LENS DRIVE DEVICE

• US 20180129064A1
• Filed: 10/31/2017
• Published: 05/10/2018
• Est. Priority Date: 11/04/2016
• Status: Active Grant

• Current Assignee: Tdk Taiwan Corp. (TDK Corporation)
• Original Assignee: TDK Corporation
• Inventors: ICHIHASHI, Shusuke
• Granted Patent: US 10,444,531 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 13/001 Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras G02B23/243 takes precedence
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• CPC Class Codes: G03B 2205/0015 by displacing one or more optical elements normal to the optical axis
• CPC Class Codes: G03B 2205/0069 using electromagnetic actuators, e.g. voice coils
• CPC Class Codes: G03B 5/04 Vertical adjustment of lens; Rising fronts
• CPC Class Codes: H02K 41/02 Linear motors; Sectional motors

Abstract

A lens drive device includes a movable portion, a fixed portion, and four suspension wires. The movable portion has a lens holder holding a lens and a magnet arranged at a position that does not overlap with the lens when viewed from a light axis direction. The fixed portion has a coil and a position sensor arranged to oppose against the magnet in the light axis direction and a circuit board having multiple wirings. The wires are arranged around the lens at approximately equal intervals in the light axis direction. The sensor and the coil are arranged to overlap with four sides of a four-sided polygon formed by connecting four wire connection positions where the wires are connected with the fixed portion. The sensor is arranged between the wire connection position closest to the sensor and the coil closest thereto.

Claims

1. A lens drive device comprising:

a movable portion having a lens holder holding a lens and a magnet arranged at a position that does not overlap with the lens when viewed from a light axis direction;

a fixed portion having a coil and a position sensor arranged to oppose against the magnet in the light axis direction and a circuit board having a plurality of wirings configured to supply electricity to the coil and the position sensor and transmit a signal from the position sensor; and

four suspension wires arranged around the lens at approximately equal intervals when viewed from the light axis direction and configured to support the movable portion against the fixed portion so that the movable portion can move relatively to the fixed portion in a vertical direction to the light axis direction by an electromagnetic force generated in the magnet and the coil,

wherein the position sensor and the coil are arranged to overlap with four sides of a four-sided polygon formed by connecting four wire connection positions where the four suspension wires are connected with the fixed portion when viewed from the light axis direction, and

the position sensor is arranged between the wire connection position closest to the position sensor and the coil closest to the position sensor.

2. The lens drive device according to claim 1, wherein the circuit board comprises:

a coil leading terminal portion provided with a plurality of leading terminals along one of the four sides of the four-sided polygon formed by connecting the wire connection positions and electrically connected with a coil wiring of the plurality of wirings for supplying electricity to the coil; and

a sensor leading terminal portion provided with a plurality of leading terminals along another one of the four sides of the four-sided polygon formed by connecting the wire connection positions and electrically connected with a sensor wiring of the plurality of wirings for supplying electricity to the position sensor and transmitting a signal therefrom.

3. The lens drive device according to claim 2, wherein

the circuit board comprises:

a board plane portion extending along the vertical direction to the light axis direction; and

a board folded portion connected with the board plane portion at a position that is more distant from a center position of the light axis direction than the four sides of the four-sided polygon formed by connecting the wire connection positions and extending along the light axis direction,

the position sensor is fixed to the board plane portion, and

the sensor leading terminal portion is arranged on the board folded portion.

4. The lens drive device according to claim 3, wherein

the circuit board is a flexible print board, and

a notch is formed on both ends of a connection portion with the board folded portion in an outer circumferential portion of the board plane portion.

5. The lens drive device according to claim 2, wherein the sensor leading terminal portion comprises:

a pair of feeding leading terminals configured to supply electricity to the position sensor; and

a signal transmission leading terminal arranged to be sandwiched by the pair of feeding leading terminals and configured to transmit a signal of the position sensor.

6. The lens drive device according to claim 3, wherein the sensor leading terminal portion comprises:

a pair of feeding leading terminals configured to supply electricity to the position sensor; and

a signal transmission leading terminal arranged to be sandwiched by the pair of feeding leading terminals and configured to transmit a signal of the position sensor.

7. The lens drive device according to claim 4, wherein the sensor leading terminal portion comprises:

a pair of feeding leading terminals configured to supply electricity to the position sensor; and

a signal transmission leading terminal arranged to be sandwiched by the pair of feeding leading terminals and configured to transmit a signal of the position sensor.