JP2001294344A - Paper multifeed detecting device and paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper multifeed detecting device for accurately detecting the multifeed of a paper on which printing is performed and also provide a paper feeding device suitable for installing a photosensor used in the paper multifeed detecting device. SOLUTION: By using a monitor region of a first paper, the normal region of the amount of transmitted light of the paper is set, and by using the amount of transmitted light of the monitor region of the sequentially fed paper, the paper length within the normal region of the paper and the paper length outside the normal region are detected, the number of the paper within the normal region is detected, and the double feeding of the paper is detected based on the detected information. When the photosensor is arranged so as to ride over a paper feeding passage, the paper feeding passage is formed in the front of a photosensor unit installed on the lower side of the paper feeding passage, and a glass member is aslant arranged so that the front in the paper feeding direction is higher than the normal paper feeding passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for providing a double feed detecting device used in a paper feeding device for separating and conveying sheets one by one and an optical sensor used in the double feeding detecting device. Paper feed device, especially, a multi-sheet feed detection device that achieves high detection performance even for paper on which printed matter is printed, and an optical sensor that is required to realize the high detection performance. And a sheet feeding device suitable for being provided.

[0002]

2. Description of the Related Art In image scanners, printers, and copiers, a paper feeder that separates and transports sheets one by one is used.

In this paper feeder, double feed of paper is inevitable due to the inherent limitation of paper separation performance. From now on, it is necessary to provide a multi-feed detecting device for detecting multi-feed of sheets.

[0004] In the conventional paper double feed detecting device, when the paper is shifted and double-fed, paying attention to the fact that the paper length becomes longer than the original paper length, the paper By detecting the length and detecting whether or not the length is longer than the original length of the sheet, processing is performed so as to detect the double feed of the sheet.

[0005]

Indeed, according to this prior art, it is possible to detect the double feed showing the form of paper misalignment with high accuracy.

However, in the case of a double feed in which sheets are conveyed in a completely overlapping manner, the double feed cannot be detected.

In order to solve this problem, a method of detecting the amount of transmitted light of a conveyed sheet using a transmission type optical sensor and detecting double feed using the detected amount has been studied.

However, in this detection method, if nothing is printed on a sheet, it is expected that a double feed that completely overlaps can be detected with high accuracy. In this case, it is impossible to determine whether the transmitted light amount has decreased due to the double feed or the transmitted light amount has decreased due to the printed matter, and thus there is a problem that it cannot be detected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a new paper multi-feed detecting device which realizes high detection performance even on paper on which printed matter is printed, and provides a high paper detection device. It is an object of the present invention to provide a new sheet feeding device suitable for providing an optical sensor required for realizing performance.

[0010]

In order to achieve this object, a multi-feed detecting apparatus according to the present invention includes a light emitting device and a light emitting device for detecting multi-feed of papers separated and conveyed one by one. A sensor configured to detect the amount of transmitted light of the conveyed sheet, a setting unit configured to set a normal range of the amount of transmitted light detected by the sensor using the conveyed sheet, and a sheet Detecting means for collecting a transmitted light amount detected by the sensor means when the paper is conveyed, and detecting a conveyance error of the conveyed paper from the collected transmitted light amount and a normal range set by the setting means; It comprises so that it may be provided.

In this configuration, the setting means sets a normal range of the paper length using the conveyed paper, and in response thereto, the detecting means sets the normal range when the paper is conveyed. In some cases, processing is performed so as to detect a paper transport error while considering whether or not the paper length falls within the normal range of the determined paper length.

In the paper double feed detecting device of the present invention thus configured, the setting means detects, for example, the transmitted light amount of the leading sheet and sets the normal range of the transmitted light amount accordingly. Then, the setting unit acquires, for example, the length of the leading sheet, and sets the normal range of the sheet length according to the length.

In response to the setting information, the detecting means collects the transmitted light amount detected by the sensor means when the sheet is conveyed, and determines whether the collected light amount falls within the normal range of the set transmitted light amount. By checking, the paper length indicating the transmitted light amount larger than the normal range, the paper length indicating the transmitted light amount smaller than the normal range, the paper length indicating the transmitted light amount falling within the normal range, and the transmitted light amount falling within the normal range And the number of paper areas indicating.

When the length of the sheet showing the transmitted light amount larger than the normal range is longer than the specified value, the detecting means determines that the paper used for setting the normal range of the transmitted light amount has been multi-fed. By making a determination, a paper transport error is detected.

Then, the detecting means determines that the length of the sheet showing the amount of transmitted light smaller than the normal range is larger than the specified value, the length of the sheet showing the amount of transmitted light falling within the normal range is smaller than the specified value, and falls within the normal range. When the number of paper areas indicating the amount of transmitted light to enter is less than the specified number, either the paper has been multi-fed or the printed matter has been printed on the paper, but if the printed matter is being printed at this time, Although the number of paper areas increases, this is not the case, so that it is determined that paper has been multi-fed, and a paper transport error is detected.

At this time, the detecting means detects a paper transport error while considering whether or not the length of the transported paper falls within the set normal range. The paper transport error is detected in consideration of the case where the error occurs.

