Projection correction device, projection system, and projection method

Abstract

A projection correction device, a projection system, and a projection method, relating to the technical field of display. The projection correction device is configured to be integrated with a projection unit. The projection correction device comprises: an image acquisition unit, which is configured to perform image acquisition on a projection picture projected by the projection unit to obtain a target picture, the target picture comprising the projection picture; and a control unit, which is configured to correct at least one of the clarity, a display position, and a picture shape of the projection picture on the basis of the target picture and the projection picture.

Description

Projection correction device, projection system and projection method Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a projection correction device, a projection system, and a projection method. Background Art

[0002] A projector is a device that can magnify and project an image. However, the projection screen of the projector may present an undesirable projection effect, such as a non-standard shape of the projected image and poor clarity of the projected image. Generally speaking, the shape and clarity of the projected image are manually adjusted, but manual adjustment requires multiple adjustments and the adjustment efficiency is very low.

[0003] Overview

[0004] The present disclosure provides a projection correction device for being configured to a projection unit, the projection correction device comprising:

[0005] An image acquisition unit is configured to acquire an image of the projection picture projected by the projection unit to obtain a target picture; the target picture includes the projection picture;

[0006] as well as,

[0007] The control unit is configured to correct at least one of the clarity, display position, and screen shape of the projection screen based on the target screen and the projection screen.

[0008] Exemplarily, the image acquisition unit is configured to be located at the same horizontal plane as the optical machine in the projection unit, and is located on a first side of the optical machine, or on a second side opposite to the first side.

[0009] Exemplarily, the control unit is specifically configured to perform a first adjustment on the focal length between the optical engine and the lens in the projection unit based on the projection picture and the target picture, and after the first adjustment, perform at least one second adjustment on the focal length based on the projection picture;

[0010] The step size of the first adjustment is greater than the step size of the second adjustment.

[0011] Exemplarily, the control unit is specifically configured to determine a first coordinate of the center point of the projection image in the target image, and perform the first adjustment according to the first coordinate.

[0012] Exemplarily, the control unit is configured with a mapping relationship table, wherein the mapping relationship table includes preset focal lengths corresponding to different object distances; wherein,

[0013] The control unit is specifically configured to obtain the object distance corresponding to the first coordinate, search the target preset focal length corresponding to the object distance from the mapping relationship table, and adjust the focal length to the target preset focal length.

[0014] Exemplarily, the second adjustment is to increase or decrease the focal length according to a preset step size; wherein,

[0015] The image acquisition unit is specifically configured to acquire a new target image after each second adjustment;

[0016] The control unit is specifically configured to determine the change in the clarity of the projection image before and after the second adjustment based on the new target image and the target image captured last time, and perform the next second adjustment based on the change until the clarity of the projection image no longer improves.

[0017] Exemplarily, the control unit is specifically configured to reduce the preset step size when the change representation clarity becomes higher, and continue the second adjustment according to the reduced preset step size.

[0018] Exemplarily, the control unit is specifically configured to determine a shape difference between the projection image and the target image, and perform a third adjustment on the projection image based on the shape difference; wherein the third adjustment includes at least cropping the projection image.

[0019] Exemplarily, the control unit is specifically configured to determine a ratio of the projection image to the target image, determine a tilt angle based on a size relationship between the ratio and a preset ratio, and perform the third adjustment on the projected image based on the tilt angle;

[0020] The tilt angle represents a twisting angle between the projection area of ​​the projection unit and the projection unit in the horizontal direction.

[0021] Exemplarily, the control unit is specifically configured to determine the tilt angle based on a size relationship between the screen ratio and a preset ratio and a position of the image acquisition unit;

[0022] The image acquisition unit is located at a first side of the optical machine or a second side opposite to the first side.

[0023] Exemplarily, the control unit is further configured to detect whether there is an obstacle on the target screen that blocks the projection screen, and when it is determined that the obstacle exists, adjust the projection range of the projection unit so that the projection range avoids the obstacle.

[0024] Exemplarily, the control unit is specifically configured to obtain the position of the obstacle, determine the projection area based on the position, and adjust the projection range to be located in the projection area.

[0025] Exemplarily, the control unit is further configured to detect whether there is a screen based on the target image; if there is a screen, perform screen entry processing on the projected image.

[0026] Exemplarily, the system further includes an image switching unit; wherein:

[0027] The image switching unit is configured to switch between a plurality of different projection images; wherein the projection unit is used to project and display the projection images;

[0028] The control unit is specifically configured to correct the clarity, the display position, and the screen shape of an object corresponding to the currently projected projection image based on the target screen and the projection screen;

[0029] Different projection images correspond to different objects in the definition, the display position and the screen shape.

[0030] Exemplarily, the plurality of projection images include icons with borders and circle-like icons.

[0031] Exemplarily, the projection image corresponding to the definition is a circular image, and the projection image corresponding to the display position and the screen shape is an image with a border.

[0032] Exemplarily, the control unit includes a processor and an actuator connected to the processor; wherein,

[0033] The processor is configured to generate a control instruction for the actuator based on the target image and the projected image, wherein the control instruction includes a correction parameter;

[0034] The actuator is configured to respond to the control instruction and adjust at least one of the focal length between the optical machine and the lens in the projection unit, the projection range of the optical machine, and the projected image according to the correction parameters to correct the clarity, display position, and display shape of the projection image.

[0035] Exemplarily, the execution mechanism includes:

[0036] a first component configured to be connected to the optical engine and / or the lens and to adjust the distance between the optical engine and the lens in the projection unit according to the correction parameter to change the focal length;

[0037] The second component is configured to be connected to the optical engine and adjust the projection range of the optical engine according to the correction parameter to change the display position.

[0038] In one example, a projection system is further provided, comprising:

[0039] A projection unit, comprising an optical engine and a lens;

[0040] as well as,

[0041] The projection correction device described in any example;

[0042] Wherein, the control unit in the projection correction device is connected to the optical machine and the lens respectively.

[0043] A projection method is provided, which is applied to the projection system, and the projection method includes:

[0044] Projecting and displaying the projected image;

[0045] Performing image acquisition on the projected image to obtain a target image; wherein the target image includes the projected image;

[0046] Based on the projection picture and the target picture, at least one of the clarity, display position and picture shape of the projection picture is corrected.

[0047] The projection correction device provided by the present disclosure can be configured with a projection unit. The projection correction device includes an image acquisition unit and a control unit. The image acquisition unit can be configured to capture an image of a projection screen projected by the projection unit to obtain a target screen; the target screen includes the projection screen, and the control unit can be configured to correct at least one of the clarity, display position, and screen shape of the projection screen based on the target screen and the projection screen. Since the clarity, display position, and screen shape of the projection screen are adjusted based on the captured projection screen and the target screen, manual adjustment of the projected image can be avoided, thereby improving adjustment efficiency and optimizing the user experience.

[0048] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below.

[0049] BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following is a brief introduction to the drawings required for the description of the embodiments or related technologies. Obviously, the drawings described below are some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without inventive efforts. It should be noted that the scales in the drawings are for illustration only and do not represent the actual scale.

[0051] FIG1 is a schematic diagram showing a trapezoidal correction in the related art;

[0052] FIG2 shows a schematic structural diagram of a projection correction device according to an embodiment of the present disclosure;

[0053] FIG3 is a schematic diagram showing a process flow of the projection correction device of the present disclosure when performing projection correction;

[0054] FIG4 is a schematic diagram showing a projection correction device that corrects projection images of multiple projection units simultaneously;

[0055] FIG5 is a schematic diagram showing the positions of an image acquisition unit and a projection unit in an embodiment of the present disclosure;

[0056] FIG6 is a schematic diagram showing the relationship between the distance between the shadow unit and the projection area (wall or screen) and the focal length;

[0057] FIG7 is a schematic diagram showing the camera viewing angles of the projection unit and the image acquisition unit;

[0058] FIG8 shows a schematic diagram of the triangular relationship of the projection image;

[0059] FIG9 is a schematic diagram showing the triangular relationship of the target images captured by the image acquisition unit when the screen is projected frontally;

[0060] FIG10 shows a schematic diagram of a model between the projected image length and the target image length;

[0061] FIG11 shows a schematic diagram of a projection scene;

[0062] FIG12 is a schematic diagram showing obstacle avoidance for the projection image shown in FIG11 ;

[0063] FIG13 shows schematic diagrams of the shapes of three projection images;

[0064] FIG14 is a schematic diagram showing the control of the correction process of switching of three projection images in FIG13 ;

[0065] FIG15 shows a schematic diagram of the connection between the actuator and the projection unit in the projection correction device;

[0066] FIG16 shows a schematic structural diagram of a projection correction device;

[0067] 17 and 18 are schematic diagrams showing the working process of the projection correction device shown in FIG. 16 ;

[0068] FIG19 shows a schematic diagram of the system structure of the projection system;

[0069] FIG20 shows a schematic flow chart of steps of a projection method in an embodiment.

[0070] Detailed description

[0071] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0072] In related technologies, when a projection unit is projecting and displaying, the projection unit may tilt horizontally and vertically, resulting in a trapezoidal shape for the projected image. This requires keystone correction. Referring to Figure 1, a schematic diagram illustrating keystone correction is shown. As shown in Figure 1, when the projection unit deflects vertically, the projected image presents a vertical trapezoidal shape; when the projection unit twists left and right, the projected image presents a horizontal trapezoidal shape. This process of correcting the projected image from a trapezoidal shape to a rectangular shape is called keystone correction. After keystone correction, the projected image appears rectangular.

[0073] In the related art, a lot of hardware is required for trapezoidal correction. For example, multiple angle sensors need to be configured to measure the tilt angle, which results in high costs.

[0074] In practice, it is generally necessary to adjust the focal length of the lens to ensure projection clarity. In related technologies, when adjusting the focal length, laser or ToF (time of flight) can be used to measure the distance between the projection unit and the projection area, and then adjust the focal length according to the distance. However, the hardware cost required for laser ranging and ToF ranging is very high.

