JP7354638B2 - Paper feeding device - Google Patents

Description

The present invention relates to a paper feeding device.

2. Description of the Related Art Paper feeding devices that supply paper (recording medium) to image forming apparatuses such as copying machines and printers are conventionally known. This type of paper feeding device includes, for example, an air-type paper feeding device (hereinafter referred to as "air feeding device") equipped with a paper storage section, a suction conveyance section, a floating air blowing section, a separation air blowing section, an exit roller section, etc. ) is known.

In the air feeding device, a floating air blower blows air onto an end surface of a sheet of paper in a sheet stack housed in a paper storage unit, thereby floating the paper from the paper stack. The floating paper is attracted to the suction conveyance section, and is sent out in the conveyance direction by the suction conveyance section. Then, the paper fed to the image forming apparatus is separated from the paper remaining in the paper storage section by the separation air blower.

In such an air feeding device, air is blown from the end surface of the paper between the sheets stacked in the paper storage unit, so that the paper behaves in a certain way, such as flapping. Generally, about 5 or 6 sheets of paper, including the paper that is fed and the paper that remains in the paper storage unit, flaps around, but depending on the strength of the air, the number of sheets of paper that flaps fluctuates, and paper conveyance failures (jams) can occur. This may occur.

For example, if the air is too weak, the number of sheets of paper that fluctuates will be about one or two, and the paper will not reach the sending part of the suction conveyance section by the timing of starting paper feeding, resulting in an unfeeding jam. In addition, if the air is too strong, the number of sheets of paper that flaps will be around 10, and the paper being fed will not be separated from the paper remaining in the paper storage unit, resulting in the need to feed multiple sheets of paper, resulting in overlapping sheets. A feed jam occurs.

For example, Patent Document 1 discloses a configuration in which the sound of air blown onto paper is detected, and when it is determined that the frequency of the detected sound exceeds a threshold value, it is determined that there is a separation failure. Thereby, this configuration reduces the occurrence of the above-mentioned double feed jam.

Japanese Patent Application Publication No. 2018-83699

By the way, depending on the type, basis weight, and size of the paper, the amount of air flutters differently even with the same amount of air, so it is necessary to change the amount of air so that the paper flaps appropriately depending on the type, basis weight, and size of the paper.

However, there are factors other than the paper type, basis weight, and size that change the way the paper flaps, such as the moisture absorption level of the paper, the brand, and how the user arranges the paper in the paper storage unit. Therefore, even if the amount of air is changed according to the type, basis weight, and size of the paper, there is a risk that the paper may not flap properly, resulting in a problem that jams may occur.

Further, since the degree of flapping of paper cannot be determined based on the air sound frequency, the above problem cannot be solved with the configuration described in Patent Document 1. Similarly, since the degree of flapping of paper cannot be determined based on sound volume, ultrasonic waves, etc., the above problem cannot be solved even with a configuration in which air is adjusted using, for example, sound volume or ultrasonic waves.

An object of the present invention is to provide a paper feeding device that can determine the state of a recording medium.

The paper feeding device according to the present invention includes:
a storage unit that stores a plurality of recording media;
a paper feeding section that feeds the recording medium accommodated in the accommodation section toward an external device;
an air generation unit that generates air toward the recording medium for the paper feeding operation by the paper feeding unit;
a determining unit that determines a state of the recording medium based on a peak point extracted from a frequency characteristic of a sound signal generated from the recording medium by the air generated by the air generating unit;
a control unit that controls the paper feeding operation according to a determination result of the determination unit;
Equipped with
The determination unit starts determining the state after a predetermined time has elapsed since the air generation unit started operating .

According to the present invention, the state of a recording medium can be determined.

1 is a diagram showing the overall configuration of an image forming system in an embodiment of the present invention. FIG. 3 is a diagram showing the main parts of the control system of the paper feeding device in the present embodiment. FIG. 3 is a diagram illustrating how sheets of paper are floated up by floating air from a stack of paper sheets. FIG. 3 is a diagram showing changes in frequency characteristics of a sound signal. FIG. 5 is a diagram showing the relationship between the sound signal and frequency that are peak points in FIG. 4; FIG. 3 is a diagram showing a table that associates frequencies with target ranges. FIG. 3 is a diagram illustrating how sheets of paper are floated up by floating air from a stack of paper sheets. FIG. 3 is a diagram illustrating how sheets of paper are floated up by floating air from a stack of paper sheets. FIG. 7 is a diagram showing the relationship between the sound signal at the peak point and the frequency when there is a frequency characteristic outside the target range. FIG. 7 is a diagram showing the relationship between the sound signal at the peak point and the frequency when there is a frequency characteristic outside the target range. FIG. 6 is a diagram showing the relationship between the frequency and the sound signal that reaches a peak point before a predetermined time has elapsed after the start of air generation. FIG. 6 is a diagram showing the relationship between the frequency and the sound signal that reaches a peak point before a predetermined time has elapsed after the start of air generation. FIG. 3 is a diagram showing a state in which eigencomponents have been extracted. FIG. 3 is a diagram showing a table that associates frequencies and eigencomponents. 7 is a flowchart illustrating an example of an operation when executing air adjustment control in a paper feeding device. 7 is a flowchart illustrating an example of an operation when executing air adjustment control in a paper feeding device. 7 is a flowchart illustrating an example of an operation when executing air adjustment control in a paper feeding device. FIG. 7 is a diagram showing the relationship between the sound signal at the peak point and the frequency when the number of sheets remaining is very small. FIG. 3 is a diagram showing an example of a display prompting the user to adjust the air. 7 is a flowchart illustrating an example of an operation when executing air adjustment control in a paper feeding device. It is a figure which shows the example of a display of the button for air adjustment. FIG. 7 is a diagram illustrating a display example of tray selection buttons. FIG. 7 is a diagram illustrating an example of a display for notifying a user that air adjustment is in progress. FIG. 6 is a diagram showing an example of a display for notifying a user of the adjusted air amount. FIG. 7 is a diagram illustrating an example of a display for prompting a user to reload sheets. FIG. 2 is a diagram showing the relationship between a sound signal containing a noise component and having a peak point and frequency.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a diagram showing the overall configuration of an image forming system 1 according to an embodiment of the present invention. As shown in FIG. 1, the image forming system 1 includes an external large-capacity paper feeder 10 (hereinafter referred to as "paper feeder 10") connected to the side of the image forming apparatus 20 (on the right side in FIG. 1). It has the following configuration.

