JPH0611626B2 - Document reverse type automatic document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention sends a document to an exposure section, performs exposure, feeds it to a reversing section, reverses it, and sends it again to the exposure section.
The present invention relates to a document reversal type automatic document feeder that allows both sides of a document to be copied.

(Prior Art) In many conventional copying machines, when copying a plurality of originals, the user puts the originals one by one on the original table and replaces them. However, when the number of originals to be copied becomes large, the originals stand still. The replacement work is quite difficult. Therefore, recently, an automatic document feeder has been developed that automatically feeds one document at a time if multiple documents are placed on top of each other at a specified position and sets them at a fixed position on the document table for copying. Has been put into practical use.

By the way, there are many so-called double-sided originals that have contents to be copied on both sides, so an automatic document feeder that can be used for such double-sided originals is also considered. In the apparatus, first, the front side of a document is copied, then the document is inverted and the back side is copied and discharged, and then the front and back are copied in the same manner, and the document is sequentially discharged.

Such a reversing type automatic document feeder is complicated in control of paper feeding and paper discharging paths as compared with an ordinary copying machine having no reversing function. In addition, the so-called jam detection and the recovery process for jamming that causes a paper jam during the conveyance of a document are similarly complicated.

Conventionally, in order to reliably set the front and back sides of a document, a document detection sensor must be provided in each document path and the stop timing of the document conveying means must be controlled for each, which complicates the structure and control of the device. There was a problem that the cost increased. Further, as the number of sensors increases and the control becomes complicated, the number of failures increases.

(Object and Structure of the Invention) The present invention has been made in view of the above points, and has document feeding, stop timing control, paper jam detection, etc. despite having a complicated function of document reversal feeding. The purpose of the present invention is to provide a reversal type automatic document feeder which is simplified and thereby has a low failure rate and a low failure rate. Therefore, the document D of the document placing section 1 is reversed and fed on the document table 29 in an arc. A first feeding path for feeding, a conveyance belt 6 capable of forward and reverse rotation for conveying the fed document D on the document table 29, and the document table reversely conveyed by the conveyance belt 6. 29
A second feeding path configured in a closed loop shape having a reversing guide portion 7 for reversing the upper original D and conveying it again on the original table 29, the first feeding path and the first feeding path. A common path C formed by the downstream side of the document feeding direction of the second feeding path
An original detecting means 10 for detecting the passage of an original and a jam of the original on the common path C, and a control means for controlling the timing of stopping the original for exposure by a signal from the original detecting means 10 are provided. The document feeding is controlled by a signal from the means.

(Example) The present invention will be described below with reference to the drawings.

FIG. 1 shows the document reversing type automatic document feeder according to the present invention in combination with the main body of the copying machine. A surrounded by a broken line is an automatic document feeder and B is a main body of the copying machine. The example illustrated here is a type in which the front and back sides of a double-sided original are copied onto two copy sheets. This copying machine allows one-sided originals to be moved and copied for copying, two-sided originals to be automatically reversed to make two-sided originals, or large-sized single-sided originals to be copied synchronously. However, the copying process of double-sided document copying will be described first, and then the single-sided copying process by synchronous feeding will be described.

The automatic document feeder includes a document placing plate 1 on which documents D are stacked and placed, and a delivery roller 2 which delivers only the uppermost document.
A feeding belt 4 for feeding the fed document in cooperation with the double feed prevention roller 3, a document feeding roller 5 arranged along the document feeding path, and A conveyor belt 6 for conveying an original document to a fixed position on a glass original table, an original document reversing guide 7, and three sets of conveying rollers 8a, 8b, 8c arranged along the original document reversing guide 7, Guide rollers 6 a, 6 b, 6 c are arranged along the line 6. The conveyor belt 6 is driven by a drive roller 6d and is switched between the driven roller 6e and a driven roller 6e in a forward direction indicated by a solid arrow and a reverse direction indicated by a broken arrow. A stopper 9 for stopping the conveyed original at a fixed position on the glass original table is provided near one end of the conveyor belt 6, and this stopper 9 is synchronized with the original feeding timing. Electromagnetically driven. The first original feeding path from the original placing plate 1 to a fixed position on the glass original table and the second original feeding path along the original reversing guide 7 are part C.
In the common path C, a document detection sensor including a light emitting element 10a and a light emitting element 10b for detecting the passage of a document is provided. Reference numeral 11 is a document discharge tray for storing discharged documents, and 12 is a document discharge sensor for detecting that the documents have been discharged.

