Electronic apparatus and control method of electronic apparatus

Abstract

To provide an image forming device which has a configuration in which both of reduction of power consumption in a power-saving state, and the reduction of a recovery time from the power-saving state due to a plurality of recovery factors are easily realized, and can be selected in accordance with needs of a user.SOLUTION: An electronic apparatus has a first substrate (100) in which a first CPU is mounted, and a second substrate (200) in which a second CPU is mounted and a predetermined function can be mounted. The electronic apparatus has control means (110, 202) which control power supply from a power source. The control means controls the power supply to the second CPU, when the electronic apparatus transfers to a power saving state, according to a discrimination result of whether or not the power supply is required for the second CPU when the electronic apparatus is at the power saving state based on whether or not the predetermined function is mounted in the second substrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic device and a method for controlling an electronic device. [Background technology]

[0002] In recent years, against the backdrop of GX (Green Transformation) and the need to reduce running costs in offices, there is a demand for power saving in image forming devices such as MFPs (Multi Functional Printers). For this reason, there is a demand not only for MFPs to be actively switched to a power saving state, but also for the power consumption value in the power saving state to be thoroughly reduced.

[0003] On the other hand, generally, when the image forming apparatus transitions to a power saving state, it takes time for the image forming apparatus to return to a high power consumption state in which printing, scanning, etc. can be performed, which means there is a trade-off in convenience for the user. Therefore, some users may desire an image forming apparatus that can return to a power saving state based on multiple return factors such as a human presence sensor.

[0004] For example, Patent Document 1 discloses a technology in which a user can input multiple instructions to an operation unit of an electronic device, and the control unit changes the power state of the electronic device based on these instructions. This enables the electronic device to transition to a state with lower power consumption or a power-saving state with slightly higher power consumption but a short recovery time. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-113365 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in Patent Document 1, the power state of the electronic device is changed by the operation unit of the electronic device notifying the control unit of the input instruction, so the power consumption of the operation unit itself cannot be minimized. In particular, in order for the operation unit to distinguish multiple instructions from the user and notify the control unit, it is necessary to keep the arithmetic control unit such as a CPU (Central Processing Unit) powered, which causes a problem that power consumption in the power saving state remains high. Therefore, there is a need for an image forming apparatus that has a configuration that easily realizes both reduction in power consumption in the power saving state and reduction in recovery time from the power saving state by multiple recovery factors, and that can be selected according to the needs of the user. [Means for solving the problem]

[0007] In order to solve the above problems, the device of the present invention is an electronic device having a first board on which a first CPU is mounted and a second board on which a second CPU is mounted and which can be equipped with a specified function, and has a control means for controlling the power supply from a power source, wherein the control means controls the power supply to the second CPU when the electronic device transitions to a power saving state in accordance with the result of a determination as to whether or not power supply to the second CPU is required when the electronic device is in a power saving state, based on whether or not the specified function is mounted on the second board. Effect of the Invention

[0008] According to the present invention, a power saving state in which the return time to the normal operating state is quick and a state in which the power consumption of the operation unit is minimized can be realized by combining a simpler configuration. [Brief description of the drawings]

[0009] [Figure 1] 1 is a system configuration diagram of an image forming apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a detailed configuration diagram of an operation unit according to the first embodiment of the present invention. [Diagram 3] FIG. 2 is a power supply system diagram of the operation unit according to the first embodiment of the present invention. [Figure 4] 1A is a connection diagram of a control unit and an operation unit configured to minimize power consumption according to the first embodiment of the present invention, and FIG. 1B is a connection diagram of a control unit and an operation unit configured to prioritize a return time to a normal operating state according to the first embodiment of the present invention. [Diagram 5] 1A is a power reset sequence diagram showing a configuration for minimizing power consumption according to the first embodiment of the present invention, and FIG. 1B is a power reset sequence diagram showing a configuration for prioritizing a return time to a normal operating state according to the first embodiment of the present invention. [Figure 6] FIG. 11 is a system configuration diagram of an image forming apparatus according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a detailed configuration diagram of an operation unit according to a second embodiment of the present invention. [Figure 8] 1A is a connection diagram of a control unit and an operation unit configured to minimize power consumption according to a second embodiment of the present invention, and FIG. 1B is a connection diagram of a control unit and an operation unit configured to prioritize a return time to a normal operating state according to a second embodiment of the present invention. [Figure 9] 13A is a power reset sequence diagram showing a configuration for minimizing power consumption according to a second embodiment of the present invention, and FIG. 13B is a power reset sequence diagram showing a configuration for prioritizing a return time to a normal operating state according to a second embodiment of the present invention. [Figure 10] FIG. 11 is a system configuration diagram of an image forming apparatus according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a detailed configuration diagram of an operation unit according to a third embodiment of the present invention. [Figure 12] 1A is a connection diagram of a control unit and an operation unit configured to minimize power consumption according to a third embodiment of the present invention, and FIG. 1B is a connection diagram of a control unit and an operation unit configured to prioritize a return time to a normal operating state according to a third embodiment of the present invention. [Figure 13] 13A is a power reset sequence diagram showing a configuration for minimizing power consumption according to a third embodiment of the present invention, and FIG. 13B is a power reset sequence diagram showing a configuration for prioritizing a return time to a normal operating state according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the components described in the embodiment are merely examples, and are not intended to limit the scope of the present invention.

