WO2023202330A1

WO2023202330A1 - Laser projection display method and laser projection display apparatus

Info

Publication number: WO2023202330A1
Application number: PCT/CN2023/084274
Authority: WO
Inventors: 崔荣荣; 郭大勃
Original assignee: 青岛海信激光显示股份有限公司
Priority date: 2022-04-20
Filing date: 2023-03-28
Publication date: 2023-10-26

Abstract

The embodiments of the present application belong to the field of image display. Disclosed are a laser projection display method and apparatus. In the embodiments of the present application, different temperature threshold values are determined according to different gray-scale values of displayed images, and the operating temperature value of a digital micromirror device is then adjusted in real time on the basis of the different temperature threshold values, such that the operating temperature value of the digital micromirror device during the process of displaying different images can be lower than an operating temperature threshold value corresponding to a corresponding image. Since the gray-scale value of an image has a positive correlation with a landed duty cycle of a micromirror, by means of the solution, the adverse effect of the landed duty cycle of the micromirror and the operating temperature value on the service life of the digital micromirror device can be reduced when each frame of image is displayed, thereby prolonging the service life of the digital micromirror device.

Description

Laser projection display method and laser projection display device

Cross-references to related applications

This application is required to be submitted to the China Patent Office on April 20, 2022, with the application number 202210419470.6, and the invention name is the display control method, device and storage medium of a digital micromirror device, and is submitted to the China Patent Office on August 16, 2022. The application number is 202210978941.7, and the invention is entitled "Control Method for Projection Equipment and Digital Micromirror Devices", which is the priority of a Chinese patent application. The entire content of which is incorporated into this application by reference.

Technical field

The present application relates to the field of projection image display, and in particular to a laser projection display method and a laser projection display device.

Background technique

Digital Micromirror Device (DMD) is one of the main components of the projection system. The digital micromirror device includes multiple micromirrors, each micromirror corresponding to a pixel. Control the grayscale of each pixel in the displayed image by controlling the "on" or "off" state of each micromirror during the display of one frame of image, and the length of time it is "on" or "off" value, thereby realizing the display of the image. However, when controlling the operation of the digital micromirror device, if the control is improper, the life of the digital micromirror device may be shortened.

Contents of the invention

On the one hand, embodiments of the present application provide a laser projection display method, which method includes:

Obtain the grayscale value of the image to be displayed, which is the next frame image of the currently displayed image;

Based on the grayscale value of the image to be displayed, determine the first operating temperature threshold of the digital micromirror device corresponding to the image to be displayed;

If the current operating temperature value of the digital micromirror device is higher than the first operating temperature threshold, the operating temperature value of the digital micromirror device is controlled to decrease, so that the digital micromirror device displays the to-be-displayed The operating temperature value of the image process is not higher than the first operating temperature threshold.

On the other hand, a laser projection display device is provided, which device includes:

An acquisition module, used to acquire the grayscale value of the image to be displayed, where the image to be displayed is the next frame image of the currently displayed image;

A determination module configured to determine the first operating temperature threshold of the digital micromirror device corresponding to the image to be displayed based on the grayscale value of the image to be displayed;

A control module configured to: if the current operating temperature value of the digital micromirror device is higher than the first operating temperature threshold, Then, the operating temperature value of the digital micromirror device is controlled to decrease, so that the operating temperature value of the digital micromirror device during the process of displaying the image to be displayed is not higher than the first operating temperature threshold.

processor;

Memory used to store instructions executable by the processor;

Wherein, the processor executes executable instructions in the memory to execute the above-mentioned laser projection display method.

On the other hand, a computer-readable storage medium is provided. A computer program is stored in the storage medium. When the computer program is executed by a computer, the steps of the above-mentioned laser projection display method are implemented.

On the other hand, a computer program product containing instructions is provided, which when run on a computer causes the computer to perform the steps of the above-mentioned laser projection display method.

Description of the 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 will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a laser projection device provided by an embodiment of the present application;

Figure 2 is a schematic diagram of the system control architecture of a laser projection device provided by an embodiment of the present application;

Figure 3 is a system architecture diagram involved in a laser projection display method provided by an embodiment of the present application;

Figure 4 is a schematic structural diagram of a projection device provided by an embodiment of the present application;

Figure 5 is a system architecture diagram involving another laser projection display method provided by an embodiment of the present application;

Figure 6 is a flow chart of a laser projection display method provided by an embodiment of the present application;

Figure 7 is a schematic flowchart of a control method for a digital micromirror device of a projection device provided by an embodiment of the present application;

Figure 8 is a schematic flow chart of another control method of a digital micromirror device provided by an embodiment of the present application;

Figure 9 is a schematic structural diagram of another projection device provided by an embodiment of the present application;

Figure 10 is a schematic structural diagram of a digital micromirror device provided by an embodiment of the present application;

Figure 11 is a schematic structural diagram of a temperature detection unit provided by an embodiment of the present application;

Figure 12 shows the embodiment of the present application, using 65°C as the reference temperature, 10,000 hours as the reference life value, and 5/95 as the reference micromirror support duty cycle, different operating temperature values and micromirror support duty cycle Compared with the life value of the corresponding digital micromirror device;

Figure 13 is a graph illustrating the influence of a micromirror bearing duty cycle and operating temperature on the life value of a digital micromirror device provided by an embodiment of the present application;

Figure 14 is a schematic structural diagram of a laser projection display device provided by an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

Before explaining the embodiments of the present application in detail, the system architecture involved in the embodiments of the present application is first introduced.

An embodiment of the present application provides a schematic structural diagram of a laser projection device. Refer to FIG. 1 . The projection device includes a casing 001 and a projection imaging system wrapped in the casing 001 . As shown in FIG. 1 , the projection imaging system may include a light source part 020 , an optical-mechanical part 030 , and a lens part 040 .

The light source unit 020 is provided with a light source, which may be a laser light source, for example. The optical-mechanical part 030 can modulate the light beam emitted by the light source to obtain a projection image to be projected and displayed. The projection image to be projected and displayed can be projected to the projection screen through the projection lens in the lens unit 040 to achieve display of the projection image.

FIG. 2 is a schematic diagram of the control system architecture of another laser projection device provided by an embodiment of the present application. Referring to FIG. 2 , the laser projection device may include: a system motherboard 100 , a display panel 200 and a power board 300 . The power board 300 is connected to the main board 100 and the display board 200 respectively, and is used to supply power to various devices or some modules on the main board 100 and the display board 200, as well as to other functional modules in the laser projection equipment, such as human eye protection modules. , fans and wireless-fidelity (WI-FI) modules. The power board 300 may also be provided with a laser driving component for driving the laser light source to emit light. Alternatively, the laser driving assembly can also be provided independently of the power board 300 .

The mainboard 100 is also connected to the display panel 200. The mainboard 100 is used to receive the image data of the projected image sent by the front-end device and decode the image data. Among them, as shown in Figure 2, the motherboard 100 can be provided with a system on chip (SoC) 101. The system-on-a-chip 101 can decode image data in different data formats into a normalized format, and transmit the image data in the normalized format to the display panel 200 . For example, the mainboard 100 may transmit image data in a normalized format to the display panel 200 through a connector.

The mainboard 100 may also be called a television (television, TV) board.

The display panel 200 may be provided with an algorithm processing module field programmable gate array (FPGA). The algorithm processing module FPGA can process the image data of the input projection screen, such as motion estimation and motion compensation (motion estimation and motion compensation, MEMC) frequency doubling processing or image correction processing.

In addition, the display panel 200 may also be provided with a display control chip 201 . The display control chip 201 can be connected to the algorithm processing module FPGA, and is used to receive the processed image data of the projection screen, and use the processed projection screen as the projection screen to be displayed.

In one implementation, the display panel 200 may not include an algorithm processing module FPGA. The display control chip 201 can be directly connected to the motherboard 100 , and the display control chip 201 can directly receive the projected image transmitted by the motherboard 100 .

In this embodiment of the present application, the display control chip 201 may include a light valve driver chip (not shown in Figure 2). The light valve driver chip can be a digital light processing (DLP) chip. The DLP chip can output a driving signal to the light source to control the light source to emit light. Wherein, the driving signal may include an image enable signal and a brightness adjustment signal. The image enable signal may also be called a primary color light enable signal. The primary color light enable signal can be expressed as X_EN, where X is the abbreviation of different primary color lights. The primary color light enable signal is used to control whether the light source emits light (that is, whether to light up), so as to control the lighting timing of multiple light sources of different colors. The brightness adjustment signal may be a pulse width modulation (pulse width modulation, PWM) signal, which is used to control the luminous brightness of the light source.

In one embodiment, the display panel 200 may also be provided with a light valve 30 . Wherein, the light modulation device can be a digital micromirror device (DMD), and the digital micromirror device can also be called a light valve. The display control chip 201 can generate a modulation driving signal for driving the light modulation device based on the projection image to be projected and displayed, and generate a driving signal for driving the light source to emit light. Based on this, the light modulation device can modulate the light beam emitted by the light source under the control of the modulation drive signal to obtain the image light beam of the projected image. The image beam can be projected to the projection screen through the projection lens to display the projected image.

Figure 3 is a system architecture diagram involving a laser projection display method provided by an embodiment of the present application. The system includes a main control circuit 10, a digital micromirror device 30, a temperature detection unit 50 and a heat dissipation unit 60. Among them, the main control circuit 10 has established communication connections with the digital micromirror device 30, the temperature detection unit 50 and the heat dissipation unit 60 respectively.

During the process of displaying the current image, the main control circuit 10 can obtain the next frame of the currently displayed image, that is, the image to be displayed, and determine the number corresponding to the image to be displayed according to the grayscale value of the image to be displayed. The first operating temperature threshold of the micromirror device 30 is the highest allowable operating temperature of the digital micromirror device when displaying the image to be displayed. After determining the first operating temperature threshold, the main control circuit 10 controls the operating temperature value of the digital micromirror device 30 during subsequent display of the image to be displayed based on the first operating temperature threshold.

For example, referring to FIG. 5 , the main control circuit 10 may include a processing unit 101 and an MCU 102 (Microcontroller Unit). It should be noted that the functions of the MCU 102 unit may also be integrated into the processing unit or other control chips. This is an example only. Among them, the processing unit 101 is used to obtain an image signal and decode the image signal to obtain an image to be displayed. For example, the image signal may be a video signal, and accordingly, the image to be displayed may be a frame of video image. After obtaining the image to be displayed, the processing unit 101 can determine the grayscale value of the image to be displayed, and then determine the first micromirror bearing of the digital micromirror device 30 when displaying the image to be displayed based on the grayscale value of the image to be displayed. Duty cycle, based on the first micromirror bearing duty cycle, it is determined that the digital micromirror device 30 is displaying the to-be-displayed The first operating temperature threshold in the process of displaying the image is determined, and the first operating temperature threshold is sent to the MCU 102 . After determining the first operating temperature threshold, the processing unit 101 can also load data to the digital micromirror device 30 based on the grayscale value of each pixel in the image to be displayed, and then control the digital micromirror device 30 to based on the loaded data. Light modulation is performed to achieve the display of the image to be displayed.

It should be noted that during the process of displaying an image, the temperature detection unit 50 can detect the internal operating temperature value of the digital micromirror device 30 in real time. Wherein, whenever the operating temperature value of the digital micromirror device 30 is detected, the temperature detection unit 50 may report the detected operating temperature value of the digital micromirror device 30 to the main control circuit 10 in real time. Based on this, during the process of displaying the current image, after determining the first operating temperature threshold, the main control circuit 10 may based on the current operating temperature value of the digital micromirror device 30 detected by the temperature detection unit 50 and the first operating temperature. threshold, the heat dissipation unit 60 is controlled to dissipate heat from the digital micromirror device 30 to adjust the operating temperature value of the digital micromirror device 30, so that the operating temperature value of the digital micromirror device during subsequent display of the image to be displayed is not higher than the an operating temperature threshold.

Wherein, the digital micromirror device 30 and the temperature detection unit 50 are both installed on the digital micromirror device board, and the temperature detection unit 50 is connected to the digital micromirror device 30 to measure the internal operating temperature value of the digital micromirror device 30, This measurement method is more accurate and has higher precision. The temperature detection unit 50 may be a temperature measurement control circuit.

In addition, referring to FIG. 5 , the heat dissipation unit 60 may include a cooling fan 601 and a radiator 602 . The cooling fan 601 faces the digital micromirror device 30 , and the heat sink 602 is in contact with the digital micromirror device 30 . The cooling fan 601 and the radiator 602 are both used to dissipate heat from the digital micromirror device 30 . In addition, the cooling fan 601 can also be used to dissipate heat from the radiator 602 . On this basis, after the aforementioned MCU 102 receives the current operating temperature value of the digital micromirror device 30 reported by the temperature detection unit 50 during the display of the current image, if the current operating temperature value of the digital micromirror device 30 is higher than the When an operating temperature threshold is reached, the MCU 102 can send a control instruction to the heat dissipation unit 60 to instruct the heat dissipation unit 60 to control the speed of the cooling fan 601 to increase, thereby improving the heat dissipation effect and thereby reducing the operating temperature value of the digital micromirror device 30. So that the operating temperature value of the digital micromirror device during subsequent display of the image to be displayed is not higher than the first operating temperature threshold.

Next, the laser projection display method provided by the embodiment of the present application will be introduced.

Figure 6 is a flow chart of a laser projection display method provided by an embodiment of the present application. This method can be applied to the main control circuit introduced in the above embodiment. As shown in Figure 6, the method includes the following steps:

Step 601: Obtain the grayscale value of the image to be displayed.

In this embodiment of the present application, the image to be displayed refers to the next frame image of the image currently being displayed. The main control circuit can decode the received image signal to obtain the image to be displayed. The image signal may be a video signal, and accordingly, the image to be displayed may be a frame of video image. Of course, in some possible implementations, the image to be displayed may also be a static image, which is not limited in the embodiments of the present application.

After obtaining the image to be displayed, the main control circuit can obtain the RGB (Red Green Blue) gray value of each pixel in the image to be displayed, based on the RGB gray value of each pixel in the image to be displayed. value to determine the grayscale value of the corresponding pixel; based on the grayscale value of each pixel in the image to be displayed, determine the grayscale value of the image to be displayed.

Illustratively, any pixel in the image to be displayed is taken as an example to illustrate the implementation process of determining the gray value of the pixel. For convenience of explanation, this pixel is called the first pixel. The main control circuit can obtain the primary color percentage corresponding to the R grayscale value, the primary color percentage corresponding to the G grayscale value, and the primary color percentage corresponding to the B grayscale value among the RGB grayscale values of the first pixel point. Afterwards, the gray value of the first pixel is determined based on the RGB gray value of the first pixel and the base color percentage corresponding to the R gray value, B gray value and G gray value respectively.

It should be noted that each pixel is composed of three primary colors, that is, red, green and blue, that is, the RGB gray value of each pixel includes R gray value, G gray value and B gray value. . During the display process of a frame of image, in order to achieve the white balance point, the three primary color display times have their own percentages in the display period, and the sum of the three primary color display time proportions is 100%. Based on this, the main control circuit can obtain the red percentage, green percentage and blue percentage of the image to be displayed when the white balance is satisfied. The red percentage is used as the base color percentage corresponding to the R gray value in the first pixel, the green percentage is used as the base color percentage corresponding to the G gray value in the first pixel, and the blue percentage is used as the base color corresponding to the B gray value in the first pixel. percentage of base color.

After obtaining the base color percentages respectively corresponding to the R grayscale value, G grayscale value and B grayscale value in the RGB grayscale value of the first pixel point, the main control circuit can calculate the first pixel point through the following formula 1 Initial gray value.
G ₀ ＝G _R *p _R +G _G *p _G +G _B *p _B (1)

Among them, G ₀ is the initial gray value of the first pixel, G _R is the R gray value, p _R is the base color percentage corresponding to the R gray value, G _G is the G gray value, and p _G is the G gray value. The corresponding base color percentage, G _B is the B gray value, p _B is the base color percentage corresponding to the B gray value.

For example, assume that the red percentage of the image to be displayed is 50%, the green percentage is 20%, and the blue percentage is 30% when the white balance is satisfied. The R gray value of the first pixel is 40% and the G gray value is 100%, the B gray value is 0, then the initial gray value of the first pixel point can be determined to be 40% through the above formula 1.

After determining the initial gray value of the first pixel, since the human eye's perception of brightness is not proportional to the light power, the main control circuit can also perform gamma correction on the initial gray value of the first pixel. Thus, the gray value of the first pixel is obtained. Among them, the main control circuit can correct the initial gray value of the first pixel point through the following formula 2.
G＝AG ₀ ^Gamma (2)

Among them, G is the gray value of the first pixel, A is a preset scaling coefficient, usually the value of the scaling coefficient is 1, and Gamma is a preset power index, usually the value can be 2.2.

For example, assuming that the initial gray value of the first pixel is 40%, then use the above formula 2 to calculate the initial gray value. The gray value of the first pixel obtained after correction is 13%.

For each pixel in the image to be displayed, the main control circuit can calculate the gray value of the corresponding pixel through the above method. Afterwards, the main control circuit can determine the grayscale value of the image to be displayed based on the grayscale value of each pixel in the image to be displayed.

For example, the main control circuit may calculate the average value of the grayscale values of the pixels in the image to be displayed, and use the average value as the grayscale value of the image to be displayed. Alternatively, the main control circuit may also obtain the mode of the grayscale values of the pixels in the image to be displayed as the grayscale value of the image to be displayed. Of course, the main control circuit can also count the grayscale values of the pixels in the image to be displayed through other statistical methods, thereby determining the grayscale value of the image to be displayed based on the statistical results, which is not limited in the embodiments of the present application.

Step 602: Based on the grayscale value of the image to be displayed, determine the first operating temperature threshold of the digital micromirror device corresponding to the image to be displayed.

In a possible implementation, the main control circuit obtains the standard life value of the digital micromirror device, and determines the first micromirror of the digital micromirror device when displaying the image to be displayed based on the gray value of the image to be displayed. Depends on duty cycle. Based on the first micromirror bearing duty cycle and the standard life value, the first operating temperature threshold is determined.

The standard life value of the digital micromirror device may refer to the prescribed life value of the digital micromirror device, for example, the prescribed life value of the type of digital micromirror device provided by the manufacturer when the digital micromirror device leaves the factory. In the embodiment of the present application, the mapping relationship between different types of digital micromirror devices and corresponding standard life values may be preset in the main control circuit. Based on this, the main control circuit can obtain the corresponding standard life value from the mapping relationship according to the model of the digital micromirror device. Alternatively, the above mapping relationship can also be stored in other devices, so that the main control circuit can obtain the standard life value of the digital micromirror device from other devices according to the model of the digital micromirror device. Alternatively, if the main control circuit and the digital micromirror device are provided by the same service provider, the standard life value of the digital micromirror device can also be directly stored in the main control circuit. In this way, the main control circuit can directly obtain the stored value. Standard life value of this digital micromirror device.

In addition, the main control circuit can also determine the first micromirror supporting duty cycle of the digital micromirror device when displaying the image to be displayed based on the grayscale value of the image to be displayed. The first micromirror supporting duty cycle is used to represent the percentage of the time the micromirror in the digital micromirror device is in the light-on state and the time it is in the light-off state during the process of displaying the image to be displayed.

