CN110491316A - A kind of projector and its method for controlling projection - Google Patents

Abstract

This application discloses a kind of projector and its method for controlling projection, the method for controlling projection of projector includes: to obtain the first information and the second information using the depth camera on the projector；According to first projector distance, the focal length of the projector lens is adjusted；According to the first projector distance and projected planar dimensions, adjust the projector to the projection plane screen size；According to the focal length adjusted and the screen size, Xiang Suoshu projection plane.The embodiment of the present application can focus automatically and adjust automatically projected picture size, meets practical application request, improves drop shadow effect, low in cost, enhances the market competitiveness of projector.

Description

A projector and its projection control method

technical field

The present application relates to the technical field of projectors, and in particular, to a projector and a projection control method thereof.

Background technique

In the related art, the focusing methods of projectors are divided into manual focusing and automatic focusing. Among them, automatic focusing is mainly divided into two types: ranging method and image detection method. Ranging method focusing usually uses infrared and ultrasonic ranging. The projector transmits infrared or ultrasonic waves to the screen and receives the infrared or ultrasonic waves emitted by the screen. The distance between the projector and the display screen is measured according to the propagation time. distance, and then adjust the focus based on this distance. The image detection method focusing is similar to the automatic focusing used in cameras and other products. By projecting a predetermined test image to the screen, using the automatic focusing component to collect the image on the screen, and comparing it with the built-in parameters, the focusing function is realized.

However, the ranging method for focusing requires additional infrared and ultrasonic modules, which increases the cost of the projector, and the infrared and ultrasonic waves are easily interfered by environmental factors. The distance from a point on the screen to the projector is measured, and the distance is not accurate. , The focusing accuracy is not high. Focusing by the image detection method also needs to increase the auto-focusing component, which will increase the cost, and because the ordinary image obtained by the image detection method lacks depth information, the function of automatically adjusting the size of the projection screen according to the distance cannot be realized.

SUMMARY OF THE INVENTION

The present application provides a projector and a projection control method thereof, which realizes automatic focus adjustment and automatic adjustment of the size of the projected picture according to the size of the projection plane, meets actual needs, has low cost, and improves the market competitiveness of the projector.

According to an aspect of the present application, a projection control method for a projector is provided, comprising:

Obtain the first information and the second information by using the depth camera on the projector; wherein the first information includes the first projection distance between the projector and the projection plane, and the second information includes the size of the projection plane;

adjusting the focal length of the projector lens according to the first projection distance;

adjusting the screen size of the projector projected onto the projection plane according to the first projection distance and the size of the projection plane;

Projecting onto the projection plane according to the adjusted focal length and the screen size.

According to another aspect of the present application, a projector is provided, the projector includes a projection unit, a processor, and a depth camera;

The depth camera is connected to the processor for acquiring first information and second information, wherein the first information includes a first projection distance between the projector and a projection plane, and the second information includes a projection plane size;

The processor is configured to adjust the focal length of the projector lens according to the first projection distance; according to the first projection distance and the size of the projection plane, adjust the projection of the projector to the projection plane screen size;

The projection unit is configured to project onto the projection plane according to the adjusted focal length and the screen size.

Applying the projector and the projection control method thereof according to the embodiment of the present application, according to the first information and the second information obtained by the depth camera on the projector, adjust the focal length of the projector lens and the screen size projected by the projector on the projection plane, and adjust according to the adjustment The rear focal length and screen size are projected onto the projection plane, thereby realizing automatic focusing and automatic adjustment of the screen size adapted to the projection plane, improving the projection effect, and meeting the actual application requirements, and only the depth camera is needed, and no additional It has low cost and is suitable for large-scale promotion and application.

Description of drawings

1 is a schematic flowchart of a projection control method for a projector according to an embodiment of the present application;

2 is a block diagram of a projector according to an embodiment of the present application;

FIG. 3 is an overall block diagram of a projector according to an embodiment of the present application.

Detailed ways

In order to make the above objects, features and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are some, but not all, embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The design concept of the present application is to use the depth camera on the projector to collect the distance from the projector to the projection plane and the size of the projection plane, and adjust the focal length of the projector lens and the projected screen size based on the distance and the size of the projection plane, and then realize Automatic focusing, automatically adjust the screen size to fit the projection plane, meet the projection requirements, improve the focusing accuracy, avoid the tedious manual focusing operation, improve the user experience, low cost, and enhance the market competitiveness of the projector .

