Abstract: A common mode choke coil comprises: a holder including side walls which have wire guide strips respectively formed at their sides and which have vertical guide grooves and horizontal flange stoppers both formed at their inner side surfaces; a coil assembly with edgewise windings of a rectangular wire provided around a bobbin with flanges; and a core securing plate spring, wherein the coil assembly is fixedly set in a correct position inside the holder such that protrusions formed at the flanges are put through the guide grooves thereby fixedly holding the bobbin in place horizontally while the flanges are locked by the flange stoppers thereby fixedly holding the bobbin in place vertically, and wherein lead wires of the edgewise windings are bent at upper ends of the wire guide strips, and then extend along the wire guide strips.

Abstract: A drum type core comprises: a flanged cylinder including a cylinder portion with a coil wound thereon, and a flange portion connected integrally with one end of the cylinder portion; and a flange piece having on its one side an engaging hole, into which the other end of the cylinder portion of the flanged cylinder is inserted. The flanged cylinder and the flange piece are made of respective different materials. The flanged cylinder has a higher permeability and saturation flux density than the flange piece, while the flange piece has a higher surface electrical resistance than the flanged cylinder. The flanged cylinder is entirely coated with a heat-resisting epoxy resin except an outer side of the flange portion. The flange piece is provided with terminal pins, around which lead wires of the coil passing by the circumference of the flange piece are bound.

Abstract: A coil device comprises at least one edgewise winding of a rectangular insulated wire and a holder on which the winding is mounted. The holder includes a plurality of terminal sections each composed of a terminal pin having one end portion adapted to be inserted in a printed circuit board, and having the other end portion embedded in the bottom side of a base section of the holder and connected to the winding. The holder further includes two side walls each having a wire path on at least one of its both sides. Each wire path has a curve guide at its lower end, and the rectangular wire is elastically curved along the curve guide and has its termination crooked and hooked around the other end portion of the terminal pin.

Abstract: A surface mount coil comprises: a flanged spool, which includes a spool section and a flange section integrally connected with one end of the spool section; a base flange, which is shaped substantially rectangular and fixedly connected to the other end of the spool section; and an edgewise wound coil, which is made of a rectangular insulated wire, and which is structured such that starting and finishing ends of the rectangular insulated wire lead out in parallel with each other around the base flange in such a manner as to extend along and on one side surface, a bottom surface, and another side surface opposite to the one side surface, and are fixed at an edge of a top surface of the base flange.

Abstract: A common mode choke coil comprises: a Mn—Zn ferrite core which is shaped square, forms a closed magnetic path, and which has an initial permeability of at least 3,000 at 100 kHz and at least 100 at 10 MHz, respectively, at room temperature; and first and second edgewise windings which are formed respectively of first and second rectangular insulated wires. The first edgewise winding is provided around a core leg of the Mn—Zn ferrite core, and the second edgewise winding is provided around a core leg of the Mn—Zn ferrite core located oppositely to the core leg having the first edgewise winding provided therearound. This structure enables the core characteristics to be fully utilized without an influence of stray capacity of winding.

Abstract: A digital reproduction signal processor relating to the present invention is provided with an analog/digital converter 4 for sampling an analog reproduction signal at a period which is longer than a digital recording channel rate, to convert to a low rate digital reproduction signal having a period which is longer than a recording channel rate, a coefficient setting unit 6 for performing a digital filtering with keeping the low rate, to generate a digital equalization signal, and an interpolator 7 for interpolating a reproduction data of the digital recording channel rate, and a half-rate Viterbi decoder 8 for taking out data. According to the digital reproduction signal processor constructed as above, even when a digital read channel employing a PRML is employed, the analog/digital converter 4 or a digital circuit operated at a channel rate can be eliminated, thereby to provide a reproduction signal processor operating with low power consumption and of low cost.

Abstract: A common mode choke coil comprises: a holder including side walls which have wire guide strips respectively formed at their sides and which have vertical guide grooves and horizontal flange stoppers both formed at their inner side surfaces; a coil assembly with edgewise windings of a rectangular wire provided around a bobbin with flanges; and a core securing plate spring, wherein the coil assembly is fixedly set in a correct position inside the holder such that protrusions formed at the flanges are put through the guide grooves thereby fixedly holding the bobbin in place horizontally while the flanges are locked by the flange stoppers thereby fixedly holding the bobbin in place vertically, and wherein lead wires of the edgewise windings are bent at upper ends of the wire guide strips, and then extend along the wire guide strips.

Abstract: A common mode choke coil comprises: a Mn—Zn ferrite core which is shaped square, forms a closed magnetic path, and which has an initial permeability of at least 3,000 at 100 kHz and at least 100 at 10 MHz, respectively, at room temperature; and first and second edgewise windings which are formed respectively of first and second rectangular insulated wires. The first edgewise winding is provided around a core leg of the Mn—Zn ferrite core, and the second edgewise winding is provided around a core leg of the Mn—Zn ferrite core located oppositely to the core leg having the first edgewise winding provided therearound. This structure enables the core characteristics to be fully utilized without an influence of stray capacity of winding.

