JP2608092B2 - Document feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder that automatically feeds a document to an exposure position.

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a document feeder that automatically feeds a document to an exposure position and discharges the document after the exposure operation is completed may be used.

[Problems to be Solved by the Invention] However, in the conventional document feeder, regardless of the size of the document, the document is conveyed one by one to the copy position of the platen glass and stopped, and the copy-exposed document is removed. At the same time as the document is discharged from the platen glass, a document transporting method is repeated in which the procedure of transporting and stopping the next document to an exposure position and performing copy exposure is repeated. In this document conveying method, there is a problem that as the size of the document becomes smaller, the space between the documents becomes wider, which results in a loss of conveying time and a reduction in the copying speed.

In addition, if the transport speed is increased more than necessary to solve this problem, noise and abrasion of the transport belt will increase, and a serious drawback that document damage when transport failure occurs increases. I was

Examples of the invention in which the above-mentioned disadvantages have been solved to some extent include, for example, JP-A-60-140364 and JP-A-61-32836.
There is an original feeding method for a copying machine disclosed in Japanese Patent Application Laid-Open Publication No. H11-209,873.

First, the original feeding method described in the former JP-A-60-140364 is as follows. That is, in the case of continuously copying an original having a size smaller than the copyable size, a copy position (image reading position) provided on the platen glass surface of the copying machine at a downstream position in the original transport direction is positioned opposite to the platen glass (image reading position). The first document placed on the document tray (upstream side) is conveyed, and the document is hit against a stopper and stopped. Subsequently, the second document is conveyed to a standby position set at an upstream position on the platen glass surface adjacent to the copying position, and the document is hit against a stopper and stopped. Thereafter, the first original is exposed, and the two originals at the standby position on the platen glass are interlocked with discharge of the exposed first original downstream of the platen glass surface. The steps of transporting the third original placed on the original tray to the copy position, and transporting the third original placed on the original tray to the standby position, and stopping are repeated.

However, in this conventional document feeding method, since the document is stopped by the mechanical stopper at the standby position, it is efficient when a document having a size A4 that is half the maximum size A3 is transported, but is small, such as B5 or a postcard size. Since a document of a size can only wait at a predetermined position with a stopper, the interval between the document being read and the next document is unnecessarily widened, and the copying efficiency is reduced. In addition, in this conventional document feeding method, the copy position on the platen glass is located on the opposite side of the document tray, so that the transport time of the first document to the copy position is, for example, half of the maximum size A3. size
Even if the document is A4 size, it requires the maximum transport time as in the case of the maximum size A3, and has a disadvantage that the work efficiency is not always sufficient.

On the other hand, the document feeding method described in the latter JP-A-61-32836 is as follows. That is, a distance slightly longer than the length of each document sequentially conveyed in the conveyance direction is detected, and a conveyance cycle time required for running the conveyance belt by this distance is set, and the document conveyance on the platen glass is set. At the copy position (image reading position) provided at the downstream position in the direction, the conveyance of the first document on the document tray is stopped by the feed roller and the conveyance belt. Subsequently, the conveyance of the second document is stopped by a feed roller and a conveyance belt at an appropriate interval at a standby position provided at an upstream position on the platen glass adjacent to the copying position. Next, in conjunction with discharging the exposed first document in the downstream direction of the platen glass, the transport belt is caused to travel for each of the transport cycle times so that the two sheets at the standby position are moved. The process of transporting the third original to the copy position and the third original to the standby position, and stopping, is repeated. In this conventional example, the positioning means for stopping at each position is not a mechanical stopper, but is controlled by the stop position control of the conveyor belt. Therefore, regardless of the size of the original, the original being read and the next original are not affected. Since the interval between the originals can be made constant, the disadvantage that the copying efficiency is reduced due to the original size is eliminated.

However, in the latter conventional method, a procedure of moving the second and subsequent originals for a predetermined transport cycle time until reaching the copy position and stopping at the standby position is performed at least once. Therefore, the greater the number of repetitions of the conveyance and the stop, the greater the possibility of slippage between the belt and the document, even if the stop position of the conveyance belt can be controlled smoothly. When the document arrives at the copy position, the document is deviated from a predetermined position, and there is a serious drawback in that the stop accuracy, which is an important function of the document transport device, is reduced.

Further, in the latter conventional method, although the drawback that the copy efficiency is reduced due to the difference in the document size is solved, there is a drawback that the control of the document interval is difficult. That is, when the first document is conveyed and the trailing edge passes through the document tray, the second document is fed from the document tray. If the speed of the paper feed roller is too fast, there is a problem that skew of the document feed occurs and misfeeds easily occur. Therefore, it is difficult to match the speed of the transport belt.
It must be slower than the speed of the conveyor belt. Therefore, the interval between the originals becomes unnecessarily large due to the speed difference and becomes uniform regardless of the original size, but there has been a problem that the copying efficiency is not always sufficient.

Further, in the above-described conventional method, for a document (for example, B4 size) having a length in the feeding direction equal to or greater than a predetermined value, the document is stopped while a part of the document is held by a driving unit such as a transport roller. As a result, there is a possibility that the document may be damaged, and in the case of a pencil document, non-negligible inconvenience such as document contamination may be caused.

Further, the above-mentioned conventional method does not have a switching means for switching between the normal method for feeding the original one by one and the continuous feeding method as described above. Therefore, for example, two originals (for example, A4 size) are placed on the platen glass. When the image reading is executed for the maximum size (for example, A3 size) when the two sheets are positioned, the image of the document other than the one to be read is read,
In the case where the image is copied, for example, there is a problem that an unnecessary image is copied.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to reduce the time required for transporting the first document to the exposure position to a minimum time irrespective of the document size. The efficiency is improved, the stopping accuracy for the original is not reduced, and the original is removed from the bundle of originals.
It minimizes the occurrence of skew and misfeeds when separating sheets, and sets the document spacing appropriately and performs the most efficient document transport control without increasing the document transport speed. It is an object of the present invention to provide a document feeder capable of switching a transfer mode in accordance with a size of a paper sheet or a command from the image forming apparatus to perform a normal single-sheet feed control.

