Variable sheet length paper feed and cutting system

Claim 2

In a xerographic copying apparatus, a process for producing copies of variable length from a continuous web, said process comprising the steps of: positioning the leading edge of said web adjacent a web sensor; feeding said web toward said web sensor; illuminating an object bearing an image to be copied; scanning said object with a moving optical element to project said image onto a charged photoconductive surface to form thereon a corresponding latent electrostatic image, said scanning step being initiated when the leading edge of said web is detected by said web sensor; depositing electroscopic toner material on the portion of said photoconductive surface bearing said latent electrostatic image, said material adhering to said surface to form a visible toner pattern corresponding to said image; measuring the distance traversed by said leading edge beyond said web sensor, and comparing the measured distance with a signal indicative of a desired web length; severing the leading portion of said web from the remainder thereof in response to the comparison between said measured distance and said desired length, so that the length of said leading portion is equal to said desired length; terminating said scanning step when the trailing edge of said leading portion traverses said web sensor; and terminating said web feeding step at a predetermined time after said web severing step is initiated.

Claim 3

The process according to claim 1, wherein said process is employed to produce two successive copies, including the additional step of delaying the web feeding step associated with said second copy for a predetermined time after initiation of the web feeding step associated with said first copy.

Claim 4

The process according to claim 1, further including the step of delaying the termination of said scanning step for a predetermined time after the trailing edge of said web portion has traversed said web sensor.

Claim 5

The process according to claim 3, wherein said photoconductive surface is caused to continuously move at a predetermined speed while said copies are being produced, the linear speed at which said object is scanned and the speed at which said web is fed being substantially equal to said predetermined speed.

Claim 6

The process according to claim 4, including the additional step of positioning said leading web portion adjacent the toner pattern on said photoconductive surface, and transferring and affixing said toner pattern to said leading web portion.

Claim 7

The process according to claim 1, wherein the distance traveled by the leading edge of said web beyond said web sensor is measured by a counter coupled to means for feeding said web, the operation of said counter being initiated when the leading edge of said web is detected by said web sensor.

Claim 8

The process according to claim 4, wherein the time interval between initiation of said web severing step and termination of said web feeding step is selected so that the leading edge of the remaining portion of said web is positioned adjacent said web sensor.

Claim 9

Xerographic copying apparatus for producing copies of vArying lengths, comprising: a charged photoconductive surface; means for illuminating an object bearing an image to be copied; scanning means responsive to a scan start signal for scanning said object with a moving optical element to project said image onto said photoconductive surface, said scanning means being responsive to a scan stop signal to return said moving optical element to a predetermined rest position; developer means for depositing electroscopic toner material on the portion of said photoconductive surface bearing said latent electrostatic image to form a visible toner pattern corresponding to said latent image; means for feeding said web to a position adjacent said toner pattern; means for transferring said toner pattern to the adjacent portion of said web and affixing said toner pattern thereto; a web sensor; means for initially positioning the leading edge of said web adjacent said web sensor; means responsive to a print signal and operative when said moving optical element is in said rest position for initiating the operation of said web feeding means to feed said web toward said web sensor and said toner image; said web sensor generating said scan start signal when the leading edge of said web is detected thereby; distance measuring means for providing a web length signal which is a measure of the distance traversed by the leading edge of said web beyond said web sensor; means for providing a web length control signal corresponding to a desired web length; means for comparing said web length signal with said web length control signal to provide a web cut signal when the distance traveled by the leading edge of said web beyond said web sensor is equal to the distance represented by said web length control signal; means for severing the leading portion of said web from the remaining portion thereof a predetermined time after the occurrence of said web cut signal; means operative a first predetermined time after the trailing edge of the severed portion of said web traverses said web detecting circuit for generating said scan stop signal; and means for terminating the operation of said web feeding means a second predetermined time after the occurrence of said web cut signal, said second predetermined time being selected to position the leading edge of the remaining portion of said web adjacent said web sensor.

