Image processing device

Abstract

This technology contributes to reducing costs when expanding the number of terminals in a controller. [Solution] The multifunction printer 1 is characterized by comprising: motors 111 to 114; motor drivers MD1 to MD4 connected to motors 111 to 114 for driving the motors 111 to 114; a main controller 100 connected to motor drivers MD1 to MD4 by a plurality of first signal lines L1; and a subcontroller 105 with a lower processing capacity than the main controller 100, which is connected to motor drivers MD1 to MD4 by at least one second signal line L2 and to the main controller 100 by at least one third signal line L3.

Description

Technical Field

[0001] The present application relates to an image processing apparatus that performs operation control with a plurality of controllers.

Background Art

[0002] Patent Document 1 describes an image reading apparatus configured to control various functions including one motor driver by one controller.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] By the way, in order for a single controller to control more functions than those controlled by the image reading apparatus described in Patent Document 1, the number of terminals and internal functions provided in the controller are insufficient, and cases can be considered where an external expansion controller is added to the controller.

[0005] In such cases, when an external expansion controller is provided with both functions capable of processing high-speed and complex signals and low-speed and simple signals, it has been necessary to select a relatively high-function, high-price controller.

[0006] An object of the present application is to provide a technology that can contribute to cost reduction when expanding the number of terminals of a controller.

Means for Solving the Problem

[0007] To achieve the above objective, the image processing apparatus described in the embodiment is characterized by comprising: a motor; a motor driver connected to the motor for driving the motor; a main controller connected to the motor driver by a plurality of first signal lines; and a subcontroller having a lower processing capacity than the main controller, which is connected to the motor driver by at least one second signal line and to the main controller by at least one third signal line. [Effects of the Invention]

[0008] According to the image processing apparatus described in the embodiment, since an inexpensive sub-controller with lower processing power than the main controller is used, it is possible to contribute to cost reduction when expanding the number of controller terminals. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing the schematic configuration of a multifunction device according to one embodiment. [Figure 2] This figure shows an example of signals transmitted and received by the main controller and sub-controller for controlling the multifunction printer shown in Figure 1. [Figure 3] This figure shows an example of a signal that differs from the one shown in Figure 2, which is transmitted and received by the main controller and sub-controller. [Figure 4] This flowchart shows the procedure for motor driver control processing performed by the main controller. [Figure 5] This flowchart shows the steps involved in the configuration process performed by the subcontroller. [Modes for carrying out the invention]

[0010] The embodiments of this application will be described in detail below with reference to the drawings.

[0011] Figure 1 is a cross-sectional view showing the schematic configuration of a multifunction device 1 according to one embodiment. The multifunction device 1 is an example of an image processing device and has printing, copying, and scanning functions, etc. The multifunction device may also have a fax function added to these functions. For the sake of explanation, the vertical and horizontal directions of the multifunction device 1 are defined below, as indicated by the arrows in Figure 1. Furthermore, the left-right direction is defined as the direction from the front of the multifunction device 1, with the left side being the left hand and the right side being the right hand of the user facing the multifunction device 1.

[0012] The multifunction device 1 comprises an image forming unit 2 and an image reading unit 9. The image forming unit 2 has a printing function that forms an image on a sheet S. The image reading unit 9 has a scanning function that reads an image from a document and generates image data of the read image.

[0013] The printing method of the image forming unit 2 is, for example, an electrophotographic method. Furthermore, the image forming unit 2 is capable of printing only monochrome images, but is not limited to this; it may also be capable of printing both color and monochrome images. The image reading unit 9 may be capable of reading both color and monochrome images, or it may be capable of reading only monochrome images.

[0014] The multifunction printer 1 is equipped with an operation panel PA on its front. The operation panel PA includes, for example, a touch panel in which a touchpad and display are integrally formed, and a key button section. The operation panel PA receives user input and outputs the received information to the main controller 100 (see Figure 2). The user can, for example, instruct the multifunction printer 1 to print and copy by operating the operation panel PA. Alternatively, cut printing and cut copying can also be instructed to the multifunction printer 1 by operating the operation panel PA. Cut printing is a job in which an image is printed onto a sheet S by the image forming unit 2, and then the sheet S is cut. Cut copying is a job in which an image is read from a document by the image reading unit 9, the read image is printed onto a sheet S by the image forming unit 2, and then the sheet S is cut.

[0015] The image forming unit 2 comprises a main body 20, a transport unit 3, a processing unit 4, a fuser 6, and a cutter 10.

[0016] The main body 20 is formed in a roughly rectangular parallelepiped shape and includes a front cover 21, a rear cover 23, a supply tray 31, a discharge tray 22, a transport path 201, and a re-transport path 202. The front cover 21 is attached to the front of the main body 20 in a manner that allows it to be opened and closed. The rear cover 23 is attached to the rear of the main body 20 in a manner that allows it to be opened and closed. The supply tray 31 is attached to the bottom of the main body 20 in a manner that allows it to be attached and detached. A sheet S is placed on the supply tray 31. The sheet S is a standard-sized sheet such as A4 size. The sheet S is a paper medium such as plain paper or cardboard, but is not limited to this and may also be OHP film. The discharge tray 22 is provided on the top of the main body 20 and the sheet S on which the image is formed is placed on the discharge tray 22.

[0017] The transport path 201 is a path for transporting the sheet S placed on the supply tray 31 to the discharge tray 22 via the process unit 4. The transport path 201 branches from the first branching position D1 into the first discharge path 201A and the second discharge path 201B. Therefore, the sheet S transported via the process unit 4 may be discharged to the discharge tray 22 via the first discharge path 201A, or via the second discharge path 201B.

[0018] The re-transport path 202 is a path for transporting the sheet S, on which an image has been formed on one side, in the opposite direction to the transport direction, and transporting it again towards the process section 4. The re-transport path 202 branches off from the transport path 201 at the second branching position D2 and rejoins the transport path 201 at the merging position J on the upstream side of the transport direction of the pre-register sensor SE1.

[0019] The conveying unit 3 includes a pickup roller 33, a separation roller 34, a registration roller 35, a conveying roller 36, a first discharge roller 85, a second discharge roller 86, a third discharge roller 87, a flapper 88, re-conveying rollers 38 and 39, a three-phase DC motor 111 for sheet conveying (see FIG. 2) and a stepping motor 112 for sheet discharge (see FIG. 2). Hereinafter, the three-phase DC motor 111 for sheet conveying may be abbreviated as the sheet conveying motor 111. Also, the stepping motor 112 for sheet discharge may be abbreviated as the sheet discharge motor 112.

[0020] The pickup roller 33 picks up the sheets S in the supply tray 31 pushed upward by the sheet pressing plate 32, and conveys the sheets S toward the conveying path 201. The separation roller 34 separates the sheets S picked up by the pickup roller 33 one by one.

[0021] The registration roller 35 is arranged on the upstream side of the process unit 4 in the conveying path 201. After aligning the leading edge of the sheet S, the registration roller 35 conveys the sheet S toward the process unit 4. The conveying roller 36 conveys the sheet S that has passed through the fixing device 6 toward the first discharge roller 85 or the third discharge roller 87.

[0022] The first discharge roller 85 and the second discharge roller 86 are arranged in the first discharge path 201A. The first discharge roller 85 and the second discharge roller 86 form a roller pair including a driving roller and a driven roller. The first discharge roller 85 is arranged at a position upstream of the cutter position B where the cutter 10 is arranged, and the second discharge roller 86 is arranged at a position downstream of the cutter position B.

[0023] The first discharge roller 85 and the second discharge roller 86 rotate in the forward direction to discharge the sheet S onto the discharge tray 22. The forward rotation is rotation that conveys the sheet S in the conveying direction, and corresponds to counterclockwise rotation about the left-right direction of the main body 20 when viewed from the left side of the apparatus as shown in FIG. 1.

[0024] Meanwhile, the third discharge roller 87 is located in the second discharge path 201B. The third discharge roller 87 is also a roller pair consisting of a drive roller and a driven roller. The third discharge roller 87 discharges the sheet S to the discharge tray 22 by rotating in the forward direction. The third discharge roller 87 also transports the sheet S to the re-transport path 202 by rotating in the opposite direction to the forward direction. Reversing is a rotation that transports the sheet S in the opposite direction to the transport direction, and as shown in Figure 1, when viewed from the left side of the device, it corresponds to a clockwise rotation with the left-right direction of the main body 20 as the axis.

[0025] Retransport rollers 38 and 39 are arranged in the retransport path 202. The retransport rollers 38 and 39 transport the sheet S that has been transported in the retransport path 202 toward the process section 4. By retransporting the sheet S, on which an image has been formed on one side, toward the process section 4 via the retransport path 202 using the retransport rollers 38 and 39, it is possible to form an image on both sides of the sheet S.

[0026] The process unit 4 forms an image on the sheet S and is housed within the main body 20. The process unit 4 includes a drum cartridge 5 and a laser unit 7. The drum cartridge 5 includes a photoreceptor drum 51, a toner storage unit 57, a supply roller 56, a developer roller 55, a charger 52, a transfer roller 53, and a pinch roller 54. The drum cartridge 5 can be removed from the main body 20 by opening the front cover 21. The pinch roller 54 of the drum cartridge 5 faces the registration roller 35. The pinch roller 54 rotates in accordance with the rotation of the registration roller 35 and transports the sheet S together with the registration roller 35.

[0027] The photoreceptor drum 51 rotates clockwise due to the driving force output from the sheet transport motor 111 (see Figure 2), thereby transporting the sheet S in the transport direction. In the photoreceptor drum 51, the forward rotation, which transports the sheet S in the transport direction, is clockwise when viewed from the left side of the device, as shown in Figure 1. The toner storage section 57 contains toner. The supply roller 56 supplies the toner from the toner storage section 57 to the developing roller 55. The charger 52 is a Scorotron-type charger that uniformly charges the surface of the photoreceptor drum 51. Note that the charger 52 may also be a charging roller.

[0028] A transfer roller 53 is positioned opposite the photoreceptor drum 51. The transfer roller 53 forms a transfer nip TN between itself and the photoreceptor drum 51 in the transport path 201. A transfer belt may be used instead of the transfer roller 53.

