Projection correction method and projection equipment

Abstract

The invention relates to a projection correction method and projection equipment, the projection equipment is provided with a motor, the motor is fixedly provided with a single-point distance detector, the projection direction of the single-point distance detector and the axial direction of the single-point distance detector form a certain included angle, and the motor is controlled to drive the distance detector to rotate under the condition that the projection equipment meets correction triggering conditions. The distance detector projects a plurality of pairs of projection points on the display plane. And then distance parameters between at least one pair of projection points and the single-point distance detector are selected, calculation is carried out in combination with the projection included angle of the single-point distance detector, and finally the deflection angle of the projection equipment is determined, so that projection correction is carried out on the projection equipment. According to the scheme, in the correction process, a correction image does not need to be additionally projected to the display plane, the whole projection correction process is achieved through the motor and the single-point distance detector which are additionally arranged, normal projection is not affected, and non-inductive projection correction can be achieved.

Description

Technical Field

[0001] The present application relates to the technical field of projection image correction, and in particular to a projection correction method and a projection device. Background Art

[0002] A projector is a device that can project images or videos onto a display plane for display. With the rapid development of science and technology and the improvement of people's living standards, projectors are increasingly used in daily production, life and study, bringing great convenience to people. During the use of a projector, it is easy for the image or video projected onto the display plane to be deformed (for example, to form a trapezoid, etc.) due to operating errors and other reasons.

[0003] In view of the above phenomenon, currently, the projection image is generally corrected by projecting a correction image onto the display plane, capturing the correction image with a camera, and then performing algorithm recognition on the correction image. However, this projection image correction method requires projecting the correction image, interrupting the normal use of the projector. Summary of the invention

[0004] Based on this, it is necessary to provide a projection correction method and a projection device to solve the problem that projection correction may affect the normal use of the projector and realize imperceptible projection correction.

[0005] In a first aspect, the present application provides a projection correction method, comprising: if a correction trigger condition is met, controlling a motor of a projection device to drive a single-point distance detector to rotate; wherein the single-point distance detector is fixedly disposed on the motor, and a projection angle between an emission direction of the single-point distance detector and an axial direction of the motor is greater than 0 degrees and less than 90 degrees; determining a deflection angle of the projection device according to the projection angle and a distance parameter between at least one pair of projection points of the single-point distance detector on a display plane and the single-point distance detector; and performing projection correction on the projection device according to the deflection angle.

[0006] In the above scheme, a motor whose axis is perpendicular to the lens plane is provided in the projection device, and a single-point distance detector whose projection direction forms a certain angle with the axis is fixedly provided on the motor. When the projection device meets the correction triggering conditions, the motor is controlled to drive the distance detector to rotate so that the distance detector projects multiple pairs of projection points on the display plane. Then, the distance parameters between at least one pair of projection points and the single-point distance detector are selected, and the calculation is performed in combination with the projection angle of the single-point distance detector to finally determine the deflection angle of the projection device, thereby performing projection correction on the projection device. In the above scheme, there is no need to additionally project a correction image onto the display plane during the correction process. The entire projection correction process is realized by the additionally provided motor and single-point distance detector, which will not affect the normal projection and can realize non-sensitive projection correction.

[0007] In a second aspect, the present application also provides a projection device, comprising a projection device body, a motor and a single-point distance detector, wherein the motor is arranged on the projection device body, the single-point distance detector is fixedly arranged on the motor, and the projection angle between the emission direction of the single-point distance detector and the axial direction of the motor is greater than 0 degrees and less than 90 degrees, and the projection device body is used to execute the above-mentioned projection correction method. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0009] Figure 1 This is a schematic diagram of an application scenario of a projection correction method in an embodiment of the present application;

[0010] Figure 2 This is a flowchart of a projection correction method in one embodiment of the present application;

[0011] Figure 3 This is a schematic diagram of the installation of a single-point distance detector in one embodiment of the present application;

[0012] Figure 4 This is a schematic diagram of the structure of a connecting piece in an embodiment of the present application;

[0013] Figure 5 This is a schematic diagram of a single-point distance detector rotating and scanning in one embodiment of the present application;

[0014] Figure 6 A schematic diagram of a triangle model constructed by rotating a single-point distance detector in an embodiment of the present application;

[0015] Figure 7 This is a flowchart of a projection correction method in another embodiment of the present application;

[0016] Figure 8 This is a schematic diagram of an effective verification process in an embodiment of the present application;

[0017] Fig. 9 This is a schematic diagram of a single-point distance detector rotating and scanning in another embodiment of the present application;

[0018] Fig.10 This is a flowchart of a projection correction method in another embodiment of the present application;

[0019] Fig.11 This is a flowchart of a projection correction method in another embodiment of the present application;

[0020] Fig.12 This is a flowchart of a projection correction method in another embodiment of the present application;

[0021] Fig.13 This is a flowchart of a projection correction method in another embodiment of the present application;

[0022] Fig.14 This is a flowchart of a projection correction method in another embodiment of the present application;

[0023] Fig.15 This is a flowchart of a projection correction method in another embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0025] The present application provides a projection correction method, which is applied to a projection device that can display pictures, text, videos, etc. through a projection function. The specific types of projection devices include but are not limited to projectors. Figure 1 The projection device specifically includes a projection device body 102, and a single-point distance detector 104 and a motor 106 disposed on the projection device body 102. The pictures, texts, videos, etc. projected by the projection device body 102 are displayed on a display plane 108. At the same time, the projection device body 102 also includes a controller for executing the projection correction method provided in the present application. The controller can be a controller in the projection device body 102 for controlling the projection display, or can be an additional setting, which can be selected in combination with actual needs.

