JPH0543091A - Device for detecting original sent on piles in image reader - Google Patents

Abstract

PURPOSE:To enable to exercise judgment on the presence of originals sent in piles in a device, in which a detecting means for originals sent in piled one on the other is adopted in a original carrying passage or the like, by paying attention to the fact that the thickness of paper varies with its size and using both information detected by a paper thickness detecting device and information on the size of a form for every original. CONSTITUTION:For an original carrying passage 5, which connects an original tray 2 and an image reading part 10, in an image reader 1, a paper thickness detecting device 20, which detects the thickness of a form, and a paper size detecting device 25, which is used for detecting the size of the form, are arranged, and the information on paper-thickness and-size, both of which are obtained from two kinds of sensors, are inputted into a controller in order to detect the presence of originals in piles. In the controller, which is used for the image reader, standard paper-thickness-data are set up for each paper-size, based on the information on both size and thickness of the form, and actual thickness of the form is compared with the standard value corresponding to the same size in order to exercise judgment on the presence of originals in piles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus such as a facsimile or an apparatus for detecting a double feeding of an original or the like by arranging a double feeding detecting means in a paper path of an electronic copying machine or the like.
The present invention relates to a device that arranges a paper thickness detection device and a paper size detection device in a paper conveyance path and can detect double feed based on information from two detection means.

[0002]

2. Description of the Related Art In an image forming apparatus such as a facsimile or an electronic copying machine, an image reading section and an original tray are connected by an original conveying path, and originals are fed one by one from the original tray to read an image. A scanning mechanism is provided for each part. Further, the recording paper creating unit in the image forming apparatus is provided with a mechanism that feeds the paper from a paper feed tray or the like, conveys the paper toward the image recording unit, and records an image on the paper. As described above, in the image forming apparatus, the means for conveying two types of papers, that is, the original and the paper, is used. However, when these papers or the originals are sent out from the tray, the papers are accurately transferred one by one. It is necessary to supply separately.

Therefore, in a paper feeding device for feeding a paper from a general tray, a paper sorting mechanism is arranged at a portion for feeding the paper from the tray, and the paper is fed by the paper handling mechanism to feed the paper in a double feed manner. It is possible to prevent the occurrence of. However, the paper separating mechanism arranged corresponding to the original tray or the paper feed tray cannot completely prevent the double feeding, and sometimes sends the original and two sheets in a state of being superposed. There's a problem. When the above-mentioned double feeding occurs, an extra blank sheet is only ejected when a recording sheet is created by a general electronic copying machine or the like, and this can be easily solved by removing the blank sheet.

However, when the sheets are separated in the sheet conveying path, the length of the sheet is changed, so that the detecting means arranged in the sheet conveying path detects an abnormality in the sheet conveying and causes a jam. A signal or the like is output to stop the operation of the device. Further, in the case of the image reading apparatus, when two originals are sent out from the original tray in a double-fed state, there arises a problem that images of the double-fed originals are missing. For example, if electric transmission occurs at the time of facsimile transmission, the missing page can be solved by transmitting it later, but the trouble of confirmation is troublesome. On the other hand, in the automatic document feeder arranged in the automatic double-sided copying machine, when a double feed occurs, there is a problem that the series of double-sided copies must be completely discarded and the copying operation must be performed again. Further, in an apparatus in which an image of a document is continuously scanned using an image reading device and the read information is stored in a storage device such as a computer, double feeding of the document becomes a greater problem. It is required to supply exactly one sheet separately.

In order to solve the above-mentioned problems, a paper thickness detecting means is provided in a paper conveying path or the like, and the thickness of the paper passing through the paper conveying path is detected to judge the double feeding state. In some cases, such means are used. However, when the paper thickness detection device is simply used, for example, thin paper such as tracing paper, relatively thick paper, and various paper thicknesses such as paper used for normal copying are mixed. When the document is fed from the document tray in this state, there is a problem that double feeding cannot be detected accurately. Therefore, in order to accurately detect the double feeding of the originals on the original conveying path, for example, Japanese Patent Laid-Open Nos. 60-144256 and 61-192.
It has been proposed to use a double feed detecting means as disclosed in Japanese Patent No. 647, etc.