[0075] In summary, in the related art, the correction of the projection image either relies on manual adjustment resulting in low adjustment efficiency, or the hardware cost required for automatic adjustment is high. In view of this, the present disclosure proposes a projection correction device, which can configure an image acquisition unit to capture the projection image, and automatically correct the image shape, display position and clarity of the projection image based on the target image captured by the projection image through the control unit. In this way, multi-angle correction of the projection image can be achieved through one image acquisition unit, and since the cost of the image acquisition unit is low, multi-angle correction of the projection image can be achieved through low-cost hardware, which not only improves the adjustment efficiency of the projection image, but also reduces the projection cost.

[0076] Referring to Figure 2, a structural schematic diagram of a projection correction device provided by the present disclosure is shown. Referring to Figure 3, a process flow diagram of the projection correction device of the present disclosure when performing projection correction is shown. As shown in Figures 2 and 3, the projection correction device of the present disclosure includes an image acquisition unit and a control unit; wherein, the projection correction device can be configured in a projection unit, which can be called a projector or projector in practice, or the projection correction device can be used in conjunction with the projection unit.

[0077] The image acquisition unit may be configured to acquire an image of the projection picture projected by the projection unit to obtain a target picture; the target picture may include the projection picture;

[0078] The control unit may be configured to correct at least one of the clarity, display position, and screen shape of the projection screen based on the target screen and the projection screen.

[0079] In this embodiment, the projection screen refers to the screen formed after the projection unit projects the image to be projected onto a screen or a wall, and the target screen refers to the screen obtained after the image acquisition unit captures the projection screen.

[0080] The image acquisition unit may be a camera, which may be connected to the control unit and transmit the captured target image to the control unit. The image acquisition unit may capture images of the projection image, and the image capture viewing angle range thereof may at least include the entire projection image. Specifically, the image capture viewing angle range of the image acquisition unit may be greater than the viewing angle range of the projection unit, so that the target image may include the entire projection image.

[0081] The control unit may include a processor and an actuator connected to the processor. The actuator may be a component including a mechanical structure, which is used to change the focal length, tilt angle, etc. of the projection unit, thereby achieving correction of the projection image.

[0082] In this embodiment, the processor of the control unit can perform image recognition on the target image and the projected image, thereby calculating whether the clarity of the projected image meets the viewing requirements, whether the shape of the projected image is rectangular, and whether the location of the projected image is obstructed. For example, the clarity of the projected image in the target image can be recognized to determine whether the clarity of the projected image meets the viewing requirements; for another example, the shape of the projected image can be recognized to determine whether the shape of the projected image is rectangular; for another example, the presence of any obstructions on the projected image can be recognized to determine whether the projected image is obstructed.

[0083] In practice, the processor can determine the adjustments to the projection unit based on the above recognition results, such as whether the image is clear, rectangular, and obscured. The adjustments may include the focal length of the projection unit, the projection range of the optical engine in the projection unit, and the image to be projected. Specifically, the focal length is related to the clarity of the projected image, the projection range of the optical engine is related to the position and shape of the projected image, and the shape of the projected image can be adjusted by adjusting the image to be projected.

[0084] Then, the processor can send a control instruction to the actuator according to the adjustment object, so that the actuator can respond to the control instruction to adjust at least one of the focal length of the projection unit, the projection range of the optical machine, and the image to be projected, thereby correcting the clarity of the projection picture, the display position of the projection picture, and the picture shape of the projection picture.

[0085] In practice, any one of the clarity, display position, and shape of the projected image can be adjusted, or any two or all three can be adjusted. When adjusting all three, they can be performed in a certain order. For example, first adjust the focal length to achieve the desired clarity, then adjust the projection range of the optical engine of the projection unit to avoid obstacles, and then adjust the shape of the projected image.

[0086] The projection correction device of this example can be incorporated into a projection unit in the related art. For example, if it is incorporated into a projection unit without keystone correction, the projection unit can be used to perform keystone correction based on the target image and the projected image captured by the image acquisition unit, thereby correcting the shape of the projected image, such as to a rectangle. For example, it can also be incorporated into a conventional projection unit without keystone correction or focal length correction. The projection unit's focal length can be adjusted based on the target image and the projected image captured by the image acquisition unit, thereby adjusting the clarity and display shape of the projected image. Thus, the projection correction device can be installed as an accessory into the projection unit, achieving automatic correction of the projection unit's projected image.

[0087] Since this example uses an image acquisition unit to capture the projection image and realize the correction of the projection image, it is less expensive and easier to implement than using laser ranging, ToF and other devices to measure the distance and then perform corrections such as image clarity.

[0088] In some embodiments, the image acquisition unit and the control unit in the projection correction device can be two separate sets of accessories, either of which can be configured as an all-in-one machine with the projection unit, such as the control unit or the image acquisition unit can be configured as an all-in-one machine with the projection unit, or both the image acquisition unit and the control unit can be configured to the projection unit to serve as an all-in-one projection machine.

[0089] Of course, in some examples, the projection correction device can be used as a separate component. In actual use, it can be coordinated with a variety of different models of projection units, so that it can automatically participate in the projection correction of a variety of projection units. For example, a projection correction device can correct the projection image of projection unit 1, and can also correct the projection image of projection unit 2.

[0090] In some scenarios, a projection correction device can simultaneously correct the projection images of multiple projection units. Specifically, FIG4 shows a schematic diagram of a projection correction device simultaneously correcting the projection images of multiple projection units. As shown in FIG4 , projection units 1 and 2 are simultaneously projecting. Projection unit 1 projects image A onto screen 1 to obtain projection image A, and projection unit 2 projects image B onto screen 2 to obtain projection image B. The image capture angle of view of the image acquisition unit in the projection correction device includes projection image A and projection image B. In actual operation, the image acquisition unit can first capture image of projection image A to obtain target image A, and then capture image of projection image B to obtain target image B. Then, based on target image A and the projected image A within target image A, the clarity, image shape, and display position of the projection image of projection unit 1 are corrected. Furthermore, based on target image B and the projected image B within target image B, the clarity, image shape, and display position of the projection image of projection unit 2 are corrected. Thus, a single projection correction device can be used to correct the images of multiple projection units.

[0091] Of course, in this scenario, the control unit in the projection correction device needs to be connected to multiple projection units. When performing image correction, if correction needs to be controlled, the distance between the optical machine and the lens can be adjusted according to the focal length of each projection unit, that is, the focal length of each projection unit can be adjusted separately. I will not go into details here.

[0092] In some examples, if the image acquisition unit is configured within the projection unit, the image acquisition unit may be positioned so that the optical engine within the projection unit is in the same horizontal plane. Thus, the target image captured by the image acquisition unit can be used to perform horizontal trapezoidal correction on the projected image. In some examples, the image acquisition unit may be positioned so that it is in the same horizontal plane as the optical engine within the projection unit. When in the same horizontal plane, the image acquisition unit may be located on a first side of the optical engine or on a second side of the optical engine opposite the first side.

[0093] Among them, the optical machine is the light source of the projection unit, which can be used to define the area where the projection image is located. The image acquisition unit can be located on the left or right side of the optical machine and on the same horizontal plane as the optical machine.

[0094] Referring to FIG5 , a schematic diagram of the positions between the image acquisition unit and the projection unit is shown. As shown in FIG5 , the projection unit includes an optical engine and a lens, wherein the image acquisition unit and the optical engine are located on the same horizontal line, and the image acquisition unit is located on the first side or the second side of the optical engine, wherein the first side can be the right side and the second side is the left side, or the first side is the left side and the second side is the right side. In other words, the image acquisition unit is located on the left or right side of the optical engine. As shown in FIG4 , the image acquisition unit is located on the left side of the optical engine. Of course, whether it is located on the left or right side, it can perform horizontal trapezoidal correction on the projected image.

[0095] In some other examples, the optical machine and the image acquisition unit may also be located on the same vertical plane and on the same straight line, and the image acquisition unit may be located on the upper or lower side of the optical machine. In this way, the target image captured by the image acquisition unit can be used to perform trapezoidal correction on the projected image in the vertical direction.

[0096] Of course, in practice, the number of image acquisition units is not limited to one, but may be multiple, such as two, one of which is located on the same horizontal line as the optical engine and is located on the left or right side of the optical engine, and the other is located on the same vertical line as the optical engine and is located above or below the optical engine. This allows the projection correction device to perform trapezoidal correction in both the horizontal and vertical directions. Specifically, the process of performing trapezoidal correction can be referred to in the subsequent embodiments and will not be elaborated on here.

[0097] In one example, the control unit can adjust the clarity of the projected image based on the target image and the projected image. Specifically, the clarity of the projected image can be adjusted by adjusting the focal length between the optical engine and the lens. In one embodiment, to improve adjustment efficiency, a combination of coarse adjustment and fine adjustment can be used. For example, the focal length can be adjusted first in larger steps and then in smaller steps.

[0098] In this example, the distance between the optical engine and the lens is called the focal length. This focal length affects the clarity of the projected image, and thus, can be adjusted by adjusting the focal length. In practice, multiple adjustments can be made to ensure the clarity of the projected image.

[0099] Specifically, the projection unit may include an optical machine and a lens, and the control unit may be specifically configured to perform a first adjustment to the focal length between the optical machine and the lens in the projection unit based on the projection picture and the target picture, and then after the first adjustment, the focal length may be adjusted at least once for the second time based on the projection picture, and the step length of the first adjustment may be greater than the step length of the second adjustment.

[0100] In this example, the size, position, and clarity of the projected image within the target image are determined based on the projected image and the target image. Thus, the focal length can be adjusted multiple times based on the size, position, and clarity. In a specific implementation, a first adjustment, i.e., a coarse adjustment, can be made to the focal length based on the size and position of the projected image within the target image. The size and position of the projected image within the target image can reflect the distance between the optical engine and the lens. Therefore, a first adjustment can be made based on the size and position of the projected image within the target image. This first adjustment allows for rapid focusing of the optical engine and the lens, thereby improving adjustment efficiency.

