Image forming device

Abstract

To provide an image forming device capable of reducing the number of harnesses that electrically connect a main board and a low-voltage board.SOLUTION: An image forming device 1 includes a main body housing 10, a fuser 70, a main board 110 capable of outputting a control signal to control the fuser 70, a low-voltage board 120 capable of outputting power to the fuser 70, a first wireless communication unit 130 electrically connected to the main board 110 and capable of transmitting the control signal, and a second wireless communication unit 140 electrically connected to the low-voltage board 120 and capable of receiving the control signal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known an image forming apparatus that includes a main board and a low-voltage board that converts AC voltage input from a commercial AC power source into a constant DC voltage and supplies the DC voltage to the main board (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-117348 Summary of the Invention [Problem to be solved by the invention]

[0004] The main board and the low-voltage board are generally electrically connected by a plurality of harnesses. However, if there are many harnesses electrically connecting the main board and the low-voltage board, there is a problem that it takes time and effort to replace the low-voltage board.

[0005] Therefore, it is desirable to be able to reduce the number of harnesses that electrically connect the main board and the low-voltage board. [Means for solving the problem]

[0006] The image forming apparatus includes a main body housing, a fixing unit, a main board, a low-voltage board, a first wireless communication unit, and a second wireless communication unit. The main board is capable of outputting a control signal for controlling the fixing unit. The low voltage substrate can output power to the fuser. The first wireless communication unit is electrically connected to the main board and is capable of transmitting a control signal. The second wireless communication unit is electrically connected to the low-voltage board and is capable of receiving a control signal.

[0007] Since the control signal from the main board can be transmitted to the low-voltage board via the first wireless communication unit and the second wireless communication unit, the harness that electrically connects the main board and the low-voltage board can be reduced.

[0008] The main board may transmit a control signal to the low-voltage board via the first wireless communication unit and the second wireless communication unit, and the low-voltage board may control the power output to the fixing unit based on the control signal.

[0009] The fuser may be equipped with a temperature sensor. The temperature sensor is electrically connected to the low-voltage board and is capable of transmitting a detection signal indicating the temperature of the fuser to the low-voltage board.

[0010] The control signal is a signal indicating a target temperature of the fixing unit, and the main board may have a main CPU, and the low-voltage board may have a low-voltage board CPU. The main CPU can transmit a control signal to the low-voltage board via the first wireless communication unit and the second wireless communication unit. The low-voltage board CPU controls the power output to the fixing unit based on the control signal and the detection signal received from the temperature sensor.

[0011] The main CPU may transmit an end signal indicating the end of printing using the image forming apparatus to the low-voltage board CPU via the first wireless communication unit and the second wireless communication unit.

[0012] The low-voltage board CPU may transmit a fixing unit abnormality signal indicating an abnormality in the fixing unit to the main CPU via the second wireless communication unit and the first wireless communication unit.

[0013] The low-voltage board CPU may receive the end signal and, if the temperature of the fixing device based on the detection signal received from the temperature sensor does not fall below a predetermined temperature within a predetermined time, send a fixing device abnormality signal to the main CPU.

[0014] The main board may have a main CPU, and the low-voltage board may have a low-voltage board CPU, and the low-voltage board may be capable of supplying a predetermined voltage to the main board. The main CPU transmits a first request signal requesting the voltage value of the voltage supplied to the main board by the low-voltage board to the low-voltage board CPU via the first wireless communication unit and the second wireless communication unit.

[0015] When the low-voltage board CPU receives the first request signal, it may transmit the voltage value to the main CPU via the second wireless communication unit and the first wireless communication unit.

[0016] The main CPU may execute a voltage determination process to determine whether or not the voltage value received from the low-voltage board CPU is normal.

[0017] The main CPU may transmit the first request signal to the low-voltage board CPU on the condition that the image forming apparatus is powered on or on the condition that a cover for opening and closing the opening of the main body housing is closed.

[0018] If the main CPU determines in the voltage determination process that the voltage value is abnormal, it may output a low-voltage substrate abnormality signal indicating an abnormality in the low-voltage substrate.

[0019] The main board may have a main CPU, and the low voltage board may have a low voltage board CPU. The main CPU transmits a second request signal requesting the period and pulse width of the zero-cross signal of the voltage of the AC power supply to the low-voltage board CPU via the first wireless communication unit and the second wireless communication unit.

[0020] When the low-voltage substrate CPU receives the second request signal, it may transmit the period and pulse width of the zero-cross signal to the main CPU via the second wireless communication unit and the first wireless communication unit.

[0021] The main CPU may execute a zero-cross signal determination process to determine whether the period and pulse width of the received zero-cross signal are normal.

[0022] The main CPU may transmit the second request signal to the low-voltage board CPU on the condition that the image forming apparatus is powered on or on the condition that a cover for opening and closing the opening of the main body housing is closed.

