JPH07281562A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device which is easy to use without increasing the handling time of an operation in the case that there is a blank document. CONSTITUTION:A line sensor 11 detects the image of a document fed in the direction of an arrow A from the document table 9 of an ADF 8 mounted at the upper surface of a copying machine that is not shown in figure, and the existance of a document image is judged by a control circuit not shown in the figure. A warning display is made on the operation panel of the copying machine when it is judged that no image exists in the document (blank document), and in the case that no instruction input is given by an operator after the lapse of a fixed time, it is judged that the blank document is intentionally inserted to start copying operation as it is. In the case that the operator gives some kind of input within the fixed time, the blank document is ejected on a paper ejecting table 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a document reading function, such as a copying machine and a facsimile, and more particularly to an image forming apparatus equipped with an automatic document feeder.

[0002]

2. Description of the Related Art An image forming apparatus having a document reading function, such as a copying machine, is equipped with an automatic document feeder for automatically feeding a document to a reading position and discharging the document after scanning the document. Copiers are well known in the art. There are two types of automatic document feeders (hereinafter abbreviated as ADF), one of which is placed on the document table with the image surface of the document to be read facing upward, and the other of which is placed downward. . Therefore, the user may not know in which direction the original should be set in the ADF, and may mistakenly set the front and back of the original for copying. Alternatively, a blank document may be mixed in a plurality of documents, or a document in the middle may be turned upside down. In such a case, an unnecessary blank copy is made, and it becomes necessary to correct the front and back of the original and copy it again, which not only takes time but also wastes resources and power.

In order to eliminate such inconvenience, it has been proposed to detect a blank original mixed in the original to stop the copying machine and give a warning to the user by a buzzer lamp or the like. ing.

[0004]

However, when a blank original is detected and the operation of the apparatus is stopped as described above,
If a blank original is erroneously detected despite the presence of an image (in the case of an ADF in which the feeding speed cannot be adjusted, the original may be fed before the sensor for detecting the blank original is ready to detect it. In such a case, scanning may be missed and the document may be erroneously detected as a blank document, or if a blank document is intentionally inserted, the device will stop and the user will have to redo the operation. There was a problem that it was troublesome and time-consuming.

Further, even if there is an original whose front and back are wrong among a plurality of originals, it is necessary to set the wrong original again and perform the operation again.

An object of the present invention is to solve the above-mentioned problems in the conventional image forming apparatus equipped with the ADF and to provide an easy-to-use image forming apparatus which does not increase the labor of operation.

[0007]

According to the present invention, there is provided an image forming apparatus equipped with an automatic document feeder for feeding a document to an image processing position. A document image presence / absence detection unit for detecting the presence / absence of an image of a document fed to the document, and the document image presence / absence detection unit again detects a document image fed by the automatic document feeder to an image processing position. When the original image presence detecting unit determines that there is no image of the original, the automatic original feeding device conveys the original again to the original image detecting position to detect the presence or absence of the original image. The presence / absence of a document image is detected again by the means, and when it is determined again that there is no image of the document, a warning signal is issued to activate the warning means of the image forming apparatus and It is solved by having a control means for controlling so as not to perform the forming operation.

In order to solve the above problems, the present invention provides an image forming apparatus equipped with an automatic document feeder for feeding a document to an image processing position, wherein the image processing position is adjusted by the automatic document feeder. A document image presence / absence detection unit for detecting the presence / absence of an image of the document fed to the sheet, and when the document image presence / absence detection unit determines that there is no image on the document, a warning signal is issued to warn the image forming apparatus. The image processing operation is started when a predetermined time has elapsed from the operation of the warning means and the operator does not input an operation, and the operator starts the operation until a predetermined time elapses from the operation of the warning means. It is proposed to provide a control means for controlling to eject the document judged to have no image to the outside of the apparatus when the operation input is input.

