Image forming apparatus

Abstract

An image forming apparatus is disclosed. The image forming apparatus includes a housing, an image forming unit, and an internal heating unit. A first measuring unit measures an environmental parameter of a mounting environment. A control unit controls power supplied to the heating unit based on the measured parameter. A first power supply supplies power to the image forming unit, operating in a first state for image forming and a second state in which less power or no power is supplied to the image forming unit. A second power supply supplies power to the first measuring unit and the control unit. The second power supply continues to supply power to the first measuring unit and the control unit when the first power supply is in the second state.

Description

Technical Field

[0001] This disclosure relates to an image forming apparatus. Background Technology

[0002] When condensation occurs in an image forming apparatus, the quality of the image formed on the sheet deteriorates, or paper jams may occur. According to Japanese Patent Publication No. 2023-037749, condensation is reduced by using an ambient heater to heat the interior of the image forming apparatus.

[0003] Because a significant amount of heating time is required to eliminate condensation, the ambient heater is always kept on according to conventional technology. In particular, the ambient heater remains on even after the image forming apparatus has transitioned from an operational state capable of forming an image to a sleep state. Therefore, conventional technology faces the challenge of further reducing the power consumption of the image forming apparatus. Summary of the Invention

[0004] This disclosure provides an image forming apparatus, comprising: a housing; an image forming unit configured to form an image on a sheet; a heating unit deployed inside the housing and configured to heat components inside the housing; a first measuring unit deployed inside or outside the housing and configured to measure environmental parameters of the mounting environment of the housing; a control unit configured to control power supplied to the heating unit based on the environmental parameters measured by the first measuring unit; a first power source configured to supply power to the image forming unit; and a second power source configured to supply power to the first measuring unit and the control unit, wherein the first power source has a first state and a second state, wherein in the first state, power for forming an image is supplied to the image forming unit, and in the second state, power less than the power supplied in the first state is supplied to the image forming unit, or no power is supplied to the image forming unit, and when the first power source is in the second state, the second power source supplies power to the first measuring unit and the control unit.

[0005] This disclosure also provides an image forming apparatus, comprising: a housing; an image forming unit configured to form an image on a sheet; a heating unit deployed inside the housing and configured to heat components inside the housing; a first measuring unit deployed inside or outside the housing and configured to measure environmental parameters of the mounting environment of the housing; a control unit configured to control power supplied to the heating unit based on the environmental parameters measured by the first measuring unit; and a first power supply configured to supply power to the image forming unit, wherein the first power supply has a first state and a second state, wherein in the first state, power for forming an image is supplied to the image forming unit, and in the second state, power less than the power supplied in the first state is supplied to the image forming unit, or no power is supplied to the image forming unit, and the first measuring unit measures the environmental parameters when the first power supply is in the second state.

[0006] The features of this disclosure will become clear from the following description of embodiments, with reference to the accompanying drawings. Attached Figure Description

[0007] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with this description, serve to illustrate the principles of the embodiments.

[0008] Figure 1 This is a diagram illustrating the image formation system.

[0009] Figure 2 It is a graph illustrating environmental parameters and calculation results.

[0010] Figure 3 This is a block diagram showing the power control unit.

[0011] Figure 4 It is a graph showing the atmospheric moisture content and the estimated moisture content in the medium, determined by ambient temperature and humidity.

[0012] Figure 5 This is a flowchart illustrating the control method.

[0013] Figure 6 This is a block diagram showing the power control unit.

[0014] Figure 7 This is a block diagram showing the power control unit.

[0015] Figure 8 This is a block diagram showing the power control unit.

[0016] Figure 9 This is a block diagram showing the power control unit.

[0017] Figure 10 This is a block diagram showing the power control unit.

[0018] Figure 11 This is a block diagram showing the power control unit.

[0019] Figure 12 This is a block diagram showing the power control unit.

[0020] Figure 13 This is a circuit diagram of the heater's controller and power supply.

[0021] Figure 14 This is a circuit diagram of the heater's controller and power supply.

[0022] Figure 15 This is a diagram illustrating the arrangement of the heater and environmental sensors. Detailed Implementation

[0023] In the following, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the scope of the claims. Several features are described in the embodiments, but not all such features are necessary, and multiple such features can be appropriately combined. Furthermore, in the drawings, the same reference numerals are given the same or similar configurations, and repeated descriptions thereof are omitted.

[0024] 1. Image Forming System like Figure 1 As shown, the image forming system 100 is a copier or multifunction peripheral that includes an image forming apparatus 10 and an image reader 20. Note that the image forming system 100 may also be a printer that does not include the image reader 20. Note that the image reader 20 may also be referred to as an image reading apparatus or a document reading apparatus.

[0025] 1-1. Image forming apparatus The image forming apparatus 10 can be a color printer or a monochrome printer. Figure 1 In the example shown, the image forming apparatus 10 is a tandem full-color printer capable of forming full-color images using an electrophotographic method. Various mechanisms are housed within a housing 10A of the image forming apparatus 10.

[0026] Image forming units 50y, 50m, 50c, and 50k form toner images in yellow, magenta, cyan, and black, respectively. Figure 1 In the illustration, when describing things common to the four colors, the suffixes y, m, c, and k added to the figure labels can be omitted.

[0027] The image forming unit 50 includes a photosensitive drum 1, an electrical device 2, an exposure device 3, a developing device 4, and a primary transfer roller 5. The photosensitive drum 1 is a cylindrical image carrier that rotates counterclockwise.

[0028] The charging device 2 can be, for example, a corona charging device that charges charged particles by corona discharge and charges the surface of the photosensitive drum 1. Therefore, the surface potential becomes a negative or positive dark potential. The charging device 2 may include rollers or lines for discharge. A high voltage, referred to as the charging voltage or charging bias, can be applied to the charging device 2. The exposure device 3 includes, for example, a semiconductor laser or an organic electroluminescent (EL) light-emitting element as a light source and scans light on the surface of the photosensitive drum 1 according to input image data. Therefore, an electrostatic latent image is formed on the surface of the photosensitive drum 1. The developing device 4 includes a container and a developing roller that supplies developer to the photosensitive drum 1. The container contains a developer comprising toner and carrier. Therefore, the electrostatic latent image on the surface of the photosensitive drum 1 is developed to form a toner image. A high voltage, referred to as the developing voltage or developing bias, is applied to the developing roller of the developing device 4.

[0029] The intermediate transfer belt 6 rotates while being stretched along multiple rollers, including the opposing roller 11. A primary transfer roller 5 is positioned at the primary transfer location opposite the photosensitive drum 1. The primary transfer roller 5 is applied a primary transfer bias voltage as a high voltage and transfers the toner image carried on the surface of the photosensitive drum 1 to the intermediate transfer belt 6. The toner images of the four color components are transferred to the intermediate transfer belt 6 in a superimposed manner (primary transfer), thereby forming a full-color toner image. The intermediate transfer belt 6 carries the full-color toner image and conveys it to the secondary transfer location. The opposing roller 11 and the secondary transfer roller 12 are positioned at the secondary transfer location.

[0030] Box 7 is a storage container for holding a stack of sheets. Figure 1 An example is shown in which the image forming apparatus 10 includes only one cartridge 7. However, the image forming apparatus 10 may include multiple cartridges 7 capable of accommodating sheets S of different types (e.g., size, thickness, or with or without surface coating). The cartridge 7 may be an optional feed device, such as a cartridge base, connected to the image forming apparatus 10. When the cartridge 7 is provided as an optional feed device, the image forming apparatus 10 includes multiple housings. That is, the image forming apparatus 10 includes a first housing in which the image forming unit 50 is provided, and a second housing in which the cartridge 7 is provided.

[0031] Feed roller 8 feeds the sheet S one sheet at a time from the stack of sheets S in box 7 onto the transport path. Transport roller 9a transports the sheet S along the transport path and feeds the sheet S to the secondary transfer position. Secondary transfer roller 12 is applied with a secondary transfer bias voltage as a high voltage and transfers the full-color toner image carried by intermediate transfer belt 6 onto the sheet S that has reached the secondary transfer position (secondary transfer).

[0032] The fixing unit 13 is a fixing unit deployed downstream of the secondary transfer position. The fixing unit 13 includes a fixing roller (or cylindrical heated film) and a pressure roller, and heats and pressurizes the sheet S on which the toner image has been transferred, thereby fixing the toner image onto the sheet S. The fixing unit 13 includes one or more heating elements (heating units for fixing) that generate heat supplied to the sheet S. Transport rollers 9b to 9e transport the sheet S that has passed through the fixing unit 13 and discharge the sheet S to the discharge tray 15 or discharge tray 17 specified by the print job information. The discharge roller 14 discharges the sheet S delivered from the transport roller 9d via the transport path 18 to the discharge tray 15. The discharge roller 16 discharges the sheet S delivered from the transport roller 9e via the transport path 19 to the discharge tray 17.

