JP2014134826A - Image processing apparatus and fan control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus capable of performing control of a fan for preventing temperature of devices and inside a controller box from increasing during transition to an energy-saving mode without impairing energy-saving effect.SOLUTION: A fan control method comprises the steps of: supplying power to fans 107 to 109 from a power supply system that is not blocked during an energy-saving mode; and holding energization input to transistors 115 to 117 that control energization to the fans 107 to 109 from an ASIC 102 that operates even in the energy-saving mode for a predetermined period by delay circuits 111 to 113 so as to maintain rotation of the fans. Accordingly, a CPU or the like in a main control unit can be cooled, and failure such as deterioration and thermal runaway can be prevented even after transition to the energy-saving mode.

Description

  The present invention relates to an image processing apparatus such as a printer, a copier, or a multifunction peripheral that requires exhaust and cooling for a controller that controls processing such as image input and print output, and a fan control method thereof.

  In recent years, in image processing apparatuses such as printers, copiers, and multi-function peripherals (MFPs), some functions remain operable when no processing or operation is performed for a certain period of time. Control is performed to maintain an energy saving state (hereinafter referred to as “energy saving state” or simply “energy saving”) that suppresses power consumption by shutting off the power supplied to the circuit unit related to the stopped function. .

  By the way, recent image processing apparatuses are equipped with devices such as a CPU (Central Processing Unit) and an ASIC (Application Specific Integrated Circuit) having a high processing capacity in a controller in order to cope with multi-function and high functionality. If the heat generation is large and proper cooling is not performed, a thermal runaway may occur, resulting in malfunction or in the worst case failure.

  Controller that stores the controller to shut off most of the power, except for some circuits such as the controller ASIC that monitors the factor (return factor) for returning to the original operating state when the device enters the energy saving state. A fan that exhausts high-temperature air in the box (hereinafter also referred to as “case fan”) and a fan that cools the substrate on which the CPU is mounted (hereinafter also referred to as “CPU fan”) are stopped.

  At this time, if the temperature in the device and the controller box is high, the device guaranteed temperature may be exceeded, or the device that continues to operate may be in a thermal runaway.

  As a method proposed in order to solve such a problem, the following patent document 1 can be exemplified.

  Patent Document 1 describes an image forming apparatus that can control the driving of a fan that cools the inside of the apparatus according to the amount of operation of the image forming apparatus. The relationship with the energy saving mode depends on the detected amount of operation. The time to shift to the energy saving mode that cannot be driven is changed. That is, if the operation amount is large, the standby state in which the fan can be driven is extended, and control is performed so that the fan can be driven for a long time.

According to the method exemplified in Patent Document 1, it is possible to avoid a situation in which the fan cannot be driven due to the transition to the energy saving mode in a state where the interior of the apparatus cannot be sufficiently cooled. However, since the method of extending the standby state is adopted, the extended period will be in the standby state just to drive the fan. By taking the standby state, the controller and image formation etc. For this reason, there is a problem in that power is continuously supplied to each processing unit, wasteful power is consumed, and the energy saving effect is reduced.
The present invention has been made in view of the above, and image processing that can control a fan that prevents the temperature in the device and the controller box from becoming high when shifting to energy saving without impairing the energy saving effect. An object is to provide a device and a fan control method.

  In order to solve the above-described problems and achieve the object, an image processing apparatus according to the present invention includes an image processing unit, a main control unit that controls the image processing unit, and a fan that exhausts and cools the main control unit. And a fan control unit that controls ON / OFF of the rotation of the fan independently of the main control unit, and controls power supply to the main control unit and the fan control unit, and at least the main control unit An energy saving control unit that shifts to an energy saving state by stopping power supply to the energy saving control unit, the energy saving control unit maintains the fan in an operating state for a predetermined period after shifting to the energy saving state, A fan rotation maintaining unit that stops power supply to the fan control unit is provided.

  A fan control method according to the present invention is a fan control method executed in an image processing apparatus, and includes a main control unit that controls an image processing unit, and rotation of a fan that exhausts and cools the main control unit. Performing power supply control to the fan control unit that performs ON / OFF control independently of the main control unit, and stopping the power supply to at least the main control unit to shift to an energy saving state; and The predetermined period after the transition to the energy saving state includes the step of stopping the power supply to the fan control unit after maintaining the fan in the operating state.

  According to the present invention, when shifting to energy saving, the rotation of the cooling fan to prevent device deterioration or thermal runaway can be maintained for a predetermined time after the energy saving transition, so that the energy saving effect is not impaired. The target cooling fan can be operated appropriately.

