Abstract:
The invention concerns a device ( 1 ) comprising: at least one component ( 7 ), at least one fan ( 4 ) for regulating the temperature of the component ( 7 ), a processor ( 5 ), and at least one temperature sensor ( 3 ), characterised in that the processor ( 5 ) is configured to control the direction of rotation of the fan ( 4 ) on the basis of the temperature of the component ( 7 ) measured by the temperature sensor ( 3 ), so as to regulate the temperature of the component ( 7 ) and the noise generated by the fan ( 4 ). The invention also concerns a method for regulating the temperature in this device.

Description:
GENERAL TECHNICAL FIELD 
       [0001]    The invention relates to a device, the temperature control whereof is provided for by a mechanical ventilation system. 
       PRIOR ART 
       [0002]    Electronic devices conventionally include at least one fan for control of their temperature. 
         [0003]    Effective temperature control is indispensable for maintaining the performance of the device. 
         [0004]    Indeed, heating of the components of the device often causes deterioration of the performance of the device. 
         [0005]    This is for example the case in electronic devices including a light emitting system, for display or projection of an image. In particular, the quality of the image displayed or projected by the light emitting system, and in particular its sharpness, depend on the proper temperature regulation of the light emitting system. A too high temperature of the components of the light emitting system degrades the quality of the produced image. 
         [0006]    In the prior art, the temperature control of at least one component of the electronic device is managed by a processor which controls the rotation speed of the fan depending on the temperature of the component. 
         [0007]    This rotation speed has in particular from one to three levels, depending on the temperature of the component. 
         [0008]    However, with this kind of control, this type of device is very noisy. In particular, the noise generated by the device increases with the heating of the device. 
         [0009]    When the device is heavily loaded (for example in the case when it displays or projects images of higher quality), or when the device is placed in an environment with a high temperature, the noise generated by the device is a maximum, which discourages and inconveniences the users. 
         [0010]    Some devices reduce the noise by reducing the rotation speed of the fan, but this is accomplished to the detriment of the performance of the device. 
         [0011]    In addition, in the case of portable devices, supposed to be mobile and usable in all circumstances (meetings, trips), the user can not use the device in an optimal and comfortable manner. 
       PRESENTATION OF THE INVENTION 
       [0012]    To compensate for these shortcomings, the invention proposes a device including at least one component, at least one fan to control the temperature of the component, a processor, and at least one temperature sensor, characterized in that the processor is configured to control the direction of rotation of the fan according to the temperature measured by the temperature sensor, so as to control the temperature of the component and the noise generated by the fan. 
         [0013]    This makes it possible to control the temperature of the components while minimizing the noise generated by the fan. 
         [0014]    The invention is advantageously complemented by the following features, taken alone or in any one of their technically possible combinations:
       the device also includes at least one outer opening of which the size is adjustable, for passing a stream of air, the processor being configured to control the direction of rotation of the fan and the size of the outer opening according to the temperature of the component;   the processor is configured to increase the size of the outer opening with an increase in the temperature of the component;   the processor is configured to control the speed of rotation of the fan according to the temperature of the component;   the fan has, for a given rotation speed:
           a direction of rotation giving a noise with a first amplitude,   another direction of rotation generating a noise with a second amplitude, greater than the first,   
           the processor being configured to select the direction of rotation of the fan generating the noise with the second amplitude when the temperature of the component exceeds a threshold;   the processor is configured to select the direction of rotation of the fan generating the noise of a second amplitude when the size of an outer opening of the device is a maximum;   the device includes a light emitting system which includes light emitting elements and optical elements for projection of an image, the component of which the temperature is controlled corresponding to the optical elements;   the device is a portable image projector.       
 
         [0025]    The invention also relates to a temperature control process in a device such as that described previously, including the step consisting of controlling the direction of rotation of the fan according to the temperature as a function of the temperature of at least one component of the device measured by the temperature sensor, so as to control the temperature of the component while minimizing the noise generated by the fan. 
         [0026]    The method can also include the step according to which, during the increase in the temperature of the component, the processor controls the size of an outer opening of the device up to its maximum size, then selects the direction of rotation of the fan according to the temperature of the component. 
