Lens moving apparatus

Patent metadata

Field	Value
Publication number	US-10216000-B2
Application number	US-201615005122-A
Country	US
Kind code	B2
Filing date	Jan 25, 2016
Priority date	Jan 23, 2015
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

Disclosed is a lens moving apparatus. The lens moving apparatus includes a moving unit having at least one lens installed therein and moving by electromagnetic interaction between magnets and coils, elastic members configured to support the moving unit, and position sensors configured to sense change of electromagnetic force emitted from the magnets according to movement of the moving unit and to output an output signal based on a result of sensing, and a primary resonant frequency of frequency response characteristics according to gain of a ratio of the output signal of the position sensors to an input signal applied to the coils is 30 Hz to 200 Hz.

First claim

What is claimed is:

1. A lens moving apparatus comprising:
a moving unit including a housing, a bobbin disposed in the housing, a magnet and a coil, wherein the bobbin is configured to be moved in a first direction in parallel to an optical axis by an electromagnetic interaction between the magnet and the coil;
an elastic member configured to support the moving unit and comprising an inner frame coupled with the bobbin, an outer frame coupled with the housing, and a frame connection part configured to connect the inner frame and the outer frame;
a position sensor configured to sense an electromagnetic force emitted from the magnet according to the movement of the bobbin and to output an output signal based on the electromagnetic force being sensed,
wherein a width of the frame connection part is at least two times greater than a thickness of the elastic member,
wherein an input signal is applied to the coil to generate the electromagnetic interaction with the magnet,
wherein a primary resonant frequency of frequency response characteristics is 30 Hz to 200 Hz, and
wherein the frequency response characteristics are related to a gain of a ratio of the output signal of the position sensor to the input signal applied to the coil.

2. The lens moving apparatus according to claim 1 , wherein a secondary resonant frequency of the frequency response characteristics according to the gain of the ratio of the output signal of the position sensor to the input signal applied to the coil exceeds 200 Hz.

3. The lens moving apparatus according to claim 2 , wherein the secondary resonant frequency is equal to or greater than 250 Hz.

4. The lens moving apparatus according to claim 1 , wherein a thickness of the elastic member is in a range of 30 μm to 50 μm, and a width of the elastic member is correspondingly equal to or greater than a range of 60 μm to 100 μm.

5. The lens moving apparatus according to claim 1 , wherein a frequency corresponding to a gain of 0 dB of the frequency response characteristics according to the gain of the ratio of the output signal of the position sensor to the input signal applied to the coil is 60 Hz to 200 Hz.

6. The lens moving apparatus according to claim 1 , wherein the primary resonant frequency is 40 Hz to 120 Hz.

7. The lens moving apparatus according to claim 1 , wherein the primary resonant frequency is 50 Hz to 100 Hz.

8. The lens moving apparatus according to claim 1 ,
wherein the elastic member includes:
upper elastic members coupled with an upper end of the bobbin and an upper end of the housing; and
lower elastic members coupled with a lower end of the bobbin and a lower end of the housing.

9. The lens moving apparatus according to claim 8 , wherein each of the upper elastic members includes:
a first inner frame coupled with the bobbin;
a first outer frame coupled with the housing; and
a first frame connection part configured to connect the first inner frame and the first outer frame,
wherein each of the lower elastic members includes:
a second inner frame coupled with the bobbin;
a second outer frame coupled with the housing; and
a second frame connection part configured to connect the second inner frame and the second outer frame, and
wherein a width of the first frame connection part is at least two times greater than a thickness of each of the upper elastic members, and
wherein a width of the second frame connection part is at least two times greater than a thickness of each of the lower elastic members.

10. The lens moving apparatus according to claim 1 , wherein the position sensor includes a driver to execute proportional integral derivative (PID) control.

11. The lens moving apparatus according to claim 1 , wherein the position sensor is mounted on a substrate and is inserted into the bobbin.

12. A lens moving apparatus comprising:
a housing;
a bobbin disposed inside the housing;
an elastic member coupled with the bobbin and the housing and comprising an inner frame coupled with the bobbin, an outer frame coupled with the housing, and a frame connection part configured to connect the inner frame and the outer frame;
a first coil disposed on the bobbin;
a magnet disposed on the housing;
a circuit board disposed under the housing;
a second coil disposed on the circuit board;
a first position sensor configured to output a first output signal based on a result of sensing strength of a magnetic field of the magnet according to a movement of the bobbin in a first direction in parallel to an optical axis; and
second position sensors configured to output a second output signal based on a result of sensing strength of a magnetic field of the magnet according to a movement of the housing in a second direction perpendicular to the optical axis,
wherein a width of the frame connection part is at least two times greater than a thickness of the elastic member,
wherein a first input signal is applied to the first coil to generate an electromagnetic interaction for the movement of the bobbin, and a second input signal is applied to the second coil to generate an electromagnetic interaction for the movement of the housing,
wherein a primary resonant frequency of frequency response characteristics has a frequency domain of 30 Hz to 200 Hz, and the frequency response characteristics are related to gain of a first transfer function,
wherein a secondary resonant frequency of the frequency response characteristics has a frequency domain exceeding 200 Hz,
wherein the first transfer function is a ratio of the output signal of the second position sensors to the second input signal applied to the second coil.

13. The lens moving apparatus according to claim 12 , wherein the elastic member includes:
upper elastic members coupled with an upper end of the bobbin and an upper end of the housing; and
lower elastic members coupled with a lower end of the bobbin and a lower end of the housing.

14. The lens moving apparatus according to claim 13 , wherein each of the upper members includes:
a first inner frame coupled with the bobbin;
a first outer frame coupled with the housing; and
a first frame connection part configured to connect the first inner frame and the first outer frame,
wherein each of the lower elastic members includes:
a second inner frame coupled with the bobbin;
a second outer frame coupled with the housing; and
a second frame connection part configured to connect the second inner frame and the second outer frame, and
wherein a width of the first frame connection part is at least two times greater than a thickness of each of the upper elastic members, and a width of the second frame connection part is at least two times greater than a thickness of each of the lower elastic member.

15. The lens moving apparatus according to claim 13 , wherein the thickness of each of the upper and lower elastic members is in a range of 30 μm to 50 μm, the width of each of the upper and lower elastic members is correspondingly equal to or greater than a range of 60 μm to 100 μm.

16. The lens moving apparatus according to claim 12 , wherein a primary resonant frequency of frequency response characteristics according to a gain of a second transfer function has a frequency domain of 30 Hz to 200 Hz, a secondary resonant frequency of frequency response characteristics according to a gain of the second transfer function has a frequency domain exceeding 200 Hz, and the second transfer function is a ratio of the output signal of the first position sensor to the first input signal applied to the first coil.

17. The lens moving

Assignees

• Lg Innotek Co Ltd

Inventors

• Park Sang Ok
• Son Byung Wook
• Yoo Kyoung Ho
• Lee Jun Taek

Classifications

• H04N23/687

  by shifting the lens or sensor position · CPC title

• G02B7/08

  adapted to co-operate with a remote control mechanism · CPC title

• H04N5/23287

  Electricity · mapped topic

• G02B27/646 Primary

  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 title

• G03B2205/0023

  by tilting or inclining one or more optical elements with respect to the optical axis · CPC title