| 摘要 |
<p>787,444. Electric recording and reproducing apparatus. WESTERN ELECTRIC CO., Inc. Dec. 28, 1955 [Dec. 31, 1954], No. 37106/55. Class 40 (2). A signal recording system for recording sound and video signals up to twenty megacycles comprises a record member having a layer of ferro-electric crystalline material, such as barium titanate, of the order of twenty-five microns thick superposed on a conducting substrate 2 such as platinum or palladium, a recording device comprising electrical contacting means 25 disposed adjacent to the surface of said record member for applying a signal voltage thereto, and means for applying a biasing potential between said recording device and said record member. The embodiment described shows a record member, Fig. 2, in which the ferro-electric material 1 and substrate 2 is mounted on a conducting base member 3, such as copper, which may be in the form of a cylinder 11, Fig. 3a. Electric signal potentials having a D.C. biasing potential added thereto are applied to the cylinder 11 by means of a spring-loaded ball-shaped contact member 25 mounted in a plastic housing 21 traversing the cylinder 11 by means of a leadscrew 22. The signals may be reproduced by applying a voltage from a carrier-wave source 50, Fig. 6, to the record member and rectifying the resulting modulated voltage developed across a series resistance 56. The Specification gives an account of the theory by which ferro-electric may be used as a record medium and shows its analogy, by means of curves comparable to hysteresis curves, Figs. 5 and 7 (not shown), to electro-magnetic material. Specification 717,104, [Group XIX], and U.S.A, Specification 2,582,993, are referred to.</p> |
