JPS63253375A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate the need for an operator to input a cutting size by discriminating the cutting length of roll sheets based on the width of the roll sheets detected by a detection means and a picture signal from a picture signal generation means. CONSTITUTION:Based on the picture signal determined by the length of an original in a picture scanning direction and a selected copying magnification, a discrimination means automatically discriminates how the roll sheets are to be cut, i.e., whether in a fixed width size or a fixed length size. According to the results that the discrimination means has discriminated, a timer means is set, and begins to count the moment a timing signal instructing the conveyance of the roll sheets to an image forming part rises. At the time of completion of the counting, a cutting means (cutter 41) operates to cut the roll sheets 31 and 33. Thus the operator need not input the cut length into a device one by one, and the timer means can precisely cut the roll sheets 31 and 33.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus such as a copying machine or a printer, and particularly to a control mechanism for cutting roll paper on which an image is to be formed.

Conventional technology and its five issues Generally speaking, copying machines that form original images on roll paper loaded in the paper feed section have two methods for cutting the roll paper: the synchronized cut method and the standard size cut method. There is.

As shown in Japanese Patent Publication No. 56-26021, the synchronized cut method cuts roll paper to a length equal to the length of the original in the image scanning direction multiplied by (n), where the copying magnification is (n). do. However, in this method, the cut length varies depending on the document length and copying magnification, and handling of the paper after cutting is complicated.

The fixed size cut method is convenient for handling because the cut sheets are the same size. By the way, roll paper can be cut into two types of standard sizes by horizontal cutting with the long side being the width direction and vertical cutting with the short side being the width direction. Which cut to perform is determined based on the length of the document and the copy magnification. Therefore, in the past, the
As disclosed in Japanese Patent No. 92, the cut length is determined by a combination of a roll paper width detection switch and a cut size changeover switch. Or Tokuko Sho 61
As shown in Publication No. 12258, when the roll paper width size matches one side of the copy size, a corresponding cut is made on the other side using a roll paper width size detection switch and a copy size selection switch. I'm trying to do it.

However, with any of these devices, it is necessary for the operator to input the cut size and copy size, which may lead to input errors in some cases, which is not desirable in terms of usability.

On the other hand, in the conventional one-length cut as described above, the cutting means is operated by a signal from a switch that can be turned on or off based on the movement of the optical system or document table. This has the problem that variations in cut length occur due to timing shifts in movement, variations in positional accuracy of the switch, variations in responsiveness, and the like.

Therefore, the image forming apparatus according to the present invention includes: (i) a detection means for detecting the width size of the roll paper loaded in the paper feed section; (i) the length of the document in the image scanning direction; (i) a width size of the roll paper detected by the detection means and an image signal from the image signal generation means; (iv) a means for generating a timing signal for conveying the roll paper to the image forming section; and (V) a set based on the determination result of the determination means. is,
The present invention is characterized by comprising: a timer means that starts counting when the timing signal rises; and (vi) a cutting means that cuts the roll paper when the timer means finishes counting.

In a configuration of 1-month or more, the cut length of the roll paper, that is, whether it is cut into a horizontal standard size or a vertical standard size, is determined by the length of the original in the image scanning direction and the selected copy magnification. The determination is automatically performed by the determination means based on the image signal indicating the image length. Further, the timer means is set based on the determination result of the determination means, and starts counting at the rising edge of the timing signal for transporting the roll paper to the image forming section, and when the count ends, the cut means operates to cut the roll paper. . Therefore, the operator does not need to input the cut length into the apparatus each time, and at the same time, the timer means cuts the roll paper to an accurate size.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described below with reference to the accompanying drawings. This embodiment includes a toner image transfer type copying machine main body (1) and an automatic document circulation conveyance device (hereinafter referred to as RADF) that automatically circulates documents by the number of copies.
(50).

[Copying machine main body] In Fig. 1, the copying machine main body (1) has a photosensitive drum (2) installed approximately in the center so that it can be rotated in the direction of arrow (a), and a main eraser lamp ( 3), electrification charger (4), inter-image eraser lamp (5), magnetic brush type developing device (6), transfer charger (7), paper separation charger (8), separation claw (9), blade type A cleaning device (10) is arranged.

The optical system (20) includes an exposure lamp (21) and a mirror (22).
).

