Safety projector and control method

Abstract

The invention relates to the technical field of projection control, and discloses a safety projector and a control method, and the safety projector comprises a safety projector used for projecting a picture onto a curtain, and an adjustment control unit used for adjusting the size, angle and picture definition of the projection picture, the safety projector and the control method have the advantages that in the projection process, heat dissipation protection is carried out on the projector, the safety of the projector is improved, the safety of the projector is improved, and the safety of the projector is improved. And the projection picture is automatically adjusted according to the number and the position of the audience, so that the projection picture is watched by the audience at a size and an angle which are more suitable for watching.

Description

Technical Field

[0001] The present invention relates to the technical field of projection control, in particular to a safety projector and a control method thereof. Background Art

[0002] A projector is a device that projects images or videos onto a screen or wall. It is widely used in education, business presentations, and entertainment. With the development of technology, the functions and performance of projectors have gradually improved, including aspects such as projection resolution, brightness, contrast, and color accuracy. In addition, it also involves the control method of the projector to achieve convenient operation and management, involving projection technology, display interface, remote control, automatic correction, and multi-screen interaction. These technologies are designed to provide high-quality projected images and provide convenient operation and management functions.

[0003] Projection technology: Projection technology involves choosing a suitable light source and projection method. Currently, common projection technologies include LCD projection, DLP (digital light processing) projection, and laser projection. Each technology has its own characteristics and application scenarios. For example, LCD projection has higher color accuracy, while laser projection has higher brightness and contrast. Display interface: In order to transmit video or image signals to the projector, an appropriate display interface is required. Common display interfaces include HDMI (High Definition Multimedia Interface), VGA (Video Graphics Array), DisplayPort, etc. These interfaces can provide high-quality image transmission and support multiple resolutions and audio output. Remote control: In order to facilitate users to operate and manage the projector, remote control technology can be used. Remote control is usually performed through It can be implemented wirelessly or wired, and may include a remote control, mobile phone application or network control interface. Through remote control, users can adjust the projector settings, switch input sources, adjust volume and other functions. Automatic correction: In order to ensure the quality of the projected image and adapt to different environmental conditions, some projectors have automatic correction functions. Automatic correction can include functions such as autofocus, auto cropping and automatic color calibration. These functions can provide a more convenient use experience and ensure the best effect of the projected image. Multi-screen interaction: With the development of multimedia technology, some projectors can support multi-screen interaction functions, which means that users can display content on multiple projection screens at the same time and interact and collaborate. Multi-screen interaction can provide a more attractive and interactive experience in scenarios such as teaching, conferences and presentations.

[0004] Existing projectors are mostly used for playing videos, etc., and the automatic calibration is mostly automatic focus, automatic cropping and automatic color calibration. It is impossible to automatically adjust the projected image according to the number and position of the audience, which makes the audience's viewing experience lacking, and its practicality also has certain limitations. Summary of the invention

[0005] The present invention provides a safety projector and a control method, which promotes solving the automatic adjustment process mentioned in the above background technology. The adjustment control unit obtains the number of people in the target scene and the seat positions of the audience in the scene through an information collection unit, calculates the vertical distance a from each audience to the screen, and compares and sorts the values ​​of each vertical distance a from small to large. The vertical distance a with the largest value indicates that the audience is farthest from the screen, and vice versa, it indicates that the audience is closest to the screen. According to the distance between the audience and the screen, an adjustment strategy is formed. The adjustment strategy includes a first adjustment strategy, a second adjustment strategy, a third adjustment strategy, and a fourth adjustment strategy. All operations for adjusting the size of the projection screen, including the first adjustment strategy, include an adjustment range, and the size of the projection screen needs to be adjusted within the adjustment range.

[0006] The present invention provides the following technical solution: a safety projector, comprising:

[0007] Projection unit: used to enter working mode from sleep mode after receiving projection data, and project the image beam of the received projection data onto the screen;

[0008] Communication unit: used to establish a wired or wireless connection with the projection data providing device, so that the projection unit can receive the projection data and perform projection;

[0009] Processing unit: used to store and process data, thereby driving the adjustment control unit to adjust the projection image according to the collected data;

[0010] Heat dissipation unit: used to dissipate heat from the internal components of the projector when it is projecting, to prevent the projector from malfunctioning due to high temperature, which could cause a fire, etc.