[0011] Example 1 First, the system configuration of an image forming apparatus 10 in this embodiment will be described with reference to FIG.

[0012] 1, an image forming apparatus 10 is composed of a control unit 100 as a first board, and an operation unit 200, a scanner unit 300, and a printer unit 400 as a second board. The boards in this embodiment are printed circuit boards.

[0013] The control unit 100 has a CPU 101, and performs operations such as controlling the power state of the image forming apparatus 10 and handling print jobs sent from peripheral devices such as a PC (Personal Computer). When the system of the image forming apparatus 10 starts up, the CPU 101 first executes a boot program stored in a ROM (Read Only Memory) 103, and loads the data in a RAM (Random Access Memory) 102. In other words, the RAM 102 is used as a work memory for the CPU 101. The boot program is, for example, a Basic Input Output System (BIOS), a Boot Loader, or an Operating System (OS).

[0014] The CPU 101 is also connected to a LAN controller 104. The LAN controller 104 is connected to peripheral devices such as a PC according to the Ethernet standard, and communicates according to the TCP / IP (Transmission Control Protocol / Internet Protocol) protocol. The CPU 101 and the LAN controller 104 are connected, for example, by a PCIe (PCI express) bus. When a print job is sent from a PC via Ethernet, a packet received by the LAN controller 104 is sent to the CPU 101. The CPU 101 issues an instruction to the image processing unit 105 to drive the scanner unit 300 and the printer unit 400 according to the sent print job.

[0015] In addition to the above-mentioned control, the image processing unit 105 has a function of performing image processing such as noise removal on the scanned data of the document input from the scanner unit 300. The processed image data is stored in the SSD 106, or converted into a format that the printer unit 400 can understand and sent to the printer unit 400 to print on a paper medium. For example, image data obtained by the scanner unit 300 is expressed in RGB (Red Green Blue), but the printer unit 400 processes it in YMCK (Yellow Magenta Cyan Black), so data conversion is required. Here, the control unit 100 and the operation unit 200 are connected by the operation unit I / F 107, the scanner unit 300 is connected by the scanner I / F 108, and the control unit and the printer unit 400 are connected by the printer I / F 109.

[0016] The power supply control unit 110 is responsible for controlling the power supply of each functional module of the control unit 100, such as the CPU 101 and the RAM 102. In addition, in this embodiment, the power supply control unit 110 also transmits a power supply control signal to the operation unit 200. Details will be described with reference to FIG.

[0017] The power supply control unit 110 controls the power supply so that the power consumption of the image forming apparatus 10 is optimized. In this embodiment, the image forming apparatus 10 has a first power supply state in which the scanner unit 300 and the printer unit 400 are energized and the image forming apparatus 10 can operate according to an instruction from a user or a print job input from a peripheral device. The image forming apparatus 10 also has a second power supply state in which the power consumption is less than that of the first power supply state. And the image forming apparatus 10 has a third power supply state in which the image forming apparatus 10 is turned off. The image forming apparatus 10 has at least these three power supply states. Here, the second power supply state refers to, for example, a sleep mode, in which the power supply to the CPU 101 of the control unit 100 is cut off and a program is held in the RAM 102. At this time, since it is necessary to respond to a print job from a peripheral device, the power supply control unit 110 executes power supply control so that the LAN controller 104 is energized. Since it is necessary to reduce the power consumption in the sleep mode as much as possible, the scanner unit 300, the printer unit 400, and other functional modules in the control unit 100 are not energized.