The paper feeding device 10 includes internally three stages of paper feeding units 10A to 10C, and feeds sheets of paper to the image forming apparatus 20 one by one. Paper corresponds to the "recording medium" of the present invention.

As shown in FIG. 2, the paper feeding device 10 includes a control section 100 having a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and the like.

The control unit 100 cooperates with the control unit 28 of the image forming apparatus 20 to centrally control the operation of each block of the paper feeding device 10. Specifically, the control section 100 controls the paper storage section 11, the suction conveyance section 12, the floating air blowing section 13, and the separation air blowing section 13 in each of the paper feeding units 10A to 10C based on control signals from the image forming apparatus 20. The operations of the blower section 14 and the exit roller section 15 are controlled. Details of the paper feed units 10A to 10C will be described later.

The image forming apparatus 20 is an intermediate transfer type color image forming apparatus using electrophotographic process technology. The image forming apparatus 20 is a vertical type in which photosensitive drums corresponding to four colors of CMYK are arranged in series in the running direction (vertical direction) of an intermediate transfer belt, and toner images of each color are sequentially transferred to the intermediate transfer belt in one step. A tandem system is used. That is, the image forming device 20 transfers (primary transfer) the toner images of each color of Y (yellow), M (magenta), C (cyan), and K (black) formed on the photosensitive drum to the intermediate transfer belt, An image is formed by superimposing toner images of four colors on an intermediate transfer belt and then transferring them to paper (secondary transfer).

The image forming apparatus 20 includes an image reading section 21 , an operation display section 22 , an image processing section 23 , an image forming section 24 , a fixing section 25 , a paper feeding section 26 , a paper transport section 27 , and a control section 28 .

The control unit 28 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU reads a program according to the processing content from the ROM, loads it into the RAM, and centrally controls the operation of each block of the image forming apparatus 20 in cooperation with the loaded program. Further, the control unit 28 cooperates with the control unit 100 of the paper feeding device 10 to control the operation of the paper feeding device 10.

The image reading unit 21 includes an automatic document feeder (ADF), a document image scanning device (scanner), and the like. In the image reading section 21, a document conveyed onto the contact glass from the automatic document feeder or a document placed on the contact glass is read by the document image scanning device, and input image data is generated.

The operation display section 22 is configured of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display section and an operation section.

The image processing unit 23 performs various correction processes such as gradation correction, color correction, and shading correction, and digital image processing such as compression processing on input image data according to initial settings or user settings. The image forming section 24 is controlled based on the image data subjected to these processes.

The image forming unit 24 forms an image using colored toners of Y component, M component, C component, and K component based on the image data. The image forming section 24 includes a photosensitive drum, a charging device, an exposure device, a developing device, and an intermediate transfer device.

In the image forming section 24, the surface of the photoreceptor drum is uniformly charged by a charging device. An exposure device irradiates the charged photoreceptor drum with laser light based on image data, thereby forming an electrostatic latent image on the surface of the photoreceptor drum. The developing device supplies toner to the photoreceptor drum on which the electrostatic latent image has been formed, thereby making the electrostatic latent image visible and forming a toner image. This toner image is transferred onto paper by an intermediate transfer device having an intermediate transfer belt or the like.

The fixing section 25 includes an upper fixing section having a fixing surface side member disposed on the fixing surface side of the paper (the surface on which the toner image is formed), and an upper fixing section disposed on the back surface of the paper (the surface opposite to the fixing surface). It includes a lower fixing section having a back side support member, a heat source, and the like. By pressing the back side support member against the fixing side member, a fixing nip is formed in which the paper is held and conveyed. The fixing unit 25 fixes the toner image onto the paper by heating and pressurizing the paper onto which the toner image has been secondarily transferred and being conveyed using a fixing nip.

The paper feed section 26 has a plurality of (three stages in FIG. 1) paper feed trays. The paper feed tray accommodates sheets of paper (standard paper, special paper) that are identified based on basis weight, size (length, width), etc., for each preset type.

The paper transport section 27 transports the paper fed from the paper feed section 26 or the paper feed device 10 to the image forming section 24 . When the paper passes through the secondary transfer section of the image forming section 24, the toner image on the intermediate transfer belt is secondarily transferred to one side (front surface) of the paper all at once, and is subjected to a fixing process in the fixing section 25. Ru. The paper on which the image has been formed is discharged to the outside of the machine by a paper discharge roller. When forming images on both sides of a sheet of paper, the sheet with the image formed on the front side is conveyed to the back side conveyance path, and then conveyed to the image forming section 24 in an inverted state.

Next, paper feed units 10A to 10C will be explained. In the following, the "paper conveyance direction" is a direction from right to left in FIGS. 1 and 3.

As shown in FIG. 1, each of the paper feeding units 10A to 10C includes a paper storage section 11, a suction conveyance section 12, a floating air blowing section 13, a separating air blowing section 14, an exit roller section 15, a guide section 16, and a sound collecting section 12. 17 and the like. Paper feeding units 10A to 10C basically have the same configuration. In the following description, the paper feed unit 10A will be explained as a representative, and the explanation of the paper feed units 10B and 10C will be omitted.

