JPH0725799Y2 - Automatic document feeder for image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention feeds originals on an original table one by one in page order onto a platen of an image forming apparatus main body from one end side of the platen. , The original is positioned so that its rear end matches the reference position on the one end side of the platen, the original is illuminated and scanned from the reference position side, and then discharged from the other end side of the platen, The present invention relates to an automatic document feeder for an image forming apparatus that stacks pages in order on a discharge tray.

[Conventional technology]

It is installed in the main body of an image forming apparatus such as a copier or a facsimile, and the originals on the original table are automatically fed to the platen in page order, and the originals after the illumination scanning are automatically ejected and the pages are ejected on the ejection tray. Various types of automatic document feeders of the above-mentioned type, which are arranged in order and stacked, have been put into practical use or proposed.

FIGS. 1A to 1D are schematic views showing some examples.

In these figures, a platen 2 made of contact glass or the like is provided on an upper portion of an image forming apparatus, for example, a main body 1 of a copying machine.
Is fixed and the automatic document feeder 4 is mounted thereon.

The automatic document feeder 4 shown in FIG.
Has a manuscript table 5 arranged above the
A document D with the image side facing up is mounted. This drawing shows a state in which two first and second originals designated by reference numerals D1 and D2 are set in page order.

In response to the document feed start signal, the first top document D1 is fed as shown by the arrow A direction. This manuscript
D1 is one end side 2a of the platen 2 as shown by an arrow B.
Is fed from the platen 2 onto the platen 2, and its rear end is positioned so as to match the reference position S on the one end side 2a of the platen 2 as shown by the chain line. At this time, the original D1 has its image surface facing the platen 2 side, that is, the lower side.

Then, the light source 19 of the imaging optical system 3 arranged below the platen 2 moves from the side of the reference position S toward the leading end side of the document D1, that is, rightward in the figure, and the image surface of the document D1 is moved. Lighting scanning. The reflected light reaches a photoconductor through a mirror or lens (not shown) of an imaging optical system, forms an electrostatic latent image there, develops it, and transfers it to a transfer paper to obtain a copy paper. To be

After the illumination scanning is completed, the document D1 on the platen 2 is discharged from the other end side 2b of the platen 2 as shown by an arrow C, is then reversed by the roller 25a, and is placed above the platen 2 as shown by the arrows E and F. It is conveyed and discharged onto the discharge tray 35 as shown by the chain double-dashed line in FIG. At this time, the original D1 has its image side facing down.

The second original D2 on the original table 5 is also fed onto the platen 2 in exactly the same manner, and after its illumination scanning, it is ejected onto the ejection tray 35 from above the original D1 with its image side facing down. To be done. In this way, the documents D1 and D2 are stacked on the discharge tray 35 in page order.

In the example of FIG. 1B, the original document on the original table 5
The operation in which D1 and D2 are sequentially fed onto the platen 2 in page order and illuminated and scanned is the same as in the case of FIG. 1 (a), but the original after the illumination scanning is the other end side of the platen 2. The sheets are stacked in page order on a discharge tray 35 provided on the right side of 2b.

In the example of FIG. 1 (c), the document table 5 is arranged on the left side of one end side 2a of the platen 2, and the document D1 having a younger page is arranged on the lowermost side of the document table 5 on the lower side. Another original D2 is stacked in page order. The originals are fed from the first (first page) original at the bottom, and the originals after the illumination scanning are sequentially stacked in page order on the discharge tray 35 arranged on the right side of the platen 2. To be done.

In FIG. 1D, the document D is fed from the document table 5 in the same manner as in FIG. 1C, and the document after the illumination scanning is the first document
Similar to FIG. 7A, an example in which the sheets are discharged onto the discharge tray 35 in page order is shown.

The case where a plurality of originals are set on the original table 5 and sequentially fed has been described above. However, even when only one original is set on the original table 5 and fed, the originals are also fed. Is discharged onto the discharge tray 35 through the same path as described above.

The automatic document feeder 4 illustrated in FIGS. 1 (a) to 1 (d)
Means that the originals on the original table 5 can be fed in the page order onto the platen 2 and can be ejected in the page order on the ejection tray 35. There is no need to fix it, and work efficiency can be improved.

[Problems to be solved by the device]

However, when each original is fed and positioned on the platen 2, the rear end of the original is aligned with the reference position S on the side where the original is fed into the platen 2, that is, one end side 2a of the platen 2. Moreover, when the document after the illumination scanning is discharged from the other end side 2b of the platen, the distance from the document set on the platen 2 to the discharge tray 35 becomes long,
It is unavoidable that it takes time to discharge the original document to the discharge tray 35.

The time required for the document discharge operation is unavoidable in order to arrange the page order of the documents on the discharge tray 35. However, in the conventional automatic document feeder, even when only one document whose page order does not matter is processed, the document is discharged to the discharge tray 35 through the long path after the illumination scanning is completed. For this reason, not only time loss occurs, but also the possibility of document transportation troubles increases.

The present invention is based on the above recognition, and when only one original whose page order does not matter is fed from the original table, the original is discharged through a shorter path than the conventional one after the illumination processing. An object of the present invention is to provide an automatic document feeder of the type described at the beginning that can be discharged to a tray.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a discharge path for discharging an illumination-scanned document from one end of the platen and a plurality of documents sequentially fed to the platen from a document table. When the original after the illumination scanning is discharged from the other end side of the platen and only one original is fed from the original table to the platen, after the illumination scanning of the original is completed, one end side of the platen is Therefore, a configuration including a control device that controls the discharge operation of the document so that the document is discharged through the discharge path is proposed.

At this time, the control device detects a first sheet feeding detection unit that detects that the first sheet has been fed from the original table, and a first sheet feeding detection unit on the table after the first sheet is fed from the original table. When the second original is not present on the original table with the original presence / absence detecting means for detecting whether or not the next second original is present, and the feeding of the first original is detected. , That only the first document that was fed first is fed from the document table, and when the second document is on the document table, multiple documents are sequentially printed from the document table. It is desirable to have a judgment means for judging that the paper will be fed.

Further, it is advantageous that the discharge path also serves as a path for reversing the double-sided document and discharging the double-sided document after the end of the illumination scanning.

