Information processing device and information processing system

Abstract

To reduce consumed power.SOLUTION: An image forming apparatus 5 has at least a commercial power supply connection operation mode in which it is connected to a commercial power supply 2 and operated by using a commercial power supply AC power of the commercial power supply 2 and an individual power supply connection operation mode in which it is operated, by using an individual power supply AC power from a UPS4 independently of the commercial power supply 2, in a state where a LINE side that is a non-ground side of the commercial power supply 2 is in its off state. The apparatus has LINE and NEUTRAL capable of being input with the commercial power supply AC power or an individual power supply AC power, a filter C37 provided between the LINE and the NEUTRAL, and a switch 46 disposed between the filter C37 and either of the LINE and the NEUTRAL for reducing consumed power of the filter C37 more in the individual power supply connection operation mode as compared with the commercial power supply connection operation mode.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an information processing apparatus and an information processing system, and is suitably applied to, for example, an image forming apparatus that receives power from a commercial power source or an uninterruptible power supply. [Background technology]

[0002] 2. Description of the Related Art Conventionally, when an image forming apparatus is used while being disconnected from a commercial power source, power is supplied from an uninterruptible power supply or a portable power source connected to the image forming apparatus (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-218672 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional image forming devices, a primary-side filter capacitor is connected to reduce noise when connected to a commercial power source, and since the primary-side filter capacitor is always in a conducting state, it is necessary to supply power to the primary-side filter capacitor even when the device is disconnected from the commercial power source and operates using power supplied from an uninterruptible power supply, making it impossible to reduce power consumption.

[0005] The present invention has been made in consideration of the above points, and aims to propose an information processing device and an information processing system that are capable of reducing power consumption. [Means for solving the problem]

[0006] In order to solve such problems, the information processing device of the present invention has at least a first mode in which it is connected to a shared power source and can operate using a first AC power from the shared power source, and a second mode in which it can operate using a second AC power from an individual power source different from the shared power source when the shared power source is turned off, and is provided with a pair of power supply lines to which the first AC power or the second AC power can be input, a capacitor installed between the pair of power supply lines, and a reduction means that is arranged between one of the pair of power supply lines and the capacitor and reduces the power consumption of the capacitor in the second mode more than in the first mode.

[0007] In addition, the information processing system of the present invention includes the above-mentioned information processing device and an individual power supply connectable to the information processing device, and the individual power supply has a storage unit capable of receiving a first AC power from a shared power supply and storing energy, a conversion unit that generates a second AC power using the energy stored in the storage unit, and an output unit that outputs the connection status with the shared power supply, and the reduction means of the information processing device switches between a first mode and a second mode based on the output of the output unit.

[0008] When operating in the second mode in which the operation of the information processing device is not affected even if the countermeasures against conducted noise are reduced compared to the first mode, the present invention can reduce the power consumption of the entire information processing device by reducing the power consumption of the capacitor. Effect of the Invention

[0009] According to the present invention, it is possible to realize an information processing device and an information processing system capable of reducing power consumption. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a block diagram showing a control configuration of the image forming system according to the first embodiment. [Diagram 2] FIG. 2 is a left side view showing the overall configuration of the image forming apparatus. [Diagram 3] FIG. 2 is a circuit diagram showing a configuration of a power supply block. [Figure 4]4 is a timing chart showing signals, voltages, and AC power consumption in a commercial power supply operation mode. [Diagram 5] 4 is a timing chart showing signals, voltages, and AC power consumption in a separate power supply connected operation mode. [Figure 6] 1A and 1B are circuit diagrams showing the operation of a triac according to a first embodiment, in which (A) is an on state and (B) is an off state. [Figure 7] 10A and 10B are circuit diagrams showing the operation (1) of a triac according to another embodiment, in which (A) is the on state and (B) is the off state. [Figure 8] 11 is a circuit diagram showing the operation (2) of a triac according to another embodiment, where (A) is the on state and (B) is the off state. [Figure 9] 11 is a circuit diagram showing the operation (3) of a triac according to another embodiment, where (A) is the on state and (B) is the off state. [Figure 10] 11 is a circuit diagram showing the operation (3) of a triac according to another embodiment, where (A) is the on state and (B) is the off state. [Figure 11] FIG. 11 is a block diagram showing a control configuration of an image forming system according to a second embodiment. [Figure 12] FIG. 13 is a block diagram showing a control configuration of an image forming system according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

[0012] 1. First embodiment [1-1. Overall configuration of image forming system] 1, an image forming system 1 as an information processing system according to the first embodiment is composed of a commercial power source 2, an AC input detection circuit 3, a UPS 4, an image forming apparatus 5, and a host 6. The commercial power source 2 is, for example, a power source of 100 V AC (AC power) supplied from an outlet.

[0013] The AC input detection circuit 3 is connected between the commercial power supply 2 and the UPS 4. The AC input detection circuit 3 is configured with a rectifier diode and a photocoupler (not shown), detects whether or not AC power is being supplied from the commercial power supply 2 to the UPS 4, and transmits the detection result as an AC input detection signal S6 to the control unit 48. Specifically, the AC input detection circuit 3 does not transmit the AC input detection signal S6 to the control unit 48 when AC power is being supplied from the commercial power supply 2 (i.e., interruption of the commercial power supply 2 has not been detected), whereas it transmits the AC input detection signal S6 to the control unit 48 when AC power is not being supplied from the commercial power supply 2 (i.e., interruption of the commercial power supply 2 has been detected).

[0014] The UPS 4 serving as an individual power supply is an uninterruptible power supply, and is connected between the AC input detection circuit 3 and the image forming apparatus 5. This UPS 4 has a battery and a DC-AC converter. The battery serving as a storage unit is capable of receiving commercial power supply AC power as first AC power, which is AC power from the commercial power supply 2, and storing energy. The DC-AC converter serving as a conversion unit uses the energy stored in the battery to generate individual power supply AC power as second AC power, which is output power from the UPS 4.

[0015] The image forming device 5 is a printer, and can operate in a commercial power connected operation mode or an individual power connected operation mode. In the commercial power connected operation mode, the commercial power source 2 is connected to the image forming device 5, and the image forming device 5 can operate using commercial power source AC power, which is AC power supplied from the commercial power source 2. In the individual power source connected operation mode, the LINE side, which is the ungrounded side of the commercial power source 2, is disconnected from the image forming device 5, and the image forming device 5 can operate using individual power source AC power, which is AC power from the UPS 4, which is an individual power source independent of the commercial power source 2.

[0016] The host 6 is connected to the image forming apparatus 5, and transmits various instructions such as print instructions to the image forming apparatus 5.

[0017] [1-2. Configuration of image forming device] As shown in Fig. 2, the image forming device 5 is a color electrophotographic printer, which prints a desired color image on paper of, for example, A3 size, A4 size, etc. In the following, the right end part in Fig. 1 is regarded as the front of the image forming device 5, and the explanation will be given after defining the up-down direction, the left-right direction, and the front-rear direction when viewed from the front.

[0018] The image forming device 5 is made up of a paper feed section 8, an image forming section 9, a fixing section 10, and a paper discharge section 11. The paper feed section 8 is made up of a paper cassette 12 that stores paper, a pickup roller 13a, a separation roller 13b, and a paper feed roller 13c that feed the paper stored in the paper cassette 12, and registration rollers 14a and 14b that transport the fed paper to the image forming section 9.

[0019] The image forming section 9 is provided above the paper cassette 12 in the image forming device 5, and includes a transfer belt 15, an image forming unit 16 (image forming units 16K, 16Y, 16M, and 16C), an LED head 17 (LED heads 17K, 17Y, 17M, and 17C), a toner cartridge 18 (toner cartridges 18K, 18Y, 18M, and 18C), and The transfer rollers 19 (transfer rollers 19K, 19Y, 19M and 19C) are provided.

[0020] The transfer belt 15 is an endless belt that is stretched around rollers arranged one at the front and one at the back with its central axis oriented in the left-right direction, and by running in conjunction with the rotation of the rollers, it places the paper handed over from the registration rollers 14a and 14b on its upper surface and transports it backward.

