JP2558893B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus for multiplex copying, and more specifically, it relates to an image forming apparatus for multiple copying, and more specifically, images of two originals are formed in the front half and the rear half of one sheet, respectively. The present invention relates to an image forming apparatus for copying.

(B) Conventional technology Conventionally, when two originals are copied side by side on one sheet, it is possible only by placing the two originals side by side on the original table, and automatically copying in the above mode. No proposal has been made for an image forming apparatus that executes the above method.

(C) Problems to be Solved by the Invention However, when copying two originals onto one sheet, it is necessary to place the two originals on the original table in a precise arrangement, and the operator must be careful. It required careful operation. Further, when there are a large number of originals, the operator has to perform the above operation many times, which requires a great deal of labor.

Therefore, according to the present invention, by changing the image forming timing of the multi-copy machine with respect to the first original or the two originals, two originals can be automatically copied onto one sheet. The purpose is to provide a device.

(D) Means for Solving the Problems The present invention has been made in view of the above circumstances,
An image forming unit is provided which reads an image of a document and forms the read image on a sheet conveyed by a conveying unit. In order to form an image by the image forming unit on different areas of the same surface of the sheet, image forming is performed. In an image forming apparatus for feeding a completed sheet to the conveying means by the re-feeding means and forming an image again on the sheet conveyed by the conveying means by the image forming means, the first sheet on the leading end side in the sheet conveying direction is provided. When the image is formed in the area of, the time after the image forming means starts the image forming operation.
After t ₃ has passed and the specified state has been reached,
When a sheet is started to be conveyed by the conveying means after t ₁ and an image is formed in the first area and an image is formed in the second area on the trailing end side of the sheet in the conveying direction, the conveying means is used. After a lapse of a predetermined time t ₂ from the start of sheet conveyance, the image forming operation by the image forming unit is started, and
a control means for controlling the image forming means and the conveying means so that an image is formed on the second area after passing through the first area by the conveying means after passing t ₃ and t ₁ . It is characterized by

For example, the image forming means has a scanning optical system for scanning and reading a document, and when the image is formed on the first area of the sheet, the predetermined state means that the scanning optical system is located at the leading edge of the document. In this state, the time required for the scanning optical system to reach the leading edge of the document after the scanning optical system starts scanning is the time t ₃ .

In the case of forming an image on the second area of the sheet, the scanning optical system starts scanning after the predetermined time t _{2 has} elapsed from the start of the sheet transportation by the transportation unit, and the _second scanning is performed. The control means controls the image forming means so as to form an image in the area.

Further, the image forming means has a photoconductor for converting the image information from the scanning optical system into a latent image and transferring the latent image as a toner image onto a sheet at a transfer position. After the predetermined time t ₁ from the reached predetermined state, the transporting means starts transporting the sheet, and the control means controls the transporting means so that the leading edge of the toner image of the photoconductor and the leading edge of the sheet coincide with each other. Be controlled.

Further, the first region is a half portion on the leading end side of the sheet in the sheet conveying direction, and the sum t ₁ + t ₂ + t ₃ of the respective times is because the sheet conveying means passes half the sheet length in the sheet conveying direction. This is the time required for carrying.

Then, the document is placed on the document placing means for reading the document.
An automatic document feeding means for automatically feeding the sheets one by one is provided, and images of a large number of the originals are sequentially arranged two by two on one sheet to automatically form an image.

(E) Operation Based on the above configuration, in the first region on the leading end side in the sheet conveying direction, a predetermined state in which a predetermined time t ₃ has elapsed after the image forming means starts the image forming operation, for example, the traveling optical system is set to the original An image is formed in the first area after a lapse of a predetermined time t ₁ from the state of reaching the leading edge, for example, a time corresponding to the leading edge of the toner image on the photoreceptor of the image forming unit and the leading edge of the sheet. .

Then, in the second area on the trailing end side of the sheet conveyance direction, the conveyance means is first driven, the image forming operation is started after a lapse of a predetermined time t ₂ , and further the time t ₃ and t _{1 are} elapsed. Then, an image is formed in the second area in a state where the image has passed through the first area.

Thus, for example, the first original placed on the original placing table is image-formed in the first area, and the second original placed at the same position is located on the trailing edge side of the sheet conveyance. The second area at the same timing as the first area.
The image is formed in the area.

(F) Example An example of the present invention will be described below with reference to the drawings.