[0033] 1-2. Image Reader Image reader 20 includes an optical housing 23 and an image sensor 24. The optical housing 23 includes a light source that illuminates a document 22 placed on a pressure plate glass 21, and a mirror that guides the light from the document 22 to the image sensor 24. The image sensor 24 receives the image light from the document 22 and generates image data. Although in Figure 1 The middle part is omitted, but an automatic document feeder (ADF) that feeds documents 22 one by one to the image reader 20 can be used.

[0034] 1-3. Power control devices and power supply devices AC control unit 31 supplies AC power from an external power source 30, such as a commercial AC power supply, to AC loads (e.g., the heating element of the fixing device 13, AC / DC conversion circuit 32, and a normally-on power supply 43). AC is an abbreviation for alternating current. DC is an abbreviation for direct current. In this specification, AC voltage, AC current, AC power, etc., are simply referred to as "alternating current". Similarly, DC voltage, DC current, DC power, etc., are simply referred to as "direct current". DC control unit 33 supplies DC power generated by AC / DC conversion circuit 32 to DC loads (e.g., a motor, exposure device 3, main controller 40, image reader 20, powered device 2, developing device 4, primary transfer roller 5, and secondary transfer roller 12). AC / DC conversion circuit 32 includes multiple DC / DC conversion circuits for generating multiple different DC voltages. Main controller 40 controls the generation of image data by image reader 20 and the formation of images on sheet S by image forming apparatus 10. Operation unit 41 provides a user interface to the user of image forming system 100. The operation unit 41 includes, for example, a touch panel 42. The touch panel 42 includes a display device that displays images and information under the control of the main controller 40, and a touch sensor that receives touch input from the user.

[0035] The image forming system 100 has multiple power modes. The operating mode (operational state) is the mode in which the image forming system 100 can form an image. In this state, the AC control unit 31 supplies the power consumed for image formation to the AC / DC conversion circuit 32, the DC control unit 33, and the main controller 40. The sleep mode (sleep state) is the mode in which the image forming system 100 cannot form an image. The power consumption of the image forming system 100 in sleep mode is less than that in operating mode. This is because the AC control unit 31 does not supply power to the AC / DC conversion circuit 32, the DC control unit 33, and the main controller 40 in sleep mode. Note that sleep mode can be a state in which the AC control unit 31 supplies less power to the AC / DC conversion circuit 32, the DC control unit 33, and the main controller 40 than the power supplied in operating mode. In this case, power consumption can also be reduced in sleep mode compared to operating mode.

[0036] On the other hand, even in sleep mode, the AC control unit 31 supplies AC power to the normally-on power supply 43. The normally-on power supply 43 is a sub-power supply that supplies power to the power control unit 44 and the heater control unit 45. Even in sleep mode, the power control unit 44 and the heater control unit 45 continue to operate. The AC / DC conversion circuit 32 can be referred to as the main power supply.

[0037] An environmental sensor 46 and a heater 47 are deployed inside the housing 7. Power is supplied to the environmental sensor 46 and heater 47 from a normally-on power supply 43 via a power control unit 44 or a heater control unit 45. Based on environmental parameters detected by the environmental sensor 46, the power control unit 44 controls the heater 47 via the heater control unit 45. In this embodiment, the power control unit 44 estimates the moisture content in the sheet S based on the environmental parameters detected by the environmental sensor 46 and controls the heater 47 such that the moisture content is within a predetermined range. In another embodiment, various control algorithms may be employed, such as turning on the heater 47 if the temperature detected by the environmental sensor 46 is less than or equal to a predetermined threshold, and turning off the heater 47 if the temperature exceeds the predetermined threshold.

[0038] An environmental sensor 48 and a heater 49 are deployed inside the image reader 20. Power is supplied to the environmental sensor 48 and heater 49 from a normally-on power supply 43 via a power control unit 44 or a heater control unit 45. The power control unit 44 estimates the moisture content inside the image reader 20 based on environmental parameters detected by the environmental sensor 48, and controls the heater 49 via the heater control unit 45 to keep the moisture content within a predetermined range. This reduces condensation on the reflectors inside the optical housing 23. Various methods can be used for the control algorithm of the heater 49, similar to those used for the heater 47.

[0039] As described above, when condensation occurs in the components housed inside the housing 10A, the quality of the image formed on the sheet S deteriorates. A certain amount of heating time is required to reduce condensation. Accordingly, heaters 47 and 49 heat the interior of the housing 10A even in sleep mode.

[0040] To reduce the power consumption of heaters 47 and 49 in sleep mode, the heaters 47 and 49 can be switched on / off based on whether the environment is prone to condensation. For this reason, the power control unit 44 and environmental sensors 46 and 48 are configured to operate in sleep mode. Figure 1 As shown, in both operating and sleep modes, the normally-on power supply 43 supplies power to the power control unit 44 and the environmental sensors 46 and 48. Not only in operating mode, but also in sleep mode, the power control unit 44 controls the heaters 47 and 49 to be turned on or off based on environmental parameters obtained from the environmental sensors 46 and 48. This allows for a reduction in the power consumption of heaters 47 and 49 in sleep mode.

[0041] Environmental sensors 46 and 48 each include, for example, a temperature sensor (e.g., a thermistor) whose resistance value changes according to the ambient temperature. The change in the thermistor's resistance value is detected as a change in voltage. Environmental sensors 46 and 48 may also each include a humidity sensor.

[0042] 2. Control methods 2-1. Basic Concepts For simplicity, heater 47 and environmental sensor 46 will be described. The following description also applies to heater 49 and environmental sensor 48. That is, in the following description, heater 47 can be interpreted as heater 49, and environmental sensor 46 can be interpreted as environmental sensor 48.

[0043] To accurately control heater 47, environmental sensor 46 measures environmental parameters at a predetermined measurement cycle (e.g., 10 minutes). This yields time-series measurement results. These results are compared to pre-set predetermined reference values ​​(e.g., corresponding time-series reference values), and the time-series difference is obtained. The time-series reference values ​​are pre-set to reduce condensation, etc. These reference values ​​can be formed, for example, from reference values ​​for daytime sleep patterns and nighttime sleep patterns. Therefore, each of the time-series reference values ​​is a set of multiple reference values ​​associated with time. The time-series reference values ​​can all be identical. In this case, the time-series reference value is essentially a single reference value. The time-series reference values ​​are provided in advance so that the measurement results obtained at a given time can be compared with reference values ​​associated with a predetermined time range including that time (difference calculation can be performed). If the sign of the time-series difference is positive N times consecutively, heater 47 is turned off. If the difference is zero, the sign of the difference can be determined to be either positive or negative. If the number of consecutive positive signs is less than N, heater 47 remains on.

[0044] Figure 2 The time-series environmental parameters, processing, and time-series calculation results measured by environmental sensor 46 are shown. The environmental parameters include temperature T_DATA and humidity H_DATA. The i-th measurement result is represented by temperature T_DATAi and humidity H_DATAi. Here, for simplicity, the focus is on temperature T_DATAi. Note that the temperature reference value corresponding to temperature T_DATAi is represented by REFi.

[0045] The power control unit 44 calculates the difference Di between the temperature T_DATAi and the reference value REFi to determine the sign of the difference Di. Here, the sign of the difference is +, -, or =. As mentioned above, = can be categorized as + or -. Based on the number of consecutive identical signs, the power control unit 44 determines whether the heater 47 should be turned off. Figure 2 The differences in temperature T_DATA0 (D0), T_DATA1 (D1), and T_DATA2 (D2) are all positive (+). That is, the sign is positive at least three times consecutively. Therefore, the power control unit 44 shuts off the heater 47. This reduces power consumption. Note that if the number of consecutive positive signs is less than three, the power control unit 44 turns the heater 47 on. This reduces condensation.

[0046] Although only temperature T_DATAi is considered here, humidity H_DATAi can also be considered. In this case, the reference value REFi corresponding to the humidity is used for difference calculation.

[0047] In addition, there is a difference Di between the values ​​calculated based on temperature T_DATAi and humidity H_DATAi (e.g., estimated moisture content) and the corresponding reference value REFi.

