Optical apparatus having a driving source for driving a lens in an optical axis direction

• US 7,525,235 B2
• Filed: 04/12/2006
• Issued: 04/28/2009
• Est. Priority Date: 04/22/2005
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sato, Takehiko, Nakashima, Shigeo
• Primary Examiner(s): Donels; Jeffrey
• Assistant Examiner(s): UHLIR, CHRISTOPHER J
• Application Number:
  US11/403,382
• Publication Number:
  US 20060238902A1
• Time in Patent Office: 1,112 Days
• Field of Search: 310/328
• US Class Current: 310/328
• CPC Class Codes: G02B 7/022 lens and mount having complementary engagement means, e.g. screw/thread
• CPC Class Codes: G02B 7/023 permitting adjustment

Abstract

An optical apparatus is disclosed in which a press contact force for bringing a vibrator and a contact member into press contact with each other is generated between them, and thereby the reaction force of the press contact force is difficult to transmit outward. The optical apparatus comprises a lens holding member which holds a lens, and a vibration type linear actuator which drives the lens holding member in an optical axis direction. The vibration type linear actuator includes a vibrator on which vibration is produced through an electromechanical energy conversion action and a contact member which is in press contact with the vibrator. The vibrator and the contact member is in press contact with each other by a magnetic force acting between them.

Claims

1. An optical apparatus comprising

a lens holding member which holds a lens;

a guide member which engages the lens holding member to guide the lens holding member in an optical axis direction;

a vibration type linear actuator which drives the lens holding member in the optical axis direction, the vibration type linear actuator including;

a vibrator which includes an electromechanical energy conversion element and a ferromagnetic elastic member having a press contact surface on which a vibration is produced by the electromechanical energy conversion element, and a magnetic contact member having a press contact surface that is in press contact with the press contact surface of the ferromagnetic elastic member of the vibrator at one side and engaged with the lens holding member at the other side thereby guiding the lens holding member in the optical axis direction according to a frictional force produced by the vibrator and a magnetic force acting between the vibrator and the magnetic contact member; and

a plate spring which holds the press contact surface of the elastic member of the vibrator in parallel with the press contact surface of the contact member, each of the press contact surfaces being a planar surface,

wherein the plate spring is deformable in a rotation direction around an axis included in a plane parallel to the press contact surfaces.

2. The optical apparatus according to claim 1, further comprising:

a spacer to which the vibrator is fixed at one side and the plate spring fixed at the other side,

wherein the plate spring has a spring constant set such that it is deformed in response to a smaller force than the magnetic force acting between the vibrator and the contact member in the direction perpendicular to the optical axis direction.