Abstract: An electron beam recording apparatus includes: a displacement detection unit including at least three displacement sensors disposed at each different angle in a radial direction of the turntable; a shape calculation unit for calculating, based on the detected displacements by the at least three displacement sensors, shape data corresponding to displacements of side surface of the turntable in the radial directions; a rotation runout computing unit for computing, based on the shape data and at least one displacement detected by the at least three displacement sensors, rotation runout of the turntable including a rotation asynchronous component and a rotation synchronous component; and a beam irradiation position adjustment unit for adjusting an irradiation position of the electron beam based on the rotation runout.

Abstract: An electron beam recording apparatus includes: a displacement detection unit including at least three displacement sensors disposed at each different angle in a radial direction of the turntable; a shape calculation unit for calculating, based on the detected displacements by the at least three displacement sensors, shape data corresponding to displacements of side surface of the turntable in the radial directions; a rotation runout computing unit for computing, based on the shape data and at least one displacement detected by the at least three displacement sensors, rotation runout of the turntable including a rotation asynchronous component and a rotation synchronous component; and a beam irradiation position adjustment unit for adjusting an irradiation position of the electron beam based on the rotation runout.

Abstract: A beam adjusting sample having a flat surface being like a plate and having two edges orthogonal to each other is employed. A beam is applied to the beam adjusting sample to detect an amount of the beam passing through the beam adjusting sample. The beam vertically scans the two edges.

Abstract: An optical disc includes an information recording layer having a record of information as a pit train with a predetermined track pitch and a light-transmissive layer formed on the information recording layer so that the information can be reproduced by a beam of light illuminated through the light-transmissive layer to the information recording layer by an objective lens. The optical disc includes a feature in that a relationship of 0.194(?/NA)2?TP ×Tmin?0.264(?/NA)2 is satisfied, provided that the track pitch is TP, a pit shortest length is Tmin, a wavelength of the light beam is ? and a numerical aperture of the objective lens is NA. The optical disc also includes a feature in that a pit width is 120 nm or smaller in a range of a track pitch of 0.280 to 0.325 ?m.

Abstract: Preceding to the reading out of the recording information of the optical disk by the pick-up, the height of the foreign material existing at the light converging position on the information reading surface is detected by the detector, and when the height of the foreign material is higher than the floating height h of the SIL, the magnetic field is generated by applying the control current corresponding to the height of the foreign material to the coil as the magnetic field generator at the timing before the foreign material is moved to the information reading position of the pick-up by the rotation of the optical disk. Then, when the magnetic field is provided to the magnetic substance fixedly holding the SIL which is floating, the movement operation to separate the SIL to the higher position than the height of the foreign material from the information reading surface together with the magnetic substance, is conducted.

Abstract: A laser-based measuring apparatus divides a light beam from a laser light source into at least two light beams, passes the light beams through different optical paths from each other, recombines the light beams, has the light beams interfere with each other to generate interfered light, opto-electrically transduces the interfered light to an optical frequency, and measures the amount of travel of an object which changes an optical path length of a portion of an optical path based on the optical frequency. The measuring apparatus has a portion for generating at least two measuring light beams from the laser light source, two reflection planes included in an object moving on a measuring axis, arranged back-to-back to each other on the measuring axis, and an opposing incident optical system for directing the measuring light beams into the reflection planes, respectively, such that the measuring light beams oppose to each other on the measuring axis.

Abstract: Disclosed is a grooving apparatus which can carry information on an information track at high recording density when carrying the information on the information track through a change in shape of a groove and which also can improve the signal-to-noise ratio of the information under reproduction. A grooving apparatus for forming a groove to function as an information track in an optical disk comprises an electron beam generator which emits an electron beam, an objective lens which focuses the emitted electron beam on the optical disk and which focuses the electron beam on a smaller range than the size of the groove, and an X-direction deflector and a Y-direction deflector which controls the electron beam so that the electron beam is focused in position on the optical disk, thereby forming the groove in the optical disk.

Abstract: A beam adjusting sample having a flat surface being like a plate and having two edges orthogonal to each other is employed. A beam is applied to the beam adjusting sample to detect an amount of the beam passing through the beam adjusting sample. The beam vertically scans the two edges.

Abstract: An electron beam apparatus for irradiating a target with an electron beam includes a reference sample including at least one reference pattern which has a plurality of lattice structures arranged along the circumference of a circle in a evaluation surface of the reference sample; and an adjustment section for adjusting the electron beam by irradiating the evaluation surface with the electron beam on the basis of electrons generated from the reference sample.

Abstract: An optical disc comprises an information recording layer having a record of information as a pit train with a predetermined track pitch and a light-transmissive layer formed on the information recording layer so that the information can be reproduced by a beam of light illuminated through the light-transmissive layer to the information recording layer by an objective lens. The optical disc is characterized in that a relationship of 0.194 (/NA)2 TP×Tmin 0.264 (/NA)2 is satisfied, provided that the track pitch is >TP, a pit shortest length is Tmin, a wavelength of the light beam is and a numerical aperture of the objective lens is NA. The optical disc is characterized in that a pit width is 120 nm or smaller in a range of a track pitch of 0.280 to 0.325 m.

