# Method and apparatus for correcting color convergence error, and device

Provided are a method and an apparatus for correcting a color convergence error, and a device. The method includes: controlling a projection system to project a first test pattern containing three sets of monochromatic test points and a second test pattern containing three sets of R, G, and B test points, to collect a first projection image and a second projection image on the projection screen; acquiring a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image; calculating color noises corresponding to R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate; calculating color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate; and adjusting an assembly parameter of the projection system.

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**Description**

**TECHNICAL FIELD**

The present disclosure relates to the field of assembling technology, and in particular a method and an apparatus for correcting a color convergence error, and a device.

**BACKGROUND**

In order to solve the defect of insufficient color gamut space in traditional display technologies, display technologies based on red (R), green (G), and blue (B) light sources have emerged, such as three-chip reflective/projection display technology, laser scanning display technology and laser projection display technology, etc. These display technologies based on RGB three-color light source can truly reproduce the rich and gorgeous colors of the objective world and provide more shocking color expression.

The display technologies based on RGB three-color light sources usually include three light sources, and each light source corresponds to one of the three primary colors. A variety of colored lights can be obtained after the lights emitted by the three light sources are mixed in different proportions.

However, due to the mechanical error of the system assembly and the chromatic aberration of the optical component, in the image displayed by the display technology based on the RGB three-color light source, there may be overlapping error in the red, green, and blue pixels, which will affect the clarity of the image. In view of this, a method for correcting the color convergence error needs to be proposed urgently.

**SUMMARY**

Various aspects of the present disclosure provide a method and an apparatus for correcting a color convergence error, and a device, which are used to detect and correct the color convergence error of a projection system, to improve the imaging quality of the projection optical module.

The present disclosure provides a method for correcting a color convergence error, including: controlling a projection system to project a first test pattern containing three sets of monochromatic test points and a second test pattern containing three sets of R, G, and B test points, to collect respectively a first projection image and a second projection image on the projection screen; where centers of three geometric figures by taking respectively the three sets of monochromatic test points as vertices superpose, and positions of the three sets of R, G, and B test points have a one-to-one correspondence with positions of the three sets of monochromatic test points; acquiring respectively a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image; calculating respectively color noises corresponding to R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate; calculating color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate; and adjusting an assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B.

Further optionally, the calculating respectively the color noises corresponding to the R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate includes: calculating respectively coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate; and determining the color noises corresponding to the R, G, and B according to the coordinate offsets.

Further optionally, the calculating respectively the coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate comprises: for the i-th set of test points in the three sets of R, G, and B test points, determining coordinates of the projection image points corresponding to the i-th set of test points according to the second center-of-mass coordinate, i=1, 2, or 3; determining coordinates of the projection image points corresponding to the i′-th set of test points on having the same position as the i-th set of test points on the first test pattern according to the first center-of-mass coordinate, i′=i; and calculating coordinate differences between the projection image points corresponding to the i-th set of test points and the projection image points corresponding to the i′-th set of test points according to the coordinates of the projection image points corresponding to the i-th set of test points and the coordinates of the projection image points corresponding to the i′-th set of test points, and taking the coordinate differences as the coordinate offsets.

Further optionally, the calculating the color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate includes: calculating center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the second center-of-mass coordinate; and correcting center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the color noises, to obtain the color coordinates of the projection image points corresponding to the three sets of R, G, and B test points.

Further optionally, the adjusting the assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B includes: calculating a superposition deviation of three colors of R, G, and B according to the color coordinates of the projection image points corresponding to the three colors of R, G, and B; if the superposition deviation is greater than a set deviation threshold, adjusting a position of a light source of the three colors of R, G, and B in the projection system, to reduce the superposition deviation.

Further optionally, any two test points in the three sets of monochromatic test points are not in the same row and not in the same column.

Further optionally, each of the three sets of monochromatic test points includes four test points.