(23), (24), lens (25), mirror (26)
), and forms an image of a document conveyed on a document slit glass (27) on a photoreceptor drum (2) in a RADF (50), which will be described below. Lens (25)
, the mirror (26) is movable in the optical axis direction by a motor (M2) according to the copying magnification; the residual charge of the photosensitive drum (2) is erased by the main eraser lamp (3) for each copying. A predetermined charge is applied to the document by a charger (4), and an image of the document is formed by an optical system (20) to form an electrostatic latent image. This electrostatic latent image is turned into a toner image by a developing device (6).

On the other hand, the paper feed section consists of a main paper feed section (30) into which roll paper (31), <33) can be selectively loaded, a sketch paper section (32), and a manual paper feed section (34) for cut paper. It is configured.

The roll paper (31), (33) is the roller (35), (
A pair of paper feed rollers (37), (38) via
The paper is pulled out, guided by various guide plates, fed to a pair of timing rollers (40), and temporarily put on standby. Also, the cut paper inserted from the manual paper feed section (34) is passed through a pair of paper feed rollers (39) to a timing roller (40).
The paper will be fed until the paper is loaded, and then it will wait for a while. Timing roller (40
) is rotated by a predetermined timing signal, and the toner image is transferred to the paper by the discharge of the transfer charger (7), and the photoreceptor drum ( 2).

The timing signal is emitted in the transfer section at the timing when the leading edge of the image formed on the photoreceptor drum (2) and the leading edge of the paper are synchronized.

(33) can be cut into a horizontal or vertical size using a cutter (41) based on a cut signal which will be described in detail below. After the transfer, the paper is transferred to a fixing device (43) via a conveyor belt (42) equipped with an air suction means (not shown).
There, the toner is fixed, and the toner is discharged to the outside of the main body (1) by the first discharge roller (44).

Further, the paper is conveyed vertically upward by belts (45) and (46), and is discharged onto a paper discharge tray (48) by a second discharge roller (47).

The photosensitive drum (2), paper feeding system, and conveyance system are driven by a main motor (Hl).

The main paper feed section (30) and the sketch paper section (32) each have three sets (7) 74')
SW3), (SW4)" (SW6) are installed. These switches are turned on and off by protrusions provided for each width size depending on the set of roll paper, and the combination of on and off is set. The width size of the set roll paper (31), (33) is detected based on the 3-bit code in accordance with the 3-bit code, and the presence or absence of the roll paper is also detected.

[Table 1] below shows the switch (SWI) of the main paper feed section (30).
) to (SW3), this [Table 1
] indicates that the switch is on and off as ``rl'', and if all the switches are off, it means that the roll paper is not set in the main paper feed section (30). Paper section (32) switches (SW4) ~ (
SW6) also performs similar detection.

[Table 1] Various sensors are installed inside the copying machine body (1). The sensors (Psi) and (PS2) are for detecting cut paper inserted into the manual paper feed section (34).

Sensor (PS3), (PS4> is the upper and lower paper feed section (3o
), (32) D loaded roll paper (31), <3
3'). Sensor (Psi)
is just before the timing roller (40) (7), and is > ?
(PS6) and (PS7) are respectively discharge rollers (44
), immediately after (47), the first passing of the paper is detected. These sensors are also used to detect paper jams and to control other operations of the copying machine main body (1).

[Automatic document circulation feeder (RADF)] In FIG. 1, the RADF (50) includes a document table (51), document conveyance rollers (52) to (57), document ejection tray (60), and document conveyance motor (M3). ).

Each conveyance roller (52) to (57) is a driven roller (52a), (53a), (53b) to (57a), respectively.
A guide member for conveying the original is appropriately installed around the guide member. In addition, a conveyance roller (54>,
(55) is a switching claw (6) for switching the circulation conveyance path.
1), (63) and guide plates (62), (64), and the transport roller (53) is provided with a switching claw (65) and a guide plate (66) for switching between circulating and discharging the original.

That is, when the switching claw (61) is also entered with the switching claw (65) entered into the conveyance path, the document is circulated and conveyed between the transport rollers (53) and (54), and then the switching claw (
63), the transport rollers (53) and (55)
When the switching claws (61) and (63) are retracted, the transfer rollers (53) and (56) circulate.

