Projection control methods, projection equipment and storage media

Abstract

This application discloses a projection control method, projection device, and storage medium. The method involves: acquiring a target projection distance; matching the target projection distance with an initial hazard detection range; determining the target hazard detection range based on the matching result; determining whether a target object exists within the target hazard detection range; and if so, controlling the reduction of the projection device's display output brightness. This method determines and adapts the target hazard detection range based on the matching result between the target projection distance and the initial hazard detection range, avoiding misjudgments caused by dust and ambient light. Furthermore, if a target object is found within the target hazard detection range, the method controls the reduction of the projection device's display output brightness, improving the reliability of the projection device's eye protection and the user experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser projection technology, and more particularly, to a projection control method, a projection device, and a storage medium. BACKGROUND

[0002] With the development of display technology, the application of projection devices is more and more widely, including education projectors, home projectors, and engineering projectors, etc. Projection technology has brought great changes to people's life, study and work. The light source of projection display has also developed from UHP bulb, xenon lamp, LED to laser, laser fluorescent powder, etc. today, which makes the performance of projection technology in all aspects have a great leap, such as laser projection technology. Laser projection technology uses laser as light source, which can most realistically reproduce the rich and gorgeous colors of the objective world, provide more powerful performance, and the laser light source has longer service life and high reliability. However, in order to improve the display brightness, the projection device emitting laser needs high power, and the laser spectrum is narrow and high in intensity, which is easy to cause harm to the human eye. SUMMARY

[0003] In view of the above problems, the present application provides a projection control method, a projection device, and a storage medium to improve the above problems.

[0004] In a first aspect, an embodiment of the present application provides a projection control method, the method comprising: acquiring a target projection distance; matching the target projection distance with an initial dangerous detection range; determining a target dangerous detection range according to the matching result; judging whether there is a target object in the target dangerous detection range; and if so, controlling to reduce the display output brightness of the projection device.

[0005] In a second aspect, an embodiment of the present application provides a projection device, comprising a data acquisition module, a projection module, and a projection control module; the data acquisition module is configured to acquire a target projection distance; the projection control module is configured to match the target projection distance with an initial dangerous detection range, and determine a target dangerous detection range according to the matching result; the data acquisition module is further configured to judge whether there is a target object in the target dangerous detection range; and the projection control module is further configured to control to reduce the display output brightness of the projection module when there is a target object according to the judgment result of the data acquisition module.

[0006] In a third aspect, an embodiment of the present application provides a computer readable storage medium, the computer readable storage medium stores program codes, wherein the program codes perform the method of the first aspect when running.

[0007] The projection control method, the projection device and the storage medium provided by the application, by acquiring a target projection distance, then matching the target projection distance with an initial dangerous detection range, determining a target dangerous detection range according to the matching result, then judging whether there is a target object in the target dangerous detection range, if there is, controlling to reduce the display output brightness of the projection device. Thus, the above-mentioned method can determine and adapt the target dangerous detection range according to the matching result of the target projection distance and the initial dangerous detection range, can avoid the misjudgment caused by dust and environmental light, further judges the case that there is a target object in the target dangerous detection range, controls to reduce the display output brightness of the projection device to adapt to the human eye, improves the reliability of the human eye protection of the projection device, and improves the user experience. BRIEF DESCRIPTION OF DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0009] Figure 1 The structure schematic diagram of the projection control system proposed by the embodiments of the application is shown.

[0010] Figure 2 The method flowchart of the projection control method proposed by an embodiment of the application is shown.

[0011] Figure 3 The installation distance setting schematic diagram of the adjacent ranging sensors proposed by the embodiments of the application is shown.

[0012] Figure 4 The method flowchart of the projection control method proposed by another embodiment of the application is shown.

[0013] Figure 5 The installation position of the TOF laser ranging sensor proposed by the embodiments of the application is shown.

[0014] Figure 6 Another example diagram of the installation position of the TOF laser ranging sensor proposed by the embodiments of the application is shown.

[0015] Figure 7 The structure schematic diagram between the projection device and the glass covered by the projection device proposed by the embodiments of the application is shown.

[0016] Figure 8 The method flowchart of the projection control method proposed by another embodiment of the application is shown.

[0017] Figure 9 A structural block diagram of a projection device for performing a projection control method according to an embodiment of the present application is shown.

[0018] Figure 10 A storage unit for storing or carrying program code for implementing a projection control method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0020] With the improvement of various aspects of the projection device, more projection devices can support laser as a light source to truly reproduce the rich and bright colors of the objective world. However, the inventors have found in research that in the process of displaying image content of different colors, not only does the display color gamut coverage rate of the image content need to reach more than 90% of the color space that can be recognized by the human eye, but the display brightness also needs to be improved to a certain extent. However, in order to improve the display brightness, the laser emitting laser needs to have high power and the laser spectrum is narrow and high in intensity, which is easy to cause harm to the human eye. And the harm caused to the human eye by different intensity lasers in the same time or the same intensity lasers in different times is not the same.

[0021] The International Electrotechnical Commission (IEC) and the Food and Drug Administration (FDA) have made safety classification and related test regulations for projection products with laser light sources (as shown in Table 1 below). Since the risk level of laser projectors generally belongs to RG2 or RG3, in order to prevent laser from causing harm to the human eye, the projector needs to be turned off or weakened within 0.25s or even shorter time when the human eye approaches the laser, so as to protect the human eye.

[0022] Table 1 Exposure time limit of IEC62471 for different risk levels and different types of light

[0023]

[0024] The prior art usually sets a human eye protection device in the projection device, specifically, when it is detected that a person enters the projection area, the response is made in time, which can prevent the strong projection laser from causing harm to the human eye to a certain extent, but the detection range has a blind area and a high misjudgment rate, which reduces the reliability of the human eye laser protection measure and has a low safety factor, causing a poor user experience, and the response speed is slow, so that the projection device still has a risk of harm to the human eye.

[0025] Therefore, in order to improve the above problems, the present application provides a projection control method and a projection device which can update the target danger detection range of the ranging sensor according to the actual target detection distance obtained in real time and at a high speed and without interruption by the multiple ranging sensors, so as to flexibly and quickly control the projection display brightness of the projection device, so that the safety factor of the projection device can be greatly improved, and the user experience is enhanced.

[0026] First, the projection control system involved in the projection control method provided by the embodiments of the present application will be introduced.

[0027] As shown in Figure 1 , it is a structure schematic diagram of the projection control system 10 provided by the embodiments of the present application. The projection control system 10 includes a data acquisition module 11, a projection module 12 and a projection control module 13. The data acquisition module 11 is electrically connected with the projection module 12, and the projection module 12 is electrically connected with the projection control module 13.

[0028] As a way, the data acquisition module 11 can be used to acquire the target projection distance. The projection control module 13 can further acquire the target projection distance from the data acquisition module 11, match the target projection distance with the initially set danger detection range, and determine the target danger detection range according to the matching result. The data acquisition module 11 can also acquire the target danger detection range from the projection control module 13, further judge whether there is a target object in the target danger detection range, and return the judgment result to the projection control module 13. The projection control module 13 is also used to control the display output brightness of the projection module 12 to be reduced when the judgment result of the data acquisition module 11 is that there is a target object, so that the image projection is performed at the reduced output brightness of the projection module 12, thereby realizing human eye protection.

[0029] In the embodiments, the target projection distance can be measured by the ranging sensor assembly, and the target projection distance measured by the ranging sensor assembly is further acquired by the data acquisition module 11. Optionally, in other embodiments, the data acquisition module 11 can include the above-mentioned ranging sensor assembly.

[0030] In this embodiment, the projection module 12 can include a projection light source, a projection light machine, a projection lens and other projection optical devices for projecting an image. The projection control module 13 can control the display output brightness of the projection module 12 by reducing the brightness of the projection light source, modulating the optical transmittance of the projection light machine, or other ways. Optionally, the projection control module 13 can also adjust in other ways to control the display output brightness of the projection module 12, which is not limited in the present application.

[0031] In this embodiment, the initial dangerous detection range can include a maximum value, and the projection control module 13 can include a first processing unit. The first processing unit can be used to match the target projection distance obtained by the projection control module 13 from the data acquisition module 11 (which can be a target projection distance measured by the ranging sensor assembly) with the pre-set initial dangerous detection range. If the target projection distance is greater than or equal to the maximum value of the initial dangerous detection range, the maximum value of the initial dangerous detection range can be used as the maximum value of the target dangerous detection range. If the target projection distance is less than the maximum value of the initial dangerous detection range, the maximum value of the target dangerous detection range can be calculated based on the target projection distance.

[0032] In this embodiment, the ranging sensor assembly can include a plurality of ranging sensors. The data acquisition module 11 can determine the target projection distance based on the target rule from the projection distance values collected by the ranging sensor assembly, i.e., based on the target rule from the projection distance values collected by the plurality of ranging sensors. In this way, the first processing unit described above can obtain the difference between the target projection distance collected by the plurality of ranging sensors and the first error parameter, and then obtain the maximum value of the target dangerous detection range based on the difference.

[0033] In this embodiment, the projection control system 10 described above can further include a detection unit and a second processing unit. The detection unit can be used to detect whether there is a projection plane in the installation direction of the ranging sensor assembly, and determine the maximum value of the initial dangerous detection range of the ranging sensor assembly according to the detection result. Optionally, the second processing unit can be used to determine the reference target projection distance obtained as the maximum value of the initial dangerous detection range if there is a projection plane, where the reference target projection distance represents the target projection distance used by the ranging sensor assembly last time. If there is no projection plane, a specified threshold distance can be determined as the maximum value of the initial dangerous detection range. Optionally, in this way, the projection control module 13 can be used to match the target projection distance with the maximum value of the initial dangerous detection range.

[0034] In this embodiment, the projection control system 10 may further include a minimum value acquisition unit, which can be used to acquire a reference distance between the light-transmitting protective component and the ranging sensing component set on the detection path of the ranging sensing component before the data acquisition module 11 acquires the target projection distance; and use the sum of the reference distance and the second error parameter as the minimum value of the initial danger detection range.

[0035] In this embodiment, the data acquisition module 11 can obtain the target projection distance by determining whether the intensity of the detection signal received by the ranging sensor component is greater than or equal to a preset ambient light interference resistance index. Optionally, if the intensity of the detection signal received by the ranging sensor component is greater than or equal to the preset ambient light interference resistance index, the target projection distance collected by the ranging sensor component can be obtained based on the detection signal intensity; alternatively, if the intensity of the detection signal received by the ranging sensor component is not greater than or equal to the preset ambient light interference resistance index, the detection signal intensity can be discarded.

[0036] It should be noted that the ranging sensing component in this embodiment may include multiple ranging sensors, which may be arranged adjacent to each other and the installation distance between the multiple ranging sensors may be set to 15cm.

[0037] In this embodiment, the projection control module 13 can also be used to acquire the motion trend of the target object before controlling the reduction of the display output brightness of the projection module 12 when the data acquisition module 11 determines that a target object exists; determine whether the motion trend meets the preset conditions; optionally, if the preset conditions are met, the control can be executed to reduce the display output brightness of the projection device (projection module 12).

[0038] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0039] Please see Figure 2 One embodiment of this application provides a projection control method applied to a projection device with projection function, the method comprising:

[0040] Step S110: Obtain the target projection distance.

[0041] It should be noted that, in this embodiment, the target projection distance can be measured by a ranging sensing component, which may include multiple ranging sensors. Optionally, the ranging sensor may be a TOF laser ranging sensor (TOF laser ranging has a detection time of only 20ms, an extremely short response time, and can effectively achieve the purpose of eye protection). The ranging sensing component may include multiple TOF laser ranging sensors, such as two, three, or more. The target projection distance refers to the projection distance value among the multiple TOF laser ranging sensors used for subsequent reference to determine the target hazard detection range of the ranging sensing component.

