Patent Application
20210364964
The present invention relates to a printing apparatus, a method of controlling the same, and a storage medium.
Heretofore, a circulation type paper conveyance method has been used as a method of forming images on both sides of each of a plurality of sheets of paper (sheets). In this method, a sheet of paper is conveyed to a transfer unit for transferring an image, an image is transferred to one side (first side) of the sheet of paper by the transfer unit, and thereafter, the sheet of paper on which the image has been transferred is sent to a reversing unit. Then, the sheet of paper whose front and back is reversed by the reversing unit is again conveyed to the transfer unit via a conveyance path for second side of the double-sided printing, and an image is transferred on the second side of the sheet of paper by the transfer unit.
In U.S. Pat. No. 4,978,980, double-sided circulation control is described in which, in double-sided printing of a plurality of sheets, a predetermined number of sheets are successively paper-fed, and thereafter paper feeding and paper refeeding are alternatingly performed, instead of performing paper feeding and paper refeeding for each sheet of paper, in order to improve the productivity of image formation.
Also, it is also required that a job in which single-sided printing and double-sided printing are mixed is executed at a high speed. In the control described in U.S. Pat. No. 4,978,980, after an image is formed on a front surface of a first sheet of paper of double-sided printing, the sheet of paper is caused to circulate in a double-sided conveyance path, and therefore a period of time is incurred until image formation is performed on the back surface. Therefore, every time switching is performed from double-sided printing to single-sided printing, a fixed time is needed, and as a result, there is a problem in that the total printing speed largely decreases.
In order to solve this problem, in a technique disclosed in Japanese Patent No. 3880281, when a sheet of paper of double-sided printing and a sheet of paper of single-sided printing are mixed, even if a sheet of paper is a sheet of paper of single-sided printing, the sheet of paper is handled as a sheet of paper of double-sided printing whose second side is blank. Also, a conveyance control method is proposed in which, as a result of successively executing double-sided printing, the double-sided circulation printing is not interrupted (forced double-sided control).
Moreover, U.S. Pat. No. 8,843,055 describes a technique for executing, at a high speed, a job in which single-sided printing and double-sided printing are mixed. According to this technique, image formation of a front surface of double-sided printing that is present after a group of pages of single-sided printing is executed prior to the group of pages of single-sided printing, and the printed sheet is caused to retreat to a double-sided conveyance path, and then printing and discharging of the group of pages of single-sided printing are performed. Thereafter, with respect to the sheet retreated to the double-sided conveyance path, printing of a remaining back surface of double-sided printing and discharging are performed. As described above, a technique for executing, at a high speed, a job in which single-sided printing and double-sided printing are mixed is proposed (overtaking double-sided control). With this, single-sided printing is executed in parallel by effectively using the period of time during which a sheet on which an image is formed on its front surface by double-sided printing waits in a double-sided conveyance path or the sheet is conveyed in the double-sided conveyance path, and as a result, the total printing time can be largely reduced relative to a known technique. Also, Japanese Patent Laid-Open No. 2018-176562 describes a technique in which, when single-sided printing is performed in double-sided circulation control in which predetermined number of sheets are successively fed in double-sided printing, and thereafter paper feeding and paper refeeding are alternatingly performed, the double-sided circulation is continued by forcibly performing double-sided printing. Also, a technique is described in which, a counter is provided for counting the number of times of successively performing the forced double-sided printing, and if the counter value exceeds a certain threshold value, the forced double-sided printing is interrupted and single-sided printing is performed.
As described above, the methods described in Japanese Patent No. 3880281 and U.S. Pat. No. 8,843,055 are conveyance control methods for executing, at a high speed, a job in which single-sided printing and double-sided printing are mixed (hereinafter called as “single/double mixed print control”). In the single/double mixed print control, the most suitable single/double mixed print control needs to be selected in accordance with the state of sheets in a printing apparatus and the single/double mixing state in a job to be executed. However, it is difficult for a user to select the single/double mixed print control that is most suitable to a job to be executed. There is a problem in that, depending on the selection of single/double mixed print control, the execution performance of a job is instead degraded.
