Toner image transfer provided with a transfer paper separating device and guide

A toner image transfer for use in an image forming apparatus provided with a rotatable photosensitive member, the toner image transfer comprising:

• a transfer charging wire for transferring a toner image from the rotatable photosensitive member to transfer paper;
• a shield casing for shielding the transfer charging wire, the shield casing including a first wall extending in parallel with the transfer charging wire and a second wall extending in parallel with the first wall and positioned downstream of the first wall with respect to the rotation of the photosensitive member, the first and second walls respectively having free ends defining an opening facing the photosensitive member, an operative plane connecting the respective free ends of the first and second walls intersecting a first reference plane, said first reference plane being parallel to a second reference plane which is tangential to the circumference of the photosensitive member where a line extending between the center of the photosensitive member and the charging wire intersects the circumference of said photosensitive member, said operative plane intersecting said first reference plane at an acute angle, the shield casing being provided with a plurality of guide operative members over the opening, the guide operative members including a first group positioned on one side of an intermediate plane perpendicularly intersecting an intermediate portion of the transfer charging wire and a second group positioned on the other side of the intermediate plane;
• an interval on the free end of the second wall between a side end supporting guide operative member operable to support the side end of the transfer paper near the second wall and an inner adjacent guide operative member positioned inside of the transfer paper and adjacent to the side end supporting guide operative member is smaller than the intervals on the free end of the second wall between the other guide operative members, at least the side end supporting guide operative member being inclined with respect to the plane intersecting the transfer charging wire in such a way that a distance between a first point where the side end edge of the transfer paper and the free end of the second wall intersect each other and a second point where the side end edge of the transfer paper and the side end supporting guide operative member intersect each other does not exceed 10 mm.

A toner image transfer for use in an image forming apparatus provided with a rotatable photosensitive member, the toner image transfer comprising:

• a transfer charging wire for transferring a toner image from the rotatable photosensitive member to transfer paper;
• a shield casing for shielding the transfer charging wire, the shield casing including a first wall extending in parallel with the transfer charging wire and a second wall extending in parallel with the first wall and positioned downstream of the first wall with respect to the rotation of the photosensitive member, the first and second walls respectively having free ends defining an opening facing the photosensitive member, an operative plane connecting the respective free ends of the first and second walls intersecting a first reference plane, said first reference plane being parallel to a second reference plane which is tangential to the circumference of the photosensitive member where a line extending between the center of the photosensitive member and the charging wire intersects the circumference of said photosensitive member, said operative plane intersecting said first reference plane at an acute angle, the shield casing being provided with a plurality of guide operative members over the opening, the guide operative members including a first group positioned on one side of an intermediate plane perpendicularly intersecting an intermediate portion of the transfer charging wire and a second group positioned on the other side of the intermediate plane, an interval on the free end of the second wall between a side end supporting guide operative member operable to support the side end of the transfer paper near the second wall and an inner adjacent guide operative member positioned inside of the transfer paper and adjacent to the side end supporting guide operative member is smaller than the intervals on the free end of the second wall between the other guide operative members, at least the side end supporting guide operative member and the inner adjacent guide operative member are arranged in such a way that a distance between a first point where the side end edge of the transfer paper and the free end of the second wall intersect each other and a second point where the inner adjacent guide operative member and the free end of the second wall intersect each other does not exceed 10 mm.

A toner image transfer for use in an image forming apparatus provided with a rotatable photosensitive member, the toner image transfer comprising:

• a transfer charging wire for transferring a toner image from the rotatable photosensitive member to transfer paper;
• a shield casing for shielding the transfer charging wire, the shield casing including a first wall extending in parallel with the transfer charging wire and a second wall extending in parallel with the first wall and positioned downstream of the first wall with respect to the rotation of the photosensitive member, the first and second walls respectively having free ends defining an opening facing the photosensitive member, an operative plane connecting the respective free ends of the first and second walls intersecting a first reference plane, said first reference plane being parallel to a second reference plane which is tangential to the circumference of the photosensitive member where a line extending between the center of the photosensitive member and the charging wire intersects the circumference of said photosensitive member, said operative plane intersecting said first reference plane at an acute angle, the shield casing being provided with a plurality of guide operative members over the opening, the guide operative members including a first group positioned on one side of an intermediate plane perpendicularly intersecting an intermediate portion of the transfer charging wire and a second group positioned on the other side of the intermediate plane, an interval on the free end of the second wall between a side end supporting guide operative member operable to support the side end of the transfer paper near the second wall and an inner adjacent guide operative member positioned inside of the transfer paper and adjacent to the side end supporting guide operative member is smaller than the intervals on the free end of the second wall between the other guide operative members, at least the side end supporting guide operative member and the inner adjacent guide operative member are arranged in such a way that a total of:
• a first distance between a first point where the side end edge of the transfer paper and the free end of the second wall intersect each other and a second point wherein the side end edge of the transfer paper and the side end supporting guide operative member intersect each other, and
• a second distance between the first point and a third point where the inner adjacent guide operative member and the free end of the second wall intersect each other;
• does not exceed 30 mm.

A toner image transfer apparatus for use in an image forming arrangement provided with a rotatable photosensitive member and wherein the toner image transfer apparatus is operable to transfer a toner image to transfer paper of different widths, the toner image transfer apparatus comprising:

• a transfer charging wire for transferring a toner image from the rotatable photosensitive member to said transfer paper;
• a shield casing for shielding the transfer charging wire, the shield casing having a first wall extending parallel with the transfer charging wire and a second wall extending parallel with the first wall and positioned downstream of the first wall with respect to the rotation of the photosensitive member, the first and second walls respectively having free ends defining an opening facing the photosensitive member;
• a plurality of spaced guide operative members disposed over the opening, said guide operative members having a plurality of first areas and a plurality of second areas respectively, said guide operative members in each of said plurality of first areas being more closely spaced from one another than the spacing of said guide operative members in each of said second areas, said plurality of first areas being spaced from one another according to the width of the transfer sheet to which the toner image is transferred such that each of said guide operative members in said first areas are operable to guide said transfer paper as said transfer paper passes over said opening in said casing.