Abstract: The optical disc apparatus of this invention includes: an optical pickup, which irradiates an optical disc with a light beam and generates a light detection signal based on the beam reflected from the disc; a search section, which controls the pickup before data is written on a storage area of the disc, thereby adjusting the beam spot location and searching a reference one of information layers stacked for a defective area in the storage area of the disc; a defect decision section for detecting an error based on the detection signal and determining a portion of the storage area, where the error has occurred, as the defective area; a defect size measuring section for measuring the size of the defective area in an area of the reference layer and generating a defect information list indicating there is the defective area in the area of the reference layer; and a recording range control section for managing, by reference to the list, the storage area such that no data will be written on a perpendicularly projecte

Abstract: A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is obtained by mutually combining a plurality of rare earth fluorides having phase transitions and having different ion radii, respectively, so that the rare earth fluoride solid solution material is free of phase transitions. A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is represented by (REyRE?1?y)F3 (0.0000<y<1.0000), wherein RE represents one or two or more selected from Sm, Eu, and Gd, and RE? represents one or two or more selected from Er, Tm, Yb, Lu, and Y. A rare earth fluoride solid solution material (polycrystal and/or single crystal) represented by MxREyRE?1?x?yFz., wherein RE is one or two or more selected from Ce, Pr, Nd, Eu, Tb, Ho, Er, Tm, or Yb, RE? is one or two or more selected from La, Sm, Gd, Dy, Lu, Y, and Sc, and M is one or more of Mg, Ca, Sr, and Ba.

Abstract: It is an object of the present invention to provide a self-coated single crystal that without any special step conducted after crystal growth, has its circumference coated with a layer of different properties. A self-coated single crystal according to the present invention is characterized in that in operations comprising melting crystal materials for a core and a clad in a single crucible and carrying out growth of a single crystal through a pulling up method or a pulling down method, a grown single crystal in an as-growth condition has its circumference self-coated with a clad whose refractive index is lower than that of the core.

Abstract: An optical disc drive according to the present invention can write data on both a write-once disc and a rewritable disc. The drive includes: a disc recognizing section 110 for recognizing the type of a given optical disc as a write-once disc or a rewritable disc; and track skipping detection signal generating section, which outputs track skipping detection signal when a first condition on tracking error is satisfied if the given optical disc, on which data is being written, has turned out to be a write-once disc. On the other hand, if the given optical disc has turned out to be a rewritable disc, the track skipping detection signal generating section outputs track skipping detection signal when a second condition on tracking error, which is different from the first condition, is satisfied. A control section stops writing the data in response to the track skipping detection signal while the data is being written.

Abstract: An optical disk apparatus is provided with an actuator that moves a beam spot that is formed by an optical head on an optical disk to recording surfaces; position control portions that control a position of the beam spot based on the output signal of the optical head; a disturbance estimation observer relating to the actuator; and a summing circuit that takes a sum of the output of the position control portion and the output of the observer, so as to drive the actuator based on the output of the summing circuit. The optical disk apparatus further is provided with a system controller that turns the observer on and off, a LPF that attenuates the high-frequency components of the output of the observer and retains the final value of the observer when the observer is turned off, and a switching circuit that switches between the output of the observer and the output of the LPF according to whether the observer is on or off.

Abstract: To control the precipitation position of a crystal and increase the yield of the crystal by performing the crystal growth according to the solvothermal method while allowing a predetermined amount of a substance differing in the critical density from the solvent to be present in the reaction vessel; and to prevent mixing of an impurity into the crystal and improve the crystal purity.