[0011] As an optional solution of the security projector and control method of the present invention, wherein: an adjustment control unit is included, and the adjustment control unit includes an adjustment data unit and an information collection unit;

[0012] The adjustment control unit obtains the number of people in the target scene and the seating positions of the audience in the scene through the information collection unit, calculates the vertical distance a from each audience to the screen, and compares and sorts the values ​​of each vertical distance a from large to small. The vertical distance a with the largest value indicates that the audience is farthest from the screen, and vice versa, it indicates that the audience is closest to the screen. The audience with the largest vertical distance a value is the first long-distance audience, and the audience is sorted from large to small according to the vertical distance a values, which are the second long-distance audience, the third long-distance audience, etc. The adjustment data unit makes a series of adjustments to the projection picture according to the distance between the audience and the screen to form an adjustment strategy.

[0013] As an optional solution of the security projector and control method of the present invention, wherein: the adjustment strategy includes a first adjustment strategy;

[0014] The first adjustment strategy: before each playback, the projection image is enlarged or reduced for debugging, so that each projection image is projected according to the farthest distance from the audience to the screen, and the vertical distance a to the screen is the largest, that is, the position information of the first remote audience. According to the position information of the audience, a size range of the projection image is determined, and the minimum value in the range is preferentially selected according to the size range. After the projection, the position information of the first remote audience is obtained again, and it is determined whether the size is suitable for viewing according to the actual situation of the audience. If it is an inappropriate size or the audience position is adjusted during the debugging time, the image projected to the screen is enlarged or reduced again.

[0015] As an optional solution of the security projector and control method of the present invention, wherein: the adjustment strategy also includes a second adjustment strategy;

[0016] After the first adjustment strategy is implemented, the picture clarity is obtained, and according to the picture clarity, whether the projection picture is blurry to the audience is analyzed, a picture analysis unit is formed, and according to the picture analysis unit, a judgment strategy is formed for the picture clarity, and according to the judgment strategy, a second adjustment strategy is adopted;

[0017] The second adjustment strategy: if the picture is the first clear picture, no adjustment is required. If the picture is the third clear picture, the picture projected onto the screen is first enlarged or reduced as a whole. If enlarging or reducing the picture can change the picture clarity, and the overall enlargement or reduction is large, the enlargement adjustment of the picture by the first adjustment strategy is abandoned, the picture size is readjusted, the second remote audience position data is selected to adjust the picture size, and the picture is adjusted again using the first adjustment strategy based on the acquired information. After the adjustment, the projected picture is analyzed again using the picture analysis unit and the judgment strategy. If the picture is the first clear picture, no adjustment is required. If the picture is still the third clear picture, the resizing operation is repeated. If the picture is the second clear picture, the picture is partially adjusted, and the local adjustment includes adjusting the projection picture resolution, focus, etc.

[0018] As an optional solution of the security projector and control method of the present invention, wherein: all operations for adjusting the size of the projection screen including the first adjustment strategy include an adjustment range, and the size of the projection screen needs to be adjusted within the adjustment range;

[0019] Adjustment range: Get the projection range of the screen. The screen frame is used as the boundary. The area inside the boundary is the projection range, and the area outside the boundary is the non-projection range. If the size of the projected image matches the projection range, it is the maximum projection size threshold. With the center of the screen as the center and a polygon with the same shape as the screen at a specified distance as the specified range, if the size of the projected image matches the specified range, it is the minimum projection size threshold.

[0020] As an optional solution of the security projector and control method of the present invention, wherein: the adjustment strategy also includes a third adjustment strategy;

[0021] The third adjustment strategy: Get the border information b(e 1 , f 1 ), including the horizontal information of the curtain frame 1 , vertical information 1 , get the border information c(e) of the image projected onto the screen 2 , f 2 ), including the horizontal information of the projected picture frame 2 , vertical information 2 , obtain the frame information d(e) of the image in the projection data 3 , f 3 ), including the horizontal information of the original picture border 3 , vertical information 3 , according to the border information b, c, d, the projection image is adjusted so that b, c, d are proportional or equal data after adjustment.

