WO2022247419A1

WO2022247419A1 - Laser projection device and image correction system

Info

Publication number: WO2022247419A1
Application number: PCT/CN2022/082299
Authority: WO
Inventors: 陈许; 肖纪臣
Original assignee: 青岛海信激光显示股份有限公司
Priority date: 2021-05-25
Filing date: 2022-03-22
Publication date: 2022-12-01
Also published as: CN113271447A; CN113271447B

Abstract

The present application belongs to the field of projection display. Disclosed are a laser projection device and an image correction system. Since an image processing circuit can perform correction processing on a second projection image on the basis of a correction parameter, which is determined by a parameter determination circuit, a display control circuit projects the second projection image, which has been subjected to the correction processing, onto a projection screen. Therefore, the position of the second projection image on the projection screen is corrected, thereby ensuring the display effect of the projected image.

Description

Laser projection equipment and image correction system

Cross References to Related Applications

This application claims the priority of the Chinese patent application with the application number 202110573759.9 and the title of the invention entitled Laser Projection Equipment and Image Correction System filed with the Chinese Patent Office on May 25, 2021, the entire contents of which are incorporated herein by reference.

technical field

The present disclosure relates to the field of projection display, in particular to a laser projection device and an image correction system.

Background technique

Ultra-short-throw laser projection equipment can project and display projected images on a projection screen. For ultra-short-focus laser projection equipment, due to the principle of projection imaging, the light is emitted obliquely upwards, so the position between the laser beam emitted by the optical engine in the ultra-short-focus laser projection equipment and the projection screen must be strictly aligned. A slight shift of the focal laser projection equipment can also cause distortion or distortion of the picture. If the user accidentally moves the ultra-short-focus laser projection device, the projected image projected and displayed by the ultra-short-focus laser projection device may exceed the projection screen, resulting in a poor display effect of the displayed projected image.

Contents of the invention

In one aspect of the present application, a laser projection device is provided. The laser projection device includes: a parameter determination circuit, an image processing circuit, a display control circuit, a light valve, and a projection lens; wherein, the parameter determination circuit is integrated in the laser In the control chip of the main board of the projection device;

The parameter determination circuit is connected to the image processing circuit, and the parameter determination circuit is used to determine a correction parameter based on the captured image, and transmit the correction parameter to the image processing circuit, wherein the captured image is for display Obtained by shooting on a projection screen with the first projected image;

The image processing circuit is connected to the display control circuit, and the image processing circuit is used to perform correction processing on the second projection image to be displayed based on the correction parameters, and transmit the corrected second projection image to the Display control circuit;

The display control circuit is used to generate a light valve control signal based on the corrected second projection image, control the light valve to modulate the light beam irradiated on its surface into an image light beam based on the light valve control signal, and The light valve control signal controls the light valve to project the image beam to the projection lens;

The projection lens is used for projecting the image beam to the projection screen, so as to correct the projection position of the second projection image on the projection screen.

Another aspect of the present application provides an image correction system, the system includes: a mobile terminal, and the laser projection device as described in the above aspect; wherein, the mobile terminal is used to photograph the projection screen to obtain the photographed image , and send the captured image to the parameter determination circuit of the laser projection device.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

FIG. 1 is a schematic structural diagram of a laser projection device provided by an embodiment of the present disclosure;

Fig. 2 is a schematic diagram of a characteristic graph provided by an embodiment of the present disclosure;

Fig. 3 is a schematic diagram of another characteristic graph provided by an embodiment of the present disclosure;

Fig. 4 is a schematic structural diagram of an image correction system provided by an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of another laser projection device provided by an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of another laser projection device provided by an embodiment of the present disclosure;

Fig. 7 is a schematic structural diagram of another image correction system provided by an embodiment of the present disclosure;

FIG. 8 is a schematic structural diagram of another laser projection device provided by an embodiment of the present disclosure.

Detailed ways

In order to make the purpose, technical solution and advantages of the present disclosure clearer, the implementation manners of the present disclosure will be further described in detail below in conjunction with the accompanying drawings.

FIG. 1 is a schematic structural diagram of a laser projection device provided by an embodiment of the present disclosure. As shown in FIG. 1 , the laser projection device 00 may include a parameter determination circuit 101 , an image processing circuit 201 , a display control circuit 202 , a light valve 300 and a projection lens 400 . The parameter determining circuit 101 is integrated in the control chip 102 of the motherboard 10 . In a specific implementation, the control chip 102 may be a system-on-chip (SoC).

The parameter determination circuit 101 is connected to the image processing circuit 201 , and the parameter determination circuit 101 is configured to determine correction parameters based on captured images, and transmit the correction parameters to the image processing circuit 201 .

Wherein, the photographed image is obtained by photographing the projection screen on which the first projection image is displayed, and the photographed image may include a frame of the projection screen and the first projection image. It can be understood that the first projected image is an image used to determine the correction parameters, and therefore may also be referred to as a correction image. The first projection image may include a plurality of feature figures arranged in an array, each feature figure may be a quadrangle or a cross, and the color of each feature figure is different from the background color of the first projection image. Referring to Fig. 2, the first projected image 000 may include 16 characteristic figures 0001 of 4×4, each of the characteristic figures 0001 may be a cross, the color of each of the characteristic figures 0001 may be black, and the first projected image 000 The background color of the can be white.

Alternatively, the first projected image may be a checkerboard image, and the first projected image may include black characteristic patterns and white characteristic patterns arranged in an array. Referring to FIG. 3 , the first projected image 000 may include a total of 576 characteristic figures 0001 of 18×32, and the 576 characteristic figures 0001 include a plurality of black quadrilaterals and a plurality of white quadrilaterals.

The image processing circuit 201 is connected to the display control circuit 202 , and the image processing circuit 201 is used for correcting the second projection image based on the correction parameters, and transmitting the corrected second projection image to the display control circuit 202 . The second projected image is an image for displaying video content.

The display control circuit 202 is used for generating a light valve control signal based on the corrected second projection image, controlling the light valve 300 to modulate the light beam irradiated on its surface into an image light beam based on the light valve control signal, and controlling the light valve 300 based on the light valve control signal. The valve 300 projects the image beam to the projection lens 400 .

The projection lens 400 is used to transmit the image beam to the projection screen, so as to correct the projection position of the corrected second projection image on the projection screen.

After receiving the corrected second projection image transmitted by the image processing circuit 201, the display control circuit 202 may generate a light valve control signal based on the pixel values of the corrected second projection image, and may control the light valve based on the corrected second projection image. The signal controls the light valve 300 . Under the control of the light valve control signal, the light valve 300 modulates the beam irradiated on its surface into an image beam, and transmits the image beam to the projection lens 400 . The projection lens 400 can project the image beam transmitted by the light valve 300 to a projection screen. By correcting the second projection image and projecting the corrected second projection image onto the projection screen, the projection position of the second projection image on the projection screen is corrected.

To sum up, the embodiment of the present disclosure provides a laser projection device. Since the image processing circuit can correct the second projected image based on the correction parameters determined by the parameter determination circuit, the display control circuit can further make the corrected processed image The second projection image is projected onto the projection screen. Therefore, the position of the second projected image on the projection screen is corrected, and the projected image is prevented from exceeding the projection screen, or the projected image displayed on the projection screen is deformed, and the display effect of the projected image is ensured.

Moreover, since the parameter determination circuit is integrated on the control chip of the main board, the internal structure of the laser projection device is effectively simplified, and the integration degree of the laser projection device is improved.

Fig. 4 is a schematic structural diagram of an image correction system provided by an embodiment of the present disclosure. As shown in FIG. 4 , the system may further include a mobile terminal 01 . In the embodiment of the present disclosure, after the laser projection device 00 displays the first projection image on the projection screen, the mobile terminal 01 can capture the projection screen and the first projection image to obtain a captured image, and can send the captured image to The parameter determination circuit 101 in the laser projection apparatus 00 . The parameter determination circuit 101 can determine correction parameters based on the captured image.

In a specific implementation manner of an embodiment of the present disclosure, if the flatness of the projection screen is good, the number of characteristic patterns included in the first projection image (that is, the corrected image) pre-stored in the laser projection device The colors are all the same, and the color of each feature figure is different from the background color of the projected image. If the image projected by the laser projection device onto the projection screen exceeds the projection screen, during the image correction process, the laser projection device projects the first projection image onto the projection screen.

For example, the first projected image may be as shown in FIG. 2 . Correspondingly, the correction parameters may include corrected positions of the multiple vertices in the second projection image in the coordinate system of the first image. If the second projected image is a quadrilateral, the vertices of the second projected image may include an upper left vertex, a lower left vertex, an upper right vertex, and a lower right vertex.

The following describes the process of the parameter determination circuit 101 determining the corrected position of the target vertex in the first image coordinate system in the second projection image, wherein the target vertex can be any vertex of the second projection image:

First, after receiving the captured image sent by the mobile terminal, the parameter determination circuit 101 can determine the target projection of the target feature figure on the projection screen according to the perspective transformation coefficient of the camera in the mobile terminal and the position of the target feature figure in the captured image. Location. The target feature graph can be the feature graph closest to the projection position of the target vertex among the multiple feature graphs. For example, assuming that the target vertex of the second projected image is the upper right vertex, the target feature figure may be the feature figure located at the upper right corner among the multiple feature figures. For example, referring to FIG. 2 , the target feature figure may be the feature figure 0001 in the upper right corner of the first projected image 000 .

Wherein, the perspective transformation coefficient can transform the position of any point in the projection screen into a position in the captured image, that is, the perspective transformation coefficient is the variation coefficient between the screen coordinate system of the projection screen and the second image coordinate system of the captured image . The perspective transformation coefficient is related to the shooting position of the camera, the distance between the camera and the projection screen, and the resolution of the camera.

Afterwards, the parameter determining circuit 101 can determine the actual relative position between the position of the target vertex of the frame of the projection screen and the target projection position, and can determine the initial relative position of the target vertex of the frame and the initial projection position of the target feature figure. Location. Furthermore, the parameter determination circuit 101 can determine the target offset according to the actual relative position and the initial relative position. The target offset is the offset of the target projection position of the target vertex of the first projection image on the projection screen relative to its initial projection position. It can be understood that the target offset may be a vector including an offset direction and an offset value.

Wherein, the initial projection position of the target feature figure is the projection position of the target feature figure on the projection screen when the first projected image does not exceed the projection screen. The target vertex of the frame may be a vertex in the same orientation as the target vertex in the second projected image among the multiple vertices of the frame. The target vertex in the first projection image is a vertex in the same orientation as the target vertex in the second projection image among the multiple vertices in the first projection image. For example, if the target vertex in the second projected image is the upper right vertex of the second target image, then the target vertex of the frame is the upper right vertex of the frame, and the target vertex of the first projected image is the upper right vertex of the first projected image vertex.

Further, the parameter determination circuit 101 can determine the pixel offset of the target vertex of the second projection image in the first image coordinate system from the pre-stored correspondence based on the target offset, so that the pixel The offset and the initial position of the target vertex of the second projected image in the first image coordinate system determine the corrected position of the target vertex of the second projected image in the first image coordinate system.

Wherein, the pixel offset may be a vector including an offset direction and an offset value. The corresponding relationship is the corresponding relationship between the offset in the screen coordinate system and the offset in the first image coordinate system.

Based on the above method, the parameter determining circuit 101 can determine the corrected position of each vertex in the first image coordinate system in the second projected image, and can transmit the corrected positions of multiple vertices in the second projected image to the image processing circuit 201 . The image processing circuit 201 may perform correction processing on the second projection image according to the corrected position of each vertex in the second projection image in the first image coordinate system, so as to obtain a corrected second projection image.

In a specific implementation, for each vertex in the second projected image, the image processing circuit 201 can move the vertex and the pixels between the initial position and the corrected position of the vertex to the corrected position of the vertex, by This enables correction processing of the second projected image.

It can be understood that, in the embodiments of the present disclosure, the target projection position, the initial projection position, and the positions of multiple vertices of the projection screen may all refer to positions in the screen coordinate system of the projection screen. The corrected position and the initial position of the vertex in the second projected image refer to the position in the first image coordinate system of the second projected image. The position of each feature figure in the captured image refers to the position in the second image coordinate system of the captured image.

Wherein, the origin of the screen coordinate system is the center point of the projection screen, the horizontal axis of the screen coordinate system is parallel to the pixel row direction of the projection screen, and the vertical axis of the screen coordinate system is parallel to the pixel column direction of the projection screen. The origin of the first image coordinate system is the center point of the second projected image, the horizontal axis of the first image coordinate system is parallel to the pixel row direction of the second projected image, and the vertical axis of the first image coordinate system is parallel to the The pixel column direction of the second projected image. The origin of the second image coordinate system is the center point of the captured image, the horizontal axis of the second image coordinate system is parallel to the pixel row direction of the captured image, and the vertical axis of the second image coordinate system is parallel to the pixel row direction of the captured image. column direction.

In a specific implementation, the target projection position of the target characteristic figure may include an abscissa and a ordinate, and the initial projection position of the target feature figure may comprise an abscissa and a ordinate. The position of the target vertex of the frame of the projection screen may include abscissa and ordinate. The actual relative position may include: a first absolute value and a second absolute value. The first absolute value is the absolute value of the first difference, the first difference is the difference between the value of the abscissa of the position of the target vertex of the border and the value of the abscissa of the target projection position, and the second absolute value is the second The absolute value of the difference, the second difference is the difference between the value of the ordinate of the position of the target vertex of the frame and the value of the ordinate of the target projection position.

The initial relative position may include: a third absolute value and a fourth absolute value, the third absolute value is the absolute value of the third difference, the third difference is the value of the abscissa of the position of the target vertex of the border and the initial projection The difference between the values of the abscissa of the position. The fourth absolute value is the absolute value of the fourth numerical value, and the fourth numerical value is a numerical difference between the numerical value of the vertical coordinate of the position of the target vertex of the frame and the numerical value of the vertical coordinate of the initial projection position.

The offset value of the above-mentioned target offset may include a first target offset value and a second target offset value, the first target offset value is the absolute value of the difference between the third absolute value and the first absolute value, and the second The target offset value is an absolute value of a difference between the fourth absolute value and the second absolute value. The offset direction of the target offset may include a first direction and a second direction, and the first direction is a direction parallel to the pixel row direction and away from the center point of the screen coordinate system. The second direction is parallel to the pixel column direction and away from the center point of the screen coordinate system. The offset value of the pixel offset may include a first pixel offset value and a second pixel offset value.

Hereinafter, the target vertex of the frame of the projection screen is the upper right vertex as an example for illustration. If the third absolute value is smaller than the first absolute value, the parameter determination circuit 101 can determine the target projection position of the upper right vertex of the first projected image relative to its initial The projection position is offset by the first target offset value along the first direction. If the abscissa of the initial position of the upper right vertex in the second projection image in the first image coordinate system is greater than 0, the parameter determination circuit 101 may determine that the abscissa of the corrected position of the upper right vertex in the second projection image is the second projection The difference between the abscissa of the initial position of the upper right vertex in the image in the first image coordinate system and the first pixel offset value. If the abscissa of the initial position of the upper right vertex in the second projection image in the first image coordinate system is less than 0, the parameter determination circuit 101 may determine that the abscissa of the corrected position of the upper right vertex in the second projection image is the second projection The sum of the abscissa of the initial position of the upper right vertex in the image in the first image coordinate system and the first pixel offset value.

If the third absolute value is greater than the first absolute value, the parameter determination circuit 101 can determine that the target projection position of the upper right vertex of the first projected image is offset by the first target in the direction opposite to the first direction relative to its initial projection position offset value. If the abscissa of the initial position of the upper right vertex in the second projection image in the first image coordinate system is greater than 0, the parameter determination circuit 101 may determine that the abscissa of the corrected position of the upper right vertex in the second projection image is the second projection The sum of the abscissa of the initial position of the upper right vertex in the image in the first image coordinate system and the first pixel offset value. If the abscissa of the initial position of the upper right vertex in the second projection image in the first image coordinate system is less than 0, the parameter determination circuit 101 may determine that the abscissa of the corrected position of the upper right vertex in the second projection image is the second projection The difference between the abscissa of the initial position of the upper right vertex in the image in the first image coordinate system and the first pixel offset value.

If the fourth absolute value is smaller than the second absolute value, the parameter determination circuit 101 may determine that the target projection position of the upper right vertex of the first projection image is offset by the second target offset value in the second direction relative to its initial projection position. The parameter determination circuit 101 can determine the corrected position of the upper right vertex by using the above method.

If the fourth absolute value is greater than the second absolute value, the parameter determination circuit 101 can determine that the target projection position of the upper right vertex of the first projected image is offset by the second target in the direction opposite to the second direction relative to its initial projection position offset value. The parameter determination circuit 101 can determine the corrected position of the upper right vertex by using the above method.

Based on the above method, the parameter determination circuit 101 can determine the correction positions of the upper left vertex, the lower left vertex, the upper right vertex and the lower right vertex of the second projected image in the coordinate system of the first image.

For example, assuming that the initial position of the upper right vertex of the second projected image is greater than the corrected position, the image processing circuit 201 may adjust the upper right vertex of the second projected image and the pixels between the initial position of the upper right vertex and the corrected position. to the corrected position. In this way, the correction processing of the second projected image is realized, that is, the second projected image is reduced, and then the second projected image is displayed within the frame of the projected screen.

In another implementation manner of the embodiment of the present disclosure, if the flatness of the projection screen is poor, the first projection image (ie, the corrected image) pre-stored in the laser projection device is a checkerboard image. If the image projected by the laser projection device to the projection screen is distorted, and/or the image exceeds the projection screen, during the image correction process, the laser projection device may project the first projection image to the projection screen.

For example, the first projected image may be the first projected image 000 shown in FIG. 3 . Each characteristic pattern in the first projection image corresponds to a pixel area of the second projection image, and the pixel area may include a plurality of pixels arranged in an array. Correspondingly, the correction parameters may include corrected positions of the plurality of pixel regions in the second projection image in the first image coordinate system.

Wherein, the characteristic pattern located at row i and column j in the first projected image corresponds to the pixel area at row i and column j in the second projected image, and each characteristic pattern is used to determine the corrected position of a corresponding pixel region. i is a positive integer less than or equal to the number of rows of the characteristic graphics included in the projected image, and j is a positive integer less than or equal to the number of columns of the characteristic graphics included in the projected image.

After the parameter determination circuit 101 receives the captured image sent by the mobile terminal 01, for each characteristic figure, the parameter determination circuit 101 can determine the target projection position of the feature figure on the projection screen, and can Position determines the actual offset of the feature. Furthermore, the parameter determination circuit 101 may determine the pixel offset in the first image coordinate system of the pixel area corresponding to the characteristic pattern in the second projected image according to the actual offset of the characteristic pattern. And the correction position of the pixel area can be determined according to the pixel offset of the pixel area. It can be understood that the pixel offset may be a vector including an offset direction and an offset value. The initial projection position of the characteristic figure is the projection position of the characteristic figure on the projection screen when the first projection image projected onto the projection screen is not deformed.

Based on the above method, the parameter determination circuit 101 can obtain the corrected position of each pixel area in the second projection image. Furthermore, the image processing circuit 201 can correct the pixels in each pixel area in the second projected image to the corrected position of the pixel area in the first image coordinate system to obtain the corrected second projected image, thereby realizing the correction of the second projected image. Second, the correction processing of the projected image ensures that the projected image displayed on the deformed projection screen will not be deformed, thereby ensuring a better display effect of the projected image.

Referring to FIG. 4 , the laser projection device may include a display panel 20, the display panel 20 may include a digital light processing (digital light processing, DLP) chip 203, and the image processing circuit 201 may be integrated in the DLP chip 203.

In an implementation manner of an embodiment of the present disclosure, the parameter determining circuit 101 and the image processing circuit 201 may be connected based on a universal serial bus (universal serial bus, USB) protocol. In a specific implementation, the USB protocol may be a USB2.0 protocol, and the transfer rate of the USB2.0 protocol may reach 60 megabits per second (MB/s). That is, the parameter determination circuit 101 can transmit 60 MB of correction parameters to the image transmission circuit per second.

Since the parameter determination circuit 101 and the image processing circuit 201 can be connected through the USB protocol, the parameter determination circuit 101 can transmit more data to the image processing circuit 201 at one time (for example, the correction of multiple pixel regions in the second projected image can be transmitted. position), which improves the efficiency of transmission of correction parameters, thereby improving the efficiency of correction of projection images.

Referring to FIG. 5 , the laser projection device may further include a USB interface circuit 103 , a switch circuit 104 and a switch control circuit 105 located on the motherboard 10 . In a specific implementation, the USB interface circuit 103 may be a USB hub, and the switch circuit may be a usb switch circuit.

The USB interface circuit 103 is respectively connected to the first end of the parameter determination circuit 101 and the switch circuit 104 , the second end of the switch circuit 104 is connected to the image processing circuit 201 , and the control end of the switch circuit 104 is connected to the switch control circuit 105 .

In a specific implementation, the USB interface circuit 103 is respectively connected to the first end of the parameter determination circuit 101 and the switch circuit 104 based on the USB protocol, and the second end of the switch circuit 104 is connected to the image processing circuit 201 based on the USB protocol.

Wherein, the parameter determination circuit 101 is used to transmit the calibration parameters to the USB interface circuit 103 , and the USB interface circuit 103 is used to transmit the calibration parameters to the switch circuit 104 . The switch circuit 104 is used for controlling the conduction of the first end and the second end in response to the switch signal sent by the switch control circuit 105 , and transmitting the correction parameters to the image processing circuit 201 .

Referring to FIG. 6 , the laser projection device may further include a control circuit 106 located on the main board 10 , and the control circuit 106 is respectively connected to the parameter determination circuit 101 , the switch control circuit 105 and the USB interface circuit 103 . After the parameter determination circuit 101 determines the correction parameter, it can transmit the correction parameter to the control circuit 106 . After receiving the correction parameter, the control circuit 106 can send a switch signal to the switch control circuit 105 . The switch circuit 104 is used to control the conduction of the first terminal and the second terminal in response to the switch signal sent by the switch control circuit 105, so that after the USB interface circuit 103 sends the calibration parameter to the switch circuit 104, the switch circuit 104 can The correction parameters are sent to the image processing circuit 201 .

Referring to FIG. 6 , the laser projection device may further include a connector 107 located on the motherboard 10 , the connector 107 is connected to the second end of the switch circuit 104 and the image processing circuit 201 based on the USB protocol. The switch circuit 104 is used to transmit the correction parameters to the image processing circuit 201 through the connector 107 .

Referring to FIG. 6, the laser projection device may also include a first interface 108 located on the mainboard, one end of the first interface 108 is connected to the third end of the switch circuit 104, and the other end of the first interface 108 is used to connect an external device . The first interface is connected to the switch circuit 104 based on the USB protocol.

The control circuit 106 is further configured to transmit a control signal to the switch control circuit 105 after detecting an instruction to connect the external device to the first interface 108 . The first interface 108 is used to transmit the data transmitted by the external device to the switch circuit 104 . The switch circuit 104 is used to control the conduction of the third terminal and the second terminal in response to the control signal sent by the switch control circuit 105 , so as to transmit the data transmitted by the external device to the image processing device 201 .

In the embodiment of the present disclosure, by adding the switch circuit 104, the parameter determination circuit 101 can transmit correction parameters with a large amount of data to the image processing circuit 201 through the switch circuit 104, thereby improving the efficiency of correction parameter transmission.

In another implementation manner of the embodiment of the present disclosure, the parameter determination circuit 101 and the image processing circuit 201 are connected based on the I2C protocol. Using the I2C protocol, the parameter determination circuit 101 can transmit a small amount of data to the image processing circuit 201 (for example, can transmit the corrected positions of a plurality of vertices in the second projected image).

7 and 8, the laser projection device may further include a main control circuit 204 located on the display panel 20, the main control circuit 204 is respectively connected with the parameter determination circuit 101 and the image processing circuit 201 based on the I2C protocol. The parameter determination circuit 101 is used to transmit the correction parameters to the image processing circuit 201 through the main control circuit 204 . In a specific implementation, the main control circuit 204 may be a micro controller unit (MCU).

The parameter determining circuit 101 can transmit the correction parameter to the main control circuit 204 , and then the main control circuit 204 can transmit the correction parameter to the image processing circuit 201 .

Referring to FIG. 8, the laser projection device may also include a target interface circuit 205 located on the display panel 20, one end of the target interface circuit 205 is connected to the connector 107, and the other end of the target interface circuit 205 is respectively connected to the main control circuit 204 and the main control circuit 204. The image processing circuit 201 is connected. The target interface circuit 205 is used to transmit the data transmitted by the first interface to the main control circuit 204 and the image processing circuit 201 respectively. The target interface circuit 205 may be a USB interface circuit.

The target interface circuit 205 is respectively connected with the connector 107, the main control circuit 204 and the image processing circuit 201 based on the USB protocol.

Referring to FIG. 6 and FIG. 8 , the laser projection device may further include a second interface 109 and a third interface 110 located on the motherboard 10 , one end of the second interface 109 is connected to the USB interface circuit 103 , and the other end is used to connect external devices. The second interface 109 is used to transmit the data transmitted by the external device to the control circuit 106 . One end of the third interface 110 is connected to the USB interface circuit 103 , and the other end is used to connect to an external device. The third interface 110 is used to transmit the data transmitted by the external device to the control circuit 106 .

Referring to FIG. 6 and FIG. 8 , the laser projection device may further include a fourth interface 111 , a fifth interface 112 and a sixth interface 113 located on the main board 10 . One end of the fourth interface 111 is connected to the control circuit 106, and the other end is used to establish a communication connection with an external device, for example, the communication connection may be a WIFI connection. For example, the control circuit 106 can establish a wireless fidelity (wireless fidelity, WIFI) connection with the mobile terminal through the fourth interface 111, and can receive network data sent by the mobile terminal. For example, the network data may be a captured image, and the control circuit 106 may further send the captured image to the parameter determination circuit 101 .

One end of the fifth interface 112 is connected to the control circuit 106, and the fifth interface 112 is used for receiving voice data, and transmitting the received voice data to the control circuit 106.

One end of the sixth interface 113 is connected to the control circuit 106, and the other end of the sixth interface 113 establishes a communication connection with the camera on the projection screen, and can receive video images collected by the camera.

Referring to FIG. 6 and FIG. 8 , the control circuit 106 is also connected to the first memory 114 , and the control circuit 106 is used to receive the stored data transmitted by the first memory 114 . The laser projection device may also include a second memory 115 , which is connected to the display control circuit 202 , and the display control circuit 202 is used for storing pixel values of pixels in the projected image into the second memory 115 .

To sum up, the embodiment of the present disclosure provides a laser projection device. Since the image processing circuit can correct the second projected image based on the correction parameters determined by the parameter determination circuit, the display control circuit can further make the corrected processed image The second projection image is projected onto the projection screen, so as to correct the position of the second projection image on the projection screen, avoiding the projection image beyond the projection screen, or deformation of the projection image displayed on the projection screen, and ensuring the display of the projection image Effect.

Moreover, since the parameter determination circuit is integrated on the control chip of the main board, compared with integrating different functions of the parameter determination circuit (that is, the function of determining the target offset and the function of determining the corrected position) on different chips, simplification The internal structure of the laser projection device.

Referring to FIG. 4 and FIG. 7 , an embodiment of the present disclosure provides an image correction system. The image correction system may include a laser projection device 00 and a mobile terminal 01. The mobile terminal 01 is used to capture a projection screen to obtain a captured image. And send the captured image to the parameter determination circuit 101 of the laser projection device 00 .

In the embodiments of the present disclosure, the terms "first", "second", "third", "fourth", fifth" and "sixth" are used for descriptive purposes only, and should not be understood as indicating or implying relative Importance. The meaning of the term "multiple" in the embodiments of the present disclosure refers to two or more than two. The "and/or" in the embodiments of the present disclosure is only a description of the relationship between associated objects, indicating that there may be three A relationship, for example, A and/or B, can mean: A exists alone, A and B exist simultaneously, and B exists alone.

The above descriptions are only optional embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection of the present disclosure. within range.

Claims

A laser projection device, characterized in that the laser projection device includes: a parameter determination circuit, an image processing circuit, a display control circuit, a light valve, and a projection lens; wherein the parameter determination circuit is integrated in the laser projection device In the control chip of the motherboard;

The parameter determination circuit is connected to the image processing circuit, and the parameter determination circuit is used to determine a correction parameter based on the captured image, and transmit the correction parameter to the image processing circuit, wherein the captured image is for display Obtained by shooting on a projection screen with the first projected image;

The image processing circuit is connected to the display control circuit, and the image processing circuit is used to perform correction processing on the second projection image to be displayed based on the correction parameters, and transmit the corrected second projection image to the Display control circuit;

The display control circuit is used to generate a light valve control signal based on the corrected second projection image, control the light valve to modulate the light beam irradiated on its surface into an image light beam based on the light valve control signal, and The light valve control signal controls the light valve to project the image beam to the projection lens;

The projection lens is used for projecting the image beam to the projection screen, so as to correct the projection position of the second projection image on the projection screen.
The laser projection device according to claim 1, wherein the display panel in the laser projection device includes a digital light processing (DLP) chip, and the image processing circuit is integrated in the DLP chip.
The laser projection device according to claim 1, wherein the parameter determination circuit is connected to the image processing circuit based on a Universal Serial Bus (USB) protocol.
The laser projection device according to claim 3, wherein the laser projection device further comprises: a USB interface circuit, a switch circuit and a switch control circuit located on the main board;

The USB interface circuit is respectively connected to the first end of the parameter determination circuit and the switch circuit, the second end of the switch circuit is connected to the image processing circuit, and the control end of the switch circuit is connected to the switch circuit. control circuit connection;

Wherein, the parameter determination circuit is used to transmit the correction parameter to the USB interface circuit, and the USB interface circuit is used to transmit the correction parameter to the switch circuit, and the switch circuit is used to respond to the The switch signal sent by the switch control circuit controls the conduction of the first terminal and the second terminal, and transmits the correction parameter to the image processing circuit.
The laser projection device according to claim 4, further comprising: a connector located on the main board;

The connector is connected to the second end of the switch circuit and the image processing circuit based on the USB protocol, and the switch circuit is used to transmit the calibration parameters to the image processing circuit through the connector.
The laser projection device according to claim 1, wherein the parameter determination circuit and the image processing circuit are connected based on an I2C protocol.
The laser projection device according to claim 6, characterized in that, the laser projection device further comprises: a main control circuit located on the display panel, the main control circuit communicates with the parameter determination circuit and the image The processing circuit is connected based on the I2C protocol;

The parameter determination circuit is used to transmit the correction parameter to the image processing circuit through the main control circuit.
The laser projection device according to claim 7, wherein the main control circuit is a micro control unit (MCU).
The laser projection device according to any one of claims 1 to 8, wherein the control chip is a system-on-chip (SoC).
An image correction system, characterized in that the system comprises: a mobile terminal, and the laser projection device according to any one of claims 1 to 9;

Wherein, the mobile terminal is used to photograph the projection screen to obtain photographed images, and send the photographed images to the parameter determination circuit of the laser projection device.