The paper storage unit 11 can accommodate a large amount of paper, and includes a paper mounting table 111 and the like. Each of the paper storage units 11 can be pulled out from the paper feeder 10 by guide rails (not shown). The paper storage section 11 corresponds to the "accommodation section" of the present invention.

The paper loading table 111 is movable up and down so that the upper end surface (the uppermost sheet) of the stack of sheets SS placed thereon is always at a constant position. The paper mounting table 111 is lowered to the lowest position when replenishing paper. The elevating and lowering operations of the paper mounting table 111 are controlled by the control unit 100.

The suction conveyance unit 12 is arranged above the paper mounting table 111, and a plurality of suction conveyance units 12 are arranged in parallel in the width direction of the paper. Each of the plurality of suction conveyance sections 12 includes an endless conveyance belt 121, an air suction section 122, and the like. The suction conveyance section 12 corresponds to the "paper feeding section" of the present invention.

The conveyor belt 121 has a large number of suction holes over its entire surface, and the suction holes suck the paper and send the paper in the paper conveyance direction. The conveyance belt 121 is wound around a roller 123 provided upstream of the air suction section 122 in the paper conveyance direction and a roller 124 provided downstream of the air suction section 122 in the paper conveyance direction. The surface on which the paper is conveyed by the conveyor belt 121 is a horizontal plane.

The plurality of rollers 123 are provided corresponding to the plurality of conveyor belts 121 and are attached to a common roller shaft. The roller shaft is connected to a drive motor 18 (see FIG. 2) via a power transmission mechanism (not shown). As the control unit 100 drives the drive motor 18, the plurality of rollers 123 rotate and the plurality of conveyance belts 121 run in a fixed direction.

The plurality of rollers 124 are provided corresponding to the plurality of conveyor belts 121 and are attached to a common roller shaft. The roller 124 rotates as the conveyor belt 121 runs.

The air suction section 122 extends toward the back of the apparatus through the plurality of conveyor belts 121, and includes a suction duct (not shown) and a suction fan (not shown). When the suction fan operates, the inside of the suction duct becomes negative pressure, and the paper is sucked onto the conveyor belt 121 through the suction hole and is attracted thereto. The operation of the suction fan is controlled by the control unit 100.

The floating air blower 13 has a blower fan and an air guide path (not shown). The floating air blower 13 is disposed, for example, inside a side edge regulating member that regulates the side edges of the sheet stack SS in the paper storage section 11. The air blowing fan is configured to control the air volume based on, for example, the length of the paper, the paper quality, the basis weight, etc., so that it can blow air at an optimal air volume. The operation of the blower fan is controlled by the control unit 100.

In the floating air blowing section 13, when the blowing fan is operated, floating air is blown upward, and is blown to the top of the sheet stack SS from both sides in the sheet width direction. As a result, the top several sheets of the sheet stack SS float up.

The separation air blower 14 has a blower fan and an air guide path. The separation air blowing section 14 is arranged so as to be able to blow air at an end downstream of the suction conveyance section 12 in the sheet conveyance direction. The air blowing fan can control the air volume based on, for example, the paper size (length, width), paper quality, basis weight, etc., so that it can blow air at an optimal air volume. The operation of the blower fan is controlled by the control unit 100.

The separation air blowing unit 14 may include a wind direction switching plate (not shown), and may be capable of switching the blowing direction of air between the vicinity of the front end of the suction conveyance unit 12 and the vicinity of the front end of the sheet stack SS. In this case, the separation air blower 14 blows floating air near the front end of the sheet stack SS when the floating air blower 13 blows the floating air, and the floating air blower 13 stops blowing the floating air. Then, separation air is blown near the front end of the suction conveyance section 12. In other words, the separation air blower 14 also functions as a floating air blower.

In the separation air blowing section 14, when the blowing fan operates, air is blown to the vicinity of the front end of the sheet stack SS or the vicinity of the front end of the suction conveyance section 12 through the ventilation opening of the air guide path. By blowing floating air near the front end of the paper stack SS, the top few sheets of the paper stack SS can be efficiently floated. Also, by blowing separation air near the front end of the suction conveyance unit 12, the second and subsequent sheets are separated from the plurality of sheets of paper attracted to the conveyance belt 121, and only the first sheet is transferred to the conveyance belt 121. 121 and can be transported.

When feeding paper, the control unit 100 switches from floating air in the floating air blower 13 and separation air blower 14 to separation air in the separation air blower 14. By doing so, the paper to be fed and the paper to remain in the paper storage section 11 are separated.

The exit roller section 15 includes an upper conveyance roller 151 (see FIG. 1) and a lower conveyance roller 152 (see FIG. 1) that comes into contact with the upper conveyance roller 151. The upper conveyance roller 151 is a driving roller, and the lower conveyance roller 152 is a driven roller. The exit roller section 15 pinches the paper conveyed by the suction conveyance section 12 between an upper conveyance roller 151 and a lower conveyance roller 152, and sends it out downstream in the paper conveyance direction.

The guide section 16 is disposed upstream of the output roller section 15 in the paper conveyance direction, and guides the paper conveyed by the suction conveyance section 12 to the exit roller section 15 .

The sound collection unit 17 is a member such as a microphone that can collect sounds. The sound collecting section 17 collects the flapping sound of the paper S when air is generated in the floating air blowing section 13 . The floating air blower 13 corresponds to the "air generator" of the present invention.

Generally, as shown in FIG. 3, when one sheet S is conveyed from the paper feeder 10 toward the image forming apparatus 20, about five or six sheets S are floated by the floating air blower 13. and adsorbs it to the suction conveyance section 12. Then, among the sheets S attracted to the suction conveyance section 12, one sheet S to be fed is separated from the other sheets S remaining in the paper storage section 11 by the separation air blowing section 14. Ru.

In other words, when one sheet of paper S is fed by the paper feeding device 10, about 5 or 6 sheets of paper, including the fed paper and the paper remaining in the paper storage section, flap around. There is.

