Projection correction method, projection device, projection system, and storage medium

Abstract

The present disclosure relates to a projection correction method, a projection device, a projection system and a storage medium, and relates to the technical field of projection. The method comprises the following steps: in the moving process of the projection device, for each current time, the projection device acquires a current attitude angle of the projection device relative to a projection area, corrects a projection image projected by the projection device according to the current attitude angle, and projects the corrected projection image. Based on this, at each time in the moving process of the projection device, the projection image can be corrected in real time, so that the projection image projected on the projection area at each time can be maintained as a rectangle. Moreover, since the projection image correction is performed once at each current time, in the user's vision, the user cannot perceive that the projection device is performing the projection image correction, thereby realizing real-time and non-perception correction of the projection device and improving the user's viewing experience.

Description

Technical Field

[0001] This disclosure relates to the field of projection technology, and more specifically, to a projection correction method, a projection device, a projection system, and a storage medium. Background Technology

[0002] During the use of projection equipment, frequent deviations occur between the projection equipment and the projection area due to the movement of the equipment, resulting in image distortion and severely impacting the user's viewing experience. Therefore, how to correct moving projected images has become a key research focus for those skilled in the art. Summary of the Invention

[0003] This disclosure provides a projection correction method, projection device, projection system, and storage medium, which can perform real-time correction of the projected image while the projection device is being moved, so that users can always view a perfect projected image.

[0004] According to a first aspect of the present disclosure, the present disclosure provides a projection correction method, including:

[0005] When the projection device enters a moving state, the current attitude angle of the projection device relative to the projection area is obtained;

[0006] The projected image projected by the projection device is corrected based on the current attitude angle, and the corrected projected image is displayed.

[0007] Return to the step of obtaining the current attitude angle of the projection device relative to the projection area until the projection device enters a stopped state.

[0008] Optionally, obtaining the current attitude angle of the projection device relative to the projection area includes:

[0009] The first measured attitude angle of the projection device at the current moment is obtained through a sensor;

[0010] The current attitude angle is determined based on the first measured attitude angle and the calibrated attitude angle, wherein the calibrated attitude angle is the attitude angle of the projection device relative to the projection area in the initial state.

[0011] Optionally, the method further includes:

[0012] The current attitude angle is corrected to obtain the corrected current attitude angle.

[0013] Optionally, the method further includes:

[0014] When the projection device enters a stopped state, based on the multi-frame attitude angle data acquired by the sensor within a target time period, a second measured attitude angle of the projection device relative to the projection area in the stopped state is determined, wherein the target time period is the time period between the first moment when the projection device begins to switch from the moving state to the stopped state and the second moment when the projection device is completely in the stopped state;

[0015] The projected image projected by the projection device is corrected based on the second measured attitude angle, and the corrected projected image is displayed.

[0016] Optionally, the method includes:

[0017] The projection device acquires multiple frames of first attitude angle data of the projection device through sensors. If the difference between two adjacent frames of the first attitude angle data is greater than a first preset angle threshold, the projection device is determined to have entered the moving state.

[0018] Optionally, the method includes:

[0019] The projection device acquires multiple frames of second attitude angle data from sensors. If the difference between two adjacent frames of second attitude angle data is less than a second preset angle threshold, the projection device is determined to enter the stop state.

[0020] According to a second aspect of the present disclosure, a projection device is provided, comprising:

[0021] The projection module is configured to project a projected image.

[0022] A sensor is configured to acquire attitude angle data of the projection device;

[0023] The controller is configured as follows:

[0024] When the projection device enters a moving state, the sensor is controlled to acquire the attitude angle data of the projection device;

[0025] The current attitude angle of the projection device relative to the projection area is determined based on the attitude angle data;

[0026] The projected image projected by the projection device is corrected based on the current attitude angle;

[0027] Control the projection module to display the corrected projected image.

[0028] Optionally, the attitude angle data includes a first measured attitude angle;

[0029] The sensor is specifically configured as follows:

[0030] Obtain the first measured attitude angle of the projection device at the current moment;

[0031] The controller is specifically configured as follows:

[0032] The current attitude angle is determined based on the first measured attitude angle and the calibrated attitude angle, wherein the calibrated attitude angle is the attitude angle of the projection device relative to the projection area in the initial state.

[0033] Optionally, the controller is further configured to:

[0034] When the projection device enters a stopped state, the sensor is controlled to acquire multiple frames of attitude angle data within a target time period, wherein the target time period is the time period between the first moment when the projection device begins to switch from the moving state to the stopped state and the second moment when the projection device is completely in the stopped state;

[0035] Based on the multi-frame attitude angle data, a second measured attitude angle of the projection device relative to the projection area in the stopped state is determined;

[0036] The projected image projected by the projection device is corrected based on the second measured attitude angle;

[0037] Control the projection module to display the corrected projected image.

[0038] Optionally, the controller is further configured to:

[0039] The current attitude angle is corrected to obtain the corrected current attitude angle.

[0040] Optionally, the controller is specifically configured as follows:

[0041] The sensor is controlled to acquire multiple frames of first attitude angle data of the projection device;

[0042] If the difference between the first attitude angle data in two adjacent frames is greater than a first preset angle threshold, the projection device is determined to have entered the moving state.

[0043] Optionally, the controller is specifically configured as follows:

[0044] The sensor is controlled to acquire multiple frames of second attitude angle data of the projection device;

[0045] If the difference between two adjacent frames of the second attitude angle data is less than a second preset angle threshold, the projection device is determined to enter the stop state.

