Image formation device, power supply device, calculation method for conversion information, and program

Abstract

To provide an image formation device capable of estimating an input voltage with high precision even if the amplification ratio of an output voltage to the input voltage of an input voltage detection circuit varies.SOLUTION: An image formation device comprises a detection part which converts an input AC input voltage into a DC output voltage and outputs it, a storage part which stores conversion information for specifying the input voltage from the output voltage, and a specification part which specifies the input voltage from the output voltage based upon the conversion information, wherein the conversion information is calculated based upon a plurality of input voltages and a plurality of output voltages output when the plurality of input voltages are input to the detection part.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an image forming apparatus, a power supply apparatus, a method for calculating conversion information, and a program.

Background Art

[0002] Conventionally, an input voltage detection circuit for detecting the magnitude of an AC input voltage has been known (for example, Patent Document 1). Further, a configuration has been conventionally known in which an input voltage input to the input voltage detection circuit is converted into a DC output voltage, and the magnitude of the input voltage is detected (estimated) from the output voltage based on conversion information.

Summary of the Invention

Problems to be Solved by the Invention

[0003] By the way, assume a configuration in which common conversion information is uniformly stored in a first image forming apparatus and a second image forming apparatus. In the above configuration, when there is no variation in the amplification ratio of the output voltage with respect to the input voltage in the input voltage detection circuit between the first image forming apparatus and the second image forming apparatus, the input voltage is estimated with high accuracy.

[0004] However, in reality, there may be a variation in the amplification ratio of the output voltage with respect to the input voltage in the input voltage detection circuit. In the above case, in a configuration in which common conversion information is uniformly stored in the first image forming apparatus and the second image forming apparatus, there may be a situation where the input voltage cannot be estimated with high accuracy. In consideration of the above circumstances, an object of the present invention is to suppress the above disadvantages.

Means for Solving the Problems

[0005] To solve the above problems, an image forming apparatus according to the present invention includes a detection unit that converts an input AC input voltage into a DC output voltage and outputs it, a storage unit that stores conversion information capable of specifying the input voltage from the output voltage, and a specifying unit that specifies the input voltage from the output voltage based on the conversion information. The conversion information is calculated based on a plurality of input voltages and a plurality of output voltages output when the plurality of input voltages are input to the detection unit. According to the above configuration, conversion information corresponding to the actual input voltage and output voltage is stored. Therefore, even when there is a variation in the amplification ratio of the output voltage with respect to the input voltage in the input voltage detection circuit, the input voltage can be estimated with high accuracy.

Effect of the Invention

[0006] According to the present invention, even when there is a variation in the amplification ratio of the output voltage with respect to the input voltage in the input voltage detection circuit, the input voltage can be estimated with high accuracy.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0008] Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a diagram for explaining the schematic configuration of an MFP (Multifunction Peripheral Product Printer) 100 which is an example of an image forming apparatus according to the present invention. As shown in FIG. 1, the MFP 100 includes a power supply device 101, an operation panel 112, a scanner unit 113, an image forming unit 114, a photosensitive drum 115, a transfer belt 116, and an image fixing unit 117.

[0009] The operation panel 140 includes a touch panel or the like that displays current setting values, selection screens, etc. and accepts inputs from the operator. The scanner unit 113 can read various images. Specifically, the scanner unit 113 includes a contact glass, and when the operation panel 112 is operated, it reads the image displayed on printing paper or the like placed on the contact glass.

[0010] The MFP 100 can print the image read by the scanner unit 113 on printing paper. Specifically, when an image is read by the scanner unit 113, the image (toner) is formed on the photosensitive drum 115 by the image forming unit 114. The image formed on the photosensitive drum 115 is transferred (primary transfer) to the transfer belt 116. Further, the image transferred to the transfer belt 116 is transferred (secondary transfer) to the printing paper. The printing paper on which the image is transferred is conveyed to the image fixing unit 117.