The sound collection unit 17 collects the sounds generated from these sheets S. The sound generated from the paper S includes a flapping sound when the paper is floated by the floating air blower 13.

The control unit 100 performs frequency analysis on the sound signal (hereinafter referred to as “sound signal”) collected by the sound collection unit 17. As a frequency analysis result of a sound signal, for example, as shown in FIG. 4, a frequency characteristic (sound pattern) of a sound signal having a plurality of peak points (formants) at a specific frequency is obtained. The sound signal may be, for example, data averaged over a sound collection period in the sound collection section 17.

Each peak point is the apex of a portion where the frequency characteristics of the sound signal are increasing. In the example shown in FIG. 3, the peak points are the points where the sound signals are P1, P2, and P3 at frequencies F1, F2, and F3.

The control unit 100 determines the flapping state of the paper based on the frequency characteristics of the flapping sound. Specifically, as shown in FIG. 5, the control unit 100 extracts a peak point from the frequency characteristics and sets the portion other than the peak point to 0. Then, the control unit 100 compares the target range set for each frequency with the corresponding sound signal, and determines whether the sound signal is within each target range. The control section 100 corresponds to the "determination section" of the present invention.

The target range is set to be a different range for each frequency. For example, in the example shown in FIG. 5, when the frequency is F1, the target range is set to the range of R1, when the frequency is F2, the range of R2 is set, and when the frequency is F3, the target range is set to the range of R3. Note that for frequencies other than F1, F2, and F3, the target range is set to a value of 0, for example.

In the following description, it is assumed that the frequency characteristics shown in FIG. 5 are those when the flapping state of the paper S is normal.

The target range of the sound signal is set, for example, in a storage unit (not shown) in advance as a table in which each frequency is associated with another (see, for example, FIG. 6). The control unit 100 refers to this table and determines whether the sound signal at each peak point is within the target range set at the corresponding frequency.

When the control unit 100 determines that all of the sound signals are within the target range, the control unit 100 determines that the fluttering state of the paper S is normal. In this case, about 5 or 6 sheets of paper are fluttering due to the air.

Furthermore, if the sound signal includes a portion that is not within the target range, the control unit 100 does not determine that all of the sound signals are within the target range.

Depending on the strength of the air in the floating air blowing section 13, the air suction section 122, and the separation air blowing section 14, the number of fluttering sheets S may vary, resulting in paper conveyance failure (jam).

For example, as shown in FIG. 7A, if the air is too weak, the number of flapping sheets of paper S will be about 1 or 2, and the paper will not reach the feeding part of the suction conveyance unit by the timing of starting paper feeding, resulting in unused sheets. A paper jam occurs.

Furthermore, as shown in FIG. 7B, if the air is too strong, the number of flapping sheets of paper S will be about 10, and the fed paper and the paper remaining in the paper storage section will not be separated completely, resulting in multiple sheets of paper S fluttering. paper will be fed, and a double feed jam will occur.

As described above, in a situation where sheet conveyance failure is likely to occur, a portion of the sound signal that falls outside the target range will occur. As an example of a situation in which paper conveyance failure is likely to occur, for example, if the peak point occurs at frequencies other than F1, F2, and F3 (see FIG. 8A), the sound signal of at least one of F1, F2, and F3 For example, there is a case where the value is outside the target range (see FIG. 8B).

In this way, if there is a sound signal that is outside the target range among the sound signals, the control unit 100 does not determine that all of the sound signals are within the target range. In other words, the control unit 100 determines that the flapping state of the paper is a state in which conveyance failure is likely to occur.

The control unit 100 controls the paper feeding operation according to the determination result of the flapping state of the paper. Specifically, when the control unit 100 determines that the fluttering state of the paper is normal, it starts feeding the paper. Further, if the control unit 100 determines that the flapping state of the paper is such that a conveyance failure is likely to occur, the control unit 100 does not start feeding the paper, and performs control so that the flapping state of the paper becomes normal.

The control for normalizing the flapping state of the paper is the control for keeping the frequency characteristics as a whole within the target range. Examples of control for normalizing the flapping state of paper include control for adjusting the amount of air.

Then, the control unit 100 performs control so that the flapping state of the paper becomes normal, collects sound again by the sound collection unit 17, and repeats the above control, so that the flapping state of the paper becomes normal. If so, start feeding paper.

In this manner, in this embodiment, since paper feeding is started when the flapping state of the paper is normal, it is possible to suppress occurrence of paper conveyance failure.

In addition, the flapping state of the paper may not be stable for a predetermined period of time (for example, 40 msec to 80 msec) after air generation starts in the floating air blower 13, the air suction unit 122, and the separation air blower 14 (for example, in Fig. 9A and FIG. 9B). FIG. 9A shows the frequency characteristics immediately after the start of air generation, and FIG. 9B shows the frequency characteristics when 40 msec has elapsed after the start of air generation.

This is because when the air generation starts, the paper S is placed on the paper stack SS, so for a predetermined period of time from the start, the sound of the paper S flapping is constant and continuous. This is due to the fact that the sound is different from the actual sound.

Therefore, the control unit 100 starts determining the flapping state after a predetermined period of time has elapsed since the floating air blower 13, the air suction unit 122, and the separation air blower 14 started operating. By doing this, it is possible to reduce the need to judge the flapping state of the paper based on the frequency characteristics of the flapping sound when the flapping state of the paper is not stable, thereby improving the accuracy of determining the flapping state of the paper. can be done.

In addition, when a paper conveyance failure occurs, the control unit 100 extracts the difference between the frequency characteristic (sound signal) at the time when the paper conveyance failure occurs and the target range as an inherent component at the time of the conveyance failure. Good (see Figure 10A). Further, the control unit 100 may store these eigencomponents for each frequency in a storage unit or the like as a table (for example, see FIG. 10B).

