JP2001072266A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which can enhance the productivity of copies and which can prevent the productivity of copies from being lowered due to the use of OHP synthetic paper. SOLUTION: In a copying machine 1, when an OHP synthetic paper mode is selected by depressing a setting key on a control panel OP, the formation of an image is carried out in such a condition that an OHP sheet OS fed from a manual insertion cassette 201d and a sheet (an insertion sheet) P fed from a paper feed cassette 201a are sucked simultaneously onto an image transfer drum 202. Accordingly, the time required for insertion of the sheet P can be greatly shortened. Accordingly, the productivity of copies is enhanced, thereby it is possible to surely prevent the productivity of copies from being lowered due to the use of OHP synthetic sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a sheet holding member such as a transfer drum capable of holding a sheet. More specifically, the present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction peripheral including a sheet holding member capable of simultaneously holding sheets of different types and sizes.

[0002]

2. Description of the Related Art An image forming apparatus, such as a color copying machine, for transferring a toner image to a sheet held on a transfer drum (sheet holding body) to form an image is widely known.
In such an image forming apparatus, there is a mode called an OHP interleaving mode in which a sheet is inserted between OHP sheets to form an image when an image is formed on the OHP sheet.
In the OHP interleaving mode, interleaving is performed by separately holding the OHP sheet and the insertion sheet one by one on the transfer drum. In addition, the transfer drum 2 ejected from the same paper feed port to the transfer drum 2
In some cases, two sheets are held at the same time.

[0003]

However, in the conventional image forming apparatus, there has been a problem that the productivity of copy is reduced when OHP interleaving is performed. This is OHP
This is because the interleaving is performed by separately holding the sheet and the insertion sheet one by one on the transfer drum, so that it takes extra time to pass the insertion sheet.

Accordingly, the present invention has been made to solve the above-described problems, and has been made to improve the productivity of copies and to reduce the productivity of copies that occurs when performing OHP interleaving. It is an object to provide an image forming apparatus capable of preventing the occurrence.

[0005]

According to an image forming apparatus according to the present invention which has been made to solve the above-mentioned problems, in an image forming apparatus for forming an image on a transfer material, a transfer material holding the transfer material is provided. Body, image forming means for forming an image on the transfer material held by the transfer material holding member, first paper feeding means for storing and transporting the transfer material, and second paper feeding means for storing and transporting the transfer material Means for transferring the transfer material from the first paper supply means and the transfer material from the second paper supply means, respectively.
Hold more than one sheet at a time.

In this image forming apparatus, first, the transfer material is carried out from the first paper supply means, and the carried out transfer material is held by the transfer holding member. Further, the transfer material is also carried out from the second paper supply means, and the carried out transfer material is held by the transfer holding member. That is, the transfer holding member holds at least one transfer material from the first sheet feeding means and at least one transfer material from the second sheet feeding means at the same time. Then, an image is formed on the transfer material held by the transfer holding member by the image forming means. This reduces the paper feed time,
The copy productivity is improved.

The image forming means is of an electrophotographic type,
Any of an electrostatic recording type and a direct recording type may be used.

Then, one of the transfer material from the first paper supply means and the transfer material from the second paper supply means is replaced with OH
By using a P sheet, OH
It is possible to shorten the time for passing the paper inserted between the P sheets. For this reason, a decrease in copy productivity that occurs in the OHP interleaving mode is prevented.

Further, in the image forming apparatus according to the present invention, it is preferable that either one of the first paper feeding means and the second paper feeding means is a manual paper feeding means.

Normally, special paper such as an OHP sheet is rarely stored in advance in paper feeding means, and is fed from a manual paper feeding means as needed. Therefore, by using one of the first and second sheet feeding units as a manual sheet feeding unit, the usability of the OHP interleaving mode is improved, and a decrease in copy productivity is prevented. Is done.

Further, in the image forming apparatus according to the present invention, the size of the transfer material from the first paper supply means may be different from the size of the transfer material from the second paper supply means.

