JP2006140170A - Electronic apparatus and its cooling method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic apparatus in which noise generated from a cooling fan is not perceived by a viewer/listener while sustaining cooling effect by the cooling fan, and to provide its cooling method and program. <P>SOLUTION: Based on the temperature at a section to be cooled measured at a temperature detecting section 25, r.p.m. of a cooling fan 23 is controlled. In a microprocessor provided at a cooling fan control section 24, average value (first average value) of voice signal level over a long time (t<SB>1</SB>) and average value (second average value) of voice signal level over a short time (t<SB>2</SB>) are calculated and compared. While controlling r.p.m. of the cooling fan 23 based on the temperature at the section to be cooled, r.p.m. of the cooling fan 23 is controlled to decrease by judging that the volume is low if the first average value is larger than the second average value and controlled to increase r.p.m. of the cooling fan 23 if the average value of first volume is smaller than the average value of second volume. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic device, an electronic device cooling method, and a program capable of preventing a viewer from sensing noise generated from a cooling fan.

  Conventionally, audio equipment that generates heat during driving has been cooled by rotating a cooling fan (FAN) and cooling it with air. In such a cooling system using a cooling fan, the temperature of the portion to be cooled is detected, and the number of rotations of the cooling fan is controlled so that the cooling can be efficiently performed. That is, when the temperature of the cooled part is high, the number of rotations of the cooling fan is increased, and when the temperature of the cooled part is low, the number of rotations of the cooling fan is reduced.

  Patent Document 1 listed below describes an invention that controls the rotational speed of a cooling fan according to ambient noise and also controls the processing speed of a processing apparatus.

Japanese Patent No. 3017138

  Further, in Patent Document 2 below, a map showing a correlation between the magnitude of a signal output from a device mounted on a vehicle and the level of noise that humans feel annoying is set in advance, and noise is referenced with reference to the map. Is described, and the number of revolutions of the cooling fan is controlled based on the estimation result and the temperature detection result.

JP 2003-148144 A

  The inventions described in Patent Document 1 and Patent Document 2 measure ambient noise and control the rotational speed of the cooling fan based on the measurement result. Therefore, under the situation where the quietness without ambient noise is maintained, the rotation speed of the cooling fan can be controlled only based on the result of temperature detection.

  By the way, in recent years, an AV system is constructed in a room such as a home so as to be referred to as a home theater or the like, and viewing with a sense of reality is performed. In general, a place used for a home theater is a space that is kept relatively quiet, and ambient noise is rarely generated. In addition, electronic devices (for example, large plasma televisions, projectors, etc.) used in home theaters are often relatively large, and it is necessary to control the cooling fan to a constant rotational speed in order to maintain the cooling effect of the electronic devices. .

  In such a home theater, when a viewer enjoys watching music or a movie, the volume heard by the viewer naturally has an inflection. However, since the conventional cooling fan control needs to maintain the cooling effect, the rotation speed of the cooling fan is kept constant even when the volume of music or movies is low. For this reason, there is a problem that the noise generated from the cooling fan is heard by the viewer.

  Accordingly, an object of the present invention is to provide an electronic device and an electronic device cooling method capable of maintaining a cooling effect even in a space where silence is maintained, and preventing a viewer from perceiving noise generated from a cooling fan, and Regarding the program.

  In order to solve the above-described problems, an electronic device according to the present invention includes a temperature detection unit that detects a temperature of a cooled portion and a predetermined audio signal level output from an audio output unit in an electronic device including a cooling fan. And controlling the number of revolutions of the cooling fan based on the measurement result by the temperature detecting means, the calculating means for calculating the first average value in the time of the second time, the second average value in the time shorter than the predetermined time, The first average value is compared with the second average value, and when the first average value is larger than the second average value, the number of revolutions of the cooling fan is decreased, and the first average value is less than the second average value. When small, the electronic device includes a control unit that performs control to increase the number of rotations of the cooling fan.

  The electronic device cooling method according to the present invention includes a temperature detection step for detecting the temperature of the cooled portion and a predetermined audio signal level output from the audio output portion in the electronic device cooling method for cooling the cooled portion with a cooling fan. And controlling the number of rotations of the cooling fan based on the measurement result of the temperature detection step, the calculation step of calculating the first average value in the time of the second time, the second average value in the time shorter than the predetermined time, The first average value is compared with the second average value, and when the first average value is larger than the second average value, the number of revolutions of the cooling fan is decreased, and the first average value is less than the second average value. An electronic device cooling method comprising a control step of performing control to increase the number of rotations of the cooling fan when it is small.