[0046] According to a third aspect of the present disclosure, a projection system is provided, including a projection device as described in any one of the second aspects and an adjustable bracket, wherein the projection device is disposed on the adjustable bracket and the adjustable bracket is used to drive the projection device to move in space.

[0047] According to a fourth aspect of the present disclosure, a non-transitory computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps of the projection correction method described in any one of the first aspects.

[0048] This disclosure relates to a projection correction method, a projection device, a projection system, and a storage medium. The method involves acquiring the current attitude angle of the projection device relative to the projection area at each current moment during the movement of the projection device. The projected image is then corrected based on this current attitude angle, resulting in the corrected projection image. Therefore, the projection device can correct the projection image in real time at every moment during its movement, ensuring that the projected image on the projection area remains rectangular at all times. Furthermore, since projection image correction is performed at every current moment, the user cannot perceive the projection device performing the correction, thus achieving real-time, seamless correction and improving the user's viewing experience. Attached Figure Description

[0049] Figure 1 This is a flowchart illustrating a projection correction method according to an exemplary embodiment.

[0050] Figure 2 This is a flowchart illustrating the process of obtaining the current attitude angle according to an exemplary embodiment.

[0051] Figure 3 This is a schematic diagram illustrating the principle of a projection correction method according to an exemplary embodiment.

[0052] Figure 4 This is a schematic diagram of the structure of a projection device according to an exemplary embodiment.

[0053] Figure 5 This is a schematic diagram of the structure of a projection system according to an exemplary embodiment.

[0054] Figure 6 This is a schematic diagram of the projection device in one embodiment. Detailed Implementation

[0055] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0056] It should be understood that the various steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0057] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0058] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0059] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0060] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0061] Figure 1 This is a flowchart illustrating a projection correction method according to an exemplary embodiment. Figure 1 As shown, this disclosure provides a projection correction method, which can be executed by a projection device, specifically by a projection correction apparatus. This apparatus can be implemented in software and / or hardware and configured within the projection device. Figure 1 As shown, the method may include the following steps.

[0062] In step 110, it is detected whether the projection device has entered a moving state.

[0063] Here, "projection device entering movement mode" refers to the projection device projecting an image while moving. For example, the projector is mounted on an adjustable stand, which is used to move the projector in space. The user can set the movement trajectory of the adjustable stand to make the projector move along a preset trajectory. Another example is that during use, the user can manually move the projector to adjust the position of the projected image.

[0064] It should be understood that the projection device being in a moving state can mean that the position of the projection device and / or the projection angle have changed.

[0065] In some embodiments, multiple frames of first attitude angle data of the projection device can be acquired by sensors, and if the difference between two adjacent frames of first attitude angle data is greater than a first preset angle threshold, it is determined that the projection device has entered a moving state.

[0066] The sensor can be an inertial measurement unit (IMU). Multiple frames of first attitude angle data can be continuously acquired by the IMU installed on the projection device. When the difference between two adjacent frames of first attitude angle data exceeds a first preset angle threshold, it is determined that the projection device has entered a moving state.

[0067] For example, the IMU can report the first attitude angle data to the projection device at a frame rate of 5 frames. When the difference between the currently reported first attitude angle data and the previously reported first attitude angle data is greater than a first preset angle threshold, it is determined that the projection device has entered a moving state.

[0068] It should be understood that the attitude angles mentioned in the embodiments of this disclosure can refer to at least one of yaw angle, roll angle, and pitch angle. The first preset angle threshold can be set to 0.1°. Of course, in actual application, the first preset angle threshold can also be set according to the actual situation.

[0069] In other embodiments, the projection device may be determined to be in a moving state when multiple consecutive differences are greater than a first preset angle threshold. For example, the projection device may be determined to be in a moving state when five consecutive differences are greater than 0.1°. Of course, the number of consecutive differences can be set according to the actual situation.

[0070] It should be understood that determining that the projection device has entered a moving state when multiple consecutive differences are greater than the first preset angle threshold can avoid misjudgments caused by vibration or other factors.

[0071] In step 120, the current attitude angle of the projection device relative to the projection area is obtained.

[0072] Here, the projection area can refer to the area used to display the projected image from the projection device. For example, the projection area can be a screen, or a projection screen defined on a wall to display the projected image, etc. The current attitude angle refers to the attitude angle of the projection device relative to the projection area at the current moment, that is, the real-time attitude angle of the projection device relative to the projection area.

[0073] The current attitude angle of the projection device relative to the projection area refers to the angle of the projection device relative to the projection area, with the projection area as a reference. For example, when the projection device is in a state of orthographic projection with the projection area, the attitude angle of the projection device relative to the projection area is 0°. When the projection area remains unchanged, but the projection angle of the projection device changes, the current attitude angle of the projection device relative to the projection area changes and is no longer maintained at 0°.

[0074] In some embodiments, the current attitude angle of the projection device relative to the projection area can be obtained by sensors disposed on the projection device. These sensors may include an IMU and / or a TOF (Time of Flight) sensor.

[0075] In step 130, the projected image projected by the projection device is corrected according to the current attitude angle, and the corrected projected image is displayed.

[0076] Here, since the current attitude angle is the attitude angle of the projection device relative to the projection area, the projected image projected by the projection device is corrected according to the current attitude angle, so that the corrected projected image projected on the projection area appears as a rectangle.