[0021] Four image forming units 16 (image forming units 16K, 16Y, 16M, and 16C (hereinafter collectively referred to as image forming units 16)) are arranged in order from the front side to the rear side above the transfer belt 15. That is, the image forming units 16 of each color are arranged in a so-called tandem system. These image forming units 16K, 16Y, 16M, and 16C correspond to the colors black (K), yellow (Y), magenta (M), and cyan (C), respectively. Moreover, the image forming units 16K, 16Y, 16M, and 16C are configured similarly to one another, and only the corresponding toner colors differ from one another.

[0022] LED heads 17K, 17Y, 17M, and 17C (hereinafter collectively referred to as LED head 17) are provided to correspond to the image forming units 16K, 16Y, 16M, and 16C, respectively. The LED head 17 is configured as a rectangular parallelepiped elongated in the left-right direction, and a plurality of LEDs (Light Emitting Diodes) are arranged inside the LED head 17 so as to be aligned in the left-right direction, and each LED is caused to emit light in a light emission pattern according to image data supplied from a control unit 48. The image forming units 16 are arranged in close proximity to the LED head 17, and exposure processing is performed by the light from the LED head 17.

[0023] Further, toner cartridges 18K, 18Y, 18M and 18C (hereinafter collectively referred to as toner cartridges 18) are connected to the upper portions of the image forming units 16K, 16Y, 16M and 16C, respectively. The toner cartridges 18 are hollow containers that are long in the left-right direction, and contain powdered toner of each color, respectively, and also incorporate a predetermined stirring mechanism.

[0024] Transfer rollers 19K, 19Y, 19M and 19C (hereinafter collectively referred to as transfer rollers 19) are provided at four positions directly below each image forming unit 16. That is, each image forming unit 16 sandwiches the upper portion of the transfer belt 15 between itself and each transfer roller 19. Incidentally, the transfer roller 19 is configured so as to be capable of being charged.

[0025] The image forming unit 16 has a charging roller 20, a toner supply roller 21, a developing roller 22, and a photoconductor drum 23. The charging roller 20 uniformly charges the surface of the photoconductor drum 23 with a high voltage. The toner supply roller 21 supplies toner to the developing roller 22. The developing roller 22 develops the electrostatic latent image formed on the surface of the photoconductor drum 23 with the toner carried by the developing roller 22. The photoconductor drum 23 is a member that carries the electrostatic latent image on its surface (surface portion), and transfers the toner image developed on the surface of the photoconductor drum 23 to paper.

[0026] The fixing unit 10 is disposed downstream of the image forming unit 9, and includes a fixing roller 24, a heater 25, and a temperature detection sensor 26. The fixing roller 24 fixes the toner transferred onto the paper to the fixing roller 24. The heater 25 is provided inside the fixing roller 24 and is, for example, a halogen lamp or a ceramic heater. The temperature detection sensor 26 is a thermistor that detects the surface temperature of the fixing roller 24. The paper discharge unit 11 has discharge rollers 27 that discharge the paper after fixing has been completed.

[0027] [1-3. Control configuration of image forming apparatus] The image forming apparatus 5 mainly includes a power supply block 30 and a control block 32 .

[0028] [1-3-1. Power supply block configuration] The power supply block 30 is made up of a filter LC35, a filter L36, a filter C37, a heater protection relay 39, an AC zero-cross detection circuit 40, a heater on / off circuit 41, a primary rectification smoothing circuit 42, a main DC-DC conversion unit 43M, a sub DC-DC conversion unit 43S, a switch 44, an AND circuit 45, and a switch 46. This power supply block 30 generally operates on the AC voltage output from the commercial power supply 2, but when the commercial power supply 2 is cut off, it operates on the AC voltage output from the UPS 4.

[0029] The filter LC35 is composed of a common mode choke coil and a capacitor, and is connected to the UPS 4. The heater protection relay 39 is connected to the commercial power source 2 or the LINE (LIVE) side of the UPS 4, and is turned on and off by a relay on / off control signal S4 output from a control unit 48 described later.

[0030] The AC zero-cross detection circuit 40 is disposed upstream of the primary rectification smoothing circuit 42, and is a circuit that outputs an AC zero-cross signal S7 to a control unit 48 (described later). The heater on / off circuit 41 is disposed upstream of the primary rectification smoothing circuit 42, and is a circuit that turns on and off the heater 25 (FIG. 2) inside the fixing unit 10 in response to a heater on / off control signal S5 output from the control unit 48.

[0031] The filter L36 and the filter C37 are each composed of a common mode choke coil and a capacitor, and are connected to the rear stage of the heater on / off circuit 41. The capacitor is a so-called X-con (X capacitor), and is connected between LINE and NEUTRAL. In the case of this embodiment, the filter C37 is connected to a switch 46 on the NEUTRAL side. The switch 46 is connected to an AND circuit 45. The AND circuit 45 receives a sleep signal S2 and an AC cutoff control signal S1 output from a control unit 48 (described later), and outputs a switch control signal S3 to the switch 46.

[0032] The primary rectification smoothing circuit 42 is a circuit that rectifies and smoothes the AC voltage supplied from the commercial power supply 2 or the UPS 4. The main DC-DC conversion unit 43M and the sub DC-DC conversion unit 43S supply DC voltage to the control block 32. Specifically, the main DC-DC conversion unit 43M supplies DC 24V to the actuator system in the control block 32, for example, and the sub DC-DC conversion unit 43S supplies DC 5V to the logic system in the control block 32, for example. Incidentally, the power supply block 30 or the control block 32 may step down DC 24V or DC 5V and supply it to the logic system in the control block 32. The type of DC voltage output from the power supply block 30 is generally determined by the configuration of the control block 32, and a DC 3.3V output is generally used in addition to DC 24V and DC 5V.

[0033] [1-3-2. Control block configuration] The control block 32 is made up of a control unit 48 , a ROM 49 , a RAM 50 , a temperature detection unit 51 , a sensor on / off circuit 52 , a high-voltage power supply 53 , a head control unit 54 , and an actuator drive unit 55 .

[0034] The control unit 48 is composed of a CPU (Central Processing Unit) not shown, and performs overall control of the image forming apparatus 5 by reading and operating a program from a ROM (Read Only Memory) 49, which is a non-volatile storage component that stores programs and setting data. When image data representing a color image to be printed is provided from the host 6, which is a higher-level device, and printing of the color image is instructed, the control unit 48 executes a print process to form a print image on the surface of paper. The control unit 48 has built-in devices such as a counter for measuring time. The RAM (Random Access Memory) 50 is a memory that stores and reads data.

[0035] The temperature detection unit 51 divides the output of the temperature detection sensor 26 (FIG. 2) inside the fixing unit 10 using resistors, and outputs a temperature detection signal to the control unit 48. The sensor on / off circuit 52 is composed of transistors, and basically, except for the warm-up operation when the image forming apparatus 5 is turned on and printing performed according to instructions from the host 6, etc., a sensor on / off signal is output from the control unit 48 to turn off the power supplied to various sensors 56 described later.

[0036] The high-voltage power supply 53 is a power supply that applies a high voltage to the photoconductor drum 23 and various rollers of the image forming unit 9 (FIG. 2). The head control unit 54 is a control unit that controls the on / off of the LED head 17 (FIG. 1). The actuator driving unit 55 is a dedicated driver that outputs a driving signal to the actuator 57 (described later) based on a logic signal output from the control unit 48.

[0037] The various sensors 56 include a paper travel path sensor (not shown) for detecting the paper position, a sensor for correcting image density and color shift, etc., which are installed in the paper feed unit 8, the image forming unit 9, the fixing unit 10, and the paper discharge unit 11. The actuators 57 include a motor, a clutch, a solenoid, and a cooling fan (not shown) which are installed in the paper feed unit 8, the image forming unit 9, the fixing unit 10, and the paper discharge unit 11, and are driven by the actuator drive unit 55.

