| 摘要 |
PURPOSE:To obtain the optical recording and reproducing device capable of making the luminous flux emitted from a collimator lens a parallel luminous flux by fluctuating the focal point distance of the collimator lens according to the temp. variation and yet using the compensation member having small thermal expansion coefft. CONSTITUTION:The fluctuation of the relative position of semiconductor laser 1 and collimator lens 20 accompanied by the temp. variation is made to compensate with the use of the compensation member 16 having small fluctuation of the focal point distance of a collimator lens accompanied by the temp. variation and thermal expansion coefft. The light emitting position of a light source is always coincident with the focal point position of a collimator lens, therefore, even if there is any temp. variation. A parallel luminous flux can always be emitted from the collimator lens and its operation property can be improved. |