[0026] For ease of understanding, the following embodiments are explained by taking the projection correction method applied to the projection device body and the controller for projection display control as an example. Figure 2 The projection correction method includes step 202, step 204 and step 206.

[0027] Step 202: If the calibration trigger condition is met, the motor of the projection device is controlled to drive the single-point distance detector to rotate.

[0028] Specifically, the single-point distance detector is fixedly mounted on the motor, and the projection angle between the emission direction of the single-point distance detector and the axial direction of the motor is greater than 0 degrees and less than 90 degrees. The single-point distance detector is a distance detector that can emit a single-point detection signal when performing distance detection, that is, a distance detector that detects the distance from one point to another. The lens plane is the plane where the lens of the optical machine of the projection device is located. Generally, when the projection device does not deflect at all, the lens plane is parallel to the display plane to ensure that the image finally projected onto the display plane is rectangular. The axial direction of the motor is the straight line where the transmission shaft of the motor is located, extending along the display plane.

[0029] In one embodiment, the axial direction of the motor is set perpendicular to the lens plane of the projection device. During the normal display of the projection device, the axial direction of the motor will be perpendicular to the display plane. At this time, it is considered that the projection device has not deflected. The motor is fixedly set on the projection device. If the projection device deflects, it will drive the motor to deflect, so that the axial direction of the motor is no longer perpendicular to the display plane. Correspondingly, at this time, the angle between the emission direction of the single-point distance detector and the display plane will also change to a certain extent. After the motor drives the single-point distance detector to rotate, there will be a certain difference in the projection point on the display plane. Therefore, the scheme of this embodiment will use the change of the projection point on the display plane after the motor of the projection device drives the single-point distance detector to rotate, to characterize the deflection between the projection device and the display plane, and then determine the deflection angle of the projection device by solving it, so as to realize the projection correction of the projection device.

[0030] It should be noted that the single-point distance detector is not the only way to be fixedly installed on the motor at a certain angle. In one embodiment, the single-point distance detector can be directly fixedly installed on the transmission shaft of the motor at a certain angle by bonding or other means. In another embodiment, it can also be realized by an additional connecting member. Specifically, it can be combined with reference to Figure 3 as well as Figure 4 First, the connecting member 302 is fixedly set on the transmission shaft of the motor 106, and then the single-point distance detector 104 is fixed to the connecting member 302, thereby completing the setting of the single-point distance detector 104.

[0031] The correction trigger condition is not unique. In one embodiment, it can be to detect whether a projection correction instruction sent by the user is received. If the projection correction instruction is received, it is considered that the correction trigger condition is met. In another embodiment, the projection device can also be provided with a device for detecting whether the projection picture is normal (for example, detecting whether a trapezoid appears, whether the picture is clear, etc.), and when the projection picture is detected to be abnormal, a related signal is output, and at this time, it can also be considered that the projection correction trigger condition is met.

[0032] It is understandable that the specific type of the single-point distance detector is not unique. In a more detailed embodiment, the single-point distance detector includes a single-point TOF (Time Of Flight) distance detector. The single-point TOF distance detector includes an emitting diode, a receiving diode, a modulation module, a demodulation module, and a processor, which are used to emit a detection signal and measure the distance from one point to another point by the time of flight measurement method. In other embodiments, the single-point distance detector can also select other devices that can realize point-to-point distance detection, which is not specifically limited.

[0033] Furthermore, to ensure the accuracy of projection correction, in one embodiment, for different types of projection devices, the projection angle between the emission direction of the single-point distance detector and the axis of the motor will also be different. Specifically, for ultra-short-focus projection devices, the projection angle can be set to be larger, and for conventional telephoto projection devices, the projection angle can be set to be smaller.

[0034] Step 204 , determining the deflection angle of the projection device according to the projection angle and the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector.

[0035] Specifically, a pair of projection points refers to two relative detection signal emission points during the process of the single-point distance detector rotating to emit the detection signal. The rotation angle of the single-point distance detector between the two emission points differs by 180 degrees. During the actual rotation process, the angle of the projection direction corresponding to the same pair of projection points will be twice the projection angle. The display plane is a plane used to display the image, text or video projected by the projection device. The specific type of display plane is not unique, as long as it can ensure that the image, text or video projected onto its surface can be displayed. For example, in one embodiment, the display plane is specifically a display screen corresponding to the projection device, and the surface of the display screen is the display plane. In another embodiment, the image, text or video to be displayed can also be directly projected onto the wall for display, and the corresponding wall surface can be regarded as the display plane.