In the examples shown in FIGS. 10A and 10B, the eigencomponents are extracted when peak points P4 and P5 occur at F4 and F5, which are different from F1, F2, and F3 in the example shown in FIG. 8A. be. In this case, as the eigencomponent, since the target range is 0 at F4 and F5, the difference between them, P4 and P5, is written in the table in association with F4 and F5.

By extracting the unique component in this way, it is possible to accurately grasp the type of conveyance failure based on the unique component, and in turn, it is possible to perform appropriate air adjustment.

Further, the control unit 100 may store the above-mentioned unique components in the storage unit for each type of transport defect.

Thereby, the type of conveyance defect can be appropriately determined based on the unique component.

Note that the state of the paper S may be determined using only the above-mentioned unique components.

Further, if the frequency characteristics do not fall within the target range after starting the air adjustment, the control unit 100 may set the air to have the frequency characteristics closest to the target range.

If the frequency characteristics do not fall within the target range even after air adjustment has started, air adjustment will be repeated endlessly. Therefore, the above situation can be avoided by setting the air to have the frequency characteristic closest to the target range.

In addition, if the frequency characteristics do not fall within the target range after starting the air adjustment, and if there are frequency characteristics related to the above-mentioned eigencomponents in the frequency characteristics, the control unit 100 determines that the eigencomponents are the most It is also possible to set the air to have a decreasing frequency characteristic.

By doing so, it is possible to set the air to have frequency characteristics that are less likely to cause conveyance defects.

In addition, if a paper conveyance failure occurs even if the frequency characteristics are within the target range, the control unit 100 may increase the amount of air that exceeds the target range, or output a notification command to prompt the replacement of parts. Also good.

Next, an example of the operation when executing air adjustment control in the paper feeding device 10 will be described. FIG. 11 is a flowchart illustrating an example of an operation when executing air adjustment control in the paper feeding device 10. The process in FIG. 11 is executed as appropriate when the image forming apparatus 20 receives a print job and the control unit 100 receives a paper feeding command.

As shown in FIG. 11, the control unit 100 starts air operation by the floating air blower 13, the air suction unit 122, and the separation air blower 14 (step S101). The control unit 100 determines whether a predetermined time has elapsed after the start of air operation (step S102).

As a result of the determination, if the predetermined time has not elapsed (step S102, NO), the process of step S102 is repeated. On the other hand, if the predetermined time has elapsed (step S102, YES), the control unit 100 starts collecting sound by the sound collection unit 17 (step S103).

The control unit 100 extracts a frequency that becomes a peak point from the frequency characteristics of the sound signal collected by the sound collection unit 17 (step S104). Next, the control unit 100 determines whether the frequency characteristics are within the target range (step S105).

As a result of the determination, if the frequency characteristics are not within the target range (step S105, NO), the control unit 100 adjusts the air (step S106). After the air is adjusted, the process returns to step S102.

On the other hand, if the frequency characteristics are within the target range (step S105, YES), the control unit 100 starts feeding the paper (step S107). After that, this control ends.

According to the present embodiment configured as described above, since the flapping state is determined based on the frequency characteristics of the paper flapping sound, it is possible to determine the flapping state of the paper. As a result, stable paper feeding can be performed regardless of the material, thickness, size, type, or environmental conditions of the paper.

Further, since the above control is performed during the paper feeding operation in the paper feeding device 10, appropriate control can be performed in real time.

In addition, since the air adjustment control is started after a predetermined period of time has elapsed from the start of air generation, it is possible to suppress the collection of flapping noise in unstable situations, which in turn improves the accuracy of air adjustment. can.

Note that in the above embodiment, when the flapping state of the paper is such that a conveyance failure is likely to occur, control is performed so that the flapping state of the paper becomes normal, but the present invention is not limited to this. For example, the control unit 100 may control the paper to be in a non-feeding state depending on the air generation time. Specifically, the control unit 100 prohibits switching from flotation air to separation air when the paper is placed in a non-feeding state.

In the case where the flapping state of the paper is such that conveyance failure is likely to occur, in the above embodiment, air adjustment is repeated in order to normalize the flapping state of the paper. However, if the paper is not fluttering properly with the air adjustment, the air adjustment will be repeated endlessly. Set the paper to non-feeding state. Then, the control unit 100 puts the paper in a non-feeding state and switches the paper feeding target to another paper feeding unit.

By doing so, it is possible to suppress endlessly repeating air adjustment in the same paper feeding unit. Further, it is possible to reduce the situation where the recording medium cannot be fed to the image forming apparatus 20. Furthermore, it is possible to prevent paper conveyance failures caused by the frequency characteristics not falling within the target range.

Further, the control unit 100 may output a notification command to notify the user that the recording medium is in a state where conveyance failure is likely to occur after the recording medium is placed in a non-feeding state.

By doing so, the user can quickly understand that the paper feeding unit to which paper is to be fed is in a situation where conveyance failure is likely to occur.

Next, an example of the operation when executing air adjustment control in this paper feeding device 10 will be described. FIG. 12 is a flowchart illustrating an example of an operation when executing air adjustment control in the paper feeding device 10. The process in FIG. 12 is executed as appropriate when the image forming apparatus 20 receives a print job and the control unit 100 receives a paper feeding command.

As shown in FIG. 12, the control unit 100 starts air operation by the floating air blower 13, the air suction unit 122, and the separation air blower 14 (step S201). The control unit 100 determines whether a predetermined time has elapsed after the start of air operation (step S202).

As a result of the determination, if the predetermined time has not elapsed (step S202, NO), the process of step S202 is repeated. On the other hand, if the predetermined time has elapsed (step S202, YES), the control unit 100 starts collecting sound by the sound collection unit 17 (step S203).

The control unit 100 extracts a frequency that becomes a peak point from the frequency characteristics of the sound signal collected by the sound collection unit 17 (step S204). Next, the control unit 100 determines whether the frequency characteristics are within the target range (step S205).