[0077] For example, based on the current attitude angle, the first coordinates of the four vertices of the original projected image projected onto the projection area on the modulation plane can be determined; based on the first coordinates and the second coordinates of the four vertices of the original projected image on the modulation plane, a perspective transformation matrix can be constructed; based on the first coordinates of the four vertices, a target rectangle can be determined; based on the third coordinates of the four vertices of the target rectangle, combined with the perspective transformation matrix, the coordinates of the four vertices of the original projected image on the modulation plane can be adjusted to obtain the corrected projected image.

[0078] The target rectangle can be an inscribed rectangle within the region bounded by the first coordinates of the four vertices; for example, it can be the largest inscribed rectangle.

[0079] It should be understood that the first and third coordinates are actually coordinates in a two-dimensional coordinate system constructed with any point in the projection area as the origin and the length and width of the projection area as the coordinate axes. The second coordinate is a coordinate in a two-dimensional coordinate system constructed with any point in the modulation plane as the origin. This perspective transformation matrix reflects the pixel changes of the image on the modulation plane projected onto the projection area.

[0080] It's worth noting that the modulation plane refers to the plane on which the light modulator (chip) of the projection device generates the image. Chips corresponding to the modulation plane include reflective image modulation chips and transmissive image modulation chips. Reflective image modulation chips include DMD chips (Digital Micromirror Device) or LCOS chips (Liquid Crystal on Silicon), while transmissive image modulation chips include LCD chips (Liquid Crystal Display).

[0081] In step 140, return to step 110 until the projection device enters a stopped state.

[0082] Here, returning to step 110 means that while the projection device is in a moving state, steps 110 to 130 are continuously executed to perform real-time correction on each projected image during the movement. Entering a stopped state means that the projection device stops moving and remains stationary.

[0083] In some embodiments, multiple frames of second attitude angle data of the projection device are acquired by sensors, and if the difference between two adjacent frames of second attitude angle data is less than a second preset angle threshold, it is determined that the projection device enters a stopped state.

[0084] Among them, multiple frames of second attitude angle data can be continuously collected by the IMU set on the projection device. When the difference between two adjacent frames of second attitude angle data is less than a second preset angle threshold, the projection device is determined to enter a stop state.

[0085] For example, the IMU can report the second attitude angle data to the projection device at a frame rate of 5 frames. When the difference between the currently reported second attitude angle data and the previously reported second attitude angle data is less than the second preset angle threshold, the projection device is determined to enter the stop state.

[0086] It should be understood that the second preset angle threshold can be set to 0.05°. Of course, in actual application, the second preset angle threshold can also be set according to the actual situation.

[0087] It is worth noting that if the difference between two adjacent frames of second attitude angle data is less than the second preset angle threshold, it indicates that the moving speed of the projection device has slowed down and it has begun to switch from the moving state to the stopped state.

[0088] In other embodiments, the projection device may be determined to enter a stopped state when multiple consecutive differences are all less than a second preset angle threshold. For example, the projection device may be determined to enter a stopped state when five consecutive differences are all less than 0.05°. Of course, the number of consecutive differences can be set according to the actual situation.

[0089] It should be understood that determining that the projection device enters a stopped state when multiple consecutive differences are less than the second preset angle threshold can avoid misjudgment.

[0090] Therefore, through steps 110 to 140 above, during the movement of the projection device, the projection device acquires its current attitude angle relative to the projection area at each current moment, and corrects the projected image based on the current attitude angle, thus projecting the corrected image. Based on this, the projection device can correct the projected image in real time at every moment during its movement, ensuring that the projected image on the projection area remains rectangular at every moment. Furthermore, since projection image correction is performed at each current moment, the user cannot perceive the projection device performing the correction, achieving real-time, seamless correction and improving the user's viewing experience.

[0091] Figure 2 This is a flowchart illustrating the process of obtaining the current attitude angle according to an exemplary embodiment. For example... Figure 2 As shown, in some feasible implementations, the current attitude angle can be obtained through the following steps.

[0092] In step 111, the first measured attitude angle of the projection device at the current moment is obtained by the sensor.

[0093] Here, the sensor can be an inertial measurement unit (IMU). This IMU can be installed on the projection device to collect the attitude angle data of the projection device. It is worth noting that the first measured attitude angle collected by the IMU is a relative concept; it is the attitude angle measured with the projection device as a reference, not relative to the projection area. This first measured attitude angle reflects the change in the attitude angle of the projection device between the current moment and the previous moment.

[0094] In step 112, the current attitude angle is determined based on the first measured attitude angle and the calibrated attitude angle, wherein the calibrated attitude angle is the attitude angle of the projection device relative to the projection area in the initial state.

[0095] Here, the calibration attitude angle is the attitude angle of the projection device relative to the projection area in its initial state. The initial state can be a stopped state, meaning the calibration attitude angle is the attitude angle of the projection device relative to the projection area obtained when the projection device is in a stopped state.

[0096] In some embodiments, the calibration attitude angle can be obtained using a time-of-flight sensor. Specifically, for each movement of the projection device, the calibration attitude angle can be measured using the time-of-flight sensor after the projection device has come to a stop.

[0097] It should be understood that the calibrated attitude angle is the attitude angle of the projection device relative to the projection area. This calibrated attitude angle reflects the positional relationship between the projection device and the projection area in the initial state.