[0038] [1-4. Detailed configuration of the power block] As shown in detail in FIG. 3, power supply block 30 is composed of a protection element 34, filter LC35, heater protection relay 39, AC zero-cross detection circuit 40, heater on / off circuit 41, filter L36, filter C37, inrush prevention circuit 38, primary rectification smoothing circuit 42, switch 44, AND circuit 45, switch 46, main DC-DC conversion unit 43M, sub DC-DC conversion unit 43S, secondary rectification smoothing circuit 78M, voltage feedback unit 79M, protection circuit 80M, secondary filter 81M, secondary rectification smoothing circuit 78S, voltage feedback unit 79S, protection circuit 80S and secondary filter 81S.

[0039] The protection element 34 is composed of a fuse for overcurrent protection, a varistor for lightning surge protection, etc., and is connected to the UPS 4. The filter LC35 is composed of a common mode choke coil 60 and a film capacitor 61, and is connected to the protection element 34. The film capacitor 61 is a so-called X-capacitor (X capacitor), and is connected between the LINE and NEUTRAL. Although not shown, a Y capacitor is also mounted between the LINE or NEUTRAL and FG (frame ground).

[0040] The heater protection relay 39 is composed of a relay 62 and a back electromotive prevention diode 63 mounted on the drive coil side of the relay 62, is connected to the LINE side, and is turned on and off by a relay on / off control signal S4 output from the control unit 48. Connecting the heater protection relay 39 to the LINE side is just one example, and the heater protection relay 39 may be connected to the NEUTRAL side, or multiple heater protection relays 39 may be connected in total, one each to the LINE side and the NEUTRAL side.

[0041] The AC zero-cross detection circuit 40 is generally configured with a rectifier diode and a photocoupler (not shown), and is disposed in the upstream stage of the primary rectification smoothing circuit 42. The AC zero-cross detection circuit 40 is a circuit that outputs an AC zero-cross signal S7 that becomes Hi level at the zero-cross point to the control unit 48. The configuration of the AC zero-cross detection circuit 40 is not particularly limited.

[0042] The heater on / off circuit 41 is composed of a triac and a phototriac (not shown), and is disposed in front of the primary rectifying smoothing circuit 42. A heater on / off control signal S5 output from the control unit 48 turns the phototriac on and off to turn the triac on and off, thereby energizing the heater 25 (FIG. 2) inside the fixing unit 10. A plurality of heater on / off circuits 41 may be provided depending on the number of heaters.

[0043] The filter L36 is a common mode choke coil. The filter C37 is a film capacitor, and a switch 46 is connected to the NEUTRAL side.

[0044] The switch 46 is composed of a triac 64, a phototriac 65, a phototriac gate current limiting resistor 66, a snubber capacitor 67, and a snubber resistor 68. The triac 64 has three terminals in total, two terminals of the main terminals MT1 and MT2, and one terminal of the gate terminal G. The main terminal MT1 of the triac 64 is connected to NEUTRAL and a rectifier diode 69, and the main terminal MT2 is connected to the filter C37. Although not shown, one of the main terminals MT1 and MT2 may be connected to LINE, the other of the main terminals MT1 and MT2 may be connected to the filter C37, and the filter C37 may be connected to NEUTRAL, thereby making the connection configuration reverse to that of the present embodiment. The gate terminal G of the triac 64 is connected to the phototriac 65, and the snubber capacitor 67 and the snubber resistor 68 are connected to the main terminal MT2 and the gate terminal G. The triac 64 is turned on when a gate voltage is applied to the gate terminal G, allowing current to pass between the main terminal terminal MT1 and the main terminal terminal MT2, and is turned off when no gate voltage is applied to the gate terminal G, preventing current from passing between the main terminal terminal MT1 and the main terminal terminal MT2.

[0045] The phototriac gate current limiting resistor 66 is connected to the main terminal MT1 of the triac 64 and the phototriac 65. The secondary photodiode of the phototriac 65 is connected to the output of the AND circuit 45, which will be described later.

[0046] FIG. 6 shows the triac 64 as a switch, and the on / off of the triac 64 will be described. In FIG. 6, only the LINE, NEUTRAL, the filter C37, and the triac 64 are shown. When a gate voltage is applied to the gate terminal G in the commercial power supply connection operation mode, the triac 64 turns on as shown in FIG. 6(A) and allows current to pass between the main terminal terminal MT1 and the main terminal terminal MT2. This causes the triac 64 to pass current through the filter C37 between LINE and NEUTRAL. On the other hand, when a gate voltage is not applied to the gate terminal G in the separate power supply connection operation mode, the triac 64 turns off as shown in FIG. 6(B) and prevents current from passing between the main terminal terminal MT1 and the main terminal terminal MT2. This causes the triac 64 to cut off current through the filter C37 between LINE and NEUTRAL.

[0047] The AND circuit 45 (FIG. 3) receives at its input the sleep signal S2 and the AC cut-off control signal S1 output from the control unit 48. The AND circuit 45 also outputs a switch control signal S3, which is an AND output of the sleep signal S2 and the AC cut-off control signal S1, to the secondary photodiode of the phototriac 65 in the switch 46.

[0048] The inrush prevention circuit 38 is disposed in the front stage of the primary rectifying smoothing circuit 42, and is a circuit that prevents inrush current when the electrolytic capacitor 70 of the primary rectifying smoothing circuit 42 is charged. The inrush prevention circuit 38 can be constructed inexpensively using a thermistor, but since it cannot prevent inrush current at high temperatures, a circuit that combines a resistor and a switching element such as a triac or relay is used in addition to the thermistor.

[0049] The primary rectifier smoothing circuit 42 is composed of a rectifier diode 69 and an electrolytic capacitor 70, and is disposed in front of the main DC-DC conversion unit 43M and the sub DC-DC conversion unit 43S. The rectifier diode 69 is composed of four diodes, and generally, an element called a bridge diode containing four elements is often used. The electrolytic capacitor 70 is generally an aluminum electrolytic capacitor.

[0050] The main DC-DC conversion unit 43M is composed of a transformer 72M, a main FET 73M, a snubber circuit 74M, a power supply control unit 75M, and an auxiliary winding rectifying and smoothing circuit 76M. The transformer 72M insulates the primary side from the secondary side, and transforms the voltage input from the commercial power supply 2 or the UPS 4 and rectified and smoothed by the primary rectifying and smoothing circuit 42. The main FET 73M turns on and off the power supplied to the primary winding side of the transformer 72M. The snubber circuit 74M is composed of a diode, a resistor, and a capacitor, and is a circuit that suppresses a surge voltage when the main FET 73M is turned off. The power supply control unit 75M determines the gate voltage on-duty of the main FET 73M mainly based on the feedback result of the DC output voltage on the secondary side. The auxiliary winding rectifying and smoothing circuit 76M is composed of a rectifying diode and an electrolytic capacitor, and mainly rectifies and smoothes the auxiliary winding output voltage that becomes the power supply voltage of the power supply control unit 75M.

[0051] The secondary rectifying and smoothing circuit 78M is connected to the rear stage of the main DC-DC conversion unit 43M, and rectifies and smoothes the secondary winding output voltage of the transformer 72M. The voltage feedback unit 79M is connected to the rear stage of the secondary rectifying and smoothing circuit 78M, and detects DC24V output from the main DC-DC conversion unit 43M and outputs the detection result to the power supply control unit 75M. In this embodiment, DC24V is a single winding output, and the secondary rectifying and smoothing circuit 78M is provided with a rectifying diode and an electrolytic capacitor. Although not shown, when DC24V and DC5V are output from two windings, a rectifying diode and an electrolytic capacitor are provided for each of DC24V and DC5V. There is also a configuration in which a DC-DC converter is connected to the single DC24V output to output DC5V. DC5V is a logic circuit of the control unit 48, and is not limited to DC5V, and may be various other voltage values ​​such as DC3.3V.

[0052] The protection circuit 80M is equipped with an overvoltage detection circuit and an overcurrent detection circuit. The overvoltage detection circuit is composed of a Zener diode and a photocoupler, and when an overvoltage is detected, the primary side power supply control unit 75M latches or intermittently stops switching. When an overvoltage is detected, the auxiliary winding voltage also rises, so it is possible to detect it with the primary side power supply control unit 75M. The overcurrent detection circuit has various circuit configurations such as current detection, DC output voltage droop detection, or fuses. It is also possible to detect an overcurrent as a primary current with the power supply control unit 75M. The secondary filter 81M is an LC filter, and although it is not essential to install it, it is used to suppress ripple voltage and ripple noise voltage.

[0053] The sub DC-DC converter 43S is configured almost the same as the main DC-DC converter 43M, and is configured with a transformer 72S, a main FET 73S, a snubber circuit 74S, a power supply controller 75S, and an auxiliary winding rectifying and smoothing circuit 76S. The transformer 72S insulates the primary side from the secondary side, and transforms the voltage input from the commercial power supply 2 or the UPS 4 and rectified and smoothed by the primary rectifying and smoothing circuit 42. The main FET 73S turns on and off the power supplied to the primary winding side of the transformer 72S. The snubber circuit 74S is configured with a diode, a resistor, and a capacitor, and is a circuit that suppresses a surge voltage when the main FET 73S is turned off. The power supply controller 75S determines the gate voltage on-duty of the main FET 73S mainly based on the feedback result of the DC output voltage on the secondary side. The auxiliary winding rectifying and smoothing circuit 76S is configured with a rectifying diode and an electrolytic capacitor, and mainly rectifies and smoothes the auxiliary winding output voltage that becomes the power supply voltage of the power supply controller 75S.

[0054] The secondary rectifying and smoothing circuit 78S is connected to the rear stage of the sub DC-DC conversion unit 43S, and rectifies and smoothes the secondary winding output voltage of the transformer 72S. The voltage feedback unit 79S is connected to the rear stage of the secondary rectifying and smoothing circuit 78S, and detects the DC 5V output from the sub DC-DC conversion unit 43S and outputs the detection result to the power supply control unit 75S.

[0055] In this embodiment, DC 5V is a single winding output, and the secondary rectifying and smoothing circuit 78S is provided with a rectifying diode and an electrolytic capacitor. As with the above-mentioned DC 24V, various configurations may be used for DC 5V.

[0056] The protection circuit 80S is equipped with an overvoltage detection circuit and an overcurrent detection circuit. The overvoltage detection circuit is composed of a Zener diode and a photocoupler, and when an overvoltage is detected, the primary side power supply control unit 75S latches or intermittently stops switching. When an overvoltage is detected, the auxiliary winding voltage also rises, so it is possible to detect it with the primary side power supply control unit 75S. The overcurrent detection circuit has various circuit configurations such as current detection, DC output voltage droop detection, fuses, etc. It is also possible to detect an overcurrent as a primary current with the power supply control unit 75S. The secondary filter 81S is an LC filter, and although it is not essential to install it, it is used to suppress ripple voltage and ripple noise voltage.

[0057] The switch 44 is a switch such as a transistor or relay that is turned on and off in response to a sleep signal S2 output from the control unit 48, and is a switch that switches whether or not the output voltage of the auxiliary winding rectifying and smoothing circuit 76S of the sub DC-DC conversion unit 43S is supplied to the power supply terminal of the power supply control unit 75M of the main DC-DC conversion unit 43M in response to the sleep signal S2 output from the control unit 48.

[0058] [1-5. Operation of image forming device] 4 and 5 show time charts of the control block 32 and the power block 30 in the representative operation modes of the image forming apparatus 5, that is, the print mode, the standby mode, the power save mode, and the sleep mode.

[0059] [1-5-1. Overall explanation of the time chart] In Figures 4 and 5, the vertical axis represents voltage except for AC power consumption SAC, and power for AC power consumption SAC, while the horizontal axis represents the passage of time, and shows eight types of waveforms: AC cut-off control signal S1, sleep signal S2, switch control signal S3, relay on / off control signal S4, heater on / off control signal S5, DC 24V output voltage, DC 5V output voltage, and AC power consumption SAC.

[0060] 4 and 5, the horizontal axis shows the case where the image forming device 5 transitions in the order of print mode, standby mode, power save mode, and sleep mode. Specifically, when the image forming device 5 is turned on at time t0, the image forming device 5 transitions to the print mode and starts a warm-up operation. When time t1 is reached, the image forming device 5 ends the warm-up operation and performs a printing operation. Thereafter, when time t2 is reached, the image forming device 5 transitions to the standby mode. When a predetermined time has elapsed since transitioning to the standby mode and time t3 is reached, the image forming device 5 transitions to the power save mode. When a predetermined time has elapsed since transitioning to the power save mode and time t4 is reached, the image forming device 5 transitions to the sleep mode.

[0061] [1-5-2. Explanation of each signal waveform] 4 and 5 are written in negative logic, and are OFF when at Hi level and ON when at Lo level. The AND circuit 45 is a positive logic AND circuit, and outputs a positive logic AND signal as the switch control signal S3. Note that a negative logic OR circuit may be provided in place of the AND circuit 45, which is a positive logic AND circuit, and the negative logic OR circuit may output a negative logic OR signal as the switch control signal S3.

[0062] The AC cut-off control signal S1 is a signal output from the control unit 48 and input to the AND circuit 45. This AC cut-off control signal S1 becomes Hi level (OFF) when the control unit 48 determines based on the AC input detection signal S6 that the AC input detection circuit 3 has detected the commercial power source 2, that is, when it has not detected cut-off of the commercial power source 2. On the other hand, the AC cut-off control signal S1 becomes Lo level (ON) when the control unit 48 determines based on the AC input detection signal S6 that the AC input detection circuit 3 has not detected the commercial power source 2, that is, when it has detected that the commercial power source 2 has been cut off.

[0063] The sleep signal S2 is a signal output from the control unit 48 and input to the AND circuit 45 and the switch 44. When the operation mode is the print mode, the standby mode, or the power save mode, this sleep signal S2 is at Hi level (OFF). This causes DC 24V to be output. On the other hand, when the operation mode is the sleep mode, the sleep signal S2 is at Lo level (ON). This causes the output of DC 24V to stop.

[0064] The switch control signal S3 is a signal output from the AND circuit 45 and input to the switch 46. The switch control signal S3 is a signal that is ANDed when the AC interruption time control signal S1 and the sleep signal S2 are input to the AND circuit 45 and output. When the switch control signal S3 is at Hi level, the filter C37 is energized. On the other hand, when the switch control signal S3 is at Lo level, the filter C37 is deenergized.

[0065] The relay on / off control signal S4 is a signal output from the control unit 48 and input to the heater protection relay 39. This relay on / off control signal S4 is at Hi level (ON) when electricity is applied to the fixing unit 10 in the print mode and standby mode operation modes, i.e., when the heater is turned on. When the relay on / off control signal S4 is at Hi level, the heater protection relay 39 is relay on. On the other hand, the relay on / off control signal S4 is at Lo level (OFF) when electricity is not applied to the fixing unit 10 in the power save mode and sleep mode operation modes, i.e., when the heater is turned off. When the relay on / off control signal S4 is at Lo level, the heater protection relay 39 is relay off.

[0066] The heater on / off control signal S5 is a signal output from the control unit 48 and input to the heater on / off circuit 41. This heater on / off control signal S5 is at Hi level (ON) when electricity is applied to the fixing unit 10 in the print mode and standby mode operation modes, i.e., when the heater is turned on. When the heater on / off control signal S5 is at Hi level, the heater on / off circuit 41 is turned on. On the other hand, when electricity is not applied to the fixing unit 10 in the power save mode and sleep mode operation modes, i.e., when the heater is turned off, the heater on / off control signal S5 is at Lo level (OFF). When the heater on / off control signal S5 is at Lo level, the heater on / off circuit 41 is turned off.

