Abstract: A smooth current calculation apparatus, which calculates a smooth current of a secondary battery, includes a digital low-pass filter (22˜27) supplied with a measured digital current value generated by digitizing a measured current value of the secondary battery. The digital low-pass filter outputs a smooth digital current value, which is created by smoothing a time fluctuation of the measured digital current value. A current fluctuation level setting part (S1) compares a difference between the measured digital current value and the smooth digital current value with a threshold value, and sets a current fluctuation level based on a result of the comparison. A filter coefficient setting part (S2) sets a filter coefficient of the digital low-pass filter in accordance with the current fluctuation level.

Abstract: A smooth current calculation apparatus, which calculates a smooth current of a secondary battery, includes a digital low-pass filter (22˜27) supplied with a measured digital current value generated by digitizing a measured current value of the secondary battery. The digital low-pass filter outputs a smooth digital current value, which is created by smoothing a time fluctuation of the measured digital current value. A current fluctuation level setting part (S1) compares a difference between the measured digital current value and the smooth digital current value with a threshold value, and sets a current fluctuation level based on a result of the comparison. A filter coefficient setting part (S2) sets a filter coefficient of the digital low-pass filter in accordance with the current fluctuation level.

Abstract: An antenna apparatus includes an antenna element, a feeder connected to the antenna element, a matching circuit connected to the feeder, a feeding point connected to the matching circuit, and a ground plate, on which the feeding point and the matching circuit are mounted. The antenna element includes a first plate section extending in parallel with the extending direction of the ground plate, a second plate section extending from the apical end of the first plate section almost perpendicularly, and a third plate section extending from the apical end of the second plate section in parallel with the first plate section. The ground plate can freely be folded up to the extending direction thereof. Interval G, length L, and ratio R satisfy the relations of formulae (1)-(3): G=R×L??(1), 3.5 mm?L?11 mm??(2), and 0.06?R?0.95??(3).

Abstract: In a flexible printed circuit (10) for electrically connecting between a fixed portion and a movable portion comprising a flexible base layer (11), a conductive layer (13) formed on a principal surface (11a) of the flexible base layer through a first adhesive agent (12), and a cover lay (15) formed on the conductive layer through a second adhesive agent (14), copper foil (22) is pasted on an upper surface (15a) of the cover lay through a conductive adhesive agent (21). The copper foil is electrically connected to a ground portion (110) using solder. The fixed portion may be an optical disc drive's body (300). The movable portion may be an optical pickup unit (100) comprising an electromagnetic radiation source (200). The copper foil is for shielding electromagnetic noises radiated from the electromagnetic radiation source. The copper foil may be disposed only the vicinity of the electromagnetic radiation source.

Abstract: In a flexible printed circuit (10) for electrically connecting between a fixed portion and a movable portion comprising a flexible base layer (11), a conductive layer (13) formed on a principal surface (11a) of the flexible base layer through a first adhesive agent (12), and a cover lay (15) formed on the conductive layer through a second adhesive agent (14), copper foil (22) is pasted on an upper surface (15a) of the cover lay through a conductive adhesive agent (21). The copper foil is electrically connected to a ground portion (110) using solder. The fixed portion may be an optical disc drive's body (300). The movable portion may be an optical pickup unit (100) comprising an electromagnetic radiation source (200). The copper foil is for shielding electromagnetic noises radiated from the electromagnetic radiation source. The copper foil may be disposed only the vicinity of the electromagnetic radiation source.