[0018] The scanner unit 300 has a scanner control unit 301 and a scanner driving unit 302. The scanner control unit 301 controls the scanner driving unit 302 to scan a paper medium placed on a document tray (not shown) of the image forming apparatus 10 and obtain image data. The scanner driving unit 302 uses, for example, a mechanism for automatically scanning paper called an ADF (Auto Document Feeder). In addition, scanning is performed by driving a sensor module that irradiates the paper medium with an LED (Light Emitting Diode) and converts the reflected light obtained into color information.

[0019] The printer unit 400 has a printer control unit 401 and a printer drive unit 402. The printer control unit 401 controls the printer drive unit 402 to draw images and characters on a paper medium stored in the image forming apparatus 10. The printer control unit 401 drives, for example, a drum for charging the paper medium and a laser unit for irradiating the charged paper medium with a laser.

[0020] The operation unit 200 is connected to the control unit 100 via a control unit I / F 206, and mainly has a function of displaying the status of the image forming apparatus 10 to the user and a function of receiving various instructions from the user. The display function uses an LCD 207, and the function of receiving various instructions uses a touch panel 208. Specifically, the touch panel 208 is used by being attached to the LCD 207, and a GUI (Graphical User Interface) such as various buttons displayed on the LCD 207 is displayed to the user through the touch panel 208. The user can reflect the desired process on the image forming apparatus 10 by pressing the touch panel 208 with a finger or a pen. The touch panel 208 can be a resistive film type or a capacitive type.

[0021] CPU 201 notifies control unit 100 of various instructions input by the user. As described above, the user presses a button displayed on operation unit 200 via touch panel 208. At that time, touch panel control IC 203 obtains coordinate information indicating which position on touch panel 208 was pressed, and outputs an interrupt signal to CPU 201. Upon receiving the interrupt signal, CPU 201 obtains coordinate information from touch panel control IC 203. CPU 201 transmits the obtained coordinate information to CPU 101.

[0022] In addition, the operation unit 200 may be equipped with a human sensor 204. The human sensor 204 may be a pyroelectric type or an ultrasonic type, and is used to detect a user approaching the image forming apparatus 10. The ultrasonic control signal output by the human sensor 204 to the outside of the image forming apparatus 10 is controlled by the CPU 101. As a specific example of a use case of the human sensor, when the human sensor detects the approach of a user, the image forming apparatus 10 starts to return from the second power state to the first power state. Furthermore, an image is displayed on the LCD 207 before the user arrives in front of the image forming apparatus, and the image forming apparatus 10 is transitioned to the first power state before the user starts to operate the touch panel 208. In the second power state, the CPU 101 is not energized as described above, but the CPU 201 notifies the power control unit 110 of the approach of the user detected by the human sensor 204. Then, the image forming apparatus 10 returns to the first power state without a user's instruction input by starting the energization of the CPU 101.

[0023] On the other hand, the human sensor 204 may be configured to be mountable as an option or the like. There may be cases where the human sensor 204 is not mounted on the operation unit 200, in which case the operation unit returns from the second power state to the first power state when the user presses the touch panel 208. An interrupt signal indicating that the touch panel 208 has been pressed is sent directly from the touch panel control IC 203 to the power control unit 110 of the control unit 100. In this case, it is assumed that the CPU 201 is not energized.

[0024] That is, the second power state has two further power states depending on whether or not the human sensor 204 is installed. When the human sensor 204 is installed, power must be applied to the CPU 201 and the human sensor 204 in the second power state, so power consumption is high. When the human sensor 204 is not installed, power is not applied to the CPU 201 in the second power state, so power consumption is low. Naturally, the former requires a short time to return from the second power state to the first power state, and the latter requires a long time. In addition, although the present embodiment will be described with or without the human sensor 204 installed, this is not limiting. For example, as the operation unit 200, either an operation unit equipped with the human sensor 204 or an operation unit not equipped with the human sensor can be attached, and control may be performed depending on which operation unit is connected.

[0025] The operation unit 200 also has a power supply control unit 202 that controls the power supply of functional modules in the operation unit 200, such as the CPU 201 and the touch panel control IC 203. The power supply control unit 202 also includes a board type determination unit 205. The board type determination unit 205 determines the type (of the board) of the connected control unit 100 by using the potential of a signal line connected between the operation unit I / F 107 and the control unit I / F 206. Note that the signal line in this embodiment may be a transmission line. The determination result is fed back to the power supply control unit 202, and the power supply control of the functional modules in the operation unit 200 is optimized. Details will be described in FIG. 2 and subsequent figures.

