A display device

Abstract

This invention relates to the field of display technology, and discloses a display device including a display panel and a backlight module. The backlight module includes multiple light-emitting units and a substrate. Multiple chips of the light-emitting units are sealed on the substrate using an encapsulation device. The encapsulation device consists of two dispensing processes. The first adhesive layer formed by the first dispensing process is doped with light-diffusing particles. When the light emitted by the multiple chips propagates through the first adhesive layer, it is refracted and reflected by the light-diffusing particles, thereby alleviating color distortion problems. At the same time, after the light enters the second adhesive layer from the first adhesive layer, the light diffusion angle increases because it is incident from a high refractive index to a low refractive index, thereby increasing the light spot size. This helps to better meet the P:H value and cost requirements, and avoids the problem of more Fresnel loss caused by multiple interfaces, thus improving the uniformity of light.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a display device. Background Technology

[0002] Some existing displays, such as LED (Light Emitting Diode) backlit LCD screens, use backlight modules to provide backlighting, enabling them to display various information such as text, graphics, animations, market data, video, and recorded signals. A backlight module consists of multiple light-emitting units, each containing multiple chips that emit light of different wavelengths. These chips are encapsulated using adhesive dispensing. However, to save costs, the number of light-emitting units in the entire backlight module is reduced, and the spacing between the units is made larger, which can easily lead to color distortion problems. Summary of the Invention

[0003] A first aspect of the present invention provides a display device, comprising:

[0004] Display panel, used for image display;

[0005] A backlight module is disposed on the incident light side of the display panel and is used to provide backlight to the display panel; the backlight module includes: a substrate and a plurality of light-emitting units; the plurality of light-emitting units are disposed on the substrate;

[0006] At least one of the light-emitting units includes: a plurality of chips for emitting light of different wavelengths and a packaging device; the packaging device is used to package the plurality of chips on the substrate;

[0007] The encapsulation device includes: a first adhesive layer formed by a first dispensing and a second adhesive layer formed by a second dispensing;

[0008] A first adhesive layer is disposed on the substrate and covers the plurality of chips. A second adhesive layer is disposed on the substrate and covers the first adhesive layer. The first adhesive layer and the second adhesive layer are bonded together. The first adhesive layer is bonded to the plurality of chips. The first adhesive layer is an adhesive layer doped with light-diffusing particles, and the second adhesive layer is a particle-free transparent adhesive layer. The first refractive index of the first adhesive layer is higher than the second refractive index of the second adhesive layer, and the center height of the first adhesive layer is 0.5-0.8 mm so that the peak light intensity in the non-central region of the light spot formed by the light emitted from the packaging device is greater than the light intensity at the center of the light spot. The bottom surface of the first adhesive layer that is bonded to the substrate is circular in shape, and the bottom surface of the second adhesive layer that is bonded to the substrate is annular in shape.

[0009] The diameter d of the bottom surface of the first adhesive layer that is bonded to the substrate ranges as follows:

[0010] d1 d D / 2;

[0011] d1 is the diameter of the outer circle of the combined array of the multiple chips;

[0012] The diameter D of the bottom surface of the second adhesive layer that is bonded to the substrate ranges as follows:

[0013] d <D 7 millimeters.

[0014] In some embodiments of the present invention, the weight concentration of light-diffusing particles doped in the first adhesive layer is not less than 10%; the light-diffusing particles include particles of a first particle size, particles of a second particle size, particles of a third particle size, and particles of a fourth particle size.

[0015] The particle size of the first particle is 0~2μm, the particle size of the second particle is 2μm~6μm, the particle size of the third particle is 6μm~16μm, and the particle size of the fourth particle is 16μm~24μm.

[0016] The weight of particles with a diameter of 0~2μm accounts for 16.9%~23.5% of the total weight of light-diffusing particles in the first adhesive layer.

[0017] The weight of particles with a diameter of 0~6μm accounts for 59.9%~80.3% of the total weight of light-diffusing particles in the first adhesive layer;

[0018] The weight of particles with a diameter of 0~16μm accounts for >95% of the total weight of light-diffusing particles in the first adhesive layer;

[0019] The weight of particles with a diameter of 0~24μm accounts for 100% of the total weight of light-diffusing particles in the first adhesive layer.

[0020] In some embodiments of the present invention, the weight concentration of light-diffusing particles doped in the first adhesive layer is not less than 10%; the light-diffusing particles include particles with a fifth particle size and particles with a sixth particle size.

[0021] The fifth particle size has a particle size of 0~6μm, and the sixth particle size has a particle size of 6μm~16μm; wherein, the weight of the fifth particle accounts for 59.9~80.3% of the total weight of the light-diffusing particles in the first adhesive layer.

[0022] In some embodiments of the present invention, the light-emitting surface of the first adhesive layer is a convex surface.

[0023] In some embodiments of the present invention, in the P:H of the backlight module Under condition 2, the light-emitting surface of the second adhesive layer is curved and the top of the light-emitting surface of the second adhesive layer is convex; where P refers to the distance between the center points of two adjacent light-emitting units and H refers to the light mixing distance.

[0024] In some embodiments of the present invention, in the backlight module P:H Under the conditions of 3.2, the light-emitting surface of the second adhesive layer is curved and the top of the light-emitting surface of the second adhesive layer is concave; where P refers to the distance between the center points of two adjacent light-emitting units and H refers to the light mixing distance.

[0025] In some embodiments of the present invention, the value of the first refractive index minus the second refractive index is not less than 0.02.

[0026] In some embodiments of the present invention, the light-diffusing particles include some or all of the following: titanium dioxide, hollow glass microspheres, barium sulfate, and zirconium oxide.

[0027] The display device provided in this embodiment of the invention includes a display panel and a backlight module. The backlight module includes multiple light-emitting units and a substrate. Multiple chips of the light-emitting units are sealed on the substrate using an encapsulation device. The encapsulation device consists of two dispensing processes. The first adhesive layer formed by the first dispensing process is doped with light-diffusing particles. When the light emitted by the multiple chips propagates through the first adhesive layer, it is refracted and reflected by the light-diffusing particles, thereby alleviating the color shift problem. At the same time, after the light enters the second adhesive layer from the first adhesive layer, the light diffusion angle increases because it is incident from a high refractive index to a low refractive index, thereby increasing the light spot size and helping to better meet the P:H value and cost requirements. Furthermore, the light can penetrate... Fresnel loss occurs at the interface between two different media. In this application, a second adhesive layer is formed by secondary dispensing. The second adhesive layer is a particle-free transparent adhesive layer. Light emitted from multiple chips enters the second adhesive layer from the first adhesive layer, meaning the light passes through the interface between the two different media, thus generating Fresnel loss. However, in this application, there is only one interface between the light-emitting surface of the first adhesive layer and the light-incident surface of the second adhesive layer. This means that there are very few interfaces that generate Fresnel loss. Therefore, this not only improves the light mixing effect in the first adhesive layer but also reduces Fresnel loss. The brightness of stray light generated by Fresnel loss is relatively low, thereby improving the uniformity of the light spot. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of a display device provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of a backlight module provided in an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of a single-dispensing light-emitting unit provided in an embodiment of the present invention;

[0032] Figure 4 A cross-sectional view of a display device provided in an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of a light spot formed by a light-emitting unit that is applied in a single dispensing process, provided in an embodiment of the present invention.

[0034] Figure 6 A schematic diagram illustrating the light intensity of a light spot formed by a single-dispensing light-emitting unit, provided in an embodiment of the present invention;

[0035] Figure 7 A schematic diagram of a light-emitting unit with secondary dispensing provided in an embodiment of the present invention;

[0036] Figure 8 This is a schematic diagram of a first adhesive layer provided in an embodiment of the present invention;

[0037] Figure 9 This is a schematic diagram of a light spot formed by a secondary dispensing light-emitting unit according to an embodiment of the present invention;

[0038] Figure 10 A schematic diagram illustrating the light intensity of a light spot formed by a secondary dispensing light-emitting unit, provided in an embodiment of the present invention;

[0039] Figure 11 A top view of a light-emitting unit with secondary dispensing provided in an embodiment of the present invention;

[0040] Figure 12 This is a schematic diagram of a second adhesive layer provided in an embodiment of the present invention. Detailed Implementation

[0041] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction in the present invention are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of the present invention. The accompanying drawings of the present invention are for illustrative purposes only and do not represent actual proportions.

[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] Combination Figure 1 As shown, a display device is illustrated, which includes a display panel 10 and a backlight module 20; the display panel 10 is used for image display, and the backlight module 20 is disposed on the light-incident side of the display panel 10 for providing backlight to the display panel 10.

[0045] In detail, with the side of the display panel 10 that displays the image as the front side, the backlight module 20 is set on the light-incident side of the display panel 10 as the back side of the display panel 10. In this way, the light emitted by the backlight module 20 is on the back side of the display panel 10, providing backlight for the display panel 10, so that the display panel 10 can display the image normally.

[0046] In some embodiments, the display panel 10 is a liquid crystal display (LCD).

[0047] Combination Figure 2As shown, the backlight module 20 includes: a substrate 21 and a plurality of light-emitting units 22; the plurality of light-emitting units 22 are disposed at intervals on the substrate 21; combined with Figure 3 As shown, P refers to the distance between the center points of two adjacent light-emitting units; H refers to the light mixing distance, for example, combining... Figure 4 As shown, a display device is illustrated. Light is emitted through the light-emitting unit 22 and then sequentially passes through the diffuser plate 30 and the optical module 31 to reach the display panel 10. H is the distance from the substrate surface to the lower surface of the film of the diffuser plate 30 in the backlight module. Optionally, the spacing can include matrix arrangement, array arrangement, or random arrangement. Figure 2 The diagram shows multiple light-emitting units 22 arranged in a matrix on a substrate 21.

[0048] At least one light-emitting unit 22 includes: a plurality of chips 24 for emitting light of different wavelengths and a packaging device 23; the packaging device 23 is used to encapsulate the plurality of chips 24 on a substrate. Typically, the packaging device 23 is an adhesive layer formed by dispensing. Different light-emitting units are provided with independent packaging devices.

[0049] For example, in combination Figure 2 As shown, multiple chips include red light chips, green light chips, and blue light chips. The red light chip emits red light, the green light chip emits green light, and the blue light chip emits blue light. Each light-emitting unit 22 consists of three chips: red light chip, green light chip, and blue light chip. The three chips are packaged on the substrate 21 using a packaging device 23. Multiple groups of chips are repeatedly glued onto the substrate 21 to form a backlight module 20.

[0050] It should be noted that the multiple chips can also be red light chips, green light chips, first blue light chips, and second blue light chips, and the light emitted by the red light chips, green light chips, first blue light chips, and second blue light chips is refracted or reflected at the light diffusion powder inside the first adhesive layer.

[0051] Multiple chips emit light of different wavelengths that propagate through the adhesive layer, mixing during the propagation process. For example, combining... Figure 3As shown, each chip in the first light-emitting unit 241 is represented by three rays to indicate the beam emitted by the chip. It can be seen that the red light emitted from the red chip R and the blue light emitted from the blue chip B pass over the area above the green chip G, which is the central area of ​​the light-emitting unit. In this area, the three colors of light are mixed, resulting in a good mixing effect in the central area. In the non-central area of ​​the first light-emitting unit 241, near the red chip R (i.e., the edge area of ​​the first light-emitting unit 241), the mixed light includes the red light emitted from the red chip R, the green light emitted from the green chip G, the blue light emitted from the blue chip B, and the blue light emitted from the blue chip B of the third light-emitting unit 243 adjacent to the first light-emitting unit 241. Although there is less blue light in the edge area of ​​the first light-emitting unit 241, it is supplemented by the blue light emitted from adjacent light-emitting units, resulting in a good overall mixing effect. Similarly, in the non-central area of ​​the first light-emitting unit 241, near the blue light chip B, the mixed light includes blue light emitted from the blue light chip B of the first light-emitting unit 241, green light emitted from the green light chip G of the first light-emitting unit 241, red light emitted from the red light chip R of the first light-emitting unit 241, and red light emitted from the red light chip R of the second light-emitting unit 242 adjacent to the first light-emitting unit 241. Overall, the emitted light also has a relatively good mixing effect.

[0052] However, adjusting the P value in the P:H ratio can reduce the number of light-emitting units. In the light mixing at the edge regions of these units, the light emitted from adjacent units decreases, leading to color shift issues. For example, when combined with… Figure 3 As shown, when P is too large, in the non-central region of the first light-emitting unit 241, the red light emitted by the red light chip R of the second light-emitting unit 242 adjacent to the first light-emitting unit 241 in the mixed light of the region near the blue light chip B will decrease, so there will be more blue light in the edge region. Similarly, in the mixed light of the region near the red light chip R, the blue light emitted by the blue light chip B of the third light-emitting unit 243 adjacent to the first light-emitting unit 241 will decrease, so there will be more red light in the edge region.

[0053] In other words, when the P value in P:H is too large, the light mixing of the light spots of two adjacent light-emitting units is not uniform. Since the light spot of the backlight module is composed of the light spots of multiple light-emitting units, when the P value in P:H is too large, it will cause the light spot of the backlight module to be uneven.

[0054] Besides the fact that an excessively high P:H ratio affects the uniformity of light output from the entire backlight module, there are other issues that affect the unevenness of light output from different chips.

[0055] Looking at the inside of each light-emitting unit, when light is emitted from the side closer to the red light chip, the intensity of the red light will be higher. Since the chip usually has a certain height, the green light chip and the blue light chip on the other side will block part of the light when emitting light from the side, which will cause a color shift on the side closer to the red light chip. Similarly, the same principle applies to the side closer to the blue light chip, which will result in a bluish color shift, and will also cause uneven light emission on the light-emitting surface.

[0056] The green light chip is in the middle. After its light is emitted from the colloid, it forms a light spot in the central area. The red and blue light chips are on the sides. The light spots they form are close to the sides. The three cannot completely overlap, which will cause color distortion and uneven light output.

[0057] For the light spot formed by the light-emitting unit, such as Figure 5 As shown, different degrees of color shift appear on both the left and right sides of the edge; the left side of the edge leans towards blue, while the right side leans towards red. Figure 6 As shown, the ratio of peak light intensity to center light intensity is 110:160, where the peak light intensity is the light intensity value of the peak value in the non-central region of the light spot, and the center light intensity is the light intensity value at the center of the light spot. It can be seen that the light spot is concentrated, has a small diffusion angle, and exhibits obvious color shift at different locations.

[0058] The characteristics of the light spot are shown in Table 1. The table below is Table 1:

[0059]

[0060] In the table, the width at 50.000% represents the angular range covered by the light ray when the light intensity drops to half of the maximum central light intensity. The direction is the measurement plane: 0° represents the horizontal section, 90° represents the vertical section, and the full width is the angular span of the entire light spot when the light intensity drops to 50%. Half-width + represents the positive value from the central axis (0 degrees) to the angle at which the light intensity drops to 50%. Half-width – represents the negative value from the central axis (0 degrees) to the angle at which the light intensity drops to 50%.

[0061] To overcome the above problems, such as Figure 7As shown, the packaging device 23 includes: a first adhesive layer 231 formed by a first dispensing and a second adhesive layer 232 formed by a second dispensing. The first adhesive layer 231 is disposed on a substrate and covers multiple chips. The second adhesive layer 232 is disposed on the substrate and covers the first adhesive layer 231. The first adhesive layer 231 is disposed between the second adhesive layer 232 and the multiple chips 24. The first adhesive layer 231 is adjacent to the multiple chips 24. The first adhesive layer 231 is an adhesive layer doped with light-diffusing particles. The second adhesive layer 232 is a particle-free transparent adhesive layer. Light emitted from the multiple chips 24 propagates in the first adhesive layer 231 with a first refractive index and is refracted or reflected at the light-diffusing particles. Light enters from the first adhesive layer 231 into the second adhesive layer 232, propagates in the second adhesive layer 232 with a second refractive index, and exits from the second adhesive layer 232. The first refractive index is higher than the second refractive index.

[0062] Specifically, light-diffusing particles are added to the first adhesive layer in a single application. Because these particles refract and reflect light, they increase the number of refractions and reflections of different wavelengths of light within the adhesive, altering the original emission path of the light within the adhesive. For example, a beam of light emitted from a chip near the edge of the adhesive, originally destined for the edge, may reach the center region after one or more random scatterings by the light-diffusing particles. Conversely, light emitted from the central chip may be scattered to the edge, thus breaking the direct correspondence between chip position and light emission point. This results in different positions on the light-emitting surface containing well-mixed light from different chips, improving the uniformity of light of the same wavelength at different positions on the light-emitting surface, as well as the uniformity of light of different wavelengths at the same and different positions on the light-emitting surface. This, in turn, improves the light emission uniformity of the light-emitting unit. When different chips simultaneously possess good light uniformity, color shift can be reduced.

[0063] For example, combining Figure 7 As shown, Figure 7 The diagram illustrates examples of light-emitting units under different implementation methods. In any light-emitting unit, the red light emitted by the red light chip encounters light-diffusing particles during propagation in the first adhesive layer 231, resulting in reflection or refraction. This allows the red light to pass through the central and non-central regions of the light-emitting unit. Similarly, the green light emitted by the green light chip encounters light-diffusing particles during propagation in the first adhesive layer 231, resulting in reflection or refraction. This allows the green light to pass through the central or non-central regions of the light-emitting unit. The blue light emitted by the blue light chip encounters light-diffusing particles during propagation in the first adhesive layer 231, resulting in reflection or refraction. This allows the blue light to pass through the central or non-central regions of the light-emitting unit. This allows the green, blue, and red light to blend better, improving the uniformity of the light spot.

[0064] The adhesive used in the second application has a different refractive index than the adhesive used in the first application. The first application uses a low-contact, high-refractive-index adhesive, while the second application uses a high-thixotropic, low-refractive-index adhesive. This means that the second adhesive layer has a lower refractive index. Because the two adhesive layers have different refractive indices, refraction can be formed at the interface between the two applications. Since the light angle can be opened when light enters from a high-refractive-index medium to a low-refractive-index medium, when light enters from the first adhesive layer 231 and exits from the second adhesive layer 232, the light spot formed is larger and can cover more of the gap between two adjacent light-emitting areas, making the light spot of the backlight module more uniform.

[0065] Furthermore, Fresnel loss occurs when light passes through the interface between two different media. In this application, a second layer of adhesive is applied to the light-emitting surface of the first adhesive layer to form a second adhesive layer. The second adhesive layer is a particle-free transparent adhesive layer. Light emitted from multiple chips enters the second adhesive layer from the first adhesive layer, meaning the light passes through the interface between the two different media, thus generating Fresnel loss. However, in this application, there is only one interface between the light-emitting surface of the first adhesive layer and the light-incident surface of the second adhesive layer, meaning there are very few interfaces that generate Fresnel loss. Therefore, this not only improves the light mixing effect in the first adhesive layer but also reduces Fresnel loss. The brightness of stray light generated by Fresnel loss is relatively low, thus improving the uniformity of the light spot.

[0066] In some embodiments, combined with Figure 8 As shown, the first adhesive layer 231 has a first surface 2311 and a second surface 2312. The first surface 2311 of the first adhesive layer 231 is attached to the substrate 21, and the second surface 2312 of the first adhesive layer 231 is the emission surface of the first adhesive layer 231. The first surface 2311 of the first adhesive layer 231 has multiple grooves 23111, and a chip is disposed in each groove. The first surface 2311 of the first adhesive layer 231 is also the bottom surface of the first adhesive layer that is attached to the substrate, covering and encapsulating multiple light-emitting chips.

[0067] Since the first adhesive layer 231 is formed by dispensing adhesive directly onto multiple chips, the groove on the first surface 2311 of the first adhesive layer 231 is formed according to the shape of multiple chips during the dispensing process.

[0068] The second surface of the first adhesive layer 231 can be of any shape. Considering the light mixing effect, the second surface 2312 of the first adhesive layer 231 proposed in this embodiment of the invention is a convex surface.

[0069] Since the encapsulation structure of this application is formed through two dispensing processes, and the adhesive used for dispensing has a certain degree of fluidity, if the second dispensing is performed after the first dispensing has cured, a longer processing time is required. If the second dispensing is performed immediately after the first dispensing, it is prone to collapse of the second dispensing. Therefore, in combination with... Figure 7As shown, the center height h of the first adhesive layer 231 proposed in this embodiment of the invention is 0.5 mm to 0.8 mm. At the same time, due to the presence of scattered ion pairs in the adhesive, and the fact that the radius of the second adhesive layer is greater than the radius of the first adhesive layer but less than or equal to 7 mm, it is not easy for the second adhesive layer to collapse.

[0070] Furthermore, by making the radius of the second dispensing larger than that of the first dispensing, the light intensity peak in the non-central region of the light spot emitted by the encapsulation device is greater than the light intensity value at the center of the light spot.

[0071] like Figure 9 As shown in the image, there was no significant difference in color cast between the left and right sides of the edge. Figure 10 As shown, the ratio of peak light intensity to center light intensity is 110:90. It can be seen that the light spot is enlarged, and the color shift at different positions is significantly improved, with a marked improvement in the uniformity of light mixing.

[0072] The characteristics of the light spot are shown in Table 2. The table below is Table 2:

[0073]

[0074] Among them, comparing the table formed by a single adhesive layer and the table formed by two dispensings proposed in the embodiment of the present invention, the values ​​of full width, half-width+, and half-width- are all greater than those of the table formed by a single adhesive layer. Therefore, the spot effect formed by two dispensings proposed in the embodiment of the present invention is better.

[0075] In some embodiments, the diameter d of the first surface 2311 of the first adhesive layer 231 ranges as follows: d1 d . It is the diameter of the bottom surface of the second adhesive layer that is bonded to the substrate.

[0076] In some embodiments, the chips are arranged sequentially, or in other ways. The diameter d1 of the outer circle of the combined chips can be the diameter of the outer circle of the combined chips.

[0077] Combination Figure 11 As shown, the diameter d1 of the outer circle of the combined chip assembly is d1, and the diameter D of the third surface of the second adhesive layer formed by the second dispensing is D. d can be between d1 and D / 2.

[0078] This value can better balance the flowability of the first and second colloids, improve production efficiency, and reduce production defects.

[0079] In some embodiments, the initial dispensing size is related to the dimensions of the three RGB chips and the overall dimensions after chip arrangement. Taking 1836-RGB as an example (1836 is the industry naming convention for chip dimensions, with a length and width of 36),... 18mil, metric approx. 920 The outer circle of the RGB three-chip (460um) has a diameter of 1.88 mm, so d is greater than 1.88 mm. At the same time, for process considerations, the maximum diameter of the secondary dispensing is 7 mm, and half of the secondary dispensing is 3.5 mm, so d is less than 3.5 mm.

[0080] Combination Figure 12 As shown, the second adhesive layer 232 provided in this embodiment of the invention has a first surface 2321, a second surface 2322, and a third surface 2323. The first surface 2321 of the second adhesive layer 232 is attached to the second surface 2312 of the first adhesive layer 231, and the second surface 2322 of the second adhesive layer 232 is the exit surface of the second adhesive layer 232. The third surface 2323 of the second adhesive layer 232 is attached to the substrate 21. The third surface 2323 of the second adhesive layer 232 is also the bottom surface of the second adhesive layer that is attached to the substrate.

[0081] In some embodiments of the present invention, the diameter D of the third surface 2323 of the second adhesive layer 232 is in the range of:

[0082] d D 7 millimeters.

[0083] The bottom surface of the first adhesive layer that adheres to the substrate is circular; the bottom surface of the second adhesive layer that adheres to the substrate is annular.

[0084] The circles described above are circular or approximately circular. In some embodiments, the approximately circular shape may be elliptical or a flattened circle similar to an ellipse, with diameters in both the major and minor axes. The diameter d of the bottom surface of the first adhesive layer that adheres to the substrate includes the minimum diameter dmin in the minor axis direction and the maximum diameter dmax in the major axis direction. The inner boundary circle of the annular ring of the bottom surface of the second adhesive layer that adheres to the substrate is aligned with the bottom surface of the first adhesive layer that adheres to the substrate, and their numerical ranges are the same. The outer boundary circle of the annular ring of the bottom surface of the second adhesive layer that adheres to the substrate is also circular or approximately circular, and also has a minimum diameter Dmin and a maximum diameter Dmax. Therefore, in some embodiments, the range of the minimum diameter dmin of the first surface of the first adhesive layer is: greater than the overall outer circle diameter of the combined multiple chips, and less than half of the maximum diameter Dmax of the third surface of the second adhesive layer. The range of the maximum diameter Dmax of the third surface of the second adhesive layer is: greater than the maximum diameter dmax of the first surface of the first adhesive layer, and less than or equal to 7 mm.

[0085] The second surface of the second adhesive layer formed by the secondary dispensing can be a curved surface, and the top of the second surface of the second adhesive layer can be any shape, such as a plane, a convex surface, or a concave surface. Furthermore, when the top of the second surface is a convex surface, it can form a semi-circle with the side surface of the second surface.

[0086] The shape of the second surface affects the diffusion of light emitted from the second adhesive layer. Specifically: a convex or hemispherical shape will reduce the diffusion angle of the light beam emitted from the second adhesive layer; a concave shape will increase the diffusion angle of the light beam emitted from the center of the top of the second adhesive layer.

[0087] Based on this, in the P:H of the backlight module Under condition 2, in the embodiments of this case, the second surface of the second adhesive layer is curved and the top of the second surface of the second adhesive layer is convex. Further, the second surface of the second adhesive layer is semi-circular, shaped like... Figure 7 The light-emitting unit on the right side of the middle.

[0088] In the backlight module P:H Under condition 3.2, in the embodiments of this case, the second surface of the second adhesive layer is curved and the top of the second surface of the second adhesive layer is concave. Specifically, the portion of the top of the second surface of the second adhesive layer near the center is concave, and the portion of the top of the second surface of the second adhesive layer outside the center is flat, as shown in... Figure 7 The light-emitting unit on the left side of the middle.

[0089] In some embodiments, the value of the first refractive index minus the second refractive index is not less than 0.02.

[0090] For example, the secondary dispensing uses low-concentration silicone without diffusing powder to increase the irradiation spot size. The silicone used in the first dispensing has a refractive index of 1.48, while the silicone used in the second dispensing has a refractive index of 1.46. Since Fresnel loss decreases as the refractive index decreases, the low-refractive-index silicone can reduce Fresnel reflection, resulting in lower brightness of stray light generated by Fresnel loss, thus improving the uniformity of the light spot.

[0091] If the light-diffusing particles in the first adhesive layer are made of particles with relatively small particle sizes, the light emitted by multiple chips may easily cause weak scattering and severe color difference after passing through the first adhesive layer. Alternatively, if the light-diffusing particles in the first adhesive layer are made of particles with relatively large particle sizes, the light emitted by multiple chips may easily cause local over-scattering after passing through the first adhesive layer. Based on the above, the light-diffusing particles provided in this embodiment of the invention include particles of a first particle size, particles of a second particle size, particles of a third particle size, and particles of a fourth particle size; the particle size of the first particle size is smaller than the particle size of the second particle size, the particle size of the second particle size is smaller than the particle size of the third particle size, and the particle size of the third particle size is smaller than the particle size of the fourth particle size.

[0092] Among them, the particle size of the first particle is 0~2. The particle size of the second particle is 2. ~6 The particle size of the third particle is 6. ~16 The fourth particle size has a particle size of 16. ~24 For particle sizes of 0~2 When light enters a particle of this size, it will be scattered, breaking up short-wavelength blue light; for particles with a diameter of 0~6... For particles with a diameter greater than 16, when light enters a particle within this diameter, Mie scattering dominates, balancing the three-color light path; When light enters a particle within a certain particle size, the large particles transmit in a concentrated bundle, which can easily lead to the light not being evenly dispersed.

[0093] In some embodiments of the present invention, the weight ratio of particles of various sizes is provided as follows:

[0094] The weight percentage of particles with the first diameter is 16.9%~23.5%, that is, particles with a diameter of 0~2 mm. The weight of these particles accounts for 16.9% to 23.5% of the total weight of light-diffusing particles in the first adhesive layer;

[0095] The weight ratio of particles with the first diameter to particles with the second diameter is 59.9% to 80.3%, that is, the particle size is 0 to 6. The weight percentage of these particles in the first adhesive layer is 59.9% to 80.3% of the total weight of light-diffusing particles; that is, the particle size is 2. ~6 The weight ratio of the particles is 43%~56.8%;

[0096] The weight ratio of particles with the first, second, and third diameters is >95%; that is, the particle size is 0~16. The weight percentage of the light-diffusing particles in the first adhesive layer is >95% of the total weight of the light-diffusing particles, and the particle size is 6. ~16 The weight percentage of the particles is 14.7% to 35.1%;

[0097] The weight ratio of particles of the first, second, third, and fourth diameters is 100%; that is, the particle size is 0~24. The weight of these particles accounts for 100% of the total weight of the light-diffusing particles in the first adhesive layer. The particle size is 16. ~24 The weight ratio of the particles is less than 5%.

[0098] In some embodiments, the light-diffusing particles provided in this invention include fifth-diameter particles and sixth-diameter particles; the particle size of the fifth-diameter particles is smaller than that of the sixth-diameter particles.

[0099] For example, the particle size of the fifth particle is 0~6. The particle size of the sixth particle is 6. ~16 Among them, the weight of the fifth-diameter particles accounts for 59.9% to 80.3% of the total weight of the light-diffusing particles in the first adhesive layer.

[0100] In some embodiments of the present invention, the light-diffusing particles include particles with a particle size of 0~6 mm. Multiple particles with a diameter of 6 ~16 Multiple particles, the first adhesive layer is doped with light-diffusing particles with a weight concentration and particle size of 0~~6. The proportion of multiple particles is directly proportional to the particle size of 6. ~16 The proportion of multiple particles is inversely proportional.

[0101] Of course, the above-mentioned different particle sizes and particle weight ratios can also be combined in other ways, specifically:

[0102] Advantages of fine particles: A high proportion of fine particles (especially 0-6µm) provides a large number of scattering points even at low concentrations, which is the basis for achieving good dispersion and color difference control. Fine particles are easier to disperse uniformly, avoiding the visual defects caused by large particles.

[0103] The significance of the concentration window: A given particle size distribution (mainly fine particles) determines the range of particle numbers (i.e., ≥10%) required to achieve optimal optical effects (dispersion and chromatic aberration control). If the concentration is too low, even the finest particles will not be effective due to insufficient quantity; if the concentration is too high, the large specific surface area of ​​fine particles will lead to a more significant cumulative effect of absorption and scattering losses, resulting in a sharp drop in efficiency.

[0104] For example, when the proportion of light-diffusing particles with a diameter of 6-16 μm in the first adhesive layer increases, the doping concentration can be appropriately reduced; if the proportion of 0-6 μm particles increases, the doping concentration can be appropriately increased.

[0105] These light-diffusing particles are characterized by a predominantly small particle size (60-80% of which are 0-6µm), which enables them to provide efficient scattering even at relatively low concentrations.

[0106] The concentration of the diffuser powder is adjusted according to factors such as the size of the RGB chip, the type of diffuser powder, different mixing schemes of diffuser powder, different particle size ratios of diffuser powder, and the refractive index of the adhesive.

[0107] In some embodiments, in order to improve the light mixing effect of the dispensing, the present invention proposes that the weight concentration of light-diffusing particles doped in the first adhesive layer is not less than 10%, so that the first adhesive layer doped with light-diffusing particles can form a percolation threshold network, ensuring that the refraction probability is equal each time.

[0108] In detail, when the weight concentration of light-diffusing particles in the first adhesive layer is less than 10%, it will lead to insufficient scattering and a color difference Δu'v' > 0.01. When the weight concentration of light-diffusing particles in the first adhesive layer is greater than 30%, it is easy to cause a sharp increase in absorption and a 30% decrease in luminous efficiency.

[0109] Furthermore, in the silicone system, the optimal weight concentration range of light-diffusing particles used for different chip sizes is 10% to 30%.

[0110] At this concentration, the following can be achieved:

[0111] Optimal dispersion effect: Light is diffused evenly, and the light spot is soft with no bright spots.

[0112] Optimal color difference control: Significantly reduces or eliminates the spatial color difference inherent in the light source.

[0113] Relatively high luminous efficiency: balances scattering effect and light loss.

[0114] Deviating from this concentration range (too low or too high) will lead to a significant deterioration in key optical properties (dispersion, chromatic aberration, luminous efficacy): insufficient concentration results in weak dispersion and large chromatic aberration; excessive concentration results in a significant decrease in luminous efficacy. In special cases, it is necessary to balance luminous efficacy and chromatic aberration by adjusting the concentration of the doped diffuser.

[0115] In some embodiments, the light-diffusing particles include some or all of the following: titanium dioxide (TiO2), hollow glass microspheres (HGMs), barium sulfate (BaSO4), and zirconium oxide (ZrO2).

[0116] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0117] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A display device, characterized in that, include: Display panel, used for image display; A backlight module is disposed on the incident light side of the display panel and is used to provide backlight to the display panel; The backlight module includes: a substrate and a plurality of light-emitting units; the plurality of light-emitting units are disposed on the substrate; At least one of the light-emitting units includes: a plurality of chips for emitting light of different wavelengths and a packaging device; the packaging device is used to package the plurality of chips on the substrate; The encapsulation device includes: a first adhesive layer formed by a first dispensing and a second adhesive layer formed by a second dispensing; A first adhesive layer is disposed on the substrate and covers the plurality of chips. A second adhesive layer is disposed on the substrate and covers the first adhesive layer. The first adhesive layer and the second adhesive layer are bonded together. The first adhesive layer is bonded to the plurality of chips. The first adhesive layer is an adhesive layer doped with light-diffusing particles, and the second adhesive layer is a particle-free transparent adhesive layer. The first refractive index of the first adhesive layer is higher than the second refractive index of the second adhesive layer, and the center height of the first adhesive layer is 0.5-0.8 mm so that the peak light intensity in the non-central region of the light spot formed by the light emitted from the packaging device is greater than the light intensity at the center of the light spot. The bottom surface of the first adhesive layer that is bonded to the substrate is circular in shape, and the bottom surface of the second adhesive layer that is bonded to the substrate is annular in shape. The diameter d of the bottom surface of the first adhesive layer that is bonded to the substrate ranges as follows: d1 d D / 2; d1 is the diameter of the outer circle of the combined array of the multiple chips; The diameter D of the bottom surface of the second adhesive layer that is bonded to the substrate ranges as follows: d <D 7 mm; In the P:H of the backlight module Under condition 2, the light-emitting surface of the second adhesive layer is curved and the top of the light-emitting surface of the second adhesive layer is convex; where P refers to the distance between the center points of two adjacent light-emitting units, and H refers to the light mixing distance; or In the backlight module P:H Under the conditions of 3.2, the light-emitting surface of the second adhesive layer is curved and the top of the light-emitting surface of the second adhesive layer is concave; where P refers to the distance between the center points of two adjacent light-emitting units and H refers to the light mixing distance.

2. The display device according to claim 1, characterized in that, The first adhesive layer is doped with light-diffusing particles at a weight concentration of not less than 10%; the light-diffusing particles include particles of a first particle size, particles of a second particle size, particles of a third particle size, and particles of a fourth particle size. The particle size of the first particle is 0~2μm, the particle size of the second particle is 2μm~6μm, the particle size of the third particle is 6μm~16μm, and the particle size of the fourth particle is 16μm~24μm. The weight of particles with a diameter of 0~2μm accounts for 16.9%~23.5% of the total weight of light-diffusing particles in the first adhesive layer. The weight of particles with a diameter of 0~6μm accounts for 59.9%~80.3% of the total weight of light-diffusing particles in the first adhesive layer; The weight of particles with a diameter of 0~16μm accounts for >95% of the total weight of light-diffusing particles in the first adhesive layer; The weight of particles with a diameter of 0~24μm accounts for 100% of the total weight of light-diffusing particles in the first adhesive layer.

3. The display device according to claim 1, characterized in that, The first adhesive layer is doped with light-diffusing particles at a weight concentration of not less than 10%; the light-diffusing particles include particles with a fifth diameter and particles with a sixth diameter. The fifth particle size has a particle size of 0~6μm, and the sixth particle size has a particle size of 6μm~16μm; wherein, the weight of the fifth particle accounts for 59.9~80.3% of the total weight of the light-diffusing particles in the first adhesive layer.

4. The display device according to claim 1, characterized in that, The light-emitting surface of the first adhesive layer is convex.

5. The display device according to claim 1, characterized in that, The value of the first refractive index minus the second refractive index is not less than 0.

02.

6. The display device according to claim 1, characterized in that, The light-diffusing particles include some or all of the following: titanium dioxide, hollow glass microspheres, barium sulfate, and zirconium oxide.

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