FIG. 2 shows an embodiment of the present invention. Reference numeral 1 is a copying machine, and 2 is its main body. Reference numeral 3 denotes a circulation type document feeder (hereinafter, referred to as RDF) for automatically feeding a document, which can be freely combined and used with the main body 2.

The main body 2 includes a platen 4, a light source 5, and mirrors 6,7,8,9,1.
Two cassettes 1 for storing 0, 11, lens 12, sheet P
The cassettes 13 and 14 are provided with paper feed rollers 15 and 16, respectively. Further, on the upper left side of the main body 2, a home position sensor S ₁ for detecting the home position of the optical system such as the light source 5 and the mirrors 6, 7, 8 is provided.
An image tip sensor S ₂ corresponding to the leading end position of the document placed on the platen 4 is provided, and a sensor S ₃ for detecting the maximum movement position of the optical system is provided on the upper right side. In the vicinity of the cassettes 13 and 14, sheet presence / absence sensors S ₄ and S ₄ for detecting the presence / absence of the sheet P, and lifters (not shown) of the cassettes 13 and 14 are shown.
Lifter sensors S ₆ and S ₇ and cassettes 13 and 14 that detect the position of
Sheet size sensors S ₈ and S ₉ for detecting the size of the sheet stored in the are provided. Then, the paper feed roller 15,
A transport roller pair 17, 18 is disposed downstream of 16,
A sheet sensor S ₁₀ for detecting the sheet P and a registration stroke pair 19 are arranged downstream of the roller pairs 17 and 18. Further, a copying unit 20 is arranged downstream of the roller pair 19, and a fixing device 22 including a conveying device 21 and a heater 22a is arranged downstream of the copying unit 20. Then, at the downstream side of the fixing device 22, the paper discharge sensor S11 and the conveyance roller 2
3, a flapper 24 and a paper discharge roller 25 are arranged, and a paper discharge tray 26 is provided downstream of the paper discharge roller 25.
Further, a re-conveying path 27 is provided by being branched to the flapper 24, and the re-conveying path 27 has a conveying roller pair 28, a sheet sensor S12, a reversing roller pair 29, a sheet sensor S13, and a re-feeding roller pair 30. Also, an intermediate tray 31 is provided. The reversing roller 29 is driven by a stepping motor (not shown) so that the sheet P can be conveyed in both upstream and downstream directions.

Further, a laser unit 32 is arranged in the main body 2, and the unit 32 includes a laser emitting section 33 and a polygon mirror 3
4. It is composed of a polygon motor 35 and a mirror 36. A reference numeral 37 in the figure denotes a shutter that blocks the light projected on the copying section 20. Further, the copying section 20 is provided with a cylindrical photosensitive drum 38, and around the drum 38,
An erase lamp 39, a primary charging device 40, a color developing device 41, a developing device 42, a transfer charging device 43, a separation charging device 44 and a cleaner 45 are arranged.

In the figure, 41a is a color developing device pressurizing solenoid, and 42a is a black developing device releasing solenoid.

On the other hand, as shown in FIG. 3, the copying machine 1 is provided with an operation section 55, and the operation section 55 has a power switch 56 at the right end, and a reset / stop key 57 and a start button 57 on the left side thereof. A key 59 is provided. Then, on the back side of the start key 59, there are arranged a color developing device selection switching key 60, a date indication key 61 for instructing a date writing mode, and a number instruction key 62 for instructing number loading.
A numeric keypad 63 is arranged on the left side of the start key 59. Further, on the back side of the ten-key pad 63, a copy number indicator 65 for displaying the number of copies input by the ten-key 63, a no-sheet indicator 66 for displaying a no-sheet alarm, and a jam alarm indicator for notifying a jam occurrence. 67 is arranged, and on the left side of the numeric keypad 63, a selection key 68 for selecting the cassette 13 or 14 and a cassette display 69 for displaying the cassette size are arranged. Further, on the left side of the selection key 68, the copy density adjustment key 70, the same size key 71, and the copy magnification are set to 1
A zoom key 72 for instructing a predetermined magnification in units of%, and a fixed magnification key 73 for instructing a fixed reduction or a fixed enlargement magnification are arranged, and a magnification display 75 for displaying the copy magnification is provided on the back side of the fixed magnification key 73. It is arranged. Various instruction keys are arranged on the left side of the zoom key 72,
Reference numeral 76 is an instruction key for instructing to erase the frame of the copy sheet, 77 is an instruction key for instructing a binding margin action at one end of the sheet, 79 is an instruction key for instructing a photo mode, 80 is a multiplex key for selecting the multiplex mode, and 81 is Page continuous shooting key to instruct page continuous shooting,
Reference numeral 82 is a double-sided copy key for selecting the double-sided copy mode, 83 is an instruction key for instructing the operation mode (sort mode or group mode) of the sorter 85 shown in FIG. 1, and 84 is a key for selecting a continuous shooting page multiplex mode described later. Is.