Further, in order to solve the above-mentioned problems, the present invention has an automatic document feeding function which has a document reversing function and can reverse a document fed to an image processing position and then feed it again to the image processing position. An image forming apparatus equipped with a paper device has an original image presence / absence detecting unit for detecting the presence / absence of an image of an original fed to an image processing position by the automatic original feeding unit, and the original image presence / absence detecting unit detects the original. If it is determined that there is no image, the document is proposed to be reversed by the automatic document feeder and conveyed again to the image processing position to control the image processing.

Further, in order to solve the above-mentioned problems, the present invention has an automatic document feeding function which has a document reversing function and can reverse a document fed to an image processing position and then feed it again to the image processing position. An image forming apparatus equipped with a paper device has an original image presence / absence detecting unit for detecting the presence / absence of an image of an original fed to an image processing position by the automatic original feeding unit, and the original image presence / absence detecting unit detects the original. When it is determined that the original image is not present, the original is inverted by the automatic original feeding device, conveyed again to the image processing position, and the presence / absence of the original image is detected again by the original image presence / absence detecting unit to detect the image of the original. It is proposed to provide control means for controlling the document to be ejected out of the apparatus without performing the image processing when it is determined again that there is no image.

Further, in order to solve the above-mentioned problems, the present invention has an automatic document feeding function which has a document reversing function and can reverse a document fed to an image processing position and then feed it again to the image processing position. An image forming apparatus equipped with a paper device has an original image presence / absence detecting unit for detecting the presence / absence of an image of an original fed to an image processing position by the automatic original feeding unit, and the original image presence / absence detecting unit detects the original. When it is determined that the original image is not present, the original is inverted by the automatic original feeding device, conveyed again to the image processing position, and the presence / absence of the original image is detected again by the original image presence / absence detecting unit to detect the image of the original. If it is determined again that there is no image, a warning signal is issued to activate the warning means of the image forming apparatus, and a control means for controlling not to perform the image forming operation is provided. To.

Further, in order to solve the above-mentioned problems, the present invention has an automatic document feeding function which has a document reversing function and can reverse a document fed to an image processing position and then feed it again to the image processing position. An image forming apparatus equipped with a paper device has an original image presence / absence detecting unit for detecting the presence / absence of an image of an original fed to an image processing position by the automatic original feeding unit, and the original image presence / absence detecting unit detects the original. When it is determined that the original image is not present, the original is inverted by the automatic original feeding device, conveyed again to the image processing position, and the presence / absence of the original image is detected again by the original image presence / absence detecting unit to detect the image of the original. When it is determined again that there is no alarm, a warning signal is issued to activate the warning means of the image forming apparatus, and even if a predetermined time elapses from the activation of the warning means, an operation by the operator is performed. If there is no force, the image processing operation is started, and if there is an operation input from the operator before the lapse of a predetermined time from the operation of the warning means, the document judged to have no image is discharged to the outside of the apparatus. It is proposed that a control means for controlling so as to be provided is provided.

[0013]

The presence / absence of the image of the document fed to the image processing position is detected by the document image presence / absence detecting means. When it is determined that the document has no image, the document is conveyed again to the document image detection position, and the presence or absence of the document image is again detected by the document image presence / absence detection unit. When it is determined that there is no image again, the warning means of the image forming apparatus is activated and the image forming operation is controlled not to be performed.

Other functions will be apparent from the description of the embodiments below.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the outline of a copying apparatus which is an embodiment of the present invention. As shown in the figure, the copying apparatus 100 includes a copying machine main body 1 including an engine that executes an image forming operation, and first to third sheet feeding devices 3 arranged below the copying machine main body 1.
-5, a fourth paper feeding device which is a large-volume paper feeding device mounted on the side surface of the main body 6, a sorter 7 for collating and sorting copies, and an ADF 8 mounted on the upper surface of the main body. An operation unit (operation panel) 2 for inputting an operation is provided on the upper front surface of the copying machine main body 1. The operation unit 2 is provided with display means (not shown) for displaying a warning described later.

