Image processing apparatus

Abstract

To further increase energy saving performance in an image processing apparatus having heaters.SOLUTION: An image processing apparatus comprises: one or more heaters; a power supply unit that includes at least one DC power supply, and that operates in one of a plurality of operating states different in total power consumption from each other; one or more driving means that drive the one or more heaters by using power supplied from the at least one DC power supply; and control means that, on the basis of the drive state of the one or more heaters, causes the power supply unit to operate in an operating state selected to reduce the excess of the total power consumption.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an image processing device. [Background technology]

[0002] Conventionally, image processing devices such as printers and scanners are exposed to various factors that cause environmental temperature fluctuations, depending on, for example, the region, season, or time of day. For example, if the temperature of a device that has cooled during the night or early morning suddenly rises after an office air conditioning system starts operating, condensation occurs inside the device, and the condensed water causes printing or operational defects. To prevent defects caused by such temperature fluctuations, techniques for managing the temperature inside the device by incorporating a heater have been known. Because such devices require the heater to operate even when not performing their intended operation, they are typically connected to an AC commercial power source to power the heater. However, when the heater is powered by an AC commercial power source, heater performance can vary depending on the device's installation environment.

[0003] Patent Document 1 discloses an image forming apparatus that converts AC voltage from a commercial power source into DC voltage and supplies power to heaters using the DC voltage. In order to prevent excessive power consumption when power is supplied from the DC power source to multiple heaters, the image forming apparatus of Patent Document 1 controls the power supply from the DC power source so that only a predetermined number of heaters are supplied with power at the same time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-53954 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology disclosed in Patent Document 1 does not take into consideration differences in the operating states of DC power supplies. For example, the power supply efficiency of a DC power supply depends on the operating states, such as the operation / stop of a power factor correction (PFC) circuit or a cooling fan, or the on / off status of each of the multiple DC power supplies that may be present. When a large amount of heat is required for the entire device, it is necessary to operate the power supply circuit sufficiently to increase the power supply efficiency. On the other hand, when only a small amount of heat is required (or no heat is required), it is desirable to reduce the power consumption of the power supply circuit in order to meet the demand for energy conservation.

[0006] In view of the above, the present invention aims to further improve the energy saving performance of an image processing apparatus having a heater. [Means for solving the problem]

[0007] According to one aspect, there is provided an image processing device comprising: one or more heaters; a power supply unit including at least one DC power supply, the power supply unit operating in one of a plurality of operating states having different total power consumptions; one or more driving means for driving the one or more heaters using power supplied from the at least one DC power supply; and control means for operating the power supply unit in an operating state selected based on the driving state of the one or more heaters so as to reduce the excess of the total power consumption. [Effects of the Invention]

[0008] According to the present invention, it is possible to further improve the energy saving performance of an image processing apparatus having a heater. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a multifunction peripheral according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of a schematic configuration of a heater-related circuit according to the first embodiment. [Figure 3] FIG. 2 is a circuit diagram for explaining control of the operation of a PFC circuit. [Figure 4] FIG. 10 is an explanatory diagram illustrating an example of a UI provided for setting one or more heaters. [Figure 5] 3 is a circuit diagram showing an example of a detailed configuration of a switching circuit and a heater driving circuit shown in FIG. 2. [Figure 6] 4 is a correspondence table that defines the correspondence between the driving state of the heater and the operating state of the power supply unit according to the first embodiment. [Figure 7] 10 is a flowchart showing an example of the flow of a state control process according to the first embodiment. [Figure 8] FIG. 10 is a block diagram showing an example of a schematic configuration of a heater-related circuit according to a second embodiment. [Figure 9] 10 is a correspondence table that defines the correspondence between the driving state of the heater and the operating state of the power supply unit according to the second embodiment. [Figure 10] 10 is a flowchart showing an example of the flow of a state control process according to the second embodiment. [Figure 11] 11 is a flowchart showing an example of a detailed flow of the heater power supply control process shown in FIG. 10. [Figure 12] FIG. 10 is a block diagram showing an example of a schematic configuration of a heater-related circuit according to a first modified example. [Figure 13] FIG. 10 is a block diagram showing an example of a schematic configuration of a heater-related circuit according to a second modified example. [Figure 14] FIG. 14 is a circuit diagram showing an example of a detailed configuration of the switch detection circuit shown in FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] <1. Equipment Overview> Fig. 1 is a schematic diagram showing an example of the configuration of a multifunction peripheral 1 according to an embodiment. Referring to Fig. 1, the multifunction peripheral 1 includes a printer unit 10, a scanner unit 50, an operation unit 70, a network interface (I / F) 75, a control unit 80, and a power supply unit 100. The multifunction peripheral 1, the printer unit 10, and the scanner unit 50 are each examples of an image processing device.

[0012] The printer unit 10 is an image forming device that forms an image on a sheet and includes a paper feed cassette 15, an image forming section 20, a conveying section 30, a fixing section 40, and an ejection tray 45.

[0013] The image forming section 20 includes process units 25Y, 25M, 25C, and 25K, an intermediate transfer belt 27, a secondary transfer unit 28, and a belt cleaner 29. The process units 25Y, 25M, 25C, and 25K are units that electrophotographically form toner images of four color components: yellow, magenta, cyan, and black, respectively. That is, the printer unit 10 according to this embodiment is a color laser printer capable of printing full-color images. However, in other embodiments, the printer unit 10 may be a monochrome printer or a printer capable of printing images using other image forming methods, such as inkjet printing. Because the process units 25Y, 25M, 25C, and 25K may have similar configurations, the following description will focus on the process unit 25Y as an example.

[0014] The process unit 25Y includes a photosensitive drum 21, a charger 22, a laser unit 23, a developing unit 24, a primary transfer roller 25, and a drum cleaner 26. The photosensitive drum 21 is an image carrier and rotates in the direction of arrow A1 in the figure. The charger 22 charges the surface of the photosensitive drum 21 to a uniform potential. The laser unit 23 has a semiconductor laser as a light source and exposes the photosensitive drum 21 to laser light in accordance with input image data to form an electrostatic latent image on the surface of the photosensitive drum 21. The developing unit 24 supplies toner to the electrostatic latent image on the surface of the photosensitive drum 21, developing the electrostatic latent image to form a toner image. A high transfer voltage is applied to the primary transfer roller 25, which transfers the toner image (here, yellow) on the surface of the photosensitive drum 21 to the intermediate transfer belt 27. Similarly, magenta, cyan, and black toner images are formed in the process units 25M, 25C, and 25K, respectively. These toner images are then transferred in order onto the yellow toner image on the intermediate transfer belt 27, forming a full-color toner image on the intermediate transfer belt 27. The intermediate transfer belt 27 transports the toner image to the position of the secondary transfer unit 28.

[0015] The paper feed cassette 15 is a storage unit that stores a stack of sheets. The transport unit 30 includes transport paths 31, 32, and 33, a feed roller 34, and a plurality of transport rollers. The feed roller 34 picks up sheets (also referred to as recording materials) P one by one from the stack of sheets stored in the paper feed cassette 15 and feeds them to the transport path 31. When the sheet P transported along the transport path 31 reaches the secondary transfer position, the secondary transfer unit 28 transfers the toner image on the intermediate transfer belt 27 onto the sheet P using a secondary transfer roller to which a high transfer voltage is applied. The transfer voltage can be optimized depending on the type of sheet P. The transport unit 30 may also have a correction mechanism (not shown) that corrects skew of the sheet P on the transport path 31.

[0016] The drum cleaner 26 removes toner remaining on the surface of the photosensitive drum 21. The belt cleaner 29 removes toner remaining on the intermediate transfer belt 27.

[0017] The fixing unit 40 has a pair of fixing rollers, and heats and presses the sheet P onto which the toner image has been transferred, thereby fixing the toner image to the sheet P. The sheet P that has passed through the fixing unit 40 is discharged onto a discharge tray 45.

