JP2002157049A - Electronic equipment, and cooling device and cooling method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid noise without lowering the rotating speed of a fan 7. SOLUTION: This cooling device for electronic equipment comprises the fan 7 for cooling a casing inner part; a detecting means 1 for detecting the internal temperature of the casing; and a drive circuit 4 for driving the fan 7 on the basis of the detection result of the detecting means 1. This device further comprises a generating means 3 for generating a control signal for modulating the ratio of drive time to drive period of the motor 6 on the basis of the detection result of the detecting means 1, and the drive circuit 4 drives the motor 6 on the basis of the control signal generated by the generating means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device, a cooling device and a cooling method thereof, and more particularly to an electronic device such as a notebook personal computer and a cooling device and a cooling method thereof.

[0002]

2. Description of the Related Art Conventionally, electronic equipment such as a notebook personal computer (hereinafter simply referred to as "PC") has a central processing unit (Central Processing Unit) inside.
Hereinafter, it is referred to as “CPU”. ) And various means whose operations are controlled by the CPU. The CPU
Since heat is generated during driving, a cooling fan is provided and this is rotated by a motor or the like to lower the temperature inside the PC so that the CPU body and various means do not fail due to heat.

FIG. 5 is a block diagram showing a schematic configuration of a conventional cooling device provided in a PC or the like. FIG.
Has a temperature detection sensor 1 for detecting the temperature inside the housing,
The motor 6 is turned on / off according to the detection result of the temperature detection sensor 1.
A driving circuit 4 for generating a driving signal to be turned off, and a driving circuit 4
Control means 8 for controlling the rotation speed of the motor based on the drive signal generated in step 1 and the detection result of the temperature detection sensor 1,
2 shows a fan 7 rotated by a motor 6.

FIG. 5 shows an on / off signal output from the temperature detection sensor 1 to the drive circuit 4, a detection result output from the temperature detection sensor 1 to the control means 8, and a motor 6 output from the drive circuit 4 to the motor 6. Each of the schematic shapes with the drive signal output in the table is also added.

When the power of the PC body is turned on, the temperature detection sensor 1 starts detecting the temperature inside the PC housing. The detected temperature result is output to the control means 8. Further, the temperature detection sensor 1 outputs an on / off signal to the drive circuit 4 when the predetermined detection result exceeds a predetermined threshold value.

When the drive circuit 4 receives an on / off signal from the temperature detection sensor 1, the drive circuit 4 generates a drive signal for turning on the motor 6 to rotate the fan 7 to cool the inside of the housing. , To the control means 8.

The control means 8 uses the input of the drive signal from the drive circuit 4 as a trigger, refers to the detection result output from the temperature detection sensor 1, and rotates the fan 7 at a rotation speed according to the detection result. For this purpose, the motor 6 is driven.
Since the motor 6 rotates the fan 7 under the control of the control means 8, it is possible to suppress an increase in the temperature inside the housing.

[0008]

However, according to the prior art, since the rotation speed of the fan is controlled in accordance with the temperature inside the housing, the wind noise of the fan and the noise generated by the fan as the temperature inside the housing increases. The noise generated by driving the motor increases. The wind noise of the fan is not so painful to humans, but the sound generated when the motor is driven has been perceived as painful or a cause of noise.

In order to avoid these problems, it is conceivable to decrease the rotation speed of the fan.
Since the inside of the housing cannot be sufficiently cooled, it is desired to avoid problems such as noise without reducing the rotation speed of the fan.

Further, the control means for controlling the driving of the motor is relatively expensive among various components provided in the cooling device, and this has been a factor which hinders the cost reduction of the cooling device.

It is an object of the present invention to avoid noise and reduce the cost of a cooling device without reducing the rotation speed of a fan.

[0012]

In order to solve the above-mentioned problems, the present invention provides a cooling means for cooling the inside of a housing, a detecting means for detecting a temperature inside the housing, and a detecting result of the detecting means. A driving circuit for driving the cooling means based on the detection signal, wherein a generation of a control signal in which a ratio of a driving time to a driving cycle of the cooling means is modulated based on a detection result of the detection means. Means, wherein the driving circuit drives the cooling means based on a control signal generated by the generating means.

Further, according to the method of cooling an electronic device of the present invention, a temperature inside the casing of the electronic device is detected, and a control signal in which a ratio of a driving time to a driving cycle of the cooling means is modulated based on the detection result is generated. The inside of the housing is cooled by driving the cooling means based on the generated control signal.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a schematic internal configuration of a PC which is an electronic apparatus according to Embodiment 1 of the present invention. In the PC shown in FIG. 1, when a user presses a required key of a keyboard 10, which is a data input unit, and inputs various data, the keyboard 10 converts the input data into a serial data using a special key matrix. Generate data.