[0067] The heater on / off control signal S5 differs from the relay on / off control signal S4 in that the relay on / off control signal S4 remains ON (Hi level) when the heater is on (i.e., continues to be on). In contrast, the heater on / off control signal S5 not only turns on but also turns off (i.e., not only Hi level but also Lo level) so that the target temperature and the actual temperature are equal to each other, depending on the detection result of the temperature detection sensor 26 that detects the surface temperature of the fixing roller 24. The on / off cycle of the heater on / off control signal S5 may be on the order of seconds or milliseconds.

[0068] The DC 24V output voltage represents the output voltage of DC 24V output from the main DC-DC conversion unit 43M. The DC 5V output voltage represents the output voltage of DC 5V output from the sub DC-DC conversion unit 43S. The AC power consumption SAC represents the AC power consumption of the input section of the protection element 34.

[0069] [1-5-3. Operation in commercial power connection mode] FIG. 4 shows a time chart of various signals, DC 24V output voltage, DC 5V output voltage, and AC power consumption SAC in a commercial power supply connected operation mode in which AC power is supplied from the commercial power supply 2 to the image forming apparatus 5.

[0070] [1-5-3-1.Print mode] First, the print mode will be described. In the print mode, the AC cutoff control signal S1 and the sleep signal S2 are at Hi level, so the switch control signal S3 is also at Hi level, and the filter C37 is energized. Therefore, reactive power is generated in the filter C37. Also, because the sleep signal S2 is at Hi level, the DC 24V output voltage is in an output state. The DC 5V output voltage is in an output state. The relay on / off control signal S4 is on at Hi level, and the heater on / off control signal S5 repeats Hi level and Lo level (on / off), but during warm-up at the start of printing (i.e., from time t0 to time t1), the heater is almost in a state of being kept on, so the AC power consumption SAC is the warm-up power consumption W1, which is the highest among the four operation modes. The print operation after the warm-up is completed (i.e., from time t1 to time t2) performs heater on / off control, so the AC power consumption SAC has a relationship of warm-up power consumption W1>printing power consumption W2.

[0071] [1-5-3-2. Standby mode] Next, the standby mode will be described. In the standby mode, since the AC cutoff control signal S1 and the sleep signal S2 are at Hi level, the switch control signal S3 is also at Hi level, and the filter C37 is energized. Therefore, reactive power is generated in the filter C37. Also, since the sleep signal S2 is at Hi level, the DC24V output voltage is in an output state. The DC5V output voltage is in an output state. The relay on / off control signal S4 is on at Hi level, and the heater on / off control signal S5 repeats Hi level and Lo level (on / off), but the heater setting temperature in the standby mode is lower than the heater setting temperature in the print mode, and the operation of the actuator 57 and the like is stopped, so the AC power consumption SAC has the following relationship: warm-up power consumption W1>printing power consumption W2>standby power consumption W3. Also, in recent years, the warm-up time has become shorter, and there are cases where the heater is turned off during standby.

[0072] [1-5-3-3. Power save mode] Next, the power save mode will be described. In the power save mode, the AC cutoff control signal S1 and the sleep signal S2 are at Hi level, so the switch control signal S3 is also at Hi level, and the filter C37 is energized. Therefore, reactive power is generated in the filter C37. Also, since the sleep signal S2 is at Hi level, the DC24V output voltage is in the output state. The DC5V output voltage is in the output state. The relay on / off control signal S4 is off at Lo level, and the heater on / off control signal S5 is off at Lo level. In the power save mode, the heater is off, and the actuator 57 and other operations are stopped, so the AC power consumption SAC has the following relationship: power consumption during warm-up W1>power consumption during printing W2>power consumption during standby W3>power consumption during power save W4. Also, there are cases where the DC24V output voltage is lowered to, for example, DC18V at this time to reduce power consumption.

[0073] [1-5-3-4. Sleep mode] Next, the sleep mode will be described. In the sleep mode, the AC cutoff control signal S1 is at Hi level, but the sleep signal S2 is at Lo level, so the switch control signal S3 is at Lo level and the current to the filter C37 is cut off. Therefore, no reactive power is generated in the filter C37. Also, since the sleep signal S2 is at Lo level, the DC24V output voltage is in an output stop state. The DC5V output voltage is in an output state. The relay on / off control signal S4 is at Lo level and off, and the heater on / off control signal S5 is at Lo level and off. Compared with the power save mode, the DC24V output voltage is in an output stop state and the 5VS load of the control unit 48 is also reduced, so the AC power consumption SAC has the following relationship: power consumption during warm-up W1>power consumption during printing W2>power consumption during standby W3>power consumption during power save W4>power consumption during sleep W5.

[0074] [1-5-4. Operation in separate power supply connection mode] FIG. 5 shows a time chart of various signals, the DC 24V output voltage, the DC 5V output voltage, and the AC power consumption SAC in the separate power supply connection operation mode in which the supply of AC power from the commercial power supply 2 is cut off and AC power is supplied to the image forming apparatus 5 from the UPS 4.

[0075] [1-5-4-1.Print mode] First, the print mode will be described. In the print mode, the sleep signal S2 is at Hi level, but the AC cutoff control signal S1 is at Lo level, so the switch control signal S3 is at Lo level and the current flow through the filter C37 is cut off. Therefore, no reactive power is generated in the filter C37. Also, since the sleep signal S2 is at Hi level, the DC24V output voltage is in the output state. The DC5V output voltage is in the output state. The relay on / off control signal S4 is on at Hi level, and the heater on / off control signal S5 repeats Hi level and Lo level (on / off), but during warm-up at the start of printing (i.e., from time t0 to time t1), the heater is almost in a state of being kept on, so the AC power consumption SAC is the warm-up power consumption W1-2, which is the highest among the four operation modes. The print operation after the warm-up is completed (i.e., from time t1 to time t2) performs heater on / off control, so the AC power consumption SAC has the relationship of warm-up power consumption W1-2>printing power consumption W2-2. In addition, because the flow of electricity to filter C37 is cut off, power consumption is reduced, and the relationships are as follows: power consumption during warm-up W1 (Figure 4) > power consumption during warm-up W1-2 (Figure 5), and power consumption during printing W2 (Figure 4) > power consumption during printing W2-2 (Figure 5).

[0076] [1-5-4-2. Standby mode] Next, the standby mode will be described. In the standby mode, the sleep signal S2 is at Hi level, but the AC cutoff control signal S1 is at Lo level, so the switch control signal S3 is at Lo level and the current flow through the filter C37 is cut off. Therefore, no reactive power is generated in the filter C37. Also, since the sleep signal S2 is at Hi level, the DC24V output voltage is in an output state. The DC5V output voltage is in an output state. The relay on / off control signal S4 is on at Hi level, and the heater on / off control signal S5 repeats Hi level and Lo level (on / off), but the heater setting temperature in the standby mode is lower than the heater setting temperature in the print mode, and the operation of the actuator 57 and the like is stopped, so the AC power consumption SAC has the following relationship: warm-up power consumption W1-2>printing power consumption W2-2>standby power consumption W3-2. Also, in recent years, the warm-up time has become shorter, and there are cases where the heater is turned off during standby. In addition, since the power consumption of filter C37 is reduced by cutting off the current flow therethrough, the standby power consumption W3 (FIG. 4) is greater than the standby power consumption W3-2 (FIG. 5).

[0077] [1-5-4-3. Power save mode] Next, the power save mode will be described. In the power save mode, the sleep signal S2 is at Hi level, but the AC cutoff control signal S1 is at Lo level, so the switch control signal S3 is at Lo level and the current flow through the filter C37 is cut off. Therefore, no reactive power is generated in the filter C37. Also, since the sleep signal S2 is at Hi level, the DC24V output voltage is in the output state. The DC5V output voltage is in the output state. The relay on / off control signal S4 is off at Lo level, and the heater on / off control signal S5 is off at Lo level. In the power save mode, the heater is off, and the actuator 57 and other operations are stopped, so the AC power consumption SAC has the following relationship: power consumption during warm-up W1-2>power consumption during printing W2-2>power consumption during standby W3-2>power consumption during power save W4-2. In addition, there are also cases where the DC24V output voltage is lowered to, for example, DC18V at this time to reduce power consumption. In addition, since the power consumption of the filter C37 is reduced by cutting off the current flowing through the filter C37, the power consumption in power save mode W4 (FIG. 4) is greater than the power consumption in power save mode W4-2 (FIG. 5).