In the double feed detecting means shown in the conventional example,
A means for detecting the paper thickness is arranged in the original conveyance path, and the information obtained by detecting the thickness of the first original from the paper thickness detecting device is used as the reference information of the paper thickness storage means, and then the originals to be sequentially sent out. By comparing the detection information of the paper thickness with respect to, the determination of the double feed is made. Further, in the above-mentioned conventional example, a reference signal of the paper thickness is set by using an average value of a fixed number of sheets, and the reference signal is compared with the signal of the paper thickness measured by the paper thickness detecting device to perform the double feeding. It is also possible to configure so as to be able to make the judgment.

As described above, when the double feed is detected by using only one paper thickness detecting device, the control device 30a as shown in the block diagram of FIG. 10 can be used.
In the circuit shown in FIG. 10, the detection signal from the paper thickness detection device 20 arranged in the paper conveyance path is sent to the amplifier 33 and the A / D converter.
It is input to the CPU 31 via the conversion means 32 so that double feed can be detected. The control operation in the control device 30a is performed as shown in the flowchart of FIG. In the flowchart of FIG. 11, while the document is being conveyed through the document conveying path, the thickness of the document is detected by the paper thickness detecting device in step b-1, and the information is transmitted to the control device. The control device compares the information on the thickness of the paper stored in advance (steps b-2 and b-3), and if the comparison value is equal to or less than the reference value, it is determined that it is not a double feed (step b-4). ), And continue scanning the image as it is.

On the other hand, when it is determined in step b-3 that the information about the thickness of the paper output from the paper thickness detecting device is equal to or larger than the reference value, the process proceeds to step b-5. It is determined that the image is in the double feed state, the operation of the image reading apparatus is stopped, and the operator is instructed to perform the double feed process. Then, in the case of determining the multi-feeding state of the document according to the control program as described above, the multi-feeding state can be easily determined by using the signal of the paper thickness from the paper thickness detecting device. In the image reading device, a reading error or the like is prevented from occurring.

[0009]

However, in the case of using the document double feed detecting means as described above, when the document is a state in which thin paper and thick paper are mixed, the reference signal is set. Have difficulty. For example, when thick paper is sent after thin paper, a problem of immediately outputting a double-feed signal occurs. If thin paper is fed in a double-feed state after thick paper, the signal from the paper thickness detection device is determined to indicate that the paper is being fed normally, and the image is read. There may be a case where the inconvenience of going cannot be prevented.

In order to solve the above problems,
For example, it is necessary to form originals using only papers of a fixed thickness without mixing originals of various paper thicknesses.
However, for example, for a document in which tracing paper and general copying paper are mixed, only tracing paper is separately copied and the thickness of the document is made uniform, which increases the burden on the operator. However, there is a problem that the efficiency of the work using the image reading device is reduced. In addition to the above-mentioned problems, in a general manuscript, a paper for composing a text portion is a general copying paper, and a drawing or the like is often a tracing paper. The sizes of these papers are slightly different. I often use things. However, in the conventional image reading device, the paper size information is used only as the information for feeding the paper from the paper feeding tray, and the paper thickness detecting device is used for detecting the double feeding of the paper. Since only the information obtained by the above method is used, the above-mentioned problem of false detection of double feeding occurs.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional double-feed detection device. It is noted that papers of different paper quality or paper thickness often have different sizes. In addition to the device, a means for detecting double feed using information from the paper size detection device is provided, and even when sheets of different paper thickness are continuously fed, it is possible to accurately determine the double feed for the sheets. It is an object of the present invention to provide a document double feeding detection device for an image reading apparatus.

[0012]

SUMMARY OF THE INVENTION According to the present invention, a detection means including a paper thickness detection device and a paper size detection device is arranged in a paper conveyance path between a paper feed tray and an image reading portion. A combination of a control device for processing information from the means, means for setting data of a reference paper thickness corresponding to the size of the paper, means for comparing the reference data and information from the detection means, And a double feed determination unit, and determines the double feed of the sheet being conveyed using the paper thickness data obtained from the paper thickness detection device and the paper size data output from the paper size detection device. Constitutes a means. Further, in the present invention, the means for setting the reference paper thickness data stores the paper thickness data of the same size paper conveyed immediately before the detection operation, and uses the data as a reference value. Or store the data of the paper thickness obtained by calculating the average value for a certain number of sheets of the same size conveyed immediately before the detection operation, and use the data as the reference value. It is possible to do so. Further, in the present invention, the means for setting the data of the reference paper thickness stores a value obtained by calculating the minimum value of the data of the paper thickness of the paper of the same size conveyed immediately before the detection operation. However, it is also possible to use the data as a reference value.