[Action]

When sequentially feeding multiple documents from the document table,
As in the conventional case, the original after the illumination scanning is discharged from the other end side of the platen, but when only one original is fed from the original table, the original is scanned after the illumination scanning is completed. It is discharged from one end side of the.

〔Example〕

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

FIG. 2 is a sectional view showing a feeding device 4 corresponding to the automatic document feeding device 4 shown in FIG.

In FIG. 2, a platen 2 made of a light-transmissive contact glass or the like is fixed to the upper part of a main body 1 of an electronic copying machine which is an example of an image forming apparatus, and an image forming optical system 3 is arranged inside the main body below the platen 2. The automatic document feeder 4 according to the present invention is mounted above the platen 2.

The automatic document feeder 4 has a document table 5, on which one or a plurality of documents D to be copied are placed, and the document is fed in page order and copied.

Here, first, the general configuration and operation of the automatic document feeder 4 for copying the most commonly used one-sided document, that is, a document having an image formed on one side while continuously feeding the document. To clarify.

The one-sided original D is stacked on the original table 5 with its image side facing upward, and when a print key (not shown) provided on the operation unit on the copying machine main body 1 side is pressed, the one-sided original D is located above the leading end of the original D. The placed calling roller 6 descends and the uppermost document is placed.
It is pressed against the surface of D1 and is rotated clockwise. As a result, the uppermost first original (first page original) D1 is sent in the direction of arrow A, and passes through the pair of separation roller 7 and blocking roller 8. Both the separating roller 7 and the blocking roller 8 rotate in the clockwise direction, so that even when two or more originals are simultaneously fed between them, only the uppermost one original D1 moves between the rollers 7 and 8. pass.

The first original D1 sent out as described above is conveyed in the direction of arrow B in the original conveying path 11 by the first and second pull-out roller pairs 9 and 10, and is held at the horizontal position shown by the solid line. It passes over the reference scale 12 and is fed onto the platen 2 from one end side 2a thereof. Above the platen 2, there is located an endless conveyor belt 15 which is wound around a belt driving roller 13 and a belt driven roller 14 and whose lower side is pressed by a plurality of pressure rollers 14a. When the document D1 is fed to the platen 2 as shown in
15 is driven in the direction of arrow C. As a result, the document is conveyed in the direction of arrow C while sliding on the platen 2.

Next, when the trailing edge of this document passes the right end face 16 of the document reference scale 12 and is separated from the end face 16 by a slight distance (10 mm in this example), the conveyor belt 15 reverses,
It is driven in the direction opposite to arrow C. Therefore, platen 2
The original document is also returned to the left in the figure, that is, in the direction opposite to the arrow C, and its rear end is the right end surface 16 of the original reference scale 12.
It is hit and the movement is stopped. As described above, in this example, the right end surface 16 of the document reference scale 12 becomes the reference position S for stopping the document at a predetermined position on the platen 2, and the rear end of the document is positioned so as to match the reference position S. Be set.

Even after the document hits the right end surface 16 of the reference scale 12, the conveyor belt 15 continues to rotate for a predetermined short time while slipping with respect to the document so that the rear end of the document is correctly positioned at the reference position S. , The skew of the document is corrected, and then the transport belt 15 is stopped.

A sensor 17 is provided in the document transport path 11, and the sensor 17
Detects the leading edge and the trailing edge of the document, and the length of the transported document is detected by this, and the sensor 17 detects the trailing edge of the document, and the document stops at a predetermined position as described above. Until that, the conveyor belt 15 is driven. The document conveyance speed is constant, and therefore the length of the document can be known from the time from when the sensor 17 detects the front end of the document to when it detects the rear end.

A sensor 18 arranged above the document table 5 detects whether or not a document exists on the document table 5.

As described above, in this example, the calling roller 6, the separation roller 7, the blocking roller 8, the pair of pullout rollers 9 and 10, and the transport belt 15 feed the originals on the original table 5 one by one to the platen 2 of the copying machine main body 1. A document feeding unit that feeds the document and stops the document at a predetermined position that matches the reference position is configured.

Also, a document transport path from the document table 5 to the platen 2
Since 11 is curved as shown in FIG. 2, the front side and the back side are reversed while the document passes therethrough. Therefore table 5
A document whose image surface is facing upward has its image surface facing downward when stopped on the platen 2.

When the original is set at a predetermined position on the platen 2, the image forming optical system 3 of the copying machine body 1 causes the original surface to move to the reference position S.
Illumination scanning is performed from the side, and a document image is formed on a photoconductor (not shown). That is, the first scanner including the light source 19 and the first mirror 20, the second mirror 21 and the third mirror 22.
The second scanner composed of the solid line moves from the home position shown by the solid line to the right according to the length of the original on the platen 2, for example, the position shown by the broken line, during which light from the light source 19 is emitted from the platen 2 Illuminates the upper document, and the reflected light is
Reflected by the second and third mirrors 20, 21, 22 and then the lens 23
After being reflected by the fixed fourth mirror 24, it reaches a photoconductor (not shown) and a document image is formed thereon. Thereby, as is known per se, an electrostatic latent image is formed on the photoconductor, this is visualized by the toner, and the visible image is transferred to a transfer paper to obtain a copy paper.

The above-described illumination scanning of the document is performed for the number of repeats input by the operator on the ten-key pad (not shown) of the operation section, or only once when not input on the ten-key pad, so that the number of copy sheets desired by the operator can be obtained. To be

When the document on the platen 2 has been illuminated and scanned a predetermined number of times as described above, the belt driving roller 13 is rotationally driven counterclockwise and the conveying belt 15 is driven in the direction of arrow C. As a result, the document is conveyed to the right in the drawing and is ejected from the other end side 2b of the platen 2.

Next, the document is fed between a pullout driving roller 25a provided on the downstream side of the platen 2 in the moving direction thereof and a pullout roller pair 25 composed of a pullout driven roller 25b forming a pair with the pullout driving roller 25a. Guide surface that is substantially U-shaped due to mechanical transport
The sheet is reversed while being guided by 26, and then conveyed in the direction of arrow E through the discharge path 31 by the plurality of conveying roller pairs 27, 28, 29, 30. At this time, the original has its image side facing up.