Abstract: The present invention provides an optical disk control device that can perform focus pulling in a short time for a target information surface of an optical disk having a plurality of information surfaces. An objective lens (23) is moved toward an optical disk (1) having a plurality of information surfaces (1A, 1B) by the output signal of a driving signal generating circuit (42B), passage of an initial focused focal position is detected by a focal point passage detecting circuit (44), and when the objective lens moves past that position only a predetermined amount closer to the optical disk, an n-rotation delay circuit (70) outputs a reversal instruction f. After changing directions and moving the objective lens away from the optical disk, a focus pulling-in circuit (32B) switches a signal “a” that is output to an actuator driving circuit (21) from the output signal of the driving signal generating circuit to the output signal of the control circuit, activates a control circuit and performs focus pulling-in.

Abstract: An optical disk device of the present application includes: a turntable 30 including plural induction grooves 31a to 31h as concave portions radially extending from vicinity of a center of the turntable 30 and having open portions in an outer periphery of the turntable 30 and plural through-holes 32a to 32h penetrating bottom faces 33a to 33h on the vicinity of the center side of the plural induction grooves 31a to 31h and a top face of the turntable 30; and an outer rotor type spindle motor 35 provided with plural fins 36a to 36h as convex portions on a rotor on a side face thereof. The optical disk device of the present application utilizes an airflow generated by rotation of the rotor of the spindle motor 35 and the turntable 30 in conjunction therewith as a dust removing wind for removing dust attaching to an objective lens side area.

Abstract: An optical pickup device 11 according to the present invention includes: a light source 1 that emits a light beam; a condensing element 5 for condensing the light beam toward an information storage medium 14; and a protruding member 101, which comes closer to the information storage medium 14 than the condensing element 5 does when the condensing element 5 faces the information storage medium 14. The protruding member 101 is shaped so as to gradually protrude toward the information storage medium 14 in a tangential direction 21 of the information storage medium 14 rotating.

Abstract: The present invention provides an oxide-base scintillator single crystal having an extremely large energy of light emission, adoptable to X-ray CT and radioactive ray transmission inspection apparatus, and more specifically to provide a Pr-containing, garnet-type oxide single crystal, a Pr-containing perovskite-type oxide single crystal, and a Pr-containing silicate oxide single crystal allowing detection therefrom light emission supposedly ascribable to 5d-4f transition of Pr.

Abstract: A material for high-temperature region piezoelectric device that can be used at a high temperature zone exceeding 400 DEG C., having a resistivity whose temperature dependence is slight. The material is characterized by having a composition selected from the group consisting of RE3Ga5?xAlxSiO14 (wherein RE represents a rare earth, and 0<x<5), RE3Ta0.5Ga5.5?xAlxO14 (wherein RE represents a rare earth, and 0<X<5.5) and RE3Nb0.5Ga5.5?xAlxO14 (wherein RE represents a rare earth, and 0<x<5.5) and by exhibiting a 100 to 600° C. resistivity change of ?104. The process for producing the same is characterized by growing a single crystal from a solution in an atmosphere of inert gas containing an oxidative gas and thereafter cooling the single crystal in an inert gas whose oxidative gas molar fraction (z) is lower than in the above growing step.

Abstract: Disclosed is a luminescent material for scintillators, which comprises a single crystal of an Yb-containing mixed-crystal oxide having a base crystal consisting of a garnet single crystal or a borate single crystal. The oxide single crystal has a composition represented by either one selected from the group consisting of R3Al5O12, R3Ga5O12, Li6R(BO3)3, LaR2Ga3O12 and Gd3R2Ga3O12, wherein R is a mixture of Yb and either one of Y, Gd and Lu. The Yb as an element capable of forming an optically active state called CTS together with a neighboring negative ion (oxygen ion).

Abstract: It is an object of the present invention to provide a pulling-down apparatus that can breed a crystal having good characteristics of scintillation. The apparatus retains in a container that can control an atmosphere a melting pot having a narrow hole at the bottom side thereof, an induction heating device, and a seed-holding device that holds a seed and is pulled down so that a crystal formed successively to the seed is pulled down. Concurrently, imaging devices are arranged that can pick up images of a solid-liquid interface between the crystal and a melt material, from different directions, and the seed-holding device can be travel along directions perpendicular to respective image pickup directions in a horizontal plane.

