Transverse position error correction method for integrated imaging system based on macro lens array

Abstract

The present invention relates to a method for correcting the lateral position error of an integrated imaging system based on a macro lens array. The method also includes obtaining the position of the convergence point of the light cone emitted by a point on the LCD plane after passing through the macro lens array and the position of the standard convergence point on the central depth plane; the standard convergence point is the point where the light cone emitted by the point on the LCD plane converges on the central depth plane after passing through the macro lens array; measuring the lateral position error of the macro lens array according to the average value and corresponding variance of the distance between the position of each convergence point and the position of the standard convergence point, and determining the measurement result; judging whether the measurement result exceeds a threshold; if it exceeds the threshold, measuring the axial position error and the lateral position error of the macro lens array, and then correcting according to the axial position error and the lateral position error of the macro lens array; if it does not exceed the threshold, performing integrated imaging. The present invention can reduce the workload and improve the display effect of integrated imaging.

Description

Technical Field

[0001] The invention relates to the field of integrated imaging, and in particular to a method for correcting lateral position errors of an integrated imaging system based on a macro lens array. Background Art

[0002] With the continuous development of research, more and more researchers have begun to use macro lens arrays in large-format integrated imaging systems. Macro lens arrays are generally embedded on a hard substrate through mechanical means. Their advantages are low cost and mature manufacturing process, and they can achieve large-format, wide-field-of-view integrated imaging display. However, their disadvantage is that the position error caused by installation or use is large. Therefore, in order to obtain better display effects, it is necessary to measure and correct the position error of the macro lens array.

[0003] However, the existing technology has the problems of large workload and low precision. Therefore, in order to solve the above problems, a method for correcting the position error of a macro lens array is proposed. Summary of the invention

[0004] The object of the present invention is to provide a method for correcting lateral position errors of an integrated imaging system based on a macro lens array, which can reduce the workload and improve the display effect of the integrated imaging.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A method for correcting lateral position errors of an integrated imaging system based on a macro lens array, comprising:

[0007] Obtaining the position of the convergence point of the light cone emitted by the point on the LCD plane after passing through the macro lens array and the position of the standard convergence point on the central depth plane; the standard convergence point is the point where the light cone emitted by the point on the LCD plane converges on the central depth plane after passing through the macro lens array;

[0008] Measuring the lateral position error of the macro lens array according to the average value and the corresponding variance of the distance between the position of each convergence point and the position of the standard convergence point, and determining the measurement result; the measurement result is used to characterize the size of the lateral position error of the macro lens array;

[0009] Determining whether the measurement result exceeds a threshold;

[0010] If the threshold is exceeded, the axial position error and the lateral position error of the macro lens array are measured, and correction is then performed based on the axial position error and the lateral position error of the macro lens array;

[0011] If the threshold is not exceeded, integrated imaging is performed.

[0012] Optionally, measuring the lateral position error of the macro lens array according to the average value and corresponding variance of the distance between the position of each convergence point and the position of the standard convergence point to determine the measurement result specifically includes:

[0013] Using the formula Determine the average value of the distance between the position of each convergence point and the position of the standard convergence point;

[0014] Using the formula Determine the variance corresponding to the average value of the distance between the position of each convergence point and the position of the standard convergence point;

[0015] Among them, d avg is the average distance between each convergence point and the standard convergence point, d var is the variance corresponding to the average value of the distance between the position of each convergence point and the position of the standard convergence point, n is the number of convergence points, d n is the distance between the position of the nth convergence point and the position of the standard convergence point.

[0016] Optionally, if the threshold is exceeded, measuring the axial position error and measuring the lateral position error of the macro lens array, and then performing correction according to the axial position error and the lateral position error of the macro lens array, specifically includes:

[0017] The axial position error is measured by adjusting the position of the holographic functional screen;

[0018] The lateral position error of the macro lens array is measured by the position change of the image.

[0019] Optionally, if the threshold is exceeded, the axial position error and the lateral position error of the macro lens array are measured, and correction is then performed according to the axial position error and the lateral position error of the macro lens array, which specifically also includes:

[0020] Using the formula determining a lateral position of the lens;

[0021] Where d is the lateral position of the lens, l1 and l2 are the axial distances between position 1 and position 2 of the holographic functional screen, g is the axial distance between the macro lens array and the LCD display, Δs bottom is the horizontal position change of the bottom pixel.