The copying machine main body 1 is based on a conventionally well-known electrophotographic method, and the basic construction and operation of each of the sheet feeding devices 3 to 6, the sorter 7 and the ADF 8 are the same as those conventionally well known. The description thereof will be omitted, and only the part relating to the invention will be described.

FIG. 2 is a block diagram showing the control system of the copying apparatus 100 described above. In this figure, reference numeral 11
Reference numeral 0 denotes a control circuit of the copying machine main body 1, which includes a CPU for controlling the operation of the entire copying apparatus, a ROM storing a control program and the like, a RAM for storing data and the like and an input / output device. The main body control circuit 110 includes a control circuit 120 for the operation unit 2, control circuits 130-160 for the first to fourth sheet feeding devices 3-6, a control circuit 170 for the sorter 7, and an ADF.
8 control circuits 180 are connected.

The operation unit control circuit 120 is provided with operation input keys and display means such as an LED, and is connected to the main body control circuit 110 by a serial transmission line. The control circuits 130 to 160 of each sheet feeding device are connected to the main body control circuit 110 by a parallel transmission line, and a sensor (not shown) that detects the size of the recording sheet stored in each sheet feeding device.
From the main body control circuit 110, and outputs signals from the main body control circuit 110 for controlling the motors, clutches, solenoids, etc. of the sheet feeding devices. Sorter control circuit 170
Has its own CPU and is connected to the main body control circuit 110 by a serial transmission line. The ADF control circuit 180 also has its own CPU and is connected to the main body control circuit 110 by a serial transmission line.

FIG. 3 is a sectional view showing the structure of the ADF 8. The ADF 8 is openably and closably mounted on the upper portion of the copying machine main body 1. When the ADF 8 is closed, the lower surface of the document conveying belt 12 comes into contact with a contact glass (not shown) of the copying machine main body 1. ing. The composite sensor 10 and the line sensor 1 are provided near the document insertion opening from the document table 9.
1 is provided. The composite sensor 10 is composed of three sensors: a document presence / absence detection sensor, a document partition plate sensor, and an entrance sensor. Note that reference numeral 13 indicates that the document is the discharge table 1.
9 is a paper ejection sensor that detects that the paper has been ejected.

A document (not shown) inserted from the document table 9 as indicated by an arrow A is conveyed to a predetermined position on the contact glass of the copying machine main body 1 by the conveying roller 15 and the conveying belt 12 to read an image. After being conveyed, the sheet is again conveyed by the conveying belt 12 and is ejected to the sheet ejection table 19 by the sheet ejection roller 16 as indicated by an arrow B. Further, the ADF 8 is capable of passing the original document conveyed onto the contact glass again to the image reading position on the contact glass by passing through the attachment position of the line sensor 11 again, and switching thereof is performed by a branch claw. 18 performed. That is, when the branch claw 18 is rotated clockwise from the illustrated document discharge position to close the document discharge path, the document transport path is switched and the document is transported by the transport belt 12.
After being conveyed above the sheet, the sheet is conveyed through the re-conveying roller 17 as shown by an arrow C and is conveyed again to the image reading position. This is performed in order to prevent erroneous detection of blank document detection, which will be described later.

By the way, the line sensor 11 has a large number of sensors 14 arranged in a line as shown in FIG. 4, and its longitudinal direction is arranged in a direction orthogonal to the document conveying direction. Each sensor 14 has a light emitting unit and a light receiving unit (both not shown). The document is fed with light from the light emitting unit, and the light receiving unit receives the light reflected from the document. Detect the image above. The detection signal is the above-mentioned A
It is sent to the DF control circuit 180 to determine the presence / absence of an image on the document, and the determination result is further sent to the main body control circuit 110. If you want to re-feed the document as described above,
The original image is detected by the line sensor 11 again. The line sensor 11 may be a contact sensor.