Abstract: A tracking error detecting apparatus converts photoelectric current obtained by a photo detector into voltage signals at current/voltage conversion circuits, and adds the voltage signals to generate two signal series at adders. The two signal series are digitalized at analog to digital converters, are subjected to interpolation processing at interpolation filters and have their zero cross points detected by zero cross point detector circuits respectively. A phase difference between the zero cross points of the two signal series is detected by a phase difference detector circuit, and the phase difference is subjected to band restriction by a low pass filter, thereby to obtain a tracking error signal. The tracking error detecting apparatus is capable of coping with speed doubling of an optical recording/reproducing apparatus and density enhancing of an optical recording medium with a small size and at low cost.

Abstract: A coil device comprises at least one edgewise winding of a rectangular insulated wire and a holder on which the winding is mounted. The holder includes a plurality of terminal sections each composed of a terminal pin having one end portion adapted to be inserted in a printed circuit board, and having the other end portion embedded in the bottom side of a base section of the holder and connected to the winding. The holder further includes two side walls each having a wire path on at least one of its both sides. Each wire path has a curve guide at its lower end, and the rectangular wire is elastically curved along the curve guide and has its termination crooked and hooked around the other end portion of the terminal pin.

Abstract: A surface mount coil comprises: a flanged spool, which includes a spool section and a flange section integrally connected with one end of the spool section; a base flange, which is shaped substantially rectangular and fixedly connected to the other end of the spool section; and an edgewise wound coil, which is made of a rectangular insulated wire, and which is structured such that starting and finishing ends of the rectangular insulated wire lead out in parallel with each other around the base flange in such a manner as to extend along and on one side surface, a bottom surface, and another side surface opposite to the one side surface, and are fixed at an edge of a top surface of the base flange.

Abstract: A drum type core comprises: a flanged cylinder including a cylinder portion with a coil wound thereon, and a flange portion connected integrally with one end of the cylinder portion; and a flange piece having on its one side an engaging hole, into which the other end of the cylinder portion of the flanged cylinder is inserted. The flanged cylinder and the flange piece are made of respective different materials. The flanged cylinder has a higher permeability and saturation flux density than the flange piece, while the flange piece has a higher surface electrical resistance than the flanged cylinder. The flanged cylinder is entirely coated with a heat-resisting epoxy resin except an outer side of the flange portion. The flange piece is provided with terminal pins, around which lead wires of the coil passing by the circumference of the flange piece are bound.

Abstract: A common mode choke coil is realized in which countermeasures against leakage flux are taken so as to reduce adverse effects on an external apparatus. Coils 291, 292 are wound around a toroidal magnetic core 22 and sandwich a partition plate 27 provided within an inner circumference of the magnetic core so as to cancel out respective magnetic fluxes produced by the coils relative to a normal mode current. A belt-like magnetic shield plate 24 is provided in a direction along leakage fluxes from the coils and attached closely to a substantially U-shaped insulating protection plate 23 having side walls 25, 25 and the insulating protection plate 23 is then detachably attached to a base 21 with catches 26 provided at both ends of the plate 23.

Abstract: In a common mode choke coil, a closed magnetic circuit core (2) is divided in parallel with its magnetic circuit, and formed by superimposing together for integration a first divided magnetic core (2a), a second divided magnetic core (2b) and a third divided magnetic core (2c) which are made of an oxide magnetic substance having the high permeability. Since the closed magnetic circuit core (2) is made of the oxide magnetic substance having the high permeability, the impedance in the low frequency band (10 kHz side) is large. Also, since the sectional area of the closed magnetic circuit core (2) (divided magnetic core) is set to be small, the permeability in the high frequency band (10 MHz side) becomes high due to the dimensional resonance phenomenon, and then the impedance also becomes large. For that reason, the noise in the wide frequency band of 10 kHz to 10 MHz can sufficiently be attenuated.

Abstract: High-order partial response equalization is performed so that the equalization error of an input signal having non-linear distortions is minimized, thereby improving the characteristics of a reproduced signal.

Abstract: A common mode choke coil is realized in which countermeasures against leakage flux are taken so as to reduce adverse effects on an external apparatus. Coils 291, 292 are wound around a toroidal magnetic core 22 and sandwich a partition plate 27 provided within an inner circumference of the magnetic core so as to cancel out respective magnetic fluxes produced by the coils relative to a normal mode current. A belt-like magnetic shield plate 24 is provided in a direction along leakage fluxes from the coils and attached closely to a substantially U-shaped insulating protection plate 23 having side walls 25, 25 and the insulating protection plate 23 is then detachably attached to a base 21 with catches 26 provided at both ends of the plate 23.

Abstract: A mold for molding a drum shaped magnetic core having two flanges connected by a coil winding core portion. The mold includes a die defining a cylindrical cavity having an inner diameter substantially equal to an outer diameter of the flanges. A pair of die inserts are movable in an orthogonal direction relative to the cylindrical cavity and define a diameter of the coil winding core portion of the drum shaped magnetic core. The diameter of the coil winding core portion is smaller than the outer diameter of the flanges. An upper punch and a lower punch are inserted into the cylindrical cavity from a corresponding end opening of the mold such that each forms a flange. A central punch is disposed coaxially within one of the punches to form the coil winding core portion.