Laser projection device and correction method of projected image thereof

Abstract

The application discloses a laser projection device and a correction method of a projected image thereof, and belongs to the field of projection display. Since an imaging assembly in the laser projection device can image the light signal reflected by the projected plane to obtain an actual depth image, and the actual depth image is sent to a control circuit. The control circuit can correct the projection position of the projected image according to the relative position between the target pixel located in the frame of the projection screen in the actual depth image and the reference pixel located outside the frame of the projection screen. Therefore, the user does not need to manually correct the projection position of the projected image, and therefore the efficiency and reliability of the correction of the projection position of the projected image are improved.

Description

[0001] This application claims priority to Chinese Patent Application No. 202010783509.3, filed on August 6, 2020, entitled "Laser Projection Device and Correction Method for Projected Image Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of projection display, and in particular to a laser projection device and a method for correcting the projected image thereon. Background Technology

[0003] A projection system may include a projection device, a projection screen, and a remote control. The projection device projects and displays a projected image onto the projection screen. When the projected image is deformed, if the projection device receives a correction command from the user via the remote control, it projects and displays a correction image, which includes feature points. Subsequently, upon receiving an adjustment command from the user via the remote control for the feature point, the projection device can adjust the position of the feature point according to the adjustment command until the feature point is within the projection screen and the size of the correction image is the initial size. Afterward, upon receiving a display command from the user via the remote control, the projection device can adjust the position of pixels in the projected image based on the movement distance of the feature point during the projection and display process, so that the projected image is within the projection screen and the size of the projected image is the initial size.

[0004] However, because users need to manually correct the projected image using a remote control, the efficiency of projected image correction is relatively low. Summary of the Invention

[0005] This disclosure provides a laser projection device and a method for correcting its projected image, which solves the problem in related technologies where users manually correct projected images via remote control, resulting in low efficiency in image correction. The technical solution is as follows:

[0006] On one hand, a laser projection device is provided, the laser projection device comprising: an imaging component, a main unit, and a control circuit located within a housing of the main unit;

[0007] The imaging component is connected to the control circuit. The imaging component is used to emit light signals to the projection plane, image the light signals reflected by the projection plane to obtain an actual depth image, and send the actual depth image to the control circuit. The depth value of each pixel in the actual depth image is used to indicate the distance between the projection point corresponding to the pixel in the projection plane and the host.

[0008] The control circuit is used to correct the projection position of the projected image based on the relative position between the target pixel located within the border of the projection screen and the reference pixel located outside the border of the projection screen in the actual depth image, wherein the orthographic projection of the projection screen onto the projection plane is located within the projection plane.

[0009] Optionally, the laser projection device further includes: a projection lens located within the housing of the host; the imaging component is located within the housing of the host and on the light-incident side of the projection lens;

[0010] The imaging component is used to transmit the light signal to the projection lens;

[0011] The projection lens is used to project the light signal onto the projection plane, and to transmit the light signal reflected by the projection plane to the imaging component.

[0012] Optionally, the laser projection device further includes: a reflector;

[0013] The imaging component is used to transmit the optical signal to the reflector;

[0014] The reflector is used to reflect the light signal transmitted by the imaging component to the projection lens, and to reflect the light signal transmitted by the projection lens to the imaging component.

[0015] Optionally, the laser projection device further includes: a reflector driving circuit and a light valve, wherein the reflector is located between the light valve and the projection lens;

[0016] The control circuit is also connected to the mirror drive circuit, and the control circuit is also used to provide a first drive signal to the mirror drive circuit;

[0017] The mirror driving circuit is also connected to the mirror, and the mirror driving circuit is used to drive the mirror to flip to the target posture in response to the first driving signal.

[0018] When the reflector is in the target posture, the reflective surface of the reflector is located on the side closer to the imaging component, and the reflector intersects with the transmission direction of the light signal emitted by the imaging component.

[0019] Optionally, the control circuit is further used for:

[0020] After correcting the projection position of the projected image, a second driving signal is provided to the reflector driving circuit;

[0021] The mirror driving circuit is used to respond to the second driving signal and drive the mirror to flip to the initial position;

[0022] When the reflector is in the initial posture, the optical path of the reflector does not intersect with the optical path of the image signal emitted by the optical valve.

[0023] Optionally, the laser projection device further includes: a projection lens located inside the housing of the host; the imaging component located outside the housing of the host, and the optical axis of the imaging component being parallel to the optical axis of the projection lens.

[0024] Optionally, the imaging component includes: a light signal transmitter and an image sensor;

[0025] The optical signal transmitter is used to transmit the optical signal;

[0026] The image sensor is connected to the control circuit. The image sensor is used to receive the light signal reflected by the projection plane, image the light signal reflected by the projection plane to obtain an actual depth image, and send the actual depth image to the control circuit.

[0027] Optionally, the control circuit is further used for:

[0028] If the absolute value of the depth difference between the depth value of the target pixel in the actual depth image and the depth value of the target pixel in the reference depth image is greater than the depth threshold, the projection position of the pixel corresponding to the target pixel in the projection image is corrected.

[0029] The reference depth image is obtained by the imaging component imaging the light signal reflected by the projection plane when the image formed by the light signal emitted by the imaging component is located within the projection screen and the size of the image is the initial size.

[0030] Optionally, the control circuit is used for:

[0031] Determine the angle between the line connecting the projection point corresponding to the target pixel in the reference depth image and the host, and the reference plane, wherein the reference plane is perpendicular to the support surface of the host;

[0032] The correction distance of the target pixel is determined based on the difference between the included angle and the depth.

[0033] The projection position of the pixel corresponding to the target pixel in the projected image is corrected according to the correction distance.

[0034] Optionally, the laser projection device further includes a motor, which is connected to both the control circuit and the projection lens.

[0035] The control circuit is also used to send an adjustment signal to the motor if the depth value of the pixel in the actual depth image is not within the focal length range of the projection lens.

[0036] The motor is used to adjust the distance between the projection lens and the projection plane in response to the adjustment signal, so that the depth value of the pixel is within the focal length range.

[0037] Optionally, the size of the projection screen is smaller than the projection range of the projection lens; the control circuit is further configured to:

[0038] If the reference pixel exists in the actual depth image, the projected image is corrected, and the corrected projected image is projected onto the projection screen so that all pixels in the corrected projected image are located within the border of the projection screen.

[0039] On the other hand, a method for correcting projected images is provided, applied to the control circuit of a laser projection device, the laser projection device further comprising: a main unit and an imaging component; the control circuit is located within the housing and connected to the imaging component, the method comprising:

[0040] Receive the actual depth image sent by the imaging component;

[0041] The projection position of the projected image is corrected based on the relative positions of the target pixels located within the border of the projection screen and the reference pixels located outside the projection screen in the actual depth image.

[0042] Wherein, the depth value of each pixel in the actual depth image is used to indicate the distance between the projection point corresponding to the pixel in the projection plane and the host. The actual depth image is obtained by the imaging component imaging the light signal reflected by the projection plane. The light signal reflected by the projection plane is the light signal emitted by the imaging component to the projection plane and the light signal reflected by the projection plane. The orthographic projection of the projection screen on the projection plane is located in the projection plane.

[0043] In another aspect, a laser projection device is provided, comprising: a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method for correcting the projected image described above.

[0044] In another aspect, a computer-readable storage medium is provided, in which instructions are stored. When these instructions are loaded and executed by a processor, they implement the method for correcting the projected image described above.

[0045] In another aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to execute the method for correcting the projected image described above.

[0046] The beneficial effects of the technical solutions provided in this disclosure include at least the following:

[0047] This disclosure provides a laser projection device and a method for correcting its projected image. The imaging component can image the light signal reflected from the projection plane to obtain an actual depth image, which is then sent to a control circuit. The control circuit can correct the projection position of the projected image based on the relative position between a target pixel within the border of the projection screen and a reference pixel outside the border of the projection screen in the actual depth image. Therefore, manual correction of the projection position is unnecessary, thus improving the efficiency and reliability of the projection position correction. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the structure of a laser projection device provided in an embodiment of this disclosure;

[0050] Figure 2 This is a schematic diagram of another laser projection device provided in an embodiment of this application;

[0051] Figure 3 This is a schematic diagram of an actual depth image provided in an embodiment of this disclosure;

[0052] Figure 4 This is a schematic diagram of the structure of a projection screen provided in an embodiment of this disclosure;

[0053] Figure 5 This is a schematic diagram of another projection screen structure provided in an embodiment of this disclosure;

[0054] Figure 6 This is a schematic diagram of another actual depth image provided in an embodiment of this disclosure;

[0055] Figure 7 This is a schematic diagram of a reference depth image provided in an embodiment of this disclosure;

[0056] Figure 8 This is a schematic diagram of a target depth image provided in an embodiment of this disclosure;

[0057] Figure 9 This is a schematic diagram illustrating the offset of a projected image toward the target side provided in an embodiment of this disclosure;

[0058] Figure 10 This is a schematic diagram showing another projection image shifted towards the target side according to an embodiment of this disclosure;

[0059] Figure 11 This is a schematic diagram of another actual depth image provided in an embodiment of this disclosure;

[0060] Figure 12 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0061] Figure 13 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0062] Figure 14 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0063] Figure 15 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0064] Figure 16 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0065] Figure 17 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0066] Figure 18 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0067] Figure 19 This is a schematic diagram illustrating the determination of a correction distance according to an embodiment of this disclosure;

[0068] Figure 20 This is a schematic diagram of the structure of another laser projection device provided in the embodiments of this disclosure;

[0069] Figure 21 This is a schematic diagram of determining the straight-line distance L3 from the projection point corresponding to each row of pixels to the projection screen, provided by an embodiment of this disclosure;

[0070] Figure 22 This is a schematic diagram illustrating a method for determining the depth value of a pixel according to an embodiment of this disclosure;

[0071] Figure 23 This is a flowchart of a method for correcting a projected image provided in an embodiment of this disclosure;

[0072] Figure 24 This is a flowchart of a method for correcting a projected image provided in an embodiment of this disclosure. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0074] Figure 1 This is a schematic diagram of the structure of a laser projection device provided in an embodiment of this disclosure. Figure 2 This is a schematic diagram of another laser projection device provided in an embodiment of this application. (In conjunction with...) Figure 1 and Figure 2 The laser projection device may include a host 10, a control circuit 20 and an imaging component 30 located in the housing 101 of the host 10.

[0075] refer to Figure 1 and Figure 2 The imaging component 30 is connected to the control circuit 20. The imaging component 30 is used to emit a light signal toward the projection plane 40, image the light signal reflected by the projection plane 40 to obtain an actual depth image, and send the actual depth image to the control circuit 20. Optionally, the light signal can be an infrared light signal.

[0076] Figure 3 This is a schematic diagram of an actual depth image provided in an embodiment of this disclosure. (Reference) Figure 3 The actual depth image 01 may include multiple pixels, and the depth value of each pixel is used to indicate the distance between the projection point corresponding to that pixel in the projection plane 40 and the host 10.

[0077] Optionally, the resolution of the actual depth image 01 can be M×N, where M and N are both positive integers greater than 1. Pixel Pij is the pixel in the i-th row and j-th column of the actual depth image 01, where i and j are both positive integers, and i is less than or equal to M, and j is less than or equal to N. For example, refer to... Figure 3 The resolution of the actual depth image 01 can be 4×6 (i.e., M=4, N=6). The depth value of pixel P11 in the first row and first column of the actual depth image 01 is 2 meters (m). That is, the distance between the projection point corresponding to pixel P11 in the projection plane 40 and the host 10 is 2m.

[0078] The control circuit 20 is used to correct the projection position of the projected image based on the relative position of the target pixel located within the border of the projection screen 41 and the reference pixel located outside the border of the projection screen 41 in the actual depth image.

[0079] The orthographic projection of the projection screen 41 onto the projection plane 40 is located within the projection plane 40. The projection screen 41 can be a planar structure, such as a circle or a polygon. Figure 4 This is a schematic diagram of the structure of a projection screen provided in an embodiment of this disclosure. For example... Figure 4 As shown, the projection screen 41 can be rectangular.

[0080] Alternatively, the projection screen 41 can be a three-dimensional structure, and the projection screen 41 may include at least one projection surface. At least one surface of the projection screen 41 is parallel to or tangent to the projection plane 40. The actual depth image includes multiple regions that correspond one-to-one with the at least one projection surface. The projection point corresponding to the pixel in each region is located within a corresponding projection surface.

[0081] Example, reference Figure 5 and Figure 6 The projection screen 41 can be a cube, and it includes three projection surfaces: projection surface 41a, projection surface 41b, and projection surface 41c. The actual depth image 01 includes three regions: region 010 to region 012. Region 010 corresponds to projection surface 41a. Region 011 corresponds to projection surface 41b. Region 012 corresponds to projection surface 41c.

[0082] It should be noted that a target pixel located within the border of the projection screen 41 means that the projection point of the target pixel on the projection plane 40 is located within the projection screen 41. A reference pixel located outside the border of the projection screen 41 means that the projection point of the reference pixel on the projection plane 40 is located outside the projection screen 41.

[0083] Because the projection screen 41 has a certain thickness, the distance between the projection point outside the frame of the projection screen 41 and the host 10 is greater than the distance between the projection point inside the frame of the projection screen 41 and the host 10. In an optional implementation of this embodiment, the control circuit 20 can determine pixels in the actual depth image whose depth value is less than a first target depth value as target pixels, and pixels in the actual depth image whose depth value is greater than or equal to the first target depth value as reference pixels. Then, the control circuit 20 can determine each vertex of the reference region enclosed by the reference pixels in the actual depth image, determine each vertex of the target region enclosed by the target pixels, and then determine the number of target pixels between each vertex in the reference region and the corresponding vertex in the target region. Finally, the control circuit 20 can correct the projection position of the projected image based on the number of target pixels. For example, the control circuit 20 can translate the projected image based on the number of target pixels to correct the projection position of the projected image.

[0084] The first target depth value is a depth value pre-stored in the control circuit 20. The reference area and the target area can be polygons.

[0085] For example, if the depth of the first target is equal to 1.2m, refer to... Figure 3 The control circuit 20 can determine that the first two rows of pixels in the actual depth image 01 are reference pixels, and the last two rows of pixels in the actual depth image 01 are target pixels. Then, the control circuit 20 can determine that the number of target pixels between each vertex of the reference region 013 enclosed by the first two rows of reference pixels (e.g., the position of pixel P11) and the corresponding vertex in the target region 014 enclosed by the last two rows of target pixels (e.g., the position of pixel P31) is 2, and correct the projection position of the projected image according to this number of target pixels.

[0086] In another optional implementation of this disclosure, the control circuit 20 pre-stores a reference depth image. This reference depth image is obtained by the imaging component 30 imaging the light signal reflected by the projection plane 40 when the image formed by the light signal emitted by the imaging component 30 is located within the projection screen 41 and the size of the image is the initial size. The control circuit 20 can determine the target depth image based on the actual depth image and the reference depth image. The depth value D3 of pixel Pij in the target depth image is equal to the difference between the depth value D1 of pixel Pij in the actual depth image and the depth value D0 of pixel Pij in the reference depth image, i.e., D3 = D1 - D0.

[0087] Subsequently, the control circuit 20 can determine first pixels as pixels in the target depth image whose absolute depth value is less than a second target depth value, and determine target pixels as pixels in the actual depth image that are located at the same position as the first pixel. Furthermore, it can determine second pixels as pixels in the target depth image whose absolute depth value is greater than or equal to the second target depth value, and determine reference pixels as pixels in the actual depth image that are located at the same position as the second pixel. Then, the control circuit 20 can determine the number of target pixels between the vertices of the reference region enclosed by the reference pixels in the actual depth image and the vertices of the target region enclosed by the target pixels, and correct the projection position of the projected image based on the number of target pixels.

[0088] The second target depth value is a depth value pre-stored in the control circuit 20. The first target depth value is greater than the second target depth value, and the reference depth image and the target depth image have the same resolution.

[0089] Example, Figure 7 This is a schematic diagram of a reference depth image provided in an embodiment of this disclosure. Figure 8This is a schematic diagram of a target depth image provided in an embodiment of this disclosure. (Reference) Figure 3 , Figure 7 and Figure 8 The control circuit 20 can determine that the depth value D3 of pixel P11 in the target depth image 03 is equal to the absolute value of the difference between the depth value 2 of pixel P11 in the actual depth image 01 and the depth value 1.1 of pixel P11 in the reference depth image 02, that is, the depth value D3 of pixel P11 in the target depth image 03 = 2 - 1.1 = 0.9.

[0090] If the depth of the second target is equal to 0.4m, refer to Figure 3 and Figure 8 The control circuit 20 can determine that the pixels in the last two rows of the target depth image 03 are the first pixels, and the pixels in the first two rows are the second pixels. Then, the control circuit 20 can determine the pixels in the actual depth image 01 that are located at the same position as the first pixels as reference pixels, i.e., the last two rows of pixels in the actual depth image 01. The pixels in the actual depth image 01 that are located at the same position as the second pixels are determined as target pixels, i.e., the first two rows of pixels in the actual depth image 01. Then, the control circuit 20 can determine that the number of target pixels between each vertex of the target region 010 enclosed by the first two rows of reference pixels (e.g., the position of pixel P11) and the corresponding vertex in the reference region 011 enclosed by the last two rows of target pixels (e.g., the position of pixel P31) is 2, and correct the projection position of the projected image based on this number of target pixels.

[0091] Optionally, during the process of correcting the projection position of the projected image based on the number of target pixels, the control circuit 20 can detect the relative positional relationship between the reference area and the target area. If the reference area is located on the target side of the target area, the control circuit 20 can determine that the projection position of the projected image on the projection screen 41 has been shifted by a number of target pixels towards the target side. Therefore, the control circuit 20 can shift the projection position of the projected image on the projection screen 41 by a number of target pixels away from the target side.

[0092] Here, the target side refers to the side of the projection point corresponding to a pixel in the actual depth image that is away from the horizontal axis of the reference coordinate system in the pixel row direction. Alternatively, the target side refers to the side of the projection point corresponding to a pixel in the actual depth image that is close to the horizontal axis of the reference coordinate system in the pixel row direction. Alternatively, the target side can refer to the side of the projection point corresponding to a pixel in the actual depth image that is close to the vertical axis of the reference coordinate system in the pixel column direction. Alternatively, the target side can refer to the side of the projection point corresponding to a pixel in the actual depth image that is away from the vertical axis of the reference coordinate system in the pixel column direction. If the projection screen 41 is rectangular, the reference coordinate system can be a coordinate system established based on the projection screen 41. This reference coordinate system can include a horizontal axis and a vertical axis, with the horizontal axis parallel to the pixel column direction and the vertical axis parallel to the pixel row direction. The origin of the reference coordinate system can be the upper left vertex of the projection screen 41.

[0093] Example, reference Figure 3 , Figure 9 and Figure 10 The reference region 013 is located above the target region 014. Therefore, the target side refers to the side of the projection point corresponding to the pixel in the actual depth image 01 that is closer to the horizontal axis of the reference coordinate system in the pixel row direction. Correspondingly, the reference... Figure 9 and Figure 10 The control circuit 20 can shift the projection position of the projected image 04 on the projection screen 41 downwards by the target number of pixels.

[0094] Optionally, such as Figure 9 As shown, the projected image 04 can be rectangular. Or, as... Figure 10 As shown, the projected image 04 can be trapezoidal.

[0095] refer to Figure 11 The reference region 013 is located to the left of the target region 014. Therefore, the target side refers to the projection point corresponding to the pixel in the actual depth image 01, on the side closer to the vertical axis of the reference coordinate system in the pixel column direction.

[0096] In summary, this disclosure provides a laser projection device. Since the imaging component can image the light signal reflected from the projection plane to obtain an actual depth image, and then send this actual depth image to the control circuit, the control circuit can correct the projection position of the projected image based on the relative position between the target pixel located within the border of the projection screen and the reference pixel located outside the border of the projection screen in the actual depth image. Therefore, there is no need for the user to manually correct the projection position of the projected image, thus improving the efficiency and reliability of the projection position correction.

[0097] refer to Figure 12 , Figure 13 , Figure 14 and Figure 15 The imaging component 30 may include an optical signal transmitter 301 and an image sensor 302. Optionally, the optical signal transmitter 301 may be a vertical cavity surface emitting laser (VCSEL).

[0098] The optical signal transmitter 301 is used to transmit optical signals. The image sensor 302 is used to receive the optical signals reflected by the projection plane 40, image the optical signals reflected by the projection plane 40 to obtain an actual depth image, and send the actual depth image to the control circuit 20.

[0099] In this embodiment, the control circuit 20 can send a start command to the light signal transmitter 301 and the image sensor 302. After receiving the start command, the light signal transmitter 301 emits a light signal in response to the start command. After receiving the start command, the image sensor 302 can image the light signal transmitted by the projection lens 50 in response to the start command to obtain an actual depth image.

[0100] Optionally, the control circuit 20 can periodically send start commands to the optical signal transmitter 301 and the image sensor 302, or the control circuit 20 can send start commands to the optical signal transmitter 301 and the image sensor 302 after receiving a calibration command. Optionally, the calibration command can be sent by the user to the control circuit 20 via a remote control.

[0101] Optionally, the image sensor 302 can be a time-of-flight (TOF) sensor. The image sensor 302 may include an array of M1×N1 photosensitive sensors. Each pixel in the actual depth image corresponds to one photosensitive sensor. M1 is the number of rows of photosensitive sensors, N1 is the number of columns of photosensitive sensors, M1 is greater than or equal to M, and N1 is greater than or equal to N.

[0102] Optionally, the image sensor 302 can determine the transmission duration t of the light signal based on the light output time value T1 of the light signal transmitter 301 and the light reception time value T2 of the photosensor corresponding to the pixel. Based on the light signal transmission speed v and transmission duration, it determines the distance D1 between the projection point corresponding to the pixel in the projection plane 40 and the host 10, thereby obtaining the actual depth image. Here, the light output time value T1 is the moment when the light signal transmitter 301 emits the laser, and the light reception time value T2 is the moment when the photosensor corresponding to the pixel receives the light signal. Both T1 and T2 are greater than 0, and t = T2 - T1.

[0103] refer to Figure 12The laser projection device may also include a projection lens 50 located within the housing 101 of the main unit 10. The projection lens 50 may include multiple lenses, among which a reflective lens 501 is used to project the received light signal onto the projection plane 40. The imaging component 30 may be located inside or outside the housing 101 of the main unit 10. The following description will take the example of the imaging component 30 being located inside the housing 101 of the main unit 10.

[0104] refer to Figure 12 , Figure 13 , Figure 16 and Figure 17 The imaging component 30 is located inside the housing 101 of the host 10 and on the light-incident side of the projection lens 50. (Reference) Figure 16 The optical path of the light signal transmitted from the imaging component 30 to the projection lens 50 is partially coincident with the optical path of the image signal transmitted from the light valve 70 to the projection lens 50, that is, the optical axis of the imaging component 30 is coaxial with the optical axis of the projection lens 50. Since the imaging component 30 is located inside the housing 101, it does not occupy the external space of the host 10 and does not affect the appearance of the host 10.

[0105] The imaging component 30 is used to emit light signals and transmit the light signals to the projection lens 50.

[0106] The projection lens 50 is used to project the light signals transmitted by the imaging component 30 onto the projection plane 40, and to transmit the light signals reflected by the projection plane 40 to the imaging component 30.

[0107] The light signal transmitter 301 emits a light signal and transmits it to the projection lens 50. The projection lens 50 projects the light signal onto the projection plane 40 and transmits the light signal reflected by the projection plane 40 to the image sensor 302. The image sensor 302 is connected to the control circuit 20 and is used to image the light signal transmitted from the projection lens 50 to obtain an actual depth image, which is then sent to the control circuit 20.

[0108] Optionally, the projection lens 50 includes a reflective lens 501 among a plurality of lenses for projecting the light signal transmitted by the imaging component onto the projection plane 40.

[0109] refer to Figure 16 and Figure 17 The laser projection device may also include a reflector 60. The imaging component 30 is used to transmit light signals to the reflector 60. The reflector 60 is used to reflect the light signals transmitted by the imaging component 30 to the projection lens 50, and to reflect the light signals transmitted by the projection lens 50 to the imaging component 30.

[0110] Optionally, the light signal transmitter 301 is used to transmit light signals to the reflector 60. The reflector 60 is used to reflect the light signals transmitted by the light signal transmitter 301 to the projection lens 50, and to reflect the light signals transmitted by the projection lens 50 to the image sensor 302.

[0111] In this embodiment, the projection lens 50 transmits the light signal reflected by the projection plane 40 to the reflector 60, which then reflects the light signal to the image sensor 302. The image sensor 302 can image the light signal reflected by the reflector 60 to obtain an actual depth image.

[0112] refer to Figure 16 The laser projection device may also include a light valve 70, with a reflector 60 located between the light valve 70 and the projection lens 50.

[0113] As an optional implementation of this disclosure, the reflector 60 may include a reflective surface and a non-reflective surface, wherein the non-reflective surface of the reflector 60 is opaque.

[0114] In this implementation, refer to Figure 17 The laser projection device may further include a mirror driving circuit 80. The control circuit 20 is also connected to the mirror driving circuit 80 and is used to provide a first driving signal to the mirror driving circuit 80. The mirror driving circuit 80 is also connected to a mirror 60 and is used to drive the mirror 60 to flip into the target orientation in response to the first driving signal. Optionally, the control circuit 20 may provide the first driving signal to the mirror driving circuit 80 simultaneously with sending a start command to the light signal transmitter 301 and the image sensor 302.

[0115] When the reflector 60 is in the target orientation, its reflective surface is located closer to the imaging component 30, and the direction of light signal transmission from the reflector 60 intersects with that of the imaging component 30. The reflective surface of the reflector 60 can totally reflect the light signal emitted by the imaging component 30 to the projection lens 50, and can also totally reflect the light signal transmitted from the projection lens 50 to the imaging component 30. In this case, the non-reflective surface of the reflector 60 intersects with the light path of the image signal emitted by the light valve 70, meaning the image signal emitted by the light valve 70 cannot be transmitted to the projection lens 50.

[0116] The angle between the reflective surface of the reflector 60 and the transmission direction of the light signal emitted by the imaging component 30 can be an acute angle, for example, 45 degrees.

[0117] Optionally, when the reflector 60 is in the target orientation, its reflective surface is located closer to the light signal transmitter 301, and the direction of transmission of the light signal emitted by the reflector 60 intersects with that of the light signal emitted by the light signal transmitter 301. The reflective surface of the reflector 60 can totally reflect the light signal emitted by the light signal transmitter 401 to the projection lens 30, and can also totally reflect the light signal transmitted from the projection lens 30 to the image sensor 402. In this case, the non-reflective surface of the reflector 60 intersects with the optical path of the image signal emitted by the light valve 70, meaning the image signal emitted by the light valve 70 cannot be transmitted to the projection lens 30.

[0118] refer to Figure 16 and Figure 17 The control circuit 20 is also used to provide a second driving signal to the mirror driving circuit 80 after correcting the projection position of the projected image. The mirror driving circuit 80 is used to drive the mirror 60 to flip back to its initial position in response to the second driving signal.

[0119] In its initial position, the reflector 60 does not intersect with the light path of the image signal emitted by the light valve 70. That is, the reflector 60 does not block the image signal emitted by the light valve 70 when in its initial position, thus ensuring the normal display of the projected image. At this time, the reflective surface of the reflector 60 cannot reflect the light signal emitted by the imaging component 30 to the projection lens, nor can it reflect the light signal transmitted by the projection lens 50 to the imaging component 30.

[0120] After receiving the actual depth image sent by the image sensor 302, the control circuit 20 can send a shutdown command to the imaging assembly 30 simultaneously with sending a second drive signal to the mirror drive circuit 80. In response to this shutdown command, the imaging assembly 30 can cease emitting light signals and stop receiving light signals reflected by the mirror 60.

[0121] Optionally, the control circuit 20 can send shutdown commands to the optical signal transmitter 301 and the image sensor 302 respectively. In response to the shutdown command, the optical signal transmitter 301 can stop emitting optical signals. In response to the shutdown command, the image sensor 302 can stop receiving optical signals reflected by the reflector 60.

[0122] As another optional implementation of this disclosure, the reflector 60 can be a prism, such as a triangular prism. Furthermore, the reflector 60 can include a reflective surface and a transmissive surface. Figure 18 This is a schematic diagram of the structure of another laser projection device provided in an embodiment of this disclosure. For example... Figure 18As shown, the reflector 60 intersects with the optical path of the image signal emitted by the light valve 70. That is, the transmissive surface of the reflector 60 can transmit the image signal emitted by the light valve 70, transmitting it to the projection lens 50, and then projecting it onto the projection plane 40 to display a projected image on the projection plane 40. The reflective surface of the reflector 60 is located near the imaging component 30, and the direction of transmission of the light signal emitted by the reflector 60 intersects with that of the imaging component 30. In this implementation, the laser projection device does not require a reflector drive circuit 80, nor does it require driving the reflector 60 to flip.

[0123] Optionally, the reflective surface of the mirror 60 is located on the side closer to the light signal transmitter 301, and the mirror 60 intersects with the transmission direction of the light signal emitted by the light signal transmitter 301. The control circuit 20 can send a shutdown command to the imaging component 30 after receiving the actual depth image sent by the imaging component 30.

[0124] refer to Figure 13 and Figure 17 The control circuit 20 may include a control sub-circuit 201 and a correction sub-circuit 202. The control sub-circuit 201 is connected to the light signal transmitter 301, the image sensor 302, the mirror drive circuit 80, the correction sub-circuit 202, and the motor 90, respectively. The control sub-circuit 201 sends start commands to the light signal transmitter 301 and the image sensor 302, and sends a first drive signal to the mirror drive circuit 80. After receiving the actual depth image sent by the image sensor 302, it sends a stop command to the light signal transmitter 301 and the image sensor 302, and sends a second drive signal to the mirror drive circuit 80.

[0125] The control subcircuit 201 is further configured to determine the relative position between a target pixel located within the border of the projection screen 41 and a reference pixel located outside the border of the projection screen 41 in the actual depth image, and send a correction command to the correction subcircuit 202, the correction command carrying the relative position. The correction subcircuit 202 is configured to, in response to the correction command, correct the projection position of the projected image based on the relative position.

[0126] In this embodiment of the disclosure, the following description will take the example where the imaging component 30 is located on the outside of the housing 101 of the host 10. (See reference...) Figure 14 and Figure 15 The imaging component 30 is located outside the housing 101 of the host 10, and the optical axis X1 of the imaging component 30 is parallel to the optical axis X2 of the projection lens 50. Since there is no need to install a reflector inside the housing, costs are saved.

[0127] The optical signal transmitter 301 is used to transmit optical signals to the projection plane 40.

[0128] The image sensor 302 is used to receive the light signal reflected by the projection plane 40, image the light signal reflected by the projection plane 40 to obtain an actual depth image, and send the actual depth image to the control circuit 10.

[0129] In this implementation, since the light signal emitted by the imaging component is an infrared signal, the laser projection device can project and display the projected image normally while the imaging component 30 emits the light signal to the projection plane 40. This achieves position correction of the projected image without affecting the user's normal viewing experience, resulting in a better user experience. The reflective lens 501 among the multiple lenses included in the projection lens 50 is used to project the image signal transmitted by the light valve onto the projection plane, thereby displaying the projected image on the projection plane.

[0130] In this embodiment, the control circuit 20 is further configured to determine the depth difference D between the depth value D1 of the target pixel in the actual depth image and the depth value D0 of the target pixel in the reference depth image 02, and to detect whether the absolute value of the depth difference D is greater than a depth threshold. If the absolute value of the depth difference D is greater than the depth threshold, the control circuit 20 can determine that the projection position of the pixel corresponding to the target pixel in the projected image is distorted. Therefore, the control circuit 20 can correct the projection position of the pixel corresponding to the target pixel in the projected image to ensure the display effect of the projected image. If the absolute value of the depth difference D is less than or equal to the depth threshold, the control circuit 20 does not need to correct the projection position of the pixel corresponding to the target pixel in the projected image. The depth threshold is a fixed depth value pre-stored in the control circuit 20.

[0131] Figure 19 This is a schematic diagram illustrating the determination of a correction distance according to an embodiment of this disclosure. (Reference) Figure 19 The control circuit 20 is used to determine the angle θ between the line L1 connecting the projection point corresponding to the target pixel in the reference depth image 02 and the host 10, and the reference plane 42. The correction distance d of the target pixel is determined based on the absolute value of the angle θ and the depth difference D, and the projection position of the projection point corresponding to the target pixel in the projected image is corrected based on the correction distance d. The reference plane 42 is perpendicular to the support surface of the host 10.

[0132] Optionally, the control circuit 20 may pre-store the projection position of the projection point corresponding to each pixel in the reference depth image on the reference plane 42. The control circuit 20 can determine the reference position A1 of the projection point corresponding to the target pixel in the reference depth image on the reference plane 42, thereby determining the line L1 connecting the projection point and the host 10. Optionally, the correction distance d can be equal to the product of the tangent of the included angle θ and the absolute value of the depth difference D, i.e., d = tanθ × |D| = tanθ × |D1 - D0|.

[0133] In this disclosure embodiment, reference is made to Figure 17 and Figure 20 During the process of correcting the projection position of the target pixel in the projected image according to the correction distance d, the control circuit 20 can detect whether the depth difference D is greater than 0. If the depth difference D is greater than 0, refer to Figure 17 and Figure 20 At this point, the projection point corresponding to the target pixel in the actual depth image is projected onto position A2 of the projection screen 41. Then, the control circuit 20 can control the projection point corresponding to the target pixel in the projected image to move a correction distance d away from the top of the projection screen 41, so that the projection point corresponding to the target pixel in the actual depth image is projected along the straight line L2.

[0134] If the depth difference is less than 0, the control circuit 20 can control the projection point in the projected image corresponding to the target pixel to move a correction distance d in a direction away from the bottom of the projection screen 41.

[0135] In this embodiment of the present disclosure, the control circuit 20 can detect whether the projected image is distorted based on the depth value of the target pixel located within the border of the projection screen 41 in the actual depth image, and when it is determined that the projected image is distorted, it corrects the projected image displayed on the projection screen 41, thereby ensuring the display effect of the projected image.

[0136] Optional, see reference Figure 17 and Figure 20 The laser projection device may also include a motor 90, which is connected to the control circuit 20 and the projection lens 50 respectively.

[0137] The control circuit 20 is also used to send an adjustment signal to the motor 90 if the depth value of a pixel in the actual depth image is not within the focal length range of the projection lens 50. The motor 90 is used to adjust the distance between the projection lens 50 and the projection plane 40 in response to the adjustment signal, so that the depth value of the pixel is within the focal length range. The focal length range of the projection lens 50 is a fixed range pre-stored in the control circuit 20.

[0138] Optionally, after receiving the actual depth image sent by the imaging component 30, the control circuit 20 can detect whether the depth value of a pixel in the actual depth image is within the focal length range of the projection lens 50. If the depth value of the pixel is not within the focal length range of the projection lens 50, the control circuit 20 can determine that the pixel corresponding to that pixel in the projected image is displayed relatively blurry on the projection screen 41, and the control circuit 20 can send an adjustment signal to the motor 90. If the depth value of the pixel is within the focal length range of the projection lens 50, the control circuit 20 can determine that the pixel corresponding to that pixel in the projected image is displayed relatively clearly on the projection screen 41, and therefore there is no need to send an adjustment signal to the motor 90.

[0139] In this embodiment of the disclosure, when the control circuit 20 determines that the depth value of a pixel in the actual depth image is not within the focal length range of the projection lens 50, it can display a prompt message on the projection screen 41. The prompt message is used to prompt the user to manually adjust the focal length range of the projection lens 50.

[0140] Optionally, if the size of the projection screen 41 is smaller than the projection range of the projection lens 50, the control circuit 20 is also used to correct the projected image if a reference pixel exists in the actual depth image, and project the corrected projected image onto the projection screen 41 so that all pixels in the corrected projected image are located within the border of the projection screen 41.

[0141] In this embodiment of the disclosure, during the process of correcting the projected image, the control circuit 20 can reduce the size of the projected image and project the reduced projected image onto the projection screen 41 so that all pixels in the projected image are located within the border of the projection screen 41.

[0142] Alternatively, the control circuit 20 can delete pixels in the projected image that correspond to the reference pixels and project the processed projected image onto the projection screen so that all pixels of the processed projected image are located within the border of the projection screen.

[0143] Alternatively, the control circuit 20 can project the pixel corresponding to the reference pixel onto the projection screen without projecting the image onto the projection screen.

[0144] Optionally, the control subcircuit 201 is further configured to send a correction command to the correction subcircuit 201 when the depth difference between the depth value of the target pixel in the actual depth image and the depth value of the target pixel in the reference depth image is greater than a depth threshold. The correction command carries the position of the target pixel in the actual depth image. The correction subcircuit 202 is configured to correct the projection position of the pixel corresponding to the target pixel in the projected image in response to the correction command.

[0145] Optionally, the control subcircuit 201 is further configured to send a correction command to the correction subcircuit 202 when it is determined that a reference pixel exists among the pixels in the actual depth image. The correction command carries the position of the reference pixel in the actual depth image. The correction subcircuit 202 is configured to correct the projected image according to the position of the reference pixel in the actual depth image in response to the correction command.

[0146] The control sub-circuit 201 is also used to send an adjustment signal to the motor 90 if the depth value of a pixel in the actual depth image is not within the focal length range of the projection lens 30.

[0147] Figure 21 This is a schematic diagram illustrating how to determine the straight-line distance L3 from the projection point corresponding to each row of pixels to the projection screen, according to an embodiment of this disclosure. (See reference) Figure 21 In determining the depth value corresponding to each pixel in the reference depth image, after the laser projection equipment is positioned so that the image formed by the light signal projected by the projection lens on the projection plane is within the projection screen 41 and the size of the image is the initial size, the vertical distance s between the host 10 and the projection screen 41 can be measured. Since the spacing between the projection points corresponding to two adjacent rows of pixels on the projection screen 41 is a fixed first spacing value, and the vertical distance between the bottom of the projection screen 41 and the support surface of the host 10 is also a fixed distance value, the worker can determine the row coordinate y of the projection point corresponding to each row of pixels in the reference depth image on the projection screen 41 based on the first spacing value and the fixed distance value. And based on the vertical distance s and the row coordinate y, the straight-line distance Dy from the projection point corresponding to each row of pixels to the straight line L3 of the projection screen 41 can be determined. The straight line L3 is parallel to the pixel column direction, and the intersection of the straight line L3 and the first side of the projection screen 41 is the midpoint of the first side. Optionally, the straight-line distance is equal to the sum of the square root of the square of the row coordinate y and the square of the vertical distance s, that is, the

[0148] Figure 22 This is a schematic diagram illustrating how to determine the depth value of each pixel according to an embodiment of this disclosure. Figure 22As shown, when placing the laser device, the user can make the extension line of the projection lens 50 intersect the extension line of the straight line L3. Since the column spacing between each column of pixels in the pixel column direction is a fixed second spacing value, the column coordinate x of the projection point located on the third side of the straight line L3 on the projection screen 41 increases sequentially from the intersection point of the straight line L3 and the projection screen 41 along the direction away from the straight line L3 by the first spacing value. Similarly, the column coordinate x of the projection point located on the fourth side of the straight line L3 in the reference depth image, starting from the intersection point of the straight line L3 and the projection screen 41, increases sequentially from the intersection point of the straight line L3 along the direction away from the straight line L3 by the first spacing value. The user can determine the depth value D0 of each pixel based on the column coordinate x and the straight line distance Dy, thereby obtaining the reference depth image.

[0149] Optionally, the depth value D0 is equal to the sum of the squares of the following coordinates x and the squares of the straight-line distance Dy, i.e., the depth value.

[0150] In this embodiment of the disclosure, for a height-adjustable projection screen, the laser projection device can also detect the position of the projection screen in real time, thereby achieving matching between the projected image and the projection screen.

[0151] It should be noted that, since the projection lens is located inside the host and the distance between the projection lens and the imaging component is relatively small, the depth value of the pixel in the depth image in this embodiment can also be considered as the distance between the projection point corresponding to the pixel in the projection plane and the projection lens.

[0152] In summary, this disclosure provides a laser projection device. Since the imaging component can image the light signal reflected from the projection plane to obtain an actual depth image, and then send this actual depth image to the control circuit, the control circuit can correct the projection position of the projected image based on the relative position between the target pixel located within the border of the projection screen and the reference pixel located outside the border of the projection screen in the actual depth image. Therefore, there is no need for the user to manually correct the projection position of the projected image, thus improving the efficiency and reliability of the projection position correction.

[0153] Figure 23 This is a flowchart illustrating a method for correcting a projected image according to an embodiment of this disclosure. This correction method can be applied to... Figure 1 , Figure 2 , Figures 12 to 22 In the control circuit 20 of the laser projection device shown. For example... Figure 23 As shown, the method may include:

[0154] Step 2301: Receive the actual depth image sent by the imaging component.

[0155] In this actual depth image, the depth value of each pixel is used to indicate the distance between the projection point corresponding to the pixel in the projection plane 40 and the host 10. The actual depth image is obtained by the imaging component imaging the light signal reflected from the projection plane.

[0156] Step 2302: Correct the projection position of the projected image based on the relative position between the target pixel located within the border of the projection screen and the reference pixel located outside the border of the projection screen in the actual depth image.

[0157] In summary, the embodiments of this disclosure provide a method for correcting a projected image. In this method, the control circuit can correct the projection position of the projected image based on the relative position between a target pixel located within the border of the projection screen and a reference pixel located outside the border of the projection screen in the actual depth image sent by the imaging component. Therefore, manual correction of the projection position of the projected image is unnecessary, thus improving the efficiency and reliability of the projection position correction.

[0158] Figure 24 This is a flowchart illustrating a method for correcting a projected image according to an embodiment of this disclosure. This correction method can be applied to... Figure 1 , Figure 2 , Figures 12 to 22 In the control circuit 20 of the laser projection device shown. For example... Figure 24 As shown, the method may include:

[0159] Step 2401: Receive the actual depth image sent by the imaging component.

[0160] In this actual depth image, the depth value of each pixel is used to indicate the distance between the projection point corresponding to the pixel in the projection plane 40 and the projection lens 50. The actual depth image is obtained by the imaging component imaging the light signal reflected from the projection plane.

[0161] Step 2402: Correct the projection position of the projected image based on the relative position between the target pixel located within the border of the projection screen and the reference pixel located outside the border of the projection screen in the actual depth image.

[0162] Step 2403: Detect whether the absolute value of the depth difference between the depth value of the target pixel in the actual depth image and the depth value of the target pixel in the reference depth image is greater than the depth threshold.

[0163] If the absolute value of the depth difference between the target pixel's depth value in the actual depth image and the target pixel's depth value in the reference depth image is greater than the depth threshold, the control circuit can execute step 2404. If the absolute value of the depth difference between the target pixel's depth value in the actual depth image and the target pixel's depth value in the reference depth image is less than or equal to the depth threshold, the process can end.

[0164] Among them, the reference depth image is the image formed by the light signal emitted by the imaging component on the projection plane when the image is located within the projection screen and the size of the image is the initial size, and the imaging component images the light signal reflected by the projection plane.

[0165] Step 2404: Correct the projection position of the pixel corresponding to the target pixel in the projected image.

[0166] When the absolute value of the depth difference between the depth value of the target pixel in the actual depth image and the depth value of the target pixel in the reference depth image is greater than the depth threshold, the control circuit corrects the projection position of the pixel corresponding to the target pixel in the projection image.

[0167] Optionally, the control circuit can determine the line connecting the projection point corresponding to the target pixel in the reference depth image to the host, the angle between the line and the reference plane, the reference plane being perpendicular to the support surface of the host, the correction distance of the target pixel being determined based on the angle and the depth difference, and the projection position of the pixel corresponding to the target pixel in the projected image being corrected based on the correction distance.

[0168] Step 2405: Detect whether the depth value of the pixel in the actual depth image is within the focal length range of the projection lens.

[0169] The control circuit can also detect whether the depth value of a pixel in the actual depth image is within the focal length range of the projection lens. If the depth value of a pixel in the actual depth image is not within the focal length range of the projection lens, the control circuit can execute step 2406. If the depth value of a pixel in the actual depth image is within the focal length range of the projection lens, the process can end.

[0170] Step 2406: Send an adjustment signal to the motor.

[0171] The laser projection device may also include a motor, which is connected to both the control circuit and the projection lens. If the control circuit detects that the depth value of a pixel in the actual depth image is within the focal length range of the projection lens, it can send an adjustment signal to the motor. The motor can then respond to the adjustment signal by adjusting the distance between the projection lens and the projection plane to ensure that the pixel's depth value is within the focal length range.

[0172] Step 2407: Detect whether there are reference pixels in the actual depth image.

[0173] In this embodiment of the disclosure, if the size of the projection screen is smaller than the projection range of the projection lens, the control circuit can also detect whether a reference pixel exists in the actual depth image. If a reference pixel exists in the actual depth image, the control circuit can execute step 2408. If no reference pixel exists in the actual depth image, the process can end.

[0174] Step 2408: Correct the projected image.

[0175] The control circuit can correct the projected image after detecting that no reference pixel exists in the actual depth image.

[0176] Step 2409: Project the corrected projection image onto the projection screen so that all pixels in the corrected projection image are within the border of the projection screen.

[0177] After correcting the projected image, the control circuit can project the corrected image onto the projection screen so that all pixels in the corrected image are within the border of the projection screen.

[0178] It should be noted that the order of steps in the projection image correction method provided in this application embodiment can be appropriately adjusted, and steps can also be deleted as needed. For example, steps 2405 to 2409 can be deleted as needed. Any variations that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application, and therefore will not be elaborated further.

[0179] In summary, the embodiments of this disclosure provide a method for correcting a projected image. In this method, the control circuit can correct the projection position of the projected image based on the relative position between a target pixel located within the border of the projection screen and a reference pixel located outside the border of the projection screen in the actual depth image sent by the imaging component. Therefore, manual correction of the projection position of the projected image is unnecessary, thus improving the efficiency and reliability of the projection position correction.

[0180] This application provides a laser projection device, including: a memory, a processor, and a computer program stored in the memory. When the processor executes the computer program, it implements the application control method shown in the above embodiment. For example, it can execute the above... Figure 23 Or the correction method for the projected image shown in 24.

[0181] This application provides a computer-readable storage medium storing instructions. When these instructions are loaded and executed by a processor to implement the application control method shown in the above embodiments, for example, the above-described instructions can be executed. Figure 23Or the correction method for the projected image shown in 24.

[0182] This application provides a computer program product containing instructions. When the computer program product is run on a computer, it causes the computer to execute the application control method shown in the above embodiments. For example, it can execute the above... Figure 23 Or the correction method for the projected image shown in 24.

[0183] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the embodiments of this application, the term "at least one" means one or more. In the embodiments of this application, the term "multiple" means two or more.

[0184] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A laser projection device, characterized in that, The laser projection device includes: an imaging component, a main unit, and a control circuit located within the housing of the main unit; The imaging component is connected to the control circuit. The imaging component is used to emit light signals to the projection plane, image the light signals reflected by the projection plane to obtain an actual depth image, and send the actual depth image to the control circuit. The depth value of each pixel in the actual depth image is used to indicate the distance between the projection point corresponding to the pixel in the projection plane and the host. The control circuit is used to correct the projection position of the projection image based on the relative position between the target pixel located within the border of the projection screen and the reference pixel located outside the border of the projection screen in the actual depth image, wherein the orthographic projection of the projection screen on the projection plane is located within the projection plane. The control circuit is also used for: If the absolute value of the depth difference between the depth value of the target pixel in the actual depth image and the depth value of the target pixel in the reference depth image is greater than the depth threshold, determine the angle between the line connecting the projection point corresponding to the target pixel in the reference depth image and the host, and the reference plane, wherein the reference plane is perpendicular to the support surface of the host. The correction distance of the target pixel is determined based on the included angle and the depth difference, and the correction distance is equal to the product of the tangent of the included angle and the absolute value of the depth difference; If the depth difference is greater than 0, the projection point in the projected image corresponding to the target pixel is controlled to move the correction distance away from the top of the projection screen; if the depth difference is less than 0, the projection point in the projected image corresponding to the target pixel is controlled to move the correction distance away from the bottom of the projection screen. The reference depth image is obtained by the imaging component imaging the light signal reflected by the projection plane when the image formed by the light signal emitted by the imaging component is located within the projection screen and the size of the image is the initial size.

2. The laser projection device according to claim 1, characterized in that, The laser projection device further includes: a projection lens located inside the housing of the host; the imaging component is located inside the housing of the host and on the light-incident side of the projection lens; The imaging component is used to transmit the light signal to the projection lens; The projection lens is used to project the light signal onto the projection plane, and to transmit the light signal reflected by the projection plane to the imaging component.

3. The laser projection device according to claim 2, characterized in that, The laser projection device also includes: a reflector; The imaging component is used to transmit the optical signal to the reflector; The reflector is used to reflect the light signal transmitted by the imaging component to the projection lens, and to reflect the light signal transmitted by the projection lens to the imaging component.

4. The laser projection device according to claim 3, characterized in that, The laser projection device further includes: a reflector driving circuit and a light valve, wherein the reflector is located between the light valve and the projection lens; The control circuit is also connected to the mirror drive circuit, and the control circuit is also used to provide a first drive signal to the mirror drive circuit; The mirror driving circuit is also connected to the mirror, and the mirror driving circuit is used to drive the mirror to flip to the target posture in response to the first driving signal. When the reflector is in the target posture, the reflective surface of the reflector is located on the side closer to the imaging component, and the reflector intersects with the transmission direction of the light signal emitted by the imaging component.

5. The laser projection device according to claim 4, characterized in that, The control circuit is also used for: After correcting the projection position of the projected image, a second driving signal is provided to the reflector driving circuit; The mirror driving circuit is used to respond to the second driving signal and drive the mirror to flip to the initial position; When the reflector is in the initial posture, the optical path of the reflector does not intersect with the optical path of the image signal emitted by the optical valve.

6. The laser projection device according to claim 1, characterized in that, The laser projection device further includes: a projection lens located inside the housing of the host; the imaging component located outside the housing of the host, and the optical axis of the imaging component being parallel to the optical axis of the projection lens.

7. The laser projection device according to any one of claims 1 to 6, characterized in that, The imaging component includes: a light signal transmitter and an image sensor; The optical signal transmitter is used to transmit the optical signal; The image sensor is connected to the control circuit. The image sensor is used to receive the light signal reflected by the projection plane, image the light signal reflected by the projection plane to obtain an actual depth image, and send the actual depth image to the control circuit.

8. A method for correcting a projected image, characterized in that, A control circuit is used in a laser projection device, the laser projection device further comprising: a main unit and an imaging component; the control circuit is located within the housing of the main unit, the control circuit is connected to the imaging component, and the method includes: Receive the actual depth image sent by the imaging component; The projection position of the projected image is corrected based on the relative positions of the target pixels located within the border of the projection screen and the reference pixels located outside the border of the projection screen in the actual depth image. If the absolute value of the depth difference between the depth value of the target pixel in the actual depth image and the depth value of the target pixel in the reference depth image is greater than the depth threshold, determine the angle between the line connecting the projection point corresponding to the target pixel in the reference depth image and the host, and the reference plane, wherein the reference plane is perpendicular to the support surface of the host. The correction distance of the target pixel is determined based on the included angle and the depth difference, and the correction distance is equal to the product of the tangent of the included angle and the absolute value of the depth difference; If the depth difference is greater than 0, the projection point in the projected image corresponding to the target pixel is controlled to move the correction distance away from the top of the projection screen; if the depth difference is less than 0, the projection point in the projected image corresponding to the target pixel is controlled to move the correction distance away from the bottom of the projection screen. In this context, the depth value of each pixel in the actual depth image is used to indicate the distance between the projection point corresponding to the pixel on the projection plane and the host. The actual depth image is obtained by the imaging component imaging the light signal reflected from the projection plane. The light signal reflected from the projection plane is the light signal emitted by the imaging component towards the projection plane and reflected by the projection plane. The orthographic projection of the projection screen onto the projection plane is located within the projection plane. The reference depth image is obtained by the imaging component imaging the light signal reflected from the projection plane when the image formed by the light signal emitted by the imaging component on the projection plane is located within the projection screen and the size of the image is the initial size.

Images