[0029] The main body 20 has a laser unit 7 at its upper interior. The laser unit 7 includes a polygon mirror (not shown), a laser light emitter, a polygon motor, a lens, and a reflector. The laser unit 7 exposes the surface of the photoreceptor drum 51 by rapidly scanning the surface of the photoreceptor drum 51 with laser light (see dashed line in Figure 1) based on image data emitted from the laser light emitter 132.

[0030] The surface of the photoreceptor drum 51 is exposed by the laser unit 7, forming an electrostatic latent image based on the image data. The developing roller 55 supplies toner to the electrostatic latent image formed on the surface of the photoreceptor drum 51, thereby forming a toner image on the surface of the photoreceptor drum 51.

[0031] A transfer voltage is applied to the transfer roller 53 by a voltage application unit (not shown). The transfer roller 53 transports the sheet S between itself and the photoreceptor drum 51, thereby transferring the toner image formed on the surface of the photoreceptor drum 51 to the sheet S as it passes through the transfer nip TN. In this way, an image is formed on the sheet S.

[0032] A fuser unit 6 is located downstream of the process unit 4 in the transport path 201. The fuser unit 6 includes a heating roller 61, a pressure roller 62, a heater (not shown), and fuser thermistors 150, 151 (see Figure 3). The heating roller 61 heats the sheet S. The pressure roller 62 forms a nip N with the heating roller 61 and pressurizes the sheet S. The pressure roller 62 rotates counterclockwise due to the driving force of the sheet transport motor 111. In the case of the pressure roller 62, the forward rotation, which is the rotation that transports the sheet S in the transport direction, is counterclockwise when viewed from the left side of the device, as shown in Figure 1.

[0033] The heater is, for example, a halogen heater, which heats the heating roller 61. The fuser thermistor 150 is located near the center of the heating roller 61 and detects the temperature of the center of the heating roller 61. The fuser thermistor 151 is located near one end of the heating roller 61 and detects the temperature of one end of the heating roller 61. The fuser thermistors 150 and 151 output signals corresponding to the detected temperatures to the main controller 100 (see Figure 2). Note that a fuser thermistor 151 that detects the temperatures of both ends of the heating roller 61 may also be used.

[0034] The fuser unit 6 heats the sheet S with the heating roller 61 and rotates the pressure roller 62, thereby pressing and transporting the sheet S with the heating roller 61 and pressure roller 62, and fixing the image formed on the sheet S by the process unit 4 to the sheet S.

[0035] The fuser 6 is configured to include a heating roller 61, a pressure roller 62, and a heater, but is not limited to this configuration. For example, the fuser 6 may have a heater, a nip plate that receives radiant heat from the heater, a heating belt that rotates around the nip plate, and a pressure roller.

[0036] Furthermore, the fuser 6 may have a substrate on which a heating pattern is formed, a belt that rotates around the substrate, and a pressure roller, with the substrate and belt in contact. Alternatively, the fuser 6 may have a heating roller, a heater, and a pressure belt.

[0037] In the first discharge path 201A, a cutter 10 is positioned at cutter position B between the first discharge roller 85 and the second discharge roller 86. The composite machine 1 stops the rotation of the first discharge roller 85 and the second discharge roller 86 so that the cutting position on the sheet S reaches cutter position B. With the rotation of the first discharge roller 85 and the second discharge roller 86 stopped, the composite machine 1 uses the cutter 10 to cut the sheet S at cutter position B.

[0038] Furthermore, the length of the second discharge path 201B is designed to be shorter than the length of the first discharge path 201A. This is to allow the sheet S to be quickly discharged to the outside of the main body 20 when the sheet S is not cut after image formation.

[0039] Next, a part of the electrical configuration of the multifunction device 1 will be explained with reference to Figures 2 and 3. As shown in Figures 2 and 3, the multifunction device 1 is equipped with a main controller 100 and a sub-controller 105. Both the main controller 100 and the sub-controller 105 are configured, for example, with an ASIC (Application Specific Integrated Circuit) and perform general control of each part of the multifunction device 1. However, the control performed by the main controller 100 and the control performed by the sub-controller 105 are separated. The sub-controller 105 was added because the number of terminals and internal functions provided by the main controller 100 alone are insufficient to control each part of the multifunction device 1. In other words, the sub-controller 105 is designed to function as an external expansion controller. Furthermore, in order to reduce the cost of adding an external expansion controller, a less expensive sub-controller 105 is used than the main controller 100. The price of a controller is roughly proportional to its processing power, so the processing power of the sub-controller 105 is lower than that of the main controller 100. Processing power is roughly proportional to the operating clock frequency. For example, while the subcontroller 105 operates at a clock frequency of 20 MHz, the main controller 100 operates at a clock frequency of 300 MHz. The specific values ​​for each operating clock frequency are merely examples, and other values ​​may be used.

[0040] As shown in Figure 2, the main controller 100 and the sub-controller 105 are connected via a third signal line L3 and communicate with each other using a UART (Universal Asynchronous Receiver Transmitter). An example of the content communicated between the main controller 100 and the sub-controller 105 via the third signal line L3 will be described later based on Figures 4 and 5.

[0041] Furthermore, as shown in Figure 2, the main controller 100 is connected to the motor drivers MD1 to MD4 via the first signal line L1. The sub-controller 105 is also connected to the motor drivers MD1 to MD4 via the second signal line L2.

