Sony Corporation

Kyoko Suzuki

Shunji Yoshimura

Tadashi Ozue

Motoi Kimura

Yuji Kumai

In a helical scanning type magnetic recording and/or reproducing apparatus for selecting one of output signals of two reproducing heads that are disposed at positions different by of 180&#xb0; and transferring the selected output signal with a rotary transformer of one channel, a rotor side winding of a reproducing signal channel of a rotary transformer is divided into two portions. The divided portions are connected at two positions that are opposite to output terminals of head amplifiers that amplify output signals of reproducing heads and that have self short-circuit switches. Without use of extra wirings, the head amplifiers are directly connected to the rotary transformer. An output signal of the reproducing head is selected by short-circuiting a self short-circuit switch of a head amplifier corresponding to a head that does not reproduce a signal.

Rotary head drum apparatus including a rotary drum having a head and a switch for selecting the head and magnetic recording and/or reproducing apparatus using the same

The invention provides a signal transmission apparatus using a rotary transformer by which a wide bandwidth and a high transfer rate can be used without a significant increase of the cost. The signal transmission apparatus includes a transmission side circuit and a reception side circuit between which a rotary transformer is interposed. A passive element circuit including an inductance element is connected to an output stage of the rotary transformer in parallel to the transformer. The passive element circuit has an inductance value set substantially equal to or lower than an equivalent inductance value when the circuit of the rotary transformer side is viewed from the reception side circuit.

Signal transmission apparatus and signal reproduction apparatus using a rotary transformer

The invention provides a signal transmission apparatus and a signal recording apparatus by which, while a rotary transformer is used, a wide bandwidth and a high transfer rate can be used without a significant increase of the cost or a bad influence on signal recording. A rotary transformer is interposed between a transmission side circuit and a reception side circuit. A passive element circuit including an inductance element is connected to an input stage, that is, the stator side, of the rotary transformer in parallel to the rotary transformer. The passive element circuit has an inductance value set equal to or lower than an equivalent inductance value when the circuit of the rotary transformer side is viewed from the transmission side circuit to achieve impedance matching.

Signal transmission apparatus and signal recording apparatus in which a rotary transformer is used

An information recording and reproducing apparatus comprises an optical device for causing a light beam to impinge upon a disc having a spiral guide groove along which a control signal is substantially recorded for scanning the spiral guide groove; a light beam modulating portion operative to intensity-modulate the light beam incident upon the disc in response to an information signal so that the information signal is intermittently recorded on the disc and operative further to cause the light beam to keep a relatively small intensity during a period in which the recording of the information signal is temporarily interrupted; a photo-detecting portion for detecting the light beam coming from the disc; a read signal processing portion operative to obtain, based on a detection output from the photo-detecting portion, a read output signal containing a read output of the control signal and a total amount signal corresponding to momentary total light amount of the light beam received by the photo-detecting portion; a variable gain control portion operative to perform a gain-control to the read output signal in response to the total amount signal when the light beam coming from the disc is detected by the photo-detecting portion; and a signal reproducing portion for obtaining a reproduced output of the control signal on the strength of the read output signal having been subjected to the gain-control performed by the variable gain control portion.

Information recording and reproducing apparatus using light beam

A processing circuit for an optical reproduction signal provided with a signal generating unit for dividing an optical reproduction signal output from a photo detector and including a plurality of signal components into a plurality of signals having frequency regions corresponding to the respective plurality of signal components and performing current/voltage conversion on the divided optical reproduction signals and a correcting unit for adding the results of the current/voltage conversion of the signal components to correct the results of the current/voltage conversion.

Growing community of inventors

Kanagawa, Japan

Kyoko Suzuki