JP2006069788A - Recording medium feeding method, and recording medium feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium feeding device, and a recording medium feeding method, capable of preventing increase of frequency of paper supply action to a paper feed cassette inside a main body of an image forming machine without elongating time from a printing demand till printing of a first recording material even in such a situation as to frequently conduct printing in mass quantity. <P>SOLUTION: In the paper feed cassettes 11 and 12 inside the main body of the image forming machine 1 and an external paper feed unit 21, paper of the same size is loaded. With the printing demand to the paper of the size, paper is first supplied from the paper feed cassette 11 closest to an electrophotography process part 2a, and then from the paper feed cassette 12 that is second closest. After that, paper is all supplied from the paper feed unit 21. Paper in the paper feed cassette 11 that is closest to the electronic photography process part 2a is thus secured, and fast copy time is shortened, while reducing paper supply frequency. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is for supplying a recording medium (recording paper) to a printing unit (image forming unit) of an image forming machine represented by a printer, a copying machine, or a multi-function machine having a plurality of functions. The present invention relates to a recording medium supply method and a recording medium supply apparatus that executes the recording medium supply method. In particular, the present invention relates to an improvement for shortening the time required for a printing operation.

  In recent years, with the increase in printing speed of image forming machines, it has become possible to obtain a large amount of printed matter in a short time. For example, it has become possible to obtain hundreds to thousands of printed matter in a relatively short time by a single print job. For this reason, in order to avoid running out of paper in the middle of a print job, it is necessary to store a large amount of recording paper in the paper feed cassette of the image forming machine.

  However, if a large amount of recording paper is to be stored in the paper feed cassette inside the image forming machine main body, the paper feed cassette becomes large, which hinders downsizing of the image forming machine.

  In view of this point, as disclosed in Patent Document 1 below, for example, an image forming machine that can mount an external sheet feeding unit (optional sheet feeding unit) having a large capacity (for example, 4000 sheets) has been proposed. ing. In other words, in the case of a user who does not require the above-described mass printing, the image forming machine can be made compact by not attaching an external paper feeding unit to the main body of the image forming machine. In the case of a user, it is possible to meet the above requirements by mounting an external paper feed unit on the main body of the image forming machine.

As a usage pattern when the external paper feeding unit is mounted on the image forming machine main body, for example, when two paper feeding units are mounted, a frequently used A4 paper is placed in the paper feeding cassette inside the image forming machine main body. The A4 paper is stored in one of the paper supply units. The other paper feeding unit stores A3 paper that is relatively infrequently used. When printing on A4 size paper is requested, the A4 size paper is first taken out from the paper cassette inside the image forming machine main body, and the printing operation is executed. This paper cassette becomes empty. At this time, the operation is switched to the paper feeding operation from the one paper feeding unit (a paper feeding unit containing A4 size paper). As described above, the reason why the paper cassette inside the image forming machine main body is preferentially used is that the distance from the paper cassette to the image forming unit (for example, the distance to the photosensitive drum) is the external paper feed. It is shorter than the distance from the unit to the image forming unit, and the time required to print the first sheet by shortening the time from when a printing request is made until the recording paper is supplied to the image forming unit (so-called first copy time) This is for shortening. The technical idea of assigning the usage priority order to the paper feed cassettes is disclosed in Patent Document 2 and Patent Document 3 below.
JP 2004-107081 A JP-A-4-123072 JP-A-6-1470

  However, when the paper cassette inside the image forming machine main body is used preferentially as described above, the capacity of the paper cassette is originally reduced due to the demand for downsizing of the image forming machine main body. When printing is frequently performed, the paper feed cassette is emptied each time. When the next print job is executed without replenishing the recording paper in the paper feeding cassette, the recording paper used for the first printing operation is supplied from the paper feeding unit.

  As described above, since the paper feed unit is externally attached to the image forming machine main body, the distance from the paper feed unit to the image forming unit of the image forming machine is long, and after the print request is made, It takes a long time to supply the recording paper. That is, it takes a long time to obtain the first printed matter (first copy time), and the time until completion of the print job is delayed accordingly.

  In order to solve this problem, it is conceivable to perform a paper replenishment operation to the paper cassette every time the paper cassette inside the image forming machine main body becomes empty. As described above, mass printing is frequently performed. In such a case, there is a problem that the sheet replenishment work needs to be performed frequently and the burden on the user is increased.

  The present invention has been made in view of the above points, and an object of the present invention is to perform frequent replenishment of paper into a paper cassette inside an image forming machine main body even in a situation where mass printing is frequently performed. The present invention provides a recording medium supply method and a recording medium supply apparatus that do not require a long time from when a print request is made until the first printed matter is obtained. .

  The solution means of the present invention devised to achieve the above object is that a plurality of recording media used for a printing operation in the printing means can be accommodated and a plurality of paper feed path lengths to the printing means are different from each other. It is premised on a recording medium supply method that includes recording medium storage means and performs an operation of supplying the recording medium from the recording medium storage means to the printing means. For this recording medium supply method, the priority of use at the time of the printing operation is set in advance in each of the recording medium accommodating means, and at the time of the printing operation, the recording medium is accommodated in a predetermined order based on the priority of use. The recording medium supply operation from the means to the printing means is performed.

  At this time, a plurality of recording medium accommodating units that accommodate recording media of the same size are set as the same size group, and the priority of use at the time of printing operation is preset for the plurality of recording medium accommodating units belonging to the same size group. Yes. The use priority order set in advance for each recording medium accommodation means is set higher for recording medium accommodation means having a shorter paper feed path length to the printing means, and there is a print request for a plurality of recording media. When the first recording medium is supplied from the recording medium containing means having the highest use priority to the printing means, and the first recording medium is supplied to the printing means, the use priority is given. The second recording medium is supplied to the printing means from the recording medium containing means other than the recording medium containing means with the highest rank.

  As a result, when supplying a plurality of recording media from the recording medium accommodating means (paper cassette or paper feeding unit), the first sheet is first fed from the recording medium accommodating means closest to the printing means. Thereafter, the second sheet can be fed from a recording medium accommodation unit other than the recording medium accommodation unit closest to the printing unit. As a result, the frequency of use of the recording medium accommodating means closest to the printing means can be reduced, and the number of recording media accommodated can be ensured over a long period of time. For this reason, even in a situation where mass printing is frequently performed, it is possible to prevent the recording medium accommodation unit closest to the printing unit from being emptied and to print the first recording medium at the start of the print job. It is possible to reduce the frequency of the recording medium replenishment work to the recording medium storage means closest to the printing means while quickly feeding the means to shorten the first copy time.

  Further, when a recording medium containing number of “0” occurs among the plurality of recording medium containing means, the recording medium containing the recording medium having the highest use priority among the recording medium containing means containing the recording medium. The recording medium is supplied from the means toward the printing means. According to this, the recording medium supply operation from the recording medium accommodating means closest to the printing means among the recording medium accommodating means accommodating the recording medium can always be performed, and the first copy time can be shortened as much as possible. Can do.

  Further, the conveyance speed of the recording medium from each recording medium housing unit toward the printing unit is set higher than the printing processing speed in the printing unit. According to this, it becomes possible to carry the next recording medium immediately before the printing means during the printing operation for the preceding recording medium, and for the next recording medium immediately after the completion of the printing operation for the preceding recording medium. The printing operation can be started and the printing operation can be shortened.

  Furthermore, the conveyance speed of the recording medium supplied from the recording medium accommodating means other than the recording medium accommodating means having the highest use priority to the printing means is set so that the recording medium accommodating means having the highest use priority is directed to the printing means. The speed is constant or high with respect to the conveyance speed of the supplied recording medium. According to this, the recording medium supply operation from the recording medium accommodating means (recording medium accommodating means having a low use priority) to the printing means can be quickly performed. The printing operation can be shortened.

  In addition, the conveyance speed of the recording medium supplied from the recording medium accommodating means other than the recording medium accommodating means with the highest use priority to the printing means or the recording medium conveyance start timing depends on the recording medium. It is assumed that it does not overlap with the preceding recording medium. As a result, it is possible to avoid a situation in which a plurality of recording media are supplied in an overlapping manner to the printing means, and a desired printed matter can be obtained without causing paper jam or the like.

  In addition, the recording medium supply apparatus which supplies a recording medium toward a printing means in each recording medium supply method mentioned above is also the category of the technical idea of this invention. In other words, the recording medium supply operation from each recording medium storage unit to the printing unit is performed in the order determined in advance based on the priority of use at the time of the printing operation preset in each recording medium storage unit. It is a recording medium supply apparatus provided with a supply order setting means for controlling each recording medium accommodation means.

