Converting images recorded on a moving magnetic medium to stationary images

Claim 2

Apparatus for converting primary images recorded on a magnetic recording medium to fixed secondary images comprising: a receptor surface having magnetic properties including a coercivity lower than that of said recording medium and greater than the maximum magnetic field of said primary images, said receptor surface being positioned adjacent said recording medium so that the local surface magnetic field of each primary image is applied to said receptor surface, means for moving said recording medium relative to said receptor surface, biasing means for intermittently applying bursts of magnetic field to said receptor surface to transfer said primary image to said receptor surface, and triggering means for triggering said biasing means to produce said bursts when said primary images are in the desired position relative to said receptor surface.

Claim 3

The apparatus recited in claim 1 wherein said recording medium is between said biasing means and said receptor surface so that said bursts of magnetic field are applied to said recording medium as well as to said receptor surface.

Claim 4

Magneto-optic apparatus for converting primary images recorded on a moving magnetic recording medium to secondary images each of which may be converted to an image, comprising: a receptor surface having magnetic properties including a coercivity lower than that of said recording medium, said receptor surface being positioned adjacent said recording medium so that the local surface magnetic field of each primary image is applied to said receptor surface, means for moving said recording medium relative to said receptor surface, a source of light which is incident on said receptor surface, means for detecting images formed by light reflected from said rEceptor surface and modulated by the magneto-optic effect of said receptor surface on said light, biasing means for intermittently applying bursts of magnetic field to said receptor surface to transfer said primary image to said receptor surface, and triggering means for triggering said biasing means to produce said bursts when said primary images are in the desired position relative to said receptor surface.

Claim 5

Magneto-optic apparatus for converting primary images recorded on a moving magnetic recording medium to secondary images each of which may be converted to an image, comprising: a receptor surface having magnetic properties including a coercivity lower than that of said recording medium, said receptor surface being positioned adjacent said recording medium so that the local surface magnetic field of each primary image is applied to said receptor surface, means for moving said recording medium relative to said receptor surface, a source of light which is incident on said receptor surface, means for detecting images formed by light reflected from said rEceptor surface and modulated by the magneto-optic effect of said receptor surface on said light, biasing means for intermittently applying bursts of magnetic field to said receptor surface to transfer said primary image to said receptor surface, and triggering means for triggering said biasing means to produce said bursts when said primary images are in the desired position relative to said receptor surface.

Claim 6

The apparatus recited in claim 3 wherein triggering signals are recorded on said magnetic medium to identify the location of each primary image on said magnetic medium, further including: a magnetic reproducing head positioned adjacent said magnetic medium to detect said triggering signals, said triggering means being responsive to said triggering signals for triggering said biasing means.

Claim 7

The apparatus recited in claim 3 wherein said magnetic recording medium is a magnetic tape which is moved across said receptor surface and wherein said biasing means includes: an electrical coil wound upon a form of nonmagnetic material, said form having a plane surface which is positioned to urge the coating of said tape into intimate magnetic coupling with said receptor surface.

Claim 8

The apparatus recited in claim 3 wherein said magnetic recording medium is a magnetic tape which is moved across said receptor surface and wherein said biasing means includes: an electrical coil positioned to apply a magnetic field to said receptor surface.

Claim 9

The apparatus recited in claim 3 wherein said local surface magnetic field of each primary image has an amplitude below the level which will affect the magnetization of said receptor surface in the absence of an assisting field.

Claim 10

The apparatus recited in claim 3 wherein said means for detecting images includes: an image detector of the type having means for scanning said images formed by said light reflected from said receptor surface, and wherein the repetition rate of said scanning is asynchronous with the production of said bursts of magnetic field.

Claim 11

The apparatus recited in claim 3 wherein said biasing means is so disposed and has a size such that all portions of said primary image are simultaneously transferred to said receptor surface to form a secondary image in congruence with the local surface magnetic field in corresponding areas of said primary image.

Claim 12

The apparatus recited in claim 3 wherein said biasing means for intermittently applying bursts of magnetic field produces a burst of magnetic field having a time duration less than 1 millisecond so that flicker is not detectable by visual observation.

Claim 13

The apparatus recited in claim 3 wherein said means for moving the recording medium and said biasing means are activated so as to yield a framing rate less than 24 frames per second but greater than eight frames to render motion smoothly.

Claim 14

The apparatus recited in claim 3 wherein each primary image is recorded on said magnetic medium by modulation of the magnetization of said medium, which magnetization is in a direction parallel to the direction of movement of said medium relative to said receptor surface and wherein said receptor surface is positioned such that its axis of easy magnetization is parallel to said movement.

Claim 15

The apparatus recited in claim 12 wherein said biasing means includes: a coil positioned to apply said bursts of magnetic field to said receptor surface in a direction which is parallel to said movement, and means connected to said coil for producing said bursts so that each is an oscillating magnetic field which has a field strength which is gradually reduced from a maximum level substantially producing magnetic saturation of said receptor surface to a minimum level which is below the coercivity of the receptor surface to produce anhysteretic remanent magnetization of said receptor surface which is a function of the local surface magnetic field of each primary image.