The present disclosure further provides an apparatus for correcting a color convergence error, including: a projecting module, configured to control a projection system to project a first test pattern containing three sets of monochromatic test points and a second test pattern containing three sets of R, G, and B test points, to collect respectively a first projection image and a second projection image on the projection screen; where centers of three geometric figures by taking respectively the three sets of monochromatic test points as vertices superpose, and positions of the three sets of R, G, and B test points have a one-to-one correspondence with positions of the three sets of monochromatic test points; a coordinate calculating module, configured to acquire respectively a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image; a noise calculating module, configured to calculate respectively color noises corresponding to R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate; a coordinate correcting module, configured to calculate color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate; and an error correcting module, configured to adjust an assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B.

Further optionally, the noise calculating module is specifically configured to: calculate respectively coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate; and determine the color noises corresponding to the R, G, and B according to the coordinate offsets.

The present disclosure further provides an electronic device, including: a memory and a processor; where the memory is used to store at least one computer instruction; and the processor is used to execute the at least one computer instruction for executing the method for correcting the color convergence error provided by the present disclosure.

In the present disclosure, the projection system is controlled to project the first test pattern and the second test pattern, and whether the three different color light points projected by the projection system being superposed are analyzed by comparing the projection results corresponding to the first test pattern and the second test pattern whether the points coincide to determine whether there is a color convergence error in the projection system. In such a technical solution, the color convergence error of the projection system may be effectively detected and corrected, which is beneficial to improve the imaging quality of the projection system.

**BRIEF DESCRIPTION OF THE DRAWINGS**

In order to more clearly explain the embodiments of the present disclosure or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative labor.

*a *

*b *

*a *

*b *

*c *

*d *

*e *

**DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS**

For making the purposes, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in combination with the drawings in the embodiments of the present disclosure. It is apparent that the described embodiments are not all embodiments but part of embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art on the basis of the embodiments in the present disclosure without creative work shall fall within the scope of protection of the present disclosure.

step **101**: controlling a projection system to project a first test pattern containing three sets of monochromatic test points and a second test pattern containing three sets of R, G, and B test points, to collect respectively a first projection image and a second projection image on the projection screen;

step **102**: acquiring respectively a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image;

step **103**: calculating respectively color noises corresponding to R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate;

step **104**: calculating color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate; and

step **105**: adjusting an assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B.

In this embodiment, the first test pattern includes three sets of monochromatic test points, and the centers of three geometric figures by taking the three sets of monochromatic test points as the vertices superpose. The monochrome may be any one of R (red), G (green), and B (blue). R, G, and B are the three primary colors of light, and a full-color image may be obtained by the projection of the projection system based on the combination of the three primary colors.

The second test pattern includes three sets of R, G, and B test points, and the positions of the three sets of R, G, and B test points have a one-to-one correspondence with positions of the three sets of monochromatic test points. In other words, the colors of the test points on the second test pattern and the test points on the first test pattern are different, but the arrangement and the number of test points are the same. The centers of three geometric figures by taking respectively the three sets of R, G, and B test points as vertices superpose. Specifically, it is assumed that a first geometric figure may be drawn by taking the set of R test points as the vertices, a second geometric figure may be drawn by taking the set of G test points as the vertices, a third geometric figure may be drawn by taking the set of B test points as the vertices, and the centers of the first geometric figure, the second geometric figure, and the third geometric figure superpose.

Optionally, the method for detecting the color convergence error according to the present disclosure can be applied to a variety of display systems based on RGB three-color light source imaging, such as a three-chip reflection/projection system based on RGB three-color light source, and a laser scanning display system based on RGB three-color light source, etc. The technical solution of the present disclosure will be illustrated by taking a three-chip reflection projection system as an example below.

The display component of the three-chip reflection projection system includes three display screens: a first display screen, a second display screen, and a third display screen. During projection, different colors of light can be used to illuminate the three display screens in the projection system. After the three display screens are illuminated by the corresponding color of light, they reflect different color of light. The photosynthetic light of different colors is emitted from the projection lens, and the test pattern is projected onto the projection screen. Ideally, that is, there is no color convergence error in the projection system, the pixel positions of the three different colors of red, green, and blue projected by the three display screens accurately superpose. Therefore, in the next step, it can be determined whether the projection system has a color convergence error based on the position feature of the projection image points in the projection image.

