Sony Corporation

Oki Electric Industry Co., Ltd.

Jx Nippon Oil Energy Corporation

Hiroshi Eto

Nobuyuki Oka

Nobuyuki Yasuda

Tetpei Yokota

Hiroshi Mukawa

Masanori Saito

Takeshi Okido

Kuniko Adegawa

Takehiro Nagaki

Yoshihiro Sanada

A refrigerating machine oil composition comprising at least one ester additive selected from tetraesters of pentaerythritol and one selected from fatty acids having 5 to 18 carbon atoms and hexaesters of dipentaerythritol and one selected from fatty acids having 5 to 18 carbon atoms, and a base oil that is an ester other than the ester additive, in which the content of the ester additive is 2 to 20 mass % based on the total amount of the refrigerating machine oil composition, and the kinematic viscosity of the refrigerating machine oil composition at 40&#xb0; C. is 3 to 500 mm/s.

Refrigerator oil composition, method for producing same, and working fluid composition for refrigerators

The difference voltage between the terminal voltage VB of a rechargeable battery BAT and a reference voltage Vz1 is amplified at an initial gain, thereby reducing an amplified voltage value S12. This amplified voltage value S12 is A/D converted into digital value S13. Further, an electrical signal S18 is detected corresponding to the ambient temperature around the battery and is then A/D converted into a digital value S19. Digital values S13 and S19 charge with the progress of charging of the rechargeable battery. The change in these digital values is read by CPU 14 one after another, and the gain used in amplification of the difference voltage is renewed by the gains corresponding to digital values S13 and S19, which are stored in advance in a ROM 20. In the same manner, the reference voltage used in amplification of the difference voltage is renewed by reference voltages Vz2, Vz3, and Vz4 one by one with the progress of charging of the rechargeable battery. When the digital value S13 is decreased, CPU 14 judges that charging of the rechargeable battery is completed, thus a voltage drop -.DELTA.V being caused in the terminal voltage VB, and controls a constant current circuit portion 17 to terminate the supply of the charging current S17.

Method for detecting fully-charged state of rechargeable battery

A disc type detection arm contacts a disc type opening formed in a disc cartridge when the disc cartridge is loaded into a recording and/or reproducing apparatus. The disc type detection arm determines the type of disc which has been loaded by the depth of the disc type opening, and controls the positioning of the magnetic head in response thereto. The magnetic head is spaced-apart from the disc when a read-only type disc is loaded, and positioned close to the disc when a read/write disc is loaded.

Disc recording and/or reproducing apparatus that positions the magnetic

A magnetic head position control apparatus for driving the magnetic head of a disc recording apparatus toward or away from the recording surface of a magneto-optical disc to effect position control of the magnetic head detects changes in the distance between the magnetic head and the magneto-optical disc by detecting changes in the capacitance between a capacitance detection electrode mounted on the magnetic head and a surface of the magnetic disc and generates a voltage to control the position of the magnetic head for maintaining it at a constant predetermined distance from the magneto-optical disc. Stray capacitance between the disc and the disc recording apparatus is based on the size of the disc, which is either detected directly or obtained from pre-recorded data on the disc, and is compensated by adding a bias voltage to the voltage generated using the capacitance detection electrode to provide further control of the position of the magnetic head.

Magnetic head position control apparatus including drive means

An apparatus for generating a magnetic field varying in response to an information signal, which comprises a base plate made of electrical insulating material, a magnetic core mounted on one of opposite surfaces of the base plate, the magnetic core having a central leg portion extending through a hole formed in the base plate so as to cause its end face to appear on the other of the opposite surfaces of the base plate, a coil member wound on the central leg portion of the magnetic core to be supplied with a current varying in response to the information signal, and a capacitance detecting electrode formed with a thin conductive layer mounted on the other of the opposite surfaces of the base plate to be opposite to a recording medium having a conductive layer, the capacitance detecting electrode being provided with a cutout for restraining eddy current loss caused in the capacitance detecting electrode.

Apparatus for generating magnetic field varying in response to an

A magnetic head position control apparatus for driving the magnetic head of a disk recording apparatus toward or away from the recording surface of a magneto-optical disk to effect position control of the magnetic head. Changes in the distance between the magnetic head and the magneto-optical disk are detected from changes in capacitance between a capacitance detection electrode mounted on the magnetic head and a surface of the magneto-optical disk. An oscillator circuit connected to the capacitance detection electrode varies its oscillation frequency in response to changes in capacitance and detects such frequency variations and controls the position of the magnetic head for maintaining it at a constant predetermined distance from the magneto-optical disk.

Growing community of inventors

Tokyo, Japan

Hiroshi Eto