  The program according to the present invention includes a temperature detection step for detecting the temperature of the cooled part in the computer, a first average value within a predetermined time of the audio signal level output from the audio output unit, and a time shorter than the predetermined time. The number of rotations of the cooling fan is controlled based on the measurement result obtained by the calculation step for calculating the second average value and the temperature detection step, and the first average value and the second average value are compared. Including a control step of performing control to lower the number of revolutions of the cooling fan when the average value is larger than the second average value and to increase the number of revolutions of the cooling fan when the first average value is smaller than the second average value. This is a program for performing processing.

  According to the present invention, the rotational speed of the cooling fan can be controlled without degrading the cooling effect even in a space where quietness is maintained. In addition, since the relative ratio between the noise generated by the rotation of the cooling fan and the output level of the volume output from the audio device can be made constant, the viewer can perceive the noise generated by the rotation of the cooling fan. Can be prevented.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that in this specification, an electronic device has a sound output function such as a television having a cooling unit such as a cooling fan (regardless of a driving method), a personal computer, a hard disk drive (HDD), or a sound output. A device connected to a device.

  In one embodiment of the present invention, an electronic device will be described as a digital broadcast receiver. FIG. 1 is a block diagram showing a digital broadcast receiving apparatus according to an embodiment of the present invention. The receiving apparatus shown in FIG. 1 can also receive analog broadcasts, but is mainly referred to as digital broadcast receiving apparatus because it mainly receives digital broadcasts. For the sake of simplicity, the description of the satellite digital broadcast receiving system using a communication satellite (CS) is omitted here.

  Terrestrial analog television broadcast signals transmitted in the VHF band (90 MHz to 220 MHz) and UHF band (440 MHz to 770 MHz) are received by the VHF antenna 1 and the UHF antenna 2 and supplied to the terrestrial analog / digital tuner 3. The terrestrial digital television broadcast signal transmitted in the UHF band is received by the UHF antenna 2 and supplied to the terrestrial analog / digital tuner 3, and the terrestrial digital audio broadcast signal transmitted on the seventh channel of the VHF is VHF. It is received by the antenna 1 and supplied to the terrestrial analog / digital tuner 3.

  In the terrestrial analog / digital tuner 3, a desired channel in the input VHF band (90 MHz to 220 MHz) and UHF band (440 MHz to 770 MHz), that is, a frequency signal is an intermediate frequency of a predetermined frequency, for example, 57 MHz. Converted to a signal. In other words, the terrestrial analog / digital tuner 3 basically has the same function as a conventional VHF / UHF tuner for receiving terrestrial analog television broadcasts.

  When receiving terrestrial analog television broadcasting transmitted in the VHF band (90 MHz to 220 MHz) and UHF band (440 MHz to 770 MHz), the intermediate frequency signal from the terrestrial analog / digital tuner 3 is the video / audio demodulator 4 for NTSC. And the video signal S1 and the audio signal S2 are obtained. The video signal S1 is supplied to one input of the video switching unit 5, and the audio signal S2 is supplied to one input of the audio switching unit 6. To be supplied.

  When receiving a terrestrial digital television broadcast transmitted in the VHF band (90 MHz to 220 MHz) and the UHF band (440 MHz to 770 MHz), the intermediate frequency signal from the terrestrial analog / digital tuner 3 is supplied to the OFDM demodulator 7 for OFDM. The signal is demodulated to obtain an MPEG transport stream TS1. The transport stream TS1 is supplied to one input of the switching unit 8 for transport stream.

  A satellite digital television broadcast signal transmitted in the SHF band (12 GHz) is received by the SHF antenna 9, converted into an intermediate frequency signal in the 1 GHz band by an LNB (low noise block) converter (not shown), and supplied to the satellite digital tuner 10. Is done. In the satellite digital tuner 10, a desired channel, that is, a frequency signal in the input intermediate frequency signal of 1 GHz band is converted into an I signal and a Q signal by direct conversion, and these signals are supplied to the QPSK demodulator 11. As a result, the QPSK signal is demodulated to obtain an MPEG transport stream TS2. The transport stream TS2 is supplied to the other input of the switching unit 8.