With the above-described configuration, in the document double feed detecting device of the image reading apparatus of the present invention, the condition that papers of different paper qualities or paper thicknesses often have different sizes is utilized, Even when sheets of different thickness are continuously fed, it is possible to accurately determine the double feeding of the sheets. Therefore, even when an image is read using a document in which a plurality of types of paper are mixed, the double feed state can be determined by storing the information on the average paper thickness for each size of the document. It can be done easily.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A document double feed detection device for an image reading apparatus according to the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 shows the configuration of the image reading apparatus of the present invention.
The image reading device 1 is configured as a device of a system in which the document P stored in the document tray 2 is conveyed toward the image reading unit 10 and the document scanned by the image reading unit 10 is stored in the document tray 9. The case is shown. In the image reading device 1, a paper feeding device 3 is arranged at a document feeding portion of a document tray 2, and the paper feeding device 3 is arranged such that a feeding belt device 4 and a separating roller 4a are opposed to each other, The originals are sent to the paper transport path 5 while being separated. Further, a plurality of transport roller devices 6, 7 ... Are arranged in the paper transport path 5 extending from the document tray 2 to the image reading unit 10, and the document is transported by the transport roller devices toward the image reading unit 10. ..

As shown in the figure, the image reading unit 10 has a scanning device 12 arranged under the platen 11 and conveying roller devices 14, 1 arranged at the upstream and downstream parts of the platen 11.
An image is scanned by the scanning device 12 while the document is being conveyed by the platen roller 5 and the platen roller 13. Then, the document whose image has been scanned by the image reading unit 10 is ejected toward the ejection tray 9 via the ejection roller 8. In the image reading apparatus of the present invention configured as described above, the paper thickness detecting device 20 is provided at a predetermined position of the paper carrying path 5 for carrying a document toward the image reading unit 10.
And the paper size detection device 25 are arranged so that the two sensors detect the paper thickness and the paper size.

Of the two types of sensors, a minute angle sensor 21 as shown in FIG. 2 can be used as the paper thickness detecting device. The sensor 21 shown in FIG.
For example, as disclosed in Japanese Patent Laid-Open No. 3-35952, the tip end of the swingable arm member 22 is lightly contacted with the lower guide plate of the sheet conveying path.
Then, when the sheet passes under the arm member 22 of the sensor 21, it is detected that the swing angle of the arm member changes according to the thickness of the sheet. The minute angle sensor 21 is capable of detecting the thickness of the paper relatively accurately, and its arm is provided so as to easily detect thin paper and thick paper, or the double feeding state of them. Member 22
The rocking position of can be set.

In addition to the use of the minute angle sensor shown in FIG. 2, the paper thickness detecting device of the present invention is arranged such that the photosensor device crosses the paper conveying path vertically as shown in FIG. It is also possible to use means for arranging and detecting the thickness of the paper. In the photo sensor device 23 shown in FIG. 3, the light source 24 is provided below the lower guide plate of the paper transport path.
The thickness of the paper can be known by arranging the light receiving element 24a and the light receiving element 24a on the upper guide plate and detecting the amount of light passing through the paper. In the paper thickness detecting means using the photosensor, for papers other than a transparent sheet member such as a plastic film, information corresponding to the light transmittance according to the paper thickness is used. Can be obtained, and the thickness of the paper can be determined by using the amount of transmitted light. When the paper is in the double feed state, the amount of light transmission is naturally different, so that it is possible to judge the double feed state.

In addition to the paper thickness detecting device shown in FIGS. 2 and 3, a paper size detecting device 25 is arranged in the paper conveying path 5 of the image reading device 1 of the present invention to feed paper from the original tray 2. The size of a document to be printed is detected. As the paper size detecting device 25, for example, as shown in FIG. 4, a width direction size detecting means 26 is arranged in a direction traversing the document conveying path, and a length direction is provided at a position along the reference line of the document conveying path. A size detecting means 27 is arranged. The width-direction size detection means 26 and the length-direction size detection means 27 are each composed of a large number of sensors. As the width-direction size detection means 26, the sensors S1 to S5 are associated with the size of the paper. The two sensors S6 and S7 are arranged in the lengthwise size detecting means 27.
Is used. As described above, a large number of sensors S1
When S7 to S7 are arranged, the sheet size can be determined as shown in Table 1 by using the sheet detection information output from each sensor.

