Power supply device and image forming apparatus

Abstract

To solve the problem in which: when a CPU on the secondary side detects a voltage and a current via a transformer, the size of an image forming apparatus increases.SOLUTION: A detection unit 164 transmits, via an antenna ANT, a detection result to a control unit 165 electromagnetically coupled to the antenna ANT. As a result of this, a transformer does not need to be provided between a first circuit 160a and a second circuit 160b, and thus an increase in size of the apparatus can be prevented while an insulating state between the first circuit 160a and second circuit 160b is maintained.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a power supply device and an image forming apparatus that control power supplied to a load. [Background technology]

[0002] Conventionally, in a device that operates using power supplied from a commercial power source, a configuration is known in which the voltage of the commercial power source input to the primary side and the current flowing to the primary side are detected on a secondary side that is insulated from the primary side.

[0003] In the image forming apparatus described in Patent Document 1, a voltage applied to a fixing heater provided on the primary side is detected on the secondary side via a transformer. A CPU controls the temperature of the fixing heater based on the detection result. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-074766 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned Patent Document 1, the transformer has a function of insulating the primary side from the secondary side and a function of transforming the voltage on the primary side and outputting it to the secondary side. The smaller the frequency of the voltage to be transformed, the more the number of turns of the transformer must be increased, and a larger transformer is required.

[0006] The frequency of the voltage transformed in Patent Document 1 is 50 Hz or 60 Hz, which is a relatively low frequency. That is, if a transformer is used in Patent Document 1, the image forming apparatus will become larger and the costs will increase.

[0007] In view of the above problems, the present invention provides a first Loop Antenna and the second Loop AntennaMaintains insulation from Communication unit Suppresses the increase in size While performing the above, communication is performed between the first loop antenna and the second loop antenna. The purpose of this document is to: [Means for solving the problem]

[0008] In order to solve the above problems, the communication unit according to the present invention comprises: A substrate; A first loop antenna provided on the substrate; a second loop antenna provided on the substrate, the second loop antenna being insulated from the first loop antenna and performing wireless communication with the first loop antenna; a transmitter provided on the substrate, connected to the first loop antenna, and configured to transmit data; a receiving unit that is provided on the substrate and insulated from the transmitting unit, the receiving unit being connected to the second loop antenna and receiving the data from the transmitting unit through the wireless communication; having When the first loop antenna and the second loop antenna are viewed along a direction perpendicular to a surface of the substrate on which the first loop antenna is provided, at least a part of the loop region of the first loop antenna and the loop region of the second loop antenna overlap each other. And, the transmission unit is operated by power generated by a voltage generated in the first loop antenna due to a voltage output from the reception unit to the second loop antenna, The receiving unit operates using power from a predetermined power source. It is characterized by: Effect of the Invention

[0009] According to the present invention, the first Loop Antenna and the second Loop Antenna Maintains insulation from Communication unit Suppresses the increase in size While performing the above, communication is performed between the first loop antenna and the second loop antenna. It is possible. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view illustrating an image forming apparatus according to a first embodiment. [Diagram 2] 2 is a block diagram showing a control configuration of the image forming apparatus according to the first embodiment. FIG. [Diagram 3] FIG. 2 is a control block diagram showing a configuration of an AC driver according to the first embodiment. [Figure 4]FIG. 2 is a block diagram showing a configuration of a triac drive circuit. [Diagram 5] 4 is a time chart showing the voltage V of an AC power supply, the current I flowing through a heating element, the H-ON signal output from a control unit, and zero cross timing. [Figure 6] 5 is a flowchart showing a method for controlling the temperature of the fixing heater according to the first embodiment. [Figure 7] FIG. 1 is a diagram showing an amplitude-modulated modulated wave. [Figure 8] FIG. 2 is a diagram showing a configuration of an antenna ANT in the first embodiment. [Figure 9] 4 is a diagram showing another configuration of the antenna ANT in the first embodiment. FIG. [Figure 10] FIG. 11 is a diagram showing a configuration of an antenna ANT in a second embodiment. [Figure 11] 13 is a diagram showing another configuration of the antenna ANT in the second embodiment. FIG. [Figure 12] 13 is a diagram showing another configuration of the antenna ANT in the second embodiment. FIG. [Figure 13] FIG. 13 is a diagram showing the configuration of an antenna ANT in a third embodiment. [Figure 14] FIG. 13 is a diagram showing the configuration of an antenna ANT in a fourth embodiment. [Figure 15] FIG. 13 is a diagram showing the configuration of an antenna ANT in a fifth embodiment. [Figure 16] FIG. 13 is a diagram showing the configuration of an antenna ANT in a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Preferred embodiments of the present invention will be described below with reference to the drawings. However, the shapes of the components and their relative positions described in the embodiments may be changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions, and the scope of the present invention is not intended to be limited to the following embodiments.

[0012] [First embodiment] [Image forming equipment] 1 is a cross-sectional view showing the configuration of a monochrome electrophotographic copying machine (hereinafter referred to as an image forming apparatus) 100 having a sheet conveying device used in this embodiment. Note that the image forming apparatus is not limited to a copying machine, and may be, for example, a facsimile machine, a printing machine, a printer, etc. Furthermore, the recording method is not limited to an electrophotographic method, and may be, for example, an inkjet method, etc. Furthermore, the type of the image forming apparatus may be either a monochrome type or a color type.

[0013] The configuration and functions of the image forming apparatus 100 will be described below with reference to Fig. 1. As shown in Fig. 1, the image forming apparatus 100 includes a document feeder 201, a reader 202, and an image printer 301.

[0014] The originals loaded on the original loading section 203 of the original feeder 201 are fed one by one by a feed roller 204 and transported along a transport guide 206 onto an original glass table 214 of the reader 202. The originals are then transported at a constant speed by a transport belt 208 and discharged to a discharge tray (not shown) by a discharge roller 205. Reflected light from an original image illuminated by an illumination 209 at the reading position of the reader 202 is guided to an image reader 111 by an optical system consisting of reflecting mirrors 210, 211, and 212, and converted into an image signal by the image reader 111. The image reader 111 is composed of a lens, a CCD which is a photoelectric conversion element, a drive circuit for the CCD, and the like. The image signal output from the image reader 111 is subjected to various correction processes by an image processor 112 which is composed of a hardware device such as an ASIC, and then output to an image printer 301. The originals are read as described above. That is, the document feeder 201 and the reader 202 function as a document reader.

[0015] Also, there are a first reading mode and a second reading mode as reading modes for an original. The first reading mode is a mode in which an image of an original conveyed at a constant speed is read by the illumination system 209 and the optical system fixed at a predetermined position. The second reading mode is a mode in which an image of an original placed on the original glass 214 of the reading device 202 is read by the illumination system 209 and the optical system moving at a constant speed. Usually, an image of a sheet-like original is read in the first reading mode, and an image of a bound original such as a book or a pamphlet is read in the second reading mode.