As described above, in the paper multi-feed detecting apparatus of the present invention, the amount of transmitted light of the paper is detected by using the transmission type optical sensor, and the multi-feed is detected by using the optical sensor in combination with the multi-feed detection using the paper length. When the configuration for detecting the multi-feeding of paper is adopted in the form of taking into account the possibility that the printed matter is printed on the paper when the configuration for detecting the High detection performance can be realized even for paper.

On the other hand, in the paper feeder of the present invention, when a configuration is adopted in which the paper is separated and transported one by one, the light emitter and the light receiver are arranged so as to sandwich the paper transport path. ,
Sensor means for detecting the amount of transmitted light of the sent paper;
Provided on the front side of the sensor means provided at the lower side of the paper transport path, forms a paper transport path, and is arranged so that the forward end of the paper transport direction is higher than the regular paper transport path. And a glass member to be provided.

When this configuration is adopted, a component of the sensor means provided on the upper side of the transport path is disposed on a cover member of the apparatus which can be opened and closed, and a cover opening / closing detection sensor for detecting opening / closing of the cover member. The opening and closing of the cover member can be detected even when the cover opening / closing detection sensor unit operates erroneously by providing the determination unit for finally determining the opening and closing of the cover member from the means and the detection value of the sensor unit. There is a case where a configuration is adopted to make it possible.

In the paper feeder of the present invention configured as described above, the sheets separated one by one are conveyed on a glass member serving as a sheet conveyance path. At this time, since the glass member is arranged inclined as described above, the paper being conveyed will be conveyed while rubbing the glass member, and thus will adhere to the glass member. Garbage such as paper dust will be removed.

Thus, in the paper feeder of the present invention,
When adopting a configuration in which an optical sensor is provided, the lower sensor component portion where dust such as paper dust easily accumulates is protected by a glass member, and the glass member is cleaned using a conveyed sheet. Therefore, when the configuration of detecting the double feed of the sheet using the optical sensor according to the double feed detecting apparatus of the present invention is adopted, the detection performance can be maintained.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail according to embodiments.

FIG. 1 shows an embodiment of a sheet feeding structure of a sheet feeding apparatus provided with the present invention.

As shown in FIG. 1, a paper feeder equipped with the present invention includes, for example, a pick roller 1 for picking up paper loaded on a popper, and a separation pad 3 for separating the paper picked by the pick roller 1. The paper is separated one by one by using a separation roller 2 that separates the sheets one by one using a sheet, a conveyance roller 4 that conveys the sheet separated by the separation roller 2, and a driven roller 5 that is driven by the conveyance roller 4. It has a configuration to transport.

Here, the cover member 6 constituting the base of the apparatus cover can be opened and closed around a fulcrum (not shown) as a rotation center, so that a jammed sheet can be taken out.

Also, a mechanical cover open detection sensor 7 used for detecting whether or not the apparatus cover is open, a plurality of mechanical paper size detection sensors 8 used for detecting the paper size, and a leading edge of the paper A mechanical paper front and rear end detection sensor 9 used for detecting the position and the rear end position is prepared.

When this configuration is adopted, in the paper feeder equipped with the present invention, in order to detect the double feeding of the paper, it is arranged on the cover member 6 so that the light emitting device arranged at the upper position of the transport path is provided. A diode 100 and a light receiving sensor 1 disposed at a lower position of the transport path so as to face the light emitting diode 100
01 is provided with the double feed detecting optical sensor 10 composed of the optical sensor 10 and the first optical sensor 10.

As shown in FIGS. 2 and 3, the double feed detecting optical sensor 10 is arranged at a substantially central position of the sheet, and is arranged in parallel with the cover open detecting sensor 7 to detect the A3 size. An A3 paper size detection sensor 8a to be used;
A4 paper size detection sensor 8 used for detecting A4 size
b, a B5 paper size detection sensor 8c used to detect the B5 size, and a B4 paper size detection sensor 8d used to detect the B4 size. Then, a paper leading and trailing edge detecting sensor 9 is disposed at a general paper center position downstream of the optical sensor 10 for double feed detection in the transport direction.

Since the light receiving sensor 101 constituting the double feed detecting optical sensor 10 is located on the lower side of the conveyance path, it is inevitable that paper dust adheres. In this case, it is impossible to detect the double feeding of the paper with high accuracy.

Therefore, as shown in FIG. 1, a configuration is adopted in which a glass plate 11 forming a conveyance path is provided on the front surface of the light receiving sensor 101, and as shown in FIG. By using the mounting member 12, a configuration is adopted in which the end of the sheet in the sheet conveying direction is inclined so as to be higher than the regular sheet conveying path.

By adopting this arrangement, the paper is conveyed while rubbing the glass plate 11, so that dust such as paper dust adhering to the glass plate 11 is removed. Accordingly, it is possible to prevent the sensitivity of the double feed detection optical sensor 10 from deteriorating.

FIG. 5 shows an embodiment of the hardware configuration of the paper feeder provided with the present invention, and FIG. 6 shows an embodiment of the software configuration of the paper feeder provided with the present invention. .

