JP2011204737A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately detect a timing of maintenance work on a filter of a ventilating opening in an electronic apparatus.SOLUTION: A projector 100 includes a housing-built-in type fan 116 cooling a heating element by sucking the outside air via the filter 112, a fan control unit 118 controlling its rotation, an atmosphere sensor 120 measuring the atmosphere in a housing, a difference value calculation unit 122 measuring a difference value between a first atmosphere PA measured when a rotational speed of the fan 116 is a first rotational speed and a second atmosphere PB measured when it is a second rotational speed higher than the first rotational speed, and a warning unit 124 informing of a warning when the difference value exceeds a threshold value T.

Description

  The present invention relates to an electronic device including a fan, and particularly to detection of filter clogging in the electronic device.

  Some electronic devices have a built-in fan. For example, a fan for removing heat generated from a CPU (Central Processing Unit) is provided for a personal computer, and a fan for removing heat generated from a lamp (light source) for a projector (projector). Is provided. In the case of an air cleaner, a fan is provided to positively capture dust contained in the outside air with a filter and to clean the outside air. In addition, the air conditioner is provided with a fan for sucking outside air and adjusting the quality such as temperature and humidity. In any case, an exhaust port and an intake port are provided in a housing of an electronic device including a fan. When the fan rotates, outside air is taken in from the intake port, and hot air generated inside the housing is discharged from the exhaust port.

  If dust accumulates in the filter provided inside the housing, the intake / exhaust efficiency deteriorates. Therefore, it is necessary to clean and replace the filter as appropriate. Even when a filter is not provided at the intake port or the like, if dust accumulates at the intake port, the intake / exhaust efficiency is still deteriorated. Also in this case, it is necessary to clean the intake port at an appropriate timing.

  The timing of such maintenance work depends greatly on the usage status of the electronic device. For example, when a projector or a personal computer is used in an environment that contains a lot of dust, naturally, clogging of the air inlet and the like tends to occur. Also, in such an environment, handling of electronic devices tends to be rough, and maintenance work is not always performed at an appropriate timing. As a result, the product life of electronic devices tends to be shortened.

JP 2009-50755 A JP 2005-181412 A

  The projector disclosed in Patent Document 1 measures a fan voltage during operation, refers to a reference voltage-rotation speed characteristic that defines a standard relationship between the fan voltage and the rotation speed, and performs a reference rotation corresponding to the fan voltage. The number is specified, and when the difference between the actual rotational speed and the reference rotational speed is large, a warning is given that clogging has occurred (see paragraphs [0052], [0053], etc. of Patent Document 1).

  Further, in Patent Document 1, considering that the atmospheric pressure changes depending on the altitude of the place where the projector is used, the reference voltage-rotation speed characteristic for the highland mode and the reference voltage-rotation speed characteristic for the flatland mode are used separately. . However, it is not practical to introduce such a complicated control system into a projector, which is an electronic device having a relatively simple configuration, in view of cost.

  The present invention has been completed in view of the above problems, and a main object of the present invention is to provide an electronic device that can appropriately notify the timing of maintenance work while having a simple configuration.

  An electronic device according to the present invention includes a fan with a built-in housing that sucks outside air through an air inlet provided in the housing, a fan control unit that controls rotation of the fan, and an air pressure that measures the pressure inside the housing. The difference between the sensor and the first atmospheric pressure measured when the rotational speed of the fan is the first rotational speed and the second atmospheric pressure measured when the rotational speed is higher than the first rotational speed. A difference value calculation unit that calculates a value and a warning unit that issues a warning when the difference value exceeds a predetermined threshold value are provided.

  The electronic device referred to here may be a device of a type that takes outside air into the housing by a fan, such as a projector, a personal computer, an air cleaner, or an air conditioner. The air pressure inside the housing changes depending on the rotation speed of the fan. When the air inlet or the like or the filter is clogged, the air pressure during the rotation of the fan is lower than when it is not. Alternatively, when the installation location of the electronic device is inappropriate, the intake / exhaust efficiency is deteriorated, so that the air pressure during the rotation of the fan tends to be low. The electronic device in the present embodiment detects the maintenance work timing of the electronic device using this atmospheric pressure lowering phenomenon. Thereby, it becomes easy to detect the timing of maintenance work appropriately, although it is a simple structure. The warning unit may change the threshold according to the atmospheric pressure. Further, if the first atmospheric pressure is the atmospheric pressure at the time of non-rotation, the control can be further simplified, but in any case, the atmospheric pressure is measured in each case of the first rotational speed and the second rotational speed larger than that. I can do it.

