TW202131070A - Direct type backlight device - Google Patents

Abstract

The invention discloses a direct type backlight device comprises a light source base and a reflective sheet. The light source base comprises a plurality of reflection cup structures. Each of reflection cup comprises a reflection cavity. A plurality of light emitting units are arranged in the plurality of reflection cavity. The reflection sheet is arranged on the side of the light source base. The reflection sheet comprises a plurality of reflective regions. Each of the reflective regions is facing one of the reflection cavity. A plurality of reflection bumps formed on each of the reflective regions. In each of the reflective regions, the plurality of reflective bumps are arranged densely in the area close to the center of the reflective region. In each of the reflective regions, the plurality of reflective bumps are arranged discretely in the area close to the center of the reflective region. Each of the reflection cavity is used to reflect the light emitted by the light emitting unit of the light source base. The invention has better uniform performance then the known technology.

Description

Direct type backlight device

The invention relates to a backlight device, in particular to a direct type backlight device.

The light source modules of existing large-scale display devices (such as TVs) can be roughly divided into edge-lit type and direct-lit type. Direct-lit backlight modules have better color performance than edge-lit backlight modules. Therefore, the direct-lit type The backlight module is one of the main technologies developed by related manufacturers in recent years. However, the existing direct-lit backlight module is prone to the problem of inconsistency in the brightness of each area.

The invention discloses a direct type backlight device, which is mainly used to improve the problems of dark and bright areas in the direct type backlight device in the prior art.

One embodiment of the present invention discloses a direct type backlight device, which includes: a light source base and a reflective sheet body. The light source base includes: a circuit board, a plurality of reflective cup structures and a plurality of light-emitting units. A plurality of reflecting cup structures are fixedly arranged on one side of the circuit board, and each reflecting cup structure is recessed to form a reflecting cavity from the side far away from the circuit board to the side close to the circuit board. Each light-emitting unit is fixedly arranged on the circuit board, and multiple light-emitting units are correspondingly located in multiple reflecting cavities. Each light-emitting unit has a top light-emitting surface and a ring light-emitting surface. The periphery of the top light-emitting surface is connected with the ring light-emitting surface. The luminous flux of the luminous surface is lower than the luminous flux of the luminous unit from the annular luminous surface. The reflection sheet body is defined with a plurality of reflection areas, the reflection sheet body is arranged above the light source seat, and each reflection area is correspondingly located directly above each reflection cup structure. The reflective sheet body includes: a substrate and multiple sets of optical structures. Multiple groups of optical structures are formed on a wide side of the substrate, and each group of optical structures is correspondingly located in each reflection area, and each group of optical structures includes a plurality of reflective convex points, and each reflective convex point can reflect the light beam emitted by the light source seat; The multiple reflective bumps in each reflective area are arranged densely as they are closer to the center of the reflective area, and arranged more dispersedly as they are farther away from the center of the reflective area; wherein the sidewall forming each reflective cavity is a reflective surface, and each reflective The reflecting surface of the cavity can reflect part of the light beam emitted by the corresponding light-emitting unit.

In summary, the direct-lit backlight device of the present invention has better light output uniformity compared to the existing direct-lit backlight module, that is, the direct-lit backlight device of the present invention can greatly improve the existing direct-lit backlight module. The obvious dark and bright areas.

In order to further understand the features and technical content of the present invention, please refer to the following detailed descriptions and drawings about the present invention, but these descriptions and drawings are only used to illustrate the present invention, and do not make any claims about the protection scope of the present invention. limit.

In the following description, if it is pointed out, please refer to a specific drawing or as shown in a specific drawing, it is only used to emphasize that in the subsequent description, most of the related content appears in the specific drawing. However, it is not limited that only the specific drawings can be referred to in this subsequent description.

Please refer to FIGS. 1 to 4 together. FIG. 1 shows a side view of the direct-lit backlight device of the present invention. A schematic side view of the reflective sheet. FIG. 3 is a schematic diagram showing the light intensity and angle distribution of each light-emitting unit of the direct-lit backlight device of the present invention, and FIG. 4 is a three-dimensional schematic view of a single light-emitting unit of the direct-lit backlight device of the present invention.

As shown in FIG. 1, the direct type backlight device 100 of the present invention includes: a light source base 1 and a reflective sheet 2. The light source base 1 includes: a circuit board 11, a plurality of reflective cup structures 12 and a plurality of light-emitting units 13. A plurality of reflective cup structures 12 are fixedly arranged on one side of the circuit board 11, and each reflective cup structure 12 is recessed to form a reflective cavity 121 from a side away from the circuit board 11 to a side close to the circuit board 11. The specific appearance of the reflective cavity 121 is not limited here, and it can be changed according to requirements.