FIG. 3 is a block diagram schematically showing a circuit configuration of a control unit according to the first embodiment. It is a figure explaining the energization state at the time of the energy saving transition in the circuit structure shown in FIG. FIG. 3 is a configuration diagram of a fan control circuit according to the first embodiment. 2 is a circuit diagram illustrating a detailed configuration of delay circuits 111, 112, and 113 according to the first embodiment. FIG. It is a timing chart in the case of maintaining rotation of a cooling fan. It is a timing chart in the case of canceling rotation maintenance of a cooling fan. 3 is an explanatory diagram illustrating an example of a table in which a load amount of a CPU 101 is associated with an image forming function. FIG. 4 is a flowchart illustrating a processing procedure from power-on to the energy saving transition of the image processing apparatus according to the first embodiment. It is a time chart which shows the level of the fan control signal when the load amount of CPU101 is high immediately before energy saving transition, and the rotation state of CPU fan and case fans 108 and 109. It is a time chart which shows the level of the fan control signal and the state of rotation of the CPU fan and the case fans 108 and 109 when the load amount of the CPU 101 is medium immediately before shifting to energy saving. It is a time chart which shows the level of the fan control signal when the load amount of CPU101 is low immediately before energy saving transition, and the rotation state of CPU fan and case fans 108 and 109. FIG. 6 is a configuration diagram of a fan control circuit according to a second embodiment. 2 is a circuit diagram showing a detailed configuration of timer circuits (delay circuits) 121, 122, 123. FIG. 6 is a flowchart illustrating a processing procedure from power-on to an energy saving transition of the image processing apparatus according to the second embodiment. It is a time chart which shows the level of the fan control signal when the load amount of CPU101 is high immediately before energy saving transition, and the rotation state of CPU fan and case fans 108 and 109. It is a time chart which shows the level of the fan control signal and the state of rotation of the CPU fan and the case fans 108 and 109 when the load amount of the CPU 101 is medium immediately before shifting to energy saving. It is a time chart which shows the level of the fan control signal when the load amount of CPU101 is low immediately before energy saving transition, and the rotation state of CPU fan and case fans 108 and 109.

  Exemplary embodiments of an image processing apparatus and a fan control method according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment 1)
The image processing apparatus according to the present embodiment includes a device that generates heat, such as a scanner or a print engine, in an image input / output unit, and a CPU having high processing capability is mounted in a main control unit. For this reason, the heat generated by itself is also added to the periphery of the CPU, resulting in a high temperature and exposed to a risk of failure such as deterioration of the CPU or thermal runaway.
In order to prevent such obstacles, a case fan that exhausts high-temperature air in a case that houses a circuit board that constitutes a main control unit or the like, or a CPU fan that directly cools a circuit board on which a device such as a CPU or ASIC is mounted Is provided.

  The rotation of the case fan and CPU fan (hereinafter referred to as “cooling fan” when these fans are collectively referred to) is controlled so that the temperature of the device mounted on the circuit board does not exceed the standard value.

  FIG. 1 is a block diagram schematically showing a circuit configuration of a control unit according to the first embodiment. Note that FIG. 1 mainly shows a circuit configuration of a main control unit and a cooling fan control unit configured by the CPU, and other devices and operation units used for image processing are omitted.

  In the configuration of FIG. 1, the CPU 101 stores an HDD (Hard Disk Drive) 103, a DRAM (Dynamic Random Access Memory) 104, a ROM (Read Only Memory) 105, and a communication interface (I / F) 106 via the ASIC 102. The device group is connected to configure the main control unit.

  The main control unit integrally controls each operation unit (device) of the image forming apparatus including a device and an operation unit not shown in FIG. 1 used for image processing.

  The ROM 105 is a memory that stores a program used by the CPU 101 for operation. The DRAM 104 is used to store data generated in the process as a work memory when the CPU 101 drives a program. The HDD 103 can store a large amount of data and is used for storing image data and storing programs.

  The CPU 101 manages image input / output processing and various devices according to instructions from the operation unit and automatically started programs, and executes control for keeping the operation state of the apparatus appropriate. Cooling fans such as the CPU fan 107 and the case fans 108 and 109 connected via the ASIC 102 are one of the objects controlled by the CPU 101 (main control unit) in order to keep the operation state of the apparatus properly.

  The rotation of the cooling fan is ON / OFF controlled so that the temperature of the device such as the CPU 101 or the ASIC 102 mounted on the circuit board that changes due to the heat generated by the operation does not exceed the standard value.

  By the way, the image processing apparatus of this embodiment performs control which transfers to the energy-saving state which suppresses power consumption, when processing and operation for a fixed time are not performed. In the energy saving state, some circuits such as the controller ASIC that monitors the factor (return factor) for returning to the original operating state remain operable, but other functions were stopped and stopped. Power consumption is reduced by shutting off the power supplied to the circuit units related to the function.

FIG. 2 is a diagram for explaining an energization state during energy saving transition in the circuit configuration shown in FIG. In FIG. 2, the ASIC 102 is energized, but other circuit elements such as the CPU 101 are not energized, as indicated by hatching. This energized state is to monitor the return factor and leave some circuits (not shown) such as ASIC and SubCPU for power control to cut off the power and reduce power consumption. Represents.
In the circuit illustrated in FIG. 2, since the ASIC 102 monitors the return factor and performs power supply control, only the circuit element is energized. In this state, the normal operation state in which the entire circuit is operable. Thus, the cooling fan control operation performed by the CPU 101 cannot be performed.