  A digital broadcast receiving device, a DVD (Digital Versatile Disc) recording / playback device connected via an external terminal or IEEE (Institute of Electrical and Electronics Engineers) 1394 I / F (Interface), D (Digital) -VHS, etc. Is also supplied to the switching unit 8. Further, the digital broadcast receiving apparatus can be connected to the Internet via a network I / F, and an information signal from the Internet is also supplied to the switching unit 8. In the switching unit 8, the transport streams TS1, TS2 and signals supplied from the outside are switched.

  The transport stream output of the transport stream switching unit 8 is supplied to the demultiplexer 12, and video data, audio data, broadcast data, and the like included in the transport stream in a time-division multiplexed manner are separated. .

  The video data and audio data separated by the demultiplexer 12 are supplied to an MPEG (Moving Picture Coding Experts Group) decoder 13 and decoded to obtain a video signal S3 and an audio signal S4. The video signal S3 from the MPEG decoder 13 is supplied to the other input of the video switching unit 5, and the audio signal S4 is supplied to the other input of the audio switching unit 6.

  In the following description, switching the switching unit 5 and the switching unit 6 to the video / audio demodulation unit 4 side is referred to as switching to the analog side. Switching to the MPEG decoder 13 side is referred to as switching to the digital side.

  The output of the video switching unit 5 is supplied to the video processing unit 14 and subjected to predetermined image processing to output video such as a CRT (Cathode Ray Tube), an LCD (Liquid Crystal Display), or a PDP (Plasma Display Panel). It is supplied to the device 15. The output of the audio switching unit 6 is supplied to the audio processing unit 16, subjected to predetermined audio processing, and supplied to the audio output device 17 such as a speaker or an amplifier. The output S8 of the sound processing unit 16 is also supplied to the cooling fan control unit 24.

  The video output device 15 is provided with a cooling fan 23. The video output device 15 such as CRT or PDP as described above is cooled by the rotation of the cooling fan 23. The rotation of the cooling fan is controlled by a cooling fan control unit 24 realized by a microprocessor or the like. The cooling fan control unit 24 may be integrated with the control unit 20 described later.

  Further, the video output device 15 includes a temperature detection unit 25 such as a temperature sensor, for example, and detects the temperature of the video output device 15. The temperature-related signal detected by the temperature detection unit 25 is converted into a temperature measurement signal S9 that is an electrical signal, and is supplied to the cooling fan control unit 24.

  The broadcast data for data broadcasting separated by the demultiplexer 12 is supplied to the broadcast data processing unit 18 and is subjected to predetermined processing according to user designation, for example, EPG (Electronic Programming Guide) display processing. The video data generation unit 19 is supplied with a control signal from the broadcast data processing unit 18, and the video data generation unit 19 generates an image signal for causing the video output device 15 to display a predetermined image. The image signal from the video data generator 19 is combined with the video signal of the broadcast signal in the video processor 14.

  The overall control of the digital broadcast receiving apparatus is performed by the control unit 20 realized by a microprocessor or the like. In the embodiment shown in FIG. 1, the control unit 20 controls operations of the terrestrial analog / digital tuner 3, the satellite digital tuner 10, the switching unit 5, the switching unit 6, and the switching unit 8. Other circuit parts not shown are also controlled by the control unit 20.

  A remote operation signal receiving unit 21 is connected to the control unit 20, and the remote control signal from the remote operation signal transmitter 22 is received by the remote operation signal receiving unit 21, the contents of the remote control signal are determined, and the user Control according to the instruction is performed by the control unit 20.

  From the control unit 20, the channel selection data S5 is supplied to the terrestrial analog / digital tuner 3 and the satellite digital tuner 10, and the tuner is switched and the channel is switched.

  Next, the control process of the cooling fan 23, which is a feature of the present invention, will be described. FIG. 2 shows the configuration of the cooling fan control unit 24. The temperature of the video output device 15 detected by the temperature detector 25 is converted into a temperature measurement signal S9 and supplied to the comparator 41. The comparator 41 compares a preset threshold value with the temperature of the video output device 15 and supplies the comparison result to the microprocessor 43.

  Based on the signal supplied from the comparator 41, the microprocessor 43 sets the predetermined rotation speed (R1) if the temperature of the video output device 15 is higher than the threshold value, and sets the predetermined rotation speed if the temperature is lower than the threshold value. A control signal for controlling the cooling fan 23 is output so that (R2) (where R1> R2).

  The control signal output from the microprocessor 43 is supplied to the drive unit 44, and the output voltage corresponding to the rotation speeds of R1 and R2 is adjusted, and the rotation speed of the cooling fan 23 is controlled. Note that the threshold value and the predetermined number of rotations (R1 and R2) are defined by the type and characteristics of the electronic device to be cooled. Further, the method of controlling the cooling fan 23 by comparing the temperature of the video output device 15 with the threshold value is an example, and other methods such as setting a plurality of threshold values may be used.

  The microprocessor 43 can perform various processes by storing a program in a ROM (Reed Only Memory) (not shown) provided in the microprocessor 43, for example. For example, the process of stopping the rotation of the cooling fan 23 may be performed when the temperature of the video output device 15 is lower than a set temperature. In addition, when the cooling fan 23 is rotated, a process for controlling the cooling target so as not to be always lower than the minimum number of rotations (minimum number of rotations) for preventing the portion to be cooled from being damaged by heat generation may be performed. .

  On the other hand, the audio signal S8 output from the audio processing unit 16 is supplied to an A / D (Analog to Digital) converter 42 provided in the cooling fan control unit 24 and converted into a digital signal. The digitized audio signal output from the A / D converter 42 is supplied to the microprocessor 43.

FIG. 3 is a graph showing the arithmetic processing for the audio signal level in this embodiment. The horizontal axis is time t, and the vertical axis is the audio signal level (N). The microprocessor 43 calculates the average value N1 (first average value) of the audio signal level in the time t _{1 by going} back the time t ₁ with reference to the timing t _{0 at} which the audio signal level exists. Also, an average value of the audio signal level N2 (second average value) at t _1> t ₂ for a period of time t _2. The time t ₁ can be set to several minutes, for example, and the time t ₂ can be set to several tens of seconds, for example.

  In the microprocessor 43, the average values N1 and N2 are compared. If N1> N2, it is determined that the sound volume output from the audio output device 17 is low, and a control signal for reducing the rotation speed of the cooling fan 23 is supplied to the drive unit 44. If N1 <N2, it is determined that the volume output from the audio output device 17 is high, and a control signal for increasing the rotation speed of the cooling fan 23 is supplied to the drive unit 44. The drive unit 44 adjusts the output voltage based on the supplied control signal, and controls the rotational speed of the cooling fan 23. The rotation speed control based on the audio signal level can be set, for example, by increasing or decreasing the rotation speed within a range of 10% with respect to the rotation speed adjusted based on the temperature of the video output device 15.

  The arithmetic processing in the microprocessor 43 may be performed continuously or at predetermined time intervals.

  When the arithmetic processing in the microprocessor 43 is continuously performed, the rotation speed of the cooling fan 23 may need to be frequently changed depending on the change in the average values N1 and N2 of the audio signal level. Therefore, the microprocessor 43 detects the difference between the average values N1 and N2 of the audio signal level, compares the detected difference with the threshold value, and assumes that there is a large change in the audio signal level when the threshold value is exceeded. The average values N1 and N2 may be compared. By doing so, it is possible to prevent the arithmetic processing from being performed for a minute change in the audio signal level.

  If the threshold can be arbitrarily set, the sensitivity to the change in the audio signal level can be adjusted by adjusting the threshold. That is, if the threshold value is reduced, the rotational speed of the cooling fan 23 can be controlled even if the difference between N1 and N2 is small, and if the threshold value is increased, the difference between N1 and N2 must be large to some extent. It is possible not to control the rotation speed of the cooling fan 23. For example, if the microprocessor 43 analyzes the audio signal level of a certain music and sets an appropriate threshold value, the rotation speed of the cooling fan 23 can be controlled more efficiently.

As described above, the rotation speed of the cooling fan 23 is controlled based on the temperature information of the video output device 15, and the average value of the audio signal level in the long-term time (t ₁ ) and the short-term time (t ₂ ). And controlling the rotational speed of the cooling fan 23 based on the comparison result, the rotational speed of the cooling fan 23 can be maintained at a constant level as a whole, and the cooling effect is not reduced.

