TWI467312B - Overheating prevention apparatus and projection apparatus - Google Patents

Description

Overheat prevention device and projection device

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an overheat prevention device for a display device, and more particularly to an overheat prevention device for use in a display device that automatically adjusts to different environments.

With the convenience brought by the development of science and technology, display devices have become an indispensable electronic product in life. Among them, it is more widely used for projection devices for large screens, such as conference rooms, home theaters, classrooms, and the like. And because its use is quite common, it is often used in a variety of different environmental conditions. Also, because the projection device uses a large amount of thermal energy when it is used, most of the projection devices are used with a heat sink, such as a fan, in order to ensure that the projection device does not cause a crash due to overheating.

However, when the fan is in operation, it often produces unavoidable noise, which in turn affects the quality of use, especially when the fan speed is set too high. Therefore, there are many ways to control the fan, in order to adjust the speed of the fan. Among them, a common way is to adjust manually. Although this method is cheap and simple in design, it is only necessary to determine the temperature of the projection device by the user's perception, and manually set the rotation speed of the fan. The determination of the occurrence of an error will also easily cause component wear of the projection device.

In addition, there is also a method of automatically setting the fan speed by using a temperature sensor, which mainly uses the temperature sensor in the projection device to determine the temperature of the use, and automatically adjusts the speed of the fan accordingly. Although this method has better judgment ability than manual adjustment, the conventional automatic sensing method usually sets the temperature critical point. If the temperature of the projection device is higher than the temperature critical point, the speed of the fan is increased; The temperature critical point reduces the speed of the fan. In this way, if the temperature of the projection device is near the critical point, the fan will increase and decrease due to the temperature, causing the speed to fluctuate, and the speed of the fan, the noise of the fan, and the operating temperature cannot be obtained. In addition to the balance, it is more likely that the service life of the fan will be reduced.

Moreover, when the projection device is used at different altitudes, the pressure sensor is used to judge the use environment, and the fan speed is adjusted according to the altitude. However, the use of pressure sensors to determine the height is too expensive and cannot be widely accepted by the public.

Therefore, how to solve the above problems, so that the projection device can adjust the heat sink according to different environments, and at the same time achieve the best balance between heat dissipation, noise and price, the industry still has to work hard.

In order to solve the foregoing problems, an object of the present invention is to provide an overheat prevention device for a display device, which can automatically and balancedly adjust the rotation speed of a fan of the overheat prevention device to ensure overheating according to different usage environments. Prevent both the device and the display device from being correct in use.

In order to accomplish the above object, the present invention provides an overheat preventing device for a display device, the display device comprising at least one fan, the at least one fan operating at at least an initial rotational speed, the overheat preventing device comprising a first temperature sensing a second temperature sensor and a processing module. The first temperature sensor is configured to sense an ambient temperature and generate a first signal according to the ambient temperature. The second temperature sensor is configured to sense an internal temperature of the display device and generate a second signal according to the internal temperature. The processing module adjusts the at least one fan to the at least one first operating speed by the first signal and the second signal.

Another object of the present invention is to provide a projection apparatus including at least one fan, a first temperature sensor, a second temperature sensor, and a processing module. The at least one fan operates at at least one initial speed. The first temperature sensor is configured to sense an ambient temperature and generate a first signal according to the ambient temperature. The second temperature sensor is configured to sense an internal temperature of the projection device and generate a second signal according to the internal temperature. The processing module adjusts the at least one fan to the at least one first operating speed by the first signal and the second signal.

Through the above content, the present invention can utilize the second sensor of the display device to detect the environment to generate parameters in various environments, and further automatically and balance the fan of the display device through the parameters. Adjustments enable the display device to function properly in a variety of different environments.

Other objects, advantages, and technical means and embodiments of the present invention will become apparent to those skilled in the <RTIgt;

Hereinafter, an overheat preventing device of the present invention will be explained by way of embodiments. It should be noted that the embodiments of the present invention are not intended to limit the invention to any specific environment, application or special mode as described in the embodiments. Therefore, the description of the embodiments is merely illustrative of the invention and is not intended to limit the invention.

Please refer to FIG. 1 , which is a schematic diagram of a display device 1 of the present invention. In the embodiment, the display device 1 is a projection device. However, the display device 1 is not limited thereto. It can be any display device that needs to prevent overheating. The display device 1 includes a fan 11 and an overheat prevention device 13. The overheat prevention device 13 further includes a first temperature sensor 131, a second temperature sensor 133, and a processing module 135 including a memory 137.

First, after the display device 1 is turned on, the fan 11 first operates at an initial rotation speed, and then the first temperature sensor 131 starts to detect an ambient temperature T _i of the environment in which the display device 1 is located, and generates according to the ambient temperature T _i . a first signal 132, and the first signal 132 is transmitted to the processing module 135; and the second temperature sensor 133 detects an internal temperature T _{c of the} display device 1 and generates a second according to the internal temperature T _c The signal 134 is transmitted to the processing module 135. At this time, the processing module 135 adjusts the fan 11 from the initial rotational speed to a first operational rotational speed in response to the first signal 132 and the second signal 134.

In detail, after the power-on, the processing module 135 determines the initial rotation speed of the fan 11 to facilitate heat dissipation during startup, and after the display device 1 operates for a predetermined period of time, the processing module 135 is based on the first The first signal 132 transmitted by the temperature sensor 131 determines the ambient temperature T _i , and determines the internal temperature T _{c of the} display device 1 according to the second signal 134 transmitted by the second temperature sensor 133. Then, the processing module 135 determines the current environmental height of the display device 1 according to the ambient temperature T _i , the internal temperature T _{c ,} and the first correspondence table 136 stored in the memory 137 .

Please refer to Figure 2A first. The first correspondence table 136 includes a first temperature correspondence 1361, a second temperature correspondence 1362, and a third temperature correspondence 1363 regarding the ambient temperature T _i and the internal temperature T _c . Among them, how to judge the height of the environment based on C _ij and I _ij will be explained in the following content. It should be specifically stated that (C ₁₁ , I ₁₁ ), (C ₁₂ , I ₁₂ ), (C ₁₃ , I ₁₃ ), (C ₁₄ , I ₁₄ ) (C ₁₅ , in the first temperature correspondence 1361 I ₁₅ ) generally exhibits a linear relationship, and therefore, for ease of understanding, the first temperature correspondence 1361 is specifically drawn as the line segment 21 in the coordinate map of FIG. 2B. Similarly, the second temperature correspondence 1362 and the third temperature correspondence 1363 are also respectively depicted as line segments 22, 23, which are described later.

First, the processing module 135 first determines the ambient height based on the value of the ambient temperature T _{i based on} the value of the internal temperature T _c . For example, when the processing module 135 determines that the value of the ambient temperature T _i is I ₁ , the processing module 135 determines whether the internal temperature T _c exceeds according to the relationship represented by the first temperature correspondence relationship 1361 (line 21). The first temperature corresponds to the value C ₁₁ corresponding to I _{1 in} the relationship 1361, thereby determining the environmental height. In more detail, if the processing module 135 determines that the value of the internal temperature T _c is less than or equal to C ₁₁ when the value of the ambient temperature T _i is I ₁ , it represents that the environmental height is in the first temperature correspondence relationship. One of the first ambient height ranges R ₁ defined by 1361.

Conversely, if processing module 135 to the value of the ambient temperature T _i of the current I ₁ is determined - T _c of the value of the internal lines is greater than C _11, it represents the height of the ambient environment has exceeded the first height range R _1, at this time The processing module 135 further determines, according to the second temperature correspondence 1362, whether the environmental height is bounded by one of the second environmental height ranges R ₂ defined by the second temperature correspondence 1362.

In more detail, after determining that the environment height has exceeded the first environmental height range R ₁ , the processing module 135 similarly uses the value of the ambient temperature T _i as a reference point, and determines the value according to the internal temperature T _c . Environmental height. For example, when the processing module 135 determines that the value of the ambient temperature T _i is I ₁ and the value of the internal temperature T _c is greater than C ₁₁ , the processing module 135 is represented by the second temperature correspondence 1362 (line 22). The relationship determines whether the value of the internal temperature T _c is less than or equal to C ₂₁ . If yes, it indicates that the environment height is in the second environment height range R ₂ ; if not, the processing module 135 further determines whether the environment height is bounded by the third temperature correspondence 1363 according to the third temperature correspondence 1363. One of the third ambient height ranges R ₃ . Similarly, the subsequent judgment actions are the same as the above-described processes, and are not described herein again.

After the processing module 135 determines the height of the environment, the fan 11 is first adjusted to the first operating speed according to the height of the environment, so that the heat dissipation mode required for the environment in which the display device 1 is located is used. . Next, the processing module 135 determines the rotational speed of the fan 11 to be changed according to the second correspondence table 138 stored in the memory 137 after confirming the environmental height at which the display device 1 is located and the first operational rotational speed.

Specifically, the second correspondence table 138 records the ambient temperature T _c when the display device 1 is in the first environmental height range R ₁ , the second environmental height range R ₂ or the third environmental height range R ₃ , respectively. And the relationship between the first operating speed and the speed of the fan 11 is adjusted from the first operating speed to a second operating speed. In short, the processing module 135 adjusts the rotation speed of the fan 11 according to the ambient temperature T _c represented by the first signal 132 and the second correspondence table 138.

Please refer to Figure 3A first. The second correspondence table 138 includes an ambient temperature T _i and the first operating speed when the display device 1 is in the first environmental height range R ₁ , the second environmental height range R _{2 ,} and the third environmental height range R ₃ , respectively. One of the first speed relationship 1381, a second speed relationship 1382, and a third speed relationship 1383. Similarly, for ease of understanding, the first speed relationship 1381 is drawn as the line segment 31 in the coordinate map of FIG. 3B. Similarly, the second speed relationship 1382 and the third speed relationship 1383 are also drawn as line segments 32 and 33, respectively.俾 Follow-up instructions.

In detail, when the display device 1 is in the first environmental height range R ₁ , the correspondence between the rotational speed of the fan 11 and the ambient temperature T _i is as shown by the first rotational speed relationship 1381 (line segment 31). For example, if the display device 1 is in the first environmental height range R ₁ , when the value of the ambient temperature T _i is equal to I ₆ , the fan 11 is adjusted to operate at the speed of W ₁₂ .

Similarly, when the display device 1 is in the second environmental height range R ₂ , the correspondence between the rotational speed of the fan 11 and the ambient temperature T _i is as shown in the second rotational speed relationship 1382 (line segment 32). For example, if the display device 1 is in the second environmental height range R ₂ , when the value of the ambient temperature T _i is equal to I ₇ , the fan 11 is adjusted to operate at the speed of W ₂₃ . In other cases, the rotation speed of the fan 11 is also adjusted in the same manner, and will not be described here.

It should be particularly emphasized that in order to ensure the operation of the display device 1 more completely, the memory 137 further stores a first upper limit value C _limit . When the ambient temperature T _i exceeds the first upper limit value C _limit , the processing module 135 The display device 1 is stopped according to the first signal 132; the memory 1352 further stores a second upper limit I _limit , and when the internal temperature T _c exceeds the second upper limit I _limit , the processing module 135 responds to the second The signal 134 stops the display device 1. In this way, the display device 1 will be able to utilize the first upper limit value C _limit and the second upper limit value I _{limit to} make the display device 1 obtain more complete overheat protection.

In summary, the display device 1 first determines the height position of the display device 1 by using the ambient temperature T _c , the internal temperature T _{i ,} and the content recorded by the first correspondence table 136, and then based on the height of the display device 1 The rotation speed of the fan 11 is determined based on the ambient temperature T _c and the contents recorded in the second correspondence table 138. In this way, the best balance between temperature and noise can be achieved at a lower cost and higher control accuracy to achieve the effects that were not possible in the prior art.

1. . . Display device

11. . . fan

13. . . Overheat prevention device

131. . . First temperature sensor

132. . . First signal

133. . . Second temperature sensor

134. . . Second signal

135. . . Processing module

136. . . First correspondence table

1361. . . First temperature correspondence

1362. . . Second temperature correspondence

1363. . . Third temperature correspondence

137. . . Memory

138. . . Second correspondence table

1381. . . First speed relationship

1382. . . Second speed relationship

1383. . . Third speed relationship

Figure 1 is a schematic view of a display device of the present invention;

2A is a first correspondence table of the present invention;

2B is a coordinate diagram of a first correspondence table of the present invention;

Figure 3A is a second correspondence table of the present invention;

Figure 3B is a graph of a second correspondence table of the present invention.

1. . . Display device

11. . . fan

13. . . Overheat prevention device

131. . . First temperature sensor

132. . . First signal

133. . . Second temperature sensor

134. . . Second signal

135. . . Processing module

137. . . Memory

Claims (8)

An overheat prevention device for a display device, the display device comprising at least one fan, the overheat prevention device comprising: a first temperature sensor for sensing an ambient temperature; and a second temperature sensor for Sensing an internal temperature of the display device; a memory for storing the first correspondence table of the ambient temperature and the internal temperature, the first correspondence table includes a first temperature correspondence; and a processing a module, configured to determine a first internal temperature threshold according to the first temperature correspondence table, and determine whether the internal temperature exceeds the first internal temperature threshold based on the ambient temperature as a reference point, and according to the determination result Adjusting the rotational speed of the at least one fan. The device of claim 1, wherein the first correspondence table stored in the memory further comprises a second temperature correspondence, and the processor is further configured to determine a second internal location according to the second temperature correspondence. a threshold value of the temperature, and increasing the rotation speed of the at least one fan when determining that the internal temperature exceeds the first internal temperature threshold, and decreasing the rotation speed of the at least one fan when determining that the internal temperature is lower than the second internal temperature threshold . The overheat prevention device of claim 1, wherein the memory further stores a first upper limit value, and when the ambient temperature exceeds the first upper limit value, the processing module stops the display device. The overheat prevention device of claim 1, wherein the memory further stores a second upper limit value, and when the internal temperature exceeds the second upper limit value, the processing module stops the display device. A projection device comprising: at least one fan; a first temperature sensor for sensing an ambient temperature; and a second temperature sensor for sensing an internal temperature of the projection device; a memory, a first correspondence table for storing the ambient temperature and the internal temperature, the first correspondence table includes a first temperature correspondence relationship; and a processing module, configured to determine, according to the first temperature correspondence table The first internal temperature threshold value is determined based on whether the internal temperature exceeds the first internal temperature threshold value when the ambient temperature is a reference point, and the rotation speed of the at least one fan is adjusted according to the determination result. The projection device of claim 5, wherein the first correspondence table stored in the memory further comprises a second temperature correspondence, and the processor is further configured to determine a second internal temperature according to the second temperature correspondence. The threshold value is increased, and the rotation speed of the at least one fan is increased when it is determined that the internal temperature exceeds the first internal temperature threshold, and the rotation speed of the at least one fan is decreased when it is determined that the internal temperature is lower than the second internal temperature threshold. The projection device of claim 5, further comprising a power supply circuit, wherein the memory further stores a first upper limit value, and when the ambient temperature exceeds the first upper limit value, the processing module controls the power supply circuit The projector is stopped. The projection device of claim 5, further comprising a power supply circuit, wherein the memory further stores a second upper limit value, and when the internal temperature exceeds the second upper limit value, the processing module controls the power supply circuit The projector is stopped.