Abstract: An electronic whiteboard capable of being drawn by using marker pens of several colors and one penholder, and a penholder for use in such an electronic whiteboard are disclosed. In a penholder for mounting marker pens, an infrared light emitting unit emits infrared light containing color information of the marker pen, an ultrasonic wave emitting unit emits a the ultrasonic wave, and color information changeover means changes over color information depending on the color of marker pen. The electronic whiteboard main body receives the infrared light and ultrasonic wave emitted from the penholder, and issues information about a position of the penholder depending on the reception timing of the infrared light and ultrasonic wave.

Abstract: In a pen holder comprising an emitter for emitting at least one of light beam and supersonic waves to be detected by a sensor so that a signal corresponding to a position of the pen holder is generated by the sensor on the basis of the detected at least one of light beam and supersonic waves, a pen holder including an opening which is arranged at a longitudinal end of the pen holder in such a manner that a front portion of the pen including an end at which end the visible line is drawn on the board projects from the opening out of the pen holder, and through which a part of the pen other than the front portion of the pen is mountable from an outside of the pen holder onto the pen holder so that the pen is held on the pen holder.

Abstract: An electronic whiteboard capable of being drawn by using marker pens of several colors and one penholder, and a penholder for use in such an electronic whiteboard are disclosed. In a penholder for mounting marker pens, an infrared light emitting unit emits infrared light containing color information of the marker pen, an ultrasonic wave emitting unit emits a the ultrasonic wave, and color information changeover means changes over color information depending on the color of marker pen. The electronic whiteboard main body receives the infrared light and ultrasonic wave emitted from the penholder, and issues information about a position of the penholder depending on the reception timing of the infrared light and ultrasonic wave.

Abstract: In a pen holder comprising an emitter for emitting at least one of light beam and supersonic waves to be detected by a sensor so that a signal corresponding to a position of the pen holder is generated by the sensor on the basis of the detected at least one of light beam and supersonic waves, a pen holder including an opening which is arranged at a longitudinal end of the pen holder in such a manner that a front portion of the pen including an end at which end the visible line is drawn on the board projects from the opening out of the pen holder, and through which a part of the pen other than the front portion of the pen is mountable from an outside of the pen holder onto the pen holder so that the pen is held on the pen holder.