An aspect of the present invention is to eliminate the above-mentioned problem with conventional technology.
A feature of the present invention is to provide a technique for enabling a printing apparatus to automatically select and execute a most suitable print control method, regarding a print job in which single-sided printing and double-sided printing are mixed.
According to a first aspect of the present invention, there is provided a printing apparatus capable of receiving and executing a print job in which single-sided printing and double-sided printing are mixed, the printing apparatus comprising:
a sheet conveyance path that includes a plurality of waiting positions at which a sheet in which printing has been performed on a first side in double-sided printing is caused to wait in order to print an image on a second side of the sheet;
a memory device that stores instructions; and
one or more processors that execute the instructions stored in the memory device to cause the printing apparatus to:
selectively execute print control such as:
(1) first print control in which single-sided printing is performed on a sheet regarding which single-sided printing is instructed, and double-sided printing is performed on a sheet regarding which double-sided printing is instructed,
(2) second print control in which printing is performed on a sheet regarding which single-sided printing is instructed that is present between a plurality of sheets regarding which double-sided printing is instructed, so as to perform conveyance control similarly to a sheet regarding which double-sided printing is instructed such that the sheet is caused to be conveyed on a conveyance path for double-sided printing of the sheet conveyance path after single-sided printing is performed, and
(3) third print control in which printing is performed, in advance to a sheet regarding which single-sided printing is instructed, on a first side of a following sheet regarding which double-sided printing is instructed, and single-sided printing is performed on the sheet regarding which single-sided printing is instructed in advance to printing on a second side of double-sided printing of the sheet,
retain information regarding a sheet to be fed in accordance with the first to third print control in a sheet feed wait queue, and
select and execute one of the first to third print control based on a printing order of single-sided printing and double-sided printing in the print job, the number of the plurality of waiting positions, and information retained in the sheet feed wait queue.
According to a second aspect of the present invention, there is provided a method of controlling a printing apparatus that includes a sheet conveyance path that includes a plurality of waiting positions at which a sheet in which printing has been performed on a first side in double-sided printing is caused to wait in order to print an image on a second side of the sheet, and can receive and execute a print job in which single-sided printing and double-sided printing are mixed, the method comprising:
selectively executing print control such as:
(1) first print control in which single-sided printing is performed on a sheet regarding which single-sided printing is instructed, and double-sided printing is performed on a sheet regarding which double-sided printing is instructed,
(2) second print control in which printing is performed on a sheet regarding which single-sided printing is instructed that is present between a plurality of sheets regarding which double-sided printing is instructed, so as to perform conveyance control such that the sheet is caused to be conveyed on a conveyance path for double-sided printing of the sheet conveyance path after single-sided printing is performed, and
(3) third print control in which printing is performed, in advance to a sheet regarding which single-sided printing is instructed, on a first side of a following sheet regarding which double-sided printing is instructed, and single-sided printing is performed on the sheet regarding which single-sided printing is instructed in advance to printing on a second side of double-sided printing of the sheet:
retaining information regarding a sheet to be fed in accordance with print control regarding the print job; and
selecting and executing one of the first to third print control based on a printing order of single-sided printing and double-sided printing in the print job, the number of the plurality of waiting positions, and information retained in the sheet feed wait queue.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Embodiments of the present invention will be described hereinafter in detail, with reference to the accompanying drawings. It is to be understood that the following embodiments are not intended to limit the claims of the present invention, and that not all of the combinations of the aspects that are described according to the following embodiments are necessarily required with respect to the means to solve the problems according to the present invention. Also, a plurality of features may be arbitrarily combined.
