Light source device, electronic blackboard system, and method of controlling light source device

1. An electronic blackboard system comprising:

a projection-type display device that projects an image on a projection surface;

a light source device that emits invisible light; and

a detecting device that detects reflection light of the invisible light reflected by a shielding object,

wherein said light source device includes:

a light source including an invisible light emitter that emits the invisible light and a visible light emitter that emits visible light; and

a propagation controller that causes the invisible light to propagate in a direction parallel or substantially parallel to the projection surface,

wherein a plane, in which the invisible light propagates, is identical or substantially identical to a plane in which the visible light propagates,

wherein the visible light is used for configuring the light source device, and

wherein the invisible light and the visible light are emitted in an identical direction, respectively.

2. The electronic blackboard system according to claim 1 , further comprising a first mode and a second mode,

wherein when the first mode is selected, said light source device emits the invisible light, and when the second mode is selected, said light source device emits the visible light or both the invisible light and the visible light.

3. The electronic blackboard system according to claim 2 , wherein when the first mode is selected, said detecting device detects the reflection light.

4. The electronic blackboard system according to claim 3 , wherein when the first mode is selected, said projection-type display device projects an image in accordance with a detection result by said detecting device.

5. The electronic blackboard system according to claim 2 , wherein when the second mode is selected, said propagation controller adjusts a region in which the visible light propagates.

6. The electronic blackboard system according to claim 2 , wherein said light source device further includes an input device, and

wherein the first mode or the second mode is selected by using said input device.

7. The electronic blackboard system according to claim 1 , wherein said light source device further includes a light source controller, and

wherein said light source controller causes said light source to emit at least one light from among the invisible light and the visible light.

8. The electronic blackboard system according to claim 1 , wherein said propagation controller scans the invisible light and the visible light.

9. The electronic blackboard system according to claim 1 , wherein said propagation controller diffuses the invisible light and the visible light.

10. The electronic blackboard system according to claim 1 , wherein the invisible light comprises an infrared ray.

11. The electronic blackboard system according to claim 1 , wherein the propagation controller adjusts a region in which the visible light propagates of emission light into a three-dimensional direction by setting a vibration amplitude and an inclination of a vibration axis in accordance with a propagation-region adjustment signal, and thereby adjusts a recognizable region into the three-dimensional direction.

12. A light source device used in an electronic blackboard system including: a projection-type display device that projects an image on a projection surface; a light source device that emits invisible light; and a detecting device that detects reflection light of the invisible light reflected by a shielding object, said light source device comprising:

a light source including an invisible light emitter that emits the invisible light and a visible light emitter that emits visible light; and

a propagation controller that causes the invisible light to propagate in a direction parallel or substantially parallel to the projection surface,

wherein a plane, in which the invisible light propagates, is identical or substantially identical to a plane in which the visible light propagates,

wherein the visible light is used for configuring the light source device, and

wherein the invisible light and the visible light are emitted in an identical direction, respectively.

13. The light source device according to claim 12 , further comprising a first mode and a second mode,

wherein when the first mode is selected, said light source emits at least the invisible light, and when the second mode is selected, said light source emits at least the visible light.

14. The light source device according to claim 13 , wherein when the second mode is selected, said propagation controller adjusts a region in which the visible light propagates.

15. A method of controlling an electronic blackboard system in which an image is projected on a projection surface and an indicated position on the projection surface which is indicated by a shielding object is recognized, said method comprising:

emitting invisible light and visible light; and

causing the invisible light to propagate in a direction parallel or substantially parallel to the projection surface,

wherein a plane, in which the invisible light propagates, is identical or substantially identical to a plane in which the visible light propagates,

wherein the visible light is used for configuring a light source device in the electronic blackboard system, and

wherein the invisible light and the visible light are emitted in an identical direction, respectively.

16. The method according to claim 15 , further comprising:

receiving an operation mode;

recognizing the indicated position when the operation mode indicates a first mode; and

adjusting a recognizable region, in which the indicated position can be recognized, when the operation mode indicates a second mode.

17. The method according to claim 16 , further comprising:

emitting the invisible light when the operation mode indicates the first mode; and

emitting the visible light when the operation mode indicates the second mode.

18. The method according to claim 16 , further comprising detecting reflection light of the invisible light reflected by said shielding object when the operation mode indicates the first mode.

19. The method according to claim 16 , further comprising projecting an image in accordance with the indicated position when the operation mode indicates the first mode.

20. The method according to claim 16 , wherein when the second mode is selected, adjusting a region in which the visible light propagates.