Recording mechanically reproducible high frequency signals on recording carriers

Claim 3

A method as defined in claim 1 wherein the beam is of the laser type.

Claim 4

A method as defined in claim 1 wherein the beam is an electron beam.

Claim 5

A method as defined in claim 1 wherein said carrier material is photosensitive and comprising the further steps of producing a photographic copy of the recorded surface and removing portions of the copy surface corresponding to those carrier surface portions struck by the beam.

Claim 6

A method as defined in claim 1, wherein said step of additionally modulating the intensity of the beam at a frequency which is double the deflecting frequency is carried out so as to cause the beam intensity to be greatest at the center of the recording track and least at the edges thereof thereby to cause the resulting recording track to be in the form of a groove which slopes downwardly from its edges to its center.

Claim 7

A method as defined in claim 1 wherein the carrier material is a plastic.

Claim 8

A method as defined in claim 1 wherein the carrier is initially transparent and is of a material which becomes modified by being darkened in response to the particular type of beam.

Claim 9

A method as defined in claim 7 comprising the further step of producing a negative copy of the recorded carrier.

Claim 10

A method as defined in claim 8 wherein said step of producing is carried out by directing ultraviolet light through the recorded carrier onto a copy blank at least one surface of which is a material which is polymerized to become insoluble by exposure to such light.

Claim 11

Apparatus for producing a mechanically reproducible recording of a high frequency signal along a recording track on one surface of a recording carrier, which surface is of a material capable of being modified in a detectable manner as a result of being struck by a beam of a particular type, the degree of modification at each point on such surface being a function of the beam intensity at that point, said apparatus comprising, in combination: means for producing a beam of such partiCular type and for directing said beam against such carrier surface while causing said beam to have, at such surface, an area not essentially larger than the width of the recording track and a dimension in the longitudinal direction of the track smaller than the track width; means for supporting the carrier so that such surface is struck by the beam and for moving the surface relative to the beam for causing the beam to trace the recording track on the surface; deflection means disposed for cyclically deflecting the beam transverse to the direction of movement of the surface relative to the beam at a frequency which is a multiple of the frequency of the signal to be recorded; and intensity modulating means operatively associated with the beam for modulating the intensity of the beam with the signal to be recorded and with a signal at a frequency which is double the deflection frequency and which has a phase such that the beam intensity varies between maximum and minimum extreme values and has one of its extreme values along the center of the track and the other of its extreme values at the edges thereof.

Claim 12

Apparatus for producing a mechanically reproducible recording of a high frequency signal along a recording track on one surface of a recording carrier, which surface is of a material capable of being modified in a detectable manner as a result of being struck by a beam of a particular type, the degree of modification at each point on such surface being a function of the beam intensity at that point, said apparatus comprising, in combination: means for producing a beam of such partiCular type and for directing said beam against such carrier surface while causing said beam to have, at such surface, an area not essentially larger than the width of the recording track and a dimension in the longitudinal direction of the track smaller than the track width; means for supporting the carrier so that such surface is struck by the beam and for moving the surface relative to the beam for causing the beam to trace the recording track on the surface; deflection means disposed for cyclically deflecting the beam transverse to the direction of movement of the surface relative to the beam at a frequency which is a multiple of the frequency of the signal to be recorded; and intensity modulating means operatively associated with the beam for modulating the intensity of the beam with the signal to be recorded and with a signal at a frequency which is double the deflection frequency and which has a phase such that the beam intensity varies between maximum and minimum extreme values and has one of its extreme values along the center of the track and the other of its extreme values at the edges thereof.