[0036] Please refer to Figure 5 After the motor drives the single-point distance detector to rotate one circle, if there is no obstruction between the projection device and the display plane, the projection points of the single-point distance detector on the display plane can form a circle (circle or ellipse, etc.), and combined with the detection signal (such as infrared) emitted by the single-point distance detector, an approximate three-dimensional cone can be constructed. At this time, select any pair of projection points, and combine the line segments between the two projection points and the single-point distance detector to form a three-dimensional cone. Figure 6The triangle shown. Wherein, A and B represent the two selected projection points respectively, C represents the emission point of the single-point distance detector, a represents the distance from the first projection point to the single-point distance detector (specifically acquired by the single-point distance detector), b represents the distance from the second projection point to the single-point distance detector, c represents the distance between the two projection points, d represents the distance from the midpoint of A and B to C, and γ is bisected by the midline, which can be regarded as the vertical distance from the projection device to the display plane, γ represents the angle of the projection direction corresponding to the same pair of projection points, and its size is twice the projection angle, and θ represents the deflection angle of the projection device. When no deflection occurs, the axis of the motor is perpendicular to the display plane, and the corresponding θ is 90 degrees. Figure 6 In the constructed triangle, since the sizes of γ, a and b are known, the actual size of θ can be obtained by solving the trigonometric function, thereby realizing projection correction.

[0037] Step 206: Perform projection correction on the projection device according to the deflection angle.

[0038] Specifically, after the deflection angle of the projection device is obtained, the controller in the projection device will perform projection correction on the projection device according to the deflection angle, thereby ensuring that the picture projected by the projection device onto the display plane is rectangular.

[0039] It should be noted that there is not only one way to correct projection. In one embodiment, the correction can be achieved by controlling the rotation of the optical motor of the projection device to control the deflection of the lens of the projection device. In another embodiment, the projection correction can be achieved by changing the angle of the projection image projected by the display device from the source of the projection image. The selection can be made based on actual needs.

[0040] In more detail, in one embodiment, the projection correction includes horizontal correction and vertical correction. Specifically, a projection point at a specific position may be selected for calculation to obtain the horizontal deflection angle and vertical deflection angle of the projection device relative to the display plane, thereby achieving horizontal correction and vertical correction of the projection device.

[0041] The solution of the present application does not require a camera or a gyroscope during projection correction, which can effectively reduce equipment costs. This projection correction method can be applied to various types of projection equipment and has a wider range of application scenarios.

[0042] In the above-mentioned projection correction method, a motor whose axis is perpendicular to the lens plane is provided in the projection device, and a single-point distance detector whose projection direction forms a certain angle with the axis is fixedly provided on the motor. When the projection device meets the correction triggering conditions, the motor is controlled to drive the distance detector to rotate so that the distance detector projects multiple pairs of projection points on the display plane. Then, the distance parameters between at least one pair of projection points and the single-point distance detector are selected, and the calculation is performed in combination with the projection angle of the single-point distance detector, and finally the deflection angle of the projection device is determined, so as to perform projection correction on the projection device. In the above-mentioned scheme, there is no need to additionally project a correction image onto the display plane during the correction process. The entire projection correction process is realized by the additionally provided motor and single-point distance detector, which will not affect the normal projection and can realize non-sensitive projection correction.

[0043] See also Figure 7 In one embodiment, step 204 includes step 702 and step 704 .

[0044] Step 702 , obtaining an initial deflection angle according to the projection angle and the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector.

[0045] Step 704 , according to the projection angle and the distance parameters between all the projection points of the single point distance detector on the display plane and the single point distance detector, the initial deflection angle is corrected to obtain the deflection angle of the projection device.

[0046] Specifically, the solution of this embodiment, when analyzing the deflection angle, first analyzes the distance parameters between the single-point distance detectors to determine an initial deflection angle. Then, the distance parameters between all the projection points and the single-point distance detectors are obtained, and multiple different deflection angles are obtained by analysis. Finally, the initial deflection angle is corrected with multiple different deflection angles to obtain a more accurate angle value as the deflection angle of the projection device, so as to perform projection correction.

[0047] Specifically, in actual application scenarios, the initial deflection angle may be obtained by analyzing and calculating only the distance parameters between one pair of projection points and the single-point distance detector, and then the initial deflection angle is corrected for all pairs of projection points. In other embodiments, an initial deflection angle may be obtained by analyzing and calculating the distance parameters between two or more pairs of projection points and the single-point distance detector, and then the initial deflection angle is corrected for all pairs of projection points. The selection may be made based on actual needs.

