Centrifugal backlight lens, backlight module and liquid crystal display device

Abstract

This application relates to the field of display panel technology, specifically disclosing a centrifugal backlight lens, a backlight module, and a liquid crystal display device. The centrifugal backlight lens includes a lens body, with an LED receiving groove on the bottom surface for accommodating LED chips, and a light-emitting surface with a concave light-controlling structure on the top surface. The center of the LED receiving groove and / or the optical center of the concave light-controlling structure on the light-emitting surface are offset relative to the central axis of the lens body, and when the center of the LED receiving groove and the optical center of the concave light-controlling structure on the light-emitting surface are simultaneously offset, they both offset synchronously in the same direction; the direction of offset forms the centrifugal direction of the centrifugal backlight lens; the offset amount is defined as d, and the diameter of the bottom surface of the lens body is D, satisfying: 0 < d ≤ D / 4. The centrifugal backlight lens of this application embodiment can achieve directional light energy enhancement, enabling more uniform brightness in the backlight module.

Description

Technical Field

[0001] This application belongs to the field of display panel technology, specifically relating to a centrifugal backlight lens, a backlight module, and a liquid crystal display device. Background Technology

[0002] Symmetrical optical lenses typically feature a symmetrical light output pattern. This design allows LED light energy to be spatially distributed in an array. However, the current use of mechanized array arrangement leads to uneven brightness, especially with dark areas appearing at the four corners and bright areas at the top and bottom, severely affecting the uniformity of the display image and making improvements expensive. Summary of the Invention

[0003] This application provides a centrifugal backlight lens, a backlight module, and a liquid crystal display device to solve the technical problem of uneven brightness in related technologies, especially the appearance of dark areas at the four corners and bright areas at the top and bottom.

[0004] In one aspect, this application provides a centrifugal backlight lens.

[0005] Secondly, this application provides a backlight module.

[0006] Thirdly, this application provides a liquid crystal display device.

[0007] The technical solutions provided in this application have the following advantages compared with the prior art: In the centrifugal backlight lens of this application embodiment, the LED receiving slot is arranged on the bottom surface of the lens body, and the light-emitting surface with the concave light control structure is located on the top surface of the lens. The optical centers of the two are spatially offset with respect to the central axis of the lens. If the two centers are offset at the same time, they are spatially offset in the same direction. At the same time, the eccentricity is limited by the size constraint of 0 < d ≤ D / 4. Based on the above-mentioned spatial matching relationship, the eccentric layout changes the original symmetrical light path direction, and the size limit avoids the problem of light path loss of control caused by excessive offset. In this way, the light is directionally focused and reinforced along the centrifugal direction, realizing directional asymmetrical light distribution, meeting the usage requirements of targeted supplementary light in the corner area of ​​the backlight, reducing the bright area at the top and bottom, and realizing the uniformity of the backlight. Attached Figure Description

[0008] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0011] Figure 1 This is a comparative diagram of the structure of the centrifugal backlight lens and the symmetrical optical lens of this application.

[0012] Figure 2 This is a schematic diagram of the liquid crystal display device of this application.

[0013] Figure 3 This is a schematic diagram of the layout of the backlight module in this application.

[0014] Figure 4 This is a schematic diagram of the symmetrical butterfly-shaped light output effect of a symmetrical optical lens.

[0015] Figure 5 This is a schematic diagram of the asymmetric butterfly-shaped light output effect of the centrifugal backlight lens of this application.

