JP6197484B2 - Image forming apparatus - Google Patents

Description

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

  In a conventional image forming apparatus, as disclosed in Patent Document 1, for example, an image forming apparatus that includes a plurality of paper feeding units and automatically selects a paper feeding unit containing a sheet used for image formation is disclosed.

JP 11-338214 A

  However, in the above-described conventional example, when the sheet feeding unit is operated for image formation to be executed from now on, for example, a sheet to be used for image formation to be executed by the user is inserted into the sheet feeding unit. If the priority of selection at the time of automatically selecting a paper feed unit is low, it may be difficult to feed paper from the operated paper feed unit.

  The present invention has been made to solve the above-described problems, and provides an image forming apparatus capable of appropriately changing the priority order for determining a sheet feeding unit that feeds a sheet.

  An image forming apparatus of the present invention made to achieve this object includes a plurality of sheet feeding units, an image forming unit that forms an image on a sheet fed from the sheet feeding unit, and a state of the sheet feeding unit A sensor that outputs a signal in accordance with the image forming unit, a receiving unit that receives an image forming instruction for causing the image forming unit to form an image, and a control unit, wherein the control unit uses the signal output by the sensor, Detection processing for detecting the supply of a sheet to the sheet feeding unit, and an elapsed time from when the detection unit detects the supply of the sheet to the sheet feeding unit until the image forming instruction is received by the reception unit And a process for changing a priority order for determining a sheet feeding unit for feeding a sheet to be used for forming an image instructed by the image formation instruction, and for supplying to the image forming unit Before the start of the paper , Specifying a target sheet feeding unit that is the sheet feeding unit whose elapsed time is shorter than a predetermined time, and changing the priority for the identified target sheet feeding unit, and the sheet feeding unit with the highest priority And an image forming process for forming an image on a sheet fed from.

  In this way, it is possible to appropriately change the priority order for determining a sheet feeding unit that feeds sheets.

  A storage unit that stores a predetermined basic priority order for determining a sheet feeding unit that feeds a sheet in forming an image instructed by the image formation instruction; In the processing, when the target paper feed unit does not exist, the basic priority is set as the main priority, and when the target paper feed unit exists, the priority of the target paper feed unit in the basic priority order. The priority that has been raised may be set as the main priority, and in the image forming process, an image may be formed on a sheet fed from the paper feeding unit having the highest main priority.

  In this way, it is possible to appropriately change the priority order for determining the sheet feeding unit for feeding sheets from the priority order before considering the target sheet feeding unit.

  The sensor outputs a signal according to the presence or absence of a sheet supplied to the sheet feeding unit, and a detachable unit that outputs a signal according to the attachment or detachment of the sheet feeding unit detachable from the apparatus main body. And the controller detects, in the detection process, a signal corresponding to the removal of the paper feeding unit from the apparatus main body by the attachment / detachment sensor, and then the attachment of the control unit. Or detecting a signal corresponding to the absence of a sheet being supplied to the sheet feeding unit by the sheet sensor. Then, the supply of the sheet to the sheet feeding unit may be detected by detecting a signal corresponding to the presence.

  In this way, after detecting a signal corresponding to the attachment of the sheet feeding unit to the apparatus main body after detachment or a signal corresponding to the absence of a sheet being supplied to the sheet feeding unit, By detecting a signal corresponding to the presence, it is possible to detect the supply of the sheet to the sheet feeding unit and appropriately change the priority order for determining the sheet feeding unit to feed the sheet. .

  In addition, when there is no sheet from the paper feeding unit that is feeding paper in the image forming process, the control unit sets the paper feeding unit that feeds paper in the priority order. It is also possible to change the sheet feeding unit to the next rank of the sheet feeding unit that is performing.

  In this way, it is possible to appropriately change the priority order for determining the sheet feeding unit that feeds the sheet, and when there is no sheet from the sheet feeding unit that was feeding the sheet, Based on the priority order for determining the paper feed unit to perform the paper feed, the paper feed unit to be fed can be changed.

  Further, in the order changing process, the control unit assigns the main priority of the target sheet feeding unit at the time of image formation instructed by the image forming instruction to a sheet feeding unit other than the target sheet feeding unit. It may be higher than the main priority.

  In this way, it is possible to appropriately raise the priority order for determining the sheet feeding unit for feeding sheets.

  In addition, when there are a plurality of the target sheet feeding units in the order changing process, the control unit determines the relative priority based on the basic priority among the target sheet feeding units when determining the main priority. The order may not be changed.

  In this way, the priority can be appropriately changed even when sheets are supplied to a plurality of sheet feeding units.

  In addition, when there are a plurality of target sheet feeding units in the order changing process, the control unit determines the target time with the shorter elapsed time between the target sheet feeding units when determining the main priority. The priority order of the sheet feeding unit may be higher.

  In this way, even when sheets are supplied to a plurality of sheet feeding units, the priority order can be appropriately changed in consideration of the length of time elapsed since the sheets were supplied. it can.

  In addition, the control unit may include a first setting unit that receives a setting related to a type of a sheet supplied to the sheet feeding unit, and the control unit may further include the elapsed time being shorter than a predetermined time in the order changing process. When there is the target sheet feeding unit for which the setting by the first setting unit is accepted when the sheet is supplied to the sheet feeding unit, the main priority of the target sheet feeding unit is set as the first priority. It may be set higher than the target sheet feeding unit that has not been set by the setting unit.

  In this way, by considering whether or not the setting relating to the type of sheet supplied to the sheet feeding unit is made, the priority order can be appropriately changed as compared with the case where no consideration is given.

  In addition, a second setting unit that receives settings relating to the type of sheet used for image formation may be provided, and settings received by the second setting unit may be received when the image forming instruction is received.

  In this way, it is possible to appropriately change the priority order for determining the sheet feeding unit that feeds the sheet, and at the time of accepting an image formation instruction to form an image in the image forming unit, image formation is performed. Settings relating to the type of sheet to be used can be made.

  In the order changing process, the control unit receives the setting by the first setting unit when the sheet is supplied to the sheet feeding unit in addition to the elapsed time being shorter than a predetermined time. Even when there is a sheet feeding unit, the sheet type received by the first setting unit is the target sheet feeding unit different from the sheet type received by the second setting unit. May not increase the priority of the target sheet feeding unit.

  In this way, the priority order can be set by considering whether or not the setting relating to the type of sheet to be supplied to the sheet feeding unit has been made and the setting content relating to the type of sheet used for image formation. It can be changed appropriately.

  Further, in the order change process, the control unit accepts the setting by the first setting unit when the sheet is supplied to the sheet feeding unit, in addition to the elapsed time being shorter than a predetermined time. Even when the target sheet feeding unit exists, the sheet type received by the first setting unit of the target sheet feeding unit is different from the sheet type received by the second setting unit. When there is the sheet feeding unit supplied with the same type of sheet set by the second setting unit, the main priority of the sheet feeding unit is set to the sheet feeding unit. It may be higher than the sheet feeding unit other than the unit.

  In this way, the target paper feed can be performed by taking into consideration whether or not the settings relating to the type of sheet supplied to the paper feed unit have been made and the setting contents relating to the type of sheet used for image formation. The priority order can be appropriately changed for other than the department.

  According to the present invention, it is possible to appropriately change the priority order for determining a sheet feeding unit that feeds a sheet.

1 is an explanatory diagram illustrating a configuration of a printer 100 according to an embodiment of the present invention. FIG. 2 is a block diagram schematically showing an electrical configuration of a printer 100. FIG. It is a schematic table showing an example of basic priority. 3 is a flowchart of a main process of a printing function performed by the printer. It is a flowchart of the priority determination process performed in the main process of FIG. It is a flowchart of the priority determination process different from FIG. 5 performed in the main process in 3rd Example. It is a flowchart of the priority determination process different from FIG.5 and FIG.6 performed in the main process in 4th Example. It is a flowchart of the priority determination process different from FIGS. 5-7 performed in the main process in 5th Example.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
[Entire printer configuration]
FIG. 1 is an explanatory diagram showing a configuration of a printer 100 (an example of an image forming apparatus) according to an embodiment of the present invention.