As shown in FIG. 5, the paper feeder equipped with the present invention has a hardware configuration in which a CPU 20, a ROM 21, a RAM 22, a non-volatile memory 23, Motor driver 24 and motor 2
5, a cover open detection sensor 7, a sheet size detection sensor 8, a sheet front and rear end detection sensor 9, an optical sensor 10 for double feed detection, and a sheet transmitted light amount detection control circuit 30.

Here, the sheet transmitted light amount detection control circuit 30
Specifically, the CPU 20 controls the multi-feed detection optical sensor 10 to detect the transmitted light amount of the sheet.
Is generated and given to the light emitting diode 100, and the constant current circuit 31 for causing the light emitting diode 100 to emit light, and the constant current value indicated by the CPU 20 to D / A
The constant current circuit 3 is converted and given to the constant current circuit 31.
A D / A converter 32 for setting a constant current value generated by 1;
An amplifier 33 for amplifying the amount of transmitted light of the paper detected by the light receiving sensor 101;
An A / D converter 34 for converting and notifying the CPU 20.

On the other hand, as shown in FIG. 6, the paper feeder equipped with the present invention has a software configuration in which the leading and trailing edges of the sheet detected by the sheet leading and trailing edge detecting sensor 9 are realized in order to realize the present invention. A multi-feed detection program that performs a process of detecting a multi-feed of paper, using as input the end position, the amount of transmitted light of the paper detected by the optical sensor 10 for double feed detection, and the paper length detected by the paper length detection program 50. 40 is provided.

For the processing of the double feed detection program 40, the RAM 22 has a MAX error occurrence counter 60, a MIN error occurrence counter 61, an OK counter 62, an OK continuous counter 63, and a 1 mm continuous OK count. Five counters, that is, the counter 64 are prepared.

The double feed detection program 40 is, for example,
The transmission light amount output from the double feed detection optical sensor 10 is obtained at a rate of once for every two motor interruptions, and a process for detecting the double feed of the paper is performed according to a process described later.

In this case, the motor interrupt is, for example, "25.4 /
When this occurs every time a sheet of "400 (mm)" is fed, the double feed detection program 40 obtains the amount of transmitted light output from the double feed detection optical sensor 10 every time the sheet is fed "0.127 mm". Will be.

On the other hand, the sheet length detection program 50 starts counting the number of motor interrupts when the sheet leading and trailing edge detecting sensor 9 detects the leading edge of the sheet. When the edge is detected, the counting is stopped to detect the length of the sheet in the transport direction, and notify the double feed detection program 40 of the length.

FIGS. 7 to 12 show an embodiment of the processing flow executed by the double feed detection program 40. FIG.

Next, according to this processing flow, the paper multi-feed detection processing executed by the present invention will be described in detail.

When the sheet conveyance is started, the double feed detection program 40 performs the processing shown in the processing flow of FIG. 7 using the first sheet.

That is, when the multi-feed detection program 40 is started in response to the start of paper conveyance, the multi-feed detection program 40
As shown in the processing flow of FIG. 7, first, in step 1, the process waits for the sheet front and rear end detection sensor 9 to detect the leading end position of the first sheet, as shown in the processing flow of FIG.

When the leading and trailing edge detecting sensor 9 detects the leading edge of the sheet (the leading edge of the sheet has already been detected at the double feed detecting optical sensor 10), the process proceeds to step 2 to control the amount of transmitted light of the sheet. The gain of the amplifier 33 of the sheet transmitted light amount detection control circuit 30 is adjusted so that the voltage value output from the circuit 30 (the transmitted light amount of the sheet detected by the double feed detection optical sensor 10) becomes an appropriate value. For example, the gain of the amplifier 33 is adjusted so that the value becomes 150 in the digital value range of 0 to 255.

By this gain adjustment, it is possible to obtain a sheet transmitted light amount indicating a voltage level suitable for the sheet being conveyed. Here, instead of adjusting the sensitivity of the multi-feed detection optical sensor 10 by adjusting the gain of the amplifier 33, the sensitivity of the multi-feed detection optical sensor 10 is adjusted by adjusting the constant current supplied to the light emitting diode 100. It is also possible to use a method of adjusting.

Subsequently, in step 3, by counting the number of motor interrupts, it is checked whether or not the motor has entered the monitor area of the paper set at, for example, 20 mm from the leading end of the paper.

As shown in FIG. 13A, the double feed detection program 40 converts a paper area partitioned between a position, for example, 20 mm from the leading edge of the paper and a position, for example, 20 mm from the trailing edge of the paper, into a monitor area of the paper. Therefore, the number of motor interrupts is counted to check whether or not the sheet monitor area has been entered.

Here, the sheet leading and trailing edge detecting sensor 9 is located on the downstream side in the transport direction from the optical sensor 10 for double feed detection, and the double feed detection program 40 determines the distance between these two sensors. By counting the number of motor interruptions while taking into account, processing is performed to check whether or not the vehicle has entered the paper monitor area.

When such a paper monitor area is set, when the paper is shifted and multi-fed, as can be seen from FIG. 13B, the transmitted light amount is different between the leading edge of the paper and the trailing edge of the paper. Is seen as one sheet of paper, so that the amount of transmitted light in this portion is not used.

