Projector
A projector of rear-projection type including a light source that outputs a laser beam and a scanner that scans a screen with the laser beam. When a laser beam with energy exceeds an accessible emission limit due to failure of the light source or the scanner, at least one optical member located in an optical path of the laser beam is arranged so as to be broken or altered in quality and to prevent or discourage the beam with energy exceeding the accessible emission limit from being output from the screen.
1. A projector of rear-projection type, comprising:
a light source that outputs a laser beam, the laser beam having an optical path; and
a scanner that scans a screen with the laser beam,
at least one optical member located in the optical path of the laser beam that is broken or altered in quality when the laser beam has an energy exceeding an accessible emission limit due to failure of the light source or the scanner to prevent the laser beam having the energy exceeding the accessible emission limit from being output from the screen.
2. The projector according to claim 1 , the first accessible emission limit being the maximum exposure level permitted when an operation of the scanner is normal and output intensity of the light source is abnormal, and the second accessible emission limit being the maximum exposure level permitted, when the output intensity of the light source is normal and the scanner stops due to failure,
an optical member located before the scanner in the optical path of the laser beam is arranged so as to be broken or altered in quality by a laser output exceeding a first accessible emission limit and an optical member located behind the scanner in the optical path of the laser beam is arranged so as to be broken or altered in quality by a laser output exceeding a second accessible emission limit, the maximum exposure level permitted when an operation of the scanner is normal and output intensity of the light source is abnormal, and the second accessible emission limit being the maximum exposure level permitted, when the output intensity of the light source is normal and the scanner stops due to failure.
3. The projector according to claim 2 , the scanner having a movable plate rotatable around a predetermined rotation axis, a solid layer melting by heat of the laser beam exceeding the first accessible emission limit, and a light reflection film being formed on a surface of the movable plate via the solid layer.
4. The projector according to claim 3 , the movable plate being formed by a material having an absorption wavelength region in a wavelength region of the laser beam.
5. The projector according to claim 2 , the screen having a coloring layer that colors by heat of the laser beam exceeding the second accessible emission limit.
6. The projector according to claim 2 , further comprising:
a projection lens provided between the scanner and the screen, the projection lens having a coloring layer that colors by heat of the laser beam exceeding the second accessible emission limit.
7. The projector according to claim 2 , further comprising:
a projection lens provided between the scanner and the screen, the projection lens being formed by a material that phase-transitions by heat of the laser beam exceeding the second accessible emission limit.
8. The projector according to claim 2 , further comprising:
a collimator or beam shaping lens provided between the scanner and the light source, the collimator or beam shaping lens having a coloring layer that colors by heat of the laser beam exceeding the first accessible emission limit.
9. The projector according to claim 2 , further comprising:
a collimator or beam shaping lens provided between the scanner and the light source, the collimator or beam shaping lens being formed by a material that phase-transitions by heat of the laser beam exceeding the first accessible emission limit.
10. The projector according to claim 2 , further comprising:
a reflection mirror provided between the scanner and the screen, the reflection mirror having a base material, a solid layer that melts by heat of the laser beam exceeding the second accessible emission limit, and a light reflection film formed on the surface of the base material via the solid layer.
11. The projector according to claim 10 , the base material being formed by a material having an absorption wavelength region in a wavelength region of the laser beam.
12. The projector according to claim 1 , further comprising:
an enlargement system provided between the screen and the scanner; and
an optical member located before the enlargement system in the optical path of the laser beam arranged so as to be broken or altered in quality when a beam with energy exceeding the accessible emission limit is output.
13. The projector according to claim 12 , further comprising:
a light collection system provided between the optical member and the enlargement system.
14. The projector according to claim 1 , wherein the at least one optical member is located before the scanner in the optical path of the laser beam.
15. The projector according to claim 1 , wherein the at least one optical member is arranged to be broken when the intensity of the laser beam output by the light source reaches a threshold level defined as the accessible emission limit.
16. The projector according to claim 1 , wherein the at least one optical member is arranged to be altered when the intensity of the laser beam output by the light source reaches a threshold level defined as the accessible emission limit.
17. The projector according to claim 1 , wherein the at least one optical member is located before the output of the projector.
18. The projector according to claim 1 , wherein the at least one optical member is broken or altered before the laser beam exits the projector when the laser beam has an energy exceeding an accessible emission limit.