A host computer 102 transmits print data to the image forming apparatus 101 according to the first embodiment via a network 103. The host computer 102 also has a function of performing image editing processing by operating an image processing application, in addition to the function of transmitting print data. The image forming apparatus 101 communicates with the host computer 102 via the network 103. In this printing system, the image forming apparatus 101 forms an image according to print data received from the host computer 102 via the network 103. Note that the network 103 may be a wired network or a wireless network. Also, a plurality of host computers 102 may be connected to the network 103, as shown in
A controller 201 controls the operations of the image forming apparatus 101 by executing software for performing various types of control of the image forming apparatus 101. A console unit 202 includes a hard key and the like that are operated by an operator and are for receiving instructions of various operations to the image forming apparatus 101 and a display unit that displays and presents various types of information to the operator. Note that the display unit may include a touch panel function. A toner supplying unit 203 supplies toner, which is developer, to an image forming unit of the image forming apparatus 101. The toner supplying unit 203 is equipped with a door, and the operator can supply toner through the door. An image forming unit 204 forms an image instructed by print data on an intermediate transfer belt 205 using toner supplied by the toner supplying unit 203. The image formed on the intermediate transfer belt 205 is transferred to a print medium such as a sheet. A fixing unit 206 applies heat and pressure to a sheet on which an image is transferred from the intermediate transfer belt 205, and fixes the toner image on the sheet. An excess toner collection unit 207 collects and accumulates toner remained on the intermediate transfer belt 205 without being transferred to a sheet. A feeding unit 208 can accumulate a plurality of sheets, and the sheets in the feeding unit 208 are respectively conveyed to the image forming unit 204 by a sheet conveyance unit 209, and are used for image formation. Also, the sheet conveyance unit 209 conveys a sheet on which an image is formed by the image forming unit 204 to the fixing unit 206 for fixing the image transferred to the sheet. A switchback unit 210 reverses the front and back of a sheet for performing printing on a second side of double-sided printing and for discharging the sheet with the back surface facing upward. A sheet loading portion 211 receives sheets from an external paper feeding apparatus. A discharging portion 212 discharges a sheet subjected to fixing processing to an external apparatus such as a discharging unit or a post processing device, for example.
A network cable 303 is for connecting to the host computer 102 and an external device, which is not illustrated, via the network 103. A line cable 304 is for connecting to an external device, which is not illustrated, via a telephone line. A CPU 305 controls this controller 201 by executing a program deployed in a RAM 306. The RAM 306 provides a work memory of the CPU 305. The RAM 306 is also used as a reception buffer for temporarily storing data received from the outside, an image buffer for temporarily storing image data that is rasterized by an RIP (Raster Image Processor) 321, and the like. A console unit interface 307 is an interface for connecting the console unit 202 and the controller 201. A network I/F 308 is an interface for connecting the controller 201 and the network 103. A modem 309 is an interface for connecting the controller 201 and the telephone line. A ROM 310 stores a boot program that is executed by the CPU 305, and the like. An HDD (hard disk drive) 311 stores a program that is executed by the CPU 305, and the like. The units described above are connected to the CPU 305 via a CPU bus 312. The CPU 305 deploys a program stored in the HDD 311 in the RAM 306 by executing the aforementioned boot program, and controls the operations of the image forming apparatus 101 by executing the deployed program.
An image bus I/F 313 functions as a bus bridge for connecting an image bus 324 for transferring image data at a high speed and the CPU bus 312. The image bus 324 is connected to a hardware group for performing image processing. The RIP 321 is a rasterizing unit that has a function of converting page description data input from the outside to bitmap image data. A RIP I/F 314 is an interface for connecting the RIP 321 and the image bus 324. A compression/decompression unit 315 performs compression and decompression of data. A sheet feed unit/discharge unit 322 includes the feeding unit 208 in
A receiving portion 401 receives a sheet from the sheet loading portion 211 to a sheet conveyance path. Also, the receiving portion 402 receives a sheet from the feeding unit 208 in
When printing is performed only on one side of a sheet and is discharged with a printed surface facing upward, the sheet is conveyed by conveyance rollers 403, 404, 405, 406, 407, and 421, in this order. That is, the sheet passes through the uppermost conveyance path in
On the other hand, when printing is performed only on one side of a sheet and is discharged with a printed surface facing downward, the sheet is conveyed by the conveyance rollers 403, 404, 405, 406, 408, 409, 410, 411, 412, 411, 413, 414, and 421, in this order. Note that the conveyance rollers 411 and 412 are forward/reverse rotatable and convey a sheet in a switchback manner. That is, a sheet is discharged in a state of the front and back of the sheet being reversed as a result of having passed through the conveyance rollers 408 to 414.