In step 3, when it is detected that the sheet has entered the paper monitor area, the process proceeds to step 4, and in accordance with the sampling period defined at a rate of one for every two motor interruptions, the optical sensor 10 for double feed detection. Is obtained and stored in a ring buffer (cleared before the paper is conveyed) (not shown). The capacity of the ring buffer will be described later.

Subsequently, at step 5, it is determined whether or not the ring buffer is full. When it is determined that the ring buffer is not full, the process returns to step 4.

On the other hand, when it is determined that the ring buffer is full, the process proceeds to step 6, where the first transmitted light amount stored in the ring buffer (the oldest data stored in the ring buffer) is processed. By comparing with the maximum transmitted light amount detected until then, the maximum transmitted light amount is updated as necessary.

Subsequently, in step 7, it is determined whether or not the sheet leading and trailing edge detection sensor 9 has detected the trailing edge position of the sheet. According to the cycle, the transmitted light amount detected by the double feed detection optical sensor 10 is obtained and stored in the ring buffer (the oldest data is deleted), and then the process returns to step S6.

On the other hand, when it is determined in step 7 that the sheet front / back end detection sensor 9 has detected the position of the rear end of the sheet, the process proceeds to step 9 where the effective transmitted light amount remaining in the ring buffer (paper monitor) By comparing the transmitted light amount of the area with the maximum transmitted light amount detected up to that time, the one indicating the maximum value of the transmitted light amounts detected in the paper monitor area is detected.

That is, the sheet front and rear end detection sensor 9 is located on the downstream side in the transport direction from the optical sensor 10 for double feed detection, and from now on, as shown in FIG. The data portion is invalid data because the double feed detection optical sensor 10 detects the state when there is no paper. Then, the newly stored data portion subsequent thereto is invalid data corresponding to the rear end portion of the sheet.

In step 9, an effective transmitted light amount (a transmitted light amount in a paper monitor area) is extracted by removing invalid data stored in the ring buffer, and the transmitted light amounts and the detected light amounts are detected. By comparing with the maximum transmitted light amount, the maximum transmitted light amount detected in the paper monitor area is detected.

As can be seen from this, the ring buffer is required to have at least a capacity capable of storing the invalid data.

Subsequently, in step 10, the detected maximum transmitted light quantity is multiplied by, for example, "1.43" to set the MAX error determination slice level, and the detected maximum transmitted light quantity is multiplied by, for example, "0.75". By doing so, the MIN error determination slice level is set.

Subsequently, in step 11, the sheet length of the first sheet used in this processing is received from the sheet length detection program 50, and the length of the first sheet is added to or subtracted from the sheet length. Is set, and the process ends.

In this way, the double feed detection program 40
Is activated in response to the start of sheet conveyance, detects the maximum amount of transmitted light detected from the monitor area of the first sheet conveyed as a processing target, and sets a prescribed coefficient value Is set, the MAX error determination slice level / MIN error determination slice level is set, the sheet length of the sheet is received from the sheet length detection program 50, and the normal range of the sheet length is set accordingly. It is.

Although not described in the processing flow of FIG. 7, if the detected maximum transmitted light amount is larger than the specified value, the printed matter is located in the area of the leading end portion of the paper used for the gain adjustment of the amplifier 33. Has been printed,
It is determined that the X error determination slice level / MIN error determination slice level could not be set, and processing is performed to re-execute the processing flow of FIG. 7 using the next sheet.

When the second and subsequent sheets are conveyed following the first sheet, the double feed detection program 40 shown in FIG.
12, using the MAX error determination slice level / MIN error determination slice level set for the first sheet to detect whether or not the conveyed sheet has been multi-fed according to the processing flow of FIG. I do.

That is, the double feed detection program 40
8 to 12 when the subsequent sheets are conveyed.
First, in step 1, the process waits for detection of the leading end position of the conveyed sheet by the sheet leading and trailing end detection sensor 9 in step 1.

When the leading and trailing edge detection sensor 9 detects the leading edge position of the sheet, the process proceeds to step 2 and the MA shown in FIG.
X error occurrence counter 60 / MIN error occurrence counter 61 / OK counter 62 / OK continuous counter 63 / 1mm
The count value of the continuous OK number counter 64 is cleared to “0”.

Subsequently, in step 3, by counting the number of motor interrupts, it is checked whether or not the apparatus has entered the paper monitor area set to 20 mm from the leading end of the paper. Is detected, the process proceeds to step 4 to obtain the amount of transmitted light detected by the optical sensor 10 for double feed detection in accordance with a sampling cycle defined at a rate of one for two motor interruptions, Store in the ring buffer (cleared before transporting the paper).

Subsequently, in step 5, it is determined whether or not the ring buffer is full. If it is determined that the ring buffer is not full, the process returns to step 4.

On the other hand, when it is determined that the ring buffer is full, the process proceeds to step 6, where the head transmitted light amount stored in the ring buffer (oldest data stored in the ring buffer) is processed. By performing the error determination process, the MAX error occurrence counter 60 /
MIN error occurrence counter 61 / OK counter 62 / O
The count value of the K continuous counter 63/1 mm continuous OK counter 64 is updated. The details of this error determination processing will be described later.