[0023] When the main CPU determines in the zero-cross signal determination process that at least one of the period and pulse width of the zero-cross signal is abnormal, it may output an AC power supply abnormality signal indicating an abnormality in the AC power supply.

[0024] The image forming apparatus may include a harness that electrically connects the main board and the low-voltage board and supplies voltage to the main board.

[0025] The first wireless communication unit may be located on the main board.

[0026] The second wireless communication unit may be located on a low voltage substrate. [Effects of the Invention]

[0027] The harness that electrically connects the main board and the low-voltage board can be reduced. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a cross-sectional view showing an image forming apparatus. [Figure 2] FIG. 2 is a block diagram showing a main board, a low-voltage board, a first wireless communication unit, and a second wireless communication unit. [Figure 3]10 is a flowchart showing an example of the operation of the main board and the low-voltage board when the image forming apparatus is turned on or when the cover is closed. [Figure 4] 4 is a flowchart continuing from FIG. 3 showing an example of the operation of the main board and the low-voltage board. [Figure 5] 10 is a flowchart illustrating an example of a first voltage determination process. [Figure 6] 10 is a flowchart illustrating an example of a second voltage determination process. [Figure 7] 10 is a flowchart illustrating an example of a zero-cross signal determination process. [Figure 8] 10 is a flowchart showing an example of the operation of the main board and the low-voltage board when a printing operation is started. DETAILED DESCRIPTION OF THE INVENTION

[0029] Next, an embodiment will be described. 1, the image forming apparatus 1 is a printer capable of forming a monochrome image on a sheet S such as paper. The image forming apparatus 1 includes a main body housing 10, a cover 20, a sheet supply unit 30, an image forming unit 40, and a discharge roller 81.

[0030] The main body housing 10 has an opening 11 . The cover 20 opens and closes the opening 11 of the main body housing 10 .

[0031] The sheet supply unit 30 includes a sheet tray 31 and a sheet supply roller 32 . The sheet tray 31 accommodates the sheets S. The sheet supply roller 32 supplies the sheet S stored in the sheet tray 31 to the image forming unit 40.

[0032] The image forming section 40 includes an exposure unit 50, a process cartridge 60, and a fixing unit 70. The exposure unit 50, the process cartridge 60, and the fixing unit 70 are located inside the main body casing 10.

[0033] The exposure unit 50 includes a light source, a deflector, a lens, a mirror, etc. The exposure unit 50 emits a light beam as shown by the imaginary line to expose the surface of the photosensitive drum 61.

[0034] With the cover 20 open, the process cartridge 60 can be attached to and detached from the main body casing 10 through the opening 11. The process cartridge 60 includes a drum cartridge 60A and a developing cartridge 60B.

[0035] The drum cartridge 60A includes a photosensitive drum 61, a charger 62, and a transfer roller 63 as an example of a transfer device. A toner image is formed on the surface of the photosensitive drum 61 .

[0036] The developing cartridge 60B is detachably attached to the drum cartridge 60A and includes a developing roller 64, a supply roller 65, a layer thickness regulating blade 66, an agitator 67, and a toner containing portion 68.

[0037] The toner storage section 68 stores toner. The agitator 67 agitates the toner in the toner storage unit 68. The agitator 67 also supplies the toner to the supply roller 65. The supply roller 65 supplies the toner to the developing roller 64 . The layer thickness regulating blade 66 comes into contact with the surface of the developing roller 64 and regulates the thickness of the toner on the developing roller 64 to a constant thickness.

[0038] The fixing unit 70 includes a heating unit 71 , a pressure roller 72 , and an intermediate discharge roller 73 . The heating unit 71 includes a heater 71A, a fixing belt 71B, a nip plate, etc. The heating unit 71 heats the sheet S. The pressure roller 72 presses the sheet S against the heating unit 71 .

[0039] The charger 62 charges the surface of the photosensitive drum 61 . The exposure unit 50 emits a light beam onto the surface of the charged photosensitive drum 61, thereby forming an electrostatic latent image on the photosensitive drum 61 based on image data. The developing roller 64 supplies toner to the surface of the photosensitive drum 61 after exposure, thereby forming a toner image on the photosensitive drum 61.

[0040] The transfer roller 63 transfers the toner image formed on the photosensitive drum 61 onto the sheet S by conveying the sheet S supplied from the sheet supply unit 30 between the photosensitive drum 61 and the transfer roller 63. The fixing device 70 fixes the toner image transferred onto the sheet S by conveying the sheet S, onto which the toner image has been transferred, between the heating unit 71 and the pressure roller 72.

[0041] The intermediate discharge rollers 73 transport the sheet S on which the toner image has been fixed toward the discharge rollers 81. The discharge rollers 81 discharge the sheet S on which the image has been formed onto the discharge tray 13.

[0042] 2, the image forming apparatus 1 further includes a main board 110, a low-voltage board 120, a first wireless communication unit 130, a second wireless communication unit 140, and an alarm device 150. The main board 110, the low-voltage board 120, the first wireless communication unit 130, and the second wireless communication unit 140 are located inside the main body housing 10.

