Abstract: Embodiments of methods and systems for controlling access to information stored on memory or data storage devices are disclosed. In various embodiments, fluid-mediated modification of information or access to information is utilized. According to various embodiments, data storage devices designed for rotating access are described which include rotation-activated fluid control mechanisms.

Abstract: A position control apparatus (optical apparatus) is disclosed which is capable of preventing disadvantages caused by the absence of a dead band while achieving a required accuracy of positional control. The position control apparatus comprises a controller which controls the drive of an object (optical member) so that the position of the object, which detected by a position detector, moves closer to a target position. The controller has a control function which does not drive the object in a case where the difference between the position detected by the position detector and the target position is within a predetermined range, and changes the predetermined range according to control modes relating to the drive of the object.

Abstract: An optical disk 101 is of a type in which information is recorded on a groove track, and an optical disk 107 is of a type in which information is recorded on a land track. The optical disk 101 has a control data area 102, and a data recording area 103 in which user data is recorded. The optical disk 107 has a control data area 108, and a data recording area 109 in which user data is recorded. A code for indicating the groove track or the land track onto which tracking servo control is executed is provided both in the control data area 102 of the optical disk 101, and in the control data area 108 of the optical disk 107.

Abstract: The invention relates to a method for evaluating a wobble signal. Also described is a circuit for performing such method and an apparatus for reading from and/or writing to optical recording media using such method or circuit. According to the invention the method includes the steps of: determining the sign of the wobble signal, the sign indicating whether a wobble period of the wobble signal is inverted or non-inverted, generating a filtered signal by a weighted averaging of the sign over two or more wobble periods, the weighted averaging being performed by subtracting a sum of the signs obtained from a second stage of delay lines from a sum of the signs obtained from a first stage delay lines, and integrating the filtered signal.

Abstract: An information recording medium of the optical information reproduction device of the present invention includes a recording unit capable of recording information three-dimensionally and provided with a track, and information is recorded by forming a plurality of recording marks along the track of the recording unit by a mark length recording method. When the track direction of the recording marks is assumed to be their longitudinal direction and the direction perpendicular to the track direction is assumed to be their lateral direction, with the present invention, for recording marks located substantially in the same plane, the total area of elongated recording marks, whose longitudinal length is greater than their lateral length, is greater than the total area of recording marks having other than elongated shapes.

Abstract: An information recording apparatus and method can prevent an information recording medium having a plurality of recording layers from being incompatible with a reproduction-only information recording medium due to an unrecorded area, which is produced by completion of recording in a middle of a data area of the recording layer. The recording layers include at least a first recording layer and a second recording layer, the first recording layer providing a reference with respect to a position of said data area in each of the recording layers. The user data is recorded in response to a recording request. After recording the user data, predetermined data is recorded in a predetermined unrecorded area in the second recording layer.

Abstract: In a DVD-R on which information is to be recorded by an information recording apparatus, prior to the recording of the information therein, there are recorded in advance at least identification information for identifying the information recording apparatus for recording the information onto the DVD-R, and recording parameter information containing optimization information for optimizing a recording state in the record processing executed by the information recording apparatus specified by the identification information. Furthermore, the information recording apparatus reads the recording parameter information at the execution of record processing to use it for the record processing.

Abstract: A high density optical disc that can be driven changeably with the existent optical disc by the same driving apparatus. On the recording surface of the optical disc, a light transmissive layer with a thickness of about 0.2 to 0.4 mm is formed. The recording face is accessed by allowing a light beam with a wavelength of 395 to 425 nm in a spot shape to be irradiated onto it. Also, the light beam is converged in a spot shape by an objective lens having the numerical aperture of about 0.62 to 0.68.