[Means for Solving the Problems] In order to achieve the above object, the present invention separates documents on a document table one by one, transports the documents to an exposure position on an exposure table of a document exposure apparatus, and stops. A document feeder, a selector configured to select one of a first document transport mode and a second document transport mode in accordance with the size of the document or an instruction signal from the document exposure device; In accordance with the selection of the first document transport mode, transport of the first document is stopped at the exposure position, and transport of the second document is stopped at a position adjacent to the exposure position and not on the exposure table upstream of the exposure position. After the exposure of the first document is completed, the first document is transported to a downstream position on the exposure table adjacent to the exposure position, and at the same time, the transport of the second document to the exposure position is stopped. This procedure is used for the third and subsequent pages. To stop the transport of the first document in sequence according to the selection of the second document transport mode by the selection means, and stop the transport of the first document to the exposure position. After the completion, the first document is transported to a predetermined position on the downstream side not on the exposure table, the transport of the second document is stopped at the exposure position, and the third and subsequent documents are sequentially repeated by repeating this procedure. Document transport control means for performing a transport stop operation.

[Operation] According to the present invention, the first document is conveyed to the exposure position and stopped, and the second document is conveyed to a position not on the upstream platen (exposure table) adjacent to the exposure position. , 1
After the exposure of the first document is completed, the first document transport mode is executed in which the first document is transported to a downstream position on the platen adjacent to the exposure position and the transport of the second document is stopped at the exposure position. Therefore, it is possible to reduce the time required to replace a small-sized document with simple control and a simple configuration, and to improve the productivity of document exposure. Further, in response to the size of the document or an instruction signal from the document exposing device, the conveyance of the first document to the exposure position is stopped, and after the exposure of the first document is completed, the first document is placed on the downstream side not on the platen. Convey to the predetermined position,
Since the second document transport mode for stopping the transport of the second document to the exposure position is selected and executed, damage to the document and control that may occur when attempting to transport a large document in the first document transport mode are eliminated. There is no complication.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2A, 2B, and 2C show the internal structure of an embodiment of an image recording apparatus (copying apparatus) to which the present invention is applied. In FIG. 1, reference numeral 100 denotes a copying apparatus main body having an image reading function and an image recording function, and 200 denotes a document feeder (hereinafter, referred to as an ADF) for automatically feeding a document.

A. Copier main body (100) In the main body 100, 101 is a platen glass (platen glass) on which a document is placed, 103 is an illumination lamp (exposure lamp) for illuminating the document, and 105, 107, and 109 are optical paths of reflected light of the document, respectively. Changing scanning reflection mirror (scanning mirror), 11
Reference numeral 1 denotes a lens having focusing and zooming functions, and 113 denotes a fourth reflection mirror (scanning mirror) for changing an optical path. Reference numeral 115 denotes an optical system motor that drives the optical system, and 117, 119, and 121 denote sensors.

131 is a photosensitive drum, 133 is a main motor for driving the photosensitive drum 131, 135 is a high-pressure unit, 137 is a blank exposure unit, 139 is a developing device, 141 is a transfer charger, 143 is a separation charger, and 145 is a cleaning device. is there.

151 is the upper cassette, 153 is the lower cassette, 155 and 1
57 is a paper feed roller, and 159 is a registration roller. Also, 1
Reference numeral 61 denotes a transport belt for transporting the recording paper on which the image has been recorded to the fixing side; 163, a fixing device for fixing the transported recording paper by thermocompression; and 167, a sensor used for double-sided recording.

The surface of the photosensitive drum 131 is made of a photoconductor and a seamless photosensitive member using a conductor. The drum 131 is rotatably supported by a shaft, and operates in response to pressing of a copy start key described later. The rotation is started by the motor 133 in the direction of the arrow in FIG. Next, when the predetermined rotation control and potential control processing (preprocessing) of the drum 131 is completed, the original placed on the original platen glass 101 is illuminated by the illumination lamp 103 integrated with the first scanning mirror 105, The reflected light of the original is supplied to a first scanning mirror 105, a second scanning mirror 107, a third scanning mirror 109, a lens 111, and a fourth scanning mirror 11
The image is formed on the drum 131 via 3.

The drum 131 is corona-charged by the high-pressure unit 135. Thereafter, the image (original image) irradiated by the illumination lamp 103 is subjected to slit exposure, and an electrostatic latent image is formed on the drum 131.

Next, the electrostatic latent image on the photosensitive drum 131 is developed by the developing roller 140 of the developing device 139 and visualized as a toner image, and the toner image is transferred onto transfer paper by the transfer charger 141 as described later. .

That is, the upper cassette 151 or the lower cassette 153
The transfer paper inside is sent into the main body device by the paper feed roller 155 or 157, is sent by the registration roller 159 in the direction of the photosensitive drum 131 at an accurate timing, and the leading end of the latent image and the leading end of the transfer paper coincide. . Then, the transfer charger 14
When the transfer paper passes between 1 and the drum 131, the toner image on the drum 131 is transferred onto the transfer paper. After the completion of the transfer, the transfer paper is separated from the drum 131 by the separation charger 143, guided to the fixing device 163 by the conveyor belt 161 and fixed by pressure and heat.
Is discharged to the paper discharge tray T outside the main body 100.

After the transfer, the drum 131 continues to rotate, and the surface thereof is cleaned by a cleaning device 145 including a cleaning roller and an elastic blade.

