Back to results
US 5,691,833 AGranted
Rotary polygon mirror device
AssigneeHitachi Koki Co., Ltd.
InventorsJunshin Sakamoto, Susumu Saito
Life of this patent
Estimating the term…
Abstract
In a rotary polygon mirror device comprising a cylinder rotatably supported for holding a polygon mirror and a casing over the outer peripheral surface of said cylinder through a predetermined gap, the thermal expansion coefficient of said casing is set for 1.2-1.6 times as large as that of said cylinder.
Claims4
A rotary polygon mirror device comprising:
- a polygon mirror;
- a rotatable cylinder for holding said polygon mirror;
- and
- a casing, disposed around an outer peripheral surface of said rotatable cylinder, for forming a predetermined gap between said outer peripheral surface of said rotatable cylinder and an inner peripheral surface of said casing;
- wherein the thermal expansion coefficient of said casing is 1.2-1.6 times as large as that of said rotatable cylinder and said rotatable cylinder is used in the rotating region of at least 20,000 revolutions per minute.
2 more elements
Dependencies are inferred from the claim text.