JP2021195249A - Feeding device - Google Patents

Abstract

To accurately determine the life of feeding means for feeding a recording material.SOLUTION: A feeding device includes: storage means; feeding means including a feeding member, a conveyance member, and a separation member; detection means; measurement means; acquisition means which finds a reference time for determining a probability that an abnormal condition occurs when the feeding means feeds a recording material from a plurality of time data measured by the measurement means, and updates the reference time every time the feeding means feeds a predetermined number of recording materials; and determination means for determining the probability that the abnormal condition occurs based on the reference time and the plurality of time data.SELECTED DRAWING: Figure 8

Description

The present invention relates to a feeding device for feeding recording materials.

In order to maintain the operational stability of the feeding device and image forming device, the life state of the feeding roller and transport roller provided in the feeding device and the risk level indicating a sign of transport trouble are detected and the device is used. A technique for notifying a user or an administrator who performs a maintenance management service is known. Further, it is required to prevent the transportation trouble by feeding back the detected information and applying it to the transportation control of the feeding device and the image forming device.

In the image forming apparatus described in Patent Document 1, the printing paper contained in the feeding tray is fed to the transport path by the feeding roller, and the time until the printing paper is detected by the sensor provided on the transport path is measured. is doing. Then, the measured time data counts the number of times the measured time data exceeds a preset threshold time according to the paper type, and when the number of times exceeds a predetermined number of times, the feeding / conveying unit is deteriorated. A method has been proposed in which a warning is issued.

Japanese Unexamined Patent Publication No. 2012-133021

However, it is known that the time data measured by the above method changes depending on the usage environment and usage conditions of the device. Specifically, when the temperature or humidity around the apparatus changes, the friction coefficient on the surface of the feeding roller or the transport roller changes, which may affect the transport performance of the printing paper.

In the image forming apparatus of Patent Document 1, the threshold time is changed depending on the paper type as described above, but since the same preset threshold time is used for the same paper type, the usage environment and usage conditions of the apparatus may change. If it changes, it may not be possible to accurately determine the deterioration of the feeding means. Therefore, when the feeding means feeds the printing paper, it is difficult to accurately determine the possibility of an abnormal state such as jam (paper jam) or double feeding due to delay.

An object of the present invention is to accurately determine the possibility that an abnormal state may occur when a feeding means feeds a recording material.

The feeding device of the present invention for achieving the above object is fed by an accommodating means for accommodating a recording material, a feeding member for feeding the recording material accommodated in the accommodating means, and the feeding member. A feeding means including a transporting member for transporting the recorded recording material, a separating member for forming a separation nip portion from the transporting member and separating a plurality of recording materials into one sheet, and feeding by the feeding means. In a feeding device having a detecting means for detecting the transmitted recording material and a measuring means for measuring the time from a predetermined timing until the detecting means detects the recording material, the feeding means detects the recording material. A reference time for determining the possibility of an abnormal state occurring at the time of feeding is obtained from a plurality of time data measured by the measuring means, and each time the feeding means feeds a predetermined number of recording materials. It is characterized by having an acquisition means for updating the reference time and a determination means for determining the possibility of the abnormal state occurring based on the reference time and the plurality of time data.

Further, the feeding device of the present invention for achieving the above object is provided by an accommodating means for accommodating the recording material, a feeding member for feeding the recording material accommodated in the accommodating means, and the feeding member. A feeding means including a transporting member that transports the fed recording material, a separating member that forms a separation nip portion from the transporting member and separates a plurality of recording materials into one, and the feeding means. Measured by the measuring means in a feeding device having a detecting means for detecting the recording material fed by the measuring means and a measuring means for measuring the time from a predetermined timing until the detecting means detects the recording material. The plurality of time data are divided into two groups according to the length of time, and the reference time for determining the possibility of an abnormal state when the feeding means feeds the recording material is set to the above 2. The abnormal state may occur based on the acquisition means obtained from the plurality of time data included in the selected group among the three groups, the reference time, and the plurality of time data included in the selected group. It is characterized by having a judgment means for judging.

Further, in the feeding device of the present invention for achieving the above object, the feeding device for accommodating the recording material, the feeding member for feeding the recording material accommodated in the accommodating means, and the feeding member are used. A feeding means including a transporting member that transports the fed recording material, a separating member that forms a separation nip portion from the transporting member and separates a plurality of recording materials into one, and the feeding means. A detection means for detecting the recording material fed by, a driving means for driving the feeding means, and a measurement for measuring the driving amount by the driving means from a predetermined timing until the detecting means detects the recording material. A plurality of drive amount data measured by the measuring means as a reference amount for determining the possibility that an abnormal state occurs when the feeding means feeds the recording material in the feeding device having the means. The abnormal state occurs based on the acquisition means for updating the reference amount, the reference amount, and the plurality of drive amount data each time the feeding means feeds a predetermined number of recording materials. It is characterized by having a determination means for determining the possibility of doing so.