B. Automatic Document Feeder (ADF) (200) FIG. 2A shows the internal configuration of the ADF 200 described above.

In the drawing, reference numeral 1 denotes a loading tray (loading table) on which documents 2 are loaded and set. The tray 1 is arranged so as to be inclined downward in the document sending direction so that the document sending side is lower. Then, the fed documents are stacked on the tray 1 in the feeding direction. Reference numeral 4 denotes a half-moon type roller which has a function of rotating in the direction of the arrow in this figure and sending out the document to the downstream separation unit. When there is no document on the tray 1, the cutout portion of the roller 4 is turned upward. It is controlled to stop toward. Reference numeral 5 denotes a feeding roller, which feeds a document on the tray 1 by rotating in the direction of the arrow in FIG. Further, 6a and 6b are separation rollers, and the separation rollers 6a and 6b
By rotating the separation belt 6 in the direction of the arrow in the drawing, the lowermost document among the documents stacked on the tray 1 is separated one by one in cooperation with the feed roller 5. The feed roller 5 and the separation belt 6 constitute a separation / feed unit.

Reference numerals 3a and 3b denote transmission type photosensors for detecting the presence or absence of a document placed on the tray 1. Reference numeral 3a denotes an LED (light emitting diode), and reference numeral 3b denotes a phototransistor. The originals sent from the separation and supply units 5 and 6 pass through the sheet path I, are sandwiched by the feed rollers 9a and 9b pressed against each other, and are rotated through the sheet path II by the rotation of the rollers in the direction of the arrow in the drawing, so that the platen glass It is sent to sheet path III on 101. The paper feed sensors 8a and 8b disposed near the upstream of the feed rollers 9a and 9b are transmissive photo sensors that detect the leading edge and the trailing edge of the document.

The full-surface belt 11 arranged close to the platen glass 101 is an endless belt having a width large enough to cover the entire surface of the sheet document, and the surface thereof is made to slide on the platen glass 101 by frictional force. It has a sufficient coefficient of friction so that it can be transported in the direction of the arrow, and has a drive roller
10a and the turn roller 10b.
And the drive roller 10a are configured not to cause a slip.

The discharge first rollers 18a and 18b disposed at the entrance of the sheet path IV downstream of the sheet path III are pressed against each other, and are discharged from the platen glass 101 by the movement of the entire belt 11 in the direction of the solid line arrow in FIG. The conveyed document is pinched and conveyed while rotating in the direction of the arrow in the drawing, and the document is discharged through the sheet path VI bent upward.
20b, and is discharged onto the upper discharge tray 24. The paper ejection sensor 19 provided in the middle of the sheet path VI is a reflection type photo sensor that detects the leading edge and the trailing edge of the document.

When reading a double-sided original, the original on the platen glass 101 is conveyed backward and conveyed to the sheet path IV due to the movement of the entire surface belt 11 in the reverse direction of the chain line arrow, and the reversal large roller 16 pressed against each other is reversed. After being held by the roller 17, the sheet is fed to the sheet path V along the roller 16 by the rotation of the large reversing roller 16 in the direction of the solid line arrow in FIG. Next, the leading edge of the document is held by the feed rollers 9a and 9b described above, and is fed again onto the platen glass 101 through the sheet path II. As a result, the front and back of the document are inverted with respect to the platen glass 101.

The feed roller 5, the half-roller roller 4, and the separation rollers 6a and 6b of the above-described separation supply unit are connected to a separation drive motor 7 via a transmission mechanism, and are driven in the direction of the arrow in FIG.

The feed rollers 9a and 9b, the belt driving rollers 10a and 10b, and the large reversing roller 16 are each driven by a belt driving motor 12 via a transmission mechanism. The motor 12 is reversible. For example, when the motor 12 rotates in the normal rotation (CW) direction, all the rollers are rotated in the directions indicated by solid arrows, while the motor 12 rotates in the reverse rotation (CCW) direction. At this time, the belt driving rollers 10a and 10b and the large reversing roller 16 rotate in the direction of the dashed arrow, but the feed rollers 9a and 9b do not rotate. On the rotation axis of the belt drive motor 12,
Electromagnetic brake 13, clock disk 14, and clock generator
15 is connected, and the clock generator is
A pulse signal is generated from 15.

Further, the first rollers 18a and 18b and the second roller 20
Each of a and 20b is connected to a paper discharge drive motor 21 via a transmission mechanism, and is driven in the direction of the arrow in FIG. A clock disk 22 and a clock generator 23 are connected to the rotation axis of the paper discharge drive motor 21, and the rotation of the motor 21 causes the clock generator to rotate.
From 23, a pulse signal is generated.

B (1). ADF (200) Belt Transport Drive Mechanism FIG. 2 (B) shows the configuration of the belt transport drive system of the ADF 200 described above.

In the figure, a motor gear 50 is fixed to the main shaft of the motor 12, and this gear 50 is one of the integrated belt driven three-stage gears 51.
Gears 51a. Since the three-stage gear 51 is fixed to the belt drive shaft 10c of the drive roller 10a that drives the transport belt (entire belt) 11, the belt 11 can be rotated by the rotation of the motor 12. The three-stage gear 51 also has a pulley portion 51b and a gear portion 51c.
51c meshes with an idler gear (intermediate gear) 52 rotatably mounted on a fixed shaft 53 fixed to the body, and the idler gear 52 meshes with a feed roller gear.

A one-way clutch is built in the feed roller gear 54, and is engaged with a feed roller shaft 62 which is a drive shaft to which a plurality of feed rollers 9a for feeding a document to the belt 11 are fixed. The one-way clutch in the feed roller gear 54 locks and transmits rotation with the feed roller shaft 62 when the motor 12 rotates in the CW direction (forward rotation direction), and transmits when the motor 12 rotates in the CCW direction (reverse rotation direction). The feed roller shaft 62 is mounted so as to run idle. That is, the motor 12
Only when it rotates in the direction, the feed roller 9a rotates in the direction of the arrow in FIG.