[0016] Inside the image printing device 301, sheet storage trays 302 and 304 are provided. Different types of recording media can be stored in the sheet storage trays 302 and 304. For example, A4 size plain paper is stored in the sheet storage tray 302, and A4 size thick paper is stored in the sheet storage tray 304. Note that the recording media refers to media on which an image is formed by the image forming device, and examples of the recording media include paper, resin sheets, cloth, overhead projector sheets, labels, etc.

[0017] The recording medium stored in the sheet storage tray 302 is fed by a paper feed roller 303, and is sent to the registration roller 308 by a transport roller 306. The recording medium stored in the sheet storage tray 304 is fed by a paper feed roller 305, and is sent to the registration roller 308 by transport rollers 307 and 306.

[0018] The image signal output from the reading device 202 is input to an optical scanning device 311 including a semiconductor laser and a polygon mirror.

[0019] The outer peripheral surface of the photosensitive drum 309 is charged by a charger 310. After the outer peripheral surface of the photosensitive drum 309 is charged, a laser beam corresponding to an image signal input from the reading device 202 to an optical scanning device 311 is irradiated onto the outer peripheral surface of the photosensitive drum 309 from the optical scanning device 311 via a polygon mirror and mirrors 312 and 313. As a result, an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 309. Note that the photosensitive drum is charged by a charging method using, for example, a corona charger or a charging roller.

[0020] The electrostatic latent image is then developed by toner in a developer 314, and a toner image is formed on the outer peripheral surface of the photosensitive drum 309. The toner image formed on the photosensitive drum 309 is transferred onto a recording medium by a transfer charger 315 provided at a position (transfer position) facing the photosensitive drum 309. In synchronization with this transfer timing, the registration rollers 308 feed the recording medium to the transfer position.

[0021] As described above, the recording medium onto which the toner image has been transferred is sent to the fixing device 318 by the conveyor belt 317, and is heated and pressurized by the fixing device 318, so that the toner image is fixed onto the recording medium. In this manner, an image is formed on the recording medium by the image forming apparatus 100.

[0022] When an image is formed in a single-sided printing mode, the recording medium that has passed through the fixing device 318 is discharged to a discharge tray (not shown) by discharge rollers 319 and 324. When an image is formed in a double-sided printing mode, the recording medium is conveyed to a reversing path 325 by discharge rollers 319, conveying rollers 320, and reversing rollers 321 after a fixing process is performed on the first side of the recording medium by the fixing device 318. The recording medium is then conveyed again to the registration rollers 308 by conveying rollers 322 and 323, and an image is formed on the second side of the recording medium by the method described above. The recording medium is then discharged to a discharge tray (not shown) by discharge rollers 319 and 324.

[0023] Furthermore, when the recording medium with an image formed on its first side is discharged face-down to the outside of image forming apparatus 100, the recording medium that has passed through fixing device 318 is conveyed through discharge rollers 319 toward conveying rollers 320. Thereafter, just before the rear end of the recording medium passes through the nip portion of conveying rollers 320, the rotation of conveying rollers 320 is reversed, and the recording medium is discharged to the outside of image forming apparatus 100 via discharge rollers 324 with the first side of the recording medium facing downward.

[0024] The configuration and functions of image forming apparatus 100 have been described above.

[0025] 2 is a block diagram showing an example of a control configuration of the image forming apparatus 100. As shown in FIG. 2, the image forming apparatus 100 is connected to an alternating current power source 1 (AC) as a commercial power source, and various devices inside the image forming apparatus 100 are operated by power supplied from the AC power source 1. As shown in FIG. 2, the system controller 151 includes a CPU 151a, a ROM 151b, and a RAM 151c. The system controller 151 is also connected to the image processing unit 112, an operation unit 152, an analog-digital (A / D) converter 153, a high voltage control unit 155, a motor control device 157, sensors 159, and an AC driver 160. The system controller 151 can transmit and receive data and commands to and from each unit connected thereto.

[0026] The CPU 151a reads out and executes various programs stored in the ROM 151b to execute various sequences related to a predetermined image formation sequence.

[0027] RAM 151c is a storage device that stores various data such as set values ​​for high voltage control unit 155, command values ​​for motor control device 157, and information received from operation unit 152.

[0028] System controller 151 transmits setting value data of various devices provided inside image forming apparatus 100, which are necessary for image processing in image processing unit 112, to image processing unit 112. Furthermore, system controller 151 receives signals from sensors 159, and sets setting values ​​of high voltage control unit 155 based on the received signals.

[0029] A high voltage control unit 155 supplies a necessary voltage to a high voltage unit 156 (charger 310, developer 314, transfer charger 315, etc.) in accordance with a set value set by the system controller 151.

[0030] Motor control device 157 controls a motor that drives a load provided inside image forming apparatus 100 in response to a command output from CPU 151a. Although only motor 509 is shown as the motor of the image forming apparatus in FIG. 2, a plurality of motors are actually provided in the image forming apparatus. Also, a configuration in which one motor control device controls a plurality of motors may be used. Furthermore, although only one motor control device is provided in FIG. 2, two or more motor control devices may be provided in the image forming apparatus.

[0031] The A / D converter 153 receives a detection signal detected by a thermistor 154 for detecting the temperature of the fixing heater 161, converts the detection signal from an analog signal to a digital signal, and transmits the digital signal to the system controller 151. The system controller 151 controls the AC driver 160 based on the digital signal received from the A / D converter 153. The AC driver 160 controls the fixing heater 161 so that the temperature of the fixing heater 161 becomes a temperature required for performing the fixing process. The fixing heater 161 is a heater used in the fixing process, and is included in the fixing unit 318.

[0032] The system controller 151 controls the operation unit 152 so that an operation screen for the user to set the type of recording medium to be used (hereinafter referred to as paper type) and the like is displayed on a display unit provided on the operation unit 152. The system controller 151 receives information set by the user from the operation unit 152, and controls the operation sequence of the image forming apparatus 100 based on the information set by the user. The system controller 151 also transmits information indicating the status of the image forming apparatus to the operation unit 152. Note that the information indicating the status of the image forming apparatus is, for example, information regarding the number of images formed, the progress of the image forming operation, and sheet jams and multiple feeds in the document reading device 201 and the image printing device 301. The operation unit 152 displays the information received from the system controller 151 on the display unit.

[0033] As described above, the system controller 151 controls the operation sequence of the image forming apparatus 100 .

[0034] [AC driver] Fig. 3 is a control block diagram showing the configuration of the AC driver. The AC driver 160 is composed of a first circuit 160a connected to the AC power supply 1 and a second circuit 160b insulated from the first circuit 160a. As shown in Fig. 3, the first circuit 160a is included in the primary side of the AC driver 160, and the second circuit 160b is included in the secondary side of the AC driver 160.

[0035] The AC driver 160 includes a detection unit 164 that detects the voltage V supplied from the AC power source 1 and the current I flowing through the fixing heater 161, a relay circuit 166 that controls the power supply from the AC power source 1 to the fixing device 318, a triac 167, and a control unit 165 that controls the relay circuit 166 and the triac 167.

