US20120107139A1 - Electronic device and cooling fan control method - Google Patents
Electronic device and cooling fan control method Download PDFInfo
- Publication number
- US20120107139A1 US20120107139A1 US13/138,932 US200913138932A US2012107139A1 US 20120107139 A1 US20120107139 A1 US 20120107139A1 US 200913138932 A US200913138932 A US 200913138932A US 2012107139 A1 US2012107139 A1 US 2012107139A1
- Authority
- US
- United States
- Prior art keywords
- revolutions
- driving voltage
- target
- temperature
- cooling fan
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/16—Cooling; Preventing overheating
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
- G06F1/16—Constructional details or arrangements
- G06F1/20—Cooling means
- G06F1/206—Cooling means comprising thermal management
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K7/00—Constructional details common to different types of electric apparatus
- H05K7/20—Modifications to facilitate cooling, ventilating, or heating
- H05K7/20009—Modifications to facilitate cooling, ventilating, or heating using a gaseous coolant in electronic enclosures
- H05K7/20209—Thermal management, e.g. fan control
Definitions
- the present invention relates to an electronic device and a cooling fan control method.
- Patent Literature 1 describes a control device that controls the number of revolutions of a cooling fan provided in the electronic device per unit time (hereinafter, simply referred to as “the number of revolutions”).
- the control device measures the temperature of the electronic device, the control device defines a target voltage on the basis of the measured temperature and changes a voltage to be supplied to the cooling fan (hereinafter, referred to as “supply voltage”) to the target voltage, thereby adjusting the number of revolutions of the cooling fan.
- supply voltage a voltage to be supplied to the cooling fan
- control device changes the supply voltage to the target voltage
- control device immediately remeasures the temperature of the electronic device, defines a new target voltage on the basis of the remeasured temperature and changes the supply voltage to the new target voltage.
- the control device described in Patent Literature 1 changes the supply voltage to the target voltage
- the control device immediately remeasures the temperature of the electronic device, defines the new target voltage on the basis of the remeasured temperature and changes the supply voltage to the new target voltage. Accordingly, for instance, in a situation where the temperature of the electronic device fluctuates, an update interval of the supply voltage shortens.
- the number of revolutions of the cooling fan may uninterruptedly vary.
- the variation in the number of revolutions of the cooling fan in turn varies the frequency characteristics of sound with rotation of the cooling fan.
- the variation in sound frequency characteristics causes a sound that is offensive to the ears of a user (hereinafter, referred to as “whining sound”).
- Patent Literature 1 a problem with the control device described in Patent Literature 1 is that, for instance, since the update interval of the supply voltage shortens in a situation where the temperature of the electronic device fluctuates, a whining sound tends to occur continuously.
- An electronic device of the present invention includes: a cooling target; a cooling fan that cools the cooling target; temperature detection means that detects a temperature of the cooling target; and control means that determines a driving voltage to be supplied to the cooling fan on the basis of the temperature of the cooling target detected by the temperature detection means, supplies the driving voltage to the cooling fan, and, when a waiting time for updating the driving voltage has elapsed after supplying the driving voltage, redetermines the driving voltage on the basis of the temperature of the cooling target detected by the temperature detection means at that point in time and supplies the driving voltage to the cooling fan.
- a cooling fan control method of the present invention is a cooling fan control method in an electronic device, the method including: detecting a temperature of a cooling target; and determining a driving voltage to be supplied to a cooling fan on the basis of the temperature of the cooling target, supplying the driving voltage to the cooling fan, and, when a waiting time for updating the driving voltage has elapsed after supplying the driving voltage, redetermining the driving voltage on the basis of the temperature of the cooling target detected at that point in time and supplying the driving voltage to the cooling fan.
- the present invention can reduce the continuously generated whining sound.
- FIG. 1 is a block diagram showing electronic device 1 of an exemplary embodiment of the present invention.
- FIG. 2 is a diagram showing an example of details represented by information registered in table 7 a.
- FIG. 3 is a diagram showing an example of details represented by information registered in table 7 b.
- FIG. 4 is a flowchart for illustrating an operation of electronic device 1 .
- FIG. 1 is a block diagram showing electronic device 1 of the exemplary embodiment of the present invention.
- electronic device 1 includes cooling target 2 , cooling fan 3 , temperature detector 4 and controller 5 .
- Controller 5 includes detector 6 , memory 7 , computing processor 8 and revolution controller 9 .
- Electronic device 1 is, for instance, a projector or a personal computer. Electronic device 1 is not limited to a projector or a personal computer, and can appropriately be changed.
- Cooling target 2 is a heat generating device and is cooled by cooling fan 3 .
- the projector uses a projection lamp as cooling target 2 .
- the personal computer uses a CPU (Central Processing Unit) as cooling target 2 .
- Cooling target 2 is not limited to a projection lamp or a CPU, and can appropriately be changed.
- Cooling fan 3 is used for cooling target 2 .
- the number of revolutions (the number of revolutions per unit time) of cooling fan 3 varies according to the supplied driving voltages. In this exemplary embodiment, the number of revolutions of cooling fan 3 increases with the supplied driving voltage.
- Temperature detector 4 can generally be referred to as temperature detection means. Temperature detector 4 detects the temperature of cooling target 2 . Temperature detector 4 may directly detect the temperature of cooling target 2 , or may detect an ambient temperature of cooling target 2 and indirectly detect the temperature of cooling target 2 from the ambient temperature. Temperature detector 4 outputs temperature information representing the temperature of cooling target 2 to controller 5 (more specifically, computing processor 8 ).
- Controller 5 can generally be referred to as control means.
- Controller 5 determines a driving voltage to be supplied to cooling fan 3 on the basis of the temperature of cooling target 2 detected by temperature detector 4 , and supplies the driving voltage to cooling fan 3 . For instance, controller 5 increases the driving voltage with the temperature of cooling target 2 .