On the other hand, the pulley portion 51b of the three-stage gear 51 and the reverse pulley gear 56
A timing belt 55 is stretched between the pulley 56a and the first gear 56b of the reverse pulley gear 56.
With the large roller gear 58 of the motor. A one-way clutch is built in the large roller gear 58, and is engaged with a reversing large roller shaft 63 which is a drive shaft to which the reversing large roller 16 is fixed. When the motor 12 rotates in the CW direction (forward rotation direction), the one-way clutch in the large roller gear 58 locks with the reversing large roller shaft 63 and transmits the rotation.
12 is mounted so as to idle with the large reversing roller shaft 63 when rotated in the CCW direction (reverse rotation direction).

Further, the second gear portion 56c of the reversing pulley gear 56 has a fixed shaft 6
It meshes with an idler gear 59 rotatably attached to zero, and the idler gear 59 meshes with a second large roller gear 61. Therefore, the first large roller gear 58 and the second large roller gear 61 attached to the reversing large roller shaft 63 are always rotating in mutually opposite directions.
A one-way clutch is also built in the second large roller gear 61, and is engaged with the reversing large roller shaft 63. The one-way clutch in the second large roller gear 61 is the motor 12
When the motor 12 rotates in the CW direction, the motor 12 idles with the reversing large roller shaft 63, and is mounted so as to lock with the reversing large roller shaft 63 when the motor 12 rotates in the CCW direction.

That is, when the motor 12 rotates in the CW direction, the driving force is transmitted in the order of 50 → 51a / 51b−55 → 56a / 56b → 58 → 63 → 16, and the reversing large roller 16 is driven through the first large roller gear 58. Rotate in the direction of the arrow in the figure. On the other hand, when the motor 12 rotates in the CCW direction, the driving force is transmitted in the order of 50 → 51a / 51b−55 → 56a / 56c → 59 → 61 → 63 → 16, and the reversing large roller 16 passes through the second large roller gear 61. Similarly, it rotates in the direction of the arrow in FIG.

B (2). ADF (200) Separation Supply Unit Drive Mechanism FIG. 2C shows the configuration of the separation supply unit drive system of the ADF 200 described above.

In the figure, a separation motor gear 72 is fixed to a main shaft 71 of the separation motor 7, and the gear 72 is a half-moon roller gear 73 fixed to one end of a half-moon roller shaft 74 which is a drive shaft to which a plurality of half-moon rollers 4 are fixed. And are engaged.

A half-moon pulley 75 is fixed to the other end of the half-moon roller shaft 74, and a timing belt 76 is stretched between the half-moon pulley 75 and a pulley portion 77a of a feeding roller gear pulley 77. The feed roller gear pulley 77 is engaged with one end of a feed roller shaft 81 which is a drive shaft to which the plurality of feed rollers 5 are fixed.

The gear portion 77b of the feed roller gear pulley 77 meshes with an idler gear 78 rotatably attached to a fixed shaft 79, and the idler gear 78 meshes with a separation gear 80 fixed to the separation shaft 8. A plurality of separation rollers 6b are fixed to the separation shaft 8. As a result, the rotation of the separation motor 7 causes the half-moon roller 4, the feed roller 5, and the separation rollers 6a and 6b to be in the second position.
It is driven in the direction of the arrow in FIG.

Further, a pulley 82 is fixed to the other end of the feed roller shaft 81, and the pulley 82 is connected to a pulley 84 on the feed roller shaft 62 via a belt 83. The electromagnetic clutch 25 is provided between the feed roller shaft 62 and the pulley 84.

On the other hand, a one-way clutch is built in the feed roller gear pulley 77, and when the gear pulley 77 is rotated in a direction to drive the feed roller 5 in the direction of the arrow in FIG. It is installed in the direction to lock with. In other words, when the feed roller shaft 81 is rotated in the above-described direction of the arrow, the shaft 81 and the pulley gear 77 idle.

B (3) Operation of Drive System of ADF (200) In the above configuration, if the motor 12 rotates in the CW direction, the feed roller shaft 62 of the feed roller 9a rotates. Subsequently, when the electromagnetic clutch 25 is turned on, the rotation of the feed roller shaft 62 is transmitted to the pulley 82 via the pulley 84 and the belt 83, and the feed roller 5 rotates in the direction of the arrow in FIG. . At this time, when there is no drive to the feed roller shaft 81 by the separation motor 7, or even when the drive is
When the rotation of the feeding roller shaft 81 is slower than the driving of the feeding roller shaft 81, the feeding roller shaft 81 and the pulley gear 77 idle, and the rotation of the feeding roller 5 is entirely controlled by the motor 12.

Here, the pulley ratio between the pulley 84 and the pulley 84 is set so that the outer peripheral speed of the feed roller 9a and the outer peripheral speed of the feed roller 5 become the same.
With the setting of 82, the original can be fed forward from the feed roller 9 while holding the loop formed in the sheet path I during this time.

Also, when the motor 12 is stopped, the separation motor 7 is rotated and the electromagnetic clutch 25 is turned on, so that 7 → 71 → 72 → 73 → 74 → 75 → 76 → 77 → 81 → 82 → 83 → 84 → The drive of the motor 62 and the motor 7 is transmitted to the feed roller shaft 62, and the feed roller 5, the separation roller 6b, the half-moon roller 4, and the feed roller 9a rotate in the direction of the arrow in FIG. At this time, since the rotation of the feed roller shaft 62 is in the idling direction by the one-way clutch in the feed roller gear 54, the separation drive system does not affect the belt conveyance drive shown in FIG. Can be rotated.

As a result, the original in the sheet path I can be sent out from the feed roller 9 onto the front platen glass 101 by the rotation of the separation motor 7.

C. Key Group (600) FIG. 3 shows an example of the arrangement of the operation unit of the copying apparatus shown in FIG.

In FIG. 3, reference numeral 602 denotes an all reset key,
Press to return to standard mode.

604 is a copy start key (copy start key),
Press to start copying.

