Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Masanori Yoshikawa

Noboru Katakabe

Kenji Asakura

Atsushi Sogami

Nobuyoshi Taguchi

Hiroyuki Matsuo

Akihiro Imai

Yasuo Fukui

Masahiro Aizawa

Hideo Hirose

Yoshiharu Yamamoto

Motonobu Yoshikawa

Hajime Yamamoto

Akinobu Okuda

Daizaburo Matsuki

Keisuke Fujimoto

Hironori Honsho

Kouji Ikeda

Masaaki Nakano

Yasutaka Tamai

Yoshihisa Fujimori

Hiroshi Terada

Keizou Takeuchi

Shuichi Watanabe

Hiromichi Miyoshi

Masawo Otsuka

Masahiro Alzawa

Ikuko Katoh

The lens barrel includes a lens frame and a cam frame. The lens frame has a body supporting a lens element in the optical system, at least three through-holes formed in the lens frame body, at least three cam members arranged on the lens frame body and at least one protruding member that protrude from the lens frame body. The cam frame has a body, at least three projection members extending from the cam frame body and inserted through the through-holes, at least three cam grooves formed in the cam frame body and the projection members to guide the cam members and to movably support the lens frame with respect to the cam frame body. The cam frame also has at least one auxiliary groove to guide the protruding member. One end of the auxiliary groove is disposed in the circumferential direction between two adjacent projection members.

Cam frame structure, lens barrel structure, shake compensation device and imaging element unit

A first reflecting optical element () and a second reflecting optical element () are provided, and the second reflecting optical element () is disposed so as to reflect incident light to be incident on the first reflecting optical element () and reflected light from the first reflecting optical element, and thus a small-sized optical scanner can be obtained.

Photo scanner and image forming device

An optical scan apparatus includes an optical deflection unit (), an image formation optical system (), and curved surface mirrors (to). Light fluxes from the image formation optical system () come onto the deflection surface () of die optical deflection unit () in an oblique direction. Light fluxes from the optical deflection unit () come onto the curved surface mirrors (to) in an oblique direction. When a boundary is a plane () including a normal at the center of the deflection surface () and parallel to the main scan direction, the curved surface mirrors (to) are arranged in the same space divided by the boundary and the scan speeds of fluxes scanning the surfaces to be scanned (to) are almost identical. Thus, it is possible to obtain identical drive frequencies of the light sources (to), thereby simplifying the circuit.

Optical scan apparatus and color image formation apparatus

In an optical scanning device using two polygon mirrors, the present invention achieves both a simplification of the device and a reduction of vibrations. An optical scanning device is provided with a first optical system including a polygon mirror and a second optical system including a polygon mirror. The polygon mirror provided in the first optical system and the polygon mirror provided in the second optical system are configured such that they rotate in mutually opposite directions. Further, the optical scanning device is provided with one BD sensor for detecting laser beams that are scanned with the polygon mirrors. Slits with mutually different widths are arranged between the BD sensor and the respective polygon mirrors of the first and second optical systems.

Optical scanning device and image forming apparatus provided with the same

In an overfilled optical scanner in which a plurality of light beams are used, a uniform luminous-energy distribution is achieved on a scanning plane to be scanned. The optical scanner includes: a light sourcefor producing a first light beam Land a second light beam L; a polygon mirror; a first image formation optical system for leading the light beams Land Lto a deflecting plane of the polygon mirror and for forming, on the deflecting plane, a line image whose width is greater than the plane width of the deflecting plane; and a second image formation optical system for leading the light beams Land Lfrom the polygon mirror to the scanning plane of a photosensitive drum and forming an image on the scanning plane. The first image formation optical system is adjusted so that the optical axes Aand Aof the first and second light beams Land Lare approximately symmetrical about the optical axis Aof the first image formation optical system. The powers of the first and second light beams Land Lare thus balanced with each other on the scanning plane.

Optical scanner and image formation apparatus including the optical scanner

A light scanner includes a semiconductor laser, a polygon mirror, a first imaging optical system for guiding a light beam from the laser to the deflection surface of the polygon mirror, a second imaging optical system of a single curved mirror for guiding the light beam from the polygon mirror to a photosensitive drum, and a photodiode for detecting the light beam scanned by the polygon mirror. The first imaging optical system, the polygon mirror, and the second imaging optical system are located at different positions in the sub-scanning direction so that the light beam from the first imaging optical system enters the deflection surface obliquely, and the light beam from the polygon mirror enters the curved mirror obliquely.

Light scanner and image forming apparatus using the same

An image reading device comprising a rotary polygon mirror () for scanning a light flux from a light source (), an imaging optical system () for forming on a reflection plane of the mirror () a linear image larger than the width in a main scanning direction of the one reflection plane, and a curved-face mirror (), wherein the light source (), the imaging optical system (), the rotary polygon mirror () and the curved-face mirror () are disposed in different positions in a sub-scanning direction, a light flux from the imaging optical system () shines obliquely onto the polygon mirror (), and a light flux reflected off the mirror () beams obliquely onto the curved-face mirror (). Since one curved-face mirror can beam a light flux reflected from the rotary polygon mirror onto a surface to be scanned and the rotary polygon mirror having a small inscribed radius and many reflection planes can be used, satisfactory optical performance and high-speed feature can be realized.

