JP2006072257A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve user's convenience with an image forming apparatus which stops supplying electric power to respective parts of the apparatus in a standby mode and enters an energy saving state, to improve energy-saving performance, and to suppress a rise in cost of equipment. <P>SOLUTION: A capacitor 19 is connected to a power line to which push switches 13 to 15 of an operation part 7 are connected and a current is supplied from a DC power unit 12 through a diode 20. A CPU 9 detects the potential of the power line through an I/O port 5. In normal operation and when a low-power-consumption mode is entered, the capacitor is charged and the power lint has a high level. When an arbitrary switch is pressed during the low-power-consumption mode transition, the capacitor is discharged and the power line changes to a low level. The CPU 9 detects this change and asserts an output control signal to the DC power unit to supply electric power to respective control plates, so that the image forming apparatus changes from the low-power-consumption mode to an image formation mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that stops power supply to each unit in the standby state and shifts to an energy saving state.

  In recent years, image forming devices have been required to improve energy-saving performance such as reduction of standby power consumption, and reference values have been clarified by public regulations. In the conventional image forming apparatus, the fixing device is overheated even in the standby state, all the control plates in the apparatus are kept in an energized state, and when an image formation request is input, a configuration that can immediately shift to an image forming operation is adopted. However, in recent image forming apparatuses, in order to reduce power consumption during standby, the fixing device is stopped in the standby state to significantly reduce power consumption. As a method to further reduce power consumption, power is supplied only to some control boards inside the device during standby, and power supply is stopped except for control boards that accept image forming commands, thereby reducing power consumption of the control boards. In this way, a method of reducing the power consumption of the entire system is adopted.

In such a low power consumption mode, several factors are assigned as conditions for returning to the image forming operation. In addition to inputting an image forming command via the network, the user can press down the switch from the operation unit. It is necessary to return from the low power consumption mode to the normal operation mode by detecting the opening / closing of the pressure plate that holds the document. In order to monitor these return factors, there is an existing technique in which an individual return factor sensor is in an active state even when power consumption is low, and a start factor input by a user is detected (see, for example, Patent Document 1). ).
JP 2001-61027 A

As described in Patent Document 1, a sensor is provided for each return factor, the output signals are collectively monitored by one control board, and power supply to the other control boards is stopped to reduce the power consumption of the control board. Although it is possible to reduce the number of sensors that are in the active state in the low power mode, the number of return factors is limited, which reduces the convenience for the user. is there. In addition, if the number of sensors to be activated is increased in order to improve the convenience for the user and the number of sensors to be activated is increased, the power consumption by the sensors increases and the power consumption in the low power consumption mode increases. A problem occurs. In addition, in the method of the above example, when the power consumption is low, there are two types of power supply systems, the power supply system that continues energization and the power supply system that is shut off, and the control board is increased in size and the number of power supply harnesses There is a possibility that many cost increase factors occur, such as an increase and the scale of the DC power supply device.
Accordingly, it is an object of the present invention to solve the above problems, improve the convenience for the user, improve the energy saving performance, and suppress the cost increase of the device.

  According to a first aspect of the present invention, in the image forming apparatus in which the power supply from the power supply device to the control plate is stopped and the low power consumption mode is set in the standby state, one end of each of the plurality of operation switches is commonly connected. And a capacitive component to which electric power is supplied from the power supply device, a detecting means for detecting the potential of the capacitive component that changes in accordance with the operation of each operation switch, and the detection unit in accordance with the detected potential. Control means for controlling whether or not to cancel the low power consumption mode is provided.

An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the detecting means monitors the potential of the capacitive component at an analog level.
According to a third aspect of the present invention, there is provided the image forming apparatus according to the first or second aspect, further comprising a charging unit that charges the capacitive component when the potential of the capacitive component is equal to or lower than a reference value in the standby state. It is characterized by.

  An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, wherein a plurality of operation switches are connected to the capacitive component, and the detection means is connected to each operation switch. A change in potential of the capacitive component due to an operation is individually detected, and the control means cancels the low power consumption mode and responds to the operation switch when a certain operation switch is operated and the potential changes. It is characterized by shifting to an operation mode.