A clear / stop key 605 has a clear key function during standby and a stop key function during copy recording. This clear key is pressed to cancel the set number of copies. The stop key is pressed to interrupt continuous copying. After the copying at the time of pressing is completed, the copying operation is stopped.

A numeric keypad 606 is pressed when setting the number of copies.

608 and 609 are copy density keys which are depressed when manually adjusting the copy density. An AE key 610 is used to automatically adjust the copy density according to the density of the original, or
Press to cancel AE (automatic density adjustment) and switch the density adjustment to manual. Reference numeral 611 denotes a cassette selection key, which is pressed to select the upper cassette 151 or the interruption cassette 153. When a document is placed on the ADF 200, the APS (automatic paper cassette selection) can be selected by the key 611. When APS is selected, a cassette having the same size as the original is automatically selected.

Reference numeral 612 denotes an equal-magnification key, which is depressed when performing actual-magnification (original size) copying. An automatic scaling key 613 is pressed when automatically reducing or enlarging the image of the original according to the designated size of the transfer paper. 614 and 615 are zoom keys, 64
Press to specify any magnification between ~ 142%. Reference numerals 616 and 617 denote fixed-size scaling keys, which are pressed when designating reduction / enlargement of a fixed-size.

A key 618 is designated when performing one-sided copying from a two-sided document. When this key is designated, the ADF 200 performs a later-described duplex mode operation.

D. Display Group (700) In FIG. 3, reference numeral 701 denotes an LCD (liquid crystal) type message display. For example, one character is composed of 5 × 7 dots, and a 40-character message can be displayed.

A copy number display 705 displays the number of copies or a self-diagnosis code. Reference numeral 706 denotes a used cassette display, which indicates which of the upper cassette 151 and the interrupted cassette 153 is selected.

Reference numeral 708 denotes an AE display, which lights when AE (automatic density adjustment) is selected with the AE key 610.

Reference numeral 710 denotes a ready / weight indicator, which is a two-color LED of green and orange, which is ready (when copying is possible)
Indicates green, and orange during wait (when copying is not possible).

E. Controller (800) FIG. 4A shows an example of a circuit configuration of the controller 800 of the embodiment shown in FIG. In FIG. 4, reference numeral 801 denotes a central processing unit (CPU) for performing arithmetic control for executing the present invention;
For example, a microcomputer μCOM87AD manufactured by NEC (NEC) is used. A read-only memory (ROM) 803 previously stores a control procedure (control program) as shown in FIG. 5A according to the present invention.
Reference numeral 801 controls the components connected via the bus in accordance with the control procedure stored in the ROM 803. A random access memory (RA) 805 is a main storage device used as storage of input data and a work storage area of the CPU 801.
M).

Reference numeral 807 denotes an interface (I / O) for outputting a CPU 801 control signal to a load such as the main motor 133, and 809 denotes an image sensor 121.
An interface 811 for inputting an input signal from a sensor or the like and transmitting it to the CPU 801, and an interface 811 for controlling input / output of the key group 600 and the display group 700. As these interfaces 807, 809, 811, for example, an input / output circuit port μPD8255 manufactured by NEC is used.

The display group 700 is each of the display units shown in FIG. 3, and uses LEDs and LCDs. A key group 600 is each key shown in FIG. 3, and the CPU 801 can determine which key has been pressed by a well-known key matrix.

F. ADF control device (900) FIG. 4 (B) shows ADF2 for performing the operation of the present invention.
9 shows a circuit configuration of a control circuit of No. 00. The controller 820 of this control circuit is mainly composed of a well-known one-chip microcomputer (hereinafter, referred to as a microcomputer) having a built-in ROM, RAM, and the like. The ADF 200 transmits and receives signals to and from the CPU 801 of the copying apparatus main body 100. Calculation control.

The input port I _{1 to} I ₃ of the controller 820 is
Original document sensor 3 provided downstream of 200 trays 1
Signals S1 and S2 from the sheet sensors 8a and 8b provided on the original transport path and signal S3 from the paper discharge sensor 19 provided on the paper discharge path are input.

Also, microcomputer interrupt terminals INT1 to INT of controller 820
2 shows a signal from a belt clock interrupter 15 for detecting rotation of the motor by a clock disk 14 attached to the motor shaft of the belt drive motor 12 described above with reference to FIG. The signal from 23 is input. These signals serve as reference clocks for the amount of movement of the paper feeding of the document as described later, and are used for each counting operation of a counter inside the controller 820.

On the other hand, the output signals O _{1 to} O ₅ of the controller 820 are connected to the operation signal of the separation drive motor 7 and the belt drive motor 12.
The CW to be forward and reverse operation, CCW signal, the electromagnetic brake 13, are output operation signals of the discharging driving motor 21 and electromagnetic clutch 25, respectively to control the output load through the driver D ₁ ~D _5, D _8.

The controller 820 exchanges signals with the CPU 801 of the copying apparatus main body 100 via the cable 901. Therefore, a document feed signal, a document discharge signal, and a mode signal are input to the input ports I _{4 to} I ₆ of the controller 820, respectively, and output ports O _{6 to} O ₇ through drivers D ₆ and D _7. A COPY request signal and a document detection signal are output. Each signal will be described later.

Reading these input signals or turning on / off the load
Turning off or the like means that the control program (control procedure) is stored in the ROM in the controller 820 as shown in FIGS.
Is controlled by the microcomputer of the controller 820 in accordance with

First, the overall control operation of the CPU 801 of the main body 100 will be described with reference to the flowchart of FIG.

When the user sets the original bundle on the original tray 1 of the ADF 200, the entrance original sensor 3 is turned on (step S01). Then, depending on the key state on the operation unit 600, either the one-side mode or the two-side mode is set. And (Step SS0
2) Wait for a key input of the copy start key 604 (step S03), and start the copying process. If it is determined in step S04 that the single-sided mode is set, the document feed signal is first turned on (step S05), so that a single-sided mode process of the ADF 200 described below is performed (step SS06). To stop.