[0018] When double-sided printing is performed, the sheet P retreats to the conveying path 32, then reverses its direction of travel and enters the double-sided conveying path 33. The sheet P returns to the conveying path 31 upside down, and the toner image is transferred to the back surface of the sheet P by the secondary transfer unit 28. The fixing unit 40 fixes the toner image to the sheet P by heating and pressurizing the sheet P again. The sheet P is then discharged to the discharge tray 45.

[0019] The scanner unit 50 is a reading device that optically reads an original. The scanner unit 50 includes a platen 51, an optical system 52, and an image sensor 53. An original to be read by the scanner unit 50 is placed on the platen 51 or fed one sheet at a time by an automatic document feeder (ADF), not shown in FIG. 1 . The optical system 52 includes a light source, a mirror, and a lens. The light source irradiates the original with white light. The light reflected from the surface of the original is further reflected by one or more mirrors, passes through a lens, and is guided to the image sensor 53. The image sensor 53 has color filters for three color components, R, G, and B, and converts the light of each color component into an image signal to generate read image data. The image sensor 53 outputs the read image data to the control unit 80.

[0020] The operation unit 70 provides a user interface for user interaction with the multifunction peripheral 1. The operation unit 70 may typically be a combination of an operation means for accepting user input (e.g., job-related instructions and various user settings) and a display means for displaying images or information, and may include a touch panel, buttons, switches, a keypad, and the like.

[0021] The network interface 75 is an interface for the multifunction peripheral 1 to communicate with other devices via a network. The network I / F 75 may be a wired interface or a wireless interface.

[0022] The control unit 80 controls the overall operation of the multifunction peripheral 1 described above. For example, when an instruction to execute a print job is received, the control unit 80 controls the printer unit 10 to form an image on a sheet based on input image data received from an external device. When an instruction to execute a scan job is received, the control unit 80 controls the scanner unit 50 to read a sheet and saves the read image data in storage (not shown) or transmits it to a specified destination. When an instruction to execute a copy job is received, the control unit 80 controls the scanner unit 50 to read a sheet and controls the printer unit 10 to form an image on another sheet based on the read image data.

[0023] The multifunction peripheral 1 further includes heaters 120a, 120b, and 120c. The heater 120a is disposed inside the scanner unit 50 and heats the optical system 52 to prevent poor reading caused by condensation. In the following description, the heater 120a is also referred to as a scanner heater. The heater 120b is disposed near the process units 25Y, 25M, 25C, and 25K and heats the image forming unit 20 (e.g., the photosensitive drum 21 and the intermediate transfer belt 27) to prevent poor image formation caused by condensation. In the following description, the heater 120b is also referred to as a drum heater. The heater 120c is disposed below the paper feed cassette 15 and heats the paper feed cassette 15 and the sheet stack therein to prevent poor conveyance caused by moisture absorption by the sheets. In the following description, the heater 120c is also referred to as a cassette heater.

[0024] In the following description, when there is no need to distinguish between heaters 120a, 120b, and 120c, the alphabet at the end of the reference numeral will be omitted and they will be collectively referred to as heater 120. While Fig. 1 shows an example in which multifunction device 1 includes three heaters 120 for heating the inside of the device, the number of heaters 120 included in multifunction device 1 may be any number equal to or greater than one.

[0025] Phenomena caused by temperature fluctuations, such as condensation inside the device or moisture absorption by sheets, can occur even when the multifunction device 1 is not operating. Therefore, the multifunction device 1 must be configured to be able to supply power to each heater 120 even when it is in a sleep mode, in which power supply to the drive system is stopped for energy conservation, or in a power-off mode. The power supply unit 100 functions as a DC power supply by converting AC voltage from a commercial power source into DC voltage. The power supply unit 100 can supply power to each heater 120 regardless of whether the multifunction device 1 is powered on or off. Furthermore, when the multifunction device 1 is powered on, the power supply unit 100 supplies power to the control system of the multifunction device 1, including the control unit 80, to operate the electronic circuits. Furthermore, the power supply unit 100 supplies power to the drive system of the multifunction device 1 to enable the operation of the drive members when the multifunction device 1 is in a standby mode, which is a preparation stage for an image formation operation, and in a print mode (or scan mode), in which an image formation operation is being performed.

[0026] In this embodiment, to enable flexible temperature management of the multifunction peripheral 1 in various temperature environments, a user can set whether to activate each heater 120 via a user interface (UI) provided by the operation unit 70. When more heaters 120 are activated, the amount of heat required for the entire device increases, resulting in increased power consumption. In this case, it is desirable to activate a means for improving power supply efficiency in the power supply unit 100. On the other hand, when some or all of the heaters 120 are not activated and the amount of heat required for the entire device is small, the power consumption of the means for improving power supply efficiency in the power supply unit 100 itself is wasted. In this case, it is desirable to reduce the excess power consumption of the power supply unit 100 to meet energy conservation requirements. Therefore, in the following sections, several examples for selectively switching the operating state of the power supply unit 100 based on the heater drive state will be described.

[0027] <2. First Example> <2-1. Heater-related circuit configuration example> Fig. 2 is a block diagram showing an example of a schematic configuration of heater-related circuits according to Example 1. In addition to the operation unit 70, network I / F 75, control unit 80, power supply unit 100, and heaters 120a, 120b, and 120c described using Fig. 1, Fig. 2 also shows a power plug 90, a switching circuit 118, and heater drive circuits 130a, 130b, and 130c.

[0028] The power supply unit 100 includes an alternating current (AC) filter 101, a rectifier diode 102, a power factor correction (PFC) circuit 103, a first direct current (DC) power supply 104, a second DC power supply 105, a fan drive circuit 106, and a cooling fan 107. The control unit 80 includes a central processing unit (CPU) 111, a random access memory (RAM) 112, and a read-only memory (ROM) 113.

[0029] The power plug 90 is connected to a commercial power supply, which is an AC power source. The AC filter 101 filters the commercial power received through the power plug 90 to remove noise. The rectifier diode 102 rectifies the AC power that has passed through the AC filter 101. The PFC circuit 103 improves the power factor of the power input from the rectifier diode 102. For example, the PFC circuit 103 can improve the power factor of the power by suppressing harmonic components of the current flowing through the circuit and improving waveform distortion. In this embodiment, the PFC circuit 103 operates in response to a PFC control signal SigP input from the CPU 111. When the PFC circuit 103 is operating, power with the power factor corrected is supplied to the first DC power source 104 and the second DC power source 105. When the PFC circuit 103 is not operating, power without power factor correction is supplied to the first DC power source 104 and the second DC power source 105.

[0030] FIG. 3 is a circuit diagram for explaining control of the operation of the PFC circuit 103 based on the PFC control signal SigP. In the example of FIG. 3, the PFC circuit 103 includes a photocoupler 115, a switch 116, and a PFC control unit 117. The photocoupler 115 includes a secondary-side light-emitting element and a primary-side light-receiving element. When the signal value of the PFC control signal SigP input from the CPU 111 indicates operation of the PFC circuit, the photocoupler 115 turns on the switch 116 to output 3.3 V of operating power to the PFC control unit 117. This causes the PFC control unit 117 to operate the PFC circuit 103, thereby improving the power factor of the power supply unit 100. When the signal value of the PFC control signal SigP indicates that the PFC circuit is to be stopped, the photocoupler 115 causes the switch 116 to cut off the supply of operating power to the PFC control unit 117. This stops operation of the PFC circuit 103.

[0031] Returning to FIG. 2 , the first DC power supply 104 generates DC power by converting the AC voltage of the power supplied from the PFC circuit 103 into a DC voltage. In this embodiment, the voltage of the DC power generated by the first DC power supply 104 is 12 V. This DC power is supplied to the heaters 120 a, 120 b, and 120 c. The DC power from the first DC power supply 104 is also output to the fan drive circuit 106 and the control unit 80.