Abstract: In order to obtain a corrected or compensated focus error signal or track error signal, it is proposed to generate primary and secondary scanning beams incident on adjacent tracks of an optical recording medium and to detect the primary and secondary scanning beams reflected from the optical recording medium in order to derive from them primary-beam and secondary-beam focus error signals or primary-beam and secondary-beam track error signals, which are subsequently normalized in order to obtain the compensated focus error signal or track error signal from the normalized primary-beam and secondary-beam error signals by means of weighted combinations. As a result of the normalization, the corrected or compensated focus error signal or track error signal is generated independently of the reflection properties of the respectively scanned track.

Abstract: An optical recording medium having a read-only storage area and a writable storage area and a recording/reproducing apparatus and method therefor. The optical recording medium is a hybrid disc having both the read-only storage area, which is suitable for mass production of information having the same contents, and the writable storage area on which data can be recorded, updated or added at a user's option.

Abstract: Plural grooves or lands formed in an information recording carrier include at least a wobbling region and data is recorded wobblingly in this wobbling region by phase shift modulation while recorded digitally with a single or multiple waves as a channel bit.

Abstract: Plural grooves or lands formed in an information recording carrier include at least a wobbling region and data is recorded wobblingly in this wobbling region by phase shift modulation while recorded digitally with a single or multiple waves as a channel bit.

Abstract: The present invention is directed to an object lens drive device adapted for moving an object lens in a focus direction of optical axis direction and in a tracking direction perpendicular to the optical axis direction, and includes a fixed position provided in such a manner that a supporting shaft is projected, a movable portion comprised of an object lens, and a bobbin adapted so that the object lens is attached and a hole through the supporting shaft is inserted is formed, the bobbin being supported movably along the supporting shaft and rotatably with the supporting shaft being as center, a drive portion including a magnet portion provided at either one of the fixed potion and the movable portion, and a coil portion provided at the other portion to move the movable portion along the supporting shaft to thereby move the object lens in the focus direction, and to rotate the bobbin with the supporting shaft being as center to thereby move the object lens in the tracking direction, and supporting means includi

Abstract: A magneto-optical readout head for reading out magnetically stored data has a high optical quality substrate and a transducer applied to the substrate formed by a Faraday rotator and a Kerr rotator, with the Kerr rotator facing the magnetic storage medium. The substrate can be provided with a shape for magnifying the domain structures of the Kerr rotator and the Faraday rotator. Linearly polarized light is passed through the substrate and the polarization vector thereof is rotated by the Faraday rotator upon passage through the Faraday rotator and the light is reflected at the Kerr rotator, and is provided with an additional rotation upon reflection.

Abstract: The invention relates to a method of producing an X-ray exposure is provided by a photoconductor, which converts X-radiation into a charge pattern, is evenly charged locally before the X-ray exposure, is discharged by the exposure as a function of the intensity of the X-radiation and the surface of which is scanned after the exposure for detecting the charge density, an image value being formed for each image point, corresponding to the discharge at the image point. The measured image values may be falsified by the self-discharge of the photoconductor induced by X-radiation. Since the self-discharge always proceeds in accordance with the same time laws, the self-discharge effects are corrected utilizing the time of the scanning instants, i.e., position in time with respect to the X-ray exposure and the end of the charging of the photoconductor in conjunction with a characteristic discharge function of the photoconductor and a correction factor.

Abstract: A device for the X-ray examination of motor vehicle tires comprises a conveyor for conveying the tires into, and out of, an X-ray examination device, in which the tires are held in examination positions, are set in rotation and are penetrated by X-rays from within outwards thereof by means of an X-ray tube arrangement, having an X-ray receiver for observing the tire regions which have been penetrated by the X-rays, and a monitor apparatus for optical representation and evaluation of the penetrated tire regions. For improved output of examined tires the X-ray examination device comprises at least two X-ray examination units laterally adjacent to the conveyor. The X-ray receiver is constructed so as to be capable of being moved alternately from one examination unit to the other examination unit, for examination of a tire in one examination unit, while at the same time an examined tire is unloaded from the other examination unit and a fresh tire is loaded thereinto.