Focusing method of projection device and projection device

Abstract

This application provides a focusing method and a projection device, comprising: projecting a first illumination beam and a second illumination beam onto a lens, the first illumination beam and the second illumination beam emanating from the same position of a spatial light modulator and having different incident angles; the first illumination beam passing through the lens and being projected onto a projection surface to form a first light spot, and the second illumination beam passing through the lens and being projected onto the projection surface to form a second light spot; calculating a focusing amount of the lens based on the relative positional relationship between the first light spot and the second light spot on the projection surface; and focusing the lens based on the focusing amount. Through the above method, this application can improve the focusing efficiency of the projection device.

Description

Technical Field

[0001] This application belongs to the field of projection technology, specifically relating to a focusing method for a projection device and a projection device. Background Technology

[0002] With the continuous development of video technology, projection video products are having an increasingly significant impact on the market. They are used in various settings such as mobile business presentations, multimedia conference rooms, classrooms, auditoriums, and public squares. In projection systems, accurate lens focus is crucial for projecting a clear and sharp image onto the screen. However, most current projectors still use the relatively traditional contrast-detection autofocus system. This involves moving the focusing lens to measure the image's contrast ratio and finding the position with the highest contrast. This process requires the lens to move over a considerable distance while continuously measuring contrast, which is relatively slow and has significant room for improvement. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a focusing method, a projection device, and a focusing system for a projection device, which can improve the focusing efficiency of the projection device.

[0004] To address the aforementioned technical problems, this application provides a focusing method for a projection device, comprising: projecting a first illumination beam and a second illumination beam onto a lens, the first illumination beam and the second illumination beam emanating from the same position of a spatial light modulator and having different incident angles; the first illumination beam passing through the lens and being projected onto a projection surface to form a first light spot, and the second illumination beam passing through the lens and being projected onto the projection surface to form a second light spot; calculating a focusing amount of the lens based on the relative positional relationship between the first light spot and the second light spot on the projection surface; and focusing the lens based on the focusing amount.

[0005] The first and second illumination beams are the same color, but they are projected onto the projection surface at different times.

[0006] The first and second illumination beams are of different colors, and the first and second illumination beams are simultaneously projected onto the projection surface.

[0007] Before calculating the lens focusing amount based on the relative positional relationship between the first and second light spots on the projection surface, the following steps are included:

[0008] The image information of the first light spot and the image information of the second light spot are obtained by capturing images with a camera. The relative positional relationship of the first light spot and the second light spot on the projection surface is calculated based on the image information of the first light spot and the image information of the second light spot.

[0009] The relative positional relationship between the first and second light spots on the projection plane is calculated based on the image information of the first and second light spots, including:

[0010] The equivalent center points of the first and second light spots are calculated using a weighted average method based on their brightness; the relative positional relationship between the first and second light spots is then calculated based on their equivalent center points.

[0011] To address the aforementioned technical problems, this application further provides a projection device, including a controller, a light source, and a lens. The light source generates a first illumination beam and a second illumination beam. The first illumination beam and the second illumination beam are emitted from the same position of a spatial light modulator toward the lens and have different incident angles to form a first light spot and a second light spot on a projection surface. The controller calculates the focusing amount of the lens based on the relative positional relationship between the first light spot and the second light spot on the projection surface, and focuses the lens based on the focusing amount.

[0012] The first and second illumination beams are the same color, but they are projected onto the projection surface at different times.

[0013] The first and second illumination beams are of different colors, and the first and second illumination beams are simultaneously projected onto the projection surface.

[0014] The projection device also includes a camera, which is used to capture image information of the first light spot and the second light spot. The controller obtains the relative positions of the first light spot and the second light spot on the projection surface based on the image information of the first light spot and the second light spot.

[0015] The controller is further used to control the camera to calculate the equivalent center point of the first light spot and the second light spot based on the image information of the first light spot and the second light spot by a brightness-weighted average method, so as to calculate the relative positional relationship of the first light spot and the second light spot according to the equivalent center point of the first light spot and the second light spot.

