Copier/duplicator System

Abstract

This invention is an improved duplex copier/duplicator system including moving set sorting trays which enables the system to perform a subsequent operation or cycle immediately after a current operation or cycle. The print button of the machine is pressed after the last exposure has been made and the signal stored, for duplex mode, while the final sheets of the current copy run are deposited in the output tray and/or in sorting mode while the moving trays are returning to a home position. The next operation commences without repressing the print button and without delay. A FLIP-FLOP circuit is employed to store the print start button signal until the duplex operation is complete and/or when sorting the moving trays are sufficiently near to their home position at which time signals are supplied to commence new duplex operation or a new sorting cycle.

Description

This invention relates to an improved copier/duplicator system which enables a subsequent operation or cycle to commence with minimum delay and without operator intervention.

In copier/duplicator systems there has been a growing concern for the time a machine operator must wait to start a new operation by pressing a button when the machine is in a ready condition. Examples of these are when a duplex operation occurs for two sided copying and sorting of copies into moving trays which move towards a home position. A typical duplex copying machine is described in U.S. Pat. No. 3,645,615 in which copy sheets are advanced through processing stations once for each side. For a description of a typical moving tray sorter reference is made to U.S. Pat. No. 3,561,754 and copending application Ser. No. 319,957 filed Dec. 29, 1972, now U.S. Pat. No. 3,788,640, entitled "Tray Apparatus" commonly assigned herewith.

The present invention is for an improved system adapted for universal usage with copier/duplicators of all types. More specifically, the improved system reduces substantially the delay time between runs and enables a new run to commence in duplex mode at a time prior to when all the sheets have been deposited in the upper tray or delivered to the sorter, and/or in sort mode at a time prior to the trays, turning to their home position.

It is therefore a general object of this invention to improve duplex copier/duplicator systems.

It is another object of the invention to produce duplex copies with a minimum of delay.

It is another object of this invention to enable the distribution of copy sheets in collated sets in moving trays in a rapid and reliable manner.

It is still a further object of the invention to commence a new run of copy sheets from a copier/duplicator towards a moving tray sorting apparatus prior to the trays returning to a home position from a previous run.

It is still a further object of the present invention to reduce significantly the time delay between multiple runs of a moving tray sorting apparatus sorting copies into collated sets.

It is still a further object of the invention to store information for a subsequent copy run during the operation of a current copy run.

The above and added advantages of the present invention will become more apparent after reading the following detailed description which refers to accompanying drawings in which:

FIG. 1 is a perspective view of a high speed duplex copier/duplicator system including a sorter/collator apparatus for use with the present invention;

FIG. 2 is a schematic view illustrating the xerographic components of the duplex copier/duplicator system;

FIG. 3 is an elevational view of the tray assemblies of the sorter/collator apparatus;

FIG. 4 is a plan view of the tray assembly of the sorter/collator apparatus;

FIG. 5 is an isometric view of the drive assembly for the sorter/collator apparatus; and

FIG. 6 is a diagram of the control circuit of the present invention.

FIG. 1 shows a duplex copier/duplicator system generally designated 2 including a copier machine 3, which is a high speed copier/duplicator capable of producing simplex or duplex copies at the option of a machine operator. The copier machine 3 has a platen 4 for receiving documents to be reproduced, and a control panel 5 which includes various control knobs, buttons and switches for selecting various modes of operation such as simplex and duplex copies and the number of copies to be reproduced. The copier/duplicator system includes a sorting apparatus 6 having tray assemblies 7.

As best shown in FIG. 2, the duplex copier/duplicator system includes an automatic xerographic apparatus which includes a photosensitive plate including a photoconductive layer 10 that a photosensitive plate including a photoconductive layer 10 that is placed over a conductive backing. The plate is formed in the shape of a drum 11 and the drum mounted upon a shaft 12 that is journaled for rotation in the machine frame. Basically, the xerographic drum is rotated in the direction indicated so as to pass sequentially through a series of xerographic processing stations. The photosensitive drum and the xerographic processing apparatus are driven at predetermined speeds relative to each other from a drive system (not shown) and the operation thereof coordinated in order to produce proper cooperation of the various processing mechanisms.

The original to be reproduced, is placed upon a transparent horizontally supported platen 4 and the original scanned by means of a moving optical scanning system and to produce a flowing light image of the original. The latent electrostatic image is carried on the drum surface from the exposure station into the developing station C.