- controller 5 determines the target number of revolutions of cooling fan 3 on the basis of the temperature of cooling target 2 and in turn determines the driving voltage on the basis of the target number of revolutions. For instance, controller 5 increases the target number of revolutions with the temperature of cooling target 2 . For instance, controller 5 increases the driving voltage with the target number of revolutions.
- controller 5 When a waiting time for updating the driving voltage (hereinafter, simply referred to as “waiting time”) has elapsed, since controller 5 supplied the driving voltage to cooling fan 3 , controller 5 redetermines the driving voltage on the basis of the temperature of cooling target 2 detected by temperature detector 4 at that point in time and supplies the redetermined driving voltage to cooling fan 3 .
- the waiting time may be determined, for instance, by controller 5 on the basis of the temperature of cooling target 2 or may be a constant value.
- controller 5 determines the target number of revolutions of cooling fan 3 on the basis of the temperature of cooling target 2 and in turn determines the waiting time on the basis of the target number of revolutions. For instance, the more a whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions, the longer is the waiting time to be determined on the basis of this target number of revolutions controller 5 .
- Detector 6 detects the number of revolutions of cooling fan 3 . Detector 6 outputs information of the number of revolutions representing the number of revolutions of cooling fan 3 to computing processor 8 .
- Memory 7 stores temperature-revolutions table (hereinafter, simply referred to as “table”) 7 a and revolutions-update waiting time table (hereinafter, simply referred to as “table”) 7 b.
- table temperature-revolutions table
- table revolutions-update waiting time table
- Table 7 a has registered therein information of the target number of revolutions that represents the target numbers of revolutions associated with the respective temperatures of cooling target 2 .
- FIG. 2 is a diagram showing an example of details represented by information registered in table 7 a.
- Table 7 b has registered therein waiting time information representing waiting times associated with the respective target numbers of revolutions of cooling fan 3 .
- the more a whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions the longer is the waiting time associated with this target number of revolutions.
- a range of the number of revolutions in which cooling fan 3 is operable is divided into a first revolution range and a second revolution range.
- the whining sound is more apt to occur than a case where the number of revolutions of cooling fan 3 is changed to the target number of revolutions in the second revolution range.
- the whining sound generated by the change of the number of revolutions of cooling fan 3 is more apt to be recognized by people than in the case where the number of revolutions of cooling fan 3 is changed to the target number of revolutions in the second revolution range.
- waiting times associated with the respective target numbers of revolutions in the first revolution range are longer than waiting times associated with the respective target numbers of revolutions in the second revolution range.
- the range of the number of revolutions in which cooling fan 3 is operable is divided into the first and second revolution ranges.
- the range of the number of revolutions in which cooling fan 3 is operable may be divided into at least three ranges. In this case, it is preferable that waiting times associated with the respective ranges be appropriately set according to a level where the whining sound is apt to be recognized due to change of the number of revolutions to the target number of revolutions in the range concerned.
- FIG. 3 is a diagram showing an example of details represented by information registered in table 7 b.
- a range of the number of revolutions that is at least the number of revolutions R 1 and not more than the number of revolutions R 2 is used as the first revolution range.
- a range of the number of revolutions less than the number of revolutions R 1 and a range of the number of revolutions more than the number of revolutions R 2 are used as the second revolution range.
- R 1 ⁇ R 2 It is preferable that R 1 and R 2 be appropriately selected according to characteristics of cooling fan 3 (e.g. the shape of cooling fan 3 ).
- the waiting time information representing the waiting time associated with the number of revolutions in the first revolution range represents time T 4 .
- the waiting time information representing the waiting time associated with the number of revolutions in the second revolution range represents time T 2 . Note that T 2 ⁇ T 4 . It is preferable that T 2 and T 4 be appropriately set according to characteristics of cooling fan 3 (e.g. the shape and weight of cooling fan 3 ).
- Computing processor 8 includes a timer and controls cooling fan 3 .
- computing processor 8 When computing processor 8 accepts the temperature information from temperature detector 4 , computing processor 8 reads information of the target number of revolutions corresponding to the temperature represented by the temperature information from memory 7 (table 7 a ).
- computing processor 8 When the target number of revolutions represented by the information of the target number of revolutions is different from the actual number of revolutions of cooling fan 3 represented by the information of the number of revolutions from detector 6 , computing processor 8 outputs the information of the target number of revolutions to revolution controller 9 .
- revolution controller 9 When revolution controller 9 accepts the information of the target number of revolutions from computing processor 8 , revolution controller 9 generates the driving voltage on the basis of the information of the target number of revolutions. For instance, revolution controller 9 increases the driving voltage with the target number of revolutions represented by the information of the target number of revolutions.
- Revolution controller 9 holds driving voltage information representing driving voltages corresponding to respective target numbers of revolutions, reads the driving voltage information corresponding to the target number of revolutions represented by the information of the target number of revolutions, and generates the driving voltage represented by the driving voltage information.
- Revolution controller 9 holds an operational formula for calculating the driving voltage using the target number of revolutions and may calculate the driving voltage using the target number of revolutions represented by the information of the target number of revolutions and the operational formula, thus generating the calculated driving voltage.
- revolution controller 9 When revolution controller 9 generates the driving voltage, revolution controller 9 supplies the driving voltage to cooling fan 3 , thereby adjusting the number of revolutions of cooling fan 3 . When revolution controller 9 supplies the driving voltage to cooling fan 3 , revolution controller 9 outputs supply completion information representing that the supply has been completed, to computing processor 8 .
- computing processor 8 When computing processor 8 accepts the supply completion information from revolution controller 9 , computing processor 8 performs a control operation, which will be described below.
- computing processor 8 reads from memory 7 the waiting time information corresponding to the target number of revolutions represented by the information of the target number of revolutions and then waits until the waiting time represented by the waiting time information read from memory 7 has elapsed. After the waiting time has elapsed, computing processor 8 reaccepts the temperature information from temperature detector 4 and also reaccepts the information of the number of revolutions from detector 5 . Computing processor 8 reads from memory 7 the information of the target number of revolutions corresponding to the temperature represented by the temperature information from the temperature detector 4 . When the target number of revolutions represented by the information of the target number of revolutions is different from the actual number of revolutions of cooling fan 3 represented by the information of the number of revolutions, computing processor 8 outputs the information of the target number of revolutions to revolution controller 9 .
