Electromagnetic record head transducer and system

Claim 2

An electromagnetic transducer head and system combination for recording low-frequency intelligence signals magnetically on a magnetic tape drawn across a surface of said head, said combination including: a magnetic core having a gap therein and defining the aforesaid surface across which the magnetic tape is drawn, and in which the gap extends across said surface and the tape is drawn across said gap from a leading edge to a trailing edge thereof; an electrically conductive nonmagnetic strip member mounted in the gap in said core and filling said gap, with an edge of said strip member extending to said surface across which the magnetic tape is drawn; an electric winding mounted on said core; a high-frequency oscillator coupled to said winding for introducing an alternating current bias signal to said winding of a frequency of the order of at least 1 megacycle to produce a bias magnetic flux across a recording zone at the trailing edge of said gap, said bias flux exhibiting a rapidly decaying characteristic at the trailing edge of said gap; and including a recording signal amplifier coupled to said winding for introducing intelligence signals to said winding, said intelligence signals having frequencies substantially below the frequency of said bias signal and producing signal fluxes in said gap which exhibit a substantially uniform characteristic across said recording zone; said recording signal amplifier including circuitry for emphasizing the amplitude of the high amplitude signals so as to compensate for magnetic saturation effects in the magnetic tape, said alternating current bias signal establishing eddy currents in said conductive strip due to transformer action between said magnetic core and said strip, and said strip acting as a shorted turn for such transformer action, said eddy currents producing an additional bias flux forcing said bias flux out of said gap and focusing the resulting composite bias flux into the region of the magnetic tape drawn across said gap.

Claim 3

An electromagnetic transducer head and system combination for recording low-frequency intelligence signals magnetically on a magnetic tape drawn across a surface of said head, said combination including: a magnetic core having a gap therein and defining the aforesaid surface across which the magnetic tape is drawn, and in which the gap extends across said surface and the tape is drawn across said gap from a leading edge to a tRailing edge thereof; an electrically conductive nonmagnetic strip member mounted in the gap in said core and filling said gap, with an edge of said strip member extending to said surface across which the magnetic tape is drawn; an electric winding mounted on said core; a high-frequency oscillator coupled to said winding for introducing an alternating current bias signal to said winding of a frequency of the order of at least one megacycle to produce a bias magnetic flux across a recording zone at the trailing edge of said gap, said bias flux exhibiting a rapidly decaying characteristic at the trailing edge of said gap; and including a recording signal amplifier coupled to said winding for introducing intelligence signals to said winding, said intelligence signals having frequencies substantially below the frequency of said bias signal and producing signal fluxes in said gap which exhibit a substantially uniform characteristic across said recording zone; said recording signal amplifier including a negative current feedback, and circuitry comprising unidirectional devices connected to shunt out said current feedback path for signal amplitudes above a predetermined amplitude threshold, said alternating current bias signal establishing eddy currents in said conductive strip due to transformer action between said magnetic core and said strip, and said strip acting as a shorted turn for such transformer action, said eddy currents producing an additional bias flux forcing said bias flux out of said gap and focusing the resulting composite bias flux into the region of the magnetic tape drawn across said gap.

Claim 4

An electromagnetic transducer head and system combination for recording low-frequency intelligence signals magnetically on a magnetic tape drawn across a surface of said head, said combination including: a magnetic core having a gap therein and defining the aforesaid surface across which the magnetic tape is drawn, and in which the gap extends across said surface and the tape is drawn across said gap from a leading edge to a tRailing edge thereof; an electrically conductive nonmagnetic strip member mounted in the gap in said core and filling said gap, with an edge of said strip member extending to said surface across which the magnetic tape is drawn; an electric winding mounted on said core; a high-frequency oscillator coupled to said winding for introducing an alternating current bias signal to said winding of a frequency of the order of at least one megacycle to produce a bias magnetic flux across a recording zone at the trailing edge of said gap, said bias flux exhibiting a rapidly decaying characteristic at the trailing edge of said gap; and including a recording signal amplifier coupled to said winding for introducing intelligence signals to said winding, said intelligence signals having frequencies substantially below the frequency of said bias signal and producing signal fluxes in said gap which exhibit a substantially uniform characteristic across said recording zone; said recording signal amplifier including a negative current feedback, and circuitry comprising unidirectional devices connected to shunt out said current feedback path for signal amplitudes above a predetermined amplitude threshold, said alternating current bias signal establishing eddy currents in said conductive strip due to transformer action between said magnetic core and said strip, and said strip acting as a shorted turn for such transformer action, said eddy currents producing an additional bias flux forcing said bias flux out of said gap and focusing the resulting composite bias flux into the region of the magnetic tape drawn across said gap.