  You may cool the heat generating body inside a housing | casing with the taken in external air. Outside air may be taken into the housing by a fan, and dust contained in the outside air may be actively captured by a filter provided at the air inlet. Alternatively, the outside air may be sucked in order to adjust the quality such as the temperature and humidity of the outside air.

  The fan control unit rotates the fan after a predetermined period of time has elapsed after the power is turned on, and the difference value calculation unit sets the difference value with the atmospheric pressure measured at the time of no rotation before the fan rotates as the first atmospheric pressure. You may measure.

  Alternatively, the difference value calculation unit may perform the first rotation after the second atmospheric pressure measured when the rotational speed of the fan reaches the second rotational speed and the rotational speed of the fan reaches the second rotational speed. You may calculate a difference value from the 1st atmospheric pressure measured when it falls to speed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes easy to provide the electronic device which is easy to alert | report the timing of a maintenance work appropriately, although it is a simple structure.

It is an external view of a projector. It is a functional block diagram of a projector. It is a 1st example of the time chart which shows the change of the rotational speed of a fan. It is a time chart which shows the change of the internal pressure in the 1st example. It is a 2nd example of the time chart which shows the change of the rotational speed of a fan.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is an external view of the projector 100. In the present embodiment, a projector 100 will be described as an example of an electronic device. The projector 100 is a device for controlling a built-in light source (not shown) and projecting an image from the projection lens 102 onto a screen. The projector 100 includes an operation button group 104 and an indicator 106 on the upper surface.

  The projector 100 includes an intake port 108 and an exhaust port 110 on the side surface, and is designed to take outside air into the housing. In the present embodiment, description will be made assuming that a filter for capturing dust is installed inside the air inlet 108. This filter can be replaced and cleaned. When the projector 100 projects an image, the built-in light source and various electronic circuits generate heat. In order to cool these heating elements, the projector 100 includes a fan (rotary blade). When the temperature in the housing rises, the fan rotates, outside air is taken in from the intake port 108, and hot air in the housing is exhausted from the exhaust port 110.

  The projector 100 further includes a barometric pressure sensor for measuring the barometric pressure in the casing (hereinafter referred to as “internal pressure”). The internal pressure changes as the fan rotates. If the fan is installed near the intake port, the internal pressure during rotation will increase, and if it is installed near the exhaust port, it will decrease. In the present embodiment, the case where the internal air pressure decreases when the fan rotates will be described, but the basic principle is the same even when the internal air pressure increases. Projector 100 uses the change in internal air pressure during fan rotation to determine the time for filter maintenance work (hereinafter, such determination processing is referred to as “maintenance determination processing”). Details of the maintenance determination process will be described later.

  FIG. 2 is a functional block diagram of the projector 100. In FIG. 2, the configuration of the projector 100 is shown not by hardware but by functional blocks. The projector 100 includes a projection unit 114, a fan 116, a fan control unit 118, an atmospheric pressure sensor 120, a difference value calculation unit 122, and a warning unit 124.

  The projection unit 114 is a functional block including a light source and various electronic circuits for projecting an image from the projection lens 102, and is also a main heat source of the projector 100. The fan control unit 118 controls the rotation speed and rotation time of the fan 116. The fan control unit 118 increases the rotation speed of the fan 116 when the temperature in the housing is high, and decreases or stops the rotation speed when the temperature is low. When the fan 116 rotates, a relatively low temperature outside air is taken into the housing from the intake port 108, and a relatively high temperature air generated around the projection unit 114 is discharged from the exhaust port 110 to the outside of the housing. A filter 112 for capturing dust is installed inside the air inlet 108. The fan 116 is provided closer to the exhaust port 110 than the intake port 108. For this reason, when the fan 116 rotates, the internal pressure decreases. When the filter 112 is clogged, the internal pressure particularly decreases.