1 is a schematic flowchart of a projection control method for a projector according to an embodiment of the present application. Referring to FIG. 1 , the projection control method for a projector according to this embodiment includes the following steps:

Step S101, using a depth camera on the projector to obtain first information and second information; wherein the first information includes a first projection distance between the projector and a projection plane, and the second information includes a projection plane size;

Step S102, adjusting the focal length of the projector lens according to the first projection distance;

Step S103, according to the first projection distance and the size of the projection plane, adjust the size of the screen projected by the projector onto the projection plane;

Step S104, projecting onto the projection plane according to the adjusted focal length and the screen size.

As shown in FIG. 1 , the projection control method of the projector in this embodiment realizes automatic focusing and avoids the cumbersome manual focusing. When the relative position between the projector and the projection plane changes, the projector automatically adjusts the focus. Adjust the focal length according to the change of distance, more intelligent. In addition, the projector automatically adjusts the screen size, that is, the projector automatically adjusts the appropriate screen size according to the actual size of the projection plane to display within the range of the projection plane, thereby improving the projection effect and meeting practical application requirements. Finally, the projection control method of the projector according to the embodiment of the present application does not need to install infrared, ultrasonic and other modules, and has high focusing precision and low cost.

It should be noted that there is no strict execution sequence between step S102 and step S103 in FIG. 1 , and may be executed sequentially or simultaneously.

The projection control method for a projector in this embodiment is applied to a smart projector with a depth camera installed. The depth camera can collect depth information of the environment. The current depth cameras can be divided into three types according to their working principles: TOF (Time of Flight, flight) time), RGB binocular, structured light. Because the TOF depth camera has a simple measurement method, fast response, and reduces the interference of background light to a certain extent, the depth camera of this embodiment adopts a time-of-flight TOF depth camera. Compared with the traditional infrared or ultrasonic ranging, the advantages of the TOF ranging in the embodiment of the present application are that the TOF obtains the distance information of a plane, while the infrared and ultrasonic can usually only obtain the distance information of one point. Therefore, the information obtained by the TOF is The amount of information is far greater than the amount of information obtained by infrared and ultrasonic, so the focusing error will be smaller. Moreover, the TOF depth camera is a standard configuration of smart projectors. The TOF depth camera is used to collect depth information and projection plane size information to realize automatic focusing and image size adjustment without additional hardware cost.

Specifically, the depth camera collects the depth image of the projection plane, and the depth of each pixel on the depth image determines the first projection distance between the projector and the projection plane. Based on this, in the aforementioned step S102, according to the first projection distance , adjusting the focal length of the projector lens includes: searching for the corresponding relationship between the preset projection distance and the focal length according to the first projection distance, and obtaining a focal length value corresponding to the first projection distance; based on the focal length value, and the corresponding relationship between the focal length and the focusing displacement, the focusing displacement is obtained; the focusing displacement is output to the driving motor of the projector, and the focal length of the projector lens is adjusted by the driving motor.

That is to say, in the embodiment of the present application, after the projector obtains the first projection distance, the corresponding relationship between the projection distance and the focal length is searched to determine the current first projection distance (the distance is the distance from the photographed object to the focal plane of the depth camera) The corresponding focal length value, for example, the first projection distance is 80 cm (for example only), then look up the correspondence between the projection distance and the focal length to determine the corresponding focal length value of 50 mm (for example only), after determining the focal length (the focal length is After the distance from the light source to the optical lens), in this embodiment, based on the corresponding relationship between the focal length and the focusing displacement, the focusing displacement corresponding to the focal length value of 50 mm is obtained, and the focusing displacement is sent to the driving motor, and the driving motor specifically performs the adjustment of the focal length. work to achieve the effect of automatic focusing.