  As shown in FIG. 1, the printer 100 according to the present embodiment includes a main body casing 110 (an example of an apparatus main body), a printing unit 10 (an example of an image forming unit), an operation panel 40 (an example of a reception unit), A paper tray 51 (an example of a paper feed unit) is mainly provided.

  The printing unit 10 is located inside the main body casing 110 and is formed with a process unit 5 that forms a toner image on a sheet by a known electrophotographic method, and a conveyance belt 7 that conveys the sheet along the process unit 5. And a fixing unit 8 for fixing the toner image on the sheet. The printing unit 10 can print a desired image on a sheet.

  The operation panel 40 is located on the upper surface of the main body casing 110 and includes a liquid crystal display (not shown) and a button group including a start key, a stop key, a numeric keypad, and the like. The operation panel 40 allows the operation status of the printer 100 to be displayed and an input operation by the user to be performed. The input operation by the user is, for example, a print instruction (an example of an image formation instruction) that is an instruction for causing the printing unit 10 to perform printing. Note that when issuing a print instruction, the user can also instruct the type (size, thickness, etc.) of paper used for printing, the paper feed tray 51 for feeding paper, and the like.

  The paper feed tray 51 is positioned at the lower part and the front part of the main body casing 110 and stacks sheets used for image formation. The printer 100 according to this embodiment includes four trays 51A, 51B, 51C, and MP trays 51D as the paper feed trays 51. The tray 51A, the tray 51B, and the tray 51C are configured so as to be able to be drawn forward with respect to the main body casing 110. The tray 51A, the tray 51B, and the tray 51C can be pulled out from the main body casing 110. The state changes individually to the mounting state by being attached to the body 110 and being housed in the main body casing 110. When the tray 51A to the tray 51C are in the detached state, the user can place the paper. Further, when the trays 51A to 51C are in the mounted state, the printer 100 can feed paper from the trays 51A to 51C. The MP tray 51D allows a user to place paper, and the printer 100 can feed paper from the MP tray 51D.

  Each of the paper feed trays 51 </ b> A to 51 </ b> D is provided with paper feed rollers 71 </ b> A to 71 </ b> D that draw the loaded paper to the transport path 11. The paper used for printing in the printing unit 10 is fed by the corresponding feed rollers 71A to 71D from any one of the tray 51A, the tray 51B, the tray 51C, and the MP tray 51D, and passes through the conveyance path 11 to process the process unit. 5, and is printed by each component of the printing unit 10. In FIG. 1, the conveyance path 11 is indicated by a one-dot chain line. In addition, conveyance rollers 74 and 75 for conveying paper are provided in the conveyance path 11, and the paper fed from one of the paper feed trays 51 is conveyed to the printing unit 10 and printed by the printing unit 10. After being discharged, it is discharged to the upper part outside the main body casing 110.

[Electrical configuration of printer]
Next, the electrical configuration of the printer 100 will be described. As shown in FIG. 2, the printer 100 includes a CPU 31 (an example of a control unit), a ROM 32, a RAM 33, a nonvolatile storage unit 34, a printing unit 10, an operation panel 40, a network interface (hereinafter referred to as a network interface). / F) 37 (an example of a reception unit), a USB interface (hereinafter referred to as a USB I / F) 38 (an example of a reception unit), a detection unit 60 (an example of a sensor), and a measurement unit 80 (measurement) An example of a part).

  The ROM 32 stores various control programs for controlling the printer 100, various settings, initial values, and the like.

  The RAM 33 is used as a work area from which various control programs are read, or as a storage area for temporarily storing data. The CPU 31 controls each component of the printer 100 while storing the processing result in the RAM 33 or the nonvolatile storage unit 34 according to the control program read from the ROM 32.

  The printing unit 10 performs printing on paper fed from the paper feed tray 51 by the CPU 31 controlling the process unit 5, the conveyance belt 7, the fixing unit 8, and the like.

  The operation panel 40 is controlled by the CPU 31 to display the operation status on a liquid crystal display (not shown). In addition, a signal corresponding to the input operation by the user is transmitted to the CPU 31.

  The network I / F 37 and the USB I / F 38 are connected to an external computer (not shown) or the like via a communication line or a USB cable, and can perform mutual data communication. For example, the printing unit 10 performs printing. A print instruction (an example of an image formation instruction) to be performed is received, and image data for image formation is received.

  The detection unit 60 includes attachment / detachment sensors 61A to 61C (an example of attachment / detachment sensors) corresponding to the trays 51A to 51C, and sheet presence / absence sensors 64A to 64D (an example of sheet sensors) corresponding to the trays 51A to 51C and the MP tray 51D. And.

  The attachment / detachment sensors 61A to 61C are provided in the vicinity of the tray 51A to the tray 51C, respectively, and transmit two kinds of signals to the CPU 31 depending on whether the tray 51A to the tray 51C is detached or attached, respectively.

  The paper presence / absence sensors 64A to 64D are provided in the vicinity of the tray 51A to the tray 51C and the MP tray 51D, respectively, depending on whether or not the paper is placed in the tray 51A to the tray 51C and on the MP tray 51D, respectively. Then, two kinds of signals are transmitted to the CPU 31.

  The measurement unit 80 measures time by controlling the start and stop of measurement by the CPU 31.

[Detect paper supply]
Subsequently, based on a signal output from the detection unit 60, a detection process for detecting that a sheet is supplied to the sheet feed tray 51 by the user will be described in detail.

  The RAM 33 includes attachment / detachment flags 62A to 62C corresponding to the trays 51A to 51C, paper presence / absence flags 65A to 65D, trays 51A to 51C, and MP trays corresponding to the trays 51A to 51C and the MP tray 51D. Corresponding to 51D, paper supply presence / absence flags 67A to 67D are stored.

  The CPU 31 stores values corresponding to signals output from the attachment / detachment sensors 61A to 61C in the attachment / detachment flags 62A to 62C, respectively. More specifically, two values depending on whether the tray 51A to the tray 51C are detached or mounted are stored.

  In the paper presence / absence flags 65A to 65D, the CPU 31 stores values corresponding to the signals output from the paper presence / absence sensors 64A to 64D, respectively. More specifically, two values are stored depending on whether or not a sheet is placed in the trays 51A to 51C and the MP tray 51D.

  The paper supply presence / absence flags 67A to 67D are respectively supplied by the user based on the values of the attachment / detachment flags 62A to 62C and the paper presence / absence flags 65A to 65D and the signals output from the attachment / detachment sensors 61A to 61C and the paper presence / absence sensors 64A to 64D. The CPU 31 stores two values depending on whether or not it is determined that the paper is supplied to the paper tray 51 (that is, whether or not the paper is supplied).

  More specifically, for example, when the tray 51A is in the detached state by being pulled out of the main body housing 100 by the user, a signal corresponding to the fact that the tray 51A is in the detached state is sent to the CPU 31 by the attachment / detachment sensor 61A. Is transmitted to. Then, the CPU 31 sets the value of the attach / detach flag 62A to the detached state. In this situation, when a signal corresponding to the detection target tray 51A being attached is transmitted to the CPU 31 by the attachment / detachment sensor 61A, the CPU 31 sets the attachment / detachment flag 62A corresponding to the detection target tray 51A. Since the value is a value indicating the detached state, it is determined that the sheet is supplied to the tray 51A. That is, it is determined that the user has placed a sheet on the tray 51A, assuming that the tray 51A has changed from the detached state to the mounted state. Then, the CPU 31 sets the value of the attachment / detachment flag 62A to the mounted state, and stores a value corresponding to the presence of paper supply in the paper supply presence / absence flag 67A. The same applies to the tray 51B and the tray 51C.

