Optical scanning apparatus, optical writing apparatus, image forming apparatus, and method of driving vibration mirror

• US 20060164710A1
• Filed: 02/08/2006
• Published: 07/27/2006
• Est. Priority Date: 05/16/2003
• Status: Active Grant

• Current Assignee: Eiji Mochizuki, Mitsumi Fujii
• Original Assignee: Eiji Mochizuki, Mitsumi Fujii
• Inventors: Mochizuki, Eiji, Fujii, Mitsumi
• Granted Patent: US 7,312,912 B2
• Time in Patent Office: Days
• US Class Current: 359/213.100
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence

Abstract

An optical scanning apparatus includes a vibration mirror having a mirror surface that reflects an optical beam. A pair of torsion beams swingably support the mirror. The mirror is vibrated in a sealed space whose pressure is adjusted such that a characteristic of the mirror falls within a predetermined range.

Claims

1-23. -23. (canceled)

24. An optical scanning apparatus, comprising;

a vibration mirror having a mirror surface that reflects an optical beam and vibrated in a vibration space formed in said optical scanning apparatus; and

a pair of torsion beams swingably supporting said vibration mirror in the vibration space,

wherein the vibration space is sealed and an air pressure therein is adjusted such that a characteristic of said vibration mirror falls within a predetermined range.

25. The optical scanning apparatus as claimed in claim 24, further comprising:

a driving voltage generator applying a voltage of a predetermined frequency to said optical scanning apparatus,

wherein the vibration mirror is driven in a band that is in the vicinity of a resonance frequency and is outside a resonance peak.

26. An optical scanning apparatus, comprising;

a vibration mirror having a mirror surface that reflects an optical beam;

a pair of torsion beams swingably supporting said vibration mirror in a sealed vibration space formed in said optical scanning apparatus; and

an air pressure adjusting part that adjusts an air pressure in the vibration space such that a characteristic of said vibration mirror falls within a predetermined range.

27. The optical scanning apparatus as claimed in claim 26, wherein the air pressure adjusting part absorbs a gas in the vibration space, and adjusts the air pressure in the vibration space by absorbing the gas therein.

28. The optical scanning apparatus as claimed in claim 27, wherein a plurality of the air pressure adjusting parts are arranged at different positions.

29. The optical scanning apparatus as claimed in claim 26, wherein the air pressure adjusting part releases a gas in the vibration space and adjusts the air pressure in the vibration space by releasing the gas therein.

30. The optical scanning apparatus as claimed in claim 29, wherein a plurality of the air pressure adjusting parts are arranged at different positions.

31. The optical scanning apparatus as claimed in claim 26, wherein a gas introduced into the vibration space is formed by mixing a plurality of kinds of gases.

32. The optical scanning apparatus as claimed in claim 31, wherein a plurality of the air pressure adjusting parts are arranged at different positions.

33. The optical scanning apparatus as claimed in claim 26, wherein the air pressure adjusting part includes a plurality of kinds of air pressure adjusting parts.

34. The optical scanning apparatus as claimed in claim 33, wherein at least one of the air pressure adjusting parts absorbs a gas and another of the air pressure adjusting parts releases a gas.

35. The optical scanning apparatus as claimed in claim 34, wherein the air pressure adjusting parts are arranged at different positions.

36. The optical scanning apparatus as claimed in claim 33, wherein the air pressure adjusting parts have different activation temperatures.

37. The optical scanning apparatus as claimed in claim 36, wherein the air pressure adjusting parts are arranged at different positions.

38. The optical scanning apparatus as claimed in claim 33, wherein the air pressure adjusting parts have different activators.

39. The optical scanning apparatus as claimed in claim 38, wherein the air pressure adjusting parts are arranged at different positions.

40. The optical scanning apparatus as claimed in claim 33, wherein the air pressure adjusting parts are arranged at different positions.

41. The optical scanning apparatus as claimed in claim 26, further comprising:

a driving voltage generator applying a voltage of a predetermined frequency to said optical scanning apparatus,

wherein the vibration mirror is driven in a band that is in the vicinity of a resonance frequency and is outside a resonance peak.

42. An optical scanning apparatus, comprising;

a vibration mirror having a mirror surface that reflects an optical beam and vibrated in a sealed vibration space formed in said optical scanning apparatus;

a pair of torsion beams swingably supporting said vibration mirror in the sealed vibration space; and

an air pressure adjusting part that adjusts an air pressure in the sealed vibration space such that a predetermined swing angle is obtained at a predetermined driving frequency or a predetermined band.