On the other hand, when the switching claw (65) is retracted from the conveyance path, the original is transferred from the conveyance roller (57) to the output tray (6o).
is discharged to the top.

Each of the above-mentioned transport rollers (52) to (57) is rotationally driven by a document transport motor (M3), and the transport speed is set to (V
), the conveying speed (V) at 0 equal magnification, which is controlled to (V/n) with respect to the copying magnification (n), is the photosensitive drum (
2) is equal to the peripheral speed and paper conveyance speed.

In addition, each sensor (PS8) to (PSI) is installed in the document transport path.
I) is installed. The sensor (PS8) detects the inserted document, and the sensor (PS9) detects the optical system (20).
The original is detected immediately before the light irradiation position by the exposure lamp (21), the sensor (PSIO) detects the original at the circulation/ejection switching section, and the sensor (PSII) detects the original to be ejected.

Next, to briefly explain its operation, the document table (51
) When the sensor (PS8) detects the leading edge of the document inserted from the
) to (57) are rotated at a peripheral speed corresponding to a preselected copying magnification. Here, the manuscript is RADF (50)
The photoreceptor is transported into the interior of the photoreceptor drum (2), passes over the glass (27), and is irradiated with light from the exposure lamp (21), where the reflected light forms an image on the photoreceptor drum (2). At the same time, the length of the original can be detected by a combination of various sensors and timers, and the switching claws (61) and (63) operate according to the length of the original, so that the original passes through the shortest circulating conveyance path. When the leading edge of the document is detected by the sensor (PSIO'), it is determined whether copying has finished or not. If the circulation for one copy has not yet been completed, the switching claw (65) is activated to transport the document. It is circulated by rollers (53). When the circulation for one copy is completed, the original is directly ejected onto the ejection tray (60) through the conveyance roller (57), and the trailing edge is connected to the sensor (PSll).
), the motor (M3) stops.

[Operation Panel] In Fig. 2, the operation panel has the following keys,
Display means etc. are installed. Each key has an internal switch that is turned on by pressing it.

(100) is a stop key for stopping the document transport operation of RADF (50), (101) to (110) are numeric keys for setting the number of copies, etc., (111)
is a clear key that functions as a stop key to cancel the multi-fubi midway through, and a clear key to clear the set numbers.
Stop key, <112) is an interrupt key to execute interrupt copying, (113), (114) are magnification up keys and magnification down keys that increase and decrease the copy magnification in steps, (115), (116) are the exposure up and down keys that increase or decrease the exposure in steps. (117) is the select key for the top picture paper section (30) or the bottom picture paper section (32), and (118) is the enlargement.

Copy magnification select key with presets of 2 steps of normal magnification and reduction, (119) is a zoom magnification select key for selecting two types of zoom magnification arbitrarily preset by the user, <120) is the zoom magnification (121) is the synchro cut designation key to cut the roll paper in synchronization with the length of the document.

The operation panel further includes a display section (140) including a display ED and a fluorescent display tube, which will be described below.

(122) and (123) are LEDs that display that the roll paper loaded in the top paper section (30) and the bottom picture paper section (32) has been selected, and the paper feed section select key (11)
7) Rotate each time the on operation is performed.

(132) and (133) are roll paper width size display sections, which are displayed based on signals from the switches (SWI) to (5W6) provided in each paper feed section (30) and (32). (124) to (127) are copy magnification selection display-LEDs, and the copy magnification selection key (118)
Rotates each time the switch is turned on. (12
8) and (129) are zoom magnification selection display LEDs,
Rotation is performed each time the zoom magnification select key (119) is turned on. (130), (131
) is a synchro cut selection display LED for the upper and lower roll paper, which rotates each time the synchro cut designation key <121) is turned on.

In the display section (140) using a fluorescent display tube, (141
) is a two-digit display segment that displays the number of copies, etc.

(142) is a 4-digit display segment that displays the selected copy magnification, and (143) is a pictorial display that instructs service personnel. (144) is a step display of exposure amount.

(145> is a toner empty display, (146> is a roll paper empty display, and (147) is a paper jam warning display.

(148) is the display during interrupt copying, (149) is the wait display during temperature control, movement of the lens (25), etc.