[0036] 3, the detection unit 164 is insulated from the control unit 165, the detection unit 164 is provided in the first circuit 160a, and the control unit 165 is provided in the second circuit 160b. The detection unit 164 is electromagnetically coupled to the control unit 165 by an antenna ANT. The control unit 165 is connected to the CPU 151a and controlled by the CPU 151a. The antenna ANT will be described later.

[0037] As shown in FIG. 3, the voltage output from the AC power supply 1 is also input to the AC / DC power supply 163. The AC / DC power supply 163 converts the AC voltage output from the AC power supply 1 into, for example, a DC voltage of 5V and 24V and outputs it. The DC voltage of 5V is supplied to the CPU 151a and the control unit 165. The DC voltage of 24V is also supplied to a relay circuit 166 and a triac driving circuit 167a. The DC voltages of 5V and 24V are also supplied to various devices inside the image forming apparatus 100. The voltage output from the AC / DC power supply 163 is not supplied to the detection unit 164. The detection unit 164 is supplied with power from the control unit 165 via an antenna ANT while remaining in an insulated state. A specific configuration will be described later.

[0038] The relay circuit 166 is controlled by a signal A output from the control unit 165. For example, when the control unit 165 outputs signal A='H', the relay circuit 166 enters a state in which power is supplied from the AC power source 1 to the fixing unit 318. When the control unit 165 outputs signal A='L', the relay circuit 166 enters a state in which the power supply from the AC power source 1 to the fixing unit 318 is cut off. For example, when the current flowing through the fixing heater 161 becomes higher than a predetermined value (i.e., when an abnormality occurs), the signal A='L' is output to the relay circuit 166. The control unit 165 outputs the signal A in response to a command from the CPU 151a.

[0039] The triac driving circuit 167a is a circuit that controls the triac 167. Fig. 4 is a block diagram illustrating the configuration of the triac driving circuit 167a. As shown in Fig. 7, the triac driving circuit 167a has a photocoupler 168 that is configured by a light-emitting element 168a provided in the second circuit 160b and a light-receiving element 168b provided in the first circuit 160a, and a driving circuit 169 that drives the triac 167 in response to the light-receiving result of the light-receiving element 168b.

[0040] When the control unit 165 outputs an H-ON signal = 'H', the light-emitting element 168a provided in the triac driving circuit 167a lights up. Then, in response to the light-receiving element 168b provided in the triac driving circuit 167a receiving the light output from the light-emitting element 168a, the driving circuit 169 drives the triac 167 so that the triac 167 is in the ON state. In this way, the triac 167 of the first circuit 160a can be controlled from the second circuit 160b side while insulation between the first circuit 160a and the second circuit 160b is maintained.

[0041] By controlling the triac 167 as described above, power is supplied to the fixing heater 161. The amount of power supplied to the fixing heater 161 is adjusted by controlling the timing at which the triac 167 is turned on.

[0042] <Temperature control of fixing heater> The following describes a method for controlling the temperature of the fixing heater 161. Power output from the AC power source 1 is supplied via an AC driver 160 to a heat generating element 161a in the fixing heater 161 provided in the fixing device 318.

[0043] The detection unit 164 detects the voltage V (the voltage V across the resistor R2) supplied from the AC power supply 1. The detection unit 164 also detects the current I flowing through the heating element 161a based on the voltage across the resistor R2.

[0044] The detection unit 164 has an A / D converter 164a that converts the input voltage V and current I from analog values ​​to digital values. The detection unit 164 samples the voltage V and current I converted by the A / D converter 164a at a predetermined period T (e.g., 50 μs). Every time the detection unit 164 samples the voltage V and current I, it accumulates V^2, I^2, and V*I as shown in the following equations (1) to (3).

[0045]

number

[0046] The detection unit 164 stores the integrated value in the memory 164b.

[0047] Furthermore, the detection unit 164 detects the timing at which the voltage V changes from a negative value to a positive value (hereinafter, referred to as the zero-cross timing).

[0048] At the zero-cross timing, the detection unit 164 calculates the effective value Vrms of the voltage V, the effective value Irms of I, and the effective value Prms of V*I (=P) using the following equations (4) to (6).

[0049]

number

[0050] The detection unit 164 stores the calculated effective values ​​Vrms, Irms, and Prms in the memory 164b. Note that the detection unit 164 resets the integrated values ​​of V^2, I^2, and V*I stored in the memory 164b every time the detection unit 164 calculates the effective values ​​Vrms, Irms, and Prms.

[0051] Furthermore, when the zero crossing timing occurs, the detection unit 164 notifies the control unit 165 via the antenna ANT in a manner to be described later, the effective values ​​Vrms, Irms, and Prms stored in the memory 164b, and the fact that the zero crossing timing has occurred.

[0052] The control unit 165 stores in the memory 165a the effective values ​​Vrms, Irms, and Prms acquired from the detection unit 164. Furthermore, the control unit 165 notifies the CPU 151a that it is zero cross timing (signal ZX).

[0053] When the CPU 151a is notified by the control unit 165 that it is a zero-cross timing, it acquires the effective values ​​Vrms, Irms, and Prms stored in the memory 165a of the control unit 165. In this manner, the CPU 151a acquires the effective values ​​Vrms, Irms, and Prms at each zero-cross timing. That is, in this embodiment, the signal ZX is a signal that serves as a trigger for the CPU 151a to acquire the effective values ​​Vrms, Irms, and Prms.

[0054] The fixing unit 318 includes a thermostat 162. The thermostat 162 has a function of preventing power from being supplied to the heating element 161a when the thermostat 162 reaches a predetermined temperature.

[0055] A thermistor 154 for detecting the temperature of the fixing heater 161 is provided near the fixing heater 161. As shown in Fig. 3, the thermistor 154 is connected to the ground (GND). The thermistor 154 has a characteristic that, for example, the resistance value decreases as the temperature increases. When the temperature of the thermistor 154 changes, the voltage Vt across both ends of the thermistor 154 also changes. The temperature of the fixing heater 161 is detected by detecting this voltage Vt.

[0056] The voltage Vt output as an analog signal from the thermistor 154 is input to the A / D converter 153. The A / D converter 153 converts the voltage Vt from an analog signal to a digital signal and outputs the digital signal to the CPU 151a.

[0057] The CPU 151a controls the triac via the control unit 165 based on the effective values ​​Vrms, Irms, and Prms acquired from the control unit 165 and the voltage Vt output from the A / D converter 153, thereby controlling the temperature of the fixing heater 161. A specific method for controlling the temperature of the fixing heater 161 will be described below.

[0058] 5 is a time chart showing the voltage V of the AC power supply 1, the current I flowing through the heating element 161a, the H-ON signal output from the control unit 165, and the zero-cross timing. As shown in FIG. 5, the period Tzx of the zero-cross timing corresponds to the period of the voltage of the AC power supply 1.

[0059] 5, the amount of current (amount of power supplied) flowing through the heating element 161a is controlled by controlling the time Th from the zero crossing timing to the timing t_on1 at which the H-ON signal = 'H' is output. Specifically, for example, the shorter the time Th, the greater the amount of current flowing through the heating element 161a. That is, when the time Th is controlled to be shorter, the temperature of the fixing heater 161 increases.