On the other hand, as shown in FIG. 1, the copying machine 1 includes a control unit 86, which controls the microcomputer, the ROM,
It is composed of RAM and timer. The sensors S ₁ , ... Are connected to the input unit of the control unit 86,
The output unit includes a laser unit 32, a shutter 37, and a buzzer 8
7, AC of lamp 5 and heater 22a etc. via AC driver 89
Each charger 40, 43, 44 and a load 90 such as a solenoid, a clutch, and a fan are connected via a load and a high-voltage generator HVT, and further, an input / output unit is provided with an operation unit 55, a sorter 85, and a document feeder. 3. A main motor 93, an optical motor 95, and a stepping motor 96 are connected via a motor control unit 92.

 Next, RDF will be described with reference to FIG.

In RDF3, 100 is a stacking tray on which the document bundle S is set. First, at the time of one-sided document, the separation motor 101 is driven to move the document bundle S by the half-moon roller 102, the separation conveyance roller 103, and the separation belt 104. By separating from the bottom one by one, by driving the belt motor 105,
The pair of registration rollers 106a and 106b and the full-face belt 107 convey the sheet to the exposure position on the platen glass 4 via the paths I-II and then stop, and the copying operation starts. After the copying is completed, the belt 107 is used for pass III and the large conveyance roller 108 is used.
Sent to path IV by the paper ejection roller 109,
It is returned to the upper surface of the document stack S again. Reference numeral 110 denotes a recycle lever that detects one circulation of the originals. The recycle levers are placed on the upper part of the original bundle S at the start of feeding the originals, and the originals are sequentially fed. When the trailing edge of the final original leaves the recycling lever 110, it falls by its own weight. By doing so, one cycle of the document is detected.

Next, in the case of a double-sided original, the original is first guided from paths I, II to III as described above, and the flapper solenoid (not shown) is driven there to switch the rotatable flapper 111 in the direction of the dotted line in FIG. Pass IV to V at the leading edge of the document
And passes through the path II by the pair of registration rollers 106a and 106b between the front surface belt 107 and the platen glass 4 (path II
Stop after transporting to I). That is, the document is inverted by the large conveyance roller 108 along the paths of paths III to IV to V to II.

Further, the number of documents can be counted by transporting the document bundle S one by one through the buses I to II to III to IV until the recycle lever 110 detects one by one.

 Next, the operation of this embodiment will be described.

When the power switch 56 is turned on, the controller 86 causes the fuser 22
The heater 22a is turned on. Then, the temperature of the fixing device 22 is 190
When the temperature reaches ℃, the main motor 93 is rotated and the photosensitive drum
When 38 turns once, the control unit 86 stops the main motor 93. Here, the copying machine 1 is in a copy ready state (standby state). Then, when the start key 59 is pressed, as shown in FIG. 5, the controller 86 turns on the main motor 93, the high-voltage generator, and the document feeder 3, and at the same time, performs the paper feeding operation, that is, the cassettes 13 and 14. After the middle plate is lifted, the clutch (not shown) of the paper feed roller 15 or 16 is turned on, and the sheet P
After a lapse of a predetermined time from the sheet sensor S ₁₀ detecting the sheet P, the clutch is turned off in a state where the sheet P contacts the registration roller pair 19 and is curved. When the sensor (not shown) detects that the photosensitive drum 38 uniformly charged by the primary charger 40 has rotated about one turn when the main motor 93 is turned on, the controller 86 turns on the lamp 5.
The optical motor 95 is turned on, the optical system such as the lamp 5 and the mirror 6 is moved forward for the exposure scanning of the original on the platen 4, and the registration is performed after a predetermined time t ₁ after the image sensor S ₂ detects the image. Turn on the roller pair 19. That is, the time from the position where a latent image is formed on the photosensitive drum 38 to which the image light from the mirror 11 or 36 is radiated and the position where the drum rotates and the toner image is transferred to the sheet. And the registration roller
The registration roller 19 is started to drive after a predetermined time t ₁ which is a difference from the time when the leading edge of the sheet is conveyed from 19 to the transfer position. Similar to the ON operation of the roller pair 19, the control unit 86 turns on the paper feed clutch for a predetermined time, rotates the paper feed rollers 15 and 16 again, and continuously feeds the sheet P. Further, the registration roller pair 19 is rotated only for the time corresponding to the sheet size. At this time, the sheet P sandwiched by the pair of registration rollers 19
Is conveyed in synchronization with the image visualized on the photosensitive drum 38. When the optical system scans the original, the laser unit
With 32, you can erase any place in the image and write simple characters such as the date and No. The image on the drum 38 is transferred to the sheet P by the transfer charger 43,
It is separated from the photosensitive drum 38 by the separation charger 44. At this time, when the optical system such as the lamp 5, the mirror 6 ... Is detected by the sensor S ₃ , the optical system is reversed and returned to the home position. The sheet P on which the image is transferred is conveyed to the fixing device 22 by the conveying unit 21, and the image is fixed by the fixing device 22. Further, the sheet P is conveyed to the flapper 24 by the conveyance roller 23.
The sheet is conveyed to a sheet discharge roller 25 by the flapper 24, and is discharged to the sheet discharge tray 26 by the roller 25.