[Control Circuit] Figure 3 shows a microprocessor (hereinafter referred to as CPU) (201) that controls the main body of the copying machine (1), and an RA.
C controls the DF (50) and optical system (20)
The input/output configuration of PU (215) is shown.

The CPU (201) is an input/output expansion integrated circuit (hereinafter referred to as I
(denoted as C) (202) ~ (204) , (206
) to (20g). IC (202)
~ (204) is used as an input IC,
The CPUs (201) and 201 are connected via a data line via a decoder (205). The input terminal has various keys,
Switches, sensors, etc. are connected. IC(20
6) ~(208) are output ICs,! -1, is used up, and the hunt roll boat is connected to the CPU (201) via the decoder (210).

In addition to various parts, the output terminal includes a fluorescent display tube display section (140) and LEDs (122) to (131).
is connected to the LED matrix (209) consisting of C
The PUs (201) and the decoders (211) respectively control the signals. Random access memory (hereinafter referred to as RAM) (212) is connected to the CPU (201
), and the memory is backed up by a battery.

Further, the CPU (201) transmits a value selected from among the nine-step exposure values to the light control circuit (213) as data.

On the other hand, the input/output port of CP IJ (215) is RAD
A motor (M2) that moves the control circuit (216), lens (25), and mirror (26) of the document transport motor (M3) of F (50) according to the selected copy magnification.
> control circuit (217) is disconnected. In addition, each sensor (PS8) ~ (
ON/OFF signals from PSII) are input, and a switching claw (61).

(63), turns on the solenoid that drives (65),
An off signal is output. Further, the CPU (215) is connected to the CPU (201) for communication via a bus (214).

[Control Procedure] The control procedure of this embodiment will be described in detail below with reference to FIGS. 4 to 16b.

Figure 4 shows the CPU (20) that controls the copying machine main body (1).
1) shows the main routine.

When the CPU (201) is reset and the program starts, first, in step (Sl), the RAM is
(212), initializes various registers, and performs initial settings to put each device into initial mode.
Next, in step (S2), an internal timer of the CPU (201) is started. This internal timer determines the time required for one routine of this main routine, and its value is set in advance in step (Sl).

Next, the subroutines shown in steps (S3) to (S5) are sequentially called, and when the processing of all subroutines is completed, the process waits for the internal timer to end in step (S6), and then returns to step (S2). The length of time of this one routine is used to count the various timers that appear in each subroutine, that is, the various timer values determine the end of the kakat by how many times this one routine is repeated.

Also, if an interrupt request is received from the CPU (215) while various processes are being executed, the CPU (215)
).

Figures 5a and 5b show the main routine steps (S3
) shows the copy operation subroutine executed in ().

First, in step (510'), it is determined whether the original insertion signal is "1".
is inserted into the RADF (50), and its tip is connected to the sensor (
PS8), this original insertion signal is set to "1." [see step (5221)].
The CPU (215) sends a message indicating that the
When this happens, the copy start flag is set to rl in step (511).

Next, in step (512), the copy start flag is set to rl,
If it is set to rl, the main motor (Ml), developing motor, etc. are turned on in step (513), and the charging charger (4) and transfer charger (7) are turned on.
etc., reset the copy start flag to "0", and set the timers (TA) and (TB). Then, in step (514), it is determined whether or not the overprint paper section (30) is selected, and if YES, step (514) is performed.
15), turn on the clutch of the overprint paper roller (37), and press N.
If o, the clutch of the sketch paper roller (38) is turned on. Now the selected roll paper (31) or (33)
Either one of them is fed toward the timing roller (40).

Next, when the judgment end timing of the timer (IA) is confirmed in step (517), the clutches of paper feed rollers (37) and (38) are turned off in step (518).

Further, when the judgment end timing of the timer (TB) is confirmed in step (519), the scan signal is set to "1" in step (520). The scan signal is
As explained in step (5224) of FIG. 16a, this is a signal for transporting the document from the position of the sensor (PS9) to the position of light irradiation by the exposure lamp (21).

Next, in step (521), the timing signal is set to rl.

Determine whether or not. The timing signal is generated by the photoreceptor drum (2
) is used to synchronize the leading edge of the original image formed on the top of the paper with the leading edge of the paper at the transfer position, and the following step (5232
) is set to rl. This timing signal is rl
, is sent from the CPU (215), the timing roller (
40) Turn on the clutch. At this point, the roll paper begins to be conveyed from the timing roller (40) to the transfer position.

