JP2007008654A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce difference of usage frequency of a plurality of sheet feeding means. <P>SOLUTION: The image forming device is provided with the plurality of sheet feeding means 30 capable of feeding the different kinds of sheets; a printer body 1 for forming an image on the sheet fed by the sheet feeding means 30; an accumulation counter 40a for counting the number of respective accumulation feeding sheets of the plurality of sheet feeding means 30; and a controller 40 for determining deviation of usage frequency of the respective sheet feeding means 30 based on the counting result of the accumulation counter 40a and changing allotment of the sheet of the respective sheet feeding means 30 so as to reduce deviation of usage frequency of the respective sheet feeding means 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus including a plurality of sheet feeding units.

  Image forming apparatuses such as copying machines and printers are generally provided with a plurality of feeding trays. Each of these feeding trays has different types (hereinafter referred to as “different types”) according to the purpose of use of the user, and includes at least one of various parameters for specifying the sheet, such as material, thickness, size, and the like. Are often set). Upon receiving a print job, the controller of the image forming apparatus receives a feed tray that stores sheets of material and thickness specified by the user, and a sheet that stores sheets of a size suitable for the image size to be formed. The tray is selected and the image forming operation is started.

  In general, when different types of sheets are set in a plurality of feeding trays, a difference in use frequency occurs between a frequently used sheet and a rarely used sheet. For example, in a general office environment, A4 size or B5 size plain paper is used with high frequency, but A3 size or B4 size plain paper or cardboard is in demand but is used less frequently. When such a frequency difference is accumulated, a large deviation occurs in the cumulative number of sheets fed between the feeding trays.

  General feeding devices use a rubber roller or rubber pad to transport and separate sheets. However, these members are worn out and deteriorated as more sheets are transported. The state deteriorates. When such deterioration progresses, the coefficient of friction of the contact surface with the sheet will eventually decrease, or the conveyance amount will decrease due to wear on the outer periphery of the roller, causing problems such as conveyance delay jams and double feeding. This state is called the life of the feeding roller and separation pad.

  As described above, if there is a bias in the usage frequency between the feeding trays, the rollers in the feeding tray that are used frequently are biased and worn out, or the rollers in the feeding tray that are used less frequently are left to deteriorate. As the product reaches the end of its life, troubles such as jams and multifeeds are likely to occur frequently. In addition, there is a problem that the service man must frequently replace the feeding roller.

  In order to improve these problems, it is necessary to make the frequency of use of the feeding tray uniform.

  Therefore, conventionally, the following method has been proposed only when sheets of the same size and type are set on a plurality of feeding trays.

A paper supply unit having a plurality of paper storage units having the same size and material of paper to be stored, and the paper storage unit to which the paper is to be fed so that the cumulative number of feeding times of each paper storage unit is uniform Is provided with selection means for selecting (see, for example, Patent Document 1).
JP 2002-255380 A

  However, the above-described conventional example is based on the premise that sheets of the same size and type are set in a plurality of feeding trays, and it is common that different types of sheets can be set in each feeding tray. It is not applicable to the use situation.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of reducing a difference in use frequency between a plurality of sheet feeding units. is there.

  In order to achieve the above object, in the present invention, a plurality of sheet feeding units capable of feeding different types of sheets, and an image forming unit for forming an image on a sheet fed by the sheet feeding unit And a cumulative feeding number counting unit that counts the cumulative feeding number of each of the plurality of sheet feeding units, and the usage frequency of each sheet feeding unit based on the count result of the cumulative feeding number counting unit. And control means for changing the sheet assignment of each sheet feeding means so as to reduce the bias.

  According to the present invention, it is possible to reduce the difference in use frequency among a plurality of sheet feeding means.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings and embodiments. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. . Further, the materials, shapes, and the like of the members once described in the following description are the same as those described in the background art unless otherwise described.

(Image forming device)
With reference to FIG. 6, an example of an image forming apparatus that can suitably employ the present invention will be described. FIG. 6 is a schematic cross-sectional view of the image forming apparatus according to the present embodiment.

