Electronic apparatus

Abstract

To provide an electronic apparatus which can suppress lighting of a display unit in a power saving mode.SOLUTION: An image forming apparatus includes: a display unit that is turned off while operating in a power-saving mode; a sub-control unit 13 that outputs a first control signal X1 when a user operation is accepted at an operation unit while operating in the power-saving mode; a main control unit 8 that, in response to input of the first control signal X1 output from the sub-control unit 13, outputs a second control signal X2 toward the sub-control unit 13 to instruct lighting of the display unit; and a gate unit 14 that is provided in a transmission path of the second control signal X2, the gate unit 14 being configured to allow the second control signal X2 to pass through when the first control signal X1 is output and not to allow the second control signal X2 to pass through when the first control signal X1 is not output.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electronic device. [Background technology]

[0002] In electronic devices such as multifunction peripherals, the operation of each part of the electronic device is controlled by signals output from a main control unit including a CPU (see Patent Document 1).

[0003] Also, there is known an electronic device that can switch its operating mode between a normal mode and a power-saving mode that consumes less power than the normal mode. In this type of electronic device, the display unit is turned off while the electronic device is operating in the power-saving mode. In this type of electronic device, when a user operation is received from the operation unit while the electronic device is operating in the power-saving mode, the operating mode is transitioned from the power-saving mode to the normal mode and the display unit is turned on.

[0004] For example, in the electronic device, when a user operation is received at the operation unit while the electronic device is operating in the power saving mode, a first control signal indicating that the operation unit has been operated is output from a sub-controller that controls the display unit and the operation unit to the main control unit. Also, in the electronic device, in response to input of the first control signal to the main control unit, a second control signal instructing the sub-controller to turn on the display unit is output from the main control unit to the sub-controller. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-50508 Summary of the Invention [Problem to be solved by the invention]

[0006] In the electronic device, noise may be mixed into a signal line used to transmit the second control signal, causing the display unit to light up even when the operation mode is the power saving mode.

[0007] An object of the present invention is to provide an electronic device that can prevent a display unit from lighting up during a power saving mode. [Means for solving the problem]

[0008] According to one aspect of the present invention, an electronic device is switchable between a normal mode and a power-saving mode in which power consumption is reduced compared to the normal mode, and includes an operation unit, a display unit, a first control unit, a second control unit, and a gate unit. The display unit is turned off when the electronic device is operating in the power-saving mode. The first control unit controls the operation unit and the display unit, and outputs a first control signal when a user operation is received on the operation unit while the electronic device is operating in the power-saving mode. The second control unit outputs a second control signal to the first control unit in response to the first control signal output from the first control unit, instructing the display unit to be turned on. The gate unit is provided in a transmission path of the second control signal, and passes the second control signal when the first control signal is output, and does not pass the second control signal when the first control signal is not output. [Effects of the Invention]

[0009] According to the present invention, it is possible to prevent the display unit from lighting up during the power saving mode. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing the system configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the configuration of the main control unit, sub-control unit, and gate unit of the image forming apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following embodiment is an example of the present invention, and does not limit the technical scope of the present invention.

[0012] [Configuration of image forming apparatus 100] First, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described with reference to Fig. 1. In Fig. 1, the image forming apparatus 100 is indicated by a dashed line.

[0013] The image forming apparatus 100 is a multifunction peripheral that has multiple functions, such as a scanning function for reading an image from a document, a printing function for forming an image on a sheet based on image data, a fax function, and a copy function. The image forming apparatus 100 is an example of an electronic device of the present invention. The present invention may also be applied to electronic devices such as scanners, printers, fax machines, copy machines, personal computers, laptop computers, televisions, microwave ovens, and refrigerators.

[0014] As shown in FIG. 1, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, an operation display unit 5, an attachment unit 6, a storage unit 7, and a main control unit 8.

[0015] The ADF 1 transports documents to be scanned by the scanning function, and includes a document setting section, a plurality of document transport rollers, a document presser, and a paper ejection section.

[0016] The image reading unit 2 realizes the scanning function and includes a document table, a light source, a plurality of mirrors, an optical lens, and a CCD (Charge Coupled Device).

[0017] The image forming unit 3 realizes the printing function and includes a photosensitive drum, a charging roller, an optical scanning device, a developing device, a toner container, a transfer roller, a cleaning device, a fixing device, and a paper discharge tray.

[0018] The paper feed unit 4 supplies sheets to the image forming unit 3. The paper feed unit 4 includes a paper feed cassette, a pickup roller, a paper feed roller, a plurality of sheet transport rollers, and a registration roller.

