Display module pixel arrangement structure capable of reducing moire patterns

Abstract

The utility model relates to the technical field of display modules, in particular to a display module pixel arrangement structure capable of reducing moire patterns, a display module comprises a substrate and a plurality of first pixels distributed on the substrate in an array mode, the distance between at least two adjacent first pixels distributed in the row direction is unequal, each first pixel comprises at least one LED chip, and the LED chips are arranged on the substrate. When each first pixel comprises more than three LED chips, the positions of the LED chips with the same primary color in each pixel are the same, and the distance between two adjacent second pixels distributed in the row direction in the photosensitive element is equal, so that the pixel spatial frequency difference between the photosensitive element and the display module is increased, the difference is increased, and the display effect is improved. And the moire patterns in the acquired image can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of display modules, and in particular to a pixel arrangement structure of a display module for reducing moiré patterns. Background Art

[0002] LED display screen is a display screen that displays various information such as text, images, videos, and video signals by controlling the display mode of semiconductor light emitting diodes. It is usually composed of a single display module or several display modules. The commonly used display module is COB display module. COB display module is a display module that directly mounts LED chips on a substrate (such as a PCB board) and then performs overall film sealing. The pixels in the COB display module are composed of LED chips, and the pixel pitch is usually 0.2mm, 0.6mm, 0.7mm, 0.9mm, 1.2mm or 2mm.

[0003] When using a camera or scanner to capture an image of an LED display screen, if the pixel spatial frequency in the camera or scanner's photosensitive element is close to the pixel spatial frequency in the display module, irregular stripes, i.e. moiré, will be generated. For example, if the first pixel of the display module and the second pixel in the photosensitive element are evenly distributed, when the photosensitive element is shooting the LED display screen, moiré is very likely to be generated due to the close pixel spatial frequencies of the two. Summary of the invention

[0004] In view of the above-mentioned technical problems existing in the prior art, the present application provides a pixel arrangement structure of a display module, which can reduce moiré patterns in captured images.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] A display module pixel arrangement structure for reducing moiré, the display module comprising: a substrate for carrying a first pixel and a driving unit;

[0007] First pixels are arrayed on the substrate, and each of the first pixels includes at least one LED chip;

[0008] A driving unit, electrically connected to the LED chip, and used to control the working state of the LED chip;

[0009] The characteristic is that, in the pixel arrangement structure, at least the intervals between two adjacent first pixels distributed in the row direction are unequal.

[0010] Its further characteristic is that

[0011] The gap between two adjacent first pixels in a row is the row gap, and the gap between two adjacent first pixels in a column is the column gap. When the row gap distances are equal, the row pitch is the reference pitch a; when the column gap distances are equal, the column pitch is the reference pitch b. When the distances between two adjacent first pixels are unequal, the distance interval between two adjacent first pixels distributed in the row direction is [a - a*β, a + a*β], and the distance interval between two adjacent first pixels distributed in the column direction is [b - β*b, b + β*b], where β represents the floating ratio of the reference pitch a or the reference pitch b.

[0012] Further, both the reference pitch a and the reference pitch b are less than or equal to 3 mm.

[0013] Further, 0 ≤ β ≤ 10%.

[0014] Further, a single first pixel includes a package body of at least one LED chip.

[0015] Further, a single first pixel includes three LED chips of different primary colors: a red LED chip, a green LED chip, and a blue LED chip, and the red LED chip, the green LED chip, and the blue LED chip are arranged at intervals in sequence from left to right and / or from top to bottom.

[0016] Further, a single first pixel includes three LED chips of different primary colors: a red LED chip, a green LED chip, and a blue LED chip, and the red LED chip, the green LED chip, and the blue LED chip are distributed in a "pin" shape.

[0017] Further, the LED chip is a Micro LED chip or a Mini LED chip.

[0018] Further, the size of the LED chip is 1 μm to 200 μm.

[0019] Further, the display module is a COB display module.

[0020] Further, the driving unit includes a driving IC, and the driving IC is distributed on the back surface of the substrate.

[0021] Adopting the technical solution of the present application can achieve the following beneficial effects:

[0022] In the display module of the present application, at least the distances between two adjacent first pixels distributed in the row direction are unequal, while in the photosensitive element, the distances between two adjacent second pixels distributed in the row direction are equal, thereby increasing the pixel spatial frequency difference between the photosensitive element and the display module. The increase in the difference is beneficial to reducing moiré patterns in the captured image. Description of the Drawings

[0023] Figure 1 A schematic diagram of a top view of a first example of a pixel arrangement structure of an existing display module;

[0024] Figure 2 This is a schematic diagram of a top view of the first embodiment of the pixel arrangement structure of the display module of the present application;

[0025] Figure 3 It is a schematic diagram of a top view of a second example of a pixel arrangement structure of an existing display module;

[0026] Figure 4 This is a schematic diagram of a top view of the second embodiment of the pixel arrangement structure of the display module of the present application;

[0027] Figure 5 It is a schematic diagram of a top view of a third example of a pixel arrangement structure of an existing display module;

[0028] Figure 6 This is a schematic diagram of a top view of the third embodiment of the pixel arrangement structure of the display module of the present application;

[0029] Figure 7 It is a schematic diagram of a top view structure in which second pixels are evenly distributed in a photosensitive element.

