JP5325528B2 - Paper transport device and paper multi-feed detection method - Google Patents

Description

  The present invention relates to a paper transport device and a paper multi-feed detection method, and more particularly to a multi-feed (a state in which a plurality of papers are transported in a superimposed manner) caused by paper transport. The present invention relates to a paper transport device that can reliably detect the paper and a paper multi-feed detection method.

  A conventional paper multi-feed detection method in a paper transport device or the like includes a displacement sensor that detects the displacement of the transport roller, and the thickness of the paper when the paper such as printing paper is transported. When the conveying roller is displaced in response to this, the amount of displacement is detected by the displacement sensor to obtain a detection value, and it is determined whether double feeding has occurred based on the magnitude of the detection value.

  As a proposal for detecting a double feed with a sensor, for example, a double feed detection sensor is configured by a circuit including a parallel plate electrode capacitor that detects a double feed of a paper provided on a paper feed side of a pickup roller in a non-contact manner. Thus, there has been disclosed a proposal for preventing the paper from being damaged as well as detecting double feeding (see, for example, Patent Document 1).

In addition, as a proposal for preventing the occurrence of paper multifeed itself, for example, there is a means for preventing the occurrence of multifeed itself by devising the paper feedout method. In the paper feed control device of the image forming apparatus paper feeding unit that performs the prevention, a proposal is made that performs one feed control for one copy and devise time control and timing of the preliminary feed control (for example, , See Patent Document 2).
Japanese Patent Application Laid-Open No. 11-301885 JP-A-6-298384

  However, in the conventional paper transport apparatus described in the background art, as described above, as a means for detecting double feeding during paper transport, the displacement of the paper transport roller using a displacement sensor is used. Since the amount is detected as a detection value, an error may occur in the detection value of the displacement amount of the roller due to the influence of noise factors such as eccentricity of the roller and dust adhesion. In some cases, even if no double feed occurs, it may be erroneously determined that double feed has occurred, and it may not be possible to accurately determine whether double feed has occurred. was there.

  The proposal disclosed in the above-mentioned Patent Document 1 has a non-contact type circuit configuration as a double feed detection sensor. However, the detected value is caused by noise factors such as eccentricity of the pickup roller and dust adhesion. Under the influence, an error may still occur.

  Further, the proposal disclosed in the above-mentioned Patent Document 1 is not a proposal for detecting double feeding of paper as disclosed in the present invention, even though it has been devised to prevent double feeding of paper.

  The present invention has been made in view of the above-described conventional problems, and erroneously determines the occurrence of double feeding even when there is a noise factor such as eccentricity of a paper conveying roller or dust adhesion. An object of the present invention is to provide a paper transport device that does not need to be performed.

  Another object of the present invention is to provide accurate double feeding of paper that does not erroneously determine the occurrence of double feeding even in the presence of noise factors such as eccentricity of the paper carrying roller and dust adhesion. It is to provide a detection method.

In order to solve the above-described problems, a paper transport device according to the present invention includes a paper transport device disposed in a paper transport path disposed in a paper feed unit, wherein the paper is disposed in a gap between adjacent fixed rollers and a displacement roller. A displacement amount sensor means for detecting a displacement amount of the displacement roller continuously or every minute time interval in a paper conveying apparatus that feeds the paper by the rotational force of the roller, and a displacement sensor Sampling period generating means for generating a sampling period for sampling the displacement amount of the displacement roller detected by the means at predetermined time intervals; and the displacement amount of the displacement roller for each sampling period generated by the sampling period generating means And adjacent displacements based on displacement data consisting of each of the displacement amounts of the displacement rollers sampled by the sampling means Respectively calculate the difference between when the displacement amount calculating means for outputting as a sequence of displacement difference data detection time from the edge detection start the paper until the edge detection end in Displacement amount difference data of the time series is given It is characterized by comprising a double feed judging means for judging that the leading edge of the paper is double fed when it is longer than the time, and an output means for outputting the judgment result.

The paper transport device according to the above feature determines the double feed when the detection time from the edge detection start of the paper leading edge to the end of the edge detection is longer than a predetermined time, thereby decentering the paper transport roller and dust. Even when there is a noise factor such as adhesion, it is possible to detect an accurate double feed of paper that does not erroneously determine the occurrence of double feed.

  In the paper conveying apparatus, the sampling period in the sampling period generating means is a minute time interval in which the influence of noise can be ignored.

  In the paper transporting apparatus, the minute time interval in which the influence of the noise can be ignored is determined by learning in advance.

  Furthermore, in the paper conveying apparatus, the noise types include roller eccentricity, dust adhesion, and temperature fluctuation.

Further, in the paper transport method according to the present invention, the papers are sandwiched one by one in the gap between the adjacent fixed roller and the displacement roller in the paper transport path placed in the paper feed unit, A paper multi-feed detection method for controlling a paper transport device for delivering the paper by the rotational force of the roller, wherein the displacement amount of the displacement roller is detected continuously or at every minute time interval. A sensor step, a sampling cycle generation step for generating a sampling cycle for sampling the displacement amount of the displacement roller detected by the displacement sensor step at predetermined time intervals, and a sampling cycle at which the sampling cycle generation step occurs A sampling step for collecting the displacement amount of the displacement roller, and a variable comprising each of the displacement amounts of the displacement roller collected by the sampling step. Respectively calculate the difference between the displacement adjacent based on the amount data, when a displacement amount calculating step of outputting as the displacement amount difference data series, from the edge detecting start of paper in Displacement amount difference data of the time series A double feed determination step for determining double feed at the leading edge of the paper when the detection time until the end of edge detection is longer than a predetermined time, and an output step for outputting the determination result are performed.

  As described above, according to the paper conveyance device and the paper double feed detection method of the present invention, in order to prevent error determination due to noise, before and after a minute time interval that can ignore the influence of noise. Because it is configured to detect the amount of displacement of the roller (difference data of the amount of displacement) and determine double feeding, etc., it is possible to generate double feeding without being affected by roller eccentricity, dust adhesion, and temperature fluctuation. This has the effect of making it possible to accurately detect.

  In addition, since the transport state of the paper can be grasped by monitoring the difference data of the displacement amount in time series, the transport state of the paper is classified according to the cases accumulated in the past from the pattern. Therefore, there is an effect that it is possible to give an accurate instruction suitable for the paper conveyance status to the paper conveyance system and the operator.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the paper transport apparatus and paper multi-feed detection method of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing the overall configuration of a paper conveying apparatus according to an embodiment of the present invention.
In the figure, a paper multifeed detection device according to this embodiment includes a fixed roller 1 that stably feeds paper, a displacement roller 2 that feeds paper while being displaced according to the thickness of the paper, and a displacement A displacement sensor 3 (displacement amount sensor means) that outputs an electrical signal corresponding to the displacement amount of the roller 2; a control board 4 that controls the whole and determines whether double feeding is performed according to the output of the displacement sensor 3; and papers And a paper feed unit 5 that feeds the paper to the roller and a paper discharge unit 6 that stacks the papers that are sent out and finally discharged.

Hereinafter, each component which the paper conveying apparatus which concerns on this embodiment has is demonstrated.
The fixed roller 1 places paper on the roller upper surface and stably feeds out along the paper feeding direction.
The displacement roller 2 sandwiches the paper in the gap between itself and the fixed roller 1 and feeds out the paper while being displaced according to the thickness of the paper. The thickness of the paper varies depending on the thickness of one leaf of the paper, and also varies depending on the number of the sandwiched paper when a double feed occurs.

  In this embodiment, the displacement sensor 3 continuously detects the displacement amount of the displacement roller 2 and outputs a continuous analog electric signal corresponding to the displacement amount. Alternatively, a digital electrical signal corresponding to the amount of displacement every two minute time intervals may be output. Further, the digital electric signal may be an electric signal indicating the amount of displacement of the displacement roller 2 in numerical form.

The control board 4 controls the electric system and the mechanical system of the entire apparatus, and determines whether or not to double feed according to the output of the displacement sensor 3 (details will be described later).
The displacement sensor 3 and some components of the control board 4 constitute a double feed detection device that employs the double feed detection method of the present invention.

  The paper feeding unit 5 accumulates paper as a stack and sends the accumulated paper to a pinching portion between the fixed roller 1 and the displacement roller 2 one by one. However, the paper feeding operation in this portion is not always stable, and the pinched portion between the fixed roller 1 and the displacement roller 2 may pinch a plurality of papers, so that the accumulated papers are fed out. This multi-leaf feed is a double feed.

  The discharge unit 6 is fed and processed in the paper feed direction, and accumulates the finally discharged paper (that is, stacks again as a stack). Note that the processing here includes printing and printing on the front surface of paper (or the back surface of paper).