Abstract: It is an object of the present invention to provide a self-coated single crystal that without any special step conducted after crystal growth, has its circumference coated with a layer of different properties. A self-coated single crystal according to the present invention is characterized in that in operations comprising melting crystal materials for a core and a clad in a single crucible and carrying out growth of a single crystal through a pulling up method or a pulling down method, a grown single crystal in an as-growth condition has its circumference self-coated with a clad whose refractive index is lower than that of the core.

Abstract: A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is obtained by mutually combining a plurality of rare earth fluorides having phase transitions and having different ion radii, respectively, so that the rare earth fluoride solid solution material is free of phase transitions. A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is represented by (REyRE?1-y)F3 (0.0000<y<1.0000), wherein RE represents one or two or more selected from Sm, Eu, and Gd, and RE? represents one or two or more selected from Er, Tm, Yb, Lu, and Y. A rare earth fluoride solid solution material (polycrystal and/or single crystal) represented by MxREyRE?1-x-yFz, wherein RE is one or two or more selected from Ce, Pr, Nd, Eu, Tb, Ho, Er, Tm, or Yb, RE? is one or two or more selected from La, Sm, Gd, Dy, Lu, Y, and Sc, and M is one or more of Mg, Ca, Sr, and Ba.

Abstract: An optical disk apparatus according to the present invention is capable of reading data from an optical disk 102 which has a plurality of information recording layers, including a first information recording layer whose distance from a disk surface is relatively small and a second information recording layer whose distance from the disk surface is relatively large. This optical disk apparatus includes: a focus control section 117 for causing a converging point of the light beam to be positioned on an arbitrary information recording layer of the optical disk 102; a tracking control section 118 for causing the converging point of the light beam to be positioned on a predetermined track of the information recording layer; and a gain switching section 108 capable of changing gain characteristics of at least one of the focus control section 117 and the tracking control section 118.

Abstract: An information processing apparatus includes: a converging section for converging light; a shifting section for shifting the focus of the light by moving the converging section perpendicularly to an information storage layer of a storage medium responsive to a drive signal; a position control section for generating a position control signal to move the converging section at variable velocities; a focus control section for generating a focus control signal based on a light amount signal representing reflected light such that the focus is located in a focus controllable range; a switching section for selectively outputting the position control or focus control signal; and a driving section for outputting a drive signal responsive to the output signal.

Abstract: An optical disc apparatus is provided, which comprising a laser light emitting portion for generating laser light for irradiating an optical disc, and a laser control portion for controlling a light emission operation of the laser light emitting portion. The laser control portion causes the laser light emitting portion to emit light with a first period during a first operation, and the laser control portion causes the laser light emitting portion to emit light with a second period during a second operation. The first period and the second period are different from each other.

Abstract: To find out a crystalline material for a high speed scintillator in place of BaF2 and the like, and a method for producing the material at a low cost. A single crystal of (Zn1?xMx)O1+x (M: Al, Ga, In, Y, Sc, La, Gd, Lu) (x=0 to 0.0500), (Zn1?xM?x)O1+2x(M?: Si, Ge, Sn, Pb)(x=0 to 0.0250) or (Zn1?xCdx)O (x=0 to 0.0500) is used as a scintillator. Defects of a ZnO single crystal can be reduced by using a platinum inner cylinder in order for a solution not to directly contact with an autoclave, for reducing impurities in the ZnO single crystal and precluding impurities interfering with scintillation, and by using LiOH and KOH as a mineralizer. ZnO can be doped with Al2O3, Ga2O3, In2O3, Si, Cd or the like by adding those materials to a starting material for the hydrothermal synthesis. The doping amounts can be controlled by changing charging amounts thereof.

Abstract: [Problems] To provide a process that allows melt growth of single crystals of a gallium-containing nitride with less dangerous, inexpensive equipment, in particular, a process that can be performed under normal pressure.