| 摘要 |
PROBLEM TO BE SOLVED: To enable a blackboard and a touch screen to be moved in the vertical reverse directions by a simple mechanism, and also, to enable the blackboard which is heavier than the touch screen to be vertically moved farther than the touch screen. SOLUTION: For this blackboard apparatus, the touch screen 3 which is lighter than the blackboard 2 is arranged on the back surface of the blackboard 2, and they are vertically moved by a vertically moving mechanism 4 in the reverse directions from each other. In the vertically moving mechanism 4, a first stringy body 5A, one end of which is connected with the blackboard 2, and the other end of which is connected with a first weight 8A, is placed on a first pulley 6A. At the same time, a second stringy body 5B, one end of which is connected with the touch screen 3, and the other end of which is connected with a second weight 8B is placed on a second pulley 6B. In addition, a first gear 7A which is connected with the first pulley 6A, and a second gear 7B which is connected with the second pulley 6B are engaged. The product of the outer diameter (R1) of the first gear 7A and the outer diameter (r2) of the second pulley 6B is set to be smaller than the product of the outer diameter (R2) of the second gear 7B and the outer diameter (r1) of the first pulley 6A. COPYRIGHT: (C)2008,JPO&INPIT
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