[0078] [1-5-4-4. Sleep mode] Next, the sleep mode will be described. In the sleep mode, since the AC cutoff control signal S1 and the sleep signal S2 are at the Lo level, the switch control signal S3 is also at the Lo level, and the current flow through the filter C37 is cut off. Therefore, no reactive power is generated in the filter C37. Also, since the sleep signal S2 is at the Lo level, the DC24V output voltage is in an output stop state. The DC5V output voltage is in an output state. The relay on / off control signal S4 is off at the Lo level, and the heater on / off control signal S5 is off at the Lo level. Compared with the power save mode, the DC24V output voltage is in an output stop state, and the 5VS load of the control unit 48 is also reduced, so the AC power consumption SAC has the following relationship: power consumption during warm-up W1-2>power consumption during printing W2-2>power consumption during standby W3-2>power consumption during power save W4-2>power consumption during sleep W5.

[0079] [1-6. Effects, etc.] In the above configuration, the image forming system 1 is provided with an AC input detection circuit 3 between the commercial power source 2 and the UPS 4, and is adapted to detect whether the AC power supply source of the image forming device 5 is the commercial power source 2 or the UPS 4. The image forming device 5 is also provided with a switch 46 as a reduction means and a current limiting means in a filter C37 which is a primary side filter capacitor (AC input filter) of the power source, and controls the energization state of the filter C37 depending on the connection state between the image forming device 5 and the commercial power source 2, and cuts off the energization of the filter C37 when a cutoff of the connection between the image forming device 5 and the commercial power source 2 is detected by an AC input detection signal S6.

[0080] Therefore, when the image forming device 5 is operating on AC power supplied from the UPS 4 after the commercial power source 2 is cut off, the amount of AC power supplied to the filter C37 from the UPS 4 can be reduced compared to when power is being supplied to the filter C37.

[0081] This allows the image forming apparatus 5 to reduce power consumption overall, and to extend the time it operates in the individual power source connected operation mode in a state in which it is disconnected from the commercial power source 2 by using an uninterruptible power supply, a portable power source, etc. Specifically, when the capacitance value of the filter C37 is set to 2 [μF], if the voltage of the commercial power source 2 is set to 200 [V], the power consumption can be reduced by about 33 [W], and if the voltage of the commercial power source 2 is set to 100 [V], the power consumption can be reduced by about 6 [W].

[0082] Here, AC power supplied from an uninterruptible power supply, portable power supply, etc. generally does not contain noise to a degree that would affect the operation of the image forming device 5, compared to AC power supplied from the commercial power supply 2. For this reason, in the individual power supply connected operation mode, filter C37 is not energized and does not function as an AC input filter, but it is unlikely that the AC power supplied from the UPS 4 will affect the operation of the image forming device 5. On the other hand, since the commercial power supply 2 is connected to devices other than the image forming device 5 (i.e., the power supply is shared with other devices), it contains conducted noise, compared to the AC power supplied from the UPS 4.

[0083] In response to this, the image forming device 5 is adapted to pass current through the filter C37 when it detects a connection between the image forming device 5 and the commercial power source 2 by the AC input detection signal S6. Therefore, in the image forming device 5 operating mode when connected to a commercial power source, the filter C37 can function as an AC input filter, and the image forming device 5 can remove conducted noise contained in the AC power supplied from the commercial power source 2 so as not to affect the operation of the image forming device 5.

[0084] In this way, when the image forming apparatus 5 operates on AC power supplied from the UPS 4, which is an AC power source that does not require measures against conducted noise, the connection of the filter C37, which is an AC input filter implemented as a measure against conducted noise when the image forming apparatus 5 is connected to the commercial power source 2, is restricted, thereby reducing power consumption by the filter C37.

[0085] According to the above configuration, the image forming apparatus 5 has at least a commercial power connected operation mode as a first mode in which it is connected to the commercial power source 2 as a shared power source and can operate using commercial power source AC power as the first AC power of the commercial power source 2, and an individual power source connected operation mode as a second mode in which it can operate using individual power source AC power as the second AC power from the UPS 4 as an independent individual power source different from the commercial power source 2 when the LINE side, which is the ungrounded side of the commercial power source 2, is cut off, and the image forming apparatus 5 is provided with LINE and NEUTRAL as a pair of power lines to which commercial power source AC power or individual power source AC power can be input, a filter C37 installed between LINE and NEUTRAL, and a switch 46 that is arranged between either LINE or NEUTRAL and the filter C37 and reduces the power consumption of the filter C37 in the individual power source connected operation mode compared to the commercial power source connected operation mode.

[0086] As a result, when the image forming device 5 operates in the operation mode when connected to an individual power source, in which the operation of the image forming device 5 is not affected even if the conduction noise countermeasures are reduced compared to the operation mode when connected to a commercial power source, the power consumption of the entire image forming device 5 can be reduced by reducing the power consumption of filter C37.

[0087] 2. Second embodiment [2-1. Overall configuration of image forming system] 11, in which the same reference numerals are used for components corresponding to those in FIG. 1, an image forming system 101 according to the second embodiment differs from the image forming system 1 according to the first embodiment in that it does not include the AC input detection circuit 3 and has a portable power source 90 instead of the UPS 4, but is otherwise configured similarly. The portable power source 90 is easier to carry than the UPS 4.

[0088] [2-2. Operation of image forming device] An operation different from that of the image forming system 1 according to the first embodiment will be described. The user of the image forming apparatus 5 operates the operation display unit of the image forming apparatus 5 to record in advance in the ROM 49 mounted on the control block 32 whether or not the commercial power source 2 is connected to the image forming apparatus 5. If the disconnection between the image forming apparatus 5 and the commercial power source 2 is recorded in the ROM 49, the control unit 48 outputs the AC disconnection control signal S1 at Lo level (on). On the other hand, if the connection between the image forming apparatus 5 and the commercial power source 2 is recorded in the ROM 49, the control unit 48 outputs the AC disconnection control signal S1 at Hi level (off). The explanation of each operation mode of the image forming apparatus 5 using the AC disconnection control signal S1 is the same as the explanation of the first embodiment using FIG. 4 and FIG. 5.

[0089] [2-3. Effects, etc.] In this way, the image forming system 101 stores in the ROM 49 as a storage means whether the AC power supply source of the image forming device 5 is the commercial power source 2 or the portable power source 90 by the user operating the operation display unit as an input means of the image forming device 5. The image forming device 5 also includes a switch 46 as a reduction means and a current limiting means in the filter C37, which is a primary side filter capacitor (AC input filter) of the power source, and the control unit 48 as an acquisition means acquires information on the connection state between the image forming device 5 and the commercial power source 2 stored in the ROM 49, and based on the information, switches between a commercial power source connected operation mode and an individual power source connected operation mode, and controls the switch 46 to control the energization state of the filter C37. The image forming device 5 cuts off the energization of the filter C37 when the cutoff of the connection between the image forming device 5 and the commercial power source 2 is stored in the ROM 49.

[0090] Therefore, when the commercial power source 2 is cut off and the image forming apparatus 5 is operating on AC power supplied from the portable power source 90, the image forming apparatus 5 can reduce the AC power supplied from the portable power source 90 to the filter C37, compared to when the filter C37 is energized. This allows the image forming apparatus 5 to reduce overall power consumption and extend the time it operates in the individual power source connected operation mode. Furthermore, compared to the image forming system 1, the image forming system 101 can omit the AC input detection circuit 3, thereby simplifying the configuration.

[0091] In other respects as well, image forming system 101 according to the second embodiment can achieve the same effects as image forming system 1 according to the first embodiment.