- computing processor 8 performs the control operation every time when receiving the supply completion information from revolution controller 9 .
- Computing processor 8 determines whether or not the waiting time has elapsed or not using the timer in computing processor 8 .
- Computing processor 8 may perform the control operation every time when outputting the information of the target number of revolutions to revolution controller 9 , instead of performing the control operation every time when receiving the supply completion information from revolution controller 9 .
- FIG. 4 is a flowchart for illustrating an operation of electronic device 1 .
- step S 1 computing processor 8 accepts the temperature information representing the temperature (Tc) of cooling target 2 for calculating the target number of revolutions, from temperature detector 4 . After computing processor 8 accepts the temperature information, computing processor 8 executes step S 2 .
- step S 2 computing processor 8 acquires from memory 7 the information of the target number of revolutions representing the target number of revolutions (Rt) corresponding to the temperature (Tc) represented by the temperature information (see FIG. 2 ). After computing processor 8 accepts the information of the target number of revolutions, computing processor 8 executes step S 3 .
- step S 3 computing processor 8 accepts from detector 6 the information of the number of revolutions representing the current number of revolutions of cooling fan 3 (Rc). After computing processor 8 accepts the information of the number of revolutions, computing processor 8 executes step S 4 .
- step S 4 computing processor 8 compares the target number of revolutions (Rt) represented by the information of the target number of revolutions with the actual number of revolutions (Rc) represented by the information of the number of revolutions. If the target number of revolutions (Rt) is equal to the actual number of revolutions (Rc), computing processor 8 returns the processing to step S 1 . On the other hand, if the target number of revolutions (Rt) is not equal to the actual number of revolutions (Rc), computing processor 8 executes step S 5 .
- step S 5 computing processor 8 outputs the information of the target number of revolutions to revolution controller 9 .
- revolution controller 9 accepts the information of the target number of revolutions, revolution controller 9 generates the driving voltage on the basis of information of the target number of revolutions.
- Revolution controller 9 supplies the driving voltage to cooling fan 3 , thereby adjusting the number of revolutions of cooling fan 3 .
- revolution controller 9 supplies the driving voltage to cooling fan 3 , revolution controller 9 outputs the supply completion information to computing processor 8 .
- computing processor 8 executes step S 6 .
- step S 6 computing processor 8 reads from memory 7 the waiting time information representing waiting time (Tx) corresponding to the target number of revolutions (Rt) represented by the information of the target number of revolutions (see FIG. 3 ).
- Tx waiting time
- Rt target number of revolutions
- FIG. 3 in a case where Rt is less than R 1 or Rt is higher than R 2 , waiting time (Tx) becomes time T 2 ; in a case where Rc is at least R 1 and not more than R 2 , waiting time (Tx) becomes time T 4 .
- computing processor 8 executes step S 7 .
- step S 7 computing processor 8 waits until waiting time (Tx) represented by the waiting time information has elapsed. After waiting time (Tx) elapsed, computing processor 8 returns the processing to step S 1 .
- controller 5 when the waiting time for updating the driving voltage has elapsed, since controller 5 supplied the driving voltage to cooling fan 3 , controller 5 redetermines the driving voltage on the basis of the temperature of cooling target 2 detected by the temperature detector 4 at that point in time and supplies the redetermined driving voltage to cooling fan 3 .
- the time interval for updating the voltage to be supplied to cooling fan 3 can be increased in comparison with a case where, immediately after the supply of the driving voltage has been completed, the driving voltage is redetermined on the basis of the temperature of cooling target 2 detected by temperature detector 4 and the redetermined driving voltage is supplied to cooling fan 3 .
- the frequency of variation in the number of revolutions of cooling fan 3 can be reduced in a situation where the temperature of cooling target 2 varies. This enables the continuously generated whining sound to be reduced.
- controller 5 determines the waiting time for updating the driving voltage on the basis of the temperature of cooling target 2 detected by temperature detector 4 .
- the driving voltage is also determined on the basis of the temperature of cooling target 2 . This allows the waiting time for updating the driving voltage to be variable according to the temperature of cooling target 2 , that is, the driving voltage.
- controller 5 determines the target number of revolutions of cooling fan 3 on the basis of the temperature of cooling target 2 and determines the waiting time for updating the driving voltage on the basis of the target number of revolutions, the more the whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions, the longer is the waiting time for updating the driving voltage determined by controller 5 preferably on the basis of the target number of revolution.
- the waiting time representing a time of waiting until the supply voltage to cooling fan 3 at the next time is set, and these waiting times are set for the respective target numbers of revolutions according to the level where the whining sound is apt to be recognized.
- controller 5 determines the target number of revolutions of cooling fan 2 using table 7 a in memory 7 on the basis of the temperature of cooling target 2 detected by temperature detector 4 .
- controller 5 may hold an operational formula for calculating the target number of revolutions using the temperature of cooling target 2 , and determine the target number of revolutions using the temperature of cooling target 2 detected by temperature detector 4 and the operational formula.
- controller 5 determines the waiting time using table 7 b in memory 7 on the basis of the target number of revolutions.
- controller 5 may hold an operational formula for calculating the waiting time using the target number of revolutions, and determine the waiting time using the target number of revolutions and the operational formula.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Human Computer Interaction (AREA)
- General Engineering & Computer Science (AREA)
- Thermal Sciences (AREA)
- Cooling Or The Like Of Electrical Apparatus (AREA)
- Control Of Electric Motors In General (AREA)
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
Abstract
An electronic device capable of reducing a continuously generated whining sound is provided. Electronic device (1) includes: cooling target (2); cooling fan (3) that cools cooling target (2); temperature detector (4) that detects the temperature of cooling target (2); and controller (5) that determines a driving voltage to be supplied to cooling fan (3) on the basis of the temperature of cooling target (2) detected by temperature detector (4), supplies the driving voltage to cooling fan (3), and, when a waiting time for updating the driving voltage has elapsed after supplying the driving voltage, redetermines the driving voltage on the basis of the temperature of cooling target (2) detected by temperature detector (4) at that point in time and supplies the driving voltage to cooling fan.