The serial data is mainly input to the keyboard controller 11 via an I / O controller 12 provided for processing input data at an early stage. The keyboard controller 11 converts the serial data into parallel data and outputs the parallel data to the CPU controller 13.

The CPU controller 13 converts the output parallel data into, for example, 3
By interrupting a 2-bit wide data signal,
The graph controller 17 causes the display unit 18 to display characters and the like based on the user's input. Note that the processing for displaying the character data on the display unit 18 and various other processing are performed by CP.
It arbitrates in U14. A program for the CPU 14 to control the operation of each unit is stored in the memory 15.
Is stored in

Further, the PC includes a power management unit (hereinafter referred to as a power management unit) for managing the power on / off of the PC main body including the hard disk 20 and the like.
Called "PMU". ) 16 are provided and the PMU
At 16, the battery may be charged based on the remaining amount of the battery. Here, the CPU 14 mainly cools the inside of the housing of the PC by the cooling device 19 because the CPU 14 causes a rise in the temperature inside the housing when driven.

FIG. 2 is a block diagram showing a schematic configuration inside the cooling device 19 of FIG. FIG. 2 shows a temperature detecting sensor 1 for detecting the temperature inside the housing, and a refining means including a firmware for generating a control signal for controlling the driving time of the motor 6 according to the detection result of the temperature detecting sensor 1. , A drive circuit 4 for generating a drive signal for driving the motor 6 based on a control signal generated by the microcomputer 3, and a drive circuit 4 for generating a drive signal for driving the motor 6 based on a control signal generated by the microcomputer 3. 2 shows a motor 6 driven in accordance with the drive signal thus generated, and a fan 7 rotated by the motor 6. Note that the motor 6 and the fan 7 constitute cooling means.

As shown in the enlarged view, the drive circuit 4 is connected to a diode 41 whose cathode is provided on the microcomputer 3 side, for example, a 5V power supply 42, an anode of the diode 41, and a base of the transistor 46. A resistor 45 having one end connected to, for example, a 12V power supply 44 and the other end connected to the collector of a transistor 46, a transistor 48 having an emitter connected to, for example, a 5V power supply 47, and a cathode having a transistor 4
And the diodes 49 and 50 connected to the collector of the reference numeral 8. Incidentally, the drive circuit 4 and the motor 6 are connected by a connector 61.

FIG. 2 shows a detection result output from the temperature detection sensor 1 to the microcomputer 3, a control signal output from the microcomputer 3 to the drive circuit 4, and a drive signal output from the drive circuit 4 to the motor 6. Each schematic shape with a signal is also added.

When the power of the PC body is turned on, the temperature detection sensor 1 starts detecting the temperature inside the PC housing. The detected temperature result is output to the microcomputer 3. Microcomputer 3
Generates a control signal for controlling the drive time of the motor 6 according to the detection result of the temperature detection sensor 1. The control signal will be described later.

The generated control signal is input to the drive circuit 4, and the drive circuit 4 generates a drive signal for driving the motor 6 based on the control signal. The motor 6 is driven by the generated drive signal, and the fan 7 rotates. Therefore, heat generated mainly by the CPU 14 is sent to the outside, so that the inside of the housing can be cooled.

FIG. 3 is a diagram showing a control signal generated by the microcomputer 3 and a drive signal generated by the drive circuit 4 in FIG. Here, for example, the following program is stored in the microcomputer 3. Note that this program can be changed for each PC product or according to conditions required by electronic devices other than the PC.

The program stored in the microcomputer 3 is, for example, as follows. That is, 1. The temperature inside the PC housing is 50 ° C with the temperature detection sensor 1.
When it is detected that the following is true, a control signal for constantly turning off the motor 6 is generated as shown in FIG.

2. When the temperature inside the housing of the PC is detected by the temperature detection sensor 1 to be 50 ° C. to 70 ° C., the ON time and the OFF time of the motor 6 per unit time are equal as shown in FIG. Such a control signal (pulse wave with a duty of 50%) is generated.

3. When the temperature inside the housing of the PC is detected by the temperature detection sensor 1 to be 70 ° C. to 80 ° C., as shown in FIG. A control signal (pulse wave with a duty of 70%) for which the time becomes 30% is generated.