FIG. 2 is a configuration diagram showing the configuration of the control board 4 of the paper conveying apparatus according to the embodiment of the present invention.
The control board 4 shown in the figure includes a sampling period generator 40 (sampling period generator) for generating a sampling period, and a sampling section 41 (sampling means) for sampling the displacement output from the displacement sensor 3 at a predetermined constant interval. ), An A / D conversion unit 42 that inputs the displacement amount sampled by the sampling unit 41 and converts it into a digital signal corresponding to the displacement amount, and a digital signal corresponding to the displacement amount output from the A / D conversion unit 42 A displacement amount calculation unit 43 (displacement amount calculation means) that converts the signal into a numerical value indicating the displacement amount, a displacement amount value output from the displacement amount calculation unit 43, and a conveyance control system (not shown) are sent out. A double feed determination unit 44 (conveyance state determination) that inputs a timing signal and a sampling timing notified from the sampling unit 41 and determines whether or not a double feed has occurred. Comprising a means), and double feed multifeed detection signal corresponding to the determination result of the double feed determination unit 44 (i.e., the judgment result output unit 45 outputs an instruction signal) to the conveyance control system (output means), a.

  The sampling period generation unit 40 generates a sampling period that forms a displacement amount check section, and outputs the sampling period to other elements that need to identify the displacement amount check section.

The sampling unit 41 collects the displacement amount output from the displacement sensor 3 at a predetermined constant interval indicated by the sampling period generation unit 40.
The A / D conversion unit 42 receives the displacement amounts sampled at predetermined intervals specified by the sampling cycle generation unit 40 by the sampling unit 41 and converts them into digital signals corresponding to the respective displacement amounts.

  The double feed determination unit 44 inputs the numerical value of the displacement amount output from the displacement amount calculation unit 43, the timing signal sent from the transport control system (not shown), and the sampling timing notified from the sampling unit 41, It is determined whether double feeding has occurred at the timing required for the check.

The determination result output unit 45 amplifies a multifeed determination signal (that is, an instruction signal to the transport control system) corresponding to the multifeed determination result in the multifeed determination unit 44 and outputs the amplified signal to the transport control system.
A specific double feed determination processing operation in the control board 4 will be described later with reference to a flowchart.

Hereinafter, a paper conveyance method according to an embodiment of the present invention will be described.
FIG. 3 is an explanatory diagram illustrating a paper conveying method according to the embodiment of the present invention.

  In the paper conveying apparatus according to the embodiment of the present invention, the amount of displacement output from the displacement sensor 3 is sampled by the sampling unit 41 at predetermined constant intervals. The displacement sampling interval (section) is set to a minute section that is not determined to be double feed by noise displacement. A threshold for determining in the double feed determination unit 44 whether or not the numerical value of the displacement output from the displacement amount calculation unit 43 is a numerical value indicating double feed is determined by learning in advance for each transport device. Can be kept.

  3A, 3B, and 3C show the passage of time in the X-axis direction and the amount of displacement in the Y-axis direction. Each black circle indicates the amount of displacement (on the X-axis) and the position (on the Y-axis) calculated by the displacement amount calculating unit 43, which are collected by the sampling unit 41.

  FIG. 3A shows a case where the edge of the sheet is detected for two sheets at an interval shorter than the sheet conveyance interval, and FIG. 3B shows a case where the edge of the sheet continues for a plurality of sheets within the sheet conveyance interval. FIG. 3C shows a case where the difference in displacement amount before and after a certain section exceeds a specified value (threshold value).

Table 1 shows the occurrence of double feed for each of the three states (state 1, state 2, and state 3) divided by the comparison results of the three threshold values TH1, TH2, and TH3 for checking the displacement amount. Indicates conditions. The threshold TH1 is a threshold for determining “rising edge detection”, the threshold TH2 is “double feed detection”, and the threshold TH3 is “flat detection”.

  In Table 1, when the displacement amount> TH1, the rising edge is detected, when the displacement amount> TH2, the occurrence of double feeding is detected, and when the displacement amount <TH3, the sheet is allowed to be in a flat state. The state where this is detected is shown.

  State 1 can occur within a period from the start of reading until the leading edge of the sheet is detected, and its double feed determination result. State 2 can occur within a period after detection of the leading edge of the sheet and until the point when paper flatness is detected. The double feed determination result, state 3 shows a state that can occur in the period from the paper flatness detection time to the end of reading, and the double feed determination result.

  Within the period corresponding to state 1, if there is “double feed detection” following “rising edge detection”, it is determined that double feed has occurred regardless of the presence or absence of “flat detection”, and there is no “double feed detection” Indicates that it is determined to be normal.

Within the period corresponding to state 2, if there is no “rising edge detection”, no “double feed detection”, and “flat detection” following the period corresponding to state 1, it is determined as normal, If “multiple feed detection” is present after “edge detection”, this means that it is determined that double feed has occurred regardless of the presence or absence of “flat detection”.
Further, when the period of “rising edge detection” is long, it indicates that it is determined that the leading edge of the paper is two sheets.