The first projection image is obtained by the projection of the projection system with regard to the first test pattern, which contains projection image points corresponding to the three sets of the monochrome test points. After the first projection image is acquired, the center-of-mass coordinates of the projection image points corresponding to the three sets of monochrome test points can be calculated as the first center-of-mass coordinate.

The second projection image is obtained by the projection of the projection system with regard to the second test pattern, which contains projection image points corresponding to three sets of R, G, and B test points. After the second projection image is acquired, the center-of-mass coordinates of the projection image points corresponding to the three sets of R, G, and B test points can be calculated as the second center-of-mass coordinate. It should be understood that the first center-of-mass coordinate/the second center-of-mass coordinate is a general term for the center-of-mass coordinate calculated according to the first projection image/the second projection image, and the first center-of-mass coordinate/the second center-of-mass coordinate may include multiple center-of-mass coordinate.

After the first center-of-mass coordinate and the second center-of-mass coordinate are determined, the color noises corresponding to R, G, and B are calculated respectively. Color noise can be considered as the image noise introduced in the three color channels of R, G, and B during the projection process, affected by the projection environment, projection hardware, or exposure time when shooting the projection image.

Then, the color coordinates corresponding to R, G, and B can be calculated based on the calculated color noises corresponding to R, G, and B and the second center-of-mass coordinate. The color coordinates refer to: the coordinates of the three color components R, G, and B contained in the image-side pixels obtained after the object-side pixels being projected by the projection system. It should be understood that when there is a color convergence error in the projection system, there is positional deviation in the coordinates of the three color components of R, G, and B contained in an image-side pixel have; on the contrary, when there is no color convergence error in the projection system, the three color components R, G, and B contained in the image point superpose.

The second test pattern contains three sets of R, G, and B test points, and the second projection image obtained by projection contains pixel component information of the three color channels of R, G, and B. Furthermore, the color coordinates corresponding to R, G, and B can be calculated according to the second center-of-mass coordinate, and corresponding color coordinate is corrected by using the color noises corresponding to R, G, and B, to obtain more accurate color coordinate values.

After the color coordinates corresponding to R, G, and B are determined, it can be determined whether the superposition degree of the three color pixels of R, G, and B meets a requirement, and the assembly parameter of the projection system can be adjusted when the requirement is not met.

In this embodiment, the projection system is controlled to project the first test pattern and the second test pattern, and whether the three different color light points projected by the projection system being superposed are analyzed by comparing the projection results corresponding to the first test pattern and the second test pattern whether the points coincide to determine whether there is a color convergence error in the projection system. In such a technical solution, the color convergence error of the projection system may be effectively detected and corrected, which is beneficial to improve the imaging quality of the projection system.

Optionally, this embodiment can be executed in a test darkroom environment as shown in *a*

*b **b*

step **201**: controlling a projection system to project a first test pattern and a second test pattern, to collect respectively a first projection image and a second projection image on a projection screen;

step **202**: acquiring respectively a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image;

step **203**: calculating respectively coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate;

step **204**: determining the color noises corresponding to the R, G, and B according to the coordinate offsets;

step **205**: calculating center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the second center-of-mass coordinate;

step **206**: correcting center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the color noises, to obtain the color coordinates of the projection image points corresponding to the three sets of R, G, and B test points;

step **207**: calculating a superposition deviation of three colors of R, G, and B according to the color coordinates of the projection image points corresponding to the three colors of R, G, and B;

step **208**: determining whether the superposition deviation is greater than a set deviation threshold; if yes, going to step **209**; if no, ending the execution; and

step **209**: adjusting a position of a light source of the three colors of R, G, and B in the projection system, and going to step **201**.

In step **201**, optionally, each set of the three sets of monochromatic test points on the first test pattern may include three, four, or even N test points, where N is an integer. The specific value of N is not limited in this embodiment.

In order to take into account both the correction efficiency and the correction effect of the color convergence error, the inventor has repeatedly tested and found that when each set of test points includes four test points, a better correction efficiency and correction effect can be achieved. For convenience of description, the following content will take each set containing four test points as an example to illustrate the technical solution of the present disclosure, but it should be understood that in fact, the technical solution of the present disclosure does not limit each set to include four test points.

