of the respective colors in such a manner that the laser beams intersect with each other at the same intersection B and thereafter respectively irradiate the photosensitive drums 7Y, 7M, 7C and 7B which correspond to the respective colors.

Image forming apparatus

A laser beam is projected from a laser oscillator 1 and converged by a condenser lens 2. The laser beam converged by the condenser lens 2 is reflected in any arbitrary direction by a scanning mirror 4 which is rotated by scanning means 3. The laser beam is linearly moved. The laser beam is reflected by a curved surface reflecting mirror 5 which is formed in a spherical surface in the primary scanning direction of the laser beam and an ellipsoid in the secondary scanning direction so that the scanned surface is scanned at a substantially predetermined speed.

Laser scanner with curved anamorphic mirror

A laser beam printer includes a movable mirror which is rotated by a scan mirror motor. Laser light is alternately deflected toward an information reading station and an information writing station by applying the laser light to the movable mirror from a semiconductor laser. The laser light is switched between writing-use light and reading-use light at the time the movable mirror is rotated through a predetermined angle. In the laser beam printer having the semiconductor laser which is used for both writing and reading information, information is written and read out during one rotation of the movable mirror. It is therefore possible to perform a reading operation and a writing operation simultaneously by simply switching the laser light at the predetermined time depending on the rotation angle of the movable mirror.

Reading and writing apparatus with rotating mirror

A polygon mirror is made by resin-forming and includes, at least on its referential surface for attachment, one or more kinds of elements selected from projections, hollow portions and through-holes. The hollow portions or through-holes are filled with an adhesive in contact with the referential surface for attachment. When only projections are used, pairs of projections are formed at corresponding positions on both the referential surface for attachment and the clamping member-receiving surface. When the polygon mirror is provided with projections in combination with hollow portions or through-holes, the projections penetrate through the respective hollow portions or through-holes.

Polygon mirror for a laser scanning optical system

A printer having a plurality of data input ports for printing out information input through each data input port on paper fed by a paper feeding device. The printer includes a main body; paper cassettes for storing the paper therein, each paper cassette made detachable from the main body; a plurality of setting portions to be set so as to direct whether or not each paper cassette is to be used for printing out information input through a predetermined data input port, the plurality of setting portions being provided for each paper cassette; a plurality of sensors for detecting the content of the setting portions when each paper cassette is installed in the main body; and a control section for, when printing out information input through each of the plurality of data input ports, controlling the paper feeding device to feed the paper within each paper cassette which is assigned for each data input port, based on results of the detection by the plurality of sensors.

Paper cassette having a plurality of switches for selecting an input

A color-picture analyzing apparatus includes a blue, green, and red-purpose lamps, preferably, fluorescent lamps; a sharp-cut filter in front of the red-purpose lamp for solely passing the red radiation; an infrared-cut filter interposed between a document having a color-picture to be analyzed and a reading sensor for cutting an infrared zone radiation; a first circuit for continuously switching on the green lamps; and a second circuit for alternatively switching on the blue and the red-purpose lamps. The red-purpose lamp can provide wide radiations covering the red spectral zone. It may be a cool white fluorescent lamp having a short afterglow time.

Color-picture analyzing apparatus for continuously switching-on green

An optical system adapted for a laser printer is characterized in that a laser generator provides a laser beam having a cross section of an ellipse whose longitudinal axis is defined by a surface of the laser generator for emitting the laser beam, a first lens receives and passes through the laser beam having the elliptic cross section toward a lower reflector, a second lens receives the laser beam having the elliptic cross section such that a laser element of the laser beam along with a direction orthogonal to the surface of the laser generator is incident upon a longitudinal side of the second lens and images the laser beam having a cross section of an approximate circle to a substantially focused spot at a surface of a light sensitive medium. The optical system is to focus the first lens by rotation with screws formed on a body tube. Preferably, the first lens comprises a focus lens of an axial symmetrical lens including a spherical lens and the second lens comprises a cylindrical lens.

Optical system for laser printer

A flying spot scanning system adapted for a laser printer is characterized in that a laser generator provides a laser beam having a cross section of an ellipse whose longitudinal axis is defined by the surface of the laser generator emitting the laser beam, a first lens receives and passes through the laser beam having the elliptic cross section toward a laser reflector, a second lens receives the laser beam having the elliptic cross section from the laser reflector, the laser beam along a direction orthogonal to the surface of the laser generator being incident upon a longitudinal side of the second lens which modifies the laser beam to a cross section of an approximate circle to a substantially focused spot on the surface of a light sensitive medium. Preferably, the first lens comprises an axially symmetrical focus lens and the second lens comprises a cylindrical lens.

Flying spot scanner for laser printer

A dot matrix pattern printer of the impact type mainly comprises a hammer of which an active portion is flattened to have a predetermined length in the lateral direction, and a vertical line element which has a predetermined length in the vertical direction and is driven to shift its position in the lateral direction. Combination of the hammer actuation, the vertical line element location, and a paper feed in the vertical direction provides a printed pattern in, for example a 5 .times. 7 dot matrix pattern.

Growing community of inventors

Yamatokoriyama, Japan

Toshio Urakawa