  In the period corresponding to the state 3, if there is another “rising edge detection”, it indicates that it is determined that the double feeding is performed.

FIG. 4 is a flowchart showing the overall flow of the double feed detection operation in the control board 4 of the paper conveying apparatus according to the embodiment of the present invention.
In the flowchart shown in the figure, steps S2 to S4 correspond to the check of state 1, steps S5 to S7 correspond to the check of state 2, and step S8 corresponds to the check of state 3.

In step S1, a “paper transport” timing signal (see FIG. 2) indicating that the paper is transported is received.
In step S <b> 2, a “roller bite” timing signal indicating that the sheet has been sent out between the fixed roller 1 and the displacement roller 2 is received.

In step S3, it is verified whether or not the leading edge of the sheet has two sheets, that is, the “double feed detection” state shown in Table 1, and if it is in the “double feed detection” state, “double feed error”. Return to the return destination (not shown) for processing the state. Otherwise, if it is not in the “double feed detection” state, the process proceeds to step S4 as normal.
In step S4, it is confirmed that the state is “rising edge detection”, and the process proceeds to step S5.

  In step S5, it is verified whether or not the leading edge of the sheet has two sheets. Here, in the “double feed detection” state shown in Table 1, the “double feed error” state processing is performed. Return to the previous position (not shown). Otherwise, if it is not in the “double feed detection” state, the process proceeds to step S6.

In step S6, whether or not the period until the end of detection of the leading edge of the sheet is longer than a predetermined time length, that is, whether or not the time until the “rising edge detection” end state is reached is longer than the predetermined time length. If the time until the end state of “rising edge detection” is longer than a predetermined time length, the process returns to the return destination (not shown) that performs the process of the “double feed error” state. Otherwise, if the time until the “rising edge detection” end state is within a predetermined time, the process proceeds to step S7.
In step S7, it is confirmed that the state is “flat detection”, and the process proceeds to step S8.

  In step S8, it is verified whether or not the “rising edge detection” state shown in Table 1 has arrived again. If it is in the “rising edge detection” state, the return destination (“double feed error” state processing) Return to (not shown). Otherwise, if it is not in the “rising edge detection” state, the process is terminated and the normal state is restored.

  Hereinafter, a detailed processing procedure of the double feed detection processing in the control board 4 of the paper transport apparatus according to the embodiment of the present invention will be described for each state 1 to state 3 with reference to flowcharts. In the following flowcharts, only the process for checking the displacement amount before and after one section is shown, and after the process here, the process including the control steps for controlling the overall flow (to be described later) ( 15), it is assumed that the processing of each state from state 1 to state 3 is repeated or the processing transitions in the order of state 1 → state 2 → state 3.

FIG. 5 is a flowchart showing a detailed procedure of the multi-feed detection process in the control board 4 of the paper conveying apparatus according to the embodiment of the present invention.
Hereinafter, with reference to the flowchart shown in FIG. 5, a detailed procedure of the double feed detection process of the control board 4 within the period corresponding to the state 1 will be described.
However, in the flowchart shown in FIG. 5, Δ is a difference in displacement amount before and after one section. In addition, in the parameter State, it is assumed that an initial setting is to immediately shift to state 1.
It is assumed that the initial values of the internal counters C1, C2, C2 ′ are set to 0.

  First, in step S03, it is determined whether or not Δ is larger than the threshold value TH2 (that is, whether or not Δ is a double feed level). If Δ is larger than the threshold value TH2, the process proceeds to step S10. If not greater than TH2, the process proceeds to step S04.

In step S04, 0 is substituted into the internal counter C2 (that is, the count of the internal counter C2 is reset).
In step S05, it is determined whether or not Δ is larger than a threshold value TH1 (that is, whether or not Δ is a value corresponding to a rising edge). If Δ is larger than the threshold value TH1, the process proceeds to step S07. If it is not greater than the threshold value TH1, the process proceeds to step S06.

In step S06, 0 is substituted into the internal counter C1 (that is, the count of the internal counter C1 is reset), and the current process is terminated.
In step S07, the internal counter C1 is incremented by +1.

In step S08, it is determined whether or not the value of the internal counter C1 is equal to or greater than 6 (which can be changed with a preset value). If the value of the internal counter C1 is equal to or greater than 6, the process proceeds to step S09 (here, the internal counter C1). The reason why the value of 6 is compared with 6 is that noise or the like is taken into account.) Otherwise, if the value of the internal counter C1 is not 6 or more, the current process is terminated.
In step S09, the rising edge has been detected six times or more at this timing (that is, it is normal), so that the transition to the state 2 is instructed by the parameter State, and the process is terminated.

