Illumination light source and two-dimensional image display using same

• US 7,677,736 B2
• Filed: 02/24/2005
• Issued: 03/16/2010
• Est. Priority Date: 02/27/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Mizuuchi, Kiminori, Kasazumi, Ken'ichi, Yamamoto, Kazuhisa
• Primary Examiner(s): Dowling; William C
• Application Number:
  US10/568,596
• Publication Number:
  US 20060285078A1
• Time in Patent Office: 1,846 Days
• Field of Search: 353/69, 353/97, 353/98, 359/197.1, 359/205.1, 359/207.1, 359/207.6, 359/208.1, 359/208.2, 359/213.1, 359/214.1, 359/215.1, 359/224.1
• US Class Current: 353/69
• 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
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

An illumination light source uses a beam to scan while a relatively small mirror, such as an MEMS mirror, is oscillated at or in the vicinity of the resonance frequency. In this instance, the scan angle is corrected with the use of a correction optical system for uniform illumination to be achieved.

Claims

1. An illumination light source comprising:

a coherent light source;

a beam scan means for scanning light from the coherent light source; and

a correction optical system that corrects a scan angle of a beam scanned by said beam scan means,

wherein said beam scan means is formed of a mirror portion and a mirror portion oscillation means; and

the mirror portion is driven by the mirror portion oscillation means at or in a vicinity of a primary resonance frequency of the mirror portion, and

wherein said correction optical system is formed of a light collection optical system having third-order spherical aberration.

6. The illumination light source according to claim 1, wherein said correction optical system is formed of a free-form mirror.

7. The illumination light source according to claim 1, wherein:

said coherent light source is formed of a red coherent light source, a green coherent light source, and a blue coherent light source.

9. A 2-D image display device comprising:

the illumination light source according to claim 1; and

a projection optical system that projects light from the illumination light source onto a screen.

2. An illumination light source comprising:

a coherent light source;

a beam scan means for scanning light from the coherent light source; and

a correction optical system that corrects a scan angle of a beam scanned by said beam scan means,

wherein said beam scan means is formed of a mirror portion and a mirror portion oscillation means; and

the mirror portion is driven by the mirror portion oscillation means at or in a vicinity of a primary resonance frequency of the mirror portion, and

wherein a light shield means for shielding, of the light from said coherent light source, light whose scan angle by said beam scan means is at a ratio equal to or larger than a specific ratio with respect to a maximum scan angle.

5. The illumination light source according to claim 2, wherein the light shield means shields the light from said coherent light source for a time that accounts for 30% or less of a scan time.

3. An illumination light source comprising:

a coherent light source;

a beam scan means for scanning light from the coherent light source; and

a correction optical system that corrects a scan angle of a beam scanned by said beam scan means,

wherein said beam scan means is formed of a mirror portion and a mirror portion oscillation means; and

the mirror portion is driven by the mirror portion oscillation means at or in a vicinity of a primary resonance frequency of the mirror portion, and

wherein a scan rate of light having passed through said correction optical system takes a minimal value at a point at which the scan angle is 0.

4. An illumination light source comprising:

a coherent light source;

a beam scan means for scanning light from the coherent light source; and

a correction optical system that corrects a scan angle of a beam scanned by said beam scan means,

wherein said beam scan means is formed of a mirror portion and a mirror portion oscillation means; and

the mirror portion is driven by the mirror portion oscillation means at or in a vicinity of a primary resonance frequency of the mirror portion, and

wherein a scan rate of light having passed through said correction optical system is 90% or less of a maximum value of the scan rate at a point at which the scan angle is 0.

8. An illumination light source comprising:

a coherent light source;

a beam scan means for scanning light from the coherent light source; and

a correction optical system that corrects a scan angle of a beam scanned by said beam scan means,

wherein said beam scan means is formed of a mirror portion and a mirror portion oscillation means; and

the mirror portion is driven by the mirror portion oscillation means at or in a vicinity of a primary resonance frequency of the mirror portion, and

wherein at least a green coherent light source is formed of a second harmonic generator device that generates green light through wavelength conversion of light from a coherent light source having an infrared wavelength.