[0019]

[Table 1]

In the above table, ◯ means ON and × means OF.
F is shown.

That is, as shown in Table 1, the detection information from each sensor is input to the control device as ON / OFF information, and the control device outputs the ON / OFF information.
The paper size can be determined from the combination of OFF signals.

As described above, by using the detection signals from the two types of sensors, the paper thickness detecting device and the paper size detecting device,
In order to detect the double feeding of the original document, in the present invention, FIG.
The controller 30 as shown in the block diagram of FIG. In the control device 30 shown in FIG. 5, as in the case of the control device shown in FIG. 10, a signal from the paper thickness detection device 20 is sent to the CPU 31 via the amplifier 33 and the A / D conversion means 32. Enter, but in addition,
CP for the paper size detection signal from the paper size detection device 25
Output to U31. Then, by using the signals from the paper thickness detection device 20 and the paper size detection device 25, FIG.
According to the flow chart of FIG.

The flow chart of FIG. 6 shows the case of performing the double feed detection operation. In the flow chart, steps a-1 and a-2 detect the paper thickness and the paper size. Is detected, and the paper thickness reference value corresponding to the paper size information is compared with the paper thickness value detected by the paper thickness detection device (steps a-3, 4). In steps a-1 to a-3, the paper thickness and paper size information input to the CPU is taken into the memory provided in the CPU, respectively, and stored as paper size and paper thickness information. Then, based on the information set in the CPU in the step a-4, the information of the detected paper thickness is compared, and if the paper thickness is equal to or less than the reference value, it is determined that the multifeed is not performed in step a-5. Judged and continue normal operation. On the other hand, when the paper thickness detected in step a-4 is equal to or larger than the reference value, it is determined in step a-6 that the multifeed is performed, and the operator is instructed to perform the multifeed processing. After the processing is performed, the normal document feeding and the image scanning of the document are continued.

In the control device of the present invention, as described above,
A paper thickness reference value for each paper size is set using the paper thickness information from the paper thickness detection device and the paper size information from the paper size detection device.
The reference value can be set as shown in FIG. In the example shown in the flowchart of FIG. 7, the same size paper that was conveyed immediately before that paper is used, and the information of the paper thickness when it is not a double feed is used, and a constant K is applied to that information.
A case where a value obtained by multiplying (for example, K = 1.5) is used as a reference value is shown. Therefore, in the flow chart of FIG. 7, in step a-10, the information on the thickness of the sheet which is not a double feed is used, and in step a-11, the value obtained by multiplying the information on the thickness of the sheet by a constant K is used as a reference value. Used as
This is used as a reference value for the paper thickness comparison in step a-3 of FIG.

Further, in the present invention, as shown in the flow chart of FIG. 8, n (for example, 3) sheets of non-double-fed sheets of the same size that have been conveyed before the step a-10. A constant K (eg K = 1.5) is added to the average value of thickness.
A case where a value obtained by multiplying by is used as a reference value is shown. In the flow chart shown in FIG. 8, a-10
In the step, the information of the paper thickness of the paper determined not to be the double feed is used, and the value is added to the information of the paper thickness of the past n-1 sheets of the same size to calculate the average value. Then, a value obtained by multiplying the average value by a constant K is set as a new reference value (step a-15), and in step a-16, the new reference value is compared with the detected paper thickness information. hand,
Try to make a double feed decision.

Further, in the present invention, as shown in the flow chart of FIG. 9, the thinnest paper among the papers conveyed up to immediately before the measurement, which does not cause double feed of the same size. It shows a case where the information on the thickness of the thin paper is used as a reference value as compared with the information on the thickness. In the flowchart of FIG. 9, step a-
Information about the paper thickness when it is determined in 20 that it is not a double feed is
Among the sheets of the same size that were previously conveyed in step -21, compare with the sheet of the smallest thickness (step a-2
2) Then, if it is determined that the paper is thinner, the process proceeds from step a-23 to a-24, the information of the paper thickness of the paper is rewritten to the information of the reference value, and a constant is added to the reference value. K
A value obtained by multiplying (K = 1/5) is used as a new reference value.