[0060] In this embodiment, the CPU 151a controls the amount of current flowing through the heating element 161a by controlling the time from the zero crossing timing to timing t_on1 via the control unit 165. As a result, the CPU 151a can control the temperature of the fixing heater 161. Note that in this embodiment, the triac 167 is controlled so that a current of the same amount and opposite polarity as the current flowing due to the output of the H-ON signal = 'H' at timing t_on1 flows through the heating element 161a. Specifically, as shown in FIG. 5, the H-ON signal = 'H' is also output at timing t_on2 when the time Tzx / 2 has elapsed from timing t_on1 (i.e., the timing after a half cycle of the voltage of the AC power source 1).

[0061] Fig. 6 is a flowchart showing a method for controlling the temperature of the fixing heater 161. Hereinafter, the temperature control of the fixing heater 161 in this embodiment will be described with reference to Fig. 6. The process of this flowchart is executed by the CPU 151a. Note that the process of this flowchart is executed, for example, when the image forming apparatus 100 is started up.

[0062] In S101, the CPU 151a sets the time Th based on, for example, a difference between the voltage Vt acquired from the A / D converter 153 and the voltage V0 corresponding to the target temperature of the fixing heater 161, and notifies the control unit 165 of the time Th. As a result, the control unit 165 outputs an H-ON signal to the triac driving circuit 167a based on the set time Th.

[0063] Thereafter, when a signal ZX is input from the control unit 165 to the CPU 151a in S102, the CPU 151a acquires the voltage Vt output from the A / D converter 153 and the effective values ​​Vrms, Irms, and Prms stored in the memory 165a of the control unit 165 in S103.

[0064] Thereafter, in S104, when the effective power value Prms is equal to or greater than the threshold value Pth (Prms≧Pth), in S109, the CPU 151a outputs an instruction to increase the currently set time Th to the control unit 165. Note that the amount by which the time Th is increased may be a predetermined amount, or may be determined based on the difference between the effective power value Prms and the threshold value Pth.

[0065] In this way, when the effective power value Prms is equal to or greater than the threshold value Pth, the time Th is set so that the effective power value Prms becomes smaller than the threshold value Pth, thereby preventing excessive power from being supplied to the fixing heater 161. As a result, an increase in power consumption can be prevented. The threshold value Pth is set to a value greater than the power that can raise the temperature of the fixing heater 161 to the target temperature.

[0066] The process then proceeds to S110.

[0067] Also, in S104, when the effective value Prms of the power is less than the threshold value Pth (Prms < Pth), the process proceeds to S105.

[0068] In S105, when the effective value Irms of the current is greater than or equal to the threshold value Ith (Irms ≥ Ith), in S109, the CPU 151a outputs an instruction to increase the currently set time Th to the control unit 165. Note that the amount by which the time Th is increased may be a predetermined amount or may be determined based on the difference value between the effective value Irms and the threshold value Ith.

[0069] In this way, when the effective value Irms is greater than or equal to the threshold value Ith, by controlling the time Th so that the effective value Irms becomes less than the threshold value Ith, it is possible to suppress the supply of excessive current to the heating element 161a. As a result, it is possible to suppress the temperature of the fixing heater 161 from rising excessively. Note that the threshold value Ith is set to a value greater than the current that can raise the temperature of the fixing heater 161 to the target temperature.

[0070] Thereafter, the process proceeds to S110.

[0071] Also, in S105, when the effective value Irms is less than the threshold value Ith (Irms < Ith), the process proceeds to S106.

[0072] In S106, when the voltage Vt acquired from the A / D converter 153 is the voltage V0 corresponding to the target temperature of the fixing heater 161, the process proceeds to S110.

[0073] Also, in S106, when the voltage Vt acquired from the A / D converter 153 is not the voltage V0 corresponding to the target temperature of the fixing heater 161, the process proceeds to S107.

[0074] If the voltage Vt is greater than the voltage V0 in S107, the CPU 151a outputs an instruction to the control unit 165 in S109 to increase the currently set time Th so that the deviation between the voltage Vt and the voltage V0 becomes smaller. Note that the amount by which the time Th is increased may be a predetermined amount, or may be determined based on the difference between the voltage V0 and the voltage Vt.

[0075] Furthermore, in S107, if the voltage Vt is smaller than the voltage V0, in S108, the CPU 151a outputs an instruction to the control unit 165 to decrease the currently set time Th so that the deviation between the voltage Vt and the voltage V0 becomes smaller. Note that the amount by which the time Th is decreased may be a predetermined amount, or may be determined based on the difference between the voltage V0 and the voltage Vt.

[0076] In S110, if the temperature control is to be continued (ie, the print job is to be continued), the process returns to S102.

[0077] Furthermore, in S110, when the temperature control is completed (that is, the print job is completed), the CPU 151a controls the control unit 165 to stop driving the triac 167 in S111.

[0078] For example, the amount of change in power caused by increasing the time Th differs between when the effective voltage value is, for example, 100 V and when it is 80 V. Specifically, the amount of change in power caused by increasing the time Th when the effective voltage value is 100 V is greater than the amount of change in power caused by increasing the time Th when the effective voltage value is 80 V. The CPU 151a controls the time Th based on the effective voltage value Vrms.

[0079] The method for controlling the temperature of the fixing heater 161 has been described above.

[0080] <Antenna> {Power supply from the control unit to the detection unit} The detection unit 164 provided in the first circuit 160a is insulated from the control unit 165 provided in the second circuit 160b, and is electromagnetically coupled to the control unit 165 by an antenna ANT consisting of a coil (winding) L1 as a first communication unit and a coil (winding) L2 as a second communication unit. An amplitude-modulated high-frequency (e.g., 13.56 MHz) signal is output to the coil L2. An AC current corresponding to the signal flows in the coil L2, and an AC voltage is generated in the coil L1 due to an AC magnetic field generated in the coil L2 due to the flow of the AC current. The detection unit 164 operates by the AC voltage generated in the coil L1. Thus, in this embodiment, power is supplied from the control unit 165 to the detection unit 164 via the antenna ANT. As a result, there is no need to provide a power source for operating the detection unit 164 in the first circuit 160a, and therefore it is possible to suppress an increase in size and cost of the device. Note that control unit 165 supplies power to detection unit 164, for example, at a cycle shorter than the cycle at which detection unit 164 detects voltage V and current I. Also, control unit 165 does not need to supply power to detection unit 164 while image forming apparatus 100 is in sleep mode.

[0081] {Data communication between the control unit and the detection unit} Fig. 7 is a diagram showing an amplitude modulated signal. As shown in Fig. 7, signals representing '0' and '1' are represented by a combination of a signal having a first amplitude and a signal having a second amplitude smaller than the first amplitude. For example, a signal representing '1' is represented by a first half of a bit represented by a signal having a first amplitude, and a second half of a bit represented by a signal having a second amplitude. Also, a signal representing '0' is represented by a first half of a bit represented by a signal having a second amplitude, and a second half of a bit represented by a signal having the first amplitude.