[0043] The main board 110 is a board capable of outputting a control signal. The control signal is a control signal for controlling the fuser 70. In the embodiment, the control signal is a signal indicating a target temperature of the fuser 70. The main board 110 transmits the control signal to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140.

[0044] The low-voltage board 120 is a board that can output power to the fixing unit 70. In this embodiment, the low-voltage board 120 controls the power output to the fixing unit 70 based on a control signal from the main board 110.

[0045] The low-voltage board 120 can supply a predetermined voltage to the main board 110. In particular, the low-voltage board 120 can convert an AC voltage supplied from an AC power source (commercial power source) into a DC voltage and supply the converted DC voltage to the main board 110.

[0046] The image forming apparatus 1 further includes a harness 160. The harness 160 electrically connects the main board 110 and the low-voltage board 120. The harness 160 is a harness for supplying a DC voltage from the low-voltage board 120 to the main board 110. In this embodiment, the low-voltage board 120 can supply a DC voltage of 24 V to the main board 110 via the harness 160. In addition, the low-voltage board 120 can supply a DC voltage of 6 V to the main board 110 via the harness 160.

[0047] The first wireless communication unit 130 is a communication unit capable of performing wireless communication with the second wireless communication unit 140. The first wireless communication unit 130 is capable of performing short-range wireless communication with the second wireless communication unit 140. Standards for short-range wireless communication include, for example, Wi-Fi (registered trademark), BLUETOOTH (registered trademark), and ZIGBEE (registered trademark).

[0048] The first wireless communication unit 130 is electrically connected to the main board 110. In the embodiment, the first wireless communication unit 130 is located on the main board 110. The first wireless communication unit 130 can transmit a control signal output by the main board 110 to the second wireless communication unit 140.

[0049] The second wireless communication unit 140 is electrically connected to the low-voltage board 120. In the embodiment, the second wireless communication unit 140 is located on the low-voltage board 120. The second wireless communication unit 140 is capable of receiving a control signal transmitted by the main board 110 via the first wireless communication unit 130. The second wireless communication unit 140 outputs the received control signal to the low-voltage board 120.

[0050] The notification device 150 is a device for notifying the user of the image forming apparatus 1 of information. The notification device 150 is, for example, a display such as a liquid crystal display, a speaker, a lamp, etc. The notification device 150 may also be configured by combining two or more displays, speakers, lamps, etc. The notification device 150 may be a display, a speaker, etc. provided in the image forming apparatus 1, or may be a display of a device separate from the image forming apparatus 1, such as a personal computer or a smartphone.

[0051] The main board 110 includes a main CPU 111 . The low-voltage board 120 has a microcomputer 121, an energy-saving circuit 122, and a heater circuit 123. The microcomputer 121 has a low-voltage board CPU . The fixing unit 70 includes a temperature sensor 74 .

[0052] The main CPU 111 can transmit a control signal for controlling the fixing unit 70 to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140. In more detail, the main CPU 111 can transmit a control signal to the low-voltage board CPU 124 via the first wireless communication unit 130 and the second wireless communication unit 140.

[0053] The temperature sensor 74 is a sensor that detects the temperature of the fixing device 70. Specifically, the temperature sensor 74 detects the temperature of the heating unit 71. As an example, the temperature sensor 74 is a thermistor. The temperature sensor 74 is electrically connected to the low-voltage board 120. The temperature sensor 74 is capable of transmitting a detection signal to the low-voltage board 120. The detection signal is a signal that indicates the temperature of the fixing device 70.

[0054] The low-voltage board CPU 124 controls the power output to the fixing device 70 based on a control signal received from the main CPU 111 and a detection signal received from the temperature sensor 74. In detail, the low-voltage board CPU 124 controls the power output to the fixing device 70 based on a control signal indicating a target temperature of the fixing device 70 and a detection signal indicating the temperature (detected temperature) of the fixing device 70 so that the detected temperature becomes the target temperature.

[0055] The heater circuit 123 can output power to the fixing device 70. More specifically, the heater circuit 123 can output power to the heater 71A of the heating unit 71. The heater circuit 123 outputs power to the heater 71A based on a command from the low-voltage board CPU 124. More specifically, the heater circuit 123 switches the heater 71A between ON and OFF based on a command from the low-voltage board CPU 124.

[0056] The image forming apparatus 1 further includes a power switch SW. The power switch SW is electrically connected to the low-voltage board 120.

[0057] When the power switch SW is operated to turn on the image forming apparatus 1, the low-voltage board CPU 124 transmits a power-on signal to the main CPU 111 via the second wireless communication unit 140 and the first wireless communication unit 130. The power-on signal is a signal indicating that the image forming apparatus 1 has been turned on.

[0058] When the power switch SW is operated while the image forming apparatus 1 is powered on, the energy saving circuit 122 switches the low voltage board 120 to an energy saving mode that reduces power consumption.