  Further, for example, when all sheets in the tray 51A are printed or the like, the sheet is not placed, and the sheet presence sensor 64A determines that the sheet is not placed in the tray 51A. The signal is transmitted to the CPU 31. Then, the CPU 31 sets the value of the sheet presence / absence flag 65A as a value indicating that no sheet is placed. In this situation, if the CPU 31 receives a signal indicating that the paper is placed in the tray 51A to be detected by the paper presence / absence sensor 64A, the CPU 31 indicates that the value of the paper presence / absence flag 65A indicates that the paper is present. Since the value indicates that the sheet is not placed, it is determined that the sheet is supplied to the tray 51A. That is, it is determined that the user has placed a sheet on the tray 51A on the assumption that the sheet has been placed in the tray 51A, and the sheet has been placed. Then, the CPU 31 sets the value of the paper presence / absence flag 65A as a value indicating that the paper is placed, and stores a value corresponding to the presence / absence of paper supply in the paper supply presence / absence flag 67A. The same applies to the tray 51B, the tray 51C, and the MP tray 51D.

  As described above, the CPU 31 performs a detection process for detecting that the user has supplied the paper to the paper feed tray 51 based on the signal output from the detection unit 60. The detection process is an example of the detection process of the present invention.

  Note that the paper supply presence / absence flag 67 is used to determine whether or not paper is supplied to the corresponding paper feed tray 51 by referring to a value by the CPU 31 in a printing function described later. More specifically, when the value corresponding to the presence of paper supply is stored in the paper supply presence / absence flag 67, the CPU 31 determines that the paper supply is made to the corresponding paper feed tray 51, and the paper supply is present. As a process according to this, time measurement is started as will be described in detail later. After starting the time measurement, the CPU 31 stores a value corresponding to the absence of paper supply in the paper supply presence / absence flag 67 in which a value corresponding to the presence of paper supply is stored.

[Priority]
Next, the priority order for determining the paper feed tray 51 for paper feed during printing will be described.

  FIG. 3 is a schematic table showing an example of basic priorities.

The non-volatile storage unit 34 (an example of a storage unit) has a basic priority (an example of a basic priority) that is an order for determining a paper feed tray 51 to be fed when printing in the printing unit 10. It is remembered.
For example, as shown in FIG. 3, the basic priority order is tray 51A → tray 51B → tray 51C → MP tray 51D. In this case, when printing is performed in the printing unit 10, paper is fed from the tray 51A. . In this embodiment, the basic priority is stored in advance in the printer 100, but may be set by the user, for example.

  When the print instruction received from the network I / F 37 or the like does not indicate the paper feed tray 51 for feeding paper, the printer 100 is determined based on the basic priority and through the priority order determination process described in detail later. Paper is fed from each of the paper feed trays 51A to 51D according to the order.

[Print function]
Hereinafter, a main process and a priority order determination process when performing printing related to the printing function of the printer 100 will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a flowchart of the main process of the printing function performed by the printer 100.

  FIG. 5 is a flowchart of the priority determination process performed in the main process of FIG.

  The main process is executed by the CPU 31 when the printer 100 is powered on. Note that when the printer 100 is turned on, the paper supply presence / absence flags 67A to 67D store values corresponding to the absence of paper supply.

  When the main process is started, the CPU 31 first determines whether or not a value corresponding to the presence of paper supply is stored in each of the paper supply presence / absence flags 67A to 67D by the above-described detection process, whereby each paper feed tray 51 is detected. It is determined whether or not a new sheet has been supplied (S100).

  When it is determined that at least one of the paper supply presence / absence flags 67A to 67D stores a value corresponding to the presence of paper supply, it is determined that a new sheet is supplied to at least one paper feed tray 51 (S100). : YES), the CPU 31 starts measuring time for the paper feed tray 51 whose value stored in the paper supply presence / absence flag 67 is a value corresponding to the presence of paper supply (S110). Then, a value corresponding to no paper supply is stored in the corresponding paper supply presence / absence flag 67, and the process proceeds to S120.

  On the other hand, when the values corresponding to the absence of paper supply are stored for all of the paper supply presence / absence flags 67A to 67D, it is determined that no paper is newly supplied by the user for all the paper feed trays 51 (S100). : NO), CPU31 transfers to the process of S120.

  In the processing of S120, the CPU 31 determines whether or not a printing instruction from the printing unit 10 has been received, for example, when the user operates an external computer or the like connected via the network I / F 37 or the like.

  When it is determined that the print instruction has been received (S120: YES), the CPU 31 measures the time by the measuring unit 80 when there is the paper feed tray 51 that has been measuring the time by the measuring unit 80. For all the paper feed trays 51X (X: any one of A to D), the measurement by the measurement unit 80 is stopped, the corresponding measurement time tX (an example of elapsed time) is stored in the RAM 33, and the measurement unit 80 The time measured by is reset to “0”. Then, “0” is stored in the RAM 33 as the value of the measurement time tX of the paper feed tray 51X that has not started measurement (S125). After the process of S125, the process proceeds to the priority order determination process of S130.

  On the other hand, if it is determined that a print instruction has not been received (S120: NO), the process returns to S100 to determine whether or not a new sheet has been supplied to each sheet feed tray 51. If there is a paper feed tray 51X that has passed a certain time (for example, 10 times the time T regarded as immediately before the print instruction) after the measurement is started in S110, the measurement for the paper feed tray 51X is stopped. And reset the measured time. Further, when it is determined that the paper is already supplied again in S110 for the paper feed tray 51 that has already started measurement in S110, for example, when the paper is supplied once and then supplied again, the measurement is performed. Start again.

  The priority determination process in S130 will be described in detail with reference to FIG.

  When the priority order determination process is started, the CPU 31 first reads the basic priority order from the nonvolatile storage unit 34 (S210).

  In this embodiment, as shown in FIG. 3, it is assumed that the basic priority order is the order of tray 51A → tray 51B → tray 51C → MP tray 51D in order from the highest order.

  After the processing of S210, the CPU 31 considers that the measurement time tX from when the paper in at least one paper feed tray 51X is supplied (measurement start) to when the print instruction is received (measurement stop) is immediately before the print instruction. Assuming that 0 <tX <T is satisfied with respect to T (> 0), it is determined whether tX is smaller than T and larger than zero. That is, for at least one paper feed tray 51, it is determined whether or not the paper is supplied by the user and the paper is supplied immediately before printing (S220).

  When it is determined that 0 <tX <T is satisfied for at least one measurement time tX, it is determined that the user has supplied the paper for at least one paper feed tray 51X and is the paper supply immediately before printing (S220). : YES), the CPU 31 increases the basic priority of the paper feed tray 51 (an example of the target paper feed unit) corresponding to the measurement time tX satisfying 0 <tX <T by one, and sets the newly determined priority. The priority order (priority order, an example of the present priority order) is stored in the RAM 33 (S230), the stored values of the measurement times tA to tD are cleared, and the priority order determination process ends. For example, when the basic priority is raised by one in the above-described basic priority, for the tray 51C, the order is tray 51A → tray 51C → tray 51B → MP tray 51D. Further, for example, when the rank is raised by one for the tray 51C and the MP tray 51D, the order is tray 51A → tray 51C → MP tray 51D → tray 51B.

  On the other hand, assuming that 0 <tX <T is not satisfied for all the measurement times tA to tD, there is no paper supply by the user for all the paper feed trays 51A to 51D or no paper supply immediately before printing. (S220: NO), the basic priority read in S210 is stored in the RAM 33 as the main priority (S240), and the priority determination process is terminated.

  When the priority order determination process of S130 is completed, the CPU 31 reads the main priority order from the RAM 33, and drives the paper supply roller 71 that feeds paper from the paper supply tray 51 having the highest priority in the main priority order to supply paper. Then, printing is performed on the paper, and the paper is discharged (S140).