The moving drum surface next transports the developed xerographic image to transfer station D. Cut sheets of final support material are also moved into the transfer station, the backside of the copy sheet is sprayed with an ion discharge from a transfer corotron 25 inducing on the sheet a charge having a polarity and magnitude sufficient to attract the toner material from the drum surface to the final support material. The induced charge also electrostatically tacks the final support material to the drum surface. In order to remove the copy sheet from the drum surface, a stripper finger 28 is positioned downstream from the transfer corotron. The finger is arranged to move between the drum surface and the copy sheet and lifts the sheet from the drum surface and the copy sheet is directed along a predetermined path of travel into contact with a stationary vacuum transport 29. The copy sheet, which has been removed from the drum surface after the transfer operation, is moved along stationary transport 29 into fusing station F.

Upon leaving the fuser, the fixed copy sheet is passed through a curvalinear sheet guide system, generally referred to as into cooperating advancing rolls 43 and 44. At this point, depending on the mode of operation selected, the copy sheet is either forwarded directly to the sorter or into the upper supply tray 52 by means of a movable sheet guide 45. In the simplex mode of operation the movable sheet guide 45 is positioned as shown by the solid lines in FIG. 2 in a position to direct copy sheets towards the sorter. When duplexed copies are to be produced, the movable guide is moved to the position shown in dashed lines and upper tray 52 conditioned to accept the simplexed copy sheets. Upon receiving a signal from machine control, upper tray 52 is conditioned to separate and forward the sheets seriatim through the xerographic processing stations once again where a second image is placed on the backside of the sheet to produce a duplex copy which is advanced to the sorter.

It is believed that the foregoing description is sufficient for purposes of the present application to show the general operation of a duplex xerographic reproducing machine. For a more detailed explanation of the copier/duplicator xerographic components reference is made to aforementioned U.S. Pat. No. 3,645,615.

Sorter apparatus 6 comprises a horizontal vacuum transport assembly 103 which receives copy sheets from the copier/duplicator and advances them to a plurality of tray assemblies 7. A drive apparatus moves the tray assemblies vertically intermittently for receiving copy sheets advanced along the transport path as will be explained hereinafter. A drive motor 111 serves to drive transport assembly 103 which uses vacuum generated by a pump 108.

The tray assemblies 7 are arranged in groups of approximately five (5) trays. Each of the tray assemblies has a tray portion 205 which is inclined at an angle of approximately 20.degree. to the horizontal and an end portion 207 which is perpendicular to the tray portion 205 and then extends in a horizontal direction at tail portion 209. Tray portion 205 and tail portion 209 are mounted on cam followers which engage the spiral slot formed in the cylindrical surface of the cam members. Tray portion 205 has a pair of cam followers 211 mounted adjacent the leading corners thereof and received in spiral grooves 221 of camming members 223 and 224 positioned at opposite side os the entrance to the tray assembly. A third cam member 225 which has spiral portions 227 for receiving cam follower 213. By this arrangement, a three point suspension is provided by the tray assemblies.

Each of the cam members 223 and 224 at the entrance of the tray assemblies and cam member 225 at the rear of the tray assemblies have the same path. The path has a series of fine closely spaced or low pitch surfaces 231 separated by a high pitch surface 233 providing separation of the tray assemblies into groups to enable multiple bin unloading. At the vicinity of sheets entering the sorter is a very high pitch portion 235. The construction of the cam members 223, 224, and 225 with pitch portion 235, renders an opening tray or bin feature as each of the tray assemblies passes the horizontal transport which moves the copy sheets into each of the tray assemblies.

The drive mechanism for moving the tray assemblies vertically includes a drive motor 250 which drives three timing belts 251, one each for the cam members 223, 224, and 225. Torque is transmitted to each of the cam members by a pulley associated with each of the cam members by a pulley associated with each of the timing belts 251. The drive motor 250, is energized intermittently by electrical signals supplied by machine control when sheets on transport assembly 105 are detected by a lamp and photocell sensing unit 253 with the aid of a reflector 255 (FIG. 5).

A plurality of switches 258 serve to determine the location of the tray assemblies relative to the sheet discharge zone by contacting tray tab portions 259 (FIG. 4) which serve as a tray coding device. Switches 258 supply a signal to machine control to indicate tray assemblies are in a ready condition to receive sheets and also to indicate when drive motor 250 should reverse. Another function of the switches is to prevent the tray assemblies from over indexing beyond the normal range by supplying a signal to machine control. One or more switches 256 are mounted near cam member 223 to control de-energization of motor 250 upon a single revolution of the cam member. In this manner the tray assemblies advance together with each tray assembly receiving a sheet in the discharge zones. Limit switches 257 are provided as a backup to detect the upper and lower limits of the path of the tray assemblies to de-energize the motor 250 to prevent damage in the event of a component failure.