As described above, in the image reading apparatus of the present invention, two types of sensors, that is, a paper thickness detecting device and a paper size detecting device, are arranged in the original conveying path, and the paper obtained from these sensors is arranged. The thickness information is classified according to the size of the paper. Then, the value obtained by multiplying the information of the paper thickness for each paper size by a constant is set as a reference value,
It becomes possible to detect the double feeding of the sheets by comparing the information of the detected sheet thickness with the reference value. In addition, in the embodiment of the present invention, the case where the double feeding is detected for the document is shown. However, in addition to the above, the paper feeding path for feeding the paper toward the recording unit is not limited to the present invention. It is also possible to provide a detection device and its control mechanism, which makes it possible to prevent double feeding of copies.

[0028]

As described above, the document double feed detection device of the image reading apparatus of the present invention uses the above-mentioned means.
With the above-mentioned configuration, by providing two types of detection means and a control device for processing the information of the paper thickness from the sensors, the control operation at the time of detecting the double feeding of the paper is accurately performed. You can Further, in the apparatus of the present invention, in general, the condition that papers having different paper qualities or paper thicknesses also have different sizes is used, and even when papers having different paper thicknesses are continuously fed, the weight of the papers is different. The sending decision can be made accurately. Therefore, even when an image is read using a document in which a plurality of types of paper are mixed, the double feed state can be determined by storing the information on the average paper thickness for each size of the document. It can be done easily.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an image reading apparatus of the present invention.

FIG. 2 is a side view showing the configuration of the paper thickness detection device of the present invention.

FIG. 3 is a side view showing the configuration of another paper thickness detection device of the present invention.

FIG. 4 is a plan view showing a configuration of a paper size detection device used in the present invention.

FIG. 5 is a block diagram showing a configuration of a control device of the present invention.

FIG. 6 is a flowchart showing an operation of double feed detection in the control device of the present invention.

FIG. 7 is a flowchart showing an operation of setting a reference value of paper thickness in the control device of the present invention.

FIG. 8 is a flowchart of another means for setting a paper thickness reference value.

FIG. 9 is a flowchart of another means for setting a reference value for paper thickness.

FIG. 10 is a block diagram showing a configuration of a control device for detecting a double feed in a conventional device.

FIG. 11 is a flowchart of an operation of double feed detection in a conventional control device.

[Explanation of symbols]

1 image reading device, 5 paper transport path, 10
Image reading unit, 12 scanning device, 20 paper thickness detection device, 21 minute angle sensor, 23 photo sensor, 25 paper size detection device, 30 control device, 31 CPU.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G03G 15/04 119 9122-2H H04N 1/00 108 J 4226-5C

Claims (4)

[Claims] 1. A control device for arranging a detection means including a paper thickness detection device and a paper size detection device in a paper conveyance path between a paper feed tray and an image reading portion and processing information from the detection means. Provided in combination, the control device is provided with means for setting data of a reference paper thickness corresponding to the size of the paper, means for comparing the reference data and information from the detection means, and double feed determination means, An image reading apparatus characterized in that double feeding of paper being conveyed is judged using data of paper thickness obtained from the paper thickness detection device and data of paper size output from the paper size detection device. Document double feed detection device. 2. The means for setting the reference paper thickness data stores the paper thickness data of the same size paper conveyed immediately before the detection operation, and uses the data as a reference value. The document double feed detection device of the image reading apparatus according to claim 1. 3. The means for setting the data of the reference paper thickness is a paper thickness obtained by calculating an average value for a fixed number of papers of the same size that have been conveyed immediately before the detection operation. 2. The document double feeding detection device for an image reading apparatus according to claim 1, wherein the data of FIG. 1 is stored and the data is used as a reference value. 4. The means for setting the reference paper thickness data stores a value obtained by calculating the minimum value of the paper thickness data of the same size paper conveyed immediately before the detection operation. 2. The document double feeding detection device for an image reading apparatus according to claim 1, wherein the data is used as a reference value.