  The image forming apparatus 100 includes a printer main body 1 that forms an image on a sheet, and a reading device 2 that functions as a copying machine. In this embodiment, a copier-type image forming apparatus provided with a reading device will be described as an example. However, the present invention can also be applied to a printer-type image forming device not provided with a reading device.

  A laser scanner 11 for writing an image on the photosensitive drum 12 is provided on the upper portion of the printer main body 1. Print data transmitted from an external device such as a personal computer is received by the controller 40 that controls the printer body 1 and is output to the laser scanner 11 as write image data.

  A plurality of sheet feeding units 30a, 30b, 30c, and 30d capable of feeding different types of sheets are positioned in the uppermost stream of sheet conveyance, and in the image forming apparatus 100 of the present embodiment, they are arranged vertically in the lower part of the apparatus. Is provided. The sheet feeding units 30a, 30b, 30c, and 30d separate and feed the feeding trays A, B, C, and D on which the sheets S are stacked and stored, and the sheet S stored in the feeding tray. It has feeding unit 31a, 31b, 31c, 31d.

  The feeding unit 31a (the feeding units 31b, 31b, and 31c have substantially the same configuration as the feeding unit 31a and will not be described), and a pickup roller 50 for picking up the sheet S in the feeding tray A; Further, a feeding roller 51 for feeding the sheet S picked up by the pickup roller 50 and a separation roller 52 that faces the feeding roller 51 and separates the sheet S by applying a separating force in the returning direction to the sheet are arranged. Has been.

Further, downstream of the feeding roller 51, the conveyance of the sheet S fed by the feeding roller 51 is taken over, and after the feeding drive of the feeding roller 51 is cut off, the sheet is separated from the feeding roller 51 and the separation roller 52. A pair of conveying rollers 36a (36b, 36c, 36d) for pulling out from the nip is provided.

  In addition to this drawing operation, the conveyance roller pair 36a also has a role of taking over conveyance of the sheet S conveyed on the vertical conveyance path 35 from a feeding unit (for example, 30d) further upstream.

  FIG. 7 is a block diagram of the control unit according to the present embodiment. The controller 40 has a built-in cumulative counter 40a for measuring the number of fed sheets, and counts the cumulative number of fed sheets for each feeding tray in conjunction with the feeding operation signal. Is stored in the memory 40b.

  A registration roller pair 81 is provided at the most downstream position of the vertical conveyance path 35, and final skew correction of the sheet and timing adjustment of image writing and sheet conveyance in the image forming unit are performed here. .

  The printer main body 1 includes a photosensitive drum 12, a charger 13 for uniformly charging the surface of the photosensitive drum 12, and a surface of the photosensitive drum 12 charged by the charger 13 by irradiating light. A laser scanner 11 for forming an image; a developing unit 14 for developing the electrostatic latent image as a toner image with a developer; a transfer roller 19 for transferring the developed toner image to the sheet S; and the toner image transferred. Thereafter, a cleaner 26 for removing the toner remaining on the photosensitive drum 12 is provided.

  On the downstream side of the image forming unit, a conveyance unit 21 for conveying the sheet S to which the toner image is transferred, and a fixing unit 22 for fixing the image on the sheet S conveyed by the conveyance unit 21 as a permanent image. Is provided.

  Further, a discharge roller 24 for discharging the sheet S on which the image has been fixed by the fixing device 22 from the printer main body 1 is provided. Further, a sheet discharged by the discharge roller 24 is provided on the upper outer side of the printer main body 1. A discharge sheet stacking tray 25 for receiving S is provided.

(Usage frequency equalization method)
In the following, a method for reducing the difference in the usage frequency of the plurality of sheet feeding units according to the present embodiment and making the usage frequency as uniform as possible will be described.

  As described above, the pickup roller 50, the feeding roller 51, and the separation roller 52 provided in the feeding unit 31 included in the sheet feeding unit are gradually consumed (abraded) as the sheet is fed. In particular, the feeding roller 51 and the separation roller 52 have a large degree of wear due to a large load during feeding, and need to be replaced several times until the image forming apparatus has reached the end of its main body life.