[0082] An amplitude-modulated signal is output to the coil L2 as shown in Fig. 7. As a result, a signal corresponding to the signal output to the coil L2 is generated in the coil L1.

[0083] For example, the detection unit 164 changes the resistance value of a variable resistor 164c provided in the detection unit 164 in response to data transmitted to the control unit 165. As a result, the signal generated in the coil L1 changes due to a change in the impedance of the coil L1, and the data is transmitted to the control unit 165. The detection unit 164 transmits the data to the control unit 165 by superimposing the data on the signal generated in the coil L1 in this manner. The data corresponds to the effective values ​​Vrms, Irms, Prms, the signal ZX indicating the zero-cross timing, and the like.

[0084] The control unit 165 extracts the data from the signal generated in the coil L2 resulting from superimposing the data on the signal generated in the coil L1 by the detection unit 164. Specifically, the control unit 165 reads the data from the detection unit 164 by detecting a change in the signal generated in the coil L2 resulting from changing the impedance of the coil L1 when the detection unit 164 superimposes the data on the signal generated in the coil L1.

[0085] In this manner, the detection unit 164 transmits data to the control unit 165 electromagnetically coupled by the antenna ANT. That is, the detection unit 164 transmits data to the control unit 165 through wireless communication between the coil L1 and the coil L2.

[0086] {Antenna ANT configuration} Next, the configuration of the antenna ANT will be described. Fig. 8 is a diagram showing the configuration of the antenna ANT in this embodiment. Note that Fig. 8 omits illustration of configurations other than the detection unit 164, the control unit 165, and the configurations included in the antenna ANT.

[0087] In the following description, the surface of circuit board 170 on which detection unit 164 is provided is referred to as a first surface, and the surface of circuit board 170 opposite to the first surface is referred to as a second surface.

[0088] The coil L1 in this embodiment includes wiring patterns P1 and P2 (broken lines) formed on a first surface of a circuit board 170 including the AC driver 160, and a jumper portion J1 formed of, for example, a conductor. One end of the wiring pattern P1 is electrically connected to a connection portion A1 of the detection portion 164, and the wiring pattern P1 is formed in a spiral shape toward a point C1 which is a connection portion with the jumper portion J1. One end of the wiring pattern P2 is electrically connected to a connection portion A2 of the detection portion 164, and the wiring pattern P2 is formed toward a point C2 which is a connection portion with the jumper portion J1. The spiral shape includes not only a shape formed of straight lines as shown in FIG. 8, but also a shape formed of curved lines.

[0089] The jumper portion J1 electrically connecting the points C1 and C2 has a vertical portion extending in the vertical direction (a direction intersecting with the first surface) and a horizontal portion extending in the horizontal direction (a direction parallel to the first surface). That is, the jumper portion J1 is provided so as not to contact the wiring patterns P1 and P2 in portions other than the points C1 and C2. The jumper portion J1 is also provided so as not to contact the coil L2. Note that, although the jumper portion J1 has a shape formed of straight lines in this embodiment, the jumper portion J1 may be formed of, for example, an arch-shaped curve.

[0090] The coil L2 in this embodiment includes wiring patterns Q1 and Q2 (dotted lines) formed on the first surface, and a jumper portion J2 made of, for example, a conductor. One end of the wiring pattern Q1 is electrically connected to a connection portion B1 of the control unit 165, and the wiring pattern Q1 is formed in a spiral shape toward a point D1 which is a connection portion with the jumper portion J2. One end of the wiring pattern Q2 is electrically connected to a connection portion B2 of the control unit 165, and the wiring pattern Q2 is formed toward a point D2 which is a connection portion with the jumper portion J2.

[0091] The jumper portion J2 electrically connecting the point D1 and the point D2 has a vertical portion extending vertically and a horizontal portion extending horizontally. That is, the jumper portion J2 is provided so as not to contact the wiring patterns Q1 and Q2 in the portions other than the point D1 and the point D2. The jumper portion J2 is also provided so as not to contact the coil L1. Note that, although the jumper portion J2 has a shape formed of straight lines in this embodiment, the jumper portion J2 may be formed of, for example, an arch-shaped curve.

[0092] As described above, the coils L1 and L2 are arranged so as not to come into contact with each other.

[0093] With the above-mentioned configuration, the coil L1 and the coil L2 are insulated from each other. As a result, the detection unit 164 provided in the first circuit 160a is insulated from the control unit 165 provided in the second circuit 160b, and is electromagnetically coupled to the control unit 165 by the antenna ANT consisting of the coil L1 and the coil L2. Specifically, an AC voltage is generated in the coil L1 by an AC magnetic field generated in the coil L2 due to an AC current flowing through the coil L2 in response to a signal output by the control unit 165. The detection unit 164 operates by the AC voltage generated in the coil L1. Thus, in this embodiment, power is supplied from the control unit 165 to the detection unit 164 via the antenna ANT. As a result, since there is no need to provide a power source for operating the detection unit 164 in the first circuit 160a, it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0094] In addition, in this embodiment, the detection unit 164 transmits data to the control unit 165, for example, by changing the impedance of the coil L1 to change the signal generated in the coil L1. The control unit 165 then detects the change and reads the data from the detection unit 164. In this manner, the detection unit 164 transmits data to the control unit 165 electromagnetically coupled by the antenna ANT. As a result, there is no need to provide a transformer between the first circuit 160a and the second circuit 160b, and it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0095] In the present embodiment, the spiral shape of the coils L1 and L2 is formed by a wiring pattern, but this is not limiting. For example, the spiral shape may be formed by a conductive wire.

[0096] In this embodiment, the detection unit 164, the control unit 165, and the coils L1 and L2 are formed on the first surface of the circuit board 170, but this is not limited thereto. For example, the detection unit 164 and the coil L1 may be formed on the first surface of the circuit board 170, and the control unit 165 and the coil L2 may be formed on the second surface opposite to the first surface. Alternatively, the detection unit 164 and the control unit 165 may be provided on the first surface, the coil L1 may be formed on the first surface, and the coil L2 may be formed on the second surface. Alternatively, the detection unit 164 and the control unit 165 may be provided on the first surface, the coil L2 may be formed on the first surface, and the coil L1 may be formed on the second surface. The wiring pattern formed on the second surface is electrically connected to the wiring pattern provided on the first surface, the detection unit 164, the control unit 165, and other circuits via a pattern provided in an opening provided in the circuit board 170, for example. The wiring pattern formed on the second surface may be electrically connected to circuits such as the wiring pattern, detection unit 164, and control unit 165 provided on the first surface by, for example, a conductor, solder, or the like through an opening provided in circuit board 170.

[0097] In this embodiment, the coils L1 and L2 are formed using the jumper parts J1 and J2, but this is not limiting. For example, as shown in FIG. 9, one end of the wiring pattern R1 formed in a spiral shape on the first surface is electrically connected to the connection part A1, and the other end of the wiring pattern R1 is electrically connected to the connection part A2. That is, the connection part A1 and the connection part A2 are electrically connected by one wiring pattern R1. Furthermore, one end of the wiring pattern S1 is electrically connected to the connection part B1 of the control part 165, and the wiring pattern S1 is formed in a spiral shape toward the point E1 which is the connection part with the jumper part J3. Moreover, one end of the wiring pattern S2 is electrically connected to the connection part B2 of the control part 165, and the wiring pattern S2 is formed toward the point E2 which is the connection part with the jumper part J3. The above-mentioned configuration may be used.