Description
- The present invention relates to an electronic device and a cooling fan control method.
- An electronic devices that prevents an increase in the temperature in a device through the use of a cooling fan has been known.
-
Patent Literature 1 describes a control device that controls the number of revolutions of a cooling fan provided in the electronic device per unit time (hereinafter, simply referred to as “the number of revolutions”). - Once the control device measures the temperature of the electronic device, the control device defines a target voltage on the basis of the measured temperature and changes a voltage to be supplied to the cooling fan (hereinafter, referred to as “supply voltage”) to the target voltage, thereby adjusting the number of revolutions of the cooling fan.
- Once the control device changes the supply voltage to the target voltage, the control device immediately remeasures the temperature of the electronic device, defines a new target voltage on the basis of the remeasured temperature and changes the supply voltage to the new target voltage.
-
- Patent Literature 1: JP2001-56724A
- After the control device described in
Patent Literature 1 changes the supply voltage to the target voltage, the control device immediately remeasures the temperature of the electronic device, defines the new target voltage on the basis of the remeasured temperature and changes the supply voltage to the new target voltage. Accordingly, for instance, in a situation where the temperature of the electronic device fluctuates, an update interval of the supply voltage shortens. - If the update interval of the supply voltage shortens, the number of revolutions of the cooling fan may uninterruptedly vary.
- The variation in the number of revolutions of the cooling fan in turn varies the frequency characteristics of sound with rotation of the cooling fan. The variation in sound frequency characteristics causes a sound that is offensive to the ears of a user (hereinafter, referred to as “whining sound”).
- Accordingly, a problem with the control device described in
Patent Literature 1 is that, for instance, since the update interval of the supply voltage shortens in a situation where the temperature of the electronic device fluctuates, a whining sound tends to occur continuously. - It is an object of the present invention to provide an electronic device and a cooling fan control method that can solve these problems.
- An electronic device of the present invention includes: a cooling target; a cooling fan that cools the cooling target; temperature detection means that detects a temperature of the cooling target; and control means that determines a driving voltage to be supplied to the cooling fan on the basis of the temperature of the cooling target detected by the temperature detection means, supplies the driving voltage to the cooling fan, and, when a waiting time for updating the driving voltage has elapsed after supplying the driving voltage, redetermines the driving voltage on the basis of the temperature of the cooling target detected by the temperature detection means at that point in time and supplies the driving voltage to the cooling fan.
- A cooling fan control method of the present invention is a cooling fan control method in an electronic device, the method including: detecting a temperature of a cooling target; and determining a driving voltage to be supplied to a cooling fan on the basis of the temperature of the cooling target, supplying the driving voltage to the cooling fan, and, when a waiting time for updating the driving voltage has elapsed after supplying the driving voltage, redetermining the driving voltage on the basis of the temperature of the cooling target detected at that point in time and supplying the driving voltage to the cooling fan.
- The present invention can reduce the continuously generated whining sound.
-
FIG. 1 is a block diagram showingelectronic device 1 of an exemplary embodiment of the present invention. -
FIG. 2 is a diagram showing an example of details represented by information registered in table 7 a. -
FIG. 3 is a diagram showing an example of details represented by information registered in table 7 b. -
FIG. 4 is a flowchart for illustrating an operation ofelectronic device 1. - An exemplary embodiment of the present invention will hereinafter be described with reference to drawings.
-
FIG. 1 is a block diagram showingelectronic device 1 of the exemplary embodiment of the present invention. - In
FIG. 1 ,electronic device 1 includescooling target 2,cooling fan 3,temperature detector 4 andcontroller 5.Controller 5 includesdetector 6,memory 7,computing processor 8 andrevolution controller 9. -
Electronic device 1 is, for instance, a projector or a personal computer.Electronic device 1 is not limited to a projector or a personal computer, and can appropriately be changed. -
Cooling target 2 is a heat generating device and is cooled by coolingfan 3. In a case whereelectronic device 1 is a projector, for instance, the projector uses a projection lamp ascooling target 2. In a case whereelectronic device 1 is a personal computer, for instance, the personal computer uses a CPU (Central Processing Unit) ascooling target 2.Cooling target 2 is not limited to a projection lamp or a CPU, and can appropriately be changed. -
Cooling fan 3 is used forcooling target 2. The number of revolutions (the number of revolutions per unit time) ofcooling fan 3 varies according to the supplied driving voltages. In this exemplary embodiment, the number of revolutions ofcooling fan 3 increases with the supplied driving voltage. -
Temperature detector 4 can generally be referred to as temperature detection means.Temperature detector 4 detects the temperature ofcooling target 2.Temperature detector 4 may directly detect the temperature ofcooling target 2, or may detect an ambient temperature ofcooling target 2 and indirectly detect the temperature ofcooling target 2 from the ambient temperature.Temperature detector 4 outputs temperature information representing the temperature ofcooling target 2 to controller 5 (more specifically, computing processor 8). -
Controller 5 can generally be referred to as control means. -
Controller 5 determines a driving voltage to be supplied to coolingfan 3 on the basis of the temperature ofcooling target 2 detected bytemperature detector 4, and supplies the driving voltage to coolingfan 3. For instance,controller 5 increases the driving voltage with the temperature ofcooling target 2. - In this exemplary embodiment,
controller 5 determines the target number of revolutions ofcooling fan 3 on the basis of the temperature ofcooling target 2 and in turn determines the driving voltage on the basis of the target number of revolutions. For instance,controller 5 increases the target number of revolutions with the temperature ofcooling target 2. For instance,controller 5 increases the driving voltage with the target number of revolutions. - When a waiting time for updating the driving voltage (hereinafter, simply referred to as “waiting time”) has elapsed, since
controller 5 supplied the driving voltage to coolingfan 3,controller 5 redetermines the driving voltage on the basis of the temperature ofcooling target 2 detected bytemperature detector 4 at that point in time and supplies the redetermined driving voltage to coolingfan 3. - The waiting time may be determined, for instance, by
controller 5 on the basis of the temperature ofcooling target 2 or may be a constant value. - In this exemplary embodiment,
controller 5 determines the target number of revolutions ofcooling fan 3 on the basis of the temperature ofcooling target 2 and in turn determines the waiting time on the basis of the target number of revolutions. For instance, the more a whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions, the longer is the waiting time to be determined on the basis of this target number ofrevolutions controller 5. -