[0059] When printing using the image forming apparatus 1 is completed, the main CPU 111 transmits an end signal to the low-voltage board CPU 124 via the first wireless communication unit 130 and the second wireless communication unit 140. The end signal is a signal indicating that printing using the image forming apparatus 1 is completed.

[0060] When the low-voltage board CPU 124 receives the end signal, it executes a fixing unit determination process. In the fixing unit determination process, the low-voltage board CPU 124 determines whether the temperature of the fixing unit 70 based on the detection signal received from the temperature sensor 74 has become equal to or lower than a predetermined temperature within a predetermined time.

[0061] When the temperature of the fixing device 70 becomes equal to or lower than a predetermined temperature within a predetermined time, the low-voltage board CPU 124 transmits a fixing device normal signal to the main CPU 111 via the second wireless communication unit 140 and the first wireless communication unit 130. When the main CPU 111 receives the fixing unit normal signal, it puts the image forming apparatus 1 into a standby state. The standby state is a state in which the image forming apparatus 1 is kept on standby in preparation for the next printing.

[0062] If the temperature of the fixing device 70 does not drop below a predetermined temperature within a predetermined time, the low-voltage board CPU 124 transmits a fixing device abnormality signal to the main CPU 111 via the second wireless communication unit 140 and the first wireless communication unit 130. The fixing device abnormality signal is a signal that indicates an abnormality in the fixing device 70.

[0063] When the main CPU 111 receives the fixing unit abnormality signal, it transmits the fixing unit abnormality signal to the notification device 150 . When the notification device 150 receives the fixing unit abnormality signal, it notifies the user that printing did not end normally. For example, the notification device 150 displays a message to the effect that printing did not end normally, or emits a warning sound or voice.

[0064] The main CPU 111 executes the voltage determination process and the zero-cross signal determination process on the condition that the image forming apparatus 1 is powered on or the cover 20 is closed.

[0065] The voltage determination process is a process for determining whether or not the voltage value received from the low-voltage board CPU 124 is normal. The main CPU 111 executes a first voltage determination process and a second voltage determination process as the voltage determination process. The zero-cross signal determination process is a process for determining whether or not the period and pulse width of the zero-cross signal of the voltage of the AC power supply received from the low-voltage board CPU 124 are normal.

[0066] In this embodiment, when the image forming apparatus 1 is turned on or the cover 20 is closed, the low-voltage board 120 outputs a DC voltage of 6V to the main board 110.

[0067] The main CPU 111 transmits a first request signal to the low-voltage board CPU 124 via the first wireless communication unit 130 and the second wireless communication unit 140. The first request signal is a signal requesting the voltage value of the voltage that the low-voltage board 120 is supplying to the main board 110.

[0068] When the low-voltage board CPU 124 receives the first request signal, it transmits the voltage value of the voltage supplied to the main board 110 to the main CPU 111 via the second wireless communication unit 140 and the first wireless communication unit 130.

[0069] When the main CPU 111 receives a voltage value, it executes a first voltage determination process. In the first voltage determination process, if the received voltage value is equal to or greater than threshold value V1 and equal to or less than threshold value V2, the main CPU 111 determines that the voltage value is normal. As an example, threshold value V1 is a value obtained by subtracting a predetermined positive value α1 from 6 V. Threshold value V2 is a value obtained by adding a predetermined positive value α2 to 6 V. The predetermined values ​​α1 and α2 may be the same value or different values.

[0070] In the first voltage determination process, if the received voltage value is less than threshold value V1 or exceeds threshold value V2, main CPU 111 determines that the voltage value is abnormal. If main CPU 111 determines that the voltage value is abnormal in the first voltage determination process, it outputs a low-voltage substrate abnormality signal. The low-voltage substrate abnormality signal is a signal that indicates an abnormality in low-voltage substrate 120. If main CPU 111 determines that the voltage value is abnormal, it transmits the low-voltage substrate abnormality signal to alarm device 150.

[0071] When the alarm device 150 receives the low-voltage substrate abnormality signal, it notifies the user of the abnormality in the low-voltage substrate 120. For example, the alarm device 150 displays a message indicating that the low-voltage substrate 120 is abnormal, or emits a warning sound or voice.

[0072] When the main CPU 111 determines in the first voltage determination process that the voltage value is normal, it transmits a first voltage switching signal to the low-voltage board CPU 124 via the first wireless communication unit 130 and the second wireless communication unit 140. The first voltage switching signal is a signal requesting that the output voltage of the low-voltage board 120 be switched from 6V to 24V.

[0073] When the low-voltage board CPU 124 receives the first voltage switching signal, it switches the output voltage from 6 V to 24 V. In addition, the low-voltage board CPU 124 transmits the voltage value of the voltage being supplied to the main board 110 to the main CPU 111 via the second wireless communication unit 140 and the first wireless communication unit 130.

