Driving apparatus

• US 20070109412A1
• Filed: 11/13/2006
• Published: 05/17/2007
• Est. Priority Date: 11/16/2005
• Status: Active Grant

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Hara, Yoshihiro
• Granted Patent: US 7,640,741 B2
• Time in Patent Office: Days
• US Class Current: 348/207.100
• CPC Class Codes: G03B 2205/0023 by tilting or inclining one or more optical elements with respect to the optical axis
• CPC Class Codes: G03B 2205/0076 using shape memory alloys
• CPC Class Codes: H04N 23/50 Constructional details
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

In an auto image stabilization system, a driving member formed as a wire of shape memory alloy (SMA) is retained by a projection of an image capturing unit. A distance Lb from the rotation center of an elastic deforming part to center of gravity (point of application) of the image capturing unit is longer than a distance La from the rotation center of the elastic deforming part to the projection (power point). In the configuration, equivalent mass (apparent mass) of the image capturing unit becomes (Lb/La) times, and it causes deterioration in response. Consequently, the driving member having an ellipse-shaped section in which a value obtained by dividing the width in the longer direction of the section by the width in the shorter direction is 1.3 or larger is employed. As a result, heat dissipation of the driving member increases, so that response in the SMA actuator can be properly improved.

Claims

1. A driving apparatus comprising:

(a) a movable part; and

(b) an actuator connected to said movable part and driving said movable part, said actuator having a first elastic part and a second elastic part which are connected to said movable part in a push-pull relation,

at least one of said first elastic part and said second elastic part being formed as a wire made of a shape memory alloy, and

a sectional shape of said wire being flattened in shape.

2. The driving apparatus according to claim 1, wherein said sectional shape of said wire is an ellipse shape.

3. The driving apparatus according to claim 1, wherein length d1 in a longer direction and length d2 in a shorter direction with regard to said sectional shape of said wire satisfy the following equation;

d1/d2≧

1.3.

4. The driving apparatus according to claim 1, wherein sectional area S of said wire satisfies the following equation;

80 μ

m²≦

S≦

5,030 μ

m².

5. The driving apparatus according to claim 1, further comprising:

(c) a sensor for obtaining a measurement value with regard to a driving of said movable part; and

(d) a controller for passing current to said wire on basis of a deviation between a drive target value of said movable part and said measurement value in order to control a driving of said movable part.

6. A driving apparatus comprising:

(a) a movable part; and

(b) an actuator connected to said movable part and driving said movable part, said actuator having a first elastic part and a second elastic part which are connected to said movable part in a push-pull relation,

at least one of said first elastic part and said second elastic part being formed as a plurality of wires made of a shape memory alloy, and

said plurality of wires stretching so as to be adjacent to each other along a same stretch route.

7. The driving apparatus according to claim 6, wherein each of said plurality of wires has a circular sectional shape having a same diameter.

8. The driving apparatus according to claim 6, further comprising:

(c) a sensor for obtaining a measurement value with regard to a driving of said movable part; and

(d) a controller for passing current to said wire on basis of a deviation between a drive target value of said movable part and said measurement value in order to control a driving of said movable part.