JP2015217534A - Control system, image forming device, control method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system and a method that can provide maximum productivity to a user and also prevent deterioration in image quality.SOLUTION: A control system, which controls an image forming device that forms based on image data an image on a recording medium by discharging liquid droplets onto a recording medium, includes: ratio calculating means that calculates a ratio of amounts of liquid droplets that should be discharged when forming the image to amounts of liquid droplets that the image forming device can discharge; temperature detecting means that detects a temperature at a designated site in the image forming device; threshold deciding means that decides based on the temperature detected by the temperature detecting means a threshold of a ratio at which speed of the image formation is reduced; and speed control means that determines whether or not the ratio calculated by the ratio calculating means is higher than the threshold decided by the threshold deciding means, and when the ratio is higher than the threshold performs control so that the speed for the image formation is reduced.

Description

  The present invention relates to a system for controlling an image forming apparatus that performs image formation, an image forming apparatus including the system, a control method, and a program for causing a computer to execute the method.

  At home, there is almost no printing in large quantities at once, and inkjet printers are often used because they can be purchased at low cost. There are two types of inkjet printers: a line type and a serial type. The line type is a type in which ink jet heads arranged to the paper width are used, paper is arranged on the lower side thereof, and the arranged heads are moved or the paper is conveyed for printing. The serial type is a type that performs printing by moving the head perpendicular to the direction in which the paper is conveyed.

  It is known that a line type ink jet printer (hereinafter referred to as a line ink jet printer) consumes more power than a serial type ink jet printer. Therefore, in order to reduce power consumption, a technique for suppressing the maximum power consumption of the head has been proposed (see, for example, Patent Document 1). In this technology, the ratio of the number of nozzles that are driven simultaneously at every moment or per unit time to the total number of nozzles is calculated, and when the ratio is equal to or greater than a predetermined value, the paper conveyance speed is calculated. It slows down and suppresses the maximum power consumption of the head.

  However, if the speed is excessively slow, there is a problem in that the productivity that should be originally provided cannot be provided to the user, and the image quality may be deteriorated.

  Therefore, it has been desired to provide a system, an apparatus, and a method that can provide maximum productivity to a user and can prevent deterioration of image quality.

  In view of the above problems, the present invention is a system for controlling an image forming apparatus that performs image formation by ejecting droplets onto a recording medium based on image data. A ratio calculating means for calculating the ratio of the amount of droplets to be ejected during image formation with respect to the amount of droplets that can be ejected, a temperature detecting means for detecting the temperature of a specified portion in the image forming apparatus, and a temperature Based on the temperature detected by the detecting means, a threshold value determining means for determining the above-mentioned ratio threshold for reducing the image forming speed, and whether the ratio calculated by the ratio calculating means is higher than the threshold value determined by the threshold determining means. And a speed control unit that performs control to reduce the speed of image formation when higher than a threshold value.

  According to the present invention, maximum productivity can be provided to a user, and deterioration of image quality can also be prevented.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment. FIG. 2 is a diagram illustrating main hardware and functional blocks included in the image forming apparatus illustrated in FIG. 1. The figure which showed the relationship between the printing rate when not controlling image formation processing, and the power consumption at the time of printing. The figure which showed the relationship between the printing speed when not controlling image formation processing, and the power consumption at the time of printing. The figure which showed the relationship between the printing rate at the time of controlling an image formation process, and the power consumption at the time of printing. The figure which showed the relationship between the printing speed at the time of controlling an image formation process, and the power consumption at the time of printing. The functional block diagram of a process control system. The flowchart which illustrated the flow of one process which a process control system performs. The figure which illustrated the table used by the process shown in FIG. The flowchart which illustrated the flow of another process which a process control system performs. The flowchart which illustrated the flow of another process which a process control system performs.

  FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the present embodiment. The image forming apparatus is not limited to this, but can be a line inkjet printer. Hereinafter, the image forming apparatus will be described as this line inkjet printer. The line ink jet printer 10 arranges ink jet heads 11 as recording heads in a fixed manner up to the width of paper as a recording medium, and transports the paper under the ink heads to land ink droplets as droplets, thereby causing an image on the paper. It is a printer that performs the formation. In FIG. 1, the width of the paper is the length in the short piece direction of the paper.