In this document reversal type automatic document feeder, it is arranged along the feeding roller 2, the double feed prevention roller 3, the feeding belt 4, the document feeding roller 5, the driving roller 6d of the conveying belt 6, and the document reversing guide 7. Transport rollers 8a, 8b, 8c
Are each driven by one original feeding motor via a clutch and a gear. Among them, the drive roller 6d switches the rotation direction when the rotation direction of the motor is switched, but the other rollers are Through the clutch mechanism, the motor is rotated in one direction regardless of the rotation direction of the motor.

On the other hand, the copying machine body B uses the conventionally known electrophotographic process, and is provided below the document reversing type automatic document feeder A described above.

The structure of the main body of the copying machine is well known and is not the gist of the present invention. Therefore, a brief description will be given. 20 is a paper feed cassette for stacking and storing the copy papers P, and 21 is the uppermost copy paper P.
Feeding roller, 22 is a paper feed guide plate, 23
Is a rotary drum having a photoconductor 23a on its surface, and a charger 24, a developing device 25, a transfer device 26, a separator 27, and a cleaning device 28 are sequentially arranged around the rotary drum.

On the other hand, on the upper surface of the main body of the copying machine, there is provided a glass original table 29 placed at a fixed position for exposing the original to be copied, and an illumination lamp 30 for exposing the original under the glass original table 29.
The movable mirrors 31 and 32, the fixed mirror 33, and the lens 34 that guide the reflected light from the document onto the photoconductor 23a are arranged.

35 is a conveyor belt for conveying the copy paper separated from the rotary drum 23 after transfer to a fixing position, 36 is a fixing device, and 37 is a fixing device.
Is a paper discharge sensor provided in a passage for discharging the fixed copy paper to the paper discharge tray 38.

In addition, a copy paper feeding roller 21 in the main body of the copying machine, a rotary drum 23, a developing roller 25a inside the developing device 25,
The conveying belt 35, the heating roller 36a of the fixing device 36, the optical scanning system, and the like are configured to be driven by a motor different from the document feeding motor provided in the automatic document feeding device A.

FIG. 2 is a block diagram of a control circuit relating to document feeding in the document reversing type automatic document feeder shown in FIG.

In the figure, 40 is a copy start button which is turned on at the start of copying, 10 is a document detection sensor including the light emitting element 10a and the light receiving element 10b shown in FIG. 1, 37 is a paper discharge sensor,
Reference numeral 41 denotes a double-sided original copy button for selecting the effect when copying a double-sided original, 50 for a synchronous feed selection button for selecting the effect when performing synchronous feeding, 42 for turning on the copy start button 40 and the double-sided original copy button 41, A memory for temporarily storing the OFF state, the output state of the document detection sensor 10, etc., 43 is a CPU for outputting a document feeding or reversing command according to a predetermined program, and 44 is a drive for driving a document feeding motor 45. This document feeding motor 45 is configured to drive the various rollers and the drive roller 6d of the conveyor belt 6 via the clutches and gears as described above. Reference numeral 46 denotes a paper feed clutch drive circuit for driving the paper feed clutch 47. By driving the paper feed clutch 47, the delivery roller 21 rotates and the copy paper P is fed.
Is fed. 48 is a warning lamp 49 for notifying a paper jam
Is a warning lamp circuit that lights up.

