| 摘要 |
PURPOSE:To obtain a titled device which is resistant to outside vibration, is small in loss of light quantity, and also is small-sized and inexpensive, by making an objective lens of an optical head slidable only in the focusing direction, making it displaceable only in the tracking control direction by providing an optical path converting means, and using a piezoelectric element or a magnetic circuit as a driving device. CONSTITUTION:Focus control is executed by applying the control voltage from a focus error detecting part which is not shown in the figure to a bend type piezoelectric element 18, and displacing the element 18 in the control direction. Also, minute tracking adjusting control is executed by flowing a control current from a tracking error detecting part to an electromagnetic coil 23, and displacing an optical head outside frame 16 in the tracking control direction to an optical head outside housing 21 through a spherical body 22 by a magnetic force operation of a magnet 24. The focus control and the tracking control are executed independently, respectively, therefore, no influence is exerted on each other. Also, since an objective lens is not inclined, high-speed access to an information track is executed easily, and it is stable to vibration from the outside. An incident position to the objective lens 14 is not varied, therefore, there is no loss of quantity of light, and dimensions of the focusing direction can be made small by a prism 19. |