[0030] Reference numerals: substrate 1 , first pixel 2 , second pixel 3 , red LED chip 201 , green LED chip 202 , blue LED chip 203 . DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0033] The display module in the LED display screen is mainly composed of a substrate 1 (such as a PCB board), a plurality of first pixels 2 arrayed on the front side of the substrate, and a plurality of driving units (not shown in the figure) distributed on the back side of the substrate. The gap between two adjacent rows of first pixels 2 is a row gap, and the gap between two adjacent columns of first pixels 2 is a column gap. In the existing display module pixel arrangement structure, the row gap spacing (i.e., row spacing) is equal, and the column gap spacing (i.e., column spacing) is equal. The row spacing is set to a (i.e., reference spacing a), and the column spacing is set to b (i.e., reference spacing b).

[0034] In the photosensitive element of the camera or other equipment, the spacing between two adjacent second pixels 3 distributed in the row direction is equal, and the spacing between two adjacent second pixels 3 distributed in the column direction is equal, referring to Figure 7 , the arrangement period of the first pixel 2 is close to the arrangement period of the second pixel 3, the spacing a1 between two adjacent second pixels distributed in the row direction is approximately equal to a, and the spacing b1 between two adjacent second pixels distributed in the column direction is approximately equal to b, that is, the spatial frequency of the first pixel in the LED display screen is close to the spatial frequency of the second pixel in the photosensitive element. In this case, when using a camera or other equipment to capture images in the LED display screen, moiré patterns are easily generated in the captured images, which seriously affects the image display effect.

[0035] In view of the above problems existing in the prior art, several specific embodiments of the pixel arrangement structure of the display module are disclosed below.

[0036] Embodiment 1: This embodiment is Figure 1 The improvement made to the existing display module pixel arrangement structure example 1 is shown.

[0037] Before improvement, refer to Figure 1 In the pixel arrangement structure of the display module, each first pixel includes an LED chip. The row spacing between two adjacent rows of first pixels 2 is equal, the column spacing between two adjacent columns of first pixels 2 is equal, and the first pixels are evenly distributed, that is, a=b=L1, L1 is less than or equal to 3mm, preferably 1.2mm.

[0038] The LED chip is soldered to the substrate 1 . In this embodiment, the LED chip is a Mini LED chip with a size of 100 μm to 200 μm, preferably 150 μm.

[0039] It should be noted that in another embodiment, the LED chip is a Micro LED chip with a size ranging from 1 μm to 100 microns, preferably 50 μm. Compared with Mini LED chips, Micro LED chips have the advantages of higher brightness and smaller size.

[0040] refer to Figure 2 In the first embodiment of the present application, the structure of the first pixel 2 is the same as Figure 1The same as shown, including an LED chip, the difference is that the specific arrangement structure of the first pixel 2 in the substrate 1 is: the spacing between two adjacent first pixels 2 distributed in the row direction is unequal, and the spacing between two adjacent first pixels 2 distributed in the column direction is unequal. Specifically: the spacing interval between two adjacent first pixels is [L1-β*L1, L1+β*L1], β represents a floating ratio, which is set according to the light output efficiency of the LED chip, the arrangement density of the first pixels in the substrate, etc. In this embodiment, β is less than or equal to 10%, preferably less than or equal to 5%. If β is greater than 10%, it is very easy to generate a dark area with a brightness lower than the surrounding area due to the excessive spacing between the two adjacent first pixels, affecting the overall display effect of the display module. In the actual design process of the display module of this application, a group of data with different values ​​is generated in the interval [L1-β*L1, L1+β*L1]. Each value is calculated based on the spacing L1 and the floating ratio, and each value represents the spacing between two adjacent first pixels.

[0041] Embodiment 2: This embodiment is to Figure 3 The improvement made in the second example of the existing display module pixel arrangement structure is shown.

[0042] Before improvement, refer to Figure 3 In the pixel arrangement structure of the display module, in order to meet the color or white light emission requirements of the display module, each first pixel includes three LED chips: a red LED chip 201 (indicated by "R" in the figure), a green LED chip 202 (indicated by "G" in the figure), and a blue LED chip 203 (indicated by "B" in the figure). The red LED chip 201, the green LED chip 202, and the blue LED chip 203 are sequentially arranged in a row direction and welded to the substrate 1. In this embodiment, the LED chip is a Mini LED chip with a size of 100μm~200μm, preferably 110μm.

