JP2016038413A - Image forming apparatus, control method of the same, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanism that determines whether or not an appropriate recording medium is used for image formation to suppress continuation of image formation with an inappropriate recording medium.SOLUTION: An image forming apparatus compares, during continuous image formation on a plurality of recording media according to setting of a job, a measurement obtained by measuring parameters related to the image formation with a predicted values stored in advance for respective types of recording media, when the difference between the measurement and predicted value is equal to or more than a predetermined threshold, determines that the image formation is carried out with a recording medium different from the settings of the job and stops the image formation, and when the difference is not equal to or more than the predetermined threshold, continues the image formation.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus that prevents the use of an incorrect printing paper type during printing, a control method thereof, and a program.

  In the field of digital printing, particularly production printing, it is desired that printers used for printing support many types of paper. For example, it is desired to deal with printing paper subjected to various types of thicknesses and surface treatments. An image forming apparatus such as a laser printer or a digital multifunction peripheral can obtain a high-quality printed matter by variously changing a printing process such as a printing speed and a toner fixing temperature. Specifically, according to the paper information set by the operator from the operation unit of the image forming apparatus, the image forming apparatus guarantees a high-quality output result by maintaining an optimal fixing temperature and fixing speed. On the other hand, if a paper different from the set paper information is mistakenly placed on the paper feed tray, the print process conditions do not match between the setting information and the appropriate settings for the actually placed paper. For this reason, printing failure may occur. For example, there are toner peeling due to fixing failure and paper warpage due to excessive heating. In view of this, Japanese Patent Laid-Open No. 2004-228561 proposes a method of installing a paper type / thickness sensor in a paper feed tray or a paper transport path and changing the printing process condition according to the paper type determined by the sensor output.

JP 2012-181223 A

  However, the above prior art has the following problems. For example, in the above prior art, it is necessary to provide a dedicated sensor having a mechanical and optical mechanism in order to detect the paper type, which increases the manufacturing cost. Further, although the detected paper thickness and approximate type can be identified, the heat capacity of the paper cannot be accurately known. In other words, since the paper type is not determined according to the heat capacity of each paper, there is still a possibility of a fixing failure, and when the operator of the image forming apparatus accidentally replenishes a different type of paper, the toner is peeled off. Such problems will occur. In this way, even when the operator places an incorrect type of paper, a difference from the paper to be placed on the main body cannot be detected, and image formation is continuously performed on the wrong paper. May end up.

  The present invention has been made in view of the above-described problems, and has a mechanism for determining whether or not a recording medium used for image formation is correct and suppressing continuation of image formation on an incorrect recording medium. The purpose is to provide.

  The present invention is an image forming apparatus, and when measuring images continuously formed on a plurality of recording media according to job settings, a measuring unit that measures parameters relating to image formation, and the measuring unit Comparison means for comparing the measured value measured with a predicted value stored in advance corresponding to each type of recording medium in the storage means, and based on the comparison result of the comparison means, the measured value and the predicted value Is equal to or greater than a predetermined threshold value, it is determined that image formation is being performed on a recording medium different from the job setting, and the image formation is stopped, and the difference is not equal to or greater than the predetermined threshold value. In this case, the image forming apparatus includes a control unit that continues image formation.

  According to the present invention, it is possible to determine whether or not a recording medium used for image formation is correct and to suppress continuation of image formation on an incorrect recording medium.

2 is a diagram illustrating a hardware configuration of the image forming apparatus. FIG. FIG. 3 is a diagram illustrating a control configuration of the image forming apparatus. FIG. 3 is a diagram illustrating a functional configuration of a printer controller. The figure which shows the cross section of a fixing | fixed part. The figure explaining the principle of IH system. The figure which shows the example of arrangement | positioning of the sensor in a fixing | fixed part. The figure which shows an example of the change table of prediction temperature and prediction electric power. The figure which shows an example of the graph of prediction temperature and change of prediction electric power. The figure which shows an example of a temperature measurement result and a power consumption measurement result. The figure which shows an example of the graph of a temperature measurement result and a power consumption measurement result. 1 is a functional block diagram of an image forming apparatus. 6 is a flowchart of a replenishment detection method for an incorrect paper type. 7 is a flowchart of fixing temperature / power comparison processing. FIG. 10 is a diagram illustrating an example of a paper refill error warning dialog. FIG. 6 is a diagram illustrating a paint and toner peeling sample. FIG. 6 is a diagram illustrating an example of a setting screen for a paper replenishment error detection function. 1 is a functional block diagram of an image forming apparatus. The functional block diagram of a fixing power consumption monitoring part. FIG. 10 is a diagram illustrating an example of a paper refill error warning dialog. The figure which shows an example of a temperature measurement result and a power consumption measurement result.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the present invention according to the claims, and all combinations of features described in the present embodiments are not necessarily essential to the solution means of the present invention. .