[0101] Among them, after the first adjustment, that is, after quick focus, the clarity of the projected image can be fine-tuned. This fine-tuning is called the second adjustment, so as to more finely adjust the clarity of the projected image. In the second adjustment, the focal length can be changed according to a preset step size, such as increasing or decreasing the focal length according to a preset step size, thereby gradually improving the clarity of the projected image. In some examples, during the process of performing the second adjustment, the change in the clarity of the projected image in the target image before and after the second adjustment can be identified. Based on this change, the direction of the second adjustment (such as increasing or decreasing the focal length) and the step size can be automatically fine-tuned, thereby gradually improving the clarity of the projected image.

[0102] By adopting the technical solution of this example, through the first adjustment, the optical machine and the lens can be quickly focused, thereby improving the focusing efficiency. Through the second adjustment, the focal length between the optical machine and the lens can be finely adjusted, thereby improving the adjustment fineness. By combining the first adjustment and the second adjustment, the efficiency of focal length adjustment can be improved, and the clarity of the projected image can be improved. The entire process is based on the target image captured by the image acquisition unit, without the need for unnecessary hardware equipment, and the cost of the projection unit can be reduced.

[0103] In one example, as described above, when the focal length is first adjusted based on the projection screen and the target screen, the distance between the projection unit and the projection area can be determined through the position and size of the projection screen in the target screen, and the focal length at a higher clarity can be determined based on the distance, thereby achieving rapid focusing.

[0104] 6 and 7 , FIG6 shows a schematic diagram of the relationship between the distance between the projection unit and the projection area (wall or screen) and the focal length, and FIG7 shows a schematic diagram of the camera viewing angle of the projection unit and the image acquisition unit. As shown in FIG6 and 7 , the position and size of the projected image in the target image can be determined based on the position of the projected image in the target image. Specifically, the control unit can be specifically configured to determine a first coordinate of the center point of the projected image in the target image and perform a first adjustment based on the first coordinate.

[0105] In one implementation, the projection screen can be a screen formed after the preset icon is projected onto the projection area, and the center point of the projection screen can be the center point of the preset icon in the target screen. Specifically, the preset icon can be a centrally symmetrical figure, such as an equilateral triangle, a circle, an isosceles trapezoid, etc., which will not be elaborated here.

[0106] Among them, the first coordinate can be the horizontal coordinate or vertical coordinate of the center point in the target picture. The first coordinate can reflect the size of the projected picture, and the size of the projected picture can reflect the distance between the projection screen and the projection unit. The distance between the screen and the projection unit, combined with the distance between the optical machine and the lens, can reflect the clarity of the projected picture.

[0107] Specifically, as shown in Figures 6 and 7, the image distance in Figure 6 is the distance between the optical center of the lens and the optical machine, and the object distance is the distance between the lens and the screen. Figure 7 is an example diagram of the horizontal cross-sectional view when looking down at the projection unit, where m1 / m2 / m3 represent the screen positions at different distances, respectively. Assuming that m1 represents 1 meter, m2 represents 2 meters, and m3 represents 3 meters. As can be seen from Figure 7, at the position of m1, the field of view of the optical machine and the field of view of the image acquisition unit intersect. At this time, the right side of the projected image overlaps with the right side of the target image, and the projected image is at the rightmost position of the target image. As the distance increases, that is, when m1 changes to m2 and then to m3 in Figure 7, it can be seen that the relative position of the projected image in the target image changes, and it continues to shift to the left.

[0108] Based on this characteristic, taking the first coordinate as the horizontal coordinate as an example, the focal length can be determined through the following process:

[0109] a. Assuming that the distance between the projector and the screen is f, and the horizontal coordinate of the center point of the projected image in the target image captured by the image acquisition unit is x, then the relationship between f and x has the following relationship (1):

[0110] f=a*x+b relation (1);

[0111] It should be noted that, with the image coordinates of the target screen as the coordinate system, the horizontal coordinate x of the center point of the projection screen in the coordinate system can be solved, and the horizontal coordinate can reflect the size and position of the projection screen.

[0112] b. Place the screen at position m1 and record a set of data (f1, x1). Place the screen at position m2 and record a set of data (f2, x2).

[0113] c. Substituting the two sets of data into equation (1) yields the values ​​of a and b. This establishes equation (1). Then, by measuring and calculating the horizontal coordinate of the center point of the projected image within the target image, substituting the horizontal coordinate value x into equation (1) yields the object distance f, which is the distance between the projection unit and the screen.

[0114] Among them, when the projection image of the projection unit reaches the clearest state on the screen, the distance between the projection unit and the screen is called the optimal object distance. When the image distance is fixed, the optimal object distance is also fixed. Generally speaking, there is a mapping relationship between the image distance and the object distance. When the object distance is known, the optimal image distance can be found according to the mapping relationship, thereby determining the focal length.

[0115] Therefore, according to the above process, it can be seen that when obtaining the first coordinate, the object distance can be obtained according to a preset formula, such as the above-mentioned relationship (1), and then according to the mapping relationship between the object distance and the image distance, the image distance (i.e., focal length) corresponding to the object distance can be obtained. Then, a first adjustment can be made according to the focal length. When making the first adjustment, the distance between the optical machine and the lens can be adjusted to the determined focal length at one time, or the distance between the optical machine and the lens can be changed to the determined focal length through multiple adjustments. Of course, when making multiple adjustments, it can also be performed according to the preset step size. Of course, the step size in the first adjustment can still be larger than the preset step size in the second adjustment, so that fast focusing can still be guaranteed.

[0116] By adopting the technical solution of this example, the focal length can be obtained directly according to the first coordinate of the center point of the projection image in the target image, thereby realizing the first adjustment. Compared with the use of laser and ToF methods, it is not only low-cost but also can determine the focal length more efficiently.

[0117] In some examples, the mapping relationship between the object distance and the image distance can be solidified as data information, stored in a processor, and retrieved when the control unit determines the first coordinates of the center point and the object distance. Specifically, after determining the object distance, the control unit can send a read instruction to a storage block in the control unit to read the mapping relationship solidified as data information, and then search the mapping relationship to find the image distance corresponding to the current object distance.

[0118] In a specific implementation, the control unit may be configured with a storage device. The data information after the mapping relationship is solidified may be referred to as a mapping relationship table. The mapping relationship table may be stored in the storage device and read from the storage device when the control unit sends a read instruction. Since the mapping relationship table needs to support search, the mapping relationship table may be solidified in the form of an SQL database to support query functions. The mapping relationship table may include preset focal lengths corresponding to different object distances. Thus, the control unit may be specifically configured to obtain the object distance corresponding to the first coordinate, search the mapping relationship table for a target preset focal length corresponding to the object distance, and adjust the focal length to the target preset focal length.

[0119] In this example, the object distance corresponding to the first coordinate can be obtained according to the above-mentioned relationship formula (1). After obtaining the object distance, the mapping relationship table can be searched, and then according to the correspondence between the object distance and the image distance in the mapping relationship table, the target preset focal length corresponding to the object distance corresponding to the first coordinate can be found, thereby adjusting the distance between the optical machine and the lens to the target preset focal length.

[0120] In the process of adjusting the distance between the optical machine and the lens to the target preset focal length, the method of adjusting to the target preset focal length once as described in the above example can be adopted, or the method of adjusting to the target preset focal length multiple times can be adopted, which will not be repeated here.

[0121] With the technical solution of this example, the mapping relationship between the object distance and the image distance is directly solidified as a mapping relationship table and stored in the control unit, and the mapping relationship table can be called after the object distance is determined. Then, the image distance corresponding to the object distance can be directly found in the mapping relationship table. In this way, the local mapping relationship table can be directly called, which improves the calling efficiency and the searching efficiency, thereby improving the efficiency of the first adjustment.

[0122] Of course, in some other examples, the mapping relationship table can also be stored in the cloud. After determining the object distance, the mapping relationship table can be called from the cloud through the network connection with the cloud, and then the image distance corresponding to the object distance can be found. In this example, the mapping relationship tables corresponding to different models and types of projection units can be stored in the cloud. When reading the mapping relationship table of a certain projection unit, a query request can be sent to the cloud. The query request can carry the model of the projection unit, so as to find the mapping relationship table that matches the model and accurately obtain the image distance corresponding to the object distance. In this implementation method, since the mapping relationship tables corresponding to projection units of multiple models are stored in the cloud, a projection correction device can perform projection correction on multiple projection units, which improves the correction flexibility and does not need to occupy the storage space of the control unit, so that the control unit can free up more resources for object distance calculation and image recognition required for subsequent correction, etc., helping to improve its operating speed.

[0123] After the first adjustment, a second adjustment is required. During the second adjustment, since it is a fine adjustment, the step size is smaller. As mentioned above, during the second adjustment process, the image acquisition unit can continuously capture the target picture, and thus judge whether the second adjustment has improved the clarity based on the clarity of the projected picture in the previously captured target picture, and then adjust the step size and direction of the second adjustment until the clarity of the projected picture can no longer be improved.

[0124] During specific implementation, the second adjustment can increase or decrease the focal length according to a preset step size, and the image acquisition unit can be configured to capture a new target picture after each second adjustment; the control unit is also specifically configured to determine the change in the clarity of the projection picture before and after the second adjustment based on the new target picture and the target picture captured last time, and perform the next second adjustment based on the change until the clarity of the projection picture can no longer be improved.