Further, in the feeding device of the present invention for achieving the above object, the feeding device for accommodating the recording material, the feeding member for feeding the recording material accommodated in the accommodating means, and the feeding member are used. A feeding means including a transporting member that transports the fed recording material, a separating member that forms a separation nip portion from the transporting member and separates a plurality of recording materials into one, and the feeding means. A detecting means for detecting the recording material conveyed by the measuring means, a driving means for driving the feeding means, and a measuring means for measuring the driving amount by the driving means from a predetermined timing until the detecting means detects the recording material. In a feeding device having a The reference amount for determining the possibility of occurrence of the state is included in the acquisition means obtained from the plurality of drive amount data included in the selected group among the two groups, the reference amount and the selected group. It is characterized by having a determination means for determining the possibility that the abnormal state occurs based on the plurality of drive amount data.

According to the present invention, it is possible to accurately determine the possibility that an abnormal state may occur when the feeding means feeds the recording material.

Cross-sectional view of the image forming apparatus in Examples 1 and 2. Sectional drawing of the paper feed mechanism in Examples 1 and 2. Graph showing the relationship between the number of paper feeds and the paper feed time in Examples 1 and 2. Graph showing frequency distribution of paper feed time in Example 1 Graph showing the influence of the remaining amount of the cassette in the first embodiment on the paper feeding time A graph showing the relationship between the number of sheets to be fed and the feeding time for explaining the method of calculating the slip index value in the first embodiment. A graph showing the relationship between the number of sheets to be fed and the slip index value in the first embodiment. Flow chart for determining the possibility of slip in Example 1 Graph showing frequency distribution of paper feed time in Example 2 A graph showing the relationship between the number of sheets to be fed and the feeding time for explaining the method of calculating the double feed index value in the second embodiment. A graph showing the relationship between the number of sheets to be fed and the double feed index value in the second embodiment. Flow chart for determining the possibility of double feeding in the second embodiment

[Example 1]
In this embodiment, a method for determining the possibility of the recording material slipping during the paper feeding operation will be described.

[Explanation of image forming apparatus]
An electrophotographic printer PR (image forming apparatus) will be described as an example of a feeding device to which this embodiment can be applied. FIG. 1 is a schematic configuration diagram of a printer PR.

The printer PR is a tandem type color laser beam printer so that a color image can be output by superimposing four color toners of yellow (Y), magenta (M), cyan (C), and black (K). It is configured. In the following description, particularly for members that do not need to distinguish between yellow, magenta, cyan, and black, the subscripts Y, M, C, and K of the reference numerals are omitted for convenience of description.

Each process cartridge 5 has a toner container 6. Further, it has a photosensitive drum 1 which is an image carrier. Further, it has a charging roller 2, a developing roller 3, a drum cleaning blade 4, and a waste toner container 7.

The charging roller 2 applies a predetermined negative electrode voltage to the photosensitive drum 1 to charge the surface of the photosensitive drum 1 to a predetermined negative electrode potential. A laser unit 8 is arranged below the process cartridge 5 to expose the photosensitive drum 1 based on an image signal. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 1. The developing roller 3 develops an electrostatic latent image by applying a predetermined negative electrode voltage to the photosensitive drum 1 and further supplying the toner contained in the toner container 6 to the photosensitive drum 1. As a result, toner images of Y, M, C, and K are formed on the surface of the photosensitive drum 1, respectively. The toner used in this embodiment is negatively charged.

The intermediate transfer body unit is composed of an intermediate transfer body 11, a drive roller 12, a tension roller 13, and an opposing roller 15. Further, the primary transfer roller 10 is arranged inside the intermediate transfer body 11 facing the photosensitive drum 1, and the transfer voltage is applied by a voltage applying means (not shown). The toner image formed on the photosensitive drum 1 is formed on the intermediate transfer body 11 by rotating each photosensitive drum 1 and the intermediate transfer body 11 in the direction of the arrow and further applying a positive voltage to the primary transfer roller 10. Primary transfer to. The toner image on the photosensitive drum 1 is primarily transferred onto the intermediate transfer body 11 in the order of Y, M, C, and K, and is conveyed to the secondary transfer roller 14 in a state where the toner images of four colors are overlapped. The toner remaining on the photosensitive drum 1 after the primary transfer is scraped off by the cleaning blade 4 and stored in the waste toner container 7.

The paper feeding mechanism 20 has a paper feeding roller 22 (feeding member) that feeds the recording material S from the accommodating cassette 21 accommodating the recording material S to the transport path 40. Further, the paper feeding mechanism 20 has a transport roller 23 (conveying member) for transporting the fed recording material S and a separation roller 24 (separation member) for separating and transporting a plurality of recording materials S into one sheet. .. The accommodating cassette 21 is removable from the apparatus main body 50 (printer housing) so that the user can replenish or replace the recording material S. Then, the recording material S conveyed from the paper feed mechanism 20 is conveyed to the secondary transfer roller 14 by the registration roller pair 25. A positive voltage is applied to the secondary transfer roller 14 in order to transfer the toner image from the intermediate transfer body 11 to the recording material S. As a result, the toner image on the intermediate transfer body 11 is secondarily transferred to the conveyed recording material S. The recording material S on which the toner image is transferred is conveyed to the fixing device 30, heated and pressurized by the fixing film 31 and the pressure roller 32, and the toner image is fixed on the surface. The recording material S on which the toner image is fixed is discharged to the outside of the apparatus main body 50 of the printer PR by the discharge roller pair 33.