[0098] For example, when the projection device is in a state of orthographic projection relative to the projection area, the calibrated attitude angle of the projection device is 0°. When the projection device moves 5° to the left in the yaw direction, the calibrated attitude angle of the projection device is -5°. When the projection device moves 5° to the right in the yaw direction, the calibrated attitude angle of the projection device is 5°.

[0099] Since the first measured attitude angle is used to reflect the change in attitude angle of the projection device between the current moment and the previous moment, and the calibrated attitude angle reflects the positional relationship between the projection device and the projection area in the initial state, the first measured attitude angle can be converted into the current attitude angle of the projection device relative to the projection area at the current moment.

[0100] For example, when the calibrated attitude angle is 5°, if the projection device does not move, the first measured attitude angle is 0°, and the current attitude angle is 0 - 5° = -5°. If the projection device moves 5° to the right in the yaw direction, the first measured attitude angle is 5°. At this time, the current attitude angle is 5° - (-5°) = 10°.

[0101] Therefore, by measuring the first attitude angle and calibrating the attitude angle, the accurate current attitude angle can be obtained, thereby enabling accurate correction of the projected image projected by the projection device.

[0102] In some embodiments, the attitude angle compensation value can be determined based on the calibrated attitude angle, and then the current attitude angle can be obtained based on the first measured attitude angle and the attitude angle compensation value.

[0103] Here, when the projection device is powered on, it determines the first measured attitude angle using the first frame of attitude angle data acquired by the IMU, and determines the calibration attitude angle using the attitude angle data acquired by the time-of-flight sensor. At this point, the difference between the first measured attitude angle and the calibration attitude angle is calculated to obtain the attitude angle compensation value. For example, assuming the calibration attitude angle is 5° and the first measured attitude angle corresponding to the first frame of attitude angle data is 0°, then the attitude angle compensation value is 0° - 5° = -5°. It should be understood that this attitude angle compensation value is equivalent to the current attitude angle of the projection device relative to the projection area in its initial state.

[0104] When the projection device enters a moving state, the first measured attitude angle of the projection device, determined by the IMU, will change continuously. For each obtained first measured attitude angle, the current attitude angle of the projection device at the current moment can be obtained based on the difference between the first measured attitude angle and the attitude angle compensation value.

[0105] For example, assuming the projection device moves 5° to the right in the yaw direction, the first measured attitude angle measured by the inertial measurement unit is 5°. Since the attitude angle compensation value is -5°, the current attitude angle is 5° - (-5°) = 10°.

[0106] It is worth noting that during the movement of the projection device, for the first measured attitude angle obtained at each moment, the current attitude angle of the projection device at the current moment can be determined based on the first measured attitude angle and the attitude angle compensation value. In this way, the projected image projected by the projection device can be corrected in real time based on the current attitude angle during the movement of the projection device, thereby realizing seamless correction of the projected image during the movement.

[0107] In some embodiments, the current attitude angle can be corrected to obtain a corrected current attitude angle, so as to correct the projected image projected by the projection device based on the corrected current attitude angle.

[0108] Here, because the IMU accumulates errors when calculating the attitude angle, the longer it operates, the greater the error becomes, leading to an error in the current attitude angle. Therefore, the projection device can correct the current attitude angle to obtain the corrected current attitude angle.

[0109] As examples, the third measurement attitude angle of the projection device can be determined by the time-of-flight sensor at first preset intervals, and then the first measurement attitude angle obtained by the inertial measurement unit at the current moment can be corrected based on the third measurement attitude angle to obtain a new first measurement attitude angle.

[0110] Here, during the movement of the projection device, the time-of-flight sensor can collect the third measurement attitude angle at a frequency of 20 frames per second. That is, the first preset duration can be 20 frames, and of course, the size of the first preset duration can also be set according to the actual situation.

[0111] Each time the time-of-flight sensor reports a third measured attitude angle to the projection device, the projection device corrects the first measured attitude angle obtained by the inertial measurement unit at the current moment based on the third measured attitude angle, thus obtaining a new first measured attitude angle. Then, based on the new first measured attitude angle and the attitude angle compensation value, the corrected current attitude angle is obtained.

[0112] It is worth noting that the corrected current attitude angle can be obtained through the formula a*H + b*K = G, where H is the third measured attitude angle, K is the first measured attitude angle, G is the new first measured attitude angle, and a and b are weight ratios. Specifically, a can be 80% and b can be 20%.

[0113] It should be understood that since the yaw angle measured by the IMU will have a larger error over time, while the roll angle and pitch angle will not have a larger error over time, and the yaw angle measured by the time-of-flight sensor will not have a larger error over time, in this embodiment of the present disclosure, the yaw angle measured by the time-of-flight sensor can be used to correct the yaw angle measured by the IMU to obtain the corrected first measured attitude angle.

[0114] As other examples, the fourth measured attitude angle of the projection device can be determined by the time-of-flight sensor at second preset intervals, and then a new attitude angle compensation value can be obtained based on the fourth measured attitude angle. Then, the corrected current attitude angle can be obtained based on the first measured attitude angle and the new attitude angle compensation value.

[0115] Here, during the movement of the projection device, the time-of-flight sensor can collect the fourth measurement attitude angle at a frequency of 20 frames per second. That is, the second preset duration can be 20 frames, and of course, the size of the second preset duration can also be set according to the actual situation.

[0116] Each time the time-of-flight sensor reports a fourth measured attitude angle to the projection device, the projection device calculates a new attitude angle compensation value based on this fourth measured attitude angle. For example, the new attitude angle compensation value is obtained based on the difference between the first and fourth measured attitude angles obtained at the current moment. It should be understood that the new attitude angle compensation value actually covers the error accumulated by the inertial measurement unit over time. Subsequent corrections to the current attitude angle using the first measured attitude angle and the new attitude angle compensation value can eliminate the error accumulated by the inertial measurement unit over time and obtain an accurate current attitude angle.

[0117] In addition, by using the fourth measured attitude angle obtained by the time-of-flight sensor to obtain a new attitude angle compensation value, it is possible not only to correct the error caused by the IMU, but also to correct the error caused by the projection device switching the projection area. Figure 3 This is a schematic diagram illustrating the principle of a projection correction method according to an exemplary embodiment. For example... Figure 3 As shown, there are two mutually perpendicular projection areas in space: a first projection area 301 and a second projection area 302. Initially, the projection device 303 projects a projected image 304 onto the first projection area 301, and the attitude angle compensation value at this point is calculated for the first projection area 301. When the projected image 304 moves to the second projection area 302, a new attitude angle compensation value needs to be calculated for the second projection area 302 due to the change in projection area. At this time, the attitude angle compensation value is corrected using a time-of-flight sensor. The time-of-flight sensor can recognize that the projected image 304 is projected onto a different projection area, thus correcting the attitude angle compensation value to the attitude angle compensation value of the projection device relative to the second projection area 302.

[0118] Therefore, by correcting the current attitude angle, a more accurate current attitude angle can be obtained, thereby ensuring accurate correction of the projected image projected by the projection device.

[0119] In some feasible implementations, when the projection device enters a stopped state, a second measured attitude angle of the projection device relative to the projection area is determined based on the multi-frame attitude angle data acquired by the sensor within the target time period. Then, the projected image projected by the projection device is corrected based on the second measured attitude angle, and the corrected projected image is displayed.

[0120] Here, multiple frames of second attitude angle data can be continuously collected by the IMU set on the projection device. When the difference between two adjacent frames of second attitude angle data is less than a second preset angle threshold, the projection device is determined to enter a stop state.

[0121] The target time period is the time between the first moment when the projection device begins to switch from a moving state to a stopped state and the second moment when the projection device is completely stopped. The first moment is the moment when the projection device first detects that the difference between two adjacent frames of second attitude angle data is less than a second preset angle threshold. The second moment is the moment when the projection device just enters the stopped state. It should be understood that the first moment actually represents the moment when the projection device begins to reduce its speed from a moving state and begins to transition to a stopped state.

[0122] For example, when the projection device detects that the difference between two adjacent frames of second attitude angle data is less than the second preset angle threshold, it can acquire multiple frames of attitude angle data through the time-of-flight sensor, and then determine the second measured attitude angle based on the multiple frames of attitude angle data.

[0123] For example, a weighted average of multiple frames of attitude angle data can be performed to obtain a second measured attitude angle.

[0124] Since the time-of-flight sensor can obtain a more accurate yaw angle, and the IMU can obtain accurate roll and pitch angles, the second measured attitude angle is obtained by weighted averaging of multiple frames of attitude angle data. This can refer to obtaining the yaw angle in the second measured attitude angle by weighted averaging of multiple frames of attitude angle data, and then obtaining the pitch angle and roll angle in the second measured attitude angle based on the pitch and roll angles of the projection device when it is stationary, obtained by the IMU.

[0125] It should be understood that the second measured attitude angle is actually the attitude angle of the projection device relative to the projection area when the projection device is in a stopped state. By correcting the projected image projected by the projection device in a stopped state according to the second measured attitude angle, the corrected projected image projected onto the projection area by the projection device in a stopped state can be presented as a rectangle.

[0126] It is worth noting that, for how to correct the projected image projected by the projection device based on the second measured attitude angle, please refer to the description of correcting the projected image projected by the projection device based on the current attitude angle in the above embodiments, which will not be described in detail here.

[0127] Therefore, by using the multi-frame attitude angle data acquired by the sensor within the target time period, the accurate second measurement attitude angle of the projection device in the stopped state can be determined, thereby enabling accurate correction of the projected image projected by the projection device in the stopped state.

[0128] The above embodiments will be described in detail below with some examples.

[0129] When the real-time correction function of the projection device is enabled, the projection device determines the calibration attitude angle of the projection device relative to the projection area in the initial state using a time-of-flight sensor. Then, the projection device collects multiple frames of the first attitude angle data of the projection device through an IMU. When the difference between two adjacent frames of the first attitude angle data is greater than a first preset angle threshold, it is determined that the projection device has entered a moving state, or when multiple consecutive differences are greater than the first preset angle threshold, it is determined that the projection device has entered a moving state. Moreover, the attitude angle compensation value is determined based on the first frame of first attitude angle data collected by the IMU and the calibration attitude angle.

[0130] During the movement of the projection device, the IMU continuously acquires the first measured attitude angle of the projection device at the current moment. Then, for each acquired first measured attitude angle, the current attitude angle of the projection device is obtained based on the first measured attitude angle and the attitude compensation angle. The projection device then corrects the projected image based on this projection attitude angle to obtain a corrected projected image. The projection device then projects this corrected projected image.

[0131] Furthermore, during the movement of the projection device, the projection device also corrects the current attitude angle by using the attitude angle data collected by the time-of-flight sensor, and obtains the corrected current attitude angle.

