Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element which is formed integrally with a substrate having a flat face and has a convex curved face so as to have a function as an optical lens is shaped such that the curvature on a first cross section including an axis in a focus direction of the optical lens and the curvature on a second cross section perpendicular to the first cross section and intersecting with the first cross section along the axis in the focus direction are different from each other, whereby the focal lengths on the first and second cross sections perpendicular to each other are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.

Abstract: The method of the present invention includes an exposing step in which a laser beam for recording modulated by an information signal corresponding to an information signal of an information concave and convex pattern formed on the optical disc is applied to an inorganic resist layer 101 formed on a substrate 100 to form an exposed pattern corresponding to the information concave and convex pattern on the optical disc, and a development step in which a concave and convex pattern corresponding to the information concave and convex pattern by the inorganic resist layer is formed. By applying a laser beam for estimation to a predetermined area on the inorganic resist layer in the exposing step to estimate recorded signal characteristics of the exposed pattern by the inorganic resist layer using reflected light of the laser beam for estimation, and controlling power of the laser beam for recording based on the estimated result, the aimed information recording on the optical disc can reliably be obtained.

Abstract: A storage device includes a first electrode, a second electrode facing the first electrode, an inter-electrode material layer provided between the first electrode and the second electrode, and a voltage application unit applying a predetermined voltage to the first and the second electrodes. Furthermore, an oxidation-reduction active material changeable into an electrode reaction inhibition layer by applying voltages to the first and the second electrodes is contained in a region that is covered by an electric field, the electric field being generated when the voltage is applied, and the electrode reaction inhibition layer is either formed along an interface region between the second electrode and the inter-electrode material layer, or changes an area thereof, or disappears depending on an application condition of the voltage to the first and the second.

Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element, which is formed integrally with a substrate having a flat face, has a convex curved face that functions as an optical lens and is shaped such that the curvature on a first cross section and the curvature on a second cross section perpendicular to and intersecting with the first cross section are different from each other, whereby the focal lengths on the first and second cross sections are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.

Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element, which is formed integrally with a substrate having a flat face, has a convex curved face that functions as an optical lens and is shaped such that the curvature on a first cross section and the curvature on a second cross section perpendicular to and intersecting with the first cross section are different from each other, whereby the focal lengths on the first and second cross sections are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.

Abstract: A storage device comprises a memory element and an applying means for applying a voltage to the memory element wherein the memory element changes its characteristic to record thereon information with application of a voltage to the memory element by the applying means, the memory element further changing its characteristic when the same information is recorded on the memory element continuously. The memory element has a recording method which comprises the steps of detecting content of information that has already been recorded on the memory element when the information is recorded, comparing the information that has already been recorded on the memory element with information to be recorded on the memory element, applying a voltage to the memory element to make an ordinary information recording process if the two information are different from each other and disabling the ordinary information recording process when the two information are identical to each other.

Abstract: A storage device is provided. The storage device includes a number of storage cells arranged and each having a storage element and an active element including a MOS transistor that controls access to the storage element, and in which applying a voltage to the storage element the resistance value of the storage element changes and information is recorded wherein the resistance value of a storage element after information has been written is prevented from becoming lower than necessary and in which information writing can be easily performed.

Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element which is formed integrally with a substrate having a flat face, has a convex curved face that functions as an optical lens and is shaped such that the curvature on a first cross section and the curvature on a second cross section perpendicular to and intersecting with the first cross section are different from each other, whereby the focal lengths on the first and second cross sections are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.

Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element, which is formed integrally with a substrate having a flat face, has a convex curved face that functions as an optical lens and is shape such that the curvature on a first cross section and the curvature on a second cross section perpendicular to and intersecting with the first cross section are different from each other, whereby the focal lengths on the first and second cross sections are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.

Abstract: An optical head, able to reduce thermal stress generated in an optical lens mounted on a bobbin, having a bobbin formed with a center hole and an optical lens mounted on the bobbin via a thermal expansion adjustment member 40 formed with an opening. The optical lens has a substrate formed by an optical material different from the bobbin in coefficient of thermal expansion. The substrate has a convex part functioning as a convex lens and a flat part positioned around the convex part. The flat part is fixed to the thermal expansion adjustment member so that the convex part fits in the opening. The optical lens is placed so that a center axis of the convex part or an extension thereof passes through the center hole of the bobbin and the center axis of the convex part coincides with a center hole of the bobbin.

Abstract: An optical element having a substrate formed by an optical material and able to improve mechanical strength, wherein the substrate has a convex part functioning as a convex lens, a flat part positioned around the convex part, and an outer circumference part positioned around the flat part. The thickness of the substrate at the outer circumference part is greater than that of the substrate at the flat part.