As shown in FIG. 2, it is shown as a schematic side view of a single reflector cup structure 12. The side of the reflective cavity 121 opposite to the circuit board 11 is a reflective surface 122, and the reflectivity of the reflective surface 122 may be greater than 90%. The reflective cup structure 12 can be made of a material with high reflectivity. For example, it can be made of a resin containing a highly reflective material composed of metal oxide particles such as titanium oxide, aluminum oxide, and silicon oxide. In different applications, the reflective cup structure 12 can be made of resin that is not doped with highly reflective materials, and the reflective cavity 121 is set on the side opposite to the circuit board 11 (for example, by coating). A layered structure with high reflectivity, and one side of the layered structure with high reflectivity can be correspondingly formed as the aforementioned reflective surface 122. In practical applications, the ratio of the width W to the height H of each reflective cavity 121 can be between 2:1 and 6:1, but not limited to this. The size and appearance of the reflective cavity 121 can be based on the light-emitting unit 13 Correspondingly change according to the difference.

It is worth mentioning that in practical applications, in the schematic side view of the reflective cavity 121, each reflective cavity 121 adjacent to the circuit board 11 may have an arc-shaped section 123, whereby the reflective cavity 121 can be more The light beam emitted by the light-emitting unit 13 is effectively reflected in the direction of the reflective sheet 2. Of course, in different embodiments, in the schematic side view of the reflective cavity 121, the reflective cavity 121 may also include only straight sections without any arc-shaped sections.

As shown in FIG. 2, each light-emitting unit 13 is fixedly disposed on the circuit board 11, and each light-emitting unit 13 is correspondingly located in each reflective cavity 121, and each light-emitting unit 13 may be located at the center and lowest position of the reflective cavity 121 correspondingly. In practical applications, the reflective cup structure 12 may include a recess 124 for accommodating the light-emitting unit 13, and the light-emitting unit 13 is correspondingly disposed in the recess 124. Each light-emitting unit 13 has a top light-emitting surface 13A and a ring light-emitting surface 13B. The periphery of the top light-emitting surface 13A is connected to the ring light-emitting surface 13B. The intensity of the beam.

As shown in Fig. 3, it shows a schematic diagram of the light intensity and angular distribution of each light-emitting unit 13. The light intensity of each light-emitting unit 13 at 0 degrees in the positive direction can be less than 50%, and the maximum light intensity falls on- Between 55° and -75° and between 55° and 75°, the light pattern of each light-emitting unit 13 is roughly half-heart-shaped. In practical applications, the width W of each light-emitting unit 13 may be between 0.1 millimeters (mm) to 2 millimeters (mm), and the length of each light-emitting unit 13 may be between 0.1 mm (mm) and 2 mm. (mm), the height H of each light-emitting unit 13 may be between 0.1 millimeters (mm) and 1.7 millimeters (mm).

As shown in FIG. 4, in a specific implementation, each light-emitting unit 13 may include a light-emitting diode 131, a half-reflective member 132 and a light-transmitting body 133. The light emitting diode 131 may be a rectangular cube, and the light emitting diode 131 has a top surface 1311 and four side surfaces 1312. The top surface 1311 is the end surface of the light emitting diode 131 opposite to the one connected to the circuit board 11. The side surface 1312 is connected with the periphery of the top surface 1311.

The semi-reflective element 132 is arranged on the top surface 1311 of the light-emitting diode 131, and part of the light beam emitted from the top surface 1311 will be reflected by the semi-reflective element 132, and the other part of the light beam can be emitted outward through the semi-reflective element 132 . In practical applications, the semi-reflective member 132 may be formed on the top surface 1311 of the light-emitting diode 131 in a coating manner, and the semi-reflective member 132 may be made of, for example, a translucent material; for example, The semi-reflective member 132 may be made of a reflective material that is thin enough to allow the light beam emitted by the light-emitting unit 13 to directly pass through. In a specific application, the semi-reflective member 132 may be formed by stacking sheet structures with different refractive indices, for example, a distributed Bragg reflector (Distributed Bragg Reflector).

The translucent body 133 is arranged to cover the semi-reflective member 132 and the light emitting diode 131. The shape of the translucent body 133 can be approximately a rectangular cube. The ring light emitting surface 13B, the top light emitting surface 13A and the top surface 1311 are arranged facing each other, and the light beam emitted by the light emitting diode 131 emits the light transmitting body 133 through which it passes. The light-transmitting body 133 is used to protect the light-emitting diode 131 and the semi-reflective element 132 to prevent the light-emitting diode 131 and the semi-reflective element 132 from being directly exposed and easily damaged. In practical applications, the semi-reflective member 132 may include _{reflective particles such as silicon dioxide (SiO 2} ) and titanium dioxide (TiO ₂ ), for example.