The paper discharge sensor 37, the copy start button 40, the double-sided original copy button 41, the synchronous feed selection button 50, and the CPU 4
3, the drive circuit 44, the paper feed clutch circuit 46, and the warning lamp circuit 48 are all provided on the copying machine main body side.
The CPU 43 controls both the document feeding sequence of the automatic document feeding device and the sequence of the electrophotographic process in the copying machine main body.

Next, the operation will be described with reference to the time chart of FIG. 3 and the flowchart of FIG.

First, a plurality of double-sided originals to be copied are placed on the original placing plate 1 with the odd-numbered pages facing up and stacked in order from the top, and the double-sided original copy button 41 is pressed and the desired number of copies is set (desired number of copies). If there is only one, setting is not necessary). After that, when the copy start button 40 is turned on (see (a) in FIG. 3 (a)), a start signal (see (b) in FIG. 3 (a)) is output, and the document feeding motor 45 is normally rotated. And a series of rollers of the automatic document feeder rotate (see FIG. 7C). As a result, the uppermost document on the document placing plate 1 is fed by the feed roller 2
Are fed by the feeding belt 4 and the feeding roller 5 and fed to the conveyor belt 6. The CPU 43 determines whether or not the double-sided original is being copied depending on whether the double-sided original copy button 41 is on or off (F-1). If the double-sided original is being copied, then it is determined whether or not the front-side copy mode of the double-sided original is selected. It is determined from the state of the start button 40 and the output state of the paper discharge sensor 37 (F-2), and in the case of the front side copy mode, the document feeding motor 45 is rotated in the normal direction (F-3). When the leading edge of the document emits light and passes the position of the document detection sensor 10 including the light receiving elements 10a and 10b during the feeding of the document, the output of the light receiving element 10b becomes as shown in (d) of FIG. . From the rise of the output signal of the document detection sensor 10 (F-4), the CPU
The timer set in 43 starts (F-5),
When the set time _{t 3} (see (e) of FIG. 3 (b)) (F-6) to protrude actuates the stopper 9 with (F-7), set a timer within CPU43 from the rising Start and (F-8) setting and time _{t 1} has elapsed (F-9) a document feeding motor 45 is stopped (F
-10). At this time, the leading edge of the original comes into contact with the stopper 9 and is set at a fixed position on the inside 29 of the glass original (at this time, the front surface (the odd page side) of the original faces downward).

On the other hand, the main body of the copying machine is ready for the electrophotographic process, and includes the rotating drum 23, the developing roller 25a, and the fixing device 3.
The heating roller 36a of No. 6 rotates, the conveyor belt 35 starts moving, and the heater of the heating roller 36a is energized.

After a predetermined time, a series of electrophotographic processes starts, this time starting with exposure of the original document by the optical scanning system. The visible image thus formed on the photoconductor 23a is transferred to the copy paper P fed from the paper feed cassette 20, is fixed by the fixing device 36, and is ejected to the paper ejection tray 38. The paper discharge sensor 37 is turned on by the copy paper to be printed.

Since the desired copy number set by the copy number setting button is stored in the memory 42, the CPU 43 counts the output from the paper ejection sensor 37, and the count value corresponds to the desired copy number data stored in the memory 42. The electrophotographic process described above is repeated until a match is found. When the count value obtained by counting the output from the paper discharge sensor 37 matches the desired copy number data, a start signal is output (see (b) in FIG. 3A).

The CPU 43 determines that the front side copy mode has ended by the output of this start signal (F-2), and outputs the motor reverse rotation signal CCW to the drive circuit 44. As a result, the document feeding motor 45 is rotated in the reverse direction (F-11), and the document which has been in the fixed position until then is conveyed by the conveying belt 6 in the direction opposite to the feeding direction (the direction of the broken line arrow) and guided to the conveying portion. Get burned. The document is transported in the document reversing guide 7 by the transport rollers 8a, 8b, 8c in the arrow direction. The set timer in the CPU43 is the elapsed time from the output of the start signal is measured (F-12), when t ₂ has elapsed (F-13) instead motor positively motor reverse rotation signal CCW which has been output so far The rotation signal CW is output, whereby the motor 45 is switched to the normal rotation (F-14). At this time, the leading edge of the document inverted by the reversing unit has reached the vicinity of the common path C, and further progresses so that the leading edge of the document passes the position of the document detection sensor 10, reaches the conveyance belt 6, and is conveyed by the conveyance belt 6. The sheet continues to be conveyed toward the original exposure position on the glass original table 29. As can be seen from FIG. 3A, the document feeding motor 4
5 is from the rise of the output of the document detection sensor 10 (F-4)
The timer stops when the set time t ₁ is passed (F-8, F-9, F-10). At this time, the original document is stopped by the stopper 9 and stands still at a fixed position on the glass original table 29, and the rear surface (the even page side) of the original document faces downward.