Next, a multiple copy mode, which is a reference example which is the basis of the present invention, will be described.

In the normal multiple copy mode, as shown in FIG. 6, an image like a copy sheet P is obtained from a document a and a document b.
As shown in FIG. 7, this multiplex copy is performed on the first original a.
Is a mode in which the sheet P is stored in the intermediate tray 31 and then the second document b is copied onto the sheet P re-fed from the intermediate tray 31. This timing chart is shown in FIG. 8 when RDF3 is not used, and in FIG. 9 when RDF3 is used. When RDF3 is not used, paper feed is started by copy start. When the paper feeding operation is completed, the optical system starts to move forward, and when the sensor S ₂ outputs the image destination signal, the control unit 86 counts the time,
When the control unit 86 counts that t ₁ time has elapsed, the control unit 86 turns on the registration roller pair 19 so that the conveyance of the sheet P is synchronized with the image on the photosensitive drum 38. FIG. 10 shows a flow chart from the start of sheet feeding to the registration roller pair 19 being turned on. Regarding the start of the registration roller pair 19 from the paper feeding shown in this flowchart, the first and second sides of the multiplex copy are the same as the case of the normal single sided copy.

Next, an embodiment according to the present invention will be described for the continuous shooting page multiplex mode selected by the key 84.

In the continuous shooting page multiplex mode, as shown in FIG. 12, a copy like a copy sheet P is made by using the originals c and d. That is, the original c is copied to the first half of the sheet P, the original d is copied to the second half of the sheet P, and two originals are staggered and copied to the first and second half of the sheet P.

The flow for performing the continuous shooting page multiplex mode is similar to general multiplex copy. FIG. 13 (a) shows the case where RDF is not used, and FIG. 13 (b) shows the case where RDF is used. . That is, when the paper feeding operation is completed, the optical system starts moving forward. When the image-front signal is emitted by the sensor S ₂ , the registration roller 19 is turned on after a certain time t ₁ and the photosensitive drum
Control is performed so that the leading edge of the image on the sheet 38 and the leading edge of the sheet P coincide with each other (see FIGS. 10 and 11).

Next, regarding the case of the second side copy,
It will be described with reference to FIG.

After the originals are exchanged, or if the originals are exchanged by RDF3, the refeeding operation is performed from the intermediate tray 31, and when this operation is completed, the registration roller 19
Is turned on, and the sheet P is conveyed to the copying unit 20. Predetermined time t ₂
After a lapse of time, the optical system starts to move forward, and the optical system and the registration roller 19 are controlled so that the image is transferred to the latter half of the sheet P. Image on drum 38 and copy sheet P at this time
The positional relationship with and is shown in FIG. As shown, the sheet P leads the image on the drum 38.

Therefore, the time t ₂ until the optical system starts to move forward after the registration roller 19 is turned on will be described. From the optical system operation start (OFF signal of the home position sensor S ₁ ) to the sensor S ₂
Is the time from when the optical system is detected to be at the image leading edge position to when it is turned on, t ₃ is a time preset as the optical system, and time t ₁ + t ₂ + t ₃ is when the registration roller 19 is the length of the sheet P. It is a time for conveying half of the time, and is a preset time, and t ₁ is, as described above, from when the signal of the image sensor S ₂ of the optical system is emitted until the registration roller 19 is turned on. Since there is time, it is possible to easily set time t ₂ , that is, the time from when the registration roller 19 is turned on to when the advance of the optical system is started.