Optionally, it can be designed that any two test points in the three sets of monochromatic test points are not in the same row and not in the same column. The advantage of this design is that each row or each column contains only one test point, which is beneficial to quickly find the projection image points row by row or column by column from the first projection image or the second projection image and calculate the center-of-mass coordinate.

The positions of the three sets of R, G, and B test points on the second test pattern have a one-to-one correspondence with the positions of the three sets of monochromatic test points on the first test pattern. Therefore, the number and the arrangement feature of the test points on the second test pattern can be directly obtained according to the number and the arrangement feature of the test points on the first test pattern, which will not be repeated here.

Optionally, the test point may be a round point, a cross point, a square point or a point of other shapes, which is not limited in this embodiment. Optionally, the background color of the first test pattern and the second test pattern may be black to avoid the introduction of other colors of light from affecting the test points.

In an optional embodiment, when each set of test points includes four test points, the distribution of a total of 12 test points in three sets on the first test pattern may be as shown in *a***1**′, **4**′, **7**′ and **10**′, the second set of test points includes test points numbered **2**′, **5**′, **8**′ and **11**′, and the third set of test points includes test points numbered **3**′, **6**′, **9**′ and **12**′. The center point of the rectangle by taking the test points numbered **1**′, **4**′, **7**′ and **10**′ as the vertices, the center point of the rectangle by taking the test points numbered **2**′, **5**′, **8**′ and **11**′ as the vertices, and the center point of the rectangle by taking the test points numbered **3**′, **6**′, **9**′ and **12**′ as the vertices superpose.

Correspondingly, the distribution of a total of 12 test points in the three sets of R, G, and B on the second test pattern may be shown in *b***1**, **4**, **7**, and **10**, the G set of test points includes test points numbered **2**, **5**, **8** and **11**, and the B set of test points includes test points numbered **3**, **6**, **9** and **12**. In the same way, the center point of the first rectangle by taking the test points numbered **1**, **4**, **7** and **10** as the vertexes, the center point of the second rectangle by taking the test points numbered **2**, **5**, **8** and **11** as the vertexes, and the center point of the third rectangle by taking the test points numbered **3**, **6**, **9** and **12** as the vertexes superpose.

In step **202**, the first projection image or the second projection image can be scanned row by row or column by column, and the center-of-mass coordinate corresponding to each scanned projection image point can be calculated, to obtain the first center-of-mass coordinate and the second center-of-mass coordinate.

In step **203**, optionally, when the coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points are calculated, the set can be used as a unit. The calculation is as follows:

for the i-th set of test points in the three sets of R, G, and B test points, determining coordinates of the projection image points corresponding to the i-th set of test points according to the second center-of-mass coordinate, i=1, 2, or 3;

determining coordinates of the projection image points corresponding to the i′-th set of test points on having the same position as the i-th set of test points on the first test pattern according to the first center-of-mass coordinate, i′=i; and

calculating coordinate differences between the projection image points corresponding to the i-th set of test points and the projection image points corresponding to the i′-th set of test points according to the coordinates of the projection image points corresponding to the i-th set of test points and the coordinates of the projection image points corresponding to the i′-th set of test points, and taking the coordinate differences as the coordinate offsets.

Taking *a **b ***0**Y is use to mark the coordinate system where the first projection image and the second projection image are located. The R set of test points on the second test pattern are marked as the first set of test points, the G set of test points are marked as the second set of test points, and the B set of test points are marked as the third set of test points. When i=1, the first set of test points includes test points numbered **1**, **4**, **7** and **10**. The coordinates of the projection image points corresponding to test points numbered **1**, **4**, **7** and **10** can be determined from the second center-of-mass coordinate, which are marked as P**1** (X**1**, Y**1**), P**4** (X**4**, Y**4**), P**7** (X**7**, Y**7**) and P**10** (X**10**, Y**10**). On the first test pattern, the 1′-th set of test points with the same position as the first set of test points includes test points numbered **1**′, **4**′, **7**′ and **10**′. The coordinates of the projection image points corresponding to test points numbered **1**′, **4**′, **7**′ and **10**′ can be determined from the second center-of-mass coordinate, which are marked as P**1**′ (X**1**′,Y**1**′), P**4**′ (X**4**′,Y**4**′), P**7**′ (X**7**′, Y**7**′) and P**10**′ (X**10**′,Y**10**′). Next, the coordinate difference ΔX**11**′ and ΔY**11**′ between the projection image points P**1**′, P**4**′, P**7**′ and P**10**′ corresponding to the 1′-th set of test points and the projection image points P**1**, P**4**, P**7** and P**10** corresponding to the 1-th set of test points are calculated:

Δ*X*1=(*X*1+*X*4+*X*7+*X*10)/4−(*X*1′+*X*4′+*X*7′+*X*10′)/4

Δ*Y*1=(*Y*1+*Y*4+*Y*7+*Y*10)/4−(*Y*1′+*Y*4′+*Y*7′+*Y*10′)/4

Similarly, when i=2 and i=3, the coordinate difference ΔX**2** and ΔY**2** between the projection image points corresponding to the 2′-th set of test points and the projection image points corresponding to the 1-th set of test points can be calculated, and the coordinate difference ΔX**3** and ΔY**3** between the projection image points corresponding to the 3′-th set of test points and the projection image points corresponding to the 3-th set of test points can be calculated.

In step **204**, after the coordinate offsets are determined, the coordinate offsets corresponding to the three colors of R, G, and B may be took respectively as the color noises corresponding to each color components. For example, following the above example, ΔX**1** and ΔY**1** can be regarded as the color noises corresponding to R, ΔX**2** and ΔY**2** can be regarded as the color noises corresponding to G, and ΔX**3** and ΔY**3** can be regarded as the color noises corresponding to B.

In step **205**, for the three sets of R, G, and B test points, the corresponding geometric shapes can be respectively outlined, and then the center point of the geometric shapes can be calculated.

Following the above example, when each set of test points includes four test points, the intersection of the diagonals of the rectangle formed by the projection image points corresponding to the four test points can be calculated as the center of the rectangle. For example, as shown in *c*_{R }(X_{R}, Y_{R}) of the straight line formed by the projection image points corresponding to the test points numbered **1** and **7** and the straight line formed by the projection image points corresponding to the test points numbered **4** and **10** can be calculated as the center of the first rectangle. As shown in *d*_{G}, Y_{G}) of the straight line formed by the projection image points corresponding to the test points numbered **2** and **3** and the straight line formed by the projection image points corresponding to the test points numbered **5** and **11** can be calculated as the center of the second rectangle. As shown in *e*_{B }(X_{B}, Y_{B}) of the straight line formed by the projection image points corresponding to the test points numbered **3** and **9** and the straight line formed by the projection image points corresponding to the test points numbered **6** and **12** can be calculated as the center of the third rectangle.

In step **206**, optionally, when the center coordinates are corrected based on the color noises, the corresponding color noise may be subtracted on the basis of the center coordinates. For example, following the above example, the color coordinate of the projection image point corresponding to the R set of test points can be (X_{R}−ΔX**1**, Y_{R}−ΔY**1**), and the color coordinate of the projection image point corresponding to the R set of test points can be (X_{G}−ΔX**2**, Y_{G}−ΔY**2**), the color coordinate of the projection image point corresponding to the R set of test points can be (X_{B}−ΔX**3**, Y_{B}−ΔY**3**).

In steps **207**-**209**, after the color coordinates of the projection image points corresponding to the three sets of R, G, and B test points are determined, the superposition deviation of the three colors of R, G, and B can be calculated based on the three color coordinates. Besides, when the superposition deviation is greater than the set deviation threshold, the position of the three-color light source in the projection system can be adjusted. After the adjustment, step **201** can be executed again to continue to detect whether there is still a color convergence error. Optionally, the deviation threshold is an empirical value related to actual demand, which is not limited in this embodiment.

In this embodiment, the projection system is controlled to project the first test pattern and the second test pattern, and whether the three different color light points projected by the projection system being superposed are analyzed by comparing the projection results corresponding to the first test pattern and the second test pattern whether the points coincide to determine whether there is a color convergence error in the projection system. In such a technical solution, the color convergence error of the projection system may be effectively detected and corrected, which is beneficial to improve the imaging quality of the projection system.

It should be understood that although the terms first, second, third, etc. may be used to describe XXX in the embodiments of the present disclosure, these XXX should not be limited only to those terms. These terms are only used to distinguish the XXX from each other. For example, a first XXX may also be referred to as a second XXX without departing from the scope of the embodiments of the present disclosure. Similarly, a second XXX may also be referred to as a first XXX.

It is also to be noted that terms “include”, “contain” or any other variants thereof are intended to include nonexclusive inclusions, thereby ensuring that a commodity or system including a series of elements not only includes those elements but also includes other elements which are not clearly listed or further includes elements intrinsic to the commodity or the system. Under the condition of no more restrictions, an element defined by statement “including a/an” does not exclude existence of another element which is the same in a commodity or system including the element.

The above describes alternative implementations of the method for correcting the color convergence error. As shown in

a projecting module **401**, configured to control a projection system to project a first test pattern containing three sets of monochromatic test points and a second test pattern containing three sets of R, G, and B test points, to collect respectively a first projection image and a second projection image on the projection screen; where centers of three geometric figures by taking respectively the three sets of monochromatic test points as vertices superpose, and positions of the three sets of R, G, and B test points have a one-to-one correspondence with positions of the three sets of monochromatic test points;

a coordinate calculating module **402**, configured to acquire respectively a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image;

a noise calculating module **403**, configured to calculate respectively color noises corresponding to R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate;

a coordinate correcting module **404**, configured to calculate color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate; and

an error correcting module **405**, configured to adjust an assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B.

Further optionally, the noise calculating module **403** is specifically configured to: calculate respectively coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate; and determine the color noises corresponding to the R, G, and B according to the coordinate offsets.

Further optionally, the noise calculating module **403** is specifically configured to: for the i-th set of test points in the three sets of R, G, and B test points, determine coordinates of the projection image points corresponding to the i-th set of test points according to the second center-of-mass coordinate, i=1, 2, or 3; determine coordinates of the projection image points corresponding to the i′-th set of test points on having the same position as the i-th set of test points on the first test pattern according to the first center-of-mass coordinate, i′=i; and calculate coordinate differences between the projection image points corresponding to the i-th set of test points and the projection image points corresponding to the i′-th set of test points according to the coordinates of the projection image points corresponding to the i-th set of test points and the coordinates of the projection image points corresponding to the i′-th set of test points, and take the coordinate differences as the coordinate offsets.

Further optionally, the coordinate correcting module **404** is specifically configured to: calculate center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the second center-of-mass coordinate; and correct center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the color noises, to obtain the color coordinates of the projection image points corresponding to the three sets of R, G, and B test points.

Further optionally, the error correcting module **405** is specifically configured to: calculate a superposition deviation of three colors of R, G, and B according to the color coordinates of the projection image points corresponding to the three colors of R, G, and B; if the superposition deviation is greater than a set deviation threshold, adjust a position of a light source of the three colors of R, G, and B in the projection system, to reduce the superposition deviation.

Further optionally, any two test points in the three sets of monochromatic test points are not in the same row and not in the same column.

Further optionally, each of the three sets of monochromatic test points comprises four test points.

The aforementioned apparatus for correcting the color convergence error can execute the method for correcting the color convergence error according to the embodiment of the present disclosure, and has the corresponding functional modules and beneficial effects for the execution method. Technical details that are not described in detail in the present embodiment can refer to the method provided in the embodiment of the present disclosure, and will not be repeated.

The internal structure and function of the apparatus for correcting the color convergence error are described above. In practice, the apparatus for correcting the color convergence error can be represented as an electronic device. As shown in **501**, a processor **502**, an input apparatus **503**, and an output apparatus **504**.

The memory **501**, the processor **502**, the input apparatus **503**, and the output apparatus **504** may be connected by a bus or other means. The bus connection is taken as an example in

The memory **501** is used to store one or more computer instructions, and can be configured to store various other data to support operations on the electronic device. Examples of such data include instructions of any application or method operated on the electronic device.

The memory **501** can be implemented by any type of volatile or non-volatile storage device or a combination of them, such as static random access memory (SRAM for short), electrically erasable programmable read-only memory (EEPROM for short), erasable Programmable Read Only Memory (EPROM for short), Programmable Read Only Memory (PROM for short), Read Only Memory (ROM for short), Magnetic Memory, Flash Memory, Magnetic Disk or Optical Disk.

In some embodiments, the memory **501** may optionally include a memory remotely set with respect to the processor **502**, and the remote memory may be connected to the electronic device. Examples of the aforementioned network include but are not limited to the Internet, corporate intranet, local area network, mobile communication network, and combinations thereof.

The processor **502** is coupled with the memory **501**, and is configured to execute the one or more computer instructions for executing the method provided in the embodiment corresponding to

The input apparatus **503** can receive inputted number or character information, and generate key signal input related to user setting and function control of the electronic device. The output apparatus **504** may include a display device such as a display screen.

Further, as shown in **505**. The power supply component **505** provides power for various components of the device where the power supply component is located. The power supply component may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the device where the power supply component is located.

The aforementioned electronic device can execute the method for correcting the color convergence error provided by the embodiments of the present application, and has the corresponding functional modules and beneficial effects for the execution method. Technical details that are not described in detail in the present embodiment can refer to the method provided in the embodiment of the present disclosure, and will not be repeated.

The apparatus embodiments described above are merely illustrative, where the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, i.e., may be located at a place, or may be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art can understand and implement without creative work.

Through the description of the above implementation modes, those skilled in the art can clearly understand that various implementation modes may be implemented by means of software and a necessary general hardware platform, and of course, by hardware. Based on such understanding, the essence of the foregoing technical solutions or portions making contribution to the prior art may be embodied in the form of software products. The computer software products may be stored in a computer-readable storage medium such as a ROM/RAM, a magnetic disk and an optical disc, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments or portions of the embodiments.

It is finally to be noted that the above embodiments are adopted not to limit but only to describe the technical solutions of the present disclosure. Although the present disclosure has been described with reference to the abovementioned embodiments in detail, those of ordinary skill in the art should know that modifications may still be made to the technical solutions recorded in each embodiment or equivalent replacements may be made to part of technical features therein. These modifications or replacements do not make the essences of the corresponding technical solutions depart from the spirit and scope of the technical solutions of each embodiment of the present disclosure.

## Claims

1. A method for correcting a color convergence error, comprising:

- controlling a projection system to project a first test pattern containing three sets of monochromatic test points and a second test pattern containing three sets of R, G, and B test points, to collect respectively a first projection image and a second projection image on the projection screen;

- wherein centers of three geometric figures by taking respectively the three sets of monochromatic test points as vertices superpose, and positions of the three sets of R, G, and B test points have a one-to-one correspondence with positions of the three sets of monochromatic test points;

- acquiring respectively a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image;

- calculating respectively color noises corresponding to R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate;

- calculating color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate; and

- adjusting an assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B.

2. The method according to claim 1, wherein the calculating respectively the color noises corresponding to the R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate comprises:

- calculating respectively coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate; and

- determining the color noises corresponding to the R, G, and B according to the coordinate offsets.

3. The method according to claim 2, wherein the calculating respectively the coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate comprises:

- for the i-th set of test points in the three sets of R, G, and B test points, determining coordinates of the projection image points corresponding to the i-th set of test points according to the second center-of-mass coordinate, i=1, 2, or 3;

- determining coordinates of the projection image points corresponding to the i′-th set of test points on having the same position as the i-th set of test points on the first test pattern according to the first center-of-mass coordinate, i′=i; and

- calculating coordinate differences between the projection image points corresponding to the i-th set of test points and the projection image points corresponding to the i′-th set of test points according to the coordinates of the projection image points corresponding to the i-th set of test points and the coordinates of the projection image points corresponding to the i′-th set of test points, and taking the coordinate differences as the coordinate offsets.

4. The method according to claim 3, wherein the adjusting the assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B comprises:

- calculating a superposition deviation of three colors of R, G, and B according to the color coordinates of the projection image points corresponding to the three colors of R, G, and B;

- if the superposition deviation is greater than a set deviation threshold, adjusting a position of a light source of the three colors of R, G, and B in the projection system, to reduce the superposition deviation.

5. The method according to claim 3, wherein any two test points in the three sets of monochromatic test points are not in the same row and not in the same column.