Detector 6 detects the number of revolutions ofcooling fan 3.Detector 6 outputs information of the number of revolutions representing the number of revolutions ofcooling fan 3 to computingprocessor 8. -
Memory 7 stores temperature-revolutions table (hereinafter, simply referred to as “table”) 7 a and revolutions-update waiting time table (hereinafter, simply referred to as “table”) 7 b. - Table 7 a has registered therein information of the target number of revolutions that represents the target numbers of revolutions associated with the respective temperatures of
cooling target 2.FIG. 2 is a diagram showing an example of details represented by information registered in table 7 a. - Table 7 b has registered therein waiting time information representing waiting times associated with the respective target numbers of revolutions of cooling
fan 3. In this exemplary embodiment, the more a whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions, the longer is the waiting time associated with this target number of revolutions. - In this exemplary embodiment, a range of the number of revolutions in which cooling
fan 3 is operable is divided into a first revolution range and a second revolution range. - In a case where the number of revolutions of cooling
fan 3 is changed to the target number of revolutions in the first revolution range, the whining sound is more apt to occur than a case where the number of revolutions of coolingfan 3 is changed to the target number of revolutions in the second revolution range. - In other words, in the case where the number of revolutions of cooling
fan 3 is changed to the target number of revolutions in the first revolution range, the whining sound generated by the change of the number of revolutions of coolingfan 3 is more apt to be recognized by people than in the case where the number of revolutions of coolingfan 3 is changed to the target number of revolutions in the second revolution range. - In table 7 b, waiting times associated with the respective target numbers of revolutions in the first revolution range are longer than waiting times associated with the respective target numbers of revolutions in the second revolution range.
- In this exemplary embodiment, the range of the number of revolutions in which cooling
fan 3 is operable is divided into the first and second revolution ranges. However, the range of the number of revolutions in which coolingfan 3 is operable may be divided into at least three ranges. In this case, it is preferable that waiting times associated with the respective ranges be appropriately set according to a level where the whining sound is apt to be recognized due to change of the number of revolutions to the target number of revolutions in the range concerned. -
FIG. 3 is a diagram showing an example of details represented by information registered in table 7 b. - In
FIG. 3 , a range of the number of revolutions that is at least the number of revolutions R1 and not more than the number of revolutions R2 is used as the first revolution range. A range of the number of revolutions less than the number of revolutions R1 and a range of the number of revolutions more than the number of revolutions R2 are used as the second revolution range. Note that R1<R2. It is preferable that R1 and R2 be appropriately selected according to characteristics of cooling fan 3 (e.g. the shape of cooling fan 3). - The waiting time information representing the waiting time associated with the number of revolutions in the first revolution range represents time T4. The waiting time information representing the waiting time associated with the number of revolutions in the second revolution range represents time T2. Note that T2<T4. It is preferable that T2 and T4 be appropriately set according to characteristics of cooling fan 3 (e.g. the shape and weight of cooling fan 3).
-
Computing processor 8 includes a timer and controls coolingfan 3. - When computing
processor 8 accepts the temperature information fromtemperature detector 4,computing processor 8 reads information of the target number of revolutions corresponding to the temperature represented by the temperature information from memory 7 (table 7 a). - When the target number of revolutions represented by the information of the target number of revolutions is different from the actual number of revolutions of cooling
fan 3 represented by the information of the number of revolutions fromdetector 6,computing processor 8 outputs the information of the target number of revolutions torevolution controller 9. - When
revolution controller 9 accepts the information of the target number of revolutions from computingprocessor 8,revolution controller 9 generates the driving voltage on the basis of the information of the target number of revolutions. For instance,revolution controller 9 increases the driving voltage with the target number of revolutions represented by the information of the target number of revolutions. -
Revolution controller 9 holds driving voltage information representing driving voltages corresponding to respective target numbers of revolutions, reads the driving voltage information corresponding to the target number of revolutions represented by the information of the target number of revolutions, and generates the driving voltage represented by the driving voltage information. -
Revolution controller 9 holds an operational formula for calculating the driving voltage using the target number of revolutions and may calculate the driving voltage using the target number of revolutions represented by the information of the target number of revolutions and the operational formula, thus generating the calculated driving voltage. - When
revolution controller 9 generates the driving voltage,revolution controller 9 supplies the driving voltage to coolingfan 3, thereby adjusting the number of revolutions of coolingfan 3. Whenrevolution controller 9 supplies the driving voltage to coolingfan 3,revolution controller 9 outputs supply completion information representing that the supply has been completed, to computingprocessor 8. - When computing
processor 8 accepts the supply completion information fromrevolution controller 9,computing processor 8 performs a control operation, which will be described below. - In the control operation,
computing processor 8 reads frommemory 7 the waiting time information corresponding to the target number of revolutions represented by the information of the target number of revolutions and then waits until the waiting time represented by the waiting time information read frommemory 7 has elapsed. After the waiting time has elapsed,computing processor 8 reaccepts the temperature information fromtemperature detector 4 and also reaccepts the information of the number of revolutions fromdetector 5.Computing processor 8 reads frommemory 7 the information of the target number of revolutions corresponding to the temperature represented by the temperature information from thetemperature detector 4. When the target number of revolutions represented by the information of the target number of revolutions is different from the actual number of revolutions of coolingfan 3 represented by the information of the number of revolutions,computing processor 8 outputs the information of the target number of revolutions torevolution controller 9. - Subsequently,
computing processor 8 performs the control operation every time when receiving the supply completion information fromrevolution controller 9. -
Computing processor 8 determines whether or not the waiting time has elapsed or not using the timer incomputing processor 8. -
Computing processor 8 may perform the control operation every time when outputting the information of the target number of revolutions torevolution controller 9, instead of performing the control operation every time when receiving the supply completion information fromrevolution controller 9. - Next, an operation will be described.
