CN114466173A - Projection equipment and projection display control method for automatically throwing screen area - Google Patents

Abstract

The utility model relates to a display device technical field, in particular to, relate to a projection equipment and automatic projection display control method who drops into curtain region, can solve to a certain extent and need manual fine setting projection angle after the adjustment of projection equipment position, or the projector is the curtain with the regional mistake recognition of large tracts of land pure colors such as wall, leads to the problem that the broadcast content can not accurate projection to curtain projection area, projection equipment includes: a projection assembly; a controller configured to: obtaining a second image based on the brightness analysis and binarization of the obtained first image gray-scale image; determining a first-level closed contour contained in a second image, wherein the first-level closed contour contains a second-level closed contour; when the secondary closed contour is judged to be a convex quadrangle, projecting the playing content to the secondary closed contour, wherein the secondary closed contour corresponds to a projection area of the curtain; wherein the curtain comprises a curtain edge band corresponding to the primary closed contour, the projected area being surrounded by the curtain edge band.

Description

Projection equipment and projection display control method automatically thrown into screen area

This application claims the priority of the Chinese patent application filed on November 16, 2021 with the application number 202111355866.0 and the invention titled "a projection device and a display control method based on geometric correction", the entire contents of which are by reference Incorporated in this application.

technical field

The present application relates to the technical field of display devices, and in particular, to a projection device and a projection display control method that is automatically put into a screen area.

Background technique

A projector is a device that can project images or videos onto a screen for display. It can be connected to a computer, VCD, DVD, BD, game console, DV, radio and television signal source, video signal source, etc. through different interfaces to play the corresponding video signal.

In some display control implementations that project non-playable content to the projection area of the screen, the Prime Projector will acquire the image of the screen area; then the acquired image will be binarized, so that the outline of the object in the image can be displayed more clearly ; Finally, based on the binarized image, the projector extracts all the closed contours contained in it, and identifies the closed contour with the largest area and the same internal color as the screen projection area.

However, when there is a large area of solid-color walls around the screen to be projected, and the edges of the walls form a closed contour, the projector will recognize the wall as a screen, causing the content to be projected to the wall but not to the specified screen.

SUMMARY OF THE INVENTION

In order to solve the problem that the projection angle needs to be manually fine-tuned after the position of the projection device is adjusted, or the projector mistakenly recognizes a large area of solid color such as a wall as a screen, resulting in that the playback content cannot be accurately projected to the screen projection area, the present application provides a projection device and a screen. A projection display control method that automatically enters the screen area.

The embodiments of the present application are implemented as follows:

A first aspect of the embodiments of the present application provides a projection device, including: a projection component for projecting playback content to a screen corresponding to the projection device; a controller configured to: based on a first image grayscale obtained by a camera Image brightness analysis, binarize the first image to obtain a second image; determine the first-level closed contour included in the second image, and the first-level closed contour contains a second-level closed contour; after determining the second-level closed contour When the contour is a convex quadrilateral, the projection component is controlled to project the playback content to the secondary closed contour, and the secondary closed contour corresponds to the projection area of the screen; A closed-profile curtain edge band, the projection area being surrounded by the curtain edge band.

A second aspect of the embodiments of the present application provides a projection display control method that is automatically thrown into a screen area, the method includes: based on the obtained first image grayscale image brightness analysis, binarizing the first image to obtain a second image, The first image is an environment image; determine the first-level closed contour included in the second image, and the first-level closed contour contains a second-level closed contour; when determining that the second-level closed contour is a convex quadrilateral, the The playback content is projected to the secondary closed contour, and the secondary closed contour corresponds to the projection area of the screen; wherein, the screen includes a screen edge band corresponding to the first closed contour, and the projection area is The curtain edge band surrounds.

The beneficial effects of the present application: by creating the first image, it is possible to obtain the image of the environment where the projector corresponds to the screen; and further by creating the grayscale map of the first image, the accuracy of the projector's recognition of the closed contour corresponding to the environmental elements can be improved ; Further by constructing the first-level and second-level closed contours, the screening range of the candidate area of the screen projection area can be narrowed; further, by determining that the second-level closed contour is a convex quadrilateral, the screen projection area included in the candidate area can be identified, and the identification of the screen projection area can be improved. The accuracy rate is high, avoiding the user's manual fine-tuning of the projection angle, and realizing that the playback content of the projector used with the screen can be automatically projected to the screen projection area after moving.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1A shows a schematic diagram of the placement of a projection device according to an embodiment of the present application;

FIG. 1B shows a schematic diagram of an optical path of a projection device according to an embodiment of the present application;

FIG. 2 shows a schematic diagram of a circuit structure of a projection device according to an embodiment of the present application;

FIG. 3 shows a schematic structural diagram of a projection device according to an embodiment of the present application;

FIG. 4 shows a schematic structural diagram of a projection device according to another embodiment of the present application;

FIG. 5 shows a schematic diagram of a circuit structure of a projection device according to an embodiment of the present application;

6A shows a schematic diagram of a screen corresponding to a projector according to an embodiment of the present application;

FIG. 6B shows a schematic diagram of a first image of an environment where a projector is located according to another embodiment of the present application;

FIG. 6C shows a schematic diagram of a first image and its corresponding grayscale image according to another embodiment of the present application;

FIG. 6D shows a schematic diagram of a second image after binarization of the image of the environment where the projector is located according to an embodiment of the present application;

FIG. 6E shows a binarization schematic diagram of a closed contour corresponding to a curtain according to an embodiment of the present application;

FIG. 6F shows a schematic diagram of identifying a large area of solid-color wall as a projection area of a screen by a projector according to an embodiment of the present application;

FIG. 7A shows a schematic diagram of a system framework for implementing display control by a projection device according to an embodiment of the present application;

FIG. 7B shows a schematic diagram of a signaling interaction sequence of a projection device implementing a radiation eye function according to another embodiment of the present application;

7C shows a schematic diagram of a signaling interaction sequence of a projection device implementing a display picture correction function according to another embodiment of the present application;

FIG. 7D shows a schematic flowchart of a projection device implementing an autofocus algorithm according to another embodiment of the present application;

7E shows a schematic flowchart of a projection device implementing trapezoidal correction and obstacle avoidance algorithms according to another embodiment of the present application;

7F shows a schematic flowchart of a projection device implementing a screen entry algorithm according to another embodiment of the present application;

FIG. 7G shows a schematic flowchart of a projection device implementing an anti-shooting eye algorithm according to another embodiment of the present application.

Detailed ways

In order to make the purpose and implementation of the present application clearer, the exemplary embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only the Some embodiments are claimed, but not all embodiments.

It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described next, rather than intending to limit the embodiments of the application. Unless otherwise specified, these terms are to be understood according to their ordinary and ordinary meanings.

The terms "first", "second", "third", etc. in the description and claims of this application and the above drawings are used to distinguish similar or homogeneous objects or entities, and are not necessarily meant to limit a particular Sequential or sequential, unless otherwise noted. It is to be understood that the terms so used are interchangeable under appropriate circumstances.

The terms "comprising" and "having" and any variations thereof, are intended to cover but not exclusively include, for example, a product or device comprising a series of components is not necessarily limited to all components explicitly listed, but may include no explicit other components listed or inherent to these products or devices.

The term "module" refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic or combination of hardware or/and software code capable of performing the function associated with that element.

FIG. 1A shows a schematic diagram of the placement of a projection device according to an embodiment of the present application.

In some embodiments, a projection device provided by the present application includes a projection screen 1 and a projection device 2 . The projection screen 1 is fixed at the first position, and the projection device 2 is placed at the second position, so that the projected picture is consistent with the projection screen 1. This step is operated by professional after-sales technicians, that is, the second position is the projection device 2. the best placement.

FIG. 1B shows a schematic diagram of an optical path of a projection device according to an embodiment of the present application.

The light-emitting component of the projection device can be implemented as a light source such as a laser or an LED. The following will take a laser type projection device as an example to describe the projection device provided by the present application and the projection display control scheme automatically thrown into the screen area.

In some embodiments, the projection apparatus may include a laser light source 100 , an optomechanical 200 , a lens 300 , and a projection medium 400 . The laser light source 100 provides illumination for the optomechanical 200 , and the optomechanical 200 modulates the light source beam, outputs it to the lens 300 for imaging, and projects it onto the projection medium 400 to form a projection image.

In some embodiments, the laser light source of the projection device includes a projection component and an optical lens component, and the projection component is specifically implemented as a laser component in the laser-type projection device provided by the present application, which will not be described in detail below;

The light beam emitted by the laser assembly can pass through the optical lens assembly to provide illumination for the optical machine. Among them, for example, the optical lens assembly requires a higher level of environmental cleanliness and airtightness sealing; while the cavity where the laser assembly is installed can be sealed with a lower sealing level of dustproof level to reduce the sealing cost.

In some embodiments, the optical mechanism 200 of the projection apparatus may be implemented to include a blue optical mechanism, a green optical mechanism, a red optical mechanism, and may also include a heat dissipation system, a circuit control system, and the like. It should be noted that, in some embodiments, the light-emitting component of the projector may also be implemented by an LED light source.

