Translating nip registration device

• US 5,219,159 A
• Filed: 06/01/1992
• Issued: 06/15/1993
• Est. Priority Date: 06/01/1992
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Malachowski, Michael A., Kluger, Jacob N.
• Primary Examiner(s): Bollinger, David H.
• Application Number:
  US07/891,106
• Time in Patent Office: 379 Days
• Field of Search: 271/228, 271/227, 271/236, 271/242, 271/252, 271/253, 271/255
• US Class Current: 271/228
• CPC Class Codes: B65H 2220/01 indicating an entity as a function of which control, adjustment or change is performed, i.e. input
• CPC Class Codes: B65H 2301/331 Skewing, correcting skew, i.e. changing slightly orientation of material
• CPC Class Codes: B65H 2404/1424 moving in parallel to their axis
• CPC Class Codes: B65H 2404/161 Means for driving a roller parallely to its axis of rotation, e.g. during its rotation
• CPC Class Codes: B65H 2511/514 Particular portion of element
• CPC Class Codes: B65H 9/002 changing orientation of sheet by only controlling movement of the forwarding means, i.e. without the use of stop or register wall
• CPC Class Codes: B65H 9/16 Inclined tape, roller, or like article-forwarding side registers

Abstract

An apparatus to bilaterally register and deskew sheets in an electrophotographic printing machine by driving the sheet against a pair of stalled drive rolls and then activating the drive rolls when the sheet is deskewed. The drive rolls are then laterally translated while the sheet is within the nips of the drive rolls. The proper side registration position of the sheet is sensed and stored and the sheet is brought to that proper registration position. Once the sheet has passed through the drive rolls, the rolls return to the center of the paper path to receive subsequent sheets. A stepper motor is used to translate the roll pairs in a lateral direction and the pulse counts are utilized to store the side registration and sheet acquisition positions thereby eliminating the need for a home position sensor or switch.

Claims

1. An apparatus for advancing a sheet in a primary sheet feeding direction and for deskewing and side registering the sheet, comprising:

means, located in a home position, for advancing the sheet in the primary sheet feeding direction, deskewing the sheet and translating the sheet in a direction substantially transverse to the primary sheet feeding direction;

means for sensing the sheet, said advancing and translating means moving in unison with the deskewed sheet in a direction substantially transverse to the primary sheet feeding direction from the home position to a side registration postion, said sensing means detecting the sheet in the side registration position; and

means for storing the registration position.

2. The apparatus according to claim 1, wherein said advancing means returns to the home position from the side registration position in response to said sensing means detecting the sheet.

3. The apparatus according to claim 2, wherein said advancing means comprises:

a roll pair defining a drive nip; and

means for translating said roll pair in a direction substantially parallel to the axis of rotation of a roll of said roll pair.

4. The apparatus according to claim 3, wherein said translating means moves said roll pair in response to a signal from said sensing means.

5. The apparatus according to claim 4, wherein said translating means comprises a stepper motor.

6. An apparatus according to claim 1, wherein said sensing means comprises an optical sensor.

7. The apparatus according to claim 2, further comprises means, responsive to a signal from said sensing means, for storing the home position of said advancing means and returning said advancing means to said stored home position after each sheet exits said advancing means.

8. An apparatus for advancing a sheet in a primary sheet feeding direction and for deskewing and side registering the sheet, comprising:

means, located in a home position, for advancing the sheet in the primary sheet feeding direction and deskewing the sheet including a roll pair defining a drive nip, and means for translating said roll pair in a direction substantially parallel to the axis of rotation of a roll of said roll pair; and

means for sensing the sheet, said advancing means moving in unison with the deskewed sheet in a direction substantially transverse to the primary sheet feeding direction from the home position to a side registration position, said sensing means detecting the sheet in the side registration position, wherein said translating means moves said roll pair in response to a signal from said sensing means and wherein said translating means further comprises a stepper motor, means for counting the steps of the stepper motor, and means for storing a particular count responsive to a signal from said sensing means.