As described above, by storing the transfer materials of different sizes in the first and second paper supply means, the transfer material can be efficiently held by the transfer material holder. For example, even when it is impossible to hold two B4 size transfer materials, two A4 size transfer materials are stored in one of the paper feeding units, so that the two transfer materials are simultaneously held in the transfer material holder. Can be done. For this reason,
The copy productivity is improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the image forming apparatus of the present invention will be described below in detail with reference to the drawings. The present embodiment is a digital color copier capable of reading an image of a document in a digital format and copying the image on paper in full color. The copy machine 1 according to the present embodiment has the entire structure shown in FIG. 1, and has an image reader IR and a page printer PRT.

The main body of the image reader IR is composed of a scanning system 30 for reading an image of an original placed on an original platen glass 31 by decomposing the image into pixels, quantization of a photoelectric conversion signal output by the scanning system 30 and various images. An image signal processing unit 10 that performs signal processing according to the formation mode is provided. A document cover 39 is mounted on the upper part of the main body so as to be openable and closable with its rear end as a fulcrum. Further, a white plate 38 for shading correction is provided at an end of the platen glass 31.

The scanning system 30 is a line operation type image reading mechanism, and includes a document irradiation lamp 32 and a mirror 33.
a, the first slider 35 and the mirrors 33b and 33c
The second slider 40, the condenser lens 34, and the CCD
Image sensor 36 composed of an array and slider 3
A scan motor 37 for driving 5, 40 is provided.

The page printer PRT includes a print processing unit 40 for outputting an exposure control signal, a print head 60 using a semiconductor laser 214 as a light source, a developing system 70A including a photosensitive drum 206 and its peripheral devices, a transfer drum 202 and a developing system 70A. A transfer system 70B including a peripheral device, a fixing / discharge system 70C including a fixing unit 210 and a discharge roller 85, and a circulating paper transport system 7 including a re-feed unit 600.
OD and the like. This page printer PRT,
A copy image is printed by an electrophotographic process based on the image data transferred from the image reader IR. At the bottom of the page printer PRT, three paper cassettes 201a and 201 capable of storing several hundred sheets of paper are provided.
1b, 201c and paper feed rollers 240a, 240
b, 240c. Further, on the side of the page printer PRT, a manual cassette 201d for performing manual paper feeding and a paper feeding roller 204d are provided.

The print head 60 includes the semiconductor laser 21
4 from the polygon mirror 21
5, the photosensitive drum 2 is deflected in the main scanning direction, passes through the f-.theta. Lens 216 and folding mirrors 217a and 217b.
06 to the exposure position. Photoconductor drum 206
, A charger 207 for uniformly charging the surface of the photosensitive drum 206, and cyan (C), magenta (M), and yellow (Y) on a latent image formed on the surface of the photosensitive drum 206 by exposure. ), And developing units 208C and 208 that form toner images corresponding to the respective component colors of black (K).
M, 208Y, 208K, etc. are arranged.

Around the transfer drum 202, a timing roller sensor 221 for detecting the leading edge of the sheet, a timing roller 203 for feeding the sheet to a transfer position in synchronization with the formation of the toner image, and a sheet for attracting the sheet to the transfer drum 202 A suction charger 204 and a suction roller 212; a transfer charger 205 for transferring a toner image onto a sheet at a transfer position;
A separation charger 209 for separating the sheet after transfer from the transfer drum 202, a push-up member 223, and a separation claw 225, an oil removing roller 224 for removing oil on the transfer drum 202 from which the sheet has been separated, and the transfer drum 2.
02 static elimination chargers 230a and 230b for static elimination,
A transfer drum sensor 219 for detecting the reference position of the transfer drum 202 is provided.

