Inventors list

Assignees list

Classification tree browser

Top 100 Inventors

Top 100 Assignees


Hirokazu Iwata

Hirokazu Iwata, Miyagi JP

Patent application numberDescriptionPublished
20080216737CRYSTAL MANUFACTURING APPARATUS - A crystal manufacturing apparatus for manufacturing a group III nitride crystal includes a crucible that holds a mixed molten liquid including an alkali metal and a group III metal; a reaction vessel accommodating the crucible in the reaction vessel; a heating device that heats the crucible with the reaction vessel; a holding vessel having a lid that is capable of opening and closing, accommodating the reaction vessel and the heating device in the holding vessel; a sealed vessel accommodating the holding vessel in the sealed vessel, having an operating device that enables opening the lid of the holding vessel for supplying source materials into the crucible and taking out a manufactured GaN crystal under a sealed condition, and closing the lid of the holding vessel that is sealed in the sealed vessel, the sealed vessel including an inert gas atmosphere or a nitrogen atmosphere; and a gas supplying device for supplying a nitrogen gas to the mixed molten liquid through each of the vessels.09-11-2008
20080264331Manufacturing Method and Manufacturing Apparatus of a Group III Nitride Crystal - A method for manufacturing a group III nitride crystal on a seed crystal in a holding vessel holding therein a melt containing a group III metal, an alkali metal and nitrogen. The manufacturing method comprises the steps of causing the seed crystal to make a contact with the melt, setting an environment of the seed crystal to a first state offset from a crystal growth condition while in a state in which said seed crystal is in contact with the melt, increasing a nitrogen concentration in the melt, and setting the environment of the seed crystal to a second state suitable for crystal growth when the nitrogen concentration of the melt has reached a concentration suitable for growing the seed crystal.10-30-2008
20090120354CRYSTAL GROWTH METHOD, CRYSTAL GROWTH APPARATUS, GROUP-III NITRIDE CRYSTAL AND GROUP-III NITRIDE SEMICONDUCTOR DEVICE - A group-III nitride crystal growth method comprises the steps of: a) preparing a mixed molten liquid of an alkaline material and a substance at least containing a group-III metal; b) causing growth of a group-III nitride crystal from the mixed molten liquid prepared in the step a) and a substance at least containing nitrogen; and c) creating a state in which nitrogen can be introduced into the molten liquid prepared by the step a).05-14-2009
20090173274PRODUCTION OF A GaN BULK CRYSTAL SUBSTRATE AND A SEMICONDUCTOR DEVICE FORMED THEREON - A crystal has a diameter of 1 cm or more and shows a strongest peak in cathode luminescent spectrum at a wavelength of 360 nm in correspondence to a band edge.07-09-2009
20090249997METHOD OF PRODUCING GROUP III NITRIDE CRYSTAL, APPARATUS FOR PRODUCING GROUP III NITRIDE CRYSTAL, AND GROUP III NITRIDE CRYSTAL - In a method of producing a group III nitride crystal in which a melt holding vessel where a melt containing a group III metal and flux is held is accommodated in a reaction vessel and a group III nitride crystal is produced as a substance containing nitrogen is supplied from an outside to the reaction vessel through a pipe, the method includes a step of forming an accumulated part of a liquid in the pipe to thereby temporarily close the pipe before growing the group III nitride crystal in the melt holding vessel.10-08-2009
20100229787Crystal Manufacturing Apparatus - A crystal manufacturing apparatus for manufacturing a group III nitride crystal includes a crucible that holds a mixed molten liquid including an alkali metal and a group III metal; a reaction vessel accommodating the crucible in the reaction vessel; a heating device that heats the crucible with the reaction vessel; a holding vessel having a lid that is capable of opening and closing, accommodating the reaction vessel and the heating device in the holding vessel; a sealed vessel accommodating the holding vessel in the sealed vessel, having an operating device that enables opening the lid of the holding vessel for supplying source materials into the crucible and taking out a manufactured GaN crystal under a sealed condition, and closing the lid of the holding vessel that is sealed in the sealed vessel, the sealed vessel including an inert gas atmosphere or a nitrogen atmosphere; and a gas supplying device for supplying a nitrogen gas to the mixed molten liquid through each of the vessels.09-16-2010
20110012235METHOD OF GROWING GROUP III NITRIDE CRYSTAL, GROUP III NITRIDE CRYSTAL GROWN THEREBY, GROUP III NITRIDE CRYSTAL GROWING APPARATUS AND SEMICONDUCTOR DEVICE - A method of growing a group III nitride crystal grows a group III nitride crystal from a solution in which an alkaline metal, a group III metal and nitrogen are dissolved, and includes, in the solution, a material which increases solubility of the nitrogen into the solution.01-20-2011

Patent applications by Hirokazu Iwata, Miyagi JP

Hirokazu Iwata, Kanagawa JP

Patent application numberDescriptionPublished
20090161142Positional Error Detection Method and Apparatus, and Computer-Readable Storage Medium - A positional error detection method forms, on a belt which is transported in a transport direction, positional error detection marks for detecting a positional error between image positions of first and second colors, detects the positional error detection marks on the belt, and computes the positional error based on the detected positional error detection marks. The positional error detection marks include first and second marks which are inclined in mutually opposite directions with respect to the transport direction, and third marks which are perpendicular to the transport direction.06-25-2009

Hirokazu Iwata, Osaka JP

Patent application numberDescriptionPublished
20090111396AM TRANSMITTER AND MODULATION METHOD USING SAME - An AM (Amplitude-Modulated) transmitter capable of improving modulation distortion is provided. An adder adds a modulation signal to a pre-set power reference signal. An APC (Automatic Power Control) amplifier compares a level of a detecting signal outputted by the LPF (Low Pass Filter) with a level of an adder signal. The APC amplifier, based on the comparison result, generates a gain controlling signal that makes a difference between a level of the detecting signal and level of the signal approach zero and feeds the gain controlling signal to a power amplifier. The power amplifier modulates the signal outputted from the amplifier by the gain controlling signal and power-amplifies the modulated signal according to a level of the gain controlling signal. Since the APC amplifier feeds the gain controlling signal to the power amplifier, a modulation degree does not depend on a nonlinear distortion characteristic of the power amplifier.04-30-2009