Next, in step (523) it is determined whether the sensor (Psi) is off-edge. The roll paper is cut as explained in FIGS. 6a and 6b, and when the cut trailing edge passes, the sensor (PS5) is turned off.

If the sensor (PS5) is off-edge, step (5)
24'), turn off the charger (4), reset the scan signal to rO', and turn off the timing roller (4).
0) disengage the clutch.

Next, in step (525), it is determined whether the return signal is "1". The return signal is sent to the sensor (
PSIO) is set to 11 when detected by [
Refer to step (5239)]. Therefore, when the CPU (215) transmits that the return signal has been set to "1.", it is determined in step (526) whether or not multi-copying has been completed. If it has not finished, set the copy start flag to "1°" in step (529).
Preparations are made to start the copy operation again. When the multi-copy operation is completed, that is, when the copy operation for the set number of copies is completed, the sensor (PS) is activated in step (527).
6) Determine whether or not it is an off-edge. If the trailing edge of the paper passes the sensor (PS6) and the sensor (PS6) is off-edge, the developing motor, transfer charger (7), etc. are turned off in step (528), and a timer (TC) is set. Further, in step (530), a timer (TC
), the main motor (Ml) is turned off in step (531), the results of the processing up to now are outputted in step (532), and this subroutine ends.

Figures 6a and 6b show step S4 of the main routine.
) shows the paper cut subroutine that is executed.

First, in step (540>), it is determined whether the original image signal is 11'' or not. [Step (52
29)], when the CPU (215) transmits that the original image signal is set to l''1'', the paper feed unit (30) or (32) selected in step (541>) Roll paper (31) or (3) set in
3) Set a timer (T1) corresponding to the width size. This timer (T1) is set, for example, to the time it takes for the roll paper to be conveyed by an arbitrary intermediate dimension between the horizontal standard size and the vertical standard size of the roll paper.

Next, in step (542) the timing signal is set to rl.

In other words, it is determined whether or not it is the timing to turn on the timing roller (40) and transport the roll paper to the transfer position. If the timing signal is 10'', step (5
47), and if it is set to "1", step (5
43), the timing flag is set to "IJ".Next, in step (544), the size determination end flag is set to "1".
．． Determine whether or not. The size determination completion flag is set to "1" when the determination of the size at which the roll paper should be cut is completed [see step (558)], therefore, rl.
If it is set to , move to step (547) and
0”, the paper feed unit (
Roll paper (31) set in (30) or (32)
) or (33), set the timer (T2) corresponding to the width size. This timer (T2) is set to the time required to cut the roll paper into a horizontal standard size. and,
In step (546), timer T2 set flag is set to 11.
Set to .

Next, in step (547), the timer (T1) is subtracted,
In step (548), it is determined whether the timer (T1) has finished counting. If the timer (T1) has not expired, the process moves to step (S59), and if it has finished, it is determined in step <549) whether or not the original image signal is 10''. The original image signal is reset to "0" when the rear edge of the original passes the light irradiation position on the glass (27) [see step (5237)]. By being conveyed at a corresponding speed, it has a meaning as a signal indicating the image length determined by the length of the document in the image scanning direction and the selected magnification. The original image signal passes through rO
When the CPU (215) sends a message indicating that the timer T2 has been reset to "0", it is determined in step (550) whether or not the timer T2 set flag is "I"0". If the timer T2 set flag is set to 1, step (558
) sets the size determination end flag to I''1. If the timer T2 set flag is 10., the paper feed unit (30) or (32) selected in step (551)
A timer (T3) corresponding to the width size of the roll paper (31) or (33) that has been completely set is set. This timer (T3) is set to the time required to cut the roll paper into a horizontal standard size.