Subsequently, in step 7, it is determined whether or not the sheet front / rear end detection sensor 9 has detected the rear end position of the sheet. According to the cycle, the transmitted light amount detected by the double feed detection optical sensor 10 is obtained and stored in the ring buffer (the oldest data is deleted), and then the process returns to step S6.

On the other hand, when it is determined in step 7 that the sheet front / back end detection sensor 9 has detected the rear end position of the sheet, the process proceeds to step 9 where the effective transmitted light amount remaining in the ring buffer (paper monitor) By performing an error determination process on the transmission light amount of the area) as a processing target, the MAX error occurrence counter 60 / the MIN error occurrence counter 61 /
OK counter 62 / OK continuous counter 63 / 1mm continuous O
The count value of the K times counter 64 is updated. The details of this error determination processing will be described later.

Subsequently, at step 10, the paper length of the paper used in this processing is received from the paper length detection program 50.

Subsequently, at step 11, the MAX error occurrence counter 60 / MI updated by the error determination process
Using the count value of the N error occurrence counter 61 / OK counter 62/1 mm continuous OK counter 64, a determination process is performed to determine whether or not the conveyed paper is a multi-feed. The details of the double feed determination process will be described later.

Subsequently, in step 12 (the processing flow in FIG. 9), it is determined whether or not double feed has been detected by the double feed determination processing, thereby determining that double feed has been detected. In some cases, the process proceeds to step 13 to display an error.

On the other hand, if it is determined in step 12 that non-multifeed has been detected, the process proceeds to step 14 to improve the detection performance, and the sheet length received in step 10 is set in the processing flow of FIG. When it is determined whether the paper length falls within the normal range of the paper length, and it is determined that the paper length does not fall within the normal range, it is normal in terms of the amount of transmitted light but abnormal in terms of the paper length. Finally, it is determined that the multi-feed is performed, and the process proceeds to step 15,
When an error is displayed and it is determined that the sheet length falls within the normal range, it is finally determined that the multi-feed is not performed, and the process ends without displaying an error.

Here, when an error is displayed, an appropriate MAX error determination slice level / MIN error determination slice level and an appropriate paper length normal range are set because the first sheet has been multi-fed. In consideration of the possibility that the next sheet may not have been printed, it is preferable that the next sheet is set as a new first sheet and the processing is restarted from the processing flow of FIG.

Next, the details of the error determination processing executed in step 6 / step 9 of the processing flow of FIG. 8 will be described with reference to the processing flows of FIGS. 10 and 11, and according to the processing flow of FIG. The details of the double feed determination process executed in step 11 of the process flow will be described.

First, the details of the error determination processing will be described with reference to the processing flows of FIGS. 10 and 11.

When the multi-feed detection program 40 enters the error judgment processing, as shown in the processing flow of FIGS. 10 and 11, first, in step 1, the transmitted light quantity to be processed is set to the MAX error judgment slice level. When it is determined whether the value is larger than the predetermined value, the process proceeds to step 2 where the count value of the MAX error occurrence counter 60 is incremented by one, the count value of the OK counter 62 is cleared, and The count value of the counter 63 is cleared, and the error determination processing ends.

Here, the transmitted light amount to be processed is MAX.
The fact that the slice level has become larger than the error determination slice level means that the MAX error determination slice level may have been set low due to the multi-feed of the first sheet. From this, the count value of the OK counter 62 (which indicates the length of the paper area indicating that the transmitted light amount is neither thick nor thin, as will be described later) is also cleared. .

On the other hand, when it is determined in step 1 that the transmitted light amount to be processed is smaller than the MAX error determination slice level, the process proceeds to step 3 where the transmitted light amount is smaller than the MIN error determination slice level. When it is determined whether or not the transmitted light amount is small, that is, when it is determined that the transmitted light amount is displaying the paper area on the black side, the process proceeds to step 4 and MI
The count value of the N error occurrence counter 61 is incremented by one.

Subsequently, in step 5, it is determined whether or not the count value of the OK continuous counter 63 indicates a value larger than 1 mm.

By this determination processing, the OK continuous counter 6
When it is determined that the count value of No. 3 indicates a value larger than 1 mm, the process proceeds to step 6 and the count value of the 1 mm continuous OK number counter 64 is incremented by one.

The 1-mm continuous OK counter 64 is provided to display the number of white areas on the sheet. When the transmitted light amount to be processed is smaller than the MIN error determination slice level, the white area is counted. Is determined, the count value of the 1 mm continuous OK counter 64 is determined in accordance with the count value of the OK continuous counter 63 indicating the length of the white area, provided that the length of the interrupted white area is long. By incrementing the numerical value by one, the discontinued white area is counted.

Subsequently, in step 7, in response to the interruption of the white area, the count value of the OK continuous counter 63 is cleared, and the error determination processing ends. Then, in step 5, when it is determined that the count value of the OK continuous counter 63 indicates a value smaller than 1 mm, it is determined that the value of 1 corresponds to the fact that the interrupted white area is not sufficiently large.
The process immediately proceeds to step 7 without incrementing the count value of the mm continuous OK counter 64, clears the count value of the OK continuous counter 63, and ends the error determination process.