[0098] Second Embodiment Description of the configuration of the image forming apparatus 100 that is the same as that of the first embodiment will be omitted.

[0099] {Antenna ANT configuration} Fig. 10 is a diagram showing the configuration of the antenna ANT in this embodiment. Note that Fig. 10 does not show components other than the detection unit 164, the control unit 165, and the components included in the antenna ANT. In Fig. 10, the wiring pattern formed on the second surface is shown in gray.

[0100] 10, in this embodiment, the wiring pattern P1 formed on the first surface is electrically connected to the wiring pattern P2 formed on the second surface at a point C1, and the wiring pattern Q1 formed on the first surface is electrically connected to the wiring pattern Q2 formed on the second surface at a point D1.

[0101] The wiring pattern provided on the second surface is electrically connected to the wiring pattern provided on the first surface, circuits such as detection unit 164, and the like, for example, via a pattern provided in an opening provided in circuit board 170. The wiring pattern provided on the second surface may be electrically connected to the wiring pattern provided on the first surface, circuits such as detection unit 164, and control unit 165, and the like, for example, via an opening provided in circuit board 170, by a conductor, solder, or the like.

[0102] As described above, the coils L1 and L2 are arranged so as not to come into contact with each other.

[0103] With the above-mentioned configuration, the coil L1 and the coil L2 are insulated from each other. As a result, the detection unit 164 provided in the first circuit 160a is insulated from the control unit 165 provided in the second circuit 160b, and is electromagnetically coupled to the control unit 165 by the antenna ANT consisting of the coil L1 and the coil L2. Specifically, an AC voltage is generated in the coil L1 by an AC magnetic field generated in the coil L2 due to an AC current flowing through the coil L2 in response to a signal output by the control unit 165. The detection unit 164 operates by the AC voltage generated in the coil L1. Thus, in this embodiment, power is supplied from the control unit 165 to the detection unit 164 via the antenna ANT. As a result, since there is no need to provide a power source for operating the detection unit 164 in the first circuit 160a, it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0104] In addition, in this embodiment, the detection unit 164 transmits data to the control unit 165, for example, by changing the impedance of the coil L1 to change the signal generated in the coil L1. The control unit 165 then detects the change and reads the data from the detection unit 164. In this manner, the detection unit 164 transmits data to the control unit 165 electromagnetically coupled by the antenna ANT. As a result, there is no need to provide a transformer between the first circuit 160a and the second circuit 160b, and it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0105] In this embodiment, the wiring pattern P1 formed on the first surface is electrically connected to the wiring pattern P2 formed on the second surface at point C1, and the wiring pattern Q1 formed on the first surface is electrically connected to the wiring pattern Q2 formed on the second surface at point D1, but this is not limited thereto. For example, the wiring pattern P1 formed on the second surface may be electrically connected to the wiring pattern P2 formed on the first surface at point C1, and the wiring pattern Q1 formed on the second surface may be electrically connected to the wiring pattern Q2 formed on the first surface at point D1.

[0106] Also, for example, a configuration as shown in Fig. 11 may be used. Specifically, a configuration may be used in which the wiring pattern P1 formed on the first surface is electrically connected to the wiring pattern P2 formed on the second surface at a point F1, and the wiring pattern Q1 formed on the second surface is electrically connected to the wiring pattern Q2 formed on the first surface at a point F2. Also, a configuration may be used in which the wiring pattern P1 formed on the second surface is electrically connected to the wiring pattern P2 formed on the first surface at a point F1, and the wiring pattern Q1 formed on the first surface is electrically connected to the wiring pattern Q2 formed on the second surface at a point F2. In Fig. 11, the wiring patterns formed on the second surface are shown in gray.

[0107] In the first and second embodiments, the coils L1 and L2 are formed in a spiral shape, but this is not limited thereto. For example, as shown in Fig. 12, the coils L1 and L2 may be arranged two-dimensionally and may have a wiring pattern formed for one revolution so as to form an antenna. In Fig. 12, the wiring pattern formed on the second surface is shown in gray.

[0108] In the first and second embodiments, coils L1 and L2 are configured such that at least a portion of the range (region) from the center of the spiral of coil L1 to the outer periphery overlaps with the range (region) from the center of the spiral of coil L2 to the outer periphery, as viewed from a direction perpendicular to the first surface, as shown in Figures 8 to 11.

[0109] In this embodiment, the surface on which the control unit 165 is provided may be the first surface or the second surface.

[0110] Third Embodiment Description of the configuration of the image forming apparatus 100 that is the same as that of the first embodiment will be omitted.

[0111] {Antenna ANT configuration} Fig. 13 is a diagram showing the configuration of the antenna ANT in this embodiment. Note that Fig. 13 omits illustration of components other than the detection unit 164, the control unit 165, and the components included in the antenna ANT.

[0112] In this embodiment, in the first circuit 160a, the detection unit 164 and the coil L1 are provided on a circuit board 170. Note that the configuration of the coil L1 is, for example, the configuration described in the first and second embodiments.

[0113] In this embodiment, the control unit 165 and the coil L2 are provided on a circuit board 171. The configuration of the coil L2 is, for example, the configuration described in the first and second embodiments.

[0114] The circuit provided on circuit board 171 is electrically connected to the circuit provided on circuit board 170 by connection portion 174 and connector 173 provided on circuit board 171. The surface of circuit board 171 opposite to the surface on which control unit 165 is provided is configured as a GND plane and is grounded.

[0115] In this embodiment, a predetermined gap is formed between circuit board 170 and circuit board 171 by spacer 172 and connector 173 provided between circuit board 170 and circuit board 171, and circuit board 171 is provided to face circuit board 170.

[0116] The coils L1 and L2 are arranged such that at least a portion of the range from the center to the outer periphery of the spiral of the coil L1 overlaps with the range from the center to the outer periphery of the spiral of the coil L2 when viewed from a direction perpendicular to the first surface.

[0117] With the above-mentioned configuration, the coil L1 and the coil L2 are insulated from each other. As a result, the detection unit 164 provided in the first circuit 160a is insulated from the control unit 165 provided in the second circuit 160b, and is electromagnetically coupled to the control unit 165 by the antenna ANT consisting of the coil L1 and the coil L2. Specifically, an AC voltage is generated in the coil L1 by an AC magnetic field generated in the coil L2 due to an AC current flowing through the coil L2 in response to a signal output by the control unit 165. The detection unit 164 operates by the AC voltage generated in the coil L1. Thus, in this embodiment, power is supplied from the control unit 165 to the detection unit 164 via the antenna ANT. As a result, since there is no need to provide a power source for operating the detection unit 164 in the first circuit 160a, it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0118] In addition, in this embodiment, the detection unit 164 transmits data to the control unit 165, for example, by changing the impedance of the coil L1 to change the signal generated in the coil L1. The control unit 165 then detects the change and reads the data from the detection unit 164. In this manner, the detection unit 164 transmits data to the control unit 165 electromagnetically coupled by the antenna ANT. As a result, there is no need to provide a transformer between the first circuit 160a and the second circuit 160b, and it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0119] In this embodiment, the length of the spacer 172 in the vertical direction is the same as the length of the connector 173 in the vertical direction, but this is not limited to the present embodiment.