After that, a series of electrophotographic processes are performed on the back surface of the original document, and the paper is ejected. At this time, the paper output sensor 37 detects the paper output. The same operation is repeated for the desired number of copies, and when the last copying machine is ejected, a start signal is output (see (a) in FIG. 3B), and the stopper 9 separates from the document conveying path (see Fig. 3 (b) (d)
Then, the CPU 43 outputs the motor reverse signal CCW, the document feeding motor 45 is rotated reversely via the drive circuit 44, and the copied document is guided to the reversing section where it is inverted and then the document feeding motor 45. Normal rotation switching (Fig. 3 (b))
(See (b)), and the next document is fed after waiting for the output from the ejection sensor 12 (see (e) in FIG. 3B). The next original is set at a fixed position on the glass original table 29 when the stopper 9 projects after time t ₃ from the detection of the leading edge of the original by the original detection sensor 10 and then the original feeding motor 45 stops after the time t ₁ . Document discharge tray 11
The originals ejected on the back have the back side up and the front side down.

In this way, the feeding path before reversing the original and the feeding path after reversing are partly common, an original detection sensor is provided in this common part C, and the fixed position of the original is set according to the time from the original detection by this sensor. If the control is performed, it becomes possible to reliably set the original at the fixed position for exposure during the front side copying and the back side copying.

By the way, although the original may be jammed in the feeding path during the feeding of the original for some reason, the original detection sensor 10 can be used to detect the jam of the original. That is, when the document passes the position of the document detection sensor 10, an output signal is input to the CPU 3 from the document detection sensor.
The time set for the output signal to be continuously input is measured by the timer set in 3, and when the time exceeds the predetermined time, it is determined that the document is stopped at the position of the document detection sensor 10. Warning lamp circuit 4 by CPU 43
A warning signal is output to 8 and a warning lamp 49 provided on the operation unit of the copying machine main body is turned on to notify the user of a document jam (see FIG. 2).

Next, the operation during synchronous feeding will be described with reference to the time chart of FIG. 5 and the flowchart of FIG.

First, a large-sized (for example, A2) original to be copied is placed on the original placing plate 1 with the front side facing upward in the order of pages, and the synchronous feed selection button 50 is pressed (see FIG. 5 (a)). . It is not necessary to set the number of copies because copying can make only one copy per synchronous feed. Next, when the copy start button 40 is turned on (see FIG. 2B), a start signal is output (see FIG. 2C), the document feeding motor 45 is rotated, and a series of the document feeding device shown in FIG. The roller rotates (see (d) in the figure). As a result, the uppermost original on the original placing plate 1 is sent out by the sending roller 2, and the glass original table 2 is fed by the feeding belt 4, the feeding roller 5, and the conveying belt 6.
9 sent up. On the other hand, in the main body of the copying machine, the illumination lamp 30 of the optical scanning system is fixed at a predetermined position at the middle point of the traveling path at the same time when the synchronous feed selection button 50 is pressed, and after a predetermined time, other series of electrophotographic processes are ready. enter.

While the document is being fed, the leading edge of the document emits light, the light receiving element 10a,
When the document detection sensor 10 composed of 10b has passed the position, the signal is output (see (e) in FIG. 5), and the paper feed clutch 47 operates in synchronization with it (see (f) in FIG. 5).
The CPU 43 determines whether or not the synchronous feed is performed depending on the ON / OFF state of the synchronous feed selection button 50 (F-1). If the synchronous feed is selected, the motor 45 is started (F-2). The paper feed clutch 47 is operated in synchronization with the rising edge of (F-3) (F-4).