<First Embodiment>
<Hardware configuration of digital MFP>
Hereinafter, a first embodiment of the present invention will be described. First, with reference to FIG. 1, a configuration of a digital multi-function peripheral 1000 that is an image forming apparatus according to the present embodiment will be described. The digital multi-function peripheral 1000 includes an image reader 1 that reads a paper document, a laser printer 6 that forms an image using an electrophotographic method, and a control unit 44. Further, when the digital multi-function peripheral 1000 is viewed from the viewpoint of the functional configuration, it is roughly divided into the following six blocks. These are an original exposure system, a controller system, a laser exposure system, an image forming system, a fixing system, and a paper feed / conveyance system.

  The control unit 44 includes a main controller 30, an HDD 31, a printer controller 32, and an option board 33. The main controller 30 is a control device having a CPU and a memory, and comprehensively controls the entire digital multi-function peripheral 1000 according to a program stored in the HDD 31. The printer controller 32 is a controller in charge of mechanical control of the laser printer 6. Responsible for controlling the machine parts in accordance with instructions from the main controller 30 to obtain a printed output. The optional accessory is also controlled by communicating with the optional accessory connected to the printer controller 32. Specifically, the optional accessories are a stacker, a saddle stitch binding machine, and the like.

  The image reader 1 includes a reader controller 3, a CCD 4, and an exposure lamp 5. The reader controller 3 controls and turns on the exposure lamp 5, causes the CCD 4 to read the image of the document, and converts the read signal into digital data.

  The laser printer 6 corresponds to each toner color, and includes laser scanner units 8, 9, 10, 11, drum units 13, 14, 15, 16, an intermediate transfer belt 17, a transfer unit 18, a fixing unit 20, and a paper discharge unit 28. , A paper feed unit 26 and a double-sided conveyance unit 27. Further, the laser printer 6 is provided with a right deck 22, a left deck 23, a third tray 24, and a fourth tray 25 for loading recording media such as paper to be fed into the apparatus. The laser printer 6 can continuously form images on a plurality of recording media using these devices. The image forming procedure will be described below.

  First, four YMCK laser scanner units 8, 9, 10, and 11 included in the laser exposure system 7 are used to electrostatically transfer the YMCK drum units 13, 14, 15, and 16 of the image forming system 12 onto the photosensitive drums. A latent image is formed. The drum units 13, 14, 15, and 16 are each provided with a photosensitive drum and a developing device corresponding to each color. The developing device includes a toner for forming an image and a carrier for applying a charge to the toner.

  The main controller 30 transmits image forming data that is the basis of the electrostatic latent image to the laser exposure system 7. The data is document data read from the image reader 1 or PDL data received by the main controller 30 from the host computer. The main controller 30 has a network function and can communicate with a host computer. As described above, the electrostatic latent image formed on the photosensitive drum by the laser of the laser scanner unit is developed when the toner in the developing device adheres thereto.

  Subsequently, the toner is transferred to the intermediate transfer belt 17 which is a belt-shaped transfer body. A full-color toner image is formed on the intermediate transfer belt 17 by transferring all of the four color toners of YMCK to the image on the drum unit. Here, apart from the description of the image forming system 12, the paper feeding and conveying system 21 will be described. The right deck 22, the left deck 23, the third tray 24, and the fourth tray 25 are paper trays for storing printing paper. The right deck 22 and the left deck 23 can store a relatively small sheet size, whereas the third tray 24 and the fourth tray 25 can store a large sheet. The paper feeding unit 26 is a mechanism for carrying the printing paper drawn from each paper tray to the image forming system 12. The duplex conveying unit 27 can convey the sheet on which one side is printed to the image forming system 12 again during duplex printing. When the printing paper taken out by the paper feeding / conveying system 21 is conveyed to the transfer unit 18 of the image forming system 12, the toner image formed on the intermediate transfer belt 17 is transferred to the printing paper. Thereafter, the toner image heated and pressure-bonded by the fixing roller of the fixing unit 20 is fixed to the printing paper, and a printed matter is completed. The printed paper is discharged out of the digital multi-function peripheral 1000 through the paper discharge unit 28.

  The fixing unit 20 includes a heater 40 and a fixing unit sensor 41. The heater 40 is used when heating the toner image to fix it on the paper. The fixing unit sensor 41 is a sensor for measuring the temperature of the paper after fixing the toner image. The paper feed unit 26 includes a paper feed unit sensor 42. The paper feed unit sensor 42 includes a plurality of sensors, and is a sensor for detecting the remaining amount of paper in each paper feed tray, the paper size, and the like.

<Controller system>
Next, a hardware configuration of the controller system 29 that controls the image forming apparatus will be described with reference to FIG. The controller system 29 includes components related to the controller shown in FIG. The main controller 30 is the center of the printer control system, and provides a printer function using the laser printer 6, the image reader 1, the operation unit 120, the external memory 121, and the like. The main controller 30 includes a CPU 112, a RAM 113, a ROM 114, an input unit 116, a printing unit I / F 117, an external memory I / F 118, a reader unit I / F 122, and an RTC 124.