[0032] The second DC power supply 105 generates DC power by converting the AC voltage of the power supplied from the PFC circuit 103 into a DC voltage. In this embodiment, the voltage of the DC power generated by the second DC power supply 105 is 24 V. This DC power is supplied in parallel with the DC power from the first DC power supply 104 to the fan drive circuit 106, and further to the control unit 80 and a drive system (not shown) of the multifunction peripheral 1. The second DC power supply 105 operates in response to a power control signal SigS input from the CPU 111. When the second DC power supply 105 is not operating, no power is supplied to the drive system of the multifunction peripheral 1.

[0033] The cooling fan 107 is a cooling unit that cools the first DC power supply 104 and the second DC power supply 105 of the power supply unit 100. The fan drive circuit 106 drives the cooling fan 107 using DC power supplied from the first DC power supply 104 or the second DC power supply 105. The fan drive circuit 106 and the cooling fan 107 operate in response to a fan control signal SigF input from the CPU 111 to the fan drive circuit 106.

[0034] As described above in relation to the control unit 80, the CPU 111 controls the execution of jobs in the multifunction peripheral 1. The RAM 112 provides a temporary storage area for calculations by the CPU 111. The ROM 113 stores computer programs to be executed by the CPU 111. Furthermore, in this embodiment, the CPU 111 also functions as a control unit that controls the supply of power from the power supply unit 100 to one or more heaters 120 based on user settings received via the UI.

[0035] FIG. 4 shows a heater setting screen 71 as an example of a UI provided by the operation unit 70 for setting each heater 120. The heater setting screen 71 shown in FIG. 4 includes a first button B1, a second button B2, and a third button B3. The first button B1 is a button for setting the operating state of the scanner heater 120a. A user can activate or deactivate the scanner heater 120a by operating the first button B1. The second button B2 is a button for setting the operating state of the drum heater 120b. A user can activate or deactivate the drum heater 120b by operating the second button B2. The third button B3 is a button for setting the operating state of the cassette heater 120c. A user can activate or deactivate the cassette heater 120c by operating the third button B3. In the example of FIG. 4, the scanner heater 120a and the cassette heater 120c are set to operate, and the drum heater 120b is set to deactivate. Based on the user settings thus received, the CPU 111 outputs drive signals Sig1, Sig2, and Sig3 to the heater drive circuits 130a, 130b, and 130c, respectively. Note that instead of the operation unit 70 of the multifunction device 1, a UI similar to the heater setting screen 71 may be provided to the user via a display of another device that communicates with the multifunction device 1.

[0036] 2, the switching circuit 118 is a switching means that opens and closes the power supply path from the first DC power supply 104 to each heater 120. When all of the drive signals Sig1, Sig2, and Sig3 output from the CPU 111 to the heater drive circuits 130a, 130b, and 130c, respectively, indicate that the corresponding heaters should be stopped, the switching circuit 118 cuts off the supply of 12V DC power from the first DC power supply 104. When one or more of the drive signals Sig1, Sig2, and Sig3 indicate that the corresponding heaters should be operated, the switching circuit 118 causes the first DC power supply 104 to supply DC power to the heater drive circuits 130a, 130b, and 130c.

[0037] The heater driving circuits 130a, 130b, and 130c are driving means that drive the heaters 120a, 120b, and 120c, respectively, using power supplied from at least one DC power supply of the power supply unit 100. When a drive signal Sig1 input from the CPU 111 indicates the operation of the scanner heater 120a, the heater driving circuit 130a drives the scanner heater 120a using DC power supplied from the first DC power supply 104. When a drive signal Sig2 input from the CPU 111 indicates the operation of the drum heater 120b, the heater driving circuit 130b drives the drum heater 120b using DC power supplied from the first DC power supply 104. When a drive signal Sig3 input from the CPU 111 indicates the operation of the cassette heater 120c, the heater driving circuit 130c drives the cassette heater 120c using DC power supplied from the first DC power supply 104. That is, in this embodiment, the heater driving circuits 130a, 130b, and 130c drive the corresponding heaters 120a, 120b, and 120c in accordance with the user settings received through the operation unit .

[0038] Each heater 120 has a resistive heating element that generates heat when current flows through it. The resistance value of the resistive heating element is appropriately selected during the design stage so that the desired amount of heat is generated in response to the supplied power. Each heater 120 may have a temperature control circuit to maintain the temperature of the heated member near a target temperature or to prevent overheating. In the example shown in FIG. 2, a thermistor 121b is located near the drum heater 120b. The resistance value of the thermistor 121b varies depending on the temperature inside the image forming unit 20. When the temperature of the heated member detected by the thermistor 121b reaches a certain threshold, the heater drive circuit 130b does not drive the drum heater 120b, even if the drive signal Sig2 indicates that the drum heater 120b is activated. Naturally, similar temperature control circuits may also be provided for the scanner heater 120a and the cassette heater 120c.

[0039] Fig. 5 shows an example of the detailed configuration of the switching circuit 118 and the heater drive circuits 130a, 130b, and 130c described above. In the example of Fig. 5, the switching circuit 118 includes a switch 119. When one or more of the drive signals Sig1, Sig2, and Sig3 indicate an ON state, the switch 119 closes the power supply path of 12V DC power, thereby enabling the supply of this DC power to the heater drive circuits 130a, 130b, and 130c.

[0040] In the heater drive circuit 130a, a series regulator 131a reduces the voltage of the DC power supplied to the heater drive circuit 130a from 12V to 3.3V and supplies the 3.3V DC power to each circuit element of the heater drive circuit 130a. A switch 132a supplies 12V DC power to the scanner heater 120a when a drive signal input from a latch circuit 133a via a transistor indicates ON. The latch circuit 133a receives a drive signal Sig1 and a latch enable signal SigL from the CPU 111. The table below is a truth table for the latch circuits of the heater drive circuits 130a to 130c.

[0041] [Table 1]

[0042] According to the above truth table, when the latch enable signal SigL indicates High, the latch circuit 133a outputs the value of the drive signal Sig1 input from the CPU 111 to the transistor in the subsequent stage. Furthermore, when the latch enable signal SigL indicates Low, the latch circuit 133a holds the value of the drive signal Sig1 that was previously input and outputs the held value to the transistor in the subsequent stage. By holding and outputting the value of the drive signal Sig1 in this way, the latch circuit 133a can operate using DC power supplied from the first DC power supply 104 even if the CPU 111 stops operating and the input of the drive signal Sig1 is discontinued.

[0043] The heater drive circuit 130c is configured similarly to the heater drive circuit 130a.

[0044] Heater drive circuit 130b is also configured similarly to heater drive circuit 130a. However, heater drive circuit 130b further includes switch 134b in the power supply path for 12V DC power, after switch 132b, which is turned on / off by the output of latch circuit 133b. When the temperature of the heated member detected by thermistor 121b rises and the voltage across thermistor 121b reaches the threshold voltage of comparator 135b, switch 134b cuts off the power supply path from switch 132b to drum heater 120b. When the temperature of the heated member drops, switch 134b resumes power supply from switch 132b to drum heater 120b.

[0045] <2-2. Controlling the operating state of the power supply> As described above, the multifunction peripheral 1 has one or more heaters 120 for heating the interior of the device. Each heater 120 is driven using power supplied from at least one DC power supply (in this embodiment, the first DC power supply 104) of the power supply unit 100. Meanwhile, the power supply unit 100 includes the following circuits that consume power by operating in accordance with control from the control unit 80: ·PFC circuit 103 Fan drive circuit 106 and cooling fan 107 ·Second DC power supply 105 The operating state of the power supply unit 100 can be divided into several states depending on whether these circuits are operating, and the total power consumption of the power supply unit 100 varies depending on the operating state. The PFC circuit 103 improves the power factor of the power supply unit 100 and increases the power capacity of the multifunction peripheral 1, but if the amount of power required by the multifunction peripheral 1 is small, it is not necessary to operate the PFC circuit 103. The cooling fan 107 ensures a stable power supply by cooling the DC power supply of the power supply unit 100, but if the amount of power used by the multifunction peripheral 1 is small, the amount of heat generated by the power supply unit 100 is also small, so it is not necessary to operate the cooling fan 107. Therefore, the CPU 111 selects an operating state of the power supply unit 100 based on the driving state of the heater 120 so as to reduce the excess of the total power consumption of the power supply unit 100, and operates the power supply unit 100 in the selected operating state.