  In the present invention, when a plurality of recording media are supplied from a recording medium supply device provided with a plurality of recording medium accommodating means (paper feeding cassettes and paper feeding units), first, the first paper is fed. The recording medium accommodating means closest to the recording medium (this recording medium accommodating means is generally disposed in the main body of the image forming machine and has a relatively small number of accommodated sheets), and then the second sheet is fed. , Recording medium accommodating means other than the recording medium accommodating means closest to the printing means (this recording medium accommodating means is generally externally attached to the image forming machine main body and has a relatively large number of accommodated sheets). I am doing so. As a result, by securing the number of recording media accommodated in the recording medium accommodating means closest to the printing means, the recording medium accommodating means is emptied even in situations where mass printing is frequently performed. Suppressing and quickly feeding the first recording medium to the printing means at the start of the print job to shorten the first copy time, while reducing the first recording medium to the recording medium accommodation means closest to the printing means. The frequency of the recording medium supply operation can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention relates to an electrophotographic printer (image forming machine) that includes four paper feed cassettes and three external paper feed units mounted in the printer body. A case where the present invention is applied will be described.

-Description of the entire image forming machine-
FIG. 1 is an overall configuration diagram of an image forming machine. The image forming apparatus 1 according to the present embodiment includes a printer unit 2 and a paper feeding unit unit 3 disposed below the printer unit 2. An electrophotographic process section (printing means) 2 a centered on the photosensitive drum 4 is disposed at a substantially central position of the printer section 2. That is, a charging unit 5, an optical scanning unit 6, a developing unit 7, a transfer unit 8, and a cleaning unit 9 are disposed around the photosensitive drum 4 as a center.

  The charging unit 5 uniformly charges the surface of the photosensitive drum 4, and the optical scanning unit 6 scans an optical image based on image data on the uniformly charged photosensitive drum 4. An electrostatic latent image is written. The developing unit 7 visualizes the electrostatic latent image written by the optical scanning unit 6 with a developer (toner), and the transfer unit 8 records an image recorded and reproduced on the photosensitive drum 4. The image is transferred onto a sheet (recording medium).

  The cleaning unit 9 removes the developer remaining on the photosensitive drum 4 so that a new image can be recorded on the photosensitive drum 4, and the cleaning unit 9 removes the developer. The residual toner is collected in a collection container (not shown) attached to the toner supply unit 10 of the developing unit 7 and discarded later.

  The paper feeding unit 3 includes first to fourth plural paper feeding cassettes (recording medium accommodating means) 11, 12, 13, and 14. The paper feeding unit 3 is a variety of recording media. For example, the sheets can be sorted and stored for each size.

  Then, the image forming machine 1 selects one cassette from these paper feed cassettes 11, 12, 13, and 14, separates the sheets one by one from the selected cassette, and transfers to the photosensitive drum 4. Supply between unit 8. The transfer unit 8 transfers the image recorded and reproduced on the photosensitive drum 4 to the supplied paper. As will be described later, since the image forming apparatus 1 is provided with three external paper feeding units 21, 22, and 23 (recording medium accommodation means), the electrophotographic process unit 2a is provided with these external paper feeding units. It is also possible to receive paper from a selected one of the paper units 21, 22, and 23.

  The first paper feed cassette 11 and the second paper feed cassette 12 are juxtaposed in the horizontal direction. A third paper feed cassette 13 is disposed below the first paper feed cassette 11 and the second paper feed cassette 12, and a fourth paper feed cassette 14 is further provided below the third paper feed cassette 13. Has been placed.

  The capacity of the third paper feed cassette 13 and that of the fourth paper feed cassette 14 are approximately the same, and the capacity of the first paper feed cassette 11 and the second paper feed cassette 12 is the same as that of the third paper feed cassette. 13 or the capacity of the fourth paper feed cassette 14 is set.

  Specifically, in the present embodiment, the first paper feed cassette 11 and the second paper feed cassette 12 both store A4 size recording paper, while the third paper feed cassette 13 and the fourth paper feed cassette. Both 14 accommodate A3 size recording paper. The relationship between these paper feed cassettes and the size of the recording paper accommodated therein is not limited to this.

  The paper feed unit 3 includes a first transport path 15 and a second transport path 16 for transporting the paper stored in the paper feed cassettes 11, 12, 13, and 14 toward the printer section 2. . The first transport path 15 transports the paper stored in the first, third, and fourth paper feed cassettes 11, 13, and 14 toward the printer unit 2, and the second transport path 16 The paper stored in the second paper feed cassette 12 is conveyed toward the printer unit 2. The first transport path 15 extends in the vertical direction along the vertical frame 17 of the paper feed unit 3, while the second transport path 16 extends in the horizontal direction along the horizontal frame. The first transport path 15 and the second transport path 16 merge inside the printer unit 2 and extend upward toward the electrophotographic process unit 2a.

  In this way, the paper feed cassettes 11 to 14, the first transport path 15, and the second transport path 16 are efficiently arranged inside the paper feed unit section 3, so that the paper feed unit section 3 can be saved. Space has been realized.