         [0027]    The different embodiments of the invention offer numerous advantages. 
         [0028]    Thus, the device allows optimization of the compromise between the control of temperature, synonym of good performance for the device, and reduction in noise for the user. For example, in the case of a device including a light emitting system configured for displaying or projecting images, the display and projection performance are ensured while still reducing noise. 
         [0029]    The device is therefore more pleasant to use. 
         [0030]    In addition, the device allows simple and optimized control of temperature, while still maintaining a reduced noise level. 
         [0031]    The solution is effectively adapted to devices containing a fan, without making a complete review of their architecture necessary. 
     
    
     
       PRESENTATION OF THE FIGURES 
         [0032]    Other features, aims and advantages of the invention will be revealed by the description hereafter, which is purely illustrative and not limiting, and which must be read with reference to the appended drawings wherein: 
           [0033]      FIG. 1  is a schematic representation of an embodiment of a device according to the invention; 
           [0034]      FIG. 2  is a schematic representation of another embodiment of a device according to the invention; 
           [0035]      FIG. 3  is a schematic representation of an embodiment of a control method according to the invention; 
           [0036]      FIG. 4  is a schematic representation of an exemplary embodiment of a control method according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
     Device 
       [0037]    Represented schematically in  FIG. 1  is an embodiment of a device  1  according to the invention. This device  1  is an electronic device, the temperature whereof must be controlled. 
         [0038]    The device  1  includes at least one component  7 . The component  7  is for example an optical and/or electronic type component, which can provide one or more functions for the device  1 . 
         [0039]    For example, in the embodiment of  FIG. 2 , the device  1  includes a light emitting system  2 , configured for displaying an image, and/or for projecting an image. 
         [0040]    This is for example a screen for displaying an image, or a system for projecting an image toward a projection surface such as a wall or any other suitable surface. 
         [0041]    In the example illustrated in  FIG. 2 , the light emitting system  2  includes light emitting elements  11  and optical elements  12 . The elements  11  are for example light emitting diodes (LEDs) of the three basic colors (red, green blue), and the optical elements  12  are a set of micro-mirrors the position and the inclination whereof are controlled electronically. The optical elements  12  can for example be integrated into a micro-chip. 
         [0042]    The elements  11  emit one or more light rays toward the elements  12 , which project the rays toward a projection surface, for projecting the image. This type of projector is known in the art. 
         [0043]    In the example of  FIG. 2 , the component  7  of which the temperature is to be controlled is a component of the system  2 , such as for example the optical elements  12 . 
         [0044]    The component  7  can also be any other component whose temperature needs to be controlled so as to maintain the performance of the device  1 , an electronic card, processor, etc. 
         [0045]    The device  1  includes at least one fan  4  for controlling the temperature of the component  7 . If applicable, several fans  4  can be present in the device  1 . 
         [0046]    The device  1  also includes a processor  5 . This can be the main processor of the device  1 , configured to manage the different electronic functions of the device  1  (interaction with the user, managing loading, managing applications, etc.), or a processor dedicated to implementing the temperature control process described hereafter. 
         [0047]    Managing the temperature of the emission system  2  is crucial for ensuring the performance of the device  1 . 
         [0048]    This temperature can particularly be measured by one more temperature sensors  3 , positioned in or in proximity to the component  7 . 
         [0049]    The temperature of the emission system  2  depends mainly:
       on the ambient temperature to which the device  1  is subjected;   on the phase of operation of the device  1  (starting phase, in operation, number of tasks carried out by the device, complexity of tasks, etc.).       
 
         [0052]    In particular, in operation, the temperature of the component  7  has a tendency to increase. 
         [0053]    However, in general, an increase in temperature of the component  7  degrades the performance of the device  1 . 
         [0054]    Moreover, the increase in the speed of rotation of the fan  4 , to reduce the increase in temperature of the component  7 , increases the noise generated by the device  1 . 
         [0055]    The processor  5  is configured to control the direction of rotation of the fan  4  depending on the temperature of the component  7 , so as to control the temperature of the component while minimizing the noise generated by the fan. 
         [0056]    In particular, the processor makes it possible to reduce the temperature of the component  7  while still minimizing the noise generated by the fan  4 . The compromise between control of temperature and reduction of noise is thus optimized, which allows the performance of the device  1  to be maintained while still reducing the noise generated. 
         [0057]    For example, in the example illustrated in  FIG. 2 , wherein the component  7  is part of the light emitting system  2 , the increase in temperature of the light emitting system  2  degrades the lighting effectiveness of the system  2 . 
         [0058]    Thus the quality of the image produced, like its sharpness or its clarity, deteriorates with the increase in temperature of the light emitting system  2 . This results particularly from performance of the light emitting elements (LEDs) with temperature. 
         [0059]    Thanks to control of the direction of rotation of the fan  4  by the processor  5 , the temperature of the light emitting system  2  is controlled while reducing the noise generated by the fan  4 . 
         [0060]    For a given rotation speed, the fan  4  generates a smaller noise in one direction of rotation compared to the other direction of rotation. 
         [0061]    Indeed, depending on the direction of rotation of the fan  4 , the stream of air is aspirated or blown. The path of the flow of air in the device  1  is therefore different, which creates a different aerodynamic noise. 
         [0062]    Likewise, given the path of the stream of air varies depending on the direction of rotation of the fan, temperature control of the component  7  varies depending on this direction of rotation. In particular, the influence of the direction of rotation of the ventilator  4  on the control of temperature depends in particular on the relative position of the fan  4  with respect to the component  7 . 
         [0063]    Generally, the direction of rotation of inducing the maximum noise is that which also allows the best reduction in the temperature of the component  7 . 
         [0064]    As mentioned previously, the fan  4  has, for a given rotation speed, a rotation direction generating a noise with a first amplitude, and another direction of rotation generating a noise with a second amplitude, greater than the first. 
         [0065]    According to one possible aspect of the control implemented by the processor  5 , it is configured to select the direction of rotation of the fan  4  generating the noise of a second amplitude when the temperature of the component  7  is greater than a threshold. 
         [0066]    Below this threshold, the processor  5  retains the rotation direction generating a smaller noise of the first amplitude. 
         [0067]    Besides the ventilator  4 , the device  1  can include at least one outer opening  10  of which the size is adjustable. It can also consist of a plurality of outer openings  10 . 
         [0068]    According to one example, the processor  5  controls a motor  14  which controls the size of the outer opening  10  (or of the plurality of openings  10 ). The outer openings  10  include for example an element sliding in front of a recess, the translation whereof controls the size of the openings  10 . 
         [0069]    These outer openings  10  allow the circulation of a stream of air toward and from the outside of the device  1 . 
         [0070]    The outer openings  10  can be positioned on an edge of the device  1 , or over the entire perimeter of the device  1 . 
         [0071]    According to one embodiment, the processor  5  is configured to control the direction of rotation of the fan  4  and the size of the outer openings  10  according to the temperature of the component  7 . 
         [0072]    This dual control makes it possible to manage more accurately the compromise existing between the temperature of the component  7  and the noise generated by the fan  4 , because another control parameter is available (size of the openings  10 ). 
         [0073]    According to a particular example, the processor  5  controls, besides the size of the openings  10 , the profile of the outer openings  10 , using the motor  14 . 
         [0074]    Different controls can be implemented in the device  1  for controlling temperature. These controls can be combined, be partially used, or not be used. 
         [0075]    According to one aspect, the processor  5  is configured to increase the size of the outer openings  10  with an increase in the temperature of the component  7 . 
         [0076]    As will be understood, the increase in size of the outer openings  10  makes it possible to reduce the temperature of the component  7 , thanks to circulation of a stream of air in the device  1 . 
         [0077]    According to another aspect, the processor  5  is configured to control simultaneously the direction of rotation of the fan  4  and its rotation speed, depending on the temperature of the component  7 . 
         [0078]    According to yet another aspect, the processor  5  is configured to select the direction of rotation of the fan  4  generating the noise with a second (maximum noise) when the size of the outer openings  10  is maximum. This means that the processor  5 , when controlling the temperature of the component  7 , first controls the increase in size of the outer openings  10 . Once this maximum size is reached, the processor  5  controls the direction of rotation of the fan  4  and, if applicable, the rotation speed of the fan  4 . 