The control unit 100 includes an MPU (not shown) provided with a CPU 70 and the like, a RAM (not shown) used for data calculation and temporary storage necessary for controlling the printer PR, a program for controlling the printer PR, and the like. A ROM (not shown) for storing various data is installed. A transport path sensor 27 is provided in the transport path 40 to detect the transported recording material S. When the transport path sensor 27 detects the recording material S, a signal notifying that fact is output to the control unit 100. The control unit 100 controls the entire electrophotographic process, and further determines whether or not a transport abnormality such as early arrival / delay or jam of the recording material S has occurred based on the signal notified from the transport path sensor 27. .. When the control unit 100 determines that a transfer abnormality has occurred, the control unit 100 causes the operation display unit 80 (operation panel) to display a message or an image for notifying the user that the transfer abnormality has occurred. Further, the control unit 100 causes the operation display unit 80 to display a message or an image indicating means for eliminating the transport abnormality, if necessary.

[Explanation of paper feed mechanism]
Next, the paper feed mechanism 20 in this embodiment will be described in detail with reference to FIG. FIG. 2 is a schematic cross-sectional view showing the paper feeding operation in this embodiment.

FIG. 2A is a cross-sectional view of the paper feeding mechanism 20 at the timing of feeding the recording material S1 located at the highest position among the plurality of recording materials S housed in the storage cassette 21. The recording material S1 in the accommodating cassette 21 is positioned by the rear end restricting plate 26 in the accommodating cassette 21, and when the recording material S1 is fed, the tip of the recording material S1 is at the set position Ps in FIG. 2A. Here, the tip of the recording material S1 is the downstream end of the recording material S1 in the paper feeding direction (feeding direction), and the rear end of the recording material S1 is the upstream end of the recording material S1 in the paper feeding direction. Is. When the pick start signal that triggers the paper feed operation is output and the paper feed operation is started, the paper feed roller 22 and the transfer roller 23 rotate in the directions of the arrows in FIG. 2 (a), respectively, and the recording material S1 feeds paper. Due to the frictional force generated between the rollers 22 and the rollers 22, the paper is fed to the right in FIG. 2A.

After that, the recording material S1 reaches the separation nip portion Pn formed by the transfer roller 23 and the separation roller 24. At this time, as shown in FIG. 2B, a frictional force is generated between the recording materials S1 and S2, and the recording material S2 may also move. Hereinafter, this phenomenon is referred to as a take-out phenomenon. When two or more recording materials S are sent to the separation nip portion Pn due to the take-out phenomenon, the transport roller 23 and the separation roller 24 separate the plurality of recording materials S into one and separate the recording materials S. It has a function of sending only the recording material S downstream. A torque limiter (not shown) is connected to the separation roller 24, and torque as a resistance force is applied in a direction opposite to the transport direction of the recording material S1. This torque is set so that when there is only one recording material S in the separation nip portion Pn, the separation roller 24 is driven by the transport roller 23 to rotate, and stops when two or more recording materials S enter the separation nip portion Pn. ing. Therefore, a plurality of recording materials S can be separated into one by the separation nip portion Pn and transported downstream.

After that, when the paper feed roller 22 and the transfer roller 23 continue to rotate, the recording material S1 passes through the registration roller pair 25, and the tip of the recording material S1 is detected by the transfer path sensor 27 as shown in FIG. 2 (c). Reach the position Pr to be. The elapsed time from the output of the pick start signal that triggers the paper feeding operation to the arrival of the recording material S1 at the transport path sensor 27 is defined as the paper feeding time. This paper feed time is measured by the CPU 70 included in the control unit 100 described with reference to FIG.

FIG. 3 is a graph showing the transition of the paper feed time with respect to the number of paper feeds monitored from the start of use of the printer PR. While continuing to use the printer PR, the roller friction coefficient changes slightly due to variations in the physical characteristics of the media used from time to time (surface properties, basis weight, rigidity, etc.) and differences in the temperature and humidity of the usage environment. Therefore, the paper feed time fluctuates irregularly. For example, it can be confirmed that the type of the recording material S changes at the timing D in FIG. 3 and the tendency of the paper feed time changes (change from the recording material E to another type of recording material F). The paper feed reference time Ts and the paper feed reference time Tm will be described in detail later.

Generally, when feeding is started from the state where the tip of the recording material S is located at the separation nip portion Pn, the feeding time is shortened, and from the state where the tip of the recording material S is located at the set position Ps. It will be longer when feeding is started. Due to such basic characteristics, irregular fluctuations in the paper feed time within a predetermined range do not directly lead to a paper feed failure. Data that suddenly deviates outward from the data distribution (paper feed time data that fluctuates beyond a predetermined range) can lead to paper feed defects. Therefore, the defect risk is evaluated by statistically calculating the reference value of the paper feed time suitable for the state at that time and observing the difference tendency from the data that suddenly deviates.