  The CPU 112 outputs an image signal as output information to the printing unit I / F 117 connected to the system bus 115 based on a control program or the like. The control program is stored in advance in the program ROM of the ROM 114, the external memory 121, or the like. The font ROM of the ROM 114 stores font data used when generating the output information. The data ROM of the ROM 114 stores information used on the host computer in the case of a printer that does not have an external memory 121 such as a hard disk. The printer controller 32 controls the laser printer 6 so as to form a print image by an electrophotographic process in accordance with an image signal transmitted from the printing unit I / F 117. As shown in FIG. 2, a finisher (saddle stitching machine) controller 125 or a stacker controller 126 is connected to the printer controller 32 when post-processing or paper stacking is performed. The reader controller 3 reads a paper document and outputs electronic data. The CPU 112 can read the electronic data of the reader controller 3 via the reader unit I / F 122.

  The CPU 112 can communicate with the host computer via the input unit 116, and is configured to notify a host computer (not shown) of information in the printer. Reference numeral 113 denotes a RAM that functions as a main memory, work area, and the like for the CPU 112, and is configured such that the memory capacity can be expanded by an optional RAM connected to an expansion port (not shown). The RAM 113 is used as an output information expansion area, environment data storage area, NVRAM, and the like. Access to the above-described external memory 121 such as a hard disk (HD) or IC card is controlled by a memory controller (MC) 118.

  The external memory 121 is connected as an option and stores font data, an emulation program, form data, and the like. Further, the external memory 121 may include at least one or more internal memory and an optional font card and a plurality of external memories storing programs for interpreting printer control languages having different language systems. . Further, it may have an NVRAM and store printer mode setting information from the operation unit 120. The operation unit 120 is provided with a touch panel type operation panel, a switch for operation, and an LED display.

  The RTC 124 is a real-time clock circuit, and is a device for measuring time and counting time at regular intervals. Since the power supply is operated from the built-in battery, the RTC itself can always operate even when the main controller 30 is stopped. In accordance with the value written from the CPU 112 to the register in the RTC, it is possible to generate an interrupt signal at a predetermined time or a predetermined time and notify the connected CPU 112 of the interrupt.

<Printer controller>
Next, the control configuration of the printer controller 32 will be described in detail with reference to FIG. The printer controller 32 includes an image formation control unit 301, a CPU 302, a paper feed control unit 304, a fixing control unit 306, and a paper discharge control unit 305 as control configurations for realizing an electrophotographic process. A paper feed sensor 42 is connected to the paper feed controller 304. The paper feed unit sensor 42 includes a plurality of sensors, and electrically detects that the paper feed stage of the paper feed unit 26 has been opened and closed. Further, the paper feed unit sensor 42 can electrically detect the size and remaining amount of paper fed to the paper feed stage of the paper feed control unit 304. The fixing control unit 306 includes a heater 40 for fixing the toner image formed on the paper by the image formation control unit 301 and a fixing unit sensor 41 for controlling the fixing temperature.

<Configuration of fixing unit>
Next, the configuration of the fixing unit 20 of the digital multi-function peripheral 1000 will be described with reference to FIGS. 4 to 6. FIG. 4 shows a cross section of the fixing unit 20. As shown in FIG. 4, the fixing unit 20 is provided with an IH unit 401 at the top. The IH unit 401 is a unit for heating a fixing film that fixes toner on a sheet, and includes an IH coil 403, an outer core 402, and a moving copper plate 404. The IH coil 403 heats the fixing film 407 by the IH method. The IH method will be described later with reference to FIG. The outer core 402 increases the heating efficiency of the fixing film 407. The moving copper plate 404 prevents the temperature of the non-sheet passing portion at the end in the longitudinal direction of the fixing film from rising when printing a small size paper.

  The fixing film unit 405 that directly contacts the paper includes a fixing film 407 and an inner core 406 inside thereof. The fixing film unit 405 is heated by the IH method, and the inner core 406 increases the heating efficiency of the fixing film. The pressure roller 408 applies pressure to the printing paper from the lower side of the drawing to further strengthen the fixing.

  The moving copper plate 404 can prevent the end of the fixing film 407 from rising in temperature, but still some heat remains. The soaking roller 409 reduces the temperature rise by releasing the heat at the end through the soaking roller 409. The web unit 410 periodically cleans the soaking roller 409.

  FIG. 5 is a diagram illustrating a heating method of the fixing belt. The digital multi-function peripheral 1000 of the present invention employs an IH (Induction Heating) system as a fixing belt heating system. This method is a method of self-heating metal using electromagnetic induction. An eddy current flows through the metal when a high-frequency alternating current flows through the coil and magnetic flux generated around the coil passes through the metal. As a result, Joule heat is generated in the metal part. This is called induction heating. In the fixing film 407 according to the present embodiment, silicon rubber is coated on a metal, and the fixing film is self-heated using this induction heating.

  FIG. 6 shows a detailed configuration of the fixing unit sensor 41 provided in the fixing unit 20. The fixing unit sensor 41 functions as a measurement unit, and includes a plurality of sensors and thermistors for temperature management provided in the fixing film unit 405 and the pressure roller 408, and measures parameters related to image formation. Here, the parameters relating to image formation indicate the fixing temperature of the recording medium after image formation measured by the fixing unit sensor 41, power consumption during image formation, and the like. In the present embodiment, control using these two parameters will be described. However, the present invention is not limited to this, and other parameters related to image formation may be used.

  As shown in FIG. 6, a fixing main thermistor 601 serving as the center of temperature control is installed at the center of the fixing film unit 405. Temperature adjustment feedback using the IH unit 401 is possible according to the fixing temperature measured by the fixing main thermistor 601. On both sides, a fixing sub thermistor 602 and a fixing sub thermistor 603 are provided for detecting abnormal temperature rise. If an abnormal temperature rise is detected due to some problem, heating of the IH unit 401 is immediately stopped. Also, a thermistor 605 before the fixing end and a thermistor 604 after the fixing end are attached to the longitudinal end of the fixing film unit 405 to monitor whether or not the fixing end becomes abnormally high in small-size paper printing. . A pressure roller thermistor 606 is attached to the pressure roller 408, and the detected temperature is used for temperature control of the fixing film unit 405.

<Fixing temperature control>
Next, the management of the fixing temperature in the digital multi-function peripheral 1000 will be described with reference to FIGS. As shown in FIG. 7, the digital multi-function peripheral 1000 has a predicted temperature change table 701 that defines how the fixing temperature during printing changes for each supported paper type. The predicted temperature change table 701 is incorporated in advance as part of the control software for the digital multi-function peripheral 1000 based on the test data of the digital multi-function peripheral vendor. The predicted temperature change table 701 defines the fixing temperature for each paper type according to the number of printed pages. As the paper type, thin paper, plain paper, coated paper 1 and emboss 8 are included. However, these paper types are only examples, and are not intended to limit the present invention, and other types of paper may be defined. As a specific example, when the number of print pages is 20, the thin paper is defined as 155 degrees, the plain paper is defined as 160 degrees, the coated paper 1 is defined as 185 degrees, and the emboss 8 is defined as 194 degrees.

  The predicted power change table 702 represents the amount of power required when the fixing temperature at the time of printing changes with the value of the predicted temperature change table 701 as a level. For example, when attention is paid to the values of plain paper and coated paper 1, the fixing target temperature is higher because the heat capacity of coated paper 1 is larger than that of plain paper. For this reason, it turns out that the electric power for heating the fixing film 407 also becomes large. In this way, the temperature change can be determined by how much the heat capacity of the paper is. Generally, the heat capacity increases as the paper weight (basis weight) increases. In the paper type, coated paper has a larger heat capacity than plain paper.

  FIG. 8 shows a predicted temperature change graph 801 and a predicted power change graph 802. These graphs are graphs of the predicted temperature change table 701 and the predicted power change table 702. The horizontal axis indicates the number of printed pages, and the vertical axis indicates the fixing temperature or power level. The total power consumption used by the digital multi-function peripheral 1000 is represented by an area surrounded by a broken line and a horizontal axis (number of pages) of the predicted power change graph 802. The predicted power change graph 802 indicates that coated paper 1 having a larger area requires more power than plain paper. Further, it indicates that heating at power level 2 is sufficient to maintain the target temperature of plain paper of 160 degrees.

  The fixing unit 20 of the digital multi-function peripheral 1000 performs feedback control by reading the fixing temperature with a sensor. If the measurement value of the fixing temperature is different from the target temperature, the heating control is changed to match the target temperature. Looking at the predicted temperature change graph 801 and the predicted power change graph 802, when a temperature higher than the target temperature is detected in the vicinity of 40 pages after printing, heating of the IH unit 401 is temporarily stopped to wait for the temperature to decrease. I understand that.

  Next, the feedback control behavior of the fixing unit 20 when the operator replenishes the paper tray with an incorrect paper will be described. 9 and 10 show changes in the fixing temperature change and the power consumption change for each paper type. Reference numeral 1001 is a graph showing changes in the fixing temperature. A numerical value 901 is represented as a line graph plotted on the graph. Reference numeral 1002 is a graph showing the power level used for heating. A numerical value of 902 is represented by a line graph plotted on the graph. The horizontal axis indicates the number of printed pages, and the vertical axis indicates the fixing temperature or power level. Here, the operation of the digital multi-function peripheral 1000 will be described in more detail using 1001 and 1002.

  9 and 10 show the fixing temperature and power level when the paper type registered in the digital multifunction peripheral 1000 is “plain paper” and the target fixing temperature is 160 degrees. Since “plain paper” is set, the power level heated first by the IH unit 401 is 2. However, if the operator mistakenly replenishes the thick paper 2, the thick paper 2 that is thicker than the plain paper and has a larger heat capacity absorbs more heat. Therefore, in printing around the fifth page, since the paper that has been replenished in error is the thick paper 2, the fixing temperature is around 145 degrees, which is lower than the predicted temperature for plain paper. Therefore, the digital multi-function peripheral 1000 usually increases the power level in order to increase the insufficient fixing temperature. This is because a fixing failure occurs if the fixing temperature and the fixing power are kept insufficient. In particular, as shown in FIG. 15, in the case of print output using a lot of paint, toner peeling tends to occur. It is also conceivable that the toner that has not been fixed remains in the fixing device and leads to contamination of the fixing roller.

  Specifically, in order to return to a normal state, the digital multi-function peripheral 1000 performs heating at a power level 4 that is higher than the standard power level 2. However, since there is a great difference from the target of 160 degrees even near the 10th page, heating is continued at the power level of 4. Since the difference from the target temperature has become smaller around the 20th page, switching to heating at a predetermined power level 2 is performed. And it keeps the state as it is until around 50 pages where the temperature is stable. However, the thick paper 2 absorbs more heat than the plain paper. As a result, the fixing temperature starts to decrease from around 60 pages. The digital multi-function peripheral 1000 starts heating at the power level 4 again. In this way, the digital multifunction peripheral 1000 performs feedback control to bring the temperature closer to the predicted temperature if there is a predetermined difference from the predicted temperature based on the measurement result of the fixing temperature on the sheet after fixing.

  The electric power used by the digital multi-function peripheral 1000 for fixing is obtained as the total of the area sandwiched between the line graph in 1002 and the horizontal axis. Compared to the area surrounded by the broken line of plain paper, the area surrounded by the broken line of the thick paper 2 is nearly double. Therefore, paying attention to the difference between the actual measurement value and the target value of the fixing power, it can be determined that the operator has replenished the wrong sheet when the difference becomes larger than a predetermined value.

<Function module configuration>
Next, the configuration of functional modules of the digital multifunction peripheral 1000 according to the present embodiment will be described with reference to FIG. Each functional module is realized by the CPU 112 executing a control program stored in the program ROM 114 of the main controller 30 using the RAM 113 or the external memory 121.

  The digital multifunction peripheral 1000 includes a paper replacement detection unit 1101, a fixing temperature adjustment unit 1102, a printing paper supply management unit 1103, a fixing temperature monitoring unit 1104, and a fixing power consumption monitoring unit 1108 as functional modules. The paper replacement detection unit 1101 determines whether the operator has opened and closed the paper feed tray and refilled the paper by the paper feed unit sensor 42 of the paper feed control unit 304. The fixing temperature monitoring unit 1104 includes therein a fixing temperature measuring unit 1105, a reference fixing temperature storage unit 1106, and a fixing temperature comparison unit 1107. The fixing temperature during printing is monitored to check whether the fixing is correctly performed. The fixing temperature measuring unit 1105 measures the temperature of the fixing film 407 by the fixing unit sensor 41 of FIG. 3, more specifically, the fixing main thermistor 601 of FIG. The reference fixing temperature storage unit 1106 stores a reference value of the fixing temperature for each sheet type shown in FIG. The fixing temperature comparison unit 1107 compares the fixing temperature output from the fixing temperature measurement unit 1105 with the target fixing temperature obtained from the reference fixing temperature storage unit 1106.

  The fixing temperature adjustment unit 1102 adjusts the fixing temperature so as to approach the reference fixing temperature according to the comparison result of the fixing temperature comparison unit 1107 and the power level required for heating shown in 702. That is, the fixing temperature adjusting unit 1102 performs the above-described feedback control of the fixing temperature. The result of the fixing temperature adjustment performed by the fixing temperature adjusting unit 1102 is monitored by the fixing power consumption monitoring unit 1008.

  The fixing power consumption monitoring unit 1008 includes a fixing power consumption measuring unit 1009, a reference fixing power consumption storage unit 1010, and a fixing power consumption comparison unit 1011. The fixing power consumption measuring unit 1009 measures the power consumed by the heater 40 of the fixing control unit 306, more specifically, the IH unit 401 of FIG. The reference fixing power consumption storage unit 1010 stores a table defining fixing power consumption values in an ideal state indicated by 702. The fixing power consumption comparing unit 1011 compares the power value measured by the fixing power consumption measuring unit 1009 with the power consumption value stored in the reference fixing power consumption storage unit 1010. Based on the comparison result, the digital multi-function peripheral 1000 determines whether the paper being printed is the paper type set in the digital multi-function peripheral 1000. If it is determined that the paper types are different, the print paper supply management unit 1103 disables the paper tray of the paper feed control unit 304 and prevents the printing with the wrong paper type from continuing. .

