OPTIMIZATION OF HEAT REGULATION IN A DEVICE COMPRISING A FAN

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.

GENERAL TECHNICAL FIELD

The invention relates to a device, the temperature control whereof is provided for by a mechanical ventilation system.

PRIOR ART

Electronic devices conventionally include at least one fan for control of their temperature.

Effective temperature control is indispensable for maintaining the performance of the device.

Indeed, heating of the components of the device often causes deterioration of the performance of the device.

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.

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.

This rotation speed has in particular from one to three levels, depending on the temperature of the component.

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.

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.

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.

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

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.

This makes it possible to control the temperature of the components while minimizing the noise generated by the fan.

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.

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.

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.

The different embodiments of the invention offer numerous advantages.

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.

The device is therefore more pleasant to use.

In addition, the device allows simple and optimized control of temperature, while still maintaining a reduced noise level.

The solution is effectively adapted to devices containing a fan, without making a complete review of their architecture necessary.

DETAILED DESCRIPTION

Device

Represented schematically inFIG. 1is an embodiment of a device1according to the invention. This device1is an electronic device, the temperature whereof must be controlled.

The device1includes at least one component7. The component7is for example an optical and/or electronic type component, which can provide one or more functions for the device1.

For example, in the embodiment ofFIG. 2, the device1includes a light emitting system2, configured for displaying an image, and/or for projecting an image.

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.

In the example illustrated inFIG. 2, the light emitting system2includes light emitting elements11and optical elements12. The elements11are for example light emitting diodes (LEDs) of the three basic colors (red, green blue), and the optical elements12are a set of micro-mirrors the position and the inclination whereof are controlled electronically. The optical elements12can for example be integrated into a micro-chip.

The elements11emit one or more light rays toward the elements12, which project the rays toward a projection surface, for projecting the image. This type of projector is known in the art.

In the example ofFIG. 2, the component7of which the temperature is to be controlled is a component of the system2, such as for example the optical elements12.

The component7can also be any other component whose temperature needs to be controlled so as to maintain the performance of the device1, an electronic card, processor, etc.

The device1includes at least one fan4for controlling the temperature of the component7. If applicable, several fans4can be present in the device1.

The device1also includes a processor5. This can be the main processor of the device1, configured to manage the different electronic functions of the device1(interaction with the user, managing loading, managing applications, etc.), or a processor dedicated to implementing the temperature control process described hereafter.

Managing the temperature of the emission system2is crucial for ensuring the performance of the device1.

This temperature can particularly be measured by one more temperature sensors3, positioned in or in proximity to the component7.

The temperature of the emission system2depends mainly:on the ambient temperature to which the device1is subjected;on the phase of operation of the device1(starting phase, in operation, number of tasks carried out by the device, complexity of tasks, etc.).

In particular, in operation, the temperature of the component7has a tendency to increase.

However, in general, an increase in temperature of the component7degrades the performance of the device1.

Moreover, the increase in the speed of rotation of the fan4, to reduce the increase in temperature of the component7, increases the noise generated by the device1.

The processor5is configured to control the direction of rotation of the fan4depending on the temperature of the component7, so as to control the temperature of the component while minimizing the noise generated by the fan.

In particular, the processor makes it possible to reduce the temperature of the component7while still minimizing the noise generated by the fan4. The compromise between control of temperature and reduction of noise is thus optimized, which allows the performance of the device1to be maintained while still reducing the noise generated.

For example, in the example illustrated inFIG. 2, wherein the component7is part of the light emitting system2, the increase in temperature of the light emitting system2degrades the lighting effectiveness of the system2.

Thus the quality of the image produced, like its sharpness or its clarity, deteriorates with the increase in temperature of the light emitting system2. This results particularly from performance of the light emitting elements (LEDs) with temperature.

Thanks to control of the direction of rotation of the fan4by the processor5, the temperature of the light emitting system2is controlled while reducing the noise generated by the fan4.

For a given rotation speed, the fan4generates a smaller noise in one direction of rotation compared to the other direction of rotation.

Indeed, depending on the direction of rotation of the fan4, the stream of air is aspirated or blown. The path of the flow of air in the device1is therefore different, which creates a different aerodynamic noise.

Likewise, given the path of the stream of air varies depending on the direction of rotation of the fan, temperature control of the component7varies depending on this direction of rotation. In particular, the influence of the direction of rotation of the ventilator4on the control of temperature depends in particular on the relative position of the fan4with respect to the component7.

Generally, the direction of rotation of inducing the maximum noise is that which also allows the best reduction in the temperature of the component7.

As mentioned previously, the fan4has, 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.

According to one possible aspect of the control implemented by the processor5, it is configured to select the direction of rotation of the fan4generating the noise of a second amplitude when the temperature of the component7is greater than a threshold.