[0042] The motor driver MD1 is connected to the sheet transport motor 111 and controls the drive of the sheet transport motor 111 based on control signals from the main controller 100 and the sub-controller 105. The sheet transport motor 111 outputs driving force to the pickup roller 33, registration roller 35, transport roller 36, re-transport rollers 38, 39, pressure roller 62, and drum cartridge 5. When the main controller 100 and the sub-controller 105 drive the sheet transport motor 111 in the forward direction via the motor driver MD1, the output of the sheet transport motor 111 transmits driving force to the transport roller 36, pressure roller 62, photoreceptor drum 51, developer roller 55, pickup roller 33, and registration roller 35. The transport roller 36, pressure roller 62, photoreceptor drum 51, developer roller 55, pickup roller 33, and registration roller 35 then rotate in a direction that transports the sheet S in the transport direction.

[0043] Specifically, the transport roller 36 and the pressure roller 62 rotate counterclockwise when viewed from the left side of the device, as shown in Figure 1. The photoreceptor drum 51 rotates clockwise. The developing roller 55 rotates counterclockwise. The pickup roller 33 rotates counterclockwise. The registration roller 35 rotates counterclockwise.

[0044] On the other hand, even if the main controller 100 and sub-controller 105 reverse-drive the sheet transport motor 111 via the motor driver MD1, the drive force is not transmitted to the transport roller 36, pressure roller 62, drum cartridge 5, pickup roller 33, and registration roller 35.

[0045] Furthermore, the main controller 100 and sub-controller 105 drive the sheet transport motor 111 in the forward direction, thereby transmitting driving force to the re-transport rollers 38 and 39, causing them to rotate clockwise. On the other hand, the main controller 100 and sub-controller 105 drive the sheet transport motor 111 in the reverse direction, thereby transmitting driving force to the re-transport rollers 38 and 39, causing them to rotate clockwise.

[0046] As described above, the sheet transport motor 111 is composed of a 3-phase DC motor, so the motor driver MD1 is a 3-phase DC motor driver. The first signal line L1 connecting the main controller 100 and the motor driver MD1 includes the CLKIN signal line L1_11, the SCS signal line L1_12, the SCLK signal line L1_13, the SDATAI signal line L1_14, the SDATAO signal line L1_15, and the HALL signal line L1_16. Here, the signal CLKIN transmitted via the CLKIN signal line L1_11 is a rotation speed command signal. The signal SCS transmitted via the SCS signal line L1_12 is a serial device selection signal. The signal SCLK transmitted via the SCLK signal line L1_13 is a serial communication clock signal. The signal SDATAI transmitted via the SDATAI signal line L1_14 is a serial communication input signal. The signal SDATAO transmitted on the SDATAO signal line L1_15 is a serial communication output signal. The signal HALL received on the HALL signal line L1_16 is a sensing signal from a Hall element. The second signal line L2, which connects the subcontroller 105 and the motor driver MD1, includes the RESET signal line L2_11. Here, the signal RESET transmitted on the RESET signal line L2_11 is a reset signal. A detailed explanation of the control signals from the main controller 100 and the subcontroller 105, and the specific control processing that the motor driver MD1 performs on the sheet transport motor 111 based on these control signals, is omitted. This is because, in this embodiment, both the 3-phase DC motor and the 3-phase DC motor driver are general-purpose and not unique. Furthermore, a key feature of this embodiment lies in which signal lines connect the main controller 100 and the motor driver MD1, and which connection lines connect the subcontroller 105 and the motor driver MD1. In other words, the key feature of this embodiment is that it defines the division of roles between the main controller 100 and the sub-controller 105 with respect to the motor driver MD1.

[0047] The reason why only the RESET signal is output from the sub-controller 105 as a control signal to the motor driver MD1, and all other signals are output or input from the main controller 100, is as follows: The sheet transport motor 111 needs to change its rotational speed while in operation, so the value of the control signal to the motor driver MD1 needs to be switched frequently. For this reason, almost all of the control signals to the motor driver MD1 are assigned to the main controller 100, which has high processing power. In contrast, the RESET signal is output to the motor driver MD1 before the sheet transport motor 111 is driven, and the value output to the motor driver MD1 is not switched while the sheet transport motor 111 is in operation. For this reason, the RESET signal is assigned to the sub-controller 105, which has low processing power.

[0048] The motor driver MD2 is connected to the sheet discharge motor 112 and controls the drive of the sheet discharge motor 112 based on control signals from the main controller 100 and the sub-controller 105. The motor driver MD2 controls the drive of the sheet discharge motor 112 in accordance with control signals from the main controller 100 and the sub-controller 105. As described above, the sheet discharge motor 112 is a stepping motor and transmits driving force to the first discharge roller 85, the second discharge roller 86, and the third discharge roller 87. When the main controller 100 and the sub-controller 105 drive the sheet discharge motor 112 in the forward direction via the motor driver MD2, the first discharge roller 85, the second discharge roller 86, and the third discharge roller 87 rotate in the counterclockwise direction. As a result, the sheet S is discharged to the discharge tray 22 via the first discharge path 201A or the second discharge path 201B. Meanwhile, the main controller 100 and the sub-controller 105 reverse the drive of the sheet discharge motor 112, thereby rotating the first discharge roller 85, the second discharge roller 86, and the third discharge roller 87 clockwise. As a result, the sheet S being transported in the second discharge path 201B is transported in the opposite direction to the transport direction.