<Processing procedure>
Next, a processing procedure during printing in the image forming apparatus will be described with reference to FIG. In particular, processing for detecting misuse of printing paper will be described. The process described below is a process of the main controller 30 and is realized by each functional module of the digital multi-function peripheral 1000 shown in FIG. Note that the program of the main controller 30 related to this flow is stored in the program ROM 114 of the main controller 30, read out to the RAM 113, and executed by the CPU 112.

  First, in step S <b> 1201, the paper replacement detection unit 1101 determines whether paper replacement or paper replenishment has been performed by an operator based on the output signal of the paper feed unit sensor 42. The output signal is, for example, a signal indicating whether the operator has opened / closed the paper feed tray or whether paper has been replenished. If the replacement / replenishment has not been performed, the determination of the printing paper has already been performed, so the subsequent processing is not performed and the processing ends. On the other hand, if it is determined that paper replacement / replenishment has been performed, the process advances to step S2102.

  In step S1202, the main controller 30 determines whether printing is being performed and fixing processing is being performed. If the fixing process is not being executed, the process ends. On the other hand, if it is determined that the fixing process is being executed, the process advances to step S1203, and the fixing temperature monitoring unit 1104 or the fixing power consumption monitoring unit 1108 functions as a timing determination unit, and the fixing temperature and power consumption parameters that are parameters relating to image formation. It is determined whether it is time to perform the comparison. Immediately after printing is performed, the fixing temperature is not stable, so it is not suitable for comparison. In addition, the influence of sudden abnormal values can be reduced by using a value obtained by averaging measured values in a short period for comparison. Therefore, in this embodiment, the comparison is performed at regular intervals such as the number of image formations, for example, the fifth page, the tenth page, and the 20th page. That is, the fixing temperature monitoring unit 1104 or the fixing power consumption monitoring unit 1108 determines whether or not these timings are reached. If it is determined that it is a comparison timing, the process advances to step S1204. If not, the process ends.

  In step S1204, the fixing temperature comparison unit 1107 and the fixing power consumption comparison unit 1111 compare a predefined reference value with a measured value during printing. Details of the comparison method will be described later with reference to FIG. The comparison result is evaluated by the fixing temperature comparison unit 1107 and the fixing power consumption comparison unit 1111 in step S1205. If no difference is recognized, it is determined that the paper used is correct, so printing is continued and the process is terminated. On the other hand, if it is determined in S1205 that a difference greater than a certain value from the reference value is recognized, the process advances to S1206, and the printing paper supply management unit 1103 sets the paper cassette of the paper feed control unit 304 currently in use to prohibit use. .

  In step S <b> 1207, the printing paper supply management unit 1103 changes the printing paper supply source if the paper stored in another paper cassette in the paper feed control unit 304 is available for printing. That is, if there is a paper cassette capable of supplying paper corresponding to the job setting, the supply source is changed to the paper cassette, and the stopped image formation is restarted. In step S1208, the printing paper supply management unit 1103 displays a warning screen on the operation unit 120, and ends the process. FIG. 14 shows a warning screen 1401 displayed on the operation unit 120. The warning screen 1401 includes an indication that an erroneous replenishment of printing paper has been detected, and a prompt to reconfirm the paper stored in the paper cassette.

  Next, the details of S1204 in FIG. 12 will be described with reference to FIG. Similar to FIG. 12, the processing of this flowchart is realized by each functional module of the digital multi-function peripheral 1000 shown in FIG. In addition, the program of the main controller 30 related to this flow is stored in the program ROM 114 of the main controller 30 and is also read in the RAM 113 and executed by the CPU 112.

  First, in step S <b> 1301, the fixing temperature measurement unit 1105 reads the setting value recorded in the external memory 121 and determines whether or not to compare the paper type at the fixing temperature. The set value recorded in the external memory 121 is updated by the input of the setting dialog of the paper replenishment error detection function shown in FIG. The dialog is displayed as a graphic image on the operation unit 120 and accepts an input from the user. The setting items displayed in the dialog can individually switch on and off the application of “paper type comparison by fixing temperature” and “paper type comparison by fixing power consumption”. That is, only one of them can be applied, or both can be applied. Further, it is also possible to input a threshold value for selecting a “paper type comparison by fixing power consumption” and comparing the read value during fixing with a reference value to determine a paper replenishment error. In FIG. 16, both the fixing temperature and the fixing power consumption are set to “25%”. Therefore, as will be described later, if there is a difference of a predetermined threshold value or more between the measured value and the predicted value, it can be determined that the sheet has been replenished by mistake.