  According to the first aspect of the present invention, a capacitive component such as a capacitor is used as a power source for detecting the return factor from the low power consumption mode, and all the operation switches for detecting the activation factor are connected to the capacitive component. Low power consumption by detecting the potential of capacitive parts due to the user operating the operation switch in the low power consumption mode where power is not supplied to all control boards by monitoring the potential of the capacitive parts Since whether or not to cancel the power mode is controlled, it is possible to improve the convenience for the user, improve the energy saving performance, and suppress the cost increase of the device.

  According to the invention of claim 2, by monitoring the potential of the capacitive component at an analog level, it is possible to recognize whether the activation factor has been input or the low level due to discharge over time, and prevent malfunction of the system. Thus, low power consumption of the image forming apparatus can be realized.

  According to the invention of claim 3, even when a long time has elapsed after shifting to the low power consumption mode by recharging the capacitive component when the potential of the capacitive component is below the reference value. By executing the recharge mode, it is possible to always monitor the input of the activation factor, and it is possible to achieve both improvement in user convenience and reduction in power consumption of the image forming apparatus.

  According to the fourth aspect of the present invention, it is possible to determine which return factor is input from the voltage fluctuation of the capacitive component, and even in an image forming apparatus having a plurality of operation modes, when returning from the low power consumption mode, It is possible to determine which operation mode to shift to and improve user convenience.

Hereinafter, a first embodiment will be described with reference to the drawings.
The image forming apparatus according to the present embodiment is characterized in that a capacitor is used as a power source of a circuit for detecting a return factor from the low power consumption mode. By connecting any switch on the operation unit and any switch that detects the return factor to the capacitor, and monitoring the potential of the capacitor with the active control board, power is not supplied to all the control boards Even in the low power consumption mode, it is possible to detect that the user has depressed the button. It also reduces power consumption for detecting activation factors and simplifies the power supply system inside the device, improving user convenience, improving energy-saving performance, and reducing device costs. To do.

FIG. 1 and FIG. 2 are a block diagram and a circuit diagram showing a configuration of a part related to a return factor of the image forming apparatus according to the present embodiment.
The image forming apparatus includes a copy function for reading a document, copying the document, a print function for inputting an image formation command and image data from a network, and outputting a print image, and an image processing unit handling image data; It incorporates a control system roughly divided into two functions: a sequence control unit that controls the operation of the entire image forming apparatus.

  In FIG. 1, a reading control plate 1 is composed of an image reading control plate for reading an original, and is in charge of processing such as control of an optical scanning device 2 having a motor, a CCD 3, and analog-digital conversion 4. Image data input from the network is subjected to processing such as image data development by the image processing control board 5. Further, a visible image is formed on the transfer paper by the writing control plate 6 that receives these image data and controls the lighting of the laser diode to form an electrostatic latent image on the photosensitive member. A sequence control board 8 for inputting commands from the operation unit 7, realizing a network communication function, and controlling operation of transfer paper and an image forming process is mounted with a CPU 9 for operation control, a ROM 10 for storing programs, a RAM 11 and the like. ing. The reading control board 1, the image processing control board 5, and the writing board 6 are image processing units.

  Even in the low power consumption mode, the sequence control board 8 is energized to monitor command input from the operation unit 7 or command input from the network. On the other hand, the control boards of the reading control board 1, the image control board 5, and the writing control board 6 are cut off in the low power mode and enter a mode for reducing power consumption as a system. Electric power to the control plates 1, 5, 6 is supplied from the DC power supply unit 12, and an output control signal output from the I / O port 4 (see FIG. 2) of the CPU 9 is input to the DC power supply unit 12. The power supply to the control plates 1, 5, 6 is controlled by the output control signal.

  Although a plurality of types can be set as return factors from the low power mode, in this embodiment, an arbitrary switch of the operation unit 7 will be described as a return factor. Push switches 13 to 15 are mounted on the operation unit 7, each of which is assigned a unique function during normal operation, and is used as a command input port by the user. As shown in FIG. 2, the push switches 13 to 15 are connected to the operation unit power supply of the DC power supply unit 12 through pull-up resistors 16 to 18 and a diode 20. Further, hardware signal lines are connected to the I / O ports 1, 2, and 3 of the CPU 9 on the sequence control board 8 from each switch. When the push switch is pushed by the user, the signal line changes to the ground level, and the low level is detected by the I / O ports 1, 2, 3, so that the command intended by the user is sent to the sequence control board 8. Recognized.