[0016] The beneficial effects of this application are as follows: Unlike the focusing methods of existing projection devices, this application can quickly calculate the adjustment direction and distance of the lens by forming at least two light spots on the projection surface and calculating the relative positional relationship of at least two light spots. Compared with the existing technical solutions that require repeated lens movement and continuous contrast measurement within a large travel range to achieve projection focusing, this application can reduce the number of measurements and achieve lens focusing by adjusting the lens sequentially, which can significantly shorten the time process for the projection device to adjust the lens to achieve focusing and improve the focusing efficiency of the projection device. At the same time, by reducing the number of lens adjustments in the projection device, this application can reduce the difficulty of focusing the projection device and reduce lens movement losses. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the projection system;

[0018] Figure 2 This is a schematic flowchart of the focusing method of the projection device of this application;

[0019] Figure 3 This is a schematic diagram of the operation of the first embodiment of the focusing method of the projection device of this application;

[0020] Figure 4 This is a schematic diagram of the second embodiment of the focusing method of the projection device of this application;

[0021] Figure 5 This is a schematic diagram of the third embodiment of the focusing method of the projection device of this application;

[0022] Figure 6 This is a schematic diagram of the structure of an embodiment of the projection device of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The terms "first" and "second" used in this application do not represent a sequential order, but only serve as indicators. The terms "and / or" used in this application are only used to describe the relationship between related objects, indicating that three relationships can exist, and are not a limitation on the relationship.

[0024] Through long-term research, the inventors of this application discovered that before a projection device achieves ideal focusing, the sharp and clear image that should be displayed upon successful focusing will be blurred. The direction and magnitude of this blur are related to the angular distribution of the illumination light and the direction and degree of defocusing. Camera systems also require fast and good focusing; the simplest method is contrast peaking. However, with advancements in camera technology, technologies such as laser rangefinder focusing and phase detection autofocus have emerged, achieving faster focusing experiences. These technologies are now widely used in the lenses of SLR cameras and smartphones. To improve the focusing speed of projection devices, the inventors of this application have introduced the concept of camera focusing into projection devices to achieve optimal focusing.

[0025] Please see Figure 1 , Figure 1 This is a schematic diagram of the projection system.

[0026] like Figure 1As shown, the projection system 10 includes a projection device 120 and a projection surface 110. The projection device 120 includes a light source 121, a spatial light modulator 122, and a lens 123. The light beam generated by the light source 121 has a certain diffusion angle and can be divided into upper and lower parts. The spatial light modulator 122 is a key device in modern optics fields such as real-time optical information processing, adaptive optics, and optical computing, and can be a liquid crystal light valve. When the projection system 10 achieves ideal focus, the light source 121 can form a light spot on the projection surface 110, thereby displaying a clear and sharp image. However, when focus is not achieved, such as... Figure 1 As shown, due to the certain diffusion angle of the light beam, the light source 121 forms two diffused light spots, the first light spot 126 and the second light spot 127, on the projection surface 110, which in turn causes the image formed on the projection surface 110 to be blurred.

[0027] In this application, the position where the light beam generated by the light source before focusing can be focused into a single spot is defined as the preset projection surface. The vertical relationship between the first spot 126 and the second spot 127 on the projection surface 110, as well as the distance between them, is related to the distance between the projection surface 110 and the preset projection surface 111. Since the distance between the projection surface 110 and the preset projection surface 111 can be calculated, the direction and distance that the lens 123 needs to adjust to achieve focusing can also be determined, and thus the direction and distance of the lens 123 can be adjusted to achieve focusing.

[0028] To address the aforementioned technical problems, this application provides a focusing method for a projection device. Please refer to [link to relevant documentation]. Figure 2 and Figure 3 , Figure 2 This is a schematic flowchart of the focusing method of the projection device of this application. Figure 3 This is a schematic diagram illustrating the operation of the first embodiment of the focusing method of the projection device of this application. Figure 2 and Figure 3 As shown, in the projection system 20 of this application, the focusing method of the projection device 220 specifically includes the following steps:

[0029] S10: Project a first illumination beam and a second illumination beam onto the lens 223. The first illumination beam and the second illumination beam are emitted from the same position of the spatial light modulator 222 and have different incident angles.