-
FIG. 4 is a flowchart for illustrating an operation ofelectronic device 1. - In step S1,
computing processor 8 accepts the temperature information representing the temperature (Tc) ofcooling target 2 for calculating the target number of revolutions, fromtemperature detector 4. After computingprocessor 8 accepts the temperature information,computing processor 8 executes step S2. - In step S2,
computing processor 8 acquires frommemory 7 the information of the target number of revolutions representing the target number of revolutions (Rt) corresponding to the temperature (Tc) represented by the temperature information (seeFIG. 2 ). After computingprocessor 8 accepts the information of the target number of revolutions,computing processor 8 executes step S3. - In step S3,
computing processor 8 accepts fromdetector 6 the information of the number of revolutions representing the current number of revolutions of cooling fan 3 (Rc). After computingprocessor 8 accepts the information of the number of revolutions,computing processor 8 executes step S4. - In step S4,
computing processor 8 compares the target number of revolutions (Rt) represented by the information of the target number of revolutions with the actual number of revolutions (Rc) represented by the information of the number of revolutions. If the target number of revolutions (Rt) is equal to the actual number of revolutions (Rc),computing processor 8 returns the processing to step S1. On the other hand, if the target number of revolutions (Rt) is not equal to the actual number of revolutions (Rc),computing processor 8 executes step S5. - In step S5,
computing processor 8 outputs the information of the target number of revolutions torevolution controller 9. Whenrevolution controller 9 accepts the information of the target number of revolutions,revolution controller 9 generates the driving voltage on the basis of information of the target number of revolutions.Revolution controller 9 supplies the driving voltage to coolingfan 3, thereby adjusting the number of revolutions of coolingfan 3. Whenrevolution controller 9 supplies the driving voltage to coolingfan 3,revolution controller 9 outputs the supply completion information tocomputing processor 8. When computingprocessor 8 accepts the supply completion information,computing processor 8 executes step S6. - In step S6,
computing processor 8 reads frommemory 7 the waiting time information representing waiting time (Tx) corresponding to the target number of revolutions (Rt) represented by the information of the target number of revolutions (seeFIG. 3 ). According toFIG. 3 , in a case where Rt is less than R1 or Rt is higher than R2, waiting time (Tx) becomes time T2; in a case where Rc is at least R1 and not more than R2, waiting time (Tx) becomes time T4. After computingprocessor 8 reads the waiting time information,computing processor 8 executes step S7. - In step S7,
computing processor 8 waits until waiting time (Tx) represented by the waiting time information has elapsed. After waiting time (Tx) elapsed,computing processor 8 returns the processing to step S1. - According to this exemplary embodiment, when the waiting time for updating the driving voltage has elapsed, since
controller 5 supplied the driving voltage to coolingfan 3,controller 5 redetermines the driving voltage on the basis of the temperature of coolingtarget 2 detected by thetemperature detector 4 at that point in time and supplies the redetermined driving voltage to coolingfan 3. - Accordingly, the time interval for updating the voltage to be supplied to cooling
fan 3 can be increased in comparison with a case where, immediately after the supply of the driving voltage has been completed, the driving voltage is redetermined on the basis of the temperature of coolingtarget 2 detected bytemperature detector 4 and the redetermined driving voltage is supplied to coolingfan 3. - Therefore, for instance, the frequency of variation in the number of revolutions of cooling
fan 3 can be reduced in a situation where the temperature of coolingtarget 2 varies. This enables the continuously generated whining sound to be reduced. - In this exemplary embodiment,
controller 5 determines the waiting time for updating the driving voltage on the basis of the temperature of coolingtarget 2 detected bytemperature detector 4. The driving voltage is also determined on the basis of the temperature of coolingtarget 2. This allows the waiting time for updating the driving voltage to be variable according to the temperature of coolingtarget 2, that is, the driving voltage. - In a case where
controller 5 determines the target number of revolutions of coolingfan 3 on the basis of the temperature of coolingtarget 2 and determines the waiting time for updating the driving voltage on the basis of the target number of revolutions, the more the whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions, the longer is the waiting time for updating the driving voltage determined bycontroller 5 preferably on the basis of the target number of revolution. - In this case, under a situation where the frequency of generating the whining sound is reduced and the probability of generating the whining sound is low, the number of revolutions of cooling
fan 3 can immediately be changed. This allows an increase in temperature of theelectronic device 1 and generation of the whining sound to be suppressed in a balanced manner. - In this exemplary embodiment, the waiting time representing a time of waiting until the supply voltage to cooling
fan 3 at the next time is set, and these waiting times are set for the respective target numbers of revolutions according to the level where the whining sound is apt to be recognized. - This allows the variation speed of the number of revolutions of the fan to be gentle for the revolution range in which the whining sound is apt to be recognized, thereby enabling the auditory grating whining sound to be reduced.