[0019] The operation display unit 5 is a user interface of the image forming apparatus 100. As shown in FIG. 1, the operation display unit 5 includes a display unit 11, an operation unit 12, and a sub-control unit 13. The display unit 11 is used to display information to the user. For example, the display unit 11 is a flat panel display such as a liquid crystal display. The operation unit 12 is used by the user to input information to the image forming apparatus 100. For example, the operation unit 12 includes operation keys and a touch panel. The sub-control unit 13 controls the display unit 11 and the operation unit 12. The sub-control unit 13 is composed of electronic circuits such as integrated circuits (ASIC, DSP).

[0020] The mounting unit 6 has a USB connection terminal to which an external electronic device capable of inputting and outputting data in accordance with the USB standard is attached / detached. For example, a storage device 200 (see FIG. 1) that can write and read data in accordance with the USB standard is attached / detached to / from the mounting unit 6. For example, the storage device 200 is a USB memory.

[0021] The storage unit 7 is a nonvolatile storage device, such as a nonvolatile memory such as a flash memory, a solid state drive (SSD), or a hard disk drive (HDD).

[0022] The main control unit 8 performs overall control of the image forming apparatus 100. As shown in FIG. 1, the main control unit 8 includes a CPU 21, a ROM 22, and a RAM 23. The CPU 21 is a processor that executes various types of arithmetic processing. The ROM 22 is a non-volatile storage device that stores in advance information such as control programs for causing the CPU 21 to execute various types of processing. The RAM 23 is a volatile or non-volatile storage device that is used as a temporary storage memory (work area) for the various types of processing executed by the CPU 21. The CPU 21 performs overall control of the image forming apparatus 100 by executing the various control programs that are stored in advance in the ROM 22.

[0023] Furthermore, the main control unit 8 can switch the operation mode of the image forming apparatus 100 between a normal mode and a power saving mode in which power consumption is reduced compared to the normal mode. The display unit 11 is turned off while the image forming apparatus 100 is operating in the power saving mode.

[0024] For example, when the operation mode of the image forming apparatus 100 is the normal mode, the main control unit 8 transitions the operation mode from the normal mode to the power saving mode when the image forming apparatus 100 remains in a non-operated state for a predetermined time period or when a predetermined operation is performed on the operation unit 12. Furthermore, when the operation mode of the image forming apparatus 100 is the power saving mode, the main control unit 8 transitions the operation mode from the power saving mode to the normal mode when a user operation is received on the operation unit 12.

[0025] For example, in the image forming apparatus 100, the main control unit 8 and the sub-control unit 13 are connected by signal lines L1 and L2 shown in Fig. 2. The signal line L1 is used to transmit a first control signal X1 (see Fig. 2) output from the sub-control unit 13 to the main control unit 8, which indicates that the operation unit 12 has been operated. The signal line L2 is used to transmit a second control signal X2 (see Fig. 2) output from the main control unit 8 to the sub-control unit 13, which instructs the display unit 11 to be turned on.

[0026] Furthermore, when a user operation is received at the operation unit 12 while the image forming apparatus 100 is operating in the power saving mode, the sub-control unit 13 outputs a first control signal X1. For example, the first control signal X1 is a signal that is output by switching the voltage of the signal line L1 from high level to low level. The sub-control unit 13 is an example of a first control unit of the present invention.

[0027] Furthermore, in response to the input of the first control signal X1 output from the sub-controller 13, the main controller 8 outputs a second control signal X2 to the sub-controller 13, instructing the display unit 11 to light up. For example, the second control signal X2 is a signal output by switching the voltage of the signal line L2 from high level to low level. The main controller 8 is an example of the second controller of the present invention.

[0028] In addition, the sub-control unit 13 turns on the display unit 11 in response to the input of the second control signal X2 output from the main control unit 8, and causes the display unit 11 to display an operation screen, etc., used to operate the image forming apparatus 100.

[0029] Incidentally, in the image forming apparatus 100, noise may be mixed into the signal line L2 (see FIG. 2), causing the display unit 11 to light up even when the operating mode is the power saving mode. For example, in the image forming apparatus 100, when the storage device 200 is attached to the attachment unit 6, electrostatic discharge may occur between the user's finger and the attachment unit 6. If the electrostatic discharge occurs while the image forming apparatus 100 is operating in the power saving mode, a high-frequency signal (noise) caused by the electrostatic discharge may be mixed into the signal line L2, causing the sub-control unit 13 to mistakenly recognize that the second control signal X2 has been input.