  The rotation speed of the cooling fan 23 when the temperature of the part to be cooled is constant is controlled, for example, as shown in Equation 1 below.

In Formula 1, N ₁ indicates the current rotation speed of the cooling fan 23, and N ₂ indicates the rotation speed after the cooling fan 23 is changed. Further, the denominator of the equation is a value obtained by dividing the integrated value of the volume in the long-term time Tlong _n at time Tlong _n. The numerator is a value obtained by dividing the integrated value of the sound volume at a short time tshort _n (where tlong _n > tshort _n ) by the time tshort _n .

  FIG. 4 shows a change in the number of revolutions when the number of revolutions of the cooling fan 23 is controlled using Equation 1. The vertical axis indicates the volume level and the number of rotations of the cooling fan 23, and the horizontal axis indicates time. Further, as shown in FIG. 4, the temperature T of the cooled part is constant.

For example, since the volume increases in the tshort ₅ interval, the value of the numerator of Equation 1, that is, the average value of the volume during a short period of time increases. However, since the sound volume has increased from a certain point in time t ₃ , the average value of the sound volume integration in the section of tlong ₅ which is the denominator value of Equation 1 also increases. Therefore, the rotational speed N ₂ of the cooling fan 23 in the tshort ₅ section does not increase as much as the volume increases.

  Even when the temperature of the cooled part changes, the temperature of the cooled part is constantly monitored and the rotation speed of the cooling fan 23 is controlled, so that damage due to heat generation of the electronic device can be prevented and The rotation speed of the cooling fan 23 can be changed based on such an audio signal level.

  The present invention can be variously modified and applied without departing from the gist of the present invention, and is not limited to the above-described embodiment. For example, the arithmetic processing for the audio signal level is not an average, and may be another arithmetic method such as taking variance.

It is a block diagram which shows the structure of the digital broadcast receiver in one Embodiment of this invention. It is a block diagram which shows the structure of the cooling fan control part in one Embodiment of this invention. It is a graph which shows the relationship between the audio | voice signal level and time in one Embodiment of this invention. It is a graph which shows the change of the rotation speed by control of the cooling fan in one Embodiment of this invention.

Explanation of symbols

15 Video output device 17 Audio output device 23 Cooling fan 24 Cooling fan control unit 25 Temperature detection unit 43 Microprocessor

Claims (4)

In electronic devices with cooling fans,
Temperature detecting means for detecting the temperature of the cooled part;
A calculation means for calculating a first average value within a predetermined time of the audio signal level output from the audio output unit, and a second average value within a time shorter than the predetermined time;
The number of rotations of the cooling fan is controlled based on the measurement result by the temperature detection means, the first average value and the second average value are compared, and the first average value is the second average value. Control means for controlling to lower the number of revolutions of the cooling fan when larger than the value and to increase the number of revolutions of the cooling fan when the first average value is smaller than the second average value. Electronic equipment.   Further, the difference between the first average value and the second average value is calculated, and when the absolute value of the difference is larger than a threshold value, the rotation speed of the cooling fan is changed. Electronics. In the electronic device cooling method in which the cooled part is cooled by the cooling fan,
A temperature detecting step for detecting the temperature of the cooled part;
A calculation step of calculating a first average value within a predetermined time of the audio signal level output from the audio output unit, and a second average value within a time shorter than the predetermined time;
The number of rotations of the cooling fan is controlled based on the measurement result of the temperature detection step, the first average value and the second average value are compared, and the first average value is the second average value. A control step of controlling to lower the rotation speed of the cooling fan when larger than the value and to increase the rotation speed of the cooling fan when the first average value is smaller than the second average value. To cool electronic equipment. A temperature detection step for detecting the temperature of the cooled part in the computer;
A calculation step of calculating a first average value within a predetermined time of the audio signal level output from the audio output unit, and a second average value within a time shorter than the predetermined time;
The number of rotations of the cooling fan is controlled based on the measurement result of the temperature detection step, the first average value and the second average value are compared, and the first average value is the second average value. When the value is larger than the value, the number of rotations of the cooling fan is decreased, and when the first average value is smaller than the second average value, a process including a control step of performing control to increase the number of rotations of the cooling fan is performed. Program for.

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