[0043] It should be noted that in another embodiment, the LED chip is a Micro LED chip with a size ranging from 1 μm to 100 microns, preferably 20 μm. Compared with Mini LED chips, Micro LED chips have the advantages of higher brightness and smaller size.

[0044] The row spacing between two adjacent rows of first pixels 2 is equal, the column spacing between two adjacent columns of first pixels 2 is equal, and the same primary color LED chips are located at the same position in each first pixel 2. The first pixels are evenly distributed, that is, a=b=L2, L2 is less than or equal to 3mm, preferably 0.9mm.

[0045] refer to Figure 4 In the second embodiment of the present application, the structure of the first pixel 2 is the same as that of the above Figure 3The same as shown, the difference is that the specific arrangement structure of the first pixels 2 in the substrate 1 is as follows: in the same pixel arrangement period, the distances between adjacent first pixels 2 distributed in the row direction are not equal, and the distances between adjacent first pixels 2 distributed in the column direction are not equal. Specifically: the distance interval between adjacent first pixels is [L2 - β * L2, L2 + β * L2], where β represents the floating ratio, and this ratio is set according to the light extraction efficiency of the LED chips, the arrangement density of the first pixels 2 in the substrate 1, etc. In this embodiment, β is less than or equal to 10%, preferably less than or equal to 5%. If β is greater than 10%, it is very easy to generate dark areas with brightness lower than the surrounding areas due to the excessive distance between adjacent first pixels 2, affecting the overall display effect of the display module. During the actual design process of the display module of the present application, within the interval [L2 - β * L2, L2 + β * L2], a set of data with different values is generated, and each value is calculated based on the distance L2 and the floating ratio. Each value represents the distance between adjacent first pixels.

[0046] Embodiment 3. This embodiment is an improvement on Figure 5 Example 3 of the pixel arrangement structure of the existing display module shown.

[0047] Before the improvement, referring to Figure 5 , in the pixel arrangement structure of this display module, to meet the requirements of color light emission or white light emission of the display module, each first pixel 2 includes three LED chips: a red light LED chip 201, a green light LED chip 202, and a blue light LED chip 203. The three LED chips are distributed in a "pin" shape. In this embodiment, the LED chips are Mini LED chips with a size of 100μm - 200μm, preferably 180μm.

[0048] It should be noted that in another embodiment, the LED chips are Micro LED chips with a size range of 1μm - 100 microns, preferably 80μm. Compared with Mini LED chips, Micro LED chips have the advantages of higher brightness and smaller size.

[0049] The row spacing between adjacent rows of first pixels 2 is equal, the column spacing between adjacent columns of first pixels 2 is equal, and the positions of the same primary color LED chips in each first pixel 2 are the same. The first pixels 2 are evenly distributed, that is, a = b = L3, and L3 is less than or equal to 3mm, preferably 2.4mm.

[0050] Referring to Figure 6 , in Embodiment 3 of the present application, the structure of the first pixel 2 is the same as the above Figure 5The same as shown, the difference is that the specific arrangement structure of the first pixel 2 in the substrate 1 is: in the same pixel arrangement period, the spacing between two adjacent first pixels 2 distributed in the row direction is unequal, and the spacing between two adjacent first pixels 2 distributed in the column direction is unequal. Specifically: the spacing interval between two adjacent first pixels is [L3-β*L3, L3+β*L3], β represents a floating ratio, which is set according to the light output efficiency of the LED chip, the arrangement density of the first pixel 2 in the substrate 1, etc. In this embodiment, β is less than or equal to 10%, preferably less than or equal to 5%. If β is greater than 10%, it is very easy to generate a dark area due to the excessive spacing between two adjacent first pixels 2, affecting the overall display effect of the display module. In the actual design process of the display module of this application, a group of data with different values ​​is generated in the interval [L3-β*L3, L3+β*L3]. Each value is calculated based on the spacing L3 and the floating ratio, and each value represents the spacing between two adjacent first pixels 2.

[0051] In the above-mentioned embodiments 1 to 3, the display module is a COB display module, and the LED chip is directly mounted on the substrate 1. It should be noted that in another embodiment, each first pixel 2 can be composed of a package of an LED chip (such as a lamp bead), and the lamp bead is mainly formed by encapsulating the surface of the LED chip with epoxy resin. Currently, commonly used lamp beads include direct plug-in type and surface mount type. Compared with lamp beads, LED chips have the advantages of small size, higher brightness, and faster heat dissipation.