Optical scanning device, image reading device provided with this, image forming device, and photographing device

By a first image forming optical system (to), a plurality of light beams from light sources (to) form linear images on a common deflecting surface () of an optical deflector (). Light beams reflected off the optical deflector () are reflected by a plurality of curved surface mirrors (to) and are allowed to scan over photosensitive members (to), respectively. The plurality of curved surface mirrors (to) are disposed on the same side with respect to a plane that includes a normal line at a center of the deflecting surface () and is parallel to a main scanning direction. Further, curved surfaces of the plurality of curved surface mirrors (to) vary in shape. Thus, a tandem type color image forming apparatus that achieves low cost and has excellent optical performance and an optical scanning device that is used favorably in the color image forming apparatus can be provided.

Optical scanning device and color image forming apparatus

An image forming apparatus includes a plurality of image forming units having a developer, a charger, and a photosensitive member; a carriage for retaining the plurality of image forming units so that they can be removed and installed, and which rotates the plurality of image forming units between an image forming position and other positions; a laser exposing device for exposing the photosensitive member at an image forming position; an intermediate transfer belt for accepting a toner image formed on the photosensitive member at the image forming position, and forming a color image; an output shaft for coupling with at least one axis end portion of the photosensitive member in the image forming position in the axial direction of the photosensitive member, and positioning the photosensitive member at a proper position; a rotation stop portion for positioning the rotation orientation of the image forming units with respect to the axis of the photosensitive members; and a retransfer roller for transferring the color image formed on the intermediate transfer belt at a retransfer position onto recording paper. Thus, it is possible to retain the image forming unit precisely and reliably at a proper position.

Image forming apparatus with plural color image forming units moveable into image forming position

An image forming apparatus capable of removing a toner remaining on the transfer belt (toner supporting member) with a simple configuration. The image forming apparatus includes an intermediate transfer belt that moves with charged toner supported on the surface thereof; a cleaner roller that is rotated while being pressed onto the intermediate transfer belt; a power source for supplying potential for electrically attracting the toner to the cleaner roller from the intermediate transfer belt; and a pretreatment roller that is pressed onto the intermediate transfer belt upstream from the cleaner roller in the moving direction of the intermediate transfer belt.

Image forming apparatus, transfer belt unit, cleaning device and cleaner unit used for image forming apparatus

A color image forming apparatus is provided, having a plurality of image forming units; a carriage for retaining and rotating the plurality of image forming units so as to move the image forming units between an image forming position and a waiting position; an intermediate transfer belt for successive transfer and superposition of toner images of various colors from a photosensitive drum of the image forming units located at the image forming position so as to form a color toner image; and a secondary transfer roller for transferring the color toner image on the intermediate transfer belt onto recording paper. The only rollers support the intermediate transfer belt are a driving roller, a following roller, a primary transfer roller and a backup roller, and the primary transfer roller and the backup roller are arranged adjacent to the driving roller.

Color image forming apparatus

A color image forming apparatus is provided, having a plurality of image forming units including a photosensitive drum, a charging device and a developing device; a carriage for retaining and rotating the plurality of image forming units so as to move the image forming units between an image forming position and a waiting position; an exposing device for exposing a surface of the photosensitive drum of the image forming unit located at the image forming position; an intermediate transfer belt for successive transfer and superposition of toner images of various colors from the photosensitive drum of the image forming units located at the image forming position so as to form a color toner image; a device for driving the photosensitive drum and the intermediate transfer belt; a position detector for detecting a reference position of the intermediate transfer belt when the intermediate transfer belt is driven; and outputting a reference position detection signal; a secondary transfer roller for transferring the color toner image on the intermediate transfer belt onto recording paper; and a controller for controlling the operation of the above structural elements. The controller determines an operation start time of the charging device and the developing device using a rotation command signal to the driving device as a reference, and an operation start time of the exposing device, the intermediate transfer belt and the secondary transfer roller using the reference position detection signal as a reference.

A color image forming apparatus is provided, and includes a plurality of image forming units including a photosensitive drum, a charging device and a developing device; a carriage for retaining and rotating the plurality of image forming units so as to move the image forming units between an image forming position and a waiting position; an exposing device for exposing a surface of the photosensitive drum of the image forming unit located at the image forming position; an intermediate transfer belt for successive transfer and superposition of toner images of various colors from the photosensitive drum of the image forming units located at the image forming position so as to form a color toner image; a driving member for driving the photosensitive drum and the intermediate transfer belt; a position detector for detecting a reference position of the intermediate transfer belt when the intermediate transfer belt is driven, and outputting a reference position detection signal; a secondary transfer roller for transferring the color toner image on the intermediate transfer belt onto recording paper; and a controller for controlling the operation of the above structural elements. The controller determines an operation start time of the charging device and the developing device using a rotation command signal to the driving member as a reference, and an operation start time of the exposing device, the intermediate transfer belt and the secondary transfer roller using the reference position detection signal as a reference.

The average friction factor between the contact surfaces of a drive roller and an intermediate transfer belt is set to not more than 0.45 and not less than 0.1, and before the primary transfer of the toner image of the last color is finished, a cleaning blade is separated from or comes into contact with the intermediate transfer belt with the drive roller as a backup member. The peripheral length of a photoconductor is greater by not more than 10% than the value obtained by dividing the length on a transfer member necessary for a predetermined image length by an integer n which is not less than 3 and not more than 9, and the ratio between the numbers of rotations of the transfer member and the photoconductor is 1:n.

Growing community of inventors

Neyagawa, Japan

Masanori Yoshikawa