[0132] When the difference between two adjacent frames of second attitude angle data acquired by the projection device via the IMU is less than a second preset angle threshold, the projection device is determined to enter a stopped state. Alternatively, if multiple consecutive differences are less than the second preset angle threshold, the projection device is determined to enter a stopped state. At this time, based on the multiple frames of attitude angle data acquired by the time-of-flight sensor within the target time period, the projection device determines its second measured attitude angle relative to the projection area in the stopped state. Then, based on the second measured attitude angle, the projected image is corrected, and the corrected image is displayed.

[0133] Therefore, the projection correction method provided in this embodiment can continuously correct the projected image when the projection device is in motion, ensuring that the projected image presented to the user remains in matrix form. Furthermore, since the correction frequency via the IMU is greater than the number of frames visible to the human eye, the user cannot perceive the projection device correcting the projected image, achieving truly imperceptible correction.

[0134] Figure 4 This is a schematic diagram illustrating the structure of a projection device according to an exemplary embodiment. For example... Figure 4 As shown, this embodiment of the disclosure provides a projection device, which includes a projection module 401, a sensor 402, and a controller 403, wherein:

[0135] Projection module 401 is configured to project a projected image;

[0136] Sensor 402 is configured to acquire attitude angle data of the projection device;

[0137] Controller 403 is configured as follows:

[0138] When the projection device enters a moving state, the control sensor 402 acquires the attitude angle data of the projection device;

[0139] Determine the current attitude angle of the projection device relative to the projection area based on the attitude angle data;

[0140] The projected image is corrected based on the current attitude angle.

[0141] Control the projection module to display the corrected projected image.

[0142] It is worth noting that the projection module 401 refers to the components required to achieve projection, including the projection unit and the drive unit that drives the projection unit, etc. The sensor 402 includes an inertial measurement unit and a time-of-flight sensor.

[0143] In some feasible implementations, the attitude angle data includes a first measured attitude angle, and sensor 402 is specifically configured as follows:

[0144] Obtain the first measured attitude angle of the projection device at the current moment;

[0145] Controller 403 is specifically configured as follows:

[0146] The current attitude angle is determined based on the first measured attitude angle and the calibrated attitude angle, wherein the calibrated attitude angle is the attitude angle of the projection device relative to the projection area in the initial state.

[0147] In some possible implementations, the controller 403 is also configured to:

[0148] When the projection device enters a stopped state, the control sensor 402 acquires multiple frames of attitude angle data within a target time period, wherein the target time period is the time period between the first moment when the projection device begins to switch from a moving state to a stopped state and the second moment when the projection device is completely stopped.

[0149] Based on multiple frames of attitude angle data, determine the second measured attitude angle of the projection device relative to the projection area when it is stationary;

[0150] The projected image projected by the projection device is corrected based on the second measured attitude angle;

[0151] The control projection module 401 displays the corrected projected image.

[0152] In some possible implementations, the controller 403 is also configured to:

[0153] The current attitude angle is corrected to obtain the corrected current attitude angle.

[0154] In some feasible implementations, the controller 403 is specifically configured as follows:

[0155] The control sensor 402 acquires the first attitude angle data of the multi-frame projection device;

[0156] If the difference between two adjacent frames of first attitude angle data is greater than a first preset angle threshold, the projection device is determined to enter a moving state.

[0157] In some feasible implementations, the controller 403 is specifically configured as follows:

[0158] The control sensor 402 acquires the second attitude angle data of the multi-frame projection device;

[0159] If the difference between two adjacent frames of second attitude angle data is less than a second preset angle threshold, the projection device is determined to enter a stopped state.

[0160] The steps performed by the projection device in the above embodiments have been described in detail in the section on projection correction methods, and will not be repeated here.

[0161] Figure 5 This is a schematic diagram illustrating the structure of a projection system according to an exemplary embodiment. For example... Figure 5 As shown, this embodiment of the present disclosure provides a projection system, including the projection device 501 and the adjustable bracket 502 provided in the above embodiments. The projection device 501 is mounted on the adjustable bracket 502, which is used to move the projection device 501 in space.

[0162] Here, the adjustable bracket 502 can be a rotatable pan-tilt head, on which the projection device 501 is mounted. The user can control the pan-tilt head to rotate as needed, thereby causing the projection device 501 to rotate. Of course, the adjustable bracket 502 can also be any other device capable of moving the projection device 501 in space.

[0163] It is worth noting that the adjustable bracket 502 can move the projection device 501 in three degrees of freedom: yaw, roll, and pitch. It can also move the projection device 501 in six degrees of freedom. The six degrees of freedom include forward / backward, left / right, up / down, yaw, roll, and pitch.

[0164] According to embodiments of this disclosure, a non-transitory computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the projection correction method provided in the above embodiments.

[0165] In the context of this disclosure, a non-transitory computer-readable storage medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A non-transitory computer-readable storage medium can be a machine-readable signal medium or a machine-readable storage medium. A non-transitory computer-readable storage medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0166] According to embodiments of this disclosure, a computer program product may also be provided, comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the projection correction method shown in the flowchart.

[0167] Figure 6 This is a schematic diagram of the projection device in one embodiment. (See attached diagram.) Figure 6 As shown, the projection device 200 includes a projection unit 210 and a drive unit 220 for driving the projection unit 210. The projection unit 210 can form an optical image and project the optical image onto the imaging medium SC.