As a result of the determination, if the frequency characteristics are not within the target range (step S205, NO), the control unit 100 determines whether the air generation time exceeds a certain time (step S206).

As a result of the determination, if the generation time does not exceed the certain time (step S206, NO), the control unit 100 adjusts the air (step S207). After the air is adjusted, the process returns to step S202.

On the other hand, if the occurrence time exceeds the certain time (step S206, YES), the control unit 100 puts the paper in a non-feeding state (step S208).

Returning to the determination in step S205, if the frequency characteristic is within the target range (step S205, YES), the control unit 100 starts feeding the paper (step S209). After step S208 or step S209, this control ends.

Further, in the above embodiment, the sound generated from the paper S is the sound of the paper flapping due to air from the floating air blower 13, but the present invention is not limited to this. For example, the sound generated by the paper S when the paper S is sucked by the air suction unit 122 or the sound when the paper S is separated by the separation air blower 14 may be used as the sound generated from the paper S. In this case, the air generating section is the air suction section 122 and the separation air blowing section 14. Further, the state of the paper S is in a paper suction state when the air generation section is the air suction section 122, and in a paper separation state when the air generation section is the separation air blowing section 14.

Further, the sound generated from the paper S may be the sound generated from the paper by all the air from the floating air blower 13, the air suction unit 122, and the separation air blower 14.

By doing this, paper feeding can be started after confirming that all air-generated sounds from the paper are normal.

Next, an example of the operation when executing air adjustment control in this paper feeding device 10 will be described. FIG. 13 is a flowchart illustrating an example of an operation when executing air adjustment control in the paper feeder 10. The process in FIG. 13 is executed as appropriate when the image forming apparatus 20 receives a print job and the control unit 100 receives a paper feeding command.

As shown in FIG. 13, the control unit 100 performs air adjustment processing in the floating air blowing unit 13 (step S301). The air adjustment process is, for example, the process of steps S101 to S106 in FIG. 11.

Next, the control unit 100 performs air adjustment processing for the air suction unit 122 (step S302). The air adjustment process is, for example, the process of steps S102 to S106 in FIG. 11.

Next, the control unit 100 performs air adjustment processing for the separation air blower 14 (step S303). The air adjustment process is, for example, the process of steps S102 to S106 in FIG. 11.

Next, the control unit 100 starts feeding paper (step S304). After that, this control ends.

Further, in the embodiment described above, the target range of the frequency characteristics of the sound signal is set for each frequency. However, if the number of sheets remaining in the paper stack SS in the paper feed unit is small, the number of sheets floating by floating air will decrease even if the paper is operating normally, so the frequency characteristics of the sound signal will not fall within the target range. There are cases.

For example, as shown in FIG. 14, when there is only a small number of sheets of paper left, the number of sheets of paper flapping due to the floating air is smaller than usual, and the peak points of the sound signal in the frequency characteristics at that time are at frequencies F1 and F2. , Suppose that the occurrence occurs at F6 other than F3.

In this case, the control unit 100 corrects the target range depending on the state of the paper. In the case of FIG. 14, the control unit 100 corrects the target range of F6 to the range of 0 to R6 according to the number of sheets.

By doing this, even if the frequency characteristics deviate from the target range due to the condition of the paper, the target range is corrected to an appropriate range according to the condition of the paper, making it possible to accurately determine the state of paper flapping. .

Furthermore, since there may be common characteristics depending on the type of paper (size, basis weight, brand, etc.), the control unit 100 may correct the target range depending on the type of paper.

Further, the control unit 100 may store a target range depending on the state of the paper or the type of paper in a storage unit or the like.

By doing so, an appropriate target range can be read out from the storage section according to the conditions, so that the state of paper flapping can be accurately determined.

Further, in the embodiment described above, the air is adjusted during the paper feeding operation in the paper feeding device 10, but the present invention is not limited to this. For example, the air in the paper feeding device 10 may be adjusted before the paper feeding operation in the paper feeding device 10 begins.

For example, when the image forming apparatus 20 first feeds paper, before the paper feeding operation or after the image forming apparatus 20 prints a certain number of sheets, the control unit 100 performs "air adjustment" as shown in FIG. Do you want to adjust the air?'' is displayed on the display unit, etc., prompting the user to adjust the air. The display unit may be provided in the image forming apparatus 20 or the paper feeding apparatus 10, for example.

If the user selects "YES", the control unit 100 adjusts the air; if the user selects "NO", the control unit 100 does not adjust the air.

When the control unit 100 adjusts the air, the control unit 100 stores the adjusted amount of air in the storage unit. As a result, the paper feeding operation is performed using the adjusted amount of air, so that the paper feeding operation can be performed accurately.

Next, an example of the operation when executing air adjustment control in this paper feeding device 10 will be described. FIG. 16 is a flowchart illustrating an example of an operation when performing air control in the paper feeder 10. The process in FIG. 16 is executed as appropriate when the user selects "YES" in FIG. 15.

As shown in FIG. 16, the control unit 100 adjusts the floating air in the floating air blower 13 (step S401). When the adjustment of the floating air is completed, the control unit 100 stores the amount of floating air in the storage unit (step S402).

Next, the control unit 100 adjusts the separation air in the separation air blower 14 (step S403). When the separation air adjustment is completed, the control unit 100 stores the amount of separation air in the storage unit (step S404). After that, this control ends.

Further, a button for air adjustment may be provided on the display section or the like, for example, as shown in FIG. 17A. When the user presses this button, a button for selecting a paper feeding unit is displayed on the display section, as shown in FIG. 17B. "Tray 1" in FIG. 17B indicates the paper feeding unit 10A, "Tray 2" indicates the paper feeding unit 10B, and "Tray 3" indicates the paper feeding unit 10C.

When the user presses any button, as shown in FIG. 17C, the display section displays "Air adjustment in progress", and during this time air adjustment is performed in the paper feed unit selected by the user.