[0120] [Fourth embodiment] Description of the configuration of the image forming apparatus 100 that is the same as that of the first embodiment will be omitted.

[0121] {Antenna ANT configuration} Fig. 14 is a diagram showing the configuration of the antenna ANT in this embodiment. Note that Fig. 14 omits illustration of components other than the detection unit 164, the control unit 165, and the components included in the antenna ANT.

[0122] In this embodiment, a circuit board 175 on which the detection unit 164 and the coil L1 are provided is provided on the first circuit 160a. Specifically, the circuit board 175 is provided such that the surface of the circuit board 175 on which the coil L1 is provided intersects with the surface of the circuit board 170 on which the circuit is mounted. The detection unit 164 is electrically connected to the circuit in the first circuit 160a of the circuit board 170 by wiring (not shown).

[0123] In this embodiment, the circuit board 176 on which the control unit 165 and the coil L2 are provided is provided on the second circuit 160a. Specifically, the circuit board 176 is provided such that the surface of the circuit board 176 on which the coil L2 is provided intersects with the surface of the circuit board 170 on which the circuits are mounted. The control unit 165 is electrically connected to the circuit in the second circuit 160b of the circuit board 170 by wiring (not shown).

[0124] The configuration of the coils L1 and L2 is, for example, the configuration described in the first and second embodiments.

[0125] 14, circuit board 175 and circuit board 176 are provided so that the surface on which coil L1 is provided and the surface on which coil L2 is provided face each other. Coils L1 and L2 are provided so that at least a part of the range from the center to the outer periphery of coil L1 overlaps with the range from the center to the outer periphery of coil L2 when viewed from a direction perpendicular to the first surface.

[0126] With the above-mentioned configuration, the coil L1 and the coil L2 are insulated from each other. As a result, the detection unit 164 provided in the first circuit 160a is insulated from the control unit 165 provided in the second circuit 160b, and is electromagnetically coupled to the control unit 165 by the antenna ANT consisting of the coil L1 and the coil L2. Specifically, an AC voltage is generated in the coil L1 by an AC magnetic field generated in the coil L2 due to an AC current flowing through the coil L2 in response to a signal output by the control unit 165. The detection unit 164 operates by the AC voltage generated in the coil L1. Thus, in this embodiment, power is supplied from the control unit 165 to the detection unit 164 via the antenna ANT. As a result, since there is no need to provide a power source for operating the detection unit 164 in the first circuit 160a, it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0127] In addition, in this embodiment, the detection unit 164 transmits data to the control unit 165, for example, by changing the impedance of the coil L1 to change the signal generated in the coil L1. The control unit 165 then detects the change and reads the data from the detection unit 164. In this manner, the detection unit 164 transmits data to the control unit 165 electromagnetically coupled by the antenna ANT. As a result, there is no need to provide a transformer between the first circuit 160a and the second circuit 160b, and it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0128] Fifth embodiment Description of the configuration of the image forming apparatus 100 that is the same as that of the first embodiment will be omitted.

[0129] {Antenna ANT configuration} Fig. 15 is a diagram showing the configuration of the antenna ANT in this embodiment. Note that in Fig. 15, configurations other than the detection unit 164, the control unit 165, and the configurations included in the antenna ANT are omitted.

[0130] In this embodiment, in the first circuit 160a, a detection unit 164 and a coil L1 are provided on a circuit board 170. In the second circuit 160b, a control unit 165 and a coil L2 are provided. In this embodiment, the coil L2 is provided at a distance that allows electromagnetic coupling with the coil L1. The configurations of the coils L1 and L2 are, for example, the configurations described in the first and second embodiments.

[0131] With the above-mentioned configuration, the coil L1 and the coil L2 are insulated from each other. As a result, the detection unit 164 provided in the first circuit 160a is insulated from the control unit 165 provided in the second circuit 160b, and is electromagnetically coupled to the control unit 165 by the antenna ANT consisting of the coil L1 and the coil L2. Specifically, an AC voltage is generated in the coil L1 by an AC magnetic field generated in the coil L2 due to an AC current flowing through the coil L2 in response to a signal output by the control unit 165. The detection unit 164 operates by the AC voltage generated in the coil L1. Thus, in this embodiment, power is supplied from the control unit 165 to the detection unit 164 via the antenna ANT. As a result, since there is no need to provide a power source for operating the detection unit 164 in the first circuit 160a, it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0132] In addition, in this embodiment, the detection unit 164 transmits data to the control unit 165, for example, by changing the impedance of the coil L1 to change the signal generated in the coil L1. The control unit 165 then detects the change and reads the data from the detection unit 164. In this manner, the detection unit 164 transmits data to the control unit 165 electromagnetically coupled by the antenna ANT. As a result, there is no need to provide a transformer between the first circuit 160a and the second circuit 160b, and it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0133] Sixth Embodiment Description of the configuration of the image forming apparatus 100 that is the same as that of the first embodiment will be omitted.

[0134] {Antenna ANT configuration} Fig. 16 is a diagram showing the configuration of the antenna ANT in this embodiment. Note that in Fig. 16, configurations other than the detection unit 164, the control unit 165, and the configurations included in the antenna ANT are omitted.

[0135] In this embodiment, as shown in Fig. 16, a coil L1 is formed by a plurality of jumper parts J1 provided on the first surface side and a wiring pattern P formed on the first surface. A connection part A1 of the detection part 164 is connected to one end of the coil L1, and a connection part B1 of the detection part 164 is connected to the other end of the coil L1. Note that, although the jumper part J1 has a shape formed by straight lines in this embodiment, the jumper part J1 may be formed by, for example, an arch-shaped curve.

[0136] In this embodiment, as shown in Fig. 16, a coil L2 is formed by a plurality of jumper parts J2 provided on the first surface side and a plurality of wiring patterns P2 formed on the first surface. A connection part A2 of the control part 165 is connected to one end of the coil L2, and a connection part B2 of the control part 165 is connected to the other end of the coil L2. Note that, although the jumper part J2 has a shape formed by straight lines in this embodiment, the jumper part J2 may be formed by, for example, an arch-shaped curve.

[0137] Moreover, the wiring patterns P1 and P2 are provided so as not to come into contact with each other.