[0074] When the main CPU 111 receives the voltage value, it executes a second voltage determination process. In the second voltage determination process, if the received voltage value is equal to or greater than threshold V3 and equal to or less than threshold V4, the main CPU 111 determines that the voltage value is normal. As an example, threshold V3 is a value obtained by subtracting a predetermined positive value β1 from 24 V. Threshold V4 is a value obtained by adding a predetermined positive value β2 to 24 V. The predetermined values ​​β1 and β2 may be the same value or different values.

[0075] In the second voltage determination process, if the received voltage value is less than the threshold value V3 or exceeds the threshold value V4, the main CPU 111 determines that the voltage value is abnormal.

[0076] If the main CPU 111 determines in the second voltage determination process that the voltage value is abnormal, it transmits a second voltage switching signal to the low-voltage board CPU 124 via the first wireless communication unit 130 and the second wireless communication unit 140. The second voltage switching signal is a signal requesting that the output voltage of the low-voltage board 120 be switched from 24V to 6V.

[0077] When the low-voltage board CPU 124 receives the second voltage switch signal, it switches the output voltage from 24V to 6V to avoid continuing to output a DC voltage of 24V.

[0078] Furthermore, if the main CPU 111 determines in the second voltage determination process that the voltage value is abnormal, it outputs a low-voltage substrate abnormality signal and transmits the low-voltage substrate abnormality signal to the alarm device 150. When the notification device 150 receives the low-voltage substrate abnormality signal, it notifies the user of the abnormality in the low-voltage substrate 120.

[0079] When the main CPU 111 determines in the second voltage determination process that the voltage value is normal, it transmits a second request signal to the low-voltage substrate CPU 124 via the first wireless communication unit 130 and the second wireless communication unit 140. The second request signal is a signal that requests the period and pulse width of the zero-cross signal of the voltage of the AC power supply.

[0080] When the low-voltage substrate CPU 124 receives the second request signal, it transmits the period and pulse width of the zero-cross signal to the main CPU 111 via the second wireless communication unit 140 and the first wireless communication unit 130.

[0081] When the main CPU 111 receives the period and pulse width of the zero-cross signal, it executes a zero-cross signal determination process. In the zero-cross signal determination process, if the period of the zero-cross signal is equal to or greater than a threshold PR1 and equal to or less than a threshold PR2, the main CPU 111 determines that the period of the zero-cross signal is normal. In the zero-cross signal determination process, if the period of the zero-cross signal is less than the threshold PR1 or if the period of the zero-cross signal exceeds the threshold PR2, the main CPU 111 determines that the period of the zero-cross signal is abnormal.

[0082] Furthermore, in the zero-cross signal determination process, if the pulse width of the zero-cross signal is equal to or greater than the threshold value PW1 and equal to or less than the threshold value PW2, the main CPU 111 determines that the pulse width of the zero-cross signal is normal. In the zero-cross signal determination process, if the pulse width of the zero-cross signal is less than the threshold value PW1 or if the pulse width of the zero-cross signal exceeds the threshold value PW2, the main CPU 111 determines that the pulse width of the zero-cross signal is abnormal.

[0083] If the main CPU 111 determines that both the period and pulse width of the zero-cross signal are normal in the zero-cross signal determination process, it executes a warm-up operation, which includes, for example, raising the temperature of the fixing unit 70 to a predetermined target temperature, rotating the photosensitive drum 61, the developing roller 64, the agitator 67, and the like, and charging the surface of the photosensitive drum 61 to a predetermined potential.

[0084] When the main CPU 111 determines in the zero-cross signal determination process that at least one of the period and pulse width of the zero-cross signal is abnormal, it outputs an AC power supply abnormality signal. The AC power supply abnormality signal is a signal that indicates an abnormality in the AC power supply. When the main CPU 111 determines that at least one of the period and pulse width of the zero-cross signal is abnormal, it transmits the AC power supply abnormality signal to the alarm device 150.

[0085] When the alarm device 150 receives the AC power supply abnormality signal, it notifies the user of the abnormality in the AC power supply. For example, the alarm device 150 displays a message indicating that the AC power supply is abnormal, or emits a warning sound or voice.

[0086] Next, an example of the operation of the main board 110 and the low-voltage board 120 will be described with reference to a flowchart. As shown in FIG. 3, when the image forming apparatus 1 is powered on or the cover 20 is closed, the low-voltage board 120 starts outputting a DC voltage of 6 V (S111).

[0087] When a predetermined time has elapsed since the image forming device 1 was turned on or the cover 20 was closed, the main board 110 transmits a first request signal to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 (S112).

[0088] When the low-voltage board 120 receives the first request signal, it reads the voltage value VD of the voltage being output to the main board 110 (S113). Next, the low-voltage board 120 transmits the read voltage value VD to the main board 110 via the second wireless communication unit 140 and the first wireless communication unit 130 (S114).

[0089] When the main board 110 receives the voltage value VD, it executes a first voltage determination process (S120). Specifically, as shown in Fig. 5, the main board 110 determines whether the voltage value VD is equal to or greater than a threshold value V1 and equal to or less than a threshold value V2 (S121).