  In order to use each of the switches 13 to 15 as a return factor from the low power consumption mode, a capacitor 19 is connected to a power supply line to which the push switches 13 to 15 are connected. A current is supplied to the capacitor 19 from the operation unit power supply via the diode 20, and the diode 20 is connected between the operation unit power supply and the capacitor 19 so that current does not leak from the capacitor 19 toward the operation unit power supply when the power supply is shut off. Is provided. This power supply line is also connected to the I / O port 5 of the CPU 9 as a hardware signal line for transmitting the activation factor signal, and the CPU 9 can detect the potential of the power supply line.

  During normal operation, charge is accumulated in the capacitor 19 and the activation factor signal is held at a high level. At the time of shifting to the low power consumption mode, the operation unit power supplied to the operation unit 7 is cut off, but the capacitor 19 is insulated by the diode 20 and the push switches 13 to 15, so that the activation factor signal is held at a high level. The In this state, when the user presses any switch of the operation unit 7, the electric charge of the capacitor 19 is discharged to the ground via one of the pull-up resistors 16 to 18 and the pressed push switch, and the activation factor signal Changes to a low level. The CPU 9 on the sequence control board 8 detects this change, inverts the output logic of the I / O port 4 with respect to the DC power supply unit 12 to assert an output control signal, and sends it to each control board of the entire image forming apparatus. Electric power is supplied. At this time, the low power consumption mode is canceled and the image forming mode is entered.

  According to the present embodiment, the capacitor 19 is connected to the power line of the operation unit 7, and the potential is monitored by the sequence control board 8, whereby the power supply to the operation unit 7 is stopped in the low power consumption mode. However, it is possible to detect the switch operation of the operation unit 7 by the user, and to achieve both low power consumption of the device and convenience for the user. In the present embodiment, the capacitor 19 is used as a constituent factor, but a similar configuration can be realized by all capacitive components capable of storing charges.

Next, a second embodiment will be described.
In the image forming apparatus according to the first embodiment, by holding the potential for detecting the activation factor by the capacitor 19, the activation factor can be received even when the power supply to each control board is stopped. . However, when the mode is shifted to the low power consumption mode, the supply of electric charge to the capacitor 19 is stopped, and the accumulated electric charge is reduced due to a leakage current or the like. When a normal I / O port is used for the detection port of the CPU 9, if the potential of the activation factor signal falls below the minimum voltage value Vin_min at which the CPU internal logic detects a high level, the detection result becomes undefined. The activation factor cannot be detected. In addition, when the potential of the activation factor signal is equal to or lower than the maximum voltage value Vin_max at which the CPU internal logic detects the low level, the CPU 9 detects the low level even when the switch of the operation unit 7 is not pressed. The problem of starting up incorrectly occurs.

  The image forming apparatus according to the present embodiment solves the above-described problem, and is characterized in that the activation factor is monitored by a port capable of detecting the analog level of the input signal. With this configuration, it is possible to detect the amount of change in the electric charge of the capacitor 19 and to recognize whether an activation factor has been input or whether it is at a low level due to discharge over time, and to prevent malfunction of the system. To do.

FIG. 3 shows the configuration of the part related to the return factor according to the present embodiment. The parts corresponding to those in FIG. 1 and FIG. FIG. 3 is also used in a third embodiment to be described later.
In the present embodiment, the activation factor signal from the operation unit 7 is input to the AD converter of the CPU 9 of the sequence control board 8 in the configuration of FIG. 2 according to the first embodiment. When the potential is monitored at the I / O port as in the first embodiment, on / off of the switches 13 to 15 is monitored based on a threshold specific to the port. For this reason, the signal can be detected only when the potential Vin of the activation factor signal is equal to or higher than the high level detection voltage lower limit value Vin_min of the I / O port. After the low power consumption mode, the time period until the potential drops to Vin_min Only normal monitoring can be performed. In the present embodiment, by using an AD converter as an input port, even if the activation factor signal is lowered to a lower potential without being restricted by a threshold such as Vin_min, the switches 13 to 13 of the operation unit 7 are used. 15 can be monitored.

FIG. 5 is a flowchart showing the processing of the CPU 9 according to this embodiment.
The CPU 9 reads the output value Vin of the AD converter (S1), shifts to the low power consumption mode (S2), and stores Vin (S3). Next, the CPU 9 periodically monitors the potential of the activation factor signal by the AD converter and records the input voltage Vin (S4, S5). After measuring Vin, it is compared with the previous measurement record (S6). If the difference is equal to or greater than the reference value (S7, Yes), it is determined that the activation factor signal is asserted, and the output control signal is asserted (S8). ) The image forming apparatus is shifted from the low power consumption mode to the normal operation mode (S9), and returned to a state in which the image forming operation is possible. Further, if the value of Vin is less than a predetermined value compared with the previous measured value (S7, No), it is determined that the voltage has dropped due to spontaneous discharge, and the stored Vin value is updated (S3) and continues. Continue the low power consumption mode.