[0022] As an optional solution of the security projector and control method of the present invention, wherein: the adjustment strategy also includes a fourth adjustment strategy;

[0023] The fourth adjustment strategy: obtain the angle g between the audience in the middle of the first row and the left and right frames of the projection screen, and obtain the optimal angle h of human vision. When the angle g<the angle h, no adjustment is made. When the angle g>the angle h, the audience is reminded to adjust their viewing position so that they can adjust to the optimal viewing position to watch the projection screen.

[0024] As an optional solution of the security projector and control method of the present invention, wherein: the picture analysis unit includes the steps of acquisition, segmentation, detection, and classification;

[0025] Acquisition: Get a frame of image from the projection screen;

[0026] Segmentation: segmenting the acquired image into several sub-images;

[0027] Detection: Detect several segmented sub-images to determine whether they are blurred;

[0028] Classification: Classify the blur judgment of sub-images, and record the data of sub-images judged as clear and blurred respectively. If more than 80% of the sub-images are judged as clear images, the projected picture is judged as the first clear picture. If less than 80% of the sub-images are judged as clear images, the projected picture is judged as a blurred picture.

[0029] As an optional solution of the security projector and control method of the present invention, wherein: the judgment strategy judges and grades the projection picture determined as a blurred picture in the picture analysis unit;

[0030] The blurred images are graded into the second clear image and the third clear image. If 50%-80% of the sub-images are judged to be clear images, the blurred image is determined as the second clear image. If less than 50% of the sub-images are judged to be clear images, the blurred image is determined as the third clear image.

[0031] The present invention has the following beneficial effects:

[0032] 1. The security projector and control method change the size, clarity, angle, etc. of the projection image by adjusting the adjustment strategy formed by the control unit, and adjust the projection image to a degree suitable for the audience to watch according to the number and position of the audience.

[0033] 2. The security projector and control method analyze the clarity of the projected image through the image analysis unit to determine whether the image is blurred. If blurred, the projected image is adjusted through an adjustment strategy to adjust it to a clear image for the audience to watch.

[0034] 3. The security projector and control method, through a judgment strategy, judges and grades the projection picture determined as a blurred picture by the picture analysis unit, and divides it into a second clear picture and a third clear picture. According to the judgment and grading, it is decided whether to adjust the projection picture as a whole or locally, so that the final projection picture is clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a system block diagram of the security projector and control method of the present invention;

[0036] Figure 2 This is a schematic diagram of a usage scenario of the present invention;

[0037] Figure 3 This is a schematic diagram of adjusting the range threshold of the present invention;

[0038] Figure 4 This is a schematic diagram of adjusting the scope of information acquisition of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the related art, the adjustment control unit includes an adjustment data unit and an information collection unit. The adjustment control unit obtains the number of people in the target scene and the seating positions of the audience in the scene through the information collection unit, calculates the vertical distance a from each audience to the screen, and compares and sorts the values ​​of each vertical distance a from large to small. The vertical distance a with the largest value indicates that the audience is farthest from the screen, and vice versa, it indicates that the audience is closest to the screen. The audience with the largest vertical distance a is the first long-distance audience, and the audience is sorted from large to small according to the vertical distance a value, in order, the second long-distance audience, the third long-distance audience, etc. The adjustment data unit makes a series of adjustments to the projection picture according to the distance between the audience and the screen to form an adjustment strategy.

[0041] Among them, the first adjustment strategy is: before each playback, the projection picture is enlarged or reduced for debugging, so that each projection picture is projected according to the farthest distance from the audience to the screen, and the vertical distance a collected to the screen is the largest, that is, the position information of the first remote audience. According to the position information of the audience, a size range of the projection picture is determined, and the minimum value in the range is preferentially selected according to the size range. After the projection, the position information of the first remote audience is obtained again, and it is determined whether the size is suitable for viewing according to the actual situation of the audience. If it is an inappropriate size or the audience position is adjusted during the debugging time, the picture projected to the screen is enlarged or reduced again.