When air adjustment is performed and the air amount is appropriately set, the set amounts of the floating air amount and separation air amount are displayed on the display unit, as shown in FIG. 17D.

If air adjustment is performed and the air amount cannot be set appropriately, as shown in FIG. 17E, a message prompting the user to reload the sheets is displayed on the display unit. Further, in this case, a display may be displayed that prompts adjustment of the regulation plate on the paper mounting table 111.

Further, the frequency characteristics may fluctuate due to a user's erroneous operation, such as a mistake in adjusting the regulating plate on the paper mounting table 111 as described above. Therefore, if the control unit 100 determines that the sound pattern includes a sound related to the user's erroneous operation based on the data acquired in advance, the control unit 100 causes the display unit to output a notification command to notify the user of information related to the erroneous operation. You can also do it.

By doing so, the user can notice that he or she has made an erroneous operation, and by correcting the erroneous operation, the paper feeding device 10 can perform a normal paper feeding operation.

In addition to the sound of paper flapping in the air, the paper feeding device 10 generates sounds such as the driving sound of the paper mounting table 111 of the paper feeding unit, the solenoid, and the motor. When the sound collection unit 17 collects these sounds, they may be generated as noise components. For example, in the example shown in FIG. 18, a peak point where the sound signal becomes P6 occurs at a frequency F7.

In such a case, the control unit 100 determines the frequency characteristics by removing the driving sound of devices other than the air supply unit, such as the floating air blower unit 13. In the case of the example shown in FIG. 18, the control unit 100 determines the frequency characteristics by removing the portion with the frequency F7.

By doing so, it is possible to accurately determine frequency characteristics without being influenced by noise components.

Further, the noise component can be a frequency characteristic based on a sound signal measured in advance. This noise component is stored in a storage unit or the like, and the control unit 100 performs the above-mentioned removal by reading it out.

Further, as the device is used, the driving sound of the device fluctuates due to changes over time. Along with this, the magnitude of the above-mentioned noise component also changes. Therefore, the control unit 100 may change the amount of noise (driving sound) removed in accordance with changes in the device over time.

Thereby, it is possible to reduce the possibility that a noise component that should be removed as a noise component is not completely removed or a sound signal that should originally be detected is removed as a noise component due to fluctuations in the drive sound due to changes over time.

Further, in the above embodiment, a preset target range is used for comparison with the frequency characteristics, but the present invention is not limited to this. For example, the control unit 100 may set the target range according to the incidence of sheet conveyance failure.

For example, even if the preset target range is based on the description in FIG. 5, when actually repeating the paper feeding operation, even if the frequency characteristics are based on the description in FIG. There may be cases where the value is extremely low.

In such a case, the control unit 100 sets the frequency characteristics based on the description in FIG. 8A as the target range, thereby setting the frequency characteristics at a setting where the incidence of paper conveyance defects in actual paper feeding operation is low as the target range. can be determined. As a result, the target range can be set to an appropriate range according to the latest state of the paper feeding device 10.

Further, the control unit 100 may set a common target range according to the occurrence rate of conveyance defects for each of the plurality of types of paper.

By doing this, it is possible to compare the occurrence rates of conveyance defects for multiple types of paper and set a common target range of frequency characteristics at a setting that lowers the overall occurrence rate of conveyance defects. . As a result, there is no need to change the target range for each type of paper, and control can be simplified.

Further, the air may be adjusted by learning the frequency characteristics of the flapping sound and the transition of the incidence of conveyance defects through machine learning or the like.

Further, in the embodiment described above, the air is adjusted in the paper feeding unit that is the paper feeding target, but the present invention is not limited to this. For example, the control unit 100 may determine the state of the paper using a paper feeding unit other than the paper feeding unit that is the paper feeding target.

By doing this, the paper feed unit that is the target paper feed unit will not adjust the air, but will concentrate on feeding paper using the set amount of air, and will adjust the air in parallel for the other paper feed units. be able to. As a result, it is possible to appropriately adjust the amount of air for paper feeding units that are not targeted for paper feeding while suppressing a decrease in productivity due to air adjustment.

Furthermore, if there is a sound signal whose frequency characteristics are determined to be outside the target range from the paper feed unit to be fed, the control unit 100 may determine whether to switch to another paper feed unit. . In this case, if the air adjustment in the other paper feed unit has not been completed, or if the type of paper stored in the other paper feed unit is different from the paper type in the paper feed unit to be fed, The control unit 100 determines not to switch to another paper feeding unit.

Also, the air adjustment in another paper feed unit has been completed, and the type of paper stored in the other paper feed unit is the same as the type of paper in the paper feed unit to be fed. In this case, the control unit 100 determines to switch to another paper feeding unit.

By doing so, it is possible to appropriately select a paper feeding unit that is less likely to cause paper conveyance defects and feed the paper, thereby reducing paper conveyance defects caused by the generation of air.

Further, in the above embodiment, control is performed to normalize the flapping state of the paper by adjusting the air, but the present invention is not limited to this, and the position of the paper mounting table 111 is adjusted. By doing so, control may be performed so that the flapping state of the paper becomes normal. In this case, the motor or the like that adjusts the position of the paper mounting table 111 is driven. Further, the driving target may be a dehumidifying heater, a dehumidifying fan, or the like.

Further, in the above embodiment, there is no mention that the paper feeding device 10 communicates with an external device other than the image forming device 20, but the paper feeding device 10 communicates with a PC (Personal Computer), a remote server, etc. You may also communicate.

By doing so, it becomes possible to display the images shown in FIG. 15, FIG. 17A, etc. using, for example, the display section of a PC. Also, by communicating with a remote server, it is possible to provide information regarding similar paper feeders and sound patterns at other locations.