It should be noted that each pixel in a frame of image corresponds to a micromirror in the digital micromirror device. When displaying a frame of image, the digital micromirror device can control the corresponding micromirror to flip based on the gray value of the pixel corresponding to each micromirror, so that the micromirror is between the light on (on) state and the light off (off) state. Switch between and control the length of time the micromirrors are in different states. In this way, the grayscale value of the pixel corresponding to the corresponding micromirror is displayed through the power accumulation of the light beam reflected to the projection lens when the light is turned on. However, when the micromirror works in a certain state for a long time, it is difficult to control the micromirror. When the mirror is flipped, the micromirror may have a slight residual tilt angle, causing the micromirror to be unable to effectively flip to another state, resulting in abnormal micromirror function and the inability to correctly display the corresponding pixels. In other words, the greater the difference in the proportion of time the micromirror is in two different states, the easier it is for the micromirror to fail, which will more likely lead to a shortening of the life of the digital micromirror device. Since the proportion of the time the micromirror is in different states is the micromirror support duty cycle, it can be seen that the greater the absolute value of the difference between the numerator and denominator of the micromirror support duty cycle, the greater the micromirror support duty cycle. The more unbalanced the length of time the mirror is in the light-on state and the light-off state, the greater the impact on the life of the digital micromirror device. According to the principle of displaying pixels by micromirrors in the aforementioned digital micromirror device, it can be known that if the micromirrors are in the light-on state for different lengths of time, the cumulative power reflected to the projection lens will be different, and the final grayscale value will be different. That is to say, the length of time the micromirror is in different states is mainly determined by the grayscale value of the pixel corresponding to the micromirror. Based on this, in the embodiment of the present application, the main control circuit can determine the first micromirror supporting duty cycle of the digital micromirror device in the process of displaying the image to be displayed based on the grayscale value of the image to be displayed, This is used to characterize the proportion of time that the micromirrors in the digital micromirror device are in the light-on state and the light-off state during the process of displaying the image to be displayed.

For example, the main control circuit may determine the first micromirror bearing duty cycle through the following formula 3 based on the grayscale value of the image to be displayed.

in, is the duty cycle of the first micromirror, and G is the grayscale value of the image to be displayed.

For example, assuming that the grayscale value of the image to be displayed is 40%, the duty cycle of the first micromirror is 40:60.

After determining the first micromirror bearing duty cycle, the main control circuit can obtain the reference life value at the reference temperature; obtain the life acceleration factor corresponding to the reference micromirror bearing duty cycle; based on the standard life value, the reference life value , the reference temperature, the reference micromirror bearing duty cycle, the corresponding life acceleration factor and the first micromirror bearing duty cycle, determine the first operating temperature threshold.

Among them, the reference temperature and the reference life value at the reference temperature are both preset. For example, the reference temperature and reference life value can be provided by the manufacturer of the digital micromirror device. In this case, the main control circuit can obtain the reference temperature and the corresponding reference life value from the product data of the digital micromirror device. In a specific implementation, the reference temperature and the reference lifetime value can also be set by the user. In this case, the reference lifetime value can be obtained by testing multiple digital micromirror device test samples whose operating temperature is maintained at the reference temperature. The test life value is determined. That is, multiple digital micromirror device test samples of the same model as the digital micromirror device can be controlled to work at a reference temperature to obtain test life values of multiple digital micromirror device test samples, and then based on the The test life values of multiple test samples determine the reference life value. For example, the average value of the multiple test life values is used as the reference life value, or the mode of the multiple test life values is used as the reference life value. This is not limited in the embodiments of the present application.

In addition, since the absolute value of the difference between the numerator and the denominator of the duty cycle of the micromirror is larger, the influence of the digital micromirror device on the The more severe the adverse effects are, that is, the easier it is to shorten the life of the digital micromirror device. Therefore, it can be seen that for a certain operating temperature, when the micromirror bearing duty cycle is 100:0 or 0:100, the life of the digital micromirror device is the minimum life value of the digital micromirror device at that operating temperature. . However, since in actual applications, the micromirror bearing duty cycle is rarely 100:0 or 0:100, therefore, in the embodiment of the present application, 5:95 and 95:5 can be used as the reference micromirror bearing duty cycle. Depends on duty cycle. Of course, other values can be used as the reference micromirror supporting duty cycle, and the embodiments of the present application do not limit this.

After determining the reference micromirror supporting duty cycle, the main control circuit can determine the life acceleration factor corresponding to the reference micromirror supporting duty cycle through the following formula 4 based on the reference micromirror supporting duty cycle.

Among them, β is the life acceleration factor corresponding to the reference micromirror bearing duty cycle, P _c is the numerator of the reference micromirror bearing duty cycle, and M _c is the denominator of the reference micromirror bearing duty cycle. When the reference micromirror duty cycle is 5:95 or 95:5, the life acceleration factor is 100/90.

After obtaining the standard life value, reference life value, reference temperature, reference micromirror bearing duty cycle, corresponding life acceleration factor and first micromirror bearing duty cycle, the main control circuit can be calculated by the following formula 5 The first operating temperature threshold of the digital micromirror device.

Among them, L is the standard life value of the digital micromirror device, T _c is the reference temperature, is the reference life value. ΔE is the preset activation energy value of the failure mechanism, k is Boltzmann’s constant, P is the numerator in the first micromirror bearing duty cycle, M is the denominator in the first micromirror bearing duty cycle, β This is the life acceleration factor corresponding to the duty cycle of the reference micromirror. Among them, when β is 100/90, the following formula 6 can be obtained from the above formula 5.

It can be seen from the above formulas 5 and 6 that the first operating temperature threshold is actually during the process of displaying the image to be displayed, that is, when the micromirror bearing duty cycle of the digital micromirror device is Depending on the duty cycle, in order to ensure that the life of the digital micromirror device is the standard life value, the maximum operating temperature threshold of the digital micromirror device is required.

It should be noted that ΔE in the above formulas 5 and 6 can be provided by the manufacturer of the digital micromirror device. Alternatively, it can also be determined based on test data obtained by testing multiple digital micromirror device test samples.

For example, when determining ΔE from test data, multiple digital micromirror device test samples can be divided into at least two sample groups, each sample group includes multiple test samples, and each sample group corresponds to a test temperature , wherein the test temperature corresponding to a certain sample group among the at least two sample groups is the aforementioned reference temperature. For convenience of explanation, the sample group whose corresponding test temperature is the reference temperature is called a reference sample group. For each sample group, control the The working temperature of the digital micromirror device test sample is maintained at the corresponding test temperature, so as to obtain the test life value of each digital micromirror device test sample in the sample group. Then, based on the test life value of each digital micromirror device test sample in the sample group, the test life value at the test temperature corresponding to the sample group is determined. For example, the average or mode of the test life values of the digital micromirror device test samples included in the sample group is determined as the test life value at the test temperature corresponding to the sample group. Through the above method, test life values corresponding to at least two test temperatures can be obtained. After that, the life acceleration factor of the digital micromirror device corresponding to the reference temperature is set to 1, based on the test life value corresponding to the reference temperature, the life acceleration factor, and any temperature Ti other than T _c in at least two test temperatures _. Test the life value and determine the life acceleration factor corresponding to _Ti through the following formula 7.

Among them, AF _i is the corresponding life acceleration factor when the test temperature is _Ti , AF _c is the corresponding life acceleration factor when the test temperature is the reference temperature T _c , which is equal to 1. is the test life value corresponding to _Ti , is the test life value corresponding to T _c .

After AF _i is determined, ΔE can be determined based on Formulas 8 and 9 below.

Among them, Q is the degradation rate of the digital micromirror device at temperature T, A ₀ is a constant, and k is Boltzmann's constant. Based on, is the degradation rate of the digital micromirror device at temperature T _c , is the degradation rate of the digital micromirror device at temperature _Ti .

It should be noted that _Ti can be the test temperature with the largest difference from T _c among at least two test temperatures. Alternatively, in a possible implementation, the above method can also be used to calculate the corresponding ΔE using each test temperature except T _c in at least two test temperatures, and then average the ΔE corresponding to each test temperature. value as the final ΔE. In addition, the temperatures in the above formulas 5-9 all refer to thermodynamic temperatures.

For example, assuming T _c is 65°C and _Ti is 25°C, is 10,000 hours, is 794512 hours, then it can be determined through the above formula 3 that AF _i is equal to 79.4512. Afterwards, based on Equation 5, it can be determined that ΔE is 0.95096eV.

For example, based on the relationship between temperature, micromirror bearing duty cycle and life value given in the above formula 5, Figure 12 shows that the reference temperature is 65 degrees, the reference life value is 10,000 hours, the reference micromirror When the bearing duty cycle is 5:95, the corresponding life values of the digital micromirror device under different operating temperatures and micromirror bearing duty ratios.

Based on the above formula 5 and Figure 12, Figure 13 provides a graph showing the influence of the micromirror duty cycle and operating temperature on the life value of the digital micromirror device. As shown in Figure 13, taking the duty cycle of the micromirror support as the horizontal axis and taking the operating temperature of the digital micromirror device as the vertical axis, the life value of the digital micromirror device corresponding to any point on the curve is the same, that is, , Figure 13 The curve in is a two-dimensional relationship curve formed by points with different operating temperatures and micromirror duty cycles under the same lifetime value. It can be seen from Figure 13 that under the same lifetime value, the greater the difference between the numerator and denominator of the micromirror bearing duty cycle of the digital micromirror device, the lower the corresponding maximum allowable operating temperature. On the contrary, the micromirror bearing duty cycle The smaller the difference between the numerator and denominator of the duty cycle, the higher the corresponding maximum allowable operating temperature. In other words, when the numerator and denominator of the duty cycle of the micromirror are greatly different, in order to increase the life of the digital micromirror device, the digital micromirror device can appropriately operate at a lower operating temperature.

The above is an implementation method for determining the first operating temperature threshold of a digital micromirror device given by the embodiment of the present application. In a specific implementation, in another possible implementation, the main control circuit may store the Under different lifetime values, the digital micromirror device corresponds to the first operating temperature threshold under different micromirror bearing duty cycles. Based on this, after determining the first micromirror support duty cycle, the main control circuit can directly obtain the first operating temperature threshold corresponding to the first micromirror support duty cycle under the target life value.

Step 603: If the current operating temperature value of the digital micromirror device is higher than the first operating temperature threshold, control the operating temperature value of the digital micromirror device to decrease so that the operating temperature of the digital micromirror device during the process of displaying the image to be displayed The value is not higher than the first operating temperature threshold.

After determining the first operating temperature threshold of the digital micromirror device when displaying the image to be displayed through the above step 602, the main control circuit may control the operating temperature of the digital micromirror device based on the first operating temperature threshold of the digital micromirror device. , so that the digital micromirror device operates at a temperature lower than the first operating temperature threshold.

For example, the digital micromirror device is usually installed on the digital micromirror device board. In the embodiment of the present application, the digital micromirror device board may also be equipped with a temperature detection unit, and the temperature detection unit is connected to the digital micromirror device. , the internal working temperature of the digital micromirror device can be detected in real time, and the detected working temperature can be reported to the main control circuit. Based on this, in the embodiment of the present application, after determining the first operating temperature threshold, the main control circuit can receive the current operating temperature value of the digital micromirror device reported by the temperature detection unit, and convert the current operating temperature value of the digital micromirror device to The operating temperature value is compared to a first operating temperature threshold. If the current operating temperature value of the digital micromirror device is higher than the first operating temperature threshold, the main control circuit may send a first control command to the heat dissipation unit. Wherein, the heat dissipation unit includes a cooling fan for dissipating heat from the digital micromirror device, and the first control command is used to instruct to increase the rotation speed of the cooling fan.

As can be seen from the foregoing introduction, the heat dissipation unit includes a heat dissipation fan and a heat sink in contact with the digital micromirror device. If the detected current operating temperature value of the digital micromirror device is not less than the first operating temperature threshold, the main control circuit can control the speed of the cooling fan to increase. In this way, on the one hand, the cooling fan can be enhanced to directly operate on the digital micromirror device. The heat dissipation effect of the heat dissipation can also improve the heat dissipation effect of the cooling fan on the radiator, thereby improving the heat dissipation effect of the radiator on the digital micromirror device, thereby reducing the operating temperature of the digital micromirror device so that it can be displayed later. During the process of displaying an image, the operating temperature value of the digital micromirror device may not be higher than the first operating temperature threshold.

In a specific implementation, if the current operating temperature value of the digital micromirror device is lower than the first operating temperature threshold, the main control circuit can maintain the operating temperature value of the digital micromirror device not to be higher than the first operating temperature threshold.

Wherein, when the current operating temperature value of the digital micromirror device is lower than the first operating temperature threshold, the main control circuit may further calculate the temperature difference between the first operating temperature threshold of the digital micromirror device and the current operating temperature. value. After that, the temperature difference is compared with the reference threshold. If the temperature difference is greater than the reference threshold, it means that the current operating temperature value is far different from the first operating temperature threshold, and the first operating temperature threshold will not be reached in a short time. , in this case, the main control circuit can temporarily not adjust the rotation speed of the cooling fan, that is, maintain the current rotation speed of the cooling fan, so as to ensure that the subsequent operating temperature value of the digital micromirror device can be lower than the first operating temperature. temperature threshold. Of course, if the temperature difference is not greater than the reference threshold, it means that although the current operating temperature value is less than the first operating temperature threshold, it is not much different from the first operating temperature threshold. In this case, as the digital micromirror As the working time of the device increases and heat accumulates, the operating temperature value of the digital micromirror device after it starts to display the image to be displayed may exceed the first operating temperature threshold. Therefore, the main control circuit can appropriately increase the speed of the cooling fan. To enhance the heat dissipation effect of the cooling fan, thereby ensuring that the operating temperature value of the digital micromirror device after starting to display the image to be displayed can be lower than the first operating temperature threshold. It should be noted that, in this case, the main control circuit controls the cooling fan's rotation speed to increase by a smaller amount than when the current operating temperature value is higher than the first operating temperature threshold.

In a specific implementation, in another possible implementation, the controller may determine a second operating temperature threshold in advance based on the first operating temperature threshold of the digital micromirror device, wherein the second operating temperature threshold is smaller than the third operating temperature threshold. An operating temperature threshold, for example, the second operating temperature threshold is equal to the first operating temperature threshold minus the reference threshold. Based on this, when the controller receives the current operating temperature value of the digital micromirror device reported by the temperature detection unit, the main control circuit can compare the current operating temperature value of the digital micromirror device with the second operating temperature threshold. If the current operating temperature value of the digital micromirror device is higher than the second operating temperature threshold, the main control circuit can send a first control command to the heat dissipation unit to increase the speed of the cooling fan to prevent subsequent damage to the digital micromirror device. The operating temperature continues to rise beyond the first operating temperature threshold. In a specific implementation, if the current operating temperature value of the digital micromirror device is not higher than the second operating temperature threshold, the main control circuit can obtain the digital micromirror device reported by the temperature detection unit within a preset time period before the current time. The working temperature value of each time, including the current time, is sorted in chronological order. Afterwards, the temperature difference between each two adjacent operating temperature values is calculated to obtain at least two temperature differences. If the at least two temperature differences are both positive and increase with time, it means that the operating temperature of the digital micromirror device is rising at an accelerated rate. At this time, the main control circuit can send the first control to the heat dissipation unit. command to increase the speed of the cooling fan, thereby achieving the effect of early intervention to prevent the operating temperature value of the digital micromirror device from rapidly rising to the first operating temperature threshold. If the at least two temperature differences are both positive and decreasing over time, it means that the rising rate of the operating temperature of the digital micromirror device is decreasing. At this time, the main control circuit may not adjust the speed of the cooling fan. Make adjustments. If the at least two temperature differences are both negative, it means that the operating temperature of the digital micromirror device has been declining. In this case, the main control circuit may not adjust the speed of the cooling fan, or the main control circuit may The control circuit can send a second control command to the cooling unit to reduce the rotation speed of the cooling fan.

After the main control circuit adjusts the speed of the cooling fan based on the current operating temperature value, subsequently, during the process of displaying the image to be displayed, the main control circuit can continue to receive the temperature of the digital micromirror device detected and reported in real time by the temperature detection unit. Working temperature value, and based on the working temperature value of the digital micromirror device received in real time and the first working temperature threshold, refer to the method introduced above to adjust the speed of the cooling fan to control the display of the image to be displayed. During the process, the operating temperature value of the digital micromirror device is not higher than the first operating temperature threshold.

It is worth noting that in the embodiment of the present application, the main control circuit can use the frame image as the image to be displayed to perform the above steps before displaying each frame image, thereby controlling the process of displaying the frame image. The operating temperature value of the digital micromirror device is not higher than the operating temperature threshold of the digital micromirror device corresponding to the frame image. Of course, in some possible implementations, the main control circuit can also obtain a frame of image to be displayed at preset time intervals, and determine an operating temperature threshold based on the image to be displayed, and then, in the next preset time, Within the time interval, that is, the operating temperature threshold is used as a reference to control the operating temperature value of the digital micromirror device within the preset time interval not to exceed the temperature threshold. Alternatively, the main control circuit can also obtain a frame of image to be displayed every N frames of images, and determine an operating temperature threshold based on the image to be displayed, and then display N+1 frames of images including the image to be displayed. , that is, using the operating temperature threshold as a reference, the operating temperature value of the digital micromirror device is controlled not to exceed the temperature threshold.

In the embodiment of the present application, different temperature thresholds are determined according to the grayscale values of different images, and then the operating temperature value of the digital micromirror device is adjusted in real time based on the different temperature thresholds, so that the digital micromirror device displays different images. The working temperature value during the process can be lower than the working temperature threshold corresponding to the corresponding image. Since the gray value of the image is positively related to the duty cycle of the micromirror, the above method can reduce the microscopic noise when displaying each frame of image. The mirror withstands the adverse effects of duty cycle and operating temperature on the life of the digital micromirror device, thereby improving the service life of the digital micromirror device.

In addition, in the embodiment of the present application, the relationship formula between the micromirror duty cycle, temperature and life value of the digital micromirror device can also be obtained by testing multiple digital micromirror device test samples, and then based on This relational formula is used to determine the first operating temperature threshold corresponding to the duty cycle of the micromirror when displaying different images, thereby achieving control of the operating temperature of the digital micromirror device when displaying different images.

The following will further introduce the operation method of controlling the operating temperature of the digital micromirror device to ensure the working life of the digital micromirror device with reference to specific examples.

FIG. 4 is a schematic structural diagram of yet another projection device provided by an embodiment of the present application. Referring to FIG. 4 , the projection device may include a main control circuit 10 , a light source 20 , a digital micromirror device 30 and a projection lens 40 .

Referring to FIG. 4 , the main control circuit 10 is connected to the light source 20 and the digital micromirror device 30 respectively. The main control circuit 10 can It is capable of receiving the image data of the projection image to be projected and displayed, and processing the image data of the projection image. Afterwards, the main control circuit 10 can send the processed image data to the digital micromirror device 30 and output a driving current signal to the light source 20 based on the processed image data.

Among them, the main control circuit 10 can be a digital light processing (digital light processing, DLP) chip. For example, the main control circuit 10 can be a DLPC chip. Alternatively, the main control circuit 10 may be a microcontroller unit (MCU), that is, a single-chip microcomputer.

The light source 20 is used to emit light driven by the driving current signal output by the main control circuit 10 . The digital micromirror device 30 is used to modulate the light beam emitted by 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 can then project the projection image to be projected onto a projection screen. The light source 20 may be a laser light source or a light-emitting diode (LED) or other types of light sources.

Continuing to refer to FIG. 4 , the projection device may further include a temperature detection unit 50 and at least one heat dissipation unit-fan 60 . The temperature detection unit 50 is connected to the main control circuit 10 and the digital micromirror device 30 respectively. The temperature detection unit 50 is used to detect the actual measured temperature of the digital micromirror device 30 and transmit the actual measured temperature of the digital micromirror device 30 to the main control circuit 10 . In a specific implementation, the temperature detection unit 50 is an NTC temperature sensor.

The main control circuit 10 is also connected to at least one heat dissipation unit-fan 60 , and the vent of the at least one fan 60 can be connected to the digital micromirror device 30 . The main control circuit 10 can also control the working state of the at least one fan 60 (for example, adjust the speed of the fan 60 ) based on the actual measured temperature of the digital micromirror device 30 transmitted by the temperature detection unit 50 , thereby adjusting the digital micromirror device 30 The effect of temperature.

Figure 7 is a schematic flowchart of a control method for a digital micromirror device of a projection device provided by an embodiment of the present application. This method can be applied to the main control circuit of the projection device, such as the main control circuit in the projection device shown in Figure 4 10. Referring to FIG. 4 , the projection device also includes: a temperature detection unit 50 , a fan 60 and a light source 20 . As shown in Figure 7, the method includes:

Step 701: In the process of the light beam emitted by the light source irradiating the digital micromirror device, obtain the actual measured temperature of the digital micromirror device collected by the temperature detection unit.

In the embodiment of the present application, the main control circuit can provide a driving signal to the light source to drive the light source to emit a light beam. Moreover, the light beam emitted by the light source can illuminate the digital micromirror device. When the light beam emitted by the light source irradiates the digital micromirror device, the temperature detection unit can detect the actual measured temperature of the digital micromirror device, and the main control circuit can then obtain the actual measured temperature of the digital micromirror device. The process of the main control circuit obtaining the actual measured temperature of the digital micromirror device can also be called the process of reading the actual measured temperature. The actual measured temperature of the digital micromirror device may be the 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 micromirrors. There are multiple hinges connected correspondingly, and each hinge is used to control the flipping of a micromirror it is connected to. The measured temperature may be the temperature of areas where multiple hinges are located on the substrate. That is, the measured temperature may be the temperature of the hinge in the digital micromirror device.

In a specific implementation, the temperature detection unit can detect the actual temperature of the digital micromirror device in real time. The main control circuit can also obtain the actual measured temperature of the digital micromirror device in real time, or the main control circuit can periodically obtain the actual measured temperature of the digital micromirror device. For example, the main control circuit can obtain the actual measured temperature of the digital micromirror device every 15 minutes.

Step 702: If it is determined that the actual measured temperature is greater than or equal to the temperature threshold, increase the rotation speed of the fan.

The temperature threshold may be a temperature value determined based on the 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 digital micromirror device is greater than or equal to the temperature threshold, the components inside the digital micromirror device (such as hinges) may malfunction (such as deformation or breakage) due to excessive temperature, thus affecting the digital micromirror device. The effect of modulating the image beam.

In this embodiment of the present application, after the main control circuit obtains the actual measured temperature of the digital micromirror device, it can detect whether the actual measured temperature is greater than or equal to the temperature threshold. If the main control circuit determines that the actual measured temperature is greater than or equal to the temperature threshold, it can increase the speed of the fan. During the rotation process, the fan can dissipate the heat of the digital micromirror device through the vent, thereby dissipating heat of the digital micromirror device. As a result, the temperature of the digital micromirror device can be effectively reduced.

Step 703: If the actual measured temperature is still greater than or equal to the temperature threshold after the fan's rotational speed reaches the rotational speed threshold, the fan is maintained at the rotational speed threshold and the brightness of the light beam emitted by the light source is reduced.

The rotation speed threshold may be the maximum rotation speed of the fan. Alternatively, the rotation speed threshold may be a rotation speed determined based on the magnitude of noise generated by the fan rotation process. When the fan speed reaches the speed threshold, the main control circuit can again obtain the actual measured temperature of the digital micromirror device detected by the temperature detection unit, and detect whether the actual measured temperature is greater than or equal to the temperature threshold. If the main control circuit determines that the actual measured temperature is still greater than or equal to the temperature threshold, it can maintain the fan's rotational speed at the rotational speed threshold and reduce the brightness of the light beam emitted by the light source. If the main control circuit determines that the actual measured temperature of the digital micromirror device is less than the temperature threshold, there is no need to reduce the brightness of the light beam emitted by the light source, and it only needs to maintain the fan's rotational speed at the rotational speed threshold.

Among them, when the rotation speed of the fan reaches the rotation speed threshold, the main control circuit may determine that the rotation speed of the fan cannot continue to increase, or if the rotation speed continues to increase, the noise of the projection device will be too high. Therefore, the main control circuit can continue to cool down the digital micromirror device by reducing the brightness of the light beam emitted by the light source.

Among them, when the light beam emitted by the light source in the projection device irradiates the digital micromirror device, the brightness of the light beam will affect the temperature of the digital micromirror device. For example, the temperature of the digital micromirror device decreases 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 micromirror device by reducing the brightness of the light beam emitted by the light source.

Step 704: Control the digital micromirror 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 the image data of the projection 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 the projected image to be projected and displayed. The projected image can be projected onto the projection screen through the projection lens of the projection device.

Among them, the main control circuit cools down the digital micromirror device by increasing the fan speed and reducing 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. Thus, the performance of each device in the digital micromirror device can be ensured, and the service life of each device in the digital micromirror device can be ensured, thereby ensuring the effect of the digital micromirror device in modulating the image beam, effectively improving the projection equipment. display effect.

In summary, embodiments of the present application provide a method for controlling a digital micromirror device of a projection device, which can determine the digital micromirror device based on the analysis of the image content during the process of the light beam emitted by the light source irradiating the digital micromirror device. The corresponding operating temperature threshold is used, and the actual measured temperature of the digital micromirror device is detected through the temperature detection unit. When the measured temperature is greater than or equal to the temperature threshold, the fan speed is increased to reduce the temperature of the digital micromirror device. Moreover, after the fan speed reaches the speed threshold, if the actual measured temperature of the digital micromirror device is still greater than or equal to the temperature threshold, the fan speed can be maintained at the speed threshold and the brightness of the light beam emitted by the light source can be reduced. As a result, the temperature of the digital micromirror device can be further reduced to prevent components inside the digital micromirror device from malfunctioning due to high temperatures, thereby effectively ensuring the display effect of the projection device.

Figure 8 is a schematic flowchart of another method for controlling a digital micromirror device of a projection device provided by an embodiment of the present application. This method can be applied to the main control circuit of the projection device, such as the main control circuit in the projection device shown in Figure 4 Circuit 10. Referring to FIG. 4 , the projection device also includes: a temperature detection unit 50 , a fan 60 and a light source 20 . As shown in Figure 8, the method includes:

Step 801: In the process of the light beam emitted by the light source irradiating the digital micromirror device, obtain the actual measured temperature of the digital micromirror device collected by the temperature detection unit.

In the embodiment of the present application, the main control circuit can provide a driving signal to the light source to drive the light source to emit a light beam. Moreover, the light beam emitted by the light source can illuminate the digital micromirror device. When the light beam emitted by the light source irradiates the digital micromirror device, the temperature detection unit can detect the actual measured temperature of the digital micromirror device, and the main control circuit can obtain the actual measured temperature of the digital micromirror device detected by the temperature detection unit. temperature. The process of the main control circuit obtaining the actual measured temperature of the digital micromirror device can also be called the process of reading the actual measured temperature. The actual measured temperature of the digital micromirror device may be the temperature inside the digital micromirror device.

For example, the digital micromirror device may include a substrate, multiple micromirrors located on the substrate, and multiple hinges connected to the multiple micromirrors in one-to-one correspondence, and each hinge is used to control the flipping of one of the micromirrors it is connected to. The measured temperature may be the temperature of areas where multiple hinges are located on the substrate. That is, the measured temperature may be the temperature of the hinge in the digital micromirror device.

Step 802: Detect whether the actual measured temperature is greater than or equal to the temperature threshold.

The temperature threshold may be a temperature value determined based on the withstand temperature of the digital micromirror device. For example, the temperature threshold may be less than or equal to the withstand temperature, and the withstand temperature may be 70°C. When the measured temperature of the digital micromirror device is greater than or equal to the temperature threshold, the components inside the digital micromirror device (such as hinges) may malfunction (such as deformation or breakage) due to excessive temperature, thus affecting the digital micromirror device. The effect of modulating the image beam.

In this embodiment of the present application, after the main control circuit obtains the actual measured temperature of the digital micromirror device, it can detect whether the actual measured temperature is greater than or equal to the temperature threshold. If the main control circuit determines that the actual measured temperature is greater than or equal to the temperature threshold, the following step 803 can be executed. If the main control circuit determines that the measured temperature is less than the temperature threshold, it can determine that there is no need to cool down the digital micromirror device, and can continue to perform the above step 801, that is, continue to obtain the measured temperature of the digital micromirror device.

Step 803: Detect whether the rotation speed of the fan reaches the rotation speed threshold.

The rotation speed threshold may be the maximum rotation speed of the fan. Alternatively, the rotation speed threshold may be a rotation speed determined based on the magnitude of noise generated by the fan rotation process.

In a specific implementation, if the rotational speed threshold is determined based on the magnitude of the noise generated during the rotation of the fan, then the rotational speed threshold can be determined based on the noise threshold and the corresponding relationship between the rotational speed of the fan and the noise.

The noise threshold may be determined based on the noise that the user can withstand when using the projection device. When the fan's rotational speed is less than the rotational speed threshold, the noise generated by the fan during rotation is also less than the noise threshold. For example, the noise threshold may be 36 decibels (dB).