[Explanation of calculation method of reference value]
Next, a method of calculating the reference value of the paper feed time will be described. The paper feed time varies greatly depending on various factors such as the paper feed port on which the recording material S is fed, the paper type, the environment, the durability of the main body, and the paper setting method by the user. Therefore, when calculating the reference value, it is necessary to use necessary and sufficient set data that can stabilize the paper feed time and ensure statistical reliability. It is desirable to utilize the latest data in order to eliminate endurance factors, and to utilize the data excluding the places where the amount of fluctuation is large. Further, the information possessed by the main body (for example, a paper type sensor, a temperature / humidity sensor, a cassette opening / closing history, a paper remaining amount sensor, etc.) may be utilized to exclude data in sections where usage conditions have changed.

FIG. 4 is a graph showing the frequency distribution of the latest 500 sheets of paper feed time data. In this embodiment, the 500 sheets of paper feed time data are treated as one set data A0, and a reference value is calculated. That is, one reference value data is calculated (updated) every 500 sheets from the start of use of the printer PR. Here, since the paper feed time may change depending on the remaining amount of the recording material S stored in the storage cassette 21, the recording stored in the storage cassette 21 in advance for the set data A0. Correction processing may be performed according to the remaining amount of the material S. Hereinafter, the reason for this and a specific correction method will be described.

When the remaining amount of the recording material S stored in the storage cassette 21 becomes low, a gap is created between the recording material S located at the highest position and the paper feed roller 22, and the middle plate is raised to fill this gap. There is a need. The method of raising and lowering the middle plate is a rotary type (a method of rotating the middle plate to lift up the recording material S) and a linear motion type (a method of moving the middle plate in the vertical direction to lift up the recording material S). It has been known. Of these, if the rotary type configuration is adopted, the feeding time may be affected by rotating the middle plate.

In the rotary configuration, there are two major factors that change the paper feed time. The first factor is that the set position Ps (described in FIG. 2) of the recording material S located at the highest position changes as the middle plate is rotated. Due to the deviation of the set position Ps, the time until the recording material S arrives at the transport path sensor 27 also changes. The second factor is that the posture (tilt) of the recording material S located at the highest position changes as the middle plate is rotated. When the posture of the recording material S changes, the angle at which the recording material S enters the transport path 40 changes, so that the route through which the recording material S passes from the separation nip portion Pn to the detection position Pr changes. At the time of full loading, the recording material S is conveyed so that the tip of the recording material S is along the outside of the transport path 40 (right side in FIG. 2). On the other hand, at the time of small loading, the recording material S is conveyed so that the tip of the recording material S is along the inside of the transport path 40 (left side in FIG. 2). Considering the above factors, the paper feed time tends to be shorter when the load is small than when the load is full. This situation is shown in FIG.

The printer PR is provided with a mechanism for detecting the remaining amount of the recording material S stored in the storage cassette 21. Specifically, the printer PR is provided with a paper surface sensor (not shown) for detecting the paper surface of the recording material S housed in the storage cassette 21, and the lift-up time until the paper surface sensor detects the recording material S or The remaining amount can be detected by measuring the lift-up drive amount. After lift-up, the CPU 70 can detect the remaining amount by counting the number of sheets to be fed. In this embodiment, the paper feed time is corrected according to the detected remaining amount. For example, when the battery is full, the correction process is not performed, and when the remaining amount is 20% to 40%, the correction time α is measured, and when the remaining amount is 0% to 20%, the correction time β (α <β). Is added to the measured paper feed time.

As described above, in acquiring the set data A0, it is desirable to utilize the data excluding the part having a large fluctuation amount, but in order to acquire a sufficient number of samples, the data of the part having a large fluctuation amount is used. If necessary, the set data A0 is corrected in advance. For example, as described with reference to FIG. 3, when the type of the recording material S accommodated in the accommodating cassette 21 is changed from the recording material E to the recording material F, the paper feeding time is slowed down as a whole. In consideration of this effect, when the data when the recording material E is fed and the data when the recording material F is fed are mixed in the 500 sheets of paper feed data, there is a large difference between the two data. Perform correction processing so that there is no difference. Specifically, processing such as adding a correction time γ to the data when the recording material E is fed, or subtracting the correction time γ from the data when the recording material F is fed is performed.

In this embodiment, it is determined that slip may occur when the recording material S is fed by the paper feeding mechanism 20. Slip means that when the paper feed roller 22 feeds the recording material S, the frictional force does not work well and slip occurs, and the timing of moving the recording material S is delayed or the recording material S is moved. Refers to the state that could not be done. In this embodiment, the paper feed time when the paper feed is started from the state where the tip of the recording material S1 is at the set position Ps in FIG. 2 is defined as the paper feed reference time Ts (reference value). Then, data indicating a time longer than this reference value is extracted and analyzed.

In the frequency distribution of FIG. 4, the paper feed reference time Ts is the value of the upper x% of the aggregate data A0 excluding some data that is suddenly delayed. In this embodiment, after confirming the distribution tendency of the paper feed reference time Ts under various conditions, x = 5%, which is the ratio at which the paper feed reference time Ts can be stably obtained under all conditions, is set. Set. It is known from experiments that x% is within 10% at the maximum (within a range of several% to 10%).