[0048] It can be understood that in actual projection correction, the number of projection points obtained is not unique, and it can be selected in combination with actual measurement needs. For example, in a more detailed embodiment, the motor drives the single-point distance detector to rotate 10 degrees each time, and obtains a measured distance, that is, a projection point. Therefore, the motor rotates one circle and just completes 36 steps, obtaining 36 projection points and distance values, that is, 18 pairs of projection points and distance parameters. In other embodiments, the number of projection point logarithms can also be set to 36 pairs, without specific limitation.

[0049] The above scheme, after analyzing and obtaining a deflection angle by combining the distance parameters between at least one pair of projection points and the single-point distance detector, uses it as the initial deflection angle, and then corrects the initial deflection angle by combining all pairs of projection points, thereby obtaining a deflection angle with higher precision and accuracy, thereby improving the accuracy of projection correction.

[0050] See also Figure 8 In one embodiment, step 704 includes step 802 , step 804 , and step 806 .

[0051] Step 802 , obtaining corresponding angle parameters according to the projection angle and the distance parameters between all the corresponding projection points of the single point distance detector on the display plane and the single point distance detector.

[0052] Step 804, verify whether the angle parameter is valid.

[0053] Step 806: If the angle parameters are valid, data correction is performed on the initial deflection angle according to the angle parameters to obtain the deflection angle of the projection device.

[0054] Specifically, the solution of this embodiment, taking into account measurement errors, device installation errors, etc., can be combined with the distance parameters corresponding to each pair of projection points for analysis during the projection correction process, and the corresponding angle parameters are analyzed for each pair of projection points. Then, all angle parameters are combined to verify the angle parameters obtained by the above analysis to determine whether the various angle parameters obtained by the current measurement are valid, that is, whether the current measurement is a valid measurement. If the angle parameters are determined to be valid, the initial deflection angle is corrected according to the angle parameters to obtain a more accurate deflection angle of the projection device.

[0055] It is understandable that the method of correcting the data of the initial deflection angle according to each angle parameter is not unique, and can be selected in combination with the actual situation. For example, in one embodiment, the initial deflection angle and each angle parameter can be combined to perform linear fitting to ultimately determine a more accurate deflection angle. In another embodiment, the initial deflection angle and each angle parameter can also be combined to perform mean value solution, etc., to obtain a more accurate deflection angle of the projection device.

[0056] When the above scheme is combined with various angle parameters to correct the initial deflection angle, it is necessary to further determine whether each angle parameter is valid, and perform correction when the angle parameters are valid to improve the accuracy and reliability of data correction.

[0057] In one embodiment, step 804 includes: checking whether the angle parameters are in a linear relationship; if so, determining that the angle parameters are valid.

[0058] Specifically, if the projection device is deflected, the single-point distance detector rotates to form a similar Fig. 9 The cone structure shown in FIG. 1 is a cone structure in which L1 and L2 represent the uppermost and lowermost sides, respectively, and L3 and L4 represent the leftmost and rightmost sides, respectively. The distance parameter detected by the single-point distance detector will gradually change in a certain linear relationship, for example, it will gradually increase, reach the uppermost or lowermost side, and then gradually decrease. When analyzing the angle parameters of each projection point arranged in a circle, if each pair of projection points is analyzed in the same direction (clockwise or counterclockwise), if the signal emitted by the single-point distance detector is not blocked, the angle parameter obtained will also show a certain linear relationship.

[0059] Therefore, in the actual calibration process, the scheme of this embodiment can be combined with the various angle parameters obtained by calculation for fitting to verify whether they are in a linear relationship. When the angle parameters are in a linear relationship, the current measurement is considered valid, that is, the angle parameters are considered valid.

[0060] The above scheme, combined with the actual measurement situation, verifies whether each angle parameter is valid by analyzing whether the angle parameters are in a linear relationship, and has the advantages of simple verification method and high verification efficiency.

[0061] Please continue reading Figure 8 In one embodiment, after step 804, step 808 is also included.

[0062] Step 808: If the angle parameter is invalid, an adjustment prompt signal is output.

[0063] Specifically, if the angle parameter is invalid during the verification process, it is likely that the single-point distance detector is radiated to an obstacle, the lens of the single-point distance detector is dirty, or the single-point distance detector is blocked. In order to ensure the reliability of projection calibration and the projection effect of the projection device, the projection device will output an adjustment prompt signal to remind the user to check whether the single-point distance detector is blocked by an obstacle or dirty.

[0064] Correspondingly, in one embodiment, if the angle parameter obtained by verification is invalid, the projection correction operation will be terminated, that is, the initial deflection angle obtained by the current analysis will be treated as invalid, thereby reducing the initial deflection angle error or low accuracy, affecting the projection correction effect.

[0065] In the above scheme, when the angle parameter is invalid, an adjustment prompt signal is output to end the data correction operation, thereby improving the accuracy of projection correction.

[0066] See also Fig.10 , in one embodiment, step 204 includes step 1002 .

[0067] Step 1002, determining the vertical deflection angle of the projection device according to the projection angle and the distance parameter between a pair of projection points of the single-point distance detector located in the vertical direction in the display plane and the single-point distance detector.

