Patent ID: 12189235

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present application provide a quantum dot lens and a backlight module. The details are described below respectively. It should be noted that a description order of the following embodiments is not intended to limit a preferred order of the embodiments.

As illustrated inFIG.5toFIG.11, one embodiment of the present application provides a quantum dot lens used to distribute light for a light source500. The quantum dot lens includes a lens body100and a quantum-dot homogeneous-sol material200. The quantum dot lens allows light-emitting viewing angles of the light source500to be increased, thereby realizing thinness, reducing a number of the light source500, and reducing cost.

The lens body100has a light incident surface110and a light exiting surface120. As illustrated inFIG.5, the light exiting surface120is defined as a surface where an end of a light exiting side of the lens body100is located. The light incident surface110is defined as a surface where an end of a light incident side of the lens body100is located. A type and a material of the lens body100are not limited by the embodiments of the present application, and the type of the lens body100is, for example, a reflective lens. The material of the lens body100is made of, for example, optical-level polymethyl methacrylate (PMMA, also known as acrylic) or a high transmittance material such as glass. In some embodiments, a shape of the lens body100is a plane-symmetry space figure. In some embodiments, the lens body100is in a conical-frustum shape.

A groove121is defined on the light exiting surface120. The quantum-dot homogeneous-sol material200is filled in the groove121. The quantum-dot homogeneous-sol material200is in a liquid state and includes quantum dots. The quantum dots are semiconductor light emitting nanocrystals, and a particle size of which generally ranges from 1 nm to 20 nm. After being excited by external energy (such as light, electricity), quantum dots of different sizes can emit lights of different colors, and colors of emitted lights can include an entire visible region from blue light to red light. The quantum dots have high luminous color purity, long service life, good stability, and colors can be customized according to requirements. After the quantum dots are excited by light and are converted into high-purity monochromatic light, they are used in panel display technology, which can effectively improve a color gamut of the panel, i.e., color reproduction ability. The quantum dots are, for example, CdSe, InP, perovskite quantum dots, etc. It should be noted that apart from including quantum dots, the quantum-dot homogeneous-sol material200can also include other components, such as solvents or other functional components according to specific requirements. In some embodiments, the quantum-dot homogeneous-sol material200includes a quantum dot material exciting red light and a quantum dot material exciting green light. An excited light of the red quantum dots and an excited light of the green quantum dots can be mixed to form a yellow light. In some embodiments, a shape of the groove121is a plane-symmetric space figure.

In the embodiments of the present application, by filling the quantum-dot homogeneous-sol material200in the groove121of the lens body100to replace an entire quantum dot film generally used in prior art, reduction of luminous efficacy of the quantum dot material incurred by film forming processes can be prevented, thereby improving luminous efficacy and power efficiency of the quantum dot material. Furthermore, taking a 32-inch backlight as an example, a size of the entire quantum dot film used in the prior art needs to be same as a size of the backlight module, i.e., the size of the entire quantum dot film is about 32 inches, and the 32-inch backlight module needs about a dozen of light emitting diode (LED) chips. In the embodiments of the present application, only the groove121of the light exiting surface120of each lens body100needs to be filled with the quantum-dot homogeneous-sol material200, and in this way, consumption of the quantum dot material can be significantly reduced. Wherein, a manufacturing process of the quantum dot film needs a plurality of processes. For example, by mixing the quantum dots with glue and coating them on a substrate (e.g., polyethylene glycol terephthalate, PET) of a barrier layer, and by bonding two substrates together, and performing curing, winding, cutting and assembling, the embodiments of the present application only need to encapsulate the quantum-dot homogeneous-sol material200in the groove121of each lens body100. In this way, the plurality of processes of production and assembly of the entire quantum dot film can be omitted.

In some embodiments of the present application, the lens body100has a central axis XX′, the groove121and the lens body100are arranged coaxially, which can also be understood as the groove121also having a central axis overlapping the central axis XX′ of the lens body100, and a bottom wall of the groove121recesses toward the light incident surface110along the central axis XX′ of the lens body100. A depth of the groove121decreases radially from the central axis XX′ of the lens body100to a periphery of the lens body100. A plane where an opening of the groove120is located is perpendicular to the central axis XX′.

In some embodiments of the present application, a central axis of the light source500overlaps the central axis XX′ of the lens body100. A light E at a front angle emitted by the light source500is allowed to pass through a position where the depth of the groove121is at a maximum.

In the embodiments of the present application, by the bottom wall of the groove121recessing toward the light incident surface110along the central axis XX′ of the lens body100and by making the depth of the groove121decrease radially from the central axis XX′ of the lens body100to the periphery of the lens body100, a light path difference (d1−d2) between the light E at the front angle and a light L at a large angle emitted by the light source500can be reduced, and the yellow-ring phenomenon can be remedied. Furthermore, by adjusting the shape and a curvature of the bottom wall of the groove121, a difference in light paths of lights at each angle is allowed to be controlled, e.g., a difference in light paths of the light E at the front angle and the light L at the large angle illustrated inFIG.5. Therefore, uniformity of colors of emitted light can be further controlled.

In some embodiments, as illustrated inFIG.5andFIG.6, the bottom wall of the groove121recesses toward a direction facing away from a center O of the light exiting surface120, i.e., an intersection of the central axis XX′ of the lens body100and the light exiting surface120. The curvature of the bottom wall of the groove121can be adjusted according to practical requirements.

As illustrated inFIG.7, E inFIG.7represents the light at the front angle, L represents the light at the large angle, d1represents a light path of the light E at the front angle passing through the quantum-dot homogeneous-sol material200, and d2represents a light path of the light L at the large angle passing through the quantum-dot homogeneous-sol material200. Wherein, a thickness of the quantum dot film20is equal to the light path of the light E at the front angle passing through the quantum-dot homogeneous-sol material200. As illustrated inFIG.7, a light path d3of the light L at the large angle passing through the quantum dot film20is greater than the light path d2of the light L at the large angle passing through the quantum-dot homogeneous-sol material200. Therefore, by making the bottom wall of the groove121recess toward the light incident surface110along the central axis XX′ of the lens body100, for example, the bottom wall of the groove121recessing toward the direction facing away from the center O of the light exiting surface120as illustrated inFIG.7, and by making the depth of the groove121decrease radially from the central axis XX′ of the lens body100to the periphery of the lens body100, the light path of the light L at the large angle is allowed to be reduced. A reduction is about a length d4illustrated inFIG.7. Therefore, the difference in the light paths of the light E at the front angle and the light L at the front angle is reduced, which can remedy the yellow-ring phenomenon at a certain extent and can allow the colors of emitted lights more uniform. In addition, the curvature of the groove121can also be adjusted to allow the light path of the light of each angle emitted from the light source500passing through the quantum-dot homogeneous-sol material200to be consistent, so that the colors of the light presented on a backlight film600from the light source500are allowed to be more uniform.

In some embodiments, as illustratedFIG.8andFIG.9, the bottom wall of the groove121is in an inverted conical shape. In other several embodiments, the bottom wall of the groove121is in an inverted pyramidal shape. It can be understood that the bottom wall of the groove121being in the inverted conical shape or in the inverted pyramidal shape neither protruding toward the center O of the light exiting surface120nor recessing toward a direction facing away from the center O of the light exiting surface120. The inverted pyramidal shape is, for example, an inverted triangular pyramidal shape, an inverted quadrangular pyramidal shape, or an inverted pentagonal pyramidal shape, etc. It can be understood that the principle of remedying the yellow-ring phenomenon in this embodiment is same as the principle of the previous embodiment, and redundant description will not be mentioned herein again. A tilting angle of the bottom wall of the groove121can be adjusted according to requirements.

In some embodiments, as illustrated inFIG.10andFIG.11, the bottom wall of the groove121protrudes toward the center O of the light exiting surface120, i.e., an intersection of the central axis XX′ of the lens body100and the light exiting surface120. It can be understood that the principle of remedying the yellow-ring phenomenon in this embodiment is same as the principle of the previous embodiment, and redundant description will not be mentioned herein again. The curvature of the bottom wall of the groove121can be adjusted according to requirements.

In some embodiments of the present application, the light source500is a Lambertian light source. The light source500is, for example, LED chips of a Lambertian shape. The shape and the curvature of the bottom wall of the groove121can be adjusted according to characteristics of the Lambertian light source to allow the light path of the light of each angle emitted from the Lambertian light source passing through the quantum-dot homogeneous-sol material200to be consistent, so that the colors of the light presented on the backlight film600from the Lambertian light source are allowed to be more uniform.

As illustrated inFIG.5,FIG.8, andFIG.10, in some embodiments, the quantum dot lens further includes a cover body300, and the cover body300covers on an opening of the groove121. In some embodiments, the cover body300is planar and is coplanar with the light exiting surface120. The cover body300is configured to isolate external water and oxygen of the groove121, preventing the quantum dots from contacting water and oxygen and failing, and prolonging service life of the quantum-dot homogeneous-sol material200.

In some embodiments, the cover body300is sealedly connected to the lens body100, which further enhances effect of isolating external water and oxygen of the groove121and further prolongs the service life of the quantum-dot homogeneous-sol material200.

In other several embodiments, the cover body300and the lens body100are integrally formed, and a liquid injection opening is defined on the cover body300. The liquid injection opening is configured to insert the quantum-dot homogeneous-sol material200into the groove121. After the quantum-dot homogeneous-sol material200is injected, the liquid injection opening is sealed to isolate external water and oxygen from the groove121. For example, the cover body300and the lens body100are integrated in one piece by injection molding, and the liquid injection opening can be defined on the cover body300in advance. After the quantum-dot homogeneous-sol material200is injected, the liquid injection opening is sealed by methods such as a glue dispensing method or a heat melting method, etc.

In some embodiments of the present application, an interior of the groove121is in a vacuum state. The vacuum state can be realized by vacuuming the interior of the groove121. Using a vacuum environment not only can effectively isolate the external water and oxygen from the groove121, but also can prevent presence of water and oxygen in the groove121from affecting performance of the quantum-dot homogeneous-sol material200, which effectively prevents failure of the quantum dots and further prolongs the service life of the quantum-dot homogeneous-sol material200.

As illustrated inFIG.5,FIG.8, andFIG.10, in some embodiments, the quantum dot lens further includes a base400, and a cavity410which is able to accommodate the light source500and which is defined on the base400. In some embodiments of the present application, a central axis of the cavity410overlaps the central axis XX′ of the lens body100. In this way, the light source500can be disposed at the center of the cavity410, which is conducive to allowing the central axis of the light source500to align with and to overlap the central axis XX′ of the lens body100, thereby allowing the light at the large angle emitted from the light source500to pass through the position where the depth of the groove121is maximum.

One embodiment of the present application further provides a backlight module. The backlight module includes at least one of any aforesaid quantum dot lens and at least one light source500. Wherein, each of the light source500is provided with the at least one quantum dot lens, and the light incident surface110of the quantum dot lens faces toward the light source500. The light source500is, for example, LED chips.

In the embodiments mentioned above, the descriptions to the various embodiments are emphasized, and the part is not described in detailed in an embodiment, can refer to the detailed description of other embodiments mentioned above.

In summary, compared to entire quantum dot films generally used in the prior art, in embodiments of the present application, the quantum-dot homogeneous-sol material200is filled in the groove121of the light exiting surface120of the lens body100, which allows luminous efficacy and power efficiency of the quantum dot material to be improved, and reduction of luminous efficacy of the quantum dot material incurred by film forming processes is prevented. Furthermore, consumption of the quantum dot material can be reduced, eliminating production and assembling processes of the quantum dot films. In addition, by controlling the shape of the bottom wall of the groove121, the depth of the groove121decreases radially from the central axis XX′ of the lens body100to the periphery of the lens body100which allows the difference in the light paths of the light E at front viewing angles and the light L at large angles, thereby alleviating the problem of uneven color of emitted light incurred by the yellow-ring phenomenon.

The quantum dot lens and the backlight module provided by the embodiments of the present application are described in detail. This article uses specific cases for describing the principles and the embodiments of the present application, and the description of the embodiments mentioned above is only for helping to understand the method and the core idea of the present application. Meanwhile, for those skilled in the art, will have various changes in specific embodiments and application scopes according to the idea of the present application. In summary, the content of the specification should not be understood as limit to the present application.