[0052] In addition, in the above-mentioned embodiments 1 to 3, the substrate 1 is a PCB board, and the first pixel 2 array is distributed on the front of the substrate. In order to realize the driving control of the first pixel 2, a driving unit is set on the back of the substrate. The driving unit includes a driving IC, and the driving IC is electrically connected to the corresponding LED chip through the circuit of the substrate 1. When the display module is working, the driving IC sends a driving control signal to the corresponding LED chip to control the LED chip to light up or turn off, or control the luminous intensity of the LED chip to realize the working state control of the LED chip. The distance between two adjacent first pixels in the display module is not equal, while in the photosensitive element, the distance between two adjacent second pixels is equal, thereby increasing the difference in pixel spatial frequency between the photosensitive element and the display module. The increase in the difference greatly weakens or even eliminates the moiré pattern in the captured image.

[0053] It should be noted that the above specific implementation only provides an embodiment in which the spacing between the first pixels in the row direction and the spacing between the first pixels in the column direction are not equal, while in the photosensitive element, the second pixels in the row direction and the second pixels in the column direction are equal. In another implementation, the spacing between the first pixels in the row direction of the display module is unequal, and the spacing between the first pixels in the column direction is equal, or the spacing between the first pixels in the row direction of the display module is equal, and the spacing between the first pixels in the column direction is unequal, while in the photosensitive element, the spacing between the second pixels in the row direction and the spacing between the second pixels in the column direction are equal. This can also increase the difference in pixel spatial frequency between the photosensitive element and the display module, which is beneficial to reducing moiré patterns in the captured image.

[0054] In the process of preparing the COB display module in the above embodiment, a die bonding machine is used to weld the first pixel 2 to the front of the PCB board. The specific steps include: S1, printing solder paste by steel screen printing process, specifically:

[0055] S101, making printing steel mesh based on the spacing data determined during the design process, Figure 2 , Figure 4 , Figure 6 Partial data of the distance between two adjacent first pixels are respectively given, and each value represents the distance between two adjacent first pixels;

[0056] S102, based on printed steel mesh, uses a printing machine to print solder paste on the corresponding position on the front of the PCB board.

[0057] S2, using a die bonding machine to place the LED chip at the corresponding solder paste position. The die bonding machine is equipped with a camera recognition system that can automatically identify the solder paste position. The solder paste position is set according to the data in the corresponding spacing range during the design process. The electrodes of the LED chip correspond to the solder paste, thereby achieving unequal spacing arrangement of two adjacent first pixels.

[0058] S3, using a reflow oven to heat the solder paste to achieve welding between the LED chip and the PCB board.

[0059] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A pixel arrangement structure of a display module for reducing moiré, the display module comprising: A substrate (1), used for carrying a first pixel; First pixels (2) are arranged in an array on the substrate (1), and each of the first pixels (2) comprises at least one LED chip; A driving unit, electrically connected to the LED chip, and used to control the working state of the LED chip; The invention is characterized in that at least the spacing between two adjacent first pixels (2) distributed in the row direction is unequal.

2. The pixel arrangement structure of the display module for reducing moiré according to claim 1, characterized in that: The gap between the first pixels (2) in two adjacent rows is the row gap, and the gap between the first pixels (2) in two adjacent columns is the column gap. The row gap when the row gaps are equal is set as the reference gap a, and the column gap when the column gaps are equal is set as the reference gap b. When the gaps between two adjacent first pixels (2) are unequal, the gap interval between the two adjacent first pixels (2) in the row direction is [a-β*a, a+β*a], and the gap interval between the two adjacent first pixels (2) in the column direction is [b-β*b, b+β*b], where β represents the floating ratio of the reference gap a or the reference gap b.

3. The pixel arrangement structure of the display module for reducing moiré according to claim 2, characterized in that: The reference spacing a and the reference spacing b are both less than or equal to 3 mm, and 0≤β≤10%.

4. The pixel arrangement structure of the display module for reducing moiré according to claim 3, characterized in that: A single first pixel (2) comprises three LED chips of different primary colors: a red LED chip (201), a green LED chip (202), and a blue LED chip (203), wherein the red LED chip (201), the green LED chip (202), and the blue LED chip (203) are arranged in sequence from left to right and / or from top to bottom.

5. The pixel arrangement structure of the display module for reducing moiré according to claim 3, characterized in that: A single first pixel (2) comprises three LED chips of different primary colors: a red LED chip (201), a green LED chip (202), and a blue LED chip (203), wherein the red LED chip (201), the green LED chip (202), and the blue LED chip (203) are distributed in a "pin" shape.

6. The pixel arrangement structure of the display module for reducing moiré according to claim 4 or 5, characterized in that: When a single first pixel (2) includes three or more LED chips, the LED chips with the same primary color are located at the same position in each of the first pixels (2).

Images