[0068] Specifically, when the projection device deflects, it may deflect in the vertical direction, or in the horizontal direction, or in both the horizontal and vertical directions. In the solution of this embodiment, taking the deflection in the vertical direction as an example, a pair of projection points in the vertical direction will be selected, and the distance parameters from the two projection points to the single-point distance detector will be obtained respectively, that is, Fig. 9 The lengths of the two sides L1 and L2 shown are used to analyze and determine the vertical deflection angle of the projection device.

[0069] It can be understood that in other embodiments, due to the limitation of the motor step size or the projection point of the single-point distance detector, there may not be a pair of projection points in the vertical direction. At this time, the one or two pairs of projection points closest to the vertical direction can be combined for analysis to finally determine the vertical deflection angle.

[0070] In more detail, in one embodiment, an initial deflection angle is first analyzed based on the projection angle and the distance parameters between a pair of projection points located in the vertical direction in the display plane and the single-point distance detector, and then the initial deflection angle is corrected in combination with the correction scheme in the above embodiment to finally obtain the vertical deflection angle.

[0071] In another embodiment, it is also possible to perform projection correction without correction, and directly analyze the vertical deflection angle based on the projection angle and the distance parameters between a pair of projection points located in the vertical direction in the display plane and the single-point distance detector.

[0072] The above scheme analyzes a pair of projection points in the vertical direction to determine the vertical deflection angle of the projection device in the vertical direction, thereby ensuring the accuracy of the vertical deflection angle.

[0073] See also Fig.11 In one embodiment, step 204 includes step 112 .

[0074] Step 112, determining the horizontal deflection angle of the projection device according to the projection angle and the distance parameter between a pair of projection points of the single-point distance detector and the single-point distance detector in the display plane and located in the horizontal direction.

[0075] Specifically, similar to the measurement method of the vertical deflection angle in the above embodiment, the solution of this embodiment uses a pair of projection points in the horizontal direction for analysis to ultimately determine the horizontal deflection angle of the projection device in the horizontal direction, which will not be described in detail. Similarly, when analyzing the horizontal deflection angle, the analysis can also be combined with a pair or two pairs of projection points closest to the horizontal direction to ultimately determine the vertical deflection angle. It is also possible to perform a correction operation during the determination of the horizontal deflection angle, which will not be described in detail.

[0076] The above scheme analyzes a pair of projection points in the horizontal direction to determine the vertical deflection angle of the projection device in the horizontal direction, thereby ensuring the accuracy of the vertical deflection angle.

[0077] See also Fig.12 , in one embodiment, step 204 includes step 122 .

[0078] Step 122, determining the deflection angle of the projection device according to the projection angle, the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector, and the corresponding relationship between the preset distance parameter, the projection angle and the deflection angle.

[0079] Specifically, the scheme of this embodiment presets the correspondence between the distance parameter, the projection angle and the deflection angle. Therefore, in the analysis process of the actual deflection angle, it is only necessary to substitute the distance parameter and the projection angle obtained from the current analysis into the preset correspondence between the distance parameter, the projection angle and the deflection angle to match them, so as to obtain the corresponding deflection angle.

[0080] It should be noted that the corresponding relationship between the preset distance parameter, projection angle and deflection angle is not stored in a unique manner in the projection device, and can be stored in the form of a graph, a table, a mathematical formula, etc., without specific limitation.

[0081] In a more detailed embodiment, the correspondence between the preset distance parameter, the projection angle and the deflection angle includes:

[0082] c2=a2+b2-2abcos(γ)

[0083] α=arccos((b2+c2-a2) / 2bc)

[0084] β=180°-α-γ

[0085] θ=γ / 2+β

[0086] Among them, a and b represent the distances from the two projection points to the single-point distance detector in a pair of projection points, and c represents the distance between the two projection points; γ represents the angle of the projection direction corresponding to the same pair of projection points, which is twice the projection angle; α represents the angle between the line segment between one of the projection points and the single-point distance detector, and the line segment between the two projection points; β represents the angle between the line segment between the other projection point and the single-point distance detector, and the line segment between the two projection points; θ represents the deflection angle. In the above correspondence, just substitute the projection angle and distance parameters to calculate γ, c, α and β in turn, and finally combine θ=γ / 2+β to calculate the deflection angle.

[0087] In one embodiment, a method for determining the correspondence between a preset distance parameter, a projection angle, and a deflection angle includes: constructing a triangle with a pair of projection points of a single-point distance detector on a display plane and the position of the single-point distance detector as vertices; and obtaining and storing the correspondence between the distance parameter, the projection angle, and the deflection angle by solving trigonometric functions.

[0088] For details, please refer to Figure 6 , A and B represent the two selected projection points respectively, C represents the emission point of the single-point distance detector, a represents the distance between the first projection point and the single-point distance detector (specifically acquired by the single-point distance detector), b represents the distance between the second projection point and the single-point distance detector, c represents the distance between the two projection points, d represents the distance from the midpoint of A and B to C, and γ is bisected by the midline, which can be regarded as the vertical distance from the projection device to the display plane, γ represents the angle of the projection direction corresponding to the same pair of projection points, and its size is twice the projection angle, and θ represents the deflection angle of the projection device.

[0089] First, combining the relationship between the exterior angle and interior angle of a triangle, we can get θ = γ / 2 + β. Figure 6 By solving the trigonometric function relationship, we can obtain β=180°-α-γ, α=arccos((b2+c2-a2) / 2bc) and c2=a2+b2-2abcos(γ) in turn, and finally determine the corresponding relationship between the distance parameter, projection angle and deflection angle.

[0090] It should be pointed out that Figure 6For example, when analyzing the vertical deflection angle, the topmost projection point of the pair of projection points in the vertical direction is taken as point A, and the bottommost projection point is taken as point B. Substitute the relevant parameters into the corresponding relationship for calculation. If the calculated θ is equal to 90°, it is considered that no vertical deflection has occurred. If it is less than 90°, it is considered that a vertical upward deflection has occurred. If it is greater than 90 degrees, it is considered that a vertical downward deflection has occurred.

[0091] Similarly, when analyzing the horizontal deflection angle, the leftmost projection point of the pair of projection points in the horizontal direction is taken as point A, and the rightmost projection point is taken as point B. The relevant parameters are substituted into the corresponding relationship for calculation. If the calculated θ is equal to 90°, it is considered that no horizontal deflection has occurred. If it is less than 90°, it is considered that a horizontal deflection to the left has occurred. If it is greater than 90 degrees, it is considered that a horizontal deflection to the right has occurred.

[0092] See also Fig.13 In one embodiment, step 206 includes step 132 and step 134 .

[0093] Step 132: Determine the required picture adjustment angle according to the deflection angle.

[0094] Step 134 , controlling the display device of the projection device to adjust the output image according to the image adjustment angle.

[0095] Specifically, the scheme of this embodiment, when performing projection correction, starts from the source of the shadow image, combines the deflection angle obtained by analysis and calculation, and determines the required picture adjustment angle, such as the need to adjust upward by x degrees, or adjust to the left by y degrees, etc., so as to control the display device of the projection device to adjust the output picture according to the picture adjustment angle, and finally ensure that the output picture is rectangular after being projected onto the display plane.

[0096] The above scheme realizes projection correction by changing the angle of the output picture of the display device of the projection equipment, thereby effectively improving the correction accuracy.

[0097] See also Fig.14 In one embodiment, the method further includes step 142 and step 144 .

[0098] Step 142, determining the vertical distance between the projection device and the display plane according to the projection angle and the distance parameter between any pair of projection points of the single-point distance detector on the display plane and the single-point distance detector.

[0099] Step 144, focusing the projection device according to the vertical distance.

[0100] For details, please refer to Figure 6, the vertical distance is the length of d. When the projection device is not deflected, the line segment corresponding to d is perpendicular to the line segment AB, so it is called the vertical distance. However, according to the deflection of the projection device, θ is no longer 90°, and the line segment where d is located is not perpendicular to the line segment AB. In the solution of this embodiment, the distance parameter corresponding to one pair of projection points is analyzed to obtain the vertical distance between the projection device and the display plane, so as to perform focus correction.

[0101] In addition to performing deflection correction on the projection device, this solution can also realize focus correction in combination with the vertical distance between the projection device and the display plane, thereby ensuring the clarity of the projection image while ensuring that the projection image is rectangular, and improving the working reliability of the projection device. Specifically, the pair of projection points used in this embodiment can be a pair of projection points in the horizontal direction or a pair of projection points in the vertical direction, and there is no specific limitation.

[0102] It should be pointed out that there is not only one way to determine the vertical distance. In a more detailed embodiment, the projection device stores the correspondence between the distance parameter, the projection angle and the vertical distance. In the actual analysis process, the vertical distance can be solved by simply substituting the distance parameter and the projection angle into the correspondence.

[0103] In more detail, in one embodiment, the distance parameter and the projection angle are substituted into the corresponding relationship, including:

[0104] c2=a2+b2-2abcos(γ)

[0105] α=arccos((b2+c2-a2) / 2bc)

[0106] β=180°-α-γ

[0107] d = sinα*b / sinβ

[0108] Therefore, in the actual calculation process, we only need to substitute a, b and the projection angle to calculate γ, α, β and d in sequence, and finally use d to achieve focus correction.

[0109] The above scheme uses the distance parameter corresponding to one pair of projection points for analysis to achieve focus correction, which has a high focus correction efficiency.

[0110] See also Fig.15 In one embodiment, the method further includes step 152 and step 154 ​​.

[0111] Step 152, determining the vertical distance between the projection device and the display plane according to the projection angle and the distance parameters between all the corresponding projection points of the single point distance detector on the display plane and the single point distance detector.

