Abstract: A coordinate input device includes a pair of cameras positioned in an upper left position and an upper right position of a display screen of a monitor lying close to a plane extending from the display screen of the monitor and views both a side face of an object in contact with a position on the display screen and a predetermined desk-top coordinate detection area to capture the image of the object with the field of view. The coordinate input device also included a control circuit which calculates the coordinate value of a pointing tool, pointing to a position within a coordinate detection field, based on video signals output from the pair of cameras, and transfers the coordinate value to a program of a computer.

Abstract: A coordinate input device includes a pair of cameras positioned in an upper left position and an upper right position of a display screen of a monitor lying close to a plane extending from the display screen of the monitor and views both a side face of an object in contact with a position on the display screen and a predetermined desk-top coordinate detection area to capture the image of the object within the field of view. The coordinate input device also includes a control circuit which calculates the coordinate value of a pointing tool, pointing to a position within a coordinate detection field, based on video signals output from the pair of cameras, and transfers the coordinate value to a program of a computer.

Abstract: A position detection device comprising a position pointer having a light reflector for reflecting light, an emitter for emitting light toward the light reflector, a light receiver for receiving light from the light reflector of the position pointer, a coordinate calculator for calculating a position coordinate of the position detecting device based on information from the light receiver. The position pointer is in the form of a pen and has a movable pen-core portion subject to displacement by the pressure on a surface of a board, a light modulator for changing characteristics of the reflection light, and a transmitter for transmitting the displacement of the pen-core portion to the light modulator. The light receiver has an up/down state detector for detecting characteristics of light changed by the light modulator and obtaining a pen-up and a pen-down information of the position pointer.

Abstract: The present invention relates to a handwriting communication system, a handwriting input device and a handwriting display device used in the system, which can communicate by handwriting among a plurality of computers connected via a network. The communication system includes a handwriting input device which is provided at a transmitting side for inputting the handwriting into a transmitting side computer, and a handwriting display device which is provided at a receiving side for displaying the handwriting based on information transmitted from the transmitting side to a receiving side computer. The present system according to the invention transmits only a contiguous image around the handwritten portion, which reduces the communication volume compared to transmitting the whole image, and which makes the real time transmission and reception of handwriting trace possible.