[0090] If the voltage value VD is not equal to or greater than the threshold V1 and equal to or less than the threshold V2 (S121, No), the main board 110 outputs a low-voltage board abnormality signal to the alarm device 150 (S122) and ends the process. The alarm device 150 notifies the user of the abnormality in the low-voltage board 120.

[0091] In step S121, if the voltage value VD is equal to or greater than the threshold value V1 and equal to or less than the threshold value V2 (Yes), the main board 110 continues the processing of the flowchart shown in Fig. 3. As shown in Fig. 3, if no abnormality is detected in the first voltage determination processing (S120), the main board 110 transmits a first voltage switching signal to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 (S131).

[0092] When the low-voltage board 120 receives the first voltage switching signal, it switches the output voltage from 6 V to 24 V (S132). Thereafter, the low-voltage board 120 reads the voltage value VD of the voltage being output to the main board 110 (S133). The low-voltage board 120 transmits the read voltage value VD to the main board 110 via the second wireless communication unit 140 and the first wireless communication unit 130 (S134).

[0093] When the main board 110 receives the voltage value VD, it executes a second voltage determination process (S140). Specifically, as shown in Fig. 6, the main board 110 determines whether the voltage value VD is equal to or greater than a threshold value V3 and equal to or less than a threshold value V4 (S141).

[0094] If the voltage value VD is not equal to or greater than the threshold V3 and equal to or less than the threshold V4 (S141, No), the main board 110 transmits a second voltage switching signal to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 (S142). When the low-voltage board 120 receives the second voltage switching signal, it switches the output voltage from 24 V to 6 V (S143).

[0095] Furthermore, the main board 110 outputs a low-voltage board abnormality signal to the notification device 150 (S144), and ends the process. The notification device 150 notifies the user of the abnormality in the low-voltage board 120.

[0096] In step S141, if the voltage value VD is equal to or greater than the threshold value V3 and equal to or less than the threshold value V4 (Yes), the main board 110 continues the processing of the flowchart shown in Fig. 3. As shown in Fig. 3, if no abnormality is detected in the second voltage determination processing (S140), the main board 110 transmits a second request signal to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 (S151).

[0097] When the low-voltage board 120 receives the second request signal, it acquires the period and pulse width of the zero-cross signal (S152). Next, the low-voltage board 120 transmits the period and pulse width of the zero-cross signal to the main board 110 via the second wireless communication unit 140 and the first wireless communication unit 130 (S153).

[0098] When the main board 110 receives the period and pulse width of the zero-cross signal, it executes a zero-cross signal determination process (S160). Specifically, as shown in Fig. 7, the main board 110 determines whether the period PR of the zero-cross signal is equal to or greater than a threshold value PR1 and equal to or less than a threshold value PR2 (S161).

[0099] If the period PR of the zero-cross signal is greater than or equal to the threshold PR1 and less than or equal to the threshold PR2 (S161, Yes), the main board 110 determines whether the pulse width PW of the zero-cross signal is greater than or equal to the threshold PW1 and less than or equal to the threshold PW2 (S162).

[0100] If the period PR is not equal to or greater than the threshold value PR1 and equal to or less than the threshold value PR2 in step S161 (No), or if the pulse width PW is not equal to or greater than the threshold value PW1 and equal to or less than the threshold value PW2 in step S162 (No), the main board 110 outputs an AC power supply abnormality signal to the alarm device 150 (S163) and ends the process. The alarm device 150 notifies the user of the abnormality in the AC power supply.

[0101] In step S162, if the pulse width PW of the zero-cross signal is equal to or greater than the threshold value PW1 and equal to or less than the threshold value PW2 (Yes), the main board 110 proceeds to step S171 in Fig. 4. Note that the order in which the period and pulse width of the zero-cross signal are determined is arbitrary.

[0102] If no abnormality is detected in the zero-cross signal determination process (step S160 in Figure 3), as shown in Figure 4, the main board 110 transmits a control signal (warm-up target temperature) to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 (S171).

[0103] When the low-voltage substrate 120 receives the warm-up target temperature, it turns on the heater 71A of the heating unit 71 (S172). Thereafter, the low-voltage substrate 120 determines whether a first predetermined time has elapsed since the heater 71A was turned on (S173). If the first predetermined time has not elapsed (No in S173), the low-voltage substrate 120 determines whether the temperature of the fixing device 70 based on the detection signal received from the temperature sensor 74 has reached the warm-up target temperature (S174).

[0104] If the warm-up target temperature has not been reached (S174, No), the low-voltage board 120 determines whether a first predetermined time has elapsed (S173). If the first predetermined time has elapsed (S173, Yes), the low-voltage board 120 transmits a fuser abnormality signal to the main board 110 via the second wireless communication unit 140 and the first wireless communication unit 130 (S181).