Further, the document has a reverse discharge roller 32 that rotates clockwise,
It is conveyed while being reversed by the driven rollers 32a and 32b that are in pressure contact with this, and passes through between the pair of discharge rollers 33 and from the discharge port 34, with the image surface facing downward, onto the discharge tray 35 as indicated by arrow F. Is discharged. Reference numeral 80 denotes an ejection sensor that detects the ejection of the document.

Here, the guide surface 26, the pull-out roller pair 25, the transport rollers 27, 28, 29, 30, the reverse sheet discharge roller 32, and the driven roller 32 thereof.
The document discharge path 31 including the a, 32b, the discharge roller pair 33, and the like will be hereinafter referred to as a first discharge path, as necessary.

The next second original document (second original document) D2 placed on the original document table 5 is also fed to the platen 2 in the same manner as described above and subjected to the illumination process, and then the first document. Discharge route 31
The first original is placed on the discharge tray 35 with the image side facing down. Such operations are sequentially performed,
Each original is fed page by page from the original table 5 onto the platen 2 of the copying machine main body 1 from one end side 2a thereof, and its rear end is at a reference position S on one end side 2a of the platen.
The original is illuminated and scanned from the reference position S side, and then discharged from the other end side 2b of the platen 2 onto the discharge tray 35. As a result, the document stack discharged onto the discharge tray 35 is initially stored in the document table 5
The pages are aligned according to the page order when the documents are set to.

The above-described structure and operation are basically the same as those of the automatic document feeder shown in FIG. 1 (a). What is different from this is the operation when only one original is set on the original table 5 and is fed, and the configuration related thereto. Hereinafter, this will be described in detail.

Also in this case, one document D is set on the document table 5 with its image facing upward, and the document fed from this is positioned at a predetermined position on the platen 2 and stopped, and the image is displayed on the image surface. The illumination scanning is performed a predetermined number of times. The operation up to this point is the same as the above-described operation when processing a plurality of originals.

Here, as indicated by a broken line in FIG. 1A, the second end of the platen 2 is ejected from the one end 2a, that is, the side of the original fed into the platen 2, after which the original having been illuminated and scanned is discharged. The discharge route 60 of the above is provided.

When the illumination scanning of the original document on the platen 2 is finished as described above, the conveyor belt 15 is driven in the clockwise direction opposite to the arrow C, unlike the case of sequentially processing a plurality of original documents. As a result, the original on the platen 2 is conveyed to the left in FIG. 2 and is ejected from one end side 2a of the platen 2. Prior to this, the original reference scale 12 is rotated about the fulcrum 36 by a rotating mechanism (not shown) constituted by a solenoid (or a spring or the like) to a position indicated by a broken line in FIG. For this reason, the document conveyed to the left from the platen 2 is smoothly moved while being guided by the upper surface of the reference scale 12 without being obstructed by the right end surface 16 of the document reference scale 12. Immediately after the leading edge of the document moving to the left has passed the reference scale 12, the scale 12 is returned to the position indicated by the solid line.

The document discharged as described above includes a reversing roller 37 that rotates clockwise, a driven roller 37a that is pressed against the reversing roller 37, and a guide 3
8 and the deflecting claw 39 occupying the position of the broken line, the reversing roller pair 32,
The sheet is discharged to the discharge tray 35 as indicated by arrows G, G1 and arrow F through the second discharge path 60 formed by 32b and the pair of discharge rollers 33.

As described above, when a plurality of originals are sequentially fed from the original table 5 to the platen 2, the originals after the end of the illumination scanning are discharged from the other end side 2b of the platen 2 as in the conventional case, and the first When the originals are stacked on the discharge tray 35 in the same page order by being conveyed through the discharge path 31 of the original, and on the other hand, only one original that does not need to be in the page order is fed from the original table 5. Discharges the original after the illumination scanning from one end side 2a of the platen 2 which is the side of the reference position S, and conveys it to the discharge tray 35 through the second discharge path 60.

When the document is discharged from the one end 2a of the platen 2 in this manner, the discharge path 60 can be remarkably shortened as compared with the conventional one. That is, as can be seen from FIG. 1 (a), if the document on the platen 2 is discharged from the other end side 2b, the document is first moved on the platen 2 in the direction of arrow C by a distance X. Since it moves and then is conveyed to the discharge tray 35 through the first discharge path 31 indicated by the arrows E and F, the entire conveyance path becomes long, but the document is on one side of the platen 2 on the reference position S side. When discharged from the end side 2a, the document is conveyed to the discharge tray 35 without passing through the path indicated by X, and through the short paths indicated by arrows G, G1, and F,
The time required for the transportation can be shortened. Moreover, if the document conveyance path is short, the possibility of jamming or other conveyance troubles is reduced. In addition, in the example shown in FIG. 2, the document discharged from one end side 2a of the platen 2 is discharged onto the discharge tray 35 with its image side facing upward, so The manuscript just copied can be immediately confirmed, and even when an erroneous manuscript is copied, it can be promptly dealt with.

In the automatic document feeder 4 shown in FIG. 1A, unlike the automatic document feeder 4 shown in FIGS. 1B to 1D, the document table 5 and the discharge tray 35 are different from each other. Since both of them are located above the platen 2, there is an advantage that the automatic document feeder 4 can be made compact, but the present invention is not limited to this type of automatic document feeder 4 and FIG. It is also applicable to the automatic document feeder 4 shown in (b) to (d). That is, as shown by the broken lines in these figures, the second discharge path 60 for discharging the document from the one end side 2a (the reference position S side) of the platen 2 is provided, and
A discharge tray 35 for receiving the original document passing therethrough is provided, and when only one original document is fed from the original document table 5 to the platen 2, when the illumination scanning is finished, the original document is discharged into the second discharge route.
When a plurality of originals are fed from the original table 5 in page order through the 60 through the discharge tray 35, the originals are discharged from the other end side 2b of the platen 2 as in the conventional case.
In these cases as well, when the original is discharged through the second discharge path 60, the original can be discharged without being conveyed the distance indicated by X on the platen 2 and the original discharging operation can be performed in a short time. Particularly, in the automatic document feeder 4 shown in FIGS. 1A and 1D, when the document is discharged from the other end side 2b, the first transport path 31 to the discharge tray 35 is formed.
The present invention can be applied to a particularly advantageous advantage because of the extremely long length. Moreover, in the case of FIG. 1 (d) as well, like the automatic document feeder 4 of FIG. 1 (a), when only one document is ejected from one end side 2a, the image surface faces upward. Discharge tray
The advantage is that it can be discharged above 35.

By the way, since the discharge paths 60 and 31 for the originals from the platen 2 are different when feeding only one original from the original table 5 and when feeding a plurality of originals in page order, It is necessary to control the driving of the rollers and the conveyor belt 15 at 31 so that the document is discharged and conveyed through each predetermined path. That is, when a plurality of documents are sequentially fed from the document table to the platen, the document after the illumination scanning is discharged from the other end side 2b of the platen, and only one document is fed from the document table to the platen. When the document is fed, it is necessary to provide a control device for controlling the document ejection operation so that the document is ejected from one end side 2a of the platen through the second ejection path 60 after the illumination scanning of the document is completed.

Such a control device can be configured in various modes. For example, an operation unit (not shown) of the main body of the copying machine is provided with a single document mode key to be pressed when copying one document, and the operator operates this key. When the document is not pressed, the document on the platen 2 passes from the other end side 2b of the platen 2 through the first discharge path 31, and when the document is pressed, the document on the platen 2 moves from one end 2a to the second side. Each element can also be controlled to be discharged through the discharge path 60.

Also, without operating the keys as described above, it is determined whether only one document is automatically fed or a plurality of documents are sequentially fed, and the document ejection direction is controlled accordingly. You can also do it.

FIG. 3 shows an example thereof, and reference numeral 65 denotes a first sheet feeding detecting means for detecting that the first sheet of the original has been fed from the original table 5. Reference numeral 66 denotes a document presence / absence detection unit that detects whether or not the next second document exists on the table 5 after the first document is fed from the document table 5.
Reference numeral 67 is a judging means for judging whether only one original is fed from the original table 5 or a plurality of originals are fed.

The first sheet feeding detecting means 65 detects that the first sheet of the original has been fed from the original table 5, and in this state it is detected that the second sheet of original does not exist on the original table 5. When it is detected by the means 66, the judging means 67 determines that only the first original document fed first is in the original table 5.
It is determined that the product was sent by Further, when the second original is present on the original table 5, it is determined that a plurality of originals are sequentially fed from the original table 5. Based on these, when ejecting the original from the platen 2,
The document discharge operation is controlled so that the document is discharged through a predetermined discharge path 60 or 31.

FIG. 4 is a block diagram showing the above control device more specifically, and its configuration will be described below in association with the automatic document feeder 4 shown in FIG.

The control device shown in FIG. 4 is provided in the automatic document feeder 4, and each portion 65, 66, 67 surrounded by a chain line is the first sheet feeding detection means and the document presence / absence detection shown in FIG. It corresponds to a means and a judgment means.

When a print key provided on the operation unit of the copying machine main body 1 is pressed to generate a document feeding start signal, this signal is input to the CPU 68, and the calling roller 6 and the separation roller 7 are based on this signal. And a motor M1 for the blocking roller 8 and a motor M2 for the pullout roller pair 9 and 10,
Also, the motor M3 for the conveyor belt 15 starts to operate together,
The original on the original table 5 is fed, but the original feeding start signal is also input to the original feeding counter 69 as shown in FIG.

The counter 69 has n-bit output terminals 1 to n, ..., When the first document feeding start signal for feeding the first document is input to the document feeding counter 69, An output of "1" appears at the output terminal of the first bit, and the output of the other output terminals, ... Becomes "0". 1
The output from the output terminal of the bit is unchanged, and the output from the other terminals is supplied to the first AND circuit 71 through the inverter 70. Therefore, the first AND circuit 71
The output of the flip-flop 73 is an H level signal.
Is input to the reset terminal of the flip-flop 73, which sets the flip-flop 73.

On the other hand, the sensor 17 described above with reference to FIG. 2 detects the trailing edge of the document, and the operation of the motor M3 for the conveyor belt 15 is controlled by the output from the CPU 68 based on this. The sensor 17 outputs an H-level signal when the document passes through it, and this signal is supplied to the CLK (clock) terminal of the flip-flop 73 via the inverter 74.

Therefore, when the trailing edge of the first document passes through the sensor 17 with the flip-flop 73 set as described above, its falling edge changes to the rising edge via the inverter 74, and the CLK of the flip-flop 73 is changed. Input to the terminal.

At this time, the flip-flop 73 is set, so
An H level first sheet detection signal is output from the output terminal Q thereof, and this is input to the second AND circuit 75.

On the other hand, the sensor 18 detects whether or not a document exists on the document table 5, as described above. When the document exists, an H level signal is output, and when the document does not exist, the sensor 18 detects whether or not the document exists. The output becomes L level, and these are input to the second AND circuit 75 via the inverter 72.

Here, if there is no document on the document table 5 after feeding the first document, the output from the sensor 18 is L.
It becomes a level, this changes to the H level via the inverter 72 and is input to the second AND circuit 75. That is, the second AND circuit 75 receives the H level signal from the flip-flop 73 and the H level signal from the sensor 18 via the inverter 72.
The bell signal is input, the output becomes H level, and this is input to the CPU 68. As a result, only one original is fed from the original table 5, and it is determined that there is no second and subsequent originals.

Based on this, the operation of the motor M3 is controlled so that the conveyor belt 15 is driven in the direction opposite to the arrow C in FIG.
The motor M5 for the reversing roller 37 and the motor M4 for the rollers 25, 27, 28, 29, 30, 32, 33 of the first transport path 31 are activated, and the original is reversed as described above. The roller 37, the paper discharge reversing roller 32, and the discharge roller pair 33 convey the second conveyance path 60 in the directions of arrows G, G1, and F, and discharge it onto the discharge tray 35.

After the first original is discharged from the original table 5, when the second original is present on the table 5, the sensor
The H level output from 18 is inverted via the inverter 72 and becomes the L level. At this time, since the H level output from the flip-flop 73 is input to the second AND circuit 75, the output to the CPU 68 becomes the L level. As a result, it is determined that a plurality of documents are sequentially fed from the document table 5.

Based on this, after the illumination scanning of the first document is completed, the operation of the motor M3 is controlled so that the conveyor belt 15 is driven in the direction of arrow C in FIG. 2, and the motor M4 is operated,
The first original is conveyed through the first discharge path 31 by the pull-out roller pair 25 and the rollers thereafter, and is discharged onto the discharge tray 35.

When the second original feeding start signal for feeding the second original is input to the original feeding counter 69, "1" is output only from the output terminal of the second bit, and the other terminal outputs. The output becomes "0", and the output from the output terminals other than the first bit is inverted by each inverter 70, so the output of the first AND circuit 71 becomes L level, and therefore the input to the reset terminal of the flip-flop 73. Becomes L level. Therefore, the flip-flop 73 remains reset, and the output from the Q terminal of the flip-flop 73 remains at the L level even if the trailing edge of the document passes the sensor 17. Even when the document feed start signal for the third and subsequent documents is input to the document feed counter 69, the third bit and the fourth bit are sequentially output.
Only the output of the output terminal of the bit-th bit becomes "1", the flip-flop 3 remains reset, and its output becomes L level.

Therefore, regardless of whether the output of the sensor 18 is at the H level or the L level, the output of the second AND circuit 75 becomes the L level, so that the second and subsequent documents are not illuminated after the illumination scanning is completed. , The respective elements are controlled by the CPU 68 so that they are all conveyed from the other end side 2b of the platen 2 through the first discharge path 31 in the directions of the arrows E and F, and each document is discharged to the discharge tray 35.
Are sequentially discharged in page order.

E1, E2, E3, E4, E5 shown in FIG. 4 are the motors M1, M2,
An encoder provided to control the speed of M3, M4, M5, etc.

Further, in FIG. 4, five motors M1 to M5 for driving the separation roller 7, the conveyor belt 15 and the like are provided for easy understanding.
Although the example in which the above is provided is shown, actually, the number of motors can be made smaller than this. For example, a motor M3 for the conveyor belt 15,
Two motors in total, one other motor that functions as the motors M1, M2, M4, and M5, are provided, and the other motor of the latter is constantly rotated, and the clutch (not shown) is controlled by the output from the CPU 68. The motor can be controlled so that the same operation as described above can be obtained.

Also, for the sake of easy understanding, in the example shown in FIG. 4, the case where a flip-flop, an AND circuit, and the like are provided has been described, but it is also clear that the control by these can be configured to be entirely processed by the CPU. .

By the way, in the above description, the case where an image formed on one side of a document is copied has been described. However, the automatic document feeder 4 shown in FIG. 2 is a so-called double-sided document in which an image is formed on both sides. Also, it is configured so that the image on each surface can be copied. When processing a two-sided original, it is necessary to first copy the image on one surface of the original, then reverse the original to make the other back face the platen 2 for copying, and then eject this original from the platen 2. However, the automatic document feeder 4 shown in FIG. 2 is configured to invert the double-sided document by using the above-described second discharge path 60 and discharge it. This has the advantage that the structure of the automatic document feeder 4 can be simplified.

Therefore, the operation and configuration when a plurality of double-sided originals are sequentially fed and the image on each side is copied will be described below.

Also in this case, as shown in FIG. 2, the original is set on the original table 5 with its front side facing up, and the uppermost original D1 is fed to the platen 2. Then, the trailing edge of the first original document stops at the reference position S, and the surface is illuminated for a predetermined number of times. Up to this operation, there is no difference from the one-sided original document described above. Absent.

When the illumination scanning of the surface is completed, the conveyor belt 15 is driven in the clockwise direction opposite to the arrow C. As a result, the first document on the platen 2 is conveyed to the left in FIG. Prior to this, the original reference scale 12 is rotated to the position shown by the broken line in FIG. Therefore, the document conveyed to the left from the platen 2 enters the second discharge path 60 while being guided by the upper surface of the reference scale 12 without being obstructed by the right end surface 16 of the document reference scale 12. Immediately after the leading edge of the document moving to the left has passed the reference scale 12, the scale 12 is returned to the position indicated by the solid line.

The document discharged as described above includes a reversing roller 37 that rotates clockwise, a driven roller 37a that is pressed against the reversing roller 37, and a guide 3
8 and the deflecting claw 39 switched to the position indicated by the solid line, the sheet is conveyed through the second discharge path 60 as shown by the arrow G while being inverted, and then is sent in the direction of the arrow H to be turned upside down.
It is sent to the platen 2 again. During this conveyance, when the leading edge detection sensor 40 provided in the conveyance path detects the leading edge of the document, the belt drive roller 13 that has been rotating clockwise until then rotates counterclockwise, and the conveying belt 15 moves in the direction of the arrow. Operates in the C direction. For this reason, the document is fed onto the platen 2 with its back side facing down without any trouble. After that, the edge of the original is placed on the reference scale 12 as in the case of surface illumination scanning.
It is applied to the right end surface 16 of the document, the document is positioned and the skew is corrected, and the document stops at the reference position. Next, the back surface of the device is illuminated, that is, the copying operation is performed a predetermined number of times.

When the illumination scanning of the back side is completed, the reference scale 12 is rotated to the position indicated by the broken line, and the document is conveyed in the direction of arrow G, as when the illumination of the front side is completed. At this time, the deflecting claw 39 is rotated to the position indicated by the broken line, so that the document is guided by this and discharged onto the discharge tray 35 through the pair of reverse discharge rollers 32, 32b and the discharge roller pair 33. In this way, the double-sided document is discharged through the second discharge path 60, and the document discharged onto the discharge tray 35 has its front side facing down.

The next second original on the original table 5 is also conveyed in the same manner, and after the illumination processing on the front surface and the rear surface is completed, the discharge tray 35
Ejected face up and face down. In this way, the originals are successively conveyed, and the page order of the original stack finally stacked on the discharge tray 35 is the same as the page order when initially set on the original table 5.

As described above, the second discharge path 60 also serves as a path for reversing the double-sided document and discharging the double-sided document after the illumination scanning of the back surface is completed. For this reason, a second one for feeding only one single-sided original and discharging it from the platen 2
It is not necessary to separately provide a discharge path 60 and a path for reversing and discharging a double-sided document, and the structure of the automatic document feeder 4 can be simplified.

By the way, the automatic document feeder 4 shown in FIG. 2 shortens the distance between the documents sequentially fed from the document table 5 as compared with the conventional automatic document feeder, and finishes processing all the documents. It is also configured to shorten the time until. Therefore, in order to understand the present invention, a more specific operation related to the present invention will be described with reference to the second embodiment.
The case of a single-sided original and the case of a double-sided original will be described with reference to FIGS. 5, 5 and 6, respectively, and then the above-described operation when only one single-sided original is fed from the original table will be described. A more specific operation example will be described.

Single-sided original document FIG. 5 is a timing chart of the automatic original document feeder 4 when a plurality of single-sided original documents are sequentially conveyed and copied. As is apparent from FIGS. 2 and 5 and the above description, when the print key of the copying machine body 1 is pressed (turned on), the calling roller 6 of the automatic document feeder 4 reads the document D on the document table 5. Pressurize the roller 6 and the separation roller 7
For a predetermined time, 0.2 seconds in the example of FIG. 5, as can be seen from (a) and (b). As a result, the manuscript table 5
The uppermost original document is sent out, and the original document is conveyed by the pullout roller pair 9 and 10 and is fed toward the platen 2. At the same time, as is clear from FIG. 5D, the conveyor belt 15 starts to rotate in the direction of arrow C shown in FIG. In this example, the peripheral speed of the conveyor belt 15 is 500 mm / sec, and the other elements of the document feeding means (pullout roller pair) are used.
The document feed speed by (9,10 etc.) is the same as the above peripheral speed, 500 mm / se.
Let c. That is, the manuscript is from the manuscript table 5 to 500
It is sent to the platen 2 at a speed of mm / sec.

The front and rear ends of the conveyed document are detected by the sensor 17, and the length of the document is detected from the relationship between the time and the document conveyance speed. In the example of FIG. 5, as can be seen from (c), it takes 0.42 seconds from the detection of the leading edge of the document by the sensor 17 to the detection of the trailing edge thereof, and the document speed is 50%.
Since it is 0 mm / sec, it can be seen that the original is A4 size and this is fed laterally. In the example shown in the figure, the conveying path from the sensor 17 to the right end surface 16 of the reference scale 12 is 180 mm, and the length of the original is 180 mm after the trailing edge of the original has passed the sensor 17.
After being transported by 10 mm, it is further transported by 10 mm and then returned by 10 mm in the opposite direction (direction opposite to arrow C in FIG. 2).
0.38 seconds after the trailing edge of the document passes through the sensor 17, that is, the conveying belt 15 continues to rotate forward until the time corresponding to feeding the document by 180 mm + 10 mm (Fig. 5 (c) (d)), The belt 15 reverses for 0.02 seconds to return the original by 10 mm, and applies its rear end (left end) to the right end face 16 of the reference scale 12 to perform its positioning and skew correction.

When the document is set at a predetermined position, the document is illuminated by the optical system 3 on the body side of the copying machine (FIG. 5 (d)). For an A4 size document that has been fed laterally,
It requires a time close to 1 second, which is 0.88 seconds or more. After the illumination is completed, the conveyor belt 15 is rotated in the forward direction for 0.52 seconds, whereby the document is conveyed until its leading edge (right end) is caught by the pullout roller pair 25, and thereafter, the first discharge path 31 including the pullout roller pair 25. And is conveyed to the discharge tray 35.

It should be noted that the above-described illumination scanning of the original document is performed once or the number of repeats keyed by the operator as described above, but FIG. 5 shows the case where one illumination scanning is performed on one original document. It is shown.

On the other hand, the second original on the original table 5 is the platen 2
It is sent after the last illumination of the first original document is started and before the illumination is finished.
Here, the last illumination is n for the original on the platen 2.
When the illumination scan is performed once, it means the nth illumination scan, and when the illumination scan is only once as in the example of FIG. 5, the illumination scan is the last illumination.

As can be seen from the above, while the final illumination of the original on the platen 2 is being performed, the feeding of the next second original is started. In the example of FIG. 5, as can be seen from (a) and (b), the calling roller 6 and the separation roller 7 are t = 0.68 seconds after the illumination of the first original on the platen 2 is started. Rotation has started, and the second document has started to be fed. At this point, the first original document on the platen 2 is still illuminated, and the leading edge of the fed second original document is at the trailing edge (left end) of the first original document on the platen 2. When the position reaches a position 50 mm before, the conveyor belt 15 starts to rotate in the normal direction, and the discharge of the first document on the platen 2 is started. Then, the second original is fed onto the platen 2 and set at a predetermined position on the platen 2 as described above. In this case as well, it is natural that the sensor 17 detects the length of the second document.

When the second original is set at a predetermined position, the ejection timing of the first original is controlled so that the preceding first original is on the first ejection path 31. That is, when the second document is set at the predetermined position, the leading edge of the first document has already reached the pull-out roller pair 25 or the subsequent transport roller pairs 27, 28, 29, 30 and is positively transported by this. It has been done. Here, the conveying member after the pull-out roller pair 25, that is, the rollers 25, 27, 28, 29,
The document feed speed for 30, 32, and 33 is 800 mm / sec in this example.
And each element is controlled so as to be faster than the document feeding speed (500 mm / sec in this example) by the document feeding unit that conveys the document toward the platen 2. For this reason,
At the time when the second document is set at a predetermined position on the platen 2, the second document is conveyed and discharged at a high speed through the first discharge path 31, and there is a problem that the two documents come into contact with each other or overlap each other. Be blocked. Moreover, the illumination scanning of the second original is not disturbed by the first original. If the coefficient of friction of the pull-out roller pair 25 with respect to the original is set to be larger than the coefficient of friction of the conveyor belt 15 with respect to the original, the first original can be conveyed while being pulled strongly by the pull-out roller pair 25. Can be prevented more reliably.

Hereinafter, the same operation is repeated for the third and subsequent documents.

As described above, since the interval between the preceding original document and the subsequent original document is narrowed, it is possible to shorten the time required for exchanging the respective original documents, and it is possible to greatly reduce the time required for copying the entire original document. In addition, it is possible to prevent the two originals from coming into contact with each other and causing a transport trouble.

Further, each original document conveyed on the original document conveyance path 11 from the original document table 5 to the platen 2 is always fed at a constant speed without stopping in this path. On the other hand, after starting feeding the preceding document, feeding the following document so as to follow it, and when the preceding document is illuminated on the platen, the next document is fed into the document conveyance path 11. When the sheet is stopped and after the illumination of the original document is finished, when ejecting the original document from the platen 2, even if the next original document, which has been waiting until then, is sent onto the platen 2, the interval between the original documents is narrowed, It is possible to improve copy production efficiency.

However, according to this configuration, the next document must be temporarily stopped in the document transport path, so the pullout roller pair
It is necessary to temporarily stop the rotation of 9,10 and then rotate them, which complicates the control. Not only that, but especially when the original feeding path 11 is curved so as to invert the original as in the example of FIG. 2, when the original is stopped in this path 11, the original is transferred to the original. There is a curling tendency along the form of the route, which deteriorates the quality and causes a transport trouble (jam).

However, in the configuration of the present example shown in FIG. 2, the feeding of the original is controlled so that the original is continuously conveyed without being stopped in the conveying path 11, and thus the above-mentioned configuration is performed. It is possible to prevent the occurrence of defects.

Further, in the configuration of FIG. 2, since the next original is started to be fed after the illumination scanning of the preceding original is started,
There is only one manuscript at maximum in 11 pages. Moreover, the document is discharged at a high speed through the first discharge path 31. this is,
This means that it is possible to reduce the number of documents existing in the entire conveyance path of the automatic document feeder 4, and in the example of the figure, the maximum number of documents existing in the automatic document feeder is three. This simplifies the processing when a document conveyance trouble occurs. That is, the processing can be performed by simply removing a small number of documents from the transport path.

By the way, in the example of FIG. 5, the feeding of the next original is started when t = 0.68 seconds have elapsed after the start of the illumination of the preceding original, but this time t can be changed depending on the length of the original. If this time t is too long, the interval between the originals will be too large and copy production efficiency will be reduced, and if the time t is too short, the interval between the originals will be too small and the originals may come into contact with each other. In other words, the time t ₁ from the start of feeding the subsequent original to the start of discharging the preceding original from the platen 2 is controlled so that it is always constant. This is achieved by detecting the length of each document by the sensor 17, setting the time for certifying the document based on this, setting the time t, and controlling the feeding start timing of the next document. Done. In this example, t = 0.68 seconds is set for an A4 size document, and control is performed so that the interval between the documents is 50 mm.

Double-sided Original Next, a more specific operation example when copying a plurality of double-sided originals in sequence will be described with reference to FIGS. 2 and 6.

As can be seen from FIGS. 6A to 6D, the feeding timing of the first document on the document table 5 is the same as that for the single-sided document, and the calling roller 6 and the separation roller 7 are used.
As a result, the first original is fed onto the platen 2 with the front side facing downward, and is positioned and set at a predetermined position on the platen 2. The surface is then illuminated. In this case as well, FIG. 6 shows the case where the illumination scanning is performed once for one document, but it may be performed multiple times.
The same applies to the number of times the back surface is illuminated, which will be described later.

As shown in FIG. 6D, after the illumination scanning of the front surface of the first original is completed, the conveyance belt 15 is reversely driven for 0.4 seconds in order to reverse the front and back of the original. Prior to this, as shown in FIG. 6 (e), the solenoid is biased for 0.2 seconds, whereby the reference scale 12 is rotated to the position shown by the broken line in FIG. In this way, the first original is conveyed on the original reference scale 12 and then the reversing roller.
It is conveyed in the direction of arrow G by 37. At this time, the deflection claw 39
Is at the position indicated by the solid line in FIG. 2, and the first document is guided by this and conveyed toward the platen 2, and is set again at a predetermined position on the platen 2 with the back surface facing downward.

On the other hand, the conveyor belt 15 is switched to the forward rotation (0.44 seconds after 0.4 seconds from the start of the reverse rotation of the conveyor belt 15) when the leading edge of the first document that has been reversed through the reversing roller 37 hits the belt 15. ), The first document is sent to the platen 2 with its back surface facing downward, and is subsequently set in a predetermined position on the platen 2 by the reverse rotation of the conveyor belt 15, and the back surface of the first document is illuminated and scanned.

Before the illumination of the back side is finished, the original reference scale 12 is rotated again to the position shown by the broken line in FIG. 2, and after the illumination scanning is finished, the conveyor belt 15 is driven in reverse to feed the first original to the discharge port 34. Turn it over. At this time, the deflecting claw 39 occupies the position shown by the broken line in FIG. 2, and the document is discharged to the discharge tray 35 with its back surface facing upward.

The calling roller 6 and the separation roller 7 start rotating again a predetermined time t after the last illumination of the first original, that is, the illumination scanning performed on the back surface of the original is started, and the original table 5 is rotated. The second upper document is fed toward the platen 2 and starts. Also in this case, the second original is continuously conveyed in the conveying path 11 without stopping, and passes the original reference scale 12 with the first original discharged from the platen 2. At this time, the reference scale 12 occupies the position shown by the solid line in FIG. 2, and the second original is fed onto the platen 2 by the transport belt 15 driven in the normal direction. The same operation as described above is repeated for the third and subsequent originals.

The above-mentioned time t is also set according to the length of the document so that the interval between the documents does not become too narrow or too wide. In the example shown in the figure, t is determined so that the time t ₁ from the start of feeding the succeeding document to the reverse rotation of the conveyor belt 15 is 0.2 seconds.

As described above, even for double-sided originals, the copying process can be performed quickly and while preventing a transportation trouble.

It should be noted that the operation of the copying machine main body 1 side is performed in synchronization with the above-described movements of the single-sided and double-sided originals, that is, operations such as feeding the original, setting it on the platen 2 at a predetermined position, and ending the illumination scanning. Naturally, each element of the main body is controlled so that copy paper can be quickly produced.

Single-Page Original Next, a more specific example of a mode in which only one original is fed from the original table 5, the illumination scanning is performed, and the original is discharged through the second discharge path 60 is shown in FIGS. 2 and 7. It will be described with reference to the drawings.

The original is fed from the original table 5 to the platen 2 and is positioned and set at a predetermined position. The original is illuminated and scanned, and the conveying belt 15 is reversed after scanning, and the original reference scale 12 is set to the first position. Rotating to the position indicated by the broken line in FIG. 2 and guiding the document to the second discharge path 60 is the same as in the double-sided document (FIGS. 7A to 7E).

The sensor 17 is located at the rear end of the document sent from the document table 5.
When the document passes through the table, the sensor 18 detects that there is no next document on the document table 5 (FIG. 7 (f)), and based on this, the control described above with reference to FIG. 4 is executed. It

When the document is conveyed through the second discharge path 60, the deflecting claw 39 occupies the position shown by the broken line in FIG. 2, and the document is discharged from the discharge port 34 to the discharge tray 35. As shown in (g), the document is detected by the paper discharge sensor 80.

Here, the time T until the document is fed from the document table 5 and the trailing edge of the document is detected by the discharge sensor 80 is about 2.5 seconds. On the other hand, when a document is discharged through the first discharge path 31 as shown in FIG. 5, the document is fed from the document table 5, and the trailing edge is detected by the discharge sensor 80. It takes about 3.2
Seconds (FIG. 5 (e)), the one discharged through the second discharge path 60 is shortened by 3.2 seconds−2.5 seconds = 0.7 seconds.
Also, in this example, the first discharge path 31 to the discharge tray 35
Although the path length of is about 840 mm,
The path length of the second discharge path 60 up to 5 is about 410 mm, which is significantly shorter than that of the first discharge path, and the possibility of document conveyance trouble is suppressed accordingly.

Further, when a document sent to the discharge tray 35 through the second discharge path 60 passes the deflecting claw 39, the document is fed to the reverse discharge roller 32 and the reverse discharge roller 32 which also constitutes a part of the first discharge path 31. Although being conveyed by the pair of paper discharge rollers 33, these rollers 32 and 33 convey the document at a speed of 800 mm / sec as described above. On the other hand, the reversing roller 37 and its driven roller
Like the conveyor belt 15, the 37a is configured to convey an original at a speed of 500 mm / sec. Moreover, the frictional force of the rollers 32 and 33 with respect to the original is larger than the friction coefficient of the rollers 37 and 37a with respect to the original. Is also set large. That is, the second
When the document sent through the discharge path 60 of the reverse cover discharge roller 32 and the driven roller 32b thereof is pulled by these, it is sent at a speed of 800 mm / sec.
7 is also pulled by the manuscript and rotates at a peripheral speed of 800 mm / sec. In this way, by increasing the document transport speed and the transport force of the document transport member closer to the document exit port 34 than that of the document transport member away from the exit port 34, the document is ejected more quickly. Can be made. Of course, the conveying speed and the conveying force of both may be set to be equal, and even in this case, the document can be discharged more quickly than in the conventional case.

Although the present invention is applied to the automatic document feeder of an analog copying machine, which is an example of an image forming apparatus, the present invention is also applicable to an automatic document feeder of an image forming apparatus such as a digital copying machine or a facsimile. Of course, can be applied.

[Effect of device]

Since the present invention is configured as described above, it has the following effects.

According to the configuration of claim 1, when a plurality of originals are fed from the original table, these originals can be discharged to the discharge tray in the page order as in the conventional case, and the page order does not matter. When only one document is fed, it can be quickly discharged to the discharge tray, and the occurrence of conveyance trouble can be suppressed.

According to the configuration described in claim 2, it is possible to discriminate between the feeding of one original and the feeding of a plurality of originals without performing a special operation.

According to the configuration described in claim 3, even when the automatic document feeder is configured to process double-sided documents, the structure can be simplified.

[Brief description of drawings]

FIGS. 1 (a) to 1 (d) are schematic views showing various automatic document feeders for explaining the conventional example and the present invention, and FIG. 2 is an upper part of a copying machine and an automatic device mounted thereon. FIG. 3 is a sectional view of the document feeding device, FIG. 3 is a block diagram of the control device, FIG. 4 is a block diagram showing a more specific example thereof, and FIG. 5 is a timing chart when copying a plurality of single-sided documents. FIG. 6 is a timing chart when copying a plurality of double-sided originals, and FIG. 7 is a timing chart when copying a single-sided original. 2 ... Platen, 2a ... One end side 2b ... Other end side, 4 ... Automatic document feeder 5 ... Document table, 35 ... Ejection tray 60 ... Ejection path, 65 ... First sheet feeding detection means 66 ... Document presence / absence detection means 67 ... Judgment means, D, D1, D2 ... Document S ... Reference position

Claims (3)

[Scope of utility model registration request] 1. A document on a document table is fed page by page onto a platen of an image forming apparatus main body from one end side of the platen, and the document is fed to one side of the platen at its rear end. Position it so that it matches the reference position on the end side,
In the automatic document feeder of the image forming apparatus, the original is illuminated and scanned from the reference position side, then ejected from the other end side of the platen, and stacked in page order on the ejection tray. When a plurality of documents are sequentially fed from the document table to the platen and the discharge path for discharging from one end of the platen, the documents after illumination scanning are discharged from the other end of the platen and When only a single document is fed from the document table to the platen, a control for controlling the document ejection operation so that the document is ejected from one end of the platen through the ejection path after the illumination scanning of the document is completed. And an automatic document feeder. 2. A first sheet feeding detection means for detecting that the first original has been fed from the original table, and the control device after the first original has been fed from the original table. An original presence / absence detecting means for detecting whether or not the next second original exists on the table, and a second original on the original table while the feeding of the first original is detected. If it does not exist, only the first original that was fed first is fed from the original table, and if the second original exists on the original table, multiple originals from the original table are fed. The automatic document feeder according to claim 1, further comprising: a determination unit that determines that the documents are sequentially fed. 3. The automatic document feeder according to claim 1, wherein the discharge path also serves as a path for reversing the double-sided original and discharging the double-sided original after the end of illumination scanning.