When the document stops at the exposure position, the ADF200 controller 82
Since the COPY request signal is turned on from 0 (step SS0
7) Turn off the original feed signal (step S0
8) Turn on the illumination lamp 103 (step S09), turn on the optical system motor 115, and scan the original (image scan).
Is started (step SS010). Then, at the end of the original scanning (step SS011), the above-described step SS
Return to 05 processing, repeat the processing of SS05 ~ SS011 below,
Image reading of a plurality of originals is performed.

On the other hand, when it is determined in step S04 that the duplex mode has been set, the document feed signal is also turned on similarly to the simplex mode (step SS012), and the ADF2
The double-sided mode process of 00 is performed (step S013), and the process proceeds to step S07. Hereinafter, image reading is performed by performing the same processing as in the single-sided mode after step SS07.

Next, referring to the flow charts shown in FIGS. 5B to 12 and the operation explanatory diagram of FIG. 13 and the configuration diagram of the ADF of FIG. The actual control operation when the ADF single-sided mode (A) and the ADF double-sided mode (B) are respectively designated by the keys will be described.

A. (Single-Sided Mode) In the Case of Copying Four Documents The flowchart in FIG. 5B shows the control procedure of the controller 820 in the single-sided mode. In this example, the controller 820 first performs step S in which the separation process shown in FIG.
In step 1, in the separation processing subroutine of FIG.
The separation driving motor 7 is started (turned on) so as to separate only the sheets (step S101). When the motor 7 starts, the half-moon roller 4 rotates and the document page advances in the sheet path I. Therefore, after the sheet feed sensor 8 detects the leading edge of the document (step S102), the separation loop timer is started (step S102). (S103) After the timer ends (after the time-up) (step S104), the separation drive motor 7 is stopped (turned off) (step S105). As a result, the original comes into contact with the nip portions of the feed rollers 9a and 9b, and stops after a predetermined amount of loop (curved shape) is formed. The above operation has an effect that even when the skew of the document occurs at the time of separation, the skew can be corrected.

Next, the process proceeds to step S2 in FIG. 5B for performing the sheet feeding process, and in the sheet feeding process subroutine in FIG. 8, the belt drive motor 12 is started to rotate forward to drive the feed rollers 9a and 9b and the full-surface belt 11. The document is conveyed from sheet paths I to II (step S201). At the same time, a size check counter in the controller 820 that counts with a clock input from the belt clock interrupter 15 is activated, and starts measuring the document size (step S202). This counter is provided inside the controller 820.

At the same time as the document is conveyed and the trailing edge passes through the paper feed sensors 8a and 8b (step S203), the above-described size check counter is stopped (step S204). In the size check subroutine shown, at the same time that the document size is determined (step S205), the registration counter RGCN for stopping the document at the exposure position on the platen glass 101 is started (step S206), and the counting of the registration counter RGCN ends. Until (Step S208), the speed of the belt drive motor 12 is reduced in order to obtain an accurate stop without variation (Step S207), and the belt drive motor 12 is stopped (off) simultaneously with the completion of the count of the registration counter RGCN. (Step S209), and the document feed is instantly stopped by the electromagnetic brake 13, whereby the platen glass 1 The document is accurately stopped at the exposure position on 01 (step S210).

Here, in the size check subroutine, as shown in FIG. 9, as a method of determining the document size, the data of the above-described size check count includes the distance from the nip position of the feed rollers 9a and 9b to the paper feed sensors 8a and 8b. A correction is made by adding a minute, and the corrected value becomes a true document size. At this time, the document feed amount and the count value by the belt clock interrupter surely match (step S220). After that, B5, A4, B4, A3
The size of the original is determined (steps S221 to 229),
Clear the size check counter and return (Step S2
30).

Next, after the above-described paper feeding process, the steps shown in FIG.
Proceeding to S3, a COPY request signal is output to the CPU 801 of the copying apparatus main body 100. The CPU 801 of the copier main body temporarily turns off the document feed signal in response to the input of the COPY request signal, and then activates the optical system to expose and copy the document page set on the platen glass 101 with the image face down. Execute Next, an image of the document page is formed on the first surface of the copy material (recording paper), and the copy material is discharged to the copy tray T with the image surface facing upward (see FIG. 1).

FIG. 5B shows the state in which the copying apparatus main body 100 is in the exposure process.
The program sequence proceeds to step S4, where it is determined whether or not all the originals have been fed based on whether the entrance original sensors 3a and 3b are off. Here, since the image recording process of the page document is still in progress, the entrance document sensors 8a and 8
Since b is in the ON state, it is next determined whether or not the mode signal from the main body 100 is continuously transmitted (step S5),
When the determination is affirmative, the flow of the subsequent program is changed based on whether the document size of the page is A4R or more based on the document size data obtained in the document size determination of the above-described size check subroutine (step S6). Here, the description will be continued assuming that the mode signal is continuous transmission designation.

If the page document size is smaller than A4R, the flow advances from step S6 to step S7 to execute the above-described separation processing (step S1) before the completion of the exposure process for the page document, thereby transmitting the next document to the feed roller 9a. , 9b, and is stopped in a state where a loop is formed.

Next, the process proceeds to step S8, where the copying apparatus main body is used.
Since the document feed signal is turned on upon completion of the exposure process for 100 document pages, the COPY request signal is turned off in response to the turning on of the document feed signal, and the next operation starts (step S).
9).

In the next step S10, the process of the paper discharge process 1 is started by interruption, and the process returns to the step S2 to start the process of feeding the page document.

Here, a processing procedure of the above-described paper discharge processing 1 will be described. The state at the time when the paper discharge processing 1 is started is shown in FIG.
The state is as shown in FIG. And the tenth
In the subroutine of the paper discharge process 1 shown in the figure, the process waits until the paper discharge sensor 19 detects the leading edge of the page document (step S30).
1).