  FIG. 1A is a diagram illustrating the inside of the case of the line inkjet printer 10, and FIG. 1B is a diagram illustrating a head group in which a plurality of inkjet heads 11 are arranged in the width direction of the paper. c) is a view of the head group as viewed from below. A line inkjet printer 10 shown in FIG. 1 includes eight inkjet heads 11 and a head tank 12 that supplies ink to each inkjet head 11. As shown in FIG. 1C, the inkjet heads 11 are attached so as to be arranged in four rows in two rows so as to extend in one direction.

  Here, the inkjet heads 11 are mounted so as to be arranged in four rows in two rows, but the present invention is not limited to this, and may be one example, three rows or more, You may attach so that 1-3 or 5 or more may be located in a line.

  Each inkjet head 11 includes one or more nozzles. The ink jet head 11 shown in FIG. 1C is configured to eject ink droplets of four colors, and includes a plurality of nozzles arranged in one direction at regular intervals for each color. The four color inks are black, cyan, yellow, and magenta that are necessary to form a color image. Note that the ink may be only black necessary for forming a monochrome image, or may be five or more colors by adding other colors.

  The line inkjet printer 10 includes a control unit such as a paper supply unit that supplies paper, a paper discharge unit that discharges printed paper, a power supply unit, and a controller. The paper feed unit, the paper discharge unit, and the like are well-known devices and will not be described here. The power supply unit and the control unit will be described later.

  The main hardware and functions of the line inkjet printer 10 will be described with reference to FIG. The line inkjet printer 10 includes a control unit 20, a carriage 30, a power supply unit (PSU) 40, and various actuators. The control unit 20 operates by receiving power from the PSU 40, receives print data as a print job from the host PC 100 connected to the line inkjet printer 10 directly or via a network, and performs image processing. The control unit 20 outputs the image-processed data to the carriage 30 and causes the carriage 30 to perform image formation on the paper, that is, printing. The control unit 20 also controls the operation of the carriage 30 and various actuators.

  In order to realize such processing and control, the control unit 20 includes a CPU 21, a ROM 22, a RAM 23, a host I / F 24, an image output control unit 25, an encoder analysis unit 26, a main scanning motor driving unit 27, and a sub scanning motor driving unit. 28 and I / O 29 are provided. The CPU 21 controls the entire line inkjet printer 10. The ROM 22 stores a program for starting the line inkjet printer 10 and testing the operation of the carriage 30 and various actuators. This program is read and executed by the CPU 21 when the line inkjet printer 10 is activated.

  The RAM 23 provides a work area when the CPU 21 performs processing and control. The host I / F 24 connects the host PC 100 to the line inkjet printer 10 and enables communication with the host PC 100. The image output control unit 25 performs image processing on the image data stored in the RAM 23 by the CPU 21 and outputs the image data to the carriage 30. The image output control unit 25 processes and outputs image data according to an instruction from the CPU 21, and at this time, in order to output it as drive data (waveform pattern), a drive waveform generation unit 25a that generates a waveform pattern is provided. Yes. The drive waveform generation unit 25a functions as drive data generation means for generating drive data. The image output control unit 25 is usually in an integrated circuit such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). The image output control unit 25 can execute specific image processing at high speed.

  The encoder analysis unit 26 acquires position information of the ink jet head 11 on the paper from an encoder that detects a position provided on the carriage 30 or the like, and analyzes the position information. Then, the encoder analyzing unit 26 outputs the analysis result to the main scanning motor driving unit 27 and the sub scanning motor driving unit 28. The main scanning motor driving unit 27 performs drive control of a motor that moves the inkjet head 11 in the main scanning direction, that is, the paper width direction, and the sub scanning motor driving unit 28 performs paper control in the sub scanning direction, that is, the paper transport direction. It controls the drive of the motor that transports. The I / O 29 is connected to a sensor or the like, receives an input of data detected by the sensor or the like, and sends it to the CPU 21. For this reason, the control unit 20 connects the CPU 21, the ROM 22, and the like to each other via a bus and exchanges information and the like.

  The carriage 30 includes a head driver 31, a head 32, and a main scanning encoder 33. The head driver 31 functions as a driving unit, receives a waveform pattern from the image output control unit 25 of the control unit 20, and drives and operates the head 32 according to the waveform pattern. The head 32 includes, for example, a piezoelectric element, converts the driving voltage output from the head driver 31 into force by the piezoelectric element, ejects ink droplets from one or more nozzles, and prints on paper. The main scanning encoder 33 detects the position of the head 32 in the main scanning direction, and outputs the position information to the encoder analysis unit 26.