  The atmospheric pressure sensor 120 is a general sensor. The atmospheric pressure varies depending on the altitude at which the projector 100 is installed, the rotational speed of the fan 116 (air fluidity), and the degree of clogging of the filter 112. The difference value calculation unit 122 calculates a difference value between the first atmospheric pressure PA when the fan 116 is not rotating and the second atmospheric pressure PB when the fan 116 is at a predetermined rotation speed. The warning unit 124 determines whether the maintenance work for the filter 112 is necessary based on the difference value.

  FIG. 3 is a first example of a time chart showing changes in the rotational speed of the fan 116. The horizontal axis indicates time, and the vertical axis indicates the rotation speed. Even if the power is turned on at time t0, the fan control unit 118 does not immediately rotate the fan 116. The difference value calculation unit 122 records the atmospheric pressure measured at time t1 when a predetermined period has elapsed since the power is turned on as the first atmospheric pressure PA. The rotational speed at which the first atmospheric pressure PA is measured is referred to as a first rotational speed VA. In the example shown in FIG. 3, the first rotation speed VA = 0.

  When the time further elapses and a predetermined time t2 is reached, the fan control unit 118 starts rotating the fan 116. The difference value calculation unit 122 records the second atmospheric pressure PB measured at time t4 when a predetermined time has elapsed after the rotation speed reaches the second rotation speed VB at time t3. In the projector 100 according to the present embodiment, when the rotational speed of the fan 116 increases, the internal pressure starts to decrease. The atmospheric pressure measured when a predetermined time has elapsed after the rotational speed reaches the second rotational speed VB is defined as the second atmospheric pressure PB so that the internal pressure can be stably measured.

  FIG. 4 is a time chart showing changes in internal pressure in the first example. Characteristic C1 indicates the internal pressure when no clogging occurs, and characteristic C2 indicates the internal pressure when clogging occurs. The first atmospheric pressure PA measured at time t1 when there is no rotation is equal to the external atmospheric pressure in the installation environment of the projector 100. When the fan 116 starts to rotate at time t2, the internal pressure gradually decreases. When no clogging has occurred, the internal pressure decreases to the second atmospheric pressure PB1 (characteristic C1). On the other hand, when clogging has occurred, the internal pressure decreases to the second atmospheric pressure PB2 (<PB1) (characteristic C2). This is because the intake efficiency has deteriorated due to clogging of the filter 112.

  Therefore, a predetermined threshold T is set in advance, and when PA−PB ≧ T, the warning unit 124 displays a warning with the indicator 106. That is, if the second atmospheric pressure PB is lowered by the threshold value T or more when the fan 116 is rotated at the second rotational speed VB, it is determined that the filter is clogged. In the case of FIG. 4, the threshold value T is set so that PA-PB2> T> PA-PB1.

  When the projector 100 is installed in a place where the external air pressure is low, for example, at a high altitude, the first atmospheric pressure PA decreases, but the second atmospheric pressure PB also decreases. Therefore, if the threshold value T is set appropriately, the filter maintenance operation timing can be appropriately detected based on PA-PB ≧ T even if the usage environment of the projector 100 changes.

  However, the rate of decrease of the second atmospheric pressure PB may change somewhat depending on the external atmospheric pressure (first atmospheric pressure PA). Therefore, the threshold value T may be changed according to the first atmospheric pressure PA in order to further increase the detection accuracy. For example, a plurality of threshold values T respectively corresponding to a plurality of first atmospheric pressures PA are set in advance, and one of the threshold values T is selected according to the actually measured first atmospheric pressure PA, and based on the selected threshold value T. Thus, it may be determined whether or not the maintenance work of the filter is necessary.

  Currently, barometric pressure sensors that are small and inexpensive enough to be installed in mobile terminals have been developed. For this reason, the mounting of the atmospheric pressure sensor 120 causes almost no problem in terms of space and cost. Further, since the atmospheric pressure sensor 120 is built in the projector 100, the aesthetic appearance is not impaired.

