阅读说明：本技术 一种投影方法、投影系统及投影仪 (Projection method, projection system and projector ) 是由 陈许 吴凯 吴超 于 2018-08-31 设计创作，主要内容包括：本申请公开了一种投影方法、投影系统及投影仪。该投影系统包括：第一数字反射镜器件DMD,第二DMD；所述第一DMD,用于根据三基色显示时序,按照相应基本色对应的各分区的光输出量,将入射到所述第一DMD的来自于光源的照明光束分区输出；所述第二DMD,用于根据基于待投影图像生成的驱动信号,对所述第一DMD分区输出的光束进行调制,调制后的光束进入投影镜头成像。(The application discloses a projection method, a projection system and a projector. The projection system includes: a first digital mirror device DMD, a second DMD; the first DMD is used for outputting the illumination light beams from the light source, which are incident to the first DMD, in a partition mode according to the three-primary-color display time sequence and the light output quantity of each partition corresponding to the corresponding primary color; and the second DMD is used for modulating the light beam output by the first DMD in a subarea mode according to a driving signal generated based on the image to be projected, and the modulated light beam enters the projection lens for imaging.)

1. A projection system, comprising: a first digital mirror device DMD, a second DMD;

the first DMD is used for outputting the illumination light beams from the light source, which are incident to the first DMD, in a partition mode according to the three-primary-color display time sequence and the light output quantity of each partition corresponding to the corresponding primary color;

and the second DMD is used for modulating the light beam output by the first DMD in a subarea mode according to a driving signal generated based on the image to be projected, and the modulated light beam enters the projection lens for imaging.

2. The projection system of claim 1, wherein the first DMD is coupled to a first driver controller and the second DMD is coupled to a second driver controller;

the first driving controller is used for determining the light output quantity respectively corresponding to the three primary colors in the corresponding subarea in the first DMD according to the brightness of different subareas in the projection image of the three primary colors in the projection area of the debugging image; according to the three-primary-color display time sequence, a driving signal is sent to the first DMD at the time corresponding to a primary color according to the light output quantity corresponding to the primary color in each partition in the first DMD; wherein a segment in the projected image of a primary color corresponds uniquely to a segment of the array of micro-mirrors in the first DMD;

and the second driving controller is used for generating a driving signal acting on the second DMD according to the image to be projected and sending the generated driving signal to the second DMD.

3. The projection system of claim 2, wherein the first drive controller comprises:

the image acquisition module is used for acquiring the projection images of the three basic colors of the debugging image in the projection area;

the image analysis module is used for respectively partitioning the projection images of the three primary colors and determining the brightness of each partition; and respectively determining the deflection amount of the micro-mirror in each partition in the first DMD according to the brightness difference of different partitions aiming at the projected image of each basic color to obtain the deflection amount of the micro-mirror corresponding to each of the three basic colors;

and the driving control module is used for sending a driving signal to the first DMD according to the deflection amount of the micro-mirror corresponding to the first basic color at the time corresponding to the first basic color according to the three-primary-color display time sequence, sending a driving signal to the first DMD according to the deflection amount of the micro-mirror corresponding to the second basic color at the time corresponding to the second basic color, and sending a driving signal to the first DMD according to the deflection amount of the micro-mirror corresponding to the third basic color at the time corresponding to the third basic color.

4. The projection system of claim 3, wherein the image analysis module is specifically configured to: performing, for the projected image of each primary color:

determining a minimum brightness among the brightness of all the partitions and a brightness difference between the brightness of other partitions and the minimum brightness;

and determining the deflection amount of the micro-mirror in each partition according to the brightness difference of each partition in the other partitions, wherein the deflection amount of the micro-mirror in the partition corresponding to the minimum brightness enables the micro-mirror to be in an on state.

5. The projection system of claim 3, wherein the image acquisition module is an image acquisition device configured to acquire projection images of three primary colors.

6. The projection system of claim 1, wherein the number of segments of the first DMD is less than or equal to the number of micromirrors of the first DMD, and the number of micromirrors contained in one segment of the first DMD is less than or equal to the number of pixel points of one segment in the first projected image.