[0046] In this embodiment, the control unit 80 has a storage unit (e.g., ROM 113) that stores in advance the amount of power required to drive each heater 120. The CPU 111 determines the amount of power required to be supplied from the power supply unit 100 by adding up the stored amounts of power for the heaters 120 that are set to be driven. In addition to the driving state of the heaters 120, the CPU 111 may also take into account the operating mode of the multifunction peripheral 1 when determining the amount of power required (for example, in standby mode and print mode, more power is consumed in the driving system). The CPU 111 then selects the operating state in which the power supply unit 100 should be operated based on a comparison between the determined amount of power required and a predetermined threshold value.

[0047] As a first example, candidates for the operating state of the power supply unit 100 include a first state in which the PFC circuit 103 is operating and the total power consumption of the power supply unit 100 is a first power value, and a second state in which the PFC circuit 103 is not operating and the total power consumption of the power supply unit 100 is a second power value. The second power value is lower than the first power value. When the required power amount determined based on the driving states of the heaters 120a to 120c is greater than a predetermined power threshold value, the CPU 111 selects the first state and operates the PFC circuit 103 in order to sufficiently cover the required power amount. On the other hand, when the determined required power amount is smaller than the power threshold value, the CPU 111 selects the second state and stops the PFC circuit 103 in order to reduce the surplus power consumption.

[0048] As a second example, candidates for the operating state of the power supply unit 100 include a first state in which the cooling fan 107 is operating and the total power consumption of the power supply unit 100 is a first power value, and a second state in which the cooling fan 107 is not operating and the total power consumption of the power supply unit 100 is a second power value. The second power value is lower than the first power value. However, the first power value and the second power value here may be different from the respective values in the above-described first example. When the required power amount determined based on the driving states of the heaters 120a to 120c is greater than a predetermined power threshold value, the CPU 111 selects the first state and operates the cooling fan 107 in order to sufficiently cover the required power amount. On the other hand, when the determined required power amount is smaller than the power threshold value, the CPU 111 selects the second state and stops the cooling fan 107 in order to reduce the surplus power consumption.

[0049] Naturally, combinations of the first and second examples can also be envisioned. For example, the CPU 111 may compare the required power amount P REQ determined based on the driving states of the heaters 120a to 120c with a first power threshold value TH1 and a second power threshold value TH2, and select the operating state of the power supply unit 100 as follows. Here, TH1 < TH2: ·P REQ < TH1, stop both the PFC circuit and the cooling fan ·TH1 ≤ PREQ <When it is TH2, only one of the PFC circuit and the cooling fan is operated. ·TH2 ≤ P REQ <In this case, both the PFC circuit and the cooling fan are operated.

[0050] Figure 6 is a correspondence table that defines the correspondence between the driving state of the heater 120 according to this embodiment and the operating state of the power supply unit 100. The leftmost column of the correspondence table represents the operation mode of the multifunction device 1. The operation mode of the multifunction device 1 is any one of "power off", "sleep", "standby", and "print". "Power off" is a state in which all functions of the multifunction device 1 are stopped. "Sleep" is a state in which only some functions of the control system of the multifunction device 1 (for example, reception of inquiries via the network I / F and responses thereto) are operating. "Standby" is a state in which no job is being executed, but all functions of the multifunction device 1 are operating or can operate immediately. "Print" is a state in which some job is being executed in the multifunction device 1.

[0051] The second to fourth columns from the left of the correspondence table respectively represent the driving states ("on" or "off") of the scanner heater 120a, the drum heater 120b, and the cassette heater 120c. There can be a total of eight driving states in combinations of the two driving states of the three heaters 120. As an example, when the scanner heater 120a is "on", it consumes 10 W of power as the rated power. When the drum heater 120b is "on", it consumes 20 W of power as the rated power. Note that even when the driving state of the drum heater 120b is "on", power supply may be cut off by the function of the temperature control circuit, but the function of the temperature control circuit shall be ignored when determining the power consumption. When the cassette heater 120c is "on", it consumes 10 W of power as the rated power.

[0052] The fifth column of the correspondence table indicates the total power requirement corresponding to the drive state of the heaters 120a-120c in each row. For example, the total power requirement for the eighth row, in which all heaters 120a-120c are "on," is 10 + 20 + 10 = 40 W. The sixth column of the correspondence table indicates the amount of power supplied from the first DC power supply 104 to the control system corresponding to the operation mode of the multifunction peripheral 1 in each row. Regardless of the drive state of the heaters 120a-120c, the power requirement of the control system is 0 W when the power is off, and 1 W when in sleep mode. In standby mode and print mode, the power requirement of the control system is a maximum of 30 W (although the actual power consumption varies depending on the type of control being performed). The seventh column of the correspondence table indicates the amount of power supplied from the second DC power supply 105 corresponding to the operation mode of the multifunction peripheral 1 in each row. Regardless of the driving state of the heaters 120a to 120c, in the power-off and sleep modes, the second DC power supply 105 is stopped and therefore its required power is 0 [W]. In the standby mode and print mode, power is supplied from the second DC power supply 105 to the driving system, and its required power is a maximum of 290 [W] (in reality, the power consumption varies depending on the operation being performed).

[0053] The eighth to eleventh columns of the correspondence table indicate how the CPU 111 selects the operating state of the power supply unit 100 for the drive states of the heaters 120a to 120c in each row. Specifically, the eighth column indicates whether the PFC circuit 103 is on or off. In the example of Fig. 6, the CPU 111 activates the PFC circuit 103 when the total amount of power required by the heaters 120a to 120c is 30 W or more, and stops the PFC circuit 103 when the total amount of power required is less than 30 W. This threshold of 30 W may correspond to the first power threshold TH1 described above.

[0054] The ninth column indicates the on / off state of the cooling fan 107. In the example of Fig. 6, the CPU 111 operates the cooling fan 107 when the total amount of power required by the heaters 120a to 120c is 40 W or more, and stops the cooling fan 107 when the total amount of power required is less than 40 W. This threshold of 40 W may correspond to the second power threshold TH2 described above.

[0055] The tenth column indicates the on / off state of the first DC power supply 104. In this embodiment, the first DC power supply 104 is always connected to a commercial power supply, so all rows in the tenth column indicate "on." Note that the power that the first DC power supply 104 can output depends on the operating states of the PFC circuit 103 and the cooling fan 107.

[0056] The 11th column represents the on / off state of the second DC power supply 105. In this embodiment, the second DC power supply 105 operates only in standby mode and print mode, so the 11th column shows "on" only in the bottom row and shows "off" in the remaining rows corresponding to power-off and sleep modes.

[0057] As an example, when both the PFC circuit 103 and the cooling fan 107 are stopped, the maximum power that the first DC power supply 104 can output is less than 30 W. When only the PFC circuit 103 is operating, the maximum power that the first DC power supply 104 can output is more than 30 W but less than 40 W. When both the PFC circuit 103 and the cooling fan 107 are operating, the maximum power that the first DC power supply 104 can output reaches 70 W. The correspondence table in FIG. 6 is based on such performance of the power supply unit 100.

[0058] In standby mode and print mode, by operating both the PFC circuit 103 and the cooling fan 107 and further operating the second DC power supply 105, sufficient power can be stably supplied to one or more heaters, the control system, and the drive system. In contrast, in power-off or sleep mode, when some heaters are set not to operate, if the PFC circuit 103 and the cooling fan 107 are operated, the power capacity of the power supply unit 100 becomes significantly larger than the required power. This means that at least a portion of the power consumed by the PFC circuit 103, the fan drive circuit 106, and the cooling fan 107 is wasted. In this embodiment, one or both of the PFC circuit 103 and the cooling fan 107 are dynamically stopped according to the above-described correspondence table (or a comparison between the required power amount and the power threshold), thereby eliminating wasted power consumption and optimizing the power consumption of the multifunction peripheral 1.

[0059] <2-3. Processing flow> 7 is a flowchart showing an example of the flow of a state control process that can be executed by the control unit 80 (e.g., CPU 111) in this embodiment to control the power supply state in the multifunction peripheral 1. In the following explanation, processing steps are abbreviated as 'S'.

[0060] The state control process in Figure 7 is started when the multifunction peripheral 1 is powered on. First, in S101, the control unit 80 is started and begins operation. In S103, the control unit 80 outputs a PFC control signal SigP to the PFC circuit 103 to start the PFC circuit 103. The control unit 80 also outputs a fan control signal SigF to the fan drive circuit 106 to start driving the cooling fan 107. The control unit 80 also outputs a power supply control signal SigS to the second DC power supply 105 to start the second DC power supply 105.

[0061] Next, in S105, the control unit 80 acquires user settings (hereinafter referred to as heater settings) related to the driving of the heaters 120a to 120c, which are received via the UI of the operation unit 70. Next, in S107, the control unit 80 checks whether the heater settings are equal to the previous required power amount P REQIf the heater setting has been changed, the process proceeds to S109.

[0062] In S109, the control unit 80 calculates the required power amount P REQ For example, the control unit 80 calculates the required power amount P by adding up the amounts of power predefined for the heaters 120 that are set to operate. REQ Next, in S111, the control unit 80 outputs drive signals Sig1, Sig2, and Sig3 to the heater drive circuits 130a, 130b, and 130c, respectively, in accordance with the heater settings.

[0063] If the heater settings have not been changed in S107, S109 and S111 are skipped. In this case, the heater drive circuits 130a, 130b, and 130c drive the corresponding heaters 120a, 120b, and 120c in accordance with the drive signal values ​​held in their respective latch circuits.

[0064] Next, in S113, the control unit 80 waits for reception of a job. The operation mode of the multifunction device 1 from S105 to S113 is the standby mode. When a job is received in the standby mode, in S115 the control unit 80 controls one or both of the printer unit 10 and the scanner unit 50 to execute the received job. The operation mode of the multifunction device 1 in S115 is the print mode (or the scan mode if a scan job is executed).

[0065] Next, in S117, the control unit 80 determines whether the multifunction device 1 should be powered off or transition to sleep mode. For example, if an operation to power off is detected on the operation unit 70, the multifunction device 1 will transition to power off. If an operation instructing a transition to sleep mode is detected, or if a predetermined length of time has passed without an operation being performed, the multifunction device 1 will transition to sleep mode. If the multifunction device 1 is to be powered off or transition to sleep mode, the process proceeds to S121. If the standby mode is to be maintained, the process returns to S105.

[0066] In S121, the control unit 80 outputs a power supply control signal SigS to the second DC power supply 105 to stop the second DC power supply 105. The subsequent processing is performed based on the required power amount P REQ The branching is performed based on a comparison between the first power threshold TH1 and the second power threshold TH2. Here, it is assumed that the first power threshold TH1 is 30 [W] and the second power threshold TH2 is 40 [W].

[0067] Required power amount P REQ is smaller than the first power threshold TH1 (P REQ <30W, S123-YES), in S125, the control unit 80 outputs a PFC control signal SigP to the PFC circuit 103 to stop the PFC circuit 103. Also, in S127, the control unit 80 outputs a fan control signal SigF to the fan drive circuit 106 to stop driving the cooling fan 107.

[0068] Required power amount P REQ is greater than the first power threshold TH1 and less than the second power threshold TH2 (30W≦P REQ <40W, S129-YES), in S131, the control unit 80 outputs the fan control signal SigF to the fan drive circuit 106 to stop driving the cooling fan 107.

[0069] Required power amount P REQ is greater than the second power threshold TH2 (40W≦P REQ ), the PFC circuit 103 and the cooling fan 107 are not stopped.

[0070] Next, in S133, the control unit 80 determines whether the multifunction device 1 should be returned to standby mode. For example, if any operation is detected on the operation unit 70, the multifunction device 1 will return from sleep mode to standby mode. In this case, the process returns to S103. If the conditions for returning to standby mode are not met, in S135 the control unit 80 determines whether to maintain sleep mode or to transition the multifunction device 1 to power off. If the sleep mode should be maintained, the process returns to S133. If the multifunction device 1 should be transitioned to power off, the process proceeds to S137. In S137, the control unit 80 stops operation, and the multifunction device 1 becomes powered off.

[0071] The flowchart of Fig. 7 is based on the relationship between the drive states of the heaters 120a, 120b, and 120c and the operating states of the power supply unit 100 defined in the correspondence table of Fig. 6. However, the relationship between the drive states of one or more heaters 120 and the operating states of the power supply unit 100 is not limited to the example described above. For example, the values ​​of the first power threshold TH1 and the second power threshold TH2 may be different from those in the example described above. Furthermore, instead of the operating state in which only the PFC circuit 103 operates, an operating state in which only the cooling fan 107 operates may be adopted.

[0072] Furthermore, the control unit 80 calculates the required power amount P based on the power consumption of components other than the heater, which depends on the operation mode of the multifunction peripheral 1, in addition to the driving state of the heater 120. REQ In particular, if there is a significant difference in the power consumption of one or both of the control system and the drive system for each operation mode, by taking such a difference into account in determining the required power amount, it is possible to more accurately determine the surplus of the total power consumption and appropriately select the operating state of the power supply unit.

[0073] Although an example has been described here in which it is determined whether to activate each circuit of the power supply unit 100 based on a comparison between the required power amount and a power threshold, the technology according to the present disclosure is not limited to such an example. For example, the control unit 80 may store in advance in memory a table that associates each heater drive state with the corresponding operating state of the power supply unit 100, and determine the operating state of the power supply unit 100 directly from the heater setting by referring to the table in memory without calculating the required power amount.

[0074] The control unit 80 may also determine the operating state of the power supply unit 100 based on the number of heaters to be driven. As one example, the control unit 80 may operate the power supply unit 100 in a first state when a first number of heaters are driven, and may operate the power supply unit 100 in a second state when a second number of heaters, which is less than the first number, are driven. As another example, the control unit 80 may operate the power supply unit 100 in the first state when at least one heater is driven, and may operate the power supply unit 100 in the second state when no heaters are driven. Here, the first state is a state in which the total power consumption of the power supply unit 100 is a first power value, and the second state is a state in which the total power consumption of the power supply unit is a second power value lower than the first power value.

[0075] Furthermore, in the first embodiment, an example was described in which the multifunction peripheral 1 (or more generally, the image processing device) has three heaters 120a, 120b, and 120c, but the technology according to the present disclosure is also applicable to cases in which the image processing device has only one heater. Additionally, the technology according to the present disclosure is also applicable to cases in which the image processing device has multiple heaters, but only one of the heaters is the subject of drive state determination. For example, the control means of the image processing device may operate the power supply unit in a first state in which the total power consumption is a first power value when one heater is driven, and may operate the power supply unit in a first state in which the total power consumption is a lower second power value when the heater is not driven.

[0076] <3. Second Example> <3-1. Heater-related circuit configuration example> Fig. 8 is a block diagram showing an example of a schematic configuration of a heater-related circuit according to the second embodiment. The circuit configuration shown in Fig. 8 differs from the circuit configuration according to the first embodiment shown in Fig. 2 in that it includes a heater power supply unit 200 and an additional cooling fan 207. In addition, the CPU 111 and switching circuit 118 in the first embodiment are replaced with a CPU 211 and switching circuit 218 in this embodiment.

[0077] The heater power supply unit 200 is a circuit that generates DC power to be supplied to the heaters 120a, 120b, and 120c. The heater power supply unit 200 includes an AC relay 201, a rectifier diode 202, a third DC power supply 204, and a fan drive circuit 206.

[0078] The AC relay 201 is supplied with AC power that has passed through the AC filter 101 of the power supply unit 100. In this embodiment, the AC relay 201 operates in response to a power supply control signal SigR input from the CPU 211. When the AC relay 201 is operating, the power from the AC filter 101 is relayed to the rectifier diode 202. When the AC relay 201 is not operating, the supply of power to the rectifier diode 202 and subsequent circuits is cut off.

[0079] The rectifier diode 202 rectifies the AC power supplied via the AC relay 201. The third DC power supply 204 generates DC power by converting the AC voltage of the power rectified by the rectifier diode 202 into a DC voltage. In this embodiment, the voltage of the DC power generated by the third DC power supply 204 is 12 V. This DC power is supplied to the heaters 120 a, 120 b, and 120 c. The DC power from the third DC power supply 204 is also output to a fan drive circuit 206.

[0080] The cooling fan 207 is a cooling unit that cools the third DC power supply 204 of the heater power supply unit 200. The fan drive circuit 206 drives the cooling fan 207 using DC power supplied from the third DC power supply 204. The fan drive circuit 206 and the cooling fan 207 operate in response to a fan control signal SigH input from the CPU 211 to the fan drive circuit 206.

[0081] Similar to the CPU 111 according to the first embodiment, the CPU 211 controls the execution of jobs in the multifunction device 1. Furthermore, in this embodiment, the CPU 211 also functions as a control unit that controls the supply of power from the heater power supply unit 200 to one or more heaters 120 based on user settings received via a UI as described with reference to FIG.

[0082] The switching circuit 218 is a switching unit that opens and closes the power supply path from the third DC power supply 204 to each heater 120. The switching circuit 218 cuts off the supply of 12V DC power from the third DC power supply 204 when all of the drive signals Sig1, Sig2, and Sig3 output from the CPU 211 to the heater drive circuits 130a, 130b, and 130c, respectively, indicate that the corresponding heaters should be stopped. The switching circuit 218 supplies DC power from the third DC power supply 204 to the heater drive circuits 130a, 130b, and 130c when one or more of the drive signals Sig1, Sig2, and Sig3 indicate that the corresponding heaters should be operated. The detailed configurations of the switching circuit 218 and the heater drive circuits 130a, 130b, and 130c may be similar to the configurations described with reference to FIG. 5 in relation to the first embodiment.

[0083] <3-2. Controlling the operating state of the power supply> Each heater 120 is driven using power supplied from at least one DC power supply (in this embodiment, the third DC power supply 204) of the heater power supply unit 200. Meanwhile, the heater power supply unit 200 includes the following circuits that consume power by operating in accordance with control from the control unit 80: Fan drive circuit 206 (and cooling fan 207) ·Third DC power supply 204 The operating state of the heater power supply unit 200 can be divided into several states depending on whether these circuits are operating or not, and each operating state varies in total power consumption of the heater power supply unit 200. Therefore, the CPU 211 selects an operating state of the heater power supply unit 200 based on the driving state of the heater 120 so as to reduce the excess of the total power consumption of the heater power supply unit 200, and operates the heater power supply unit 200 in the selected operating state.

[0084] In this embodiment, the control unit 80 has a storage unit that stores in advance the amount of power required to drive each heater 120. The CPU 211 determines the amount of power required to be supplied from the heater power supply unit 200 by adding up the stored amounts of power for the heaters 120 that are set to be driven. In addition to the driving state of the heaters 120, the CPU 211 may also take into account the operating mode of the multifunction peripheral 1 when determining the amount of power required. The CPU 211 then selects the operating state in which the heater power supply unit 200 should be operated based on a comparison between the determined amount of power required and a predetermined threshold value.

[0085] As a first example, the candidate operating states include a first state in which the cooling fan 207 is operating and the total power consumption of the heater power supply unit 200 is a first power value, and a second state in which the cooling fan 207 is not operating and the total power consumption of the heater power supply unit 200 is a second power value. The second power value is lower than the first power value. When the required power amount determined based on the operating states of the heaters 120a to 120c is greater than a predetermined power threshold, the CPU 211 selects the first state and operates the cooling fan 207 to fully cover the required power amount. On the other hand, when the determined required power amount is less than the power threshold, the CPU 211 selects the second state and stops the cooling fan 207 to reduce excess power consumption.

[0086] As a second example, candidates for the operating state include a third state in which power is supplied from the third DC power supply 204 to one or more heaters 120, and a fourth state in which the power supply path through the third DC power supply 204 is interrupted. A fourth power value, which is the total power consumption of the heater power supply unit 200 in the fourth state, is lower than a third power value, which is the total power consumption of the heater power supply unit 200 in the third state. When one or more of the heaters 120a to 120c are set to operate, the CPU 211 selects the third state and relays power to the AC relay 201. On the other hand, when all of the heaters 120a to 120c are set to stop, the CPU 211 selects the fourth state to interrupt the power supply path to the AC relay 201 in order to reduce the excess power consumption.

[0087] Of course, combinations of the first and second examples can also be envisioned. For example, the CPU 211 may select the operating state of the heater power supply unit 200 as follows based on the driving states of the heaters 120a to 120c. Here, TH3 is a third power threshold: ·P REQ = 0, stop the third DC power supply 204 and the cooling fan 207 ·0 < P REQ < TH3, operate the third DC power supply 204 and stop the cooling fan 207 ·TH3 ≤ P REQ In this case, operate the third DC power supply 204 and the cooling fan

[0088] FIG. 9 is a correspondence table defining the correspondence between the driving state of the heater 120 according to the present embodiment and the operating states of the power supply unit 100 and the heater power supply unit 200. The leftmost column of the correspondence table represents the operation mode of the multifunction device 1. The operation mode of the multifunction device 1 is any one of "power off", "sleep", "standby", and "print".

[0089] The second to fourth columns from the left in the correspondence table indicate the drive states ("on" or "off") of the scanner heater 120a, drum heater 120b, and cassette heater 120c. The required power amounts of heaters 120a, 120b, and 120c are assumed to be 10W, 20W, and 10W, respectively, as in the first embodiment.

[0090] The fifth column of the correspondence table represents the total amount of power required for the heater power supply unit 200, corresponding to the drive state of the heaters 120a-120c in each row. The sixth column of the correspondence table represents the amount of power supplied from the first DC power supply 104 to the control system, corresponding to the operation mode of the multifunction peripheral 1 in each row. The seventh column of the correspondence table represents the amount of power supplied from the second DC power supply 105, corresponding to the operation mode of the multifunction peripheral 1 in each row. Regardless of the drive state of the heaters 120a-120c, the second DC power supply 105 is stopped in power-off mode and sleep mode, so its required power is 0 [W]. In standby mode and print mode, power is supplied from the second DC power supply 105 to the drive system, and the required power is a maximum of 290 [W].

[0091] The eighth to eleventh columns of the correspondence table indicate how the CPU 211 selects the operating state of the power supply unit 100 for the drive states of the heaters 120a to 120c in each row. In this embodiment, the PFC circuit 103 of the power supply unit 100 is controlled to stop in power-off and sleep mode and to operate in standby mode and print mode. The cooling fan 107 is also controlled to stop in power-off and sleep mode and to operate in standby mode and print mode. The first DC power supply 104 is always connected to a commercial power source and operates unless the power is off. The second DC power supply 105 is also controlled to stop in power-off and sleep mode and to operate in standby mode and print mode.

[0092] The 12th and 13th columns of the correspondence table indicate how the CPU 211 selects the operating state of the heater power supply unit 200 for the driving states of the heaters 120a to 120c in each row.

[0093] The twelfth column indicates the on / off state of the third DC power supply 204. In the example of Fig. 9, when at least one heater 120 is operating, that is, when the total amount of power required for the heater power supply unit 200 is greater than zero, the third DC power supply 204 operates regardless of the operating mode of the multifunction peripheral 1.

[0094] The thirteenth column indicates the on / off state of the cooling fan 107. In the example of Fig. 9, the CPU 211 operates the cooling fan 207 when the total amount of power required by the heaters 120a to 120c is 40 W or more, and stops the cooling fan 207 when the total amount of power required is less than 40 W. This threshold of 40 W may correspond to the third power threshold TH3 described above.

[0095] As an example, when the cooling fan 207 is stopped, the maximum power that the third DC power supply 204 can output is less than 40 W. When the cooling fan 207 is operating, the maximum power that the third DC power supply 204 can output is 40 W or more. The correspondence table in FIG. 9 is based on such performance of the heater power supply unit 200.

[0096] In this embodiment, one or both of the third DC power supply 204 and the cooling fan 207 are dynamically stopped in accordance with the above-mentioned correspondence table (or a comparison between the required power amount and the power threshold), thereby eliminating wasteful power consumption and optimizing the power consumption in the multifunction device 1.

[0097] <3-3. Processing flow> FIG. 10 is a flowchart showing an example of the flow of a state control process that can be executed by the control unit 80 (for example, the CPU 211) to control the power supply state in the multifunction peripheral 1 in this embodiment.

[0098] The state control process in Fig. 10 is started in response to the power being turned on of the multifunction peripheral 1. First, in S201, the control unit 80 is started and begins operation. In S203, the control unit 80 outputs a PFC control signal SigP to the PFC circuit 103 to start the PFC circuit 103. The control unit 80 also outputs a fan control signal SigF to the fan drive circuit 106 to start driving the cooling fan 107. The control unit 80 also outputs a power control signal SigS to the second DC power supply 105 to start the second DC power supply 105.

[0099] Next, in S205, the control unit 80 acquires the heater setting received via the UI of the operation unit 70. Next, in S207, the control unit 80 determines whether the heater setting is equal to the previous required power amount P REQ If the heater setting has been changed, the process proceeds to S209.

[0100] In S209, the control unit 80 calculates the required power amount P REQ For example, the control unit 80 calculates the required power amount P by adding up the amounts of power predefined for the heaters 120 that are set to operate. REQ Next, in S210, the control unit 80 executes a heater power supply control process to set the operating state of the heater power supply unit 200. Details of the heater power supply control process will be described later with reference to FIG. 11. Next, in S211, the control unit 80 outputs drive signals Sig1, Sig2, and Sig3 to the heater drive circuits 130a, 130b, and 130c, respectively, in accordance with the heater setting.

[0101] If the heater settings have not been changed in S207, S209 to S211 are skipped. In this case, the heater drive circuits 130a, 130b, and 130c drive the corresponding heaters 120a, 120b, and 120c in accordance with the drive signal values ​​held in their respective latch circuits.

[0102] Next, in S213, the control unit 80 waits for reception of a job. The operation mode of the multifunction device 1 from S205 to S213 is the standby mode. When a job is received in the standby mode, in S215 the control unit 80 controls one or both of the printer unit 10 and the scanner unit 50 to execute the received job. The operation mode of the multifunction device 1 in S215 is the print mode (or the scan mode if a scan job is executed).

[0103] Next, in S217, the control unit 80 determines whether the multifunction device 1 should be powered off or transition to sleep mode. For example, if an operation to power off is detected on the operation unit 70, the multifunction device 1 will transition to power off. If an operation instructing a transition to sleep mode is detected, or if a predetermined length of time has passed without an operation being performed, the multifunction device 1 will transition to sleep mode. If the multifunction device 1 is to be powered off or transition to sleep mode, the process proceeds to S221. If the standby mode is to be maintained, the process returns to S205.

[0104] In S221, the control unit 80 outputs a power supply control signal SigS to the second DC power supply 105 to stop the second DC power supply 105. Next, in S223, the control unit 80 outputs a PFC control signal SigP to the PFC circuit 103 to stop the PFC circuit 103. Next, in S225, the control unit 80 outputs a fan control signal SigF to the fan drive circuit 106 to stop driving the cooling fan 107.

[0105] Next, in S233, the control unit 80 determines whether the multifunction device 1 should be returned to standby mode. For example, if any operation is detected on the operation unit 70, the multifunction device 1 will return from sleep mode to standby mode. In this case, the process returns to S203. If the conditions for returning to standby mode are not met, in S235 the control unit 80 determines whether to maintain sleep mode or to transition the multifunction device 1 to power off. If sleep mode should be maintained, the process returns to S233. If the multifunction device 1 should be transitioned to power off, the process proceeds to S237. In S237, the control unit 80 stops operation, and the multifunction device 1 enters a power-off state.

[0106] FIG. 11 is a flowchart showing an example of the detailed flow of the heater power supply control process in S210 of FIG.

[0107] Referring to FIG. 11, first, in S241, the control unit 80 calculates the required power amount P REQ Determine whether P is equal to zero. REQ If equal to zero, in S243, the control unit 80 outputs a power supply control signal SigR to the AC relay 201 to cut off the power supply path to the third DC power supply 204, which is the heater power supply.

[0108] P REQ If is greater than zero, in S245, the control unit 80 outputs a power supply control signal SigR to the AC relay 201 to supply power from the commercial power supply to the third DC power supply 204. Next, in S247, the control unit 80 calculates the required power amount P REQ is compared with the third power threshold TH3=40[W].

[0109] Required power amount P REQ is smaller than the third power threshold TH3 (P REQ <40W, S247-YES), the control unit 80 does not start the cooling fan 207 for cooling the heater power supply (stops the cooling fan 207). REQIf the power consumption is equal to or greater than the third power threshold TH3, the control unit 80 outputs a fan control signal SigH to the fan drive circuit 206 in S249, causing the cooling fan 207 to start driving.

[0110] The flowchart of Fig. 11 is based on the relationship between the drive states of the heaters 120a, 120b, and 120c and the operating state of the heater power supply unit 200 defined in the correspondence table of Fig. 9. However, the relationship between the drive states of one or more heaters 120 and the operating state of the heater power supply unit 200 is not limited to the example described above. For example, the value of the third power threshold TH3 may be different from that in the example described above.

[0111] Also in this embodiment, the control unit 80 may store in advance in memory a table that associates each heater driving state with the corresponding operating state of the heater power supply unit 200, and determine the operating state of the heater power supply unit 200 directly from the heater setting without calculating the required power amount.

[0112] <4. Modifications> <4-1. First modified example> Various modifications can be made to the above-described embodiment and two examples. For example, at least one heater 120 of the multifunction peripheral 1 may be operated by receiving AC power instead of DC power.

[0113] Fig. 12 is a block diagram showing an example of a schematic configuration of a heater-related circuit according to a first modified example. The circuit configuration shown in Fig. 12 differs from the circuit configuration according to the first embodiment shown in Fig. 2 in that it has an AC-powered scanner heater 320a and a switch 330 instead of a DC-powered scanner heater 120a and heater drive circuit 130a. In addition, the CPU 111 and switching circuit 118 in the first embodiment are replaced with a CPU 311 and switching circuit 318 in this embodiment.

[0114] The switching circuit 318 is a switching means that opens and closes the power supply path from the first DC power supply 104 to the drum heater 120b and the cassette heater 120c. The switching circuit 218 cuts off the supply of 12V DC power from the first DC power supply 104 when both of the drive signals Sig2 and Sig3 output from the CPU 311 to the heater drive circuits 130b and 130c, respectively, indicate that the corresponding heaters should be stopped. The switching circuit 318 supplies DC power from the first DC power supply 104 to the heater drive circuits 130b and 130c when one or more of the drive signals Sig2 and Sig3 indicate that the corresponding heaters should be operated.

[0115] The switch 330 is a switching means that can be physically opened and closed by the user. One end of the switch 330 is connected to a branch point between the AC filter 101 and the rectifier diode 102, and the other end of the switch 330 is connected to the scanner heater 320a. When the user closes the switch 330, AC power that has passed through the AC filter 101 is supplied to the scanner heater 320a. In other words, the switch 330 can open and close the power supply path from the commercial power source to the scanner heater 320a. The scanner heater 320a is a resistive heating element disposed inside the scanner unit 50. When the switch 330 is closed, the scanner heater 320a heats the optical system 52 using AC power supplied from the commercial power source, thereby preventing reading errors caused by condensation.

[0116] In this modification, the CPU 311 can acquire only the settings of the driving states of the drum heater 120b and the cassette heater 120c via a UI such as the heater setting screen 71 in Fig. 4. Therefore, based on the driving states of these two heaters 120, the CPU 311 selects the operating state of the power supply unit 100 so as to reduce the surplus of the total power consumption of the power supply unit 100, and operates the power supply unit 100 in the selected operating state.

[0117] <4-2. Second modified example> 13 is a block diagram showing an example of a schematic configuration of a heater-related circuit according to Modification 2. In Modification 2 as well, at least one heater 120 of the multifunction peripheral 1 is operated by receiving a supply of AC power instead of DC power.

[0118] 12, the circuit configuration shown in Fig. 13 differs in that a switch detection circuit 431 is provided between the scanner heater 320a and the switch 330. In addition, the CPU 311 in the first modified example is replaced with a CPU 411 in this embodiment.

[0119] The switch detection circuit 431 detects the open / closed state of the switch 330 and outputs a detection signal SigW indicating the detected state to the CPU 411. FIG. 14 shows an example of the detailed configuration of the switch detection circuit 431. In the example of FIG. 14, the switch detection circuit 431 includes a photocoupler 432. A light-emitting element on the primary side of the photocoupler 432 emits light when the switch 330 is closed by the user and current flows from the power supply unit 100 to the scanner heater 320a. A light-receiving element on the secondary side detects the light and outputs a detection signal SigW to the CPU 411.

[0120] The CPU 411 can acquire the settings of the operating states of the drum heater 120b and the cassette heater 120c via a UI such as the heater setting screen 71 in FIG. 4. In addition, the CPU 411 can acquire the open / closed state of the switch 330 (or the operating state of the scanner heater 320a) based on the detection signal SigW input from the switch detection circuit 431. For example, when the switch 330 is open (power supply to the scanner heater 320a is cut off), the CPU 411 may stop the power supply from the power supply unit 100 to the drum heater 120b and the cassette heater 120c regardless of the heater setting. Alternatively, when the switch 330 is closed (power is supplied to the scanner heater 320a), the CPU 411 may supply power from the power supply unit 100 to the drum heater 120b and the cassette heater 120c regardless of the heater setting. Then, based on the driving states of the three heaters 120, the CPU 311 selects an operating state of the power supply unit 100 so as to reduce the excess of the total power consumption of the power supply unit 100, and operates the power supply unit 100 in the selected operating state.

[0121] In the two variants described above, when some heaters are set not to operate (for example, by inputting on a screen or operating a physical switch), the power consumption in the power supply unit can be optimized, thereby enhancing the energy saving effect.

[0122] <5. Summary> Up to this point, embodiments of the technology according to the present disclosure, as well as various related examples and modifications, have been described using FIGS. 1 to 14. In the above-described embodiments, an image processing apparatus includes one or more heaters and a power supply unit including at least one DC power supply, and the power supply unit operates in one of a plurality of operating states with different total power consumptions. The one or more heaters are driven using power supplied from the at least one DC power supply. A control means of the image processing apparatus operates the power supply unit in an operating state selected based on the driving state of the one or more heaters so as to reduce the surplus of the total power consumption. This configuration prevents surplus power from being consumed when some heaters are not driven, thereby enhancing energy-saving effects. Furthermore, when many or all of the heaters are driven, a circuit that contributes to improving the power capacity or power supply efficiency of the power supply unit is activated, thereby ensuring a stable power supply.

[0123] <6. Other embodiments> The above-described embodiment can also be realized in the form of a process in which a program for realizing one or more functions is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program, or by a circuit (e.g., ASIC) that realizes one or more functions.

[0124] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0125] 1: multifunction peripheral (image processing device), 10: printer unit (image forming device / image processing device), 15: paper feed cassette (storage unit), 20: image forming unit, 30: paper feed conveyance unit, 40: fixing unit, 45: discharge tray, 50: scanner unit (reading device / image processing device), 52: optical system, 70: operation unit (operation means), 75: communication interface, 80: control unit, 83: ROM (storage means), 100: power supply unit, 103: power factor correction circuit, 104: first direct current (DC ) power supply, 105: second DC power supply, 106: fan drive circuit, 107: cooling fan (cooling means), 120a: scanner heater, 120b: drum heater, 120c: cassette heater, 130a to 130c: heater drive circuit (drive means), 204: third DC power supply, 206: fan drive circuit, 207: cooling fan (cooling means), 320a: scanner heater (further heater), 330: switch (opening / closing means), 431: switch detection circuit, P: sheet

Claims

1. one or more heaters; a power supply unit including at least one DC power supply, the power supply unit operating in one of a plurality of operating states having different total power consumptions; one or more driving means for driving the one or more heaters using power supplied from the at least one DC power source; a control means for operating the power supply unit in an operating state selected based on a driving state of the one or more heaters so as to reduce the surplus of the total power consumption; An image processing device comprising:

2. the power supply unit includes at least one circuit that operates in response to control from the control means and consumes power; The plurality of operating states of the power supply unit are a first state in which the at least one circuit is activated and the total power consumption of the power supply units is a first power value; and a second state in which the at least one circuit is not operating and the total power consumption of the power supply unit is a second power value lower than the first power value; The image processing device according to claim 1 , comprising:

3. the one or more heaters include a plurality of heaters; The control means When a first number of heaters among the plurality of heaters are driven, the power supply unit operates in the first state; operating the power supply unit in the second state when a second number of heaters, which is less than the first number, among the plurality of heaters are driven; The image processing device according to claim 2 .

4. The control means When at least one heater among the one or more heaters is driven, the power supply unit operates in the first state; operating the power supply unit in the second state when none of the one or more heaters is driven; The image processing device according to claim 2 .

5. the at least one DC power supply converts AC voltage of a commercial power supply into DC voltage and supplies power at the DC voltage; the at least one circuit includes a power factor correction circuit that corrects a power factor in the at least one DC power source; The image processing device according to claim 2 .

6. 3. The image processing apparatus according to claim 2, wherein said at least one circuit includes a drive circuit for driving a cooling means for cooling said at least one DC power supply.

7. The at least one DC power source a first DC power source that supplies power to the one or more heaters; a second DC power source for supplying power to the control means; Including, The plurality of operating states of the power supply unit are a third state in which power is supplied from the first DC power supply to the one or more heaters and the total power consumption of the at least one DC power supply is a third power value; and a fourth state in which the power supply path via the first DC power supply is interrupted and the total power consumption of the at least one DC power supply becomes a fourth power value that is lower than the third power value; The image processing device according to claim 1 , comprising:

8. 2. The image processing device according to claim 1, wherein the control means selects the operating state in which the power supply unit should be operated based on a comparison between a required power amount determined based on the driving state of the one or more heaters and a predetermined threshold value.

9. the one or more heaters include a plurality of heaters; The image processing device includes: a storage means for storing the amount of power required to drive each of the plurality of heaters; Furthermore, the control means determines the required amount of power by summing the amounts of power stored in the storage means for the heaters that are set to operate. The image processing device according to claim 8 .

10. The image processing device according to claim 8 , wherein the control means determines the required amount of power based on the driving state of the one or more heaters and power consumption of components other than the one or more heaters that depend on an operation mode of the image processing device.

11. The image processing device includes: an operation means for receiving a setting as to whether or not each of the one or more heaters is to be operated; Furthermore, the one or more driving means drives the one or more heaters in accordance with the settings received by the operation means; The image processing device according to claim 1 .

12. The image processing device includes: a further heater powered by power supplied from the AC power supply; an opening / closing means for opening and closing a power supply path from the AC power source to the additional heater; Furthermore, the control means controls the driving state of the one or more heaters based on the open / close state of the opening / closing means. The image processing device according to claim 1 .

13. the image processing device includes an image forming device that forms an image on a sheet, the one or more heaters include a heater for heating a storage section that stores a sheet stack; The image processing device according to claim 1 .

14. the image processing device includes an image forming device that forms an image on a sheet, the one or more heaters include a heater for heating an image forming section; The image processing device according to claim 1 .

15. the image processing device includes a reading device that optically reads an original; the one or more heaters include a heater for heating an optical system of the reading device; The image processing device according to claim 1 .

Images