43. The optical scanning apparatus as claimed in claim 42, wherein the air pressure adjusting part absorbs a gas in the vibration space, and adjusts the air pressure in the vibration space by absorbing the gas therein.

44. The optical scanning apparatus as claimed in claim 43, wherein a plurality of the air pressure adjusting parts are arranged at different positions.

45. The optical scanning apparatus as claimed in claim 42, wherein the air pressure adjusting part releases a gas in the vibration space and adjusts the air pressure in the vibration space by releasing the gas therein.

46. The optical scanning apparatus as claimed in claim 45, wherein a plurality of the air pressure adjusting parts are arranged at different positions.

47. The optical scanning apparatus as claimed in claim 42, wherein a gas introduced into the vibration space is formed by mixing a plurality of kinds of gases.

48. The optical scanning apparatus as claimed in claim 47, wherein a plurality of the air pressure adjusting parts are arranged at different positions.

49. The optical scanning apparatus as claimed in claim 42, wherein the air pressure adjusting part includes a plurality of kinds of air pressure adjusting parts.

50. The optical scanning apparatus as claimed in claim 49, wherein at least one of the air pressure adjusting parts absorbs a gas and another of the air pressure adjusting parts releases a gas.

51. The optical scanning apparatus as claimed in claim 50, wherein the air pressure adjusting parts are arranged at different positions.

52. The optical scanning apparatus as claimed in claim 49, wherein the air pressure adjusting parts have different activation temperatures.

53. The optical scanning apparatus as claimed in claim 52, wherein the air pressure adjusting parts are arranged at different positions.

54. The optical scanning apparatus as claimed in claim 49, wherein the air pressure adjusting parts have different activation temperatures.

55. The optical scanning apparatus as claimed in claim 54, wherein the air pressure adjusting parts are arranged at different positions.

56. The optical scanning apparatus as claimed in claim 49, wherein the air pressure adjusting parts are arranged at different positions.

57. The optical scanning apparatus as claimed in claim 42, further comprising:

a driving voltage generator applying a voltage of a predetermined frequency to said optical scanning apparatus,

wherein the vibration mirror is driven in a band that is in the vicinity of a resonance frequency and is outside a resonance peak.

58. An image forming apparatus, comprising:

an optical scanning apparatus;

a photo conductor on which an electrostatic image is formed by said optical scanning apparatus;

a developing part developing the electrostatic image by a toner; and

a transfer part transferring a developed toner image onto a sheet medium,

said optical scanning apparatus including;

a vibration mirror having a mirror surface that reflects an optical beam and vibrated in a vibration space formed in said optical scanning apparatus; and

a pair of torsion beams swingably supporting said vibration mirror in the vibration space,

wherein the vibration space is sealed and an air pressure therein is adjusted such that a characteristic of said vibration mirror falls within a predetermined range.

59. An image forming apparatus, comprising:

an optical scanning apparatus;

a photo conductor on which an electrostatic image is formed by said optical scanning apparatus;

a developing part developing the electrostatic image by a toner; and

a transfer part transferring a developed toner image onto a sheet medium,

said optical scanning apparatus including;

a vibration mirror having a mirror surface that reflects an optical beam and vibrated in a sealed vibration space formed in said optical scanning apparatus;

a pair of torsion beams swingably supporting said vibration mirror in the sealed vibration space; and

an air pressure adjusting part that adjusts an air pressure in the sealed vibration space such that a characteristic of said vibration mirror falls within a predetermined range.

60. An image forming apparatus, comprising:

an optical scanning apparatus;

a photo conductor on which an electrostatic image is formed by said optical scanning apparatus;

a developing part developing the electrostatic image by a toner; and

a transfer part transferring a developed toner image onto a sheet medium,

said optical scanning apparatus including;

a vibration mirror having a mirror surface that reflects an optical beam and vibrated in a sealed vibration space formed in said optical scanning apparatus;

a pair of torsion beams swingably supporting said vibration mirror in the sealed vibration space; and

an air pressure adjusting part that adjusts an air pressure in the sealed vibration space such that a predetermined swing angle is obtained at a predetermined driving frequency or a predetermined band.