4. If the temperature detection sensor 1 detects that the temperature inside the housing of the PC is 80 ° C. or higher, FIG.
As shown in (d), a control signal (pulse wave with a duty of 90%) is generated such that the on time of the motor 6 is 90% and the off time is 10% per unit time.

When the detection result is output from the temperature detection sensor 1 in a state where such a program is stored in the microcomputer 3, the microcomputer 3 changes the state shown in FIGS. 3 (a) to 3 (d) according to the detection result. One of the control signals shown is output to the drive circuit 4. The drive circuit 4 generates a drive signal according to the pulse waves shown in FIGS. 3A to 3D (FIGS. 3E to 3D).
(H)), output to the motor 6.

Here, when the temperature inside the housing becomes 50 ° C. or more, the motor 6 is controlled so as to be repeatedly turned on / off. During the off time, there is no sound generated by driving the motor 6. Further, during this time, the fan 7 keeps rotating by inertia, so that the cooling effect inside the housing of the PC can be maintained.

As a result, the driving time of the motor 6 is reduced, so that the life of the motor 6 is extended, and the power required for driving the motor 6 can be relatively reduced.

(Embodiment 2) FIG. 4 is a block diagram showing a schematic internal configuration of a PC which is an electronic apparatus according to Embodiment 2 of the present invention. As shown in FIG. 4, the PC of the present embodiment has a PMU and a keyboard controller 11 built in a cooling device 19. In this case, as shown in FIG. 2, a microcomputer 3 is newly provided in the cooling device 19, so that the PMU and the keyboard controller 11 are stored therein. The operation in FIG. 4 is the same as the operation in FIG. 1, and the same parts are denoted by the same reference numerals.

As described above, in each embodiment of the present invention, the case where the microcomputer 3 generates the control signal by modulating the pulse width based on the detection result of the temperature detection sensor 1 has been described. May be generated to modulate the control signal, and furthermore, the control signal may be generated by modulating both the pulse width and the pulse period.

Although the case where the fan 7 is rotated by the motor 6 has been described as an example, a cooling means such as a Peltier effect element may be used. In this case, the time of current flowing from one semiconductor element included in the circuit element to the other semiconductor element may be controlled.

[0035]

As described above, the present invention generates a control signal in which the ratio of the drive time to the drive cycle of the fan is modulated based on the detection result of the detection means, and controls the fan based on the control signal. Since the fan is rotated, noise can be avoided without reducing the rotation speed of the fan.

Further, since the cooling device of the present invention does not use expensive components and the like, it is possible to reduce the cost of the cooling device main body and the cost of electronic equipment provided with the cooling device.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic internal configuration of a PC that is an electronic apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration in the cooling device of FIG. 1;

FIG. 3 is a diagram showing a control signal generated by a microcomputer of FIG. 2 and a drive signal generated by a drive circuit.

FIG. 4 is a block diagram illustrating a schematic internal configuration of a PC which is an electronic apparatus according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a schematic structure of a conventional cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Temperature detection sensor 3 Microcomputer (microcomputer) 4 Drive circuit 6 Motor 7 Fan 10 Keyboard 11 Keyboard controller 12 I / O controller 13 CPU controller 14 CPU 15 Memory 16 PMU 17 Graph controller 18 Display unit 19 Cooling device 20 Hard disk

Claims (6)

[Claims] 1. An electronic apparatus comprising: a cooling unit that cools an inside of a housing; a detecting unit that detects a temperature inside the housing; and a driving circuit that drives the cooling unit based on a detection result of the detecting unit. The cooling device according to claim 1, further comprising: a generating unit configured to generate a control signal obtained by modulating a ratio of a driving time to a driving cycle of the cooling unit based on a detection result of the detecting unit. The driving circuit is generated by the generating unit. A cooling device for driving the cooling means based on a control signal. 2. The cooling device according to claim 1, wherein said cooling means includes a fan or a Peltier effect element. 3. The electronic device is a computer, wherein the driving unit includes a controller that controls an operation of a data input unit of the computer, and a management unit that manages an operation of a power supply of the computer main body. The cooling device according to claim 1 or 2, wherein 4. The cooling device according to claim 1, wherein the central processing unit inside the housing is cooled. 5. A control signal in which a temperature inside a housing of an electronic device is detected, a control signal in which a ratio of a drive time to a drive cycle of a cooling unit is modulated based on the detection result is generated, and the control signal is generated based on the generated control signal. A method for cooling an electronic device, wherein the inside of a housing is cooled by driving a cooling unit. 6. An electronic apparatus comprising the cooling device according to claim 1. Description: