Abstract Magnetic brush developing apparatus for developing a latent image on a moving insulating layer with magnetic developer, the apparatus comprising first magnetic means having a longitudinal axis extending substantially parallel to the moving, latent image bearing layer and substantially transverse to the direction of movement thereof, the first magnetic means having only one plane of polarization which is directed substantially transverse both to the longitudinal axis and the moving, latent image bearing layer to produce a first magnetic field at the layer, means for moving the magnetic developer through the first magnetic field to initiate development of the latent image, second magnetic means having a longitudinal axis extending substantially parallel to the moving, latent image bearing layer and substantially transverse to the direction of movement thereof, the second magnetic means being subsequent to the first magnetic means along the direction of movement of the image bearing layer and being polarized at a plurality of predetermined angles about the longitudinal axis where, at each angle, the second magnetic means is polarized in a direction substantiallly transverse to the longitudinal axis to thereby produce a plurality of magnetic fields at the layer, means for transferring the magnetic developer from the first magnetic field produced by the first magnetic means to the plurality of magnetic fields produced by the second magnetic means to continue and complete the development of the latent image, the second magnetic means compensating the tendency of the rectangular magnet to underdevelop the latent image portions adjacent the end portions of the first magnetic means and the first magnetic means compensating the tendency of the second magnetic means to nonuniformly develop the latent image.
Magnetic brush developing apparatus for developing a latent image on a moving insulating layer with magnetic developer, said apparatus comprising a rectangular magnet having a longitudinal axis extending substantially parallel to said moving, latent image bearing layer and substantially transverse to the direction of movement thereof, said rectangular magnet having only one plane of polarization which is directed substantially transverse both to said longitudinal axis and said moving, latent image bearing layer to produce a first magnetic field at said layer; means for moving said magnetic developer through said first magnetic field to initiate development of said latent image; at least one cylindrical magnet having a longitudinal axis extending substantially parallel to said moving, latent image bearing layer and substantially transverse to the direction of movement thereof, said cylindrical magnet being subsequent to said rectangular magnet along the direction of movement of said image bearing layer and being polarized at a plurality of predetermined angles about said longitudinal axis where, at each angle, said cylindrical magnet is polarized in a direction substantially transverse to said longitudinal axis to thereby produce a plurality of magnetic fields at said layer; means for transferring said magnetic developer from said first magnetic field produced by said rectangular magnet to said plurality of magnetic fields produced by said cylindrical magnet to continue and complete the development of said latent image; said cylindrical magnet compensating the tendency of said rectangular magnet to underdevelop the latent image portions adjacent the end portions of the rectangular magnet and said rectangular magnet compensating the tendency of said cylindrical magnet to nonuniformly develop the latent image.
Claim 2
Dependent Claim
266 words
Magnetic brush developing apparatus for developing a latent image on a moving insulating layer with magnetic developer, said apparatus comprising a rectangular magnet having a longitudinal axis extending substantially parallel to said moving, latent image bearing layer and substantially transverse to the direction of movement thereof, said rectangular magnet having only one plane of polarization which is directed substantially transverse both to said longitudinal axis and said moving, latent image bearing layer to produce a first magnetic field at said layer; means for moving said magnetic developer through said first magnetic field to initiate development of said latent image; at least one cylindrical magnet having a longitudinal axis extending substantially parallel to said moving, latent image bearing layer and substantially transverse to the direction of movement thereof, said cylindrical magnet being subsequent to said rectangular magnet along the direction of movement of said image bearing layer and being polarized at a plurality of predetermined angles about said longitudinal axis where, at each angle, said cylindrical magnet is polarized in a direction substantially transverse to said longitudinal axis to thereby produce a plurality of magnetic fields at said layer; means for transferring said magnetic developer from said first magnetic field produced by said rectangular magnet to said plurality of magnetic fields produced by said cylindrical magnet to continue and complete the development of said latent image; said cylindrical magnet compensating the tendency of said rectangular magnet to underdevelop the latent image portions adjacent the end portions of the rectangular magnet and said rectangular magnet compensating the tendency of said cylindrical magnet to nonuniformly develop the latent image.
Claim 3
Dependent Claim
27 words
Apparatus as in claim 1 where both said moving means and said transferring means comprise rotatable, hollow cylinders concentric with said first and second magnetic means respectively.