  For this reason, if a specific feeding unit among a plurality of feeding units is biased and used at a high frequency, only the rollers of the feeding unit deteriorate early and reach the replacement life earlier, and the The transmission unit replacement time will be off. As a result, the number of maintenance cycles for roller replacement increases, and conversely, troubles such as jams and double feeds occur due to long operation while maintenance of some feeding units is required. To do.

  Therefore, in the image forming apparatus of the present invention, the controller 40 is provided with a function for making the usage frequency of each feeding tray as uniform as possible.

  As described above, the controller 40 is provided with the cumulative counter 40a that counts the number of sheets fed from each feeding tray, and measures the accumulated feeding number from each feeding tray. Is stored in the memory 40b in the controller 40. Further, the controller 40 is also provided with a preliminary counter 40c for calculating the latest use frequency of each sheet feeding means within a predetermined period until now, and measures the number of sheets fed within a certain period retroactive from the present, The value is constantly updated and recorded in the memory 40b in the controller 40. That is, this value is the latest usage frequency of the sheet set in each feeding tray.

  It should be noted that it is possible to change the setting of how long the usage frequency is to be measured from the present time according to the usage status of the device of the user. In this embodiment, it is assumed that the usage status of a general office is assumed. The week is set.

  Other functions of the controller 40 include a bias detection function that determines whether or not the usage status of each feeding tray is biased, and each feed that can reduce the bias when it is determined that the usage status is biased. And a frequency equalizing function for estimating sheet allocation to the tray.

  An outline of the flow of processing is shown in the flowchart of FIG. FIG. 1 is a flowchart illustrating frequency equalization processing according to the present embodiment.

  Note that the following processing can be performed in hardware and software by the controller 40 serving as a prediction unit combining a known calculation unit (CPU) 40d and storage unit (memory) 40b.

  First, when the bias detection process is started by the timer every predetermined period, the controller 40 refers to the value of the cumulative number of fed sheets of each sheet feeding unit measured by the cumulative counter 40a (S1). Next, the difference DIF between the value Cmin of the sheet feeding unit having the largest cumulative number of sheets and the value Cmax of the sheet feeding unit having the smallest cumulative number of sheets is compared with the set threshold value TH (S2). In this embodiment, the threshold value TH is set to 30000 sheets. When the difference DIF does not exceed the threshold value TH (No), it is determined that the usage frequency of each sheet feeding unit is not so biased, and the bias detection process is terminated.

  When the difference DIF exceeds the threshold value TH (Yes), the values measured by the spare counter 40c are referred to for the two feeding trays (S3), and the recent usage frequencies are compared (S4).

  As a result, when the recent usage frequency F1 of the sheet feeding unit having the smallest cumulative feeding number is lower than the recent usage frequency F2 of the sheet feeding unit having the largest cumulative feeding number (Yes), it will continue. It is determined that there is no expectation that the usage frequency bias of both feeding trays will be improved, and a warning signal is output (S5). On the other hand, if the recent usage frequencies of the two are opposite (No), the disparity in the cumulative number of sheets to be fed may be reduced in a future printing operation, and the process is terminated without outputting a warning signal.

  Here, the frequency of use refers to the frequency with which the sheet feeding means feeds sheets, and can be expressed as the number of sheets fed per unit time, for example. Then, it is possible to predict to some extent the degree of wear of parts such as a feeding roller and a separation pad after that according to the use frequency.

  The frequency equalization process is started when a warning signal is output in the bias detection process (S6).

  In the processing of the present embodiment, the controller 40 is set to the cumulative feeding number C of each sheet feeding means measured by the cumulative counter 40a and each sheet feeding means (or each feeding tray) measured by the spare counter. Based on the information on the latest use frequency F of the sheet type), a sheet type that is preferably used in each subsequent feeding tray is derived. Alternatively, when there are a plurality of feeding trays for feeding the same type of sheet, it is derived which feeding tray is preferably used preferentially.