[Explanation of calculation method of slip index value and judgment method of possibility of slip]
Next, a method for calculating a slip indicator value H _S with the reference value will be described with reference to FIG. FIG. 6 is a graph showing the relationship between the number of sheets to be fed and the feeding time of the aggregated data A0. In addition, in order to make the graph easier to see, not all the data for 500 sheets are plotted here. The white circle data on the graph is data (delay data) indicating a time longer than the paper feed reference time Ts. When the paper feed mechanism 20 starts to slip due to the durability transition, the surface condition of the recording material S, or the like, the degree of delay of the white circle data on the graph becomes large. In view of this tendency, the average value of the absolute value of the difference to the open circle data from the paper feeding reference time Ts and slip indicator value H _S. That is, the slip indicator value H _S can be determined by the following equation.

This time, as the method for quantifying the index value, the absolute value of the difference is averaged, but other parameters such as the sum of the absolute values of the simple difference or the root mean square may be used. The slip index value H _S is one calculated every 500 sheets of paper feed time data (the aggregate data A0). Incidentally, the slip index value _{H S} is acquired by CPU70 included in the control unit 100.

Next, a method of determining the possibility of slipping will be described with reference to FIG. 7. Figure 7 is obtained by the results of calculating the slip index value H _S from the start of use of the printer PR every 500 sheets in the graph. With increasing number of fed sheets, it can be seen that the slip index value H _S is gradually increased. In this embodiment, two threshold values H _SA and H _SB are prepared, and the possibility of slip occurring by the control unit 100 is determined as follows.

_{H S} ≦ H _SA: less likely slip occurs _{H SA <H S ≦ H SB} : potential slip occurs normally _{H SB} <H _S: threshold likely slip occurs depending on the application, Not limited to two, three or more may be prepared. The control unit 100 may notify the user or the administrator who performs the maintenance management service of the printer PR of the obtained determination result. When notifying, the control unit 100 determines in real time which state the paper feed mechanism 20 is in, and notifies the user or the administrator each time. As the number of paper feeds increases, the paper feed roller 22 wears, and the frequency of notification that there is a high possibility of slipping increases.

FIG. 8 is a flowchart for determining the possibility of slip occurring in this embodiment. The control based on FIG. 8 is executed by the CPU 70 based on a program stored in a ROM (not shown) or the like mounted on the control unit 100. The CPU 70 executes this control every time it acquires 500 sheets of paper feed time data (aggregate data A0).

First, the CPU 70 acquires the paper feed reference time Ts, which is the upper x% value of the aggregate data A0 (S10). Then, CPU 70 is based on the formula described above, obtaining the slip index value _{H S} (S11). CPU 70 compares the threshold value _{H SA} set in advance and slip indicator value _{H S} (S12), if the slip index value _{H S} is the threshold _{H SA} less, CPU 70 was feeding the recording material S by the paper feed mechanism 20 In this case, it is determined that the possibility of slipping is low (S14). If the slip indicator value _{H S} is larger than the threshold _{H SA,} CPU 70 then compares the slip index value _{H S} with a preset threshold _{H SB (H SA <H SB} ) (S13). If the slip index value H _S is smaller than or equal to the threshold H _SB, CPU 70 will slip determined that can occur is common when feeding the recording material S by the paper feed mechanism 20 (S15). If the slip indicator value _{H S} is larger than the threshold _{H SB,} CPU 70 will slip is determined to likely occur when feeding the recording material S by the paper feed mechanism 20 (S16). When it is determined that the possibility of slipping is high, the CPU 70 determines that the life of the paper feed roller 22 included in the paper feed mechanism 20 is short, and prompts the user or the administrator to replace the paper feed roller 22 through the operation display unit 80 or the like (S17). ). This completes the control of this flowchart.

From the above, according to the present embodiment, it is possible to accurately determine the possibility of slipping when the feeding means feeds the recording material.

[Example 2]
In this embodiment, a method for determining the possibility that the recording material may be double-fed during the paper feeding operation will be described. The description of the main part is the same as that of the first embodiment, and here, only the part different from the first embodiment will be described.

[Explanation of calculation method of reference value]
In this embodiment, it is determined that double feeding may occur when the recording material S is fed by the feeding mechanism 20. In the double feed, during the paper feeding operation of the recording material S1, the recording material S2 placed under the recording material S1 is taken out by the frictional force generated between the recording material S1 and the recording material S1 and overlaps with the recording material S1. In this state, the tip of the recording material S2 exceeds the separation nip portion Pn. In this embodiment, the paper feed time when the paper feed is started from the state where the tip of the recording material S1 is at the separation nip portion Pn in FIG. 2 is defined as the paper feed reference time Tm (reference value). Then, data indicating a time shorter than this reference value is extracted and analyzed.

A method of calculating the paper feed reference time Tm will be described with reference to FIG. FIG. 9 is a graph showing the frequency distribution of the same paper feed time data as in FIG. Here, as in the first embodiment, the paper feed time may change depending on the remaining amount of the recording material S stored in the storage cassette 21, so that the storage cassette for the aggregate data A0 is obtained in advance. Correction processing may be performed according to the remaining amount of the recording material S housed in 21.

