Abstract: A transcription system, for determining a position of a stylus relative to a writing surface by receiving supersonic wave transmitted from the stylus when the stylus is positioned adjacent the writing surface, has a pair of supersonic wave detectors provided on a whiteboard. The supersonic wave detector has a detector cover for covering at least a front portion of a supersonic wave receiver of the supersonic wave detector with reference to the supersonic wave transmitted from the stylus. The detector cover has a hole, which is defined right in front of the receiver, having a diameter smaller than a diameter of the receiver. The detector cover further has a conical reflection board provided adjacent the hole of the detector cover.

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: A transcription system, for determining a position of a stylus relative to a writing surface by receiving supersonic wave transmitted from the stylus when the stylus is positioned adjacent the writing surface, has a pair of supersonic wave detectors provided on a whiteboard. The supersonic wave detector has a detector cover for covering at least a front portion of a supersonic wave receiver of the supersonic wave detector with reference to the supersonic wave transmitted from the stylus. The detector cover has a hole, which is defined right in front of the receiver, having a diameter smaller than a diameter of the receiver. The detector cover further has a conical reflection board provided adjacent the hole of the detector cover.

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 blackboard apparatus, which reads a writing on a writing sheet fitted on a blackboard framework and which electronically copies the writing onto a recording medium. The apparatus includes a blackboard framework foldable together with the writing sheet, and a stand supporting the blackboard framework and a copying device. The stand is reducible in size while supporting the blackboard framework and the writing sheet in their folded position and the copying device. The length of the stand is reducible after the blackboard framework and the writing sheet have been folded to reduce their lengths. The blackboard framework and the writing sheet which have been folded are overturned into a space between opposite legs of the stand and the legs are then closed.