Claims
- 1. A method to provide improved stripping of a transfer member from a photoconductive surface after transfer of a developed latent electrostatic image to the transfer member via transfer effecting means comprising the steps of:
- charging the lead edge of the transfer member with an AC corona emission means having a high DC bias of opposite polarity from that of the transfer effecting means, and
- charging the body of the transfer member with said AC corona emission means having a DC bias which is different from the high D.C. bias but of sufficient magnitude and polarity to prevent retransfer of the developed image to the photoconductive surface and to minimize the charge on the transfer member to prevent electron discharge from the transfer member to machine elements in contact therewith after stripping the member from the photoconductive surface.
- 2. A method to provide improved stripping of a transfer member from a photoconductive surface after transfer of a developed electrostatic image to the transfer member via transfer effecting means comprising the steps of:
- charging the lead edge of the transfer member with an AC corona emission means having a first DC bias of opposite polarity from that of the transfer effecting means, and
- charging the body of the transfer member with said AC corona emission means having a second DC bias of opposite polarity from that of the transfer effecting means, but which is of a different magnitude from said first DC bias.
- 3. A method to provide improved stripping of a transfer member from a photoconductive surface after transfer of a developed electrostatic image to the transfer member via transfer effecting means comprising the steps of:
- charging the lead edge of the transfer member with an AC corona emission means having a first DC bias of opposite polarity from that of the transfer effecting means, and
- charging the body of the transfer member with said AC corona emission means having a second DC bias of the same polarity as that of the transfer effecting means.
- 4. A method to provide improved stripping of a transfer member from a photoconductive surface after transfer of a developed latent electrostatic image to the transfer member comprising the steps of:
- a. charging the lead edge of the transfer member to provide a charge of a first magnitude on the edge, and then
- b. charging the image bearing portion of the transfer member without altering the charge on the lead edge to provide a charge of a second magnitude on the portion which is different from said first magnitude.
- 5. A method to provide improved stripping of a transfer member from a photoconductive surface after transfer of a developed latent electrostatic image to the transfer member comprising the steps of:
- a. charging the lead edge of the transfer member to provide a first charge on the edge, and then
- b. charging the image bearing portion of the transfer member without altering the charge on the lead edge to provide a second charge on the portion which is different from the first charge.
- 6. A method to provide improved stripping of a transfer member from a photoconductive surface after transfer of a developed latent electrostatic image to the transfer member via transfer effecting means comprising the steps of:
- charging the lead edge of the transfer member with a first DC biased AC corona emission, the DC bias being of opposite polarity from that of the transfer effecting means, and
- charging the image bearing portion of the transfer member without altering the charge on the lead edge with a second DC biased AC corona emission which is different from the first emission, but which is of a magnitude and polarity to prevent retransfer of the developed image to the photoconductive surface and to minimize the charge on the transfer member to prevent electron discharge from the transfer member to machine elements after stripping the member from the photoconductive surface.
- 7. In an electrostatic reproduction machine having a photoconductive surface and means for forming a powder image thereon in conformity with the image on a document to be reproduced and thereafter transferring the powder image via transfer effecting means to the surface of suitable support material electrostatically tacked to the photoconductive surface, means for removing the support material from the photoconductive surface comprising:
- a corona discharge device continuously supplied with high voltage alternating current for treating said support material after transfer of the powder image thereto;
- a first source of DC voltage for biasing said corona discharge device to provide a first charge from the corona discharge device to the lead edge of the support material which is of opposite polarity from that of the transfer effecting means;
- a second source of DC voltage for biasing said corona discharge device to provide a second charge from the corona discharge device to the body of the transfer member, and
- switch means adapted to connect said first source of DC voltage to said corona discharge device for treating the lead edge of the support material and for connecting said second source of DC voltage to said corona discharge device for treating the body of the support material.
- 8. In an electrostatic reproduction machine having a photoconductive surface adapted to be charged, exposed, and to carry an electrostatic latent image thereon, and developing means positioned at a development zone to develop the electrostatic image on said surface, the developed image being adapted for transfer via transfer effecting means to a suitable receiving member electrostatically tacked to said surface for transfer of the developed image thereto, the combination comprising:
- a corona discharge device continuously supplied with high voltage alternating current to product ion emissions therefrom;
- a first source of DC voltage for appropriately biasing said corona discharge device to provide a first charge on the leading edge of the receiving member which reduces the electrostatic force holding the lead edge of the receiving member on said surface, and
- a second source of DC voltage for biasing said discharge device to provide a second charge on the body of the receiving member which is different from said first charge but which prevents retransfer of the transferred developed image from the receiving member to the photoconductive surface.
- 9. In an electrostatic reproduction machine having a moving photoconductive surface adapted to be charged, exposed, and to carry an electrostatic latent image thereon, and developing means positioned at a development zone to develop the moving electrostatic image on said surface, the developed image being adapted for transfer via transfer effecting means to a suitable receiving member electrostatically tacked to said surface for transfer of the developed image thereto, the transfer member having an inherent beam strength which tends to lift the transfer member off of a curved portion of the photoconductive surface, the combination comprising:
- a first source of DC voltage of opposite polarity from that of the transfer effecting means for biasing said discharge device to provide a charge on the leading edge of the receiving member so that the electrostatic force holding the lead edge on said surface is less than the lifting force on the lead edge caused by the inherent beam strength of the receiving member; and
- a second source of DC voltage for biasing said discharge device to provide a charge on the body of the receiving member which is different from the charge provided by the first source on the lead edge but which prevents retransfer of the transferred developed image from the receiving member to the photoconductive surface.
Parent Case Info
This is a continuation of U.S. Application Ser. No. 335,967, filed Feb. 26, 1973 and now abandoned.
US Referenced Citations (9)
Continuations (1)
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Number |
Date |
Country |
Parent |
335967 |
Feb 1973 |
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