[0042] Understandably, although projection devices are configured with an optimal projection distance at the factory for users to refer to and adjust, or are installed according to a set distance ratio during installation, the projection distance may still need to be readjusted during actual use due to changes in the venue, obstructions from foreign objects, equipment aging, etc. In this case, for projection devices equipped with multiple distance sensors, the projection distance (i.e., the distance from the projection device to the projection screen) will be re-determined by multiple distance sensors.

[0043] For example, as one approach, multiple Time-of-Flight (TOF) laser rangefinders can be installed near the projection light source of a projection device (e.g., vertically upwards on either side of the projection light source) to measure the distance from the projection device to the projection screen (i.e., the projection distance). It is understandable that for multiple TOF laser rangefinders, due to differences in installation angles and possible variations in the position of the projection device, the projection distance measured by different TOF laser rangefinders at the same time may differ, or the projection distance measured by the same TOF laser rangefinder may differ at different times. It should be noted that the installation direction of the TOF laser rangefinder is not unique; it can be installed facing away from the projection device (i.e., the non-projection direction). For example, assuming the projection screen is mounted on a TV wall, the projection device is placed on a coffee table (the horizontal distance between the coffee table and the TV wall is 1.5 meters), and the user is sitting on a sofa (the distance between the sofa and the coffee table is the same as the distance between the coffee table and the TV wall, i.e., the horizontal distance between the sofa and the coffee table is 1.5 meters and the horizontal distance between the sofa and the TV wall is 3 meters), the user's direction is the projection direction facing away from the projection device. Similarly, when the TOF laser rangefinder is installed with the back of the projection direction of the projection device, the projection distances measured by multiple TOF laser rangefinders will also differ (errors).

[0044] To reduce or minimize such measurement errors, one approach in this application is to obtain the minimum or average value of multiple projected distances measured by multiple TOF laser ranging sensors (where the minimum value can be understood as the range of projected distances that are included in all multiple projected distance values, and taking the minimum value allows the multiple projected distance values ​​to intersect in the plane where the minimum value is located, i.e., coplanar) and use the minimum or average value as the target projected distance. This makes the multiple projected distance values ​​(here, the target projected distance) more balanced, thereby reducing the error.

[0045] In one approach, the distance sensor can continuously detect the projected distance in real time, thereby determining whether the projected distance has changed. Specifically, the reflective detector of the TOF laser distance sensor emits a detection signal to the projection screen. The projection screen reflects this signal, and the TOF laser distance sensor receives the signal reflected back from the projection screen, detecting the distance from the projection screen to the projection device, and thus obtaining the projected distance measured by multiple TOF laser distance sensors. In another implementation, the projection device can read the projected distance values ​​measured by multiple TOF laser distance sensors and use the minimum or average value among these values ​​as the target projected distance acquired by the distance sensing component.

[0046] Step S120: Match the target projection distance with the initial hazard detection range.

[0047] The initial hazard detection range refers to the detection distance at which the TOF laser rangefinder sensor detects the presence of a target object (such as a person or small animal) within the laser's illumination range. Typically, when a projection device leaves the factory, the position of the installed TOF laser rangefinder sensor is fixed, thus setting a fixed initial hazard detection range. Optionally, the initial hazard detection range can be set by a third-party supplier, or by the user based on the projection ratio (including different hazard detection distance ranges corresponding to different projection distances) provided at the factory. By setting the initial hazard detection range, automatic eye protection can be achieved when the user turns on the projection device after purchase, preventing excessively strong laser light from harming the eyes of the target object. Optionally, this initial hazard detection range includes a hazard distance detection range, such as 0-50cm in the projection direction of the projection device; specific values ​​are only examples and do not constitute limitations.

[0048] In this situation, if the projection device changes position, the original initial hazard detection range may not be able to accurately detect target objects within the laser illumination range at the new projection distance, leading to misjudgment. To effectively avoid potential misjudgments during the TOF laser ranging sensor detection process, this application embodiment can match the target projection distance acquired in real time by the TOF laser ranging sensor with a pre-set initial hazard detection range.

[0049] For example, in one implementation, the target projection distance (i.e., the minimum or average of multiple projection distances) can be matched with a pre-set initial hazard detection range to determine whether the target distance is within the initial hazard detection range, so as to adjust the hazard detection distance of the ranging sensor component in real time according to the judgment result.

[0050] Step S130: Determine the target hazard detection range based on the matching results.

[0051] In one approach, the ranging sensor component can automatically calculate a new hazard detection distance range based on the matching results and send it to the projection device. The projection device can then use this new hazard detection distance range as the target hazard detection range, thus determining the target hazard detection range of the ranging sensor component based on the matching results. Specifically, the TOF laser ranging sensor with the minimum measured projection distance value can match its measured projection distance value with the initial hazard detection range, calculate a new hazard detection distance range based on the matching result, and send it to the projection device. Alternatively, any one of multiple TOF laser ranging sensors can match the average of the projected distances measured by the multiple TOF laser ranging sensors with the initial hazard detection range, calculate a new hazard detection distance range based on the comparison result, and send it to the projection device. Optionally, the TOF laser ranging sensor can actively send the calculated new hazard detection distance range to the projection device, or it can send the new hazard detection distance range to the projection device after receiving a hazard detection distance acquisition command from the projection device. The specific implementation method is only an example and does not constitute a limitation of this solution.

[0052] Alternatively, the ranging sensor component can also send the matching results to the projection device, so that the projection device can redetermine the target hazard detection range of the ranging sensor component based on the matching results.

[0053] By redefining the target hazard detection range of the ranging sensing component, the TOF laser ranging sensor can achieve a faster and more flexible detection response, reducing the false alarm rate. At the same time, by adopting the new target hazard detection range, the hazard detection distance of the TOF laser ranging sensor can be better matched with the actual projection distance of the projection device, thereby improving the stability of the projection system.

[0054] Step S140: Determine whether there is a target object within the target hazard detection range.

[0055] In this application, the target object can be a person or a living organism such as an animal. Unless otherwise specified, subsequent embodiments will be described with a person as the target object.

[0056] As one approach, during the real-time, high-speed, and uninterrupted acquisition of target detection distance by the TOF laser rangefinder, if a human signal is detected, the TOF laser rangefinder will further determine whether the human signal is within its target hazard detection range. Optionally, if so, the TOF laser rangefinder will determine that a target object exists within its target hazard detection range. Optionally, if not, the TOF laser rangefinder will determine that no target object exists within its target hazard detection range.