[0026] 2 is a diagram showing the connection between the control unit 100 and the operation unit 200 in detail. As described above, the operation unit I / F 107 and the control unit I / F 206 are connected. The operation unit I / F 107 is connected to the CPU 101 and the power supply control unit 110. The control unit I / F 206 is connected to the power supply control unit 202, the board type determination unit 205, the CPU 201, the touch panel control IC 203, and the LCD 207. In this embodiment, the board type determination unit 205 is realized by a single signal line. The operation unit I / F 107 and the control unit I / F 206 are connected by a communication standard capable of transmitting video signals, such as Display Port or HDMI (registered trademark) (High Definition Multimedia Interface).

[0027] Here, the power supply and signals exchanged between the operation unit I / F 107 and the control unit I / F 206 will be described. 1 is a power supply for the operation unit 200 supplied from a power supply circuit (not shown) of the control unit 100. The power supply control unit 110 also transmits a power supply control signal 1 to the power supply control unit 202. The power supply control signal 1 is used to control a power supply control circuit 209 of the power supply control unit 202. A board type discrimination signal and a power supply control signal 2 are connected from the operation unit I / F 107 to the power supply control unit 202 and are used to control the power supply control circuit 210. As described above, in this embodiment, the board type discrimination signal is the board type discrimination unit 205 in FIG. 1 and is used within the power supply control unit 202, so it is included in the power supply control unit 202. The board type discrimination signal and the power supply control signal 2 are signals that are generated by circuits (not shown) in this figure and have two potential values, High or Low. Specifically, a potential higher than the threshold value is High, and a potential lower than the threshold value is Low.

[0028] The video signal is transmitted from the CPU 101 to the LCD 207 via the operation unit I / F 107 and the control unit I / F 206. The CPU 101 transmits image information generated by a GPU (Graphic Processing Unit) (not shown) using the video signal. The touch panel control IC 203 transmits an interrupt signal notifying that the touch panel 208 has been pressed by the user to the power supply control unit 110 as a return interrupt signal. In the case where the human sensor 204 is mounted, if the CPU 201 determines that the human sensor 204 has detected the approach of the user, it outputs a return interrupt signal. Finally, when data is transmitted and received between the CPU 101 and the CPU 201, an inter-CPU communication signal is used. For example, when the CPU 101 acquires the coordinate information of the pressed position on the touch panel 208 acquired by the CPU 201 as described above, this inter-CPU communication signal is used.

[0029] Here, the power supply control circuit 209 and the power supply control circuit 210 in the power supply control unit 202 will be described. When the power supply control signal 1 output from the power supply control unit 110 is asserted, the power supply control circuit 209 controls the power supply V1 From power supply V 2 The power supply control circuit 210 is controlled by a logic IC (Integrated Circuit) that generates a logical sum of a board type discrimination signal (board type discrimination unit 205) and a power supply control signal 2. When the logic IC asserts an output signal, the power supply V 3 From power supply V 4 Generate.

[0030] Now, let us use Figure 3 to calculate the power supply V 1 ~Power V 4 A detailed explanation of each power supply will be provided. 1 As described above, the power supply V is supplied from the control unit 100 to the operation unit 200. 2 ~Power V 4 is the power supply V 1 This power is generated by a transistor (denoted by Tr) and a regulator (denoted by Reg) based on the power, and is supplied to each functional module of the operation unit 200.

[0031] Power supply V 2 is the power supply V 1 Based on the transistor Tr 1 This power supply is generated by the transistor Tr 1 is the power supply control circuit 209 in FIG. 3 is the power supply V 1 This is a power supply generated by a regulator Reg (not shown) based on the power supply V 3 is the transistor Tr 2 Power supply V 4 It is also used to generate the power supply V 4 is supplied to the CPU 201 and the human sensor 204. Of course, if the human sensor 204 is not installed, the signal is not supplied. 2 is the power supply control circuit 210 in FIG. 3 is the power supply V 1 For example, the power supply V 1 From V 3The Enable terminal of the regulator that generates the regulator's input power V 1 The configuration is such that the input is pulled up to

[0032] Next, the potential states of the board type discrimination signal and power supply control signal 2 will be described with reference to Fig. 4(a). Fig. 4(a) is a diagram showing the case where the operation unit 200 is connected to the control unit 100 when the human sensor 204 is not installed, that is, in a configuration that thoroughly reduces power consumption in the second power supply state. Here, the board type discrimination signal is pulled down at the operation unit I / F 107 end of the control unit 100, so the potential is Low. In other words, if the board type discrimination signal is Low, it can be determined that the human sensor 204 is not installed. Also, at the operation unit I / F 107 end of the control unit 100, the power supply control signal 2 is pulled down to the power supply V b Because it is pulled up to the power supply V b When is turned on, it becomes High.

[0033] Here, the power supply V b is a power supply that is supplied in the first power supply state but not in the second power supply state. Details will be described in FIG. 5(a). Also, the power supply V b is the power supply V 3 It will be introduced later than

[0034] Next, the potential states of the board type discrimination signal and the power supply control signal 2 will be described with reference to Fig. 4(b). Fig. 4(b) is a diagram showing the case where the operation unit 200 is connected to the control unit 100 in a configuration where a human sensor 204 is installed, that is, where the return time to the first power supply state is prioritized over the reduction of power consumption in the second power supply state. Here, the board type discrimination signal at the operation unit I / F 107 end of the control unit 100 is connected to the power supply V a Because it is pulled up to the power supply V a When the power is turned on, the potential is High. In other words, if the board type discrimination signal is High, it can be determined that the human sensor 204 is mounted. The power supply control signal 2 is processed in the same manner as in FIG. 4(a).

[0035] Here, the power supply Va is the power supplied in both the first power state and the second power state, as will be described in detail in FIG. 5(b).

[0036] The functional modules and various power supplies and signals described above will be explained using timing charts in accordance with the power supply state of the image forming apparatus 10.

[0037] FIG. 5(a) is a timing chart for the case where the human sensor 204 is not installed, like FIG. 4(a). This timing chart will be explained starting from the third power state. When the power button of the image forming apparatus 10 is pressed in the third power state, the image forming apparatus 10 starts to transition to the first power state. When the power state is the third power state, all power supplies and signals are low. Next, when the system of the image forming apparatus 10 starts up in section A, the power V supplied from the control unit 100 to the operation unit 200 is 1 As mentioned above, the power supply V 3 Also power supply V 1 Next, the power supply control signal 1 is asserted, and the power supply V 2 Then, the power supply V b When power is applied to the transistor Tr in FIG. 2 When the power supply V 4 The power supply V 4 When the voltage reaches the specified voltage and the CPU 201 becomes operable, a reset control circuit (not shown) deasserts (changes from low to high) the reset signal of the touch panel control IC 203 and the CPU 201. Since the touch panel control IC 203 is an IC controlled by the CPU 201, it remains reset until the CPU 201 becomes operable. When the control in section A is completed, the power state becomes the first power state.

[0038] In section B, a transition from the first power state to the second power state is implemented. The trigger for the transition from the first power state to the second power state may be, for example, a sleep transition instruction from the user or the passage of a predetermined period of time without operation of the touch panel 208. First, the power control signal 2 is transmitted to the control unit 100, which controls the power supply V b As a result, the board type discrimination signal is low, as shown in FIG. 4(a), and the transistor Tr 2 is turned off and the power supply V 4 At this time, the reset signal of the CPU 201 is supplied to the power supply V 4 The power supply control signal 1 is deasserted (changed from high to low) before the supply of power V is stopped. 2 The supply of will be stopped.

[0039] By these controls, in the second power state, power supply (electricity supply) to the CPU 201 is stopped, so that the power consumption of the operation unit 200 is minimized, and accordingly, the power consumption of the image forming apparatus 10 can also be minimized. In addition, since it is necessary to resume the system of the image forming apparatus 10 by pressing the touch panel 208 by the user, the power supply V 3 needs to be supplied.

[0040] Section C is a process in which the power state is transitioned from the second power state to the first power state by, for example, pressing the touch panel 208 by the user. b is supplied, the power supply control signal 2 becomes High. This causes the transistor Tr 2 is turned ON again, and the power supply V 4 Starts to rise. As in section A, the power supply V 4 When the power supply V reaches the specified voltage, the reset signal of the CPU 201 is deasserted by a reset control circuit (not shown). 2 When these processes are completed, the state transitions to the first power supply state.

[0041] Section D is a process in which, for example, a user turns off a power switch (not shown) provided in the image forming apparatus 10, and the power of each functional module is turned off. b As a result, the board type discrimination signal is low, as shown in FIG. 4(a), and the transistor Tr 2 is turned off and the power supply V 4 At this time, the reset signal of the CPU 201 is supplied to the power supply V 4 The power supply control signal 1 is asserted before the power supply V is stopped. 2 Finally, the supply of power V supplied from the control unit 100 is stopped. 1 begins to fall, and the power supply V 3 At this point, a reset control circuit (not shown) resets the touch panel control IC 203 to the power supply V 3 It shall be asserted before the falling edge of

[0042] Fig. 5(b) is a timing chart in the case where the human sensor 204 is installed, like Fig. 4(b), and a description of the same points as Fig. 5(a) will be omitted.

[0043] In section A, the board type discrimination unit 205 (board type discrimination signal) is V a When the power supply V a is a power supply that is turned on in both the first power supply state and the second power supply state. 2 is turned ON, and the power supply V 4 However, although it does not matter which of the power supply control signal 2 and the board type determination unit 205 rises first, in this embodiment, it is assumed that the board type determination unit 205 rises first.

[0044] In section B, the power supply V bAlthough the power supply control signal 2 also falls due to the falling edge of a Since the power is supplied even in the second power state, the board type determination unit 205 becomes High, and the transistor Tr 2 remains ON and the power supply V 4 This control enables the CPU 201 and the human presence sensor 204 to operate in the second power state. That is, when the human presence sensor 204 detects the approach of a user in the second power state, the CPU 201 asserts a return interrupt signal and returns to the first power state.

[0045] In section D, the basic operation is the same as in FIG. 5(a), but the power supply V 4 Since the power supply V is controlled by the logical sum of the power supply control signal 2 and the board type discrimination unit 205, the power supply V 4 In this embodiment, the difference is that the supply of the power V is stopped. a is the power supply V b (It will become Low later than

[0046] With the above configuration, when a human sensor is mounted, the board type discrimination signal becomes High, and when the board type discrimination unit 205 determines that the potential is High, it controls the CPU 201 to turn on the power supply V 4 On the other hand, when the human sensor is not mounted, the board type discrimination signal becomes Low, and when the board type discrimination unit 205 determines that the potential is Low, it controls the CPU 201 to supply the power supply V 4 This makes it possible to realize, with a simpler configuration, a power-saving state in which a human sensor is installed and the return time to the normal operating state is quick, and a state in which a human sensor is not installed and power is not supplied to the CPU, thereby minimizing power consumption of the operation unit, based on the presence or absence of a human sensor.

[0047] Example 2 In this embodiment, an example will be described in which the board type determination unit 205 that was included in the operation unit 200 in the first embodiment is included in the control unit 100. Note that explanations of system configurations, circuit operations, and other points that are the same as those in the first embodiment will be omitted.

[0048] 6 shows the system configuration of image forming apparatus 10 in this embodiment. Unlike embodiment 1, substrate type discrimination unit 205 in embodiment 1 is provided on the control unit 100 side as substrate type discrimination unit 111 in embodiment 2. Further, substrate type discrimination unit 111 is included in power supply control unit 110. That is, in this embodiment, control unit 100 discriminates its own substrate type, and feeds back the result to the control of power supply control circuit 210 in operation unit 200.

[0049] 7 is a diagram showing in detail the connection between the control unit 100 and the operation unit 200 in this embodiment. The board type discrimination unit 111 (board type discrimination signal) takes a logical OR with the power supply control signal 2 by a logic IC, and is used as a control signal for the power supply control circuit 210 of the operation unit 200 as described above. As a result, the power supply V supplied to the CPU 201 and the human sensor 204 4 Controls the ON timing of the

[0050] Next, the potential states of the board type discrimination signal and the power supply control signal 2 will be described with reference to FIGS.

[0051] FIG. 8(a) is a diagram showing a case where the human sensor 204 is not installed, that is, in a configuration for thoroughly reducing power consumption in the second power state, in which the operation unit 200 is connected to the control unit 100. First, the board type discrimination signal is pulled down at the operation unit I / F 107 end of the control unit 100, and is at a low level. In other words, the control unit 100 indicates that it is equipped with the human sensor 204 by setting the board type discrimination signal to low. On the other hand, the power supply control signal is b It is pulled up to the power supply V b When V is turned on, it indicates High. b As in the first embodiment, it is assumed that the power supply is turned on in the first power supply state but is not turned on in the second power supply state.

[0052] 8(b) is a diagram showing a case where the operation unit 200 is connected to the control unit 100 in a configuration in which a human sensor 204 is installed, that is, in which the return time to the first power state is prioritized over the reduction of power consumption in the second power state. Here, the board type discrimination signal is pulled up to the power supply Va, so that the power supply V a When the power supply V is turned on, the power supply control signal 2 is also turned on. b Because it is pulled up to the power supply V b When the power supply V a is a power supply that is turned on in both the first power state and the second power state.

[0053] The functional modules and various power supplies and signals described so far will be explained in accordance with the power supply state of the image forming apparatus 10 using timing charts in FIGS.