  If it is determined in step S1301 that the sheet type is compared at the fixing temperature, the fixing temperature measuring unit 1105 measures the fixing temperature during printing measured by the fixing unit sensor 41 and stored in the memory or the like in step S1302. read out. In step S1303, the reference fixing temperature storage unit 1106 reads the reference fixing temperature corresponding to the current number of printed pages. In step S <b> 1304, the fixing temperature comparison unit 1107 compares both values and determines whether a difference equal to or greater than the threshold value at the time of fixing temperature recording recorded in the external memory 121 is recognized. If there is a difference greater than or equal to the threshold value, the process advances to step S1310, and the fixing temperature comparison unit 1107 stores the difference and ends the series of processes.

  On the other hand, if the fixing temperature comparison unit 1107 does not recognize the difference in S1304, the process proceeds to S1305, and the process proceeds to a process for comparing the paper type with the fixing power consumption. In step S <b> 1305, the fixing power consumption measuring unit 1109 reads the setting value recorded in the external memory 121 and determines whether to compare the paper type based on the fixing power consumption. If it is set to compare the paper type with the fixing power consumption, the process advances to step S1306, and the fixing power consumption measuring unit 1109 reads the accumulated power consumption from the start of the job. In step S1307, the reference fixing power consumption storage unit 1110 reads the reference fixing power consumption corresponding to the current number of printed pages. In step S <b> 1308, the fixing power consumption comparison unit 1111 compares both values and determines whether or not a difference equal to or greater than the threshold value at the time of fixing power consumption recorded in the external memory 121 is recognized. If there is a difference greater than or equal to the threshold value, the process advances to step S1310, and the fixing power consumption comparison unit 1111 stores the difference and ends the series of processes. On the other hand, if the difference is not recognized, the process advances to step S1309, and the fixing power consumption comparison unit 1111 stores that there is no difference, and ends the series of processes.

  As described above, the image forming apparatus according to the present embodiment detects that the paper type used for printing is different from the preset paper type by measuring and monitoring the fixing temperature and power consumption during printing. can do. Thereby, it is possible to prevent the operator from continuing to use the wrong paper. Therefore, it is possible to prevent the image forming apparatus from being soiled due to printing failure, and the usable time of the printing system can be extended.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 17 and 20. In the first embodiment, the fixing temperature monitoring unit 1104 and the fixing power consumption monitoring unit 1108 have only one reference table. However, in this embodiment, a case where a plurality of such tables are held will be described. In the following, only the parts different from the first embodiment will be described. First, the functional module according to the present embodiment will be described with reference to FIG.

  The actual measurement value of the fixing temperature may be affected by the outside air temperature and humidity of the digital multi-function peripheral 1000. The digital multi-function peripheral 1000 is provided with a cassette heater in the paper feed control unit 304 and has a function of protecting printing paper from changes in outside air temperature and humidity. However, if the difference is too large from the outside air temperature and humidity at the time when the reference fixing temperature storage unit 1106 is created, the comparison result of the fixing temperature comparison unit 1107 may be affected. In order to prepare for such an event, the functional block diagram of FIG. 17 includes a reference fixing temperature storage unit 1703 and a reference fixing power consumption storage unit 1704. Each storage unit includes a plurality of storage areas and can store a plurality of tables.

  Each reference value table is a table corresponding to each outside air temperature and humidity. In the present embodiment, the reference value table to be applied is switched according to values acquired from the outside air temperature measuring unit 1701 that measures the outside air temperature and the outside air humidity measuring unit 1702 that detects the outside air humidity.

  Details of the switching control will be described. The digital multi-function peripheral 1000 classifies the usage environment based on data acquired from the outside air temperature measurement unit 1701 and the outside air humidity measurement unit 1702. Specifically, the control is changed for each of four types of usage environments of “normal temperature”, “low temperature”, “high temperature”, and “high temperature and high humidity”. In other words, the digital multi-function peripheral 1000 holds a reference fixing temperature storage unit 1703 and a reference fixing power consumption storage unit 1704 for each of four types.

  In FIG. 20, 2001 is an example of a fixing temperature change table in a “low temperature” environment, and 2002 is an example of a power consumption change table in a “low temperature” environment. The fixing temperature change table 2001 in the low temperature environment is different from the fixing temperature change table 901 in the normal temperature environment. In particular, the temperature of the cardboard 2 and the coated paper 1 is lower by about 5 degrees in the low temperature environment. This indicates that the printing paper is hardly heated due to the extremely low temperature. As a result, the power consumption change table 2002 indicates that more power is required than the power consumption change table 902 in the room temperature environment. In addition to these tables, a similar fixing temperature change table and power consumption change table are provided for use environments of “high temperature” and “high temperature and high humidity”. Contrary to the low temperature environment, the printing paper is more easily heated than the normal temperature environment, and the power consumption value is reduced.

  As described above, in the image forming apparatus according to the present embodiment, the reference fixing temperature storage unit 1703 and the reference fixing power consumption storage unit 1704 are held in correspondence with a plurality of environmental conditions and used during printing. Determine the environment and apply the optimal table. Accordingly, it is possible to prevent the accuracy of the control described in the first embodiment from being lowered according to the use environment in which the image forming apparatus is installed. That is, stable paper type monitoring can be performed even under the influence of outside air temperature and outside air humidity.