[0057] By detecting whether a target object exists within the target hazard detection range, the projection device can respond promptly based on the judgment result, including (immediately) reducing the display brightness of the projection laser, (briefly or for a certain period of time) turning off the projection laser, and / or (continuously or intermittently) issuing alarm prompts, thereby reducing the risk of the target object's eyeball being irradiated by the laser and improving the safety factor and user experience of the laser projection device.

[0058] It should be noted that, in order to improve the reliability and accuracy of eye protection, and to enhance the accuracy of the TOF laser rangefinder in detecting the presence of a target object within its target hazard detection range, multiple TOF laser rangefinders in this embodiment are arranged adjacent to each other, and the installation distance between the multiple TOF laser rangefinders is set to approximately 15cm. Figure 3 The diagram shown illustrates the installation distance settings for adjacent ranging sensors. Figure 3 The 12.5° in the figure represents the detection half-angle of the ToF laser rangefinder (the detection angle is 25°, which is a solid angle), and the 33.8cm represents the projected distance detected by a single ToF laser rangefinder. The specific values ​​of the detection half-angle and the projected distance are only examples and do not constitute a limitation on this solution.

[0059] Optionally, the face size is approximately no more than 15cm wide. By setting the installation distance between multiple TOF laser rangefinders to approximately 15cm, the danger detection range of the TOF laser rangefinders can cover the face as much as possible. This allows multiple sensors to detect the approach of a person's head even if there are gaps or detection errors, thus achieving eye protection.

[0060] Step S150: Control the reduction of the display output brightness of the projection device.

[0061] Understandably, if the TOF laser rangefinder determines that there is a target object within its target danger detection range, the projection device will control and reduce (including reduce to 0, i.e., turn off) the display output brightness of the projection device to suit the human eye.

[0062] Optionally, to prevent adverse consequences caused by errors in reducing the display output brightness of the projection device, such as damage to the eyes caused by untimely shutdown due to sudden malfunction, or delay in shutting down the laser display output brightness due to device aging or poor circuit contact, the projection device can be controlled to issue an alarm to the user while reducing the display output brightness. For example, it can issue a voice prompt or a prompting sound. The specific content and method of the prompt are not limited in this application embodiment.

[0063] One approach is to determine the presence of a target object within the target hazard detection range. The distance between the target object and the ranging sensor component can be obtained, and the current safety level of the target object can be calculated based on this distance. Then, a corresponding safe brightness value is obtained based on the safety level, and the display output brightness of the projection device is reduced to the corresponding safe brightness value. Here, the current safety level of the target object represents the degree of danger at the user's location based on the distance between the target object and the ranging sensor component. Optionally, a greater distance between the target object and the ranging sensor component indicates greater safety; conversely, if the target object is close enough to the ranging sensor component, for example, at a distance of 5 meters, 2 meters, or 1 meter, the safety level is lower. As an implementation method, the correspondence between safety levels and corresponding safe brightness values ​​can be pre-set and stored. This allows the projection device to reduce its display output brightness to the corresponding safe brightness value when it detects that the distance between the target object and the ranging sensor component has reached the minimum safety level (i.e., the set closest distance (or distance range) between the target object and the ranging sensor component).

[0064] For example, in a specific application scenario, safety levels can be set to A, B, and C. If the distance between the target object and the ranging sensor is 1-5 meters, the corresponding safety level is A. Similarly, if the distance is 6-8 meters, the corresponding safety level is B; and if the distance is 9-10 meters, the corresponding safety level is C. Optionally, the safety brightness value corresponding to safety level A is 5, to safety level B is 10, and to safety level C is 15. As one implementation method, assuming the detected distance between the target object and the ranging sensor is 7 meters, the current safety level of the target object can be determined to be B. To protect the human eye in a timely manner, the display output brightness of the projection device can be reduced to the safety brightness value of 10.

[0065] It should be noted that the examples and specific values ​​of safe brightness values ​​mentioned above are for illustrative purposes only and are not intended to be limiting. The naming rules and setting methods for safety levels are also not intended to be limiting.

[0066] This application provides a projection control method that obtains the target projection distance, matches it with an initial hazard detection range, determines the target hazard detection range based on the matching result, and then detects whether a target object exists within the target hazard detection range. If so, it controls the reduction of the display output brightness of the projection device. This method determines the target hazard detection range adapted to the ranging sensor component based on the matching result of the target projection distance and the initial hazard detection range, avoiding misjudgments caused by dust and ambient light. Furthermore, if a target object is found within the target hazard detection range, the method controls the reduction of the display output brightness of the projection device to suit the human eye, greatly improving the reliability of eye protection for the projection device and enhancing the user experience.

[0067] Please see Figure 4 Another embodiment of this application provides a projection control method applied to a projection device with projection function, the method comprising:

[0068] Step S210: Determine the target projection distance from the projection distance values ​​collected by the ranging sensor component based on the target rules.

[0069] The ranging sensing component may include multiple ranging sensors, and the target rule is a determination condition used to determine the target projected distance from the projected distance values ​​collected by the multiple ranging sensors. For example, as described in the previous embodiment, the target projected distance may be the minimum value of the projected distances collected by the multiple ranging sensors. In this case, if the target rule selects the minimum value from the projected distance values ​​collected by the multiple ranging sensors, then the minimum value can be determined as the target projected distance. Similarly, if the target rule is to obtain the average value of the projected distance values ​​collected by the multiple ranging sensors, then the average value can be determined as the target projected distance.

[0070] It should be noted that the principle and beneficial effects of selecting the minimum or average value of the projected distance values ​​collected by multiple ranging sensors as the target projected distance can be referred to the description in the foregoing embodiments, and will not be repeated here.

[0071] It should be noted that in some possible implementations, if there is only one ranging sensor, the projected distance value collected by the ranging sensor can be directly determined as the target projected distance.

[0072] It should be noted that the sensing signal from a person approaching or tending to approach the projection device varies depending on the installation orientation of the ranging sensor on the projection device. To minimize the harm to the eyes caused by the projector's laser, this embodiment of the application can first determine the installation orientation of the ranging sensor component before obtaining the target projection distance.

[0073] Specifically, the distance sensor can have a built-in orientation indicator. Before leaving the projection device, this indicator can be set according to its installation orientation within the device. Optionally, if the distance sensor is installed facing the projection direction of the projection device, its orientation indicator can be set to "1", while if the distance sensor is installed away from the projection direction, its orientation indicator can be set to "-1". In this way, the projection device can determine the installation orientation of each distance sensor within the device by recognizing its orientation indicator.

[0074] Optionally, the projection device can also be equipped with a ranging sensor management module. In some embodiments, the projection device can instruct all the ranging sensors installed inside it to emit detection signals toward the same object, assuming that the object is facing the projection direction. These ranging sensors can then calculate the distance to the object based on the strength of the signal returned by the object. In this way, the obtained distance values ​​can be divided into larger and smaller values. It is understood that the ranging sensors installed inside the projection device facing the projection direction are closer to the object. The ranging sensors that measure smaller distance values ​​can be identified as those installed facing the projection device, while the ranging sensors that measure larger distance values ​​can be identified as those installed facing away from the projection device.

[0075] Based on the installation direction of the ranging sensor component, it is possible to further detect whether there is a projection plane available for projection along the installation direction of the ranging sensor component. This allows for the determination of the maximum value of the initial hazard detection range of the ranging sensor component based on the detection results. The detection method for determining the existence of a projection plane can employ existing detection technologies and will not be elaborated upon here. It should be noted that the projection plane can be understood as the plane where the projection screen of the aforementioned embodiment is located, or as the plane where the projection area of ​​the projection device is located.

[0076] In one implementation, if a projection plane exists, the obtained reference target projection distance can be determined as the maximum value of the initial hazard detection range, where the reference target projection distance represents the target projection distance previously used by the ranging sensor component. For example, the reference target projection distance can be the maximum value of the hazard detection distance used by the ranging sensor component during the last projection, as remembered.

[0077] As another implementation, if no projection plane exists, the specified threshold distance can be directly determined as the maximum value of the initial hazard detection range. This specified threshold distance can be a pre-defined distance value or a fixed distance value set by the system.

[0078] As one approach, before obtaining the target projection distance, a reference distance can be obtained between the light-transmitting protective component (e.g., glass) positioned along the detection path of the ranging sensor component and the ranging sensor component. This reference distance, combined with a second error parameter, is then used as the minimum value of the initial hazard detection range. Referring to the description in the foregoing embodiments, the second error parameter can be understood as the thickness of the glass covering the projection device. Optionally, the second error parameter is a constant value to mitigate errors, and its specific value can be set according to the thickness of the glass.

[0079] For example, in a specific application scenario, such as Figure 5 As shown, multiple Time-of-Flight (TOF) laser rangefinders (three are shown in the figure, equivalent to the TOF laser rangefinder system labeled in the figure) are installed in a direction close to the projection device and the projection light source (vertically upwards in the figure, i.e., installed above the projection device facing the projection direction). This installation method brings the TOF laser rangefinders relatively close to the projection light source, so once the TOF laser rangefinder detects a human target, the human target will largely appear within the coverage area of ​​the projection light source. In this case, regardless of the direction from which the human approaches the projection light source, the TOF laser rangefinder can reliably detect the presence of the human target in approximately 20ms. It is worth noting that since the TOF laser rangefinder emits a laser and receives the signal returned by the obstacle, in order to eliminate dust interference and protect the TOF laser rangefinder as much as possible, a glass can be placed over the TOF laser rangefinder. The sum of the distance (d) between the TOF laser rangefinder and the glass covering it and the second error parameter (x) of the glass is set as the minimum value of the dangerous detection distance range of the TOF laser rangefinder, which can be represented by Dmin. Then Dmin = d + x cm (where x is a relatively small value that can be used to avoid the influence of the glass, such as 2, 3, etc., and the specific value is not limited).

[0080] Optionally, regarding the maximum value of the hazard detection distance range, if a projection plane can be detected, the distance between the detected projection plane and the projection device can be set as the maximum value Dmax of the hazard detection distance range. If no usable projection plane can be detected in this installation direction, 50cm can be set as the maximum value Dmax of the hazard detection distance range.

[0081] In another specific application scenario, such as Figure 6As shown, multiple Time-of-Flight (TOF) laser rangefinders (five are shown in the figure, equivalent to the TOF laser rangefinder system labeled in the figure) are installed in a direction with a large angle between the projection device and the direction of the projection light source (for example, facing away from the projection direction and towards the user). This installation method is opposite to the projection direction of the projection light source, which can pre-determine the potential danger of a person approaching. Similarly, in this installation method, the sum of the distance (d) between the TOF laser rangefinder and the glass covering it and the second error parameter (x) of the glass can be set as the minimum value Dmin of the dangerous detection distance range of the TOF laser rangefinder, where Dmin = d + x cm; and 50 cm can be set as the maximum value Dmax of the dangerous distance range.

[0082] Step S220: Match the target projection distance with the initial hazard detection range.

[0083] Understandably, based on the above description, the target projection distance can be matched with the maximum value of the initial hazard detection range.

[0084] Step S230: If the target projection distance is greater than or equal to the maximum value of the initial hazard detection range, the maximum value of the initial hazard detection range is taken as the maximum value of the target hazard detection range; if the target projection distance is less than the maximum value of the initial hazard detection range, the maximum value of the target hazard detection range is calculated based on the target projection distance.

[0085] It should be noted that the initial hazard detection range in the embodiments of this application refers to a hazard detection distance range. Therefore, it can be understood that the initial hazard detection range includes the maximum value.

[0086] As one approach, if the target projection distance obtained in step S220 is greater than or equal to the maximum value of the initial hazard detection range, the maximum value of the initial hazard detection range can be directly determined as the maximum value of the target hazard detection range, which can increase the accuracy of the detection distance.