- In the exemplary embodiment,
controller 5 determines the target number of revolutions of coolingfan 2 using table 7 a inmemory 7 on the basis of the temperature of coolingtarget 2 detected bytemperature detector 4. However,controller 5 may hold an operational formula for calculating the target number of revolutions using the temperature of coolingtarget 2, and determine the target number of revolutions using the temperature of coolingtarget 2 detected bytemperature detector 4 and the operational formula. - In the exemplary embodiment,
controller 5 determines the waiting time using table 7 b inmemory 7 on the basis of the target number of revolutions. However,controller 5 may hold an operational formula for calculating the waiting time using the target number of revolutions, and determine the waiting time using the target number of revolutions and the operational formula. - Although the present invention has been described above with reference to the exemplary embodiment, the present invention is not limited to the exemplary embodiment. Various modifications that a person skilled in the art can understand may be made to the configuration and details of the present invention within the scope of the invention of the application.
-
-
- 1 electronic device
- 2 cooling target
- 3 cooling fan
- 4 temperature detector
- 5 controller
- 6 detector
- 7 memory
- 8 computing processor
- 9 revolution controller
Claims (6)
1. An electronic device, comprising:
a cooling target;
a cooling fan that cools said cooling target;
a temperature detection unit that detects a temperature of said cooling target; and
a control unit that determines a driving voltage to be supplied to said cooling fan on the basis of the temperature of said cooling target detected by said temperature detection unit, supplies the driving voltage to said cooling fan, and, when a waiting time for updating the driving voltage has elapsed after supplying the driving voltage, redetermines the driving voltage on the basis of the temperature of said cooling target detected by said temperature detection unit at that point in time and supplies the driving voltage to said cooling fan.
2. The electronic device according to claim 1 , wherein said control unit further determines the waiting time for updating the driving voltage on the basis of the temperature of said cooling target detected by said temperature detection unit.
3. The electronic device according to claim 2 , wherein said control unit determines a target number of revolutions of said cooling fan on the basis of the temperature of said cooling target detected by said temperature detection unit, and further determines the waiting time for updating the driving voltage on the basis of the target number of revolutions, and wherein the more a whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions, the longer is the waiting time for updating the driving voltage that is determined on the basis of the target number of revolutions.
4. A cooling fan control method in an electronic device, the method comprising:
detecting a temperature of a cooling target; and
determining a driving voltage to be supplied to a cooling fan on the basis of the temperature of said cooling target, supplying the driving voltage to said cooling fan, and, when a waiting time for updating the driving voltage has elapsed after supplying the driving voltage, redetermining the driving voltage on the basis of the temperature of said cooling target detected at that point in time and supplying the driving voltage to said cooling fan.
5. The cooling fan control method according to claim 4 , the method further comprising determining the waiting time for updating the driving voltage on the basis of the temperature of said cooling target.
6. The cooling fan control method according to claim 5 , the method further comprising:
determining a target number of revolutions of said cooling fan on the basis of the temperature of said cooling target,
determining the waiting time for updating the driving voltage on the basis of the target number of revolutions, and
wherein the more a whining sound is apt to occur owing to the number of revolutions being changed to the target number of revolutions, the longer is the waiting time for updating the driving voltage that is determined on the basis of the target number of revolutions.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2009/059519 WO2010137102A1 (en) | 2009-05-25 | 2009-05-25 | Electronic device and cooling fan control method |
Publications (1)
Publication Number | Publication Date |
---|---|
US20120107139A1 true US20120107139A1 (en) | 2012-05-03 |
Family
ID=43222246
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/138,932 Abandoned US20120107139A1 (en) | 2009-05-25 | 2009-05-25 | Electronic device and cooling fan control method |
Country Status (5)
Country | Link |
---|---|
US (1) | US20120107139A1 (en) |
EP (1) | EP2437583A4 (en) |
JP (1) | JP5219007B2 (en) |
CN (1) | CN102450113B (en) |
WO (1) | WO2010137102A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130287595A1 (en) * | 2012-04-25 | 2013-10-31 | Sunonwealth Electric Machine Industry Co., Ltd. | Cooling system for use in a portable communication device |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104154022B (en) * | 2014-08-15 | 2016-09-07 | 广东易事特电源股份有限公司 | Fan speed-governing method in inverter |
CN105792606B (en) * | 2016-03-31 | 2017-12-26 | 海信集团有限公司 | The heat dissipating method of fan rotational frequency control method, device and optical projection system |
CN108105119B (en) * | 2017-12-18 | 2019-11-08 | 青岛海信激光显示股份有限公司 | A kind of target method for starting fan |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6340874B1 (en) * | 2000-05-30 | 2002-01-22 | Daystream Info Inc | Method and apparatus utilized in computer type systems for control of variable speed fans to reduce their noise |
US6381406B1 (en) * | 2001-03-02 | 2002-04-30 | Hewlett-Packard Company | Adaptive synchronous DC fan speed controller |
US6601168B1 (en) * | 1999-11-19 | 2003-07-29 | Hewlett-Packard Development Company, L.P. | Computer fan speed system to reduce audible perceptibility of fan speed changes |
US6643128B2 (en) * | 2001-07-13 | 2003-11-04 | Hewlett-Packard Development Company, Lp. | Method and system for controlling a cooling fan within a computer system |
US6737824B1 (en) * | 2002-09-30 | 2004-05-18 | National Semiconductor Corporation | Fan acceleration control |
US6755616B1 (en) * | 2003-02-04 | 2004-06-29 | Inventec Corporation | Method of noise value control by controlling the rotation rate of a fan |