[0011] The image fixing unit 117 fixes the image formed on the printing paper to the printing paper. Specifically, the image fixing unit 117 has a fixing heater 111 that generates heat by the supplied power (see FIG. 2(a) described later). The printing paper on which the image is transferred is heated by the fixing heater 111. The image formed on the printing paper can be fixed to the printing paper by being heated by the fixing heater 111.

[0012] The power supply device 101 supplies the power supplied from the AC power supply 200, which is an external power supply, to each component in the MFP 100. For example, the power supply device 101 supplies an AC voltage to the fixing heater 111 described above. Also, after converting the AC voltage into a DC voltage, the power supply device 101 supplies it to the CPU (Central Processing Unit) 110 described later.

[0013] In addition, the power supply device 101 includes an input voltage detection circuit 104 to control the AC voltage supplied to each component (such as the fixing heater 111) (see FIGS. 2(a) and 2(b) described later). When an AC voltage (hereinafter referred to as "input voltage Vi") is input from the AC power supply 200 to the above input voltage detection circuit 104, the input voltage detection circuit 104 outputs a DC voltage (hereinafter referred to as "output voltage Vo") corresponding to the input voltage Vi (converts the AC voltage into a DC voltage). The above output voltage Vo is output to the CPU 110 side, and the input voltage Vi before conversion is specified (estimated) from the output voltage Vo.

[0014] Although it will be described in detail later, the input voltage detection circuit 104 includes a transmission means for transmitting the input voltage Vi from the input side (AC power supply 200 side) to the output side (CPU 110 side). In the present embodiment, a photocoupler PC is adopted as the transmission means. According to the above configuration, for example, there is an advantage that the input voltage detection circuit 104 can be miniaturized as compared with a configuration adopting a transformer as the transmission means.

[0015] However, there is a situation where the amplification ratio of the transmission means in the input voltage detection circuit 104 (the ratio of the output voltage Vo to the input voltage Vi) may vary. For example, assume an input voltage detection circuit 104A having a photocoupler PCA as the transmission means and an input voltage detection circuit 104B having a photocoupler PCB as the transmission means. In the above case, originally, the amplification ratios of the photocoupler PCA and the photocoupler PCB are common.

[0016] However, the amplification ratios of the respective photocouplers PC may not actually be common (vary). In the above case, even when the input voltage Vi is common, the output voltages Vo of the input voltage detection circuit 104A and the input voltage detection circuit 104B are different. That is, even when the input voltage Vi is common, there may arise a problem that the input voltages Vi detected by the input voltage detection circuit 104A and the input voltage detection circuit 104B are different.

[0017] In consideration of the above circumstances, in this embodiment, a configuration is provided to suppress the above-mentioned problem. Specifically, the MFP 100 refers to the conversion information Dc in order to specify the input voltage Vi from the output voltage Vo. In this embodiment, the conversion information Dc is variably (adjusted and) set according to the actual amplification ratio of the photocoupler PC. The above configuration will be described in detail later.

[0018] FIG. 2(a) is a diagram for explaining the hardware configuration of the MFP 100 according to this embodiment. As shown in FIG. 2, the MFP 100 includes the above-described power supply device 101 and the controller 106. Note that in FIG. 2(a), a part of each configuration of the MFP 100 is extracted and shown.

[0019] The controller 106 controls the entire MFP 100, and controls, for example, drawing, communication, input from the operation panel 112, and the like. The controller 106 includes a CPU 110, which is a main part of a computer, an ASIC (Application Specific Integrated Circuit) 107, a memory 108, and a power control circuit 109.

[0020] In addition to the above components, the controller 106 includes a system memory (MEM-P) and a local memory (MEM-C). Each of the above memories includes, for example, a ROM that stores a program for realizing each function (such as a printing function) of the MFP 100, and a RAM that temporarily stores each piece of information generated during the execution of the program. The memory 108 stores each piece of information including the conversion information Dc described later. As the above memory 108, for example, an HD (Hard Disk) can be adopted.

[0021] The power supply device 101 supplies power from an external AC power supply 200 to each component. Specifically, the power supply device 101 includes a DC voltage generation circuit 102 and an AC voltage generation circuit 103. The DC voltage generation circuit 102 converts the AC voltage from the AC power supply 200 into a DC voltage and generates a DC voltage of a predetermined magnitude from the DC voltage. The DC voltage generated by the DC voltage generation circuit 102 is supplied to, for example, the controller 106 (CPU 110).