However, at this time, the entire belt 10
Does not drive. Therefore, during this standby, once step S2
Returning to FIG. 5, when the sheet feeding process for the next original page is performed, and the steps S3 to S7 in FIG. 5B are further executed, the positional relationship of the original is as shown in FIG. 13B.
Further, the processing of the paper discharge processing 1 is also started for the page document (step S10).

Further, during the process of feeding the document of the page, the leading edge of the document of the page is detected by a discharge sensor as shown in FIG.
When the sheet 19 is detected, the sheet is discharged from the sheet discharge sensor 19 to the second roller.
The belt counter BC1 is activated by a count value corresponding to the distance to the nip between 20a and 20b (step S302), and waits until the belt counter BC1 ends (counts up) (step S303).

When the count of the belt counter BC1 is completed, the paper discharge drive motor 21 is turned on (step S304), the page document is started to be pulled out, and the paper discharge sensor 19 waits for the trailing edge of the document to be detected (step S304). S305).

Thereafter, as shown in FIG. 13 (D), even if the page document feeding process (step S2) is completed and the entire belt 10 is stopped, the page document is still discharged by the discharge rollers 20a and 20b. The discharge is continued in the direction of the arrow, and at the same time as the paper discharge sensor 19 detects the trailing end of the page document, the paper discharge counter counted by the clock of the paper discharge clock interrupter 23 is started to completely discharge this document. At the same time (step S306), the speed of the discharge drive motor 21 is controlled to improve the consistency at the time of discharging the document (step S30) until the discharge counter ends.
7) Wait for the end of counting from the paper discharge counter (step S308). When the count of the paper discharge counter is completed, the paper discharge drive motor 21 is turned off, and the document is discharged onto the paper discharge tray 24, and this paper discharge process is completed (step S30).
9).

At this time, the feed amount by the discharge counter and the discharge roller 20
The feed amounts by a and 20b surely match.

After that, while the entrance document sensors 3a and 3b detect a document, the above-described processing sequence is repeated.

Thereafter, when the above-described entrance document sensors 3a and 3b stop detecting the document, in the present embodiment, when the process of feeding the document of the page is completed and the determination process of step S4 is performed,
If the entrance document sensors 3a and 3b are off, a negative determination is made, so the process proceeds to step S11, where the document detection signal is turned off and a document discharge signal from the copying apparatus main body 100 is set (step S12). Then, the COPY request signal is turned off (step S13), and the processing of the paper discharge processing 2 is started by interruption (step S14).

The state of the positional relationship of the original at this time is as shown in FIG. 13 (E), and in the routine of the paper discharging process 2, the pages staying on the platen glass 101 as shown in FIG. The belt drive motor 12 is turned on by normal rotation to discharge the document (step S311).

At this time, the original of the page is simultaneously executing the above-described paper discharge processing 1.

When the paper ejection sensor 19 detects the leading edge of the page document (step S312), the first paper ejection process is performed in the same manner as in the paper ejection processing 1 described above.
The counting operation of the belt counter BC1 is started (step S313). When the counting of the counter BC1 is completed (step S314), the discharge drive motor 21 is turned on (step S315), and the separation process of the next original is performed. Second belt counter for determining timing to permit start
Start the count operation of BC2 (step S31)
6). In this embodiment, the rear end of the document is
The count value of the counter BC2 up to the position away from the position of 0b is set in advance. That is, as shown in FIG. 13 (F), {(length of document) −l} is set as the counter value of counter BC2. 1 is the distance between the belt roller 10b and the sensor 19.

When the count of the belt counter BC2 ends (step S317), the belt drive motor 12 is turned off (step S317).
(S318), a separation start permission flag is set (step S319). Here, since there is no next document to be separated, the actual operation is not affected. The effect of this flag will be described later.

Thereafter, similar to the paper discharge process 1, a sequence for aligning the discharged documents is executed, and the process ends (steps S320 to S32).
3).

Also, when the mode signal is not the continuous feed designation in step S5 in FIG. 5B, or when the document size is A4R in step S6.
In the above case, in order to stop the above-described continuous feed mode and change to a sequence in which the original can be reliably pulled out by the discharge rollers 20a and 20b, the process proceeds to step S15, where the original is fed from the CPU 801 of the main body 100 from the copying apparatus. It waits for a paper signal to be set. When this signal is set, the COPY request signal is turned off (step S16), and the above-described paper discharge processing 2 is started by interruption (step S17).

Thereafter, as shown in FIG. 13 (F), at step S319 in the page document discharge process 2, it is detected that the separation start permission flag is set (step S18), and at the same time, this flag is reset. Then, the separation process of the next document, that is, the document of the page is started (step S19). Thereafter, as described above, the above-described processing is repeated until all the originals from the original tray 1 are exhausted.

B. (Duplex mode) In the case of an example of copying two originals on both sides The flowchart of FIG. 6 shows a control procedure of the controller 820 in the duplex mode. When the double-sided mode is designated, first, the above-described separation processing of the lowermost original (page /, see FIG. 14A) on the original tray 1 is performed in the same manner as in the single-sided mode (steps S51 and S7). After performing the sheet feeding process (see step S52, see FIG. 8), the process proceeds to step S53 where a reversal process is performed to copy the page.
In the reversing process routine of FIG. 12, the belt driving motor 12 drives the entire surface belt 11 to convey the original on the platen glass 101 from the sheet path III to the sheet path IV.
Is turned on in reverse (step S410).

As a result, the original is rotated by the large reverse roller 16 and the small reverse roller 17.
When the paper feed sensors 8a and 8b detect the leading edge of the document (step S402), the reversing loop counter is started. (Step S403) After the counting of this counter is completed (Step S404), the belt drive motor 12 is turned off (Step S405). As a result, a loop for correcting skew is formed in the same manner as the separation process, and the process waits (No.
(See FIG. 14 (B)).

