US Patent No. 10,331,274

LIGHT SOURCE DEVICE, ELECTRONIC BLACKBOARD SYSTEM, AND METHOD OF CONTROLLING LIGHT SOURCE DEVICE


Patent No. 10,331,274
Issue Date June 25, 2019
Title Light Source Device, Electronic Blackboard System, And Method Of Controlling Light Source Device
Inventorship Ryoji Takahashi, Tokyo (JP)
Assignee NEC DISPLAY SOLUTIONS, LTD., Tokyo (JP)

Claim of US Patent No. 10,331,274

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.