Looking at the frequency distribution in FIG. 9, it can be seen that the paper feed time data can be roughly divided into two groups. Considering the configuration of the paper feed mechanism 20, there is a high probability that the tip position of the recording material S housed in the storage cassette 21 exists at the set position Ps or the separation nip portion Pn. When the tip of the recording material S is at the set position Ps, the distance from the tip of the recording material S to the transport path sensor 27 is longer than that when the tip of the recording material S is at the separation nip portion Pn. Therefore, the group having the shorter time length (subset A1) corresponds to the paper feed time data in the state where the tip of the recording material S1 is in the separation nip portion Pn. The group (subset A2) having a longer time length corresponds to the paper feed time data in a state where the tip of the recording material S1 is in the separation nip portion Pn.

In this embodiment, the data separation algorithm is applied to the set data A0, and only the constituent data of the subset A1 is taken out. In this example, the separation process is performed using a Gaussian mixture model. The Gaussian mixed model is a model that approximates data by superimposing a plurality of Gaussian distributions (normal distributions). In addition, other clustering methods such as the k-means method may be used. Due to the characteristics of the paper feed mechanism 20, the extracted subset A1 has a peak distribution at the paper feed time corresponding to the state where the tip of the recording material S is at the separation nip portion Pn where the taken-out subsequent paper is blocked. Appears. Since it is necessary to determine the possibility of double feeding from the paper feed time data of the recording material S that was not blocked by the separation nip portion Pn, the paper feed time (highest frequency) of the distribution peak of the subset A1. The paper feed time) was set to the paper feed reference time Tm. Although the paper feed reference time Tm is set as the distribution peak of the subset data A1 this time, it may be the average value or the median value of the paper feed time data included in the subset A1.

[Explanation of how to calculate the double feed index value and how to determine the possibility of double feed]
Next, a method of calculating the double feed index value H _m by using the reference value will be described with reference to FIG. 10. FIG. 10 is a graph showing the relationship between the number of sheets to be fed and the feeding time of the aggregated data A0. In addition, in order to make the graph easier to see, not all the data for 500 sheets are plotted here. The white circle data on the graph is data (early arrival data) indicating a time shorter than the paper feed reference time Tm. When the tendency of double feeding by the paper feed mechanism 20 begins to appear due to the transition of durability, the state of the surface of the recording material, and the like, the frequency of cases in which the succeeding paper cannot be completely blocked by the separation nip portion Pn increases. Therefore, the number of white circle data on the graph increases, and the difference from the paper feed reference time Tm also increases. In view of this tendency, the root mean square of the difference from the paper feed reference time Tm to the white circle data is defined as the double feed index value H _m . That is, the double feed index value H _m is calculated by the following formula.

This time, the root mean square was used as the method for quantifying the index value, but other parameters such as the simple sum of the absolute values of the differences or the average value of the absolute values of the differences may be used. This double feed index value _Hm is calculated once for every 500 sheets of paper feed time data (aggregate data A0). Incidentally, the double feed index value _{H m} are acquired by CPU70 included in the control unit 100.

Next, a method of determining the possibility of double feeding will be described with reference to FIG. 11 is obtained by the results of calculating the double feed index value H _m from the start of use of the printer PR every 500 sheets in the graph. Two threshold H _mA in this _example, providing a H _mB, double feed by the control unit 100 as follows to determine the possibility of occurrence.

_{H m} ≦ H _mA: double feed H _mA is less likely to occur _{<H m} ≦ _{H mB:} Weight possibility transmission occurs is usually _{H mB} <H _m: threshold are likely to overlap feed occurs Depending on the application, not only two but three or more may be prepared. The control unit 100 may notify the user or the administrator who performs the maintenance management service of the printer PR of the obtained determination result. Unlike the slip index value H _s in Example 1, the double feed index value H _m does not deteriorate as the durability progresses, as shown in FIG. The double feed index value H _m largely depends on the surface property (friction coefficient) of the recording material S, and this surface property is of course different depending on the type of the recording material S, and even if the same paper type is used, a lot of paper or the like. It is known that the inter-book section is also different. By mainly notifying the dealer of such information, the dealer can provide a higher quality service, such as introducing the recording material S of a different paper type to the user who is using the printer PR in an environment where it is easy to carry over. Will be able to provide.

FIG. 12 is a flowchart for determining the possibility of double feeding in this embodiment. The control based on FIG. 12 is executed by the CPU 70 based on a program stored in a ROM (not shown) or the like mounted on the control unit 100. The CPU 70 executes this control every time it acquires 500 sheets of paper feed time data (aggregate data A0).

