Hitachi Maxell, Limited

Trek, Inc.

Other

Manabu Tani

Masafumi Yoshihiro

Hiroyuki Awano

Masaki Sekine

Katsuji Nakagawa

Bruce T Williams

Toshio Uehara

Akiyoshi Itoh

Norio Ohta

Katsusuke Shimazaki

Kouichirou Wakabayashi

Hiroki Takao

Susumu Aoki

Ikuo Shinta

Hitoshi Kawamura

Akiyoshi Itou

Takashi Hasuda

Keisuke Taguchi

Hiroshi Ido

A drive device in which the frequency of a drive waveform applied to a piezoelectric element is easily settable with less obligation to consider resonance in a stationary member. The device includes a piezo element that expands and contracts according to a drive voltage, a transmission shaft that receives vibration produced by the piezo element, a stationary member that holds the transmission shaft in a slidable state along the longitudinal direction of the transmission shaft, and a lens holder that is displaced together with the piezo element and transmission shaft relative to the stationary member according to drive of the piezo element. The piezo element and the transmission shaft move in the moving direction of the lens holder in synchronization with the lens holder according to drive of the piezo element in the state where the piezo element is spaced from the stationary member. By employing this structure, the frequency of the drive waveform applied to the piezo element can be set easily without considering resonance in the stationary member.

Drive device, image acquisition device, and electronic apparatus

A recording method for recording information on a recording layer of a magneto optical recording medium by radiating a recording light beam onto the medium while applying a magnetic field in a recording direction to the medium. The method includes applying a magnetic field having a magnetic field strength H1 in the recording direction when recording a record mark having a mark length A on the recording layer, and applying a magnetic field have a magnetic field strength H2 in the recording direction when recording a record mark having a mark length B (B&ne;A) on the recording layer. Independent of the lengths of the magnetic domains recorded on the recording layer, the record information can be transferred to a reproducing layer making it possible to reproduce high density record information.

Magneto-optical recording apparatus using multiple magnetic field strengths for recording different mark lengths

When recording marks having various lengths are recorded to represent information on a magneto-optical recording medium, a mark length-correcting circuit is used to correct a mark length nT with a mark length correction amount Lc determined for each mark length so that the recording is performed with a shorter mark length nT&prime;&equals;nT&minus;Lc. When reproduction is performed on the magneto-optical recording medium, an appropriate reproducing light power and an appropriate reproducing magnetic field intensity can be easily selected for any recording mark having any length. Thus, the reproducing power margin is widened. The recording method is effective on a magneto-optical recording medium of the MAMMOS type comprising a recording layer and a reproducing layer, in which the light and the magnetic field are applied during the reproduction to transfer a magnetic domain from the recording layer to the reproducing layer in a magnified form.

Method for recording mark length shorter than channel bit length on magneto-optical medium

An electrostatic force microscope wherein electrostatic force applied to the detector is determined through obtaining the field distribution on several different shaped detectors with the calculation of the voltage distribution near the detector with the Finite Element Method to direct the measurement of the absolute charge amount on surface under test so that one can define the differences between the analysis and the results from the parallel plate model. Of interest is how large the error in the charge detection occurs in conjunction with thickness change of dielectric materials to be tested. There is provided a detector with cantilever which has proper shape for the spatial resolution of 10&mgr; made out of nickel foil for an electrostatic force microscope and the electrostatic force which appeared on it has been calculated.

Electrostatic force detector with cantilever for an electrostatic force microscope

Disclosed are a reproducing method and a reproducing apparatus capable of performing reproduction with a wide power margin, as well as a recording method and a recording apparatus preferably used for super high density recording. A recording and reproducing apparatus principally comprises a magnetic field-applying unit, a laser beam-radiating section, and a signal processing system. A magnetic coil which is provided for the magnetic field-applying unit, is arranged so that its axis of magnetic field generation is oblique to a surface of an information-recording medium A reproducing magnetic field is applied in an oblique direction to the surface of the information-recording medium by using the magnetic coil while radiating a reproducing light beam to the medium by using the laser beam-radiating section. Accordingly, the leak magnetic field in the in-plane direction from a recording magnetic domain in a recording layer is amplified. The inversion of magnetization in a reproducing layer tends to occur, and the reproducing power margin is widened. The recording and reproducing apparatus is also capable of recording information. An extremely minute recording magnetic domain can be formed in the recording layer of the information-recording medium.

METHOD AND APPARATUS FOR RECORDING AND REPRODUCING INFORMATION BY APPLYING FIELD IN A DIRECTION OTHER THAN THE DIRECTION OF MAGNETIZATION OR THE DIRECTION TO A SURFACE OF AN INFORMATION RECORDING MEDIUM

The magneto-optical recording medium has a magnetic domain magnification reproducing layer and an information recording layer. Clock marks are formed on the information recording layer, making it possible to generate a reproducing clock on the basis of these. The clock marks are detected either by irradiating directly with light of wavelength &lgr; (&lgr; &ne;&lgr; ), being different from the light of wavelength &lgr; which is used for reproducing the recording marks, or by applying a direct-current magnetic field, transferring and enlarging the clock marks on to the magnetic domain magnification reproducing layer, and detecting the reproduction signals from this magnetic domain magnification reproducing layer. Since the reproducing clock is in exact synchronisation with the recording marks, it is eminently suitable as a clock for pulse-modulated reproducing light and reproducing magnetic fields used when reproducing the reproducing layer.

Magneto-optical recording medium having clock-marks on recording layer and apparatus for recording and reproducing same

A bit of binary information which is one of &ldquo;1&rdquo; and &ldquo;0&rdquo; is assigned to a domain pattern which is a combination of a recorded magnetic domain and a magnetic domain magnetized in the direction opposite to the direction in which the recording domain is magnetized. A bit of binary information which is the other of &ldquo;1&rdquo; and &ldquo;0&rdquo; is assigned to a domain pattern consisting of two magnetic domains magnetized in the same direction as the foregoing magnetic domain is magnetized. Consequently, two or more consecutive bits of record information are formed, on a recording layer, as a series of domain patterns each of which is a combination, as a record information unit, of a recorded magnetic domain and a magnetic domain magnetized in the direction opposite to the direction in which the recording domain is magnetized. Independent of the lengths of the magnetic domains recorded on the recording layer, the record information can be transferred to a reproducing layer. This makes it possible to reproduce high-density record information securely or reliably.

Magneto-optical recording method capable of adjusting the sizes magnetic domain

An electrostatic force microscope for measuring electrostatic force of a sample under test including a detector comprising a cantilever arm having a tip formation at one end and located so that electrostatic force is induced at the tip due to electrostatic charge on the sample under test, an optical system for transforming bending of the cantilever arm due to electrostatic force induced at the tip into an electrical signal containing a frequency component of the electrostatic force induced at the detector tip, a source for applying bias voltage to the detector, a detector for detecting the frequency component of the electrostatic force induced at the detector tip so that a measurement of electrostatic force on the sample under test can be obtained, and an electrostatic shield operatively associated with the cantilever arm. The shield is located between the cantilever arm and the sample under test, in particular in close spaced relation to the arm. The cantilever arm and the shield are maintained at the same electrical potential so that lines of electrostatic force are terminated at the shield.

Growing community of inventors

Ibaraki, Japan

Manabu Tani