“Control of cooling fan when shifting to energy-saving state (basic operation)”
When the transition to the energy saving state shown in FIG. 2 is suddenly made from the normal operating state in which the entire circuit can operate, and the cooling fan is stopped, as described in [Background Art], the CPU deteriorates due to high temperatures. And can't prevent obstacles such as thermal runaway. In addition, if the cooling fan is continuously driven by taking a method of extending the energy saving transition period, as described in the section “Problems to be solved by the invention”, wasteful power consumption occurs, and the energy saving effect is improved. The problem of lowering occurs.
Therefore, in this embodiment, the problem is solved by adding means for continuing the rotation of the cooling fan for a predetermined time (hereinafter referred to as “fan rotation maintaining unit”) even after shifting to the energy saving state.

  The fan rotation maintaining unit performs the operation of continuing the rotation by turning on the cooling fan for a predetermined time after shifting to the energy saving state, that is, without the CPU 101 operating in the normal time.

In order to perform this operation, here, power is supplied to the cooling fan from the power supply system that is not shut off even in the energy saving state, and the ASIC 102 that operates even in the energy saving state and means for ON / OFF control of the cooling fan ( A control operation for maintaining the operation of the cooling fan for a predetermined time is performed using an additional circuit provided in the input stage of the fan control circuit 140) described later.
By providing such a fan rotation maintaining unit, the cooling fan control that prevents the temperature in the device and the controller box from becoming high after the transition to the energy saving state is performed without impairing the energy saving effect. Can do.

"Circuit configuration of the fan rotation maintaining unit"
FIG. 3 is a configuration diagram of the fan control circuit according to the first embodiment. The fan control circuit shown in FIG. 3 shows a circuit that operates after transition to energy saving. As shown in FIG. 3, the fan control circuit of the present embodiment mainly includes an operation unit 130, the above-described ASIC 102, a power supply system 120 that is not cut off during energy saving, and a fan rotation maintaining unit 140. Moreover, although not shown in FIG. 3, the CPU 101 described above is also provided.

  The operation unit 130 receives various operation inputs from the user. In the present embodiment, the operation unit 130 is a reset for forcibly stopping the rotations maintained by the CPU fan 107, the case fan (1) 108, and the case fan (2) 109 during energy saving transition from the user. Accept input. As will be described later, this reset input is input to the fan rotation maintaining unit 140 as a reset signal.

  The fan rotation maintaining unit 140 is a circuit that controls the rotation of the CPU fan 107, the case fan (1) 108, and the case fan (2) 109 (hereinafter collectively referred to as “cooling fan”). In this fan control circuit, three fans, the CPU fan 107, the case fan (1) 108, and the case fan (2) 109, are connected to the power supply system 120 that is not cut off even during the energy saving transition period, and each fan rotates. ON / OFF control is performed by ON / OFF control of energization from the power supply to each fan.

  ON / OFF of energization to each fan is determined by the magnitude of the input signal to the switching transistors 115, 116, 117 connected to each fan. This input signal is a base input voltage when the switching transistor is a bipolar Tr (Transistor), and a gate input voltage when the switching transistor is a FET (Field Effect Transistor).

  After the transition to the energy saving state, the fan rotation maintaining unit 140 controls the cooling fan to be ON for a predetermined time estimated that the temperature of the CPU or the like does not exceed the standard value, and continues the rotation of the cooling fan.

  As shown in FIG. 3, the fan rotation maintaining unit 140 includes delay circuits 111, 112, 113 and transistors 115, 116, 117. In the present embodiment, a method of performing ON / OFF control of rotation of the cooling fan by ON / OFF control of energization to the cooling fan is adopted. Accordingly, the input from the ASIC 102 instructing power supply control from the power source is held as the energization input by the delay circuits 111, 112, 113 in the fan rotation maintaining unit 140 for the predetermined time for maintaining the rotation of the cooling fan, and the cooling fan is rotated. The circuit is configured to maintain the ON control state.

  By turning ON / OFF the power supply to the cooling fan, the rotation input of the cooling fan is held by the delay circuits 111, 112, and 113 by the delay circuits 111, 112, and 113, so that the cooling fan can be switched to the energy saving state. The operation of continuing the rotation of the motor can be performed only with logic and a relatively low-capacitance capacitor.

  Further, as shown in FIG. 3, the ASIC 102 provides the delay circuits 111, 112, and 113 with a fan control signal for instructing to maintain the rotation of the cooling fan and a fan for instructing to release the rotation of the cooling fan. A rotation maintenance release signal or a reset signal by a reset input from the operation unit 130 is input.

  In this embodiment, a circuit having a one-shot timer IC is used as the delay circuits 111, 112, and 113 for holding energization input. The fan rotation maintaining unit 140 including the delay circuits 111, 112, and 113 will be described in detail below.

  The delay circuits 111, 112, and 113 are generally configured by one one-shot timer IC, a resistor and a capacitor outside thereof, and have a simple configuration with a relatively small number of components. FIG. 4 is a circuit diagram showing a detailed configuration of delay circuits 111, 112, and 113 according to the first embodiment. As shown in FIG. 4, the delay circuits 111, 112, and 113 of this embodiment include, as main elements, a one-shot timer IC 150 (hereinafter referred to as “timer IC 150”), a resistor 142, a capacitor 141, and a pull And an up resistor 148. Here, the resistor 142 has a resistance value R1, and the capacitor 141 has a capacitance C1.

