摘要:
An optical disc recording/reproduction apparatus for recording and/or reproducing a data by applying a beam from an optical head unit through a substrate onto/from a recording layer of the optical disc through, wherein the substrate of the optical disc is 0.3 mm or below; the optical head unit comprises: an objective lens for converging an incident beam and emitting the beam toward the optical disc; a forward lens for converging the beam introduced through the objective lens and applying the beam to the optical disc; a lens holder where the objective lens and the forward lens are fixed; and an actuator for driving the objective lens and the forward lens as a unitary block and controlling at least focusing, the objective lens and the forward lens having a total numerical aperture of 0.8 or above.
摘要:
This invention intends to provide an optical pickup of which it is possible to limit aberrations within a tolerable limit without incorporating a special device for that purpose even if errors arise in thickness of component lenses of a two-lens system constituting an element of the pickup. This object is achieved by providing an optical pickup incorporating a two-lens system with first and second lenses 13 and 14 being arranged in the following manner: the first lens has a first surface 15 to receive a laser beam radiated from a semiconductor laser and a second surface 16 to direct the laser beam transmitted from the first surface 15 towards the second lens 14; the second lens 14 has a third surface 17 to receive the light flux transmitted from the second surface 16 and a fourth surface 18 to direct the light flux transmitted from the third surface 17 towards an optical disc placed opposite thereto; and the first and fourth surfaces are used as a reference during positioning.
摘要:
The present invention provides an optical disc recording/reproduction apparatus and method capable of carrying out an accurate recording or reproduction when using a lens unit consisting of at least two lenses, which comprises: first drive means for driving both of the first lenses and the second lens in a focusing direction; second drive means for relatively driving the second lens with respect to the first lens in the focusing direction; focus servo means for carrying out focus servo by driving the first drive means so as to drive both of the first lens and the second lens in the focusing direction; and jog mode adjustment means for driving the second drive means after the focus servo is locked, so as to carry out a jog mode adjustment of the position of the second lens with respect to the first lens.
摘要:
An optical pickup device for improving the numerical aperture of an objective lens and for assuring high-reliability recording/reproduction of information signals. The optical pickup device has a first lens 6 having a curvilinear or planar surface facing an optical recording medium 5 and having the numerical aperture set to a pre-set value, and a second lens 3 arranged for clamping the first lens 6 between t and the optical recording medium 5. The optical pickup device also has a light-converging optical system for converging the reflected light from the surface of the optical recording medium 5 and a first movement unit 2 for moving the first objective lens 6 and the second lens 3 along the direction of the optical axis with respect to the second objective lens 3. The optical pickup device also has a second movement unit 11 for moving the first objective lens 6 along the direction of the optical axis relative to the second objective lens 3 and a fixation unit 12 for fixing the first objective lens 6 moved by the second movement unit 9. The method for adjusting the optical processing device includes a step of adjusting the position along the optical axis of the first objective lens 6 and a step of fixing the position of the first lens 6.
摘要:
A recording/reproducing apparatus for an optical recording medium which is used for recording and/or reproducing information on/from the optical recording medium by irradiating the optical recording medium with a laser light using two-group objective lenses comprising at least two lenses as the first and second lenses, is provided so as to comprise a light source emitting the laser light, the first lens for focusing the laser light emitted from the light source, the second lens arranged between the first lens and the optical recording medium, and a device for moving both the first and second lenses relative to each other to change the distance between them in the optical axis direction of the laser beam, so that the moving device moves the second lens to change the distance between the first and second lenses. Consequently, this invention can provide the recording/reproducing apparatus with a larger numerical aperture (NA) and reduce the influence of spherical aberration on the light beam to realize high density recording/reproducing of information signals.
摘要:
An optical disc recording/reproduction apparatus for recording and/or reproducing a data by applying a beam from an optical head unit through a substrate onto/from a recording layer of the optical disc through, wherein the substrate of the optical disc is 0.3 mm or below; the optical head unit comprises: an objective lens for converging an incident beam and emitting the beam toward the optical disc; a forward lens for converging the beam introduced through the objective lens and applying the beam to the optical disc; a lens holder where the objective lens and the forward lens are fixed; and an actuator for driving the objective lens and the forward lens as a unitary block and controlling at least focusing, the objective lens and the forward lens having a total numerical aperture of 0.8 or above.
摘要:
A method for designing an objective lens apparatus formed by at least two lenses, a first lens and a second lens, which includes the steps of: measuring aberration which occurs when a light beam is converged by the first lens; setting the first lens is set such that the aberration occurring in the first lens satisfies Marechal's criterion, in accordance with the measurement results; measuring aberration which occurs when a light beam is converged by the first lens and the second lens; and setting the second lens such that the aberrations occurring in the first lens and the second lens satisfy Marechal's criterion, in accordance with the measurement results. Accordingly, an objective lens apparatus with a small aberration and a large numerical aperture NA can be designed by this method.
摘要翻译:一种用于设计由至少两个透镜,第一透镜和第二透镜形成的物镜设备的方法,包括以下步骤:测量当光束被第一透镜会聚时发生的像差; 设置第一透镜被设置为使得根据测量结果,发生在第一透镜中的像差满足Mar + E,acu e + EE chal's标准; 测量当第一透镜和第二透镜会聚光束时发生的像差; 并且根据测量结果设置第二透镜,使得发生在第一透镜和第二透镜中的像差满足Mar + E,acu e + EE chal's标准。 因此,可以通过该方法设计具有小像差和大数值孔径NA的物镜设备。
摘要:
An optical pickup device for condensing the light from a light source on a signal recording surface of an optical recording medium, such as an optical disc. A semi-spherical lens of the optical pickup device has a surface 9b facing an optical disc 20 and has a pre-set refractive index. The optical pickup device also has a slider 12 adapted for securing the lens 9 and for being in sliding contact with an optical disc 20, and a spring plate 13 adapted for thrusting and supporting the slider in sliding contact with the optical disc 20. With the optical pickup device, high density reproduction may be realized, while the tolerance value for warping during disc molding or the tolerance value for warping due to moisture absorption may be increased. In addition, the production yield and the degree of freedom in selecting the disc materials may be improved.
摘要:
An optical pickup apparatus is constructed of an objective lens for condensing a light beam emitted from a light source toward an optical recording medium, and a convex lens arranged between the optical recording medium and the objective lens in which a surface thereof upon which the luminous flux projected from the objective lens is incident is a convex spherical surface with a radius of curvature which is a predetermined value, and another surface thereof which is located near and opposite to a surface portion of the optical recording medium which is a plane. With this arrangement, a tolerance with respect to decentering of the convex lens in connection with the optical axis of the objective lens is increased, so that an occurrence of aberration is reduced.
摘要:
A focus controller for focusing a light beam and positioning the focused light beam onto a signal recording layer of a signal recording media is disclosed. The controller comprises a light beam focusing means having a numerical aperture of 0.6 or more; a focus controlling means for positioning the light beam focused by the light beam focusing means onto the signal recording layer of the recording media; and an offset adjusting means for adjusting an offset between the focused light beam positioned by the focus controlling means and the signal recording layer of the recording media. The controller positions the light beam focused by an objective lens onto the signal recording layer of a recording media; moves the objective lens within a predetermined optical-axial range, detects an amplitude of a signal read from the recording media at either end of the optical-axial range, and adjusts an offset between the focused light beam positioned by the objective lens and the signal recording layer, depending on a difference between the amplitudes of the detected reproduced signal.