7. The projection system of claim 1, further comprising an illumination light path, the first DMD disposed in or before the illumination light path;

the illumination light path is used for shaping the light beam emitted by the first DMD, and the shaped light beam meets the light spot size and the incident angle required by the incident of the second DMD.

8. A projector, characterized by comprising: a light source, a projection lens, and the projection system of any one of claims 1 to 7;

the light source provides illumination for the projection system, and the projection system modulates light source beams, outputs the light source beams to the projection lens for imaging, and projects the light source beams to a projection medium to form a projection picture.

9. The projection system of claim 8, wherein the light source is a laser light source or a hybrid laser and phosphor light source, the laser light source comprising a two-color laser light source or a three-primary color laser light source.

10. A projection method implemented based on the projection system of any one of claims 1 to 7, comprising:

according to a three-primary-color display time sequence and the display time of a primary color, sending a driving signal to a first DMD according to the light output quantity corresponding to the primary color in each partition of the first DMD to drive a micro mirror in the corresponding partition, generating a driving signal according to a to-be-projected image and sending the driving signal to a second DMD so that the second DMD modulates the light beam of the primary color emitted from the first DMD partition, and enabling the modulated light beam to enter a projection lens for imaging;

wherein the amount of light output corresponding to a key color in each section of the first DMD is determined based on the brightness of the different sections of the debug image in the projected image of the key color in the projection area.

11. The method of claim 10, wherein determining the amount of light output for a key color in each segment of the first DMD based on the brightness of different segments of a projected image of the key color in the projected area from the debug image comprises:

partitioning a projected image of one basic color of the debugging image in a projection area, and determining the brightness of each partition;

and respectively determining the deflection amount of the micro-mirrors in each partition of the first DMD according to the brightness difference of different partitions, wherein the polarization amount of the micro-mirrors in one partition corresponds to the light output amount of the partition.

12. The method of claim 11, wherein the separately determining the amount of deflection of the micromirrors in each of the segments in the first DMD based on the differences in brightness of the different segments comprises:

determining a minimum brightness among the brightness of all the partitions and a brightness difference between the brightness of other partitions and the minimum brightness;

and determining the deflection amount of the micro-mirrors in the subareas according to the brightness difference of each of the other subareas.

Technical Field

The present disclosure relates to the field of projection display, and in particular, to a projection method, a projection system, and a projector.

Background

Projectors are becoming more popular as computer graphic image output devices in teaching, demonstration, entertainment, work, and the like. A Digital Light Processing (DLP) projector is a projector adopting a special Light source modulation method, and because a full Digital reflection method is used, the DLP projector not only can make a projection display image more detailed, but also can effectively reduce the volume and weight of the projector, thereby being widely used.

DLP projectors use a Digital Micromirror Device (DMD) as a main component to implement Digital optical processing. The DMD is controlled by an image display driving signal to switch thousands of micromirrors back and forth between "on" and "off" states. The micro-mirror in the 'on' state reflects light into the lens, and accordingly generates a bright point on the projection screen; the "off" state of the micro-mirror will cause light to be reflected off the lens and absorbed as stray light, which in turn creates a dark spot on the projection screen. Therefore, the light quantity entering the lens is determined by the overturning angle and the overturning time length of each micro-reflector, and a projection display image is formed on the projection screen after the light quantity is reflected by all the micro-reflectors on the DMD and passes through the lens.

The existing three-primary-color ultra-short-focus laser projector has the problem of uneven chromaticity of a projection picture, so how to improve the chromaticity uniformity of the projection picture is a problem to be solved urgently.

Summary of the invention

The invention provides a projection method, a projection system and a projector, which are used for reducing the chromaticity difference of different areas in a projection picture.