  The timer IC 150 has a function as a one-shot timer IC, and mainly includes a differential circuit 143, 144, an RS-flip flop (RS-FF) 145, an output circuit (OUT) 146, and a transistor 149. ing.

  In the circuit at the time of energy saving transition, the fan control signal from the ASIC 102 is input to the switching transistors 115, 116, 117 as the fan power Sw Tr control signal through the delay circuits 111, 112, 113.

  Specifically, the default output from the output circuit (OUT) 146 of the timer IC 150 is an L level signal. When the fan rotation maintenance release signal is in the H level and the L level fan control signal is input to the delay circuits 111, 112, and 113, an L pulse is input to Vtrig, and the output circuit (OUT) 146 is thereby input. The output from is at the H level for a certain time. As a result, the fan power Sw Tr control signal is output at the H level by the OR circuit 147, and the rotation of the cooling fan is maintained. FIG. 5 is a timing chart when the rotation of the cooling fan is maintained.

  Here, the delay circuits 111, 112, and 113 delay the timing at which the output of the timer IC 150 changes with respect to the input trigger to the timer IC 150 by the resistance value R1 of the resistor 142 and the capacitance C1 of the capacitor 141 (C1). XR1 value) is determined. That is, an arbitrary delay time can be set by changing the values of the resistance value R1 and the capacitance C1.

  Further, when the reset signal is input from the operation unit 130 while the fan control signal is at the L level, or when the fan control signal is set to the L level, the fan rotation maintenance release signal from the ASIC 102 is in the L level state. In some cases, a reset signal is input to the timer IC 150, and the output signal from the output unit (OUT) 146 becomes L level by the RS-FF 145. As a result, the OR circuit 147 causes the fan power supply Sw Tr control signal to become L level, and the rotation of the cooling fan is released. That is, the rotation of the cooling fan maintained after the energy saving transition is forcibly stopped. FIG. 6 is a timing chart in the case of releasing the rotation maintenance of the cooling fan.

  That is, when the ASIC 102 issues a fan control signal as a trigger during energy saving transition, control of delay time and energization according to the value of (C1 × R1) of the resistor 142 and the capacitor 141 in the delay circuits 111, 112, 113 is performed. Since the signal is input to the switching transistors 115, 116, and 117, the operation of the cooling fan can be continued for a predetermined time after the energy saving transition, and the cooling capacity can be changed.

  Further, when the resistance value R1 of the resistor 142 and the capacitance value (C1 × R1) of the capacitor 141 in the delay circuits 111, 112, and 113 are set so as to obtain an appropriate delay time, high performance is achieved. For models equipped with CPUs and CPUs with high operating clock frequency and large heat generation, the resistance and capacitor values are determined so that the cooling fan rotation maintenance time is long. Conversely, models and operating clocks equipped with low-performance CPUs are used. In a CPU with low frequency and low heat generation, setting the rotation maintenance time of the fan as short as possible makes it possible to reduce the minimum rotation maintenance time and contribute to power saving.

  As described above, by using the timer IC 150 having the one-shot timer function for the delay circuits 111, 112, and 113, it is possible to determine the time until the cooling fan is stopped relatively accurately by the resistance and capacitor capacity outside the IC. it can. Further, the cost can be kept low by adopting a circuit having a relatively simple structure called a one-shot timer IC.

"Control of rotation maintenance for multiple cooling fans"
Here, in the fan control circuit of the present embodiment, as shown in FIG. 3, the fan rotation maintaining unit for each of the three fans of the CPU fan 107, the case fan (1) 108, and the case fan (2) 109 is provided. 140.
When performing rotation maintenance control with such a circuit configuration, instead of uniformly performing rotation maintenance operations for each fan during energy-saving transitions, it is possible to respond to the expected rise in temperature and adapt to the required cooling capacity. By causing each cooling fan to perform the above, an appropriate operation state can be obtained.

  In addition, although it is the same as the change of the delay time described above in that the cooling capacity is changed, the above method of changing the delay time by changing the (C × R) value can be adapted to different CPU performance depending on the model. It cannot be adapted to changes in the operating state of the CPU.

  On the other hand, in this embodiment, the ASIC 102 as a monitoring unit monitors the operation state of the CPU, and when the cooling capacity required corresponding to the load of the CPU 101 is different, the three cooling fans are operated independently. It can be adapted by optimizing the operation by selecting a variation of operation, whether to operate two cooling fans in combination, or to operate all three cooling fans. .

  In this embodiment, the load amount of the CPU 101 is determined based on the image forming function currently being executed. FIG. 7 is an explanatory diagram illustrating an example of a table in which a load amount of the CPU 101 is associated with an image forming function. In this embodiment, such a table is stored in the ROM 105.