The push-up member 223 can push up or release the sheet by the solenoid SL1. . Further, the oil removing roller 224 is
The transfer drum 202 can be brought into contact with or separated from the transfer drum 202 by the solenoid SL2. Further, the suction roller 212 moves the transfer drum 202 by the solenoid SL3.
Can be in contact with or separated from.

The refeed unit 600 is mounted on the side of the page printer PRT as an additional device for automating double-sided copying. The re-feed unit 600 has a function of temporarily storing the paper discharged from the main body of the page printer PRT by the discharge rollers 85 in the duplex copy mode, performing switchback conveyance, and returning the paper to the main body of the page printer PRT. . For this reason, the sheet re-feed unit 600 causes the sheet discharged from the discharge roller 85 to move downward in FIG. 1 by the switching claw 601 and the transport roller 602, and when the rear end reaches the sheet sensor SE61, the forward / reverse roller 603 is inverted. The paper is returned to the main body of the page printer PRT. A horizontal transport roller 86 is provided in the main body of the page printer PRT, and the returned paper is guided to the transfer drum 202 again so as to be turned upside down from the previous time. Further, a paper discharge tray 211 is attached outside the re-feed unit 600.

An operation panel OP for inputting an operation instruction for the entire copying machine is provided at an upper portion of the copying machine 1. As shown in FIG. 2, the operation panel OP has a touch panel 91 for making detailed settings such as copy density and magnification, and a numeric keypad 9 for inputting numbers such as the number of copies and a copy magnification.
2, a clear key 93 for returning the set value to the standard value "1", a panel reset key 94 for returning the set value set in the copying machine 1 to the standard value, a stop key 95 for stopping the copy operation, and a copy operation. A start key 96 for starting is provided.

Further, a setting key 97 for setting an OHP interleaving mode as a copy mode is provided on the operation panel OP.
A setting key 98 for setting an interleaf copy mode in which copying is also performed on interleaf paper, a read completion key 99 for inputting completion of reading of all originals to the apparatus, and the set copy mode is an OHP interleaf mode. And a display unit 98a for displaying that the mode is the slip sheet copy mode. When the OHP interleaving mode is set but the interleaving copy mode is not set, the interleaving blank mode is set.

A schematic configuration of a control system for sheet conveyance in the copying machine 1 will be described. As shown in FIG. 3, this control system is mainly configured by a CPU 60 that performs overall control of the entire copying machine. The CPU 60 includes a paper feed drive circuit 6 for controlling the driving of each of the paper feed rollers 204a to 204d.
2. The transfer drum drive circuit 61 that controls the drive of the transfer drum 202, the transfer drum sensor 219, the timing roller sensor 221, the touch panel 91, and the like are connected.

Next, the operation of the copying machine 1 will be described. When the operator sets a document on the platen glass 31 and inputs a copy start command, the image reader IR performs the following operation. First, an image is read by the scanning system 30. That is, in the scanning system 30, the CPU
By the control of 60, the first slider 40 and the second slider 35 move in the main scanning direction while the document irradiation lamp 32 emits light. This image reading is performed a total of four times in order to obtain image data for each color component of cyan (C), magenta (M), yellow (Y), and black (K).

The image data is sent to the image signal processing unit 1
0, each color component is separated, and shading correction, gamma correction, scaling processing,
It receives rotation processing and other image processing.

On the other hand, in the page printer PRT, the CPU
Under the control of 60, one sheet suitable for the size of the document is taken out from one of the paper cassettes 201 a to 201 c or the manual cassette 201 d and is conveyed to the transfer drum 202. In addition, the photosensitive drum 206 and the transfer drum 202 are rotated, and their peripheral devices are driven.

In synchronization with the conveyance of the sheet, first, the image data corresponding to cyan (C) among the image data decomposed into the respective color components by the image signal processing unit 10 is sent to the print processing unit 40. Therefore, an exposure control signal corresponding to cyan (C) is output from the print processing unit 40, and the electrostatic latent image of cyan (C) is written on the photosensitive drum 206 by the print head 60. A toner image is formed on the latent image by the developing device 208C, and the toner image is transferred to the transfer drum 202.
Is transferred to the paper adsorbed on the paper. Thereafter, the same processing is performed for the components of magenta (M), yellow (Y), and black (K).

The sheet on which the toner images of the four colors have been transferred is separated from the transfer drum 202 by the separation charger 209, the push-up member 223, and the separation claw 225. The separated sheet is fixed by the fixing unit 210 and then discharged face-up onto the sheet discharge tray 211.
However, in the case of the duplex copy mode, the refeed unit 6
After being switched back at 00, the sheet is guided to the transfer drum 202 again by the horizontal transport roller 86.

Next, a control routine of the copier 1 for performing a printing process by the above basic operation will be described. First,
A main routine executed by the CPU 60 will be described, and then a subroutine in the main routine will be described.

CPU 6 shown in the flowchart of FIG.
The main routine executed at 0 will be described. First, initial settings are made (# 1). Next, an internal timer for keeping the processing time of one routine constant is set and time measurement is started (# 2). Then, a key input process for an input signal is executed from the operation panel OP (#
3). Subsequently, it is determined whether or not the copy flag F is "1"(# 4). The copy flag F is a flag set in the key input process, and details thereof will be described later. When the copy flag F is "1"(# 4: YES), after the copying operation, that is, the image forming operation is performed under the operating conditions set in the key input process (# 5),
Control processing of other internal mechanisms is executed (# 6). The other processes include a cleaning process of the transfer drum 202, a display process of the touch panel 91, a temperature control process of the fixing device 210, and the like. After that, it waits for the end of counting of the internal timer (# 7), and returns to the process of # 2. If the copy flag F is not "1" in # 4 (# 4: NO),
The process goes to # 7 by bypassing # 5 and # 6.

Next, # 3 shown in the flowchart of FIG.
Will be described with reference to the flowchart of FIG. First, it is determined whether or not the OHP interleaving mode is set (# 8). This determination is made by turning on the setting key 97 of the operation panel OP. When the OHP interleaving mode is set (# 8: YES), the display unit 97a is turned on,
Further, it is determined whether or not copying is to be performed on the slip sheet, that is, whether or not the slip sheet copy mode is set (# 9). This determination is made by turning on the setting key 98 of the operation panel OP. When the slip-sheet copy mode is set (# 9: YES), the display section 98a is turned on and the slip-sheet copy mode is set (# 10). on the other hand,
If the slip sheet copy mode is not set (# 9:
NO), the slip sheet blank copy mode is set (# 1)
1). When the slip-sheet copy mode or the slip-sheet blank mode is thus set, the number of sheets that can be attracted to the transfer drum is determined by the CPU 60 based on the diameter of the transfer drum and the size of the sheet to be fed. In addition, in # 8, O
If the HP slip sheet mode is not set (# 8: N
O), bypassing # 9 to # 11 and proceeding to # 12.

Next, the input from the ten keys 92 is accepted (# 12), and other key inputs are processed (# 13). Thereafter, it is determined whether or not the print key 96 has an on-edge (# 14). If there is an on-edge (# 14: YES), the above-described copy flag F is set to "1"(# 15), and the process returns to the main routine. On the other hand, if there is no on-edge (#
14: NO), and immediately return to the main routine. The copy flag F is reset when a series of copying operations is completed.

When the print key 96 is pressed to return to the main routine, the copy flag F is set to "1" at # 15, so that the copy operation and other processing are performed at # 5 and # 6 shown in FIG. Is executed. At this time, the copy operation in # 5 is performed under the conditions set in the key input processing subroutine shown in FIG. 5, that is, in accordance with the copy mode set in the processes in # 8 to # 11, the copy operation set in # 12. The copying operation for the number of sheets is performed.

Here, the copying operation when the OHP interleaving mode which is a feature of the present invention is set will be described in detail with reference to the flowchart of FIG. # 1 shown in FIG.
In steps # 5 and # 16, when the print key 96 is pressed and the copy flag F is set to "1", the paper feed drive circuit 6
2. The transfer drum drive circuit 61 is turned on, and the transfer drum 202 is driven to rotate (# 16). And
When the transfer drum 202 rotates and the on output of the transfer drum sensor 219 is detected (# 17: YES), after a lapse of a predetermined time from the ON timing, the upper sheet cassette 201a in which the A4 horizontal sheet is set is set. Paper feed roller 2
04a is driven, and a paper (A4 landscape) sheet feeding operation is started (# 18). Subsequently, after a predetermined time has elapsed from the turning on of the paper feed roller 204a, the paper feed roller 204d of the manual feed cassette 201d in which the OHP sheet is set is set.
Is turned on, and an OHP sheet feeding operation is started (# 19). The above-mentioned predetermined time is determined by the system speed of the copier 1, the distance of the transport path, and the sheet interval.

Then, it is determined whether or not the leading edge of the sheet fed from the sheet cassette 201a is detected by the timing roller sensor 221 (# 20). When the ON output of the timing roller sensor 221 is detected (# 20: YES), the feeding operation of the paper and the OHP sheet is stopped after a predetermined time has elapsed (# 21,
# 22). On the other hand, if the ON output of the timing roller sensor 221 is not detected (# 20: NO), the standby state is established. The predetermined time is determined by the system speed of the copier 1, the distance of the transport path, the paper size, and the paper interval.

After the paper feeding operation is stopped, the transfer drum sensor 21
When the ON output of No. 9 is detected (# 23: YES), the timing roller 203 is rotated (# 24), and the paper and the OHP sheet are conveyed to the transfer drum 202. And
As shown in FIG. 7, the paper P and OH are transferred to the transfer drum 202 by the suction charger 204 and the suction roller 212.
The P sheet OS is sucked (# 25). The timing at which the timing roller 203 is turned on and the like are controlled so that the sheet interval when the sheet and the OHP sheet are attracted to the transfer drum 202 is constant. For example, if the diameter is 200
mm transfer drum, use paper (A4
Since the width of the OHO sheet is 210 mm, the sheet interval is 104 mm (= (200 × 3.14-2).
The timing is controlled so as to be 10 × 2) / 2).

After the timing roller 203 is stopped (# 26), the OH adsorbed on the transfer drum 202 by the developing system 70A and the transfer charger 205.
An image forming process is performed on the P sheet OS (# 2)
7). Here, at the same time as the OHP sheet OS, the transfer drum 2
If the slip sheet copy mode is set, the same image forming processing as that performed on the OHP sheet OS is performed on the sheet P sucked at 02. Note that when the interleaf blank mode is set, the image forming process on the paper P is not performed.

Thereafter, a separation process (# 2) by the separation charger 209, the push-up member 223, and the separation claw 225 is performed.
8) The fixing process by the fixing device 210 (# 29) and the discharge process by the discharge roller 85 and the like are executed (# 30), and it is determined whether or not there is the next paper feed (# 31). If there is the next paper feed (# 31: YES), the process returns to # 17 and the same processing as described above is repeated. On the other hand, if there is no next paper feed (# 31: NO), the copying operation ends and returns to the main routine.

As described in detail above, according to the copying machine 1 of the present embodiment, the setting key 9 of the operation panel OP
7, the OHP sheet OS from the manual feed cassette 201d and the paper cassette 2
01a from the transfer drum 202
In this state, the image is formed while being sucked at the same time. For this reason, the time for passing the paper P is greatly reduced. As a result, the productivity of copy is improved.
It is possible to reliably prevent a decrease in copy productivity that has occurred when performing P-insertion.

The above-described embodiment is merely an example, and does not limit the present invention in any way. Needless to say, various improvements and modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, transfer materials of the same size (A4 size paper and OHP sheet)
Is illustrated on the transfer drum. However, as shown in FIG. 8, it is also possible to simultaneously absorb B4 size paper PB4 and A5 size paper PA5, that is, transfer materials of different sizes.

Further, as shown in FIG. 9, when the diameter of the transfer drum is large, two or more transfer materials can be adsorbed. For example, as shown in the drawing, if three transfer materials are adsorbed, two OHP sheets OS1 and OS2 and a sheet P1 are adsorbed by the first adsorption, and two sheets P2 and P2 are adsorbed by the second adsorption. P3 and OHP sheet OS3
, Three sets of OHP slip sheets can be created more efficiently. By repeating the same operation, OHP interleaving can be performed very efficiently even when there are many originals.

Further, in the above-described embodiment, the case where paper is fed from the upper paper feed cassette 201a and the manual feed cassette 201d has been described as an example. However, the present invention is not limited to these paper feed means, and a combination of other paper feed means, for example, Paper cassette 2
Needless to say, the present invention can be applied to a combination of the paper feed cassettes 01a and 201b or the paper feed cassette 201c and the manual feed cassette 201d.

Further, in the above-described embodiment, the transfer material holding member provided with the transfer drum is exemplified, but a transfer belt may be provided instead of the transfer drum.

[0044]

As described above, according to the image forming apparatus of the present invention, two or more transfer materials carried out from different paper feeding means are simultaneously held on the transfer holding body. This allows
Copy productivity is improved. For this reason, even when performing OHP interleaving, the productivity of the copy does not decrease.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a copying machine according to an embodiment.

FIG. 2 is a plan view showing a configuration of an operation panel.

FIG. 3 is a block diagram illustrating a configuration of a control unit (mainly, a sheet transport system) in the copying machine of FIG. 1;

FIG. 4 is a flowchart showing a control process of an overall operation in the copying machine of FIG. 1;

FIG. 5 is a flowchart illustrating a key input control process.

FIG. 6 is a flowchart illustrating a control process of a copying operation when an OHP interleaving mode is set.

FIG. 7 is an explanatory diagram for explaining a state in which a transfer material is attracted to a transfer drum.

FIG. 8 is an explanatory diagram for explaining a state in which transfer materials of different sizes are attracted to a transfer drum.

FIG. 9 is an explanatory diagram for explaining a state in which two or more transfer materials are attracted to a transfer drum and a procedure for performing OHP interleaving in such a state.

[Explanation of symbols]

 1 Copy machine 97 Setting key (OHP interleaf mode) 98 Setting key (Interleaf copy mode) 202 Transfer drum 204 Suction charger 212 Suction roller 201a-201c Paper cassette 201d Manual cassette OP Operation panel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 DC19 ED17 ED18 ED24 FA15 FA27 FA30 3F343 FA07 FA09 FB02 FB03 FB04 HA12 HA14 HB02 HB03 KB03 KB07 KB17 KB18 MB03 MB10 MB13 MB19 MC21 MC22

Claims (4)

[Claims] 1. An image forming apparatus for forming an image on a transfer material, comprising: a transfer material holder for holding the transfer material; an image forming means for forming an image on the transfer material held by the transfer material holder; A first paper supply unit for storing and carrying out the transfer material, and a second paper supply unit for storing and carrying out the transfer material, wherein the transfer material holding body is provided with a transfer material from the first paper supply unit. And an image forming apparatus for simultaneously holding one or more sheets of the transfer material from the second sheet feeding means. 2. The image forming apparatus according to claim 1, wherein one of the transfer material from the first paper supply unit and the transfer material from the second paper supply unit is an OHP sheet. An image forming apparatus comprising: 3. The image forming apparatus according to claim 1, wherein one of the first sheet feeding unit and the second sheet feeding unit is a manual sheet feeding unit. apparatus. 4. The image forming apparatus according to claim 1, wherein a size of the transfer material from the first paper supply unit and a size of the transfer material from the second paper supply unit are different. Image forming apparatus.