[0030] Specifically, the illumination beams projected onto lens 223 can be two sets, namely a first illumination beam and a second illumination beam. The first illumination beam and the second illumination beam are emitted from the same position of spatial light modulator 222 and have different incident angles. Alternatively, there can be two or more sets with different incident angles emitted from the same position of spatial light modulator 222. Each set of illumination beams can be generated by one set of illumination sources. In some specific application scenarios, each set of illumination beams can also be generated by multiple sets of illumination sources. This is not a limitation.

[0031] Optionally, in some specific application scenarios, the light source 221 in the projection device 220 may include at least two sets of illumination sources, namely a first set of illumination sources 2211 and a second set of illumination sources 2212, for generating a first illumination beam and a second illumination beam.

[0032] Optionally, the first illumination beam and the second illumination beam are emitted from the same position on the spatial light modulator 222, which can be understood as not being the same position in an absolute sense. Not limited to this embodiment, based on the technical solution provided by this invention, the technical solution of this application can also be achieved by having the first illumination beam and the second illumination beam emitted from two positions on the spatial light modulator 222 that are not observable to the naked eye and have extremely small differences; this is not a limitation.

[0033] S20: The first illumination beam passes through the lens 223 and is projected onto the projection surface 210 to form a first light spot 226, and the second illumination beam passes through the lens 223 and is projected onto the projection surface 210 to form a second light spot 227.

[0034] Specifically, the first illumination beam and the second illumination beam emitted towards the lens 223 are emitted from the same position of the spatial light adjuster 222 but with different incident angles. As a result, after passing through the lens 223, the first illumination beam and the second illumination beam are projected onto the projection surface 210 to form corresponding first light spot 226 and second light spot 227. The first light spot 226 and the second light spot 227 will not completely overlap. Specifically, they can partially overlap or not overlap at all. No limitation is made here.

[0035] S30: Based on the relative positional relationship between the first light spot 226 and the second light spot 227 on the projection surface 210, the focusing amount of the lens 223 is calculated.

[0036] The relative positional relationship of at least two light spots on the projection surface 210 is related to the direction and distance that the lens 223 needs to adjust for focusing. The required focusing amount of the lens 223 can be calculated by calculating the relative positional relationship of the first light spot 226 and the second light spot 227 on the projection surface 210.

[0037] Optionally, in other embodiments, before calculating the focusing amount of the lens 223 based on the relative positional relationship of the first light spot 226 and the second light spot 227 on the projection surface 210, it is necessary to acquire image information of the first light spot 226 and the second light spot 227 by capturing images with a camera, and calculate the relative positional relationship of the first light spot 226 and the second light spot 227 on the projection surface based on the image information of the first light spot 226 and the second light spot 227.

[0038] Optionally, the relative positional relationship between the first light spot 226 and the second light spot 227 on the projection surface 210 can be calculated based on the image information of the first light spot 226 and the second light spot 227 using the following steps.

[0039] Step 1: Calculate the equivalent center point of the first light spot 226 and the second light spot 227 using a weighted average method based on the brightness of the first light spot 226 and the second light spot 227.

[0040] Since the first light spot 226 and the second light spot 227 have a certain distribution range on the projection surface 210, if the relative positional relationship between the first light spot 226 and the second light spot 227 is directly calculated based on the light spots on the projection surface 210, the calculation error will be large. Therefore, the center point of the light spot can be calculated based on the brightness of each light spot using a weighted average method. The relative positional relationship of the light spots can then be calculated using the center point of the light spot, which can improve the accuracy of the relative positional relationship calculation. In other embodiments, any calculation method that can improve the accuracy of the relative positional relationship calculation can be applied, and no limitation is made here.

[0041] Step 2: Calculate the relative positional relationship between the first light spot 226 and the second light spot 227 based on the equivalent center point of the first light spot 226 and the equivalent center point of the second light spot 227.

[0042] Specifically, after obtaining the relative positional relationship between the first light spot 226 and the second light spot 227, the focusing amount of the lens 223 can be calculated using the following steps.

[0043] Step 3: Calculate the deviation data between the preset focus point and the actual imaging spot based on the relative position data.

[0044] In actual projection, it is impossible to focus the projection device 220 to the ideal focus point, and there is a certain deviation between the focus point after focusing and the ideal focus point. In this application, the focus point after focusing in the actual projection process is defined as the preset focus point, and the light spot of the light source 221 on the projection surface 210 before focusing in the actual projection process is defined as the actual imaging light spot. Before focusing, the actual imaging light spot formed by the light source 221 on the projection surface 210 cannot be focused, and its position is related to the deviation data of the preset focus point and the focusing amount required for the lens 223 to focus.

[0045] Specifically, the relative positional relationship between the first light spot 226 and the second light spot 227 varies depending on the lens 223 and / or the illumination beam angle, and the corresponding relationship between the deviation data between the preset focus point and the actual imaging light spot. In some specific application scenarios, before the projection device is put into use at the factory, relevant technicians can measure the above-mentioned correspondence and create a corresponding lookup table so that the focusing process during the use of the projection device can quickly calculate the deviation data between the preset focus point and the actual light spot.

[0046] Step 4: Calculate the adjustment direction and adjustment distance of the lens based on the deviation data between the preset focus point and the actual focus point.

[0047] Specifically, in this embodiment, the projection device 220 may include a spatial light modulator 222 and a lens 223. The positional relationship between the spatial light modulator 222 and the lens 223 can be calculated by the deviation data between the preset focus point and the actual focus point, thereby obtaining the specific focusing amount required by the lens 223, that is, the specific adjustment direction and adjustment distance of the lens 223.

[0048] S40: Focus lens 223 based on the focusing amount.

[0049] Furthermore, based on the required focusing amount of lens 223, the relative positional relationship between lens 223 and spatial light modulator 222 can be adjusted, thereby enabling different illumination beams to be focused at projection surface 210. This allows different illumination beams with different projection angles to form a light spot on projection surface 210, presenting a clear and sharp image. Thus, focusing of lens 223 in projection device 220 can be achieved with only one lens adjustment operation, which can greatly improve the focusing efficiency of projection device 220.

[0050] like Figure 3 As shown, in the projection system 20 of this embodiment, the configuration of the projection surface 210, the spatial light modulator 222, and the lens 223 in the projection device 220 can be the same as in the previous embodiment, and will not be repeated here. Unlike the previous embodiment, in this embodiment, the illumination source 221 of the projection device 220 can be further configured to include a first set of illumination sources 2211 and a second set of illumination sources 2212. The illumination sources 221 project two sets of illumination beams onto the projection surface 210, forming corresponding first light spot 226 and second light spot 227 on the projection surface 210. Specifically, in this embodiment, step S10 may include the following process:

[0051] S11: Control the first group of lighting sources 2211 to work and project the corresponding first group of lighting beams onto the projection surface 210 to form the corresponding first light spot 226 on the projection surface 210.

[0052] S12: Control the second group of lighting sources 2212 to work and project the corresponding second group of lighting beams onto the projection surface 210 to form the corresponding second light spot 227 on the projection surface 210.

[0053] Specifically, in this embodiment, the colors of the first group of illumination beams generated by the first group of illumination light sources 2211 and the second group of illumination beams generated by the second group of illumination light sources 2212 can both be any one of red, orange, yellow, green, blue, purple, or white.

[0054] Furthermore, the colors of the illumination beams produced by the first group of illumination light sources 2211 and the second group of illumination light sources 2212 can be set to be different, so that the colors of the first group of illumination beams are different from those of the second group of illumination beams. In the specific implementation of step S10, the first group of illumination light sources 2211 and the second group of illumination light sources 2212 can be controlled to work simultaneously, forming a first light spot 226 and a second light spot 227 of different colors on the projection surface 210.

[0055] In other embodiments, the first group of lighting sources 2211 and the second group of lighting sources 2212 can be controlled to work in sequence and form a first light spot 226 and a second light spot 227 of different colors on the projection surface 210.

[0056] In this embodiment, the projection angles of the illumination beams generated by the first group of illumination light sources 2211 and the second group of illumination light sources 2212 toward the projection surface 210 are further set to have a certain difference, so that the positions of the first light spot 226 and the second light spot 227 will not completely overlap, specifically they can partially overlap or completely separate.

[0057] The relative positional relationship between the first light spot 226 and the second light spot 227 is related to the relative positional relationship between the first group of lighting sources 2211 and the second group of lighting sources 2212.

[0058] For example, in an application scenario where the first group of lighting sources 2211 and the second group of lighting sources 2212 are arranged vertically in a direction perpendicular to the beam projection, the first light spot 226 and the second light spot 227 are also arranged vertically along the extension direction of the projection surface 210. In an application scenario where the first group of lighting sources 2211 and the second group of lighting sources 2212 are arranged side by side in a direction perpendicular to the beam projection, the first light spot 226 and the second light spot 227 can be formed in a corresponding side by side distribution. The specific relative positional relationship of different groups of lighting sources in the lighting source 221 is not limited here.

[0059] Please see Figure 4 , Figure 4 This is a schematic diagram illustrating the operation of the second embodiment of the focusing method of the projection device of this application. Figure 4 As shown, in the projection system 30 of this embodiment, the configuration of the projection surface 310, the spatial light modulator 322 in the projection device 320, and the lens 323 can be the same as in the previous embodiment, and will not be repeated here. In this embodiment, the illumination source 321 can be configured to include a first group of illumination sources 3211 and a second group of illumination sources 3212. The colors of the first group of illumination beams generated by the first group of illumination sources 3211 and the second group of illumination beams generated by the second group of illumination sources 3212 are all any one of red, orange, yellow, green, blue, purple, and white. Unlike the first embodiment, in this embodiment, the colors of the illumination beams generated by the first group of illumination sources 3211 and the second group of illumination sources 3212 can be the same.

[0060] In this embodiment, during the specific implementation of step S10, the first group of illumination sources 3211 and the second group of illumination sources 3212 can be controlled to turn on and off in a timely manner. For example, the first group of illumination sources 3211 can be controlled to work first, forming a corresponding first light spot 326 on the projection surface 310. Then, the first group of illumination sources 3211 can be controlled to stop working, and then the second group of illumination sources 3212 can be controlled to work, forming a corresponding second light spot 327 on the projection surface 310. The order in which the first group of illumination sources 3211 and the second group of illumination sources 3212 work in a timely manner can be flexibly adjusted, and is not limited here.

[0061] In other embodiments, during the specific implementation of step S10, the first group of lighting sources 3211 and the second group of lighting sources 3212 are also controlled to work simultaneously to form a first light spot 326 and a second light spot 327 of the same color on the projection surface 310. This is not limited here.

[0062] Specifically, in this embodiment, the projection angles of the illumination beams generated by the first group of illumination sources 3211 and the second group of illumination sources 3212 toward the projection surface 310 are also set to have a certain difference, so that the first light spot 326 and the second light spot 327 can partially overlap or be completely separated. Furthermore, the positional distribution of the first light spot 326 and the second light spot 327 on the projection surface 310 is related to the relative positional arrangement of the first group of illumination sources 3211 and the second group of illumination sources 3212, which will not be elaborated here.

[0063] Further, please refer to Figure 5 , Figure 5 This is a schematic diagram of the third embodiment of the focusing method of the projection device of this application.

[0064] Specifically, in the projection system 40 of this embodiment, the arrangement of the projection surface 410 and the spatial light modulator 422 and lens 423 in the projection device 420 can be the same as in any of the embodiments described above. Furthermore, the projection angle of the illumination beam generated by each group of illumination sources in the illumination source 421 toward the projection surface 410 is different, similar to either the first or second embodiment, and will not be repeated here. Unlike the embodiments described above, in this embodiment, the illumination source 421 is configured to include more than two groups of illumination sources.

[0065] Furthermore, in this embodiment, the color settings of each group of lighting sources can be the same or different. In application scenarios where the colors of each group of lighting sources are the same, different groups of lighting sources can be controlled to turn on in a specific time sequence; in application scenarios where the colors of at least two groups of lighting sources are different, different groups of lighting sources can be controlled to turn on simultaneously. The opening and closing of multiple groups of lighting sources can be flexibly adjusted according to the different settings of the lighting sources, and no restrictions are imposed here.