[0054] Fig. 9(a) is a timing chart in the case where the human sensor 204 is not installed, like Fig. 8(a). The operation is the same as Fig. 5(a) in the first embodiment, and the only difference is that the operation of the board type determination unit 205 is changed to the board type determination unit 111. Here, the board type determination unit 111 is pulled down to low by the power supply control unit 110, so it is low in all states as shown in Fig. 9(a). Therefore, the power supply V b is turned on and V is turned on only when power control signal 2 is high. 4 That is, in FIG. 9(a), in the second power state, the power supply V b The supply of V 4 Accordingly, the supply of power is stopped, so that the power consumption in the second power state can be minimized.

[0055] On the other hand, Fig. 9(b) is a timing chart in the case where the human sensor 204 is installed, like Fig. 8(b). The operation is the same as Fig. 5(b) in the first embodiment, and the only difference is that the board type determination unit 205 is replaced by the board type determination unit 111. Also in this embodiment, the board type determination unit 111 starts up earlier than the power supply control signal 2, but this is not limiting. Here, the board type determination unit 111 starts up earlier than the power supply V a Because it is pulled up to V, the second power state 4 This allows the CPU 201 to detect the approach of a user by the human presence sensor 204 even in the second power state. Then, the system of the image forming apparatus 10 can be restored to the first power state by a restoration interrupt signal.

[0056] In this way, unlike the first embodiment, the control unit 110 can appropriately control the power supply state of the image forming apparatus 10 during power saving by determining its own board type.

[0057] Example 3 In the third embodiment, a configuration will be described in which the control unit 100 determines whether or not the human sensor 204 is connected to the operation unit 200 as an option. In other words, in the image forming apparatus 10, the user can select whether or not to install the human sensor 204 when purchasing the apparatus, so there are cases where the human sensor 204 is installed and cases where it is not installed, as described in the first and second embodiments. Naturally, in this embodiment, the device connected as an option is the human sensor 204, but the presence or absence of other devices may be determined. Note that explanations of parts that are the same as those in the first and second embodiments, such as the system configuration and circuit operation, will be omitted.

[0058] 10 is a system configuration diagram of an image forming apparatus 10 in a third embodiment. A feature of this embodiment is that a power supply control unit 110 of a control unit 100 has a human sensor presence / absence determination unit 112. This human sensor refers to a human sensor 204 provided in an operation unit 200.

[0059] Next, the connection between the operation unit I / F 107 and the control unit I / F 206 will be described in detail with reference to FIG. 11. The difference from the first and second embodiments is the method of generating a signal connected to the power supply control circuit 210. Specifically, the signal is generated by the logical sum of a human sensor presence / absence discrimination signal (human sensor presence / absence discrimination unit 112) in which the potential on the transmission path (signal wiring) is uniquely determined to be High or Low depending on the presence or absence of the human sensor 204, and the power supply control signal 2. Since it is assumed that the human sensor 204 is mounted by soldering on a general PCB (Printed Circuit Board), it is possible to control the potential on a specific signal wiring depending on whether it is mounted or not. Details will be described with reference to FIG. 12(b).

[0060] 12(a) is a diagram showing a case where the human sensor 204 is not installed, that is, in a configuration for thoroughly reducing power consumption in the second power state, in which the operation unit 200 is connected to the control unit 100. As shown in the figure, a human sensor presence / absence determination signal is generated by the control unit 100 through the power supply V a 2, the power supply V 3 After being pulled up in the operation unit 200, the logic is inverted in a logic IC (inverter) at the subsequent stage and transmitted from the control unit I / F 206 to the operation unit I / F 107. Since the human sensor 204 is not mounted as shown in the figure, the potential of the human sensor presence / absence discrimination signal at the operation unit I / F 107 terminal is Low while the inverter is energized. Here, the inverter is connected to the power supply V 3 On the other hand, the power supply control signal 2 is driven by the power supply V b Because it is pulled up to the power supply V b The signal generated by the logic IC that takes the logical sum of the human sensor presence / absence discrimination signal and the power supply control signal 2 is sent from the operation unit I / F 107 to the control unit I / F 206 and is used to control the power supply control circuit 210 as shown in FIG. a is turned on in both the first and second power states, and the power supply V b is turned on in the first power state but is not turned on in the second power state.