[0125] Among them, the preset step size can be set to 5 to 10 mm, for example, it can be 5 mm. After each second adjustment, the control unit can send an image acquisition instruction to the image acquisition unit, so that the image acquisition unit can acquire a new target picture. The new target picture still includes the projection picture. Therefore, the change in clarity of the projection picture can be determined based on the new target picture and the target picture acquired last time. The change in clarity can include higher clarity or lower clarity. Among them, when the clarity increases, the focal length can continue to be increased or decreased according to the preset step size along the direction of the last second adjustment. If the focal length was increased according to the preset step size last time, the focal length will still be increased according to the preset step size this time. If the focal length was decreased according to the preset step size last time, the focal length will still be decreased according to the preset step size this time.

[0126] In practice, if the clarity becomes low, the focal length can be increased or decreased according to the preset step size in the opposite direction of the last second adjustment. If the focal length was increased according to the preset step size last time, the focal length can be decreased according to the preset step size this time. If the focal length was decreased according to the preset step size last time, the focal length can be increased according to the preset step size this time.

[0127] Among them, until the clarity of the projected image no longer improves means: in the process of performing the second adjustment for n consecutive times, the clarity changes from high to low and then from low to high, which represents that the clarity continues to change between lower and higher levels. Therefore, it represents that there is one second adjustment in the n second adjustments that reaches the highest clarity. Therefore, the second adjustment in which the clarity changes from low to high can be used as the final adjustment result.

[0128] Exemplarily, the process of performing the second adjustment may be as follows:

[0129] a. The image acquisition unit captures the target image and transmits it to the control unit. The control unit calculates the clarity of the projected image in the target image and saves it as the initial clarity;

[0130] b. The control unit shortens the focal length between the optical machine and the lens according to the preset step size. The image acquisition unit then captures the target image and transmits it to the control unit. The control unit then calculates the clarity of the projected image in the target image as the current clarity.

[0131] c. Compare the current resolution with the initial resolution. If the image is clearer, continue shortening the distance between the optical engine and the lens. If the image is blurry, increase the focal length between the optical engine and the lens and update the initial resolution to the current resolution.

[0132] d. The image acquisition unit repeatedly captures the target image and transmits it to the control unit, which then compares the current clarity with the initial clarity. If the current clarity is clearer, the distance between the optical engine and the lens is further increased, and step d is repeated until the current image is blurrier than the previous one, indicating that focusing is complete. If the image is blurry, the distance between the optical engine and the lens is shortened, and the second adjustment is completed.

[0133] By adopting the technical solution of this example, a second adjustment can be made according to the change in the clarity of the projected image in the target image, so that the adjustment process can always rely on the target image captured by the image acquisition unit, thereby improving the flexibility and automaticity of micro-adjustment.

[0134] In yet other examples, to achieve finer-grained fine-tuning, when the clarity of the projected image improves after the second adjustment, to avoid continuing the second adjustment in the same direction, which would otherwise result in blurred clarity due to an excessively large step size, the second adjustment can be performed with a smaller step size than the previous second adjustment when the projected image becomes clearer. The control unit can be specifically configured to reduce the preset step size when the change in clarity of the projected image indicates an increase in clarity, and to continue the second adjustment with the reduced preset step size.

[0135] For example, assuming that the preset step size is set to 10mm, then during the last second adjustment, the focal length was shortened by 10mm. After shortening, it was found that the clarity of the projected image became higher, which indicates that shortening the focal length can make the projected image clearer. In the next second adjustment, the focal length can be shortened by 8mm or 5mm. The reduction amount of the preset step size can be determined as needed, such as the reduction amount can be set to 2mm, 1mm or 3mm. The technical solution of this example can avoid the problem of repeated readjustment due to excessive fine-tuning when fine-tuning according to the same preset step size, so that the desired clarity can be gradually adjusted in the same direction (increase or shorten), thereby improving the accuracy of fine-tuning.

[0136] The following describes the process of performing trapezoidal correction on the projected image.

[0137] As shown in Figure 1, trapezoidal correction is performed for the situation where the projection image is trapezoidal due to the tilt of the projection unit in the horizontal and vertical directions. In practice, it can be determined whether it is tilted in the horizontal direction or in the vertical direction based on the shape of the projected image, and then targeted trapezoidal correction can be performed.

[0138] When the image acquisition unit captures the projected image, the target image it captures is rectangular. If the projected image is also rectangular, there is no shape difference between the two. However, if the projected image is non-rectangular, there is a significant shape difference between the two. Therefore, in some examples, the control unit can be specifically configured to determine the shape difference between the projected image and the target image, and perform a third adjustment on the projected image based on the shape difference. The third adjustment includes at least cropping the projected image.

[0139] In practice, if there is a shape difference between the projected image and the target image, the type of shape difference can be determined. Specifically, by comparing the projected image with the target image, it can be determined whether the projected image is a trapezoid in the horizontal or vertical direction. As shown in Figure 1, if the upper and lower sides of the projected image are not parallel to the upper and lower sides of the target image, it is determined to be a horizontal trapezoid, and it can be determined that the projection unit is tilted in the horizontal direction, in which case horizontal trapezoid correction is required. If the left and right sides of the projected image are not parallel to the left and right sides of the target image, it is determined to be a vertical trapezoid, and it can be determined that the projection unit is tilted in the vertical direction, in which case vertical trapezoid correction is required.

[0140] After determining whether the shape is horizontal trapezoidal or vertical trapezoidal, corresponding trapezoidal correction, ie, a third adjustment, may be performed on the projected image. The third adjustment may be either horizontal trapezoidal correction or vertical trapezoidal correction.

[0141] In a specific implementation, the third adjustment may be made to the projected image. This adjustment may be pixel-level adjustment or image cropping, so that the shape of the projected image adapts to the projection state of the projection unit when it is tilted. For example, the pixels of the projected image may be adjusted to compensate for the trapezoidal shape of the projection image, thereby compensating the trapezoidal projection image into a rectangular shape. For details, please refer to related technologies and will not be elaborated here.

[0142] It should be noted that in this example, the projected image is a data image, and an image processing program can be set in the control unit and / or the projection unit. The image processing program can be used to perform operations such as cropping on the projected image so that the projected image has a rectangular screen after being projected.

[0143] Of course, when performing trapezoidal correction based on the shape difference between the projected image and the target image, you can first perform trapezoidal correction in one direction. If the correction fails to correct the trapezoidal defect, you can choose to perform trapezoidal correction in another direction until the trapezoidal projection image is corrected to a rectangle. For example, if the projection image is a horizontal trapezoid, you can first perform trapezoidal correction on the projected image in the right direction. If the correction is unsuccessful, it means that the projection unit is not tilted to the right horizontally. In this case, trapezoidal correction can be performed on the original projected image in the left direction, which will definitely correct the problem. The same applies to vertical trapezoidal correction.

[0144] In some examples, the direction in which the projection unit is tilted can be determined by the aspect ratio between the projected image and the target image, and then, when performing the third adjustment, keystone correction can be performed specifically in the tilted direction.

[0145] During specific implementation, the control unit can be specifically configured to determine the ratio of the projection screen to the target screen, and based on the size relationship between the screen ratio and the preset ratio, determine the tilt angle, and perform a third adjustment on the projected image based on the tilt angle; wherein the tilt angle represents the torsion angle between the projection area of ​​the projection unit and the projection unit in the horizontal direction.

[0146] 8 and 9 , which illustrate a mathematical relationship model between the projected image when the screen is projected frontally and the target image captured by the image acquisition unit. As shown in FIG8 and 9 , if the position of the optical machine is regarded as a vertex of a triangle, the vertical intersection of the optical machine projection light and the screen, as well as the intersection with the outermost edge of the screen, are the other two vertices of the triangle. Based on the triangular relationship, the lengths of the projected image and the target image can be calculated as follows:

[0147] As shown in Figure 8, the triangular relationship of the projection screen is shown, f is the straight-line distance between the screen and the projection unit, and is also the straight-line distance between the image acquisition unit and the target screen. The field of view of the projection screen (the field of view of the optical machine) is β, and L and R are equal; as shown in Figure 9, the triangular relationship of the target screen captured by the image acquisition unit is shown, f is the straight-line distance between the screen and the projection unit, and is also the straight-line distance between the image acquisition unit and the target screen. The field of view of the target screen (image acquisition unit) is α, and L' and R' are equal; wherein, α is greater than β.

[0148] The lengths of the projected image and the target image are as follows:

[0149] w1=L'+R'=f*tanα+f*tanα;

[0150] w2=L+R=f*tanβ+f*tanβ;

[0151] Where w1 is the width of the target image, w2 is the width of the projection image, and the ratio pw of the projection image to the target image can refer to the following relationship (2):

[0152] pw=tanα / tanβ Relationship (II)

[0153] As can be seen from equation (2), the ratio of the projected image to the target image is independent of the projection distance. Therefore, in actual algorithm development and design, if the ratio of the target image to the projected image does not meet the equation pw = tanα / tanβ, then it can be determined to be a non-front projection state.

[0154] Therefore, whether the screen is tilted can be determined based on whether the screen ratio meets the preset ratio, where the preset ratio is tanα / tanβ, which can be a fixed value. If the screen ratio is not the preset ratio, it can be determined that trapezoidal correction is required.

[0155] FIG10 shows a schematic diagram of a model between the projected image length and the target image length. As shown in FIG10 , when the projection unit is twisted, it causes a relative tilt between the projection unit and the screen. When the projection unit is in the front projection position and the screen is tilted, the two also tilt relative to each other. Therefore, whether the screen is tilted or the projection unit is tilted, it can be regarded as a tilt of the screen. Therefore, FIG10 uses the tilt of the screen as an example for explanation.

[0156] Assuming that the position of the image acquisition unit 1 is shifted to the left relative to the position of the optical machine 2, it will be found that when the screen is twisted, the ratio of the projected image and the captured image will change; when the screen rotates clockwise, that is, at the A+ position in the figure, if the projection vertical distance changes from the vertical intersection of the optical machine and the screen to the vertical intersection of the camera and the screen, that is, the position of the dotted line A+' in the figure, observing the image will find that the actual A+ has moved upward by a certain position compared to the A+' when there is no horizontal offset. Therefore, the captured image will become larger relative to the projected image. In other words, the proportion of the projected image in the target image will become smaller.

[0157] When the screen rotates counterclockwise, that is, at position A- in the figure, if the vertical distance of the projection changes from the vertical intersection of the optical machine and the screen to the vertical intersection of the camera and the screen, that is, the position of the dotted line A-' in the figure, observing the image will find that the actual A- has moved downward by a certain position compared to A-' when there is no horizontal offset. Therefore, the captured image will become smaller relative to the projected image. In other words, the proportion of the projected image in the captured image will become larger.

[0158] Therefore, trapezoidal correction can be performed in the corresponding direction based on whether the aspect ratio is larger or smaller than the preset ratio. Specifically, if the aspect ratio is smaller than the preset ratio, it can be determined that the screen has rotated clockwise, and vice versa, the screen has rotated counterclockwise. Therefore, the optical machine trapezoidal value is adjusted according to the change in the ratio value, so that the projection unit projects a rectangular shape on the inclined surface, completing the correction.

[0159] Specifically, after determining the size relationship, the difference between the aspect ratio and the preset ratio can be further followed up to determine the tilt angle, wherein the larger the difference, the larger the tilt angle, and the smaller the difference, the smaller the tilt angle. The tilt angle can represent the relative positional relationship between the screen and the projection unit. Specifically, the tilt angle can be understood as the angle between the plane where the screen is located and the plane where the optical engine in the projection unit is located. Since the tilt direction has been determined based on the aspect ratio, the tilt angle can also carry a direction, so that a third adjustment can be made to the projected image based on the tilt angle.

[0160] Among them, when performing the third adjustment according to the tilt angle, it can be performed according to the trapezoidal correction described in the relevant technology, which will not be described in detail here.

[0161] Of course, as shown in FIG10 , the explanation is made by taking the image acquisition unit on the left side of the optical machine in the projection unit as an example. In FIG10 , the tilt angle and direction of the projection unit relative to the screen can be determined based on the size relationship between the picture ratio and the preset ratio. For example, when the picture ratio is greater than the preset ratio, it is determined that a counterclockwise rotation occurs, and when the picture ratio is less than the preset ratio, it is determined that a clockwise rotation occurs. Therefore, when determining the tilt direction, it can be accurately confirmed based on the positional relationship between the image acquisition unit and the optical machine.

[0162] During specific implementation, the control unit can be specifically configured to determine the tilt angle based on the size relationship between the picture ratio and the preset ratio, and the position of the image acquisition unit; wherein the position of the image acquisition unit can be the first side or the second side of the optical machine, and the first side and the second side are opposite sides.

[0163] As described above, the image acquisition unit can be located on the left or right side of the optical engine and on the same horizontal line as the optical engine, or on the upper or lower side of the optical engine and on the same vertical line as the optical engine. Thus, the tilt angle can be determined based on the relative positional relationship between the image acquisition unit and the optical engine. It should be noted that this tilt angle also includes the tilt direction.

[0164] For example, if the image acquisition unit is located on the left side of the optical engine, when the aspect ratio is greater than a preset ratio, it can be determined that the screen has rotated counterclockwise, and the tilt angle can be further determined based on the difference between the aspect ratio and the preset ratio. If the aspect ratio is less than the preset ratio, it can be determined that the screen has rotated clockwise, and the tilt angle can be further determined based on the difference between the aspect ratio and the preset ratio. Conversely, if the image acquisition unit is located on the right side of the optical engine, when the aspect ratio is greater than the preset ratio, it can be determined that the screen has rotated clockwise, and when the aspect ratio is less than the preset ratio, it can be determined that the screen has rotated counterclockwise.

[0165] When the image acquisition unit is located on the upper side or the lower side of the optical machine, the direction in which the screen tilts can also be determined based on the size relationship between the picture ratio and the preset ratio.

[0166] By adopting the technical solution of this example, the tilting direction of the screen can be determined according to the position of the image acquisition unit, so that the trapezoidal correction can be performed in the correct direction.

[0167] Next, the process of performing obstacle avoidance based on the target image and the projected image is described.

[0168] In practice, during the projection process of the projection unit, there may be objects near the projection area, such as furniture or other items placed between the screen and the projection unit. When the object is in the projection light path of the optical machine, it will block the projection image. Referring to Figure 11, a schematic diagram of a projection scene is shown. As shown in Figure 11, a vertical fan is placed between the screen and the projection unit, resulting in partial obstruction of the projection image. In this case, it is generally necessary to manually remove the obstacle, such as shifting the vertical fan. However, in some scenarios, the placed objects are not very portable or even cannot be moved, which makes it impossible for the projection image to avoid obstacles. In response to this situation, in one example, the projection range of the optical machine is manually adjusted to avoid obstacles in the projection area. However, this type of adjustment consumes manpower, takes a long time to avoid obstacles, and is less efficient.

[0169] In this example, the presence of an obstacle can be determined by identifying the obstacle on the projected image in the target image. When the presence of an obstacle is determined, the position of the obstacle can be further identified to determine the projection area so that the projection area avoids the location of the obstacle.

[0170] In a specific implementation, the control unit may also be configured to detect whether there is an obstacle on the target screen that blocks the projection screen, and when it is determined that there is an obstacle, adjust the projection range of the projection unit so that the projection range avoids the obstacle.

[0171] Among them, when the control unit detects whether there is an obstacle blocking the projection screen on the target screen, it can identify the continuity of the projection screen. If the projection screen is discontinuous, it means that part of the content of the projection screen is projected onto the obstacle, resulting in discontinuity of the screen and other content that does not belong to the projection screen. Therefore, the projection range of the projection unit can be adjusted.

[0172] In one example, when performing obstacle detection, a detection model can be called for implementation. The detection model can be configured in a control unit or stored in the cloud. The detection model can be obtained by training a preset model multiple times using multiple projection screen samples as training samples. The multiple projection screen samples include screen samples collected when there are no obstacles and screen samples collected when there are obstacles. The labels used for training can include 0 and 1, 0 represents the absence of an obstacle and 1 represents the presence of an obstacle. The preset model can be a classification model, and the prediction result output by it represents whether there is an obstacle in the projection screen sample that hinders the projection.

[0173] Therefore, the detection model can be used to improve the generalization of obstacle detection in the projection screen, so that the projection correction device can be applied to a variety of projection scenarios, helping a variety of projection units to avoid projection obstacles in different scenarios.

[0174] The projection range can be adjusted by adjusting the four coordinate positions of the optical engine. These four coordinates are the coordinates of the four vertices of the projection area where the projection image is located. During adjustment, it is necessary to ensure that there are no obstacles within the area enclosed by the four vertex coordinates. Specifically, the area enclosed by the four vertex coordinates is the projection area, and the coordinates of any point in the projection area do not coincide with the coordinates of an obstacle, so that the projection range avoids obstacles.

[0175] Exemplarily, referring to FIG12 , a schematic diagram of the projection screen shown in FIG11 after obstacle avoidance is shown. As shown in FIG12 , after adjusting the projection range of the optical machine, the projection range avoids obstacles, so that the complete unobstructed projection screen can be seen.

[0176] Exemplarily, when adjusting the projection range, the present invention can determine a predetermined projection range in the target picture according to the location of the obstacle, and the predetermined projection range can be a rectangular shape. Then, the four vertex coordinates of the predetermined projection range are obtained, and the four vertex coordinates are converted into world coordinates. Then, the world coordinates of the converted four vertices are converted into optical coordinates of the coordinate system where the optical machine in the projection unit is located, and the optical coordinates of the four vertices are sent to the projection unit, so that the projection unit drives the projection range of the optical machine to the four optical coordinate positions according to the four optical coordinates, thereby achieving correction of the projection range.

[0177] In one implementation of this example, the position of the obstacle can be determined first, and then a suitable range can be selected as the projection range based on the position of the obstacle. Specifically, the control unit can be configured to obtain the position of the obstacle, determine the projectable area based on the position of the obstacle, and adjust the projection range to be within the projectable area.

[0178] In this implementation, the position of the obstacle may refer to the position of the obstacle in the target image. In practice, the obstacle may be of irregular shape. Therefore, the obstacle may be subjected to contour detection to detect the outline of the obstacle, thereby obtaining the coordinates of each position point on the contour in the target image. Then, fitting is performed based on the coordinates of each position point, such as fitting a position box, thereby circumscribing the rectangular area where the obstacle is located. It should be noted that the rectangular area is the area in the target image.

[0179] After defining the rectangular area where the obstacle is located (hereinafter referred to as the obstacle area), you can select an area from the target image outside the rectangular area (hereinafter referred to as the non-obstacle area) as the projection range. The projection range is also a rectangular area. In practice, a rectangular area in the non-obstacle area close to the obstacle area can be used as the projection range. For example, as shown in Figure 11, the projection range is adjacent to the obstacle, that is, the projected image and the obstacle are adjacent but not intersecting. This allows for a maximum projection range.

[0180] It should be noted that the size of the projection range can be changed before and after adjustment to avoid obstacles as much as possible.

[0181] In practice, when projection is performed, it is possible to detect whether a screen exists. When a screen exists, the projection image needs to be projected onto the screen. At this time, the optical machine in the projection unit needs to position the projection range onto the screen.

[0182] In one example, the control unit can also detect whether there is a screen based on the target picture, and if there is a screen, the projection image is processed into the screen. In practice, when detecting whether there is a screen based on the target picture, the picture area in the target picture can be classified and detected. For example, the target picture includes the projection picture, and can also include objects outside the projection picture, such as walls, obstacles, etc. During the detection, the types corresponding to the various picture areas included in the target picture can be detected, such as the projection picture type, obstacle type, screen type and wall type. In this way, through the detected types, it can be determined whether there is a screen. If there is a screen, the control unit can further detect the area where the screen is located, and inform the projection unit of the result of the existence of the screen and the area where the screen is located, so that the projection unit projects the projection image to the area where the screen is located. This process can be called screen processing.

[0183] Specifically, since it is necessary to detect the types corresponding to the various picture areas included in the target picture, in another example, the target picture can be input into the target model, and the types of the various picture areas in the target picture can be detected by the target model. The target model can perform multi-classification tasks, and can be used to extract features of the input target picture, and identify the types of the various picture areas based on the feature map obtained after feature extraction. The target model can be trained using multiple acquired image samples as training samples. The acquired image samples are obtained by the image acquisition unit through image acquisition of the projection picture. The multiple acquired image samples can include images with and without a screen. Specifically, each acquired image sample can carry a label, and the label includes a category label indicating whether a screen exists, and a location label of the area where the screen is located. The category label and the location label can be manually labeled or not, which will not be elaborated here.

[0184] Therefore, using the target model, it is possible to determine whether a screen exists within the target image and the area within which the screen is located. Thus, when the presence of a screen is detected, the area within which the screen is located can also be determined. In practice, the control unit can obtain the vertex coordinates of the four vertices of the screen within the target image based on the area within which the screen is located. These vertex coordinates are then converted into world coordinates, which are then converted into coordinates within the projection unit's coordinate system. This allows the optical engine within the projection unit to position the projection range within the area within which the screen is located, thereby enabling projection display.

[0185] In this example, if the target picture captured by the image acquisition unit only contains part of the boundary of the screen, such as when the image acquisition unit performs image capture on the projection picture, if the target picture only contains the lower boundary and left and right boundaries of the screen, but not the upper boundary, then when determining the coordinates of the four vertices of the screen, the coordinates of the remaining two vertices can be predicted through the two known endpoints of the lower boundary and the known lengths of the left and right boundaries of the screen. The prediction process can be integrated into the process of training the target model, so that the target model has the ability to predict the area where the screen is located.

[0186] Of course, when the screen is not detected, it means that there is no screen. At this time, the projected image can be directly projected and displayed without the need for screen entry processing.

[0187] In some examples, as described above, the clarity, picture shape and display position of the projected image can be corrected. When all three are corrected, they are generally performed in a certain order. In this example, the correction order of the above three can be pre-fixed in the control unit, so that the control unit can correct the clarity, picture shape and display position of the projected image in turn according to the established correction order.

[0188] For example, assuming the correction order is: clarity, image shape, and display position, the control unit can first correct the clarity. During the clarity correction, the image acquisition unit can capture a target image containing the projection image, thereby determining the object distance between the projection unit and the screen (or wall) based on the horizontal coordinate of the center point of the preset icon in the projection image in the target image, and then obtaining the focal length corresponding to the object distance (i.e., the target preset focal length), thereby adjusting the focal length to the target preset focal length. Then, a second adjustment is performed. In the second adjustment, according to the change in clarity of the projection image in the target image captured by the image acquisition unit, a corresponding second adjustment is performed, thereby gradually adjusting to the desired clarity. After the clarity correction is completed, the image shape can be corrected. At this time, the image acquisition unit can again capture the projection image, then determine the image ratio of the projection image in the target image, compare the image ratio with the preset ratio, determine the tilt angle based on the size relationship, and perform trapezoidal correction on the projection image according to the tilt angle.

[0189] In another example, the correction that needs to be performed can be indicated by a projected image. In this example, different projected images can be used to indicate different corrections. The control unit can be configured to identify the type of projected image and then perform corresponding corrections on the projected image based on the identified type.

[0190] In a specific implementation, the projection correction device may further include an image switching unit; wherein: the image switching unit is configured to switch between a plurality of different projection images; wherein the projection unit is used to project and display the projection image;

[0191] The control unit is specifically configured to correct the clarity, display position and screen shape of the object corresponding to the currently projected projection image based on the target screen and the projection screen;

[0192] Among them, different projected images correspond to different objects in clarity, display position and picture shape.

[0193] In this example, the image switching device may be configured in the projection unit or not, wherein the image switching device can send the projection image to be projected to the lens for projection display. Specifically, the image switching unit may also be connected to the control unit and, in some cases, can be controlled by the control unit to switch the projection image to be projected.

[0194] The image switching unit may switch between the multiple projection images according to the correction sequence described above, such as switching from the previous projection image to the next projection image, thereby triggering the correction sequence.

[0195] In practice, the image acquisition unit can be connected to the image switching unit. Each time the image switching unit switches the projected image, it can send a drive signal, such as a high-level signal, to the image acquisition unit, thereby driving the image acquisition unit to capture the projected image and obtain a target image. The image acquisition unit can then send the target image to the control unit, which first identifies the image type of the projected image in the target image and then corrects the object corresponding to that image type in terms of clarity, display position, and image shape.

[0196] Of course, in some examples, the image switching unit can also be manually controlled to switch the projected image, so that the objects that need to be corrected can be appropriately corrected, while the objects that do not need to be corrected do not need to be corrected. Of course, it is also convenient to disrupt the correction order in some scenarios and perform correction according to the correction order required by the user.

[0197] In this example, the control unit can be configured to first identify the projection image corresponding to the projection screen in the target screen and identify its image type. The image type can represent the shape type of the projection image, or, in some other examples, the image type can represent the identification of the projection image. Different projection images have different identifications, and different identifications can be associated with different corrections.

[0198] During specific implementation, a correction thread corresponding to each identifier may be pre-set in the control unit. When the identifier of the projected image in the target screen is identified, the correction thread corresponding to the identifier may be started to perform the corresponding correction process.

[0199] By adopting the technical solution of this example, since the required correction can be directly indicated by the projected image, the automation of the projection correction can be improved, and the user does not need to manually specify the correction order, thereby improving the efficiency and automation of the projection correction.

[0200] In one implementation of this example, the multiple projection images may have differences in shape, and thus different corrections may be indicated based on the projection images having different shapes.

[0201] Of course, in further implementations, the multiple projected images may differ in content. For example, different projected images may include different text, and different text can distinguish different corrections. Alternatively, the multiple projected images may differ in both content and text, and both can be used to distinguish different corrections.

[0202] In some examples, multiple projected images may include icons with borders and circular icons. The bordered icons can be used to correct the image shape and display position. This is because image shape correction typically involves trapezoidal correction, so bordered icons can enhance the shape of the projected image, helping to more accurately identify front projection. For display position correction, bordered icons can enhance the integrity and continuity of the borders, helping to identify obstacles at the boundaries of the projection area, thereby improving obstacle avoidance capabilities.

[0203] Among them, a circular icon can be used for clarity correction, and the projected image corresponding to the clarity is a circular image. Therefore, the preset icon described above can be a circular icon. When using a circular icon, since the circular icon is a centrally symmetrical figure, the center point of the circular icon can be clearly identified, thereby facilitating the determination of the horizontal coordinate of the center point in the target image.

[0204] Exemplarily, referring to Figures 13 and 14, Figure 13 shows a schematic diagram of the shapes of three projected images, and Figure 14 shows a schematic diagram of the control of the correction process of the three projected image switching in Figure 13. As shown in Figures 13 and 14, the image switching unit switches the projected image to image 13, which is an image with a border, which can be a discontinuous border, and sends a high-level signal to the image acquisition unit. The image acquisition unit responds to the high-level signal and performs image acquisition on the projected screen of image 13 to obtain the target screen 13. Then, the image acquisition unit sends the target screen 13 to the control unit. The control unit determines whether a screen entry detection is required based on the type of the target screen 13, that is, whether a screen needs to be detected. If a screen is detected, the screen entry processing is performed. After the screen entry processing is completed, the switching signal is fed back to the image switching unit.

[0205] If the control unit does not detect the screen, it feeds back a switching signal indicating that the screen does not exist to the image switching unit.

[0206] Regardless of whether there is a screen, the image switching unit can switch to the next projected image 12 in response to the switching signal sent by the control unit. Image 12 is a circular icon. At this time, the circular icon is projected. At the same time, the image switching unit sends a high-level signal to the image acquisition unit. The image acquisition unit then performs image acquisition on the projected screen (circular icon) to obtain the target screen 12 and sends the target screen 12 to the control unit. The control unit first detects the type of projected image 12 in the target screen 12. If it is detected that it is a circular icon, it starts the focus correction process. Since the focus correction process includes the first adjustment and the second adjustment, in practice, the image switching unit may not switch the projected image during the first adjustment and the second adjustment until the control unit completes the second adjustment. At this time, the control unit sends a switching signal to the image switching unit again.

[0207] In response to the switching signal that arrives again, the image switching unit switches to the next projected image 13. Image 13 is an image with a border. However, it is different from image 11. Its border can be composed of QR codes on the four corners. As shown in Figure 14, image 11 is used to indicate trapezoidal correction. At the same time, the image switching unit sends a high-level signal to the image acquisition unit, and the image acquisition unit starts to acquire images of the new projection screen. Then, the newly acquired target screen 13 is sent to the control unit. The control unit first detects the type of the projection image 13 in the target screen 13. If it is detected that it is an icon with a QR code border, the screen shape correction process is started. During the screen shape correction process, the projection image switching may not be performed until the control unit completes the trapezoidal correction. At this time, the control unit sends a switching completion signal to the image switching unit. At this time, the image switching unit can be in a dormant state so that the projection unit can project and display the normal image required for projection, or the image switching unit can switch to the normal image required by the user for projection and display.

[0208] The structure of the projection correction device is described below. In some examples, the control unit may include a processor and an actuator connected to the processor, which may be connected to the projection unit. The processor may generate correction parameters based on the target image and the projected image. The correction parameters may include tilt angle, focal length, and position parameters depending on the object being corrected. For example, in clarity correction, the correction parameters may include focal length. In image shape correction, the correction parameters may include tilt angle. In display position correction, the correction parameters may include position parameters of the projection range, such as the coordinates of the four vertices of the projection range.