  When paper is set in each of the paper feed cassettes 11, 12, 13, 14, the paper feed cassette 11, 12, 13, 14 is pulled out toward the front side of the main body of the image forming machine 1 to replenish the paper. Do.

  By the way, when the paper is jammed in the first transport path 15, the guide 15a (indicated by the hatched portion in the figure) constituting the first transport path 15 is rotated around the back side of the paper feed unit 3 as a fulcrum. Let Thereby, the paper jammed in the first transport path 15 can be removed. This removal operation is performed using a work space secured in advance between the first transport path 15 and the frame 17.

  Further, when the paper is jammed in the second transport path 16, the guide 16a (indicated by a hatched portion in the figure) constituting the second transport path 16 is rotated with the back side of the paper feed unit 3 as a fulcrum. Let As a result, the paper jammed in the second transport path 16 can be removed. This removal operation is performed after securing the work space below the second transport path 16 by pulling out the first paper feed cassette 11 and the second paper feed cassette 12 arranged in parallel to the front side of the user. It will be.

  In the image forming apparatus 1 of the present embodiment, the paper cassettes 11 and 12 can be pulled out at the same time. However, the present invention is not necessarily limited to this configuration, and each paper cassette can be pulled out independently. It is good also as a structure. In this case, the working space for removing the paper jammed in the second transport path 16 may be secured below the second transport path 16 by pulling out the paper feed cassette 11 toward the front side.

  A manual paper feed unit 18 in which a relatively small amount of paper is set is provided on the upstream side of the second transport path 16. In general, a special sheet is highly likely to be set in the manual sheet feeding unit 18. This is because the paper can be easily exchanged or set in the manual paper feeding unit 18. Paper can be supplied from the manual paper feed unit 18 to the second transport path 16 via the third transport path 18a.

  Further, in the image forming apparatus 1 according to the present embodiment, first to third three paper feeding units 21, 22, and 23 are attached / detached as optional devices to the side (right side in FIG. 1) of the paper feeding unit section 3. It is connected freely. These sheet feeding units 21, 22, and 23 have a larger capacity (for example, 4000 sheets can be accommodated) than the sheet feeding cassettes 11-14. Specifically, the first paper feed unit 21 is mounted on the side surface of the main body of the image forming machine 1, the second paper feed unit 22 is mounted on the side surface of the first paper feed unit 21, and the second paper feed unit 22. A third paper feeding unit 23 is mounted on the side surface of the paper.

  Below the manual sheet feeding unit 18, a fourth conveyance path 19 is provided that extends in the horizontal direction and has an upstream end opened to the side surface of the sheet feeding unit 3. In addition, a lead-out port is provided on one side surface (left side surface in the drawing) of each paper feeding unit 21, 22, 23, and an introduction port is provided on the other side surface (right side surface in the drawing). In addition, sheet conveyance paths 21a, 22a, and 23a (see broken lines in the figure) are formed from the introduction port to the discharge port. Pick-up rollers 21b, 22b, and 23b for taking out the recording paper stored in the paper feeding units 21, 22, and 23 at the downstream ends (near the outlet) of the paper transport paths 21a, 22a, and 23a. A pair of transport rollers 21c for transporting the recording paper taken out by the pickup rollers 21b, 22b, and 23b and the recording paper transported from the upstream paper feed unit toward the fourth transport path 19 downstream, 22c and 23c are provided.

  The outlet of the first paper feed unit 21 mounted on the side surface of the paper feed unit 3 is opposed to the upstream end opening of the fourth transport path 19. The paper stored in the paper or the paper transported through the paper transport path 21 a in the first paper feed unit 21 is sent out toward the fourth transport path 19.

  In addition, the introduction port of the first paper feed unit 21 faces the lead-out port of the second paper feed unit 22, and the paper accommodated in the second paper feed unit 22 or the second paper feed unit 22. The sheet conveyed through the inner sheet conveyance path 22 a is sent out toward the fourth conveyance path 19 via the sheet conveyance path 21 a of the first sheet feeding unit 21.

  Similarly, the inlet of the second paper feed unit 22 faces the outlet of the third paper feed unit 23, and the paper stored in the third paper feed unit 23 is the second paper feed unit 22. The sheet transport path 22 a and the sheet transport path 21 a of the first paper feed unit 21 are sent out toward the fourth transport path 19.

  The type of recording paper stored in each of the paper feeding units 21, 22, 23 will be described in detail. The first paper feeding unit 21 includes the first paper feeding cassette 11 and the second paper feeding cassette 12. Similarly, the A4 size recording paper is stored, while the second paper feed unit 22 and the third paper feed unit 23 store the A3 size paper in the same manner as the third paper feed cassette 13 and the fourth paper feed cassette 14. Recording paper. The relationship between the paper feeding units 21, 22, 23 and the size of the recording paper accommodated therein is not limited to this.

  Note that the recording paper conveyance speed (paper conveyance speed in each conveyance path) from each of the paper supply cassettes 11 to 14 and the paper supply units 21 to 23 to the electrophotographic process unit 2a is the printing in the electrophotographic process unit 2a. It is set higher than the processing speed (the peripheral speed of the photosensitive drum 4). Further, the conveyance speed of the recording paper supplied from the paper supply units 21 to 23 attached to the main body of the image forming machine 1 toward the paper supply unit unit 3 is determined by the paper feed cassette in the main body of the image forming machine 1. The speed of the recording paper supplied from 11 to 14 toward the electrophotographic process unit 2a is constant or high. For example, the transport speed from the paper feed units 21 to 23 is twice the print processing speed, and the transport speed from the paper feed cassettes 11 to 14 is 1.5 times the print processing speed. These speeds are determined by the rotational speeds of the transport rollers provided in the transport paths 15, 16, 19, 21a, 22a, and 23a.

-Explanation of paper feeding operation-
A feature of this embodiment is a paper feeding operation at the time of execution of a print job for requesting printing of a plurality of sheets. Hereinafter, a configuration for performing the paper feeding operation and the paper feeding operation will be described.

  A controller (not shown) that comprehensively controls the image forming apparatus 1 sets a supply order for selecting the paper feed cassettes 11 to 14 and the paper feed units 21 to 23 for feeding paper when executing a print job. Means are provided. The supply order of the recording paper determined by the supply order setting unit will be described later.

  The plurality of paper feed cassettes 11 to 14 and the paper feed units 21 to 23 are set in advance with the priority of use during the printing operation. Specifically, the priority order of use is set between paper feed cassettes and paper feed units that store recording paper of the same size. In the case of this embodiment, since the first paper feed cassette 11, the second paper feed cassette 12, and the first paper feed unit 21 contain recording paper of the same size (A4 size), these three parties are designated as the same size paper group. The use priority is set as The use priority order is set higher as the paper feed path length to the electrophotographic process unit 2a is shorter. That is, the first paper feed cassette 11 is “use priority 1 (use priority 1 when A4 size is selected)” and the second paper feed cassette 12 is “use priority 2 (use priority 2 when A4 size is selected). ) ”, The first paper feeding unit 21 is set to“ use priority 3 (use priority 3 when A4 size is selected) ”.

  Similarly, the third paper feed cassette 13, the fourth paper feed cassette 14, the second paper feed unit 22, and the third paper feed unit 23 contain the same size (A3 size) of recording paper. Also, the use priority order is set for the same size paper group. Also, the use priority order is set higher as the paper feed path length to the electrophotographic process unit 2a is shorter. That is, the third paper cassette 13 is “use priority 1 (use priority 1 when A3 size is selected)” and the fourth paper cassette 14 is “use priority 2 (use priority 2 when A3 size is selected). ) ”, The second paper feed unit 22 is“ use priority 3 (use priority 3 when A3 size is selected) ”, and the third paper feed unit 23 is“ use priority 4 (use priority when A3 size is selected) ”. Ranking 4) ”is set for each.

  When the supply order setting unit receives a print job signal for a print request for three A4 size papers, the supply order setting unit firstly outputs the first paper from the first paper feed cassette 11 which is set to use priority order 1 when A4 size is selected. The sheet feeding operation is executed, and then the sheet feeding operation from the second sheet feeding cassette 12 set to the use priority order 2 is executed, and then the first sheet feeding set to the use priority order 3 is performed. The sheet feeding operation from the unit 21 is executed. If the print job signal is for four or more A4 size sheets, the sheet feeding operation from the first sheet feeding unit 21 is repeated after the sheet feeding operation from the first sheet feeding unit 21 is executed. I am doing so.

  When a print job signal for a print request for three A3 size papers is received, first, a paper feed operation from the third paper feed cassette 13 set to use priority order 1 when A3 size is selected is executed. Thereafter, the sheet feeding operation from the fourth sheet feeding cassette 14 set to the use priority order 2 is executed, and then the sheet feeding operation from the second sheet feed unit 22 set to the use priority order 3 is performed. To be executed. When a print job signal for a print request for four A3 size papers is received, first, a paper feed operation from the third paper feed cassette 13 set to use priority order 1 when A3 size is selected is executed. Thereafter, the sheet feeding operation from the fourth sheet feeding cassette 14 set to the use priority order 2 is executed, and then the sheet feeding operation from the second sheet feed unit 22 set to the use priority order 3 is performed. In addition, after that, the sheet feeding operation from the third sheet feeding unit 23 set to the use priority order 4 is performed. When the print job signal is for five or more A3 size sheets, the sheet feeding operation from the third sheet feeding unit 23 is repeated after the sheet feeding operation from the third sheet feeding unit 23 is executed. I am doing so.

  Hereinafter, the procedure of the print processing operation in this embodiment will be described with reference to the flowchart of FIG. Here, a description will be given by taking as an example the execution time of a print job for A4 size paper.

  First, when a print request is made to the image forming machine 1 in step ST1, it is determined in step ST2 whether or not input of printing conditions is completed. If the input of the printing conditions has not yet been completed (No in step ST2), the process proceeds to step ST3, and a message for prompting the input of the printing conditions is displayed on the operation panel of the image forming machine 1. To do.

  When the input of the printing conditions is completed (when YES is determined in step ST2), the process proceeds to step ST4, and the recording paper having the size set by the printing conditions is stored in a plurality of paper feeding units (paper feeding cassettes and paper feeding units). ) Is determined. If it is determined that the recording paper having a size that matches the printing conditions is present only in one paper feeding unit, the other paper feeding unit that should accommodate the recording paper of this size is empty. In step ST5, a message for prompting paper supply is displayed on the operation panel.

  On the other hand, if there are recording sheets having a size that matches the printing conditions in a plurality of sheet feeding units, the process proceeds to step ST6, and the sheet feeding unit (recording medium accommodation unit) set to use priority 1 is set. The paper feeding operation is executed. Here, since the A4 size is set under the above printing conditions, paper is fed from the first paper feed cassette 11.

  In this way, a paper feeding operation is performed from the paper feeding unit set to use priority 1 to the electrophotographic process unit 2a. The electrophotographic process unit 2a performs a predetermined image on the recording paper. A forming operation (printing process) is performed (step ST7). The printed matter thus obtained is discharged onto a paper discharge tray provided on the upper part of the printer unit 2.

  In parallel with the printing operation, it is determined whether or not the next recording sheet needs to be fed based on the printing conditions, that is, whether or not the print job is completed in the current printing operation (step ST8). ). If this determination is No, the paper feeding operation is not continued and the standby mode is entered after the printing operation is completed. On the other hand, if it is determined that the next recording sheet needs to be fed, the process proceeds to step ST9, where the rear end (upstream end in the transport direction) of the first recording sheet and the next transport (second sheet) are performed. Wait until the timing when the leading edge of the recording paper (downstream end in the transport direction) overlaps on the transport path elapses. After the elapse of this timing, the process proceeds to step ST10, and the paper feeding operation from the paper feeding unit set to use priority 2 is executed. That is, paper is fed from the second paper cassette 12.

  In this way, the paper feeding operation from the paper feeding unit set to the use priority 2 to the electrophotographic process unit 2a is executed, and the electrophotographic process unit 2a performs a predetermined image on the recording paper. A forming operation is performed (step ST11). The printed matter thus obtained is discharged onto a paper discharge tray provided on the upper part of the printer unit 2.

  In parallel with this printing operation, it is determined whether or not the next recording sheet needs to be fed based on the above printing conditions, that is, whether or not the print job is completed in the current printing operation ( Step ST12). If this determination is No, the paper feeding operation is not continued and the standby mode is entered after the printing operation is completed. On the other hand, if it is determined that the next recording sheet needs to be fed, the process proceeds to step ST13, and the rear end (upstream end in the transport direction) of the second recording sheet and the next transport (third sheet). Wait until the timing when the leading edge of the recording paper (downstream end in the transport direction) overlaps on the transport path elapses. After the elapse of this timing, the process proceeds to step ST14, where the paper feeding operation from the paper feeding unit set to use priority 3 is executed. That is, paper is fed from the first paper feed unit 21.

  In this way, a paper feeding operation is performed from the paper feeding unit set to use priority 3 toward the electrophotographic process unit 2a. The electrophotographic process unit 2a performs a predetermined image on the recording paper. A forming operation is performed (step ST15). The printed matter thus obtained is discharged onto a paper discharge tray provided on the upper part of the printer unit 2.

  In parallel with this printing operation, it is determined whether or not the next recording sheet needs to be fed based on the above printing conditions, that is, whether or not the print job is completed in the current printing operation ( Step ST16). If this determination is No, the paper feeding operation is not continued and the standby mode is entered after the printing operation is completed. On the other hand, if it is determined that it is necessary to feed the next recording sheet, the process proceeds to step ST17, and the first sheet feeding unit 21 (the sheet feeding unit having the use priority 3 (lowest priority)) is similar to the above. The paper feeding operation is executed.

  Then, while it is determined that it is necessary to feed the next recording sheet (while it is determined Yes in step ST19), the sheet feeding operation from the first sheet feeding unit 21 is repeated. If it is determined that it is no longer necessary to feed the next recording sheet (No in step ST19), the standby mode is entered after the end of the printing operation without continuing the sheet feeding operation. .

  In the above description of the paper feeding operation, a case has been described in which a print job is performed on A4 size paper, that is, a case where a print request is made for the same size recording paper stored in the three recording medium storage units. When a print job is executed on A3 size paper, that is, when a print request is made for the same size recording paper stored in the four recording medium storage means, substantially the same paper feeding operation is performed. When executing a print job for the A3 size paper, the recording paper is fed one by one from the recording medium storage unit having the highest usage priority to the electrophotographic process unit 2a, and then the usage priority 4 (lowest The paper feeding operation from the third paper feeding unit 23 set to (priority order) is repeated.

  By performing the paper feeding operation as described above, the first paper feed cassette 11 closest to the electrophotographic process unit 2a when printing on A4 size paper, or the closest to the electrophotographic process unit 2a when printing on A3 size paper. It is possible to secure the number of recording sheets stored in the third sheet cassette 13 (only one sheet is used in one printing job). As a result, even in a situation where mass printing is frequently performed, the first sheet at the start of the print job is suppressed by preventing the paper cassettes 11 and 13 closest to the electrophotographic process unit 2a from becoming empty. The recording paper supply operation to the paper feeding cassettes 11 and 13 closest to the electrophotographic process unit 2a is performed while quickly feeding the recording paper to the electrophotographic process unit 2a to shorten the first copy time. The frequency can be reduced.

  In the paper feeding operation, if any of the paper feeding units that should store recording paper of a size that matches the printing conditions is empty, a message for prompting paper supply is displayed on the operation panel. However, even if this paper replenishment operation is not performed, the electrophotographic process starts with the recording medium storage means having the highest use priority among the recording medium storage means currently storing recording paper. A sheet feeding operation toward the unit 2a may be performed.

-Variation of paper feeding operation-
Next, a modified example of the paper feeding operation will be described. In the above-described embodiment, after the recording sheets are fed to the electrophotographic process unit 2a one by one in order from the recording medium storage unit having the highest usage priority, the paper feeding unit that has the lowest usage priority is set. The paper feeding operation from is to be repeated. In the following modifications, the sheet feeding order is different from that in the above embodiment. Hereinafter, each modification will be described.

(First modification)
The first modification is a paper feeding operation in which recording paper inside the main body of the image forming machine 1 is used as little as possible. That is, in order to shorten the first copy time, first, the first recording sheet is used with the priority of use 1 and the second sheet is supplied from the external paper feeding unit. I try to use paper. Specifically, at the time of a print request for A4 size paper, the first recording paper is fed from the first paper feed cassette 11, the second recording paper is fed from the first paper feed unit 21, Subsequent recording sheets are fed from the first sheet feeding unit 21.

  On the other hand, when a print request is made for A3 size paper, the first recording paper is fed from the third paper feeding cassette 13, the second recording paper is fed from the second paper feeding unit 22, The third recording sheet is fed from the third sheet feeding unit 23, and the subsequent recording sheets are also fed from the third sheet feeding unit 23. Alternatively, the second recording sheet may be fed from the second sheet feeding unit 22, and the subsequent recording sheets may be fed from the second sheet feeding unit 22.

(Second modification)
The second modification relates to a sheet feeding operation particularly when the length of the sheet conveyance path from the sheet feeding unit to the electrophotographic process unit 2a is long. The order of introducing the recording sheets into the electrophotographic process unit 2a is different. This will be specifically described below.

  First, when a print request is made for A4 size paper, the first recording paper is fed from the first paper feed cassette 11 and the second recording paper is fed from the second paper feed cassette 12. However, the length of the conveyance path from the first paper supply unit 21 to the electrophotographic process unit 2a is long, and from the start of the paper supply operation of the first paper supply unit 21 until the recording sheet actually reaches the electrophotographic process unit 2a. When a long time is required, the paper feeding operation of the first paper feeding unit 21 is started before the paper feeding operation of the second paper feeding cassette 12 is started. In other words, the recording sheets supplied to the electrophotographic process unit 2a include the first sheet (sheet feeding from the first sheet feeding cassette 11) and the second sheet (sheet feeding from the second sheet feeding cassette 12). The third sheet (sheet feeding from the first sheet feeding unit 21) is fed in the order, but the sheet feeding start timing is the sheet feeding in the order of the first sheet, the third sheet, and the second sheet. A paper operation is performed. The start timing of the sheet feeding operation of the first sheet feeding unit 21 is such that the third recording sheet fed from the first sheet feeding unit 21 is fed from the second sheet feeding cassette 12. The timing is set such that it is positioned upstream of the second recording sheet and the downstream end of the third recording sheet does not overlap the upstream end of the second recording sheet. The Also in this example, the fourth and subsequent recording sheets are fed from the first sheet feeding unit 21.

-Other embodiments-
The embodiment and the modification described above are electrophotographic printers, which are provided with four paper feeding cassettes, and three external paper feeding units are mounted on the image forming machine main body. The case where the present invention is applied to the above has been described. The present invention is not limited to this, and can also be applied to a copying machine or a multifunction machine having both a printer function and a copying function. Further, the number of paper feed cassettes inside the image forming machine main body and the number of external paper feed units are not limited to those described above.

1 is an overall configuration diagram of an image forming machine according to an embodiment. FIG. 6 is a flowchart illustrating a procedure of a printing process operation.

Explanation of symbols

2a Electrophotographic process part (printing means)
11 First paper feed cassette (recording medium storage means)
12 Second paper feed cassette (recording medium storage means)
13 Third paper feed cassette (recording medium storage means)
14 Fourth paper feed cassette (recording medium storage means)
15 First transport path 16 Second transport path 19 Fourth transport path 21 First paper feed unit (recording medium housing means)
22 Second paper feeding unit (recording medium housing means)
23 Third paper feeding unit (recording medium housing means)

Claims (10)

There are a plurality of recording medium accommodating means capable of accommodating a plurality of recording media to be used for a printing operation in the printing means and having different feed path lengths to the printing means, and these recording medium accommodating means to the printing means A recording medium supply method for performing a recording medium supply operation,
Each of the recording medium accommodation means is set in advance with a priority for use during a printing operation, and during the printing operation, the recording medium accommodation means is directed from the recording medium accommodation means to the printing means in a predetermined order based on the usage priority. A recording medium supply method, wherein the recording medium supply operation is performed. In the recording medium supply method according to claim 1,
A plurality of recording medium accommodating means for accommodating recording media of the same size are set as the same size group, and a priority for use during a printing operation is preset for a plurality of recording medium accommodating means belonging to the same size group. A recording medium supply method. In the recording medium supply method according to claim 1 or 2,
A recording medium supply method characterized in that the use priority order set in advance for each recording medium accommodation unit is set higher for a recording medium accommodation unit having a shorter paper feed path length to the printing unit. In the recording medium supply method according to claim 1, 2, or 3,
A recording medium supply method comprising: supplying a first recording medium from a recording medium storage unit having the highest use priority to a printing unit when a print request is made for a plurality of recording media. In the recording medium supply method according to claim 4,
After the first recording medium is supplied to the printing unit, the second recording medium is supplied to the printing unit from the recording medium storage unit other than the recording medium storage unit having the highest use priority. And a recording medium supply method. In the recording medium supply method according to any one of claims 1 to 5,
When a recording medium containing number of “0” occurs among the plurality of recording medium containing means, the recording medium containing means having the highest use priority among the recording medium containing means containing the recording medium is used. A recording medium supply method comprising: supplying a recording medium toward a printing unit. In the recording medium supply method according to any one of claims 1 to 6,
A recording medium supply method, characterized in that a recording medium conveyance speed from each recording medium accommodating means to a printing means is higher than a printing processing speed in the printing means. In the recording medium supply method according to any one of claims 1 to 7,
The conveyance speed of the recording medium supplied from the recording medium accommodating means other than the recording medium accommodating means with the highest use priority to the printing means is supplied from the recording medium accommodating means with the highest use priority to the printing means. A method of supplying a recording medium, characterized in that the recording medium is set at a constant speed or a high speed relative to a conveying speed of the recording medium. In the recording medium supply method according to any one of claims 1 to 8,
The recording medium transport speed or the recording medium transport start timing supplied from the recording medium housing unit other than the recording medium housing unit with the highest use priority to the printing unit is the recording medium that precedes the transport path. A method for supplying a recording medium, characterized in that the recording medium does not overlap the medium. A recording medium supply apparatus according to any one of claims 1 to 9, wherein the recording medium supply apparatus supplies a recording medium toward a printing means.
Each recording is performed so that the recording medium supply operation from each recording medium accommodating means to the printing means is performed in a predetermined order based on the priority of use at the time of the printing operation preset in each recording medium accommodating means. A recording medium supply apparatus comprising supply sequence setting means for controlling medium accommodation means.

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