First, the CPU 70 divides the set data A0 into two groups (subsets A1 and A2) (S20). The CPU 70 selects the group (subset A1) having the shorter time from the two groups (S21). Then, the CPU 70 obtains the paper feed reference time Tm from the paper feed time data included in the group having the shorter time (S22). Then, CPU 70 is based on the formula described above, obtaining the double feed index value _{H m} (S23). The CPU 70 compares the double feed index value H _m with the preset threshold value H _mA (S24), and if the double feed index value H _m is equal to or less than the threshold value H _mA , the CPU 70 supplies the recording material S by the paper feed mechanism 20. It is determined that the possibility of double feeding in the case of paper is low (S26). When the double feed index value H _m is larger than the threshold value H _mA , the CPU 70 then _{compares the double feed index value H m} with the preset threshold value H _m (H _mA <H _mB ) (S25). If the double feed index value H _m is equal to or less than the threshold value H _mB , the CPU 70 determines that it is normal for the double feed to occur when the recording material S is fed by the paper feed mechanism 20 (S27). When the double feed index value H _m is larger than the threshold value H _mB , the CPU 70 determines that there is a high possibility that double feed will occur when the recording material S is fed by the paper feed mechanism 20 (S28). This completes the control of this flowchart. As described above, the double feed index value H _m does not deteriorate as the durability progresses. Therefore, when it is determined in this embodiment that the double feed is likely to occur, the CPU 70 notifies the end of the life of the roller. I don't do it.

From the above, according to the present embodiment, it is possible to accurately determine the possibility of double feeding when the feeding means feeds the recording material.

[Modification example]
In Example 1 above, the possibility of slipping and the possibility of double feeding were determined respectively, but both the possibility of slipping and the possibility of double feeding were determined. It may be configured to notify the user and the dealer collectively.

Further, in the first embodiment, the paper feed reference time Ts is extracted as the upper x% value of the aggregate data A0, but the present invention is not limited to this. Similar to the second embodiment, the set data A0 may be divided into two groups (subsets A1 and A2), and the group A2 having the longer time may be selected to acquire the paper feed reference time Ts. Specifically, similarly to the method described in the second embodiment, the paper feed time (the paper feed time having the highest frequency) of the distribution peak of the group A2 may be set as the paper feed reference time Ts, and is included in the group A2. The average value or the median value of the paper feed time data may be used as the paper feed reference time Ts.

Further, in the second embodiment, the paper feed reference time Tm is extracted from the paper feed time data included in the group A1, but the present invention is not limited to this. Similar to the first embodiment, the paper feed reference time Tm may be acquired as the lower y% value of the aggregate data A0. It is necessary to set a value smaller than x% for y%, and it is preferable to set a value of 1% to 2% according to experiments.

Further, in the first and second embodiments described above, the paper feed roller 22 starts counting the paper feed time from the timing when the paper feed roller 22 starts paper feed, but the present invention is not limited to this. For example, a new sensor may be arranged at a position different from the transport path sensor 27, and the counting of the paper feed time may be started from the timing when the recording material S is detected by the new sensor. Alternatively, the counting of the paper feed time may be started from the timing when the recording material S is detected by the transport path sensor 27, and the counting of the paper feed time may be finished at the timing when the recording material S is detected by the new sensor.

Further, in Examples 1 and 2 described above, it has been determined that an abnormal state may occur when the paper feed mechanism 20 feeds the recording material S, but the present invention is applied to a place other than the paper feed mechanism 20. You may. For example, by monitoring the paper feed time between arbitrary two points on the transport path 40 located on the downstream side of the paper feed mechanism 20, the transport load fluctuation that may occur when the recording material S passes through this section. It is possible to determine the possibility of sudden slip caused by.

Further, in Examples 1 and 2 described above, the paper feed time is adopted as the processing data for determining the possibility that an abnormal state may occur, but the paper feed time is not limited to this. For example, the drive amount by the motor (actuator) that drives the paper feed roller 22 or the transfer roller 23 may be adopted as the processing data. As the reference amount, instead of the paper feed reference time Ts and the paper feed reference time Tm, the reference drive amount data is obtained, and the absolute sum of the differences and the like are obtained in the same manner as in the methods described in Examples 1 and 2. And compare with the threshold. If the drive amount is adopted as the processing data, it is possible to cope with a case where the recording material S is fed by the paper feed roller 22 and then the transfer speed of the recording material S is switched and controlled.

20 Paper feed mechanism 21 Storage cassette 22 Paper feed roller 23 Transport roller 24 Separation roller 27 Transport path sensor 100 Control unit PR printer

Claims (18)