On the other hand, when it is determined in step 3 that the amount of transmitted light to be processed is greater than the MIN error determination slice level, that is, a white paper area where the amount of transmitted light is appropriate (the thickness of the paper is not thick and thin When it is determined that the display is not performed, step 8 (FIG. 11)
Then, the count value of the OK counter 62 is incremented by one, and the count value of the OK continuous counter 63 is incremented by one.

Subsequently, in step 9, it is determined whether or not the count value of the OK continuous counter 63 indicates a value larger than 1 mm. To clear the count value of the MIN error occurrence counter 61, terminate the error determination process, and determine that the value does not indicate a large value, without clearing the count value of the MIN error occurrence counter 61, The error determination processing ends.

Here, when the count value of the OK continuous counter 63 indicates a value larger than 1 mm,
The reason for clearing the count value of the error occurrence counter 61 is that it is considered that printed matter such as characters is printed on such a paper portion, and the MIN error is caused by a cause other than the original cause of the MIN error. It is considered that.

Next, according to the processing flow of FIG.
The details of the double feed determination processing executed in step 11 of the processing flow of FIG.

When the multi-feed detection program 40 enters the multi-feed detection process, first, in step 1, the count value of the MAX error occurrence counter 60 is set to "1" of the sheet length as shown in the processing flow of FIG. When it is determined whether the distance is equal to or more than the distance of ８ ”, and when it is determined that the distance is equal to or more than the distance of“ １ ／ ”of the sheet length, the process proceeds to step 2 and the position of the first sheet is increased. Since the conveyed sheet is thinner, it is determined that an error has occurred, and the multifeed detection processing ends.

That is, the MAX error occurrence counter 60
If the count value indicates a certain sheet length, the MAX error determination slice level may have been erroneously set to a small value because the first sheet used for setting the MAX error determination slice level was multi-fed. Therefore, it is determined that there is an error.

On the other hand, when it is determined in step 1 that the count value of the MAX error occurrence counter 60 does not correspond to the distance equal to or more than "1/8" of the sheet length, the process proceeds to step 3, where the MIN error occurrence counter 61 It is determined whether or not the count value is equal to or more than the distance of “１ ／” of the sheet length, and
When it is determined that the distance is not equal to or more than the distance of "1/4" of the sheet length, the process proceeds to step 7, where it is determined that the conveyed sheet is normal because the sheet is not thick, and the double feed detecting process is terminated.

On the other hand, if it is determined in step 3 that the count value of the MIN error occurrence counter 61 is equal to or greater than the distance of "1/4" of the sheet length, the process proceeds to step 4, where the count value of the OK counter 62 is determined. Is smaller than the distance of "1/8" of the paper length, it is determined whether or not "1" of the paper length.
If it is determined that the distance does not correspond to less than the distance of / 8 ", the process proceeds to step 7, and it is determined that the sheet is normal because the transmitted light amount of a considerable portion of the sheet is between the MAX error determination slice level and the MIN error determination slice level. Then, the double feed detection processing ends.

On the other hand, if it is determined in step 4 that the count value of the OK counter 62 is less than the distance of "1/8" of the sheet length, the process proceeds to step 5 and the 1 mm continuous O
It is determined whether or not the count value of the K-number counter 64 is less than 3, and when it is determined that the count value is not less than 3, the process proceeds to step 7, where it is determined that the count is normal, and the double feed detection process ends.

As described above, the 1 mm continuous OK counter 64 indicates the number of white areas of the sheet. As can be seen from FIG. Considering that two white regions will be detected according to the leading edge portion and the trailing edge portion of the paper, and that a considerable number of white regions will be detected when printed matter is printed on the paper. When it is determined that the count value of the 1 mm continuous OK number counter 64 is not less than 3, it is determined to be normal.

On the other hand, if it is determined in step 5 that the count value of the 1 mm continuous OK number counter 64 is less than 3, the process proceeds to step 6, where it is determined that an error has occurred, and the double feed detection processing ends.

Here, when the printed matter is not printed on the paper and the paper is not multi-fed, the count value of the 1 mm continuous OK number counter 64 indicates less than 3 such as "0". However, in this case, step 3
In accordance with the processing in step 4, it is determined that the operation is normal, so that no inconvenience occurs.

Thus, the double feed detection program 40
Sets the normal range of the amount of transmitted light of the sheet using the monitor area of the first sheet, and uses the amount of transmitted light of the monitor area of the sheet that is subsequently conveyed to determine the normal range of the conveyed sheet. In addition to detecting the length of paper that falls within the normal range and the length of paper that does not fall within the normal range, the number of areas within the normal range is detected, and processing is performed to detect double feed of paper by using the detection information. It is.

At this time, even when it is detected that the multi-feed is not detected in terms of the amount of transmitted light, if the length of the first sheet does not match the length of the conveyed sheet, the first sheet is It is determined that the sheet is multi-fed or the conveyed sheet is multi-fed, an error is displayed, and the transmitted light amount of the conveyed sheet is larger than the transmitted light amount of the first sheet. Sometimes, it is determined that the first sheet has been multi-fed, and processing is performed so as to display an error.