In accordance with the present invention the waiting period before duplexing onto the second side of the copy sheets or between runs for producing collated sets is minimized several seconds by enabling the machine operator to position the original document on the platen while processing the final sheets of the present copy run are being delivered to the upper tray or to the sorter and/or the tray assemblies are returning to their home position. In other words the print signal for duplexing or for the next sorting run may commence prior to the completion of advancing copy sheets for side one copying or sorting of copies into sets of a current run.

Referring now specifically to FIG. 1 and the circuit of FIG. 6 there is shown a start print button S-1 on the control panel 5 which starts the machine on a copying cycle. Normally nothing will occur upon pressing start print button S-1 unless the machine is in a ready condition. The ready condition is indicated by a signal input 301 to a NAND gate 303 which is coupled in a FLIP-FLOP with AND gate 305 to form a latch circuit. If the machine is otherwise in a ready condition and start print button S-1 is pressed a signal 307 is supplied in gate 305 which produces an output signal 311. Signal 311 is inverted by an inverter 313 before being supplied to a NAND gate 317. NAND gate 317 also receives a ready signal 321 from machine control in response to the condition of copy sheets received in upper tray 52 and the position of the tray assemblies which operate switches 258 as previously described. When simplex copying for side one of an original is complete a duplex start inhibit signal 320 goes from a LOW to a HIGH. Similarly when the tray assemblies are returning to the home position and are in a predetermined position a sort ready inhibit signal 321 from machine control goes from a LOW to a HIGH. When these conditions occur the HIGH signals are supplied to gate 317 which produces an output signal 331 to both reset the latch circuit and commence a new operating cycle which can be either a duplex or sorting operation.

It will now be appreciated that the start print signal is stored until a copier ready signal 301 is present and neither a duplex ready inhibit signal 320 nor a sorter ready inhibit signal 321 is present. Thus, the start of a new operation is delayed only until simplex copying or sorting is completed and no longer. Since the start print button S-1 is pressed once and the signal stored, the next operation commences automatically without repressing the button. Moreover, the operator can replace the document on the platen with the next document for duplex copying or a new sorting run thereby saving time. The system will then proceed in automatic fashion without operator attention or repressing the start print button.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

Claims

What is claimed is:

1. In a copier/duplicator system in which copy sheets are reproduced from documents and distributed for sorting into trays moved past a sheet discharge zone to sort copy sheets into collated sets, an improved control circuit for minimizing the delay between sorting runs comprising:

first circuit means including first gate means to receive signals indicative of a copier/duplicator system ready condition and a second gate means to receive signals indicative of a start print condition,

second circuit means including third gate means to receive signals from said first circuit means and to receive signals from machine control indicative of the position of said moving trays to start another sorting cycle,

said third gate means generating output signals to reset said first circuit means and initiate the next sorting cycle.

2. A system according to claim 1 wherein said first circuit means is a latch circuit which is set by start print signals.

3. In a duplex copier/duplicator system in which copy sheets are advanced through processing stations to produce copies on one side thereof, then received in a tray in inverted form, and then advanced a second time to produce duplex copies, an improved control circuit for minimizing the delay when completing the copying run on the first side before commencing the duplex run comprising:

first circuit means including first gate means to receive signals indicative of a copier/duplicator system ready condition and a second gate means to receive signals indicative of a start print condition,

second circuit means including third gate means to receive signals from said first circuit means and to receive signals from machine control indicative of the ready condition of the advancing of one sided copy sheets from a receiving tray for commencing the duplex cycle,

said third gate means generating output signals to reset said first circuit means and initiate the duplex cycle.

4. A system according to claim 3 wherein said first circuit means is a latch circuit which is set by start print signals.

5. In a copier/duplicator system in which multiple operations are performed through copy processing stations, an improved control circuit for minimizing the delay in commencing the next operation comprising:

first circuit means including first gate means to receive signals indicative of a copier/duplicator system ready condition and a second gate means to receive signals indicative of a start print condition,

second circuit means including third gate means to receive signals from said first circuit means and to receive signals from machine control indicative of the ready condition for commencing the next operation,

said third gate means generating output signals to reset first circuit means and initiate the next operation automatically.

6. A system according to claim 5 wherein said first circuit means is a latch circuit which is set by start print signals.