[0042] After the first adjustment strategy is implemented, the picture clarity is obtained, and based on the picture clarity, it is analyzed whether the projected picture is blurry to the audience, forming a picture analysis unit, and based on the picture analysis unit, a judgment strategy for the picture clarity is formed, and based on the judgment strategy, the second adjustment strategy is adopted.

[0043] Among them, the second adjustment strategy: if the picture is the first clear picture, no adjustment is required. If the picture is the third clear picture, the picture projected to the screen is first enlarged or reduced as a whole. If enlarging or reducing the picture can change the picture clarity, and the overall enlargement or reduction degree is large, the enlargement adjustment of the picture by the first adjustment strategy is abandoned, the picture size is readjusted, and the second remote audience position data is selected to adjust the picture size. The picture is adjusted again using the first adjustment strategy based on the acquired information. After the adjustment, the projected picture is analyzed again using the picture analysis unit and the judgment strategy. If the picture is the first clear picture, no adjustment is required. If the picture is still the third clear picture, the resizing operation is repeated. If the picture is the second clear picture, the picture is partially adjusted, and the local adjustment includes adjusting the projection picture resolution, focus, etc.

[0044] Among them, the third adjustment strategy: obtain the border information b(e 1 , f 1 ), including the horizontal information of the curtain frame 1 , vertical information 1 , get the border information c(e) of the image projected onto the screen 2 , f 2 ), including the horizontal information of the projected image border 2 , vertical information 2 , obtain the frame information d(e) of the image in the projection data 3 , f 3 ), including the horizontal information of the original picture border 3 , vertical information 3 , according to the border information b, c, d, the projection image is adjusted so that b, c, d are proportional or equal data after adjustment.

[0045] Among them, the fourth adjustment strategy is: obtain the angle g between the audience in the middle of the first row and the left and right frames of the projection screen, and obtain the optimal angle h of human vision. When the angle g<the angle h, no adjustment is made. When the angle g>the angle h, the audience is reminded to adjust the viewing position so that the audience can adjust to the optimal viewing position to watch the projection screen.

[0046] After the first adjustment strategy is implemented, the picture clarity is obtained, and based on the picture clarity, it is analyzed whether the projected picture is blurry to the audience, forming a picture analysis unit, and based on the picture analysis unit, a judgment strategy for the picture clarity is formed, and based on the judgment strategy, the second adjustment strategy is adopted.

[0047] Among them, all operations for adjusting the size of the projection picture, including the first adjustment strategy, include an adjustment range, and the size of the projection picture needs to be adjusted within the adjustment range.

[0048] In an embodiment of the present application, the judgment strategy judges and grades the projection picture determined as a blurred picture in the picture analysis unit, and divides it into a second clear picture and a third clear picture. If 50%-80% of the sub-pictures in the sub-pictures are judged as clear images, the blurred picture is determined as the second clear picture. If less than 50% of the sub-pictures in the sub-pictures are judged as clear images, the blurred picture is determined as the third clear picture.

[0049] Example

[0050] A safety projector, comprising:

[0051] Projection unit: used to enter working mode from sleep mode after receiving projection data, and project the image beam of the received projection data onto the screen;

[0052] Communication unit: used to establish a wired or wireless connection with the projection data providing device, so that the projection unit can receive the projection data and perform projection;

[0053] Processing unit: used to store and process data, thereby driving the adjustment control unit to adjust the projection image according to the collected data;

[0054] Heat dissipation unit: used to dissipate heat from the internal components of the projector when it is projecting, to prevent the projector from malfunctioning due to high temperature, which could cause a fire, etc.

[0055] A safety projector and a control method, comprising:

[0056] An adjustment control unit, the adjustment control unit comprising a data adjustment unit and an information collection unit;

[0057] like Figure 2 As shown, the adjustment control unit obtains the number of people in the target scene and the seating positions of the audience in the scene through the information collection unit, calculates the vertical distance a from each audience to the screen, and compares and sorts the values ​​of each vertical distance a from large to small. The vertical distance a with the largest value indicates that the audience is farthest from the screen, and vice versa, it indicates that the audience is closest to the screen. The audience with the largest vertical distance a is the first long-distance audience, and the vertical distance a values ​​are sorted from large to small, such as the second long-distance audience, the third long-distance audience, etc. The adjustment data unit makes a series of adjustments to the projection picture according to the distance between the audience and the screen to form an adjustment strategy.