On the basis that the depth camera obtains the first projection distance and the size of the projection plane, in the aforementioned step S103, adjusting the size of the picture projected to the projection plane according to the first projection distance and the size of the projection plane includes: comparing the The size of the projection plane and the preset maximum picture size, where the preset maximum picture size is the picture size projected by the projector to the projection plane under the first projection distance, if the size of the projection plane is greater than or is equal to the preset maximum screen size, the preset maximum screen size is determined as the screen size projected on the projection plane; if the projection plane size is smaller than the preset maximum screen size, the preset maximum screen size is reduced. Set the maximum screen size to the first screen size, and determine the first screen size as the screen size projected on the projection plane, wherein the first screen size is equal to the projection plane size, or the first screen size The difference between the size and the size of the projection plane is less than a first threshold.

It should be noted that the size of the projection screen is not only related to the distance from the projector to the projection plane, but also related to the size of the projection plane. Considering the factors of distance, generally speaking, the picture with far distance is larger, and the picture with close distance is small; under the premise of a certain distance, the size of the projection plane determines the size of the picture. If the picture size is too large, the picture will exceed the projection plane and the projection will not effectively. Therefore, in this embodiment, the depth camera is used to obtain the size of the entire projection plane, and the size of the projection plane is compared with the size of the preset maximum picture size. If the size of the projection plane is greater than or equal to the preset maximum picture size, the preset maximum picture The size is determined as the size of the picture projected on the projection plane; if the size of the projection plane is smaller than the preset maximum picture size, the preset maximum picture size is reduced to the first picture size, and the first picture size is determined as the size of the picture projected on the projection plane. size.

The preset maximum picture size here is the maximum picture size projected by the projector to the projection plane under the first projection distance; the first picture size may be equal to the projection plane size, or the difference between the first picture size and the projection plane size is less than The first threshold, that is, the first picture size is slightly smaller than the projection plane size.

In order to ensure the screen projection effect, this embodiment adopts the idea of proportional scaling when automatically adjusting the screen size, that is, reducing the preset maximum screen size to the first screen size includes: reducing the preset maximum screen size to the first screen size , keep the ratio of length to width of the preset maximum screen size unchanged.

For example, on the premise that the projection distance is 60 cm, the size of the display screen is length: 52 cm, width: 29 cm, and the ratio of length to width is approximately equal to 1.7. When the size of the target projection screen is relatively small, corresponding to reducing the length and width of the screen to the maximum range that the target projection screen can support, keep the aspect ratio still at 1.7, and obtain the adjusted screen size, for example, the length is: 26 cm, width: 15 cm.

It can be seen from the above that the projection control method of the projector according to the embodiment of the present application realizes automatic focusing, automatically adjusts the screen size to fit the projection plane, satisfies the projection requirements, improves the focusing accuracy, and avoids tedious manual focusing. operation, improving the user experience.

FIG. 2 is a block diagram of a projector according to an embodiment of the present application. Referring to FIG. 2 , the projector 200 of this embodiment includes a projection unit 203, a processor 202, and a depth camera 201;

The depth camera 201, connected to the processor 202, is configured to acquire first information and second information, wherein the first information includes a first projection distance between the projector and the projection plane, and the second Information including projected plane dimensions;

The processor 202 is configured to adjust the focal length of the projector lens according to the first projection distance; adjust the projection of the projector to the projection plane according to the first projection distance and the size of the projection plane screen size;

The projection unit 203 is configured to project onto the projection plane according to the adjusted focal length and the screen size.

In one embodiment of the present application, the depth camera 201 is a time-of-flight TOF depth camera.

Because the projected image area of the projector needs to be completely within the detection area of the depth camera, so that the depth camera can prevent the projected image from going beyond the projection screen during projection. Therefore, the field of view of the TOF depth camera in this embodiment is larger than that of the projector lens. field of view. That is, the maximum field of view FOV (Field of View) of the depth camera 201 is larger than the maximum field of view FOV of the projector lens. The TOF depth camera continuously detects the depth information of the projection plane, so as to obtain the maximum size of the projection plane and the distance between the projection plane and the projector.

The depth information of a complete plane can be obtained through the TOF depth camera, so as to know the distance of the projection plane (such as the display screen) and the size of the projection plane. These two pieces of information are used to adjust the focal length of the lens and the display size of the projection screen respectively.

In an embodiment of the present application, the projector further includes a drive motor, and the processor 202 is configured to search for the corresponding relationship between the preset projection distance and the focal length according to the first projection distance, and obtain a corresponding relationship between the first projection distance and the focal length. The focal length value corresponding to the projection distance, and based on the focal length value and the corresponding relationship between the focal length and the focusing displacement, the focusing displacement is obtained; the focusing displacement is output to the driving motor; the driving motor is used for according to the The focusing displacement adjusts the focal length of the projector lens.

In an embodiment of the present application, the processor 202 is configured to compare the size of the projection plane with a preset maximum picture size, where the preset maximum picture size is the first projection of the projector in the first projection The screen size projected to the projection plane under the distance; if the projection plane size is greater than or equal to the preset maximum screen size, the preset maximum screen size is determined as the screen size projected to the projection plane; If the size of the projection plane is smaller than the preset maximum picture size, the preset maximum picture size is reduced to a first picture size, and the first picture size is determined as the picture size projected on the projection plane, wherein , the first picture size is equal to the projection plane size, or the difference between the first picture size and the projection plane size is smaller than a first threshold.

It should be noted that, the exemplary explanation of each function performed by each component in the projector shown in FIG. 2 is consistent with the exemplary explanation in the foregoing method embodiments, and will not be repeated here.

FIG. 3 is an overall block diagram of a projector according to an embodiment of the present application. Referring to FIG. 3 , the TOF depth camera of the projector in this embodiment obtains raw data from the projection plane to the projector, and after the processor obtains the raw data from the TOF depth camera Perform analysis to obtain projection distance information and size information of the projection plane.

Referring to Fig. 3, the processor sends the projection distance information to the distance and focal length algorithm processing unit, and the distance and focal length algorithm processing unit outputs a focal length value to the drive motor that specifically performs the focusing operation according to the functional relationship between the distance and the focal length. The drive motor controls the lens to move to the position indicated by the focal length value.

Referring to Fig. 3, the processor sends the projection distance information and the size information of the projection plane to the picture size algorithm processing unit, and the picture size algorithm processing unit calculates the projected picture jointly according to the obtained projection distance information and the boundary size of the projection plane. Size, send the size information of the projected screen to the DMD optical machine that specifically performs screen size adjustment. It can be understood that the image in the projector is generated by DMD (Digital Micromirror Device, digital micromirror device), DMD is composed of many small mirrors, the number of mirrors is determined by the display resolution, and each micromirror controls the projection screen. One pixel, the number of micro lenses corresponds to the resolution of the projected picture.

In this embodiment, under the condition that the projection distance is constant, when the size of the projection plane is larger than the maximum projection picture, the picture is projected onto the projection plane according to the maximum projection picture. If the size of the projection plane is smaller than the maximum projection picture , it is necessary to reduce the size of the largest projection screen to fit the size of the projection plane. In this way, the effect of automatically adjusting the size of the screen projected to the projection plane according to the size of the projection plane is realized, which optimizes the user experience.

It should be noted that the terms "first", "second", etc. in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that objects so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those described herein.

To sum up, by applying the projector and the projection control method thereof according to the embodiment of the present application, the depth camera on the projector is used to collect the distance between the projector and the projection plane and the size of the projection plane, and according to the distance information and the size of the projection plane The functions of automatically adjusting the focal length and automatically adjusting the size of the projected image are realized, thereby simplifying the system design and operation process, saving the cost, improving the user experience, and increasing the market competitiveness of the projector.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flows of a flowchart and/or a block or blocks of a block diagram.

It should be noted that the terms "comprising", "comprising" or any other variation thereof are intended to cover a non-exclusive inclusion such that a process, method, article or device comprising a series of elements includes not only those elements, but also includes no explicit Other elements listed, or those inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

In the description of the present application, numerous specific details are set forth. It will be understood, however, that the embodiments of the present application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Similarly, it is to be understood that in the above description of example embodiments of the present application, various features of the present application are sometimes grouped together into a single embodiment in order to simplify the present disclosure and to aid in the understanding of one or more of the various inventive aspects. , figures, or descriptions thereof. This disclosure, however, should not be interpreted as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this application.

The above descriptions are only specific implementations of the present application, and those skilled in the art can make other improvements or modifications on the basis of the above-mentioned embodiments under the above teachings of the present application. Those skilled in the art should understand that the above-mentioned specific description is only for better explaining the purpose of the present application, and the protection scope of the present application is subject to the protection scope of the claims.

Claims (10)

1. a kind of method for controlling projection of projector characterized by comprising

The first information and the second information are obtained using the depth camera on the projector；Wherein the first information includes described The first projector distance between projector and projection plane, second information includes projected planar dimensions；

According to first projector distance, the focal length of the projector lens is adjusted；

According to first projector distance and the projected planar dimensions, the projector is adjusted to the projection plane Screen size；

According to the focal length adjusted and the screen size, Xiang Suoshu projection plane.

2. method for controlling projection as described in claim 1, which is characterized in that described according to first projector distance, adjustment The focal length of the projector lens includes:

According to first projector distance, the corresponding relationship of preset projector distance Yu the focal length is searched, is obtained and described the The corresponding focal length value of one projector distance；

Corresponding relationship based on the focal length value and the focal length and focusing displacement, obtains focusing displacement；

By the driving motor of the focusing displacement output to the projector, by the institute of driving motor adjustment projector lens State focal length.

3. method for controlling projection as described in claim 1, which is characterized in that described according to first projector distance and institute Projected planar dimensions are stated, the screen size that adjustment projects to the projection plane includes:

Compare the projected planar dimensions and default maximum screen size, wherein the default maximum screen size is the throwing Shadow instrument projects to the screen size of the projection plane under first projector distance,

If the projected planar dimensions are greater than or equal to the default maximum screen size, by the default maximum picture ruler The very little screen size for being determined as projecting to the projection plane；

If the projected planar dimensions are less than the default maximum screen size, the default maximum screen size is reduced extremely First screen size is determined as projecting to the screen size of the projection plane by the first screen size, wherein described The difference that one screen size is equal between the projected planar dimensions or first screen size and the projected planar dimensions is small In first threshold.

4. method for controlling projection as claimed in claim 3, which is characterized in that described to reduce the default maximum screen size extremely First screen size includes: to keep described default when reducing default maximum screen size to first screen size The ratio between the length of maximum screen size and width are constant.

5. a kind of projector, which is characterized in that the projector includes projecting cell, processor and depth camera；

The depth camera is connected to the processor, for obtaining the first information and the second information, wherein the first information Including the first projector distance between the projector and projection plane, second information includes projected planar dimensions；

The processor, for adjusting the focal length of the projector lens according to first projector distance；According to described first Projector distance and the projected planar dimensions, adjust the projector to the projection plane screen size；

The projecting cell, for according to the focal length adjusted and the screen size, Xiang Suoshu projection plane.

6. projector as claimed in claim 5, which is characterized in that the projector further includes driving motor,

The processor, for searching according to first projector distance, preset projector distance is corresponding with the focal length to be closed System obtains focal length value corresponding with first projector distance, based on the focal length value and the focal length and displacement of focusing Corresponding relationship obtains focusing displacement；By focusing displacement output to the driving motor；

The driving motor, for the focal length according to projector lens described in the focusing adjustment of displacement.

7. projector as claimed in claim 5, which is characterized in that

The processor, for the projected planar dimensions and default maximum screen size, wherein the default maximum is drawn Face size is the screen size that the projector projects to the projection plane under first projector distance；

If the projected planar dimensions are greater than or equal to the default maximum screen size, by the default maximum picture ruler The very little screen size for being determined as projecting to the projection plane；If the projected planar dimensions are less than the default maximum picture Size then reduces the default maximum screen size to the first screen size, first screen size is determined as projecting to The screen size of the projection plane, wherein first screen size is equal to the projected planar dimensions or first picture Difference between face size and the projected planar dimensions is less than first threshold.

8. projector as claimed in claim 7, which is characterized in that the processor is reducing the default maximum picture ruler When first screen size, keep the length of the default maximum screen size and the ratio between width constant.

9. the projector as described in any one of claim 5 to 8, which is characterized in that the depth camera is flight time TOF Depth camera.

10. projector as claimed in claim 9, which is characterized in that the field range of the TOF depth camera is greater than the throwing The field range of shadow instrument camera lens.