  Then, the ASIC 102 determines the currently executed image forming function from the operation input of the operation unit 130 and the state of the process, and refers to the table of FIG. Monitor the amount of load. In the example of FIG. 7, if the currently executed function is a printer function, the ASIC 102 determines that the load amount of the CPU 101 is 1 level during load or high load. Note that the example of FIG. 7 is an example, and the present invention is not limited to this. For example, in the example of FIG. 7, two load amounts are set for each of the printer function and the scanner function, but the table of FIG. 7 is configured so that one load amount is set for each function. May be.

  In the present embodiment, the table shown in FIG. 7 is stored in the ROM 105. However, the present invention is not limited to this, and the CPU 101 shown in FIG. You may comprise so that the relationship of load amount may be judged in the flow of a process.

  When shifting to the energy saving state, select a variation to continue the rotation according to the CPU load being monitored for a certain time (in this embodiment, 5 minutes) before the energy saving transition, and the selected variation Accordingly, the cooling fan to be operated by the fan rotation maintaining unit 140 is determined.

  FIG. 8 is a flowchart illustrating a processing procedure from power-on to the energy saving transition of the image processing apparatus according to the first embodiment. When the image processing apparatus is powered on (step S11), a startup process is performed. When this activation process is completed (step S12), the ASIC 102 monitors the load on the CPU 101 (step S13). Specifically, as described above, the ASIC 102 periodically acquires the image forming function currently being executed by the image processing apparatus, refers to the table shown in FIG. Determine the amount. And ASIC102 will be in the detection waiting state of an energy saving transition factor (step S14: No).

  When the energy saving transition factor is detected (step S14: Yes), the load amount of the CPU 101 for 5 minutes before the energy saving transition is determined (step S15). If the load amount is high, the fan control signal is set to L level while maintaining the fan rotation maintenance release signal for all the cooling fans at H level (step S22). And it transfers to an energy saving state (step S23). Thereby, all the rotations of the CPU fan 107 and the case fans 108 and 109 are maintained for a certain time after the energy saving transition.

  FIG. 9A is a time chart illustrating the level of the fan control signal and the rotation state of the CPU fan and the case fans 108 and 109 when the load amount of the CPU 101 is high immediately before the energy saving transition. Here, before the energy saving transition, as shown by High, the fan control signal is in a state where the energization control signal is input from the ASIC 102 to each cooling fan, and the CPU fan 107 and the case fan (1 ) 108 and the case fan (2) 109 are operating.

  As shown in FIG. 9A, when the CPU load amount for 5 minutes before the energy saving transition is large, that is, when the CPU load is high, it is estimated that the CPU is hot. Select the variation that is the target of operation by the fan rotation maintaining unit 140 for all the cooling fans to be triggered, trigger the one-shot timer IC of each cooling fan, and control the energization over the delay time even after energy saving transition Is input to the switching transistors 115, 116, and 117 to continue the operation of the cooling fan.

  Returning to FIG. 8, in step S15, when the load amount of the CPU 101 for 5 minutes before the energy saving transition is under load (1 during load, 2 during load in FIG. 7), the fan rotation for the case fans 108 and 109 is maintained. The release signal is set to L level (step S19), and the fan control signal is set to L level (step S20). And it transfers to an energy saving state (step S21). As a result, only the CPU fan 107 is kept rotating for a certain time after the energy saving transition, and the rotation of the case fans 108 and 109 is stopped.

  FIG. 9-2 is a time chart showing the level of the fan control signal and the state of rotation of the CPU fan and the case fans 108 and 109 when the load on the CPU 101 is medium immediately before the transition to energy saving.

  As shown in Fig. 9-2, when the CPU load for 5 minutes before the energy saving transition is moderate, it is estimated that there is some margin in the CPU temperature, so after the energy saving transition with a larger cooling fan The case fan (1) 108 and the case fan (2) 109, which can be sources of noise, are stopped simultaneously with the energy saving transition.

  On the other hand, since the CPU fan 107 cannot estimate that the CPU temperature is still sufficiently low, the CPU fan 107 selects a variation to be operated by the fan rotation maintaining unit 140 and triggers the one-shot timer IC of the CPU fan 107. After the energy saving transition, the energization control signal is input over the delay time to continue the operation of the cooling fan.

  Returning to FIG. 8, when the load amount of the CPU 101 for 5 minutes before the energy saving transition is low (load low 1, load low 2 in FIG. 7) in step S15, the CPU fan 107 and case fans 108, 109 are loaded. Is set to L level (step S16), and the fan control signal is set to L level (step S17). And it transfers to an energy saving state (step S18). Thereby, after the energy saving transition, the rotation of all the cooling fans of the CPU fan 107 and the case fans 108 and 109 stops.

  FIG. 9C is a time chart illustrating the level of the fan control signal and the rotation state of the CPU fan and the case fans 108 and 109 when the load amount of the CPU 101 is low immediately before the energy saving transition.

  As shown in Fig. 9-3, if the CPU load for 5 minutes before energy saving transition is very low, it is estimated that the CPU temperature has already dropped, so all fans will stop at the same time as energy saving transition Let

  Note that FIG. 3 shows the circuit that operates after the transition to energy saving. As described above, in the normal operation in which the main control unit is operable, the switching transistors 115, 116, When the circuit configuration performed by the operation 117 is adopted, the delay circuits 111, 112, and 113 by the one-shot timer IC are unnecessary during the normal operation, and thus the control is invalidated and activated during the energy saving transition period. Need to do.

