Abstract: A memory device able to be produced without requiring high precision alignment, a method of production of the same, and a method of use of a memory device produced in this way, wherein a peripheral circuit portion (first semiconductor portion) formed by a first minimum processing dimension is formed on a substrate, a memory portion (second semiconductor portion) formed by a second minimum processing dimension smaller than the first minimum processing dimension is stacked above it, and the memory portion (second semiconductor portion) is stacked with respect to the peripheral circuit portion (first semiconductor portion) with an alignment precision rougher than the second minimum processing dimension or wherein memory cells configured by 2-terminal devices are formed in regions where word lines and bit lines intersect in the memory portion, and contact portions connecting the word lines and bit lines and the peripheral circuit portions are arranged in at least two columns in directions in which the word lines

Abstract: A memory device able to be produced without requiring high precision alignment, a method of production of the same, and a method of use of a memory device produced in this way, wherein a peripheral circuit portion (first semiconductor portion) formed by a first minimum processing dimension is formed on a substrate, a memory portion (second semiconductor portion) formed by a second minimum processing dimension smaller than the first minimum processing dimension is stacked above it, and the memory portion (second semiconductor portion) is stacked with respect to the peripheral circuit portion (first semiconductor portion) with an alignment precision rougher than the second minimum processing dimension or wherein memory cells configured by 2-terminal devices are formed in regions where word lines and bit lines intersect in the memory portion, and contact portions connecting the word lines and bit lines and the peripheral circuit portions are arranged in at least two columns in directions in which the word lines

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 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 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 method for manufacturing an optical disc master using an existing exposure system, and a method for manufacturing an optical disc having higher recording capacity. The method for manufacturing an optical disc, using a master to produce the optical disc having an irregular pattern thereon, the master being produced by the steps of forming a resist layer composed of a resist material including an incomplete oxide of a transition metal such as W or Mo on a substrate, the oxygen content of the incomplete oxide being smaller than the oxygen content of the stoichiometric composition corresponding to a valence of the transition metal; selectively exposing the resist layer with laser according to a recording signal pattern; and developing the resist layer to form the predetermined irregular pattern.

Abstract: A memory element in which recording and reading-out of information can easily be performed and which can be manufactured easily using a comparatively simple manufacturing method and a storage device using the memory element are provided. A memory element 10 includes an amorphous thin-film 4 that is in between a first electrode 2 and a second electrode 5, in which at least one electrode in the first electrode 2 and the second electrode 5 contains Ag or Cu and the amorphous thin-film 4 is composed of Ge, and at least one element selected from S, Se, Te and Sb. Also a storage device includes the memory element 10, a wiring connected to the side of the first electrode 2 and a wiring connected to the side of the second electrode 5, in which a memory element 10 is arranged in large numbers.

Abstract: A memory device 10 has an arrangement in which a memory thin film 4 is sandwiched between first and second electrodes 2 and 6, the memory thin film 6 contains at least rare earth elements, the memory thin film 4 or a layer 3 in contact with the memory thin film 4 contains any one of elements selected from Cu, Ag, Zn and the memory thin film 4 or the layer 3 in contact with the memory thin film 4 contains any one of elements selected from Te, S, Se. The memory device can record and read information with ease stably, and this memory device can be manufactured easily by a relatively simple manufacturing method.

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 device used for converging a light beam on a signal recording surface of an optical disc includes an optical lens for converging the light beam on a signal recording surface of the optical disc and a light barrier portion provided on a surface of the optical lens facing the optical disc. The light barrier portion includes a light transmitting aperture through which is transmitted the light beam converged by the optical lens. The light beam illuminated on the optical disc has its diameter controlled by this light transmitting aperture. The light radiated by a light source so as to be incident to the optical device is converged by the optical lens. The light converged by the optical lens is transmitted through the light transmitting aperture and illuminated on the signal recording surface of the optical disc.