Although not described above, when sampling the transmitted light amount of the paper detected by the optical sensor 10 for double feed detection, the current sampling value changes abruptly when viewed from before and after the sampling value. If so, it considers it as noise and ignores it.

In step 2 of the processing flow of FIG.
The gain of the amplifier 33 of the sheet transmitted light amount detection control circuit 30 is adjusted using the leading end of the first sheet. At this time, the output voltage of the sheet transmitted light amount detection control circuit 30 is used as a monitor. When the paper portion is reliably detected due to a certain value or less or the rate of change thereof becomes a certain value or less, processing is performed so as to start the gain adjustment.

The paper feeder of the present invention employs a configuration in which the double feed detecting optical sensor 10 is provided at the central position of the paper. From this, it is possible to detect a special sheet called an OMR sheet inserted at a rate of one in hundreds of sheets of the job.

That is, as shown in FIG. 15, the OMR sheet has a shape in which the central portion is cut off, so that when the sheet size detection sensor 8 detects the leading edge of the sheet, the light for double feed detection is detected. By checking whether or not the sensor 10 detects the leading edge of the sheet, the OMR sheet can be detected.

The paper feeder of the present invention employs a configuration in which the double feed detection optical sensor 10 is provided at the central position of the paper, so that the paper size detection sensor 8 cannot detect A6 or the like. The presence or absence of such a small sheet can be detected.

Further, since the light emitting diode 100 of the double feed detecting optical sensor 10 is disposed on the cover member 6, when the apparatus cover is opened, the double feed detecting optical sensor 10 reduces the transmitted light amount of zero value. Will be detected.

On the other hand, if the user accidentally touches the cover open detection sensor 7 while the apparatus cover is open, the cover open detection sensor 7 detects that the apparatus cover has been closed, and this causes the motor 25 to rotate. It can happen that you are in danger after starting.

Therefore, when the cover open detection sensor 7 detects the opening of the apparatus cover and the cover open detection sensor 7 shifts to the detection of the close of the apparatus cover, the double feed detecting optical sensor 10 transmits zero value. It is determined whether or not the light amount is detected, and when the transmitted light amount of zero value is detected, the cover open detection sensor 7 is detected.
Is processed so as to judge that a malfunction has occurred.

By providing this function, even if the user accidentally touches the cover open detection sensor 7 while the apparatus cover is open, the motor 25 may start rotating. It does not happen and safety can be secured.

Further, in the embodiment, as described in step 2 of the processing flow of FIG. 7, when the sheet leading and trailing edge detecting sensor 9 detects the leading edge position of the sheet, the amplifier of the sheet transmitted light amount detection control circuit 30 The configuration of adjusting the gain of 33 was adopted.

According to this adjustment method, an erroneous gain adjustment is performed when a printed material is printed at the leading edge of the sheet. At this time, as described above, MA
Although no problem occurs because an X error is detected, it is preferable if the X error can be prevented.

Therefore, at the time of shipment, the gain of the amplifier 33 is adjusted using a certain sheet so that the amount of transmitted light detected by the multi-feed detection optical sensor 10 becomes a value “X”. X is stored in the non-volatile memory 23, and various amplifiers "Y" are assumed in advance, and the amplifier 3 corresponding to the difference value "XY" between those "Y" and "X".
The gain correction amount of No. 3 is obtained, and is tabulated and stored in the nonvolatile memory 23.

When the processing of the first sheet is started, the amount of transmitted light detected by the multi-feed detecting optical sensor 10 is set to the detection area of the monitor area of the first sheet without performing the gain of the amplifier 33. The maximum value “Y” is detected and “Y”
And “X”, a difference value “XY” is calculated, and the table is used as a search key to look up the table to determine the amount of correction of the gain of the amplifier 33 and adjust the gain of the amplifier 33 accordingly. May be adopted.

At this time, in accordance with the adjustment, the maximum value “Y” of the transmitted light amount of the first sheet is corrected in accordance with the calculation processing to obtain the maximum error determination slice level / MIN.
The error determination slice level is set, and the multi-feed detection process for the second and subsequent sheets starts.

In the embodiment, the processing flow of FIG. 7 is executed at the time of starting the sheet conveyance. However, the processing flow of FIG. 7 is periodically executed, or the processing flow of FIG. A configuration of executing a processing flow may be adopted.

[0113]

As described above, the multi-feed detecting apparatus of the present invention detects the amount of transmitted light of a sheet using a transmission type optical sensor while detecting the multi-feed using the sheet length. When using a configuration to detect multifeeds by using a multi-feed, a configuration is adopted in which multifeeds of paper are detected in a form that takes into account the possibility that printed materials may be printed on paper. High detection performance can be realized even for such a sheet.

In the paper feeder of the present invention, when adopting a configuration in which an optical sensor is provided, the lower sensor component where dust such as paper dust easily accumulates is protected by a glass plate. Since the glass plate is cleaned by using the conveyed paper, the detection is performed when the multi-feed detection of the paper is performed using the optical sensor according to the multi-feed detection device of the present invention. Performance can be maintained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a sheet feeding configuration.