In a first aspect, a projection system is provided, comprising: a first DMD, a second DMD; the first DMD is used for outputting the illumination light beams from the light source, which are incident to the first DMD, in a partition mode according to the three-primary-color display time sequence and the light output quantity of each partition corresponding to the corresponding primary color; and the second DMD is used for modulating the light beam output by the first DMD in a subarea mode according to a driving signal generated based on the image to be projected, and the modulated light beam enters the projection lens for imaging.

In one possible implementation, the first DMD is coupled to a first drive controller and the second DMD is coupled to a second drive controller. The first driving controller is used for determining the light output quantity respectively corresponding to the three primary colors in the corresponding subarea in the first DMD according to the brightness of different subareas in the projection image of the three primary colors in the projection area of the debugging image; according to the three-primary-color display time sequence, a driving signal is sent to the first DMD at the time corresponding to a primary color according to the light output quantity corresponding to the primary color in each partition in the first DMD; wherein a segment in the projected image of a primary color corresponds uniquely to a segment of the array of micro-mirrors in the first DMD. And the second driving controller is used for generating a driving signal acting on the second DMD according to the image to be projected and sending the generated driving signal to the second DMD.

In one possible implementation, the first driving controller includes: the image acquisition module is used for acquiring the projection images of the three basic colors of the debugging image in the projection area; the image analysis module is used for respectively partitioning the projection images of the three primary colors and determining the brightness of each partition; and respectively determining the deflection amount of the micro-mirror in each partition in the first DMD according to the brightness difference of different partitions aiming at the projected image of each basic color to obtain the deflection amount of the micro-mirror corresponding to each of the three basic colors; and the driving control module is used for sending a driving signal to the first DMD according to the deflection amount of the micro-mirror corresponding to the first basic color at the time corresponding to the first basic color according to the three-primary-color display time sequence, sending a driving signal to the first DMD according to the deflection amount of the micro-mirror corresponding to the second basic color at the time corresponding to the second basic color, and sending a driving signal to the first DMD according to the deflection amount of the micro-mirror corresponding to the third basic color at the time corresponding to the third basic color.

In a possible implementation manner, the image analysis module is specifically configured to: performing, for the projected image of each primary color: determining a minimum brightness among the brightness of all the partitions and a brightness difference between the brightness of other partitions and the minimum brightness; and determining the deflection amount of the micro-mirror in each partition according to the brightness difference of each partition in the other partitions, wherein the deflection amount of the micro-mirror in the partition corresponding to the minimum brightness enables the micro-mirror to be in an on state.

In a possible implementation manner, the image acquisition module is an image acquisition device, and is configured to acquire projection images of three primary colors.

In a possible implementation manner, the number of the partitions of the first DMD is less than or equal to the number of the micromirrors of the first DMD, and the number of the micromirrors included in one partition of the first DMD is less than or equal to the number of the pixel points of one partition in the first projected image.

In a possible implementation manner, the lighting system further includes an illumination light path, and the first DMD is arranged in the illumination light path or arranged in front of the illumination light path; the illumination light path is used for shaping the light beam emitted by the first DMD, and the shaped light beam meets the light spot size and the incident angle required by the incident of the second DMD.

In a second aspect, there is provided a projector including: a light source, a projection lens, and a projection system as described in any of the above first aspects; the light source provides illumination for the projection system, and the projection system modulates light source beams, outputs the light source beams to the projection lens for imaging, and projects the light source beams to a projection medium to form a projection picture.

In a possible implementation manner, the light source is a laser light source or a mixed light source of laser and fluorescence, and the laser light source includes a bicolor laser light source or a tricolor laser light source.

In a third aspect, there is provided a projection method implemented by the projection system of any of the first aspect or the projector of any of the second aspect, including: according to the three-primary-color display time sequence and the display time of a primary color, a driving signal is sent to the first DMD according to the light output quantity corresponding to the primary color in each partition of the first DMD to drive the micro-mirrors in the corresponding partitions, the driving signal is generated according to the image to be projected and sent to the second DMD so that the second DMD modulates the light beam of the primary color emitted from the first DMD partition, and the modulated light beam enters the projection lens to be imaged. Wherein the amount of light output corresponding to a key color in each section of the first DMD is determined based on the brightness of the different sections of the debug image in the projected image of the key color in the projection area.