Moreover, when printing is performed on both sides of a sheet, the sheet is conveyed by the conveyance rollers 403, 404, 405, 406, 408, 409, 410, 411, 412, 411, 415, 416, 417, 418, 419, 420, 403, 404, 405, 406, 407, and 421, in this order. Note that, in the case of double-sided printing as well, a conveyance path including the conveyance rollers 411 and 412 is a portion for conveying a sheet in a switchback manner, and control is performed in a state of the conveyance rollers being in reverse rotation. Also, the conveyance rollers 406 and 411 are provided with a mechanism (e.g., flapper) for switching the conveyance path for conveying a sheet.
Next, double-sided circulation control will be described with reference to
Next, detailed descriptions will be given regarding
In a model in which a first sheet is refed after three sheets are fed, a control as shown in
“(The number of sheets that can be successively fed before starting paper refeeding)×2-1” is the number of sheets of double-sided circulation. In the example in
As shown in
In this way, in the normal double-sided, it is necessary to, when switching from double-sided printing to single-sided printing is performed, switch to sheet conveyance control for single-sided printing, after once completing paper refeeding of sheets of double-sided printing (double-sided printing). Hereinafter, this switching operation is expressed as “double-sided circulation is interrupted”.
That is, here, the ninth sheet that is a double-sided printing target subsequent to the first to eighth sheets that are single-sided printing targets is fed in advance to the single-sided printing, and printing is performed on the first side of the ninth sheet. Next, the single-sided printing is performed on the first to eighth sheets that are overtaken and on which single-sided printing is to be performed (print range 711). Thereafter, printing is performed on the second side of the ninth sheet whose first side has been printed. In
The control method of the overtaking double-sided will be described with reference to sheet feed wait queues 721 to 729 in
The sheet feed wait queue is a data structure on the RAM 306, and express a sheet to be fed from now. Here, a single-sided printing sheet or a double-sided printing sheet is added to the sheet feed wait queue in the printing order, and erased from the queue at the timing at which paper feeding is performed (regarding the case of double-sided printing, at the timing at which paper feeding is performed for printing on a first side (front surface) not for printing on a second side (back surface).
In the sheet feed wait queue 721, first to eighth sheets on which single-sided printing is to be performed are expressed by 1S to 8S, and a ninth sheet on which double-sided printing is to be performed is expressed by 9D. S and D here are suffixes expressing single-sided (Simplex) and double-sided (Duplex). In the overtaking double-sided, it is confirmed whether a sheet for double-sided printing is present in “number of sheets of double-sided circulation-1” sheets following the first sheet in the sheet feed wait queue. If such a sheet is present, the sheet on which double-sided printing is to be performed is fed first. In the sheet feed wait queue 721, sheets “2S, 3S, 4S, 5S, 6S, 7S, 8S, and 9D” are present as sheets following the sheet 1S. In the first embodiment, the number of sheets of double-sided circulation is nine, as described above, and therefore it is determined whether or not a double-sided printing sheet is present in 9−1=8 sheets from the sheet 2S. In the sheet feed wait queue 721, the sheet 9D is just present as the eighth sheet from the sheet 2S. Therefore, the sheet 9D is fed in advance to the sheet 1S. The sheet that is determined to be fed is expressed by (underline+italic font) in each sheet feed wait queue. Note that a sheet waiting for being refed is not included in
In sheet feed wait queues 821 and 822, because a sheet for a double-sided printing is not present in eight sheets following sheets 1S and 2S, respectively, the sheets 1S and 2S are respectively fed and single-sided printing is executed. Next, in a sheet feed wait queue 823, because a sheet 11D on which double-sided printing is to be performed is present in eight sheets following the sheet 3S, the sheet 11D for following double-sided printing is fed firstly. Also, in a next sheet feed wait queue 824, the sheet 11D is fed in the sheet feed wait queue 823, 11D is erased from the sheet feed wait queue. Moreover, a sheet 12D of double-sided printing becomes present in eight sheets following the sheet 3S. Therefore, the sheet 12D of the following double-sided printing is precedingly fed. Also, in a sheet feed wait queue 825, similarly to the sheet feed wait queue 824, a sheet 13D of the following double-sided printing is precedingly fed.