[0092] 3. Third Embodiment [3-1. Overall configuration of image forming system] As shown in FIG. 12 in which the same reference numerals are used for components corresponding to those in FIG. 1, an image forming system 201 according to the third embodiment differs from the image forming system 1 according to the first embodiment in that it does not have an AC input detection circuit 3 and has a UPS 204 instead of the UPS 4, but is otherwise configured in the same manner.

[0093] The UPS 204 according to the third embodiment is different from the UPS 4 according to the first embodiment in that it has an output unit, but is otherwise configured in the same manner. The output unit outputs the connection state with the commercial power source 2 to the control unit 48 as a UPS power failure mode detection signal S8. Specifically, the UPS 204 does not transmit the UPS power failure mode detection signal S8 to the control unit 48 when AC power is being supplied from the commercial power source 2 (i.e., interruption of the commercial power source 2 has not been detected), whereas it transmits the UPS power failure mode detection signal S8 to the control unit 48 when AC power is not being supplied from the commercial power source 2 (i.e., interruption of the commercial power source 2 has been detected) and AC power is being supplied from a battery (not shown) inside the UPS 204 to the power source block 30. The UPS 204, which is an uninterruptible power supply device, generally has a function of outputting the UPS power failure mode detection signal S8.

[0094] [3-2. Operation of image forming device] An operation different from that of the image forming system 1 according to the first embodiment will be described. When the control unit 48 receives the UPS power failure mode detection signal S8 and detects a disconnection between the image forming apparatus 5 and the commercial power source 2, it outputs the AC disconnection control signal S1 at Lo level (on). On the other hand, when the control unit 48 does not receive the UPS power failure mode detection signal S8 and detects a connection between the image forming apparatus 5 and the commercial power source 2, it outputs the AC disconnection control signal S1 at Hi level (off). The explanation of each operation mode of the image forming apparatus 5 using the AC disconnection control signal S1 is the same as the explanation of the first embodiment using Figs. 4 and 5.

[0095] [3-3. Effects, etc.] In this way, the image forming system 201 is provided with the UPS 204 between the commercial power source 2 and the image forming apparatus 5, and detects whether the AC power supply source of the image forming apparatus 5 is the commercial power source 2 or the UPS 204 based on the UPS power failure mode detection signal S8 of the UPS 204. The image forming apparatus 5 is also provided with a switch 46 as a reduction means and a current limiting means in a filter C37 which is a primary side filter capacitor (AC input filter) of the power source, and controls the energization state of the filter C37 depending on the connection state between the image forming apparatus 5 and the commercial power source 2, and cuts off the energization of the filter C37 when a cutoff of the connection between the image forming apparatus 5 and the commercial power source 2 is detected based on the UPS power failure mode detection signal S8.

[0096] Therefore, when the commercial power source 2 is cut off and the image forming apparatus 5 is operating on AC power supplied from the UPS 204, the image forming apparatus 5 can reduce the AC power supplied from the UPS 204 to the filter C37, compared to when the filter C37 is energized. This allows the image forming apparatus 5 to reduce overall power consumption and extend the time it operates in the individual power source connected operation mode. Furthermore, compared to the image forming system 1, the image forming system 201 can omit the AC input detection circuit 3, thereby simplifying the configuration.

[0097] In other respects as well, image forming system 201 according to the third embodiment can achieve the same effects as image forming system 1 according to the first embodiment.

[0098] [4. Other embodiments] In the above-mentioned first embodiment, the case where the triac 64 (switch 46) is connected as a reduction means and a current limiting means between the NEUTRAL side terminal of the filter C37 and NEUTRAL has been described. The present invention is not limited to this, and a capacitor 92 may be additionally connected between the NEUTRAL side terminal of the filter C37 and NEUTRAL. In this case, when the triac 64 is turned on as shown in FIG. 7(A) in the commercial power supply connected operation mode, the filter C37 is in a state where it is energized between LINE and NEUTRAL. On the other hand, when the triac 64 is turned off as shown in FIG. 7(B) in the individual power supply connected operation mode, the filter C37 and the capacitor 92 are connected in series between LINE and NEUTRAL and are in a state where they are energized. In this case, the capacitance value between LINE and NEUTRAL is smaller in the individual power supply connected operation mode than in the commercial power supply connected operation mode. The same applies to the second and third embodiments.

[0099] Also, a resistor 93 may be added and connected between the NEUTRAL side terminal of the filter C37 and NEUTRAL. In this case, when the triac 64 is turned on in the commercial power supply operation mode as shown in FIG. 8A, the filter C37 is energized between LINE and NEUTRAL. On the other hand, when the triac 64 is turned off in the separate power supply operation mode as shown in FIG. 8B, the filter C37 and the resistor 93 are connected in series between LINE and NEUTRAL and are energized. In this case, the current flowing through the filter C37 is smaller in the separate power supply operation mode than in the commercial power supply operation mode. The same applies to the second and third embodiments.

[0100] Furthermore, a coil 94 may be added and connected between the NEUTRAL side terminal of the filter C37 and NEUTRAL. In this case, when the triac 64 is turned on in the commercial power supply operation mode as shown in FIG. 9A, the filter C37 is energized between LINE and NEUTRAL. On the other hand, when the triac 64 is turned off in the separate power supply operation mode as shown in FIG. 9B, the filter C37 and the coil 94 are connected in series between LINE and NEUTRAL and are energized. In this case, the current flowing through the filter C37 is smaller in the separate power supply operation mode than in the commercial power supply operation mode. The same applies to the second and third embodiments.

[0101] In this manner, the image forming apparatus 5 may be provided with the triac 64 (switch 46) and an impedance element which is a capacitor 92, a resistor 93 or a coil 94 as a current limiting means. In this case, the triac 64 is disposed between either LINE or NEUTRAL and the filter C37. The impedance element is disposed in parallel with the triac 64 between either LINE or NEUTRAL and the filter C37. The triac 64 conducts between either LINE or NEUTRAL and the filter C37 in the commercial power supply connected operation mode, while connecting the impedance element between either LINE or NEUTRAL and the filter C37 in the separate power supply connected operation mode.

[0102] Furthermore, for example, a capacitor 95 may be added between LINE and NEUTRAL as a parallel capacitor in parallel with the filter C37. In this case, when the triac 64 is turned on in the commercial power supply operation mode as shown in FIG. 10(A), the filter C37 and the capacitor 95 are connected in parallel between LINE and NEUTRAL and are in a conducting state. On the other hand, when the triac 64 is turned off in the separate power supply operation mode as shown in FIG. 10(B), only the capacitor 95 is conducting between LINE and NEUTRAL. In this case, in the separate power supply operation mode, the NEUTRAL side terminal of the filter C37 is disconnected, but only the capacitor 95 is conducting between LINE and NEUTRAL. Therefore, the capacitance value between LINE and NEUTRAL is smaller in the separate power supply operation mode than in the commercial power supply operation mode. The same applies to the second and third embodiments.

[0103] Furthermore, in the above-mentioned first embodiment, the switch 46 is configured by the triac 64, the phototriac 65, the phototriac gate current limiting resistor 66, the snubber capacitor 67, and the snubber resistor 68. However, the present invention is not limited to this, and the switch 46 may be configured as a relay or other various other configurations as long as it is arranged between either the LINE or NEUTRAL and the filter C37 and can connect either the LINE or NEUTRAL and the filter C37 in the commercial power supply connected operation mode and can disconnect either the LINE or NEUTRAL and the filter C37 in the individual power supply connected operation mode. The same applies to the second and third embodiments.

[0104] Furthermore, in the above-described first embodiment, a description has been given of a case in which the AC input detection circuit 3 transmits the AC input detection signal S6 to the control unit 48. The present invention is not limited to this, and the AC input detection circuit 3 may transmit the AC input detection signal S6 to the host 6, and the host 6 may notify the control unit 48, which serves as an acquisition unit, of the interruption of the commercial power supply 2.

[0105] Furthermore, in the above-described second embodiment, a case has been described in which whether or not the commercial power source 2 is connected to the image forming apparatus 5 is recorded in advance in the ROM 49 by the user operating the operation display unit of the image forming apparatus 5. The present invention is not limited to this, and it is also possible for the user to notify the host 6 of whether or not the commercial power source 2 is connected to the image forming apparatus 5, the host 6 notifying the control unit 48 as an acquisition unit, and the control unit 48 recording it in the ROM 49.

[0106] Furthermore, in the above-described third embodiment, a case has been described in which the UPS 204 transmits the UPS power failure mode detection signal S8 to the control unit 48. The present invention is not limited to this, and the UPS 204 may transmit the UPS power failure mode detection signal S8 to the host 6, and the host 6 may notify the control unit 48, which serves as an acquisition unit, of the interruption of the commercial power supply 2.

[0107] Furthermore, in the above-mentioned first embodiment, the present invention has been described as being applied to an image forming apparatus 5 that operates on AC power from the commercial power source 2 as a shared power source in the commercial power connected operation mode. The present invention is not limited to this, and the shared power source may be a power source that is self-generated and shared with other devices, and the present invention may be applied to an image forming apparatus 5 that operates on AC power from the shared power source in the commercial power connected operation mode. The same applies to the second and third embodiments.

[0108] Furthermore, in the above-mentioned first embodiment, the present invention has been described as being applied to an image forming apparatus 5 having four image forming units 16. However, the present invention is not limited to this, and the present invention may be applied to an image forming apparatus 5 having various numbers of image forming units 16, such as three or less or five or more. The same applies to the second and third embodiments.

[0109] Furthermore, in the above-mentioned first embodiment, the present invention has been described as being applied to the image forming apparatus 5 which is a single-function printer. However, the present invention is not limited to this, and may be applied to image forming apparatuses having various other functions, such as an MFP (Multi Function Peripheral) having the functions of a copier or facsimile machine. The same applies to the second and third embodiments.

[0110] Furthermore, in the above-mentioned first embodiment, the present invention has been described as being applied to the image forming apparatus 5. However, the present invention is not limited to this, and the present invention may be applied to various devices that operate on AC power supplied from the commercial power source 2 or the UPS 4. The same applies to the second and third embodiments.

[0111] Furthermore, the present invention is not limited to the above-mentioned embodiments and other embodiments. In other words, the scope of application of the present invention also extends to embodiments in which the above-mentioned embodiments and part or all of the above-mentioned other embodiments are arbitrarily combined. The scope of application of the present invention also extends to cases in which a part of the configuration described in any of the above-mentioned embodiments and other embodiments is extracted and replaced or diverted with a part of the configuration of any of the above-mentioned embodiments and other embodiments, or a part of the extracted configuration is added to any of the embodiments.

[0112] Furthermore, in the above-described embodiment, the image forming apparatus 5 is configured as an information processing apparatus by using LINE and NEUTRAL as a pair of power supply lines, a filter C37 as a capacitor, and a switch 46 as a reduction means. However, the present invention is not limited to this, and the information processing apparatus may be configured by using a pair of power supply lines, a capacitor, and a reduction means having various other configurations. [Industrial Applicability]

[0113] The present invention can be used in an image forming apparatus that receives power from, for example, a commercial power source or an uninterruptible power supply. [Explanation of symbols]

[0114] 1, 101...image forming system, 2...commercial power supply, 3...AC input detection circuit, 4, 204...UPS, 5...image forming device, 6...host, 8...paper feed section, 9...image forming section, 10...fuser section, 11...paper discharge section, 12...paper cassette, 13a...pickup roller, 13b...separation roller, 13c...paper feed roller, 14a, 14b...registration roller, 15...transfer belt, 16...image forming unit, 17...LED head, 18...toner cartridge, 19...transfer roller, 20...charging roller, 21...toner supply roller, 22... ...developing roller, 23...photosensitive drum, 24...fixing roller, 25...heater, 26...temperature detection sensor, 27...discharge roller, 30...power block, 32...control block, 34...protection element, 35...filter LC, 36...filter L, 37...filter C, 38...inrush prevention circuit, 39...heater protection relay, 40...AC zero cross detection circuit, 41...heater on / off circuit, 42...primary rectification smoothing circuit, 43M...main DC-DC conversion unit, 43S...sub DC-DC conversion unit, 44...switch, 45...AND circuit, 46...switch, 48...Control unit, 49...ROM, 50...RAM, 51...Temperature detection unit, 52...Sensor on / off circuit, 53...High voltage power supply, 54...Head control unit, 55...Actuator drive unit, 56...Various sensors, 57...Actuator, 60...Common mode choke coil, 61...Film capacitor, 62...Relay, 63...Back electromotive prevention diode, 64...Triac, MT1, MT2...Main terminal, G...Gate terminal, 65...Phototriac, 66...Phototriac gate current limiting resistor, 67...Snubber capacitor , 68... snubber resistor, 69... rectifier diode, 70... electrolytic capacitor, 72M, 72S... transformer, 73M, 73S... main FET, 74M, 74S... snubber circuit, 75M, 75S... power supply control section, 76M, 76S... auxiliary winding rectifier smoothing circuit, 78M, 78S... secondary rectifier smoothing circuit, 79M, 79S... voltage feedback section, 80M, 80S... protection circuit, 81M, 81S... secondary filter, 90... portable power supply, 92, 95... capacitor, 93... resistor, 94... coil, S1... AC cutoff control signal, S2... sleep signal,S3: switch control signal, S4: relay on / off control signal, S5: heater on / off control signal, S6: AC input detection signal, S7: AC zero cross signal, S8: UPS power outage mode detection signal, SAC: AC power consumption.

Claims

1. An information processing device having at least a first mode in which the information processing device is connected to a shared power source and can operate using a first AC power from the shared power source, and a second mode in which the information processing device can operate using a second AC power from an individual power source different from the shared power source while the shared power source is turned off, a pair of power supply lines to which the first AC power or the second AC power can be input; a capacitor disposed between the pair of power supply lines; a reduction means arranged between one of the pair of power supply lines and the capacitor, the reduction means reducing the power consumption of the capacitor in the second mode more than in the first mode; An information processing device comprising:

2. The reduction means is a current limiting means for reducing the current flowing to the capacitor in the second mode more than in the first mode. The information processing device according to claim 1 .

3. The current limiting means cuts off current flow to the capacitor in the second mode. The information processing device according to claim 2 .

4. The current limiting means is a switch that is disposed between one of the pair of power supply lines and the capacitor, and that connects the one of the pair of power supply lines and the capacitor in the first mode, and that disconnects the one of the pair of power supply lines and the capacitor in the second mode; The information processing apparatus according to claim 3 ,

5. The current limiting means is The switch; a parallel capacitor disposed between the pair of power supply lines in parallel with the capacitor; The information processing apparatus according to claim 4 ,

6. The current limiting means is The switch; an impedance element arranged in parallel with the switch between one of the pair of power supply lines and the capacitor; The information processing apparatus according to claim 4 ,

7. An acquisition means for acquiring information regarding connection to the shared power source. Further equipped with The reduction means switches between the first mode and the second mode based on the information acquired by the acquisition means.

7. An information processing apparatus according to claim 1.

8. A storage means for storing information regarding a connection to the common power source; an input means for inputting information related to the connection; Equipped with The reduction means switches between the first mode and the second mode based on the information stored in the storage means. The information processing device according to claim 7.

9. The acquiring means acquires information regarding a connection to the shared power source from outside the information processing device. The information processing device according to claim 7.

10. The individual power source is an uninterruptible power supply. The information processing device according to claim 1 .

11. The individual power source is a portable power source. The information processing device according to claim 1 .

12. The information processing device according to any one of claims 1 to 10, the individual power source connectable to the information processing device; having The individual power sources include: a storage unit capable of receiving the first AC power from the shared power source and storing energy; a conversion unit that generates the second AC power by using the energy stored in the storage unit; an output unit that outputs a connection state with the common power source; Equipped with The reduction means of the information processing device switches between the first mode and the second mode based on an output of the output unit. Information processing system.

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