Ricoh Company, Ltd.

Seiko Yamamoto

Naoyuki Ishikawa

Katsuyuki Omura

Masafumi Nagao

Masanobu Yamagata

Noritada Ohi

Yoshiaki Oshima

A position detection device for detecting positions of a non-emitter and an emitter in a detection area includes one or more reflective members disposed around the detection area, illumination light sources to emit light toward the reflective member, light receiving sensors to receive light from the reflective member and light from the light emitter, and a control device to control the illumination light sources and the light emitter. Based on previous detection statuses of the non-light emitter and the light emitter, the control device sets a time ratio of a time of a non-light emitter detection mode to a time of a light emitter detection mode, and sets timings of the non-light emitter detection mode and the light emitter detection mode.

Position detection device, image display device and image display system

A coordinate detecting apparatus includes: a plurality of light-emitting and -receiving units arranged along an outer edge of the coordinate input area, the plurality of light-emitting and -receiving units each including a light-emitting part and a light-receiving part; at least one retroreflective member arranged along the outer edge of the coordinate input area; and a control unit to control the plurality of light-emitting and -receiving units to detect coordinates of a position of input made with a designation input unit in a first detection state or a second detection state.

Coordinate detecting apparatus, system, and coordinate detecting method

Growing community of inventors

Tokyo, Japan

Seiko Yamamoto