In step S10, the counters C2 and C2 ′ are counted up in increments of +1, respectively.
In step S11, it is determined whether or not the value of the counter C2 is equal to or greater than 6 (can be changed with a preset value). If the value of the internal counter C2 is equal to or greater than 6, the process proceeds to the return destination in the case of double feed detection (here. Therefore, the reason why the value of the internal counter C2 is compared with 6 is that noise or the like is taken into account.) Otherwise, if the value of the internal counter C2 is not 6 or more, the current processing is terminated.

FIG. 6 is an explanatory diagram showing the amount of displacement when the edge of the paper is normally detected. In the amount of displacement shown in the figure, there is a section where the difference Δ of the displacement amount is larger than the threshold value TH1 in one section. Since the difference Δ of the displacement amount is a displacement amount for one sheet, the edge of the sheet Shows a case where the is detected normally.
(Table 2) shows the determination corresponding to the case shown in FIG. 6, that is, the normal determination conditions in the state 1 of (Table 1).

FIG. 7 is an explanatory diagram showing the amount of displacement when the edge of the sheet is detected for two sheets.
In the displacement amount shown in the figure, the displacement amount difference Δ in one section is larger than the threshold value TH1, and the displacement amount difference Δ is larger than the threshold value TH2, and the displacement amount for two sheets before and after this section. Since the change is shown, the case where the edge of the paper is detected as a double feed is shown.
(Table 3) shows the determination corresponding to the case shown in FIG. 6, that is, the conditions for the double feed determination in the state 1 of (Table 1).

FIG. 8 is a flowchart showing a detailed procedure of the double feed detection process in the control board 4 of the paper conveying apparatus according to the embodiment of the present invention.
Hereinafter, with reference to the flowchart shown in FIG. 8, the detailed procedure of the double feed detection process of the control board 4 in the period corresponding to the state 2 will be described.
However, in the flowchart shown in FIG. 8, Δ is a difference in displacement amount before and after one section. Further, the internal counters C1, C2, C2 ′ hold values in step S09 in the flowchart shown in FIG. 5, and C3 is set to an initial value 0.

First, in step S12, it is determined whether or not the displacement amount difference Δ is larger than the threshold value TH2 (that is, whether or not the displacement amount difference Δ corresponds to detection of double feed), and the displacement amount difference Δ is the threshold value TH2. If it is larger (that is, in the case of double feed detection), the process proceeds to step S22. Otherwise, if the displacement amount difference Δ is not greater than the threshold value TH2 (that is, not in double feed detection), the process proceeds to step S13.
In step S13, 0 is assigned to the internal counter C2 (that is, the internal counter C2 is reset).

  Next, in step S14, it is determined whether or not the displacement amount difference Δ is larger than the threshold value TH1 (that is, whether or not the displacement amount difference Δ corresponds to detection of a rising edge). When it is larger than TH1 (that is, when the rising edge is detected), the process proceeds to step S20. Otherwise, when the displacement amount difference Δ is not larger than the threshold value TH1 (that is, when the rising edge is not detected), the process proceeds to step S15. .

  In step S15, it is determined whether or not the displacement amount difference Δ is smaller than the threshold value TH3 (that is, whether it corresponds to flatness detection). If the displacement amount difference Δ is smaller than the threshold value TH3 (that is, in the case of flatness detection). ) Proceeds to step S17, and otherwise the process proceeds to step S16 if the displacement difference Δ is not smaller than the threshold value TH3 (that is, not flat detection).

In step S16, 0 is substituted into the internal counter C3, and the current process is terminated.
In step S17, the internal counter C3 is incremented by +1.
In step S18, considering the case of noise or the like, it is verified whether or not the value of the internal counter C3 is 6 or more (this value is only an example and can be set to an arbitrary value). If the value is 6 or more, the process proceeds to step S19 (the reason why the value of the internal counter C3 is compared with 6 is because noise or the like is taken into account), otherwise, the value of the internal counter C3. If is not 6 or more, the current process is terminated.

  In step S19, the flatness detection after the rising edge detection is detected at least six times at this timing (that is, it is normal), so that 0 is substituted into the internal counter C1 and the state 3 is to be shifted. Instructed by the parameter State, the process ends.