Next, in a sheet feed wait queue 826, a sheet 14D of double-sided printing is present in eight sheets following the sheet 3S. However, as shown in
Similarly, in sheet feed wait queues 827 to 833, similarly to the sheet feed wait queue 826, the sheet 14D of double-sided printing is present in eight sheets following the first sheet. Because three sheets have been precedingly fed, the sheets 3S, 4S, 5S, 6S, 7S, 8S, 9S, and 10S that are first in the respective sheet feed wait queues are fed.
Then, after the sheet 10S of single-sided printing that is the tenth sheet in the sheet feed wait queue 833 has been fed, the sheet 11D that has been fed in the sheet feed wait queue 823 and is present in the waiting position 501 for double-sided printing is refed. Originally, the sheet 11D can be refed after nine sides of sheets after being fed. In
In a sheet feed wait queue 834, because the number of sheets of double-sided printing that have been precedingly fed becomes two, the sheet 14D is to be fed. After the sheet 14D is fed, and printing is performed on the first side of the sheet 14D, the sheet 12D is refed for performing printing on the second side of the sheet 12D, and the sheet 15D is fed in the sheet feed wait queue 835 for performing printing on the first side of the sheet 15D.
Next, the control method at the time of the overtaking double-sided control will be described with reference to the flowchart in
First, in step S901, the CPU 305 determines whether or not a sheet is present in the sheet feed wait queue on the RAM 306. If it is determined that a sheet is present, the processing is advanced to step S902, and if not, the processing is returned to step S901, and a sheet waiting for paper feeding being registered is waited for. In step S902, the CPU 305 determines which of single-sided printing and double-sided printing is to be performed on the first sheet in the sheet feed wait queue. In the case of single-sided printing, the processing is advance to step S903, and in the case of double-sided printing, the processing is advanced to step S907. In step S903, the CPU 305 determines whether or not a double-sided printing sheet is present in sheets of the number corresponding to “the number of sheets of double-sided circulation of the normal double-sided-1” from the sheet next to the first sheet in the sheet feed wait queue. Here, the number of sheets of double-sided circulation of the normal double-sided is nine, as shown in
On the other hand, in step S903, if the CPU 305 determines that a double-sided printing sheet is present until the above-described eighth sheet, the processing is advanced to step S905. In step S905, the CPU 305 determines whether or not a vacant double-sided waiting position for the overtaking double-sided is present. For example, in the example in
In step S907, the CPU 305 determines whether or not a vacant waiting position for a double-sided printing sheet is present. If it is determined that a vacancy is present, the processing is advanced to step S909, the CPU 305 feeds the first double-sided printing sheet in the sheet feed wait queue, and ends this processing. On the other hand, in step S907, if the CPU 305 has determined that a vacant waiting position is not present, the processing is advanced to step S908. In step S908, the CPU 305 determines whether or not a sheet in a double-sided waiting position has been fed, and if it is determined that a sheet in the double-sided waiting position has been fed, the processing is advanced to step S909, and if a sheet has not been not fed, the processing remains in step S908 until a sheet in the double-sided waiting position is fed.