Further, in the above embodiment, the air adjustment control is performed after a predetermined period of time has elapsed since the start of the air operation, but the present invention is not limited to this. Air adjustment control may be started before time elapses (for example, in the state shown in FIG. 9B).

Further, in the embodiment described above, the sound collecting section 17 is provided within the paper storage section 11, but the present invention is not limited thereto, and may be provided at a location other than the paper storage section 11. However, in consideration of the accuracy of collecting the sound generated from the paper, it is preferable to provide it near a location where air is generated, such as inside the paper storage section 11.

Further, in the above embodiment, the state of the paper is determined by extracting the peak point in the frequency characteristic and setting the portion other than the peak point to 0, but the present invention is not limited to this, and the portion other than the peak point does not have to be 0.

Further, in the embodiment described above, the control section 100 also serves as the determination section, but the present invention is not limited to this, and the control section and the determination section may be provided separately.

Further, in the above embodiment, the paper feeding device 10 is provided outside the image forming apparatus 20, but the present invention is not limited to this, and the paper feeding device may be provided inside the image forming apparatus. .

In addition, the above-mentioned embodiments are merely examples of implementation of the present invention, and the technical scope of the present invention should not be construed as limited by these. That is, the present invention can be implemented in various forms without departing from its gist or main features.

1 Image forming system 10 Paper feeding device 10A Paper feeding unit 10B Paper feeding unit 10C Paper feeding unit 11 Paper storage section 12 Adsorption conveyance section 13 Floating air blowing section 14 Separation air blowing section 15 Exit roller section 16 Guide section 17 Sound collecting section 18 Drive motor 20 Image forming device 21 Image reading section 22 Operation display section 23 Image processing section 24 Image forming section 25 Fixing section 26 Paper feeding section 27 Paper transport section 28 Control section 100 Control section 111 Paper mounting table 121 Transport belt 122 Air suction section 123 Roller 124 Roller

Claims (19)

a storage unit that stores a plurality of recording media;
a paper feeding section that feeds the recording medium accommodated in the accommodation section toward an external device;
an air generation unit that generates air toward the recording medium for the paper feeding operation by the paper feeding unit;
a determining unit that determines a state of the recording medium based on a peak point extracted from a frequency characteristic of a sound signal generated from the recording medium by the air generated by the air generating unit;
a control unit that controls the paper feeding operation according to a determination result of the determination unit;
Equipped with
The determination unit starts determining the state after a predetermined time has elapsed since the air generation unit started operating.
Paper feed device. The determination unit extracts the peak point of a portion where the frequency characteristic increases as the frequency increases, sets the portion other than the peak point to 0, and determines the state of the recording medium.
A paper feeding device according to claim 1 . The determination unit determines whether the peak point is within each target range set for each frequency corresponding to the peak point .
A paper feeding device according to claim 1 or claim 2 . The control unit performs control so that the frequency characteristic as a whole falls within the target range when the determination unit determines that the frequency characteristic includes a portion that is not within the target range.
A paper feeding device according to claim 3 . If the frequency characteristics as a whole do not fall within the target range, the control unit places the recording medium in a non-feeding state according to a time period during which the air is generated by the air generation unit.
A paper feeding device according to claim 4 . A plurality of the accommodating parts are provided,
When the determination unit determines that the frequency characteristic includes a portion that is not within the target range, the control unit sets the recording medium in the storage unit to be fed to a non-feeding state, and transfers the recording medium to another storage unit. set as paper feed target,
A paper feeding device according to claim 3 . The air generating section generates floating air that floats a plurality of recording media from the storage section toward the paper feeding section, recording media that are fed by the paper feeding section, and recording media that remain in the storage section. It is possible to switch between separation air and
When the recording medium is placed in a feeding state, the control unit performs control to switch air blown to the recording medium between the floating air and the separation air, and puts the recording medium in a non-feeding state. In this case, prohibit the control to switch the air ;
A paper feeding device according to claim 5 or claim 6 . If the frequency characteristics as a whole do not fall within the target range, the control unit sets the air to have a frequency characteristic closest to the target range.
A paper feeding device according to claim 4 . The determination unit sets the target range according to the incidence of conveyance failure of the recording medium in the paper feeding operation.
The paper feeding device according to any one of claims 3 to 8 . The determination unit sets a common target range according to the occurrence rate of the conveyance failure in each of the plurality of types of recording media.
A paper feeding device according to claim 9 . When a conveyance failure of the recording medium occurs, the determination unit extracts a difference between a frequency characteristic when the conveyance failure occurs and the target range as an inherent component at the time of the conveyance failure.
The paper feeding device according to any one of claims 3 to 10 . Equipped with a storage section,
The determination unit stores the unique component in the storage unit for each type of conveyance defect.
A paper feeding device according to claim 11 . Equipped with a storage section,
The determination unit causes the storage unit to store the target range according to the type of the recording medium or the state of the recording medium.
The paper feeding device according to any one of claims 3 to 11 . The determination unit corrects the target range according to the type of the recording medium or the state of the recording medium.
The paper feeding device according to any one of claims 3 to 13 . A plurality of the accommodating parts are provided,
The determination unit determines the state of the recording medium in the storage unit to which paper is fed.
A paper feeding device according to any one of claims 1 to 14 . A plurality of the accommodating parts are provided,
The determination unit determines the state of the recording medium in a storage unit other than the storage unit to which paper is fed.
A paper feeding device according to any one of claims 1 to 14 . The determination unit determines the state by removing driving sounds of devices other than the air generation unit.
A paper feeding device according to any one of claims 1 to 16 . The determining unit determines the state by removing driving sound of a device other than the air generating unit such that the removal amount of the driving sound is changed in accordance with a change over time.
A paper feeding device according to any one of claims 1 to 16 . The control unit outputs a notification command to notify the user of information related to the erroneous operation, when the sound signal related to the erroneous operation by the user is included in the sound signal .
A paper feeding device according to any one of claims 1 to 18 .

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