[0066] By setting at least two sets of illumination beams with different projection angles, at least two light spots formed on the projection surface can be made to not completely overlap or not overlap. The relative positional relationship between different light spots can be calculated, and then the focusing distance and focusing direction of lens 423 can be calculated to achieve focusing of lens 423.

[0067] To address the aforementioned technical problems, this application further provides a projection device; please refer to [link to relevant documentation]. Figure 6 , Figure 6 This is a schematic diagram of the structure of an embodiment of the projection device of this application.

[0068] like Figure 6 As shown, the projection device 50 includes a controller 51, a light source 52, a spatial light modulator 53, and a lens 54. The light source 52 is used to generate a first illumination beam and a second illumination beam. The first illumination beam and the second illumination beam are emitted from the same position of the spatial light modulator 53 toward the lens 53 and have different incident angles to form a first light spot and a second light spot on the projection surface 60. The controller 51 is used to calculate the focusing amount of the lens 53 based on the relative positional relationship between the first light spot and the second light spot on the projection surface 60, so as to focus the lens 53 based on the focusing amount of the lens 53.

[0069] Furthermore, the projection device 50 also includes a camera 55, which is used to capture image information of the first light spot and the second light spot. The controller 51 obtains the relative positions of the first light spot and the second light spot on the projection surface 60 based on the image information of the first light spot and the second light spot.

[0070] Specifically, in this embodiment, the camera 55 can be installed on the housing of the projection device 50 (not shown) or on a fixed bracket (not shown). The shooting direction of the camera 55 can be set to face the projection surface 60 so that when the illumination beam generated by the light source 52 forms a light spot on the projection surface 60, the position of the light spot of different illumination beams on the projection surface 60 can be captured. The specific installation position of the camera 55 is not limited here.

[0071] Optionally, when the controller 51 controls the light source 52 to project the first illumination beam and the second illumination beam onto the lens 54, the first illumination beam and the second illumination beam generated by the light source 52 have the same color, but the first illumination beam and the second illumination beam are projected onto the projection surface 60 at different times. In other embodiments, the first illumination beam and the second illumination beam generated by the light source 52 have the same color, and the first illumination beam and the second illumination beam may also be projected onto the projection surface 60 simultaneously, which is not limited here.

[0072] Optionally, when the controller 51 controls the light source 52 to project the first illumination beam and the second illumination beam onto the lens 54, the first illumination beam and the second illumination beam generated by the light source 52 are of different colors, and the first illumination beam and the second illumination beam are simultaneously projected onto the projection surface 60. In other embodiments, when the first illumination beam and the second illumination beam generated by the light source 52 are of different colors, the time at which the first illumination beam and the second illumination beam are projected onto the projection surface 60 may also be different, which is not limited here.

[0073] Furthermore, the controller 51 can obtain the relative positional relationship of the light spots of different illumination beams on the projection surface 60 based on the shooting results of the camera 55, so that the controller 51 can calculate the direction and distance that the lens 54 needs to be adjusted for accurate focusing based on the relative positional relationship of the light spots of different illumination beams.

[0074] Furthermore, the light source 52 includes at least two sets of illumination sources, and the controller 51 is further used to control the at least two sets of illumination sources to project at least two corresponding light spots onto the projection surface 60.

[0075] In this embodiment, the light source 52 may include at least two sets of illumination sources, and the corresponding light spots formed by the at least two sets of illumination sources on the projection surface 60 may not completely overlap or may not overlap at all, so as to facilitate the calculation of the relative positional relationship of the corresponding light spots.

[0076] Furthermore, the controller 51 is further configured to calculate the equivalent center point of each light spot using a weighted average method based on the brightness of each light spot, and calculate the relative position data of at least two light spots based on the equivalent center point, and further calculate the deviation data between the preset focus point and the actual focus point based on the relative position data, so as to calculate the adjustment direction and adjustment distance of the lens 54 based on the deviation data.