  In this way, in this embodiment, when shifting to energy saving, the rotation of the cooling fan to prevent device deterioration or thermal runaway can be maintained for a predetermined time after the energy saving transition. The target cooling fan can be appropriately operated without impairing the operation.

  Also, in this embodiment, the minimum necessary amount is selected by selecting which variation to continue rotation according to the load amount for 5 minutes before the energy saving transition of the monitored CPU load and stopping unnecessary cooling fans. The power consumption can be reduced and the generation of noise after energy saving can be suppressed.

(Embodiment 2)
In the first embodiment, the circuit having the one-shot timer IC is used as the delay circuit for holding the energization input. However, in the second embodiment, the delay time for maintaining the rotation is variable as the delay circuit. A timer circuit that can be set to is used for the delay circuit.

  FIG. 10 is a configuration diagram of the fan control circuit according to the second embodiment. The fan control circuit shown in FIG. 10 shows a circuit that operates after transition to energy saving. As shown in FIG. 10, the fan control circuit according to the present embodiment mainly includes an operation unit 130, an ASIC 102, a power supply system 120 that is not cut off during energy saving, and a fan rotation maintaining unit 1040. Further, although not shown in FIG. 10, the CPU 101 described above is also provided.

  The fan rotation maintaining unit 1040 is a circuit that controls the rotation of the CPU fan 107, the case fan (1) 108, and the case fan (2) 109 (cooling fan), as in the first embodiment. Also in this embodiment, in the fan control circuit, the three fans of the CPU fan 107, the case fan (1) 108, and the case fan (2) 109 are connected to the power supply system 120 that is not cut off even during the energy saving transition period. Then, ON / OFF control of rotation of each cooling fan is performed by ON / OFF control of energization from the power source to each cooling fan.

“Fan rotation maintaining unit using variable delay timer circuit for delay circuit”
As shown in FIG. 10, the fan rotation maintaining unit 1040 of the present embodiment includes delay circuits 121, 122, 123 and transistors 115, 116, 117. The delay circuits 121, 122, and 123 are timer circuits. Note that the transistors 115, 116, and 117 are the same as those in the first embodiment.

  Since this timer circuit can arbitrarily set a delay time for continuously operating the cooling fan during energy saving transition, and can adapt to changes in the operating state of the CPU, the one-shot timer IC shown above is externally attached. It is possible to solve the problem that cannot be applied by changing the delay time according to the resistance and capacitor values.

  In the circuit at the time of energy saving transition, the fan control signal from the ASIC 102 is input to the switching transistors 115, 116, and 117 as the fan power Sw Tr control signal through the delay circuits 121, 122, and 123 including timer circuits.

  That is, when the ASIC 102 issues an L level fan control signal as a trigger during energy saving transition, the switching transistor 115 outputs a control signal for energization with a delay time corresponding to the time set in the timer circuit of the delay circuits 121, 122, 123. 116, 117, the operation of the cooling fan can be continued for a predetermined time after the transition to energy saving, and the cooling capacity can be changed.

  FIG. 11 is a circuit diagram showing a detailed configuration of the timer circuits (delay circuits) 121, 122, and 123. As shown in FIG. 11, the timer circuits 121, 122, and 123 include a counter 1042, a delay time setting register 1041, and a control logic 1044 that includes a comparator 1043.

  A desired delay time is set in the delay time setting register 1041 from the main control unit. The setting of the delay time in the delay time setting register 1041 can be executed by preparing a procedure that allows the set value to be changed by a command from the main control unit during energy saving transition.

  The control logic 1044 receives a fan control signal from the ASCIC 102 and a reset signal from the operation unit 130. When an L level fan control signal is input to the control logic 1044, the control logic 1044 instructs the counter 1042 to count the elapsed time from the input time point. The counter 1042 is a circuit that counts elapsed time in response to this command.

  The comparator 1043 is a circuit that compares the elapsed time counted by the counter 1042 with the delay time set in the delay time setting register 1041. If the elapsed time has not reached the delay time, the control logic 1044 sends out an H level fan power Sw Tr control signal to the transistors 115, 116, and 117. As a result, the rotation of the cooling fan is maintained for the delay time after the transition to energy saving.

  When the control logic 1044 receives a reset signal, the control logic 1044 causes the counter 1042 to stop counting elapsed time and sends an L level fan power Sw Tr control signal to the transistors 115, 116, and 117. As a result, the rotation of the cooling fan maintained after the energy saving transition is forcibly stopped.

  In other words, the timer circuit of the present embodiment can arbitrarily change the delay time depending on the setting, so that the rotation maintaining time of the cooling fan that rotates after the energy saving transition can be optimized. However, there may be a difference between the setting and the actual cooling effect depending on the use state or use environment of the image processing apparatus.

  For example, even if the cooling fan rotation maintenance time is shortened, there are cases where the required cooling effect is obtained and operation is not hindered. In such cases, it is desired to eliminate waste of power and noise due to the operation of the cooling fan. A request arises.