In one possible implementation, determining the light output amount corresponding to a primary color in each of the partitions in the first DMD according to the brightness of different partitions in a projected image of the primary color in the projection area of the debug image includes: partitioning a projected image of one basic color of the debugging image in a projection area, and determining the brightness of each partition; and respectively determining the deflection amount of the micro-mirrors in each partition of the first DMD according to the brightness difference of different partitions, wherein the polarization amount of the micro-mirrors in one partition corresponds to the light output amount of the partition.

In a possible implementation manner, the separately determining the deflection amount of the micro mirrors in each of the sub-areas in the first DMD according to the brightness difference of the different sub-areas includes: determining a minimum brightness among the brightness of all the partitions and a brightness difference between the brightness of other partitions and the minimum brightness; and determining the deflection amount of the micro-mirrors in the subareas according to the brightness difference of each of the other subareas.

In the above embodiments of the present application, the projection system is provided with the first DMD for controlling the color map of the projection screen in addition to the second DMD for projecting an image. When projection is carried out, the first DMD can output the illumination light beams from the light source entering the first DMD in a partitioning mode according to the three-primary-color display time sequence and the light output quantity of each partition corresponding to the corresponding primary color, the second DMD can modulate the light beams output by the first DMD in the partitioning mode according to the driving signal generated based on the image to be projected, and the modulated light beams enter the projection lens for imaging. The first DMD can output the illumination light beams from the light source, which are incident to the first DMD, in the subareas according to the light output quantity of each subarea corresponding to the corresponding basic color according to the three-primary-color display time sequence, so that the brightness of different subareas in different primary-color display time can be controlled, the brightness of a projection picture tends to be uniform in the three-primary-color display time, and further, the chromaticity of the projection picture tends to be uniform.

Drawings

FIG. 1 is a schematic diagram of a DMD used in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a projection system according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of another projection system according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of another projection system according to an embodiment of the present disclosure;

FIG. 5 is a schematic view of a partition in an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a first control drive controller in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a projector according to an embodiment of the present application;

FIG. 8 is a schematic diagram illustrating a positional relationship between a three-primary-color laser light source including a light uniformizing element and a first DMD according to an embodiment of the present disclosure;

fig. 9 is a schematic flowchart of determining deflection amounts of micro mirrors corresponding to three primary colors according to an embodiment of the present application;

fig. 10 is a schematic projection flow chart provided in an embodiment of the present application.

Detailed Description

For the chromaticity uniformity of the projection picture, under an ideal condition, the tricolor brightness of each pixel point in a frame of projection image is the same. In order to improve the chromaticity uniformity of the projection picture, a DMD for controlling the light output amount is arranged between a light source and the DMD for projection display, so that the light output amount of a light beam incident to a rear-stage DMD (i.e., the DMD for projection display) is controlled by the DMD, and the three primary colors of the projection picture are adjusted in brightness, so that the chromaticity uniformity of the projection picture is realized.

The DMD is a bistable spatial light modulator composed of thousands of micro-mirrors (precision, micro-mirrors) formed by adding a rotating mechanism that can modulate the reflective surface to a standard Semiconductor process of Complementary Metal Oxide Semiconductor (CMOS). Data is loaded into a memory cell positioned below the micro-mirrors, the data electrostatically controls the deflection states of the micro-mirrors in a binary manner, and the angle and duration of deflection of each micro-mirror are independently controlled, thereby directing reflected light and modulating gray scale. Fig. 1 exemplarily shows deflection of two micromirrors on the DMD and a case of reflecting light. It can be seen that the micro mirrors 10 are deflected at different angles from the micro mirrors 20, and the micro mirrors 10 are deflected at angles by which the light emitted from the light source 30 can be reflected onto the light absorption unit 40, and the micro mirrors 20 are deflected at angles by which the light emitted from the light source 30 can be reflected onto the lens 50.

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Referring to fig. 2, a schematic structural diagram of a projection system provided in an embodiment of the present application is shown. The projection system is applicable to short-focus projectors.

As shown, projection system 100a may include a first DMD101 and a second DMD 102.

The first DMD101 is configured to output the illumination light beam from the light source incident to the first DMD101 in a divided manner according to the light output amount of each divided region corresponding to the corresponding primary color based on the three primary color display timing. And the second DMD102 is used for modulating the light beam output by the first DMD101 in a partitioning manner according to a driving signal generated based on the image to be projected, and the modulated light beam enters the projection lens for imaging.

It should be noted that fig. 2 only exemplarily illustrates the structure of the projection system, and in practical applications, the positions or the placement angles of the first DMD101 and the second DMD102 are not limited to those illustrated in fig. 2. In addition, in the path of the light beam propagating in the projection system, other devices may also be provided, which is not limited in this application.

Alternatively, based on projection system 100a shown in fig. 2, in some embodiments, in order to make the light beam incident on second DMD102 conform to the spot size and incident angle required for second DMD102 to be incident, an illumination light path 103 may be provided between first DMD101 and second DMD102, as shown in fig. 3. This configuration is suitable for the case where the resolution of first DMD101 is greater than the resolution of second DMD102, and in this case, the incident light spot of first DMD101 is greater than the incident light spot of second DMD 102. Of course, this configuration is also applicable to the case where the resolution of first DMD101 is less than or equal to the resolution of second DMD 102.

In the projection system 100b shown in fig. 3, an illumination optical path 103 is provided between the first DMD101 and the second DMD102 in addition to the projection system 100 a. The light beam emitted from the first DMD101 enters the illumination light path 103, is shaped by the illumination light path 103, and is emitted to the second DMD102 after being processed to conform to the spot size and the incident angle required by the incident of the second DMD 102.

The illumination light path 103 may be implemented by one or more optical devices, such as a collecting mirror, and the like, which is not limited to this embodiment.

Of course, the first DMD101 may also be disposed within the illumination light path.

Alternatively, in some embodiments, a first driver controller is coupled to first DMD101 and a second driver controller is coupled to second DMD102 based on projection system 100a shown in fig. 2 or projection system 100b shown in fig. 3.

Fig. 4 schematically shows a projection system 100c, which further includes a first driving controller 104 and a second driving controller 105 on the basis of the projection system 100a shown in fig. 2.

As shown in fig. 4, in projection system 100c, first DMD101 and second DMD102 are provided in this order in the light beam propagation direction. First DMD101 is coupled to first drive controller 104 and second DMD102 is coupled to second drive controller 105.

Based on the projection system, the outgoing light beam of the light source is incident to the first DMD101, the first DMD101 reflects the incoming light beam to the second DMD102, the second DMD102 reflects the incoming light beam to the projection lens, and the projection lens projects the light beam on the projection screen.

The first driving controller 104 is configured to determine light output amounts respectively corresponding to three primary colors in corresponding partitions in the first DMD101 according to luminances of different partitions in three primary color projection images of the debug image in the projection area; according to the three-primary-color display time sequence, a driving signal is sent to the first DMD101 at the time corresponding to the first primary color according to the light output quantity corresponding to the first primary color in each area of the first DMD101 so as to drive the micro mirrors in the corresponding subareas, and therefore the brightness of the projection picture of the first primary color is controlled at the first primary-color display time; sending a driving signal to the first DMD101 according to the light output quantity corresponding to the second primary color in each area in the first DMD101 at the time corresponding to the second primary color to drive the micro mirrors in the corresponding subarea, so as to control the brightness of the projection picture of the second primary color at the second primary color display time; and sending a driving signal to the first DMD101 according to the light output amount corresponding to the third primary color in each area in the first DMD101 at the time corresponding to the third primary color to drive the micromirrors in the corresponding sub-area, thereby controlling the brightness of the projected picture of the third primary color at the third primary color display time. Thus, the chromaticity of the projection picture can be controlled.