In step S20, the internal counter C1 is incremented by +1.
In step S21, it is verified whether or not the sum of the values of the internal counters C1 and C2 ′ is equal to or greater than 24 (this value is only an example and can be set to an arbitrary value), and the values of the internal counters C1 and C2 ′ are verified. If the total of the number of sheets exceeds 24, double feed detection in which the leading edge of the sheet is displaced (when the interval until the rising edge is detected, that is, when the section detected as one sheet is long is regarded as double feed). (Here, the reason why the values of the internal counters C1, C2 ′ are compared with 24 is because noise and the like are taken into account), and the values of the internal counters C1, C2 ′ If the total is not more than 24, the current process is terminated.
In step S22, the internal counters C2 and C2 ′ are incremented by an increment of +1.

  In step S23, considering the case of noise or the like, whether or not the value of the internal counter C2 is equal to or greater than 6 (this value is only an example and can be set to an arbitrary value) (that is, double feed detection is 6). If the value of the internal counter C2 is 6 or more, the process proceeds to the return destination in the case of double feed detection in which the leading edge of the sheet is slightly shifted (here, the internal counter C2). The reason why the value of 6 is compared with 6 is that noise or the like is taken into account). Otherwise, if the value of the internal counter C2 is not 6 or more, the current process is terminated.

FIG. 9 is an explanatory diagram showing the amount of displacement when the flatness of the paper is normally detected.
In the displacement amounts in the state 1 to the state 2 shown in the figure, the difference Δ between the displacement amounts continues to be zero when there is no sheet at first, but after that, when the rising edge is detected (that is, one sheet is detected). Before and after the section, the displacement amount difference Δ becomes larger than the threshold value TH1, and after this time, the displacement amount difference Δ continues to be zero again. This state indicates a case where the rising edge of the paper is normally detected.
(Table 4) shows the determination corresponding to the case shown in FIG. 6, that is, the conditions for normal determination in the state 2 of (Table 1).

FIG. 10 is an explanatory diagram showing the amount of displacement when double feeding is detected when the leading edge of the paper is detected.
In the displacement amounts in the state 1 to the state 2 shown in the figure, the difference Δ of the displacement amount continues to be zero when there is no sheet at first, but after that, when the rising edge is detected (that is, two sheets are detected). The difference Δ between the displacement amounts before and after the section is larger than the threshold value TH2, and the case where double feeding of two sheets is detected at the time of detecting the leading edge of the sheet is shown. As described above, in the case where the leading end of the sheet is shifted and double feeding is performed, the rising edge of two sheets of the sheet can be detected even after the leading end is normally detected (that is, immediately after the end of the state 1). is there.
Table 5 shows the determination corresponding to the case shown in FIG. 6, that is, the conditions of the double feed determination at the time of detecting the leading edge of the sheet in the state 2 of (Table 1).

FIG. 11 is an explanatory diagram showing another amount of displacement when double feeding is detected when the leading edge of the paper is detected.
The displacement amount shown in the figure is the displacement amount in the state 1 to the state 2 in the case where there is no sheet at first, and the difference Δ of the displacement amount continues to be zero. Since the detection period until the detection) is longer than the predetermined period (that is, the number of sections exceeds the predetermined number of sections), the leading edge of the sheet is shifted and the double feed is shown. As described above, in the case where the leading edge of the sheet is shifted and double feeding, the edge for two sheets cannot be detected, and the detection period of the rising edge may be long.
(Table 6) shows the determination corresponding to the case shown in FIG. 6, that is, the other conditions of the double feed determination at the time of detecting the leading end of the sheet in the state 2 of (Table 1).

FIG. 12 is a flowchart showing a detailed procedure of the double feed detection process in the control board 4 of the paper conveying apparatus according to the embodiment of the present invention.
Hereinafter, with reference to the flowchart shown in FIG. 12, a detailed procedure of the double feed detection process of the control board 4 in the period corresponding to the state 3 will be described.
However, in the flowchart shown in FIG. 12, Δ is a difference in displacement amount before and after one section. Further, it is assumed that the value in step S19 of the flowchart shown in FIG. 8 is stored in the internal counter C1.

  First, in step S24, it is determined whether or not the displacement amount difference Δ is larger than the threshold value TH1 (that is, whether rising detection has been performed). If the displacement amount difference Δ is larger than the threshold value TH1, the process proceeds to step S26. When the displacement amount difference Δ is not greater than the threshold value TH1, the process proceeds to step S25.

In step S25, 0 is substituted for the internal counter C1 (that is, the internal counter C1 is reset), and the current process is terminated.
In step S26, the internal counter C1 is incremented by increment +1.
In step S27, it is verified whether or not the value of the internal counter C1 is 6 or more (this value is only an example and can be set to an arbitrary value). If the value of the internal counter C1 is 6 or more, the second time. (In this case, the reason for comparing the value of the internal counter C1 with 6 is that noise is taken into account), but the value of the internal counter C1 If is not 6 or more, the current process is terminated.