On the other hand, if it is determined that the document is still passing through the light irradiation position and the document image signal is still set to rl in step (549), the timer T2 set flag is set to rl in step (553). Determine whether or not. Timer T
If the 2-set flag has been set to rl, the paper feed unit (30) or (32) selected in step (554)
A timer (T4) is set by correcting the timer (T2) in accordance with the width size of the roll paper (31) or (33) set in the paper roll. This timer (T4) is a timer (
T2) is corrected to the time required to cut the roll paper into a vertical size and set. And step (555
), the timer T2 set flag is reset to "r□", the timer T4 set flag is set to "1", and the size determination end flag is set to "1" in step (558). On the other hand, if the timer T2 set flag is "0.", the paper feed unit (30) selected in step (556)
Alternatively, a timer (T5) corresponding to the width size of the roll paper (31) or (33) set in (32) is set. This timer (T5) is set to the time required to cut the roll paper into a vertical size. Then, in step (557), the timer T5 set flag is set to rl, and in step (558), the size determination end flag is set to "
1. Set to .

That is, in the above cut size determination routine, the state of the original image signal is determined when the timer (11) finishes counting [see steps (548) and (549)], and the original image signal is reset to r□. For example, it is determined to cut to a horizontal standard size, and if rl remains set, it is determined to be cut to a vertical size. Specifically, if the original image signal has been reset to ``0.'' and the timing signal has already risen to ``1'' at this time, the original image signal will be cut to the horizontal standard size set in step (545). The timer (T2) is maintained in the set state, and if the timing signal has not risen to rl, the timer (T3) for cutting to the horizontal standard size is set in step (551). On the other hand, if the timing signal rises to "1" while the original image signal remains set to "1", that is, the timer (T
2) is set, in step (554) this timer (T2) is corrected and a timer (T4) for cutting to a vertical size is set. Further, if the timing signal has not risen to "1", step (55
6) Timer (T5) for cutting to vertical size
Set.

After determining the size to be cut as described above, it is determined in step (559) whether or not the timing flag is "1", and if rl, that is, the roll paper is not transported from the timing roller Once started, steps (560), <564), (568), (
In step 572), it is determined whether each timer set flag is "1" or not, and the following routine with the timer set flag set to "1" is executed. That is, each step (561), (565
), (569).

(573) and timer (T2), (T3), (T4)
, (T5), each step (562), (5
66), (570), (574) to set the timer (?2)
, (T3), (T4), and (T5) have finished counting, each step (563), (
567), (571).

(575) turns on the cutter (41), resets each timer set flag to "0", and resets the timing flag and size determination end flag to "0". It can be cut to horizontal or vertical size.

FIG. 7 shows a key processing subroutine that can be executed in step (S5) of the main routine.

In this subroutine, in step (5100), the magnification up key (113) is processed, and the step (Slot
) to process the magnification down key (114), step (51
02) to process the interrupt key (112), step (51)
03) to process the paper size select key (117), and step (5104) to process the step exposure key (115)
, (116), and the document stop key (100) are sequentially executed in step (5105).

FIG. 8 shows a subroutine for processing the magnification up key (113) executed in step (5100).

First, in the step (SLio), use the magnification up key (113
), the step (Sill) is confirmed.
The magnification key displays LED (124) to (129) are turned off in step (5112), and 171,000 is added to the magnification. This is repeated every time the magnification up key (113) is pressed, and as a result, if it is determined in step (5113) that the magnification exceeds the maximum setting value of 1.420, the magnification is increased to 1.420 in step (5114). Correct to.

FIG. 9 shows a subroutine for processing the magnification down key (114) that can be executed in step (5101).

First, in step (5120), use the magnification down key (114).
) is confirmed to be on-edge, step (5121)
Turn off the magnification key display LED (124) to (129), and change the magnification to 171000 in step (5122).
Subtract. This is repeated every time the magnification down key (114) is pressed, and as a result, step (5123)
If it is determined that the magnification has fallen below 0.500, the magnification is corrected to o or soo in step (5124).

FIG. 10 shows the subroutine for processing the interrupt key (112) executed in step (5102).

First, when it is confirmed in step (5130) that the interrupt key (112) is on, in step (5131) the 0 display (148), which determines whether or not the interrupt copying in progress display (14B) is turned off, is turned off. If so, the display (148) is lit in step (5132), the current floppy mode is memorized in RAM (212), and if the 0 display (14B) that allows interrupts is lit, the display (148) is lit in step (5133). The display (148) is turned off and the copy mode is restored.

FIG. 11 shows a subroutine for processing the vapor size select key (117) executed in step (5103).

First, when it is confirmed in step (5140) that the paper size select key (117) is on, it is determined in step (5141) whether or not the main paper feed section (30) has been selected. If the main paper feed section (30) has been selected, the sketch paper section (32) is selected in step (5142). Furthermore, if the sketch paper section (32) is selected, the main paper feed section (30) is selected in step (5143). Then, the paper size set in the paper feed section (30) or (32) selected in step (5144) is displayed on the display section (132) or (133).

FIG. 12 shows a subroutine for processing step exposure keys (115), (116), and (116) executed in step (5104).

First, in step (5150), the exposure up key (115
) on-edge is confirmed, step (5151)
It is determined whether the exposure step is the maximum value or not. If it is the maximum value, the process moves to step <5156), and if it is not the maximum value, the exposure step is increased by one step in step (5152). Next, in step (5156), the exposure step data is sent to the dimming circuit (213). do.

On the other hand, in step (5153), the exposure down key (116) is
) is confirmed to be on-edge, step (5154)
It is determined whether the exposure step is the minimum value or not. If it is the minimum value, the process moves to step (5156), and if it is not the minimum value, the exposure step is decreased by one step in step (5155).Next, in the same step (5156) as described above, the exposure step data is transferred to the dimming circuit (213). ).

FIG. 13 shows a subroutine for processing the document stop key (100) that can be executed in step (5105).

First, in step (5160), the original stop key (10
0) is confirmed to be on-edge, step (5161
), set the original stop signal to "1." Then,
In step (5162), the operation of each element of the copying machine main body (1) is stopped. At the same time, step (5163)
Reset the copy start flag and scan signal to "0" and reset the timers (TA), (TB), and (TC).

FIG. 14 shows the main routine of the CPU (215) that controls the optical system (20) and RADF (50).

When the CPU (215) is reset and the program starts, first, in step (5200), various registers are initialized and initial settings are made to put each device into the initial mode.Next, step (5201)
starts the internal timer of the CPU (215). This internal timer determines the time required for one routine of this main routine, and its value is set in advance in steps (52
00).

Next, the subroutines shown in steps (5202) and (5203) are sequentially called, and when the processing of all subroutines is completed, the process waits for the internal timer to end in step (5204), and then returns to step (5201). This one
The length of the routine time is used to count the various timers that appear in each subroutine. That is, the various timer values determine the end of counting based on how many times this one routine has been repeated.

Also, if an interrupt request is received from the CPU (201) while various processes are being executed, the CPU (201) requests an interrupt in step (5205).
01).

FIG. 15 shows the lens control subroutine executed in step (5202) of the main routine, in which the motor (M2) is controlled in accordance with the copy magnification transmitted from the CPU (201) in step (5210), and the lens (25 ), move the mirror (26).

Figures 16a and 16b show a subroutine for document conveyance foot roll executed in step (5203) of the main routine.

First, in step (5220) it is determined whether the sensor (PS8) is on-edge, and if it is on-edge, step (5220) is performed.
5221), the original insertion signal is set to "1" and the original transport motor (ti3) is turned on. Now the manuscript is RAD
F (50). Next, step (5)
Step 222) determines whether or not the sensor (PS9') is on-edge. If it is on-edge, that is, if the leading edge of the document reaches the sensor (PS9), the document transport motor (M3) is turned off in step (5223). Then, the return signal and original insertion signal are reset to 10''.

Next, in step (5234), it is determined whether the scan signal is "1." If it is "1", [see step (520), and in step (5225), the document transport motor (H3) is
Turn on. In this case, the motor (M3) is controlled at a speed according to the copy magnification, and the document is conveyed from the position of the sensor (PS9>).At the same time, timers (TD) and (TE) are set in step (S226). .Timer (I
D) is set to the time required for the leading edge of the document to reach the light irradiation position on the glass (27) from the sensor (PS9), taking into consideration the document transport speed according to the copy magnification. Further, the timer (TE) is similarly set to a time at which the timing for turning on the timing roller (40) is issued in consideration of the document conveyance speed according to the copy magnification.

Next, in step (5227), the timer (TD") is subtracted, and in step (5228), it is determined whether or not the timer (ID) has finished counting. If the timer (TD) has finished, that is, the original When the leading edge reaches the light irradiation position, the original image signal is set to I″1″ in step (5229).

Then, in step (5230), the timer (TE) is subtracted, and when it is confirmed in step (5231) that the timer (TE) has finished counting, the timing signal is set to 11'' in step (5232).