In some embodiments, the present application provides a projection device, including a three-color optical engine and a controller; wherein, the three-color optical engine is used to modulate a laser for generating a user interface including pixel points, including a blue optical engine, a green optical engine, and a red optical engine Optical machine; the controller is configured to: obtain the average gray value of the user interface; when it is determined that the average gray value is greater than the first threshold and its duration is greater than the time threshold, control the working current value of the red optical engine according to The preset gradient value is reduced to reduce the heat generation of the three-color optical engine. It can be found that by reducing the working current of the red optical engine integrated in the three-color optical engine, the overheating of the red optical engine can be controlled, so as to control the overheating of the three-color optical engine and the projection equipment.

The optomechanical 200 may be implemented as a trichromatic optomechanical that integrates a blue optomechanical, a green optomechanical, and a red optomechanical.

Hereinafter, the technical solution provided by the present application will be described by taking the implementation of the optical machine 200 of the projection apparatus as including a blue light machine, a green light machine, and a red light machine as an example.

In some embodiments, the optical system of the projection device is composed of a light source part and an opto-mechanical part. The function of the light source part is to provide illumination for the opto-mechanical part, and the function of the opto-mechanical part is to modulate the illumination beam provided by the light source. projection screen.

In some embodiments, the light source part specifically includes a housing, a laser assembly, and an optical lens assembly, and the light beam emitted by the laser assembly is shaped and combined by the optical lens assembly, thereby providing illumination for the optical machine. Among them, laser components include light-emitting chips, collimating lenses, wires and other devices, but they are usually packaged components. When used as components, compared with optical lenses, they are also used as precision components. The cleanliness of the optical lens to the environment The requirements will be higher, because if the surface of the lens is dusty, on the one hand, it will affect the processing effect of the lens on light, resulting in the attenuation of the outgoing light, which will ultimately affect the effect of the projection equipment projected through the lens. On the other hand, the dust will absorb high-energy The laser beam generates heat, which can easily damage the lens.

In some embodiments, the optical lens assembly includes at least a convex lens, wherein the convex lens is an integral part of the telescope system, and the telescope system is usually composed of a convex lens and a concave lens, and is used for condensing the laser beam of a larger area to form a smaller area of the laser beam. laser beam. Convex lenses are usually larger in surface shape, and are usually set close to the laser light exit. They can receive large-area laser beams, and are also convenient for beam transmission as large windows to reduce light loss.

The optical lens assembly may also include a concave lens, a combining lens, a homogenizing component, or a dissipating spot component, etc., which are used to reshape and combine the laser beam to meet the requirements of the lighting system.

In some embodiments, the laser components include a red laser module, a green laser module, and a blue laser module, and each laser module and the corresponding installation port are protected from dust by a sealing ring (fluorine rubber or other sealing materials can be used) Sealed installation.

FIG. 2 shows a schematic diagram of a circuit structure of a projection device according to an embodiment of the present application.

In some embodiments, the projection device provided by the present disclosure includes multiple sets of lasers. By arranging a brightness sensor in the light exit path of the laser light source, the brightness sensor can detect the first brightness value of the laser light source, and send the first brightness value to the Display control circuit.

The display control circuit can acquire the second brightness value corresponding to the driving current of each laser, and when it is determined that the difference between the second brightness value of the laser and the first brightness value of the laser is greater than a difference threshold, determine that the laser COD failure; then the display control circuit can adjust the current control signal of the corresponding laser driving component of the laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the blue laser; the projection device can eliminate the laser's failure in time. COD failure reduces the damage rate of the laser and ensures the image display effect of the projection equipment.

In some embodiments, the projection apparatus may include a display control circuit 10 , a laser light source 20 , at least one laser driving component 30 and at least one brightness sensor 40 , and the laser light source 20 may include a one-to-one correspondence with the at least one laser driving component 30 at least one laser. Wherein, the at least one refers to one or more, and the multiple refers to two or more.

In some embodiments, the projection device includes a laser driving component 30 and a brightness sensor 40. Correspondingly, the laser light source 20 includes three lasers corresponding to the laser driving components 30 one-to-one, and the three lasers may be blue lasers respectively. 201 , a red laser 202 and a green laser 203 . The blue laser 201 is used for emitting blue laser light, the red laser 202 is used for emitting red laser light, and the green laser 203 is used for emitting green laser light. In some embodiments, the laser driving assembly 30 may be implemented to include a plurality of sub-laser driving assemblies, which correspond to lasers of different colors respectively.

The display control circuit 10 is used to output the primary color enable signal and the primary color current control signal to the laser driving component 30 to drive the laser to emit light. Specifically, as shown in FIG. 2 , the display control circuit 10 is connected to the laser driving component 30 for outputting At least one enable signal corresponding to the three primary colors of each frame of images in the multi-frame display images, respectively transmitting the at least one enable signal to the corresponding laser driving component 30, and outputting a signal corresponding to each frame of image. The three primary colors correspond to at least one current control signal, and the at least one current control signal is respectively transmitted to the corresponding laser driving component 30 . Exemplarily, the display control circuit 10 may be a microcontroller unit (MCU), also known as a single-chip microcomputer. Wherein, the current control signal may be a pulse width modulation (pulse width modulation, PWM) signal.

In some embodiments, the display control circuit 10 can output the blue PWM signal B_PWM corresponding to the blue laser 201 based on the blue primary color component of the image to be displayed, and output the blue PWM signal B_PWM corresponding to the red laser 202 based on the red primary color component of the to-be-displayed image The red PWM signal R_PWM outputs the green PWM signal G_PWM corresponding to the green laser 203 based on the green primary color component of the image to be displayed. The display control circuit can output the enable signal B_EN corresponding to the blue laser 201 based on the lighting duration of the blue laser 201 in the driving cycle, and output the enable signal B_EN corresponding to the red laser 202 based on the lighting duration of the red laser 202 in the driving cycle. Based on the enable signal R_EN of the green laser 203 in the driving period, the enable signal G_EN corresponding to the green laser 203 is output.

The laser driving component 30 is connected with the corresponding laser, for responding to the received enable signal and the current control signal, to provide the corresponding driving current to the laser to which it is connected, and each laser is used for the driving current provided in the laser driving component 30 driven by the light.

In some embodiments, blue laser 201, red laser 202, and green laser 203 are connected to laser driver assembly 30, respectively. The laser driving component 30 can provide corresponding driving current to the blue laser 201 in response to the blue PWM signal B_PWM and the enable signal B_EN sent by the display control circuit 10 . The blue laser 201 is used to emit light under the driving of the driving current.

The brightness sensor is arranged in the light output path of the laser light source, usually on one side of the light output path, without blocking the light path. As shown in FIG. 2 , at least one brightness sensor 40 is disposed in the light output path of the laser light source 20, and each brightness sensor is connected to the display control circuit 10 for detecting the first brightness value of a laser, and converting the first brightness value to the first brightness value. sent to the display control circuit 10 .

In some embodiments, the display control circuit 10 is further configured to obtain a second brightness value corresponding to the driving current of each laser, if the difference between the second brightness value of the laser and the first brightness value of the laser is detected to be greater than The difference threshold indicates that the laser has a COD failure, and the display control circuit 10 can adjust the current control signal of the laser drive assembly 30 until the difference is less than or equal to the difference threshold, that is, the COD of the laser is eliminated by reducing the driving current of the laser. Fault. Specifically, both the first brightness value and the second brightness value are represented as light output power values, wherein the second brightness value may be stored in advance, or may be the brightness value returned by the brightness sensor in a normal lighting state. If a COD failure occurs in the laser, usually due to a sudden drop in its optical output power, the first brightness value returned by the brightness sensor will be less than half of the normal second brightness value. When it is confirmed that the above fault occurs, the display control circuit will reduce the current control signal of the laser driving component corresponding to the laser, and continuously collect and compare the brightness signal returned by the brightness sensor.

In some embodiments, if the detected difference between the second brightness value of the laser and the first brightness value of the laser is less than or equal to the difference threshold, indicating that the laser has no COD failure, the display control circuit 10 does not need to adjust the The current control signal of the laser driving component 30 corresponding to the laser.

Wherein, the display control circuit 10 may store the corresponding relationship between the current and the luminance value. The brightness value corresponding to each current in the corresponding relationship is the initial brightness value that the laser can emit when the laser works normally under the driving of the current (that is, when the COD failure does not occur). For example, the brightness value can be the initial brightness of the laser when it is first turned on when it is driven by the current.

In some embodiments, the display control circuit 10 may obtain the second brightness value corresponding to the driving current of each laser from the corresponding relationship, where the driving current is the current actual operating current of the laser, and the second brightness value corresponding to the driving current It is the brightness value that the laser can emit when it works normally under the driving current. The difference threshold may be a fixed value pre-stored in the display control circuit 10.

In some embodiments, when the display control circuit 10 adjusts the current control signal of the laser driving component 30 corresponding to the laser, it can reduce the duty cycle of the current control signal of the laser driving component 30 corresponding to the laser, thereby reducing the driving of the laser current.

In some embodiments, brightness sensor 40 may detect a first brightness value of blue laser 201 and send the first brightness value to display control circuit 10. The display control circuit 10 can acquire the driving current of the blue laser 201, and acquire the second brightness value corresponding to the driving current from the corresponding relationship between the current and the brightness value. Afterwards, it is detected whether the difference between the second brightness value and the first brightness value is greater than the difference threshold. If the difference is greater than the difference threshold, it indicates that the blue laser 201 has a COD failure, and the display control circuit 10 can reduce the difference with the threshold. The current control signal of the laser driving component 30 corresponding to the blue laser 201 . Afterwards, the display control circuit 10 can obtain the first brightness value of the blue laser 201 and the second brightness value corresponding to the driving current of the blue laser 201 again, and the difference between the second brightness value and the first brightness value is greater than When the difference threshold is reached, the current control signal of the laser driving component 30 corresponding to the blue laser 201 is reduced again. This cycle is repeated until the difference is less than or equal to the difference threshold. Thus, by reducing the driving current of the blue laser 201, the COD failure of the blue laser 201 is eliminated.

In some embodiments, the display control circuit 10 may monitor, in real time, whether each laser occurs according to the first brightness value of each laser acquired by at least one brightness sensor 40 and the second brightness value corresponding to the driving current of each laser COD failure. When it is determined that any laser has a COD failure, the COD failure of the laser can be eliminated in time to reduce the duration of the COD failure of the laser, reduce the damage of the laser, and ensure the image display effect of the projection equipment.

FIG. 3 shows a schematic structural diagram of a projection device according to an embodiment of the present application.

In some embodiments, the laser light source 20 in the projection device may include a blue laser 201 , a red laser 202 and a green laser 203 which are independently arranged. The projection device may also be referred to as a three-color projection device, the blue laser 201 , the red laser 201 Both the laser 202 and the green laser 203 are MCL-type packaged lasers, which are small in size and facilitate compact arrangement of optical paths.

In some embodiments, referring to FIG. 3 , the at least one brightness sensor 40 may include a first brightness sensor 401 , a second brightness sensor 402 and a third brightness sensor 403 , wherein the first brightness sensor 401 is a blue brightness sensor or a white brightness sensor The second brightness sensor 402 is a red light brightness sensor or a white light brightness sensor, and the third brightness sensor 403 is a green light brightness sensor or a white light brightness sensor.

Wherein, the first brightness sensor 401 is arranged in the light exit path of the blue laser 201, specifically, it can be arranged on the side of the light exit path of the collimated beam of the blue laser 201. Similarly, the second brightness sensor 402 is arranged in the red In the light output path of the laser 202, it is specifically arranged on the side of the light output path of the collimated beam of the red laser 201, and the third brightness sensor 403 is arranged in the light output path of the green laser 203, specifically, is arranged on the collimated beam of the green laser 203. side of the light exit path. Since the laser light emitted by the laser has no attenuation in its light output path, the brightness sensor is arranged in the light output path of the laser, which improves the detection accuracy of the first brightness value of the laser by the brightness sensor.

The display control circuit 10 is also configured to read the brightness value detected by the first brightness sensor 401 when controlling the blue laser 201 to emit blue laser light. And when the blue laser 201 is controlled to be turned off, the reading of the brightness value detected by the first brightness sensor 401 is stopped.

The display control circuit 10 is further configured to read the brightness value detected by the second brightness sensor 402 when controlling the red laser 202 to emit red laser light, and stop reading the brightness value detected by the second brightness sensor 402 when the red laser 202 is turned off. Brightness value.

The display control circuit 10 is further configured to read the brightness value detected by the third brightness sensor 403 when controlling the green laser 203 to emit green laser light, and stop reading the brightness value detected by the third brightness sensor 403 when the green laser 203 is turned off brightness value.

It should be noted that there may also be one brightness sensor, which is arranged in the light combining path of the three-color laser.

FIG. 4 shows a schematic structural diagram of a projection device according to another embodiment of the present application.

In some embodiments, the projection apparatus may further include a light guide 110, which serves as a light-collecting optical component for receiving and homogenizing the three-color laser light in a combined light state.

In some embodiments, the brightness sensor 40 may include a fourth brightness sensor 404, which may be a white light brightness sensor. The fourth brightness sensor 404 is disposed in the light exit path of the light pipe 110, for example, disposed on the light exit side of the light pipe, close to its light exit surface. And, the above-mentioned fourth brightness sensor is a white light brightness sensor.

The display control circuit 10 is also configured to read the brightness value detected by the fourth brightness sensor 404 when the blue laser 201, the red laser 202 and the green laser 203 are controlled to be turned on at different times, so as to ensure that the fourth brightness sensor 404 can detect to the first brightness value of the blue laser 201 , the first brightness value of the red laser 202 and the first brightness value of the green laser 203 . And when the blue laser 201, the red laser 202 and the green laser 203 are all turned off, the reading of the brightness value detected by the fourth brightness sensor 404 is stopped.

In some embodiments, the fourth brightness sensor 404 is always on during the process of projecting the image by the projection device.

In some embodiments, referring to FIGS. 3 and 4 , the projection apparatus may further include a fourth dichroic plate 604 , a fifth dichroic plate 605 , a fifth mirror 904 , a second lens assembly 90 , and a diffusion wheel 150 , TIR lens 120 , DMD 130 and projection lens 140 . Wherein, the second lens assembly 90 includes a first lens 901 , a second lens 902 and a third lens 903 . The fourth dichroic plate 604 can transmit blue laser light and reflect green laser light. The fifth dichroic plate 605 can transmit red laser light and reflect green laser light and blue laser light.

The blue laser light emitted by the blue laser 201 passes through the fourth dichroic plate 604, and then is reflected by the fifth dichroic plate 605 and enters the first lens 901 for condensing. The red laser light emitted by the red laser 202 passes through the fifth dichroic plate 605 and directly enters the first lens 901 for condensing. The green laser light emitted by the green laser 203 is reflected by the fifth reflecting mirror 904, and then reflected by the fourth dichroic plate 604 and the fifth dichroic plate 605 in turn, and then enters the first lens 901 for condensing. The blue laser, red laser and green laser condensed by the first lens 901 pass through the rotating diffusing wheel 150 to dissipate the speckle in time division, and are projected to the light pipe 110 for uniform light, and then pass through the second lens 902 and the third lens After being shaped by 903, it enters the TIR lens 120 for total reflection, is reflected by the DMD 130 and then passes through the TIR lens 120, and finally is projected onto the display screen through the projection lens 140 to form the image to be displayed.

FIG. 5 shows a schematic diagram of a circuit structure of a projection device according to an embodiment of the present application.

In some embodiments, the laser driving assembly 30 may include a driving circuit 301, a switching circuit 302, and an amplifying circuit 303. The driving circuit 301 may be a driving chip. The switch circuit 302 can be a metal-oxide-semiconductor (MOS) transistor.

The drive circuit 301 is connected to the switch circuit 302, the amplifier circuit 303 and the corresponding lasers included in the laser light source 20, respectively. The drive circuit 301 is used to output the drive current to the corresponding laser in the laser light source 20 through the VOUT terminal based on the current control signal sent by the display control circuit 10, and transmit the received enable signal to the switch circuit 302 through the ENOUT terminal. Wherein, the laser may include n sub-lasers connected in series, which are sub-lasers LD1 to LDn respectively. n is a positive integer greater than 0.

The switch circuit 302 is connected in series in the current path of the laser, and is used to control the conduction of the current path when the received enable signal is an effective potential.

The amplifying circuit 303 is respectively connected to the detection node E in the current path of the laser light source 20 and the display control circuit 10, and is used to convert the detected driving current of the laser assembly 201 into a driving voltage, amplify the driving voltage, and convert the amplified The driving voltage is transmitted to the display control circuit 10 .

The display control circuit 10 is further configured to determine the amplified driving voltage as the driving current of the laser, and obtain the second luminance value corresponding to the driving current.

In some embodiments, the amplifying circuit 303 may include: a first operational amplifier A1, a first resistor (also known as a sampling power resistor) R1, a second resistor R2, a third resistor R3 and a fourth resistor R4.

The non-inverting input terminal (also known as the positive terminal) of the first operational amplifier A1 is connected to one end of the second resistor R2, and the inverting input terminal (also known as the negative terminal) of the first operational amplifier A1 is respectively connected to one end of the third resistor R3 and the first terminal. One end of the four resistors R4 is connected, and the output end of the first operational amplifier A1 is connected to the other end of the fourth resistor R4 and the processing sub-circuit 3022 respectively. One end of the first resistor R1 is connected to the detection node E, and the other end of the first resistor R1 is connected to the reference power terminal. The other end of the second resistor R2 is connected to the detection node E, and the other end of the third resistor R3 is connected to the reference power terminal. The reference power terminal is the ground terminal.

In some embodiments, the first operational amplifier A1 may further include two power terminals, one of which is connected to the power terminal VCC, and the other power terminal may be connected to the reference power terminal.

The large driving current of the laser included in the laser light source 20 generates a voltage drop after passing through the first resistor R1, and the voltage Vi at one end of the first resistor R1 (ie, the detection node E) is transmitted to the first operational amplifier A1 through the second resistor R2 The non-inverting input terminal of , is amplified N times by the first operational amplifier A1 and then output. The N is the amplification factor of the first operational amplifier A1, and N is a positive number. The amplification factor N can make the value of the voltage Vfb output by the first operational amplifier A1 to be an integer multiple of the value of the driving current of the laser. For example, the value of the voltage Vfb may be equal to the value of the driving current, so that the display control circuit 10 can determine the amplified driving voltage as the driving current of the laser.

In some embodiments, the display control circuit 10, the driving circuit 301, the switching circuit 302 and the amplifying circuit 303 form a closed loop to realize feedback adjustment of the driving current of the laser, so that the display control circuit 10 can pass the second The difference between the brightness value and the first brightness value can adjust the driving current of the laser in time, that is, adjust the actual luminous brightness of the laser in time, avoid COD failure of the laser for a long time, and improve the accuracy of laser emitting control.

It should be noted that, referring to FIG. 3 and FIG. 4 , if the laser light source 20 includes a blue laser 201 , a red laser 202 and a green laser 203 . The blue laser 201 may be positioned at the L1 position, the red laser 202 may be positioned at the L2 position, and the green laser 203 may be positioned at the L3 position.

Referring to FIG. 3 and FIG. 4 , the laser light at the L1 position is transmitted through the fourth dichroic plate 604 once, and then reflected once through the fifth dichroic plate 605 before entering the first lens 901. The light efficiency at the L1 position is P1=Pt×Pf. Among them, Pt represents the transmittance of the dichroic plate, and Pf represents the reflectivity of the dichroic plate or the fifth reflectance 904.

In some embodiments, among the three positions of L1, L2 and L3, the light efficiency of the laser light at the L3 position is the highest, and the light efficiency of the laser light at the L1 position is the lowest. Since the maximum optical power output by the blue laser 201 is Pb=4.5 watts (W), the maximum optical power output by the red laser 202 is Pr=2.5W, and the maximum optical power output by the green laser 203 is Pg=1.5W. That is, the maximum optical power output by the blue laser 201 is the largest, the maximum optical power output by the red laser 202 is second, and the maximum optical power output by the green laser 203 is the smallest. Thus the green laser 203 is placed at the L3 position, the red laser 202 is placed at the L2 position, and the blue laser 201 is placed at the L1 position. That is, the green laser 203 is arranged in the light path with the highest light efficiency, so as to ensure that the projection device can obtain the highest light efficiency.

In some embodiments, the display control circuit 10 is further configured to restore the current control signal of the laser driving component corresponding to the laser when the difference between the second luminance value of the laser and the first luminance value of the laser is less than or equal to the difference threshold To the initial value, the initial value is the size of the PWM current control signal to the laser in a normal state. Therefore, when a COD failure occurs in the laser, it can be quickly identified, and measures to reduce the driving current can be taken in time to reduce the continuous damage of the laser itself and help its self-recovery. The whole process does not require disassembly and human interference, which improves the laser light source. The reliability of use ensures the projection display quality of the laser projection equipment.

The embodiments of the present application can be applied to various types of projection devices. The following will take a projector as an example to describe a projection device and a projection display control method that is automatically thrown into the screen area.

The projector is a device that can project images or videos onto the screen. The projector can communicate with computers, radio and television networks, the Internet, video compact discs (VCD: Video Compact Disc), digital video discs (DVD: Digital Versatile Disc Recordable), game console, DV, etc. to play the corresponding video signal. Projectors are widely used in homes, offices, schools, and entertainment venues.

FIG. 6A shows a schematic diagram of a screen corresponding to a projector according to an embodiment of the present application.

In some embodiments, the projection screen is used in movies, offices, home theaters, large-scale conferences and other occasions, and the tools used to display images and video files can be set to different sizes according to actual needs; in some embodiments In order to make the display effect more in line with the user's viewing habits, the aspect ratio of the projector corresponding to the screen is usually set to 16:9, and the laser component can project the playback content to the screen corresponding to the projector, as shown in Figure 6A.

Most screens look white, but in fact, different curtain materials have different reflection characteristics for light, and the reflectivity of different colors of light is also different. Common curtains include diffuse reflection screens and retrograde screens;

The white plastic screen is a typical diffuse scattering screen. The diffuse scattering screen scatters the incident light of the projector evenly in all directions, and the same image can be seen at every angle; the diffuse reflection screen has an ultra-wide audio-visual range and softness. However, pay attention to the influence of external light and cluttered light; in an environment with external light and cluttered light, the external light, cluttered light and the imaged light are scattered, reflected, and overlapped with the imaged light, resulting in low image quality; A typical diffuse screen maximizes its performance when used in a dedicated screening room with no external light, cluttered light.

It should be noted that the wall also has the characteristics of diffuse scattering, but due to the lack of color correction and no light absorption, the image displayed when used as a screen will have color misalignment, chromatic dispersion, vignetting in dark parts, brightness and contrast. Not enough and so on; so the wall as a screen is not a good choice.

The glass bead screen is a typical retrograde screen. Since the glass beads on the screen will reflect the light back with the incident direction of the projected light as the center, bright and vivid images can be seen in the usual viewing and listening position; Due to the diffuse scattering of the screen, the brightness of the image seen near the front of the screen and the image seen at a larger angle will be different; near the front of the screen, you can see images with good brightness, contrast, and layers; In an environment with external light and cluttered light, since the screen reflects the external light and the cluttered light back along the incident direction, the projector's image light and external light, the cluttered light rarely overlap, so that bright colors can be obtained. image.

It is understandable that a screen with a wide viewing angle and low gain should be selected when there are a large number of users or when viewing horizontally; a screen with a narrow viewing angle and high gain should be selected for viewing in a narrow and long space; selecting a screen with appropriate gain will help improve the screen's performance. Contrast, increase the grayscale of the image, brighten the color, and increase the observability of the image; diffuse reflection and retrograde screens can be used in places with good shading and light absorption, and retrograde screens can be selected in the family living room; projector desktop placement can be selected Any screen, and the projector can be mounted on a ceiling with diffuse reflection or a screen with a larger half-value angle.

In some embodiments, the surrounding edges of the screen corresponding to the projector have dark edge lines. Because the edge lines usually have a certain width, the dark edge lines may also be called edge strips. The projection device, And the projection display control method of automatically entering the screen area will use the edge band characteristics of the screen to accurately identify the screen in the environment stably and efficiently, and realize the rapid automatic screen entry after the projector position moves. The screen is shown in Figure 6A.

In some embodiments, the projector provided by the present application is configured with a camera. After the user moves the projector, the controller will control the camera to photograph the environment where the projection device is located so that the laser component can accurately project the playback content to the projection area of the screen again. In order to obtain the first image, through the analysis and processing of the first image, the location of the screen projection area can be determined, that is, the controller controls the projector camera to obtain the first image of the projection device corresponding to the screen area, which can reduce the calculation of the subsequent algorithm to identify the screen. quantity.

The first image will contain a variety of environmental objects, such as curtains, TV cabinets, walls, ceilings, coffee tables, etc. It should be found that the corresponding curtain of the projector provided by the present application contains dark curtain edges, as shown in FIG. 6B . Show;

The controller of the projector analyzes and processes the first image, identifies the curtain through the algorithm in the above-mentioned environmental factors contained in the first image, and controls the projection orientation of the laser assembly, so as to accurately project the playback content to the projection of the above-mentioned curtain. area.

In some embodiments, in order to more easily and accurately identify the projection area of the curtain among the environmental factors in the first image, the controller will obtain the most suitable binary value based on the brightness analysis of the grayscale image of the first image at the moment of obtaining the environmental image. By obtaining the most suitable binarization threshold above, the contour extraction of each environmental element in the second image can be kept as clearly as possible, which is convenient for subsequent algorithms Extraction of closed contours in .

First, the controller generates its corresponding grayscale distribution based on the acquired first image, i.e. a grayscale image, and the right image as shown in Figure 6C is the grayscale image corresponding to the first image;

Then, the controller will determine the grayscale value corresponding to the maximum brightness ratio in the grayscale map of the first image, and the 255 grayscale map can reflect the proportion of the brightest part of the first image in the entire image, such as Figure 6C The brightest part of the grayscale image is assumed to be at 130;

Finally, the controller selects a preset number of gray-level values within a preset range above and below the gray-level value as the threshold value with the gray-level value obtained above as the center, and repeatedly binarizes the first image until the first image is binarized. The extraction of the typical characteristics of the screen from the two images reaches a preset condition, and a second image is obtained. It can be understood that the grayscale value when the second image is obtained is the binarization threshold that should be selected.

For example, in the case where the black area is fixed in FIG. 6C, the starting point of the binarization threshold of the first image can be tentatively set to 130; , 136, 138, and 140 are the binarization thresholds to binarize the first image respectively to obtain a plurality of binarized images; The binarized image is identified as the second image; the curtain feature, that is, the combination of the dark curtain edge band and the white curtain projection area, is specifically represented in the binarized image as the first-level closed contour contains the second-level closed contour, and the said The binarized image is shown in Figure 6D.

In some embodiments, in the binarization process for the first image, the binarization threshold can be selected as a fixed value; however, for the scene of extracting the curtain area when taking pictures with the projector camera, the effect is sometimes not good, because the shooting environment is not suitable for The final image imaging has a huge impact. If a higher threshold is selected at night, most areas may be binarized as edges.

It can be understood that the most accurate method is to traverse all the thresholds, that is, the thresholds traverse 0-255, and perform edge image analysis on the obtained binarized image to obtain the second image with the best edge image effect. However, the binarization of the complete traversal method will lead to a large amount of computation; therefore, the projection display control method for automatic input into the screen area provided by this application adopts grayscale image brightness analysis to create a threshold preferred interval, and at the threshold Perform traversal detection in the preferred interval to obtain the optimal binarized image.

In some embodiments, after the projector controller completes the binarization of the first image, the controller will identify and extract the closed contour included in the second image. When the closed contour also includes a secondary closed contour, it can be temporarily determined that the closed contour is The combination of closed contours matches the color characteristics of the curtain to a certain extent.

It can be understood that, corresponding to the color and structural characteristics of the curtain, during the identification process of the closed contour, the outer edge line of the curtain edge band will be identified as a closed contour with a larger range, which can also be called a first-level closed contour; The inner edge line will be identified as a closed contour with a smaller range, which can also be called a second-level closed contour, that is, the controller will determine the first-level closed contour contained in the second image, and the first-level closed contour contains a second-level closed contour. Close the outline.

For example, in the second image containing multiple environmental factor images, the controller analyzes and identifies the closed contour corresponding to each environmental element image in the image, and searches for the closed contour with the above-mentioned hierarchical relationship as the candidate screen projection area, that is, the controller All first-level closed contours containing secondary closed contours in the second image will be acquired first, and single-level closed contours that do not contain secondary closed contours will be eliminated.

The first-level closed contour may also be referred to as the parent closed contour, and the second-level closed contour contained therein may also be referred to as the child closed contour, that is, the first-level closed contour and the second-level closed contour have a parent-child relationship; it can be understood that in the second image Among the identified multiple parent closed contours containing child closed contours, there must be one closed contour corresponding to the curtain, that is, only the area containing the parent and child closed contours may be used as the candidate area of the curtain projection area;

For example, in the schematic diagram of the closed contour shown in FIG. 6E , four closed contours A, B, C, and D are identified in total; among them, A is the first-level closed contour, that is, the parent closed contour; B, C, and D are the A contour containing The secondary closed contour of , that is, the sub-closed contour; the controller takes the secondary closed contours of B, C, and D as the candidate area of the screen projection area, and continues the algorithm identification.

In some embodiments, the controller performs convex quadrilateral identification and determination on the acquired secondary closed contour in the above-mentioned candidate area. If the secondary closed contour is a convex quadrilateral, the controller will determine that the secondary closed contour is corresponding to the curtain. The projection area of the screen, that is, the projection area surrounded by the dark edge of the curtain, controls the projection of the laser component that controls the projector to the secondary closed contour, so that the playback content is accurately projected and covers the projection area corresponding to the curtain.

First, after the camera obtains the first image of the environment where the projector is located, in order to more accurately extract the closed contour in the image, the controller binarizes the first image to obtain the second image, and then extracts the second image based on the second image. Various closed contours, in order to better reflect the environmental elements corresponding to the closed contours.

It can be found that environmental elements such as furniture, home appliances, objects and walls in the living room of the first image can be well identified in the binarized image as long as their colors have a dark and light contrast relationship with the surrounding environment. The area on the edge of the curtain, the white curtain area on the edge of the curtain, the area of the TV cabinet, the sofa, the coffee table, etc., can be accurately identified by the controller.

Then, the controller will perform polygonal fitting on the obtained secondary closed contour in the above-mentioned hierarchical relationship area, because the projection area of the screen is a standard rectangle, so the controller will fit the result as a quadrangular contour in the secondary closed contour. It is determined as the candidate area of the screen projection area; in this way, the closed contour will be proposed as a triangle, circle, pentagon, or other irregular closed contour, so that the subsequent algorithm can continue to identify the rectangular closed contour corresponding to the screen projection area.

After recognizing multiple quadrilateral secondary closed contours, the controller will determine the concave-convexity of multiple candidate areas, that is, determine the concave-convexity of multiple quadrilateral secondary closed contours, and determine the candidate area that is a convex quadrilateral as corresponding to the curtain projection area.

Among them, in a concave quadrilateral, some sides are extended to both sides, and the other sides are not on the same side of the straight line obtained by the extension; in a convex quadrilateral, if any side is extended to both sides, all other sides are on the same side of the extended straight line;

A concave quadrilateral is different from a convex quadrilateral in that there is one and only one angle greater than 180°, but less than 360°; among the other three angles, the two angles adjacent to the largest angle must be acute angles; the opposite angle of the largest angle can be an acute angle, Right angle or obtuse angle; the angle outside the figure above the largest angle is equal to the sum of the other three interior angles; a convex quadrilateral is a quadrilateral with no angle greater than 180°, and the straight line on any side does not pass through other line segments, that is, the other three sides are in the fourth The side of the line where the side lies, and the sum of any three sides is greater than the fourth side. For example, assuming that the identified secondary closed contours are as shown in Figure 6E, the controller will polygon-fit three secondary closed contours B, C, and D;

Among them, B is identified as a quadrilateral closed contour, C is identified as a pentagonal closed contour, and D is identified as a nearly circular closed contour; therefore, the quadrilateral closed contour of B will continue to be reserved as the secondary closed contour corresponding to the projection area of the screen In the candidate area, the closed contours of C and D will be eliminated in the candidate area;

According to the structure and shape characteristics of the curtain, the controller judges the concavity and convexity of the obtained B quadrilateral closed contour; because the curtain can only be a convex quadrilateral, the controller can judge the concavity and convexity through the concave-convex quadrilateral judgment algorithm, which can be implemented, for example, for:

For a convex quadrilateral, two triangles are obtained by connecting any non-adjacent points, and the area of the original quadrilateral should be the same as the sum of the areas of the two triangles; for a convex quadrilateral, only the concave point corresponds to the two obtained by connecting the line. The area of the original quadrilateral is equal to the sum of the areas of the two triangles mentioned above. Through the implementation of the convex quadrilateral determination algorithm, the images corresponding to other irrelevant environmental factors contained in the primary closed contour can be eliminated, so as to accurately obtain the convex quadrilateral secondary closed contour corresponding to the projection area of the screen.

It can be understood that through the above algorithm steps, the accuracy of the projector's identification of the screen projection area can be improved, and whether the screen is solid or not can be identified; when the projector plays any screen, the screen projection area can be extracted.

That is, when the second-level closed contour identified by the controller also includes a third-level closed contour, the third-level closed contour corresponds to the image generated by the playback content, and when the controller detects that the second-level closed contour contains a third-level closed contour, the controller The three-level closed contour will not be extracted and analyzed, which can ensure that the projector can be moved when the projector is working, and the projector can still be automatically entered into the screen, and the projected content can be accurately put into the screen projection area.

It can be understood that in the implementation of the algorithm for identifying the projection area of the screen, the dark edge of the screen corresponds to the first-level closed contour identified by the controller, and the white screen area inside the dark border corresponds to the second-level convex quadrilateral identified by the controller. Close the outline.

In some embodiments, the controller uses the closed contour with the largest area in the first image as the identification condition of the projection area of the screen.

After the projector obtains the first image of its environment, it can select a fixed binarization threshold, such as binarizing the first image at 20% brightness to obtain the second image. The area does not form a closed contour, resulting in obvious errors in subsequent closed contour extraction; then find the closed contour with the largest area among all closed contours, and determine whether the color of the closed contour is consistent; if it is determined that the color of a closed contour is consistent and If the area is the largest, the closed contour is determined to be the projection area of the screen, as shown in Figure 6F.

However, the instant projector can extract accurate closed contours, but when there is a large area of solid color closed contour area in the first image of the captured image, the final result obtained by the algorithm may be biased, such as the large area solid color wall as shown in Figure 6F area.

Based on the above-mentioned introduction of the display control scheme for automatically putting the playing content into the screen projection area by the display device and the related drawings, the present application also provides a projection display control method for automatically putting the playback content into the screen area, the method comprising: based on the acquisition time The grayscale image brightness of the first image is analyzed, and the first image is binarized to obtain a second image, the first image is an environmental image; the first-level closed contour included in the second image is determined, and the first-level closed contour is determined. The contour contains a second-level closed contour; when it is determined that the second-level closed contour is a convex quadrilateral, project to the second-level closed contour to cover the projection area corresponding to the screen; A curtain edge band, the projection area is surrounded by the curtain edge band, and the curtain is used to display the projection of the playing content. The method has been described in detail in the display device realizing the display control scheme in which the playback content is automatically put into the projection area of the screen, and will not be repeated here.

In some embodiments, binarizing the first image to obtain the second image based on the brightness analysis of the gray-scale image of the first image at the acquisition moment specifically includes: determining a gray-scale value corresponding to the maximum brightness ratio in the gray-scale image of the first image ; Selecting a preset number of gray-level values as the threshold value to repeatedly binarize the first image with the gray-level value as the center, and extracting the typical characteristics of the screen to reach the preset condition The binarized image is used as the second image. The method has been described in detail in the display device realizing the display control scheme in which the playback content is automatically put into the projection area of the screen, and will not be repeated here.

In some embodiments, determining in the second image the projection area corresponding to the curtain including the second-level closed contour specifically includes: acquiring all first-level closed contours including the second-level closed contour in the second image; Polygon fitting is performed on the contour, and the secondary closed contour whose fitting result is a quadrilateral contour is determined as the candidate area of the screen projection area; The projection area corresponding to the curtain. The method has been described in detail in the display control scheme in which the display device realizes the automatic input of the playing content into the projection area of the screen, and will not be repeated here.

In some embodiments, in the process of determining in the second image that the projection area corresponding to the screen includes a secondary closed contour, the method further includes: the secondary closed contour may further include a tertiary closed contour generated by playing content When the contour is selected, no extraction analysis is performed on the three-level closed contour. The method has been described in detail in the display device realizing the display control scheme in which the playback content is automatically put into the projection area of the screen, and will not be repeated here.

In some embodiments, acquiring the first image of the environment where the projection device is located specifically includes the controller acquiring the first image of the area where the screen is located. The method has been described in detail in the display device realizing the display control scheme in which the playback content is automatically put into the projection area of the screen, and will not be repeated here.

In some embodiments, the laser light emitted by the projector is reflected by a nano-scale mirror of a Digital Micromirror Device (DMD: Digital Micromirror Device) chip, wherein the optical lens is also a precision component. When the image plane and the object plane are not parallel, the projection will be made. The image to the screen is geometrically distorted.

FIG. 7A shows a schematic diagram of a system framework for implementing display control by a projection device according to an embodiment of the present application.

In some embodiments, the projector provided by the present application has the feature of telephoto micro-projection, and the projector includes a controller, and the controller can display and control the optical-mechanical image through a preset algorithm, so as to realize automatic keystone correction of the displayed image. , automatic screen entry, automatic obstacle avoidance, automatic focus, and anti-shooting eyes and other functions.

It can be understood that the projector can realize flexible position movement in the telephoto micro-projection scene through the display control method based on geometric correction provided in this application; The controller can control the projector to realize the automatic display correction function, so that it can automatically return to normal display.

In some embodiments, the display control system based on geometric correction provided by the present application includes an application service layer (APK Service: Android application package Service), a service layer, and an underlying algorithm library.

The application service layer is used to realize the interaction between the projector and the user; based on the display of the user interface, the user can configure the parameters of the projector and the display screen, and the controller can coordinate and call the algorithm services corresponding to various functions. , which can realize the function of automatically correcting the display screen of the projector when the display is abnormal.

The service layer may include calibration service, camera service, Time of Flight (TOF: Time of Flight) service, etc., the service can focus on the application service layer (APK Service) upward, and realize the corresponding specific functions of different service configurations of the projector; service The layer is connected to data collection services such as algorithm libraries, cameras, and time-of-flight sensors to realize the functions of encapsulating the underlying complex logic and transmitting business data to the corresponding service layer.

The underlying algorithm library can provide correction services and control algorithms for the projector to implement various functions. For example, the algorithm library can complete various mathematical operations based on OpenCV, so as to provide basic capabilities for the correction service. OpenCV is a cross-platform computer vision and machine learning software library released under the BSD license (open source) and can run on operating systems such as Linux, Windows, Android and Mac OS.

In some embodiments, the projector is further configured with a gyroscope sensor; during the movement of the projector, the gyroscope sensor can sense the position movement, actively collect movement data, and then send the collected data to the application service layer through the system framework layer , in order to support the application data required in the process of user interface interaction and application program interaction, and the collected data can also be used for data invocation by the controller in the implementation of the algorithm service.

In some embodiments, the projector is configured with a time of flight (TOF: Time of Flight) sensor, and after the time of flight sensor collects corresponding data, the data will be sent to the time of flight service corresponding to the service layer;

The time-of-flight service continues to send the data collected by the time-of-flight sensor to the application service layer of the projector through the process communication framework (HSPCore). .

In some embodiments, the projector is configured with a camera for capturing images, which may be implemented as a binocular camera, or a depth camera, etc.; The collected image data is sent to the process communication framework (HSP Core) and/or the projector calibration service for the realization of the projector function.

In some embodiments, the projector calibration service can receive the camera acquisition data sent by the camera service, and the controller can call respective corresponding control algorithms in the algorithm library for different functions to be implemented.

In some embodiments, data interaction can be performed with the application service through the process communication framework, and then the calculation results are fed back to the calibration service through the process communication framework, and the calibration service sends the obtained calculation results to the projector operating system to generate corresponding control Signaling, and send the control signaling to the optical-mechanical control driver to control the working condition of the optical-mechanical and realize the automatic correction of the display effect.

FIG. 7B shows a schematic diagram of a signaling interaction sequence of a projection device implementing a radiation eye function according to another embodiment of the present application.

In some embodiments, the projector provided by the present application can realize the function of preventing eye shot. In order to prevent the user from accidentally entering the range of the laser beam emitted by the projector and cause visual damage, when the user enters the preset specific non-safety area where the projector is located, the controller can control the user interface to display the corresponding prompt information to remind the user to leave. In the current area, the controller can also control the user interface to reduce the display brightness to prevent the laser from causing damage to the user's eyesight.

In some embodiments, when the projector is configured in a children's viewing mode, the controller will automatically turn on the anti-eye switch.

In some embodiments, after the controller receives the position movement data sent by the gyroscope sensor, or after receiving the foreign object intrusion data collected by other sensors, the controller will control the projector to turn on the anti-eye switch.

In some embodiments, when data collected by a time-of-flight (TOF) sensor, a camera device, or other device triggers any preset threshold condition, the controller will control the user interface to reduce the display brightness, display prompt information, and reduce the optical-mechanical transmit power , brightness and intensity to protect the user's eyesight.

In some embodiments, the projector controller may control the calibration service to send signaling to the time-of-flight sensor to query the projector's current device status, and the controller then accepts data feedback from the time-of-flight sensor.

The calibration service can send a notification algorithm service to the process communication framework (HSP Core) to start the anti-eye process signaling; the process communication framework (HSP Core) will call the service capability from the algorithm library to call the corresponding algorithm service, such as taking pictures. Detection algorithm, screenshot algorithm, and foreign object detection algorithm, etc.;

The process communication framework (HSP Core) returns the foreign object detection result to the correction service based on the above algorithm service; for the returned result, if the preset threshold condition is reached, the controller will control the user interface to display prompt information and reduce the display brightness. The signaling sequence is shown in the figure 7B.

In some embodiments, when the anti-eye switch of the projector is on, when the user enters a preset specific area, the projector will automatically reduce the intensity of the laser light emitted by the optical machine, reduce the display brightness of the user interface, and display safety prompts. The projector can control the above-mentioned anti-shooting eye function through the following methods:

The controller uses the edge detection algorithm to identify the projection area of the projector based on the projection picture obtained by the camera; when the projection area is displayed as a rectangle or a rectangle-like shape, the controller obtains the coordinate values of the four vertices of the above-mentioned rectangular projection area through a preset algorithm;

When realizing the detection of foreign objects in the projection area, the perspective transformation method can be used to correct the projection area into a rectangle, and the difference between the rectangle and the projection screenshot can be calculated to determine whether there are foreign objects in the display area; if the result of the judgment is that there are foreign objects, the projector Automatically trigger the anti-eye function to start.

When realizing the detection of foreign objects in a certain area outside the projection range, the difference between the camera content of the current frame and the camera content of the previous frame can be used to determine whether foreign objects enter the area outside the projection range; The meter automatically triggers the anti-eye function.

At the same time, the projector can also use a time-of-flight (ToF) camera or a time-of-flight sensor to detect real-time depth changes in a specific area; if the depth value changes beyond a preset threshold, the projector will automatically trigger the anti-eye function.

In some embodiments, the projector determines whether the anti-eye function needs to be turned on based on the collected flight time data, screenshot data, and camera data analysis.

For example, according to the collected flight time data, the controller performs depth difference analysis; if the depth difference is greater than the preset threshold X, when the preset threshold X is implemented as 0, it can be determined that there is a foreign object in a specific area of the projector . If the user is located in the specific area and his eyesight is at risk of being damaged by the laser, the projector will automatically activate the anti-eye function to reduce the intensity of the laser light emitted by the opto-mechanical machine, reduce the brightness of the user interface display, and display safety prompts.

For another example, the projector performs an additive color mode (RGB) difference value analysis according to the captured screenshot data. If the color additive mode difference value is greater than the preset threshold Y, it can be determined that a foreign object has been located in a specific area of the projector; the If there is a user in a specific area, and their eyesight is at risk of being damaged by the laser, the projector will automatically activate the anti-eye function, reduce the intensity of the laser emitted, reduce the brightness of the user interface display, and display the corresponding safety prompt information.

For another example, the projector obtains projection coordinates according to the collected camera data, then determines the projection area of the projector according to the projection coordinates, and further performs additive color mode (RGB) difference analysis in the projection area. If the color additive mode difference is greater than With the preset threshold Y, it can be determined that a foreign object has been placed in a specific area of the projector. If there is a user in the specific area, his vision is at risk of being damaged by the laser, and the projector will automatically activate the anti-eye function to reduce the intensity of the emitted laser. , Reduce the display brightness of the user interface and display the corresponding security prompt information.

If the acquired projection coordinates are in the extended area, the controller can still perform additive color mode (RGB) difference analysis in the extended area; if the color additive mode difference is greater than the preset threshold Y, it can be determined that there is a foreign object in the projector If there is a user in the specific area, there is a risk of their eyesight being damaged by the laser emitted by the projector. The projector will automatically activate the anti-eye function, reduce the intensity of the emitted laser, reduce the brightness of the user interface display, and display the corresponding safety The prompt information is shown in Figure 7G.

FIG. 7C shows a schematic diagram of a signaling interaction sequence in which a projection device implements a display picture correction function according to another embodiment of the present application.

In some embodiments, the projector can monitor the movement of the device through a gyroscope, or a gyroscope sensor, in general. The calibration service sends a signaling to the gyroscope to query the device status, and receives a signaling from the gyroscope to determine whether the device has moved.

In some embodiments, the display correction strategy of the projector may be configured such that when the gyroscope and the time-of-flight sensor change at the same time, the projector will preferentially trigger keystone correction; after the gyroscope data is stabilized for a preset period of time, the controller starts triggering Keystone correction; and the controller can also configure the projector not to respond to the commands issued by the remote control keys when keystone correction is in progress; In order to cooperate with the realization of keystone correction, the projector will print a pure white graphics card.

Among them, the keystone correction algorithm can construct the transformation matrix of the projection surface and the optomechanical coordinate system under the world coordinate system based on the binocular camera; further combine the optomechanical internal parameters to calculate the homography of the projected image and the playing card, and use the homography to realize Arbitrary shape conversion between the projection screen and the playing card.

In some embodiments, the calibration service sends signaling to the process communication framework (HSP CORE) for notifying the algorithm service to initiate the keystone calibration process, and the process communication framework further sends service capability invocation signaling to the algorithm service to obtain capability corresponding algorithm;

The algorithm service obtains and executes the photographing and picture algorithm processing services, and the obstacle avoidance algorithm service, and sends them to the process communication framework in the form of signaling; in some embodiments, the process communication framework executes the above algorithms, and feeds back the execution results to Correction service, the execution result may include photographing success and obstacle avoidance success.

In some embodiments, the projector will control the user interface to display an error return prompt if the error correction service occurs during the execution of the above algorithm or the data transmission process, and control the user interface to display the keystone correction and autofocus map cards again.

Through the automatic obstacle avoidance algorithm, the projector can identify the screen; and use the projection change to correct the projected image to display in the screen, so as to achieve the effect of aligning with the edge of the screen.

Through the autofocus algorithm, the projector can use the time-of-flight (ToF) sensor to obtain the distance between the optical machine and the projection surface, find the optimal image distance in the preset mapping table based on the distance, and use the image algorithm to evaluate the clarity of the projected image, Based on this, fine adjustment of the image distance is realized.

In some embodiments, the automatic keystone correction signaling sent by the correction service to the process communication framework may include other functional configuration instructions, for example, may include control instructions such as whether to implement synchronous obstacle avoidance, whether to enter the screen, etc.

The process communication framework sends the service capability call signaling to the algorithm service, so that the algorithm service obtains and executes the autofocus algorithm, so as to adjust the viewing distance between the device and the screen; in some embodiments, after applying the autofocus algorithm to realize the corresponding function, the algorithm The service may also obtain execution of an automatic screen entry algorithm, which may include a keystone correction algorithm.

In some embodiments, the projector automatically enters the screen, and the algorithm service can set the 8-position coordinates between the projector and the screen; then again through the auto-focus algorithm, the viewing distance between the projector and the screen can be adjusted; finally, the correction result Feedback to the correction service, and control the user interface to display the correction results, as shown in Figure 7C.

In some embodiments, the projector can obtain the current object distance through an auto-focus algorithm and use its configured laser ranging to calculate the initial focal length and search range; then the projector drives the camera to take pictures, and uses the corresponding algorithm Evaluate clarity.

Within the above search range, the projector searches for the possible best focal length based on the search algorithm, and then repeats the above steps of taking pictures and sharpness evaluation, and finally finds the optimal focal length through sharpness comparison, and completes the automatic focus.

For example, after the projector is started, the user moves the device; the projector automatically completes the calibration and then refocuses, and the controller will detect whether the autofocus function is turned on; when the autofocus function is not turned on, the controller will end the autofocus business; When the function is turned on, the projector will obtain the detection distance of the time-of-flight (TOF) sensor through the middleware for calculation;

The controller queries the preset mapping table according to the obtained distance to obtain the approximate focal length of the projector; then the middleware will set the obtained focal length to the projector's optomechanical;

After the optical machine emits laser light at the above-mentioned focal length, the camera will execute the photographing instruction; the controller judges whether the projector focusing is completed according to the obtained photographing result and the evaluation function; if the judged result meets the preset completion condition, the control auto-focusing process ends; If the judgment result does not meet the preset completion conditions, the middleware will fine-tune the focal length parameters of the projector's optical machine. For example, the focal length can be gradually fine-tuned by a preset step, and the adjusted focal length parameters will be set to the optical machine again. Finally, the optimal focal length is found through sharpness comparison to complete the autofocus, as shown in Figure 7D.

In some embodiments, the projector provided by the present application may implement a display correction function through a keystone correction algorithm.

First, based on the calibration algorithm, two sets of external parameters between the two cameras and between the camera and the opto-mechanical can be obtained, that is, the rotation and translation matrices; then the specific checkerboard graphics card is played through the projector's optomechanical, and the projected checkerboard angle is calculated. Point depth value, for example, the xyz coordinate value is obtained through the translation relationship between the binocular cameras and the principle of similar triangles; then the projection surface is fitted based on the xyz, and the rotation relationship and translation relationship with the camera coordinate system are obtained. , which may specifically include a pitch relationship (Pitch) and a yaw relationship (Yaw).

The Roll parameter value can be obtained through the gyroscope configured by the projector to combine the complete rotation matrix, and finally calculate the external parameters from the projection plane in the world coordinate system to the optical-mechanical coordinate system.

Combining the R and T values of the camera and the optomechanical obtained by the calculation in the above steps, the conversion relationship between the world coordinate system of the projection surface and the optomechanical coordinate system can be obtained; combined with the internal parameters of the optomechanical, the points of the projection surface can be formed to the optomechanical chart. Homography matrix of points.

Finally, select a rectangle on the projection surface, and use the coordinates corresponding to the homography inverse optomechanical chart. This coordinate is the correction coordinate. Set it to the optomechanical to realize trapezoidal correction.

For example, the projector controller obtains the depth value of the corresponding point of the photo pixel, or the coordinates of the projection point in the camera coordinate system; through the depth value, the middleware obtains the relationship between the optical-mechanical coordinate system and the camera coordinate system;

Then the controller calculates the coordinate value of the projection point in the optomechanical coordinate system, and obtains the angle between the projection surface and the optomechanical plane based on the coordinate value fitting plane, and then obtains the projection point in the world coordinate system of the projection surface according to the angle relationship. The corresponding coordinates of ; according to the coordinates of the chart in the optical-mechanical coordinate system and the coordinates of the corresponding points on the projection plane of the projection plane, the homography matrix can be calculated.

The controller determines whether there is an obstacle based on the obtained data; when the obstacle exists, the rectangular coordinates are arbitrarily selected on the projection plane under the world coordinate system, and the area to be projected by the optomechanical is calculated according to the homography relationship; when the obstacle does not exist, the For example, the controller can obtain the feature points of the QR code, and then obtain the coordinates of the QR code on the pre-drawn card, and then obtain the homography relationship between the camera photo and the drawing card, and convert the obtained coordinates of the obstacles into the card, then Get the coordinates of the obstacle occlusion chart.

According to the coordinates of the occluded area of the obstacle map in the optomechanical coordinate system, the occlusion area coordinates of the projection surface are obtained through homography matrix transformation, and the rectangular coordinates are arbitrarily selected on the projection surface in the world coordinate system, while avoiding obstacles. The sexual relationship is used to find the area to be projected by the optomechanical, and the logic flow is shown in Figure 7E.

It can be understood that the obstacle avoidance algorithm uses the algorithm (OpenCV) library to complete the contour extraction of foreign objects when selecting the rectangular step in the trapezoidal correction algorithm process, and avoids the obstacle when selecting the rectangle to realize the projection obstacle avoidance function.

In some embodiments, the middleware obtains the two-dimensional code image card captured by the camera, identifies the feature points of the two-dimensional code, and obtains the coordinates in the camera coordinate system; the controller further obtains the preset image card in the optical-mechanical coordinate system. to solve the homography relationship between the camera plane and the optomechanical plane; based on the above homography relationship, the controller identifies the coordinates of the four vertices of the screen captured by the camera, and obtains the coordinates of the four vertices of the screen captured by the camera according to the homography matrix. The extent of the graph card is shown in Figure 7F.

It can be understood that, in some embodiments, the screen entry algorithm is based on the algorithm library (OpenCV), which can identify the outline of the largest black closed rectangle and extract it, and determine whether it is 16:9 size; The corner points are used to calculate the homography between the projection surface (curtain) and the optical-mechanical playback graphics card. Convert the four vertices of the curtain to the optical-mechanical pixel coordinate system through the homography, and convert the optical-mechanical graphics card to the four vertices of the curtain. Completing the calculation comparison.

The telephoto micro-projection TV has the characteristics of flexible movement, and the projection picture may be distorted after each displacement. In addition, if the projection surface is blocked by foreign objects, or the projection picture is abnormal from the curtain, the projector provided by this application, and the geometric correction-based The display control method can automatically complete the correction for the above problems, including the realization of functions such as automatic keystone correction, automatic screen entry, automatic obstacle avoidance, automatic focusing, and anti-shooting eyes.

The beneficial effects of the embodiments of the present application are that, by creating the first image, the image of the environment where the projector is located corresponding to the screen can be obtained; further, by creating the gray-scale map of the first image, the projector can improve the recognition of the closed contour corresponding to the environmental elements by the projector. By further constructing the first-level and second-level closed contours, the screening range of the candidate area of the screen projection area can be narrowed; by further determining that the second-level closed contour is a convex quadrilateral, the screen projection area included in the candidate area can be identified, and the identification is improved. The accuracy of the screen projection area, avoiding the user's manual fine-tuning of the projection angle, and realizing that the projector used with the screen can be automatically projected to the screen projection area after moving.

Furthermore, those skilled in the art will appreciate that aspects of this application may be illustrated and described in several patentable categories or situations, including any new and useful process, machine, product, or combination of matter, or combinations of them. of any new and useful improvements. Accordingly, various aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as a "data block", "controller", "engine", "unit", "component" or "system". Furthermore, aspects of the present application may be embodied as a computer product comprising computer readable program code on one or more computer readable media.

A computer storage medium may contain a propagated data signal with the computer program code embodied therein, for example, on baseband or as part of a carrier wave. The propagating signal may take a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. Computer storage media can be any computer-readable media other than computer-readable storage media that can communicate, propagate, or transmit a program for use by being coupled to an instruction execution system, apparatus, or device. Program code on a computer storage medium may be transmitted by any suitable medium, including radio, cable, fiber optic cable, RF, or the like, or a combination of any of the foregoing.

The computer program coding required for the operation of the various parts of this application may be written in any one or more programming languages, including object-oriented programming languages such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python etc., conventional procedural programming languages such as C language, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages such as Python, Ruby and Groovy, or other programming languages, etc. The program code may run entirely on the user's computer, or as a stand-alone software package on the user's computer, or partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the latter case, the remote computer may be connected to the user's computer through any network, such as a local area network (LAN) or wide area network (WAN), or to an external computer (eg, through the Internet), or in a cloud computing environment, or as a service Use eg software as a service (SaaS).

In addition, unless explicitly stated in the claims, the order of processing elements and sequences described in the present application, the use of numbers and letters, or the use of other names are not intended to limit the order of the procedures and methods of the present application. While the foregoing disclosure discusses by way of various examples some embodiments of the invention that are presently believed to be useful, it is to be understood that such details are for purposes of illustration only and that the appended claims are not limited to the disclosed embodiments, but rather The requirements are intended to cover all modifications and equivalent combinations falling within the spirit and scope of the embodiments of the present application. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described systems on existing servers or mobile devices.

Similarly, it should be noted that, in order to simplify the expressions disclosed in the present application and thus help the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, various features are sometimes combined into one embodiment, in the drawings or descriptions thereof. However, this method of disclosure does not imply that the subject matter of the application requires more features than those mentioned in the claims. Indeed, there are fewer features of an embodiment than all of the features of a single embodiment disclosed above.

Each patent, patent application, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited in this application is hereby incorporated by reference in its entirety. Application history documents that are inconsistent with or conflict with the content of this application are excluded, as are documents (currently or hereafter appended to this application) that limit the broadest scope of the claims of this application. It should be noted that, if there is any inconsistency or conflict between the descriptions, definitions and/or terms used in the attached materials of this application and the content of this application, the descriptions, definitions and/or terms used in this application shall prevail .

Claims (10)

1. A projection device, comprising:

the projection component is used for projecting the playing content to a curtain corresponding to the projection equipment;

a controller configured to:

performing binarization on the first image to obtain a second image based on the brightness analysis of a first image gray-scale image obtained by a camera;

determining a primary closed contour contained in the second image, wherein the primary closed contour contains a secondary closed contour;

when the secondary closed contour is judged to be a convex quadrangle, controlling the projection component to project the playing content to the secondary closed contour, wherein the secondary closed contour corresponds to a projection area of the curtain; wherein the curtain comprises a curtain edge band corresponding to the primary closed contour, the projected area being surrounded by the curtain edge band.

2. The projection device of claim 1, wherein the controller is configured such that, in binarizing the first image into the second image based on camera-acquired grayscale map luminance analysis of the first image, the controller:

determining a gray scale value corresponding to the maximum brightness ratio in the first image gray scale image;

and selecting a preset number of gray scale values as a threshold value by taking the gray scale values as the center, carrying out binarization on the first image, and taking a binarization image containing curtain characteristics as the second image.

3. The projection device of claim 1, wherein the controller is configured to, in the step of determining a projection area corresponding to a curtain containing the secondary closed contour in the second image, the controller:

acquiring all primary closed contours including the secondary closed contours in the second image;

performing polygon fitting on the secondary closed contour, and judging the secondary closed contour with a fitting result of a quadrilateral contour as a candidate area of a curtain projection area;

and judging the unevenness of the candidate area of the screen projection area, and judging the candidate area with a convex quadrilateral result as the projection area corresponding to the screen.

4. The projection device of claim 1, wherein the controller is configured to, in determining a projection area corresponding to the curtain that includes a secondary closed contour in the second image, the controller:

when the secondary closed contour further comprises a tertiary closed contour generated by projection of the projection device, the controller does not perform extraction analysis on the tertiary closed contour.

5. The projection device of claim 1, wherein the controller is configured to, in controlling the camera to obtain a first image of an environment in which the projection device is located:

and controlling the camera to acquire a first image of an area where the projection equipment corresponding to the curtain is located.

6. A projection display control method for automatically throwing into a curtain area is characterized by comprising the following steps:

performing binarization on a first image to obtain a second image based on the brightness analysis of the obtained first image gray-scale image, wherein the first image is an environment image;

determining a primary closed contour contained in the second image, wherein the primary closed contour contains a secondary closed contour;

when the secondary closed contour is judged to be a convex quadrangle, projecting the playing content to the secondary closed contour, wherein the secondary closed contour corresponds to a projection area of the curtain; wherein the curtain comprises a curtain edge band corresponding to the primary closed contour, the projected area being surrounded by the curtain edge band.

7. The projection display control method of automatically feeding a curtain region as claimed in claim 6, wherein in the step of binarizing the first image to obtain the second image based on the gray-scale image luminance analysis of the first image, the method specifically comprises:

determining a gray scale value corresponding to the maximum brightness ratio in the first image gray scale image;

and selecting a preset number of gray scale values as a threshold value by taking the gray scale values as the center, carrying out binarization on the first image, and taking the binarized image containing curtain characteristics as the second image.

8. The method for controlling projection display of automatically feeding into a curtain area as claimed in claim 6, wherein the step of determining the projection area corresponding to the curtain containing the secondary closed contour in the second image specifically comprises:

acquiring all primary closed contours including the secondary closed contours in the second image;

performing polygon fitting on the secondary closed contour, and judging the secondary closed contour with a fitting result of a quadrilateral contour as a candidate area of a curtain projection area;

and judging the unevenness of the candidate area of the screen projection area, and judging the candidate area with a convex quadrilateral result as the projection area corresponding to the screen.

9. The method of claim 6, wherein in determining a projection area corresponding to the screen that includes a secondary closed contour in the second image, the method further comprises:

when the three-level closed contour generated by projection is also included in the two-level closed contour, the three-level closed contour is not subjected to extraction analysis.

10. The projection display control method of automatically feeding a curtain area as claimed in claim 6, wherein the step of obtaining the first image of the area where the curtain is located includes obtaining the first image of the area where the curtain is located.

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