When the copy magnification is changed, the time t ₃ from the start of the operation of the optical system until the sensor S ₂ detects that the optical system is at the image tip position changes. This obviously changes the time t ₂ .

If a DC motor is used to drive the optical system, time t ₃
Although somewhat varies, when using the stepping motor, since the time t ₃ can be known accurately, a copy of the second half of the copy sheet P can be accurately.

In order to set the time t ₃ , firstly, the time from the start of the advance of the optical system to the detection of the image tip by the sensor S ₂ is set in advance and stored in the control unit 86. Secondly, there is a method in which the control unit 86 calculates the rising characteristics of the optical system. When a stepping motor is used to drive the optical system, the time t ₃ can be calculated in advance at each copy magnification, so this value can be stored in the control unit 86 and the calculation can be omitted during the copy operation. .

Depending on the copy magnification, the timing to start the advance of the optical system may be 17th less than the timing to turn on the registration roller 19.
As shown in the figure, although it may be faster, since the position to transfer the image (the center of the sheet P) is known, the time t ₄ for moving the half of the sheet P length by the registration roller 19
Since the times t ₁ and t ₂ are known in advance, the value of the time t ′ ₃ (the time difference between the start of the advance of the optical system and the turn-on of the registration roller 19) can be obtained.

Thus, the copy as shown in FIG. 12 can be obtained accurately.

The above description is for carrying out the continuous shooting page multiplex mode by shifting the timing of copying the second side of the multiplex copying, but performing the continuous shooting page multiplex mode by shifting the timing of copying on the first side of the multiplex copying. You can also do it. RDF
Fig. 18 shows the timing chart when not using the
The timing chart when F is used is shown in FIG. By doing so, a copy as shown in FIG. 20 can be made.

Although not shown in the timing chart, unnecessary portions of the image can be erased by the laser unit 32. 12th
Explaining with reference to the figure, when copying the original c,
The image area of the portion corresponding to the right side of the copy sheet P is erased, and when copying the document d, the image area of the portion corresponding to the left side of the copy sheet P is erased.

Further, in FIGS. 15 and 19, RDF is used to obtain one copy sheet P from two originals, but when there are three or more originals, the flowchart shown in FIG. 21 is used. As described above, when the originals are exchanged one after another and copying is continued, copy sheets as shown in FIGS. 12 and 20 can be obtained one after another.

(G) Effect of the Invention As described above, according to the present invention, an image read from two originals is processed into a first region on the leading end side and a second region on the trailing end side of one sheet in the conveyance direction. Since the images can be formed side by side in the area, it does not require troublesome work such as accurately arranging two originals on the original placing table, and saves the number of sheets while saving labor, and also saves resources. be able to.

Further, when an image is formed in the second area, the image forming operation is started by the image forming means after a predetermined time has elapsed from the start of the sheet conveyance by the conveying means, so that the second area on the rear end side in the conveying direction is also formed. The image can be formed quickly as in the first area, and the image forming efficiency can be improved.

Further, by driving the scanning optical system for reading the original by the stepping motor, the accuracy of forming the images of the two originals side by side on one sheet can be improved.

Further, by being able to copy the images of the two originals with the right and left sides of the one sheet being different from each other, there is an effect that it can be applied to either Japanese-style binding or Western-style binding.

In addition, the automatic document feeding means can arrange the images of a large number of documents one by one on two sheets one by one and automatically copy the images, which can significantly reduce the labor of the operator.