  FIG. 5 is a second example of a time chart showing changes in the rotation speed of the fan 116. In the second example, when the power is turned on at time t0, the fan control unit 118 immediately rotates the fan 116. At time t1, the fan 116 reaches the second rotational speed VB. The difference value calculation unit 122 records the atmospheric pressure measured at time t2 when a predetermined period has elapsed from time t1 as the second atmospheric pressure PB.

  When the temperature in the housing decreases and cooling is no longer necessary, the fan control unit 118 stops the fan 116. When the fan 116 stops, the internal pressure increases. The difference value calculation unit 122 records the internal atmospheric pressure measured at the time t4 after a predetermined time from the time t3 when the fan 116 stops as the first atmospheric pressure PA. The difference value calculation unit 122 calculates a difference value based on the first atmospheric pressure PA and the second atmospheric pressure PB. If PA−PB ≧ T, the warning unit 124 displays a warning.

  The fan 116 of the projector 100 normally repeats the stop period and the rotation period according to the temperature inside the housing. In the first example, the first atmospheric pressure PA is measured by setting the power-on time as the stop period. However, in the second example, the first atmospheric pressure PA is measured using the opportunity to shift to the stop period after the power is turned on. Yes. For this reason, the fan control part 118 has the merit that the fan 116 can be controlled by the system similar to a general projector.

  In both cases of the first example and the second example, when it is determined that the filter maintenance work is necessary, the warning unit 124 holds the determination result without performing re-measurement / re-determination at the next power-on. A warning may be displayed. Further, the difference value calculation unit 122 and the warning unit 124 do not always need to execute the maintenance determination process. For example, when PA-PB is sufficiently smaller than threshold value T, that is, when PA-PB <U (<< T), the maintenance determination process at the next power-on may be skipped. The projector 100 according to the present embodiment can detect not only filter clogging, but also intake / exhaust port clogging and a decrease in intake / exhaust efficiency due to inappropriate grounding of the projector 100.

  The present invention has been described based on the embodiments. It will be understood by those skilled in the art that the embodiments are illustrative, and that various modifications and changes are possible within the scope of the claims of the present invention, and that such modifications and changes are also within the scope of the claims of the present invention. By the way. Accordingly, the description and drawings herein are to be regarded as illustrative rather than restrictive.

  DESCRIPTION OF SYMBOLS 100 Projector, 102 Projection lens, 104 Operation button group, 106 Indicator, 108 Intake port, 110 Exhaust port, 112 Filter, 114 Projection part, 116 Fan, 118 Fan control part, 120 Barometric pressure sensor, 122 Difference value calculation part, 124 Warning Department.

Claims (8)

A fan with a built-in housing that sucks outside air into the housing via an air inlet provided in the housing;
A fan control unit for controlling rotation of the fan;
A pressure sensor that measures the pressure inside the housing;
A difference value between the first atmospheric pressure measured when the rotational speed of the fan is the first rotational speed and the second atmospheric pressure measured when the second rotational speed is higher than the first rotational speed. A difference value calculation unit for calculating
A warning unit that issues a warning when the difference value is equal to or greater than a predetermined threshold;
An electronic device comprising:   The electronic device according to claim 1, wherein the fan is provided to cool a heating element inside the housing.   The electronic device according to claim 1, wherein the fan is provided to capture dust in the outside air by a filter provided at the intake port.   The electronic device according to claim 1, wherein the fan is provided to suck and reform outside air.   The electronic device according to claim 1, wherein the warning unit changes the threshold value according to atmospheric pressure.   The electronic apparatus according to claim 1, wherein the first atmospheric pressure is a non-rotating atmospheric pressure. The fan control unit rotates the fan after a predetermined period has elapsed after power is turned on,
7. The difference value calculation unit measures the difference value by using, as the first atmospheric pressure, an atmospheric pressure measured during non-rotation before the fan rotates. Electronic equipment.   The difference value calculating unit is configured to measure the second atmospheric pressure measured when the rotational speed of the fan reaches the second rotational speed, and after the rotational speed of the fan reaches the second rotational speed. The electronic apparatus according to claim 1, wherein the difference value is calculated from the first atmospheric pressure measured when the speed decreases to the first rotation speed.

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