  The head 32 is not limited to a piezo method including a piezoelectric element, but a thermal method in which bubbles are generated in the ink by heating with a heater and the ink is ejected, or ink is charged and sucked onto a substrate separated from the nozzle. It is possible to employ an electrostatic method or the like that discharges water.

  The PSU 40 is connected to an external commercial alternating current (AC) power supply 110 by a power cable or the like, and converts it into a direct current (DC) power supply. Then, the PSU 40 supplies the converted DC power to the control unit 20, the carriage 30, and various actuators.

  The various actuators include a sub-scanning encoder 50, a main scanning motor 51, a sub-scanning motor 52, various sensor actuators 53, and the like. The sub scanning encoder 50 detects the position of the head 32 in the sub scanning direction. The main scanning motor 51 is driven by the main scanning motor driving unit 27 and moves the head 32 in the main scanning direction. For example, the main scanning motor 51 moves the head 32 in order to adjust the position of the head 32 in the main scanning direction. The sub-scanning motor 52 is driven by the sub-scanning motor driving unit 28 and conveys the paper in the sub-scanning direction. Various sensor actuators 53 operate various sensors. Examples of the sensor include a temperature sensor that detects the temperature of a designated portion described later.

  The line inkjet printer 10 ejects ink droplets from a plurality of nozzles provided on a plurality of heads 32 to form an image, but does not eject ink droplets that can be ejected from all nozzles during image formation. Absent. For this reason, the ratio of the amount of ink droplets to be actually ejected at the time of image formation with respect to the amount ejectable from all the nozzles can be defined as the printing rate.

  The printing rate increases as the area of the image formed on the paper increases and the color becomes darker because the number of nozzles used and the amount of ink droplets to be ejected increase. Therefore, in printing such as filling the entire paper with a high density, the power consumed to eject ink droplets increases, and the power consumption of the entire printer also increases. Since the line inkjet printer 10 forms an image using a plurality of heads 32 at the same time, the ratio of the power consumed by the head 32 to the power consumed by the entire printer is high. Power consumption will be greatly affected.

  The relationship between the printing rate and the power consumption during printing will be described with reference to FIG. There are three main power consumptions during printing: power consumption consumed by the controller 20, power consumed by the motor, and power consumed by the head. The power consumption of the control unit 20 is generally constant regardless of the processing and control contents. Further, if the printing speed is constant, the power consumption of the motor is also constant because the paper transport speed in the sub-scanning direction is also constant.

  However, since the power consumption of the head increases according to the printing rate, the maximum power consumption of the entire printer is a value indicated by the maximum power consumption A in FIG. Here, when paying attention to the PSU 40 that supplies power to the motor and the head, the power supply capability of the PSU 40 is the maximum power consumption A in order to avoid a shortage of power supply under all assumed conditions. Must satisfy the value of. For this reason, the line inkjet printer 10 incorporates the PSU 40 designed to satisfy the value of the maximum power consumption A. However, when the printing rate is low, most of the power supply capability is not utilized.

  The relationship between the printing speed and the power consumption during printing when the printing rate is constant will be described with reference to FIG. As described above, there are three power consumptions during printing, and the power consumption of the control unit 20 is constant. However, the power consumption per unit time of the motor related to paper conveyance increases as the printing speed increases. Moreover, since the power consumption of the head needs to shorten the ink ejection cycle as the printing speed increases, the number of ejections per unit time increases and the power consumption increases. Thus, the power consumption during printing when printing at the maximum speed is a value indicated by the maximum power consumption B in FIG.

  Based on the above, the relationship between the printing rate and the power consumption during printing when the printing speed is ½ that of the above example will be described with reference to FIG. Referring to FIG. 5, the power consumption of the control unit 20 is the same value as the example shown in FIG. 3 and a constant value regardless of the change in the printing speed. However, the power consumption of the motor is a value smaller than the example shown in FIG. The power consumption of the head increases according to the printing rate, but the maximum value is ½ of the example shown in FIG. 3 because the printing speed is ½. That is, the value indicated by the maximum power consumption C is lower than the value of the maximum power consumption A shown in FIG. 3 when a document having a high printing rate is printed.