Claim 16

The apparatus recited in claIm 12 wherein said biasing means further includes: a coil positioned to apply said bursts of magnetic field to said receptor surface in a direction which is parallel to said movement, and means connected to said coil for producing said bursts so that each burst is a unidirectional field having an initial polarity and an initial amplitude greater than the coercivity of said receptor surface to erase the previously transferred secondary image, said unidirectional field being switched to the opposite polarity with an amplitude less than the coercivity of said receptor surface to produce remanent magnetization of said receptor surface which is a function of the local surface magnetic field of each primary image.

Claim 17

The apparatus recited in claim 12 wherein said biasing means includes: a coil positioned to apply said bursts of magnetic field to said receptor surface in a direction which is transverse to said movement, and means connected to said coil for producing said bursts so that each is an oscillating magnetic field which has a field strength which is gradually reduced from a maximum level substantially producing transverse magnetic saturation of said receptor surface to a minimum level which is substantially below the anisotropy field of the receptor surface to produce remanent magnetization of said receptor surface which is a function of the local surface which is a function of the local surface magnetic field of each primary image.

Claim 18

The apparatus recited in claim 12 wherein said biasing means further includes: a coil positioned to apply said bursts of magnetic field to said receptor surface in a direction transverse to said movement, and means connected to said coil for producing said bursts so that each burst is in a unidirectional field having a peak amplitude substantially greater than the anisotropy field of said receptor surface to produce remanent magnetization of said receptor surface which is a function of the local surface magnetic field of each primary image.

Claim 19

The apparatus recited in claim 3 wherein each primary image is recorded on said magnetic medium by modulation of the magnetization of said medium in the plane of said medium but where magnetization of said medium is transverse to the direction of movement of said medium relative to said receptor surface and wherein said receptor surface is positioned such that its axis of easy magnetization is transverse to said direction of movement.

Claim 20

The apparatus recited in claim 17 wherein said biasing means further includes: a coil positioned to apply said bursts of magnetic field to said receptor surface parallel to the easy direction of magnetization of said receptor surface, and means connected to said coil for producing said bursts so that each is an oscillating magnetic field which has a field strength which is gradually reduced from a maximum level substantially producing magnetic saturation of said receptor surface to a minimum level which is below the coercivity of the receptor surface to produce anhysteretic remanent magnetization of said receptor surface which is a function of the local surface magnetic field of each primary image.

Claim 21

The apparatus recited in claim 17 wherein said biasing means further includes: a coil positioned to apply said bursts of magnetic field to said receptor surface parallel to the easy direction of magnetization of said receptor surface, and means connected to said coil for producing said bursts so that each burst is a unidirectional field having an initial polarity and an initial amplitude greater than the coercivity of said receptor surface to erase the previously transferred secondary image, said unidirectional field being switched to the opposite polarity with an amplitude less than the coercivity of said receptor surface to produce remanent magnetization of said receptor surface which is a function of the local surface magnetic field of each primary image.

Claim 22

The apparatus recited in claim 17 wherein said biasing means further includes: a coil positioned to apply said bursts of magnetic field to said receptor surface parallel to said direction of movement, and means connected to said coil for producing said bursts so that each is an oscillating magnetic field which has a field strength which is gradually reduced from a maximum level substantially producing transverse magnetic saturation of said receptor surface to a minimum level which is substantially below the anisotropy field of the receptor surface to produce remanent magnetization of said receptor surface which is a function of the local surface magnetic field of each primary image.

Claim 23

The apparatus recited in claim 17 wherein said biasing means further includes: a coil positioned to apply said bursts of magnetic field to said receptor surface in a direction parallel to said movement, and means connected to said coil for producing said bursts so that each burst is a unidirectional field having a peak amplitude substantially greater than the anisotropy field of said receptor surface to produce remanent magnetization of said receptor surface which is a function of the local surface magnetic field of each primary image.

Claim 26

The method recited in claim 22 further including: applying light to said receptor surface, detecting images formed by light reflected from said receptor surface and modulated by the magneto-optic effect of said receptor surface on said light.

Claim 27

The method recited in claim 22 further comprising: applying said bursts of magnetic field to said recording medium and to said receptor surface.

Claim 28

The apparatus recited in claim 22 further comprising: means for applying said bursts of magnetic field to said recording medium and to said receptor surface.

Claim 29

Apparatus for converting primary images recorded on a magnetic recording medium to secondary images, each of which may be converted to an image comprising: a receptor surface having a coercivity greater than the maximum field of said primary images positioned adjacent said recording medium, means for moving said recording medium relative to said receptor surface so that the local surface magnetic field of each primary image is applied to said receptor surface, and means for intermittently applying bursts of magnetic field to said receptor surface when said primary images are in the desired position relative to said receptor surface so that primary images on said recording medium are converted to secondary images in said receptor surface.

Claim 30

Apparatus for converting primary images recorded on a magnetic recording medium to secondary images, each of which may be converted to an image comprising: a receptor surface having a coercivity greater than the maximum field of said primary images positioned adjacent said recording medium, means for moving said recording medium relative to said receptor surface so that the local surface magnetic field of each primary image is applied to said receptor surface, and means for intermittently applying bursts of magnetic field to said receptor surface when said primary images are in the desired position relative to said receptor surface so that primary images on said recording medium are converted to secondary images in said receptor surface.

Claim 31

The apparatus recited in claim 26 further including: means for applying light to said receptor surface, means for detecting images formed by light reflected from said receptor surface and modulated by the magneto-optic effect of said receptor surface on said light.