  Then, the sheet types used in each feeding tray are preferentially allocated so as to be used in the feeding tray with the smallest cumulative number of sheets in order from the sheet type having the most frequently used material and size. Thereby, the allocation of the sheet types recommended to be used in each feeding tray is determined, and the difference in the usage frequency of the plurality of sheet feeding units can be reduced by the subsequent feeding operation.

  Next, a specific processing flow will be described assuming a situation where these functions actually operate. In the image forming apparatus of this embodiment, a schedule operation using a timer is possible. When a predetermined time is reached once a week, a bias check of the usage status of each sheet feeding unit is automatically performed by a bias detection process. To do.

  The controller 40 outputs an operation command for bias detection processing for determining whether the use frequency is biased in each feeding tray. Assume that when this operation command is issued, the profile of each feeding tray is as shown in FIG. At this time, the difference DIF between the value Cmax (43057 sheets) of the feeding tray A having the largest cumulative feeding number and the value Cmin (12502 sheets) of the feeding tray D having the smallest cumulative feeding number is 30555 sheets. is there. As described above, in this embodiment, the bias determination threshold value TH is set to 30000 sheets, so the value of the difference DIF exceeds the threshold value TH.

  Further, when comparing the recent usage frequency of the sheets set in both feeding trays, the feeding tray A (F2 = 1509 sheets / week) is more frequently than the feeding tray D (F1 = 109 sheets / week). Is used, the warning signal is output (S5).

  When the warning signal is output, the frequency equalization process is started (S6), and each feeding tray obtained by the process described above is used to eliminate the uneven use frequency in the future image forming operation. The result of the ideal assignment of the sheet type is output (S7). In this embodiment, the profile after reassignment of the sheet type used in each feeding tray is as shown in FIG. The output result is displayed on a display unit as a notification unit that notifies the user of the sheet assignment.

  The notification means according to the present invention is not limited to a display unit such as a display described later, and may be configured to notify the user by voice or notify the user by blinking the light emitting element.

  The display unit 3 of the image forming apparatus 100 displays a message recommended to the user to change the sheet type assignment status to each feeding tray to the profile shown in FIG. 3 (S8). Here, the cardboard A3 having the smallest cumulative number of sheets to be fed is set in the sheet tray A having the largest cumulative number of sheets to be fed, and the sheet having the next cumulative number of sheets to be fed is next to the sheet Tray C having the largest cumulative number of sheets to be fed Paper A3 is set. Also, the next most common is the feeding tray B, but the feeding tray D has the most recent frequency, and therefore the plain paper A4 having the largest cumulative number of sheets fed to the feeding tray B having the least recent frequency. To be set. In this way, the user changes the sheet allocation to the feeding tray in accordance with this instruction (by exchanging the sheets of the paper type allocated to each feeding tray as shown in FIG. 3). (S9) Through the subsequent printing operation, the difference in the cumulative number of sheets fed between the sheet feeding means is gradually reduced. If the check by the bias detection process is periodically performed as in the present embodiment, the deviation of the cumulative number of sheets fed between the sheet feeding units is suppressed within a certain range, and the usage frequency of the plurality of sheet feeding units is used. Can be reduced.

  Next, processing in this embodiment for a case where the same type and size of sheet materials are set in a plurality of feeding trays will be described. In the image forming apparatus according to the present exemplary embodiment, the priority order to be used is assigned to the plurality of feeding trays on which the same sheet is set, and the sheets remain in the feeding tray with the higher priority order. Is a mechanism that always feeds from there.

  Assume that the profile of each feeding tray is as shown in FIG. 4 when an operation command for bias detection processing is issued. At this time, the difference between the value Cmax (44160 sheets) of the feeding tray A having the largest cumulative feeding number and the value Cmin (13022 sheets) of the feeding tray C having the smallest cumulative feeding number is 31138. . Since the bias determination threshold value TH in the present embodiment is set to 30000 sheets, the value of the difference DIF exceeds the threshold value TH.

  Further, comparing the recent usage frequency of the sheets set in both feeding trays, the feeding tray A (F2 = 1612 sheets / week) is more frequently used than the feeding tray C (F1 = 109 sheets / week). Is used, the warning signal is output (S5).