  Therefore, in the present embodiment, as in the first embodiment, the reset signal is input to the control logic 1044 by the reset input from the operation unit 130 before the rotation maintaining time of the cooling fan to be rotated after the energy saving transition has elapsed. The cooling fan is forcibly stopped.

"Rotation maintenance control by changing the set value to the timer circuit"
As exemplified in the fan control circuit using the delay circuit composed of the timer circuit of FIG. 11, the CPU circuit 107, the case fan (1) 108, and the case fan (2) 109 have three timer circuits. Control can be performed to maintain the fan rotation according to the delay time set in the delay time setting register 1041.

  When performing such rotation maintenance control, instead of uniformly performing the rotation maintenance operation of each cooling fan at the time of energy saving transition, each operation corresponding to the expected increase in temperature and corresponding to the required cooling capacity is performed. An appropriate operating state can be obtained by setting a timer circuit for the cooling fan to perform.

  In addition, in the point which changes cooling capacity, it is the same as embodiment by the above-mentioned one-shot timer IC, However, In the said embodiment, as the operation | movement was demonstrated with reference to FIG. ), The adaptability is limited because the cooling fan that performs the rotation maintaining operation is selected.

  In contrast, in the present embodiment, when the cooling capacity required corresponding to the operation state of the CPU is different, in addition to selecting the cooling fan that performs the rotation maintaining operation, the rotation of the three cooling fans is performed. Since the maintaining time can be set, the variation of the operation can be further increased, and a more appropriate operation can be selected.

  Also in this embodiment, the required cooling capacity can be estimated by the load amount on the CPU. When the load amount on the CPU is monitored and the state is shifted to the energy saving state, a predetermined time before the energy saving transition (in this embodiment, Depending on the load amount of the CPU being monitored in 5 minutes), it is selected which variation to continue the rotation, and the cooling fan to be operated by the fan rotation maintaining unit 1040 is determined according to the selected variation.

  FIG. 12 is a flowchart illustrating a processing procedure from power-on to the energy saving transition of the image processing apparatus according to the second embodiment. When the image processing apparatus is powered on (step S31), a startup process is performed. When this activation process is completed (step S32), the ASIC 102 monitors the load on the CPU 101 (step S33). Specifically, the load amount of the CPU 101 is determined by the same method as in the first embodiment. And ASIC102 will be in the detection waiting state of an energy-saving shift factor (step S34: No).

  When the energy saving transition factor is detected (step S34: Yes), the load amount of the CPU 101 for 5 minutes before the energy saving transition is determined (step S35). If the load amount is high, the delay time is set to 5 minutes in the delay time setting register 1041 of the timer circuit (step S42). Then, the fan control signal is set to L level (step S43). And it transfers to an energy saving state (step S44). Thereby, the rotation of the CPU fan 107 and the case fans 108 and 109 is maintained for the delay time of 5 minutes after the energy saving transition.

  FIG. 13A is a time chart illustrating the level of the fan control signal and the rotation state of the CPU fan and the case fans 108 and 109 when the load amount of the CPU 101 is high immediately before the energy saving transition. Here, before the energy saving transition, the fan control signal is in a state where the energization control signal is inputted from the ASIC 102 to each fan as indicated by High, and the CPU fan 107 and the case fan (1). 108, the case fan (2) 109 is operating.

  As shown in FIG. 13A, when the load amount of the CPU for 5 minutes before the energy saving transition is large, that is, when the CPU load is high, it is estimated that the CPU is at a high temperature. At this time, all the cooling fans including the CPU fan 107 are targeted for operation by the fan rotation maintaining unit 1040, and the timer circuit of each fan is operated with a delay time (rotation) so that each cooling fan is operated for a relatively long time. Set the maintenance time to 5 minutes.

  The timer circuit is operated by a trigger input from the ASIC 102 to the timer circuits (delay circuits) 121, 122, 123 during energy saving transition, and an energization control signal is input to the switching transistors 115, 116, 117 over a set delay time. Continue to rotate the cooling fan.

  Returning to FIG. 12, in step S35, when the load amount of the CPU 101 for 5 minutes before the energy saving transition is under load (1 during load, 2 during load in FIG. 7), it is stored in the delay time setting register 1041 of the timer circuit. The delay time is set as 2 minutes (step S39). Then, the fan control signal is set to L level (step S40). And it transfers to an energy saving state (step S41). Thereby, the rotation of the CPU fan 107 and the case fans 108 and 109 is maintained for the delay time of 2 minutes after the energy saving transition.

  FIG. 13-2 is a time chart illustrating the level of the fan control signal and the state of rotation of the CPU fan and the case fans 108 and 109 when the load on the CPU 101 is medium immediately before the transition to energy saving. As shown in FIG. 13-2, when the CPU load for 5 minutes before the energy saving transition is medium, the rotation maintaining time of each cooling fan may be shorter than when the CPU load is high. As illustrated in Fig. 5, the operation is performed with a delay time of 2 minutes.