[0138] With the above-mentioned configuration, the coil L1 and the coil L2 are insulated from each other. As a result, the detection unit 164 provided in the first circuit 160a is insulated from the control unit 165 provided in the second circuit 160b, and is electromagnetically coupled to the control unit 165 by the antenna ANT consisting of the coil L1 and the coil L2. Specifically, an AC voltage is generated in the coil L1 by an AC magnetic field generated in the coil L2 due to an AC current flowing through the coil L2 in response to a signal output by the control unit 165. The detection unit 164 operates by the AC voltage generated in the coil L1. Thus, in this embodiment, power is supplied from the control unit 165 to the detection unit 164 via the antenna ANT. As a result, since there is no need to provide a power source for operating the detection unit 164 in the first circuit 160a, it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0139] In addition, in this embodiment, the detection unit 164 transmits data to the control unit 165, for example, by changing the impedance of the coil L1 to change the signal generated in the coil L1. The control unit 165 then detects the change and reads the data from the detection unit 164. In this manner, the detection unit 164 transmits data to the control unit 165 electromagnetically coupled by the antenna ANT. As a result, there is no need to provide a transformer between the first circuit 160a and the second circuit 160b, and it is possible to suppress an increase in size and cost of the device while maintaining an insulating state between the first circuit 160a and the second circuit 160b.

[0140] The functions of the CPU 151a in the first to fifth embodiments may be implemented in the control unit 165, or the functions of the control unit 165 may be implemented in the CPU 151a.

[0141] The voltage V, the current I, the current I2, and the like in the first to fifth embodiments correspond to parameters related to the power supplied to the load.

[0142] Moreover, the triac drive circuit 167a and the triac 167 in the first to fifth embodiments are included in the adjusting means and the triac circuit, respectively.

[0143] In the first to fifth embodiments, the CPU 151a acquires the effective value in response to the input of the signal ZX, but this is not limited to the above. For example, the CPU 151a may acquire the effective value when the time measured by a timer provided inside the CPU 151a reaches a time corresponding to one period of the voltage V. In other words, the signal ZX does not have to be input from the control unit 165 to the CPU 151a.

[0144] In the first to fifth embodiments, the triac 167 is used as a configuration for adjusting the power supplied to the heating element 161a, but this is not limited to this. For example, a configuration may be used in which the power supplied to the heating element 161a is adjusted by changing the resistance of the circuit in the first circuit 160a to modulate the amplitude of the voltage and current supplied to the heating element 161a.

[0145] In the first to fifth embodiments, the detection unit 164 transmits data to the control unit 165 by changing the impedance of the coil L1 to modulate the amplitude of the signal generated in the coil L1, but this is not limited to the above. For example, the detection unit 164 may be configured to transmit data to the control unit 165 by modulating the frequency of the signal generated in the coil L1.

[0146] In the first to fifth embodiments, NFC (Near Field Communication) is used as a method for performing wireless communication between the detection unit 164 and the control unit 165, but the method for performing wireless communication between the detection unit 164 and the control unit 165 is not limited to this. For example, a method such as infrared communication may be used as a method for performing wireless communication between the detection unit 164 and the control unit 165.

[0147] In the first to fifth embodiments, the first circuit 160a is connected to a commercial power source, but this is not limiting. For example, the first circuit 160a may be configured to be connected to a predetermined power source such as a battery.

[0148] The detection unit 164 and the coil L1 are included in a first communication unit, and the detection unit 164 is included in a transmission unit. The coil L2 is included in a second communication unit. The resistor R3 is included in a detection means. [Explanation of symbols]

[0149] 1 Commercial power supply 100 Image forming device 151a CPU 160 AC Driver 161 Fixing heater 161a Heating element 164 Detector 165 Control Unit 318 Fixing unit L1, L2 coils P1, P2, Q1, Q2 wiring pattern J1, J2 jumper section

Claims

1. A substrate; A first loop antenna provided on the substrate; a second loop antenna provided on the substrate, the second loop antenna being insulated from the first loop antenna and performing wireless communication with the first loop antenna; a transmitter provided on the substrate, connected to the first loop antenna, and configured to transmit data; a receiving section provided on the substrate and insulated from the transmitting section, the receiving section being connected to the second loop antenna and receiving the data from the transmitting section through the wireless communication; having when the first loop antenna and the second loop antenna are viewed along a direction perpendicular to a surface of the substrate on which the first loop antenna is provided, at least a portion of a loop region of the first loop antenna and a loop region of the second loop antenna overlap each other, the transmitting unit is operated by power generated by a voltage generated in the first loop antenna due to a voltage output from the receiving unit to the second loop antenna, The communication unit, wherein the receiving section operates using power from a predetermined power source.

2. The substrate is provided with a first circuit including the first loop antenna and the transmitting unit, and a second circuit including the second loop antenna and the receiving unit, 2. The communication unit according to claim 1, wherein the first circuit and the second circuit are insulated.

3. The communication unit described in claim 1 or 2, characterized in that the first loop antenna comprises a first spiral portion printed in a spiral shape on the first surface of the substrate and one end connected to the transmitter unit, and a first wiring portion printed on a second surface opposite the first surface and electrically connecting the other end of the first spiral portion to the transmitter unit.

4. The communication unit described in claim 3, characterized in that the second loop antenna comprises a second spiral portion printed in a spiral shape on the first surface and one end connected to the receiving unit, and a second wiring portion printed on the second surface and electrically connecting the other end of the second spiral portion to the receiving unit.

5. The communication unit described in claim 3, characterized in that the second loop antenna comprises a second spiral portion printed in a spiral shape on the second surface and one end connected to the receiving unit, and a second wiring portion printed on the first surface and electrically connecting the other end of the second spiral portion to the receiving unit.

6. the first loop antenna comprises: a first spiral portion printed in a spiral shape on the first surface of the substrate and having one end connected to the transmitter portion; and a jumper portion having one end electrically connected to the other end of the first spiral portion at a first connection point on the first surface and having the other end electrically connected to the transmitter portion at a second connection point on the first surface; 3. The communication unit according to claim 1, wherein a gap is provided between a portion of the jumper portion between the first connection point and the second connection point and the first surface.

7. 3. The communication unit according to claim 1, wherein the second loop antenna is printed on a second surface of the substrate opposite to the first surface on which the first loop antenna is printed.

8. A communication unit described in any one of claims 1 to 7, characterized in that the wiring of the first loop antenna printed on a first surface of the substrate and the wiring of the first loop antenna printed on a second surface opposite the first surface are electrically connected through an opening provided in the substrate.

9. The communication unit according to claim 1 , wherein the first loop antenna and the second loop antenna perform the wireless communication by NFC.

10. A communication unit according to claim 2 or any one of claims 3 to 9 which cites claim 2, the first circuit is connected to a second predetermined power source; the transmission unit includes a detection unit that detects a parameter related to power supplied from the second predetermined power source to a load connected to the first circuit; A power supply device characterized in that the receiving unit includes a control unit that controls the power supplied to the load based on the detection result of the detection unit as the data transmitted from the transmitting unit via the wireless communication.

11. 11. The power supply device according to claim 10, wherein the second predetermined power supply is a commercial power supply.

12. A power supply device according to claim 11; A heater as the load; A second detection unit that detects a temperature of the heater; a fixing unit for fixing the toner image on the sheet to the sheet by heat from the heater; having The image forming apparatus according to claim 1, wherein the control unit controls power supplied to the heater based on the temperature detected by the second detection unit.

Images