  After completion of the process of S140, the CPU 31 determines whether or not all printing instructed by the print instruction has been completed (S150). When it is determined that the printing instructed by the print instruction has been completed (S150: YES), the process returns to the process of S100 for determining whether or not the paper is supplied to each paper feed tray 51.

  On the other hand, if it is determined that the printing instructed by the printing instruction has not been completed (S150: NO), the CPU 31 places the paper on the paper presence sensor 64 corresponding to the paper feed tray 51 that has been feeding paper. It is determined whether or not a value corresponding to not being stored is stored. That is, it is determined whether or not the paper feed tray 51 that has been feeding paper is out of paper (S160).

  When it is determined that the paper feed tray 51 that has been feeding paper is out of paper (S160: YES), the CPU 31 performs feeding in this priority order when performing printing in S140. Assume that paper is supplied from the paper feed tray 51 next to the paper tray 51 (S170). Thus, after the process shifts to S140, the paper is supplied from the paper feed tray 51 of the next rank of the paper feed tray 51 that has been feeding paper.

  On the other hand, if it is determined that the paper feed tray 51 that has been feeding is not out of paper (S160: NO), the process returns to S140 to continue feeding from the paper feed tray 51 that was feeding, Continue printing.

  When it is determined in S110 that paper has been supplied to each paper feed tray 51, the measurement unit 80 starts measuring time, and a series of processes in which measurement by the measurement unit 80 is performed until a print instruction is received in S120. It is an example of the measurement process of this invention.

  In addition, by the processing of S220 and S230, the paper used for printing instructed by the printing instruction is performed by raising the main priority of the paper feeding tray 51 corresponding to the measurement time tX satisfying 0 <tX <T by one. The priority order determination process of S130 prior to S140 is an example of the order change process of the present invention. Further, when there is no paper feed tray 51 corresponding to the measurement time tX satisfying 0 <tX <T (S220: NO), the basic priority is set as the main priority (S240), and the measurement satisfying 0 <tX <T is achieved. When there is a paper feed tray 51 corresponding to the time tX (S220: YES), the priority is increased by one from the basic priority of the paper feed tray 51X corresponding to the measurement time tX satisfying 0 <tX <T. (S230) The priority order determination process of S130 is an example of the order change process of the present invention.

  Further, the process of S140 in which paper is fed from the paper feed tray 51 having the highest priority in this priority order and printing is an example of the image forming process of the present invention. If it is determined in S160 that the paper feed tray 51 that has been feeding paper is out of paper, in this priority order, the paper feed tray 51 of the next order of the order of the paper feed tray 51 that has been feeding paper. The process of S140 in which the sheet is fed and printed is also an example of the image forming process of the present invention.

  The priority order may be overwritten as the basic priority order and stored in the nonvolatile storage unit 34 and used for subsequent printing, or may not be stored in the nonvolatile storage unit 34. .

  In the configuration as in the present embodiment, the printer 100 feeds the size of the paper placed on the paper feed tray 51 such that the printer 100 determines the size of the paper by feeding paper, for example. This is particularly effective when the configuration does not have a means for making a determination in advance.

<Effect>
According to the present embodiment, for the paper feed tray 51 in which the measurement time tX from when the paper is supplied until the printing instruction to be printed by the printing unit 10 is received is shorter than the time T that is regarded as immediately before the printing instruction, the paper is It is possible to facilitate paper feeding assuming that not much time has passed since the feeding. In other words, when a user supplies paper for use in printing, there is a high possibility that a print instruction will be given immediately after supply. However, if the user accidentally notices that the paper has run out and supplies paper, the print instruction will be given immediately. It is considered unlikely that Accordingly, it is possible to appropriately change the priority order for determining the paper feed tray 51 for feeding paper.

  Also, printing is performed based on the priority order that is changed with respect to the priority order of the paper feed tray 51 that is determined to have been supplied immediately before printing with respect to the basic priority order stored in the nonvolatile storage unit 34. be able to. Accordingly, the priority order for determining the paper feed tray 51 for feeding paper is appropriately changed from the priority order before considering the paper feed tray 51 that is determined to have been supplied with paper immediately before printing. Can do.

  Further, after detecting a signal corresponding to the attachment of the paper feed tray 51 to the main body housing 110 after being detached or a signal corresponding to the absence of paper being supplied to the paper feed tray 51, By detecting a signal corresponding to the presence, the supply of paper to the paper feed tray 51 is detected, and the priority order for determining the paper feed tray 51 to feed paper is appropriately changed. Can do.

  Further, when there is no more paper from the paper feed tray 51 that has fed paper, the paper feed tray 51 to be fed is changed based on the priority order for determining the paper feed tray 51 to be fed. I can do it. Accordingly, it is possible to appropriately change the priority order for determining the paper feed tray 51 for feeding paper, and to feed paper from the appropriate paper feed tray 51 when the paper has run out from the paper feed tray 51 that has fed paper. Easy to do paper.

(Second embodiment)
Next, a second embodiment will be described. The points not described are the same as in the first embodiment.

  In the second embodiment, in the priority determination process of S130, it is determined that the user has supplied paper for at least one of the paper feed trays 51A to 51D and that the paper is supplied immediately before printing ( S220: YES), instead of the process of S230, the CPU 31 sets the basic priority of the paper feed tray 51X corresponding to the measurement time tX satisfying 0 <tX <T to the measurement time tX not satisfying 0 <tX <T. The priority newly determined by raising the order of the corresponding paper feed tray 51 is stored in the RAM 33 as the main priority (S231). Then, after the process of S231, the stored values of the measurement times tA to tD are cleared, and the priority order determination process ends.

  That is, for example, when only the measurement time tC of the tray 51C satisfies 0 <tC <T, in the first embodiment, the CPU 31 determines that the main priority of the tray 51C is the second priority. On the other hand, in the second embodiment, the CPU 31 raises the priority of the tray 51C higher than the tray 51A, the tray 51B, and the MP tray 51D corresponding to the measurement time tX that does not satisfy 0 <tX <T. . That is, the main priority is set to tray 51C → tray 51A → tray 51B → MP tray 51D, and the main priority of the tray 51C is set to the first priority. For example, when the measurement time tC of the tray 51C and the measurement time t of the MP tray 51D satisfy 0 <tC <T and 0 <tD <T, in the first embodiment, the CPU 31 determines that the tray 51C and MP The main priority of the tray 51D is assumed to be the second order and the third order, respectively, but in the second embodiment, it is more than the tray 51A and the tray 51B corresponding to the measurement time tX that does not satisfy 0 <tX <T. Increase the ranking. That is, the main priority order is tray 51C → MP tray 51D → tray 51A → tray 51B, and the main priority order of the tray 51C and the MP tray 51D is the first order and the second order, respectively. At this time, the relative priority on the basic priority of the tray 51C and the MP tray 51D is not changed and the rank is raised. For example, when 0 <tD <tC <T is satisfied, the MP tray 51D is set as the first rank, the tray 51C is set as the second rank, and this priority is set as MP tray 51D → tray 51C → tray 51A → tray. It may be 51B. In other words, when there are a plurality of paper feed trays 51X satisfying 0 <tX <T, the main priority of the paper feed trays 51X having a shorter measurement time tX may be set higher.

<Effect>
According to the present embodiment, when a print instruction is received, the paper feed tray 51X whose measurement time tX is shorter than the time T that is regarded as immediately before the print instruction is supplied with paper for use in printing instructed by the print instruction. The priority for determining the paper feed tray 51 for feeding paper is determined to be higher than the paper feed trays 51 other than the paper feed tray 51 determined to have been supplied immediately before printing. Can also be high. Therefore, the priority order for determining the paper feed tray 51 for feeding paper can be appropriately raised.