  Returning to FIG. 12, when the load amount of the CPU 101 for 5 minutes before the energy saving transition is low (load low 1, load low 2 in FIG. 7) in step S35, the delay time setting register 1041 of the timer circuit is set. The delay time is set as 0 minutes (step S36). Then, the fan control signal is set to L level (step S37). And it transfers to an energy saving state (step S38). As a result, the rotation of the CPU fan 107 and the case fans 108 and 109 is stopped immediately after the transition to energy saving.

  FIG. 13C is a time chart illustrating the level of the fan control signal and the rotation state of the CPU fan and the case fans 108 and 109 when the load amount of the CPU 101 is low immediately before the energy saving transition. As shown in FIG. 13-3, when the CPU load for 5 minutes before the energy saving transition is very low, it is estimated that the CPU temperature has already decreased. Stop.

  Note that FIG. 10 shows the circuit that operates after the transition to energy saving. As described above, in the normal operation in which the main control unit can operate, the energization control of the cooling fan is controlled by the switching transistors 115, 116, 116 through the ASIC 102. When the circuit configuration performed by the operation 117 is employed, the delay circuits 121, 122, and 123 by the timer circuit are not necessary during the normal operation, so that this circuit is invalidated and controlled to be activated during the energy saving transition period. There is a need.

  In addition, the specific values of the delay times shown in the present embodiment are examples, and are not limited to these.

  In this way, in this embodiment, when shifting to energy saving, the rotation of the cooling fan to prevent device deterioration or thermal runaway can be maintained for a predetermined time after the energy saving transition. The target cooling fan can be appropriately operated without impairing the operation.

  In this embodiment, depending on the variation of the monitored CPU load for 5 minutes before the energy saving transition, in which variation the rotation of each cooling fan is to be stopped / continued, the CPU load is By setting the corresponding predetermined time, it is possible to further optimize the control operation that eliminates noise caused by unnecessary operation of the cooling fan and obtains the necessary cooling capacity with minimum power consumption.

101 CPU
102 ASIC
107 CPU fan 108, 109 Case fan 111, 112, 113 Delay circuit (timer IC)
121, 122, 123 Delay circuit (timer circuit)
130 Operation unit 140, 1040 Fan rotation maintaining unit

JP 2004-163628 A

To solve the above problems and achieve the object, an image processing apparatus according to the present invention includes a main control unit that performs predetermined control, and fan for exhausting or cooling of the main control unit, the fan times A fan control unit that controls rotation, the fan control unit to the main control unit based on the temperature of the main control unit before shifting to a state of stopping the power supply to the main control unit The rotation of the fan is continued for a predetermined period after the power supply is stopped, and the rotation of the fan is stopped .

Claims (9)

An image processing apparatus,
An image processing unit;
A main control unit for controlling the image processing unit;
A fan for exhausting and cooling the main control unit;
Independent of the main control unit, a fan control unit for ON / OFF control of rotation of the fan;
An energy-saving control unit that controls power supply to the main control unit and the fan control unit, and at least stops power supply to the main control unit to shift to an energy-saving state;
The energy saving control unit is a fan rotation maintaining unit that stops power supply to the fan control unit after maintaining the fan in an operating state for a predetermined period after transition to the energy saving state,
An image processing apparatus comprising: The fan control unit performs rotation ON / OFF control of the fan by energization control,
The fan rotation maintaining unit includes a delay circuit that holds an energization input so as to perform ON control for the predetermined period until power supply to the fan control unit is stopped, and delays energization control in the fan control unit. The image processing apparatus according to claim 1.   The image processing apparatus according to claim 2, wherein the delay circuit includes a one-shot timer IC, a capacitor having a predetermined capacitance, and a resistor having a predetermined resistance value. The main control unit includes a CPU (Central Processing Unit),
The image processing apparatus according to claim 3, wherein the capacitance and the resistance value are determined based on a value corresponding to a delay time suitable for a type of the CPU and an operation clock frequency. The fan includes a first fan used for the entire main control unit and a second fan used for the CPU,
The energy saving control unit includes a monitoring unit that monitors the load amount of the CPU in a certain time before the energy saving transition,
The fan rotation maintaining unit selects one or both of the first fan and the second fan based on the load amount, and maintains the selected operating state of the first fan or the second fan. 5. The image processing apparatus according to claim 4, wherein power supply to the fan control unit is stopped afterwards.   The image processing apparatus according to claim 2, wherein the delay circuit is a timer circuit capable of variably setting the predetermined period. The main control unit includes a CPU,
The energy saving control unit
A monitoring unit for monitoring the load amount of the CPU in a certain time before energy saving transition;
A setting unit for setting the predetermined period in the timer circuit based on the load amount;
The image processing apparatus according to claim 6, further comprising:   The image processing apparatus according to claim 1, wherein the energy saving control unit forcibly stops the operating fan after the transition to the energy saving state. A fan control method executed in an image processing apparatus,
Control of power supply to a main control unit that controls the image processing unit and a fan control unit that controls ON / OFF of the rotation of the fan that exhausts and cools the main control unit independently of the main control unit A step of shifting to an energy saving state by stopping power supply to at least the main control unit;
For a predetermined period after the transition to the energy saving state, after maintaining the fan in the operating state, stopping the power supply to the fan control unit;
The fan control method characterized by including.

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