The original is sent on the glass original table 29 by the conveyor belt 6 and is exposed and scanned by the illumination lamp 30 fixed at a predetermined position, and a series of electrophotographic processes are performed in the main body of the copying machine. After copying, the document is discharged to the document discharge tray 11, and the discharge is detected by the document discharge sensor 12 (fifth
(See (g) in the figure). In the CPU 43, the document discharge sensor 12
Of the output signal of (F-5, F-6), and the document feeding motor 45 is stopped in synchronization with the trailing edge of the output signal (F-
7). The same operation is repeated for the second and subsequent pages of the document.

In this way, the copy paper is fed simultaneously with the output of the signal of the document detection sensor, and since the document detection sensor is placed closer to the document exposure position than before, it is less affected by document slip and belt slip, and the copy paper is not affected. It is possible to form a copy image at a desired position.

In this embodiment, the combination of the document reversing type automatic document feeder according to the present invention and the copying machine capable of copying only on one side of the copy paper has been described, but the document images are formed on both sides of one copy paper. It is also possible to combine with a copying machine capable of automatically copying, or with an image recording device such as a facsimile, or an image reading device.

(Effects of the Invention) As described above, in the present invention, the document placing section 1
First feeding path for reversing and feeding the document D on the document table 29 in an arc, and a forward / reverse transport belt for transporting the fed document D on the document table 29. 6 and a reversing guide portion 7 for reversing the original D on the original table 29 that is fed back by the conveyor belt 6 and conveying it again on the original table 29.
Of the feeding path, a common path C formed by the first feeding path and a portion of the second feeding path on the downstream side in the document conveying direction, and passage of a document through the common path C and document jamming are detected. A document detecting means 10 for controlling the document and a control means for controlling the timing of the document stop for exposure by a signal from the document detecting means 10 are provided, and based on the detection signal from the document detecting means,
Since it is configured to control the document feeding, the document feeding, the stop timing control, the paper jam detection, etc. can be simplified even though it has a complicated function of document reversing feeding. Thus, it is possible to provide a reversing type automatic document feeder having a low cost and a low failure rate.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an original reversing type automatic document feeder according to the present invention in combination with a copying machine main body, and FIG. 2 is a document fixed position setting control of the original reversing type automatic document feeder according to the present invention. FIG. 3A is a block diagram of the circuit, and FIG. 3A is a time chart of a fixed position setting operation for the front and back sides of the original by the original reversing automatic original feeding apparatus of the present invention. A time chart, FIG. 4 is a flow chart of the original fixed position setting operation of the double-sided original according to the present invention, FIG. 5 is a time chart of the synchronous feeding operation of the original reverse type automatic original feeding apparatus according to the present invention, and FIG. It is a flowchart of a feeding operation. 1 ... original placing plate, 6 ... transport belt, 7 ... original reversing guide, 9 ... stopper, 12 ... original ejection sensor,
37 ... Ejection sensor, 40 ... Copy start button, 41 ...
… Double sided document copy button, 45 …… Document feeding motor

Claims (1)

[Claims] 1. A first feeding path for reversing and feeding a document D of a document placing portion 1 onto a document table 29 in an arc, and the fed document D on the document table 29. A transport belt 6 capable of forward and reverse rotation for transporting, and a reversing guide portion 7 for reversing the document D on the document table 29 that is fed back by the transport belt 6 and transporting the document D again onto the document table 29. A second feeding path having a closed loop shape, a common path C formed by the first feeding path and a downstream side portion of the second feeding path in the document conveying direction, and the common path. Document detecting means 10 for detecting passage of a document and document jamming, and the document detecting means.
A document reversing type automatic document feeder, which is provided with control means for controlling the timing of stopping the document for exposure according to a signal from 10.