[0030] In contrast to this, in the image forming apparatus 100 according to the embodiment of the present invention, it is possible to prevent the display unit 11 from lighting up during the power saving mode, as will be described below.

[0031] Specifically, the operation and display unit 5 includes a gate unit 14 shown in FIG.

[0032] Gate unit 14 is provided on signal line L2, which is a transmission path for second control signal X2. For example, gate unit 14 is provided on a sub-control board on which sub-control unit 13 is mounted. The sub-control board is connected via a harness to a main control board on which each component of main control unit 8 is mounted. Signal line L2 extends from CPU 21 to sub-control unit 13 via printed wiring formed on the main control board, the harness, and printed wiring formed on the sub-control board.

[0033] The gate unit 14 passes the second control signal X2 when the first control signal X1 is output, and does not pass the second control signal X2 when the first control signal X1 is not output.

[0034] For example, the gate unit 14 is an OR gate having a first input terminal connected to the signal line L1, a second input terminal connected to the signal line L2, and an output terminal. As a result, even if a high-frequency signal (noise) mixes into the signal line L2 in the harness and the voltage of the signal line L2 momentarily switches to a low level, the voltage of the input terminal of the sub-control unit 13 to which the second control signal X2 is input is maintained at a high level as long as the voltage of the signal line L1 is at a high level (as long as the first control signal X1 is not output).

[0035] Instead of the OR gate, the gate unit 14 may include a NOR gate whose output terminal is connected to the input terminal of a NOT gate.

[0036] Alternatively, the first control signal X1 may be a signal that is output by switching the voltage of the signal line L1 from low to high, and the second control signal X2 may be a signal that is output by switching the voltage of the signal line L2 from low to high. In this case, the gate unit 14 may be an AND gate having a first input terminal connected to the signal line L1, a second input terminal connected to the signal line L2, and an output terminal.

[0037] Alternatively, the first control signal X1 may be a signal output by switching the voltage of the signal line L1 from high to low, and the second control signal X2 may be a signal output by switching the voltage of the signal line L2 from low to high. In this case, the gate unit 14 may include an AND gate having a first input terminal connected to the signal line L1 via a NOT gate, a second input terminal connected to the signal line L2, and an output terminal.

[0038] Alternatively, the first control signal X1 may be a signal output by switching the voltage of the signal line L1 from low to high, and the second control signal X2 may be a signal output by switching the voltage of the signal line L2 from high to low. In this case, the gate unit 14 may include an OR gate having a first input terminal connected to the signal line L1 via a NOT gate, a second input terminal connected to the signal line L2, and an output terminal.

[0039] In this way, in the image forming apparatus 100, the gate unit 14 is provided on the signal line L2 so as to pass the second control signal X2 when the first control signal X1 is being output and not pass the second control signal X2 when the first control signal X1 is not being output, thereby making it possible to prevent the display unit 11 from lighting up during the power saving mode due to noise mixed into the signal line L2.

[0040] [Notes on the Invention] The following is a summary of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0041] <Appendix 1> an electronic device whose operating mode can be switched between a normal mode and a power saving mode in which power consumption is reduced compared to the normal mode, the electronic device comprising: an operation unit; a display unit that is turned off when the electronic device is operating in the power saving mode; a first control unit that controls the operation unit and the display unit and outputs a first control signal when a user operation is accepted by the operation unit while the electronic device is operating in the power saving mode; a second control unit that outputs a second control signal to the first control unit in response to input of the first control signal output from the first control unit, the second control signal instructing the display unit to be turned on; and a gate unit that is provided in a transmission path of the second control signal, and that passes the second control signal when the first control signal is output, and does not pass the second control signal when the first control signal is not output. [Explanation of symbols]

[0042] 1 ADF 2 Image reading unit 3 Image forming unit 4 Paper feed section 5 Operation display section 6 Mounting part 7 Memory section 8 Main control section 11 Display section 12 Control section 13 Sub-control section 14 Gate section 100 Image forming device

Claims

[Claim 1] An electronic device capable of switching an operation mode between a normal mode and a power saving mode in which power consumption is reduced more than in the normal mode, An operation unit; a display unit that is turned off while the electronic device is operating in the power saving mode; a first control unit that controls the operation unit and the display unit, and outputs a first control signal when a user operation is received on the operation unit while the electronic device is operating in the power saving mode; a second control unit that outputs a second control signal to the first control unit instructing the display unit to light up in response to the first control signal output from the first control unit; a gate unit provided in a transmission path of the second control signal, the gate unit passing the second control signal when the first control signal is being output and not passing the second control signal when the first control signal is not being output; An electronic device comprising:

Images