[0016] Figure label: 100. Centrifugal backlight lens; 101. LED receiving slot; 102. Concave light control structure; 200. Symmetrical optical lens; 300. Backlight module; 301. Back panel; 302. LED light strip; 303. Diffuser plate; 304. Reflective film; 305. Brightness enhancement film; 400. Liquid crystal display device; 401. Liquid crystal panel; A. Top left partition; B. Top center partition; C. Top right partition; D. Left middle partition; E. Center partition; F. Right middle partition; G. Bottom left partition; H. Middle bottom partition; I. Bottom right partition. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0019] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0020] like Figures 1-5 As shown, the centrifugal backlight lens of this application embodiment includes a lens body. The bottom surface of the lens body is provided with an LED receiving groove 101 for accommodating LED chips, and the top surface is constructed as a light-emitting surface with a concave light control structure 102. The center of the LED receiving groove 101 and / or the optical center of the concave light control structure 102 of the light-emitting surface are offset relative to the central axis of the lens body. When the center of the LED receiving groove 101 and the optical center of the concave light control structure 102 of the light-emitting surface are offset at the same time, they are offset synchronously in the same direction. The direction of offset forms the centrifugal direction of the centrifugal backlight lens 100. The offset amount is defined as d, and the bottom diameter of the lens body is D, satisfying: 0 < d ≤ D / 4.

[0021] This embodiment breaks the uniform light distribution pattern of traditional symmetrical lenses by unidirectionally offsetting the center of the LED receiving slot 101 or the optical center of the concave light control structure 102 on the light-emitting surface relative to the central axis of the lens body. This causes the emitted light energy to generate a centrifugal focusing effect in space. This design can guide the light energy to converge in a more desired direction, such as the corners or the center area, according to the actual brightness requirements of the display area, thereby improving the brightness and image uniformity of the target area without increasing the number of light sources or optical films. The offset is limited to within one-quarter of the diameter of the lens bottom surface, which ensures a significant centrifugal effect while avoiding excessive light concentration that could lead to localized overbrightness or increased light loss.

[0022] Specifically, the lens body is typically injection molded from optical-grade plastics such as polymethyl methacrylate or polycarbonate. An LED receiving groove 101, located at the center of the bottom surface, is used to accommodate and position the LED chip; the groove shape is adapted to the LED chip package shape. The light-emitting surface on the top surface has a concave light-controlling structure 102, the curved profile of which determines the refraction and deflection angle of the emitted light. The core of the centrifugal design lies in: within the bottom diameter D of the lens body, shifting the center position of the LED receiving groove 101 a distance d relative to the geometric center axis of the lens body in a certain direction, or similarly shifting the optical center of the concave light-controlling structure 102 on the light-emitting surface by d, or both shifting synchronously. When both shift synchronously, the shift direction remains consistent, forming a unified centrifugal direction. The centrifugal effect is more pronounced with the synchronous shift scheme. Experimental verification shows that the range of the shift amount d can produce sufficient polarization without wasting light due to excessive eccentricity causing leakage from the lens sidewalls. The offset direction, or centrifugal direction, can be horizontal, vertical, or oblique at any angle to the horizontal direction, depending on the position and orientation requirements of each lens zone in the backlight module 300.

[0023] In a preferred embodiment, the light-emitting surface of the lens body can adopt a refractive design, that is, after the light is emitted by the LED chip, it is refracted into the lens body through the side wall of the LED receiving groove 101, and then refracted a second time by the concave light control structure 102 of the light-emitting surface before being emitted. The light distribution is controlled by refraction throughout the process.

[0024] In some embodiments, the centrifugal direction is any one of transverse, longitudinal, or oblique. The light output pattern of the centrifugal backlight lens 100 is an asymmetrical butterfly light distribution curve, and the light is enhanced along the centrifugal direction.

[0025] In this embodiment, lateral centrifugal force is suitable for guiding light energy to concentrate on the left and right sides of the display screen, longitudinal centrifugal force is suitable for guiding light energy in the vertical direction, and oblique centrifugal force is suitable for directional supplementary lighting in the four corner areas. The asymmetric butterfly light distribution curve means that the light intensity is significantly enhanced in the centrifugal direction and correspondingly weakened in the reverse direction, forming a directional light energy distribution gradient.

[0026] As shown in the attached diagram, the centrifugal direction is determined by the position of the lens in the backlight module 300: for example, lenses located on the left and right edge zones of the display area adopt a horizontal centrifugal direction, pointing towards the center area; lenses located on the upper and lower edge zones adopt a vertical centrifugal direction, also pointing towards the center area; lenses located in the four corner zones adopt an oblique centrifugal direction, pointing towards the corresponding corner of the display area. In practical applications, only the offset direction of the LED receiving slot 101 and the light-emitting surface concave light control structure 102 relative to the central axis of the lens body needs to be adjusted during the lens mold design stage to achieve switching between different centrifugal directions. There is no need to change the external dimensions and mounting interface of the lens, which is conducive to the universality of components and adaptability to backlight modules 300 or displays of various sizes.

[0027] In some embodiments, the centrifugal backlight lens 100 is a refractive optical lens or a reflective optical lens.

[0028] In this embodiment, the centrifugal design can be applied to both refractive and reflective lenses. Refractive lenses alter the light path by refracting light through the lens material itself; they are simple in structure, easy to mold, and suitable for the current mainstream direct-lit backlight module 300. Reflective lenses, on the other hand, have a reflective surface inside or on the surface of the lens, causing light to be reflected before being emitted. This is suitable for scenarios requiring a greater deflection of the light emission angle, or for use in thin modules with limited space and height. Both share the same centrifugal principle—achieving asymmetric light distribution by shifting the optical centers of the LED's input and output sides; the only difference lies in the mode of light propagation.

[0029] The backlight module 300 of the present application embodiment is described below, including a back plate 301, an LED light strip 302 disposed on the back plate 301, a plurality of optical lenses mounted on the LED light strip 302, and a diffuser plate 303 located above the optical lenses; the optical lenses include a symmetrical optical lens 200 and a centrifugal backlight lens 100 as described in any of the above embodiments.

[0030] In this embodiment, the backlight module 300 arranges symmetrical lenses and centrifugal backlight lenses 100 on the same back plate 301, breaking away from the traditional approach of using the same type of lens for all modules. The symmetrical lenses provide reference illumination, while the centrifugal backlight lenses 100 directionally distribute light energy in local areas. The two work together to ensure that the brightness distribution within the entire effective display area remains basically uniform, thus solving the problems of darker corners and brighter edges in traditional solutions.

[0031] Specifically, the backplate 301 is a metal stamping or plastic molding part, providing structural support for the entire module. LED chips are mounted at regular intervals along the plane of the backplate 302, with an optical lens mounted above each LED chip. The diffuser 303 is located a certain distance above the lens array, further scattering and softening the highly directional light emitted from the lenses to form a uniform surface light output. In terms of lens selection, traditional symmetrical lenses are used in some areas, while centrifugal backlight lenses 100 are used in other areas. The dimensions and mounting interfaces of both are consistent, allowing for direct interchangeability. The specific rules for the mixed arrangement will be detailed in subsequent embodiments.

[0032] In some embodiments, the effective display area of ​​the backlight module 300 is divided into nine zones arranged in a 3x3 grid: upper left zone, upper middle zone, upper right zone, middle left zone, center zone, middle right zone, lower left zone, lower middle zone, and lower right zone; wherein, the center zone is equipped with a symmetrical optical lens 200, and the other zones except the center zone are equipped with centrifugal backlight lenses 100.

[0033] Preferably, the centrifugal direction of the centrifugal backlight lens 100 in the upper left partition points to the upper left corner of the effective display area, and the centrifugal direction of the centrifugal backlight lens 100 in the upper right partition points to the upper right corner of the effective display area; the centrifugal direction of the centrifugal backlight lens 100 in the lower left partition points to the lower left corner of the effective display area, and the centrifugal direction of the centrifugal backlight lens 100 in the lower right partition points to the lower right corner of the effective display area; the centrifugal direction of the centrifugal backlight lens 100 in the upper middle partition and the lower middle partition both point to the center partition; the centrifugal direction of the centrifugal backlight lens 100 in the left middle partition and the right middle partition both point to the center partition.