Abstract: Data reading can be easily and precisely performed by setting specific conditions in writing into a selected memory cell. A memory cell has a structure, in which an interelectrode material layer is sandwiched between a first electrode and a second electrode. Data is stored by a change in a resistance value between the first electrode and the second electrode. The resistance value when a memory element is in a high resistance state is expressed as R_mem_high; the resistance value when the memory element is in a low resistance state is expressed as R_mem_low1; the resistance value of a load circuit is expressed as R_load; the reading voltage is expressed as Vread by setting the voltage of a second power supply line to the reference voltage; and the threshold voltage is expressed as Vth_critical. In writing data into the memory cell, the low resistance state is created so that these parameters satisfy specific relations.

Abstract: An optical device used for converging a light beam on a signal recording surface of an optical disc includes an optical lens for converging the light beam on a signal recording surface of the optical disc and a light barrier portion provided on a surface of the optical lens facing the optical disc. The light barrier portion includes a light transmitting aperture through which is transmitted the light beam converged by the optical lens. The light beam illuminated on the optical disc has its diameter controlled by this light transmitting aperture. The light radiated by a light source so as to be incident to the optical device is converged by the optical lens. The light converged by the optical lens is transmitted through the light transmitting aperture and illuminated on the signal recording surface of the optical disc.

Abstract: An optical device used for converging a light beam on a signal recording surface of an optical disc includes an optical lens for converging the light beam on a signal recording surface of the optical disc and a light barrier portion provided on a surface of the optical lens facing the optical disc. The light barrier portion includes a light transmitting aperture through which is transmitted the light beam converged by the optical lens. The light beam illuminated on the optical disc has its diameter controlled by this light transmitting aperture. The light radiated by a light source so as to be incident to the optical device is converged by the optical lens. The light converged by the optical lens is transmitted through the light transmitting aperture and illuminated on the signal recording surface of the optical disc.

Abstract: An optical device used for converging a light beam on a signal recording surface of an optical disc includes an optical lens for converging the light beam on a signal recording surface of the optical disc and a light barrier portion provided on a surface of the optical lens facing the optical disc. The light barrier portion includes a light transmitting aperture through which is transmitted the light beam converged by the optical lens. The light beam illuminated on the optical disc has its diameter controlled by this light transmitting aperture. The light radiated by a light source so as to be incident to the optical device is converged by the optical lens. The light converged by the optical lens is transmitted through the light transmitting aperture and illuminated on the signal recording surface of the optical disc.

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 memory device is obtained in which stable recording of information can be performed and a period of time required for the recording of information can be shortened.

Abstract: A memory device is provided in which recording of multi-valued data can be performed at a high speed and the recording of multi-valued data can be performed with a drive circuit having comparatively simple configuration.

Abstract: The method of the present invention includes: an exposing process in which an inorganic resist layer 101 formed on a substrate 100 is irradiated with recording laser light modulated by an information signal corresponding to an information signal of an information concave and convex pattern formed on an optical disc to form an exposed pattern corresponding to the information concave and convex pattern on the optical disc, and after the above process a development process in which development processing is performed on the inorganic resist layer to form a concave and convex pattern corresponding to the information concave and convex pattern of the inorganic resist layer; in the above exposing process, after a trial exposure is performed on a non-recording area of the above resist layer, the exposed portion is irradiated with evaluation laser light and a recording signal characteristic of the above resist layer is evaluated from the reflected light to determine based on the evaluation result an optimum focus pos

Abstract: An optical device is provided which has a light converging unit for converging the light illuminated on a magneto-optical recording layer of an optical recording medium and a magnetic field generating unit provided on the light converging unit towards the optical recording medium. The diameter of the light beam radiated on the magneto-optical recording layer of the optical recording medium is controlled by a light transmitting hole of the magnetic field generating unit. The light beam illuminated on the magneto-optical recording layer of the optical recording medium is not fluctuated in diameter so that it is possible to produce a magnetic field at a low power consumption. In addition, the magnetic field generating unit is not liable to be ruptured. There is also provided a recording and/or reproducing apparatus employing this optical device.