  When a warning signal is output, frequency equalization processing is started (S6), and each supply obtained in the above-described processing is performed so that the uneven usage frequency is naturally eliminated in future image forming operations. The estimation result of the ideal allocation of the sheet type used in the feeding tray is output (S7). In this case, the profile after reassignment of the sheet type used in each feeding tray is as shown in FIG. At this time, for two feeding trays on which A4 size plain paper of the same type is set, the higher selection priority is automatically set in order from the smallest number of sheets to be reassigned to the feeding tray. Assigned.

  On the display unit 3 of the image forming apparatus 100, a message recommended to the user to change the sheet allocation state to each feeding tray to this profile is displayed (S8). When the user inputs a setting change to the display unit 3 and the types of sheets actually set in the respective feeding trays are switched by the user, the types of sheets displayed on the display unit are transferred to the respective sheet feeding units. The controller 40 recognizes it through the detection means for detecting that it is loaded according to the means, and applies this priority order (S9, S10). By providing such detection means, it is possible to reduce mistakes in replacing a plurality of sheet types. Then, the value of the spare counter is changed in accordance with the feeding tray for changing the sheet type (S11).

  In addition, this invention is not limited to the Example described above. In this embodiment, the configuration is such that the schedule management is performed and the bias detection process is periodically executed. However, the configuration may be performed every day within a predetermined time after the power of the apparatus main body is turned on.

  Further, a configuration may be employed in which the difference in the cumulative number of sheets to be fed is always counted for each print job, and the previous processing is performed when the difference exceeds a threshold.

  Further, instead of the cumulative number of sheets fed by the respective sheet feeding means, the configuration may be such that the preceding process is performed every time the cumulative number of sheets fed to the apparatus main body reaches a predetermined number. For example, the cumulative number of sheets fed to the apparatus main body may be set every 100,000 sheets.

Further, each sheet feeding means information whose sheet allocation has been changed may be transmitted to the outside via the communication means. By configuring in this way, it is possible to inform the external service center of the frequency of use of each sheet feeding means, and it is possible to predict the replacement timing of the rollers and separation pads, thereby improving maintenance efficiency. Can do.

  Moreover, it is good also as a structure which a user instructs | indicates the trigger of a bias detection process from the outside, or the instruction | indication by remote operation from the external service station side connected with the communication line. With this configuration, in a situation where some parts of the sheet feeding unit are consumed and jamming is likely to occur, the frequency of use of the sheet feeding unit can be reduced by an instruction from the outside. In addition, it is possible to reduce conveyance defects until maintenance is performed.

  Further, in this embodiment, the degree of wear of the members used in each feeding tray is made uniform by comparing the difference of the cumulative number of sheets fed by the cumulative counter and the rearrangement using the recent usage frequency by the spare counter. A reallocation process is being performed. However, the present invention is not limited to this processing algorithm. If more advanced calculation processing can be performed on the controller side, it is more effective to record the past size change history, usage frequency tendency of each sheet type, etc., and use this information for processing. Can be made uniform.

  Further, since the transport distance required to transport one sheet varies depending on the sheet size, the above processing may be performed not only on the number of sheets but also on the total transport distance (= feed sheet number × paper size). In this way, the degree of wear of the feeding members such as the pickup roller, feeding roller, and separation roller can be made more uniform in each sheet feeding member. For this reason, the parts replacement timings of the respective sheet feeding means can be made uniform, and the maintenance efficiency can be improved.

  In the description of the present embodiment, it is described that the sheets on each feeding tray are replaced. However, if the sheet storage portions of the feeding trays A to D are detachable from the printer main body 1 and can be interchanged with each other, the position of the sheet can be changed for each feeding tray. The types of sheets that are preferably fed by the sheet feeding means may be exchanged.

  As described above, according to the present invention, not only between a plurality of sheet feeding units on which the same type of sheets are stacked, but also on a plurality of sheets on which different types of sheets are stacked, which has been impossible in the past. Also between the feeding means, the difference in the usage frequency of each sheet feeding means can be reduced.