  For this reason, when printing a document having a printing rate higher than a predetermined printing rate, it is possible to reduce power consumption during printing by performing a control for reducing the printing speed. However, simply lowering the printing speed only takes printing time, and thus productivity is lowered. Also, if the printing speed is slowed down, the ink droplet landing position accuracy is lowered and the image quality is deteriorated.

  Therefore, as shown in FIG. 6, a threshold corresponding to the printing speed (speed limiting threshold) is provided, and the printing rate below the speed limiting threshold is the normal printing speed, and the printing rate higher than that is half that printing speed. Try to print. As a result, the printing rate below the speed limit threshold can provide the maximum productivity to the user, and the PSU 40 adopts a small and low-cost one with a rating satisfying the maximum power consumption C. However, it is not necessary to exceed the power rating.

  There are mainly two factors that determine the power rating of the PSU 40. One is a current rating value of a component such as a field effect transistor (MOSFET) mounted on the PSU 40, and the other is a junction temperature rating of a component also mounted on the PSU 40. The junction temperature is the temperature of the chip joint surface of the semiconductor component. The current rating value is uniquely determined by the current value passing through the component, but the junction temperature rating is determined in combination by the environmental temperature, heat dissipation conditions, continuous heat accumulation conditions, etc. is there. For this reason, in the case where the junction temperature rating is dominant, the continuous current accumulation condition, that is, not the maximum value of the pulse current, but the average value of the current consumption within a certain period often becomes a problem.

  Therefore, instead of using a predetermined numerical value for the speed limit threshold, the temperature of the PSU 40 is monitored and determined according to the temperature, thereby realizing control corresponding to a continuous heat accumulation state.

  FIG. 7 is a functional block diagram of a control system for realizing this control. The control system may be mounted in the line inkjet printer 10, or only the means for monitoring the temperature may be mounted in the line inkjet printer 10, and the other means may be configured as a separate external device. Other means may be implemented as a functional unit in a server or the like connected to the line inkjet printer 10 via a network.

  The control system controls the line inkjet printer 10 including a plurality of heads each having one or more nozzles. This control system includes a ratio calculation unit 60, a temperature detection unit 61, a threshold value determination unit 62, an information storage unit 63, and a speed control unit 64. The ratio calculation unit 60 calculates the printing rate based on the image data received by the line inkjet printer 10 from the host PC 100. The printing rate can be calculated as the ratio of the amount of ink that should actually be discharged out of the amount of ink that can be discharged from the head 32 per unit time.

  The value of the ink amount that can be ejected from the head 32 per unit time can be stored as a set value in the ROM 22 or a storage device such as a flash memory or HDD not shown in FIG. The actual amount of ink to be ejected is calculated using the received image data, paper size, normal printing speed, and other information to calculate the amount of ink and the time required to print the image. It can be calculated by obtaining.

  The temperature detection unit 61 is a temperature sensor, detects the temperature of a designated part such as the joint surface, and notifies the threshold determination unit 62 of the detected temperature. The threshold determination unit 62 determines a speed limit threshold corresponding to the printing speed based on the temperature notified from the temperature detection unit 61. The threshold value determination unit 62 refers to the information stored in the information storage unit 63 when making this determination. The details of the method determined by the threshold determination unit 62 and the information stored in the information storage unit 63 will be described later.

  The speed control unit 64 compares the print rate calculated by the ratio calculation unit 60 with the speed limit threshold value determined by the threshold value determination unit 62, and determines whether the print rate is higher than the speed limit threshold value. When the printing rate is higher than the speed limit threshold value as a result of the determination, the speed control unit 64 keeps the normal printing speed as described with reference to FIG. 6, and when the printing rate is higher than the speed limit threshold value, Control to execute printing at a speed slower than the printing speed. Incidentally, the printing speed can be slowed by lowering the ink droplet ejection cycle and lowering the paper transport speed, and can be controlled by adjusting them.

  Processing performed by the control system will be described in detail with reference to FIG. The control system starts processing from step 800 when print data is transmitted from the host PC 100 to the line inkjet printer 10 and the line inkjet printer 10 receives the print data. In step 810, the temperature detector 61 detects the temperature (Tpsu) of the PSU 40 and acquires the temperature. The temperature of the PSU 40 is the temperature of the joint surface. Then, the temperature detection unit 61 notifies the threshold value determination unit 62 of the temperature.