[0049] Since the seat ejection motor 112 is a stepping motor, the motor driver MD2 is a stepping motor driver. The first signal line L1 connecting the main controller 100 and the motor driver MD2 includes the STEP signal line L1_21 and the VREF signal line L1_22. Here, the signal STEP transmitted on the STEP signal line L1_21 is a rotation step command signal. The signal VREF transmitted on the VREF signal line L1_22 is a current amount command signal. The second signal line L2 connecting the subcontroller 105 and the motor driver MD1 includes the SLEEP signal line L2_21, the ENABLE signal line L2_22, the DIR signal line L2_23, and the USM[1:0] signal line L2_24. Here, the signal SLEEP transmitted on the SLEEP signal line L2_21 is a driver enable / disable command signal. The signal ENABLE transmitted via the ENABLE signal line L2_22 is an excitation enable / deactivate signal. The signal DIR transmitted via the DIR signal line L2_23 is a rotation direction command signal. The signal USM[1:0] transmitted via the USM[1:0] signal line L2_24 is an excitation phase command signal. A detailed explanation of the control signals from the main controller 100 and the sub-controller 105, and the specific control processing that the motor driver MD2 performs on the seat ejection motor 112 based on these control signals, will be omitted. This is because, in this embodiment, both the stepping motor and the stepping motor driver are general-purpose and not unique. Furthermore, a key feature of this embodiment lies in determining which signal lines connect the main controller 100 and the motor driver MD2, and which connection lines connect the sub-controller 105 and the motor driver MD2. In other words, a key feature of this embodiment lies in determining the division of roles between the main controller 100 and the sub-controller 105 with respect to the motor driver MD2.

[0050] The reason why the main controller 100 outputs the signals STEP and VREF as control signals to the motor driver MD2, and the sub-controller 105 outputs the signals SLEEP, ENABLE, DIR, and USM[1:0] is as follows: The seat ejection motor 112 needs to change its rotational speed while in operation, so the values ​​of the control signals to the motor driver MD2 need to be switched frequently. For this reason, the signals STEP and VREF, which are necessary for changing the rotational speed among the control signals to the motor driver MD2, are assigned to the main controller 100, which has high processing power. In contrast, the signals SLEEP, ENABLE, DIR, and USM[1:0] are output to the motor driver MD2 before the seat ejection motor 112 is driven, and the values ​​output to the motor driver MD2 are not switched while the seat ejection motor 112 is in operation. For this reason, the signals SLEEP, ENABLE, DIR, and USM[1:0] are assigned to the sub-controller 105, which has low processing power.

[0051] Motor driver MD3 is connected to the FB (flatbed) stepping motor 113 included in the image reading unit 9. Motor driver MD4 is connected to the ADF (automatic document feeder) stepping motor 114 included in the image reading unit 9. Hereinafter, the FB stepping motor 113 may be referred to as the FB motor 113, and the ADF stepping motor 114 may be referred to as the ADF motor 114. The image reading unit 9 is configured to read images on a document by switching between FB reading, in which the FB motor 113 drives a drive pulley (not shown) to move a CIS (contact image sensor) unit (not shown) in the sub-scanning direction to read an image on the document placed on the platen glass 91 (see Figure 1), and ADF reading, in which the CIS unit is fixed and the ADF motor 114 drives a transport roller (not shown) to transport the document to the CIS unit and read an image on the document. If FB reading is selected, motor driver MD3 controls the drive of FB motor 113 based on control signals from main controller 100 and sub-controller 105. On the other hand, if ADF reading is selected, motor driver MD4 controls the drive of ADF motor 114 based on control signals from main controller 100 and sub-controller 105.

[0052] The first signal line L1 connecting the main controller 100 and the motor driver MD3 includes the STEP signal line L1_31 and the VREF signal line L1_32, as well as the USM[1:0] signal line L1_33. On the other hand, the second signal line L2 connecting the sub-controller 105 and the motor driver MD3 includes the SLEEP signal line L2_31, the ENABLE signal line L2_32, and the DIR signal line L2_33. Compared to the first and second signal lines L2 connecting the main controller 100 and the motor driver MD2, the difference is that the USM[1:0] signal line L1_23, which was included in the second signal line L2, is now included in the first signal line L1. This difference also applies to the first and second signal lines L1 and L2 connecting the main controller 100 and the motor driver MD4. This is because the FB motor 113 and the ADF motor 114 need to switch their excitation phase while in operation.

[0053] Next, we will explain whether the various control components, including various sensors, are connected to the main controller 100 or the sub-controller 105.

[0054] The ADF front sensor 120 and the ADF rear sensor 121 are connected to the main controller 100. The ADF front sensor 120 and the ADF rear sensor 121 need to accurately measure the timing of sheet transport during ADF transport. For this reason, the detection of sensor outputs from each sensor 120 and 121 is assigned to the main controller 100.

[0055] In contrast, the FB cover sensor 131 and the ADF cover sensor 125 are connected to the sub-controller 105. The states of the FB cover sensor 131 and the ADF cover sensor 125 are detected independently of the drives of the FB motor 113 and the ADF motor 114. For this reason, the detection of sensor outputs from each of the sensors 131 and 125 is assigned to the sub-controller 105.