[0022] The AC voltage generation circuit 103 converts the AC voltage from the AC power supply 200 into a predetermined magnitude and supplies the converted AC voltage to each component of the MFP 100 (such as the fixing heater 111). Specifically, the AC voltage generation circuit 103 includes an input voltage detection circuit 104 and a power supply circuit 105. The input voltage detection circuit 104 outputs a DC output voltage Vo corresponding to the AC input voltage Vi input from the AC power supply 200. The output voltage Vo is input to the ASIC 107 of the controller 106.

[0023] When the output voltage Vo is input, the controller 106 (CPU 110) refers to the conversion information Dc in the memory 108 and identifies (estimates) the input voltage Vi from the output voltage Vo. Further, the CPU 110 causes a control signal based on the estimation result of the input voltage Vi to be output from the power control circuit 109 to the power supply circuit 105 of the power supply device 101. The power supply circuit 105 controls, for example, the AC voltage input to the fixing heater 111 according to the control signal. According to the above configuration, an appropriate AC voltage is supplied to each component of the MFP 100 according to the magnitude of the input voltage Vi.

[0024] FIG. 2(b) is a circuit diagram of a specific example of the input voltage detection circuit 104. The input voltage detection circuit 104 includes each resistor R (1 to 10), each diode D (1 to 5), each capacitor C (1 to 5), each operational amplifier A (1, 2), and a photocoupler PC. Each of the above components functions as a rectifier circuit Cr, a smoothing circuit Cs, and a filter circuit Cf as shown in FIG. 2(b).

[0025] As described above, the input voltage Vi is input from the AC power supply 200 to the input voltage detection circuit 104. When the input voltage Vi is input, a current having a magnitude corresponding to the input voltage Vi flows through the input side of the photocoupler CP in the input voltage detection circuit 104. Further, when a current flows through the input side of the photocoupler CP, a DC output voltage Vo corresponding to the magnitude of the current is output through the smoothing circuit Cs and the filter circuit Cf.

[0026] As described above, the output voltage Vo is input to the controller 106, and the input voltage Vi is estimated from the output voltage Vo. Specifically, the input voltage Vi is estimated from the output voltage Vo based on the conversion information Dc. The above conversion information Dc is preset based on the amplification ratio of the photocoupler CP. Specifically, the conversion information Dc is stored in the conversion information setting process (see FIG. 5) described later.

[0027] In the above configuration, if there is a difference between the amplification ratio of the photocoupler CP assumed when setting the conversion information Dc and the actual amplification ratio of the photocoupler CP, there is a situation where the accurate input voltage Vi cannot be estimated. Considering the above situation, in the present embodiment, the conversion information Dc (linear format C described later) is variably set according to the actual amplification ratio of the photocoupler CP. The above configuration will be described in detail later with reference to FIG. 4. Note that the photocoupler CP in the input voltage detection circuit 104 may be other optical transmission elements. Further, an isolation transformer may be used instead of the photocoupler CP.

[0028] FIG. 3 is a functional block diagram of the image forming apparatus 10 according to the present embodiment. For example, when the above-described CPU 110 executes a program, the MFP 100 functions as the image forming apparatus 10. As shown in FIG. 3, the image forming apparatus 10 includes a detection unit 11, a specification unit 12, and a storage unit 13.

[0029] The detection unit 11 converts the input AC input voltage Vi into a DC output voltage Vo and outputs it. Specifically, the detection unit 11 includes a photocoupler CP in which the input side (AC power supply 200 side) and the output side (controller 106 side) are insulated, a current corresponding to the input voltage Vi flows on the input side, and a voltage corresponding to the current is output. For example, the above-described input voltage detection circuit 104 functions as the detection unit 11.