[0077] Specifically, the controller 51 first calculates the equivalent center point of each light spot, and then calculates the relative position data between different light spots. This makes the calculation of the relative position data of different light spots more accurate, and thus it can more accurately calculate the deviation data between the current actual focus point of the lens 54 and the preset focus point, determine the specific adjustment direction and distance of the lens 54, and achieve more precise focusing of the lens 54.

[0078] Specifically, the projection device 50 can be a projector, a smart terminal, or other electronic devices with projection capabilities, and there are no restrictions here.

[0079] In summary, this application sets at least two sets of illumination sources in the projection device, and sets the corresponding light spots formed by the at least two sets of illumination sources on the projection surface to have certain differences. Then, by recording the relative positional relationship of different light spots on the projection surface, the deviation data between the current focus point of the lens in the projection device and the preset focus point can be calculated. Based on this deviation data, the lens can be focused by adjusting the lens once, which can greatly improve the focusing efficiency of the projection device lens, shorten the focusing time, and reduce the difficulty of focusing the projection device.

[0080] The above description is merely an implementation method of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A focusing method for a projection device, characterized in that, include: A first illumination beam and a second illumination beam are projected onto the lens. The first illumination beam and the second illumination beam are emitted from the same position of the spatial light modulator and have different incident angles. The first illumination beam passes through the lens and is projected onto the projection surface to form a first light spot, and the second illumination beam passes through the lens and is projected onto the projection surface to form a second light spot; Based on the relative positional relationship between the first light spot and the second light spot on the projection surface, the focusing amount of the lens is calculated; The lens is focused based on the aforementioned focusing amount; Before calculating the focusing amount of the lens based on the relative positional relationship between the first light spot and the second light spot on the projection surface, the following steps are included: The image information of the first light spot and the image information of the second light spot are acquired by capturing images with a camera. Based on the image information of the first light spot and the image information of the second light spot, the relative positional relationship between the first light spot and the second light spot on the projection surface is calculated. The calculation of the relative positional relationship between the first light spot and the second light spot on the projection surface based on the image information of the first light spot and the image information of the second light spot includes: The equivalent center point of the first light spot and the second light spot is calculated using a weighted average method based on the brightness of the first light spot and the second light spot; The relative positional relationship between the first light spot and the second light spot is calculated based on the equivalent center point of the first light spot and the equivalent center point of the second light spot.

2. The focusing method according to claim 1, characterized in that, The first illumination beam and the second illumination beam are the same color, but the first illumination beam and the second illumination beam are projected onto the projection surface at different times.

3. The focusing method according to claim 1, characterized in that, The first illumination beam and the second illumination beam are of different colors, and the first illumination beam and the second illumination beam are simultaneously projected onto the projection surface.

4. A projection device, characterized in that, The projection device includes a controller, a light source, a spatial light modulator, and a lens. The light source generates a first illumination beam and a second illumination beam. The first illumination beam and the second illumination beam are emitted from the same position of the spatial light modulator toward the lens and have different incident angles to form a first light spot and a second light spot on the projection surface. The controller calculates the focusing amount of the lens based on the relative positional relationship between the first light spot and the second light spot on the projection surface, so as to focus the lens based on the focusing amount of the lens. The projection device also includes a camera, which is used to capture image information of the first light spot and the second light spot. The controller obtains the relative positions of the first light spot and the second light spot on the projection surface based on the image information of the first light spot and the second light spot. The controller is further configured to control the camera to calculate the equivalent center point of the first light spot and the second light spot based on the image information of the first light spot and the second light spot using a brightness-weighted average method, so as to calculate the relative positional relationship of the first light spot and the second light spot according to the equivalent center point of the first light spot and the second light spot.

5. The projection device according to claim 4, characterized in that, The first illumination beam and the second illumination beam are the same color, but the first illumination beam and the second illumination beam are projected onto the projection surface at different times.

6. The projection device according to claim 4, characterized in that, The first illumination beam and the second illumination beam are of different colors, and the first illumination beam and the second illumination beam are simultaneously projected onto the projection surface.

Images