US7184654B2 (en) * | 2005-01-24 | 2007-02-27 | Denso Corporation | Semiconductor device control apparatus and method |
US7628024B2 (en) * | 2004-04-01 | 2009-12-08 | Kabushiki Kaisha Toshiba | Information processing apparatus |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11251776A (en) * | 1998-02-27 | 1999-09-17 | Nec Eng Ltd | Control method of air quantity of air-cooling equipment |
JPH11272365A (en) * | 1998-03-25 | 1999-10-08 | Toshiba Corp | Speed control system for cooling fan and electronic instrument |
JP3769200B2 (en) * | 2001-03-06 | 2006-04-19 | インターナショナル・ビジネス・マシーンズ・コーポレーション | Cooling fan control method and apparatus |
CN1189804C (en) * | 2003-01-02 | 2005-02-16 | 明基电通股份有限公司 | Heat-dissipating control method and equipment |
US7343505B2 (en) * | 2004-10-28 | 2008-03-11 | International Business Machines Corporation | Method and apparatus for thermal control of electronic components |
CN1949117A (en) * | 2005-10-11 | 2007-04-18 | 鸿富锦精密工业(深圳)有限公司 | Fan speed controlling system and method |
CN101092967A (en) * | 2006-06-20 | 2007-12-26 | 仁宝电脑工业股份有限公司 | Control method for fan |
CN200989319Y (en) * | 2006-09-28 | 2007-12-12 | 新巨企业股份有限公司 | Fan voltage-stabilizing controller |
JP2008227127A (en) * | 2007-03-13 | 2008-09-25 | Seiko Epson Corp | Cooling fan drive control system, projector, program, information storage medium, and cooling fan drive control method |
-
2009
- 2009-05-25 CN CN200980159467.8A patent/CN102450113B/en not_active Expired - Fee Related
- 2009-05-25 EP EP09845169.3A patent/EP2437583A4/en not_active Withdrawn
- 2009-05-25 WO PCT/JP2009/059519 patent/WO2010137102A1/en active Application Filing
- 2009-05-25 US US13/138,932 patent/US20120107139A1/en not_active Abandoned
- 2009-05-25 JP JP2011515765A patent/JP5219007B2/en not_active Expired - Fee Related
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6601168B1 (en) * | 1999-11-19 | 2003-07-29 | Hewlett-Packard Development Company, L.P. | Computer fan speed system to reduce audible perceptibility of fan speed changes |
US6340874B1 (en) * | 2000-05-30 | 2002-01-22 | Daystream Info Inc | Method and apparatus utilized in computer type systems for control of variable speed fans to reduce their noise |
US6381406B1 (en) * | 2001-03-02 | 2002-04-30 | Hewlett-Packard Company | Adaptive synchronous DC fan speed controller |
US6643128B2 (en) * | 2001-07-13 | 2003-11-04 | Hewlett-Packard Development Company, Lp. | Method and system for controlling a cooling fan within a computer system |
US6737824B1 (en) * | 2002-09-30 | 2004-05-18 | National Semiconductor Corporation | Fan acceleration control |
US6755616B1 (en) * | 2003-02-04 | 2004-06-29 | Inventec Corporation | Method of noise value control by controlling the rotation rate of a fan |
US7628024B2 (en) * | 2004-04-01 | 2009-12-08 | Kabushiki Kaisha Toshiba | Information processing apparatus |
US7184654B2 (en) * | 2005-01-24 | 2007-02-27 | Denso Corporation | Semiconductor device control apparatus and method |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130287595A1 (en) * | 2012-04-25 | 2013-10-31 | Sunonwealth Electric Machine Industry Co., Ltd. | Cooling system for use in a portable communication device |
US9243642B2 (en) * | 2012-04-25 | 2016-01-26 | Sunonwealth Electric Machine Industry Co., Ltd | Cooling system for use in a portable communication device |
Also Published As
Publication number | Publication date |
---|---|
EP2437583A1 (en) | 2012-04-04 |
JP5219007B2 (en) | 2013-06-26 |
JPWO2010137102A1 (en) | 2012-11-12 |
EP2437583A4 (en) | 2016-10-12 |
WO2010137102A1 (en) | 2010-12-02 |
CN102450113B (en) | 2015-02-18 |
CN102450113A (en) | 2012-05-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6017787B2 (en) | Power supply for gas discharge lamps | |
CN108241422B (en) | Electronic device and thermal control method based on battery temperature in electronic device | |
CN111052035B (en) | Electronic device and operation control method thereof | |
CN107085462B (en) | Electronic device for managing power and method of controlling the same | |
US20150349570A1 (en) | Method for operating a portable electronic device | |
KR102251992B1 (en) | Method for controlling current and electronic device | |
US10908568B2 (en) | Electronic device for controlling IoT device to correspond to state of external electronic device and operation method thereof | |
KR20180013280A (en) | Wireless power receiving device and method for controlling thereof | |
JP6383356B2 (en) | Brightness control method, apparatus and program product | |
KR20170117782A (en) | Method and apparatus for protecting a battery | |
US20120107139A1 (en) | Electronic device and cooling fan control method | |
US9429148B2 (en) | Fan control system and fan controlling method thereof | |
KR20150080582A (en) | Variable touch screen scanning rate based on user presence detection | |
WO2014136585A1 (en) | Measurement system, integrated controller, sensor device control method, and program | |
US10382219B2 (en) | Method, apparatus, and non-transitory computer-readable recording medium storing program for estimating operator | |
US9576328B2 (en) | Information processing apparatus, information processing method, and non-transitory computer readable medium | |
US11385600B2 (en) | Timer measurement device, electronic timepiece, timer measurement method, and non-transitory computer readable storage medium storing program | |
US20130154599A1 (en) | Methods for Reducing Power Consumption of Electronic Systems | |
US10185377B2 (en) | Heat dissipation method and electronic device using the same | |
JP2011209146A (en) | Electronic equipment, failure determination program, and failure determination method | |
JPWO2018154970A1 (en) | Information processing apparatus, information processing method, and program | |
US10444297B2 (en) | Electronic system and method for recognizing status of power-supply device | |
US20200080902A1 (en) | Temperature control system for central processing unit and temperature control method thereof | |
JP2015225947A (en) | Electronic apparatus | |
US20160313707A1 (en) | Method and apparatus for adjustment of analog movement hands of timepiece |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NEC DISPLAY SOLUTIONS, LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NAITOU, MICHITAKA;MASUDA, NAOKI;REEL/FRAME:027613/0830 Effective date: 20111228 Owner name: NEC DISPLAY SOLUTIONS, LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NAITOU, MICHITAKA;MASUDA, NAOKI;REEL/FRAME:027728/0992 Effective date: 20111228 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |