JPH0799441B2 - Duplex copying machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided copying machine for copying on both sides of copy paper.

2. Description of the Related Art A double-sided automatic copying machine for copying on both sides of copy paper is known. In this type of copying machine, when copying a plurality of single-sided originals on both sides of each copy sheet, conventional copying machines copy originals of different sizes onto both sides of the same size copy sheet. Was there. Therefore, when the copy paper is selected based on a large original, the margin for the next small original is too large, and when the copy paper is selected based on the small original, the next large original is selected. There is a defect that an image loss may occur on the copy paper for the original.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a copying machine which can automatically copy a copying machine suitable for each original size when the original size is different.

The copying machine of the present invention comprises an automatic double-sided copying means for automatically copying on the front and back sides of copy paper, a document size commanding means,
An automatic copy sheet selection means for selecting a copy sheet based on an instruction of the original size instruction means; an original size for back side copying instructed by the original size instruction means during execution of automatic double-sided copying and automatic copy sheet selection; A size comparing means for comparing the original size at the time of front side copying, and when the original size at the time of back side copying is different from the original size at the time of front side copying, the copy paper on the front side is discharged as it is and at the time of back side copying. The present invention is characterized by further comprising control means for sending a copy paper different from the above corresponding to the size of the original to perform copying.

Embodiment 1 In FIG. 1, reference numeral 1 denotes an automatic double-sided copying machine, which scans a document (shown in the figure) placed on a document table 2 with an optical system 3 to form an image of the document on the photosensitive drum 4. Project on top to create an electrostatic latent image of the original. This electrostatic latent image is transferred onto a copy sheet, a document image is formed on the copy sheet with toner, copying is performed, and the copy sheet is discharged from the discharge port 5.

Since this type of copying operation is similar to a known one, a more detailed description will be omitted.

An automatic document feeder (ADF) 300 is placed on the copying machine 1, and a paper feeding section 500 is provided below the copying machine 1.

Reference numeral 301 denotes a motor for rotating the ADF document conveying belt 320, and 302 denotes a document feeding roller for feeding a document from a document tray.

Reference numeral 303 is a document reversing unit, and 303M is a motor for driving the document reversing unit.

Reference numeral 304 denotes a switching claw that switches whether the document is discharged to the document discharge tray or is fed to the document reversing unit 303.

Reference numeral 310 denotes a sensor for detecting the feeding state of the document and its length, and 311 a sensor for detecting whether there is a document in the document tray.

Reference numeral 312 is a sensor that detects whether or not a document has passed.

With the above configuration, the originals on the original tray 321 are taken out one by one by the original feeding roller 302, sent to the original placing table 2 by the conveyor belt 320, and scanned for copying. Outlet 322 at appropriate timing
Emitted from. When the original is a double-sided original, the original is inverted by the original reversing unit 303 and is again sent to the original placing table 2 by the conveyor belt 320.

In the paper feed unit 500, 500A is a paper feed cassette that can store copy papers up to B4 size, and 500B is a paper feed cassette that can store copy papers up to A3 size. Copy paper of a required size is supplied from each paper feed cassette to the photosensitive drum 4 through the paper feed path 510 one by one.

501 is a discharge switching claw, 502 is a re-feed roller, 503 is a re-feed roller up / down solenoid, 504 is a re-feed clutch, 505 is an alignment solenoid, 582 is a paper sensor, 551-553, 554-556.
Are paper size detection sensors.

FIG. 2 shows the layout of the operation keys on the operation panel of the copying machine. The operation panel 70 includes a print key 71 for starting a copying operation, a numerical display device 72 capable of displaying four-digit numerical values, ten keys 80 to 89 corresponding to numerical values of 1, 2, ..., 9,0, respectively. Interrupt key 90 to instruct interrupt copy,
A clear / stop key 91, a selection key 92 for selecting a copy paper size, up and down keys 93, 94 for stepwise changing / designating the copy image density are arranged. 95
Is a double-sided select switch for instructing copying on both sides of one copy sheet, and 95a is a display lamp that lights up when double-sided selection is performed. Reference numerals 92a to 92d are size display lamps for displaying the copy paper size.

FIG. 3 shows a paper storage mechanism provided in the re-feed tray 400. Reference numeral 572 is a limiter switch for the copy paper length direction, 573 is a limiter switch for the copy paper width direction, and 593, 594 are dividers for moving the copy paper length direction. It is a plate.

Reference numeral 595 is a partition plate in the width direction of the copy paper. Reference numeral 505 is an alignment solenoid for turning on one shot and swinging the lever 600 to align the width direction of the copy paper when the copy paper enters.

FIG. 4 shows the configuration of the control device of the copying machine. 201 is a first CPU that controls the operation of the copying machine main body, 202 is a second CPU that controls the original scanning portion, 204 is a switch matrix, and 205 is a switch matrix.
Is a drive circuit of a DC motor M3 for scanning an original, 206 is a drive circuit of a stepping motor M4 for zooming, and 207 is a decoder. The output terminals A1 to A7 are the main motor of the copying machine, the developing motor, the timing roller clutch, and
It is connected to a transistor (not shown) for driving and switching each of the upper sheet feeding clutch, the lower sheet feeding clutch, the charger, and the transfer charger.

208 is an output port expansion IC for a stepping motor. Reference numeral 542 represents a stepping motor for moving the partition plates 593 and 594, and 543 represents a stepping motor for moving the partition plate 595.

FIG. 5 shows a motor 302M for driving a document feeding roller, a motor 303M for driving a document reversing unit, a solenoid 304S for driving a switching claw, and a CPU for an ADF control to which each sensor 310 to 312 is connected.

301A and 301B represent control signals for switching between normal rotation and reverse rotation of the motor 301 of the document conveyance belt 320.

FIG. 6 shows a schematic flowchart of the CPU 201. When the CPU 201 is reset and the program is started, in step S1, talia of the RAM, initialization of the CPU 201 for setting various registers, and initial setting for setting the device to the initial mode are performed.

Next, in step S2, the internal timer, which is built in the CPU 201 and whose value is set by initialization in advance, is started.

Next, the subroutines shown in the flowchart are sequentially called in steps S3 to S7, and when all the subroutine processing is completed, one routine is ended by waiting for the end of the internal timer that was initially set. The time length of this one routine is used to count the various timers that appear in the subroutine. (Various timer values determine the end of the timer depending on how many times this one routine is counted.) Further, the CPU 201 calls all subroutines and then performs data communication with other CPUs 202 and 203.

FIG. 7 shows a copy operation routine.

In step S10, when the print key 71 is turned ON, the process proceeds to step S11. If the ADF (automatic document feeder) 300 is not used, the print flag is set to 1 in step S12. If it is determined in step S13 that the document is placed on the ADF tray 321 if ADF is used, the ADF start signal 1 is set in step S14. If the ADF 300 is used in step S15 at the timing other than the ON edge of the print key 71, step S16
When it is detected that the document fixed position signal from the ADF 300 has become 1, the print flag is set to 1 in step S17.

Next, when it is detected that the print flag is 1 in step S18 and the double-sided preparation flag is 0 in step S19, the processes of steps S20 to S25 are executed. This double-sided preparation flag is a flag that is set in the double-sided copy preparation subroutine of step S5. For details, see FIG. 9 and the partition plates 593, 594, 595 in the re-feed tray 400 after the double-sided select switch 95 is pressed. Is 1 until the movement of is completed.

In step S20, the print flag S20 is set to 0, and step
Call S6's automatic paper select routine. The automatic paper selection routine S6 will be described in detail with reference to FIGS. 11 and 12, and is a process for automatically selecting and feeding a copy paper of a size suitable for the size of the original.

A step S21 decides whether or not the size incompatibility flag which is set when the copy paper of the size suitable for the size of the original document is not loaded in the copying machine in the step S6 is 0. If YES in step S21, that is, if copy paper of an appropriate size is set, the copy start flag for starting the copy operation is set to 1 in step S22.

In step S23, it is determined whether or not the display lamp 95a indicating that the double-sided copy is selected is turned on, and in step S24, whether the second copy flag indicating the copy of the second side is 0 or not. Determine whether or not. Then, when the double-sided copy is selected and the copy is the first side, step S2
In step 5, the second copy flag, which indicates copying of the first side, is set to 1.

In step S26, it is determined whether or not the second copy flag is 1, and if it is 1, that is, the copying of the second side, the process proceeds to step S27, and if it is 0, that is, the copying of the first side, the process shown in FIG. The copying process shown in (b) and (d) is executed.

In step S27, it is determined whether the copy original on the first side and the copy original on the second side are the same size. If they are the same size, the copy process shown in FIGS. 7B and 7D is performed. To execute.

On the other hand, if NO in step S27, that is, if the size of the copy original on the first side and the copy original on the second side are different, the process proceeds to the process shown in FIGS. Preparation for executing the copying process by ejecting the copied copy paper on the first side stored in the printer as it is and setting the copied original on the second side as a copy on the first side on a new copy paper I do.

FIGS. 7B and 7D are flowcharts showing details of the copying process. When the copy start flag becomes 1 in block 10, the main motor, the developing motor, the charging, transfer, and exposure lamps are turned on, and the copy start flag is set to 0,
Set TA (timer A) and TB (timer B). When the upper sheet feeding is selected, the upper sheet feeding roller clutch is selected. When the lower sheet feeding is selected, the lower sheet feeding roller clutch is selected. When the second copy flag is 1, that is, when the second side is copied. Performs processing for turning on the refeed low clutch. At (block 11), the TA is judged, and at the timing when the TA ends, the vertical re-feed roller clutch is turned off. In (block 12), the judgment of T-B is performed, and when it is the timing for the end of T-B, the scan signal is turned on. In (block 13), when the timing signal becomes 1, the timing roller CL is turned on and T-
Set C. In (block 14), at the timing when TC ends, the charging, the scan signal, the timing roller CL, and the exposure lamp are turned off. (Block 1
In 5), when the return signal is 1, that is, when the return is started, it is judged whether the multi-copy has finished copying,
If not, the copy start flag is set to 1. When the first copy flag is 1, the first copy flag is set to 0 and the second copy flag is set to 1. On the other hand, when the first copy flag is 0, the scanner that has left the fixed position returns and the fixed position switch is turned on, the developing motor and the transfer are set to 0, the second copy flag is set to 0, and T-D is set. set. At (block 16), the main motor is turned off at the timing when TD ends. (Block 1
In 7), output the results of the processing so far.

FIGS. 7C and 7E show processing when the size of the copy original on the second side is different from the size of the copy original on the first side.

When it is determined in step S29 that the copy start flag is 1, the process proceeds to step S30, the copy start flag is 0, the main motor is turned on, the timing roller is turned on, and the timer A is set. The clutch 504 is turned on.

When it is determined in step S32 that the timer A has ended, the process advances to step S33 to turn off the refeed roller clutch 504 and set the timer E. The timer E is set to a value such that the trailing edge of the previously fed paper ends feeding according to the paper length.

If it is determined in step S34 that the timer E has ended, and if it is determined in step S35 that the set number of sheets have been re-fed, the process proceeds to steps S36 to S39.

In step S36, the timing roller is turned off.

In step S37, the timer D is set.

In step S38, the second indicating that the copy is the second side.
Set the copy flag to 0.

In step S39, the print flag is set to 1.

In step S40, it is determined whether the timer D has ended, and when it is determined that the timer D has ended, the main motor is turned off in step S41, the above result is output in step S42, and the process returns.

By the processes of steps S29 to S36, when the size of the copy original on the second side is different from the size of the copy original on the first side, the copy paper on the first side which has been copied on the first side is the second copy. It is discharged as it is without being copied on the surface. In addition, the second copy flag is set to 0 in step S38, and the print flag is set to 1 in step S39.
By doing so, it becomes possible to copy the currently set second side copy original onto the first side of a new copy sheet. That is, the processing from step S10 onward is executed again, a copy sheet of the optimum size is selected for the copy original on the second side, and the copy original on the second side is copied onto the copy sheet.

FIG. 8 shows an automatic paper selection routine.

The manuscript size data detected and transmitted by the CPU 203 is converted by a magnification and temporarily stored in the A register in the CPU 203. The paper size of the first paper feed port of the copying machine main body is compared with the A register, and if they are equal, the size incompatibility flag is set to 0 in step S85, and the first paper feed port is selected. Next, in step S84, the paper size of the second paper feed port and the A register are similarly compared. First paper feed port, second
If it is not the same as the paper feed port, the size mismatch flag is set to 1 in step S85.

FIG. 9 shows a double-sided copy preparation routine.

In step S901, the ON edge of the display lamp 95a is judged to be ON.
When edge, that is, double-sided copy is selected, the double-sided preparation flag is set to 1 in step S902, and the discharge switching solenoid 501 is turned on in step S903 so that the copy paper whose surface has been copied is fed to the re-feed tray side. To do. Further, the re-feed roller up / down solenoid 503 is turned on to retract the re-feed roller upward.

Next, in step S904, the stepping motors 542 and 543 are reversed. That is, in order to move the partition plates 593, 594, 595 to the reference position first, the partition plates 593, 594 move toward the limiter switch 572, and the partition plate 595 moves the limiter switch.
Move in the direction of 573. Then limiter switch 5
If it is detected in step S905 that 72 is turned on, step
The stepping motor 542 is switched to normal rotation in S906, the value of 420 mm (maximum length) -paper length is stored in the A register in step S907, and it is determined in step S910 that the partition plates 593 and 594 have moved by the amount corresponding to the A register. Then, the stepping motor 542 is turned off. Similarly, in the width direction, when it is detected that the limiter switch 573 is turned on in step S910, the stepping motor 543 is switched to the normal rotation, and the paper width value of 207 mm (maximum width) is stored in the B register in step S912. Then, when the partition plate 595 has moved by the amount of the B register, the stepping motor 543 is turned off (step S914). All stepping motors 542 and 543 are OFF
Then, in step S916, the both-sides preparation flag is set to 0. As a result, the preparation for receiving the copy paper on which the first copying was performed is ready.

FIG. 10 shows a double-sided selection routine.

If the ON edge of the double-sided select key 95 is detected in step S1002 when it is detected in step S1001 that copying is not in progress, if the indicator lamp 95a is ON in step S1003, it is turned OFF in step S1004, and if OFF, it is turned ON in step S1005. To

FIG. 11 shows the paper select routine.

When it is determined in step S1101 that copying is not in progress, if the ON of the paper select switch 92 is detected in step S1102, if the first edge is currently selected at the ON edge, the second edge is selected. If the second paper feed port is selected, the first grade paper port is selected and the paper size code is input. Then, in step S1106, the paper size code conversion routine is called to turn on one of the set paper size LEDs 92a to 92d (step S110).
7).

The paper size code conversion routine is shown in FIG.

If the input size code is 1, it is a B5 length code, so a memory of paper length 257 mm and paper width 182 mm is stored.

Below, if the size code is 2, 3 and 4, respectively, A4 length, B
4 vertical and A3 vertical, so each paper length 297mm, width 21
0mm, paper length 364mm, width 257mm, paper length 420mm, width
Memory 297mm.

Also, if 5, 6 are B5 horizontal and A4 horizontal, paper length 182 mm, width 128.5 mm, paper length 210 mm, width 148.5 mm, respectively.
To memory.

FIG. 13 shows a schematic flowchart of the CPU 203.

When the CPU 203 is reset and the program starts, the RAM is cleared, the CPU is initialized when various registers are set, and the device is initialized.

Next, the internal timer, which is built into the CPU and whose value is set in advance by default, is started.

Next, the subroutines shown in the flowchart are sequentially called, and when all the subroutine processing is completed, one routine is completed after waiting for the completion of the internal timer that was initially set. The length of time of this one routine is used to count the various timers that appear in the subroutine. The various timer values determine the end of the timer depending on how many times this one routine is counted. Also, CPU2
Data communication with 01 is performed by an interrupt routine regardless of the main routine by an interrupt request from the CPU 201.

FIG. 14 shows the original control routine.