In the above step 802, if the main control circuit detects that the actual measured temperature of the digital micromirror device is greater than or equal to the temperature threshold, it can detect whether the rotation speed of the fan reaches the rotation speed threshold. If the main control circuit detects that the rotational speed of the fan does not reach the rotational speed threshold, it may determine that the digital micromirror device can be cooled down by adjusting the rotational speed of the fan, and perform the following step 804. If the main control circuit detects that the rotational speed of the fan reaches the rotational speed threshold, it can determine that the rotational speed of the fan cannot continue to increase, or if the rotational speed continues to increase, the noise of the projection device will be too high. Therefore, the main control circuit can perform the following step 805 to continue cooling the digital micromirror device through other methods.

Step 804: Increase the fan speed.

In the above step 803, if the main control circuit detects that the rotation speed of the fan does not reach the rotation speed threshold, it can determine that the digital micromirror device can be cooled down by adjusting the rotation speed of the fan, and therefore the rotation speed of the fan can be increased. During the rotation process, the fan can dissipate the heat of the digital micromirror device through the vents, thereby protecting the digital micromirror device. The role of heat dissipation. As a result, the temperature of the digital micromirror device can be effectively reduced.

Step 805: Maintain the fan speed threshold, and determine the brightness adjustment amount of the projection image projected by the projection device based on the difference between the actual measured temperature of the digital micromirror device and the temperature threshold.

In the above step 803, if the main control circuit detects that the rotation speed of the fan reaches the rotation speed threshold, the rotation speed of the fan can be maintained at the rotation speed threshold. Furthermore, the main control circuit can determine the brightness adjustment amount of the projection image projected by the projection device based on the difference between the actual measured temperature of the digital micromirror device and the temperature threshold.

Among them, the brightness adjustment amount ΔL can satisfy:

Wherein, ΔT is the temperature adjustment amount of the digital micromirror device, and the ΔT can be determined based on the difference between the actual measured temperature of the digital micromirror device and the temperature threshold. For example, the ΔT may be greater than or equal to the difference between the measured temperature of the digital micromirror device and the temperature threshold. C is the conversion constant between the brightness of the light beam emitted by the light source and the thermal power of the digital micromirror device, and R is the thermal resistance constant of the digital micromirror device.

When the light beam emitted by the light source in the projection device irradiates the digital micromirror device, the brightness of the light beam will affect the temperature of the digital micromirror device. For example, the temperature of the digital micromirror device decreases 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 micromirror device by reducing the brightness of the light beam emitted by the light source. The brightness of the light beam emitted by the light source is positively related to the brightness adjustment amount of the projection image projected by the projection device. Therefore, the main control circuit can determine the brightness adjustment amount of the projection image projected by the projection device based on the adjustment amount of the temperature of the digital micromirror device, and then determine the adjustment amount of the brightness of the light beam emitted by the light source, thereby further reducing the temperature of the digital micromirror device. temperature.

Step 806: Determine the current adjustment amount of the driving current of the light source according to the brightness adjustment amount of the projection image projected by the projection device.

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

Step 807: Adjust the driving current of the light source according to the current adjustment amount.

In this embodiment of the present application, 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 becomes the target current. The difference between the target current and the driving current of the light source before adjustment is the current adjustment amount.

Among them, since the current adjustment amount is determined based on the difference between the actual measured temperature of the digital micromirror device and the temperature threshold, when the target drive current is used to drive the light source to emit a beam, the temperature of the digital micromirror device will also decrease to the temperature threshold. Or below the temperature threshold, thereby achieving cooling processing of the digital micromirror device.

Step 808: Control the digital micromirror device to modulate the light beam emitted by the light source into a projection image.

Among them, the main control circuit cools down the digital micromirror device by increasing the fan speed and reducing 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. Thus, the performance of each device in the digital micromirror device can be ensured, and the service life of each device in the digital micromirror device can be ensured, thereby ensuring the effect of the digital micromirror device in modulating the image beam, effectively improving the projection The display effect of the device.

Among them, the sequence of the steps of the method for controlling the digital micromirror device of the projection device provided by the embodiments of the present application can be appropriately adjusted, and the steps can also be increased or decreased accordingly according to the situation. For example, step 806 can be deleted according to the situation. That is to say, the main control circuit can directly determine the current adjustment amount of the driving current of the light source based on the difference between the actual measured temperature of the digital micromirror device and the temperature threshold. Any person familiar with the technical field can easily think of changing methods within the technical scope disclosed in this application, which should be covered by the protection scope of this application, and therefore will not be described again.

The above embodiments of the present application provide a method for controlling a digital micromirror device of a projection device. This method can also be based on the temperature threshold corresponding to the digital micromirror device, and detect the actual measured temperature of the digital micromirror device through the temperature detection unit. When the measured temperature is greater than or equal to the temperature threshold, increase the speed of the fan to reduce the temperature of the digital micromirror. device temperature. Moreover, after the fan speed reaches the speed threshold, if the actual measured temperature of the digital micromirror device is still greater than or equal to the temperature threshold, the fan speed can be maintained at the speed threshold and the brightness of the light beam emitted by the light source can be reduced. As a result, the temperature of the digital micromirror device can be further reduced to prevent components inside the digital micromirror device from malfunctioning due to high temperatures, thereby effectively ensuring the display effect of the projection device.

FIG. 9 is a schematic structural diagram of a projection device provided by an embodiment of the present application. Referring to FIG. 9 , the projection device includes: a main control circuit 10 , a digital micromirror device 30 , a temperature detection unit 50 , a fan 60 and a light source 20 .

The temperature detection unit 50 is used to detect the actual temperature of the digital micromirror device 30 when the light beam emitted by the light source 20 irradiates the digital micromirror device 30 . The main control circuit 10 is used to increase the rotation speed of the fan 60 if it is determined that the actual measured temperature is greater than or equal to the temperature threshold. If the actual measured temperature is still greater than or equal to the temperature threshold after the rotation speed of the fan 60 reaches the rotational speed threshold, the fan 60 will maintain the rotation speed. threshold, and reduce the brightness of the light beam emitted by the light source 20, and control the digital micromirror device 30 to modulate the light beam emitted by the light source 20 into a projected 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 beam. Furthermore, the light beam emitted by the light source 20 can be irradiated to the digital micromirror device 30 . When the light beam emitted by the light source 20 irradiates the digital micromirror device 30 , the temperature detection unit 50 can detect the actual measured temperature of the digital micromirror device 30 , and the main control circuit 10 can further obtain the temperature detected by the temperature detection unit 50 . The measured temperature of the digital micromirror device 30 . The actual measured temperature of the digital micromirror device 30 may be the temperature inside the digital micromirror device 30 .

In a specific implementation, the temperature detection unit 50 can detect the actual temperature of the digital micromirror device 30 in real time. The main control circuit 10 can also obtain the actual measured temperature of the digital micromirror device 30 detected by the temperature detection unit 50 in real time, or the main control circuit 10 can periodically obtain the measured temperature of the digital micromirror device detected by the temperature detection unit 50 The measured temperature is 30. For example, the main control circuit 10 can obtain the actual measured temperature of the digital micromirror device 10 every 15 minutes.

After acquiring the actual measured temperature of the digital micromirror device 30 detected by the temperature detection unit 50, the main control circuit 10 can detect whether the actual measured temperature is greater than or equal to the temperature threshold. If the main control circuit 10 determines that the actual measured temperature is greater than or equal to the temperature threshold, it can increase the rotation speed of the fan 60 . During the rotation process, the fan 60 can dissipate the heat of the digital micromirror device 30 through the vents, thereby dissipating the heat of the digital micromirror device 30 . Therefore, the temperature of the digital micromirror device 30 can be effectively reduced.

The temperature threshold may be a temperature value determined based on the withstand temperature of the digital micromirror device 30 . For example, the temperature threshold may be less than or equal to the withstand temperature, and the withstand temperature may be 70°C. When the actual measured temperature of the digital micromirror device 30 is greater than or equal to the temperature threshold, the internal devices (such as hinges) of the digital micromirror device 30 may malfunction due to excessive temperature, thus affecting the modulation of the image beam by the digital micromirror device 30 Effect. Therefore, the main control circuit 10 can cool down the digital micromirror device 30 by increasing the rotation speed of the fan 60 to ensure the performance of each component in the digital micromirror device 30 .

After increasing the rotational speed of the fan 60, if the main control circuit 10 determines that the rotational speed of the fan 60 reaches the rotational speed threshold, it can again obtain the actual measured temperature of the digital micromirror device 30 detected by the temperature detection unit 50, and detect whether the actual measured temperature is greater than or equal to the temperature threshold. If the main control circuit 10 determines that the actual measured temperature is still greater than or equal to the temperature threshold, it can maintain the rotational speed of the fan 60 at the rotational speed threshold and reduce the brightness of the light beam emitted by the light source 20 . If the main control circuit 10 determines that the actual measured temperature of the digital micromirror device 30 is less than the temperature threshold, it does not need to reduce the brightness of the light beam emitted by the light source 20 and only needs to maintain the rotation speed of the fan 60 at the rotation speed threshold.

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

When the rotational speed of the fan 60 reaches the rotational speed threshold, the main control circuit 10 can determine that the rotational speed of the fan 60 has no limit. If the rotation speed continues to increase, the noise of the projection equipment will be too high. Therefore, the main control circuit 10 can continue to cool down the digital micromirror device 30 by reducing the brightness of the light beam emitted by the light source 20 .

Furthermore, when the light beam emitted by the light source 20 in the projection device irradiates the digital micromirror device 30 , the brightness of the light beam will affect the temperature of the digital micromirror device 30 . For example, the temperature of the digital micromirror device 30 will decrease as the brightness of the light beam emitted by the light source 20 decreases. Therefore, the main control circuit 10 can further reduce the temperature of the digital micromirror device 30 by reducing the brightness of the light beam emitted by the light source 20 .

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

The main control circuit 10 cools down the digital micromirror device 30 by increasing the rotation speed of the fan 60 and reducing the brightness of the light beam emitted by the light source 20, so that the temperature of the digital micromirror device 30 is lower than the temperature threshold. Therefore, the performance of each device in the digital micromirror device 30 can be ensured, and the service life of each device in the digital micromirror device 30 can be extended, thereby ensuring the effect of the digital micromirror device 30 in modulating the image beam, effectively Improved the display effect of the projection equipment.

In a specific implementation, the main control circuit 10 is used for:

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

In the embodiment of the present application, if the main control circuit 30 detects that the rotation speed of the fan 60 reaches the rotation speed threshold, and the actual measured temperature of the digital micromirror device 30 is greater than or equal to the temperature threshold, the rotation speed of the fan 60 can be maintained at the rotation speed threshold. And based on the difference between the actual measured temperature of the digital micromirror device 30 and the temperature threshold, the brightness adjustment amount of the projection image projected by the projection device is determined.

Among them, the brightness adjustment amount ΔL can satisfy:

Wherein, ΔT is the adjustment amount of the actual measured temperature of the digital micromirror device. The ΔT can be determined based on the difference between the actual measured temperature of the digital micromirror device 30 and the temperature threshold. For example, the ΔT can be greater than the actual measured temperature of the digital micromirror device 30 and the temperature threshold. The difference between the temperature thresholds. C is the conversion constant between the brightness of the light beam emitted by the light source 20 and the thermal power of the digital micromirror device 30 , and R is the thermal resistance constant of the digital micromirror device 30 .

The brightness of the light beam emitted by the light source 20 is positively related to the brightness adjustment amount of the projection image projected by the projection device. Therefore, the main control circuit 10 can determine the projection projected by the projection device based on the adjustment amount of the temperature of the digital micromirror device 30 . The adjustment amount of the brightness of the shadow image is determined, thereby determining the adjustment amount of the brightness of the light beam emitted by the light source 20 , thereby further reducing the temperature of the digital micromirror device 30 .

In a specific implementation, after determining the brightness adjustment amount of the light source 20 , the main control circuit 10 may further determine the current adjustment amount of the driving current of the light source 20 . Afterwards, the main control circuit 10 can 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 by the light source 20 by adjusting the driving current of the light source 20 .

Figure 10 is a schematic structural diagram of a digital micromirror device provided by an embodiment of the present application. Referring to Figure 10, the digital micromirror device 30 may include: a substrate 31, a plurality of micromirrors 32 located on the substrate, and a plurality of micromirrors. The mirror 32 corresponds to a plurality of hinges 33 connected one by one.

Each hinge 33 is used to control the flipping of a micromirror 32 connected to it. The temperature detection unit 50 is used to detect the temperature of the area on the substrate 31 where the plurality of hinges 33 are located. That is, the actual measured temperatures detected by the temperature detection unit 50 are the temperatures of the hinges 33 in the digital micromirror device 30 . The temperature threshold may be determined based on the withstand temperatures of the plurality of hinges 33 .

The plurality of micromirrors 32 in the digital micromirror device 30 correspond to the plurality of pixels in the projection image to be projected by the projection device. When the light beam projected by the light source 20 irradiates the plurality of micromirrors 32 on the digital micromirror device 30 , the plurality of hinges 33 can control the plurality of micromirrors 32 to flip based on the image data of the projection image to be displayed.

When the temperature of the area where the multiple hinges 33 in the digital micromirror device 30 are located exceeds the temperature threshold, the hinges 33 may malfunction. For example, hinge 33 breaks. Or the hinge 33 is not broken but is deformed, so that the hinge 33 cannot control the flipping of the micromirror 32 it is connected to based on the image data. This fault can also be called a hinge failure fault. When the hinge 33 fails, the hinge 33 cannot control the flipping of the micromirror 32 connected to it based on changes in image data, causing the pixel corresponding to the micromirror 32 to fail. Pixel failure means that some pixels in the projected image are white dots, black dots, or flickering dots. A pixel failure that is easily discernible to the human eye is a white point failure. When the white point failure occurs in the projected image, the display effect of the projected image will be seriously affected.

Therefore, in the embodiment of the present application, the temperature detection unit 50 can be used to detect the temperature of the area where the multiple hinges 33 are located on the substrate 31 of the digital micromirror device 30, and the temperature in the area where the multiple hinges 33 are located is greater than the temperature threshold, The digital micromirror device 30 is cooled down to avoid failures of the hinges 33 and to extend the service life of the hinges 33 .

Continuing to refer to FIG. 9 , the temperature detection unit 50 may include: a detection diode 51 and a temperature detection chip 52 . Among them, the detection diode 51 is located on the substrate 32 of the digital micromirror device 30 in the area where the plurality of hinges 33 are located. The temperature detection chip 52 is located outside the substrate 31 .

As shown in Figure 11, the first detection pin D+ of the temperature detection chip 52 and the first terminal of the detection diode 51 TEMP_P is connected, and the second detection pin D- of the temperature detection chip 52 is connected to the second terminal TEMP_N of the detection diode 51 .

In the embodiment of the present application, the detection diode 51 is used to detect the actual measured temperature in the area where the multiple hinges 33 on the substrate 31 of the digital micromirror device 30 are located, and transmit the actual measured temperature to the temperature detection chip 52 in the form of a differential signal. The first detection pin D+ and the second detection pin D-. The temperature detection chip 52 can process the differential signal to determine the actual measured temperature of the digital micromirror device 30 .

For example, the temperature detection chip 52 may be a TMP411 chip. The TMP411 can communicate with the main control circuit 10 through an internal integrated circuit (inter-integrated circuit, I2C) bus. The I2C bus includes a serial data line (SDA) and a serial clock line (SCL). Referring to FIG. 11 , the SDA terminal of the temperature detection chip 52 can be connected to the SDA terminal of the main control circuit 10 , and the SCL terminal of the temperature detection chip 52 can be connected to the SCL terminal of the main control circuit 10 . The temperature detection chip 52 can send the actual measured temperature of the digital micromirror device 30 to the SDA terminal of the main control circuit 10 through the SDA terminal, so that the main control circuit 10 can perform further processing based on the actual measured temperature.

In a specific implementation, continuing to refer to FIG. 11 , the temperature detection unit 50 may further include: a first resistor R1 , a second resistor R2 and a matching capacitor C1 .

As shown in Figure 11, the first resistor R1 is connected in series between the first detection pin D+ and the first terminal TEMP_P of the detection diode 51, and the second resistor R2 is connected in series between the second detection pin D- and the detection diode 51. between TEMP_N at the second end. One end of the matching capacitor C1 is connected to the first terminal TEMP_P of the detection diode 51 , and the other end of the matching capacitor C1 is connected to the second terminal TEMP_N of the detection diode 51 .

Among them, the first resistor R1 and the second resistor R2 are used for impedance matching and coupling with the matching capacitor C1 to ensure the integrity of the differential signal during transmission, thereby enabling actual measurement inside the digital micromirror device 30 Remote acquisition of temperature. For example, the resistance values of the first resistor R1 and the second resistor R2 may both be 51 kiloohms (kΩ). The capacitance value of the matching capacitor C1 may be 100 picofarads (pF).

In a specific implementation, continuing to refer to FIG. 11 , the temperature detection unit 50 may further include: a third resistor R3 , a fourth resistor R4 and a voltage stabilizing capacitor C2 .

As shown in FIG. 11 , one end of the third resistor R3 is connected to the first power 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 end of the temperature detection chip 52 . One end of the voltage stabilizing capacitor C2 is connected to the third power supply terminal V3 and the power supply terminal VCC of the temperature detection 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 to pull up the level of the SDA terminal of the main control circuit 10 and the SDA terminal of the temperature detection chip 52 through the first power supply terminal V1. The fourth resistor R4 is used to pull up the level of the SCL terminal of the main control circuit 10 and the SCL terminal of the temperature detection 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 detection chip 52 . For example, the resistance values of the third resistor R3 and the fourth resistor R4 may both be 10 kΩ, and the capacitance value of the voltage stabilizing capacitor C2 may be 0.1 microfarad (μF). The voltage value of the power supply connected to the first power supply terminal V1, the second power supply terminal V2 and the third power supply terminal V3 can be determined based on the operating voltage of the digital micromirror device 30, for example, the voltage of the power supply connected to the three power supply terminals The value may be a voltage value equal to the operating voltage of the digital micromirror device 30 . For example, when the operating voltage of the digital micromirror device 30 is 3.3 volts (V). The voltage value of the power supply connected to the three power supply terminals may also be 3.3V.

To sum up, the above embodiments of the present application provide a projection device. In a specific solution for specifically controlling the operating temperature of the digital micromirror device, the main control circuit in the projection device can illuminate the digital micromirror device with the light beam emitted by the light source. In the process of installing the micromirror device, the temperature detection unit detects the actual temperature of the digital micromirror device, and when the actual measured temperature is greater than or equal to the temperature threshold, the fan speed can be increased to reduce the temperature of the digital micromirror device. Moreover, after the fan speed reaches the speed threshold, if the actual measured temperature of the digital micromirror device is still greater than or equal to the temperature threshold, the main control circuit can maintain the fan speed at the speed threshold and reduce the brightness of the light beam emitted by the light source. . As a result, the temperature of the digital micromirror device can be further reduced to prevent components inside the digital micromirror device from malfunctioning due to high temperatures, thereby effectively ensuring the display effect of the projection device.

Moreover, embodiments of the present application also provide a projection device. The projection device may include a processor and a memory. Instructions are stored in the memory. The instructions are loaded and executed by the processor to implement the above method. The embodiments provide a digital micromirror device. Control method, such as the method shown in Figure 7 or Figure 8.

Embodiments of the present application provide a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. The computer program is loaded by a processor and executes the control method of a digital micromirror device provided in the above method embodiments. For example, the method shown in Figure 7 or Figure 8.

Embodiments of the present application also provide a computer program product containing instructions. When the computer program product is run on a computer, it causes the computer to execute the control method of the digital micromirror device provided by the above method embodiment, for example, as shown in Figure 7 or Figure 8 method shown.

Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware, or can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. The above-mentioned The storage media mentioned can be read-only memory, magnetic disks or optical disks, etc.

Next, the laser projection display device provided by the embodiment of the present application will be introduced.

Referring to Figure 14, an embodiment of the present application provides a laser projection display device 900. The device 900 includes:

The acquisition module 901 is used to obtain the grayscale value of the image to be displayed, where the image to be displayed is the next frame image of the currently displayed image;

Determination module 902, configured to determine the digital micromirror device corresponding to the image to be displayed based on the grayscale value of the image to be displayed. The first operating temperature threshold;

Control module 903, configured to control the operating temperature value of the digital micromirror device to decrease if the current operating temperature value of the digital micromirror device is higher than the first operating temperature threshold, so that the digital micromirror device displays the image to be displayed in the process of displaying the image. The operating temperature value is not higher than the first operating temperature threshold.

In a specific implementation, the determination module 902 is mainly used to:

Obtain the standard life value of the digital micromirror device;

Based on the grayscale value of the image to be displayed, determine the first micromirror bearing duty cycle of the digital micromirror device when displaying the image to be displayed;

Based on the first micromirror bearing duty cycle and the standard life value, the first operating temperature threshold is determined.

In a specific implementation, the determination module 902 is mainly used to:

Get the reference life value at the reference temperature;

Obtain the life acceleration factor corresponding to the duty cycle of the reference micromirror;

The first operating temperature threshold is determined based on the standard life value, the reference life value, the reference temperature, the life acceleration factor corresponding to the reference micromirror bearing duty cycle and the first micromirror bearing duty cycle.

In a specific implementation, the determination module 902 is mainly used to:

The first operating temperature threshold is determined by the following formula;

Among them, L is the standard life value, is the reference life value, ΔE is the preset activation energy value of the failure mechanism, k is the Boltzmann constant, and P is the molecule in the duty cycle of the first micromirror, which is used to characterize the micromirrors in digital micromirror devices. The percentage of time the micromirror is in the light-on state, M is the denominator in the duty cycle of the first micromirror, used to characterize the percentage of time the micromirror in the digital micromirror device is in the light-off state, β is The reference micromirror bears the life acceleration factor corresponding to the duty cycle, T _c is the reference temperature, and _Ti is the first operating temperature threshold.

In a specific implementation, the determination module 902 is mainly used to:

Based on the grayscale value of the image to be displayed, the first micromirror bearing duty cycle is determined through the following formula;

in, is the duty cycle of the first micromirror, and G is the gray value of the image to be displayed.

In a specific implementation, the control module 903 is mainly used for:

A first control command is sent to the heat dissipation unit, which includes a heat dissipation fan used to dissipate heat from the digital micromirror device. The first control command is used to instruct the rotation speed of the heat dissipation fan to increase to reduce the operating temperature of the digital micromirror device.

In a specific implementation, the device 900 is also used for:

If the current operating temperature value of the digital micromirror device is not higher than the first operating temperature threshold, the operating temperature value of the digital micromirror device is maintained not higher than the first operating temperature threshold.

In a specific implementation, the acquisition module 901 is mainly used for:

Obtain the red, green and blue RGB grayscale value of each pixel in the image to be displayed;

Based on the RGB gray value of each pixel in the image to be displayed, determine the gray value of the corresponding pixel;

Based on the gray value of each pixel in the image to be displayed, the gray value of the image to be displayed is determined.

In a specific implementation, the acquisition module 901 is mainly used for:

Determine the initial gray value of the first pixel based on the base color percentage corresponding to the R gray value, G gray value and B gray value respectively in the RGB value of the first pixel and the RGB gray value of the first pixel. , the first pixel is any pixel in the image to be displayed;

Perform gamma correction on the initial grayscale value of the first pixel point to obtain the grayscale value of the first pixel point.

In summary, in the above embodiments of the present application, different temperature thresholds are determined according to the grayscale values of different images, and then the operating temperature value of the digital micromirror device is adjusted in real time based on the different temperature thresholds, so that the digital micromirror The operating temperature value of the device during the display of different images can be lower than the operating temperature threshold corresponding to the corresponding image. Since the gray value of the image is positively related to the micromirror bearing duty cycle, the above solution can reduce the time required to display each frame. The micromirror during image processing can withstand the adverse effects of duty cycle and operating temperature on the life of the digital micromirror device, thereby increasing the service life of the digital micromirror device.

It should be noted that when the laser projection display device provided in the above embodiments controls the digital micromirror device to achieve image display, the division of the above functional modules is only used as an example. In practical applications, the above functions can be allocated according to needs. Different functional modules are completed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the laser projection display method embodiments of the laser projection display device provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be described again here.

Embodiments of the present application also provide a computer-readable storage medium. When instructions in the storage medium are executed by a processor, the laser projection display method provided by the above embodiments can be executed. For example, the computer-readable storage medium may be ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc. It is worth noting that the computer-readable storage media mentioned in the embodiments of this application may be non-volatile storage media, in other words, may be non-transitory storage media.

It should be understood that all or part of the steps to implement the above embodiments can be implemented through software, hardware, firmware, or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The computer instructions may be stored in the computer-readable storage medium described above.

That is, in some embodiments, a computer program product containing instructions is also provided, which when run on a computer causes the computer to execute the laser projection display method provided in the above embodiments.

The above description is not intended to limit the embodiments of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

A laser projection display method, characterized in that the method includes:

Obtain the grayscale value of the image to be displayed, which is the next frame image of the currently displayed image;

Based on the grayscale value of the image to be displayed, determine the first operating temperature threshold of the digital micromirror device corresponding to the image to be displayed;

If the current operating temperature value of the digital micromirror device is higher than the first operating temperature threshold, the operating temperature value of the digital micromirror device is controlled to decrease, so that the digital micromirror device displays the to-be-displayed The operating temperature value of the image process is not higher than the first operating temperature threshold.
The method of claim 1, wherein determining the first operating temperature threshold of the digital micromirror device corresponding to the image to be displayed based on the grayscale value of the image to be displayed includes:

Obtain the standard life value of the digital micromirror device;

Based on the grayscale value of the image to be displayed, determine the first micromirror bearing duty cycle of the digital micromirror device when displaying the image to be displayed;

The first operating temperature threshold is determined based on the first micromirror bearing duty cycle and the standard lifetime value.
The method of claim 2, wherein determining the first operating temperature threshold based on the first micromirror bearing duty cycle and the standard life value includes:

Get the reference life value at the reference temperature;

Obtain the life acceleration factor corresponding to the duty cycle of the reference micromirror;

Based on the standard life value, the reference life value, the reference temperature, the life acceleration factor corresponding to the reference micromirror bearing duty cycle and the first micromirror bearing duty cycle, the third micromirror bearing duty cycle is determined. an operating temperature threshold.
The method according to claim 3, characterized in that the life acceleration factor corresponding to the standard life value, the reference life value, the reference temperature, the reference micromirror bearing duty cycle and the The first micromirror relies on a duty cycle to determine the first operating temperature threshold, including:

The first operating temperature threshold is determined by the following formula;

Wherein, said is the standard life value, said is the reference life value, said is a preset failure mechanism activation energy value, said is Boltzmann's constant, said is said first micromirror The numerator in the bearing duty cycle is used to characterize the percentage of time that the micromirror in the digital micromirror device is in the light-on state, which is the denominator in the first micromirror bearing duty cycle. , used to characterize the percentage of time that the micromirror in the digital micromirror device is in the light-off state, where the said is the life acceleration factor corresponding to the duty cycle of the reference micromirror, and the said is the reference temperature, Said is the first operating temperature threshold.
The method according to any one of claims 2 to 4, characterized in that, based on the gray value of the image to be displayed, determining the first micromirror of the digital micromirror device when displaying the image to be displayed. Depends on duty cycle, including:

Based on the grayscale value of the image to be displayed, the first micromirror bearing duty cycle is determined through the following formula;

Wherein, the said is the duty cycle of the first micromirror, and the said is the grayscale value of the image to be displayed.
The method of claim 1, wherein the controlling the operating temperature value of the digital micromirror device to decrease includes:

Send a first control command to the heat dissipation unit, the heat dissipation unit includes a cooling fan for dissipating heat of the digital micromirror device, the first control command is used to instruct to increase the rotation speed of the cooling fan to reduce the Describe the operating temperature value of the digital micromirror device.
The method of claim 1, further comprising:

If the current operating temperature value of the digital micromirror device is not higher than the first operating temperature threshold, the operating temperature value of the digital micromirror device is maintained not higher than the first operating temperature threshold.
The method according to claim 1, characterized in that obtaining the grayscale value of the image to be displayed includes:

Obtain the red, green, and blue RGB grayscale values of each pixel in the image to be displayed;

Based on the RGB grayscale value of each pixel in the image to be displayed, determine the grayscale value of the corresponding pixel;

Based on the gray value of each pixel in the image to be displayed, the gray value of the image to be displayed is determined.
The method of claim 8, wherein determining the gray value of the corresponding pixel based on the RGB gray value of each pixel in the image to be displayed includes:

Based on the base color percentage corresponding to the R gray value, G gray value and B gray value respectively in the RGB value of the first pixel and the RGB gray value of the first pixel, determine the Initial gray value, the first pixel is any pixel in the image to be displayed;

Perform gamma correction on the initial gray value of the first pixel point to obtain the gray value of the first pixel point.
A laser projection display device, characterized in that the device includes:

An acquisition module, used to acquire the grayscale value of the image to be displayed, where the image to be displayed is the next frame image of the currently displayed image;

A determination module configured to determine the first operating temperature threshold of the digital micromirror device corresponding to the image to be displayed based on the grayscale value of the image to be displayed;

a control module, configured to control the operating temperature value of the digital micromirror device to decrease if the current operating temperature value of the digital micromirror device is higher than the first operating temperature threshold, so that the digital micromirror device The operating temperature value during displaying the image to be displayed is not higher than the first operating temperature threshold.