[0058] The adjustment strategy includes a first adjustment strategy;

[0059] The first adjustment strategy: before each playback, the projection image is enlarged or reduced for debugging, so that each projection image is projected according to the farthest distance from the audience to the screen, and the vertical distance a to the screen is the largest, that is, the position information of the first remote audience. According to the position information of the audience, a size range of the projection image is determined, and the minimum value in the range is preferentially selected according to the size range. After the projection, the position information of the first remote audience is obtained again, and it is determined whether the size is suitable for viewing according to the actual situation of the audience. If it is an inappropriate size or the audience position is adjusted during the debugging time, the image projected to the screen is enlarged or reduced again.

[0060] The adjustment strategy also includes a second adjustment strategy;

[0061] After the first adjustment strategy is implemented, the picture clarity is obtained, and according to the picture clarity, whether the projection picture is blurry to the audience is analyzed, a picture analysis unit is formed, and according to the picture analysis unit, a judgment strategy is formed for the picture clarity, and according to the judgment strategy, a second adjustment strategy is adopted;

[0062] The second adjustment strategy: if the picture is the first clear picture, no adjustment is required. If the picture is the third clear picture, the picture projected onto the screen is first enlarged or reduced as a whole. If enlarging or reducing the picture can change the picture clarity, and the overall enlargement or reduction is large, the enlargement adjustment of the picture by the first adjustment strategy is abandoned, the picture size is readjusted, the second remote audience position data is selected to adjust the picture size, and the picture is adjusted again using the first adjustment strategy based on the acquired information. After the adjustment, the projected picture is analyzed again using the picture analysis unit and the judgment strategy. If the picture is the first clear picture, no adjustment is required. If the picture is still the third clear picture, the resizing operation is repeated. If the picture is the second clear picture, the picture is partially adjusted, and the local adjustment includes adjusting the projection picture resolution, focus, etc.

[0063] The adjustment strategy also includes a third adjustment strategy;

[0064] The third adjustment strategy: Get the border information b(e 1 , f 1 ), including the horizontal information of the curtain frame 1 , vertical information 1 , get the border information c(e) of the image projected onto the screen 2 , f 2 ), including the horizontal information of the projected image border 2 , vertical information 2 , obtain the frame information d(e) of the image in the projection data 3 , f 3), including the horizontal information of the original picture border 3 , vertical information 3 , according to the border information b, c, d, the projection image is adjusted so that b, c, d are proportional or equal data after adjustment.

[0065] The adjustment strategy also includes a fourth adjustment strategy;

[0066] The fourth adjustment strategy: obtain the angle g between the audience in the middle of the first row and the left and right frames of the projection screen, and obtain the optimal angle h of human vision. When the angle g<the angle h, no adjustment is made. When the angle g>the angle h, the audience is reminded to adjust their viewing position so that they can adjust to the optimal viewing position to watch the projection screen.

[0067] In the security projector and control method, all operations for adjusting the size of the projection screen, including the first adjustment strategy, include an adjustment range, and the size of the projection screen needs to be adjusted within the adjustment range;

[0068] Adjustment range: Figure 3 , 4 As shown, the projection range of the screen is obtained, with the screen frame as the boundary, the area within the boundary is the projection range, and the area outside the boundary is the non-projection range. If the projection screen size is consistent with the projection range, it is the maximum projection size threshold. With the center of the screen as the center and a polygon with the same shape as the screen at a specified distance as the specified range, if the projection screen size is consistent with the specified range, it is the minimum projection size threshold.

[0069] This solution takes into account that it is more complicated to determine whether the image is clear and to define the image clarity, and the second adjustment strategy needs to adjust the clarity of the projected image based on the determined image clarity.