[0112] Step 154, focusing the projection device according to the vertical distance.

[0113] Specifically, unlike the above-mentioned embodiment in which focusing is performed based on one pair of projection points, in the scheme of this embodiment, the distance parameters between all pairs of projection points and the single-point distance detector are analyzed, and each pair of projection points can be analyzed to obtain a distance. Finally, the mean of all distances is solved, etc., to obtain the vertical distance between the projection device and the display plane, so as to perform focus correction.

[0114] The above scheme uses all distance parameters corresponding to the projection points to analyze and implement focus correction, which has high focus correction accuracy.

[0115] In one embodiment, the focus correction of the projection device is performed according to the vertical distance, including: determining the focus distance of the projection device according to the vertical distance and the corresponding relationship between the preset vertical distance and the focus distance; and pushing the optical motor of the projection device according to the focus distance to achieve focus correction.

[0116] Specifically, the scheme of this embodiment presets a correspondence between the vertical distance and the focus distance. During the focus correction process, the calculated vertical distance is substituted into the correspondence for matching to obtain the focus distance, thereby controlling the movement of the optical motor of the projection device to complete the focus operation. This focus correction method is simple to operate and has a high focus correction efficiency.

[0117] In order to facilitate understanding of the technical solution of the present application, the present application is explained below in conjunction with more detailed embodiments.

[0118] First, after receiving the projection correction instruction sent by the user, the controller of the projection device controls the motor to drive the single-point distance detector to rotate. During this process, every time the single-point distance detector rotates 10 degrees, a projection point is formed on the display plane and a distance measurement is performed until the single-point distance detector rotates one circle, obtaining 18 pairs of projection points and 18 pairs of distance parameters.

[0119] The controller substitutes the distance parameter between the projection point in the vertical direction and the single-point distance detector, as well as the projection angle, into c2=a2+b2-2abcos(γ), α=arccos((b2+c2-a2) / 2bc), β=180°-α-γ and θ=γ / 2+β to calculate and obtain the vertical deflection angle. Then, the controller realizes vertical deflection correction by controlling the output picture of the display device of the projection equipment to deflect accordingly in the vertical direction.

[0120] The controller substitutes the distance parameter between the projection point in the horizontal direction and the single-point distance detector, and the projection angle into c2=a2+b2-2abcos(γ), α=arccos((b2+c2-a2) / 2bc), β=180°-α-γ and θ=γ / 2+β to calculate and obtain the horizontal deflection angle. Then, the controller realizes horizontal deflection correction by controlling the output picture of the display device of the projection equipment to deflect accordingly in the horizontal direction.

[0121] Furthermore, the controller also substitutes the distance parameters between at least one pair of projection points and the single-point distance detector, and the projection angle, into c2=a2+b2-2abcos(γ), α=arccos((b2+c2-a2) / 2bc), β=180°-α-γ and d=sinα*b / sinβ for calculation, and finally determines the vertical distance. Then, the vertical distance is substituted into the corresponding relationship between the preset vertical distance and the focus distance to determine the focus distance of the projection device; the optical motor of the projection device is driven according to the focus distance to achieve focus correction.

[0122] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0123] Please refer to Figure 1 The present application also provides a projection device, including a projection device body 102, a motor 104 and a single-point distance detector 104, the motor 104 is arranged on the projection device body 102, and the axial direction of the motor 104 is perpendicular to the lens plane of the projection device body 102, the single-point distance detector 104 is fixedly arranged on the motor 104, and the projection angle between the emission direction of the single-point distance detector 104 and the axial direction of the motor 104 is greater than 0 degrees and less than 90 degrees, and the projection device body 102 is used to execute the above-mentioned projection correction method.

[0124] Specifically, the projection device body 102 is a component used to realize the normal projection display function in the projection device, including a housing, a lens, an optical motor, a display device and a controller, etc., which are not specifically limited. The technical solution of the present application is to set an additional motor in addition to the optical motor of the projection device body to drive the single-point distance detector to rotate to realize projection correction. The projection correction method is shown in the above-mentioned embodiments and the accompanying drawings, and will not be repeated here.

[0125] It is understood that the specific type of the single-point distance detector 104 is not unique. In a more detailed embodiment, the single-point distance detector 104 includes a single-point TOF distance detector. The single-point TOF distance detector includes an emitting diode, a receiving diode, a modulation module, a demodulation module, and a processor, which are used to emit a detection signal and measure the distance from one point to another point by a time-of-flight measurement method. In other embodiments, the single-point distance detector 104 can also select other devices that can realize point-to-point distance detection, which is not specifically limited.

[0126] It should be noted that, in one embodiment, the projection device is further provided with a limiter, which limits the initial position and / or the end position of the single-point distance detector 104, so as to achieve precise rotation angle control during the rotation of the limiter. Specifically, the type of the limiter is not limited, and can be an optical coupler, etc., which is not specifically limited and can be selected in combination with actual needs.

