DE976728C - Carrier for magnetograms - Google Patents

Description

(WiGBI. P. 175)

ISSUED MARCH 26, 1964

K 1607 IXa / 42 g

The invention relates to a carrier for magnetograms, in which a perpendicular to its surface or middle surface and transversely to the sound recording web laid cross-section the profile of a Saw or double saw with congruent magnetizable teeth.

The previously known magnetographic sound carrier with separate guide grooves next to the Recording surfaces or with guide dams have the disadvantage that the previously common Shapes of the tone grooves results in a relatively small magnetically usable area. this will particularly noticeable on records, cones or rollers as well as on endless ribbons with grooves, where the sound carrier cannot be chosen arbitrarily large for practical reasons or should.

Furthermore, one has sound carriers with sawtooth-shaped cross-sectional profiles at right angles to the sound track made in which the saw teeth are in the shape of isosceles triangles, both of which Flanks are magnetizable. This improves the utilization of the magnetogram carrier surface. However, the two tooth flanks of adjacent tone grooves are so close to each other that a Crosstalk from one groove to the other cannot be avoided.

All other things being equal, the width of the tone grooves can be found in the latter Carriers with magnetizable sawtooth profiles

409 542/7

reduce if, according to the invention, both flanks of the teeth are of different lengths.

As a result, compared to the known isosceles tooth flanks, the surface of which at certain In contrast, tooth height and width have a minimum value, the magnetizable surface enlarged.

The enlargement of the magnetizable area can be used once to reduce crosstalk to decrease even further. This is also helped by the magnetizable shorter flank, which is called magnetic screen between the adjacent parts of two adjacent longer ones Flanks. Furthermore, if the crosstalk is sufficiently small, the magnification can be increased Use the magnetizable surface to reduce the width of the saw teeth and thus to accommodate a larger number of tone grooves in a given space.

The magnetogram carrier according to the invention brings compared to the isosceles sawtooth profile the further advantage that jamming in the case of clay tracks lying spirally in one plane are not possible. As is well known, the radii of curvature of such clay tracks decrease from the outside inside. The scanning element of a magnetic head located in an isosceles sawtooth profile must therefore be located in the sound path each time a magnetogram carrier is run through Longitudinal extension either adapt to the different radii of curvature, which is a premature Wear of both the scanning element and the magnetogram carrier result, or that Sensing organ is lifted out of the lower part of the sound path at almost all points, whereby the effect is impaired.

The unequal length of the tooth flanks magnetized on both flanks, however, makes it possible with any radius of curvature of the sound tracks the concern of the scanning element on the narrow one Flank of the tooth profile with always equally good contact on the longer flank. The sawtooth profile is open to one side for the corresponding audio head sliding therein, so that unavoidable Do not disturb inaccuracies in the groove profile. The head can be the full length of the long, sloping slope Cover the profile, as it can occasionally protrude on the free side. It makes sense that a much better utilization of the sound carrier is given.

The figures characterize the principle of the invention without claim to scale accuracy, because you can choose different angles and proportions. In particular, the Place sharp rounded edges.

Fig. Ι shows in a cross section at right angles to the sound path, a sound carrier with a one-sided Toothed and seated scanning element, which is designed as a beveled pole piece or double pole piece can be, the steep flank being open to the right.

Fig. 2 shows in the same cross section a double-sided recordable magnetogram carrier with a double saw profile, with the teeth offset from one another on both sides to achieve the To prevent crosstalk through the carrier as possible. The steep flank is behind left open.

In the figures, 1 denotes the sound carrier, 2 the shorter and 3 the longer flank of the sawtooth profile, 4 the overlying pole piece.

The sound head 4 can be designed so that it does not or only the steep flank of the groove lowest part magnetized. This can be due to its shape or a cladding of the adjacent head side be effected by using magnetic isolation. Furthermore, that of the profile surface 2 facing side of the pole piece, useful slightly rounded, for tonearms conventional design, which pivot about a pivot point, the contact with the groove wall 2 to facilitate or secure and at the same time the changing radii of curvature of the grooves of Compensate for spiral tracks on records.

Claims (1)

PATENT CLAIM: Carrier for magnetograms, in which a cross-section at right angles to its surface or central surface and transversely to the sound recording path has the profile of a saw or double saw with congruent magnetizable teeth, characterized in that both flanks (2, 3) of the teeth are of different lengths. Considered publications:
German Patent Nos. 144 178, 225036; British Patent No. 512,766;
U.S. Patent Nos. 907,383, 1,609,540. 1 sheet of drawings © 409 542/7 3.64