FIG. 5 is a block diagram showing the control system of the ADF 8. In this figure, reference numeral 180 is the above-mentioned ADF control circuit, which is connected to the main body control circuit 110. The ADF control circuit 180 includes a carry motor 20.
1, a document presence / absence sensor 202, a document partition plate sensor 203,
The entrance sensor 204, the paper discharge sensor 205, etc. are connected.
The transport motor 201 is a motor that drives a transport roller and a transport belt for transporting the document set on the document table 9 onto the contact glass of the main body of the copying machine and further discharging the same, and includes an encoder 212. The output from the encoder 212 is sent to the control circuit 180 and used for controlling the carry motor 201. The document presence / absence sensor 202 is a sensor that detects a document inserted from the document table 9, and is one of the composite sensors 10 shown in FIG. The document partition plate sensor 203 is a sensor that detects a state of a partition plate (not shown) for partitioning a document discharged to a discharge table, and an input from this sensor enables a plurality of jobs to be partitioned. It has multiple inputs. The entrance sensor 204 is also one of the composite sensors 10 shown in FIG. 3, and it is possible to detect the length of the document in the conveyance direction depending on the time when the sensor is on. Note that reference numeral 20
6 to 210 represent various inputs to the control circuit 180 and various outputs from the control circuit 180. That is, the job switching input 206 for instructing the job switching, the ADF 8
Display output 20 to display means (not shown) provided in the
7, the input 208 from the line sensor 11 shown in FIG.
Other inputs 209, 210 and other outputs 211.

FIG. 6 is a flow chart showing the basic operation of the copying apparatus 100 of this embodiment. As shown in this drawing, first, in step (hereinafter abbreviated as S) 1, when the power of the copying apparatus is turned on, initialization is performed (S).
2) Stand-by state, then normal mode (S
3) It becomes possible to execute the operation described later.

FIG. 7 is a flowchart showing the operation of the copying apparatus 100 in the normal mode (normal state). That is, first, it is determined whether the ADF 8 is connected (mounted) to the copying machine body 1 (S1). If the ADF 8 is connected, it is determined whether a document is set on the document table 9 of the ADF (S2). When the original is set, the copy operation (image forming operation) is started (S3), and when the copy operation is completed (S4), the normal state is restored. If the ADF 8 is not connected and no document is set on the document table, the process returns to the main routine.

FIG. 8 is a flow chart showing the processing when there is a blank original. When the copying apparatus 100 is in the normal state, the original is set on the original table 9 of the ADF (S1).
Then, the start button for instructing the start of copying is pressed (S2)
Then, the set original is conveyed onto the contact glass of the copying machine main body 1. At this time, the image of the document is detected by the line sensor 11 described above. Then, the ADF control circuit 180 determines whether or not the document has an image (S3). If there is an image on the document, the copying operation is started (S4) and the normal state is restored. If there is no image on the original, the original is conveyed again as described above, and it is again checked that the original has no image (S5). If it is determined that there is an image, the process proceeds to S4 and the copy operation is started. If it is determined that there is no image by detecting the original image again, a warning display indicating that there is a blank original is displayed (S6), and the original is ejected (S7).

As described above, in the copying apparatus 100 of the present embodiment, if a blank original is present in the originals fed from the ADF 8, it is checked again whether or not it is a blank original. The number of erroneous detections for determining a blank document is reduced, and as a result, there is no need to stop the apparatus and redo the operation, and the labor of the operation is not increased.

By the way, a blank sheet may be intentionally mixed in a series of documents consisting of a plurality of sheets. For example, when clarifying the classification and division of documents. In such a case, according to the control shown in FIG. 8, a blank document is detected and the operation of the apparatus is stopped. When a blank sheet is intentionally mixed, it is convenient not to stop the operation of the apparatus and copy the blank sheet as a blank sheet. Therefore, as another embodiment of the present invention, after a blank document is detected, if there is no instruction from the operator for a certain period of time, the copying operation is performed as it is, and if any input is made by the operator within a certain period of time. It is suggested that the blank document be discharged to the discharge table. Hereinafter, the example will be described.
Since the copying machine of this embodiment has the same structure as the copying machine 100 of the previous embodiment, only the control when a blank original is detected will be described.

