Title:
ROTARY POLYGON MIRROR
Document Type and Number:
Japanese Patent JPH02264916
Kind Code:
A
Abstract:
PURPOSE:To decrease air resistance received by a rotary polygon mirror and to effectively suppress the occurrence of noise by making an angle formed by a flat surface and a mirror at the back side of a rotational direction greater than an angle formed by a flat surface and a mirror at the forwarding side of the rotational direction. CONSTITUTION:The flat surface 5 is formed on the boundary part between adjoining mirrors 4 of the rotary polygon mirror. The angle beta formed by the flat surface 5 and the mirror 4 at the forwarding side of the rotational direction is set greater than the angle formed by the flat surface and the mirror at the back side of the rotational direction. When the rotary polygon mirror is rotated, the air separated from the edge part 6 of the mirror 4 at the forwarding side of the rotational direction flows along the mirror 4 almost in parallel to the mirror 4 at the back side of the rotational direction by the flat surface 5. The air flows circularly and vortex 9 is produced in a space part. However, air resistance which the rotary polygon mirror receives can be decreased so that the occurrence of noise is effectively suppressed. Consequently, the disturbance of an electrostatic latent image formed on a photosensitive body can be prevented.
Inventors:
OSHIMA HIROKO
Application Number:
JP8731889A
Publication Date:
October 29, 1990
Filing Date:
April 06, 1989
Export Citation:
Assignee:
RICOH KK
International Classes:
G02B26/12; G02B26/10; (IPC1-7): G02B26/10
Attorney, Agent or Firm:
Akira Kashiwagi