[0056] As shown in Figure 3, the rear end sensor SE0, the front register sensor SE1, the rear register sensor SE2, the discharge sensor SE3, and the front cover sensor 140 are connected to the main controller 100.

[0057] The rear end sensor SE0 is positioned in the transport path 201 near and downstream of the separation roller 34 and detects the passage of the sheet S. The rear end sensor SE0 can be a sensor with an actuator that oscillates when the sheet S contacts it, or an optical sensor, etc. The rear end sensor SE0 outputs an ON signal when the sheet S is passing and an OFF signal when the sheet S is not passing. The pre-register sensor SE1 is positioned in the transport path 201 upstream of the registration roller 35 and detects the passage of the sheet S. The pre-register sensor SE1 has the same configuration as the rear end sensor SE0. The post-register sensor SE2 is positioned in the transport path 201 upstream of the fuser 6, specifically between the registration roller 35 and the transfer roller 53, and detects the passage of the sheet S. The post-register sensor SE2 has the same configuration as the rear end sensor SE0. The discharge sensor SE3 is positioned in the transport path 201 between the fuser 6 and the transport roller 36 and detects the passage of the sheet S. The discharge sensor SE3 has the same configuration as the rear end sensor SE0.

[0058] The reason why the detection of the rear end sensor SE0, the front register sensor SE1, the rear register sensor SE2, and the discharge sensor SE3 is assigned to the main controller 100 is as follows: The rear end sensor SE0, the front register sensor SE1, the rear register sensor SE2, and the discharge sensor SE3 need to accurately measure the transport position of the sheet S while the image forming unit 2 is in operation.

[0059] The front cover sensor 140 is positioned near the front cover 21 and detects when the front cover 21 is opened or closed. If the front cover 21 is opened while the image forming unit 2 is operating, it is necessary to stop the operation of the image forming unit 2, such as the sheet transport motor 111 and the sheet discharge motor 112, and display an error. For this reason, it is necessary to detect the front cover 21 accurately and quickly, so the detection of the sensor output of the front cover sensor 140 is assigned to the main controller 100.

[0060] The rear cover sensor 141 is connected to the sub-controller 105. The rear cover sensor 141 is located near the rear cover 23 (see Figure 1) and detects the opening and closing of the rear cover 23. Even if the rear cover 23 is opened while the image forming unit 2 is operating, the operation of the image forming unit 2 is not stopped, and no error is displayed. Therefore, since it is not necessary to detect the rear cover 23 accurately and quickly, the detection of the sensor output of the rear cover sensor 141 is assigned to the sub-controller 105. One example of a case where the rear cover 23 is opened while the image forming unit 2 is operating is when the user selects so-called "straight paper output". Straight paper output is when the sheet S that has passed through the transport roller 36 is discharged from the rear of the main unit 20 through the open rear cover 23 without being transported by the discharge rollers 85-87. Straight paper output is selected when printing on thick paper.

[0061] The fuser thermistors 150 and 151 are connected to the main controller 100. The temperature output from the fuser thermistors 150 and 151 is used for heater feedback control. In order to perform this feedback control accurately and quickly, it is necessary to accurately and quickly detect the temperature from the fuser thermistors 150 and 151, so the detection of the temperature output from the fuser thermistors 150 and 151 is assigned to the main controller 100.

[0062] The temperature and humidity sensor 160, the in-machine thermistor 161, the toner IC 170, and the drum IC 180 are connected to the subcontroller 105. The external and internal temperature and humidity of the multifunction printer 1 are acquired at slow acquisition intervals, for example, on the order of several hundred milliseconds to several thousand milliseconds. For this reason, the detection of the sensor outputs of the temperature and humidity sensor 160 and the in-machine thermistor 161 is assigned to the subcontroller 105. Since the access frequency of consumable ICs, including the toner IC 170 and the drum IC 180, is low, their detection is also assigned to the subcontroller 105.

[0063] The control processes performed by the multifunction device 1, configured as described above, particularly the main controller 100 and subcontroller 105, will be explained in detail below with reference to Figures 4 and 5.

[0064] Figure 4 shows the procedure for motor driver control processing performed by the main controller 100. The target of the motor driver control processing is the motor driver MD2.

[0065] In Figure 4, the main controller 100 waits until it receives a print job (S10: NO). When it receives a print job (S10: YES), the main controller 100 commands the sub-controller 105 to set the following signals (S11). The signals to be set are the SLEEP signal, the ENABLE signal, the DIR signal, and the USM[1:0] signal. In other words, the main controller 100 commands the sub-controller 105 via the third signal line L3 using the UART, specifying the values ​​for the SLEEP signal, the ENABLE signal, the DIR signal, and the USM[1:0] signal.

[0066] Figure 5 shows the procedure for the setting process performed by the sub-controller 105. When the sub-controller 105 receives a command from the main controller 100 (S30:YES), it sends the following signals to the motor driver MD2 (S31). The signals to be sent are the SLEEP signal, the ENABLE signal, the DIR signal, and the USM[1:0] signal. The main controller 100 sends an instruction specifying the values ​​of each signal, so the sub-controller 105 sends a signal with the value corresponding to this instruction to the motor driver MD2.