9. An apparatus for advancing a sheet in a primary sheet feeding direction and for deskewing and side registering the sheet, comprising:

means, located in a home position, for advancing the sheet in the primary sheet feeding direction and deskewing the sheet;

means for sensing the sheet, said advancing means moving in unison with the deskewed sheet in a direction substantially transverse to the primary sheet feeding direction from the home position to a side registration position, said sensing means detecting the sheet in the side registration position wherein said advancing means returns to the home position from the side registration position in response to said sensing means detecting the sheet; and

means, responsive to a signal from said sensing means, for storing the side registration position of said advancing means and returning said advancing means to said stored side registration position when said advancing means moves, from the home position to a position spaced from the side registration position wherein said advancing means returns to the home position from the side registration position in response to said sensing means detecting the sheet.

10. An electrophotographic printing machine of the type in which a sheet is advanced in a primary sheet feeding direction and is deskewed and side registered, wherein the improvement comprises:

means, located in a home position, for advancing the sheet in the primary sheet feeding direction, deskewing the sheet and translating the sheet in a direction substantially transverse to the primary sheet feeding direction;

means for sensing the sheet, said advancing and translating means moving in unison with the deskewed sheet in a direction substantially transverse to the primary sheet feeding direction from the home position to a side registration position, said sensing means detecting the sheet in the side registration position; and

means for storing the registration position.

11. The printing machine according to claim 10, wherein said advancing means returns to the home position from the side registration position in response to said sensing means detecting the sheet.

12. The printing machine according to claim 11, wherein said advancing means comprises:

a roll pair defining a drive nip; and

means for translating said roll pair in a direction substantially parallel to the axis of rotation of a roll of said roll pair.

13. The printing machine according to claim 12, wherein said translating means moves said roll pair in response to a signal from said sensing means.

14. The printing machine according to claim 13, wherein said translating means comprises a stepper motor.

15. A printing machine according to claim 10, wherein said sensing means comprises an optical sensor.

16. The printing machine of claim 10, wherein the sheet being advanced is a copy sheet.

17. The printing machine of claim 10, wherein the sheet being advanced is an original document.

18. An electrophotographic printing machine of the type in which a sheet is advanced in a primary sheet feeding direction and is deskewed and side registered, wherein the improvement comprises:

means, located in a home position, for advancing the sheet in the primary sheet feeding direction and deskewing the sheet including a roll pair defining a drive nip, and means for translating said roll pair in a direction substantially parallel to the axis of rotation of a roll of said roll pair; and

means for sensing the sheet, said advancing means moving in unison with the deskewed sheet in a direction substantially transverse to the primary sheet feeding direction from the home position to a side registration position, said sensing means detecting the sheet in the side registration position, wheren said translating means moves said roll pair in response to a signal from said sensing means and wherein said translating means further comprises a stepper motor, means for counting the steps of the stepper motor, and means for storing a particular count responsive to a signal from said sensing means.

19. The printing machine according to claim 18, further comprises means, responsive to a signal from said sensing means, for storing the home position of said advancing means and returning said advancing means to said stored home position after each sheet exits said advancing means.

20. The printing machine according to claim 18, further comprises means, responsive to a signal from said sensing means, for storing the side registration position of said advancing means and returning said advancing means to said stored side registration position when said advancing means moves, from the home position to a position spaced from the side registration position.

21. A method for deskewing and side registering a sheet in an electrophotographic printing machine comprising the steps of:

advancing the sheet in the primary sheet feed direction until a portion of the sheet engages a non-operative roll pair so as to deskew the sheet;

actuating the roll pair after deskewing the sheet to advance the sheet in the primary sheet feed direction;

moving the roll pair in unison with the advancing sheet in a direction transverse to the primary sheet feed direction from a home position to a side registration position; and

sensing the presence of the sheet in the side registration position; and

storing the registration position.

22. The method of claim 21, further comprising storing the home position of said roll pair and returning said roll pair to the stored home position after each sheet exits roll pair.

23. A method for deskewing and side registering a sheet in an electrophotographic printing machine comprising the steps of:

advancing the sheet in the primary sheet feed direction until a portion of the sheet engages a non-operative roll pair so as to deskew the sheet;

actuating the roll pair after deskewing the sheet to advance the sheet in the primary sheet feed direction;

moving the roll pair in unison with the advancing sheet in a direction transverse to the primary sheet feed direction from a home position to a side registration position;

sensing the presence of the sheet in the side registration position;

storing the home position of said roll pair and returning said roll pair to the stored home position after each sheet exits roll pair; and

storing the sensed proper side registration position of said roll pair and returning said roll pair to the stored side registration position when said roll pair moves, from the home position to a position spaced from the side registration position.