In the sheet feed wait queues 821 and 822 in
In the sheet feed wait queues 823, 824, and 825 in
In the sheet feed wait queues 826 to 833 in
In the sheet feed wait queues 834 and 835 in
The forced double-sided is aimed at improving performance by causing the double-sided circulation to be not interrupted as a result of causing a single-sided printing sheet that is present between sheets that are double-sided printing targets to be conveyed in the double-sided path after single-sided printing is performed. Note that the double-sided printing target sheet is a sheet on which images regarding which double-sided printing is instructed to be performed in a print job should be printed. Similarly, the single-sided printing target sheet is a sheet on which an image regarding which single-sided printing is instructed to be performed in a print job should be printed. When single-sided printing target sheets are successively present from the head of a print job, as shown in
In sheet feed wait queues 1126 and 1127, the processing is executed in the order from step S901 to step S902, step S903, and step S904, and the single-sided printing target sheets 6S and 7S at the head in the respective sheet feed wait queues are fed. In sheet feed wait queues 1128 to 1130, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S906, and double-sided printing target sheets 16D, 17D, and 18D that are found in step S903 are fed, instead of the first sheet in each sheet feed wait queue.
In sheet feed wait queues 1131 to 1138, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S904, and single-sided printing target sheets 8S to 15S at the head in the respective sheet feed wait queues are fed.
In sheet feed wait queues 1139 and 1140, the processing is executed in the order from step S901 to step S902, step S907, and step S909, or in the order from step S901 to step S902, step S907, step S908, and step S909, and double-sided printing target sheets 19D and 20D at the head in the respective sheet feed wait queues are fed.
When comparison is made regarding performance between the normal double-sided, forced double-sided, and overtaking double-sided described above, as indicated by reference numerals 1151 and 1152, the normal double-sided and the overtaking double-sided are better relative to the forced double-sided in performance in an amount corresponding to two sides of sheets.
In
In sheet feed wait queues 1226 and 1227, the processing is executed in the order from step S901 to step S902, step S903, and step S904, and single-sided printing target sheets 6S and 7S at the head in the respective sheet feed wait queues are fed, and printing is performed on the first sides thereof. In sheet feed wait queues 1228 to 1230, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S906, the double-sided printing target sheets 16D to 18D that were found in step S903 are fed, instead of the first sheet in the sheet feed wait queues 1228-1230, and printing is performed on the first sides thereof.
Then, in sheet feed wait queues 1231 to 1238, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S904, the single-sided printing target sheets 8S to 15S at the head in the respective sheet feed wait queues 1231-1238 are fed, and printing is performed on the first sides thereof.
In the example in
In the overtaking double-sided, the number of sheets of double-sided circulation is five, therefore the number of double-sided printing target sheets that can be fed precedingly to the single-sided printing is three. The overtaking double-sided is advantageous if the number of double-sided printing target sheets that can be precedingly fed is three or less. This is because, if the number of successive double-sided printing target sheets is larger than three, only the double-sided printing target sheets that are not precedingly fed are conveyed on the double-sided path after the double-sided printing target sheets that were precedingly fed have been refed. These sheets correspond to the sheets 19D and 20D in
In sheet feed wait queues 1326 to 1328, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S906, and double-sided printing sheets 13D, 14D, and 15D that were found in step S903 are fed, instead of the first sheet in each sheet feed wait queue.
In sheet feed wait queues 1329 to 1335, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S904, and single-sided printing sheets 6S to 12S at the head in the respective sheet feed wait queues 1329-1335 are fed, and printing is performed on the front surfaces thereof.
Then, in sheet feed wait queues 1336 to 1337, the processing is executed in the order from step S901 to step S902, step S907, and step S909, or in the order from step S901 to step S902, step S907, step S908, and step S909, and double-sided printing target sheets 16D and 17D at the head in the respective sheet feed wait queues 1336 and 1337 are fed.
In
In contrast, in
Moreover, as shown in
In sheet feed wait queues 1426 to 1428, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S906, and the double-sided printing target sheets 9D to 11D that were found in step S903 are fed, instead of the first sheet in the sheet feed wait queue 1426-1428, and printing is performed on the first side thereof.