[0087] For example, in a specific application scenario, assuming the initial hazard detection range is 0-50cm, meaning the maximum initial hazard detection range is 50cm, and the target projection distance is 60cm, the TOF laser rangefinder used in this application, by emitting and receiving invisible laser light with a wavelength of 940nm, can quickly and accurately obtain the distance to the nearest target within the detection range by measuring the time difference of flight. It exhibits excellent resistance to ambient light interference, is suitable for bright environments, and is highly stable and reliable. For instance, its second-generation product, VL53L0X, requires a measurement time of 33ms in long-distance measurement mode, with a maximum distance of 200cm; even in high-speed measurement mode with a measurement time of only 20ms, its measurement distance can reach over 50cm. Therefore, 50cm (i.e., the maximum value of the initial hazard detection range) can be directly determined as the maximum value of the target hazard detection range.

[0088] Optionally, the maximum initial hazard detection range of 50cm mentioned above is based on the fact that most TOF laser rangefinders can measure up to 50cm. However, in actual operation, the measurement range of some TOF laser rangefinders in high-speed measurement mode is much higher than 50cm. In this case, in order to reduce measurement error, an elastic distance parameter can be set so that when the target projection distance is greater than or equal to the maximum value of the initial hazard detection range, the sum of the maximum value of the initial hazard detection range and the elastic distance parameter can be determined as the maximum value of the target hazard detection range.

[0089] For example, continuing with the above example, if the elastic distance parameter is set to 5cm, 55cm (i.e., the sum of the maximum value of the initial hazard detection range and the elastic distance parameter) can be directly determined as the maximum value of the target hazard detection range.

[0090] Alternatively, if the target projection distance obtained in step S220 is less than the maximum value of the initial hazard detection range, the maximum value of the target hazard detection range can be determined based on the projection distance value collected by the ranging sensor component. Specifically, the difference between the target projection distance collected by multiple ranging sensors and the first error parameter can be obtained, and then the maximum value of the target hazard detection range can be obtained based on the value. Optionally, if the target projection distance is less than the maximum value of the initial hazard detection range, the position of the projection device may have moved. To improve the accuracy and reliability of the TOF laser ranging sensor's detection performance, it is necessary to determine the maximum value of the target hazard detection range based on the currently actually collected projection distance value.

[0091] Understandably, to avoid interference from dust and ambient light, such as Figure 7As shown, in this embodiment, the projection device is covered with an anti-interference material 201. For example, material 201 can be glass or other suitable anti-interference materials. Similarly, an anti-interference material 203 is also provided on the side of the projection device near the light output port of the projection laser. The materials 201 and 203 can be the same or different; their thicknesses can also be the same or different, and can be set according to actual conditions, without specific limitations. Figure 7 The distance from the projection device to material 201 is indicated by the symbol 202.

[0092] One approach is to subtract the minimum projected distance values ​​collected by multiple ranging sensors from a first error parameter to obtain the maximum target hazard detection range. The first error parameter can be understood as the thickness parameter of the material covering the light-emitting surface of the projection laser on the projection device, for example... Figure 7 The thickness of material 203 is shown. By subtracting the minimum projection distance collected by the ranging sensor from the first error parameter, reflection errors caused by dust or ambient light can be reduced, thereby improving the projection accuracy of the projection device and enhancing the user experience.

[0093] For example, in a specific application scenario, with Figure 7 For example, assuming the thickness of material 203 is 0.5cm, and the minimum value of the projected distance collected by multiple ranging sensors is 30cm, the maximum value of the target danger detection range can be obtained as 28cm.

[0094] It should be noted that, based on the above description, as one approach, if the TOF laser rangefinder sensor is installed inside the projection device facing the projection direction, and the maximum value of the target projection distance is less than the maximum value of the preset initial hazard detection range, referring to the principle of calculating the maximum value of the new target hazard detection range described in the aforementioned embodiments and the above examples, the maximum value of the new target hazard detection range can be obtained as Dmax = (d1, d2…dn)min - xcm, where d1, d2…dn represent the minimum value among the projection distance values ​​measured by multiple TOF laser rangefinder sensors.

[0095] It should be noted that if no projection plane is detected under this installation method, the maximum value of the target hazard detection range can still be set to Dmax = 50cm, that is, it remains unchanged.

[0096] It is worth noting that when the TOF laser rangefinder is installed inside the projection device with its back to the projection direction, the principle for redetermining the maximum value of the target hazard detection range of the rangefinder is similar to that when it is installed facing the projection direction, and will not be elaborated here.

[0097] Step S240: Determine whether there is a target object within the target hazard detection range.

[0098] Step S250: Control the reduction of the display output brightness of the projection device.

[0099] This application provides a projection control method that determines a target projection distance based on projection distance values ​​collected from multiple ranging sensors of a ranging sensing component according to target rules. The target projection distance is then matched with a pre-set initial hazard detection range. If the target projection distance is greater than or equal to the maximum value of the initial hazard detection range, the maximum value of the initial hazard detection range is determined as the maximum value of the target hazard detection range. If the target projection distance is less than the maximum value of the initial hazard detection range, the maximum value of the target hazard detection range is determined based on the projection distance values ​​collected by the ranging sensing component. The method then detects whether a target object exists within the target hazard detection range. If so, it controls the reduction of the display output brightness of the projection device. This method achieves the determination of a target hazard detection range adapted to the ranging sensing component based on the matching result of the target projection distance and the initial hazard detection range, improving the flexibility and accuracy of redetermining the target hazard detection range. Furthermore, if a target object is found within the target hazard detection range, the method controls the reduction of the display output brightness of the projection device to suit the human eye, greatly improving the reliability of eye protection for the projection device.

[0100] Please see Figure 8 Another embodiment of this application provides a projection control method applied to a projection device with projection function, the method comprising:

[0101] Step S310: Determine whether the strength of the detection signal received by the ranging sensor component is greater than or equal to the preset ambient light interference resistance index.

[0102] Among them, the ambient light interference resistance index refers to the preset parameter (SignalLimit) of the TOF laser rangefinder sensor.