[Brief description of drawings]

FIG. 1 is a control block diagram of an embodiment of the present invention, FIG. 2 is a vertical sectional side view showing the whole, FIG. 3 is a front view showing its operating portion, and FIG. 4 is a vertical sectional view showing its original feeding device. FIG. 5 is a side view, FIG. 5 is a time chart of the image formation, and FIG. 6 is an explanatory view of general double copy which is a reference example which is a basis of the present invention.
Figure 7 (a) shows the case where RDF is not used, and Figure 7 (b) shows R
Flowchart when DF is used, Fig. 8 is a time chart of general double copying when RDF is not used, Fig. 9 is a general double copy when RDF is used, and Fig. 10 is from feed to registration roller on. Flow chart of copying, FIG. 11 is an explanatory view showing the relationship between the sheet and the photosensitive drum, FIG. 12 is an explanatory view of image formation in the continuous shooting page multiplex mode which is an embodiment of the present invention, and FIG. 13 (a). Is a case of not using RDF, Fig. 13 (b) is a flowchart in the continuous shooting page multiplex mode when RDF is used, and Fig. 14 is a case of not using RDF.
Fig. 5 is a time chart in the continuous shooting page multiplex mode when using RDF, Fig. 16 is an explanatory diagram showing the relationship between the sheet and the photosensitive drum, and Fig. 17 is a time chart when the copy magnification is changed. , Fig. 18 shows the case when RDF is not used and Fig. 19 shows the case when RDF is used and the order of the first and second manuscript images is reversed, Fig. 20 shows the case. FIG. 21 is an explanatory diagram of image formation, and FIG. 21 is a flowchart in the case where a large number of originals are automatically set to the continuous shooting page multiplex mode. 1 ... Image forming device (copying machine), 3 ... Automatic document feeding means (document feeding device), 4 ... Document placing means (platen), 5-12 ... Image forming means (scanning optical system) , 19 ……
Transporting means (registration roller), 20 ... Image forming means (copying section), 27, 31 ... Transporting path (re-transporting path, intermediate tray), 3
8: photoconductor (photosensitive drum), 84: instruction means (key for selecting continuous shooting page multiplex mode), 86: control means (control section), 95: stepping motor (optical motor), c,
d: two originals, P: sheet, S: original (bundle of originals).

Claims (6)

(57) [Claims] 1. An image forming means for reading an image of a document and forming the read image on a sheet conveyed by a conveying means, wherein the image is formed by the image forming means on different areas of the same surface of the sheet. For this purpose, in an image forming apparatus in which an image-formed sheet is fed to the conveying means by the re-feeding means, and an image is formed again on the sheet conveyed by the conveying means by the image forming means, in the sheet conveying direction. When the image is formed in the first area on the front end side, the time t ₃ elapses after the image forming means starts the image forming operation.
For a predetermined time t ₁
When the sheet is started to be conveyed by the conveying means after the passage of time and an image is formed in the first area and an image is formed in the second area on the trailing end side of the sheet in the conveying direction, the sheet of the conveying means After a lapse of a predetermined time t ₂ from the start of conveyance, the image forming operation by the image forming means is started, and further, the time t ₃
And a control means for controlling the image forming means and the conveying means so as to form an image in the second area after passing the first area by the conveying means after passing t ₁ and t ₁ . An image forming apparatus characterized by the above. 2. The image forming means has a scanning optical system for scanning and reading an original, and in the case of forming an image on a first area of a sheet, the predetermined state means that the scanning optical system is an original. 2. The image forming apparatus according to claim 1, wherein the time T ₃ is the time taken from the start of scanning by the scanning optical system until the scanning optical system reaches the leading edge of the document in a state where the scanning optical system has reached the leading edge of the original. 3. When an image is formed on the second area of the sheet, the scanning optical system starts scanning after the lapse of the predetermined time t ₂ from the start of the conveyance of the sheet by the conveying means. The image forming apparatus according to claim 2, wherein the control unit controls the image forming unit so as to form an image in the second area. 4. The image forming means has a photoconductor for converting image information from the scanning optical system into a latent image and transferring the latent image as a toner image onto a sheet at a transfer position. After a predetermined time t ₁ from the predetermined state where the leading end of the sheet is reached, the feeding unit starts feeding the sheet, and the control unit sets the leading edge of the toner image of the photoconductor and the leading edge of the sheet to coincide with each other. The image forming apparatus according to claim 2, wherein the conveying means is controlled. 5. The first region is a half portion of the sheet on the leading end side in the sheet conveying direction, and the sum t ₁ + t ₂ + t ₃ of the respective times is such that the sheet conveying section is half the sheet conveying direction length. The image forming apparatus according to claim 1, wherein the image forming apparatus has a time required to carry the sheet to pass. 6. An automatic document feeding means for automatically feeding the originals one by one to an original placing means for reading the originals, and two sheets of the images of a large number of the originals one by one in sequence. The image forming apparatus according to claim 1, wherein the image forming apparatuses are arranged on top of each other to automatically form an image.