[0022] Optionally, if the threshold is exceeded, the axial position error and the lateral position error of the macro lens array are measured, and correction is then performed according to the axial position error and the lateral position error of the macro lens array, which specifically also includes:

[0023] The lateral position error of the macro lens array is corrected by rearranging the positions of the corresponding primitive image pixels.

[0024] Optionally, the correction of the lateral position error of the macro lens array by rearranging the positions of the corresponding primitive image pixels specifically includes the following formula:

[0025]

[0026] Among them, x correct is the horizontal coordinate after correction, x ideal is the horizontal coordinate of the pixel corresponding to the ideal case, z R is the axial distance of the standard convergence point.

[0027] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0028] The present invention provides a method for correcting the lateral position error of an integrated imaging system based on a macro lens array. Under the effect of the lateral position error of the macro lens array, the pixels converged at the reconstruction point will no longer converge at one point under ideal conditions, and these pixels will be imaged at other points in the same depth plane. The present invention uses the average value and variance of the distance from the reconstruction point (convergence point) to these points to measure the size of the lateral position error of the macro lens array. When the measurement result does not exceed the threshold, imaging is performed directly. When it exceeds the threshold, the error is measured and corrected, thereby reducing the workload and further improving the display effect of the integrated imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 A schematic flow chart of a method for correcting lateral position errors of an integrated imaging system based on a macro lens array provided by the present invention;

[0031] Figure 2 This is a schematic diagram of the characterization of the macro lens array without position error;

[0032] Figure 3 Schematic diagram for characterizing the lateral position error of the macro lens array;

[0033] Figure 4 Schematic diagram of the measurement of the lateral position of the lens in the macro lens array;

[0034] Figure 5 Schematic diagram of the lateral position error correction principle. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The purpose of the present invention is to provide a method for correcting the lateral position error of an integrated imaging system based on a macro lens array, which can reduce the workload and improve the display effect of the integrated imaging.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Figure 1 The figure is a flow chart of a method for correcting lateral position errors of an integrated imaging system based on a macro lens array provided by the present invention. Figure 1 As shown, the present invention provides a method for correcting lateral position errors of an integrated imaging system based on a macro lens array, comprising:

[0039] S101, obtaining the position of the convergence point of the light cone emitted by the point on the LCD plane after passing through the macro lens array and the position of the standard convergence point on the central depth plane; the standard convergence point is the point where the light cone emitted by the point on the LCD plane converges on the central depth plane after passing through the macro lens array;

[0040] S102, measuring the lateral position error of the macro lens array according to the average value and the corresponding variance of the distance between the position of each convergence point and the position of the standard convergence point, and determining the measurement result; the measurement result is used to characterize the size of the lateral position error of the macro lens array;

[0041] S102 specifically includes:

[0042] Ideally, the macrolens array has no position error, such as Figure 2 As shown in the figure, taking the local part of the lens array as an example, the ideal display end lens center positions are a, b, and c, with point b as the origin O, the X and Y axes parallel to the lens array row and column directions, and the Z axis perpendicular to the lens array direction, the lens array row and column spacing are w and l, and the depth of the lens array and LCD plane is 0 and z1. The three points D, E, and F on the LCD plane pass through the corresponding lens centers a, b, and c, forming a reconstruction point (standard convergence point) R on the center depth plane.

[0043] Assume that the coordinates of the original lens array center a, b, c are (x a ,y a ,0)、(x b ,yb ,0)、(x c ,y c ,0), then the following relationship exists:

[0044] x a =x b =0,x c =l (1)

[0045] y a =w,y b =y c =0 (2)

[0046] Assume that the coordinates of any reconstructed point R in space are (x R ,y R ,z R ), the focal length of the unit lens in the lens array is f, then we can get,

[0047]

[0048] The parametric equation of the straight line aR can be expressed as follows:

[0049]

[0050] Similarly, the parametric equations of the lines bR and cR can be obtained. Let the lines aR, bR, and cR intersect the LCD plane at point D(x D ,y D ,z1),E(x E ,y E ,z1),F(x F ,y F ,z1), the corresponding parameters of the linear parametric equation are s1, s2, s3, then the following relationship exists:

[0051] z1=z R +z R ×s1=z R +z R ×s2=z R +z R ×s3 (5)