In sheet feed wait queues 1429 to 1431, the processing is executed in the order from step S901 to step S902, step S903, step S905, and step S904, the single-sided printing target sheets 6S to 8S at the head in the respective sheet feed wait queues 1429-1431 are fed, and single-sided printing is performed thereon.
In
In step S1501, the CPU 305 determines whether or not the first sheet of the sheet feed wait queue on the RAM 306 is a single-sided printing target sheet. Note that the sheet feed wait queue is created according to the rule described with reference to
In step S1502, the CPU 305 determines whether or not all sheets waiting for being fed are single-sided printing target sheets. If it is determined that all sheets in the sheet feed wait queue are single-sided printing target sheets, the processing is advanced to step S1509, and operations according to the normal double-sided will be performed. On the other hand, if at least one sheet is a double-sided printing target sheet, the processing is advanced to step S1503. This is because, if all sheets are single-sided printing target sheets, the state in which single-sided and double-sided are mixed is not achieved, and therefore the control for improving the performance itself such as the forced double-sided or the overtaking double-sided becomes meaningless. Therefore, the processing is advanced to a step in which normal double-sided operation is to be performed, and a single-sided printing target sheet is subjected to single-sided printing.
In step S1503, the CPU 305 determines whether or not the sheet that has been fed immediately before is a double-sided printing target sheet, and if it is determined to be the double-sided printing target sheet, the processing is advanced to step S1504, and if the sheet that has been fed immediately before is a single-sided printing target sheet, the processing is advanced to step S1506. Step S1506 is a step in which the forced double-sided is excluded. The forced double-sided is not established if the sheet that has been fed immediately before is the single-sided printing target sheet. Therefore, if the sheet that has been fed immediately before is the single-sided printing target sheet, the forced double-sided is excluded. The fact that the forced double-sided is disadvantageous when the sheet that has been fed immediately before is the single-sided printing target sheet has been described with reference to
In step S1504, the CPU 305 determines whether or not a sheet waiting for being refed is present in the sheet feed wait queue. If the sheet waiting for being refed is not present, the processing is advanced to step S1506, and if the sheet waiting for being refed is present, the processing is advanced to step S1505. This is because, if the sheet that has been fed immediately before has been subjected to paper refeeding for double-sided printing (second side) (not first side in double-sided printing), a state is achieved in which the sheet is ready to be discharged to the outside of the image forming apparatus as a sheet on which double-sided printing has already performed. The forced double-sided is control in order to not interrupt the double-sided circulation even if a single-sided printing target sheet is present, and therefore it is not established if a sheet waiting for being refed is not present and the double-sided circulation is interrupted. Therefore, when a sheet waiting for being refed is not present, the forced double-sided is excluded.