[0034] This embodiment implements a lens selection and centrifugal arrangement scheme based on the specific nine-square grid partitioning. Specifically, the central partition maintains symmetrical lenses to provide a basic illumination reference; the four corner partitions use oblique centrifugal lenses to direct light energy to their respective corner directions, compensating for insufficient corner brightness; the upper-middle and lower-middle partitions use vertical centrifugal lenses, and the left-middle and right-middle partitions use horizontal centrifugal lenses, all converging light energy towards the central partition to increase central brightness while reducing edge brightness. This scheme increases the brightness of the four corners from about 40% in the traditional scheme to about 60%, the central brightness from 100% to about 120%, and reduces the brightness of the top and bottom and left and right edges from 90% and 80% to about 70% and 65% respectively, resulting in a more balanced brightness across all areas. In particular, the improvement in central brightness is equivalent to or greater than that of a single brightness enhancement film 305, saving the need for additional brightness enhancement film 305.

[0035] In some embodiments, based on the brightness of the central partition when the entire effective display area is equipped with symmetrical optical lenses 200, the relative brightness of each partition satisfies the following: the relative brightness range of the central partition is 115%-125%; the relative brightness range of the upper left, upper right, lower left, and lower right partitions is 55%-65%; the relative brightness range of the upper center and lower center partitions is 65%-75%; and the relative brightness range of the left center and right center partitions is 60%-70%.

[0036] Referring to the attached diagram, compared to the traditional backlight module layout where all zones are arranged with symmetrical optical lenses, resulting in a symmetrical overall light output pattern, the brightness of the central zone in this traditional layout is taken as 100% as the reference standard. The approximate brightness range data is as follows: A for the upper left zone, B for the upper middle zone, C for the upper right zone, D for the left middle zone, E for the central zone, F for the right middle zone, G for the lower left zone, H for the lower middle zone, and I for the lower right zone.

[0037] In this embodiment, the target brightness range of each zone is significantly improved compared to the traditional fully symmetrical scheme after using a centrifugal backlight lens 100. The central zone reaches 115% to 125% of the baseline value, the four corner zones maintain a relative brightness of 55% to 65% to eliminate vignetting, and the edge zones can be controlled between 60% and 75% to avoid bright edges. The approximate brightness range data is as follows:

[0038] Based on actual testing, the brightness distribution data of the 300 backlight module, which is based on the 32, 43, 55, and 65-inch mass-produced backlight modules, is as follows, under the same LED light strip 302 design.

[0039]

[0040] The brightness data shows that the backlight module 300 of this embodiment can achieve a more flexible and reasonable distribution of system LED light energy, which significantly improves the brightness of the center and balances the brightness of the four corners, top and bottom, and left and right sides.

[0041] In some embodiments, the backlight module 300 further includes a reflective film 304 disposed between the back plate 301 and the LED light strip 302; a brightness enhancement film 305 may optionally be disposed above the diffuser plate 303.

[0042] Specifically, the reflective film 304 is located between the backplate 301 and the LED strip 302, typically in the area around the backplate 301, and tilted towards the diffuser plate 303. It reflects scattered light back towards the diffuser plate 303, improving light energy utilization. The brightness enhancement film 305 can be optionally installed above the diffuser plate 303, depending on the product specifications, to further gather large-angle light and improve brightness when viewed directly. In this embodiment, the use of a centrifugal lens has significantly improved the brightness of the central area, and the brightness is uniform around the perimeter. To save costs, for backlight modules 300 with less stringent configuration requirements, the brightness enhancement film 305 can be omitted, or the number of brightness enhancement films 305 can be reduced, while still achieving or even exceeding the effect of traditional backlight modules, thereby achieving cost reduction.

[0043] The following describes a liquid crystal display device 400 according to an embodiment of this application, including a backlight module 300 of any of the above embodiments, and a liquid crystal panel 401 disposed on the light-emitting side of the backlight module 300.