  Thereby, it is possible to prevent exchangeable members such as a feeding roller and a separation roller included in a specific sheet feeding unit from being biased and consumed in a short period of time or being left unused for a long period of time. The frequency of troubles such as jams and double feeds can be reduced.

  In addition, since all feeding rollers, separation rollers, etc. can be used at the same pace, the maintenance interval for parts replacement by service personnel can be maximized, and consumable parts for all sheet feeding means can be removed in a single maintenance. Since they can be exchanged at the same time, the number of service personnel dispatches can be greatly reduced.

It is a flowchart which shows an example of the frequency equalization process based on the Example of this invention. It is a figure which shows an example of the profile of each feeding tray. It is a figure which shows an example of the profile after the reallocation of the sheet | seat kind used by each feeding tray. It is a figure which shows an example of the profile of each feeding tray. It is a figure which shows an example of the profile after the reallocation of the sheet | seat kind used by each feeding tray. 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment. It is a block diagram of the control part which concerns on an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer main body 3 Display part 30a, 30b, 30c, 30d Sheet feeding means 31a, 31b, 31c, 31d Feeding unit 40 Controller 40a Cumulative counter 40b Memory 40c Preliminary counter 50 Pickup roller 51 Feeding roller 52 Separating roller A, B , C, D Feeding tray S sheet

Claims (11)

A plurality of sheet feeding means capable of feeding different types of sheets;
An image forming unit that forms an image on a sheet fed by the sheet feeding unit;
A cumulative feeding number counting means for counting the cumulative feeding number of each of the plurality of sheet feeding means;
Based on the counting result of the cumulative feeding number counting means, the deviation of the usage frequency of each sheet feeding means is determined, and the sheet of each sheet feeding means is reduced so as to reduce the deviation of the usage frequency of each sheet feeding means. Control means for changing the allocation;
An image forming apparatus comprising:   When the difference in the cumulative number of sheets fed by any two of the plurality of sheet feeding means is greater than a predetermined value based on the count result of the cumulative feeding number counting means, 2. The image forming apparatus according to claim 1, wherein the sheet allocation is changed, and the sheet allocation is not changed when the difference in the cumulative number of fed sheets is smaller than a predetermined value. Use frequency calculating means for calculating the frequency of use of each of the plurality of sheet feeding means within a predetermined period until now,
Based on the counting result of the cumulative feeding number counting means and the calculation result of the use frequency calculating means, the difference between the cumulative feeding number of any two sheet feeding means among the plurality of sheet feeding means is greater than a predetermined value. Of the two sheet feeding means, the other sheet feeding means having a larger cumulative feeding number is used because one of the two sheet feeding means has a smaller cumulative feeding number. The image forming apparatus according to claim 1, wherein the control unit changes the sheet allocation when the frequency of use of the unit is lower.   The image forming apparatus according to claim 1, further comprising a notifying unit that notifies the sheet allocation changed by the control unit.   The image forming apparatus according to claim 4, wherein the notification unit is capable of transmitting a result of sheet allocation to an external device via a communication unit.   4. The image forming apparatus according to claim 2, wherein a warning signal is output when the control unit needs to allocate a sheet.   When the types of sheets set in the sheet feeding unit are the same in two or more sheet feeding units, allocation is performed so that the sheet feeding unit with a small cumulative number of sheets to be used is preferentially used. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   7. The image forming apparatus according to claim 1, wherein the control unit starts determining the deviation of the usage frequency of each sheet feeding unit at a predetermined period.   8. The determination according to claim 1, wherein the determination of the deviation in the usage frequency of each sheet feeding unit by the control unit is started within a predetermined period after the power of the apparatus main body is turned on. Image forming apparatus.   8. The determination of the bias in the usage frequency of each sheet feeding means by the predicting means is started every time the cumulative number of sheets fed to the apparatus main body reaches a predetermined number. The image forming apparatus according to claim 1. 8. The image formation according to claim 1, wherein the determination of the deviation of the usage frequency of each sheet feeding unit by the prediction unit is started by an instruction from the outside via the receiving unit. apparatus.

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