  In addition, when a print instruction is received, regarding a plurality of paper feed trays 51 that are determined to have been supplied with paper immediately before printing, in the printing instructed for printing, paper is supplied immediately before printing. The priority order is not changed because it is difficult to make a determination to change the basic priority order that should be adopted when the paper feed tray 51 to be judged does not exist. Accordingly, the priority order can be appropriately changed even when there is paper supply immediately before printing on the plurality of paper feed trays 51.

  In addition, when the print instruction is received, the paper feed tray 51 that is determined to have supplied the paper most recently from the time when the print instruction is received and that the paper has been supplied immediately before printing is issued. Assuming that there is a higher possibility that paper has been supplied for use in printing, the priority order for determining the paper feed tray 51 for feeding paper can be made higher.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. The points not described are the same as in the first embodiment.

  In the third embodiment, when the user supplies / or supplies paper to the paper feed tray 51, the printer 100 is connected to the operation panel 40 or an external device connected via the network I / F 37 or USB I / F 38. A screen for making settings related to the type of paper supplied to / from the paper feed tray 51 is displayed on the computer or the like, and settings for the paper type are accepted as required by the user. That is, in the detection process, for example, when a value corresponding to the presence of paper supply is stored in the paper supply presence / absence flag 67, the CPU 31 connects to an external computer connected via the operation panel 40 or the network I / F 37. A screen for setting the type of paper supplied to the paper feed tray 51 corresponding to the paper supply presence / absence flag 67 storing a value corresponding to the presence of paper supply is displayed, and the operation panel 40 or the network I / F 37 is displayed. A setting for the paper type is accepted from an external computer or the like connected via the computer as required by the user. In addition, when the CPU 31 receives a setting for the paper type from the user from an external computer or the like connected via the operation panel 40 or the network I / F 37, the CPU 31 stores the paper in the nonvolatile storage unit 34 according to the presence of paper supply. In response to the paper feed tray 51 corresponding to the paper supply presence / absence flag 67 storing the stored value, the fact that the setting of the paper type has been received from the user is stored. The operation panel 40, the network I / F 37, and the USB I / F 38 are examples of a first setting unit. When it is determined that the paper feed tray 51 is in the detached state, the paper stored with a value corresponding to the presence of paper supply in an external computer connected via the operation panel 40 or the network I / F 37 or the like. A screen for setting the type of paper supplied to the paper feed tray 51 corresponding to the supply presence / absence flag 67 is displayed, and from an external computer or the like connected via the operation panel 40 or the network I / F 37, the user can The configuration may be such that settings are received for the paper type as required.

  FIG. 6 is a flowchart of priority order determination processing different from FIG. 5 performed in the main processing in the third embodiment.

  In FIG. 6, the processes of S310, S320, S340, and S360 are the same as the processes of S210, S220, S240, and S230, respectively.

  In the third embodiment, in the priority determination process, when it is determined that the user has supplied paper for at least one of the paper feed trays 51A to 51D and that the paper is supplied immediately before printing (S320: YES), the CPU 31 stores, in the nonvolatile storage unit 34, the fact that the setting of the paper type has been received from the user for the paper feed tray 51 determined to have been supplied with the paper immediately before at least one printing. (S330). That is, it is determined whether or not a setting is accepted for the paper type from the user via the operation panel 40 or the network I / F 37 for the paper feed tray 51 to which the paper was supplied immediately before printing.

  With regard to the paper feed tray 51 that is determined to have been supplied with the paper immediately before at least one printing, it is assumed that the user has received a setting for the paper type, and the operation panel 40 or the network I / F 37 is used. When the CPU 31 determines that the setting for the paper type has been received from the user (S330: YES), the CPU 31 receives the setting for the paper type from the user, and the paper feed tray 51 that has been supplied with the paper immediately before printing. By setting the basic priority higher than the order of the paper feed tray 51 that has not received the setting for the paper type from the user and was supplied with the paper immediately before printing, the newly determined priority is set as the main priority. The value is stored in the RAM 33 (S370), the stored values of the measurement times tA to tD are cleared, and the priority determination process is terminated. To.

  That is, for example, when the measurement time tC of the tray 51C and the measurement time t of the MP tray 51D satisfy 0 <tC <T and 0 <tD <T, in the first embodiment, the CPU 31 determines that the tray 51C and MP Although the main priority order of the tray 51D is the second order and the third order, respectively, in the third embodiment, for example, the fact that the setting is accepted from the user for the paper type corresponding to the MP tray 51D is stored. If it is not stored that the setting of the paper type is accepted from the user corresponding to the tray 51C, only the MP tray 51D is supplied from the user when the paper is supplied immediately before printing. Assuming that the setting for the type of paper to be received is received, the rank of the MP tray 51D is raised above the rank of the tray 51C. That is, for example, it is assumed that the main priority of the tray 51C and the MP tray 51D is the second rank and the first rank, respectively.

  On the other hand, regarding the paper feed tray 51 for which it has been determined that all sheets have been supplied immediately before printing, it is determined that it has not been stored that the setting of the sheet type has been received from the user. When it is determined that the setting for the paper type is not received from the user via / F37 or the like (S330: NO), the CPU 31 supplies the paper corresponding to the measurement time tX satisfying 0 <tX <T, as in S230. A new priority determined by raising the basic priority of the tray 51 by 1 is stored in the RAM 33 as the main priority (S360), and the priority determination process is terminated. In the process of S360, the CPU 31 may store the basic priority read in S310 in the RAM 33 as the main priority, similarly to S340. That is, any configuration may be used as long as the paper feed tray 51 corresponding to the measurement time tX satisfying 0 <tX <T is changed to a lower rank than the main priority determined in S370. If only one paper feed tray 51 is determined to have been supplied immediately before printing, in S370 the main priority is set higher than the main priority determined in S360. Any configuration may be used.

<Effect>
According to the present embodiment, when the print instruction is received, the measurement time tX is shorter than the time T regarded as immediately before the print instruction, and the supply related to the type of paper supplied when the paper is supplied is set. As for the paper tray 51, it is assumed that the possibility that the paper is supplied for use in the printing instructed by the print instruction is higher than that of the paper feeding tray 51 in which the setting relating to the type of the supplied paper is not performed. Can be raised more. Therefore, by considering whether or not the setting relating to the type of paper to be supplied to the paper feed tray 51 is made, the priority order can be appropriately changed as compared with the case where no consideration is given.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG. The points not described are the same as in the third embodiment.

  In the fourth embodiment, when a printing instruction is received from the network I / F 37 or the like by a user operation, the type of paper used for printing is also instructed. This instruction may directly specify the type of paper, or specify the contents of printing (printing using specific paper such as photo printing or text printing, designation of image quality, etc.), etc. The type of paper may be indirectly specified by. The operation panel 40, the network I / F 37, and the USB I / F 38 are examples of a second setting unit. In the fourth embodiment, it is assumed that several types of basic priorities are stored in the printer 100 in advance according to the types of paper used for printing, such as size and material. For example, the basic priority corresponding to the case where the paper type is A4 plain paper is stored as the basic priority shown in FIG. 3, and in addition, the basic priority corresponding to the case where the paper type is postcard. Are stored in the order of MP tray 51D → tray 51A → tray 51B → tray 51C in order from the highest.

  FIG. 7 is a flowchart of priority order determination processing different from that in FIGS. 5 and 6 performed in the main processing in the fourth embodiment.

  FIG. 7 is obtained by adding S365 and related processing to FIG. In the process of S360, the basic priority read in S310 is stored in the RAM 33 as the main priority. In the fourth embodiment, the process of S310 determines the type of paper used for printing that is also instructed in the print instruction, and the basic priority corresponding to the determined paper type is determined from the stored basic priority. Is a process of reading

  The CPU 31 determines that the fact that the setting of the paper type has been received from the user is stored for the paper feed tray 51 determined to have been supplied with the paper immediately before at least one printing operation. When it is determined that a setting has been received from the user via the network I / F 37 or the like for the type of paper supplied to the corresponding paper feed tray 51 (S330: YES), the print instruction is received from the network I / F 37 or the like. It is determined whether there is a paper feed tray 51 in which the type of paper used for printing matches the type of paper supplied to the corresponding paper feed tray 51 (S365).

