1. An illumination device comprising:
a substrate including a fluorescent layer, and capable of rotating around a predetermined rotary shaft;
a light source, the light source intermittently emitting an excitation light to excite the fluorescent layer;
a rotational period determination device adapted to control the rotation of the substrate so that, when the substrate is rotating, a first area of the fluorescent layer is irradiated with the excitation light in one round, and at least a part of the first area is not irradiated with the excitation light in another round; and
an electric motor adapted to rotate the substrate.
2. The illumination device according to claim 1, wherein
the rotational period determination device controls the rotation of the substrate so that, when the substrate is rotating, an area of the fluorescent layer irradiated with the excitation light in the one round and an area of the fluorescent layer irradiated with the excitation light in the another round does not overlap each other.
3. The illumination device according to claim 1, wherein
the rotational period determination device controls the rotation of the substrate so that, when the substrate is rotating, an area of the fluorescent layer that is not irradiated with the excitation light in the one round and an area of the fluorescent layer that is not irradiated with the excitation light in the another round does not overlap each other.
4. The illumination device according to claim 1, wherein
assuming that the fluorescent layer is divided into a plurality of segments along a rotational direction of the substrate, a cumulative light intensity of the excitation light incident on a first segment out of the plurality of segments per unit time is equal to a cumulative light intensity of the excitation light incident on a second segment out of the plurality of segments different from the first segment per unit time.
5. The illumination device according to claim 4, wherein
the rotational period determination device controls the rotation of the substrate so that the rotation of the substrate is asynchronous with emission of the excitation light.
6. The illumination device according to claim 1, wherein
the another round is a round following the one round.
7. The illumination device according to claim 4, wherein
the another round is a round following the one round.
8. The illumination device according to claim 4, wherein
the cumulative light intensity of the excitation light irradiated per unit time is equal between all of the segments.
9. The illumination device according to claim 1, further comprising:
an emission timing generation device adapted to generate an emission timing signal for controlling an emission timing of the light source, the emission timing signal having a period synchronous with a frame period,
wherein the rotational period determination device determines a rotational period, which is a non-integral multiple of a period of the emission timing signal, as a rotational period of the substrate.
10. The illumination device according to claim 9, wherein
the rotational period determination device determines the rotational period which is a quotient of the period of the emission timing signal and a non-integral number.
11. The illumination device according to claim 9, further comprising:
a light detection section adapted to detect fluorescence emitted from the fluorescent layer;
a light source drive section adapted to make the light source emit light at the period of the emission timing signal; and
a light source output level adjustment section,
wherein the light source output level adjustment section generates an emission level correction signal in accordance with a detection result of the light detection section, and
the light source drive section corrects an output level of the excitation light emitted from the light source in accordance with the emission level correction signal.
12. The illumination device according to claim 11, wherein
the rotational period determination device determines the rotational period which is a quotient of the period of the emission timing signal and a non-integral number.
13. The illumination device according to claim 9, wherein
assuming that a duty ratio of a light-emitting period of the light source is \u03b4 (0<\u03b4<1), the rotational period determination device determines a period, which is (1+\u03b4) times of the period of the emission timing signal, as the rotational period of the substrate.
14. The illumination device according to claim 13, wherein
the duty ratio \u03b4 is smaller than or equal to 0.5.
15. A projector comprising:
a substrate including a fluorescent layer, and capable of rotating around a predetermined rotary shaft;
a light source, the light source intermittently emitting an excitation light to excite the fluorescent layer;
a rotational period determination device adapted to control the rotation of the substrate so that, when the substrate is rotating, a first area of the fluorescent layer is irradiated with the excitation light in one round, and at least a part of the first area is not irradiated with the excitation light in another round;
an electric motor adapted to rotate the substrate;
a light modulation element adapted to modulate fluorescence emitted from the fluorescent layer with an image signal; and
a projection optical system adapted to project the fluorescence modulated by the light modulation element.
16. The projector according to claim 15, wherein
assuming that the fluorescent layer is divided into a plurality of segments along a rotational direction of the substrate, a cumulative light intensity of the excitation light incident on a first segment out of the plurality of segments per unit time is equal to a cumulative light intensity of the excitation light incident on a second segment out of the plurality of segments different from the first segment per unit time.
17. The projector according to claim 15, further comprising:
an emission timing generation device adapted to generate an emission timing signal for controlling an emission timing of the light source, the emission timing signal having a period synchronous with a frame period;
a light detection section adapted to detect fluorescence emitted from the fluorescent layer;
a light source drive section adapted to make the light source emit light at the period of the emission timing signal; and
a light source output level adjustment section,
wherein the rotational period determination device determines a rotational period, which is a non-integral multiple of a period of the emission timing signal, as a rotational period of the substrate,
the light source output level adjustment section generates an emission level correction signal in accordance with a detection result of the light detection section, and
the light source drive section corrects an output level of the excitation light emitted from the light source in accordance with the emission level correction signal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A cooling system for a hot plate, comprising:
a hot plate having a plurality of internal pipelines, wherein each pipeline has an inlet and an outlet, the inlet is suitable for a cooling fluid to enter and the outlet is suitable for the cooling fluid to exhaust.
2. The cooling system of claim 1, wherein the cooling fluid is a gas.
3. The cooling system of claim 1, wherein the cooling fluid is a liquid.
4. The cooling system of claim 1, wherein the cooling fluid is a mixture of gas and liquid.
5. The cooling system of claim 2, wherein the cooling gas is selected from a group consisting of air, nitrogen, carbon dioxide and inert gas.
6. The cooling system of claim 3, wherein the cooling liquid is selected from a group consisting of water, cold medium or hot medium.
7. The cooling system of claim 4, wherein the mixture of gas and liquid is selected from a group consisting of air, nitrogen, carbon dioxide, inert gas, water, cold medium and hot medium.
8. A cooling system for a hot plate, comprising:
a hot plate having a plurality of internal pipelines, wherein the pipelines have a common inlet and a common outlet, the common inlet is suitable for a cooling fluid to enter and the common outlet is suitable for the cooling fluid to exhaust.
9. The cooling system of claim 8, wherein the cooling fluid is a gas.
10. The cooling system of claim 8, wherein the cooling fluid is a liquid.
11. The cooling system of claim 8, wherein the cooling fluid is a mixture of gas and liquid.
12. The cooling system of claim 9, wherein the cooling gas is selected from a group consisting of air, nitrogen, carbon dioxide and inert gas.
13. The cooling system of claim 10, wherein the cooling liquid is selected from a group consisting of water, cold medium or hot medium.
14. The cooling system of claim 11, wherein the mixture of gas and liquid is selected from a group consisting of air, nitrogen, carbon dioxide, inert gas, water, cold medium and hot medium.