Projector and method for controlling same
In order to minimize a change in the luminance of a projected image caused by a lamp refreshing process, projector 10 according to the present invention includes lamp refreshing controller 13 which, upon detecting that the lighting power of lamp 15 is lower than rated power thereof for a given period of time, increases the lighting power of lamp 15 to the rated power and, after elapse of a predetermined period of time, reduces the lighting power to an original level thereof, and aperture data generator 16 which controls the aperture of optical diaphragm 18 depending on a change in the lighting power to keep constant the amount of light passing through optical diaphragm 18.
1. A projector including a lamp and an optical diaphragm for adjusting an amount of light emitted from said lamp, said projector comprising:
a lamp refreshing controller which, upon detecting a lighting power that lights said lamp as being lower than a rated power of said lamp for a given period of time, increases the lighting power to the rated power, and, after an elapse of a predetermined period of time, reduces the lighting power to an original level thereof; and
an aperture data generator which controls an aperture of said optical diaphragm depending on a change in the lighting power to keep constant an amount of light passing through said optical diaphragm,
wherein said lamp refreshing controller determines a value of the lighting power at a time that the lighting power is to be increased to the rated power, and the predetermined period of time based on a value of the lighting power and a period of time that the lamp has been lighted with the lighting power before the lighting power is to be increased to the rated power.
2. The projector according to claim 1 , wherein said lamp refreshing controller changes the lighting power stepwise.
3. The projector according to claim 1 , wherein said predetermined period of time is equal to or greater than a period of time required to recover lamp characteristics according to a halogen cycle of said lamp.
4. The projector according to claim 1 , further comprising:
a display device for modulating the light emitted from said lamp,
wherein said lamp, said optical diaphragm, and said display device are arranged in an order named along an optical path.
5. The projector according to claim 1 , further comprising:
a display device for modulating the light emitted from said lamp,
wherein said lamp, said display device, and said optical diaphragm are arranged in an order named along an optical path.
6. The projector according to claim 2 wherein said predetermined period of time is equal to or greater than a period of time required to recover lamp characteristics according to a halogen cycle of said lamp.
7. The projector according claim 2 , further comprising:
a display device for modulating the light emitted from said lamp,
wherein said lamp, said optical diaphragm, and said display device are arranged in an order named along an optical path.
8. The projector according claim 3 , further comprising:
a display device for modulating the light emitted from said lamp,
wherein said lamp, said optical diaphragm, and said display device are arranged in an order named along an optical path.
9. The projector according to claim 2 , further comprising:
a display device for modulating the light emitted from said lamp,
wherein said lamp, said display device, and said optical diaphragm are arranged in an order named along an optical path.
10. The projector according to claim 3 , further comprising:
a display device for modulating the light emitted from said lamp,
wherein said lamp, said display device, and said optical diaphragm are arranged in an order named along an optical path.
11. The projector according to claim 1 , wherein the lamp refreshing controller is configured to linearly change the amount of light emitted from said lamp to the lighting power of said lamp.
12. The projector according to claim 1 , wherein the rated power is defined as an electric power that results in stability of a halogen cycle of said lamp, and the rated power includes a dimmer-mode electric power.
13. The projector according to claim 1 , wherein a period of time during which the lamp refreshing controller increases the lighting power to the rated power is a period of time required for an evaporated electrode substance to be deposited on electrodes of said lamp for recovering characteristics of said lamp.
14. A method of controlling a projector including a lamp and an optical diaphragm for adjusting an amount of light emitted from said lamp, said method comprising:
upon detecting a lighting power that lights said lamp as being lower than a rated power of said lamp for a given period of time, increasing, with a lamp refreshing controller, the lighting power to said rated power, and, after an elapse of a predetermined period of time, reducing, with said lamp refreshing controller, the lighting power to an original level thereof;
controlling, with an aperture data generator, an aperture of said optical diaphragm depending on a change in the lighting power to keep constant an amount of light passing through said optical diaphragm; and
determining a value of the lighting power at a time that the lighting power is to be increased to the rated power, and the predetermined period of time based on a value of the lighting power and a period of time that the lamp has been lighted with the lighting power before the lighting power is to be increased to the rated power.
15. The method according to claim 14 , wherein said lamp refreshing controller changes said lighting power stepwise.
16. The method according to claim 14 , wherein said predetermined period of time is equal to or greater than a period of time required to recover lamp characteristics according to a halogen cycle of said lamp.
17. The method according to claim 15 , wherein said predetermined period of time is equal to or greater than a period of time required to recover lamp characteristics according to a halogen cycle of said lamp.
18. The method according to claim 14 , wherein said controlling comprises linearly changing the amount of light emitted from said lamp to the lighting power of said lamp.
19. The method according to claim 14 , wherein the rated power is defined as an electric power that results in stability of a halogen cycle of said lamp, and the rated power includes a dimmer-mode electric power.
20. The method according to claim 14 , wherein a period of time during which the lamp refreshing controller increases the lighting power to the rated power is a period of time required for an evaporated electrode substance to be deposited on electrodes of said lamp for recovering characteristics of said lamp.