6. The method according to claim 3, wherein each of the three sets of monochromatic test points comprises four test points.

7. The method according to claim 2, wherein the adjusting the assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B comprises:

- calculating a superposition deviation of three colors of R, G, and B according to the color coordinates of the projection image points corresponding to the three colors of R, G, and B;

- if the superposition deviation is greater than a set deviation threshold, adjusting a position of a light source of the three colors of R, G, and B in the projection system, to reduce the superposition deviation.

8. The method according to claim 2, wherein any two test points in the three sets of monochromatic test points are not in the same row and not in the same column.

9. The method according to claim 2, wherein each of the three sets of monochromatic test points comprises four test points.

10. The method according to claim 1, wherein the calculating the color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate comprises:

- calculating center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the second center-of-mass coordinate; and

- correcting center coordinates of three geometric figures by taking respectively the projection image points corresponding to the three sets of R, G, and B test points as vertices according to the color noises, to obtain the color coordinates of the projection image points corresponding to the three sets of R, G, and B test points.

11. The method according to claim 10, wherein the adjusting the assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B comprises:

- calculating a superposition deviation of three colors of R, G, and B according to the color coordinates of the projection image points corresponding to the three colors of R, G, and B;

- if the superposition deviation is greater than a set deviation threshold, adjusting a position of a light source of the three colors of R, G, and B in the projection system, to reduce the superposition deviation.

12. The method according to claim 10, wherein any two test points in the three sets of monochromatic test points are not in the same row and not in the same column.

13. The method according to claim 10, wherein each of the three sets of monochromatic test points comprises four test points.

14. The method according to claim 1, wherein the adjusting the assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B comprises:

15. The method according to claim 1, wherein any two test points in the three sets of monochromatic test points are not in the same row and not in the same column.

16. The method according to claim 1, wherein each of the three sets of monochromatic test points comprises four test points.

17. An apparatus for correcting a color convergence error, comprising:

- a projecting module, configured to control a projection system to project a first test pattern containing three sets of monochromatic test points and a second test pattern containing three sets of R, G, and B test points, to collect respectively a first projection image and a second projection image on the projection screen;

- wherein centers of three geometric figures by taking respectively the three sets of monochromatic test points as vertices superpose, and positions of the three sets of R, G, and B test points have a one-to-one correspondence with positions of the three sets of monochromatic test points;

- a coordinate calculating module, configured to acquire respectively a first center-of-mass coordinate and a second center-of-mass coordinate corresponding to projection image points on the first projection image and the second projection image;

- a noise calculating module, configured to calculate respectively color noises corresponding to R, G, and B according to the first center-of-mass coordinate and the second center-of-mass coordinate;

- a coordinate correcting module, configured to calculate color coordinates corresponding to the R, G, and B according to the color noises corresponding to the R, G, and B and the second center-of-mass coordinate; and

- an error correcting module, configured to adjust an assembly parameter of the projection system according to the color coordinates corresponding to the R, G, and B.

18. The apparatus according to claim 17, wherein the noise calculating module is specifically configured to:

- calculate respectively coordinate offsets of the projection image points corresponding to the three sets of R, G, and B test points relative to the projection image points corresponding to the three sets of monochrome test points according to the first center-of-mass coordinate and the second center-of-mass coordinate; and

- determine the color noises corresponding to the R, G, and B according to the coordinate offsets.

19. An electronic device, comprising: a memory and a processor;

- wherein the memory is used to store at least one computer instruction;

- the processor is used to execute the method according to claim 1.

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**Patent History**

**Patent number**: 11153544

**Type:**Grant

**Filed**: Sep 6, 2018

**Date of Patent**: Oct 19, 2021

**Patent Publication Number**: 20210211625

**Assignee**: GOERTEK INC. (Weifang)

**Inventors**: Xinxin Han (Weifang), Zhiyong Zhao (Weifang), Nanjing Dong (Weifang), Debo Sun (Weifang)

**Primary Examiner**: Brian P Yenke

**Application Number**: 17/058,619

**Classifications**

**Current U.S. Class**:

**Positional Servo Systems (e.g., Servomechanisms) (318/560)**

**International Classification**: H04N 9/31 (20060101); H04N 9/73 (20060101);