[0030] The storage unit 13 stores conversion information Dc that can specify the input voltage Vi from the output voltage Vo. In the present embodiment, the linear format C shown in Equation 1 described later is adopted as the conversion information Dc. By substituting the output voltage Vo into the above linear format C, the input voltage Vi is calculated (estimated). Further, although it will be described in detail with reference to FIG. 4, the conversion information Dc (linear format C) is calculated based on a plurality of input voltages (ViL, ViH) and a plurality of output voltages (VoL, VoH) output when the plurality of input voltages are input to the detection unit 11.

[0031] The conversion information Dc of the present embodiment is calculated in a process before the image forming apparatus 10 is shipped and stored in the storage unit 13. However, in the period after the image forming apparatus 10 is shipped, it may be configured to be able to update the conversion information Dc. For example, when a predetermined period (e.g., one year) has elapsed since the image forming apparatus 10 was shipped, the image forming apparatus 10 may execute a conversion information setting process (see FIG. 5) described later, and the conversion information Dc may be updated.

[0032] Based on the conversion information Dc, the specifying unit 12 specifies the input voltage Vi from the output voltage Vo. Specifically, when the output voltage Vo is input from the detection unit 11, the specifying unit 12 substitutes the output voltage Vo into the linear form C (conversion information Dc), and stores the calculation result as the input voltage Vi. For example, the above-described CPU 110 functions as the detection unit 11. Note that the power supply device 101 may be configured to include the above-described detection unit 11, specifying unit 12, and storage unit 13. The above power supply device 101 functions as the power supply device of the present invention.

[0033] FIG. 4 is a diagram for explaining a specific example of the conversion information Dc. There is a situation where the relationship between the input voltage Vi and the output voltage Vo can be represented by the linear form C shown in Equation 1 below. In consideration of the above situation, in the present embodiment, the linear form C is adopted as the conversion information Dc. However, the conversion information Dc is not limited to the above example. For example, a conversion data table that stores a plurality of combinations (Vo, Vi) of the output voltage Vo and the input voltage Vi calculated by substituting the output voltage Vo into the linear form C may be adopted as the conversion information Dc.

[0034]

Equation

[0035] A and B in Equation 1 are constants. However, as described above, the conversion information Dc (line format C) changes according to the amplification ratio of the photocoupler PC in the detection unit 11 (input voltage detection circuit 104). Therefore, there is a situation where the constants A and B in the line format C change according to the photocoupler C. In consideration of the above circumstances, in the present embodiment, before shipping the image forming apparatus 10, the process of inputting the input voltage (ViL, ViH) to the detection unit 11 and measuring the actual output voltage (VоL, VоH) is repeated twice by changing the input voltage Vi.

[0036] Specifically, the image forming apparatus 10 includes a variable resistor whose resistance value can be variably set. In the process before shipping the image forming apparatus 10, the variable resistor is set to a resistance value such that the output voltage Vо becomes a predetermined value (about 2.536 volts) when the median value Vim (about 230 volts) of the input voltage Vi is input. Thereafter, the output voltage VоL when the input voltage ViL (ViL = about 182 volts) is input to the detection unit 11 is measured, and the output voltage VоH when the input voltage ViH (ViH = about 276 volts) is input is measured. According to the present embodiment described above, the following equations (1) and (2) are obtained.

[0037]

Equation

[0038] In the present embodiment, the constants A and B are calculated from the simultaneous equations of equations (1) and (2), and the line format C including the calculated constants A and B is obtained. Further, the conversion information Dc indicating the line format C is generated and stored in the storage unit 13. When the input voltage Vi is input to the detection unit 11 and the output voltage Vо is output during the period after the image forming apparatus 10 is shipped, the output voltage Vо is substituted into the line format C (refer to Equation 1) set before shipping, and the input voltage Vi is calculated (specified). Note that a configuration may be adopted in which three or more input voltages Vi are input to the input voltage detection circuit 104 and the line format C is obtained.

[0039] FIG. 4 shows three specific examples of the conversion information Dc. Specifically, FIG. 4 shows a line format CL, a line format CM, and a line format CH obtained from the input voltage detection circuit 104 including each photocoupler CP having a different amplification ratio. Note that the horizontal axis in FIG. 4 indicates the input voltage Vi, and the vertical axis indicates the output voltage Vo. As described above, regardless of which photocoupler CP is included (regardless of which line format C), the output voltage Vo when the input voltage Vi is the median value ViM (about 230 volts) is a predetermined numerical value (about 2.536 volts) in common.

[0040] However, the amplification ratio of each photocoupler CP may vary depending on the input voltage Vi. Therefore, as understood from FIG. 4, the input voltage Vi at which the common output voltage Vo is detected may differ depending on the type of the set line format C (CL, CM, CH). Specifically, the farther the input voltage Vi is from the median value ViM, the greater the difference (variation) in the input voltage Vi at which the common output voltage Vo in each line format C is detected becomes.

[0041] For example, when the conversion information Dc is the line format CM and the input voltage Vi is 240 volts (median value ViM + 10 volts), the output voltage Vo, when the conversion information Dc is set to the line format CH, is detected when the input voltage Vi is 239 volts (error = about 1 volt). On the other hand, when the conversion information Dc is the line format CM and the input voltage Vi is 264 volts (median value ViM + 34 volts), the output voltage Vo, when the conversion information Dc is set to the line format CH, is detected when the input voltage Vi is 261 volts (error = about 3 volts).

[0042] As described above, in the present embodiment, when the input voltage Vi is input to the detection unit 11, the output voltage Vo is actually measured, and the conversion information D is set according to the actual measurement value (according to the actual amplification value of the photocoupler CP). Therefore, even when there is a variation in the amplification value of the photocoupler Pc, the accurate input voltage Vi is specified (estimated) from the output voltage Vo.

[0043] FIG. 5 is a flowchart of the conversion information setting process. In the present embodiment, in a process before the image forming apparatus 10 is shipped, when an external device is attached to the image forming apparatus 10, the conversion information setting process is executed. Note that each step (S101 to 104) of the conversion information setting process is executed in cooperation between the image forming apparatus 10 and the external device. However, all steps of the conversion information setting process may be configured to be executed by the external device, or may be configured to be executed by the image forming apparatus 10. Further, in a configuration where all steps of the conversion information setting process are executed by the image forming apparatus 10, the conversion information setting process may be configured to be executed without attaching the external device.

[0044] When the conversion information setting process is started, an input voltage ViL (about 187 volts) is input to the detection unit 11, and an output voltage VоL is stored in the memory (S101). Note that the memory in which the output voltage VоL is stored in step S101 may be provided in the image forming apparatus 10 or in the external device. Further, means for detecting the magnitude of the output voltage VоL (for example, a voltage measurement circuit) may be provided in the image forming apparatus 10 or in the external device (the same applies in S102). When the output voltage VоL is stored in the memory, an input voltage ViH (about 276 volts) is input to the detection unit 11, and an output voltage VоH is stored in the memory (S102).

[0045] Thereafter, a line format C is calculated based on the input voltage ViL used in step S101, the stored output voltage VоL, the input voltage ViH used in step S102, and the stored output voltage VоH (S103). Further, the line format C calculated in step S103 is stored as conversion information Dc in the storage unit 13 of the image forming apparatus 10 (S104). When the conversion information Dc is stored, the conversion information setting process ends.

[0046] Note that each function executed in the embodiment described above can be realized by one or more processing circuits. Here, the "processing circuit" in this specification refers to a processor programmed to execute each function by software, such as a CPU implemented by an electronic circuit, an ASIC (Application Specific Integrated Circuit) designed to execute each function described above, a DSP (digital signal processor), an FPGA (field programmable gate array), and devices such as conventional circuit modules.

[0047] <Summary of the operations and effects of the exemplary embodiments of the present embodiment> <First aspect> The image forming apparatus (10) of this aspect includes a detection unit (11) that converts an input AC input voltage (Vi) into a DC output voltage (Vo) and outputs it, a storage unit (13) that stores conversion information capable of specifying the input voltage from the output voltage, and a specification unit (12) that specifies the input voltage from the output voltage based on the conversion information (Dc). The conversion information is calculated based on a plurality of input voltages (ViL, ViH) and a plurality of output voltages (VoL, VoH) output when the plurality of input voltages are input to the detection unit. According to this aspect, even when there is variation in the amplification ratio of the output voltage with respect to the input voltage in the detection unit (input voltage detection circuit), the input voltage can be estimated with high accuracy.

[0048] <Second aspect> In the image forming apparatus of this aspect, the detection unit includes a photocoupler in which the input side and the output side are insulated, a current corresponding to the input voltage flows on the input side, and a voltage corresponding to the current is output. According to this aspect, for example, compared with a configuration in which a transformer is adopted instead of a photocoupler, the detection unit (input voltage detection circuit) can be miniaturized.

[0049] <Third aspect> In the image forming apparatus according to this aspect, the conversion information is calculated in a process before the image forming apparatus is shipped and stored in the storage unit. According to this aspect, appropriate conversion information is stored in the storage unit before the image forming apparatus is first used by the user.

[0050] <Fourth Aspect> The power supply device according to this aspect includes a detection unit that converts an input AC input voltage into a DC output voltage and outputs it, a storage unit that stores conversion information that can identify the input voltage from the output voltage, and a specifying unit that specifies the input voltage from the output voltage based on the conversion information. The conversion information is calculated based on a plurality of input voltages and a plurality of input voltages output when the plurality of input voltages are input to the detection unit. According to this aspect, the same effect as that of the first aspect can be obtained.

[0051] <Fifth Aspect> The method for calculating conversion information according to this aspect is a method for calculating conversion information in an apparatus including a detection unit that converts an input AC input voltage into a DC output voltage and outputs it, a storage unit that stores conversion information that can identify the input voltage from the output voltage, and a specifying unit that specifies the input voltage from the output voltage based on the conversion information. The method includes a step (S103 in FIG. 5) of calculating conversion information based on a plurality of input voltages and a plurality of input voltages output when the plurality of input voltages are input to the detection unit. According to this aspect, the same effect as that of the first aspect can be obtained.

[0052] <Sixth Aspect> The program according to this aspect causes a computer to execute each step of the fifth aspect. According to this aspect, the same effect as that of the first aspect can be obtained.

Explanation of Reference Numerals

[0053] 10... Image forming apparatus, 11... Detection unit, 12... Specifying unit, 13... Storage unit.

Prior Art Documents

Patent Documents

[0054]

Patent Document 1

Claims

1. A detection unit that converts an input AC input voltage into a DC output voltage and outputs it; A storage unit that stores conversion information capable of specifying the input voltage from the output voltage; A specifying unit that specifies the input voltage from the output voltage based on the conversion information An image forming apparatus comprising: The conversion information is calculated based on a plurality of the input voltages and a plurality of the output voltages output when the plurality of input voltages are input to the detection unit. Image forming apparatus.

2. The detection unit includes a photocoupler in which an input side and an output side are insulated, a current corresponding to the input voltage flows on the input side, and a voltage corresponding to the current is output. The image forming apparatus according to claim 1.

3. The conversion information is calculated in a process before the image forming apparatus is shipped and stored in the storage unit. The image forming apparatus according to claim 1 or claim 2.

4. A detection unit that converts an input AC input voltage into a DC output voltage and outputs it; A storage unit that stores conversion information capable of specifying the input voltage from the output voltage; A specifying unit that specifies the input voltage from the output voltage based on the conversion information A power supply device comprising: The conversion information is calculated based on a plurality of the input voltages and a plurality of the output voltages output when the plurality of input voltages are input to the detection unit. Power supply device.

5. A detection unit that converts an input AC input voltage into a DC output voltage and outputs it; A storage unit that stores conversion information capable of specifying the input voltage from the output voltage; A specifying unit that specifies the input voltage from the output voltage based on the conversion information A method for calculating the conversion information in an apparatus comprising: A step of calculating the conversion information based on a plurality of the input voltages and a plurality of the output voltages output when the plurality of input voltages are input to the detection unit The method for calculating the conversion information comprising.

6. A program for causing a computer to execute the step according to claim 5.

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