Claim 10

Xerographic copying apparatus for producing copies of vArying lengths, comprising: a charged photoconductive surface; means for illuminating an object bearing an image to be copied; scanning means responsive to a scan start signal for scanning said object with a moving optical element to project said image onto said photoconductive surface, said scanning means being responsive to a scan stop signal to return said moving optical element to a predetermined rest position; developer means for depositing electroscopic toner material on the portion of said photoconductive surface bearing said latent electrostatic image to form a visible toner pattern corresponding to said latent image; means for feeding said web to a position adjacent said toner pattern; means for transferring said toner pattern to the adjacent portion of said web and affixing said toner pattern thereto; a web sensor; means for initially positioning the leading edge of said web adjacent said web sensor; means responsive to a print signal and operative when said moving optical element is in said rest position for initiating the operation of said web feeding means to feed said web toward said web sensor and said toner image; said web sensor generating said scan start signal when the leading edge of said web is detected thereby; distance measuring means for providing a web length signal which is a measure of the distance traversed by the leading edge of said web beyond said web sensor; means for providing a web length control signal corresponding to a desired web length; means for comparing said web length signal with said web length control signal to provide a web cut signal when the distance traveled by the leading edge of said web beyond said web sensor is equal to the distance represented by said web length control signal; means for severing the leading portion of said web from the remaining portion thereof a predetermined time after the occurrence of said web cut signal; means operative a first predetermined time after the trailing edge of the severed portion of said web traverses said web detecting circuit for generating said scan stop signal; and means for terminating the operation of said web feeding means a second predetermined time after the occurrence of said web cut signal, said second predetermined time being selected to position the leading edge of the remaining portion of said web adjacent said web sensor.

Claim 11

The apparatus according to claim 8, further including means for delaying the operation of said web feeding means to produce a succeeding copy, the operation of said web feeding means being delayed for a predetermined time after the web feeding means has commenced operation to produce the preceding copy.

Claim 12

The apparatus according to claim 8, wherein said means for measuring the distance traversed by the leading edge of said web beyond said web sensor comprises pulse generating means coupled to said web feeding means, and a counter for counting the pulses generated by said pulse generating means, the operation of said counter being initiated when the leading edge of said web is detected by said web sensor.

Claim 13

Apparatus according to claim 8, wherein said moving optical element scans said object with a beam having a predetermined width, and said first predetermined time is selected so that said scanning means overscans said object by an amount substantially equal to the width of said beam.

Claim 14

Apparatus according to claim 8, wherein said web severing means comprises a cutting roller having a web cutting knife blade therein, the cutting edge of the blade protruding beyond the periphery of the roller, and a platen roller positioned in juxtaposition with said cutting roller, said rollers being disposed on opposite sides of said web, means for rotating said platen roller at a peripheral speed equal to the speed of said web, and means responsive to said web cut signal for rotating said cutting roller at said peripheral speed through a single revolution to sever said web wheN the cutting edge of said knife engages said web and the periphery of said platen roller.

Claim 15

Apparatus according to claim 12, further including detent means for parking said cutting roller at a predetermined angular position with respect to said web in the absence of said web cut signal.

Claim 16

In a xerographic copying apparatus, a process for producing copies of variable length from a continuous paper web, said method comprising the steps of: positioning the leading edge of said web adjacent a web sensor; illuminating an object bearing an image to be copied; scanning said object with a moving optical element to project said image onto a photoconductive surface to form thereon a corresponding latent electrostatic image; feeding said web toward said web sensor, said web feeding step being initiated when said optical element reaches a predetermined angular position; depositing electroscopic toner material on the portion of said photoconductive surface bearing said latent electrostatic image, said material adhering to said surface to form a visible toner pattern corresponding to said image; measuring the distance traversed by said leading edge beyond said web sensor, and comparing the measured distance with a signal indicative of a desired web length; severing the leading portion of said web from the remainder thereof in response to the comparison between said measured distance and said desired length, so that the length of said leading portion is equal to said desired length; terminating said scanning step when the trailing edge of said leading portion traverses said web sensor; and terminating said web feeding step at a predetermined time after said web severing step is initiated.

Claim 17

In a xerographic copying apparatus, a process for producing copies of variable length from a continuous paper web, said method comprising the steps of: positioning the leading edge of said web adjacent a web sensor; illuminating an object bearing an image to be copied; scanning said object with a moving optical element to project said image onto a photoconductive surface to form thereon a corresponding latent electrostatic image; feeding said web toward said web sensor, said web feeding step being initiated when said optical element reaches a predetermined angular position; depositing electroscopic toner material on the portion of said photoconductive surface bearing said latent electrostatic image, said material adhering to said surface to form a visible toner pattern corresponding to said image; measuring the distance traversed by said leading edge beyond said web sensor, and comparing the measured distance with a signal indicative of a desired web length; severing the leading portion of said web from the remainder thereof in response to the comparison between said measured distance and said desired length, so that the length of said leading portion is equal to said desired length; terminating said scanning step when the trailing edge of said leading portion traverses said web sensor; and terminating said web feeding step at a predetermined time after said web severing step is initiated.