摘要:
An optical disc device of the present invention includes spherical aberration changing means for changing spherical aberration occurring on a converging position of a light beam converged by a lens, an actuator for moving the spherical aberration changing means in a relatively precise manner, and an actuator for moving the spherical aberration changing means in a relatively rough manner. The optical disc device drives a second actuator and a third actuator based on a signal of spherical aberration detecting means and performs control so that spherical aberration is almost 0. The third actuator moves the spherical aberration changing means based on a direct current component included in a signal of the spherical aberration detecting means, and the second actuator moves the spherical aberration changing means based on an alternating current component included in the signal of the spherical aberration detecting means.
摘要:
An optical disc drive includes a light source, a lens, a focusing section, a spherical aberration corrector, a focus signal generator, a gain calculator and a processor. The focusing section forms a beam spot in a focusing state on the information storage layer of an optical disc by controlling the position of the lens. The spherical aberration corrector changes a spherical aberration with the beam spot in a focusing state according to a drive value of a driving signal supplied to the spherical aberration corrector. The focus signal generator generates a focus signal representing the focusing state of the beam spot. The gain calculator calculates a loop gain of a focus control system in response to the focus signal. The processor determines the drive value for the spherical aberration corrector by the loop gain.
摘要:
In performing CLV readout, a target frequency is corrected based on current and target numbers of revolutions of a disk motor during a seek operation, thereby controlling the frequency of a read clock signal at a value approximately equal to the corrected target frequency. In performing CAV readout on the other hand, the frequency of the read clock signal is approximately equalized with a data read frequency at a seek destination. By performing these frequency control operations, data reading can be started quickly enough after the seek operation is finished. In reading out information from a recordable disk with wobbling tracks on a data portion, frequency control is performed using a wobble signal with respect to an unrecorded data portion, and phase locking control is performed using a data signal with respect to an address portion. In this manner, an address can be read out constantly.
摘要:
A speed profile constituting the target speed for the next drive process during searching is generated by target speed generating section 140 and tracking actuator 132 is driven using the error signal in regard to the speed of movement of the light beam calculated by movement speed detection section 141 from a pulse signal obtained by converting the TE signal to binary form. Also linear motor 139 is driven using the difference signal obtained from the target speed and the speed of movement. Tracking actuator 132 is controlled so as to suppress swinging of focusing lens 107 during searching and linear motor 139 moves, during searching, under tracking control to a target speed.
摘要:
An optical disk apparatus includes a rotating device for rotating a recording medium at a prescribed reproduction rate. A converging device converges a light beam on the recording medium. A moving device moves the converging device so as to cause the converged light beam to cross a track of the recording medium. A light detection device has four areas for receiving light reflected by the recording medium and respectively outputting first, second, third and fourth detection signals. A phase correction device outputs first and second correction signals respectively by correcting the phase of the first and second detection signals in accordance with a correction amount. A tracking error detection device detects a positional offset between the converged light beam and the track based on a phase difference between first and second addition signals and outputs a tracking error signal indicating the positional offset. The first addition signal is obtained by adding the first correction signal and the fourth detection signal. The second addition signal is obtained by adding the second correction signal and the third detection signal. A tracking control device performs feedback control of the moving device so that the light beam converged on the recording medium is positioned on the track, based on the tracking error signal. An adjustment device adjusts the correction amount for the phase correction device based on an asymmetry level based on the tracking error signal without causing the tracking control device to perform feedback control.
摘要:
A catalytic cracking catalyst is provided which has high cracking activity and with which the production of FCC gasoline having a high octane number can efficiently proceed without lowering a gasoline yield. Also provided are a process for producing the catalyst and a method of the catalytic cracking of a hydrocarbon oil with the catalyst.The catalyst for catalytic cracking of a hydrocarbon oil comprises a crystalline aluminosilicate, a binder, and a clay mineral in a certain proportion, wherein the content of sodium and potassium therein is 0.5% by mass or lower in terms of oxide (Na2O and K2O) amount, the content of at least one rare earth metal therein is 3.0% by mass or lower in terms of oxide (RE2O3, wherein RE is a rare earth element) amount, the [RE2O3+Na2O+K2O]/[crystalline aluminosilicate] ratio by mass is 0.1 or lower, and the catalyst has a xenon adsorption amount, as measured at an adsorption temperature of 25° C. and a partial xenon pressure of 650 torr, of 2.20×1020 molecules or more per g of the catalyst. Also provided are a process for producing the catalyst and a method of catalytic cracking of a hydrocarbon oil with the catalyst.
摘要:
In a recording medium including stacked recording layers, management data requiring reliability is recorded in the recording layer far from the surface of the recording medium and data bodies are recorded in the recording layer close to the surface of the recording medium. Thus a data file can be read even if defects such as fingerprints and scratches occur on the surface of the recording medium.
摘要:
A microscope system includes a transmission illumination optical system having a light source and a condenser lens; a first dry objective having a magnification of from 20 or higher to 40 or lower and capable of viewing by at least one of a differential interference viewing method and a modulation contrast viewing method; and a second dry objective having a magnification of from 60 or higher to 100 or lower and capable of viewing by a differential interference viewing method; the first objective and the second objective being exchangeable.
摘要:
There is provided an optical disc device including an objective lens, a lens actuator for driving the objective lens, a light-receiving unit, and a system control unit which determines, at startup, the values of parameters to be set for recording or reproducing data in or from the respective information layers, and performs setting and management of recording inhibition or reproduction inhibition for the respective information layers, wherein, even when an error occurs because the values of the parameter groups for the respective layers cannot be determined in an optical disc having laminated plural information layers, recording or reproduction can be performed for at least the layers for which the parameters can be correctly determined, without stopping the startup. Thereby, the states of the respective information layers are managed for each information layer, and reproduction or recording operation is rapidly started in the respective layers to effectively utilize the multilayer disc.
摘要:
An immersion microscope objective lens of the present invention has: in order from an object, a first lens group G1 having positive refractive power and having a cemented lens of a plano convex lens having a plane facing the object and a meniscus lens having a concave surface facing the object, and a single meniscus lens having a convex surface facing the object; a second lens group having positive refractive power and having a plurality of cemented lenses; and a third lens group having negative refractive power and having a cemented meniscus lens having a concave surface facing an image, and a cemented meniscus lens having a concave surface facing the object. And the following conditional expressions 0.12