In step S1505, the CPU 305 determines whether or not the number of single-sided printing target sheets, among the sheets waiting for being fed in the sheet feed wait queue, is less than “the number of sheets of double-sided circulation of the normal double-sided-1” (less than a first threshold value). If the determination is affirmative, the processing is advanced to step S1507, and if the number is “the number of sheets of double-sided circulation of the normal double-sided-1” or more (greater than or equal to the first threshold value), the processing is advanced to step S1506. This is because, when a single-sided printing target sheet is mixed between a plurality of double-sided printing target sheets, if the number of successive single-sided printing target sheets is more than a predetermined number of sheets, the performance of the forced double-sided becomes disadvantageous. Therefore, if single-sided printing target sheets of the number greater than or equal to “the number of sheets of double-sided circulation of the normal double-sided-1” are present, the forced double-sided is excluded. This case has been described with reference to
In step S1506, the CPU 305 determines whether or not the number of double-sided printing target sheets, among the sheets waiting for being fed in the sheet feed wait queue, is less than “(the number of sheets of double-sided circulation of the overtaking double-sided+1)/2” (less than a second threshold value). If the number is less than “(the number of sheets of double-sided circulation of the overtaking double-sided+1)/2”, the CPU 305 selects the overtaking double-sided in step S1510. On the other hand, if the number is more than “(the number of sheets of double-sided circulation of the overtaking double-sided+1)/2” (greater than or equal to the second threshold value), in step S1506, the CPU 305 selects the normal double-sided in step S1509, and ends this processing. This is because, if the number of double-sided printing target sheets, among the sheets waiting for being refed, is greater than or equal to “(the number of sheets of double-sided circulation of the overtaking double-sided+1)/2”, there is a waste period in which the double-sided circulation cannot be continued and paper feeding is not performed. This case has been described with reference to
In the example in
In step S1507, the CPU 305 determines whether or not the number of double-sided printing target sheets, among the sheets waiting for being fed in the sheet feed wait queue, is less than “(the number of sheets of double-sided circulation of the overtaking double-sided+1)/2” (less than the second threshold value), and if the determination is affirmative, the CPU 305 advances the processing to step S1511, selects the forced double-sided, and ends this processing. On the other hand, in step S1507, if the CPU 305 determines that the number of double-sided printing sheets, among the sheets waiting for being fed, is more than “(the number of sheets of double-sided circulation of the overtaking double-sided+1)/2” (greater than or equal to the second threshold value), the processing is advanced to step S1508. Step S1507 is a step that is executed when the number of single-sided printing target sheets that are present between double-sided printing target sheet bundles is determined to be less than the predetermined number of sheets, in the determination in steps S1503, S1504, and S1505. That is, this is a case where it is determined that the overtaking double-sided or the forced double-sided is advantageous relative to the normal double-sided. This case has been described with reference to
In step S1508, the CPU 305 determines whether or not the number of single-sided printing target sheets, among the sheets waiting for being fed in the sheet feed wait queue, is greater than or equal to “(the number of sheets of double-sided circulation of the normal double-sided+1)/2-1” (greater than or equal to a third threshold value). Here, if it is determined that the number is greater than or equal to the third threshold value, the CPU 305 selects the overtaking double-sided in step S1510, and ends this processing. On the other hand, in step S1508, if the number of single-sided printing target sheets is less than “(the number of sheets of double-sided circulation of the normal double-sided+1)/2-1” (less than the third threshold value), the CPU 305 selects the forced double-sided in step S1511, and ends this processing. This case has been described with reference to
As described above, according to the first embodiment, when a print job in which a single-sided printing target sheet and a double-sided printing target sheet are mixed is executed, the image forming apparatus can execute the job while appropriately selecting the most suitable single/double mixed print control method at the timing of paper feeding, in accordance with the contents of the job and the information regarding the sheet feed wait queue.
Next, a second embodiment of the invention will be described using a diagram for describing a UI in
This screen includes an automatic switching button 1601, a normal double-sided button 1602, a forced double-sided button 1603, and an overtaking double-sided button 1604. These buttons are formed as a toggle button, and only one of the buttons 1601 to 1604 can be selected. In
In step S1701, the CPU 305 reads out the setting value set by the user using the UI in
Also, if the “overtaking double-sided” is not selected in step S1702, in step S1703, the CPU 305 determines whether or not the setting value set by the user with the UI in
As described above, according to the second embodiment, when a print job is to be executed in which a single-sided printing target sheet and a double-sided printing target sheet are mixed, the image forming apparatus can appropriately select the most suitable single/double mixed print control method in accordance with the job contents and the information regarding the sheet feed wait queue, and can execute the job. Also, there is an effect that, with respect to a job in which single-sided printing and double-sided printing are mixed, setting can be configured such that a user can select any switching of the single/double mixed print control.
Embodiments of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2020-89929, filed May 22, 2020, and Japanese Patent Application No. 2021-41643, filed Mar. 15, 2021, which are hereby incorporated by references herein in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-089929 | May 2020 | JP | national |
| 2021-041643 | Mar 2021 | JP | national |