[0070] In this embodiment, the picture analysis unit includes the steps of collection, segmentation, detection, and classification;

[0071] Acquisition: Get a frame of image from the projection screen;

[0072] Segmentation: segmenting the acquired image into several sub-images;

[0073] Detection: Detect several segmented sub-images to determine whether they are blurred;

[0074] Classification: Classify the blur judgment of sub-images, and record the data of sub-images judged as clear and blurred respectively. If more than 80% of the sub-images are judged as clear images, the projected picture is judged as the first clear picture. If less than 80% of the sub-images are judged as clear images, the projected picture is judged as a blurred picture.

[0075] In this embodiment, the judgment strategy judges and grades the projection picture determined as a blurred picture in the picture analysis unit;

[0076] The blurred images are graded into the second clear image and the third clear image. If 50%-80% of the sub-images are judged to be clear images, the blurred image is determined as the second clear image. If less than 50% of the sub-images are judged to be clear images, the blurred image is determined as the third clear image.

[0077] The projection data providing device in the embodiments of the present disclosure may include, but is not limited to, mobile terminals such as laptop computers, PADs (tablet computers), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), and the like, as well as fixed terminals.

[0078] The projection data providing device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) or a program loaded from a storage device into a random access memory (RAM). In the RAM, various programs and data required for the operation of the electronic device are also stored. The processing device, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0079] Typically, the following devices may be connected to the I / O interface: input devices including, for example, a touch screen, a touch pad, an image sensor, a microphone, etc.; output devices including, for example, a liquid crystal display (LCD), a speaker, etc.; storage devices including, for example, a magnetic tape, a hard disk, etc.; and communication devices. The communication devices may allow the projection data providing device to communicate with other devices wirelessly or by wire to exchange data.

[0080] The embodiment of the present disclosure further provides a non-transitory computer-readable storage medium, which stores computer instructions for causing the computer to execute the security projector and control method in the aforementioned method embodiment.

[0081] It should be noted that more specific examples of computer-readable storage media may include portable computer disks, hard disks, erasable programmable read-only memories (EPROMs or flash memories), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the present disclosure, computer-readable storage media may be any tangible medium that contains or stores a program, which may be used by or in conjunction with an instruction execution system, apparatus, or device, and the computer-readable medium may be contained in the electronic device; or it may exist independently without being assembled into the electronic device.

[0082] The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device can implement the solution provided by the method embodiment.

[0083] Computer program code for performing operations of the present disclosure may be written in one or more programming languages ​​or a combination thereof, and may be executed entirely on a user's computer, partially on a user's computer, as a stand-alone software package, partially on a user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0084] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A security projector, characterized in that: include: Projection unit: used to enter working mode from sleep mode after receiving projection data, and project the image beam of the received projection data onto the screen; Communication unit: used to establish a wired or wireless connection with the projection data providing device, so that the projection unit can receive the projection data and perform projection; Processing unit: used to store and process data, thereby driving the adjustment control unit to adjust the projection image according to the collected data; Heat dissipation unit: used to dissipate heat from the internal components of the projector when it is projecting, to prevent the projector from malfunctioning due to high temperature, which could cause a fire, etc.

2. The control method of the security projector according to claim 1, characterized in that: It includes an adjustment control unit, which includes an adjustment data unit and an information collection unit; The adjustment control unit obtains the number of people in the target scene and the seating positions of the audience in the scene through the information collection unit, calculates the vertical distance a from each audience to the screen, and compares and sorts the values ​​of each vertical distance a from large to small. The vertical distance a with the largest value indicates that the audience is farthest from the screen, and vice versa, it indicates that the audience is closest to the screen. The audience with the largest vertical distance a value is the first long-distance audience, and the audience is sorted from large to small according to the vertical distance a values, which are the second long-distance audience, the third long-distance audience, etc. The adjustment data unit makes a series of adjustments to the projection picture according to the distance between the audience and the screen to form an adjustment strategy.

3. The control method of the security projector according to claim 2, characterized in that: The adjustment strategy includes a first adjustment strategy; The first adjustment strategy: before each playback, the projection image is enlarged or reduced for debugging, so that each projection image is projected according to the farthest distance from the audience to the screen, and the vertical distance a to the screen is the largest, that is, the position information of the first remote audience. According to the position information of the audience, a size range of the projection image is determined, and the minimum value in the range is preferentially selected according to the size range. After the projection, the position information of the first remote audience is obtained again, and it is determined whether the size is suitable for viewing according to the actual situation of the audience. If it is an inappropriate size or the audience position is adjusted during the debugging time, the image projected to the screen is enlarged or reduced again.