[0048] Although heater 47 and environmental sensor 46 have been described herein, in the above description, the terms heater 47 and environmental sensor 46 may be replaced by heater 49 and environmental sensor 48. Heater 47 and heater 49 are controlled independently of each other. That is, the reference value and the number of consecutive identical symbols used for heater 47 may be the same as or different from the reference value and the number of consecutive identical symbols used for heater 49.

[0049] 2-2. Power Control Unit Figure 3 An example of a power control unit 44 is shown. A central processing unit (CPU) 301 controls heaters 47 and 49 according to a control program stored in a non-volatile memory of a storage device 302. The storage device 302 includes read-only memory (ROM), random access memory (RAM), etc.

[0050] CPU 301 performs various functions by executing control programs. However, it should be noted that one or more of the functions described below can be implemented by hardware different from CPU 301 (e.g., integrated circuits).

[0051] Timer 311 times the measurement cycle of the environmental parameters. Measurement counter 312 counts the number of measurements of the environmental parameters. For example, if measurements are performed in 10-minute cycles, the number of measurements per 24 hours is 144. When measurement counter 312 is an incrementing counter, the count value of measurement counter 312 is used as index i for temperature T_DATAi and humidity H_DATAi. When measurement counter 312 is a decrementing counter, the difference between the upper limit of the number of measurements and the count value is used as index i. When a measurement cycle is input from operation unit 41, CPU 301 calculates the upper limit or initial value of measurement counter 312 based on the measurement cycle and sets the upper limit or initial value in measurement counter 312.

[0052] Temperature detection unit 313 uses ambient sensors 46 and 48 to detect ambient temperature. For example, temperature detection unit 313 converts the voltage values ​​output from ambient sensors 46 and 48 into ambient temperature, assigns index i obtained from measurement counter 312 to the ambient temperature to generate temperature T_DATAi, and stores temperature T_DATAi in the RAM area of ​​storage device 302. CPU 301 is connected to ambient sensors 46 and 48 via a communication bus such as an I2C bus or a 1-Wire bus.

[0053] The humidity detection unit 314 uses environmental sensors 46 and 48 to detect ambient humidity. For example, the humidity detection unit 314 converts the voltage values ​​output from environmental sensors 46 and 48 into ambient humidity, assigns the index i obtained from the measurement counter 312 to the ambient humidity to generate humidity H_DATAi, and stores humidity H_DATAi in the RAM area of ​​the storage device 302.

[0054] Estimation unit 320 is optional and calculates the atmospheric moisture content and the estimated moisture content of sheet S. The estimated moisture content of sheet S is an estimate of the moisture content contained in sheet S.

[0055] Figure 4 A table is shown for calculating the atmospheric moisture content and the estimated moisture content of sheet S in box 7 based on temperature T_DATA and humidity H_DATA. When each of temperature T_DATA and humidity H_DATA is a voltage value, temperature T_DATA and humidity H_DATA are pre-converted to ambient temperature and ambient humidity using formulas or tables. With an ambient temperature of 15°C and an ambient humidity of 50%, the atmospheric moisture content is calculated to be 6.4 g / m³. 3 g / m 3 It is an abbreviation for grams per cubic meter. Generally speaking, the amount of saturated steam at 15°C is 12.8 g / m³. 3 Therefore, multiplying 12.8 by 0.5 gives 6.4 g / m³. 3 The estimated moisture content of sheet S depends on the state and properties (type) of sheet S. Here, the estimated moisture content for a given plain paper is illustrated. In this example, the estimated moisture content of sheet S is 0.11 g / m². 3 At an ambient temperature of 20°C and a humidity of 70%, the atmospheric moisture content is 12.11 g / m³. 3 The estimated moisture content of sheet S is 0.17 g / m². 3 .

[0056] The atmospheric moisture content and the estimated moisture content of sheet S corresponding to the combination of ambient temperature and humidity not listed in this table can be calculated by interpolation. This table can be stored in a storage device (memory, hard disk) in the main controller 40, or in a memory in the power control unit 44.

[0057] The acquisition unit 331 obtains the reference value REFi corresponding to the count value (index i) of the measurement counter 312 from the storage device 302, and sets the reference value REFi in the difference unit 332. The difference unit 332 calculates the difference Di between the environmental parameter DATAi output from the temperature detection unit 313, humidity detection unit 314, or estimation unit 320 and the corresponding reference value REFi, and outputs the difference Di to the sign counter 333. For example, the difference unit 332 can output a "1" indicating a positive difference or a "0" indicating a negative difference.

[0058] When the difference Di is positive (+), the sign counter 333 increments the count value N by 1. When the difference Di is zero, the sign counter 333 also increments the count value N by 1. When the difference Di is negative (-), the sign counter 333 resets the count value N to zero.

[0059] The determining unit 334 determines whether the count value N of the symbol counter 333 is greater than or equal to a threshold Nth. If the count value N associated with the environmental sensor 46 is greater than or equal to the threshold Nth, the determining unit 334 shuts off the heater 47 via the heater control unit 45. If the count value N associated with the environmental sensor 48 is greater than or equal to the threshold Nth, the determining unit 334 shuts off the heater 49 via the heater control unit 45. In this way, the estimating unit 320, the obtaining unit 331, the difference unit 332, the symbol counter 333, and the determining unit 334 are provided independently for each of the heaters 47 and 49.

[0060] 2-3. Flowchart Figure 5 The control methods for heaters 47 and 49 are shown. Although heater 47 and ambient sensor 46 are used herein for ease of description, the description of heater 47 and ambient sensor 46 can be replaced by the description of heater 49 and ambient sensor 48. First, heater 47 is turned on.

[0061] In S501, CPU 301 (measurement unit 310) initializes measurement counter 312 and symbol counter 333. For example, it sets each of measurement counter 312 and symbol counter 333 to zero.

[0062] In S502, CPU 301 (measurement unit 310) obtains a timer value from timer 311 and determines whether the measurement timing has arrived based on the timer value. For example, the measurement timing arrives at each measurement cycle (e.g., 360 seconds). If the timer value corresponds to the measurement timing, then CPU 301 will proceed from S502 to S503.

[0063] In S503, CPU 301 (measurement unit 310) uses environmental sensor 46 to measure environmental parameters. The environmental parameters DATAi are stored in the RAM area of ​​storage device 302. In S504, CPU 301 increments measurement counter 312 by 1.

[0064] In S505, CPU 301 (measurement unit 310) determines whether the measurement has ended based on the count value of measurement counter 312. When the count value reaches the upper limit every 24 hours (e.g., 144), CPU 301 ends the measurement of the environmental parameters. If the count value has not yet reached the upper limit, then CPU 301 will proceed from S505 to S506.

[0065] In S506, CPU 301 (acquisition unit 331) acquires a reference value REFi corresponding to the count value of measurement counter 312 from storage device 302. In S507, CPU 301 (difference unit 332) calculates the difference Di between environmental parameter DATAi and reference value REFi.

[0066] In S508, CPU 301 (differentiation unit 332) determines whether the sign of the difference Di is positive. If the sign is negative, CPU 301 proceeds from S508 to S512. In S512, CPU 301 (differentiation unit 332) resets the sign counter 333. That is, zero is set to the count value of the sign counter 333. Afterwards, CPU 301 proceeds from S512 to S513. In S513, CPU 301 (determination unit 334) keeps the heater 47 on. If the heater 47 is off, CPU 301 switches the heater 47 from off to on. Afterwards, CPU 301 proceeds from S513 to S502.

[0067] If the sign in S508 is positive, then CPU 301 will advance the processing from S508 to S509. If the difference Di is zero, then CPU 301 can also advance the processing from S508 to S509.

[0068] In S509, CPU 301 (differentiation unit 332) increments the sign counter 333 by 1. In S510, CPU 301 (determination unit 334) obtains the number of consecutive positive signs from the sign counter 333 and determines whether the consecutive number N is greater than or equal to the threshold Nth. If the consecutive number N is not greater than or equal to the threshold Nth, then CPU 301 proceeds from S510 to S513. If the consecutive number N is greater than or equal to the threshold Nth in S510, then CPU 301 proceeds from S510 to S511.

[0069] In S511, CPU 301 (determining unit 334) shuts off heater 47 via heater control unit 45. Afterward, CPU 301 advances processing from S511 to S502.

[0070] In this way, according to this example, heaters 47 and 49 can be accurately controlled based on the number of consecutive signs of the difference between environmental parameters and reference values. Accordingly, the moisture content in the casing 10A will be accurately maintained within an appropriate range, and condensation will be unlikely to occur.

[0071] 3. Other examples of control methods 3-1. Basic Concepts In the example above, the on / off state of heaters 47 and 49 is controlled based on the consecutive number N of identical symbols. Besides the consecutive number N of identical symbols, other factors can be considered for the on / off control of heaters 47 and 49. For example, in addition to the consecutive number N of symbols determined for ambient temperature or humidity, the moisture content in the atmosphere or the estimated moisture content of sheet S can also be considered.

[0072] 3-2. Mechanism of condensation Condensation occurs as a result of water vapor present in the air being cooled and liquefied. Conversely, condensation is condensed into water vapor by heating and diffuses into the air. This relationship is known as the amount of water vapor that can exist in the air at a given temperature. For example, when the humidity is 80%, the dew point (the temperature at which condensation occurs) relative to that humidity can be derived from the temperature-saturated vapor pressure relationship. Water vapor pressure changes exponentially with increasing temperature, and an effective way to prevent condensation is to raise the temperature.

[0073] That is, CPU 301 can obtain the state of condensation occurring on the reflector inside the optical box 23 based on the atmospheric moisture content determined by the ambient temperature and humidity. Similarly, CPU 301 can obtain the estimated moisture content (amount of moisture contained) of the sheet S from the ambient temperature and humidity.

[0074] Such as about Figure 5 As described, CPU 301 can measure ambient temperature and humidity at predetermined measurement cycles and store the measurement results in storage device 302. CPU 301 can analyze long-term measurement results to pre-determine the ambient temperature, ambient humidity, and atmospheric moisture content that will affect the image. For example, CPU 301 can adjust a threshold Nth compared to a continuous number N based on the analysis results, or it can modify a reference value based on the analysis results.

[0075] Figure 6Another example implemented by the CPU 301 of the power control unit 44 is shown. (The details are omitted.) Figure 3 Description of common parts. The estimation unit 320 calculates the estimated moisture content of the sheet S based on the ambient temperature and humidity measured by the ambient sensor 46. The setting unit 601 determines a threshold Nth associated with the heater 47 based on the estimated moisture content, and sets the threshold Nth in the determination unit 334. Note that the formula or table used to determine the threshold Nth based on the estimated moisture content is stored in the ROM area of ​​the storage device 302.

[0076] Similarly, the estimation unit 320 calculates the atmospheric moisture content in the image reader 20 based on the ambient temperature and humidity measured by the ambient sensor 48. The setting unit 601 determines a threshold Nth associated with the heater 49 based on the atmospheric moisture content and sets the threshold Nth in the determination unit 334. Note that the formula or table used to determine the threshold Nth based on the atmospheric moisture content is stored in the ROM area of ​​the storage device 302.

[0077] Therefore, the on / off control of heaters 47 and 49 is performed taking into account or estimating the moisture content in the atmosphere. This allows for further reduction in the power consumption of heaters 47 and 49.

[0078] Figure 7 Another example implemented by the CPU 301 of the power control unit 44 is shown. (The details are omitted.) Figure 3 Description of the common parts. The estimation unit 320 calculates the estimated moisture content of the sheet S based on the ambient temperature and humidity measured by the ambient sensor 46. The modification unit 701 modifies the reference value REFi associated with the heater 47 based on the estimated moisture content and outputs the modified reference value REFi to the difference unit 332.

[0079] Similarly, estimation unit 320 calculates the atmospheric moisture content in image reader 20 based on the ambient temperature and humidity measured by ambient sensor 48. Modification unit 701 modifies the reference value REFi associated with heater 49 based on the atmospheric moisture content and outputs the modified reference value REFi to difference unit 332.

[0080] Therefore, the on / off control of heaters 47 and 49 is performed taking into account or estimating the moisture content in the atmosphere. This allows for further reduction in the power consumption of heaters 47 and 49.

[0081] Figure 8Another example implemented by the CPU 301 of the power control unit 44 is shown. When a consecutive number N is greater than or equal to a threshold Nth in the determination unit 334, the CPU 301 can continuously keep the heater 49 on if the atmospheric moisture content is outside a predetermined range (e.g., the atmospheric moisture content is greater than or equal to a predetermined value). Specifically, the determination unit 801 determines whether the atmospheric moisture content in the image reader 20 is greater than or equal to a predetermined value and outputs the determination result to the determination unit 802. The determination unit 334 determines whether a consecutive number N is greater than or equal to the threshold Nth and outputs the determination result to the determination unit 802. If the consecutive number N is less than the threshold Nth in the determination unit 334, the determination unit 802 keeps the heater 49 on. If the consecutive number N is greater than or equal to the threshold Nth, but the atmospheric moisture content is greater than or equal to the predetermined value, the determination unit 802 also keeps the heater 49 on. If the consecutive number N is greater than or equal to the threshold Nth, and the atmospheric moisture content is less than the predetermined value, the determination unit 802 switches the heater 49 from on to off.

[0082] Similarly, when the consecutive quantity N is greater than or equal to the threshold Nth, if the estimated moisture content of the sheet S is outside a predetermined range (e.g., the estimated moisture content is greater than or equal to a predetermined value), the CPU 301 can continuously keep the heater 47 on. Specifically, the determination unit 801 determines whether the estimated moisture content of the sheet S is greater than or equal to the predetermined value and outputs the determination result to the determination unit 802. The determination unit 334 determines whether the consecutive quantity N is greater than or equal to the threshold Nth and outputs the determination result to the determination unit 802. If the consecutive quantity N is less than the threshold Nth in the determination unit 334, the determination unit 802 keeps the heater 47 on. If the consecutive quantity N is greater than or equal to the threshold Nth, but the estimated moisture content is greater than or equal to the predetermined value, the determination unit 802 also keeps the heater 47 on. If the consecutive quantity N is greater than or equal to the threshold Nth, and the estimated moisture content is less than the predetermined value, the determination unit 802 switches the heater 47 from on to off.

[0083] Meanwhile, when the external power source 30 is commercial AC power, the voltage and frequency of the AC power will vary. In this case, the amount of power supplied to heaters 47 and 49 also varies, and therefore the heat generated also varies. Accordingly, CPU 301 can calculate the heat generated by heaters 47 and 49 by measuring the voltage and frequency of the AC power, and modify the reference value or threshold Nth according to the heat generated.

[0084] Figure 9Another example implemented by the CPU 301 of the power control unit 44 is shown. The voltage detection unit 911 detects the voltage value of the AC power supplied from the external power source 30. The frequency detection unit 912 detects the frequency of the AC power supplied from the external power source 30. The setting unit 901 determines the heat output of the heater 47 based on the voltage value, frequency, and resistance value of the heater 47, calculates a threshold Nth based on this heat output, and sets the threshold Nth for the heater 47 in the determination unit 334. A formula or table for calculating the threshold Nth based on the heat output is stored in the ROM area of ​​the storage device 302.

[0085] Similarly, the setting unit 901 determines the heat output of the heater 49 based on the voltage value, frequency, and resistance value of the heater 49, calculates a threshold Nth based on the heat output, and sets the threshold Nth for the heater 49 in the determining unit 334. A formula or table for calculating the threshold Nth based on the heat output is stored in the ROM area of ​​the storage device 302.

[0086] Figure 10 Another example implemented by the CPU 301 of the power control unit 44 is shown. The modification unit 1001 determines the heat output of the heater 47 based on the voltage value detected by the voltage detection unit 911, the frequency detected by the frequency detection unit 912, and the resistance value of the heater 47, and modifies the reference value REFi for the heater 47 based on this heat output. For example, if the heat output is greater than expected, the reference value REFi is decreased. If the heat output is less than expected, the reference value REFi is increased. The formula for modifying the reference value REFi based on the heat output is stored in the ROM area of ​​the storage device 302.

[0087] Similarly, the modification unit 1001 determines the heat output of the heater 49 based on the voltage value detected by the voltage detection unit 911, the frequency detected by the frequency detection unit 912, and the resistance value of the heater 49, and modifies the reference value REFi for the heater 49 based on this heat output. For example, if the heat output is greater than expected, the reference value REFi is decreased. If the heat output is less than expected, the reference value REFi is increased. The formula for modifying the reference value REFi based on the heat output is stored in the ROM area of ​​the storage device 302.

[0088] Figure 11 Another example implemented by the CPU 301 of the power control unit 44 is shown. The amount of moisture contained in the sheet S varies depending on the type of sheet S (e.g., basis weight, thickness, presence or absence of surface coating, presence or absence of surface treatment, material). Therefore, depending on the type of sheet S, the threshold Nth for the heater 47 can be set, or the table used in the estimation unit 320 can be switched.

[0089] The media detection unit 1111 detects the type of sheet S contained in the cartridge 7. The media detection unit 1111 can be deployed in the cartridge 7 or on the transport path. The media detection unit 1111 can specify the type of sheet S based on information input from the operation unit 41.

[0090] Setting unit 1101 determines a threshold Nth based on the detection result of media detection unit 1111, and sets the threshold Nth in setting unit 334. For example, storage device 302 can store the threshold Nth for each type of sheet S. Setting unit 1101 obtains the threshold Nth corresponding to the detection result of media detection unit 1111 from storage device 302.

[0091] The setting unit 1101 can determine a table or formula for estimating the moisture content based on the detection results of the media detection unit 1111, and set the table or formula in the estimation unit 320. For example, the storage device 302 can store tables or formulas for each type of sheet S. The setting unit 1101 obtains the table or formula corresponding to the detection results of the media detection unit 1111 from the storage device 302.

[0092] Figure 12 Another example is shown, implemented by the CPU 301 of the power control unit 44. The acquisition unit 331 switches or selects a reference value REFi based on the type of sheet S. For example, the storage device 302 stores reference values ​​REFi for each type of sheet S. The acquisition unit 331 obtains the reference value REFi from the storage device 302 based on the detection result of the media detection unit 1111.

[0093] 4. Circuit Diagram 4-1. DC Electric Drive Figure 13The circuitry related to the control of heater 47 is shown. A power supply IC 52, which receives AC power input from an external power source 30, and a transformer T1 connected to the power supply IC 52 are provided on the primary side of a normally-connected power supply 43. The power supply IC 52 includes circuitry for detecting the voltage and frequency of the AC power, a switching circuitry for switching the voltage applied to the primary winding of transformer T1, etc. Diode D1, coil L1, capacitors C1 and C2, and a DC / DC converter 63 are provided on the secondary side of transformer T1. Diode D1, coil L1, and capacitors C1 and C2 form a rectifier circuit for rectifying the AC power generated in the secondary winding of transformer T1, and a smoothing circuit for smoothing the pulsating current output from the rectifier circuit to generate DC power. The first DC voltage generated here drives heater 47 via heater control unit 45. DC / DC converter 63 converts the input first DC voltage to generate a second DC voltage with a predetermined voltage value. DC / DC converter 63 is a low-dropout (LDO) regulator, etc. The second DC voltage is used as the power supply voltage for power control unit 44. A second DC voltage is also applied to resistor R1 and ambient sensor 46. The connection point between resistor R1 and ambient sensor 46 is connected to the input terminal of power control unit 44. The voltage applied to the input terminal changes according to the temperature detected by ambient sensor 46. Power control unit 44 can detect ambient temperature and ambient humidity based on the voltage applied to the input terminal.

[0094] The heater control unit 45 includes a switch SW1 that can be manually switched between on and off by the user. Switch SW1 receives a first DC voltage supply via a semiconductor switch (transistor Tr1). Accordingly, when the user manually switches switch SW1 from off to on, the power control unit 44 inputs an on / off signal to the control terminal of transistor Tr1. Therefore, the power supplied to the heater 47 is switched on / off. Transistor Tr1 is, for example, a MOS field-effect transistor (FET). MOS is an abbreviation for Metal-Oxide-Semiconductor.

[0095] Power supply IC 52 is connected to power control unit 44 via signal line 53. Power control unit 44 can obtain the frequency and voltage values ​​of the AC power measured by power supply IC 52 via signal line 53. Signal line 53 supplies a voltage that has been stepped down to a level that can be measured by the AD converter in power control unit 44. Circuitry that ensures proper insulation distance between the primary and secondary sides (e.g., optocoupler, transformer) can be connected at the midpoint of signal line 53.

[0096] When the room where the image forming system 100 is installed is unoccupied, the switch SW1 will not be manually operated. For example, at night or on holidays, the user or maintenance personnel cannot manually turn the switch SW1 off or on. According to this example, the power control unit 44, which operates by receiving power from the normally powered power supply 43, controls the heater 47 to be off or on even during periods when no one is present (such as at night or on holidays).

[0097] Although heater 47 and ambient sensor 46 are described herein, the same circuitry applies to heater 49 and ambient sensor 48.

[0098] 4-2. AC drive Figure 14 Another circuit involving the control of heater 47 is shown. Here, heaters 47 and 49 are driven by AC power supplied from an external power source 30. Furthermore, Figure 14 The internal configuration of the power supply IC 52 is shown in detail. Filter 54 is a line filter that filters the AC input from the input terminals AC_H and AC_N. Diode bridge 55 is a rectifier circuit that converts the input AC into pulsating current. Capacitor C3 forms a smoothing circuit that smooths the pulsating current into DC. The generated DC is supplied to PWM circuit 58 via diode D2. PWM circuit 58 controls the switching of transistor Tr3, matching the aforementioned first DC voltage with a target voltage. Transistor Tr3 is, for example, a FET. This switches the current flowing through the primary winding of transformer T1, thereby generating AC in the secondary winding of transformer T2.

[0099] The first DC voltage is divided by resistors R2 and R3 and Zener diode ZD1, and the divided voltage is applied to the light-emitting diode (LED) of optocoupler P1. Optocoupler P1 is provided to isolate the primary-side circuit system from the secondary-side circuit system. The LED, which is subjected to a voltage proportional to the first DC voltage, emits light according to the applied voltage. The phototransistor of optocoupler P1 generates a feedback signal based on the light output from the LED and inputs this feedback signal to PWM circuit 58. PWM circuit 58 drives transistor Tr3 according to the input feedback signal. Thus, the first DC voltage is maintained at the target voltage.

[0100] The detection circuit 77 detects the voltage and frequency of the alternating current input from the input terminals AC_H and AC_N. As mentioned above, the detection circuit 77 can be installed in the power supply IC 52, but here it is deployed externally to the power supply IC 52. The transformer T2 is an electrical component used to insulate the primary side circuit system from the secondary side circuit system. The alternating current input from the input terminals AC_H and AC_N is applied to the primary winding of the transformer T2, thereby generating an alternating current associated with the primary side alternating current in the secondary winding. The alternating voltage in the secondary side is divided by resistors R4 and R5, and the divided voltage is supplied to the AD converter 73 through signal line 53b. The AD converter 73 can be installed inside the power control unit 44. This allows the power control unit 44 to obtain the voltage and frequency of the alternating current supplied from the external power supply 30. By measuring the frequency and voltage of the alternating current, the power control unit 44 can accurately calculate the power consumption of heaters 47 and 49. CPU 301 can accurately calculate the power consumption of heaters 47 and 49 based on their resistance value R, as well as the AC voltage and frequency. The power consumption of heaters 47 and 49 can be obtained by dividing the square of the effective value of the AC voltage by the resistance value R. The effective value of the AC voltage can be determined by multiplying the average value of the AC voltage by a waveform factor corresponding to the frequency. The amount of heat generated or power consumed by heaters 47 and 49 can be determined by integrating the power consumption over time.

[0101] Therefore, based on the voltage and frequency of the AC power supply depending on the installation environment of the image forming system 100, the power consumption of heaters 47 and 49 can be accurately calculated.

[0102] The power control unit 44 uses transistor Tr2, resistor R6, and optocoupler P2 to control the heater control unit 45. Accordingly, the on / off states of heaters 47 and 49 are controlled. Optocoupler P2 is provided to isolate the primary-side circuit system from the secondary-side circuit system. Transistor Tr2 is switched on / off by the on / off signals of heaters 47 and 49 output from the power control unit 44. Therefore, the light-emitting diode of optocoupler P2 is switched on / off, and the phototransistor of optocoupler P2 is switched on / off.

[0103] The heater control unit 45 switches heaters 47 and 49 on / off according to a signal supplied from optocoupler P2. In the heater control unit 45, a semiconductor switch (e.g., a triac, FET) is connected in series with switch SW1. As a result of switching the semiconductor switch on / off according to the signal supplied from optocoupler P2, the AC power supplied from external power source 30 to heaters 47 and 49 is switched on / off.

[0104] The media sensor 72 is a sensor that detects the type (e.g., basis weight) of the sheet S contained in the cartridge 7. The media detection unit 1111 specifies the type of the sheet S based on the detection result of the media sensor 72. This allows the CPU 301 to select the aforementioned formula or table according to the type of the sheet S. Therefore, the quality of the image formed on the sheet S is maintained, and paper jams on the sheet S caused by condensation are suppressed.

[0105] 5. Profile data Based on the measured ambient temperature and the power consumption of heater 47, CPU 301 can calculate the impact of external air temperature on image forming system 100 based on the distance between heater 47 and ambient sensor 46. When heaters 47 and 49 are continuously on for several hours, the temperature affected by the heat emitted by heaters 47 and 49 remains constant. Therefore, the measurement data obtained by ambient sensors 46 and 48 are data affected by the heat from heaters 47 and 49, as well as the temperature and humidity outside the image forming system 100. Thus, the changes in air temperature and humidity ultimately measured by ambient sensors 46 and 48 reflect the influence of the external atmosphere beyond the ambient air surrounding ambient sensors 46 and 48.

[0106] CPU 301 samples ambient temperature and humidity at predetermined measurement cycles and stores the data in storage device 302. Accordingly, time-series data (profile data) of environmental parameters are obtained every 24 hours, week, month, or season. Here, profile data can be the difference between the measured environmental parameters and reference values.

[0107] The measured environmental parameters vary with the seasons. This is because the environmental parameters depend on the installation location of the image forming system 100. Depending on the floor where the image forming system 100 is installed, the environmental parameters can differ. When sunlight (e.g., afternoon sunlight) shines on the image forming system 100 through a window, the environmental parameters are affected by the amount of sunlight. This amount varies depending on the distance and direction between the image forming system 100 and the window. The environmental parameters also vary depending on the distance and direction between the image forming system 100 and the air conditioning equipment. By measuring profile data for each installation location, the impact of the installation location on the environmental parameters can be predicted. Time-series reference values ​​corresponding to the installation location can be updated based on the measured profile data. By doing so, heaters 47 and 49 are controlled according to the installation location, thus reducing condensation in the housing 10A. The atmospheric moisture content is maintained within a predetermined range, and the amount of moisture contained in the sheet S is maintained within a predetermined range, so that the image quality meets the expected quality. The amount of power consumption of heaters 47 and 49 can be reduced without compromising image quality.

[0108] 6. Arrangement of heaters and environmental sensors Figure 15 The arrangement of multiple heaters and multiple environmental sensors is shown. The housing 10A includes a top surface 10T, a front surface 10F, a rear surface 10B, a left side surface 10L, a right side surface 10R, etc. As described above, heater 47 and environmental sensor 46 are deployed near the box 7 containing the sheet S. Heater 49 and environmental sensor 48 are deployed in the image reader 20 to reduce condensation on the mirror in the image reader 20.

[0109] In this example, a heater 81 and an ambient sensor 80 are further added. The heater 81 and ambient sensor 80 are deployed near components involved in the image formation process (e.g., photosensitive drum 1, intermediate transfer belt 6, fixing device 13). This is because these components are also susceptible to condensation due to the moisture content in the atmosphere. The heater 81 and ambient sensor 80 are controlled in the same manner as the heater 47 and ambient sensor 46 described above.

[0110] The medium sensor 72 is not a sensor that directly measures ambient temperature and humidity. However, the type or state of the sheet S obtained by the medium sensor 72 is useful for selecting reference values, formulas, or tables for controlling the on / off state of heaters 47 and 49.

[0111] 7. Summary According to the example above, except in situations with high power consumption (such as during operation), the image forming system 100 transitions from operating mode to sleep mode. On the other hand, the normally-on power supply 43 can supply power to the power control unit 44 even in sleep mode. The power control unit 44 can switch heaters 47, 49, and 81 from on to off based on environmental parameters in sleep mode. Therefore, the power consumption of heaters 47, 49, and 81 in sleep mode can be further reduced.

[0112] Heaters 47, 49, and 81 are switched on / off based on a predetermined reference value that ensures image quality is maintained and prevents errors such as paper jams. Accordingly, the power consumption of heaters 47, 49, and 81 can be reduced. Furthermore, the quality of the image formed on the sheet S is maintained immediately after the image forming apparatus 10 returns from sleep mode to operating mode. Immediately after the image forming apparatus 10 returns from sleep mode to operating mode, paper jams on the sheet S are less likely to occur.

[0113] Heaters 47, 49, and 81 are controlled according to the voltage and frequency of the alternating current supplied from external power source 30. Accordingly, the power supplied to heaters 47, 49, and 81 can be controlled more precisely.

[0114] like Figure 1, Figure 15 As shown, heaters 47, 49, and 81 each serve as heating units for heating components inside the housing 10A. Heaters 47, 49, and 81 can each serve as heating units for heating components containing moisture or components whose performance deteriorates due to condensation. The heater control unit 45 and the normally-on power supply 43 each serve as supply units for supplying power to the heating units. Environmental sensors 46, 48, and 80, as well as the media sensor 72, are deployed inside or outside the housing 10A and each serve as a measuring unit for measuring environmental parameters of the installation environment of the housing 10A in a time series. Environmental parameters may be, for example, humidity, atmospheric moisture content, or the amount of moisture contained in the sheet S. The storage device 302 serves as a storage unit for storing a time series reference value REFi used as a reference for the environmental parameters. The power control unit 44 and the CPU 301 each serve as control units for controlling the power supplied from the supply unit to the heating units based on multiple differences Di between the time series environmental parameters measured by the measuring units and the time series reference values ​​stored in the storage unit. Accordingly, the heating units will be accurately controlled, and the power consumption of the heating units will be reduced.

[0115] CPU 301 can control the power supplied from the supply unit to the heating unit based on the number of symbols of multiple differences Di (e.g., the number N of consecutive identical symbols). Accordingly, power consumption will be reduced when heating through the heating unit is unnecessary. When the number of consecutive identical symbols of multiple differences Di is greater than or equal to a threshold, CPU 301 can reduce the power supplied from the supply unit to the heating unit. When the number of consecutive identical symbols of multiple differences Di is greater than or equal to the threshold, CPU 301 can turn off the heating unit, and when the number of consecutive identical symbols of multiple differences Di is less than the threshold, the heating unit remains on. Therefore, both power consumption and condensation can be reduced.

[0116] The detection circuit 77 serves as a measurement unit, measuring the voltage and frequency of the AC power supplied to the heating unit via the supply unit. The CPU 301 can control the power supplied from the supply unit to the heating unit based on multiple differences Di, the voltage value, and the frequency. For example, when the number of consecutive identical symbols of the multiple differences Di is greater than or equal to a threshold Nth, the CPU 301 is configured to reduce the power supplied from the supply unit to the heating unit. In this case, the threshold Nth can be determined based on the voltage value and the frequency.

[0117] like Figure 1As shown, box 7 serves as a receiving unit for accommodating sheet S. Medium detection unit 1111 and medium sensor 72 each serve as detection units for detecting the state or type of sheet S. Conveyor roller 9a, etc., are examples of conveying units for conveying sheet S. Image forming unit 50 is an example of an image forming unit that forms an image on sheet S. CPU 301 can control the power supplied from the supply unit to the heating unit based on multiple differences Di and the detection results of the detection unit. For example, when the number of consecutive positive signs of multiple differences Di is greater than or equal to a threshold Nth, CPU 301 reduces the power supplied from the supply unit to the heating unit. In this case, the threshold Nth can be determined based on the detection results of the detection unit. The detection results include the moisture content contained in sheet S, or characteristic information (e.g., basis weight, thickness, etc.) indicating the characteristics of sheet S that affect the moisture content.

[0118] The supply unit (e.g., heater control unit 45) may include a switch (e.g., switch SW1, transistor Tr1, Tr2) that supplies AC power from an external power source 30 to the heating unit. The CPU 301 controls the switch based on multiple differential Di values.

[0119] The supply unit (e.g., a normally-on power supply 43) may include a conversion unit (e.g., a transformer T1, a diode D1, a capacitor C1, etc.) that converts AC power supplied from an external power source 30 into DC power, and a switch (e.g., a transistor Tr1) that supplies DC power to the heating unit. The CPU 301 may control the switch based on multiple differential Di values.

[0120] The AC control unit 31 and AC / DC conversion circuit 32 are examples of a first power supply (main power supply) that supplies power to the image forming unit. The normally-on power supply 43 is an example of a second power supply (sub-power supply) that supplies power to the control unit. The first power supply has a state where it does not supply power to the image forming unit (sleep mode) and a state where it supplies power to the image forming unit (operation mode). The first power supply has a first state where it supplies power for image formation to the image forming unit. The first power supply has a second state where it supplies power to the image forming unit at a level lower than that supplied in the first state, or does not supply power to the image forming unit. When the first power supply is in the second state, the second power supply supplies power to the first measurement unit and the control unit. Alternatively, the second power supply can be configured to supply power to the control unit regardless of whether the first power supply is in the first or second state. Accordingly, power can be supplied to the heating unit even when the image forming system 100 is in sleep mode. Furthermore, the heating unit can be turned on / off even in sleep mode.

[0121] The heating unit may include a first heating element (e.g., heater 47) and a second heating element (e.g., heater 49). Storage device 302 may store a first time-series reference value associated with the first heating element and a second time-series reference value associated with the second heating element. CPU 301 controls the power supplied from the supply unit to the first heating element based on multiple differences between time-series environmental parameters measured by the measurement unit and the first time-series reference values ​​stored in the storage unit. CPU 301 controls the power supplied from the supply unit to the second heating element based on multiple differences between time-series environmental parameters measured by the measurement unit and the second time-series reference values ​​stored in the storage unit. In this way, multiple heating elements can be controlled independently. Accordingly, the power consumed by the heating elements will be reduced more accurately, and the frequency of problems such as condensation will also be reduced. Storage device 302 stores multiple reference values ​​corresponding to multiple times and each serving as a reference for environmental parameters. CPU 301 obtains multiple measurement values ​​by measuring environmental parameters at each of the multiple times. The CPU 301 controls the power supplied to the heating unit based on multiple differences obtained by calculating the difference between each of the multiple measurements and the reference value at the corresponding time.

[0122] A first heating element is disposed in a receiving unit that holds the sheet S. A second heating element is disposed in a reading unit (e.g., an image reader 20) that reads an image of a document.

[0123] The measurement unit may include a first sensor (e.g., environmental sensor 46) deployed around the first heating element and a second sensor (e.g., environmental sensor 48) deployed around the second heating element. The CPU 301 controls the power supplied from the supply unit to the first heating element based on multiple differences between time-series environmental parameters measured by the first sensor and first time-series reference values ​​stored in the storage unit. The CPU 301 controls the power supplied from the supply unit to the second heating element based on multiple differences between time-series environmental parameters measured by the second sensor and second time-series reference values ​​stored in the storage unit. In this way, multiple heating elements can be controlled independently based on their respective detection results.

[0124] The heating unit can be deployed to heat components of an image forming unit (e.g., photosensitive drum 1, intermediate transfer belt 6, etc.) that form an image on the sheet S.

[0125] Environmental parameters include at least one of temperature and humidity.

[0126] Storage device 302 stores time-series reference values ​​or tables for calculating time-series reference values ​​for each of multiple installation environments that are different from each other. CPU 301 obtains the time-series reference values ​​or tables from storage device 302 according to the installation environment of image forming apparatus 10.

[0127] The time-series reference values ​​or tables stored in storage device 302 can provide each day of the year. The time-series reference values ​​or tables can provide each week of the year. The time-series reference values ​​or tables can provide each month of the year. The time-series reference values ​​or tables can provide each season of the year. The time-series reference values ​​or tables can provide each geographical area (e.g., latitude and longitude, floor level) where the image forming apparatus 10 can be installed. The time-series reference values ​​or tables can provide each of a plurality of daylight amounts (e.g., afternoon sunlight) illuminating the image forming apparatus 10 through a window located in the room where the image forming apparatus 10 is installed. The time-series reference values ​​or tables can provide each of a plurality of distances between the image forming apparatus 10 and air conditioning equipment located in the room where the image forming apparatus 10 is installed. The time-series reference values ​​or tables can provide each of a plurality of room floors (e.g., first floor, second floor) where the image forming apparatus 10 can be installed. The time-series reference values ​​or tables can provide each of a plurality of distances from a window located in the room where the image forming apparatus 10 is installed to the image forming apparatus 10.

[0128] 8. Other remarks Because the main controller 40 is stopped in sleep mode, the power control unit 44 is responsible for controlling heaters 47, 49, etc. However, this is just an example. In operating mode, instead of the power control unit 44, the main controller 40 can be responsible for controlling heaters 47, 49, etc. In this case, the power control unit 44 will transmit the measurement results obtained by the environmental sensors 46 and 48 in operating mode to the main controller 40.

[0129] Time-series reference values, formulas, tables, or summary data can be stored in a large-capacity storage device (e.g., hard disk drive (HDD), solid-state drive (SSD), etc.) provided in the main controller 40. In this case, when the image forming system 100 transitions from operating mode to sleep mode, the CPU 301 can obtain a portion of the data required in sleep mode from the main controller 40 and store this data in the RAM area of ​​the storage device 302. For example, in a year's reference values, a day's reference values ​​can be stored in the RAM area of ​​the storage device 302. Thus, the storage area of ​​the storage device 302 is effectively utilized. Time-series environmental parameters measured in sleep mode are useful for generating reference values ​​during sleep mode. When the image forming apparatus 10 has transitioned from operating mode to sleep mode, the power control unit 44 can summarize the time-series environmental parameters collected during sleep mode and transmit them to the main controller 40. Since the main controller 40 includes a large-capacity storage device, environmental data can be stored in the large-capacity storage device for a long period (e.g., one month, six months, one year) and used to generate reference values. The main controller 40 can display log data on the operation unit 41 regarding the on / off status of heaters 47 and 49 during a predetermined period, including the time when the image forming apparatus 10 is in sleep mode. This will allow the user to know that heaters 47 and 49 are intermittently turned off during sleep mode. That is, the user will be able to intuitively know that power consumption has been reduced.

[0130] Regarding the on / off control of heaters 47 and 49, several cases considering the frequency of the AC power supplied from external power source 30 have been described. Generally, the frequency of the AC power does not affect the power of heaters 47 and 49. However, since the circuit impedance and power transmission efficiency associated with heaters 47 and 49 change according to frequency, the effective value of the current is affected by the frequency. For example, assuming heater 47 has a resistance of 100Ω and the AC power has a voltage of 100V and a frequency of 50Hz, the effective value of the current is 1A. Furthermore, the power consumption of heater 47 is 100W. On the other hand, assuming the AC power has a frequency of 60Hz and an effective value of 1.02A, the power consumption in this case is 102W. Therefore, taking the power consumption at 50Hz as a reference, the frequency correlation factor for the power consumption at 60Hz is 1.02 (=102 / 100). Assuming the AC voltage is 110V and its frequency is 50Hz, the effective value of the AC power is 1.09A. In this case, the frequency correlation factor is 0.99. This is the frequency correlation factor in the formula shown below.

[0131] Here, when the temperature of the atmosphere inside box 7 increases by ΔT, ΔT can be calculated using the following formula: ΔT = ((Power consumption of heater 47 × Heating time) / (Specific heat capacity of atmosphere × Volume of atmosphere)) × Coefficient × Frequency correlation factor ... Formula 1 Here, the coefficient is determined based on the difference between the estimated ΔT and the temperature measured by the environmental sensor 46. The volume of the atmosphere inside box 7 varies depending on the type and quantity of sheets S contained in box 7. This coefficient is determined by performing tests on various volumes. Note that a reference value can be set based on ΔT, or a threshold Nth for the number of symbols can be set.

[0132] Meanwhile, the measurement results of environmental sensors 46 and 48 are affected by the external air temperature. For example, suppose that when the external air temperature changes by ΔT1, the measurement result of environmental sensor 46 changes by ΔT2. In this case, the following formula holds true.

[0133] ΔT1 - ΔTx = ΔT2···Formula 2 Here, ΔTx is determined according to Formula 1. That is, ΔT1, which indicates the influence of the external air temperature, is obtained based on ΔT2 and ΔTx. As the CPU 301 displays the result of ΔT1 on the operation unit 41, the user can know the influence of the external air temperature.

[0134] Other embodiments One or more embodiments of the present invention can also be implemented by a computer of a system or apparatus that reads and executes computer-executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more fully referred to as a "non-transitory computer-readable storage medium") to perform the functions of one or more embodiments described above and / or includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing the functions of one or more embodiments described above, and by a method executed by a computer of a system or apparatus, for example by reading and executing computer-executable instructions from a storage medium to perform the functions of one or more embodiments described above and / or controlling one or more circuits to perform the functions of one or more embodiments described above. The computer may include one or more processors (e.g., a central processing unit (CPU), a microprocessor unit (MPU)) and may include a network of individual computers or individual processors to read and execute computer-executable instructions. The computer-executable instructions may, for example, be provided to the computer from a network or storage medium. The storage medium may, for example, include a hard disk, random access memory (RAM), read-only memory (ROM), storage devices for distributed computing systems, optical discs (such as CDs, DVDs, or Blu-ray discs). TM One or more of the following: flash memory devices, memory cards, etc.

[0135] Other embodiments The embodiments of the present invention can also be implemented by the following method: providing software (including computer program products of computer programs) that performs the functions of the above embodiments to a system or device via a network or various storage media, and the computer (central processing unit (CPU) or microprocessor unit (MPU) of the system or device) reads and executes the computer program.

[0136] While this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the following claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An image forming apparatus, comprising: case; An image forming unit is configured to form an image on a sheet; The heating unit is deployed inside the housing and configured to heat the components inside the housing; The first measuring unit is deployed inside or outside the housing and is configured to measure environmental parameters of the housing's installation environment; The control unit is configured to control the power supplied to the heating unit based on environmental parameters measured by the first measuring unit; The first power source is configured to supply power to the image forming unit; as well as The second power source is configured to supply power to the first measurement unit and the control unit. The first power supply has a first state and a second state. In the first state, power for forming an image is supplied to the image forming unit. In the second state, power less than the power supplied in the first state is supplied to the image forming unit, or no power is supplied to the image forming unit. When the first power supply is in the second state, the second power supply supplies power to the first measurement unit and the control unit.

2. The image forming apparatus according to claim 1, wherein, The second power supply is configured to supply power to the first measurement unit and the control unit regardless of whether the first power supply is in the first state or the first power supply is in the second state.

3. The image forming apparatus according to claim 1, further comprising: The storage unit is configured to store multiple reference values, each corresponding to a different time period and used as a reference for environmental parameters. The first measurement unit obtains multiple measurement values ​​by measuring environmental parameters at each of the multiple times, and The control unit controls the power supplied to the heating unit based on multiple differences, which are obtained by calculating the difference between each of the multiple measurements and a reference value at the corresponding time.

4. The image forming apparatus according to claim 3, wherein, The control unit controls the power supplied to the heating unit based on the number of identical symbols among the plurality of different symbols.

5. The image forming apparatus according to claim 3, wherein, When the number of consecutive identical symbols of the plurality of differences is greater than or equal to a threshold, the control unit reduces the power supplied to the heating unit.

6. The image forming apparatus according to claim 3, wherein, When the number of consecutive identical symbols of the plurality of differences is greater than or equal to a threshold, the control unit controls the heating unit to be turned off, and when the number of consecutive identical symbols of the plurality of differences is less than the threshold, the control unit controls the heating unit to be turned on.

7. The image forming apparatus according to claim 3, further comprising: The second measuring unit is configured to measure the voltage and frequency of the alternating current supplied to the heating unit. The control unit controls the power supplied to the heating unit based on the multiple differences, voltage values, and frequencies.

8. The image forming apparatus according to claim 7, in, The control unit is configured to reduce the power supplied to the heating unit when the number of consecutive identical symbols of the plurality of differences is greater than or equal to a threshold, and The threshold is determined based on the voltage value and frequency.

9. The image forming apparatus according to claim 3, further comprising: The receiving unit is configured to receive the sheet; The detection unit is configured to detect the state or type of the sheet; as well as The conveying unit is configured to convey the sheet material. The control unit controls the power supplied to the heating unit based on the detection results of the plurality of difference and detection units.

10. The image forming apparatus according to claim 9, wherein, The control unit is configured to reduce the power supplied to the heating unit when the number of consecutive identical symbols of the plurality of differences is greater than or equal to a threshold, and The threshold is determined based on the detection results of the detection unit.

11. The image forming apparatus according to claim 9, wherein, The test results include the moisture content of the sheet, or characteristic information indicating sheet properties that affect the moisture content.

12. The image forming apparatus according to any one of claims 1 to 11, further comprising: The switch is configured to supply AC power received from an external power source to the heating unit. The control unit controls the switch based on environmental parameters.

13. The image forming apparatus according to any one of claims 1 to 11, further comprising: The conversion unit is configured to convert AC power supplied from an external power source into DC power. as well as The switch is configured to supply direct current to the heating unit. The control unit controls the switch based on environmental parameters.

14. The image forming apparatus according to claim 3, in, The heating unit includes a first heating element and a second heating element. The storage unit stores a first time-series reference value associated with the first heating element and a second time-series reference value associated with the second heating element, and The control unit is configured to: The power supplied to the first heating element is controlled based on multiple differences between the time-series environmental parameters measured by the first measurement unit and the first time-series reference values ​​stored in the storage unit. as well as The power supplied to the second heating element is controlled based on multiple differences between the time-series environmental parameters measured by the first measurement unit and the second time-series reference values ​​stored in the storage unit.

15. The image forming apparatus according to claim 14, in, The first heating element is disposed in the receiving unit configured to receive the sheet, and The second heating element is disposed in the image reading unit configured to read the document.

16. The image forming apparatus according to claim 14, in, The first measurement unit includes: The first sensor is deployed around the first heating element; and The second sensor is deployed around the second heating element, and The control unit is configured to: The power supplied to the first heating element is controlled based on multiple differences between time-series environmental parameters measured by the first sensor and first time-series reference values ​​stored in the storage unit; and The power supplied to the second heating element is controlled based on multiple differences between time-series environmental parameters measured by the second sensor and second time-series reference values ​​stored in the storage unit.

17. The image forming apparatus according to any one of claims 1 to 11, wherein, The heating unit is deployed to heat the components of the image forming unit configured to form an image on the sheet.

18. The image forming apparatus according to any one of claims 1 to 11, wherein, The heating unit is deployed to heat components containing moisture or components whose performance deteriorates due to condensation.

19. The image forming apparatus according to any one of claims 1 to 11, wherein, Environmental parameters include at least one of temperature and humidity.

20. The image forming apparatus according to any one of claims 1 to 11, wherein, The first measurement unit measures environmental parameters when the first power supply is in the second state.

21. The image forming apparatus according to any one of claims 1 to 11, wherein, The second state is the state where no power is supplied to the image forming unit.

22. The image forming apparatus according to claim 3, in, The storage unit stores time-series reference values, or tables for calculating the time-series reference values, for each of multiple installation environments that are different from each other. The control unit obtains time-series reference values ​​or tables from the storage unit based on the installation environment of the image forming apparatus.

23. The image forming apparatus according to claim 22, in, The time series reference values ​​or tables are set for the following: Every day of the year; Every week of the year; Every month of the year; Every season of the year; Each geographic region in multiple geographic areas can be equipped with an image forming device; Each of the multiple amounts of daylight is shone through a window located in the room where the image forming apparatus is installed; Each of a plurality of distances between the image forming apparatus and an air conditioning unit installed in the room where the image forming apparatus is installed; Each of multiple room floors capable of housing an image forming apparatus; as well as Each of the multiple distances from the window in the room where the image forming apparatus is installed to the image forming apparatus.

24. An image forming apparatus, comprising: case; An image forming unit is configured to form an image on a sheet; The heating unit is deployed inside the housing and configured to heat the components inside the housing; The first measuring unit is deployed inside or outside the housing and is configured to measure environmental parameters of the housing's installation environment; The control unit is configured to control the power supplied to the heating unit based on environmental parameters measured by the first measuring unit; as well as The first power source is configured to supply power to the image forming unit. The first power supply has a first state and a second state. In the first state, power for forming an image is supplied to the image forming unit. In the second state, power less than the power supplied in the first state is supplied to the image forming unit, or no power is supplied to the image forming unit. The first measurement unit measures environmental parameters when the first power supply is in the second state.

25. The image forming apparatus according to claim 24, further comprising: The storage unit is configured to store multiple reference values, each corresponding to a different time period and used as a reference for environmental parameters. The first measurement unit obtains multiple measurement values ​​by measuring environmental parameters at each of the multiple times. The control unit controls the power supplied to the heating unit based on multiple differences, which are obtained by calculating the difference between each of the multiple measured values ​​and a reference value at the corresponding time. The first power source is in the second state for at least a portion of the multiple times.

26. The image forming apparatus according to claim 25, further comprising: The receiving unit is configured to receive the sheet; The detection unit is configured to detect the state or type of the sheet; as well as The conveying unit is configured to convey the sheet material. The control unit controls the power supplied to the heating unit based on the detection results of the plurality of difference and detection units.

27. The image forming apparatus according to any one of claims 24 to 26, wherein, Environmental parameters include at least one of temperature and humidity.

28. The image forming apparatus according to any one of claims 24 to 26, further comprising: The switch is configured to supply AC power received from an external power source to the heating unit. The control unit controls the switch based on environmental parameters.

29. The image forming apparatus according to any one of claims 24 to 26, further comprising: The conversion unit is configured to convert AC power supplied from an external power source into DC power. as well as The switch is configured to supply direct current to the heating unit. The control unit controls the switch based on environmental parameters.

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