Abstract: An operation input device includes an infrared irradiation unit radiates infrared, a capturing unit detects the infrared to capture an image, an luminance calculating unit calculates, in a captured image, a luminance difference between a luminance of a first area irradiated with the infrared by the infrared irradiation unit and a luminance of a second area arranged outside the first area, an infrared control unit adjusts an irradiation intensity of the infrared to be radiated from the infrared irradiation unit so that the luminance difference calculated by the luminance calculating unit becomes a predetermined target value, an image processing unit detects a shape of an indication object from the captured image, a determination unit determines an operation by the indication object from the shape detected by the image processing unit, and a command unit makes a device to be operated perform a function corresponding to the determined operation determined.

Abstract: An operation input device includes an infrared irradiation unit radiates infrared, a capturing unit detects the infrared to capture an image, an luminance calculating unit calculates, in a captured image, a luminance difference between a luminance of a first area irradiated with the infrared by the infrared irradiation unit and a luminance of a second area arranged outside the first area, an infrared control unit adjusts an irradiation intensity of the infrared to be radiated from the infrared irradiation unit so that the luminance difference calculated by the luminance calculating unit becomes a predetermined target value, an image processing unit detects a shape of an indication object from the captured image, a determination unit determines an operation by the indication object from the shape detected by the image processing unit, and a command unit makes a device to be operated perform a function corresponding to the determined operation determined.

Abstract: An optical radio communication system comprising a first light transmitting system and a second light transmitting system. Each of said first and second light transmitting system comprising a transmitting means and a receiving means. Said transmitting means comprising a light emitting element positioned in a region including and surrounding a focal point of a first parabolic reflector for emitting light beams, said first parabolic reflector having an inner reflective surface for reflecting said light beams emitted from said light emitting element, and a means for driving said light emitting element with a signal to be transmitted.