FIG. 2 is an explanatory diagram of a sensor configuration.

FIG. 3 is an explanatory diagram of a sensor configuration.

FIG. 4 is an explanatory diagram of an arrangement of glass plates.

FIG. 5 is an explanatory diagram of a hardware configuration.

FIG. 6 is an explanatory diagram of a software configuration.

FIG. 7 is a processing flow of a double feed detection program.

FIG. 8 is a processing flow of a double feed detection program.

FIG. 9 is a processing flow of a double feed detection program.

FIG. 10 is a processing flow of a double feed detection program.

FIG. 11 is a processing flow of a double feed detection program.

FIG. 12 is a processing flow of a double feed detection program.

FIG. 13 is an explanatory diagram of a paper monitor area.

FIG. 14 is an explanatory diagram of a ring buffer.

FIG. 15 is an explanatory diagram of an OMR sheet.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pick roller 2 separation roller 3 separation pad 4 transport roller 5 driven roller 6 cover member 7 cover open detection sensor 8 paper size detection sensor 9 paper leading and trailing edge detection sensor 10 double feed detection optical sensor 11 glass plate 100 light emitting diode 101 light receiving Sensor

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor ▲ Matsuda Kazuki 98 Uno-ki-nu, Unoki-cho, Hebei-gun, Ishikawa Pref. F-Term Co., Ltd. CC03 CC04 CC11 DA04 DA06 DB05 DB16 DC13

Claims (10)

[Claims] 1. A sheet multi-feed detecting device used in a sheet feeding device that separates and conveys sheets one by one, comprising a light emitting device and a light receiving device, and a sensor for detecting a transmitted light amount of the sheet. Means, setting means for setting a normal range of the transmitted light amount detected by the sensor means using the paper, and collecting the transmitted light amount detected by the sensor means when the paper is conveyed; And a detecting means for detecting a transport error of the paper according to the normal range. 2. The sheet multi-feed detecting device according to claim 1, wherein the detecting means includes: a sheet length indicating a transmitted light amount larger than the normal range; a sheet length indicating a transmitted light amount smaller than the normal range; Determining the sheet length indicating the amount of transmitted light falling within the normal range and the number of paper areas indicating the amount of transmitted light falling within the normal range, and detecting a transport error of the sheet according to the length. Detection device. 3. The sheet multi-feed detecting device according to claim 2, wherein the detecting means is configured to determine whether the sheet length indicating a transmitted light amount larger than the normal range is larger than a specified value and a transmitted light amount smaller than the normal range. Is longer than the specified value,
When the sheet length indicating the transmitted light amount falling within the normal range is smaller than a specified value, and the number of the paper areas indicating the transmitted light amount falling within the normal range is smaller than a specified number, it is determined that the paper transport error has occurred. A multi-feed detecting device characterized by detecting. 4. The sheet double feed detecting device according to claim 1, wherein the setting unit sets a normal range of the sheet length using the sheet, and the detecting unit sets the normal range of the sheet length. A multi-feed detecting apparatus for detecting a transport error of a sheet while considering whether or not the sheet length is within a normal range when the sheet is transported. 5. The sheet multi-feed detecting device according to claim 1, wherein a sheet leading end position detected by a sheet leading end detecting sensor provided separately from said sensor is detected, and said sensor is detected. A sheet double feed detecting device, comprising: a determination unit configured to determine whether or not a special sheet has been conveyed from a leading edge position of the sheet. 6. The sheet multi-feed detecting device according to claim 1, wherein the setting unit detects the sensor when the sheet used for setting a normal range of the transmitted light amount is conveyed. When the transmitted light quantity detected by the means is monitored and it is detected whether the detected transmitted light quantity is equal to or less than a predetermined value or the change rate of the transmitted light quantity is equal to or less than a predetermined value, and the condition is satisfied. The paper double feed detection device is characterized in that the normal range of the transmitted light amount is set using the transmitted light amount of the sheet. 7. The multi-feed detecting apparatus according to claim 1, wherein said setting means adjusts the detection sensitivity of said sensor means when setting a normal range of the amount of transmitted light. The multi-feed detection device for paper. 8. The sheet multi-feed detecting device according to claim 1, wherein the maximum value of the amount of transmitted light of the sheet used for setting the setting means and the amount of transmitted light of the adjustment sheet are determined. And an adjusting means for adjusting the detection sensitivity of the sensor means. 9. A sheet feeding device for separating and conveying sheets one by one, wherein a light emitting device and a light receiving device are arranged so as to sandwich a sheet conveying path, and a sensor means for detecting a transmitted light amount of the sheet. And provided on the front surface of the sensor means constituting device provided at the lower side of the paper transport path to form a paper transport path, and the paper transport direction destination is higher than the regular paper transport path. And a glass member disposed at an angle. 10. The sheet feeding device according to claim 9, wherein a component of the sensor means provided on the upper side of the transport path is disposed on a cover member that can be opened and closed by the device, and the cover member is opened and closed. A sheet opening / closing detection sensor for detecting the opening and closing of the cover member based on a detection value of the sensor.