Hitachi, Ltd.

Kenichi Nagashima

Kenichi Saito

Tsuyoshi Nakagawa

Masahito Suzuki

Yasushi Neho

Shinji Matsushita

Tatsuhiko Matsuoka

Masaaki Eishima

Katsuhiro Arakawa

Susumu Saito

Hajime Yamagami

Masao Miyawaki

Masato Kurita

Shigenori Yamagata

Tomoyasu Itou

Akihiko Seki

Takeshi Maeda

Atsuhiro Higa

Even though a laser diode is within the operation guarantee temperature range, the rise time characteristics required to protect and maintain the writing quality right away may not be present at a lower temperature. By sufficiently increasing the rise time, a laser diode control method of the present invention makes it possible to write readily. A laser diode control device includes a temperature sensor for detecting temperature of a laser diode. When a detected temperature by the temperature sensor is equal to or below a predetermined value within the operation guarantee temperature range, a seek motor controls the position of a pickup to move the pickup to a region outside a recording region of a recording medium. In this way, a current exceeding a threshold current value is supplied to the laser diode, and the writing operation starts after the laser diode temperature is increased up to a level where the rise time characteristics required to protect and maintain the writing quality is present.

Laser diode control method, laser diode control device, and information recording/playback apparatus

In an information processing apparatus such as a space-saving type personal computer having a liquid-cooling type cooling system, the presence of a cooling liquid, the presence of a frozen state of the cooling liquid and the temperature of the cooling liquid are detected. When a freeze of the cooling liquid is detected, a CPU is throttled down to defrost the cooling liquid, or the cooling liquid is heated to be prevented from being frozen. Alternatively, a warning of detection of a freeze may be displayed. Alternatively, activation of the system may be stopped or operation of the system may be interrupted. By such measures, system failure is prevented from being caused by leaking, shortage, freezing, etc. of the cooling liquid.

Method of controlling cooling system for a personal computer and personal computer

A desk-top type computer with a built-in LCD includes a chassis, a planar display attached to the chassis, a mother board attached to the chassis, heat generating portions including a CPU mounted on the mother board, and a memory device electrically connected to the mother board. A heat receiving head is fixed to at least one of the heat generating portions including the CPU, and the head is connected a tube filled with a cooling liquid. The tube is arranged in a serpentine or zigzag shape in a clearance between the chassis and the planar display facing the chassis. The cooling medium liquid circulating in the tube serves as a heat transferring medium to absorb the heat at the heat generating portion, and radiate the heat through the tube disposed in the clearance between the LCD and the chassis.

Liquid cooling system for all-in-one computer

In a liquid-cooling system for a notebook personal computer having a body part including a CPU and a chip set respectively mounted on a mother board and an HDD, and a display part rotatably supported by the body part, a heat receiving head is fixed to at least one heat generation part including the CPU. A tube filled with cooling liquid is connected to the heat receiving head. The tube connected to the heat receiving head is disposed in series on at least one heat generation part including the chip set so as to collect the heat generated from each heat generation part. The tube is also laid in a meandering or zigzagging pattern between a liquid crystal panel and a housing of the display part. The heat generated from each heat generation part is absorbed at part of the tube by the cooling liquid that circulates in the tube and functions as a heat transfer medium. The absorbed heat is then radiated at another part of the tube. Consequently, the heat generated from the chip set including the CPU and other heat sources such as the HDD can be radiated together to the outside. Local temperature rising is prevented. An uniform temperature environment is attained on all the surfaces of the body part.

Liquid cooling system for notebook computer

In an information processing apparatus, a heat-generating portion including at least a CPU is cooled by circulation of a cooling liquid, the temperature of the cooling liquid is measured and the operating condition of a pump for circulating the cooling liquid is obtained in accordance with the measured temperature of the cooling liquid. The pump is operated on the basis of the operating condition to control the flow rate of the circulated cooling liquid. Further, even after the system for the information processing apparatus stops, the circulation of the cooling liquid is continued until the temperature of the heat-generating portion becomes not higher than a predetermined value.

In a liquid-cooling system for a notebook personal computer having a body part including a CPU and a chip set respectively mounted on a mother board and an HDD, and a display part rotatably supported by the body part, a heat receiving head is fixed to at least one heat generation part including the CPU. A tube filled with cooling liquid is connected to the heat receiving head. The tube connected to the heat receiving head is disposed in series on at least one heat generation part including the chip set so as to collect the heat generated from each heat generation part. The tube is also laid in a meandering or zigzagging pattern between a liquid crystal panel and a housing of the display part. The heat generated from each heat generation part is absorbed at part of the tube by the cooling liquid that circulates in the tube and functions as a heat transfer medium. The absorbed heat is then radiated at another part of the tube. Consequently, the heat generated from the chip set including the CPU and other heat sources such as the HDD can be radiated together to the outside.

Notebook computer having a liquid cooling device

In a memory control apparatus which has a main memory constructed by a plurality of memory areas and a cache memory which can be accessed at a speed higher than that of the main memory and in which the main memory or the cache memory is accessed in response to a memory access request from an access request side and data is read out and transferred to the access request side, an accessing speed of every plurality of memory areas in the main memory is identified and an area that is cachable for the cache memory among the plurality of memory areas in the main memory is set in accordance with the identified accessing speed of every plurality of memory areas in the main memory. In a memory control apparatus for performing an interleave access or a non-interleave access to an information memory medium having a plurality of banks of different capacities, a boundary address indicative of a boundary between the interleave access area and the non-interleave access area is compared with an access address to the information memory medium, and on the basis of the comparison result, the interleave access or non-interleave access is executed to the information memory medium.

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Ebina, Japan

Kenichi Nagashima