  According to the present embodiment, the CPU 9 reduces the restriction due to the voltage level of the activation factor signal, enables the activation factor signal to be monitored with higher accuracy, and reduces the convenience of the user and the power consumption of the device. It becomes possible.

Next, a third embodiment of the present invention will be described.
In the image forming apparatus according to the second embodiment, the malfunction detection of the system is suppressed by detecting the factor detection at the time of activation at an analog level and determining whether the factor of activation is an input of a low level due to natural discharge. After the capacitor 19 releases the potential due to leakage current or the like, it becomes impossible to detect the key input to the operation unit 7 and to return from the low power consumption mode.

  The image forming apparatus according to the present embodiment solves the above-mentioned problem, and has a mode in which the capacitor 19 is recharged when the input signal level to the activation factor detection port becomes a certain value or less. And This makes it possible to constantly monitor the input of the activation factor and improve the convenience of the user by executing the recharge mode even when a long time has passed after shifting to the low power consumption mode. it can.

FIG. 3 shows the configuration of the part related to the return factor according to the present embodiment.
In the second embodiment, the activation factor is monitored even in a lower potential state by monitoring the activation factor signal with the AD converter. However, even when the AD converter is used, if the capacitor 19 is completely discharged, the states of the activation factor switches 13 to 15 cannot be monitored. Further, in a state where the potential is significantly reduced, the potential difference between the standby state and the case where the switch of the operation unit 7 is pressed becomes small, and erroneous detection due to noise or the like may occur.

FIG. 6 is a flowchart showing the processing of the CPU 9 according to this embodiment.
The CPU 9 reads the output value Vin of the AD converter (S11) and shifts to the low power consumption mode (S12). Next, the CPU 9 periodically monitors the potential of the activation factor signal by the AD converter and reads the input voltage Vin (S13, S14). After Vin is measured, it is compared with the reference value (S15). If Vin falls below the reference value (S15, Yes), the output control signal is asserted (S16), and the system is temporarily shifted to the normal operation state (S16). S17). As a result, electric power is also supplied to the operation unit 7 and electric charges are accumulated in the capacitor 19, so that the potential of the activation factor signal rises to the power supply voltage Vcc. The input voltage Vin of the activation factor signal is read (S18). When Vin exceeds the reference value (S19, Yes), the sequence control board 8 negates the output control signal for the DC power supply unit 12 again (S20). Transition to low power consumption mode.

  According to the present embodiment, even when an image formation command is not input for a long time, it is possible to keep the activation factor signal potential in a standby state at a certain value or more, thereby preventing erroneous activation factor detection or detection omission. Can do.

Next, a fourth embodiment of the present invention will be described.
In the image forming apparatus according to the first embodiment, in the low power mode, it is possible to monitor activation factors with less power consumption. However, since all activation factors are monitored simultaneously, which activation factor is input. It was difficult to judge. For this reason, in an image forming apparatus that may shift to a plurality of operation modes after returning from the low power mode, it is difficult to determine which operation mode to return to. Multiple functions are built into the image forming device. When an image reading function is used as an example and the image forming device is started up as a scanner device, the initialization operation is executed for the fixing device and image forming process of the image forming device. There is no need to do. However, when it is unclear which switch of the operation unit 7 is pressed, it is necessary to initialize the maximum configuration capable of realizing all the functions, which causes an increase in system startup time and power consumption required for the initialization operation.

  The image forming apparatus according to the present embodiment solves the above-described problem. The activation factor is monitored by an analog amount, and it can be determined which return factor is input from the voltage fluctuation when the activation factor is input. Features. Accordingly, even in an image forming apparatus having a plurality of operation modes, it is possible to determine which operation mode is to be shifted when returning from the low power mode, and to improve user convenience.

FIG. 4 shows the configuration of the part related to the return factor according to the present embodiment. The parts corresponding to those in FIG. 1, FIG. 2, and FIG.
In the image forming apparatus according to the present embodiment, a component 21 having a resistance component between the capacitor 19 serving as the voltage source of the activation factor signal, the switches 13 to 15 of the operation unit 7, and the input port of the CPU 9 of the sequence control board 8, respectively. 22.