A storage means for accommodating recording materials,
A plurality of sheets are formed by forming a feeding member for feeding the recording material housed in the housing means, a transport member for transporting the recording material fed by the feeding member, and a separation nip portion from the transport member. A feeding means including a separating member for separating the recording material into one sheet, and
A detection means for detecting the recording material fed by the feeding means, and
In a feeding device having a measuring means for measuring the time from a predetermined timing until the detecting means detects a recording material.
A reference time for determining the possibility that an abnormal state may occur when the feeding means feeds the recording material is obtained from a plurality of time data measured by the measuring means, and the feeding means obtains a predetermined number of sheets. The acquisition means for updating the reference time each time the recording material of the above is sent, and
A feeding device comprising: a determination means for determining the possibility of occurrence of the abnormal state based on the reference time and the plurality of time data. A storage means for accommodating recording materials,
A plurality of sheets are formed by forming a feeding member for feeding the recording material housed in the housing means, a transport member for transporting the recording material fed by the feeding member, and a separation nip portion from the transport member. A feeding means including a separating member for separating the recording material into one sheet, and
A detection means for detecting the recording material fed by the feeding means, and
In a feeding device having a measuring means for measuring the time from a predetermined timing until the detecting means detects a recording material.
A plurality of time data measured by the measuring means are divided into two groups according to the length of time, and it is for determining the possibility that an abnormal state occurs when the feeding means feeds the recording material. An acquisition means for obtaining a reference time from the plurality of time data included in the selected group among the two groups, and
A feeding device comprising: a determination means for determining the possibility of occurrence of the abnormal state based on the reference time and the plurality of time data included in the selected group. The accommodating means includes a regulating plate that regulates the rear end of the recording material in the feeding direction of the recording material.
The reference time obtained by the acquisition means is obtained by the measuring means when the recording material is fed from the state where the rear end of the recording material is positioned on the regulation plate and the recording material is housed in the accommodating means. The feeding device according to claim 2, wherein the feeding device corresponds to the measured time. Claim 2 or 3 is characterized in that the reference time is the time having the highest frequency among the plurality of time data included in the group having the longer time length among the two groups. Feeding device described in. The second or third aspect of the present invention, wherein the reference time is the average value or the median value of the plurality of time data included in the group having the longer time length among the two groups. Feeding device. The determination means determines the possibility that the abnormal state may occur based on the reference time and the time data longer than the reference time from the plurality of time data included in the selected group. The feeding device according to any one of claims 2 to 5, wherein the feeding device is characterized. The determination means obtains the absolute value of the difference between the reference time and the time data longer than the reference time, and determines that the larger the sum of the absolute values of the differences, the higher the possibility that the abnormal state will occur. The feeding device according to claim 6, wherein the feeding device is characterized by the above. The feeding device according to any one of claims 2 to 7, wherein the abnormal state is a state in which the recording material is delayed due to slipping. The reference time determined by the acquisition means is the time measured by the measuring means when the recording material is fed from the state where the tip of the recording material is in the separation nip portion in the feeding direction of the recording material. The feeding device according to claim 2, wherein the feeding device corresponds to the same. The claim is characterized in that the reference time is the time having the highest frequency among the frequency distributions of the plurality of time data included in the group having the shorter time length among the two groups. The feeding device according to 2 or 9. The second or ninth aspect of the present invention, wherein the reference time is the average value or the median value of the plurality of time data included in the group having the shorter time length among the two groups. Feeding device. The determination means determines the possibility that the abnormal state may occur based on the reference time and the time data shorter than the reference time from the plurality of time data included in the selected group. The feeding device according to any one of claims 2 or 9 to 11, wherein the feeding device is characterized. The determination means obtains the absolute value of the difference between the reference time and the time data shorter than the reference time, and determines that the larger the sum of the absolute values of the differences, the higher the possibility that the abnormal state will occur. 12. The feeding device according to claim 12. The feeding device according to any one of claims 2 or 9 to 13, wherein the abnormal state is a state in which a plurality of recording materials are not separated into one in the separation nip portion. .. The feeding device according to any one of claims 2 to 14, wherein the acquiring means updates the reference time each time the feeding means feeds a predetermined number of recording materials. .. The feeding device according to any one of claims 2 to 14, wherein the predetermined timing is a timing at which the feeding member starts feeding the recording material. A storage means for accommodating recording materials,
A plurality of sheets are formed by forming a feeding member for feeding the recording material housed in the housing means, a transport member for transporting the recording material fed by the feeding member, and a separation nip portion from the transport member. A feeding means including a separating member for separating the recording material into one sheet, and
A detection means for detecting the recording material fed by the feeding means, and
The driving means for driving the feeding means and
In a feeding device having a measuring means for measuring a driving amount by the driving means from a predetermined timing until the detecting means detects a recording material.
A reference amount for determining the possibility of an abnormal state occurring when the feeding means feeds the recording material is obtained from a plurality of drive amount data measured by the measuring means, and the feeding means is predetermined. An acquisition means for updating the reference amount each time the number of recording materials is sent, and
A feeding device comprising: a determination means for determining the possibility of occurrence of the abnormal state based on the reference amount and the plurality of drive amount data. A storage means for accommodating recording materials,
A plurality of sheets are formed by forming a feeding member for feeding the recording material housed in the housing means, a transport member for transporting the recording material fed by the feeding member, and a separation nip portion from the transport member. A feeding means including a separating member for separating the recording material into one sheet, and
A detection means for detecting the recording material conveyed by the feeding means, and
The driving means for driving the feeding means and
In a feeding device having a measuring means for measuring a driving amount by the driving means from a predetermined timing until the detecting means detects a recording material.
A plurality of drive amount data measured by the measuring means are divided into two groups according to the magnitude of the drive amount, and it is determined that an abnormal state may occur when the feeding means feeds the recording material. A reference amount for obtaining a reference amount for the above two groups from the plurality of drive amount data included in the selected group, and an acquisition means.
A feeding device comprising: a determination means for determining the possibility of occurrence of the abnormal state based on the reference amount and the plurality of drive amount data included in the selected group.

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