CN115225878A

CN115225878A - Projection equipment and control method of digital micromirror device thereof

Info

Publication number: CN115225878A
Application number: CN202210978941.7A
Authority: CN
Inventors: 崔荣荣
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2022-10-21

Abstract

The application discloses a projection device and a control method of a digital micro-mirror device of the projection device, and the method can detect the actual measurement temperature of the digital micro-mirror device through a temperature sensor in the process that light beams emitted by a light source irradiate the digital micro-mirror device, and can increase the rotating speed of a fan when the actual measurement temperature is larger than or equal to a temperature threshold value so as to reduce the temperature of the digital micro-mirror device. And after the rotating speed of the fan reaches the rotating speed threshold value, if the actually measured temperature of the digital micro-mirror device is still larger than or equal to the temperature threshold value, the rotating speed of the fan can be kept at the rotating speed threshold value, and the brightness of the light beam emitted by the light source is reduced. Therefore, the temperature of the digital micro-mirror device can be further reduced, so that the device in the digital micro-mirror device is prevented from being broken down due to high temperature, and the display effect of the projection equipment is effectively ensured.

Description

Projection equipment and control method of digital micro-mirror device thereof

Technical Field

The present disclosure relates to the field of projection display technologies, and in particular, to a projection device and a method for controlling a Digital Micromirror Device (DMD) of the projection device.

Background

Laser projection devices typically include a laser light source, a display control chip (e.g., a digital light processing chip), a DMD, and a projection lens. The DMD is used for modulating laser beams emitted by the laser light source into image beams based on control signals output by the display control chip, and the projection lens is used for projecting the image beams onto a projection screen.

The DMD comprises a plurality of micro mirrors arranged in an array and a plurality of hinges connected with the micro mirrors in a one-to-one correspondence mode, and each hinge is used for controlling the micro mirrors connected with the hinge to turn over so as to modulate laser beams. Since the DMD is heated by the laser beam for a long time, the hinge in the DMD is prone to malfunction (e.g., deform or break) at high temperature, which may affect the display effect of the laser projection device.

Disclosure of Invention

The application provides a projection device and a control method of a digital micromirror device thereof, which can solve the problem of poor display effect of the projection device in the related art. The technical scheme is as follows:

in one aspect, a method for controlling a digital micromirror device of a projection apparatus is provided, the projection apparatus further comprising: a temperature sensor, a fan and a light source; the method comprises the following steps:

acquiring the actual measurement temperature of the digital micromirror device acquired by the temperature sensor in the process of irradiating the digital micromirror device by the light beam emitted by the light source;

if the measured temperature is determined to be greater than or equal to the temperature threshold, increasing the rotating speed of the fan;

if the actual measurement temperature is still greater than or equal to the temperature threshold value after the rotating speed of the fan reaches the rotating speed threshold value, the rotating speed threshold value of the fan is kept, and the brightness of the light beam emitted by the light source is reduced;

and controlling the digital micro-mirror device to modulate the light beam emitted by the light source into a projection image.

In another aspect, a projection apparatus is provided, the projection apparatus comprising: the system comprises a main control circuit, a digital micro-mirror device, a temperature sensor, a fan and a light source;

the temperature sensor is used for detecting the actually measured temperature of the digital micromirror device in the process that the light beam emitted by the light source irradiates the digital micromirror device;

the master control circuit is configured to:

if the fact that the measured temperature is larger than or equal to the temperature threshold value is determined, increasing the rotating speed of the fan;

if the actually measured temperature is still larger than or equal to the temperature threshold value after the rotating speed of the fan reaches the rotating speed threshold value, keeping the rotating speed threshold value of the fan, and reducing the brightness of the light beam emitted by the light source;

In still another aspect, a projection apparatus is provided, which includes a processor and a memory, where the memory stores instructions that are loaded and executed by the processor to implement the control method of the digital micromirror device according to the above aspect.

In still another aspect, a computer-readable storage medium is provided, in which a computer program is stored, the computer program being loaded by the processor and executing the control method of the digital micromirror device according to the above aspect.

In still another aspect, a computer program product containing instructions is provided, which when run on a computer causes the computer to execute the method for controlling a digital micro-mirror device according to the above aspect.

The beneficial effect that technical scheme that this application provided brought includes at least:

the application provides a projection device and a control method of a digital micro-mirror device thereof, and the method can detect the actual measurement temperature of the digital micro-mirror device through a temperature sensor in the process that a light beam emitted by a light source irradiates the digital micro-mirror device, and can increase the rotating speed of a fan when the actual measurement temperature is larger than or equal to a temperature threshold value so as to reduce the temperature of the digital micro-mirror device. And after the rotating speed of the fan reaches the rotating speed threshold value, if the actually measured temperature of the digital micro-mirror device is still greater than or equal to the temperature threshold value, the rotating speed of the fan can be kept at the rotating speed threshold value, and the brightness of the light beam emitted by the light source is reduced. Therefore, the temperature of the digital micro-mirror device can be further reduced, so that the device in the digital micro-mirror device is prevented from being broken down due to high temperature, and the display effect of the projection equipment is effectively ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a projection apparatus provided in an embodiment of the present application;

fig. 2 is a schematic flowchart illustrating a method for controlling a digital micromirror device of a projection apparatus according to an embodiment of the present application;

fig. 3 is a schematic flowchart of another control method for a digital micromirror device according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a digital micromirror device according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a temperature sensor according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a projection apparatus provided in an embodiment of the present application, and referring to fig. 1, the projection apparatus may include a main control circuit 10, a light source 20, a digital micro-mirror device 30, and a projection lens 40.

Referring to fig. 1, the main control circuit 10 is connected to a light source 20 and a digital micromirror device 30, respectively. The main control circuit 10 is capable of receiving image data of a projected image to be projected and displayed and processing the image data of the projected image. Thereafter, the main control circuit 10 can transmit the processed image data to the digital micro mirror device 30 and output a driving current signal to the light source 20 based on the processed image data.

The main control circuit 10 may be a Digital Light Processing (DLP) chip. For example, the master control circuit 10 may be a DLPC chip. Alternatively, the main control circuit 10 may be a Micro Controller Unit (MCU), i.e., a single chip microcomputer.

The light source 20 is used for emitting light under the driving of the driving current signal output by the main control circuit 10. The digital micro-mirror device 30 is configured to modulate a light beam emitted from the light source 20 based on the image data output by the main control circuit 10 to obtain a projection image to be projected and displayed. The projection lens 40 may further project the projection image to be projected and displayed to a projection screen. The light source 20 may be a laser light source or other types of light sources such as a light-emitting diode (LED).

With continued reference to fig. 1, the projection device may further include a temperature sensor 50 and at least one fan 60. The temperature sensor 50 is connected to the main control circuit 10 and the digital micromirror device 30, respectively. The temperature sensor 50 is configured to detect a measured temperature of the digital micromirror device 30 and transmit the measured temperature of the digital micromirror device 30 to the main control circuit 10.

The main control circuit 10 is also connected to at least one fan 60, and the ventilation opening of the at least one fan 60 can be connected to the dmd 30. The main control circuit 10 can also control the operating status of the at least one fan 60 (e.g., adjust the rotation speed of the fan 60) based on the measured temperature of the dmd 30 transmitted by the temperature sensor 50, so as to adjust the temperature of the dmd 30.

Fig. 2 is a flowchart illustrating a method for controlling a digital micromirror device of a projection apparatus according to an embodiment of the present application, where the method can be applied to a main control circuit of the projection apparatus, such as the main control circuit 10 in the projection apparatus shown in fig. 1. Referring to fig. 1, the projection apparatus further includes: a temperature sensor 50, a fan 60, and a light source 20. As shown in fig. 2, the method includes:

step 101, in the process that a light beam emitted by a light source irradiates the digital micro-mirror device, acquiring the measured temperature of the digital micro-mirror device acquired by a temperature sensor.

In this embodiment, the master control circuit can provide a driving signal to the light source to drive the light source to emit a light beam. And the light beam emitted by the light source can irradiate the digital micro-mirror device. In the process that light beams emitted by the light source irradiate the digital micromirror device, the temperature sensor can detect the actually measured temperature of the digital micromirror device, and the main control circuit can further acquire the actually measured temperature of the digital micromirror device. The process of the main control circuit acquiring the measured temperature of the digital micromirror device can also be referred to as a process of reading the measured temperature. Wherein the measured temperature of the digital micromirror device may be a temperature inside the digital micromirror device.

For example, the digital micromirror device may include a substrate, a plurality of micromirrors disposed on the substrate, and a plurality of hinges connected to the micromirrors in a one-to-one correspondence, each hinge for controlling the turning of one of the micromirrors connected thereto. The measured temperature may be a temperature of an area of the substrate where the plurality of hinges are located. That is, the measured temperature may be a temperature of a hinge in the digital micromirror device.

Alternatively, the temperature sensor may detect the measured temperature of the digital micromirror device in real time. The main control circuit may also obtain the measured temperature of the digital micromirror device in real time, or the main control circuit may periodically obtain the measured temperature of the digital micromirror device. For example, the main control circuit may obtain the measured temperature of the digital micromirror device every 15 minutes.

And 102, if the measured temperature is determined to be greater than or equal to the temperature threshold value, increasing the rotating speed of the fan.

Wherein the temperature threshold may be a temperature value determined based on a withstand temperature of the digital micromirror device. For example, the temperature threshold may be less than or equal to the withstand temperature, which may be 70 degrees celsius (° c). When the measured temperature of the dmd is greater than or equal to the temperature threshold, a device (e.g., a hinge) inside the dmd may malfunction (e.g., deform or break) due to an excessively high temperature, thereby affecting the effect of the dmd on modulating the image beam.

In this embodiment, after the main control circuit obtains the measured temperature of the digital micromirror device, it may be detected whether the measured temperature is greater than or equal to a temperature threshold. If the main control circuit determines that the measured temperature is greater than or equal to the temperature threshold value, the rotating speed of the fan can be increased. The fan can radiate the heat of the digital micromirror device through the ventilation opening in the rotating process, so that the effect of radiating the digital micromirror device is achieved. Therefore, the temperature of the digital micro-mirror device can be effectively reduced.

And 103, if the actually measured temperature is still greater than or equal to the temperature threshold value after the rotating speed of the fan reaches the rotating speed threshold value, keeping the rotating speed threshold value of the fan and reducing the brightness of the light beam emitted by the light source.

Wherein the threshold rotational speed may be a maximum rotational speed of the fan. Alternatively, the rotational speed threshold may be a rotational speed determined based on the magnitude of noise generated during the rotation of the fan. When the rotating speed of the fan reaches the rotating speed threshold, the main control circuit can acquire the measured temperature of the digital micromirror device detected by the temperature sensor again and detect whether the measured temperature is greater than or equal to the temperature threshold. If the main control circuit determines that the actually measured temperature is still larger than or equal to the temperature threshold, the rotating speed of the fan can be kept at the rotating speed threshold, and the brightness of the light beam emitted by the light source is reduced. If the main control circuit determines that the actually measured temperature of the digital micromirror device is smaller than the temperature threshold, the brightness of the light beam emitted by the light source does not need to be reduced, and only the rotating speed of the fan is kept at the rotating speed threshold.

It is understood that when the rotation speed of the fan reaches the threshold rotation speed, the main control circuit may determine that the rotation speed of the fan cannot be increased any more, or if the rotation speed is increased any more, the noise of the projection device may be too high. Therefore, the main control circuit can continuously cool the digital micromirror device in a manner of reducing the brightness of the light beam emitted by the light source.

It will also be appreciated that when a light beam from a light source in a projection device is directed onto a digital micromirror device, the brightness of the light beam may affect the temperature of the digital micromirror device. For example, the temperature of the dmd may decrease as the brightness of the light beam emitted by the light source decreases. Therefore, the main control circuit can further reduce the temperature of the digital micro-mirror device by reducing the brightness of the light beam emitted by the light source.

And 104, controlling the digital micro-mirror device to modulate the light beam emitted by the light source into a projection image.

In the embodiment of the present application, the main control circuit can output image data of a projected image to be projected and displayed to the digital micromirror device. After receiving the image data, the digital micromirror device can modulate the light beam emitted by the light source to obtain a projection image to be projected and displayed. The projection image can be projected to a projection screen through a projection lens of the projection device.

It can be understood that the main control circuit cools the digital micromirror device by increasing the rotation speed of the fan and decreasing the brightness of the light beam emitted by the light source, so that the temperature of the digital micromirror device is lower than the temperature threshold. Therefore, the performance of each device in the digital micromirror device can be ensured, the service life of each device in the digital micromirror device is prolonged, the effect of modulating the image light beam by the digital micromirror device can be further ensured, and the display effect of the projection equipment is effectively improved.

In summary, the embodiments of the present application provide a method for controlling a digital micromirror device of a projection apparatus. The method can detect the actual measurement temperature of the digital micro-mirror device through the temperature sensor in the process that the light beam emitted by the light source irradiates the digital micro-mirror device, and can increase the rotating speed of the fan when the actual measurement temperature is larger than or equal to the temperature threshold value so as to reduce the temperature of the digital micro-mirror device. And after the rotating speed of the fan reaches the rotating speed threshold value, if the actually measured temperature of the digital micro-mirror device is still larger than or equal to the temperature threshold value, the rotating speed of the fan can be kept at the rotating speed threshold value, and the brightness of the light beam emitted by the light source is reduced. Therefore, the temperature of the digital micro-mirror device can be further reduced, so that the device in the digital micro-mirror device is prevented from being broken down due to high temperature, and the display effect of the projection equipment is effectively ensured.

Fig. 3 is a flowchart illustrating a control method for a digital micromirror device of a projection apparatus according to another embodiment of the present application, where the method can be applied to a main control circuit of the projection apparatus, such as the main control circuit 10 in the projection apparatus shown in fig. 1. Referring to fig. 1, the projection apparatus further includes: a temperature sensor 50, a fan 60, and a light source 20. As shown in fig. 3, the method includes:

step 201, in the process that the light beam emitted by the light source irradiates the digital micromirror device, the measured temperature of the digital micromirror device, which is acquired by the temperature sensor, is acquired.

In this embodiment, the master control circuit can provide a driving signal to the light source to drive the light source to emit a light beam. And the light beam emitted by the light source can irradiate the digital micro-mirror device. In the process that light beams emitted by the light source irradiate the digital micromirror device, the temperature sensor can detect the actually measured temperature of the digital micromirror device, and the main control circuit can further acquire the actually measured temperature of the digital micromirror device detected by the temperature sensor. The process of the main control circuit acquiring the measured temperature of the digital micromirror device can also be referred to as a process of reading the measured temperature. Wherein the measured temperature of the digital micromirror device may be a temperature inside the digital micromirror device.

For example, the digital micromirror device may include a substrate, a plurality of micromirrors located on the substrate, and a plurality of hinges connected to the micromirrors in a one-to-one correspondence, each hinge for controlling the turning of one of the micromirrors connected thereto. The measured temperature may be a temperature of an area of the substrate where the plurality of hinges are located. That is, the measured temperature may be a temperature of a hinge in the digital micromirror device.

Step 202, detecting whether the measured temperature is greater than or equal to a temperature threshold.

Wherein the temperature threshold may be a temperature value determined based on a withstand temperature of the digital micromirror device. For example, the temperature threshold may be less than or equal to the withstand temperature, which may be 70 ℃. When the measured temperature of the dmd is greater than or equal to the temperature threshold, a device (e.g., a hinge) inside the dmd may malfunction (e.g., deform or break) due to the excessively high temperature, thereby affecting the effect of the dmd in modulating the image beam.

In this embodiment, after the main control circuit obtains the measured temperature of the digital micromirror device, it may be detected whether the measured temperature is greater than or equal to a temperature threshold. If the main control circuit determines that the measured temperature is greater than or equal to the temperature threshold, the following step 203 may be executed. If the main control circuit determines that the measured temperature is less than the temperature threshold, it may be determined that the digital micromirror device does not need to be cooled, and the step 201 may be continuously performed, that is, the measured temperature of the digital micromirror device is continuously obtained.

And step 203, detecting whether the rotating speed of the fan reaches a rotating speed threshold value.

Wherein the rotational speed threshold may be a maximum rotational speed of the fan. Alternatively, the rotational speed threshold may be a rotational speed determined based on the magnitude of noise generated during the rotation of the fan.

Alternatively, if the rotation speed threshold is a rotation speed determined based on the magnitude of the noise generated during the rotation of the fan, the rotation speed threshold may be determined based on the noise threshold and the corresponding relationship between the rotation speed of the fan and the noise.

Wherein the noise threshold may be determined based on the noise that the user is able to withstand during use of the projection device. When the rotating speed of the fan is smaller than the rotating speed threshold value, the noise generated by the fan in the rotating process is also smaller than the noise threshold value. For example, the noise threshold may be 36 decibels (dB).

In step 202, if the main control circuit detects that the measured temperature of the dmd is greater than or equal to the temperature threshold, it may detect whether the rotation speed of the fan reaches the rotation speed threshold. If the main control circuit detects that the rotation speed of the fan does not reach the rotation speed threshold, it may be determined that the digital micromirror device can be cooled by adjusting the rotation speed of the fan, and the following step 204 is executed. If the main control circuit detects that the rotation speed of the fan reaches the rotation speed threshold, it may be determined that the rotation speed of the fan cannot be increased any more, or if the rotation speed is increased any more, the noise of the projection device may be too high. Therefore, the main control circuit can execute the following step 205 to continue cooling the digital micromirror device by other means.

And step 204, increasing the rotating speed of the fan.

In step 203, if the main control circuit detects that the rotation speed of the fan does not reach the rotation speed threshold, it can be determined that the digital micro-mirror device can be cooled by adjusting the rotation speed of the fan, so that the rotation speed of the fan can be increased. The fan can radiate the heat of the digital micromirror device through the ventilation opening in the rotating process, so that the effect of radiating the digital micromirror device is achieved. Therefore, the temperature of the digital micro-mirror device can be effectively reduced.

And step 205, keeping the fan at the rotating speed threshold, and determining the brightness adjustment quantity of the projection image projected by the projection equipment based on the difference value between the measured temperature of the digital micro-mirror device and the temperature threshold.

In step 203, if the main control circuit detects that the rotation speed of the fan reaches the rotation speed threshold, the rotation speed of the fan may be maintained at the rotation speed threshold. And the main control circuit can determine the brightness adjustment quantity of the projection image projected by the projection equipment based on the difference value between the measured temperature of the digital micro-mirror device and the temperature threshold value.

Wherein, the brightness adjustment amount Δ L may satisfy:

where Δ T is a temperature adjustment amount of the digital micromirror device, the Δ T may be determined based on a difference between a measured temperature of the digital micromirror device and a temperature threshold. For example, the Δ T may be greater than or equal to a difference between a measured temperature of the digital micromirror device and a temperature threshold. C is the conversion constant of the brightness of the light beam emitted by the light source and the thermal power of the digital micro-mirror device, and R is the thermal resistance constant of the digital micro-mirror device.

It is understood that when a light beam emitted from a light source in a projection apparatus is irradiated onto a digital micromirror device, the brightness of the light beam affects the temperature of the digital micromirror device. For example, the temperature of the dmd may decrease as the brightness of the light beam emitted by the light source decreases. Therefore, the main control circuit can further reduce the temperature of the digital micro-mirror device by reducing the brightness of the light beam emitted by the light source. Wherein, the brightness of the light beam emitted by the light source is positively correlated with the brightness adjustment quantity of the projection image projected by the projection equipment. Therefore, the main control circuit can determine the brightness adjustment quantity of the projection image projected by the projection equipment based on the adjustment quantity of the temperature of the digital micro-mirror device, and further determine the adjustment quantity of the brightness of the light beam emitted by the light source, so that the temperature of the digital micro-mirror device is further reduced.

And step 206, determining the current adjustment quantity of the driving current of the light source according to the brightness adjustment quantity of the projection image projected by the projection equipment.

In the embodiment of the present application, a corresponding relationship between an adjustment amount of luminance of a projection image projected by a projection device and a current adjustment amount of a driving current of a light source is stored in a main control circuit in advance. The correspondence may be determined before the projection device leaves a factory and stored in the projection device. Wherein the brightness adjustment amount of the projected image projected by the projection apparatus may be positively correlated with the current adjustment amount of the driving current of the light source. The main control circuit can determine the current adjustment amount of the driving current of the light source based on the corresponding relation after determining the brightness adjustment amount of the projection image projected by the projection equipment.

And step 207, adjusting the driving current of the light source according to the current adjustment quantity.

In this embodiment, the main control circuit can reduce the driving current of the light source according to the current adjustment amount, so that the driving current of the light source is the target current. And the difference value between the target current and the driving current of the light source before adjustment is a current adjustment amount.

It can be understood that, since the current adjustment amount is determined based on the difference between the measured temperature of the digital micromirror device and the temperature threshold, when the light source is driven to emit the light beam by using the target driving current, the temperature of the digital micromirror device will also decrease to or below the temperature threshold, thereby implementing the temperature reduction process for the digital micromirror device.

And step 208, controlling the digital micro-mirror device to modulate the light beam emitted by the light source into a projection image.

It can also be understood that, the order of the steps of the control method for the digital micromirror device of the projection apparatus provided in the embodiment of the present application may be appropriately adjusted, and the steps may also be correspondingly increased or decreased according to the situation. For example, step 206 may be deleted as appropriate. That is, the main control circuit may directly determine the current adjustment amount of the driving current of the light source based on the difference between the measured temperature of the digital micromirror device and the temperature threshold. Those skilled in the art can easily conceive of various methods within the technical scope of the present disclosure, and therefore, the detailed description is omitted.

In summary, the embodiments of the present application provide a method for controlling a digital micromirror device of a projection apparatus. The method can detect the actually measured temperature of the digital micromirror device through the temperature sensor, and can increase the rotating speed of the fan when the actually measured temperature is greater than or equal to the temperature threshold value so as to reduce the temperature of the digital micromirror device. And after the rotating speed of the fan reaches the rotating speed threshold value, if the actually measured temperature of the digital micro-mirror device is still larger than or equal to the temperature threshold value, the rotating speed of the fan can be kept at the rotating speed threshold value, and the brightness of the light beam emitted by the light source is reduced. Therefore, the temperature of the digital micro-mirror device can be further reduced, so that the device in the digital micro-mirror device is prevented from being broken down due to high temperature, and the display effect of the projection equipment is effectively ensured.

Fig. 4 is a schematic structural diagram of a projection apparatus provided in an embodiment of the present application, and with reference to fig. 4, the projection apparatus includes: a main control circuit 10, a digital micro-mirror device 30, a temperature sensor 50, a fan 60 and a light source 20.

The temperature sensor 50 is used for detecting the measured temperature of the digital micro-mirror device 30 during the process that the light beam emitted by the light source 20 irradiates the digital micro-mirror device 30. The main control circuit 10 is configured to increase the rotation speed of the fan 60 if it is determined that the measured temperature is greater than or equal to the temperature threshold, maintain the rotation speed threshold of the fan 60 and reduce the brightness of the light beam emitted by the light source 20 if the measured temperature is still greater than or equal to the temperature threshold after the rotation speed of the fan 60 reaches the rotation speed threshold, and control the digital micro-mirror device 30 to modulate the light beam emitted by the light source 20 into a projection image.

In the embodiment of the present application, the main control circuit 10 can provide a driving signal to the light source 20 to drive the light source 20 to emit a light beam. And, the light beam emitted from the light source 20 can be irradiated to the digital micro-mirror device 30. In the process that the light beam emitted from the light source 20 irradiates the digital micro-mirror device 30, the temperature sensor 50 can detect the measured temperature of the digital micro-mirror device 30, and the main control circuit 10 can further acquire the measured temperature of the digital micro-mirror device 30 detected by the temperature sensor 50. Wherein the measured temperature of the digital micromirror device 30 can be a temperature inside the digital micromirror device 30.

Alternatively, the temperature sensor 50 may detect the measured temperature of the digital micromirror device 30 in real time. The main control circuit 10 may also obtain the measured temperature of the digital micro-mirror device 30 detected by the temperature sensor 50 in real time, or the main control circuit 10 may periodically obtain the measured temperature of the digital micro-mirror device 30 detected by the temperature sensor 50. For example, the main control circuit 10 may obtain the measured temperature of the digital micromirror device 10 every 15 minutes.

The main control circuit 10 may detect whether the measured temperature is greater than or equal to the temperature threshold after acquiring the measured temperature of the digital micromirror device 30 detected by the temperature sensor 50. If the main control circuit 10 determines that the measured temperature is greater than or equal to the temperature threshold, the rotation speed of the fan 60 can be increased. The fan 60 can dissipate heat of the dmd 30 through the ventilation opening during the rotation process, thereby dissipating heat of the dmd 30. Thereby, the temperature of the digital micromirror device 30 can be effectively reduced.

Wherein the temperature threshold may be a temperature value determined based on a withstand temperature of the digital micromirror device 30. For example, the temperature threshold may be less than or equal to the withstand temperature, which may be 70 ℃. When the measured temperature of the dmd 30 is greater than or equal to the temperature threshold, a device (e.g., a hinge) inside the dmd 30 may malfunction due to an excessively high temperature, thereby affecting the effect of the dmd 30 to modulate the image beam. Therefore, the main control circuit 10 can reduce the temperature of the digital micromirror device 30 by increasing the rotation speed of the fan 60 to ensure the performance of each device in the digital micromirror device 30.

After increasing the rotation speed of the fan 60, if it is determined that the rotation speed of the fan 60 reaches the threshold rotation speed, the main control circuit 10 may obtain the measured temperature of the digital micro-mirror device 30 detected by the temperature sensor 50 again, and detect whether the measured temperature is greater than or equal to the threshold temperature. If the main control circuit 10 determines that the measured temperature is still greater than or equal to the temperature threshold, the rotation speed maintained by the fan 60 can be maintained at the rotation speed threshold, and the brightness of the light beam emitted by the light source 20 can be reduced. If the main control circuit 10 determines that the measured temperature of the digital micromirror device 30 is less than the temperature threshold, it is only necessary to keep the rotation speed of the fan 60 at the rotation speed threshold without reducing the brightness of the light beam emitted by the light source 20.

The threshold rotation speed of the fan 60 may be a maximum rotation speed of the fan. Alternatively, the threshold rotational speed may be a rotational speed determined based on the amount of noise generated during the rotation of the fan 60. Alternatively, if the rotation speed threshold value may be a rotation speed determined based on the magnitude of noise generated during the rotation of the fan 60, the rotation speed threshold value may be determined based on the noise threshold value and the corresponding relationship between the rotation speed of the fan 60 and the noise.

It is understood that when the rotation speed of the fan 60 reaches the rotation speed threshold, the main control circuit 10 may determine that the rotation speed of the fan 60 cannot be increased any more, or if the rotation speed is increased any more, the noise of the projection apparatus may be too high. Therefore, the main control circuit 10 can continue to cool the digital micromirror device 30 by decreasing the brightness of the light beam emitted from the light source 20.

It is also understood that when a light beam emitted from the light source 20 in the projection apparatus is irradiated onto the dmd 30, the brightness of the light beam may affect the temperature of the dmd 30. For example, the temperature of the dmd 30 may decrease as the brightness of the light beam emitted by the light source 20 decreases. Therefore, the main control circuit 10 can further lower the temperature of the dmd 30 by reducing the brightness of the light beam emitted from the light source 20.

The main control circuit 10 can output image data of a projection image to be projection-displayed to the digital micromirror device 30 while reducing the brightness of the light beam emitted from the light source 20. The digital micromirror device 30, upon receiving the image data, can modulate the light beam emitted from the light source 20 to obtain a projected image to be projected and displayed. The projection image can be projected to a projection screen through a projection lens.

It is understood that the main control circuit 10 cools the digital micro-mirror device 30 by increasing the rotation speed of the fan 60 and decreasing the brightness of the light beam emitted from the light source 20, so that the temperature of the digital micro-mirror device 30 is lower than the temperature threshold. Therefore, the performance of each device in the digital micromirror device 30 can be ensured, the service life of each device in the digital micromirror device 30 is prolonged, the effect of modulating the image light beam by the digital micromirror device 30 can be further ensured, and the display effect of the projection equipment is effectively improved.

Optionally, the main control circuit 10 is configured to:

based on the difference between the measured temperature of the digital micromirror device 30 and the temperature threshold, the brightness adjustment amount of the projected image projected by the projection equipment is determined. The brightness of the light beam emitted by the light source 20 is adjusted based on the brightness adjustment amount.

In this embodiment, if the main control circuit 30 detects that the rotation speed of the fan 60 reaches the rotation speed threshold and the measured temperature of the digital micro-mirror device 30 is greater than or equal to the temperature threshold, the rotation speed of the fan 60 may be maintained at the rotation speed threshold, and the brightness adjustment amount of the projection image projected by the projection apparatus is determined based on the difference between the measured temperature of the digital micro-mirror device 30 and the temperature threshold.

Wherein, the brightness adjustment amount Δ L may satisfy:

where Δ T is an adjustment amount of the measured temperature of the digital micromirror device, the Δ T may be determined based on a difference between the measured temperature of the digital micromirror device 30 and a temperature threshold, for example, the Δ T may be greater than a difference between the measured temperature of the digital micromirror device 30 and the temperature threshold. C is a conversion constant of the luminance of the light beam emitted from the light source 20 and the thermal power of the dmd 30, and R is a thermal resistance constant of the dmd 30.

It will be appreciated that the brightness of the light beam emitted by the light source 20 is positively correlated to the amount of brightness adjustment of the projected image projected by the projection device. Therefore, the main control circuit 10 can determine the brightness adjustment amount of the projection image projected by the projection apparatus based on the adjustment amount of the temperature of the digital micro-mirror device 30, and further determine the adjustment amount of the brightness of the light beam emitted by the light source 20, thereby further reducing the temperature of the digital micro-mirror device 30.

Optionally, after determining the brightness adjustment amount of the light source 20, the main control circuit 10 may further determine a current adjustment amount of the driving current of the light source 20. Then, the main control circuit 10 may adjust the driving current of the light source 20 according to the current adjustment amount. That is, the main control circuit 10 adjusts the brightness of the light beam emitted from the light source 20 by adjusting the driving current of the light source 20.

Fig. 5 is a schematic structural diagram of a digital micromirror device according to an embodiment of the present application, and referring to fig. 5, the digital micromirror device 30 may include: the micro-mirror device includes a substrate 31, a plurality of micro-mirrors 32 disposed on the substrate, and a plurality of hinges 33 connected to the micro-mirrors 32 in a one-to-one correspondence.

Wherein each hinge 33 is used to control the turning of one micromirror 32 connected thereto. The temperature sensor 50 is used to detect the temperature of the region of the substrate 31 where the plurality of hinges 33 are located. That is, the measured temperature detected by the temperature sensor 50 is the temperature of the plurality of hinges 33 in the digital micromirror device 30. The temperature threshold may be determined based on a tolerance temperature of the plurality of hinges 33.

It is understood that the plurality of micro-mirrors 32 in the digital micro-mirror device 30 correspond one-to-one to a plurality of pixels in a projected image to be projected by the projection apparatus. When the light beam projected by the light source 20 is irradiated to the plurality of micro mirrors 32 on the digital micro mirror device 30, the plurality of hinges 33 may control the plurality of micro mirrors 32 to be flipped based on image data of the projection image to be displayed.

When the temperature of the region where the plurality of hinges 33 in the digital micromirror device 30 is located exceeds a temperature threshold, the hinges 33 can be caused to malfunction. For example, the hinge 33 has a fracture failure. Or the hinge 33 is not broken and deformed so that the hinge 33 cannot control the turning of the micromirror 32 connected thereto based on the image data, which failure may also be referred to as a hinge failure. When the hinge 33 fails, the hinge 33 cannot control the micro mirror 32 connected thereto to flip based on the change of the image data, thereby causing the pixel corresponding to the micro mirror 32 to fail. The pixel failure means that part of pixel points in the projected image are white points, black points or flash points. Pixel failures that are readily apparent to the human eye are white point failures. When the white point fault occurs in the projected image, the display effect of the projected image is seriously affected.

Therefore, in the embodiment of the present application, the temperature sensor 50 may be used to detect the temperature of the area where the plurality of hinges 33 are located on the substrate 31 of the digital micromirror device 30, and the temperature of the area where the plurality of hinges 33 are located is greater than the temperature threshold, so as to cool the digital micromirror device 30, thereby avoiding the plurality of hinges 33 from malfunctioning, and prolonging the service life of the plurality of hinges 33.

With continued reference to fig. 4, the temperature sensor 50 may include: a sense diode 51 and a temperature sense chip 52. Wherein the detection diode 51 is located on the substrate 32 of the digital micro-mirror device 30 at the area where the plurality of hinges 33 are located. The temperature detection chip 52 is located outside the substrate 31.

As shown in FIG. 6, the first test pin D + of the temperature test chip 52 is connected to the first terminal TEMP _ P of the test diode 51, and the second test pin D-of the temperature test chip 52 is connected to the second terminal TEMP _ N of the test diode 51.

In the embodiment of the present application, the sensing diode 51 is used for sensing the measured temperature of the area of the substrate 31 where the plurality of hinges 33 are located in the dmd 30 and transmitting the measured temperature to the first sensing pin D + and the second sensing pin D-of the temperature sensing chip 52 in the form of differential signals. The temperature sensing chip 52 can process the differential signal to determine the measured temperature of the digital micromirror device 30.

For example, the temperature detecting chip 52 may be a TMP411 chip. The TMP411 may communicate with the main control circuit 10 through an inter-integrated circuit (I2C) bus. The I2C bus includes a serial data line (SDA) and a Serial Clock Line (SCL). Referring to fig. 6, the SDA terminal of the temperature detection chip 52 may be connected to the SDA terminal of the master control circuit 10, and the SCL terminal of the temperature detection chip 52 may be connected to the SCL terminal of the master control circuit 10. The temperature detection chip 52 can send the measured temperature of the digital micro-mirror device 30 to the SDA end of the main control circuit 10 through the SDA end, so that the main control circuit 10 performs further processing based on the measured temperature.

Optionally, with continued reference to fig. 6, the temperature sensor 50 may further include: the circuit comprises a first resistor R1, a second resistor R2 and a matching capacitor C1.

As shown in FIG. 6, the first resistor R1 is connected in series between the first sensing pin D + and the first terminal TEMP _ P of the sensing diode 51, and the second resistor R2 is connected in series between the second sensing pin D-and the second terminal TEMP _ N of the sensing diode 51. One end of the matching capacitor C1 is connected to the first end TEMP _ P of the sensing diode 51, and the other end of the matching capacitor C1 is connected to the second end TEMP _ N of the sensing diode 51.

The first resistor R1 and the second resistor R2 are used for impedance matching, and are coupled to the matching capacitor C1 to ensure the integrity of the differential signal in the transmission process, so that remote acquisition of the measured temperature inside the digital micromirror device 30 can be realized. For example, the first resistor R1 and the second resistor R2 may each have a resistance value of 51 kilo-ohms (k Ω). The capacitance value of the matching capacitor C1 may be 100 picofarads (pF).

Optionally, with continued reference to fig. 6, the temperature sensor 50 may further include: a third resistor R3, a fourth resistor R4 and a voltage stabilizing capacitor C2.

As shown in fig. 6, one end of the third resistor R3 is connected to the first power source terminal V1, and the other end of the third resistor R3 is connected to the SDA terminal of the temperature detection chip 52. One end of the fourth resistor R4 is connected to the second power terminal V2, and the other end of the fourth resistor R4 is connected to the SCL terminal of the temperature detecting chip 52. One end of the voltage stabilizing capacitor C2 is connected to the third power terminal V3 and the power terminal VCC of the temperature detecting chip 52, and the other end of the voltage stabilizing capacitor C2 is connected to the ground terminal.

The third resistor R3 and the fourth resistor R4 are pull-up resistors, and the third resistor R3 is used for pulling up the levels of the SDA end of the main control circuit 10 and the SDA end of the temperature detection chip 52 by the first power terminal V1. The fourth resistor R4 is used for pulling up the level of the SCL terminal of the main control circuit 10 and the SCL terminal of the temperature detecting chip 52 through the second power terminal V2. The voltage stabilizing capacitor C2 is used to stabilize the level of the power supply terminal VCC of the temperature detecting chip 52. For example, the third resistor R3 and the fourth resistor R4 may each have a resistance value of 10k Ω, and the voltage stabilizing capacitor C2 may have a capacitance value of 0.1 microfarad (μ F). The voltage values of the power supplies to which the first power supply terminal V1, second power supply terminal V2, and third power supply terminal V3 are connected may be determined based on the operating voltage of the digital micromirror device 30, for example, the voltage values of the power supplies to which the three power supply terminals are connected may be equal to the voltage value of the operating voltage of the digital micromirror device 30. For example, when the digital micromirror device 30 operates at 3.3 volts (V). Wherein, the voltage value of the power supply connected to the three power supply terminals may also be 3.3V.

To sum up, this application embodiment provides a projection equipment, and the in-process that the main control circuit in this projection equipment can shine to the digital micro mirror device at the light beam that the light source sent, detects the measured temperature of digital micro mirror device through temperature sensor to can be when this measured temperature is greater than or equal to the temperature threshold, increase the rotational speed of fan, in order to reduce the temperature of digital micro mirror device. And after the rotating speed of the fan reaches the rotating speed threshold value, if the actually measured temperature of the digital micromirror device is still greater than or equal to the temperature threshold value, the main control circuit can enable the rotating speed of the fan to keep the rotating speed threshold value and reduce the brightness of the light beam emitted by the light source. Therefore, the temperature of the digital micromirror device can be further reduced, so that the device in the digital micromirror device is prevented from being broken down due to high temperature, and the display effect of the projection equipment is effectively ensured.

Embodiments of the present application further provide a projection device, which may include a processor and a memory, where the memory stores instructions that are loaded and executed by the processor to implement the method for controlling a digital micromirror device, such as the method shown in fig. 2 or fig. 3.

The present application provides a computer-readable storage medium, in which a computer program is stored, and the computer program is loaded by a processor and executes a control method of a digital micro-mirror device provided in the above method embodiments, such as the method shown in fig. 2 or fig. 3.

Embodiments of the present application further provide a computer program product containing instructions, which when run on a computer, cause the computer to execute the method for controlling a digital micromirror device provided by the above method embodiments, such as the method shown in fig. 2 or fig. 3.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

It is to be understood that the term "at least one" in this application refers to one or more, and the meaning of "a plurality" refers to two or more.

The terms "first," "second," and the like in this application are used for distinguishing between similar items and items that have substantially the same function or similar functionality, and it should be understood that "first," "second," and "nth" do not have any logical or temporal dependency or limitation on the number or order of execution.

The above description is only exemplary of the application and should not be taken as limiting the application, and any modifications, equivalents, improvements and the like that are made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A method of controlling a digital micromirror device of a projection apparatus, the projection apparatus further comprising: a temperature sensor, a fan and a light source; the method comprises the following steps:

acquiring the actually measured temperature of the digital micromirror device acquired by the temperature sensor in the process of irradiating the digital micromirror device by the light beam emitted by the light source;

2. The method of claim 1, wherein reducing the brightness of the light beam emitted by the light source comprises:

determining the brightness adjustment quantity of a projection image projected by the projection equipment based on the difference value between the actually measured temperature of the digital micromirror device and the temperature threshold value;

and adjusting the brightness of the light beam emitted by the light source based on the brightness adjustment amount.

3. The method according to claim 2, wherein the brightness adjustment amount Δ L satisfies:

wherein Δ T is a temperature adjustment amount of the digital micromirror device, C is a conversion constant of the luminance of the light beam emitted by the light source and the thermal power of the digital micromirror device, and R is a thermal resistance constant of the digital micromirror device.

4. The method of claim 2, wherein adjusting the brightness of the light beam emitted by the light source based on the brightness adjustment comprises:

determining a current adjustment quantity of a driving current of the light source according to a brightness adjustment quantity of a projected image projected by the projection equipment;

and adjusting the driving current of the light source according to the current adjustment amount.

5. The method of any of claims 1-4, wherein the threshold speed is determined based on a noise threshold and a fan speed to noise correspondence.

6. A projection device, characterized in that the projection device comprises: the system comprises a main control circuit, a digital micro-mirror device, a temperature sensor, a fan and a light source;

the master control circuit is configured to:

7. The projection device of claim 6, wherein the digital micromirror device comprises: the micro-mirror comprises a substrate, a plurality of micro-mirrors positioned on the substrate and a plurality of hinges connected with the micro-mirrors in a one-to-one correspondence manner, wherein each hinge is used for controlling the turnover of one micro-mirror connected with the hinge;

the temperature sensor is used for detecting the temperature of the area where the hinges are located on the substrate.

8. The projection device of claim 7, wherein the temperature sensor comprises: the temperature detection chip is connected with the detection diode;

the detection diode is positioned on the substrate in the area where the plurality of hinges are positioned;

the temperature detection chip is located outside the substrate, a first detection pin of the temperature detection chip is connected with a first end of the detection diode, and a second detection pin of the temperature detection chip is connected with a second end of the detection diode.

9. The projection device of claim 8, wherein the temperature sensor further comprises: the circuit comprises a first resistor, a second resistor and a matching capacitor;

the first resistor is connected between the first detection pin and the first end of the detection diode in series, and the second resistor is connected between the second detection pin and the second end of the detection diode in series;

one end of the matching capacitor is connected with the first end of the detection diode, and the other end of the matching capacitor is connected with the second end of the detection diode.

10. The projection device of any of claims 6 to 9, wherein the master control circuit is configured to:

determining the brightness adjustment quantity of the projection image projected by the projection equipment based on the difference value between the actually measured temperature of the digital micromirror device and the temperature threshold value;