[0105] When the main board 110 receives the fuser abnormality signal from the low-voltage board 120, it transmits the fuser abnormality signal to the notification device 150 (S182) and ends the process. The notification device 150 notifies the user of the abnormality in the fuser 70.

[0106] In step S174, if the temperature of the fixing device 70 reaches the warm-up target temperature (Yes), the low-voltage board 120 transmits a fixing device warm-up completion signal to the main board 110 via the second wireless communication unit 140 and the first wireless communication unit 130 (S191).

[0107] The main board 110 receives the fixing unit warm-up end signal (S192). If the warm-up operation of the entire image forming apparatus 1 is completed (S193, Yes), the main board 110 ends the process.

[0108] 8, when the main board 110 receives a print job and starts a printing operation, it transmits a control signal (print target temperature) to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 (S211). When the low-voltage board 120 receives the print target temperature, it turns on the heater 71A and controls the heater 71A based on the print target temperature (S212).

[0109] When printing is completed (S213, Yes), the main board 110 transmits an end signal to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 (S221). When the low-voltage board 120 receives the end signal, it turns off the heater 71A (S222). Thereafter, the low-voltage board 120 determines whether a second predetermined time has elapsed since the heater 71A was turned off (S223).

[0110] If the second predetermined time has elapsed (S223, Yes), the low-voltage board 120 determines whether the temperature of the fuser 70 has fallen below a predetermined temperature (S224). If the temperature of the fuser 70 has not fallen below the predetermined temperature (S224, No), the low-voltage board 120 transmits a fuser abnormality signal to the main board 110 via the second wireless communication unit 140 and the first wireless communication unit 130 (S231).

[0111] When the main board 110 receives the fuser abnormality signal from the low-voltage board 120, it transmits the fuser abnormality signal to the notification device 150 (S232) and ends the process (abnormal end). The notification device 150 notifies the user that printing did not end normally.

[0112] In step S224, if the temperature of the fixing unit 70 is equal to or lower than the predetermined temperature (Yes), the low-voltage board 120 transmits a fixing unit normal signal to the main board 110 via the second wireless communication unit 140 and the first wireless communication unit 130 (S241). When the main board 110 receives the fixing unit normal signal, it ends the process and puts the image forming apparatus 1 into a standby state (normal end).

[0113] Next, the effects of the embodiment will be described. The ability to transmit control signals from the main board 110 to the low-voltage board 120 via the first wireless communication unit 130 and the second wireless communication unit 140 makes it possible to reduce the number of harnesses that electrically connect the main board 110 and the low-voltage board 120. This reduces the effort required when replacing the low-voltage board 120.

[0114] Although the embodiment has been described above, the image forming apparatus can be modified as appropriate as exemplified below.

[0115] For example, signals from the low voltage board 120 may be transmitted to the main board 110 via a harness.

[0116] In the above-described embodiment, the temperature sensor 74 of the fixing unit 70 was electrically connected to the low-voltage board 120 and was capable of transmitting a detection signal to the low-voltage board 120, but for example, the temperature sensor may be electrically connected to the main board and be capable of transmitting a detection signal to the main board.

[0117] In the above-described embodiment, the main board 110 transmits the target temperature of the fuser 70 as a control signal to the low-voltage board 120, but this is not limiting. For example, the main board may calculate a control amount for the fuser (heater, etc.) based on the target temperature of the fuser and the temperature of the fuser based on a detection signal received from a temperature sensor, and transmit the calculated control amount to the low-voltage board as a control signal.

[0118] In the above embodiment, the low-voltage board 120 was capable of supplying two types of DC voltages (24V and 6V) to the main board 110, but for example, the low-voltage board may be capable of supplying three or more types of DC voltages to the main board, or may be capable of supplying one type of DC voltage to the main board. If the low-voltage board is capable of supplying multiple types of DC voltages to the main board, it is desirable for the main board to perform voltage determination processing for each voltage.

[0119] In the above-described embodiment, the main CPU 111 executes the voltage determination process, but for example, the low-voltage substrate CPU may execute the voltage determination process. Similarly, in the above-described embodiment, the main CPU 111 executes the zero-cross signal determination process, but for example, the low-voltage substrate CPU may execute the zero-cross signal determination process.

[0120] In the above-described embodiment, the first wireless communication unit 130 is located on the main board 110, but for example, the first wireless communication unit may not be located on the main board and may be electrically connected to the main board by a harness. Similarly, in the above-described embodiment, the second wireless communication unit 140 is located on the low-voltage board 120, but for example, the second wireless communication unit may not be located on the low-voltage board and may be electrically connected to the low-voltage board by a harness.

[0121] In the above-described embodiment, the image forming apparatus 1 is a printer capable of forming only monochrome images, but the image forming apparatus may be, for example, a printer capable of forming color images, a copier, a multifunction peripheral, or the like.