         [0079]    The device  1 , which includes the component  7 , can for example be a portable image projector. In this case, it includes a light emitting system  2 . 
         [0080]    This type of projector is transported by the user, like a USB key, and allows him to project images in different circumstances. 
         [0081]    It can also consist of other portable devices requiring temperature control and a reduction in operating noise. 
         [0082]    Without limitation, it can also consist of a USB key, a photographic device, a camera, a computer, a projector or a portable telephone, including one or more components whose temperature must be controlled. 
       Examples of Control 
       [0083]    In  FIG. 3 , a temperature control method in the device  1  described previously includes in particular the step E 2  consisting of controlling the direction of rotation of the fan  4  according to the temperature of at least one component  7  of the device  1 , so as to control the temperature of the component  7  while minimizing the noise generated by the fan  4 . The temperature of the component  7  is measured by the aforementioned temperature sensor  3  and transmitted to the processor  5  (step E 1 ). 
         [0084]    According to one aspect of the method, if the device  1  includes at least one outer opening  10 , the processor  5  controls the size of the opening  10  up to its maximum size, then selects the direction of rotation of the fan  4  according to the temperature of the component  7 . 
         [0085]    A particular and non-limiting example of control is described hereafter, with reference to  FIG. 4 . 
         [0086]    During starting of the device  1 , the temperature T 2  measured (step E 3 ) by the sensor  3  for the component  7  is low. The processor  5  selects the direction of rotation of the fan  4  as the direction generating a first magnitude noise (low noise). The processor  5  keeps the outer openings  10  closed (step E 4 ). 
         [0087]    When the temperature T 2  of a component  7  (such as for example the optical elements  12  of the light emitting system  2 ) exceeds a threshold T θ , the processor  5  begins to increase the size of the outer openings  10  so as to reduce the temperature of the component  7  (step E 5 ). 
         [0088]    This makes it possible to maintain the performance of the device  1 , like the lighting effectiveness of the image projected by the system  2 , despite the increase in temperature, while still minimizing the noise of the fan  4 . As emphasized previously, the increase in temperature degrades the quality of the image in the case of a light emitting system  2 . 
         [0089]    When the temperature T 2  of a component  7  (such as for example the optical elements  12  of the light emitting system  2 ) exceeds a threshold T β , where T β &gt;T θ , and the size of the outer openings  10  is a maximum, the processor  5  selects the direction of rotation of the fan  4  generating a noise with a second amplitude (maximum noise, step E 6 ). 
         [0090]    This direction of rotation of the fan  4  makes it possible to further cool the component  7 . Although the direction of rotation of the fan  4  is more noisy, this makes it possible to preserve the performance of the device  1 , such as for example the quality of the image displayed or projected by the system  2 , even though the temperature T 2  of the component  7  is high. 
         [0091]    In this example, the speed of rotation of the fan  4  is assumed constant. However, this can also be controlled by the processor  5 , and vary in the event of an increase in temperature. 
         [0092]    Likewise, simultaneous control of the size of the outer openings  10  and of the direction of rotation of the fan  4  (and/or its speed of rotation) can be implemented. In particular, it is not necessary that the openings  10  have reached their maximum size to change the direction of rotation of the fan  4 . 
         [0093]    Likewise, the control implemented in the device  1  can depend on several temperature thresholds for the component  7 , but also depend on several measured temperatures. 
         [0094]    In the example above, only the temperature of the component  7  has been take into account (such as for example the optical elements  12 ) to the extent that it is the more representative temperature. 
         [0095]    However, the temperature of other components  7  of the optical system  2  can be taken into account in controlling the fan  4  and the openings  10 . In the example of  FIG. 2 , the temperature of the light emitting elements  11  can also be taken into account by the processor  5 . 
         [0096]    The invention allows optimized management of the compromise between the performance of the device and the noise generated by the device. It applies particularly, but without limitation, to devices configured to project or display an image.