FIG. 13 is an explanatory diagram showing the amount of displacement when the flatness is normally detected from the detection of the leading edge of the paper.
In the displacement amounts in the states 1 to 3 shown in the figure, the difference Δ between the displacement amounts continues to be zero when there is no sheet at first. Thereafter, the rising edge is normally detected (that is, one sheet is detected). Thereafter, normal flatness detection continues, and the rising edge is normally detected (that is, the end of one sheet is detected).
Table 7 shows the determination corresponding to the case shown in FIG. 13, that is, the conditions for normal determination after detection of the leading edge of the sheet in state 3 of (Table 1).

FIG. 14 is an explanatory diagram showing the amount of displacement when the flatness is normally detected from the detection of the leading edge of the paper.
In the displacement amounts in the states 1 to 3 shown in the figure, the difference Δ between the displacement amounts continues to be zero when there is no sheet at first. Thereafter, the rising edge is normally detected (that is, one sheet is detected). After that, normal flat detection continued, but in the middle of this, the rising edge was detected again normally (that is, the rising edge was detected twice).
(Table 8) shows the determination corresponding to the case shown in FIG. 14, that is, the conditions for the double feed determination after detecting the leading edge of the sheet in the state 1 of (Table 1).

FIG. 15 is a flowchart showing a detailed procedure of the double feed detection process in the control board 4 of the paper conveying apparatus according to the embodiment of the present invention.
Hereinafter, with reference to the flowchart shown in FIG. 15, the detailed procedure of the double feed detection process including the control step for controlling the overall flow of the control board 4 in the period of all the states will be described.
However, in the flowchart shown in FIG. 15, Δ is a difference in displacement amount before and after one section. Further, it is assumed that the initial values of the internal counters C1, C2, and C3 are set to zero.

  Each step (step S01 to step S27) in the flowchart shown in FIG. 15 is the same as the step in the flowchart (FIGS. 5, 8, and 12) except for step S01 and step S02. Only S01 and step S02 will be described.

  In step S01, a difference between the current sampling data Dn (displacement amount) and the 19th previous sampling data Dn-19 (displacement amount) is calculated to obtain a displacement amount difference Δ. Here, in this embodiment, the 19 sampling intervals indicate one interval for checking the displacement amount (a minute interval in which the output fluctuation is not affected). 1 shows a difference in displacement amount before and after one section. In the present invention, in general, this sampling interval can be changed to other values.

  Next, in step S02, according to the value of the parameter State instructing state transition, the control flow is changed to the state 1 process (FIG. 5), the state 2 process (FIG. 8), and the state 3 process (FIG. 12). , Transition to either.

Note that output fluctuation factors that affect the amount of displacement include roller eccentricity, displacement sensor resolution, A / D converter resolution, and the like. In the case of roller eccentricity, the amount of eccentricity changes from the maximum to the minimum in half the circumference of the roller. Assuming that the variation due to roller eccentricity is linear, the preferred sampling interval is given by equation (1).

(Equation 1)
(Roller A eccentricity + Roller B eccentricity) x Sampling section / (Roller division number / 2)
+ Output fluctuations other than eccentricity <Allowable output fluctuations …………………… (1)

Equation (1) is modified to obtain Equation (2) as a suitable sampling interval.

(Equation 2)
Sampling interval <
(Allowable output fluctuation-Output fluctuation other than eccentricity) x (Number of roller divisions / 2)
/ (Roller A eccentricity + Roller B eccentricity) ... (2)

In the present embodiment, the sampling period forming this sampling interval is generated by the sampling period generator 40 (FIG. 2).

  As described above, in the paper conveyance device of the present embodiment, in order to prevent error determination due to noise, the amount of displacement of the roller (displacement amount of the displacement amount) before and after a minute time interval that can ignore the influence of noise. Difference data) is calculated by the displacement amount calculation unit 43, and the double feed determination unit 44 refers to the difference data of the displacement amount to determine double feed or the like. Therefore, the influence of roller eccentricity, dust adhesion, and temperature fluctuation is affected. There is an effect that it is possible to accurately detect the occurrence of double feed without receiving it.

  Further, since the displacement amount calculation unit 43 calculates the difference data of the displacement amount indicating the conveyance state of the paper as time series data, the double feed determination unit 44 calculates the paper type from the time series data pattern. It is possible to classify the transport state according to the cases accumulated in the past, and it is possible to give an accurate instruction suitable for the transport state of the paper to the paper transport system and the operator.

  It should be noted that at least a part of the processing of each component in the control board 4 of the paper conveying apparatus according to the present invention is executed by computer control, and the above processing is shown in the flowcharts of FIGS. The program to be executed by the computer according to the above procedure may be distributed after being stored in a computer-readable recording medium such as a semiconductor memory, a CD-ROM, or a magnetic tape. A computer including at least a microcomputer, a personal computer, and a general-purpose computer may read the program from the recording medium and execute the program.

It is a block diagram which shows the whole structure of the paper conveying apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the control board 4 of the paper conveying apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the conveyance method of paper based on embodiment of this invention. It is a flowchart figure which shows the whole flow of the double feed detection operation | movement in the control board 4 of the paper conveying apparatus which concerns on embodiment of this invention. It is a flowchart figure which shows the detailed procedure of the double feed detection process in the control board 4 of the paper conveying apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the displacement amount when the edge of a paper is detected normally. It is explanatory drawing which shows the displacement amount when the edge of a sheet | seat is detected for 2 sheets of sheets. It is a flowchart figure which shows the detailed procedure of the double feed detection process in the control board 4 of the paper conveying apparatus which concerns on embodiment of this invention. FIG. 10 is an explanatory diagram illustrating a displacement amount when flatness of a sheet is normally detected. FIG. 10 is an explanatory diagram illustrating a displacement amount when double feeding is detected when detecting the leading edge of a sheet. FIG. 10 is an explanatory diagram showing another amount of displacement when double feeding is detected at the time of detecting the leading edge of a sheet. It is a flowchart figure which shows the detailed procedure of the double feed detection process in the control board 4 of the paper conveying apparatus which concerns on embodiment of this invention. FIG. 10 is an explanatory diagram showing a displacement amount when flatness is normally detected from detection of the leading edge of a sheet. FIG. 10 is an explanatory diagram showing a displacement amount when flatness is normally detected from detection of the leading edge of a sheet. It is a flowchart figure which shows the detailed procedure of the double feed detection process in the control board 4 of the paper conveying apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed roller 2 Displacement roller 3 Displacement sensor 4 Control board 5 Paper feed part 6 Discharge part 40 Sampling period generation part 41 Sampling part 42 A / D conversion part 43 Displacement amount calculation part 44 Double feed determination part 45 Output part

Claims (5)

Paper that sandwiches the paper one by one in the gap between adjacent fixed rollers and displacement rollers in the paper conveyance path placed in the paper supply unit, and delivers the paper by the rotational force of the rollers In the kind of transport device,
Displacement amount sensor means for detecting the displacement amount of the displacement roller continuously or every minute time interval;
Sampling period generating means for generating a sampling period for sampling the displacement amount of the displacement roller detected by the displacement sensor means at predetermined time intervals;
Sampling means for collecting the displacement amount of the displacement roller for each sampling period generated by the sampling period generating means;
Displacement amount calculating means for calculating a difference between adjacent displacement amounts based on displacement amount data composed of each displacement amount of the displacement roller sampled by the sampling means, and outputting as time-series displacement amount difference data;
A double feed determining means for determining double feed and the Kamirui tip when the detection time from the edge detection start the paper until the edge detection end in Displacement amount difference data of the time series is longer than the predetermined time,
Output means for outputting the determination result;
A paper conveying apparatus characterized by comprising:   2. The paper conveying apparatus according to claim 1, wherein the sampling period in the sampling period generating means is a minute time interval in which the influence of noise can be ignored.   3. The paper conveying apparatus according to claim 2, wherein the minute time interval in which the influence of the noise can be ignored is determined by learning in advance.   4. The paper conveying apparatus according to claim 2, wherein the noise type includes roller eccentricity, dust adhesion, and temperature fluctuation. Paper that sandwiches the paper one by one in the gap between adjacent fixed rollers and displacement rollers in the paper conveyance path placed in the paper supply unit, and delivers the paper by the rotational force of the rollers A paper double feed detection method for controlling a paper transport device,
A displacement amount sensor step for detecting the displacement amount of the displacement roller continuously or every minute time interval;
A sampling period generating step for generating a sampling period for sampling the displacement amount of the displacement roller detected by the displacement sensor step at predetermined time intervals;
A sampling step of collecting the displacement amount of the displacement roller for each sampling cycle generated by the sampling cycle generation step;
A displacement amount calculating step for calculating a difference between adjacent displacement amounts based on displacement amount data composed of each displacement amount of the displacement roller sampled by the sampling step, and outputting as time-series displacement amount difference data;
And multifeed detection step of determining double feeding and the Kamirui tip when the detection time from the edge detection start the paper until the edge detection end in Displacement amount difference data of the time series is longer than the predetermined time,
An output step for outputting the determination result;
A method for detecting double feed of papers.

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