<Modification>
The present invention is not limited to the above embodiment, and various modifications can be made. In the first embodiment, the paper replenishment error warning dialog shown in FIG. 14 only warns that a paper type error has been detected. For example, if the paper being printed is the paper that the operator wants to use and forgets to register the paper information in the paper feed control unit 304, the digital multifunction peripheral 1000 presents the expected paper type to the operator. It is desirable to be able to help register paper information.

  FIG. 18 shows a modification of the fixing power consumption monitoring unit 1108 according to the first embodiment described in FIG. The fixing power consumption monitoring unit 1800 includes a printing paper estimation unit 1801 in addition to the configuration of the fixing power consumption monitoring unit 1108. The fixing power consumption measuring unit 1109 measures the fixing power consumption consumed by the fixing control unit 306 at regular time intervals. The reference fixing power consumption storage unit 1110 holds fixing power consumption data for various paper types. The print paper estimation unit 1801 compares the two to estimate a correct paper type candidate currently being printed. Then, the correct paper type estimated on the warning screen of FIG. Thereby, the user can change the setting information and prevent the image formation from being continued under an incorrect condition.

<Other embodiments>
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

  1101: Paper replacement detection unit, 1102: Fixing temperature adjustment unit, 1103: Printing paper supply management unit, 1105: Fixing temperature measurement unit, 1106: Reference fixing temperature storage unit, 1107: Fixing temperature comparison unit, 1109: Fixing power consumption measurement Part 1110: reference fixing power consumption storage part 1111: fixing power consumption comparison part

Claims (12)

An image forming apparatus,
A measurement unit that measures parameters related to image formation when continuously forming images on a plurality of recording media according to job settings;
A comparison unit that compares the measurement value measured by the measurement unit with a predicted value stored in advance corresponding to each type of recording medium in the storage unit;
Based on the comparison result of the comparison means, if the difference between the measured value and the predicted value is greater than or equal to a predetermined threshold, it is determined that image formation is being performed on a recording medium different from the job setting. An image forming apparatus comprising: a control unit that stops image formation and continues image formation when the difference is not equal to or greater than the predetermined threshold value. A detecting means for detecting whether or not the recording medium is replenished;
The image forming apparatus according to claim 1, wherein the comparison unit compares the measured value with the predicted value when it is detected that the replenishment of the recording medium has been performed by the detection unit. . A timing determination unit that determines whether or not it is a timing to perform the comparison by the comparison unit based on the number of images formed on the current recording medium;
The comparison means is the case where the detection means detects that the recording medium has been replenished and the timing determination means determines that it is the timing for comparison. The image forming apparatus according to claim 2, wherein a value is compared with the predicted value.   4. The image according to claim 1, wherein the parameter related to image formation is at least one of a fixing temperature of the recording medium after image formation and power consumption during image formation. Forming equipment.   The image forming apparatus according to claim 4, further comprising a setting unit that sets the predetermined threshold value corresponding to at least one of the fixing temperature and the power consumption. The storage means further stores a predicted value corresponding to each use environment of the image forming apparatus,
The image forming apparatus according to claim 1, wherein the comparison unit selects a predicted value to be used from the storage unit according to a current use environment. Means for measuring the outside temperature of the image forming apparatus;
Means for measuring the outside air humidity of the image forming apparatus,
The image forming apparatus according to claim 6, wherein the comparison unit selects the predicted value to be used from the storage unit according to at least one of the measured outside air temperature and the outside air humidity.   8. The control unit according to claim 1, further comprising a screen for prompting reconfirmation of a cassette in which a recording medium different from the setting of the job is stored when image formation is stopped. The image forming apparatus according to claim 1. Means for predicting the correct type of recording medium when the type of storage medium in the job setting is incorrect;
The image forming apparatus according to claim 8, wherein the control unit further displays a predicted type of a correct recording medium when the image formation is stopped.   When the image forming is stopped, if there is a cassette capable of supplying a recording medium corresponding to the job setting, the control unit supplies the recording medium from the cassette and restarts the image forming. The image forming apparatus according to claim 1. There is a control method in the image forming apparatus,
A measurement step of measuring parameters related to image formation when the measurement means is continuously forming images on a plurality of recording media according to job settings;
A comparison step in which the comparison unit compares the measurement value measured in the measurement step with a predicted value stored in advance corresponding to each type of recording medium in the storage unit;
When the difference between the measured value and the predicted value is greater than or equal to a predetermined threshold based on the comparison result in the comparison step, the control unit performs image formation on a recording medium different from the job setting. And controlling the image forming apparatus to stop the image formation and execute a control step of continuing the image formation when the difference is not equal to or greater than the predetermined threshold value.   A computer-readable program for causing a computer to function as the image forming apparatus according to claim 1.