[0061] FIG. 12(b) is a diagram showing a case where the operation unit 200 is connected to the control unit 100 in a configuration in which the human sensor 204 is mounted, that is, in which the return time to the first power state is prioritized over the reduction of power consumption in the second power state. The contents are the same as those shown in FIG. 12(a) except that the human sensor 204 is mounted. Here, the human sensor presence / absence determination signal is connected to a specific ground terminal of the human sensor 204. In other words, when the human sensor 204 is mounted, the input of the inverter of the operation unit 200 becomes Low. Therefore, the output of the inverter becomes High, and is transmitted from the control unit I / F 206 to the operation unit I / F 107. Then, a signal generated by the logical sum of this signal and the power control signal 2 is transmitted from the operation unit I / F 107 to the control unit I / F 206.

[0062] Next, FIG. 13(a) will be used to show a timing chart of each functional module, various power supplies, and signals in the configuration in the connection diagram of FIG. 12(a). FIG. 13(a) is a timing chart in the case where the human sensor 204 is not mounted, just like FIG. 12(a). The operation is the same as FIG. 9(a) in the second embodiment, except that the operation of the board type discrimination unit 111 is changed to the human sensor presence / absence discrimination unit 112 (human sensor presence / absence discrimination signal). In section A, the human sensor presence / absence discrimination signal is output as Low by the operation unit 200, so that it is Low in all states as shown in FIG. 13(a). As a result, the power supply V b is turned on and V is turned on only when power control signal 2 is high. 4 That is, in FIG. 13(a), in the second power state, the power supply V b The supply of V 4 Accordingly, the supply of power is stopped, so that the power consumption in the second power state can be minimized.

[0063] On the other hand, Fig. 13(b) is a timing chart in the case where a human sensor 204 is mounted, like Fig. 12(b). The operation is the same as Fig. 9(b) in the second embodiment, and the only difference is that the operation of the board type discrimination unit 111 has been changed to the human sensor presence / absence discrimination unit 112 (human sensor presence / absence discrimination signal). Also in this embodiment, the human sensor presence / absence discrimination unit 112 is set to start up earlier than the power supply control signal 2, but this is not limiting. Here, the human sensor 204 is mounted, so the human sensor presence / absence discrimination signal goes High as described above and is input to the control unit 100. In other words, even in the second power supply state, V 4 This allows the CPU 201 to detect the approach of a user by the human presence sensor 204 even in the second power state. Then, the system of the image forming apparatus 10 can be restored to the first power state by a restoration interrupt signal.

[0064] In this way, unlike the first and second embodiments, the power supply state of the image forming apparatus 10 during power saving can be appropriately controlled by the control unit 110 determining the presence or absence of a specific device mounted on the operation unit 200.

Claims

1. An electronic device having a first board on which a first CPU is mounted, and a second board on which a second CPU is mounted and capable of mounting a predetermined function, A control means for controlling the supply of power from a power source; having The control means controls the power supply to the second CPU when the electronic device transitions to a power saving state, according to a determination result of whether or not power supply to the second CPU is required when the electronic device is in a power saving state, based on whether or not the predetermined function is mounted on the second board.

1. An electronic device comprising:

2. The predetermined function is a human presence sensor.

2. The electronic device according to claim 1 .

3. The power saving state is a state in which power supply to the first CPU is cut off.

2. The electronic device according to claim 1 .

4. a transmission line connecting the first substrate and the second substrate; having The control means determines whether or not the second board has the predetermined function mounted thereon by using a potential on the transmission line.

2. The electronic device according to claim 1 .

5. The discrimination based on potential uses only one signal of the transmission line.

5. The electronic device according to claim 4.

6. The control means is mounted on the first substrate.

2. The electronic device according to claim 1 .

7. The control means is mounted on a second substrate.

2. The electronic device according to claim 1 .

8. The transition to the power saving state refers to a transition from a state in which power is supplied to the first CPU to a state in which power is not supplied to at least the first CPU.

2. The electronic device according to claim 1 .

9. The power supply used by the second CPU is generated on the second board.

2. The electronic device according to claim 1 .

10. The first substrate and the second substrate are printed circuit boards.

2. The electronic device according to claim 1 .

11. A method for controlling an electronic device having a first board on which a first CPU is mounted and a second board on which a second CPU is mounted and capable of mounting a predetermined function, comprising the steps of: a power supply control unit that controls power supply from a power supply; having A step of controlling the power supply to the second CPU when the electronic device transitions to a power saving state in accordance with a determination result of whether or not power supply to the second CPU is required when the electronic device is in a power saving state, the determination result being based on whether or not the predetermined function is mounted on the second board. A method for controlling an electronic device comprising:

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