| 摘要 |
PURPOSE:To decrease the friction between shafts by setting support points P1-PN so as to balance vectors P1- PN drawn fro the center of the support shaft toward each support point P1/PN of a neutral point holder at the center of the support shaft. CONSTITUTION:In activating two spiralsprings 9, 10 acting like support springs at both ends of the neutral point holder 11 symmetrically to the support shaft, since the force from the support spring caused by the turning of the lens holder is acted on the pins 6, 7 fitted symmetrically from the center of the lens holding body 2, the friction between the shafts is less and smooth turning of the lens holder is attained. In general, in the vectors P- PN toward the force operating points P1-PN from the turning center 31 of the support shaft 31, when the condition of P1+ P2+ PN=0 is satisfied, the lens support 21 is driven smoothly in the turning and axial directions and it is preferable for the simple practical use with ¦ P1¦=¦ P2¦=...=¦ PN¦.
|
