| 摘要 |
PURPOSE:To thin the titled scanner while holding the inclination accuracy and the stability at the time of a high speed rotation of a rotary body, by providing a gas bearing part for generating the dynamic pressure of gas at the time of a rotation of the rotary body and holding the axial direction of a rotary member and its inclination in a state of non-contact, between a base plate and a plane part of the rotary member. CONSTITUTION:An optical deflector in an optical scanner is provided with a plane part of a rotary member 51 for holding a rotary body containing a rotary polyhedron mirror 52, and a dynamic pressure gas bearing for generating the dynamic pressure by the rotation between plane parts of a base plate 61 placed so as to be opposed to said plane part and supporting the rotary member 51 in a state of non-contact. Also, in the radial direction of the rotary member 51, a control member for supporting mainly its unbalanced force, for instance, a fixed axis 60 in this embodiment is provided. Accordingly, by the dynamic pressure gas bearing part, the support in the axial direction of the rotary member 51 is executed, and also, its inclination can also be held simultaneously. In such a way, the optical deflector can be thinned remarkably, and also, the optical scanner which has applied this device can be thinned and miniaturized. |