[0103] Since ToF laser rangefinders measure distance by emitting and receiving invisible laser light with a wavelength of 940nm, a larger amplitude signal value of the returned wave indicates a stronger signal value from the target, meaning the target is closer. However, the ToF laser rangefinder is covered by glass, and the glass, dust in the air, and ambient light can all weaken the returned signal, affecting the accuracy of the measurement results. Therefore, to prevent misjudgments caused by dust and ambient light, an anti-ambient light interference index can be set. By setting an appropriate SignalLimit value, weak detection signals returned by non-target obstacles such as dust and ambient light can be filtered out, thereby eliminating misjudgments and improving measurement accuracy.

[0104] It is worth noting that the required SignalLimit value will vary depending on the laser rangefinder sensor. This can be tested and set based on actual measurement experience. For example, for the VL53L0X laser rangefinder module, setting the SignalLimit of its corresponding laser rangefinder sensor to 1.0*65536 during initialization can almost eliminate false readings.

[0105] In one approach, in this embodiment of the application, a ToF laser ranging sensor or a projection device can determine whether the intensity of the detection signal received by the ranging sensing component is greater than or equal to a preset ambient light interference resistance index. Optionally, if not, that is, when the returned detection signal from the obstacle target is lower than the SignalLimit value, this detection signal can be considered an invalid detection signal, thereby reducing the problem of misjudgment caused by errors.

[0106] Step S320: Obtain the target projection distance collected by the ranging sensing component based on the intensity of the detected signal.

[0107] It is understandable that if the judgment result in step S310 is that the intensity of the detection signal received by the ranging sensing component is greater than or equal to the preset anti-ambient light interference index, the target projection distance can be obtained based on the corresponding detection signal intensity, thereby improving the accuracy and reliability of the measurement.

[0108] Step S330: Match the target projection distance with the initial hazard detection range.

[0109] Step S340: Determine the target hazard detection range of the ranging sensing component based on the matching results.

[0110] Step S350: Determine whether there is a target object within the target hazard detection range.

[0111] Step S360: Obtain the motion trend of the target object.

[0112] In this embodiment, the movement trend of the target object can be understood as the changing trend of the distance between the target object and the projection device. It is understood that if the target object is detected within the target hazard detection range, and the distance between the target object and the projection device increases (i.e., the distance between the target object and the projection device becomes farther), the influence of the laser beam intensity of the projection device on the target object will decrease, making it safer and increasing the safety level. However, if the target object gets closer to the projection device, there is a risk of it coming into contact with the laser beam. In this case, there is a possibility of fatal injury due to insufficient protection.

[0113] Therefore, to avoid such harm, this application embodiment, upon detecting a target object within the target hazard detection range, will further acquire the movement trend of the target object. One method is to continuously acquire the distance between the target object and the projection device in real time, and compare the next acquired distance value with the previous value to analyze the target object's movement trend in real time.

[0114] Step S370: Determine whether the movement trend meets the preset conditions.

[0115] Optionally, the preset condition can be that the distance between the target object and the projection device decreases three or more times. In this case, it can be determined that the target object is at risk of continuously approaching the TOF laser rangefinder and coming into contact with the laser light source.

[0116] One method is to determine whether the motion trend meets the preset conditions by checking if the number of times the distance between the target object and the projection device decreases compared to the previous distance between the target object and the projection device is greater than 3.

[0117] Step S380: Execute the control to reduce the display output brightness of the projection device.

[0118] Optionally, if the judgment result of step S370 is that the motion trend meets the preset conditions, the projection device will control the reduction of the display output brightness of the projection device to adapt to the vision of the target object, thereby achieving eye protection.

[0119] In this embodiment, if the judgment result of step S370 is that the movement trend does not meet the preset conditions, it can be considered that the current location has a high safety level, and the intensity of such detection signal is discarded to avoid misjudgment, thereby improving the stability of the projection device operation.

[0120] Step S390: Discard the detected signal strength.

[0121] Optionally, if the determination result of step S310 is that the intensity of the detection signal received by the ranging sensor component is less than the preset anti-ambient light interference index, then it can be considered that the detection signal received by the distance sensor component is a signal reflected by dust, light-transmitting protective components or other small obstacles, and is an invalid signal, so the detection signal intensity is discarded.

[0122] This application provides a projection control method that determines whether the intensity of the detection signal received by the ranging sensor is greater than or equal to a preset ambient light interference resistance index. If so, the method obtains the target projection distance based on the detection signal intensity, matches the target projection distance with an initial hazard detection range, determines the target hazard detection range based on the matching result, detects whether a target object exists within the target hazard detection range, and obtains the movement trend of the target object. If the movement trend meets preset conditions, the method controls and reduces the display output brightness of the projection device. This reduces projection errors caused by misjudgments from the ranging sensor and improves the safety factor of the projection device by judging the movement trend of the target object.

[0123] The following will combine Figure 9 This application describes a projection device.

[0124] Please see Figure 9 Based on the above-described projection control method, this application embodiment also provides another projection device 100 capable of executing the aforementioned projection control method. The projection device 100 includes one or more (only one shown in the figure) processors 102, a memory 104, a data acquisition module 11, a projection module 12, and a projection control module 13 that supports controlling and reducing the display output brightness of the projection device 100. The memory 104 stores programs capable of executing the contents of the aforementioned embodiments, and the processor 102 can execute the programs stored in the memory 104.

[0125] The processor 102 may include one or more processing cores. The processor 102 connects to various parts within the projection device 100 using various interfaces and lines, and performs various functions and processes data of the projection device 100 by running or executing instructions, programs, code sets, or instruction sets stored in the memory 104, and by calling data stored in the memory 104. Optionally, the processor 102 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 102 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 102 and may be implemented separately using a communication chip.

[0126] The memory 104 may include random access memory (RAM) or read-only memory (ROM). The memory 104 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 104 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as video image projection playback), and instructions for implementing the various method embodiments described above. The data storage area may also store data created during the use of the projection device 100 (such as audio and video data, chat log data, etc.).