[0122] The elements described in the above-described embodiment and modifications may be implemented in any combination. [Explanation of symbols]

[0123] 1. Image forming device 10 Main unit housing 70 Fixing unit 110 Main board 120 Low voltage board 130 First wireless communication unit 140 Second wireless communication unit

Claims

1. An image forming apparatus, A main body housing; A fixing unit; a main board capable of outputting a control signal for controlling the fixing unit; a low-voltage substrate capable of outputting power to the fixing unit; a first wireless communication unit electrically connected to the main board and capable of transmitting the control signal; an image forming apparatus comprising: a second wireless communication unit electrically connected to the low-voltage board, the second wireless communication unit being capable of receiving the control signal;

2. the main board transmits the control signal to the low-voltage board via the first wireless communication unit and the second wireless communication unit; 2. The image forming apparatus according to claim 1, wherein the low-voltage board controls the power output to the fixing unit based on the control signal.

3. 3. The image forming apparatus according to claim 2, wherein the fixing unit includes a temperature sensor electrically connected to the low-voltage board and capable of transmitting a detection signal indicating the temperature of the fixing unit to the low-voltage board.

4. the control signal is a signal indicating a target temperature of the fixing unit, the main board has a main CPU capable of transmitting the control signal to the low-voltage board via the first wireless communication unit and the second wireless communication unit, 4. The image forming apparatus according to claim 3, wherein the low-voltage board has a low-voltage board CPU that controls the power output to the fixing unit based on the control signal and the detection signal received from the temperature sensor.

5. The image forming apparatus according to claim 4, wherein the main CPU transmits an end signal indicating the end of printing using the image forming apparatus to the low-voltage board CPU via the first wireless communication unit and the second wireless communication unit.

6. 6. The image forming apparatus according to claim 5, wherein the low-voltage board CPU transmits a fuser abnormality signal indicating an abnormality in the fuser to the main CPU via the second wireless communication unit and the first wireless communication unit.

7. 7. The image forming apparatus according to claim 6, wherein the low-voltage board CPU receives the end signal and, if the temperature of the fixing device based on the detection signal received from the temperature sensor does not fall below a predetermined temperature within a predetermined time, sends the fixing device abnormality signal to the main CPU.

8. The main board has a main CPU, the low-voltage board has a low-voltage board CPU; the low-voltage board is capable of supplying a predetermined voltage to the main board; 2. The image forming apparatus according to claim 1, wherein the main CPU transmits a first request signal to the low-voltage board CPU via the first wireless communication unit and the second wireless communication unit, requesting the voltage value of the voltage supplied to the main board by the low-voltage board.

9. 9. The image forming apparatus according to claim 8, wherein when the low-voltage board CPU receives the first request signal, the low-voltage board CPU transmits the voltage value to the main CPU via the second wireless communication unit and the first wireless communication unit.

10. 10. The image forming apparatus according to claim 9, wherein the main CPU executes a voltage determination process for determining whether the voltage value received from the low-voltage board CPU is normal.

11. The main CPU On the condition that the image forming device is turned on, or On the condition that a cover for opening and closing the opening of the main body housing is closed, 11. The image forming apparatus according to claim 10, wherein the first request signal is sent to the low-voltage board CPU.

12. 11. The image forming apparatus according to claim 10, wherein the main CPU outputs a low-voltage board abnormality signal indicating an abnormality in the low-voltage board when the main CPU determines in the voltage determination process that the voltage value is abnormal.

13. The main board has a main CPU, the low-voltage board has a low-voltage board CPU; 2. The image forming apparatus according to claim 1, wherein the main CPU transmits a second request signal requesting the period and pulse width of the zero-cross signal of the voltage of the AC power supply to the low-voltage board CPU via the first wireless communication unit and the second wireless communication unit.

14. The image forming apparatus according to claim 13, wherein when the low-voltage board CPU receives the second request signal, the low-voltage board CPU transmits the period and pulse width of the zero-cross signal to the main CPU via the second wireless communication unit and the first wireless communication unit.

15. 15. The image forming apparatus according to claim 14, wherein the main CPU executes a zero-cross signal determination process for determining whether or not the period and pulse width of the received zero-cross signal are normal.

16. The main CPU On the condition that the image forming device is turned on, or On the condition that a cover for opening and closing the opening of the main body housing is closed, 16. The image forming apparatus according to claim 15, wherein the second request signal is sent to the low-voltage board CPU.

17. 16. The image forming apparatus according to claim 15, wherein the main CPU outputs an AC power supply abnormality signal indicating an abnormality in the AC power supply when it determines in the zero-cross signal determination process that at least one of the period and pulse width of the zero-cross signal is abnormal.

18. 2. The image forming apparatus according to claim 1, further comprising a harness that electrically connects the main board and the low-voltage board, the harness supplying a voltage to the main board.

19. 2. The image forming apparatus according to claim 1, wherein the first wireless communication unit is located on the main board.

20. 2. The image forming apparatus according to claim 1, wherein the second wireless communication unit is located on the low-voltage board.

Images