[0127] In the above scheme, a motor 104 whose axis is perpendicular to the lens plane is provided on the projection device body 102, and a single-point distance detector 104 whose projection direction forms a certain angle with the axis is fixedly provided on the motor 104. When the projection device meets the correction triggering condition, the motor 104 is controlled to drive the distance detector to rotate so that the distance detector projects multiple pairs of projection points on the display plane. Then, the distance parameters between at least one pair of projection points and the single-point distance detector 104 are selected, and the calculation is performed in combination with the projection angle of the single-point distance detector 104, and finally the deflection angle of the projection device is determined, so as to perform projection correction on the projection device. In the above scheme, during the correction process, there is no need to additionally project a correction image onto the display plane. The entire projection correction process is realized by the additionally provided motor 104 and the single-point distance detector 104, which will not affect the normal projection and can realize non-sensing projection correction.

[0128] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A projection correction method, characterized in that: include: If the calibration trigger condition is met, the motor of the projection device is controlled to drive the single-point distance detector to rotate; wherein the single-point distance detector is fixedly arranged on the motor, and the projection angle between the emission direction of the single-point distance detector and the axial direction of the motor is greater than 0 degrees and less than 90 degrees; Determine the deflection angle of the projection device according to the projection angle and the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector; Projection correction is performed on the projection device according to the deflection angle.

2. The projection correction method according to claim 1, characterized in that: Determining the deflection angle of the projection device according to the projection angle and the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector includes: Obtaining an initial deflection angle according to the projection angle and a distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector; According to the projection angle and the distance parameters between all the paired projection points of the single-point distance detector on the display plane and the single-point distance detector, data correction is performed on the initial deflection angle to obtain the deflection angle of the projection device.

3. The projection correction method according to claim 2, characterized in that: The method of performing data correction on the initial deflection angle according to the projection angle and the distance parameters between all the paired projection points of the single-point distance detector on the display plane and the single-point distance detector to obtain the deflection angle of the projection device includes: Obtaining corresponding angle parameters according to the projection angle and the distance parameters between all the corresponding projection points of the single-point distance detector on the display plane and the single-point distance detector; Check whether the angle parameter is valid; If the angle parameters are valid, performing data correction on the initial deflection angle according to the angle parameters to obtain the deflection angle of the projection device; If the angle parameter is invalid, an adjustment prompt signal is output.

4. The projection correction method according to claim 3, characterized in that: The checking whether the angle parameter is valid includes: Verifying whether the angle parameters are in a linear relationship; If there is a linear relationship, it is determined that the angle parameter is valid.

5. The projection correction method according to any one of claims 1 to 4, characterized in that: Determining the deflection angle of the projection device according to the projection angle and the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector comprises: Determine the vertical deflection angle of the projection device according to the projection angle and the distance parameter between a pair of projection points of the single-point distance detector located in the vertical direction in the display plane and the single-point distance detector; And / or, the horizontal deflection angle of the projection device is determined according to the projection angle and the distance parameter between a pair of projection points of the single-point distance detector located in the horizontal direction in the display plane and the single-point distance detector.

6. The projection correction method according to any one of claims 1 to 4, characterized in that: Determining the deflection angle of the projection device according to the projection angle and the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector includes: The deflection angle of the projection device is determined according to the projection angle, the distance parameter between at least one pair of projection points of the single-point distance detector on the display plane and the single-point distance detector, and the corresponding relationship between the preset distance parameter, the projection angle and the deflection angle.

7. The projection correction method according to claim 6, characterized in that: The method for determining the corresponding relationship between the preset distance parameter, the projection angle and the deflection angle includes: Constructing a triangle with a pair of projection points of the single-point distance detector on the display plane and the position of the single-point distance detector as vertices; The corresponding relationship between the distance parameter, the projection angle and the deflection angle is obtained and stored by solving the trigonometric function.

8. The projection correction method according to any one of claims 1 to 4, characterized in that: The performing projection correction on the projection device according to the deflection angle comprises: Determining a required picture adjustment angle according to the deflection angle; The display device of the projection device is controlled to adjust the output image according to the image adjustment angle.

9. The projection correction method according to claim 1, characterized in that: Also includes: Determine the vertical distance between the projection device and the display plane according to the projection angle and the distance parameter between any pair of projection points of the single-point distance detector on the display plane and the single-point distance detector; and perform focus correction on the projection device according to the vertical distance; Or, the projection correction method further includes: The vertical distance between the projection device and the display plane is determined according to the projection angle and the distance parameters between all the projection points of the single-point distance detector on the display plane and the single-point distance detector; and the focus correction of the projection device is performed according to the vertical distance.

10. A projection device, characterized in that: It includes a projection device body, a motor and a single-point distance detector, wherein the motor is arranged on the projection device body, the single-point distance detector is fixedly arranged on the motor, and the projection angle between the emission direction of the single-point distance detector and the axial direction of the motor is greater than 0 degree and less than 90 degrees, and the projection device body is used to execute the projection correction method described in any one of claims 1 to 9.

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