Below this threshold, the processor5retains the rotation direction generating a smaller noise of the first amplitude.

Besides the ventilator4, the device1can include at least one outer opening10of which the size is adjustable. It can also consist of a plurality of outer openings10.

According to one example, the processor5controls a motor14which controls the size of the outer opening10(or of the plurality of openings10). The outer openings10include for example an element sliding in front of a recess, the translation whereof controls the size of the openings10.

These outer openings10allow the circulation of a stream of air toward and from the outside of the device1.

The outer openings10can be positioned on an edge of the device1, or over the entire perimeter of the device1.

According to one embodiment, the processor5is configured to control the direction of rotation of the fan4and the size of the outer openings10according to the temperature of the component7.

This dual control makes it possible to manage more accurately the compromise existing between the temperature of the component7and the noise generated by the fan4, because another control parameter is available (size of the openings10).

According to a particular example, the processor5controls, besides the size of the openings10, the profile of the outer openings10, using the motor14.

Different controls can be implemented in the device1for controlling temperature. These controls can be combined, be partially used, or not be used.

According to one aspect, the processor5is configured to increase the size of the outer openings10with an increase in the temperature of the component7.

As will be understood, the increase in size of the outer openings10makes it possible to reduce the temperature of the component7, thanks to circulation of a stream of air in the device1.

According to another aspect, the processor5is configured to control simultaneously the direction of rotation of the fan4and its rotation speed, depending on the temperature of the component7.

According to yet another aspect, the processor5is configured to select the direction of rotation of the fan4generating the noise with a second (maximum noise) when the size of the outer openings10is maximum. This means that the processor5, when controlling the temperature of the component7, first controls the increase in size of the outer openings10. Once this maximum size is reached, the processor5controls the direction of rotation of the fan4and, if applicable, the rotation speed of the fan4.

The device1, which includes the component7, can for example be a portable image projector. In this case, it includes a light emitting system2.

This type of projector is transported by the user, like a USB key, and allows him to project images in different circumstances.

It can also consist of other portable devices requiring temperature control and a reduction in operating noise.

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

InFIG. 3, a temperature control method in the device1described previously includes in particular the step E2consisting of controlling the direction of rotation of the fan4according to the temperature of at least one component7of the device1, so as to control the temperature of the component7while minimizing the noise generated by the fan4. The temperature of the component7is measured by the aforementioned temperature sensor3and transmitted to the processor5(step E1).

According to one aspect of the method, if the device1includes at least one outer opening10, the processor5controls the size of the opening10up to its maximum size, then selects the direction of rotation of the fan4according to the temperature of the component7.

A particular and non-limiting example of control is described hereafter, with reference toFIG. 4.

During starting of the device1, the temperature T2measured (step E3) by the sensor3for the component7is low. The processor5selects the direction of rotation of the fan4as the direction generating a first magnitude noise (low noise). The processor5keeps the outer openings10closed (step E4).

When the temperature T2of a component7(such as for example the optical elements12of the light emitting system2) exceeds a threshold Tθ, the processor5begins to increase the size of the outer openings10so as to reduce the temperature of the component7(step E5).

This makes it possible to maintain the performance of the device1, like the lighting effectiveness of the image projected by the system2, despite the increase in temperature, while still minimizing the noise of the fan4. As emphasized previously, the increase in temperature degrades the quality of the image in the case of a light emitting system2.

When the temperature T2of a component7(such as for example the optical elements12of the light emitting system2) exceeds a threshold Tβ, where Tβ>Tθ, and the size of the outer openings10is a maximum, the processor5selects the direction of rotation of the fan4generating a noise with a second amplitude (maximum noise, step E6).

This direction of rotation of the fan4makes it possible to further cool the component7. Although the direction of rotation of the fan4is more noisy, this makes it possible to preserve the performance of the device1, such as for example the quality of the image displayed or projected by the system2, even though the temperature T2of the component7is high.

In this example, the speed of rotation of the fan4is assumed constant. However, this can also be controlled by the processor5, and vary in the event of an increase in temperature.

Likewise, simultaneous control of the size of the outer openings10and of the direction of rotation of the fan4(and/or its speed of rotation) can be implemented. In particular, it is not necessary that the openings10have reached their maximum size to change the direction of rotation of the fan4.

Likewise, the control implemented in the device1can depend on several temperature thresholds for the component7, but also depend on several measured temperatures.

In the example above, only the temperature of the component7has been take into account (such as for example the optical elements12) to the extent that it is the more representative temperature.

However, the temperature of other components7of the optical system2can be taken into account in controlling the fan4and the openings10. In the example ofFIG. 2, the temperature of the light emitting elements11can also be taken into account by the processor5.

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.