  When there is a paper feed tray 51 in which the type of paper used for printing received together with the print instruction from the network I / F 37 or the like matches the type of paper supplied to the corresponding paper feed tray 51 (S365: YES) The CPU 31 raises only the basic priority order of the paper feed tray 51 that is received from the network I / F 37 or the like and that matches the type of paper used for printing and the type of paper supplied to the relevant paper feed tray 51. Thus, the newly determined priority order is stored in the RAM 33 as the main priority order (S371), the stored values of the measurement times tA to tD are cleared, and the priority order determination process ends.

  On the other hand, when there is no paper feed tray 51 in which the type of paper used for printing received from the network I / F 37 or the like matches the type of paper supplied to the corresponding paper feed tray 51 (S365: NO), the CPU 31 As in S340 and S360, the basic priority read in S310 is stored in the RAM 33 as the main priority (S380), and the priority determination process is terminated. In the process of S380, for the paper feed tray 51 in which the type of paper used for printing and the type of paper supplied to the corresponding paper feed tray 51 do not match, the priority order is arbitrarily lowered. It may be configured to have this priority order. In this way, it is possible to make it difficult to feed paper from the paper feed tray 51 on which paper that does not match the type of paper used for printing is placed.

<Effect>
According to the present embodiment, the priority order for determining the paper feed tray 51 for feeding paper can be changed appropriately, and the setting relating to the type of paper used for printing can be made when a print instruction is received. Can be accepted.

  Further, when the print instruction is received, the setting is performed even if the measurement time tX is shorter than the time T that is regarded as immediately before the print instruction and the paper feed tray 51 is set with respect to the type of paper to be supplied. If the type of paper used and the type of paper used for printing are different, it is unlikely that the paper has been supplied for use in the printing instructed by the printing instruction, and the priority order for the paper feeding order is set. Can not raise. Therefore, the priority order can be changed appropriately by considering whether or not the setting relating to the type of paper supplied to the paper feed tray 51 has been made and the setting content relating to the type of paper used for printing. I can do it.

(5th Example)
Next, a fifth embodiment will be described with reference to FIG. The points not described are the same as in the first embodiment.

  FIG. 8 is a flowchart of priority order determination processing different from those in FIGS. 5 to 7 performed in the main processing in the fifth embodiment.

  In the fifth embodiment, as in the third embodiment, when the CPU 31 stores a value corresponding to the presence of paper supply in the paper supply presence / absence flag 67 in the detection process, the CPU 31 controls the operation panel 40 or the network I / F 37. A screen for setting the type of paper supplied to the paper feed tray 51 corresponding to the paper supply presence / absence flag 67 storing a value corresponding to the presence of paper supply is displayed on an external computer or the like connected via the computer. Assume that settings are accepted for the paper type as required by the user via the operation panel 40 or the network I / F 37. Similarly to the fourth embodiment, when a printing instruction is received by a user operation from an external computer connected via the network I / F 37 or the like, the type of paper used for printing is also instructed. Shall be.

  In the fifth embodiment, it is assumed that the tray 51B and the tray 51C cannot be fed in printing using glossy paper as the paper type.

  In FIG. 8, it is assumed that the processes of S410, S420, and S440 are the same as the processes of S210, S220, and S240, respectively.

  In the priority determination process, when it is determined that the user has supplied paper for at least one of the paper feed trays 51A to 51D and the paper is supplied immediately before printing (S420: YES), the CPU 31 performs printing. It is determined whether or not at least one paper feed tray 51X to which paper was supplied immediately before is a paper feed tray 51 that cannot be fed due to the setting of the type of paper used for printing (S430). That is, for example, when printing using glossy paper is instructed, the paper feed tray 51X to which paper was supplied immediately before printing is either the tray 51B or the tray 51C, or the tray 51A and It is determined whether it is any of the MP trays 51D.

  When it is determined that at least one paper feed tray 51X to which paper was supplied immediately before printing is a paper feed tray 51 that cannot be fed due to the setting of the type of paper used for printing (S430: YES), the CPU 31 informs the operation panel 40 or the network I / F 37 or USB I / F 38 that the setting of the paper type used for printing or the setting of the paper type of the paper feed tray 51 may be incorrect. To the external computer connected via the network, prompts the user to confirm or change the setting, and accepts the change of the setting from the external computer or the like connected via the operation panel 40 or the network I / F 37 (S450). ). In such a case, for example, when printing using glossy paper is instructed, one of the tray 51B and the tray 51C is included in the paper feed tray 51X that has been supplied with paper immediately before printing. This is the case. Of the paper feed trays 51X to which the paper was supplied immediately before printing, all of the paper feed trays 51 that cannot be fed may be notified or used for printing. The configuration may be such that only the one that can have the highest priority among the paper feed trays 51 that cannot be fed in the setting of the paper type is determined and notified. The operation panel 40 is an example of a notification unit.

  On the other hand, when it is determined that all the paper feed trays 51X to which the paper was supplied immediately before printing are paper feed trays 51 that can be fed due to the setting of the type of paper used for printing (S430: NO) After the processing of S450 and S450, the CPU 31 raises the basic priority of the paper feed tray 51 that is capable of feeding paper by setting the type of paper used for printing when paper is supplied immediately before printing. Thus, the priority order newly determined is stored in the RAM 33 as the main priority order (S460), and the priority order determination process is terminated.

<Effect>
According to the present embodiment, when the paper feed tray 51 determined to have been supplied immediately before printing is a paper feed tray 51 that cannot be used for printing, the paper supplied to the paper feed tray 51 is used. The user can be prompted to confirm the setting of at least one of the type of sheet and the type of sheet used for printing.

(Sixth embodiment)
Next, a sixth embodiment will be described. The points not described are the same as those in the fifth embodiment.

  In the sixth embodiment, when a printing instruction is received by a user operation from an external computer or the like connected via the operation panel 40 or the network I / F 37, the paper feed tray 51 used for printing is also included. When instructed, the type of paper used for printing is instructed. For example, when the type of paper supplied to the tray 51A instructed together with the print instruction is glossy paper, the type of paper used for printing is glossy paper. Further, it is assumed that there is one paper feed tray 51X that is determined to have supplied paper immediately before printing.

  In the sixth example, the process of S431 that replaces the process of S430 and the process related to S431 are different from those of the fifth example.

  In the sixth embodiment, in the process of S431, which is the process after S420: YES, the CPU 31 is set together with the paper feed tray 51X to which the paper was supplied immediately before printing, at the time of printing instruction. It is determined whether the paper feed tray 51 is not selected. That is, for example, when the tray 51A is set, the paper feed tray 51X to which the paper was supplied immediately before printing is one of the tray 51B, the tray 51C, and the MP tray 51D, or the tray 51A. It is judged whether it is.

  When it is determined that the paper feed tray 51X that is determined to have been supplied immediately before printing is not the paper feed tray 51 that is set together with the print instruction (S431: YES), the CPU 31 performs printing. The operation panel 40 or the like is notified that there is a possibility that the setting of the paper feed tray 51 to be used is incorrect, the user is prompted to confirm or change the setting, and the connection is made via the operation panel 40 or the network I / F 37 or the like. A setting change is received from an external computer or the like (S451).

On the other hand, when it is determined that the paper feed tray 51X that is determined to have been supplied immediately before printing is the paper feed tray 51 that is set together with the print instruction (S431: NO), the CPU 31 Then, by setting the basic priority of the paper feed tray 51 set together with the print instruction as the first priority, the newly determined priority is stored in the RAM 33 as the main priority (S461), and the priority is determined. The process ends.
Note that if there are a plurality of paper feed trays 51X that are determined to have been supplied with paper immediately before printing, printing instructions for all of the paper feed trays 51X that are determined to have been supplied with paper immediately before printing are printed. When determining that the paper feed tray 51 is not set at the same time, the CPU 31 may be configured to notify the operation panel 40 or the like that the setting of the paper feed tray 51 used for printing may be incorrect. It is done. On the other hand, if there is a paper feed tray 51 that is set at the time of the print instruction for the paper feed tray 51X that is determined to have been supplied immediately before printing, the CPU 31 performs the same process as in S461. Process.

<Effect>
According to this embodiment, when the paper feed tray 51 that is determined to have been supplied immediately before printing is a paper feed tray 51 that is not set to be used for printing, the type of paper used for printing is determined. The user can be prompted to confirm the settings. Accordingly, when the paper feed tray 51 to which paper is supplied for use in printing instructed by the print instruction is not set to be used for printing, the user is prompted to confirm the setting, and the priority order is confirmed. Can be changed more appropriately than when not prompting the user.

(Other examples)
(1) In the above-described embodiment, the image forming apparatus is the printer 100. However, the image forming apparatus is not limited to this, and may be, for example, an inkjet printer or a multifunction machine having a copy function and a FAX function in addition to a printer function.

  (2) In the above-described embodiment, the processing is executed by one CPU 31. However, the configuration is such that processing is executed by a plurality of CPUs 31, only hardware circuits such as ASIC (Application Specific Integrated Circuit), or the CPU 31 and the hardware. A configuration in which processing is executed by a circuit may be used.

  (3) In the above embodiment, the order is determined as the basic priority for each paper feed tray 51, but this need not be the case. That is, the basic priority order does not exist for each paper feed tray 51 and may be the same order. In such a configuration, when a print instruction is issued, the order is changed for the paper feed tray 51 that is determined to have been supplied immediately before printing, and the priority is set. The configuration may be such that paper is fed from the paper tray 51.

  (4) In the above embodiment, paper supply is performed by either a combination of the value of the attachment / detachment flag 62 and the detection result of the attachment / detachment sensor 61, or a combination of the value of the paper presence / absence flag 65 and the detection result of the paper presence / absence sensor 64. It has been determined whether or not it exists, but for the paper feed trays 51A to 51C, the combination of the value of the attachment / detachment flag 62 and the detection result of the attachment / detachment sensor 61, the value of the paper presence / absence flag 65, and the detection of the paper presence / absence sensor 64. When it is determined that there is paper supply for both combinations of results, the paper supply presence / absence flag 67 may store a value corresponding to the presence of paper supply.

  (5) In the above-described embodiment, when it is determined that the paper is supplied immediately before printing for the plurality of paper feed trays 51, for example, the priority is not changed without changing the relative order based on the basic priority. The priority is set higher as the time from the paper supply to the print instruction is shorter, or the like. For example, the higher the paper feed tray 51 used, the higher the priority. Etc.

  (6) In the above embodiment, the paper feed unit is the paper feed trays 51A to 51C that can be attached to and detached from the main body casing 110 and the MP tray 51D that can directly place paper. Not limited. For example, the paper feed unit may be a manual feed port that feeds paper after the paper is directly abutted against a roller for carrying the paper and the paper is conveyed in a small amount. In this case, a sensor that outputs a signal corresponding to the presence / absence of a sheet is provided on the front side of the roller, and the control unit determines that the sheet is supplied or not when the sensor outputs a signal corresponding to the presence / absence of the sheet. Configuration is conceivable.

  (7) In the detection process, when the value of the paper presence / absence flag 65X of the paper feed tray 51X is a value indicating that no paper is loaded, the CPU 31 determines that the paper feed tray 51X is attached to the main body casing 110 by the user. When the signal corresponding to the separation state is transmitted by the attachment / detachment sensor 61X, the type of the paper placed on the paper feed tray 51X is notified to the operation panel 40 or the like. It may be configured to. That is, when a sheet is not placed on the paper feed tray 51X and the tray is detached, the operation panel 40 or the like is notified of the type of paper placed on the paper feed tray 51X. In such a configuration, a change in the type of paper placed on the paper feed tray 51X from the type of paper placed by the user's operation is received from the operation panel 40 or the like. Also good. In such a configuration, it is possible to detect the detachment of the paper feed tray 51 from the main body casing 110 and notify the user of information relating to the paper supplied to the paper feed tray 51. Thus, the user can recognize the information on the supplied paper and supply the paper to the paper feed tray 51. Therefore, it is possible to appropriately change the priority order related to the sheet feeding order while considering the convenience in supplying the sheets to the sheet feeding tray 51. In addition, when a sheet different from the information related to the sheet supplied to the sheet feeding tray 51 is placed, the setting can be changed to the supplied sheet. Therefore, it is possible to appropriately change the priority order related to the sheet feeding order while considering the convenience in supplying the sheets to the sheet feeding tray 51.

  (8) In the third embodiment, when the user supplies / or supplies paper to the paper feed tray 51, the printer 100 supplies the operation panel 40 or the like to the paper supplied / or to the paper feed tray 51. A screen for performing settings relating to the type of paper is displayed, and the setting for the paper type is accepted as required by the user. When the CPU 31 accepts a setting for the paper type from the user, the paper type The fact that the setting has been received from the user is stored in the nonvolatile storage unit 34, but this need not be the case. For example, in the configuration in which the time when the setting is changed is stored, the setting related to the type of paper supplied to the paper feed tray 51 and / or the time T2 before and after the paper supply to the paper feed tray 51 is detected. When the operation is performed, the CPU 31 may store the fact that the setting of the paper type has been received from the user in the nonvolatile storage unit 34.

  (9) In the third embodiment, when the CPU 31 stores a value corresponding to the presence of paper supply in the paper supply presence / absence flag 67 in the detection process, the CPU 31 stores a value corresponding to the presence of paper supply in the operation panel 40 or the like. The screen for setting the paper type supplied to the paper feed tray 51 corresponding to the paper supply presence / absence flag 67 is displayed, and the setting for the paper type is accepted as required by the user. At this time, if the setting received from the user regarding the paper type is not the type of paper that can be supplied to the paper feed tray 51 corresponding to the paper supply presence / absence flag 67 storing a value corresponding to the presence of paper supply. Alternatively, the configuration may be such that the operation panel 40 or the like is prompted to confirm the setting of the paper type. In this way, if the setting relating to the type of paper supplied to the paper feed tray 51 is not the type of paper that can be supplied, the user can be prompted to confirm. Therefore, it is possible to appropriately change the priority order while taking into consideration the case where the setting related to the type of paper supplied to the paper feed tray 51 is not the type of paper that can be supplied.

  (10) In the fourth embodiment, there is no paper feed tray 51 in which the type of paper used for printing received from the network I / F 37 or the like matches the type of paper supplied to the corresponding paper feed tray 51. In the case (S365: NO), in the process of S380, the CPU 31 stores the basic priority determined in S310 as the main priority in the RAM 33, but the type of paper used for printing received from the network I / F 37 or the like. If there is a paper feed tray 51X that matches the type of supplied paper, this priority order is stored in the RAM 33 with the basic priority order of the paper feed tray 51X as the first priority. May be. At this time, the CPU 31 further informs the operation panel 40 and the like that paper is fed from the paper feed tray 51X in which the type of paper used for printing received from the network I / F 37 and the like matches the type of supplied paper. The structure which alert | reports may be sufficient. In this way, when the print instruction is received, the measurement time tX is shorter than the time T that is regarded as immediately before the print instruction, and the paper feed tray 51 is set with respect to the type of paper to be supplied. However, if the set paper type and the paper type used for image formation are different, the setting contents relating to the paper type supplied to the paper feed tray 51 and the paper type used for printing In the case where there is a paper feed tray 51 that matches, the priority can be set higher than that of the paper feed trays 51 other than the paper feed tray 51. Accordingly, by considering whether or not the setting relating to the type of paper to be supplied to the paper feed tray 51 and the setting content relating to the type of paper used for printing are taken into consideration, the paper is supplied immediately before printing. Priorities other than the paper feed tray 51 determined to have occurred can be appropriately changed. Further, when the print instruction is received, the setting is performed even if the measurement time tX is shorter than the time T that is regarded as immediately before the print instruction and the paper feed tray 51 is set with respect to the type of paper to be supplied. When the type of paper used and the type of paper used for printing are different, the user can feed paper from the paper feed tray 51 which is set to supply the type of paper that matches the type of paper used for printing. Can be notified. Accordingly, by notifying the user when changing the priority order, the priority order can be changed more appropriately than when notifying the user when changing the priority order.

  (11) In the sixth embodiment, when a print instruction is received from the network I / F 37 or the like by a user operation, the paper feed tray 51 used for printing is also instructed, so that the paper used for printing is The configuration was instructed. In such a configuration, when the instructed paper feed tray 51 is not capable of paper feeding due to the accepted printing function, confirmation of settings for the paper feed tray 51 used for printing in the network I / F 37 or the like. The structure which alert | reports to the effect of prompting may be sufficient. Note that, as such a case, for example, when photo printing is instructed, photo paper cannot be fed from the tray 51C instructed together. In this way, if the setting related to the paper feed tray 51 used for printing is not the usable paper feed tray 51, the user can be prompted to confirm. Therefore, it is possible to appropriately change the priority order regarding the sheet feeding order while considering that the setting related to the sheet feeding tray 51 used for printing is not the usable sheet feeding tray 51.

  (12) In the above embodiment, when the measurement time tX is shorter than the time T regarded as immediately before the print instruction, it is determined that the paper is supplied to the paper feed tray 51X immediately before printing. Not necessarily. For example, when there is a paper feed tray 51X that is shorter than the time T that is regarded as immediately before the print instruction assuming that the measurement time tX satisfies 0 <tX <T, the supply that satisfies the measurement time tX satisfies T ≦ tX <2T. The configuration may be such that it is determined whether or not the paper tray 51X exists, and if it is present, the paper supply tray 51X also determines that the paper has been supplied immediately before printing. In this way, even if it takes a long time to supply paper by supplying paper to the plurality of paper feed trays 51 for use in printing, it is determined that paper has been supplied immediately before printing. The paper tray 51 can be determined more appropriately.

10 Printing Unit 11 Transport Path 31 CPU
34 Nonvolatile memory 51 Paper feed tray

Claims (13)

Multiple paper feeders,
An image forming unit that forms an image on a sheet fed from the sheet feeding unit;
A sensor that outputs a signal corresponding to the state of the paper feed unit;
An accepting unit for accepting an image forming instruction for causing the image forming unit to form an image;
A control unit,
The controller is
A detection process for detecting the supply of a sheet to the sheet feeding unit based on the signal output by the sensor;
A measurement process for measuring an elapsed time from when the sheet supply to the sheet feeding unit is detected in the detection process until the image forming instruction is received by the receiving unit;
A process of changing a priority order for determining a sheet feeding unit that feeds a sheet to be used for forming an image instructed by the image formation instruction, and before the start of sheet feeding to the image forming unit, An order change process that identifies a target sheet feeding unit that is the sheet feeding unit whose elapsed time is shorter than a predetermined time, and raises the priority for the identified target sheet feeding unit;
An image forming apparatus that executes an image forming process for forming an image on a sheet fed from the paper feeding unit having the highest priority. A storage unit that stores a predetermined basic priority order for determining a sheet feeding unit that feeds a sheet in forming an image instructed by the image formation instruction;
In the order changing process, the control unit sets the basic priority as the main priority when the target paper feeding unit does not exist, and sets the basic priority when the target paper feeding unit exists. The priority order of raising the priority order of the target paper feed unit is defined as the main priority order,
The image forming apparatus according to claim 1, wherein in the image forming process, an image is formed on a sheet fed from the paper feeding unit having the highest priority. The sensor includes a sheet sensor that outputs a signal corresponding to the presence or absence of a sheet supplied to the sheet feeding unit, and an attachment / detachment sensor that outputs a signal corresponding to the attachment / detachment of the sheet feeding unit detachable from the apparatus main body. Have
In the detection process, the control unit detects a signal corresponding to the attachment after detecting the signal corresponding to the separation of the sheet feeding unit from the apparatus main body by the attachment / detachment sensor. The sheet supply to the sheet feeding unit is detected by the detection or the signal corresponding to the absence of the sheet being fed to the sheet feeding unit is detected by the sheet sensor. The image forming apparatus according to claim 2, wherein a sheet supply to the sheet feeding unit is detected by detecting a signal according to a certain condition.   In the image forming process, the control unit performs feeding of the paper feeding unit that feeds paper in the priority order when the sheet is exhausted from the paper feeding unit that is feeding paper. The image forming apparatus according to claim 2, wherein the sheet feeding unit is changed to the sheet feeding unit of the next order of the sheet feeding unit.   In the order changing process, the control unit assigns the book priority of the target sheet feeding unit at the time of image formation instructed by the image formation instruction to the book feeding unit other than the target sheet feeding unit. The image forming apparatus according to claim 2, wherein the image forming apparatus has a higher priority.   In the order changing process, when there are a plurality of the target paper feeding units, the control unit determines the relative priority based on the basic priority among the target paper feeding units when determining the main priority. The image forming apparatus according to claim 2, wherein the order is not changed. In the order changing process, the control unit, when there are a plurality of the target paper feed unit,
6. The image according to claim 2, wherein when the main priority order is determined, the priority order of the target paper feed unit having the shorter elapsed time is higher between the target paper feed units. 6. Forming equipment. A first setting unit that receives a setting relating to a type of sheet supplied to the sheet feeding unit;
In the order changing process, the control unit receives the setting by the first setting unit when the sheet is supplied to the sheet feeding unit in addition to the elapsed time being shorter than a predetermined time. The main priority of the target paper feeding unit is set higher than that of the target paper feeding unit not set by the first setting unit when a paper feeding unit exists. The image forming apparatus according to any one of the above. A second setting unit that accepts settings relating to the type of sheet used to form an image;
The image forming apparatus according to claim 8, wherein when the image forming instruction is received, a setting by the second setting unit is received.   In the order changing process, the control unit receives the setting by the first setting unit when the sheet is supplied to the sheet feeding unit in addition to the elapsed time being shorter than a predetermined time. Even when there is a sheet feeding unit, the sheet type received by the first setting unit is the target sheet feeding unit different from the sheet type received by the second setting unit. The image forming apparatus according to claim 9, wherein the priority order of the target paper feed unit is not increased. In the order changing process, the control unit receives the setting by the first setting unit when the sheet is supplied to the sheet feeding unit in addition to the elapsed time being shorter than a predetermined time. Even when a sheet feeder is present, when the sheet type received by the first setting unit of the target sheet feeder is different from the sheet type received by the second setting unit,
When there is the sheet feeding unit to which the sheet of the same type as the sheet type set by the second setting unit exists, the main priority of the sheet feeding unit is set as the sheet feeding unit. The image forming apparatus according to claim 10, wherein the image forming apparatus is higher than any other sheet feeding unit . A notification unit for notifying a user;
In the rank changing process, the control unit is configured to set the first setting unit when the target sheet feeding unit is the sheet feeding unit that cannot be used to form an image instructed by the image forming instruction. 12. The image forming apparatus according to claim 9, wherein the user is notified that confirmation of at least one of the setting by the second setting unit and the setting by the second setting unit is prompted. A notification unit for notifying a user;
The second setting unit receives a setting relating to a sheet type used for image formation by receiving a setting of the paper feeding unit used for image formation.
In the order changing process, the control unit prompts the second setting unit to confirm the setting when the target sheet feeding unit is not the sheet feeding unit whose setting is received by the second setting unit. The image forming apparatus according to claim 9, wherein the user is notified of the fact.