[0067] Returning to Figure 4, the main controller 100 then outputs the signal VREF to the motor driver MD2 (S12). As a result, the sheet ejection motor 112 enters a standby state.

[0068] Next, the main controller 100 executes the sheet transport start process (S13). The sheet transport start process includes outputting signals such as CLKIN, SCS, SCLK, SDATAI, and SDATAO to the motor driver MD1 in order to start driving the sheet transport motor 111.

[0069] The main controller 100 then waits until the discharge sensor SE3 switches from off to on (S14: NO). Once the discharge sensor SE3 switches from off to on (S14: YES), the main controller 100 detects the leading edge of the conveyed sheet S in the conveying direction via the discharge sensor SE3, and proceeds to the next step, S15. In S15, a periodic pulse is output as the signal STEP to the motor driver MD2 (S15). As a result, the sheet discharge motor 112 starts rotational driving.

[0070] Next, the main controller 100 waits until the transport of the sheets S to the last page of the print job is complete (S16: NO). Once the transport of the sheets S to the last page of the print job is complete (S16: YES), it stops the periodic pulse output to the motor driver MD2 as the signal STEP (S17). As a result, the sheet ejection motor 112 stops its rotational drive.

[0071] Next, the main controller 100 commands the sub-controller 105 to set the following signals (S18). The signals to be set are the same as in S11: SLEEP, ENABLE, DIR, and USM[1:0]. In other words, the main controller 100 commands the sub-controller 105 via the third signal line L3 using UART, specifying the values ​​for each of the SLEEP, ENABLE, DIR, and USM[1:0] signals. However, the difference is that in S11, the values ​​specified are for starting the seat ejection motor 112, whereas in S18, the values ​​specified are for stopping the seat ejection motor 112.

[0072] Furthermore, after the main controller 100 stops outputting the signal VREF to the motor driver MD2 (S19), it terminates the motor driver control process.

[0073] In step S32 of the setup process in Figure 5, when the sub-controller 105 receives a command from the main controller 100 (S32:YES), it sends the following signals to the motor driver MD2 (S33). The signals to be sent are the same as in S31: SLEEP, ENABLE, DIR, and USM[1:0]. The main controller 100 sends an instruction specifying the values ​​of each signal, so the sub-controller 105 sends a signal with the corresponding value to the motor driver MD2. After that, the sub-controller 105 finishes the setup process.

[0074] Although the controlled object in Figures 4 and 5 is the motor driver MD2, the other motor drivers MD1, MD3, and MD4 can also be controlled similarly by analogy applying the control processes in Figures 4 and 5.

[0075] As described above, the multifunction device 1 of this embodiment is characterized by comprising: motors 111 to 114; motor drivers MD1 to MD4 connected to motors 111 to 114 for driving the motors 111 to 114; a main controller 100 connected to motor drivers MD1 to MD4 by a plurality of first signal lines L1; and a subcontroller 105 with a lower processing capacity than the main controller 100, which is connected to motor drivers MD1 to MD4 by at least one second signal line L2 and to the main controller 100 by at least one third signal line L3.

[0076] Thus, in the multifunction device 1 of this embodiment, a less expensive sub-controller 105 with lower processing power than the main controller 100 is used, which contributes to reducing costs when expanding the number of controller terminals.

[0077] Furthermore, the signals transmitted on the first signal line L1 are signals whose values ​​change while the motors 111 to 114 are being driven, while the signals transmitted on the second signal line L2 are characterized by having a lower frequency of value changes than the signals transmitted on the first signal line L1. Thus, the signals handled by the sub-controller 105 are signals whose values ​​change less frequently than the signals transmitted on the first signal line L1, and can therefore be adequately handled by the sub-controller 105.

[0078] Furthermore, the signal transmitted on the second signal line L2 is characterized in that the signal value does not change while the motors 111 to 114 are being driven. As a result, the sub-controller 105 does not need to switch the signal value while the motors 111 to 114 are being driven, so a controller with low processing power can be used as the sub-controller 105.

[0079] Furthermore, motors 112 to 114 are stepping motors, motor drivers MD2 to MD4 are stepping motor drivers, a plurality of first signal lines L1 include at least a STEP signal line and a VREF signal line, a second signal line L2 consists of a plurality of signal lines and includes at least a SLEEP signal line, an ENABLE signal line and a DIR signal line, and the main controller 100 transmits information regarding the SLEEP signal, ENABLE signal and DIR signal to the sub-controller 105 via a third signal line L3. This allows the main controller 100 to handle complex control and the sub-controller 105 to handle simple control when controlling motor drivers MD2 to MD4.

[0080] Furthermore, the multiple first signal lines L1 are characterized by including signal lines for USM[1:0]. This allows the main controller 100 to be entrusted with the control of the signal USM[1:0] transmitted via the USM[1:0] signal lines.

[0081] Furthermore, the second signal line L2 is characterized by including a signal line for USM[1:0]. This allows the subcontroller 105 to be entrusted with the control of the signal USM[1:0] transmitted via the USM[1:0] signal line.