  In step 820, the threshold value determination unit 62 determines the speed limit threshold value (Cv_th) of the printing rate based on the notified PSU temperature. The speed limit threshold value can be determined using, for example, a table shown in FIG. FIG. 9 is a table showing the relationship between the PSU temperature and the printing speed limit threshold. This table is a table in which the PSU temperature, the print rate speed limit threshold, and the post-limit print speed (Spd_lim) are stored in association with each other. According to this table, when a temperature of 80 ° C. or higher is notified from the temperature detection unit 61, the threshold value determination unit 62 determines the speed limit threshold value of the printing rate as 10% and notifies the speed control unit 64 of the threshold value. To do.

  FIG. 9 shows an example in the case of performing control having one type of printing rate speed limit threshold according to the PSU temperature. That is, only the speed limit threshold value corresponding to the case where the printing speed is 1/2 of the normal speed can be obtained. Such a table is stored in the information storage unit 63 as correspondence information in which the PSU temperature and the speed limit threshold value are associated with each other, and can be referred to when the threshold value determination unit 62 is necessary. As the information storage unit 63, the ROM 22 or the like shown in FIG. 2 can be used, and a flash memory, HDD, or the like (not shown) can also be used.

  Referring to FIG. 8 again, in step 830, the ratio calculation unit 60 calculates the print rate (Cv) of the print page based on the image data included in the print data. When the number of printed pages is over a plurality of pages, the printing rate can be calculated for each page. In the example shown in FIG. 8, the printing rate is calculated after the speed limit threshold is calculated. However, the printing rate may be calculated before the temperature detection or the speed limit threshold is calculated. You may implement in parallel with them.

  In step 840, the speed control unit 64 compares the print rate calculated by the ratio calculation unit 60 with the speed limit threshold value determined by the threshold value determination unit 62, and determines whether the print rate is higher than the speed limit threshold value. Judging. If it is determined that the printing rate is equal to or lower than the speed limit threshold, the speed control unit 64 controls to print at a normal speed in step 850. On the other hand, if it is determined that the printing rate is higher than the speed limit threshold value, the process proceeds to step 860, and the speed control unit 64 prints at the speed set as the limited printing speed with reference to the table shown in FIG. Control to do. In this way, printing is performed while controlling the printing speed, and when the print page is output, the process proceeds to step 870 and the process is terminated.

  In the example shown in FIG. 8, the table shown in FIG. 9 is used, and only the speed limit threshold corresponding to the case where the printing speed is ½ of the normal speed is obtained. The printing speed is not limited to 1/2 of the normal speed, and may be 1/4 or 3/4 of the normal speed. As a result, more optimized productivity can be provided to the user.

  In this case, for each PSU temperature, a table in which the speed limit threshold is associated with the limited print speed is prepared, and when the print ratio of the print page is calculated, the print speed can be determined with reference to the table. it can. The printing speed can be determined as a printing speed corresponding to the speed limiting threshold by searching a speed limiting threshold corresponding to the calculated printing rate from the table.

  With reference to FIG. 10, the process which the control system in this case performs is demonstrated. Similar to step 800 shown in FIG. 8, the process is started from step 1000 when the line inkjet printer 10 receives the print data. In step 1010, the temperature detection unit 61 detects the temperature (Tpsu) of the PSU 40 and acquires the temperature. Then, the temperature detection unit 61 notifies the threshold value determination unit 62 of the temperature.

  In step 1020, the threshold value determination unit 62 calculates a printing rate speed limit threshold value (Cv_th) based on the notified PSU temperature. The threshold value determination unit 62 calls a table in which the print rate speed limit threshold value corresponding to the PSU temperature is associated with the print speed. In step 1030, the ratio calculation unit 60 calculates the print rate (Cv) of the print page based on the image data included in the print data. When the number of printed pages is over a plurality of pages, the printing rate can be calculated for each page. In the example shown in FIG. 10, the printing rate is calculated after acquisition of the speed limit threshold or the like. However, the calculation of the printing rate may be performed before acquisition of the temperature detection or the speed limit threshold or the like, You may implement in parallel with them.