Abstract: An electron beam apparatus for irradiating a target with an electron beam includes a reference sample including at least one reference pattern which has a plurality of lattice structures arranged along the circumference of a circle in a evaluation surface of the reference sample; and an adjustment section for adjusting the electron beam by irradiating the evaluation surface with the electron beam on the basis of electrons generated from the reference sample.

Abstract: Disclosed is a grooving apparatus which can carry information on an information track at high recording density when carrying the information on the information track through a change in shape of a groove and which also can improve the signal-to-noise ratio of the information under reproduction. A grooving apparatus for forming a groove to function as an information track in an optical disk comprises an electron beam generator which emits an electron beam, an objective lens which focuses the emitted electron beam on the optical disk and which focuses the electron beam on a smaller range than the size of the groove, and an X-direction deflector and a Y-direction deflector which controls the electron beam so that the electron beam is focused in position on the optical disk, thereby forming the groove in the optical disk.

Abstract: A laser-based measuring apparatus divides a light beam from a laser light source into at least two light beams, passes the light beams through different optical paths from each other, recombines the light beams, has the light beams interfere with each other to generate interfered light, opto-electrically transduces the interfered light to an optical frequency, and measures the amount of travel of an object which changes an optical path length of a portion of an optical path based on the optical frequency. The measuring apparatus has a portion for generating at least two measuring light beams from the laser light source, two reflection planes included in an object moving on a measuring axis, arranged back-to-back to each other on the measuring axis, and an opposing incident optical system for directing the measuring light beams into the reflection planes, respectively, such that the measuring light beams oppose to each other on the measuring axis.

Abstract: The invention relates to an optical disc of the next generation which is capable of recording data at a high density by using an optical system having a larger numerical aperture and a reproduce beam of light with a shorter wavelength than those used with a conventional DVD. The optical disc includes an information recording layer where information is recorded as an array of pits at a predetermined track pitch, and a light transmitting layer formed on the information recording layer and having a film thickness of 0.13 mm or less. The information recorded therein is reproduced upon irradiation of a beam of light having a wavelength ranging from 400 nm to 415 nm onto the information recording layer through the light transmitting layer from an objective lens having a numerical aperture ranging from 0.75 to 0.86. In this disc, a taper angle of the pits is 55 degrees or higher.

Abstract: Preceding to the reading out of the recording information of the optical disk by the pick-up, the height of the foreign material existing at the light converging position on the information reading surface is detected by the detector, and when the height of the foreign material is higher than the floating height h of the SIL, the magnetic field is generated by applying the control current corresponding to the height of the foreign material to the coil as the magnetic field generator at the timing before the foreign material is moved to the information reading position of the pick-up by the rotation of the optical disk. Then, when the magnetic field is provided to the magnetic substance fixedly holding the SIL which is floating, the movement operation to separate the SIL to the higher position than the height of the foreign material from the information reading surface together with the magnetic substance, is conducted.

Abstract: An information recording apparatus including a device for driving an optical-disk's master disk, an electron lens barrel for having an electron beam irradiate a recording surface of a disk, a translational device for producing, between the disk and the electron lens barrel, a relative movement in a direction parallel to the recording surface and a container for enclosing the elements of the apparatus adapted to support a vacuum atmosphere. The driving device includes a turn table 4, a spindle 14a for supporting the turn table, a motor 14 for driving the spindle, and a magnetic shield for preventing magnetic fields of the motor from leaking outward. The motor is enclosed in the shield to prevent its magnetic fields from affecting the electron beam, which makes it possible to record information with high accuracy. The use of the motor as a drive source realizes easier and more responsive control of the turn table than that in the prior art.

Abstract: An electron beam projection apparatus including electron injection unit for irradiating an object with an electron beam. The electron injection unit includes a substrate, a cathode formed on the substrate for emitting the electrons, a control electrode formed on the substrate via an insulation layer in a manner enclosing the cathode for accelerating the electrons, and an anode formed on the control electrode via an insulation layer in a manner enclosing the cathode for converging the electron beam. The electron beam projection apparatus further including detecting unit formed on the anode via an insulation layer for detecting secondary electrons emitted from the object irradiated with the electron beam and differential pumping unit for producing a low vacuum condition in an space where the electron beam travels from the microscopic electron injection unit to the object.

Abstract: An object carriage system is developed which can suppress any vibration even if an object to be carried contains a source of vibration. The object carriage system comprises a carriage for carrying an object, a resilient supporting means for resiliently supporting the carriage over the floor, a vibration suppressing means for suppressing the vibration of the carriage relative to the floor, acceleration detecting means for detecting an acceleration of the carriage and producing a corresponding acceleration signal, a mass movably supported by the carriage, and driving means for driving the mass in the direction in which the acceleration takes place in accordance with the acceleration signal.

Abstract: A pickup system for an optical information recording and/or reproducing apparatus includes a support device for the lens element including pairs of cantilevel-like springs separately disposed in first and second perpendicular directions for flexing in respectively orthogonal directions.

Abstract: An MFB loudspeaker comprising a detector element mounted on a diaphragm on a specific position, i.e., a nodal line of a primary resonance mode thereof for generating a voltage proportional to a component indicative the vibratory characteristics of the diaphragm.