[0127] The data acquisition module 11 is used to acquire the target projection distance (the distance from the projection device to the projection plane). The ranging sensing component includes multiple ranging sensors, such as multiple TOF laser ranging sensors. The data acquisition module 11 can communicate with various networks such as the Internet, corporate intranets, and wireless networks, or communicate with other devices via wireless networks. The aforementioned wireless networks may include cellular telephone networks, wireless local area networks, or metropolitan area networks. The data acquisition module 11 is also used to determine whether a target object exists within the target hazard detection range.

[0128] The projection module 12 is used to project the content to be projected onto the projection device 100, such as a laser projection.

[0129] The projection control module 13 is used to match the target projection distance with the initial hazard detection range, and determine the target hazard detection range based on the matching result. The projection control module 13 is also used to control the reduction of the display output brightness of the projection module 12 when the data acquisition module 11 determines that a target object exists. In other words, it determines the hazard detection range of multiple ranging sensors in real time, so that when a target object exists within the ranging sensor's hazard detection range, the output brightness of the projection device can be flexibly reduced to suit the human eye, thereby achieving reliable eye protection.

[0130] Please refer to Figure 10 This diagram illustrates a structural block diagram of a computer-readable storage medium provided in an embodiment of this application. The computer-readable medium 600 stores program code that can be called by a processor to execute the methods described in the above method embodiments.

[0131] The computer-readable storage medium 600 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium 600 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 600 has storage space for program code 610 that performs any of the method steps described above. This program code can be read from or written to one or more computer program products. The program code 610 may be compressed, for example, in a suitable form.

[0132] In summary, the projection control method, projection device, and storage medium provided in this application acquire a target projection distance; then match the target projection distance with an initial hazard detection range; further determine the target hazard detection range based on the matching result; then determine whether a target object exists within the target hazard detection range; if so, control the reduction of the display output brightness of the projection device. Thus, by using the above method, a target hazard detection range adapted to the ranging sensor component is determined based on the matching result of the target projection distance and the initial hazard detection range. This avoids misjudgments caused by dust and ambient light. Furthermore, if a target object is found within the target hazard detection range, the display output brightness of the projection device is reduced to suit the human eye, greatly improving the reliability of the projection device's eye protection and enhancing the user experience.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A projection control method characterized by comprising: The method comprises: When the detection signal strength received by the ranging sensor assembly is greater than or equal to a preset anti-environmental light interference index, obtaining a projection distance value collected by the ranging sensor assembly based on the detection signal strength; the ranging sensor assembly comprises a plurality of ranging sensors; Determining a target projection distance from the projection distance values collected by the ranging sensor assembly according to a target rule; Matching the target projection distance with an initial dangerous detection range, if the target projection distance is greater than or equal to a maximum value of the initial dangerous detection range, taking the maximum value of the initial dangerous detection range as a maximum value of a target dangerous detection range, if the target projection distance is less than the maximum value of the initial dangerous detection range, calculating the maximum value of the target dangerous detection range based on the target projection distance; Judging whether there is a target object within the target dangerous detection range; If there is, controlling to reduce the display output brightness of the projection device.

2. The method of claim 1, wherein, The step of calculating the maximum value of the target dangerous detection range based on the target projection distance comprises: Obtaining a difference value between the target projection distance collected by the plurality of ranging sensors and a first error parameter, and obtaining the maximum value of the target dangerous detection range according to the difference value, the first error parameter being a thickness parameter of a material covering a light emitting surface of the projection laser of the projection device.

3. The method of claim 1, wherein, Before the step of determining the target projection distance, the method further comprises: Detecting whether there is a projection plane in the installation direction of the ranging sensor assembly; Determining a maximum value of an initial dangerous detection range of the ranging sensor assembly according to the detection result; The matching of the target projection distance with the initial dangerous detection range comprises: Matching the target projection distance with the maximum value of the initial dangerous detection range.

4. The method of claim 3, wherein, The step of determining the maximum value of the initial dangerous detection range of the ranging sensor assembly according to the detection result comprises: If there is a projection plane, determining a reference target projection distance obtained as the maximum value of the initial dangerous detection range, the reference target projection distance representing a target projection distance used by the ranging sensor assembly last time; If there is no projection plane, determining a specified threshold distance as the maximum value of the initial dangerous detection range.

5. The method of claim 1, wherein, Before the step of determining the target projection distance, the method further comprises: Obtaining a reference distance between a light-transmitting protection component arranged on a detection path of the ranging sensor assembly and the ranging sensor assembly; Taking the sum of the reference distance and a second error parameter as a minimum value of the initial dangerous detection range, the second error parameter being a constant value set according to the thickness of the glass covering above the projection device.

6. The method of claim 1, wherein, The method further comprises: When the detection signal strength received by the ranging sensor assembly is less than the preset anti-environmental light interference index, discarding the detection signal strength.

7. The method according to any one of claims 2 to 6, characterized in that, The plurality of ranging sensors are arranged adjacently, and the installation distance between the plurality of ranging sensors is set to 15 cm.

8. The method of claim 1, wherein, Before the step of controlling to reduce the display output brightness of the projection device, the method comprises: Obtaining a motion trend of the target object; Judging whether the motion trend meets a preset condition; If yes, executing the control to reduce the display output brightness of the projection device.

9. A projection apparatus, characterized by, The ranging sensing component includes a plurality of ranging sensors; When the ranging sensing component receives a probe signal with a strength greater than or equal to a preset anti-environmental-light-interference index, the data acquisition module is configured to acquire a projection distance value collected by the ranging sensing component based on the probe signal strength, and determine a target projection distance from the projection distance value collected by the ranging sensing component according to a target rule; The projection control module is configured to match the target projection distance with an initial dangerous detection range, and if the target projection distance is greater than or equal to a maximum value of the initial dangerous detection range, take the maximum value of the initial dangerous detection range as a maximum value of a target dangerous detection range, and if the target projection distance is less than the maximum value of the initial dangerous detection range, calculate the maximum value of the target dangerous detection range based on the target projection distance; The data acquisition module is further configured to determine whether a target object exists within the target dangerous detection range; The projection control module is further configured to control the display output brightness of the projection module to be reduced when the data acquisition module determines that a target object exists.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores program code, wherein the program code is executed by a processor to perform the method of any one of claims 1-8.

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