[0168] The projection unit 210 includes a light source unit 211, a light modulator 212, and an optical system 213. The driving unit 220 includes a light source driving unit 221 and a light modulator driving unit 222.

[0169] The light source unit 211 may include solid-state light sources such as light-emitting diodes (LEDs), lasers, and pump lamps. The light source unit 211 may include optical elements such as lenses and polarizers for improving the optical characteristics of the projected light, as well as dimming elements for adjusting the luminous flux.

[0170] The light source driving unit 221 can control the operation of the light source in the light source unit 211, including turning it on and off, according to the instructions of the control unit 250.

[0171] The light modulator 212 includes a display panel 215, which can be a transmissive liquid crystal display (LCD), a reflective liquid crystal on silicon (LCOS), or a digital micromirror device (DMD).

[0172] The optical modulator 212 is driven by the optical modulator driver unit 222, which is connected to the image processing unit 245.

[0173] The image processing unit 245 inputs image data to the light modulator driving unit 222. The light modulator driving unit 222 converts the input image data into a data signal suitable for the operation of the display panel 215. Based on the converted data signal, the light modulator driving unit 222 applies voltage to each pixel of each display panel 215 and draws an image on the display panel 215.

[0174] The optical system 213 includes a lens or mirror that causes the incident image light PLA to form an image on the imaging medium SC. The optical system 213 may also include a zoom mechanism that magnifies or reduces the image projected onto the imaging medium SC and a focus adjustment mechanism that performs focus adjustment.

[0175] The projection device 200 also includes an operation unit 231, a signal receiving unit 233, an input interface 235, a storage unit 237, a data interface 241, an interface unit 242, a frame memory 243, an image processing unit 245, and a control unit 250. The input interface 235, storage unit 237, data interface 241, interface unit 242, image processing unit 245, and control unit 250 can communicate with each other via an internal bus 207.

[0176] The operation unit 231 can generate corresponding operation signals based on the operation of various buttons and switches on the surface of the projection device 200 housing, and output them to the input interface 235. The input interface 235 includes circuitry that outputs the operation signals input from the operation unit 231 to the control unit 250.

[0177] After receiving signals (such as infrared signals or Bluetooth signals) sent from the control device 5 (such as a remote control), the signal receiving unit 233 can decode the received signals to generate corresponding operation signals. The signal receiving unit 233 outputs the generated operation signals to the input interface 235. The input interface 235 outputs the received operation signals to the control unit 250.

[0178] Storage unit 237 may be a magnetic recording device such as a hard disk drive (HDD), or a storage device using semiconductor storage elements such as flash memory. Storage unit 237 stores programs executed by control unit 250, data processed by control unit 250, image data, etc.

[0179] Data interface 241 includes a connector and interface circuitry, enabling wired connection with other electronic devices 100. Data interface 241 can also be a communication interface for communicating with other electronic devices 100. Data interface 241 receives image data, sound data, etc., from other electronic devices 100. In this embodiment, the image data can be content images.

[0180] Interface unit 242 is a communication interface for communicating with other electronic devices 100 according to the Ethernet standard. Interface unit 242 includes a connector and interface circuitry for processing signals transmitted by the connector. Interface unit 242 is an interface substrate including the connector and interface circuitry and is connected to the main substrate of control unit 250, which is a substrate on which processor 253 and other components are mounted. The connector and interface circuitry constituting interface unit 242 are mounted on the main substrate of control unit 250. Interface unit 242 can receive setting information or instruction information transmitted by other electronic devices 100.

[0181] The control unit 250 includes a memory 251 and a processor 253.

[0182] Memory 251 is a storage device that non-volatilely stores programs and data executed by processor 253. Memory 251 is composed of semiconductor storage elements such as magnetic storage devices, flash read-only memory (ROM), or other types of non-volatile storage devices. Memory 251 may also include random access memory (RAM) that constitutes the working area of ​​processor 253. Memory 251 stores data processed by control unit 250 and control programs executed by processor 253.

[0183] The processor 253 can be a single processor or a combination of multiple processor groups. The processor 253 executes control programs to control various parts of the projection device 200. For example, the processor 253 performs corresponding image processing based on operation signals generated by the operation unit 231, and outputs the parameters used in the image processing (such as parameters for keystone correction of the image) to the image processing unit 245. Furthermore, the processor 253 can control the light source in the light source unit 211 to turn on, off, or adjust its brightness by controlling the light source drive unit 221.

[0184] The image processing unit 245 and the frame memory 243 can be constructed from integrated circuits. Integrated circuits include large-scale integrated circuits (LSI), application-specific integrated circuits (ASIC), and programmable logic devices (PLD), where PLD may include field-programmable gate arrays (FPGA). Integrated circuits may also include a portion of analog circuitry, or a combination of a processor and integrated circuits. Combinations of processors and integrated circuits are referred to as microcontroller units (MCU), system-on-chips (SoC), system LSIs, chipsets, etc.

[0185] The image processing unit 245 can store the image data received from the data interface 241 in the frame memory 243. The frame memory 243 includes multiple memory banks, each containing storage capacity for writing one frame of image data. The frame memory 243 can be constructed from synchronous dynamic random access memory (SDRAM) or dynamic random access memory (DRAM).

[0186] The image processing unit 245 can perform image processing on the image data stored in the frame memory 243, including resolution conversion, size adjustment, distortion correction, shape correction, digital zoom, image tone adjustment, and image brightness adjustment.

[0187] The image processing unit 245 can also convert the input frame frequency of the vertical synchronization signal into a drawing frequency and generate a vertical synchronization signal with a drawing frequency. The generated vertical synchronization signal is called the output synchronization signal. The image processing unit 245 then outputs the above-mentioned output synchronization signal to the optical modulator driver unit 222.

[0188] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

[0189] Furthermore, although the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in sequential order. Multitasking and parallel processing may be advantageous in certain environments. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Although the subject matter has been described using the language of specific methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely exemplary forms of implementing the claims. Regarding the apparatus in the above embodiments, the specific manner in which the various modules perform operations has been described in detail in the embodiments relating to the method and will not be elaborated upon here.

Claims

1. A projection correction method, characterized in that, include: When the projection device enters a moving state, the current attitude angle of the projection device relative to the projection area is obtained; The projected image projected by the projection device is corrected based on the current attitude angle, and the corrected projected image is displayed. Return to the step of obtaining the current attitude angle of the projection device relative to the projection area until the projection device enters a stopped state; The step of obtaining the current attitude angle of the projection device relative to the projection area includes: The first measurement attitude angle of the projection device at the current moment is obtained through a sensor; the sensor is an inertial measurement unit. The current attitude angle is obtained based on the difference between the first measured attitude angle and the attitude angle compensation value. The attitude angle compensation value is determined based on the difference between the first frame of attitude angle data collected by the sensor and the calibration attitude angle determined by the time-of-flight sensor. The calibration attitude angle is the attitude angle of the projection device relative to the projection area in the initial state. The method further includes: At each second preset time interval, the fourth measurement attitude angle of the projection device is determined by the time-of-flight sensor; A new attitude angle compensation value is obtained based on the difference between the first measured attitude angle and the fourth measured attitude angle obtained at the current moment.

2. The method according to claim 1, characterized in that, The method further includes: When the projection device enters a stopped state, based on the multi-frame attitude angle data acquired by the sensor within a target time period, a second measured attitude angle of the projection device relative to the projection area in the stopped state is determined, wherein the target time period is the time period between the first moment when the projection device begins to switch from the moving state to the stopped state and the second moment when the projection device is completely in the stopped state; The projected image projected by the projection device is corrected based on the second measured attitude angle, and the corrected projected image is displayed.

3. The method according to claim 1 or 2, characterized in that, The method includes: The projection device acquires multiple frames of first attitude angle data of the projection device through sensors. If the difference between two adjacent frames of the first attitude angle data is greater than a first preset angle threshold, the projection device is determined to have entered the moving state.

4. The method according to claim 1 or 2, characterized in that, The method includes: The projection device acquires multiple frames of second attitude angle data from sensors. If the difference between two adjacent frames of second attitude angle data is less than a second preset angle threshold, the projection device is determined to enter the stop state.

5. A projection device, characterized in that, include: The projection module is configured to project a projected image. A sensor is configured to acquire attitude angle data of the projection device; The sensor is an inertial measurement unit; The controller is configured as follows: When the projection device enters a moving state, the sensor is controlled to acquire the attitude angle data of the projection device; The current attitude angle of the projection device relative to the projection area is determined based on the attitude angle data; The projected image projected by the projection device is corrected based on the current attitude angle; Control the projection module to display the corrected projected image; Determining the current attitude angle of the projection device relative to the projection area based on the attitude angle data includes: The first measured attitude angle of the projection device at the current moment is determined based on the attitude angle data; The current attitude angle is obtained based on the difference between the first measured attitude angle and the attitude angle compensation value. The attitude angle compensation value is determined based on the difference between the first frame of attitude angle data collected by the sensor and the calibration attitude angle determined by the time-of-flight sensor. The calibration attitude angle is the attitude angle of the projection device relative to the projection area in the initial state. The controller is also configured to: At each second preset time interval, the fourth measurement attitude angle of the projection device is determined by the time-of-flight sensor; A new attitude angle compensation value is obtained based on the difference between the first measured attitude angle and the fourth measured attitude angle obtained at the current moment.

6. The projection device according to claim 5, characterized in that, The controller is also configured to: When the projection device enters a stopped state, the sensor is controlled to acquire multiple frames of attitude angle data within a target time period, wherein the target time period is the time period between the first moment when the projection device begins to switch from the moving state to the stopped state and the second moment when the projection device is completely in the stopped state; Based on the multi-frame attitude angle data, a second measured attitude angle of the projection device relative to the projection area in the stopped state is determined; The projected image projected by the projection device is corrected based on the second measured attitude angle; Control the projection module to display the corrected projected image.

7. The projection device according to claim 5 or 6, characterized in that, The controller is specifically configured as follows: The sensor is controlled to acquire multiple frames of first attitude angle data of the projection device; If the difference between the first attitude angle data in two adjacent frames is greater than a first preset angle threshold, the projection device is determined to have entered the moving state.

8. The projection device according to claim 6, characterized in that, The controller is specifically configured as follows: The sensor is controlled to acquire multiple frames of second attitude angle data of the projection device; If the difference between two adjacent frames of the second attitude angle data is less than a second preset angle threshold, the projection device is determined to enter the stop state.

9. A projection system, characterized in that, The invention includes a projection device as described in any one of claims 5 to 8 and an adjustable bracket, wherein the projection device is mounted on the adjustable bracket and the adjustable bracket is used to move the projection device in space.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the projection correction method as described in any one of claims 1 to 4.

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