  In step 1040, the speed controller 64 determines whether the printing rate calculated by the ratio calculator 60 is higher than any speed limit threshold on the table called by the threshold determiner 62. When it is determined that the printing rate is equal to or less than all the speed limit thresholds, the speed control unit 64 controls to print at a normal speed in step 1050. On the other hand, if it is determined that the printing rate is higher than any of the speed limit threshold values, the process proceeds to step 1060, and the speed control unit 64 prints at a printing speed corresponding to the calculated printing rate of the table. Control. In this way, printing is performed while controlling the speed, and when the print page is output, the process proceeds to step 1070 and the process is terminated.

  So far, the method of determining the speed limit threshold and the printing speed using the table by the threshold determination unit 62 has been described. However, the present invention is not limited to this. For example, the speed limit threshold value and the printing speed can be given as a function of the PSU temperature, and can be determined by calculating using a mathematical expression represented by the function. This example will be described with reference to FIG.

  Similar to step 800 shown in FIG. 8, the process is started from step 1100 when the line inkjet printer 10 receives the print data. In step 1110, the temperature detection unit 61 detects the temperature (Tpsu) of the PSU 40 and acquires the temperature. Then, the temperature detection unit 61 notifies the threshold value determination unit 62 of the temperature.

  In step 1120, the threshold value determination unit 62 calculates the speed limit threshold value (Cv_th) of the printing rate based on the notified PSU temperature. Here, the threshold value determination unit 62 calculates the speed limit threshold value and the print speed by substituting the PSU temperature into a given function, and determines the speed limit threshold value and the print speed. In step 1130, the ratio calculation unit 60 calculates the print rate (Cv) of the print page based on the image data included in the print data. When the number of printed pages is over a plurality of pages, the printing rate can be calculated for each page. In the example shown in FIG. 11, the printing rate is calculated after acquiring the speed limit threshold or the like. However, the calculation of the printing rate may be performed before acquiring the temperature detection or the speed limit threshold or the like. You may implement in parallel with them.

  In step 1140, the speed control unit 64 compares the print rate calculated by the ratio calculation unit 60 with the speed limit threshold value determined by the threshold value determination unit 62, and whether the print rate is higher than the calculated speed limit threshold value. Judge whether. When it is determined that the printing rate is equal to or less than the speed limit threshold, the speed control unit 64 controls to print at a normal speed in step 1150. On the other hand, if it is determined that the printing rate is higher than the speed limit threshold value, the process proceeds to step 1160, and the speed control unit 64 controls to print at the printing speed determined in step 1120. In this way, printing is performed while controlling the speed, and when a print page is output, the process proceeds to step 1170 and this process is terminated.

  The units and parts that cause a temperature increase in continuous printing have been described above limited to the PSU 40, but such units and parts are not limited to the PSU 40. Therefore, even if the temperatures of the units and parts other than the PSU 40 are acquired and the speed limit threshold value is calculated from the temperatures, it is assumed that the same effect as described above can be obtained. An example of such a unit or component is the drive waveform generator 25a shown in FIG. Since the drive waveform generator 25a is a unit or component that is in the integrated circuit and generates heat when operated as described above, its power rating is determined in a complex manner including not only the current rating value but also the junction temperature rating. Because it is a unit or a part. As other examples, the head driver 31 and the head 32 shown in FIG.

  By providing a control system that performs the above-described control, the maximum power consumption can be reduced. Therefore, the power rating of the PSU 40 and the like to be mounted can be reduced, the image forming apparatus can be downsized, and can be provided at low cost. . Even in this case, printing can be executed at the maximum printing speed, and the maximum productivity can be provided to the user. Further, since printing is executed at the maximum printing speed, it is possible to minimize the deterioration of the ink droplet landing position accuracy and to prevent the deterioration of the image quality.

  Also, more optimized by allowing multiple speed limit thresholds and printing speeds to be set or calculated as a function rather than one speed limit threshold and printing speed for each temperature range Productivity can be provided to the user. Further, by performing control based on the temperature of the head 32 and the like as well as the PSU temperature, the same effect as described above can be obtained.

  The control system, image forming apparatus, and control method of the present invention have been described in detail with reference to the embodiments shown in the drawings, but the present invention is not limited to the above-described embodiments. Therefore, other embodiments, additions, changes, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and as long as the effects and advantages of the present invention are exhibited in any aspect, the present invention It is included in the range. Therefore, the present invention can provide a program for causing a computer to execute the processing control method, a recording medium on which the program is recorded, and the like.