[0044] In this embodiment, the backlight module 300 is applied to a complete liquid crystal display device 400. The liquid crystal panel 401 is mounted above the light-emitting side of the backlight module 300, namely above the diffuser plate 303 and the brightness enhancement film 305. The uniform surface light source provided by the backlight module 300 is selectively modulated after passing through the pixel array of the liquid crystal panel 401, forming a visible image in the direction of the human eye. Since the backlight module 300 has achieved optimized brightness distribution through a centrifugal lens scheme, the liquid crystal panel 401 does not need additional compensation for regional brightness differences, which helps reduce the complexity of the panel driving circuit and reduces contrast loss caused by regional brightness compensation. This liquid crystal display device 400 can be applied to various direct-lit backlight display products such as televisions, monitors, and commercial advertising screens. It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0045] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0046] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A centrifugal backlight lens, characterized in that, Includes a lens body, the bottom surface of which is provided with an LED receiving groove for accommodating LED chips, and the top surface is constructed as a light-emitting surface with a concave light control structure; The center of the LED receiving groove and / or the optical center of the concave light control structure of the light-emitting surface are offset relative to the central axis of the lens body. When the center of the LED receiving groove and the optical center of the concave light control structure of the light-emitting surface are offset at the same time, they are offset in the same direction. The direction of offset forms the centrifugal direction of the centrifugal backlight lens. Let the offset be d, and the bottom diameter of the lens body be D, satisfying: 0 < d ≤ D / 4.

2. The centrifugal backlight lens according to claim 1, characterized in that, The centrifugal direction can be any one of horizontal, vertical, or oblique.

3. The centrifugal backlight lens according to claim 1, characterized in that, The light output pattern of the centrifugal backlight lens is an asymmetrical butterfly-shaped light distribution curve, and the light is enhanced along the centrifugal direction.

4. The centrifugal backlight lens according to claim 1, characterized in that, The centrifugal backlight lens is a refractive optical lens or a reflective optical lens.

5. A backlight module, characterized in that, It includes a back plate, an LED light strip disposed on the back plate, a plurality of optical lenses mounted on the LED light strip, and a diffuser plate located above the optical lenses; The optical lens includes a symmetrical optical lens and a centrifugal backlight lens as described in any one of claims 1-4.

6. The backlight module according to claim 5, characterized in that, The effective display area of ​​the backlight module is divided into nine zones arranged in a 3x3 grid: upper left zone, upper center zone, upper right zone, middle left zone, center zone, middle right zone, lower left zone, lower center zone, and lower right zone. The central partition is equipped with a symmetrical optical lens, and the other partitions are equipped with the centrifugal backlight lens.

7. The backlight module according to claim 6, characterized in that, The centrifugal backlight lens of the upper left partition points to the upper left corner of the effective display area, and the centrifugal backlight lens of the upper right partition points to the upper right corner of the effective display area. The centrifugal backlight lens of the lower left partition points to the lower left corner of the effective display area, and the centrifugal backlight lens of the lower right partition points to the lower right corner of the effective display area. The centrifugal direction of the centrifugal backlight lenses in the upper and lower middle sections both points towards the central section; The centrifugal direction of the centrifugal backlight lenses in the left and right center sections both points towards the center section.

8. The backlight module according to claim 5, characterized in that, Based on the brightness of the central partition when the entire effective display area is equipped with symmetrical optical lenses, the relative brightness of each partition satisfies: The relative brightness range of the central zone is 115%-125%; The relative brightness range of the upper left, upper right, lower left, and lower right partitions is 55%-65%. The relative brightness range of the upper and lower middle zones is 65%-75%. The relative brightness range of the left and right center zones is 60%-70%.

9. The backlight module according to claim 5, characterized in that, It also includes a reflective film disposed between the back plate and the LED light strip; optionally, a brightness enhancement film is disposed above the diffuser plate.

10. A liquid crystal display device, characterized in that, It includes a backlight module as described in any one of claims 5-9, and a liquid crystal panel disposed on the light-emitting side of the backlight module.

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