[0052] From the formula, we can get that s1=s2=s3. Therefore, we can find the corresponding coordinates of points D, E, and F. In actual situations, the lateral position error of the macro lens array during the display process is characterized as follows: Figure 3As shown. Considering only the lateral position error, that is, when the center of the lens array has a position error only in the direction parallel to the LCD plane, the light cones emitted by points D, E, and F still converge on the central depth plane, but no longer converge at one point, that is, the light cones emitted by points D, E, and F pass through the actual lenses A, B, and C with deviations on the lens array and converge at points d, e, and f on the central depth plane, respectively. Similarly, the larger the mean and variance of the line segments dR, eR, and fR, the larger the lateral position error. Therefore, the mean and variance of the line segments dR, eR, and fR can be used to measure the lateral position error of the macro lens array.

[0053] The coordinates of the actual points A, B, and C at the center of the lens array are (x A ,y A ,z A )、(x B ,y B ,z B )、(x C ,y C ,z C ),but:

[0054] z A =z B =z C =0 (6)

[0055] The parametric equation of line AD is:

[0056]

[0057] Similarly, the parametric equations of lines BE and CF can be obtained. Lines AD, BE, CF intersect the depth plane where point R is located at point d(x d ,y d ,z d )、e(x e ,y e ,z e )、f(x f ,y f ,z f ), the corresponding parameters of the straight line parametric equation are t1, t2, t3. Since points d, e, and f are on the central depth plane of point R, we have:

[0058] z d =z e =z f =z R (8)

[0059] Combining the formula, we can find t1, and thus get the coordinates of point d. Similarly, we can get the coordinates of points e and f. Let the distances of line segments dR, eR, and fR be d1, d2, and d3 respectively, then:

[0060]

[0061] Similarly, we can get d2 and d3.

[0062] Calculate the mean and variance of the line segments dR, eR, and fR to measure the lateral position error of the macrolens array:

[0063] The average value of the line segments dR, eR, and fR is d avg ,but:

[0064]

[0065] The corresponding variance d var for:

[0066]

[0067] S103, determining whether the measurement result exceeds a threshold;

[0068] S104, if the error exceeds the threshold, measuring the axial position error and measuring the lateral position error of the macro lens array, and then performing correction according to the axial position error and the lateral position error of the macro lens array;

[0069] S104 specifically includes:

[0070] Using the formula Determine the average value of the distance between the position of each convergence point and the position of the standard convergence point;

[0071] Using the formula Determine the variance corresponding to the average value of the distance between the position of each convergence point and the position of the standard convergence point;

[0072] Among them, d avg is the average distance between each convergence point and the standard convergence point, d var is the variance corresponding to the average value of the distance between the position of each convergence point and the position of the standard convergence point, n is the number of convergence points, d n is the distance between the position of the nth convergence point and the position of the standard convergence point.

[0073] S104 specifically includes:

[0074] When integrated imaging display is performed, the holographic functional screen can be used to receive the formed image, and the axial position error can be measured by adjusting the position of the holographic functional screen;

[0075] When the holographic functional screen moves at different depths, the position of the image will change. The gap between pixels is magnified so that different pixels can be identified, and the lateral position error of the macro lens array is measured by the change in the position of the image.

[0076] S104 specifically includes:

[0077] like Figure 4 As shown, the axial distance between the lens array and the LCD display screen is g, and the axial distances between the lens array and the holographic functional screen at position 1 and position 2 are l1 and l2 respectively. An appropriate number of pixels are selected, μ is the pixel interval size, and n is the number of pixel intervals. When the holographic functional screen is placed at position 1, a certain number of pixels are imaged on the holographic functional screen. The holographic functional screen is adjusted to position 2 so that these pixels are imaged on the holographic functional screen, and the bottom of the image falls on the z-axis. The lateral position change of the bottom pixel is Δs. bottom , the lateral position coordinate of the lens is d, thus, the lateral position of the lens can be expressed as:

[0078] Using the formula determining a lateral position of the lens;

[0079] Where d is the lateral position of the lens, l1 and l2 are the axial distances between position 1 and position 2 of the holographic functional screen, g is the axial distance between the macro lens array and the LCD display, Δs bottom is the horizontal position change of the bottom pixel.

[0080] S104 specifically includes:

[0081] Based on the measurement of the lateral position error, it is corrected. After the lateral position of the lens is obtained, the correct pixel position can be obtained according to the ideal reconstruction point position and the actual lateral position; that is, the lateral position error of the macro lens array is corrected by rearranging the corresponding primitive image pixel point position. Figure 4 As shown, ideally the corresponding pixel horizontal coordinate is x ideal To ensure that the pixel can still be imaged at point R, the horizontal coordinate of the pixel after correction should be x correct .

[0082]

[0083] Among them, x correct is the horizontal coordinate after correction, x ideal is the horizontal coordinate of the pixel corresponding to the ideal case, z R is the axial distance of the standard convergence point.

[0084] When the distance between the plane where the ideal position of the lens center is located and the reconstruction point is large and much larger than the distance between the lens array and the LCD plane, that is, z R >>g, the formula can be simplified to:

[0085] x correct =dd ideal +x ideal ;

[0086] At this time, the correction of the lateral position error has nothing to do with the location of the reconstruction point, but only with the lateral position of the lens, which makes the correction simpler. Let the ideal pixel in the primitive image be numbered i, the corrected pixel in the primitive image be numbered j, and the pixel size be μ. According to the formula, we can get:

[0087]

[0088] in, According to the formula, it can be found that the ideal pixel number i in the primitive image and the corrected pixel number j in the primitive image are linearly related, that is, for the same primitive image, as long as its pixels are moved by the same horizontal distance, the horizontal position error can be corrected.

[0089] S105: If the threshold value is not exceeded, integrated imaging is performed.

[0090] The present invention changes the position and size of the image by moving the holographic functional screen, and proposes a method for measuring the lateral position of the macro lens array, which is subtracted from the ideal lateral position, thereby realizing the measurement of the lateral position error of the macro lens array. In addition, the relationship between the ideal pixel number and the corrected compensation pixel number under the lateral position error of the macro lens array is derived. This patent proposes a method for correcting the lateral position error of the macro lens array, thereby alleviating the impact of the lateral position error of the macro lens array on the display effect. A method for measuring and correcting the lateral position error of an integrated imaging system based on a macro lens array.

[0091] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0092] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for correcting lateral position errors of an integrated imaging system based on a macro lens array, characterized in that: include: Obtain the position of the convergence point of the light cone emitted by a point on the LCD plane after passing through the macro lens array on the central depth plane and the position of the standard convergence point; The standard convergence point is the point where the light cones emitted from a point on the LCD plane converge on the central depth plane after passing through the macro lens array; Measuring the lateral position error of the macro lens array according to the average value and the corresponding variance of the distance between the position of each convergence point and the position of the standard convergence point, and determining the measurement result; the measurement result is used to characterize the size of the lateral position error of the macro lens array; Determining whether the measurement result exceeds a threshold; If the threshold is exceeded, the axial position error and the lateral position error of the macro lens array are measured, and correction is then performed based on the axial position error and the lateral position error of the macro lens array; If the threshold is not exceeded, integrated imaging is performed; If the threshold is exceeded, the axial position error and the lateral position error of the macro lens array are measured, and correction is performed according to the axial position error and the lateral position error of the macro lens array, specifically including: The axial position error is measured by adjusting the position of the holographic functional screen; Measuring the lateral position error of the macro lens array by the position change of the image; Using the formula determining a lateral position of the lens; Where d is the lateral position of the lens, l1 and l2 are the axial distances between position 1 and position 2 of the holographic functional screen, g is the axial distance between the macro lens array and the LCD display, Δs bottom is the horizontal position change of the bottom pixel; Correcting the lateral position error of the macro lens array by rearranging the positions of the corresponding primitive image pixels; Among them, x correct is the horizontal coordinate after correction, x ideal is the horizontal coordinate of the pixel corresponding to the ideal case, z R is the axial distance of the standard convergence point.

2. The method for correcting lateral position errors of an integrated imaging system based on a macro lens array according to claim 1, characterized in that: The step of measuring the lateral position error of the macro lens array according to the average value and corresponding variance of the distance between the position of each convergence point and the position of the standard convergence point, and determining the measurement result specifically includes: Using the formula Determine the average value of the distance between the position of each convergence point and the position of the standard convergence point; Using the formula Determine the variance corresponding to the average value of the distance between the position of each convergence point and the position of the standard convergence point; Among them, d avg is the average distance between each convergence point and the standard convergence point, d var is the variance corresponding to the average value of the distance between the position of each convergence point and the position of the standard convergence point, n is the number of convergence points, d n is the distance between the position of the nth convergence point and the position of the standard convergence point.

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