DESCRIPTION OF SYMBOLS 10 ... Line inkjet printer, 11 ... Inkjet head, 12 ... Head tank, 20 ... Control part, 21 ... CPU, 22 ... ROM, 23 ... RAM, 24 ... Host I / F, 25 ... Image output control part, 25a ... Drive Waveform generation unit, 26 ... encoder analysis unit, 27 ... main scanning motor driving unit, 28 ... sub-scanning motor driving unit, 29 ... I / O, 30 ... carriage, 31 ... head driver, 32 ... head, 33 ... main scanning encoder 40 ... PSU, 50 ... sub-scanning encoder, 51 ... main scanning motor, 52 ... sub-scanning motor, 53 ... various sensor actuators, 60 ... ratio calculation unit, 61 ... temperature detection unit, 62 ... threshold determination unit, 63 ... speed Control unit, 64 ... information storage unit, 100 ... host PC, 110 ... commercial AC power supply

JP 2013-132752 A

Claims (10)

A system for controlling an image forming apparatus for forming an image by discharging droplets on a recording medium based on image data,
A ratio calculating means for calculating a ratio of the amount of the droplets to be ejected at the time of image formation to the amount of the droplets that can be ejected by the image forming apparatus, using the image data;
Temperature detecting means for detecting the temperature of a designated part in the image forming apparatus;
Based on the temperature detected by the temperature detecting means, a threshold value determining means for determining a threshold value of the ratio for reducing the speed of image formation;
Speed control means for determining whether or not the ratio calculated by the ratio calculation means is higher than the threshold value determined by the threshold value determination means, and performing control for reducing the image forming speed when the ratio is higher than the threshold value; Including the control system. Storage means for storing correspondence information in which the temperature of the part and the threshold value of the ratio are associated with each other;
The control system according to claim 1, wherein the threshold value determination unit determines the threshold value with reference to the correspondence information stored in the storage unit. In the correspondence information, a plurality of threshold values of the ratio are associated with each temperature of the part,
The threshold value determining unit refers to the correspondence information based on the temperature detected by the temperature detection unit and the ratio calculated by the ratio calculation unit, and determines the threshold value. Control system.   2. The control system according to claim 1, wherein the threshold value determination unit calculates the threshold value from the temperature detected by the temperature detection unit using a mathematical expression in which the threshold value of the ratio is expressed as a function of the temperature of the part.   The control system according to claim 1, wherein the temperature detection unit detects a temperature of a power supply unit in the image forming apparatus as the temperature of the designated portion. The image forming apparatus is a line-type inkjet printer in which recording heads are arranged up to the width of paper as the recording medium,
The ratio calculation means calculates, as the ratio, a printing rate that represents a ratio of the amount of ink droplets to be ejected from the recording head per unit time to the amount of ink droplets that can be ejected from the recording head per unit time. The control system according to any one of claims 1 to 5. The inkjet printer includes drive data generation means for generating drive data for driving the recording head, and drive means for driving the recording head based on the drive data generated by the drive data generation means,
The control system according to claim 6, wherein the temperature detection unit detects the temperature of the one or more recording heads, the drive data generation unit, or the drive unit as the temperature of the designated portion.   An image forming apparatus including the control system according to claim 1. A method for controlling an image forming apparatus that performs image formation by discharging droplets onto a recording medium based on image data,
Using the image data, calculating a ratio of the amount of droplets to be ejected during image formation to the amount of droplets that can be ejected by the image forming apparatus;
Detecting a temperature of a designated part in the image forming apparatus;
Determining a threshold of the ratio to reduce the speed of image formation based on the temperature detected in the detecting step;
Determining whether the ratio calculated in the calculating step is higher than the threshold value determined in the determining step, and performing control to reduce an image forming speed when the ratio is higher than the threshold value. , Control method. A program for causing a computer to execute a method for controlling an image forming apparatus that performs image formation by discharging droplets onto a recording medium based on image data,
Using the image data, calculating a ratio of the amount of droplets to be ejected during image formation to the amount of droplets that can be ejected by the image forming apparatus;
Causing the temperature detecting means to detect the temperature of the designated part in the image forming apparatus;
Determining a threshold of the ratio to reduce the speed of image formation based on the temperature detected in the detecting step;
Determining whether or not the ratio calculated in the calculating step is higher than the threshold value determined in the determining step, and performing control to reduce an image forming speed when the ratio is higher than the threshold value. Let the program.