Next, in step (5233) it is determined whether the sensor (PS9) is off-edge or not, and if it is off-edge, the timer (TF) is set in step (5234) and the timing signal is reset to r□. Timer (IF)
is set to the time required for the trailing edge of the document to pass from the sensor (PS9) to the light irradiation position, taking into account the document transport speed according to the copy magnification. Next, in step (5235), the timer (TF) is subtracted, and when it is confirmed that the timer (TF) has finished counting in step (5236), step (
5237), the original image signal is reset to "O".

Next, in step (5238), it is determined whether the sensor (PSIO) is on-edge, and if it is, the return signal is set to "1" in step (5239), and in step (5240), it is determined whether the copy is completed or not. If the copy is completed, the switching claw (6
The original is ejected with 5) turned off. On the other hand, if the copying is not completed, the switching claw (65) is turned on in step (5242) to switch to document circulation.

Next, in step (5243) it is determined whether the sensor (PSII) is off-edge or not, and if it is off-edge, a timer (TG) is set in step (5244). Timer (
TG) is set to the time from when the trailing edge of the original passes the sensor (PSII) until it is ejected to the ejection tray (60). Therefore, in step (5245) the timer (TG
) is subtracted and the timer (TG) is set at step (5246).
When the end of counting is confirmed, step (5247)
At this time, the original transport motor (M3) is turned off, and the return signal is reset to "ro".

On the other hand, in step (5248), the document stop signal is set to "1".
”, and if it is “1”, [step (516
1)], and in step (5249) the document transport motor (
M3) is turned off. At the same time, in step (5250), the timing signal, return signal, and original image signal are reset to OJ, and the timer (TD), (TE), (TF),
(rG) and stop controlling the RADF (50).

[Other Examples] Note that the present invention is not limited to the above embodiments,
Various modifications can be made within the scope of the gist.

In particular, regarding document scanning methods, in addition to RADF, which circulates the document, there are also methods that transport the document one sheet at a time.
A method in which the document table is moved back and forth, or a method in which the document table is fixed and the optical system is moved back and forth may be used.

As is clear from the above description, according to the present invention, there is provided a detection means for detecting the width size of the roll paper loaded in the paper feed section;
generating means for generating an image signal indicating an image length determined by the length of the original in the image scanning direction and the selected copying magnification; Since the machine is equipped with a discrimination means that discriminates the cut length of the roll paper based on the image signal, the cut length of the roll paper is automatically determined by the discrimination means, and the operator does not have to input the cut length into the device each time. is eliminated, improving usability. Moreover, in addition to the above-mentioned configuration, a timing signal generation means for transporting the roll paper to the image forming section, and a timer means that is set based on the determination result of the determination means and starts counting when the timing signal rises; Since the apparatus includes a cutting means for cutting the roll paper when the timer means finishes counting, the cutting timing of the roll paper can be accurately controlled by the timer means, and variations in cut length can be eliminated.

[Brief explanation of drawings]

The drawings show an embodiment of the image forming apparatus according to the present invention, in which Fig. 1 is a schematic diagram of the entire apparatus, Fig. 2 is a plan view of the operation panel, Fig. 3 is a block diagram of the control circuit, and Fig. 4 is a block diagram of the control circuit. 16a to 16b are flowcharts showing the control procedure. (1)... Copying machine main body, (2>... Photosensitive drum,
(20)...Optical system, (31), (33>...Roll paper, (40)...Timing roller, (41)...
・Cutter, (50)... Automatic document circulation conveyance device (RA
DF), (PS9)...Document detection sensor.

Claims (1)

[Claims] 1. In an image forming apparatus capable of forming an image with variable magnification on a roll paper loaded in a paper feed unit, there is provided a detection means for detecting the width size of the roll paper loaded in the paper feed unit; , generating means for generating an image signal indicating an image length determined by the length of the original in the image scanning direction and the selected copying magnification; and a width size of the roll paper detected by the detecting means and from the image signal generating means. determining means for determining the cut length of the roll paper based on the image signal of the image forming unit; generating means for generating a timing signal for conveying the roll paper to the image forming section; An image forming apparatus comprising: a timer unit that starts counting when a timing signal rises; and a cutting unit that cuts the roll paper when the timer unit finishes counting.