[0082] Furthermore, the motor 111 is a DC motor, the motor driver MD1 is a DC motor driver, and the multiple first signal lines L1 include at least a CLKIN signal line L1_11, an SCS signal line L1_12, an SCLK signal line L1_13, an SDATAI signal line L1_14, an SDATAO signal line L1_15, and a HALL signal line L1_16, and the second signal line L2 includes at least a RESET signal line L2_11, and the main controller 100 transmits information regarding the RESET signal to the sub-controller 105 via a third signal line L3. This allows the main controller 100 to handle complex control and the sub-controller 105 to handle simple control when controlling the motor driver MD1.

[0083] Furthermore, the main controller 100 is connected to at least one of the following sensors: ADF front sensor 120, ADF rear sensor 121, rear end sensor SE0, front register sensor SE1, rear register sensor SE2, discharge sensor SE3, front cover sensor 140, and fuser thermistors 150, 151. Since rapid or accurate detection is required for the sensor outputs of each of the ADF front sensor 120, ADF rear sensor 121, rear end sensor SE0, front register sensor SE1, rear register sensor SE2, discharge sensor SE3, front cover sensor 140, and fuser thermistors 150, 151, their detection can be assigned to the main controller 100.

[0084] Furthermore, the subcontroller 105 is connected to at least one of the following sensors: the FB cover sensor 131, the ADF cover sensor 125, the rear cover sensor 141, the temperature and humidity sensor 160, and the in-machine thermistor 161. Since rapid or accurate detection is not particularly required for the sensor outputs of the FB cover sensor 131, the ADF cover sensor 125, the rear cover sensor 141, the temperature and humidity sensor 160, and the in-machine thermistor 161, their detection can be assigned to the subcontroller 105.

[0085] Furthermore, the subcontroller 105 is connected to at least one of the toner IC 170 and the drum IC 180. Since the access frequency to the consumable ICs, including the toner IC 170 and the drum IC 180, is low, their detection can be assigned to the subcontroller 105.

[0086] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0087] (1) In the above embodiment, a multifunction device 1 was given as an example of an image processing device, but the image processing device is not limited to a multifunction device 1, and may be a standalone printer or copier.

[0088] (2) In the above embodiment, the number of terminals of the main controller 100 is expanded by adding one sub-controller 105 to the main controller 100. The number of controllers to be added is not limited to one, but may be two or more. [Explanation of Symbols]

[0089] 1...Multifunction printer, 100...Main controller, 105...Sub-controller, 111...3-phase DC motor for sheet transport, 112...Stepping motor for sheet ejection, 113...Stepping motor for FB, 114...Stepping motor for ADF, 120...ADF front sensor, 121...ADF rear sensor, 125...ADF cover sensor, 131...FB cover sensor, 140...Front cover sensor, 141...Rear cover sensor, 150,151...Fuser thermistor, 160...Temperature and humidity sensor, 161...In-machine thermistor, 170...Toner IC, 180...Drum IC, L1...First signal line, L2...Second signal line, L3...Third signal line, MD1~MD4...Motor driver, SE0...Rear end sensor, SE1...Front sensor, SE2...Rear sensor, SE3...Ejection sensor.

Claims

1. Motor and, To drive the motor, a motor driver connected to the motor, The motor driver and the main controller are connected by a plurality of first signal lines. A sub-controller having a lower processing capacity than the main controller, which is connected to the motor driver by at least one second signal line and to the main controller by at least one third signal line, An image processing apparatus characterized by comprising:

2. The signal transmitted on the first signal line is a signal whose value changes while the motor is being driven. The signal transmitted on the second signal line has a lower frequency of signal value changes than the signal transmitted on the first signal line. The image processing apparatus according to feature 1.

3. The signal transmitted on the second signal line is such that the signal value does not change while the motor is being driven. The image processing apparatus according to claim 2.

4. The motor is a stepping motor, The motor driver is a stepping motor driver, The aforementioned plurality of first signal lines include at least a STEP signal line and a VREF signal line. The second signal line consists of multiple signal lines, and includes at least a sleep signal line, an enable signal line, and a dir signal line. The main controller transmits information regarding the sleep signal, the enable signal, and the dir signal to the subcontroller via the third signal line. The image processing apparatus according to claim 2.

5. The aforementioned plurality of first signal lines further include USM[1:0] signal lines, The image processing apparatus according to feature 4.

6. The second signal line further includes a signal line for USM[1:0], The image processing apparatus according to feature 4.

7. The motor is a DC motor, The motor driver is a DC motor driver, The aforementioned plurality of first signal lines include at least a CLKIN signal line, an SCS signal line, a SCLK signal line, an SDATAI signal line, an SDATAAO signal line, and a HALL signal line. The second signal line includes at least a RESET signal line. The main controller transmits information regarding the RESET signal to the sub-controller via the third signal line. The image processing apparatus according to claim 2.

8. The main controller is connected to at least one of the following sensors: ADF front sensor, ADF rear sensor, rear end sensor, front register sensor, rear register sensor, discharge sensor, front cover sensor, and fixing thermistor. The image processing apparatus according to feature 1.

9. The subcontroller is connected to at least one of the following sensors: FB cover sensor, ADF cover sensor, rear cover sensor, temperature and humidity sensor, and in-machine thermistor. The image processing apparatus according to feature 1.

10. The subcontroller is connected to at least one of the toner IC and the drum IC. The image processing apparatus according to feature 1.

Images