BIAXIAL SCANNING MIRROR FOR IMAGE FORMING APPARATUS AND METHOD FOR OPERATING THE SAME

• US 20110310451A1
• Filed: 06/21/2010
• Published: 12/22/2011
• Est. Priority Date: 06/21/2010
• Status: Active Grant

• Current Assignee: Gredman Taiwan Limited
• Original Assignee: TOUCH MICRO-SYSTEM TECHNOLOGY CORP. (Walsin Lihwa Corporation)
• Inventors: LIN, Hung Yi
• Granted Patent: US 8,305,671 B2
• Time in Patent Office: Days
• US Class Current: 359/200.6
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129

Abstract

A biaxial scanning minor is disclosed in the present invention. The minor includes: a first wafer having several cavities forming a first row and a second row, several permanent magnets each installed in one of the cavities, a spacer and a second wafer. The second wafer includes: a minor unit, rotating around a first axis, for reflecting light beams; and a rotating unit, formed around the minor unit, for rotating the minor unit around a second axis which is perpendicular to the first axis. At least one coil substrate having a planar coil is assembled in the rotating unit.

Claims

1. A biaxial scanning minor for an image forming apparatus, comprising:

a first wafer having a plurality of cavities forming a first row and a second row;

a plurality of permanent magnets each installed in one of the plurality of cavities, two adjacent permanent magnets of the same row having an air gap formed therebetween;

a second wafer, comprising;

a minor unit, rotating around a first axis, for reflecting light beams; and

a rotating unit, formed around the minor unit, for rotating the minor unit around a second axis which is perpendicular to the first axis;

at least one coil substrate having a planar coil, assembled in the rotating unit; and

a spacer, formed between the first wafer and the second wafer, for separating the first wafer and the second wafer.

2. The biaxial scanning minor according to claim 1, wherein the minor unit is driven by a comb drive actuator.

3. The biaxial scanning minor according to claim 1, wherein the minor unit is actuated by rotation of the rotating unit around the second axis.

4. The biaxial scanning minor according to claim 1, wherein resonant frequency of the minor unit around the first axis is higher than that of the rotating unit around the second axis.

5. The biaxial scanning minor according to claim 1, wherein the coil substrate has a thickness smaller than 150 μ

m.

6. The biaxial scanning minor according to claim 1, wherein the rotating unit has at least one slot for vertically receiving the coil substrate.

7. The biaxial scanning mirror according to claim 1, wherein the air gap has a width smaller than 250 μ

m.

8. The biaxial scanning mirror according to claim 1, wherein the air gap has a magnetic flux larger than 0.82 Tesla.

9. The biaxial scanning mirror according to claim 1, wherein the coil substrate is formed by micro-electro-mechanical systems (MEMS) process.

10. A method of operating a biaxial scanning mirror according to claim 1, comprising the steps of:

a) generating a first magnetic field by the permanent magnets in the first row;

b) generating a second magnetic field of which direction is opposite to that of the first magnetic field by the permanent magnets in the second row;

c) providing a first signal to the planar coil for triggering the mirror unit to rotate around the first axis; and

d) providing a second signal to the planar coil for triggering the rotating unit to rotate around the second axis.

11. The method according to claim 10, wherein the first signal is sinusoidal with a frequency larger than 18 KHz and the second signal has a waveform of saw-tooth with a frequency of 60 Hz.

12. A method of operating a biaxial scanning mirror according to claim 1, comprising the steps of:

a) generating a first magnetic field by the permanent magnets in the first row;

b) generating a second magnetic field of which direction is opposite to that of the first magnetic field by the permanent magnets in the second row;

c) providing a first signal to the mirror unit for triggering the mirror unit to rotate around the first axis; and

d) providing a second signal to the planar coil for triggering the rotating unit to rotate around the second axis.

13. The method according to claim 12, wherein the first signal is sinusoidal with a frequency larger than 18 KHz and the second signal has a waveform of saw-tooth with a frequency of 60 Hz.

14. The method according to claim 12, wherein the first signal is provided to the mirror unit via a comb drive actuator.

15. The method according to claim 12, wherein the mirror unit is electrostatically triggered and the rotating unit is magnetically triggered.