4. The control method of the security projector according to claim 3, characterized in that: The adjustment strategy also includes a second adjustment strategy; After the first adjustment strategy is implemented, the picture clarity is obtained, and according to the picture clarity, whether the projection picture is blurry to the audience is analyzed, a picture analysis unit is formed, and according to the picture analysis unit, a judgment strategy is formed for the picture clarity, and according to the judgment strategy, a second adjustment strategy is adopted; The second adjustment strategy: if the picture is the first clear picture, no adjustment is required. If the picture is the third clear picture, the picture projected onto the screen is first enlarged or reduced as a whole. If enlarging or reducing the picture can change the picture clarity, and the overall enlargement or reduction is large, the enlargement adjustment of the picture by the first adjustment strategy is abandoned, the picture size is readjusted, the second remote audience position data is selected to adjust the picture size, and the picture is adjusted again using the first adjustment strategy based on the acquired information. After the adjustment, the projected picture is analyzed again using the picture analysis unit and the judgment strategy. If the picture is the first clear picture, no adjustment is required. If the picture is still the third clear picture, the resizing operation is repeated. If the picture is the second clear picture, the picture is partially adjusted, and the local adjustment includes adjusting the projection picture resolution, focus, etc.

5. The control method of the security projector according to claim 4, characterized in that: All operations for adjusting the size of the projection image, including the first adjustment strategy, include an adjustment range, and the size of the projection image must be adjusted within the adjustment range; Adjustment range: Get the projection range of the screen. The screen frame is used as the boundary. The area inside the boundary is the projection range, and the area outside the boundary is the non-projection range. If the size of the projected image matches the projection range, it is the maximum projection size threshold. With the center of the screen as the center and a polygon with the same shape as the screen at a specified distance as the specified range, if the size of the projected image matches the specified range, it is the minimum projection size threshold.

6. The control method of the security projector according to claim 4, characterized in that: The adjustment strategy also includes a third adjustment strategy; The third adjustment strategy: obtain the border information b (e1, f1) of the curtain border, including the horizontal information e1 and the vertical information f1 of the curtain border, obtain the border information c (e2, f2) of the picture projected onto the curtain, including the horizontal information e2 and the vertical information f2 of the projected picture border, obtain the border information d (e3, f3) of the picture in the projection data, including the horizontal information e3 and the vertical information f3 of the original picture border, and adjust the projected picture according to the border information b, c, d so that b, c, d are proportional or equal data after adjustment.

7. The control method of the security projector according to claim 4, characterized in that: The adjustment strategy also includes a fourth adjustment strategy; The fourth adjustment strategy: obtain the angle g between the audience in the middle of the first row and the left and right frames of the projection screen, and obtain the optimal angle h of human vision. When the angle g<the angle h, no adjustment is made. When the angle g>the angle h, the audience is reminded to adjust their viewing position so that they can adjust to the optimal viewing position to watch the projection screen.

8. The control method of the security projector according to claim 4, characterized in that: The picture analysis unit includes the steps of collection, segmentation, detection and classification; Acquisition: Get a frame of image from the projection screen; Segmentation: segmenting the acquired image into several sub-images; Detection: Detect several segmented sub-images to determine whether they are blurred; Classification: Classify the blur judgment of sub-images, and record the data of sub-images judged as clear and blurred respectively. If more than 80% of the sub-images are judged as clear images, the projected picture is judged as the first clear picture. If less than 80% of the sub-images are judged as clear images, the projected picture is judged as a blurred picture.

9. The control method of the security projector according to claim 8, characterized in that: The judgment strategy judges and grades the projection picture determined as a blurred picture in the picture analysis unit; The blurred images are graded into the second clear image and the third clear image. If 50%-80% of the sub-images are judged to be clear images, the blurred image is determined as the second clear image. If less than 50% of the sub-images are judged to be clear images, the blurred image is determined as the third clear image.

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