FIG. 9 is a flow chart showing the processing when there is a blank original in this embodiment. When the copying apparatus of this embodiment is in the normal mode, a document is set on the document table 9 of the ADF (S1), and when the start button for instructing the copy is pressed (S2), the set document is copied. It is conveyed onto the contact glass of the machine body 1. At this time, the image of the document is detected by the line sensor 11 described above. Then, the ADF control circuit 180 determines whether or not the original has an image (S3). If there is an image on the document, the copying operation is started (S4) and the normal state is restored. The processing up to this point is the same as in the previous embodiment. If there is no image on the original, a warning display indicating that there is a blank original is displayed (S5) and the operator waits for an instruction input (S5).
6). If there is no instruction input from the operator even after a certain period of time, it is determined that the blank original has been intentionally inserted, and the copying operation is started as it is (proceeding to S4). If there is any input from the operator within a certain period of time, the blank document is discharged to the discharge table (S7).
After that, it returns to the normal state.

In the present embodiment, a warning is displayed when there is a blank original in the original, and when the blank original is intentionally inserted, copying is performed as it is. Thus, it is possible to save the operator the trouble of performing the operation again.

Next, still another embodiment of the present invention will be described. The copying apparatus of this embodiment is the same as the copying apparatus 100 of the above-described embodiment described with reference to FIGS. 1 to 8 except that the configuration of the automatic document feeder (ADF) is different and the control when detecting a blank document is different. Therefore, only different parts will be described.

FIG. 10 shows the structure of the ADF 28 mounted on the copying machine of this embodiment. This ADF28
Has a reversing unit 30, and allows the copying machine to read both the front and back sides of the original. This ADF28
In FIG. 1, the line sensor 21 for detecting the original image is arranged on the right side of the conveyor belt 22 in the figure.

In the ADF 28, in the single-sided original mode, the original is placed on the original table 29 with its image side facing down.
Set on top. A document (not shown) inserted as indicated by an arrow A is conveyed on the contact glass 20 of the copying machine main body through the conveyance path 31. The original after the image reading is carried to the reversing unit 30 by the conveyor belt 22 and the reversing roller 34. The original that has entered the reversing unit 30 is switched back by the reverse rotation of the reversing roller 34, and is discharged to the original table 29 through the conveyance path 32 as shown by arrow B. At this time, the branch claw 35 is at the position shown in the figure,
The document switched back from the reversing unit 30 is the transport path 31.
It is guided in the direction of the transport path 32 while preventing the traveling in the direction.

In the double-sided original mode, the original is set on the original table 29 with its front side facing down. A document (not shown) inserted as indicated by an arrow A is conveyed on the contact glass 20 of the copying machine main body through the conveyance path 31. The original after the image reading is carried to the reversing unit 30 by the conveyor belt 22 and the reversing roller 34.
The document sent to the reversing unit 30 is switched back when the reversing roller 34 reverses. At this time, the branching claw 35 rotates clockwise from the position shown in the figure to close the conveyance path 32, and guides the switched back document to the conveyance path 31. The original is again conveyed on the contact glass 20 of the main body of the copying machine through the conveying path 31. At this time, the back surface of the original is opposed to the contact glass 20.
Then, the document whose back side has been read is sent to the reversing unit again, and this time, it passes through the conveyance path 33 and the document table 29.
Is discharged to.

FIG. 11 is a flow chart showing the processing when there is a blank original in this embodiment. When the copying apparatus is in a normal state, an original is set on the original table 29 of the ADF (S1), and a start button for instructing the start of copying is pressed (S2). It is transported onto the contact glass. At this time, the image of the document is detected by the line sensor 21 described above.
Then, the ADF control circuit 1 determines whether the document has an image or not.
It is determined by S80 (S3). If there is an image on the document, the copying operation is started (S4) and the normal state is restored. If there is no image on the document, enter the ADF document reverse mode (S
5) The image forming operation is performed after turning over the original.
Then, after the copying operation of all the originals is completed, the normal state is restored.

In the present embodiment, when there is a blank original, the original is automatically turned over and copied.
It is possible to save the operator the trouble of turning over the original and re-performing copying.

By the way, in the case of a blank original having no image on both sides of the original, the blank sheet on the back side of the original is copied by the control described with reference to FIG. 11, and an unnecessary blank copy is performed. Therefore, as still another embodiment of the present invention, it is proposed that when there is a blank original on both sides, the original is ejected without performing the copying operation. The embodiment will be described below with reference to the flowchart shown in FIG.

When the copying apparatus is in a normal state, an original is set on the original table 29 of the ADF (S1) and the start button for instructing copying is pressed (S2). It is conveyed onto the contact glass of the main body 1. At this time, the image of the document is detected by the line sensor 21 described above. Then, the ADF control circuit 180 determines whether or not the original has an image (S3).
If there is an image on the document, the copying operation is started (S4) and the normal state is restored. If there is no image on the original, the ADF original inversion mode is entered (S5) and the original is turned over. At this time,
The above-mentioned line sensor 21 detects the image of the original again to determine the presence or absence of the image (S6). If there is an image on the back side of the document, the process proceeds to S4 to start the copying operation and return to the normal state. If there is no image on the back side of the document, the document is discharged (S7) and the normal state is restored without performing the copying operation.

In the present embodiment, when there is a blank original on both the front and back sides, the original is ejected without performing the copying operation, so that useless blank copying is not performed.

Next, still another embodiment of the present invention will be described. The copying apparatus of this embodiment is the same as the above-described embodiment described with reference to FIGS. 10 to 12 except that the control in the case of detecting a blank document is different, and therefore only different parts will be described.

FIG. 13 is a flow chart showing the processing when there is a blank original in the copying machine of this embodiment.
When the copying apparatus is in a normal state, an original is set on the original table 29 of the ADF (S1), and when the start button for instructing the start of copying is pressed (S2), the set original is stored in the copying machine main body 1. It is transported onto the contact glass. At this time, the image of the document is detected by the line sensor 21 described above. Then, the ADF control circuit 180 determines whether or not the original has an image (S3). If there is an image on the document, the copying operation is started (S4) and the normal state is restored. If there is no image on the original, the ADF original inversion mode is entered (S5) and the original is turned over. At this time, the line sensor 21 detects the image of the document again to determine the presence or absence of the image (S6). If there is an image on the back side of the document, the process proceeds to S4 to start the copying operation and return to the normal state. If there is no image on the back side of the original, a warning that the original is a blank original is displayed (S7), and the normal state is restored without performing the copying operation.

In the present embodiment, if there is a blank original on both the front and the back among the originals fed from the ADF 28, the copying operation is not performed and a warning that the original is a blank original is displayed. Never make a blank copy.

By the way, when a blank sheet is intentionally mixed in a series of plural documents, the copying machine detects a blank sheet original and stops the apparatus operation according to the control explained with reference to FIG. I will end up. When a blank sheet is intentionally mixed, it is convenient not to stop the operation of the apparatus and copy the blank sheet as a blank sheet. Therefore, as still another embodiment of the present invention, after detecting blank originals on both front and back sides, if there is no instruction from the operator for a certain period of time, the copying operation is performed as it is, and some instruction is input from the operator within a certain period of time. If so, it is suggested that the blank document be discharged to the discharge table. Hereinafter, the control will be described with reference to the flowchart shown in FIG.

When the copying apparatus is in a normal state, an original is set on the original table 29 of the ADF (S1) and the start button for instructing copying is pressed (S2). It is conveyed onto the contact glass of the main body 1. At this time, the image of the document is detected by the line sensor 21 described above. Then, the ADF control circuit 180 determines whether or not the original has an image (S3).
If there is an image on the document, the copying operation is started (S4) and the normal state is restored. If there is no image on the original, the ADF original inversion mode is entered (S5) and the original is turned over. At this time,
The above-mentioned line sensor 21 detects the image of the original again to determine the presence or absence of the image (S6). If there is an image on the back side of the document, the process proceeds to S4 to start the copying operation and return to the normal state. If there is no image on the back side of the document, a warning that the document is a blank document is displayed (S7). And
Waiting for instruction input from the operator (S6), if no instruction input from the operator even after a certain period of time, it is determined that the blank document is intentionally inserted, and the copying operation is started as it is. Yes (proceed to S4). If there is any input from the operator within a fixed time, the blank document is discharged to the discharge table (S9), and then the normal state is restored.

In this embodiment, a warning is displayed when there is a blank original on both the front and back sides, and when the blank original is intentionally inserted, it is copied as it is. Therefore, it is possible to save the operator from having to perform the operation again.

[0046]

As described above, according to the copying apparatus of the present invention, the presence / absence of an image on a document is detected, and if there is no image on the document, the presence / absence of a document image is detected again.
Erroneous detection in the presence / absence detection of a document image is eliminated, and the labor of operation is not increased.

According to the structure of the second aspect, a warning is displayed when there is a blank original in the original, and a copy is performed as it is when the blank original is intentionally inserted. Therefore, it is possible to save the operator from having to perform the operation again.

According to the third aspect of the present invention, when there is a blank original, the original is automatically turned over to make a copy, so that the operator can save the trouble of turning over the original and making a copy again.

According to the fourth aspect of the present invention, when there is a blank original on both the front and back sides, the original is ejected without performing the copying operation, so that useless blank copying is not performed.

According to the fifth aspect of the present invention, when there is a blank original on both the front and back sides, a warning that the original is a blank original is displayed without performing the copying operation, so that useless blank copying is not performed. .

According to the structure of claim 6, when there is a blank original on both the front and back sides, a warning is displayed, and when the blank original is intentionally inserted, copying is performed as it is. Therefore, it is possible to save the operator from having to perform the operation again.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a copying apparatus which is an embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the copying apparatus.

FIG. 3 is a sectional view showing a configuration of an automatic document feeder of the copying apparatus.

FIG. 4 is a schematic diagram showing an automatic document feeder installed in the apparatus.
It is a perspective view showing a line sensor for detecting a document image.

5 is a block diagram showing a control system of the automatic document feeder shown in FIG.

6 is a flowchart showing a basic operation of the copying apparatus shown in FIG.

FIG. 7 is a flowchart showing an operation of the copying apparatus shown in FIG. 1 in a normal mode (normal state).

FIG. 8 is a flowchart showing a process when there is a blank original in the copying apparatus shown in FIG.

FIG. 9 is a flowchart showing a process when there is a blank original according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view showing the configuration of an automatic document feeder installed in a copying machine according to still another embodiment of the present invention.

FIG. 11 is a flowchart showing a process in the case where there is a blank document in the embodiment.

FIG. 12 is a flowchart showing a process when there is a blank original according to still another embodiment of the present invention.

FIG. 13 is a flowchart showing a process when there is a blank original according to still another embodiment of the present invention.

FIG. 14 is a flowchart showing a process when there is a blank original according to still another embodiment of the present invention.

[Explanation of symbols]

 1 Copying Machine Main Body 2 Operation Section 3, 4, 5, 6 Paper Feeding Device 7 Sorter 8 Automatic Document Feeding Device 9, 29 Document Table 11, 21 Line Sensor 12 Conveyor Belt 18, 35 Branching Claw 19 Paper Ejection Table 20 Contact Glass 30 Reversing Units 31, 32, 33 Document Conveying Path 100 Copying Device 110 Main Body Control Circuit 120 Operating Unit Control Circuit 130 to 160 Paper Feeding Device Control Circuit 170 Sorter Control Circuit 180 ADF Control Circuit

Claims (6)

[Claims] 1. An image forming apparatus equipped with an automatic document feeder for feeding a document to an image processing position, wherein the presence or absence of an image of the document fed to the image processing position by the automatic document feeder is detected. A document image presence / absence detecting unit is provided, and the automatic document feeder is provided so that a document fed to an image processing position can be conveyed again to a document image detecting position by the document image presence / absence detecting unit. When it is determined that there is no image of the document by the automatic document feeder, the document is conveyed again to the document image detection position, and the document image presence / absence detection unit again detects the presence or absence of the document image. When it is determined again that there is no image, a warning signal is issued, the warning means of the image forming apparatus is operated, and a control means for controlling not to perform the image forming operation is provided. An image forming apparatus comprising: 2. An image forming apparatus equipped with an automatic document feeder for feeding a document to an image processing position, wherein the presence or absence of an image of the document fed to the image processing position by the automatic document feeder is detected. A document image presence / absence detection unit is provided, and when the document image presence / absence detection unit determines that there is no image on the document, a warning signal is issued to activate the warning unit of the image forming apparatus, and a predetermined operation is performed from the activation of the warning unit. If there is no operation input from the operator even after a lapse of time, the image processing operation is started, and if there is an operation input from the operator before the lapse of a predetermined time from the operation of the warning means, the image does not exist. An image forming apparatus comprising: a control unit that controls a document determined to be discharged to the outside of the apparatus. 3. An image forming apparatus equipped with an automatic document feeder, which has a document reversing function and is capable of reversing a document fed to an image processing position and then re-feeding it to the image processing position. An original image presence / absence detection unit for detecting the presence / absence of an image of the original fed by the sheet feeding device to the image processing position is provided, and when the original image presence / absence detection unit determines that there is no image of the original, the original document is detected. An image forming apparatus comprising: a control unit that reverses the sheet by the automatic document feeder and conveys it again to an image processing position to perform image processing. 4. An image forming apparatus equipped with an automatic document feeder which has a document reversing function and is capable of reversing a document fed to an image processing position and then re-feeding it to the image processing position. A document image presence / absence detection unit for detecting the presence / absence of an image of the document fed to the image processing position by the sheet feeding device is provided, and if the document image presence / absence detection unit determines that there is no image of the document, the document is detected. The automatic document feeder reverses the sheet, conveys it to the image processing position again, and the original image presence / absence detection unit again detects the presence / absence of an original image, and performs image processing when it is determined again that there is no image on the original. An image forming apparatus comprising: a control unit that controls the document to be discharged outside the apparatus without using the document. 5. An image forming apparatus equipped with an automatic document feeder, which has a document reversing function and is capable of reversing a document fed to an image processing position and then re-feeding it to the image processing position. A document image presence / absence detection unit for detecting the presence / absence of an image of the document fed to the image processing position by the sheet feeding device is provided, and if the document image presence / absence detection unit determines that there is no image of the document, the document is detected. The automatic document feeder reverses the sheet and conveys it again to the image processing position, and the original image presence / absence detecting unit again detects the presence / absence of the original image, and issues a warning signal when it is determined again that there is no image of the original. The image forming apparatus is provided with a control means for activating the warning means of the image forming apparatus and controlling not to perform the image forming operation. 6. An image forming apparatus equipped with an automatic document feeder, which has a document reversing function and is capable of reversing a document fed to an image processing position and then re-feeding it to the image processing position. A document image presence / absence detection unit for detecting the presence / absence of an image of the document fed to the image processing position by the sheet feeding device is provided, and if the document image presence / absence detection unit determines that there is no image of the document, the document is detected. The automatic document feeder reverses the sheet and conveys it again to the image processing position, and the original image presence / absence detecting unit again detects the presence / absence of the original image, and issues a warning signal when it is determined again that there is no image of the original. The warning means of the image forming apparatus is activated, and the image processing operation is started if there is no operation input from the operator even after a predetermined time has elapsed from the activation of the warning means. When there is an operation input from the operator before the lapse of a predetermined time from the operation of the means, it is provided with a control means for controlling to discharge the document judged to have no image to the outside of the apparatus. Image forming apparatus.