| 摘要 |
<p>PURPOSE: A focusing device of beam projector is provided to simplify a structure and to improve design freedom degree. CONSTITUTION: A focusing device of beam projector comprises a drive motor(M), a projection lens barrel(22) and a cam(21). A spiral groove(210) is included along the outer circumference of the cam. The cam is connected to the drive motor. A shaft is located on the projection lens barrel to be connected with the spiral groove. The projection lens barrel focuses by spirally sliding according to the rotation of the cam. The end part of shaft is inserted into the spiral groove. The shaft is guided to linearly move to the direction which is in parallel with the rotary shaft of the cam.</p> |