Abstract: A first optical device according to the present invention comprises a base made of a first optical material and a second optical material having a refractive index different from that of the first optical material, and the base has a concavity, and the second optical material is filled in this concavity. A second optical device according to the present invention comprises a base made of a first optical material and a second optical material having a refractive index different from the first optical material, and the base comprises first and second faces facing each other, a first concavity is formed in the first face and a second concavity is formed in the second face, and the second optical material is filled in the first and second concavities.

Abstract: A recording medium manufacturing method comprises a process for forming a thermosensitive material layer 12 on a substrate comprising a recording medium or a recording medium manufacturing master, a process for forming a denatured portion 12s of a pattern corresponding to target very small concavities and convexities on the thermosensitive material layer by irradiating laser light on the thermosensitive material layer with patterns corresponding to target very small concavities and convexities and a process for forming target very small concavities and convexities by patterning the thermosensitive material layer by developing the thermosensitive material layer 12. In particular, in the laser light irradiation, there can be formed patterns independent of the length of the very small concavities and convexities by irradiation of laser light modulated by a frequency higher than a period of very small concavities and convexities.

Abstract: A resist material and a nanofabrication method provide high-resolution nanofabrication without an expensive irradiation apparatus using, for example, electron beams or ion beams. That is, the resist material and the nanofabrication method provide finer processing using exposure apparatuses currently in use. A resist layer of an incompletely oxidized transition metal such as W and Mo is selectively exposed and developed to be patterned in a predetermined form. The incompletely oxidized transition metal herein is a compound having an oxygen content slightly deviated to a lower content from the stoichiometric oxygen content corresponding to a possible valence of the transition metal. In other words, the compound has an oxygen content lower than the stoichiometric oxygen content corresponding to a possible valence of the transition metal.

Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element which is formed integrally with a substrate having a flat face and has a convex curved face so as to have a function as an optical lens is shaped such that the curvature on a first cross section including an axis in a focus direction of the optical lens and the curvature on a second cross section perpendicular to the first cross section and intersecting with the first cross section along the axis in the focus direction are different from each other, whereby the focal lengths on the first and second cross sections perpendicular to each other are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.

Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element which is formed integrally with a substrate having a flat face and has a convex curved face so as to have a function as an optical lens is shaped such that the curvature on a first cross section including an axis in a focus direction of the optical lens and the curvature on a second cross section perpendicular to the first cross section and intersecting with the first cross section along the axis in the focus direction are different from each other, whereby the focal lengths on the first and second cross sections perpendicular to each other are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.

Abstract: A recording medium manufacturing method comprises a process for forming a thermosensitive material layer 12 on a substrate comprising a recording medium or a recording medium manufacturing master, a process for forming a denatured portion 12s of a pattern corresponding to target very small concavities and convexities on the thermosensitive material layer by irradiating laser light on the thermosensitive material layer with patterns corresponding to target very small concavities and convexities and a process for forming target very small concavities and convexities by patterning the thermosensitive material layer by developing the thermosensitive material layer 12. In particular, in the laser light irradiation, there can be formed patterns independent of the length of the very small concavities and convexities by irradiation of laser light modulated by a frequency higher than a period of very small concavities and convexities.

Abstract: A first optical device according to the present invention comprises a base made of a first optical material and a second optical material having a refractive index different from that of the first optical material, and the base has a concavity, and the second optical material is filled in this concavity. A second optical device according to the present invention comprises a base made of a first optical material and a second optical material having a refractive index different from the first optical material, and the base comprises first and second faces facing each other, a first concavity is formed in the first face and a second concavity is formed in the second face, and the second optical material is filled in the first and second concavities.

Abstract: A first optical device according to the present invention comprises a base made of a first optical material and a second optical material having a refractive index different from that of the first optical material, and the base has a concavity, and the second optical material is filled in this concavity. A second optical device according to the present invention comprises a base made of a first optical material and a second optical material having a refractive index different from the first optical material, and the base comprises first and second faces facing each other, a first concavity is formed in the first face and a second concavity is formed in the second face, and the second optical material is filled in the first and second concavities.

Abstract: An optical system capable of reducing trouble in assembly and skew adjustment, comprising first and second optical lenses arranged so that their optical axes coincide or substantially coincide, wherein the first optical lens has a substrate comprised of an optical material, the substrate has a convex portion serving as a convex lens, a flat portion positioned around the convex portion, and an outer circumference portion positioned around the flat portion, a thickness of the substrate at the outer circumference portion is greater than a thickness of the substrate at the convex portion, and the outer circumference portion of the first optical lens and that of the second optical lens are fixed in place by an adhesive so that the convex portion of the first optical lens faces the convex portion of the second optical lens.