[0209] In practice, the correction parameters can be output to the actuator, so that the actuator corrects the focal length of the projection unit, the projection range of the optical machine, and the projected image according to the correction parameters.

[0210] In a specific implementation, the processor can be configured to generate a control instruction to the actuator based on the target image and the projection image, and the control instruction may include a correction parameter; wherein the actuator can be configured to respond to the control instruction and adjust at least one of the focal length between the optical machine and the lens in the projection unit, the projection range of the optical machine, and the projection image according to the correction parameter to correct the clarity, display position, and display shape of the projection image.

[0211] In this example, after the processor generates correction parameters based on the target image and the projected image, it can encapsulate the correction parameters into control instructions and send the control instructions to the actuator. The actuator can include multiple types, and different actuators can be used to perform corresponding operations on different objects of the projection unit, such as hardware mechanisms and software mechanisms. The hardware mechanism can include a focal length adjustment mechanism and an optical-mechanical adjustment mechanism.

[0212] Among them, the focal length adjustment mechanism can adjust the distance between the optical machine and the lens. In practice, the focal length adjustment mechanism may include a drive motor, which can be connected to the lens or the optical machine to drive one of the two to move forward and backward, thereby changing the focal length.

[0213] The optical adjustment mechanism can change the projection range of the optical machine, thereby playing a role in image obstacle avoidance. It should be noted that the adjustment of the projection range includes changing the area of ​​the projection range and changing the position of the projection range on the screen or wall.

[0214] The software mechanism may be program software embedded in the projection unit or in the control unit, which may be used to perform a third adjustment on the projected image, such as cropping the projected image, to compensate for the problem of non-front projection.

[0215] In practice, the processor can send control instructions to the corresponding actuator based on the object to be corrected, causing the corresponding actuator to perform corrections according to the correction parameters. Specifically, as described above, the processor can first identify the type of the projected image in the target image, and then determine the object to be corrected based on the identified type. Then, the processor can send control instructions to the actuator corresponding to the object to be corrected.

[0216] Of course, in some examples, the actuators in the projection correction device can be configured within the projection unit, or not. Hardware mechanisms, such as the focus adjustment mechanism and the optical-mechanical adjustment mechanism, can be configured within the projection unit and integrated with it. Software mechanisms can be configured within the projection correction device, independent of the projection unit, or, of course, integrated with the projection unit is also possible.

[0217] 15 , a schematic diagram illustrating the connection between the actuator and the projection unit in the projection correction device is shown. As shown in FIG15 , in this example, the actuator may include a first component, namely a focus adjustment mechanism, which is configured to be connected to the optical engine and / or lens and adjust the distance between the optical engine and the lens in the projection unit according to the correction parameters to change the focal length.

[0218] The actuator may further include a second component, which is an optical-mechanical adjustment mechanism, and may be configured to be connected to the optical machine and adjust the projection range of the optical machine according to correction parameters to change the display position.

[0219] The projection correction device disclosed in the present invention is described below with reference to an example.

[0220] Referring to Figures 16, 17 and 18, Figure 16 shows a structural schematic diagram of the projection correction device, and Figures 17 and 18 respectively show a workflow schematic diagram of the projection correction shown in Figure 16. As shown in Figures 16-18, the projection correction device includes an image acquisition unit, a control unit and an image switching unit, wherein the image acquisition unit is connected to the control unit and the image switching unit respectively, and the control unit is also connected to the image switching unit. The control unit includes a processor and an actuator, which can be connected to the processor, and the actuator includes a first component and a second component, the first component is connected to the lens of the projection unit, and the second component is connected to the optical machine. The entire projection correction device can be configured in the projection unit, so that the projection unit is called an integrated device.

[0221] Among them, the image acquisition unit is located on the same horizontal line as the optical machine in the projection unit and is located on the left side of the optical machine. The distance between it and the optical machine can be 5cm to 10cm. The field of view angle of the image acquisition unit is α, and the field of view angle of the optical machine is β, wherein α is greater than β.

[0222] The workflow is as follows:

[0223] First, the image switching unit sends a first projection image to the projection unit, and at the same time, sends a high-level signal to the image acquisition unit. The first projection image can be the above-mentioned image 12. The first projection image 12 is a circular icon, and the circular icon is projected out; in response to the high-level signal, the image acquisition unit can start image acquisition of the first projection image 12, obtain the first target picture 12, and send the first target picture 12 to the control unit.

[0224] Next, the processor in the control unit identifies the type of projected image in the target screen and determines that focusing is required. This process can be a fast focusing process, that is, the first adjustment process mentioned above. Specifically, the processor identifies the horizontal coordinate of the center point of the first projected image 12 in the first target screen 12, calculates the object distance between the projection unit and the screen or wall based on the horizontal coordinate, and then obtains the target preset focal length. The target preset focal length is used as the first correction parameter 12. The processor encapsulates the first correction parameter 12 into a control instruction and sends the control instruction to the first component. The first component completes fast focusing according to the first adjustment process described in the above example. After fast focusing is completed, the first component feeds back an end signal to the processor, and the processor then sends a switching signal to the image switching unit.

[0225] The image switching unit switches to the second projected image, which can be the above-mentioned projection image 13. Image 13 is an image with a border, which can be a discontinuous border, and sends a high-level signal to the image acquisition unit. The image acquisition unit responds to the high-level signal and performs image acquisition on the projection screen of image 13 to obtain the second target screen 13. Then, the image acquisition unit sends the second target screen 13 to the control unit. The control unit determines whether screen entry detection is required based on the type of projection image 13 in the second target screen 13, that is, whether a screen needs to be detected. If a screen is detected, screen entry processing is performed.

[0226] Specifically, when the processor detects the presence of a screen, it can identify the four vertex coordinates of the screen in the second target screen 13, and then convert the four vertex coordinates into world coordinates, and then continue to convert them into the coordinates of the four vertices of the projection range of the optical machine in the projection unit. The coordinates of the four vertices of the projection range of the optical machine are used as the second correction parameters 13. Then, after encapsulating the second correction parameters 13, a control instruction is obtained, and the control instruction is fed back to the second component, so that the optical machine positions the projection range on the screen.

[0227] After the second component is executed, it will feedback the end signal to the processor, and then the processor will send a switching signal to the image switching unit. The image switching unit will start to switch to the third projection image, which can be the above-mentioned image 13. At the same time, the image switching unit sends a high-level signal to the image acquisition unit, and the image acquisition unit starts to capture the third projection image 13. Then, the newly captured third target screen 13 is sent to the processor. The processor first detects the type of the third projection image 13 in the third target screen 13. If it detects that it is an icon with a QR code border, the screen obstacle avoidance process will be started.

[0228] If there is no screen, the image switching unit can switch the projected image to image 11 and start the picture shape correction process. If it is determined that trapezoidal correction is required in the horizontal direction, the tilt angle can be obtained based on the difference between the picture ratio and the preset ratio. The tilt angle is the third correction parameter 13. The third correction parameter is encapsulated as a control instruction and sent to the image processing program (built into the projection unit) so that the image processing program can correct the subsequent projected image.

[0229] After the processor finishes sending, it sends a switching signal to the image switching unit again. At this time, the image switching unit starts to switch to the first projected image 12, that is, the circular icon, thereby starting to indicate a second adjustment of the focal length, that is, fine-tuning. Similarly, the image acquisition unit again captures the projection screen of the first projected image 12 to obtain a fourth target screen, and sends the fourth target screen to the processor. The processor sends the preset step length as the fourth correction parameter to the first component. The first component starts to lengthen or shorten the focal length according to the preset step length. The image acquisition unit continues to capture the fourth target screen. The processor determines the clarity of the projection screen before and after the second adjustment until the clarity no longer improves, and the correction ends.

[0230] At this time, the control unit sends a switching completion signal to the image switching unit. At this time, the image switching unit can be in a dormant state so that the projection unit can project and display the normal image required for projection, or the image switching unit can switch to the normal image required by the user for projection and display. In the normal image projection display, the image processing program processes the normal image according to the third correction parameter to overcome the defect that the projected image is trapezoidal.

[0231] It should be noted that, as shown in Figure 18, the projection image used for obstacle avoidance can be consistent with the projection image used for screen entry detection, such as both can be projection image 13, or the projection image used for obstacle avoidance can be consistent with the projection image used for trapezoidal correction, such as both can be projection image 11.

[0232] Based on the same inventive concept, the present disclosure also provides a projection system, as shown in Figure 19, which shows a system structure schematic diagram of the projection system. As shown in Figure 19, it includes a projection unit, which includes an optical machine and a lens, and a projection correction device described in any of the above examples. The control unit in the projection correction device is respectively connected to the optical machine and the lens.

[0233] The projection correction device can be integrated with the projection unit to form an all-in-one device. Alternatively, as described above, it can be used independently of the projection unit, and the projection correction device is used to cooperate with the projection unit to perform projection correction.

[0234] Based on the same inventive concept, the present disclosure further provides a projection method, which can be applied to the projection system described in the above embodiment. FIG. 20 shows a schematic flow chart of the steps of the projection method. As shown in FIG. 20 , the projection method can specifically include the following steps:

[0235] Step S101: Projecting and displaying a projection image.

[0236] Step S102: performing image acquisition on the projected screen to obtain a target screen; wherein the target screen includes the projected screen.

[0237] Step S103: Based on the projected image and the target image, correct at least one of the clarity, display position, and image shape of the projected image.

[0238] The projection unit can project and display a projected image. During the projection display process, the projected image can be captured. As shown above, the image capture unit has a capture angle greater than the angle of view of the optical engine in the projection unit, so that the captured target image includes the projected image. In practice, the projection correction device can correct at least one of the clarity, display position, and image shape of the projected image based on the projected image and the target image.

[0239] By adopting the technical solution of this projection method, the projection display can be corrected based on the target image captured by the image acquisition unit, thereby reducing the cost of correcting the projection display and improving the correction efficiency.