As an example, when the switch 13 is pressed, the potential input to the AD converter of the CPU 9 is at the ground level. When the switch 14 is pressed, the input voltage Vin to the AD converter is assumed that the potential of the capacitor 19 is Vo.
Vin = R2 / (R4 + R2) x Vo
It is prescribed. This is because the input impedance of the AD converter is high, and Vin is almost determined only by the divided voltage of the resistor. When switch 15 is pressed,
Vin = R3 ÷ (R4 + R5 + R3) x Vo
It becomes. In the standby state, Vin = Vo. This data is sequentially updated, and by comparing with the previous measurement result at the time of potential measurement, it is possible to uniquely determine which switch has been pressed.

FIG. 7 is a flowchart showing the processing of the CPU 9 according to this embodiment.
The CPU 9 reads the output value Vin of the AD converter (S31), shifts to the low power consumption mode (S32), and stores Vin (S33). Next, the CPU 9 periodically monitors the potential of the activation factor signal by the AD converter and records the input voltage Vin (S34, S35). After measuring Vin, it is compared with the previous measurement record (S36). If the difference is higher than the reference value 1 (S37, Yes), it is determined that the switch 13 is pressed (S38), and the output control signal is asserted. Then, the image forming apparatus is shifted from the low power consumption mode to the copy mode (S40). If the difference is equal to or less than the reference value 1 (S37, No), the difference is compared with the reference value 2 (S41). If the difference is higher than the reference value 2 (S41, Yes), the switch 14 is pressed. In step S42, the output control signal is asserted (S43), and the image forming apparatus is shifted from the low power consumption mode to the printer mode (S44). Further, if the difference is equal to or less than the reference value 2 (S41, No), the difference is compared with the reference value 3 (S45). If the difference is higher than the reference value 3 (S45, YES), the switch 15 is pressed. In step S46, the output control signal is asserted (S47), and the image forming apparatus is shifted from the low power consumption mode to the scanner mode (S48). If the difference is 3 or less (NO in S45), the low power consumption mode is maintained as it is.

  According to the present embodiment, in an image forming apparatus having a plurality of operation modes, even when a function-specific key is pressed by a user, it is possible to detect which function switch has been pressed, and the corresponding operation mode. Paralleling makes it possible to minimize the initialization time of the system and the power required for it.

FIG. 2 is a block diagram showing a configuration of a part related to a return factor of the image forming apparatus according to the embodiment of the present invention. FIG. 2 is a circuit diagram showing a configuration of a portion related to a return factor of the image forming apparatus according to the first embodiment of the present invention. FIG. 6 is a circuit diagram illustrating a configuration of a portion related to a return factor of an image forming apparatus according to second and third embodiments of the present invention. FIG. 10 is a circuit diagram illustrating a configuration of a portion related to a return factor of an image forming apparatus according to a fourth embodiment of the present invention. It is a flowchart which shows the operation | movement by 2nd Embodiment. It is a flowchart which shows the operation | movement by 3rd Embodiment. It is a flowchart which shows the operation | movement by 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reading control board 5 Image control board 6 Writing control board 7 Operation part 8 Sequence control board 9 CPU
12 DC power supply unit 13, 14, 15 Push switch 19 Capacitor

Claims (4)

In the image forming apparatus in which the power supply from the power supply device to the control plate is stopped in the standby state to enter the low power consumption mode.
Capacitive components to which one end of each of the plurality of operation switches is connected in common and power is supplied from the power supply device,
Detecting means for detecting a potential of the capacitive component that changes in accordance with an operation of each operation switch;
An image forming apparatus comprising: control means for controlling whether or not to release the low power consumption mode in accordance with the detected potential.   The image forming apparatus according to claim 1, wherein the detection unit monitors the potential of the capacitive component at an analog level.   3. The image forming apparatus according to claim 1, further comprising a charging unit configured to charge the capacitive component when the potential of the capacitive component becomes a reference value or less in the standby state.   The detecting means individually detects a change in potential of the capacitive component due to operation of each operation switch, and the control means sets the low power consumption mode when a certain operation switch is operated and there is a potential change. The image forming apparatus according to claim 1, wherein the image forming apparatus is released and shifted to an operation mode corresponding to the operation switch.

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