When there is a document in the document tray (311 is ON), CPU20
The ADF start signal changes from 1 to 1. Alternatively, if the original feeding flag is 1 and the front surface flag is 0, that is, in the mode in which the front surface of the original is copied, the conveyance belt motor is turned on.
ON, turn on the document feed motor. Next, a document feeding process routine is executed. When scanning for the set number of copies is completed, the scan end flag is set to 1. When the scanning end flag is 1, when the double-sided original signal is 0, that is, when the original is a single-sided original, the front surface flag is set to 0, the scanning end flag is set to 0, and the original discharge processing routine is performed. For a two-sided original, when the front side flag is 0, that is, when the back side copy of the two-sided original is finished, the same processing as that for the one-sided original is performed.
When it is 1, the document inversion process is performed.

FIG. 15 shows a document feeding process routine.

When a document is fed and switch 310 is turned on, flag K is set to 1
And start timer A1. This timer A1 is for turning off the document feeding motor, and the timer value until the document reaches the position where the document is driven by the conveyor belt is set. This prevents the next original from being fed if the motor is still rotating even after feeding the previous original.

Next, when the flag K is 1, the OFF edge of the switch 310 comes, that is, when the trailing edge of the document is detected, the flag K is set to 0 and the timer A2 is started. The value of the timer A2 is set to a value until the trailing edge of the document reaches the document leading edge fixed position on the document glass. Then, at the end of AIMA A1
When the timer A2 is turned off, the conveyor belt motor is turned off, and the document fixed position signal is sent to the CPU 201.

FIG. 16 shows a document discharge processing routine.

If there is still another original in the original tray, the original feeding flag is set to 1. If not, the conveyor belt motor is normally rotated and the timer B is started. The timer B is set to the time when the original (in the case of MMax) on the original glass can be discharged. When the timer B ends, the conveyor belt motor is turned off.

FIG. 17 shows a document size detection routine.

The timer DU is started at the ON edge of the document detection sensor 310.

Next, when the OFF edge of the document detection sensor 310, that is, the trailing edge of the document passes, the timer DU is stopped, and a value obtained by multiplying the value at that time by the document transport speed, that is, the document length is stored in the A register. . The size of each document is determined by the value of the A register.

In the above-described embodiment, the document size and the copy paper size are automatically detected by the respective sensors, and the command for ejecting the copy paper or the double-sided copy is issued. The copy paper size may be instructed.

EFFECTS OF THE INVENTION As described in detail above, this invention is
If the size of the original to be copied on the back side is different from the size of the copy paper when the front side of the original is copied, the copy paper that has been copied on the front side is ejected as it is, and the front side corresponding to the original size at the time of back side copying. Copying is performed by sending a copy paper different from that used for copying. Therefore, it is possible to prevent a part of the original document from falling off the copy paper and to prevent the margin from becoming very large on the copy paper.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a copying machine used in the present invention, FIG. 2 is a plan view of an operation panel, and FIG. 3 (a) is a side view showing a relationship between a refeed tray and a sensor. FIG. 6B is a plan view of FIG. 3A, FIGS. 4 and 5 are block diagrams showing an example of the control circuit, and FIGS. 6 to 17 are flowcharts showing the operation. 1 ... Copying machine, 2 ... Original placing table, 4 ... Photosensitive drum, 5 ... Ejecting port, 95 ... Duplex copy select switch, 300 ... Automatic document feeder, 400 ... Refeed tray, 500 …… Paper feeder.

Claims (1)

[Claims] 1. An automatic double-sided copying means for automatically copying on the front and back sides of a copy sheet, a document size commanding means, and an automatic copy sheet selecting means for selecting a copy sheet based on a command from the document size commanding means. Size comparison means for comparing the original size at the time of back side copying and the original size at the time of front side copying instructed by the original size command means at the time of executing automatic double-sided copying and automatic copy paper selection, and the original size at the time of back side copying If the original size is different from the original size when copying on the front side, the copy paper on the front side is ejected as it is, and a copy paper different from the above corresponding to the original size at the time of back side copying is sent to perform copying. A double-sided copying machine characterized by comprising means.