[0240] In some examples, when correcting the clarity of a projected image based on the projected image and the target image, a first adjustment can be made to the focal length between the optical engine and the lens in the projection unit based on the projected image and the target image. After the first adjustment, at least one second adjustment can be made to the focal length based on the projected image; wherein the step size of the first adjustment is greater than the step size of the second adjustment. The specific process can refer to the process described in the above example and is not further described here.

[0241] In some other examples, when performing the first adjustment, first coordinates of the center point of the projection image in the target image may be determined, and the first adjustment may be performed based on the first coordinates.

[0242] In another implementation of this example, when performing the first adjustment based on the first coordinate, the object distance corresponding to the first coordinate can be obtained, and the target preset focal length corresponding to the object distance can be found in a mapping table. The focal length between the optical engine and the lens can then be adjusted to the target preset focal length. The mapping table can be configured in a control unit of the projection correction device and can include preset focal lengths corresponding to different object distances.

[0243] In some examples, when making the second adjustment, the focal length can be increased or decreased according to a preset step size, and after each second adjustment, a new target image is captured. Based on the new target image and the target image captured last time, the change in the clarity of the projected image before and after the second adjustment is determined, and the next second adjustment is made based on the change until the clarity of the projected image no longer improves.

[0244] In a further implementation of this example, when the change representation clarity becomes higher, the preset step size may be reduced, and the second adjustment may be continued according to the reduced preset step size.

[0245] In yet another example, a shape difference between the projected image and the target image may be determined, and a third adjustment may be performed on the projected image based on the shape difference, wherein the point adjustment at least includes cropping the projected image.

[0246] In another implementation of this example, the ratio of the projected image to the target image may be determined, and based on a size relationship between the ratio and a preset ratio, a tilt angle may be determined, and the third adjustment may be performed on the projected image based on the tilt angle.

[0247] The tilt angle represents a twisting angle between the projection area of ​​the projection unit and the projection unit in the horizontal direction.

[0248] In another implementation of this example, when determining the tilt angle, the tilt angle can be determined based on the size relationship between the picture ratio and the preset ratio, and the position of the image acquisition unit; wherein the position of the image acquisition unit is the first side of the optical machine or the second side opposite to the first side.

[0249] The control unit is further configured to detect whether there is an obstacle on the target screen that blocks the projection screen, and when it is determined that the obstacle exists, adjust the projection range of the projection unit so that the projection range avoids the obstacle.

[0250] In some optional examples, the position of the obstacle may be acquired, and a projection area may be determined based on the position, and the projection range may be adjusted to be located in the projection area.

[0251] In some optional examples, it is also possible to detect whether there is a screen based on the target image; if there is a screen, the projection image is processed to enter the screen.

[0252] In some optional examples, image switching may be performed between a plurality of different projection images; wherein the projection unit is used to project and display the projection image;

[0253] Then, based on the target image and the projected image, the clarity, the display position, and the image shape of the object corresponding to the currently projected image may be corrected;

[0254] Different projection images correspond to different objects in the definition, the display position and the screen shape.

[0255] In some optional examples, the plurality of projected images include icons with borders and circle-like icons.

[0256] In some optional examples, the projection image corresponding to the clarity is a circular image, and the projection image corresponding to the display position and the screen shape is an image with a border.

[0257] In some optional examples, the control unit of the projection correction device includes a processor and an actuator connected to the processor; wherein,

[0258] The processor is configured to generate a control instruction for the actuator based on the target image and the projected image, wherein the control instruction includes a correction parameter;

[0259] The actuator is configured to respond to the control instruction and adjust at least one of the focal length between the optical machine and the lens in the projection unit, the projection range of the optical machine, and the projected image according to the correction parameters to correct the clarity, display position, and display shape of the projection image.

[0260] In some optional examples, the actuator includes:

[0261] a first component configured to be connected to the optical engine and / or the lens and to adjust the distance between the optical engine and the lens in the projection unit according to the correction parameter to change the focal length;

[0262] The second component is configured to be connected to the optical engine and adjust the projection range of the optical engine according to the correction parameter to change the display position.

[0263] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0264] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, commodity, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, commodity, or device that includes the element.

[0265] The above is a detailed introduction to a projection correction device, a projection system, and a projection method provided by the present disclosure. Specific examples are used herein to illustrate the principles and implementation methods of the present disclosure. The description of the above embodiments is only used to help understand the method of the present disclosure and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present disclosure, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present disclosure.

[0266] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0267] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

[0268] References herein to "one embodiment," "an embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Furthermore, please note that instances of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0269] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present disclosure may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0270] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present disclosure may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0271] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A projection correction device, characterized in that: Used to be configured to the projection unit, the projection correction device includes: An image acquisition unit is configured to acquire an image of the projection picture projected by the projection unit to obtain a target picture; the target picture includes the projection picture; as well as, The control unit is configured to correct at least one of the clarity, display position, and screen shape of the projection screen based on the target screen and the projection screen.

2. The projection correction device according to claim 1, characterized in that The image acquisition unit is configured to be on the same horizontal line as the optical machine in the projection unit, and is located on a first side of the optical machine, or on a second side opposite to the first side.

3. The projection correction device according to claim 1, characterized in that The control unit is specifically configured to perform a first adjustment on a focal length between an optical engine and a lens in the projection unit based on the projection picture and the target picture, and after the first adjustment, perform at least one second adjustment on the focal length based on the projection picture; The step size of the first adjustment is greater than the step size of the second adjustment.

4. The projection correction device according to claim 3, characterized in that: The control unit is specifically configured to determine a first coordinate of the center point of the projection image in the target image, and perform the first adjustment according to the first coordinate.

5. The projection correction device according to claim 4, characterized in that: The control unit is configured with a mapping relationship table, which includes preset focal lengths corresponding to different object distances; wherein, The control unit is specifically configured to obtain the object distance corresponding to the first coordinate, search the target preset focal length corresponding to the object distance from the mapping relationship table, and adjust the focal length to the target preset focal length.

6. The projection correction device according to claim 3, characterized in that: The second adjustment is to increase or decrease the focal length according to a preset step size; wherein, The image acquisition unit is specifically configured to acquire a new image after each second adjustment. Target screen; The control unit is specifically configured to determine the change in the clarity of the projection image before and after the second adjustment based on the new target image and the target image captured last time, and perform the next second adjustment based on the change until the clarity of the projection image no longer improves.

7. The projection correction device according to claim 6, characterized in that: The control unit is specifically configured to reduce the preset step size when the change representation clarity becomes higher, and continue the second adjustment according to the reduced preset step size.

8. The projection correction device according to claim 1, characterized in that: The control unit is specifically configured to determine a shape difference between the projection image and the target image, and perform a third adjustment on the projection image according to the shape difference; wherein the third adjustment at least includes cropping the projection image.

9. The projection correction device according to claim 8, characterized in that: The control unit is specifically configured to determine a ratio of the projection image to the target image, determine a tilt angle based on a size relationship between the ratio and a preset ratio, and perform the third adjustment on the projection image based on the tilt angle; The tilt angle represents a twisting angle between the projection area of the projection unit and the projection unit in the horizontal direction.

10. The projection correction device according to claim 9, characterized in that: The control unit is specifically configured to determine the tilt angle based on a size relationship between the screen ratio and a preset ratio and a position of the image acquisition unit; The image acquisition unit is located at a first side of the optical machine or a second side opposite to the first side.

11. The projection correction device according to claim 1, characterized in that: The control unit is further configured to detect whether there is an obstacle on the target screen that blocks the projection screen, and when it is determined that the obstacle exists, adjust the projection range of the projection unit so that the projection range avoids the obstacle.

12. The projection correction device according to claim 11, characterized in that: The control unit is specifically configured to obtain the position of the obstacle, determine the projection area based on the position, and adjust the projection range to be located in the projection area.

13. The projection correction device according to claim 1, characterized in that: The control unit is further configured to detect whether there is a screen based on the target image; if there is a screen, perform screen entry processing on the projected image.

14. The projection correction device according to claim 1, characterized in that The system further includes an image switching unit; wherein: The image switching unit is configured to switch between a plurality of different projection images; wherein the projection unit is used to project and display the projection images; The control unit is specifically configured to correct the clarity, the display position, and the screen shape of an object corresponding to the currently projected projection image based on the target screen and the projection screen; Different projection images correspond to different objects in the definition, the display position and the screen shape.

15. The projection correction device according to claim 14, characterized in that: The plurality of projected images include icons with borders and circle-like icons.

16. The projection correction device according to claim 14, characterized in that: The projection image corresponding to the definition is a circular image, and the projection image corresponding to the display position and the screen shape is an image with a frame.

17. The projection correction device according to claim 1, characterized in that: The control unit includes a processor and an actuator connected to the processor; wherein, The processor is configured to generate a control instruction for the actuator based on the target image and the projected image, wherein the control instruction includes a correction parameter; The actuator is configured to respond to the control instruction and adjust at least one of the focal length between the optical machine and the lens in the projection unit, the projection range of the optical machine, and the projected image according to the correction parameters to correct the clarity, display position, and display shape of the projection image.

18. The projection correction device according to claim 17, characterized in that: The executive mechanism comprises: a first component configured to be connected to the optical engine and / or the lens and to adjust the distance between the optical engine and the lens in the projection unit according to the correction parameter to change the focal length; The second component is configured to be connected to the optical engine and adjust the projection range of the optical engine according to the correction parameter to change the display position.

19. A projection system, characterized in that: include: A projection unit, comprising an optical engine and a lens; as well as, The projection correction device according to any one of claims 1 to 18; Wherein, the control unit in the projection correction device is connected to the optical machine and the lens respectively.

20. A projection method, characterized in that: Applied to the projection system of claim 19, the projection method comprises: Projecting and displaying the projected image; Performing image acquisition on the projected image to obtain a target image; wherein the target image includes the projected image; Based on the projection picture and the target picture, at least one of the clarity, display position and picture shape of the projection picture is corrected.

Images