Ricoh Company, Ltd.

Tohoku Ricoh Co., Ltd.

Ntn Corporation

Makoto Endo

Noriyuki Kadowaki

Yoshihiro Takahashi

Yukio Itami

Natsuhiko Mori

Tetsuya Kurimura

Hidetoshi Kojima

Takashi Tanaka

Tomotaka Takamura

Takao Abe

Takeshi Kikuchi

Tomoyuki Murakami

Kazuhiro Koseki

Masao Hatayama

Kazuhiko Koseki

Takeshi Tanaka

A polygon scanner including a polygon mirror, a bearing, a polygon motor, and a scanner board is mounted in an optical housing. A scanner-unit attachment portion to which the polygon scanner is attached is formed as a convex portion protruded from a bottom plate of the optical housing such that at least a planar shape of the polygon mirror is surrounded by the convex portion. The scanner board makes a tight contact with an upper surface of the convex portion in direct contact with each other, so that a bottom of the polygon scanner is covered by the convex portion and the bottom plate of the optical housing in a sealed manner.

Image forming apparatus

An optical deflector, a method of producing the optical deflector, an optical scanning device, and an image forming apparatus are disclosed that are able to save resources, provide high reliability at low cost, and enable stacked and relatively-offset polygon mirrors to be arranged precisely. The optical deflector includes a rotary member supported by a bearing with plural polygon mirrors fixed thereon. The polygon mirrors are stacked along a rotation axis of the rotary member, the polygon mirrors are relatively offset by a predetermined angle in a rotation plane of the rotary member, and an effective deflection area of each of the reflection surfaces of any one of the polygon mirrors is positioned away from a center of the corresponding reflection surfaces of the other one of the polygon mirrors in the direction of the rotation axis.

Optical deflector, production method thereof, optical scanning device, and image forming apparatus

A hydrodynamic bearing unit is provided, by which the touch between oil and a sealing member in a housing is prevented to prevent oil leakage. A bearing member made of a sintered lubricant-containing metal is disposed along the inner periphery of the housing and a spindle is supported in a non-contact manner by the hydrodynamic oil pressure that is generated in a bearing gap by the rotation of the spindle. The opening of the housing is sealed by the sealing member. A ventilation path is formed so as to communicate a sealed space enclosed by the distal end of the spindle at the bottom of the housing, the bearing member and the housing with open air. An oil reservoir is formed between the inner periphery of the housing and the outer periphery of the bearing member at the end portion of the opening side of the housing. The oil reservoir is made so as to communicate with the ventilation path.

Hydrodynamic bearing unit

Growing community of inventors

Miyagi, Japan

Makoto Endo