After the above-described reversing process is completed, next, as in the single-sided mode, the sheet feeding process is performed (step S54), and the COPY request signal is turned on (step S55).
When the original feed signal from 01 is set (step S5
6), the COPY request signal is turned off (step S57).

Next, in order to copy the page, the above-described reversing process is performed (step S58), and the sheet feeding process is performed (step S59), and the COPY request signal is turned on (step S6).
0). Next, the output state of the entrance document sensor 3 at this time is determined, and if the next document is detected (step
S61), the process proceeds to step S62, and the CPU 801 of the copying apparatus main body 100
After waiting for the setting of the document feed signal from the printer, the COPY request signal is turned off (step S63), and the above-described paper discharge process 2 is started as an interrupt (step S64).

Further, after the discharged original reaches the above-mentioned predetermined position (see FIG. 14E) and the separation start permission flag is set (step S65), the separation start permission flag is reset (step S66). The above step S51
Then, the processing of the next document is started. Thereafter, the above-described processing procedure is repeated until there is no document in the document stacking tray 1, that is, until the entrance document sensor 3 does not detect the document in the above-described step S 61, and the entrance document sensor 61 detects the document in step S 61. If not, step S6
Go to 7 to turn off the original detection signal and
Wait for the setting of the original output signal from U801 (step S6
8) Then, the COPY request signal is turned off (step S67), and the above-described paper discharge processing 2 is started and ended (step S70).

The above-described operation is sequentially performed on the stacked originals on the original mounting table 1 so that one side of the original in the same page order as the original set on the mounting table 1 of the ADF 200 is placed on the discharge tray T of the copying apparatus 100. Copies or duplex copies are obtained.

[Effects of the Invention] As described above, according to the present invention, the conveyance of the first document to the exposure position is stopped, and the second document is placed on the upstream platen (exposure table) adjacent to the exposure position. Is stopped, and after the exposure of the first document is completed, the first document is transported to a downstream position on the platen adjacent to the exposure position, and at the same time, the transport of the second document is stopped at the exposure position. Since the first document transport mode is executed, the exchange time of a small-sized document can be reduced by simple control and simple configuration, and the productivity of document exposure is improved. Further, in response to the size of the document or an instruction signal from the document exposing device, the conveyance of the first document to the exposure position is stopped, and after the exposure of the first document is completed, the first document is placed on the downstream side not on the platen. A second document which is transported to a predetermined position and stops transporting the second document to the exposure position;
Since the original transport mode is selected and executed, there is no possibility of damaging the original and complicating the control which would occur when a large-size original is transported in the first original transport mode.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing the overall configuration of an image forming apparatus to which the present invention is applied, FIG. 2 (A) is a schematic diagram showing the configuration of the document feeder of the embodiment of FIG. 1, FIG. FIG. 2B is a plan view showing a configuration of a belt transport drive mechanism of the document transport device, FIG. 2C is a plan view showing a configuration of a separation / feed unit drive mechanism of the document transport device, and FIG. 3 is FIG. Operation unit (operation panel) of the device of the embodiment of the present invention
FIG. 4 is a block diagram showing a circuit configuration of a control system of the embodiment of FIG. 1, FIG. 5 (A) is a flowchart showing an overall control procedure of the embodiment of the present invention, FIG. 5 (B) is a flowchart showing a control procedure in the single-sided mode of the embodiment of the present invention, FIG. 6 is a flowchart showing a control procedure in the double-sided mode of the embodiment of the present invention, and FIGS. 13 is a flow chart showing a subroutine in the control procedure of FIG. 5 or FIG. 6. FIGS. 13 (A) to 13 (F) are views showing a use state showing a document conveyance state and a positional relationship in a one-sided mode according to the embodiment of the present invention. FIGS. 14 (A) to 14 (F) are views showing the use of the document in the double-sided mode according to the embodiment of the present invention. 1. Loading tray (loading table) 2. Documents 3a, 3b Inlet document sensor 6. Separation roller 7. Separation drive motor 8a, 8b Feed sensor 9a, 9b ... Feed roller, 10a, 10b ... Roller, 12 ... Belt drive motor, 13 ... Electromagnetic brake, 15 ... Belt clock interrupter, 16 ... Large reversing roller, 17 ... Reversing roller, 19 ... Ejection sensor , 21: paper ejection drive motor, 23: paper ejection clock interrupter, 25: electromagnetic clutch, 100: image forming apparatus main body, 101: platen glass (platen glass), 115: optical motor, 117 …… Home position sensor, 121 …… Image sensor, 133 …… Main motor, 135 …… High pressure unit, 137 …… Blank exposure unit, 155,157 …… Paper feed roller, 159 …… Register roller, 200 …… Document feed Device (ADF), 600 …… Key group, 700 …… Display group, 801 ... CPU of main unit, 820 ... Controller of ADF.

Claims (1)

(57) [Claims] An original transporting apparatus for separating originals on an original mounting table one by one, transporting the originals to an exposure position on an exposure table of an original exposure apparatus, and stopping the originals. Selecting means for selecting one of a first document transport mode and a second document transport mode in accordance with the instruction signal; and selecting the first document transport mode in accordance with the selection of the first document transport mode by the selecting means. Stop transporting the original to the exposure position,
The second document is conveyed to a position upstream of the exposure table and not on the exposure table adjacent to the exposure position, and after the exposure of the first document is completed, the first document is exposed to the exposure position adjacent to the exposure position. At the same time when the document is conveyed to the downstream position on the table, the conveyance of the second document is stopped at the exposure position, and for the third and subsequent documents, this procedure is repeated to sequentially stop the conveyance, and According to the selection of the second document transport mode, the transport of the first document is stopped at the exposure position, and the first document is stopped.
After the exposure of the first document is completed, the first document is conveyed to a predetermined downstream position not on the exposure table, and the second document is stopped at the exposure position. And a document transport control means for repeating the procedure to sequentially stop the transport.