In practical applications, each light emitting diode 131 may emit light beams of different wavelengths according to requirements. In the embodiment where the light-emitting diode 131 emits a blue light beam with a wavelength of 460 nm to 470 nm, the light-transmitting body 133 may be doped with a color conversion material, and the color conversion material may include phosphors, II- Materials such as group VI semiconductor nanocrystals or group III-V semiconductor nanocrystals, and the blue light beam emitted by the light-emitting diode 131 passes through the color conversion material in the light-transmitting body 133, and then is converted into a white light beam and emitted outward . In addition, the light-transmitting body 133 may be provided with diffusion particles and the like, which is not limited here.

As described above, through the arrangement of the semi-reflective member 132, the luminous flux of the light beam emitted from the top light-emitting surface 13A of the light-emitting unit 13 will be significantly lower than the light flux of the light beam emitted by the light-emitting unit 13 from the annular light-emitting surface 13B. Therefore, the uniformity of the light beam emitted by the direct-lit backlight device 100 can be improved, and the problem that the user can easily directly observe the light spots formed by the light beams emitted from the top light-emitting surface 13A of each light-emitting unit 13 can be avoided. In other words, the direct-lit backlight device 100 provided with the semi-reflective member 132 has better light output uniformity than the direct-lit backlight device 100 not provided with the semi-reflective member 132, and is less likely to be observed by the user. To a clear spot of light.

It is worth mentioning that the light-emitting diode 131 of each light-emitting unit 13 may be a flip chip, and each light-emitting unit 13 may also include an adapter board 134. The transfer board 134 includes an insulating structure and a conductive wiring structure. The flip-chip packaged light-emitting chip is fixed to the transfer board 134, and the flip-chip packaged light-emitting chip is electrically connected with the conductive wiring structure, and the flip-chip packaged light-emitting chip passes through the transfer board 134 , Fixed to the circuit board 11, and the flip-chip packaged light-emitting chip is electrically connected to the circuit board 11 through the adapter board 134, and the circuit board 11 transmits power and control signals to the flip-chip packaged light-emitting chip through the adapter board 134.

Through the arrangement of the above-mentioned transfer board 134, the problem of peeling (peeling) of the flip-chip packaged light-emitting chip during the process of mounting on the circuit board 11 can be greatly reduced; more specifically, in the prior art, the flip chip is directly The light-emitting chip is fixed on the circuit board 11. In this fixing method, the electrode structure of the flip-chip light-emitting chip will easily be directly heated and expand during the fixing process, which will cause the problem of peeling of the electrode structure. In contrast, if the flip-chip packaged light-emitting chip is fixed on the circuit board 11 through the adapter board 134, the related heat energy will not be directly transferred to the flip-chip packaged light-emitting chip during the process of fixing the light-emitting unit 13 to the circuit board 11 , And most of the heat energy will be absorbed by the transfer board 134 first, so that the flip-chip packaged light-emitting chip will not be prone to the peeling problem mentioned above.

Please refer to Figure 1, Figure 2, Figure 5 and Figure 6. Figure 5 shows a front view of the inner side of the reflective sheet body of the direct type backlight device of the present invention, and Figure 6 shows the reflection of the direct type backlight device of the present invention A front view of a single reflective area of the sheet. The reflective sheet body 2 is arranged above the light source base 1. The reflective sheet 2 includes: a substrate 21 and multiple sets of optical structures 22. The two opposite wide sides of the substrate 21 are defined as an inner side 211 and an outer side 212 respectively.

The base material 21 defines a plurality of reflection areas 21A on the inner surface 211. When the reflective sheet 2 is fixedly arranged above the light source base 1, the inner side surface 211 of the substrate 21 faces the light source base 1, and each reflective area 21A is correspondingly located directly above each reflective cup structure 12, and each reflective area The center C of 21A is correspondingly located above the center of the top light emitting surface 13A of the light emitting unit 13. More specifically, the center C of each reflective area 21A and the center of the top light emitting surface 13A of the light emitting unit 13 are located on the same axis.

In practical applications, each reflective area 21A corresponds to the orthographic projection area of the orthographic projection of each reflective cup structure 12 to the reflective sheet body 2, or the reflective area 21A may be equal to the reflective cup structure 12 to the reflective sheet. The orthographic projection area of the orthographic projection in the direction of the body 2; the center C of each reflective area 21A falls within the orthographic projection area of the orthographic projection of each light-emitting unit 13 in the direction of the reflective sheet 2.

Multiple groups of optical structures 22 are formed on the inner side surface 211 of the substrate 21, and each group of optical structures 22 is correspondingly located in each reflection area 21A, and each group of optical structures 22 includes a plurality of reflective convex points 221. The multiple reflective bumps 221 in each reflective area 21A are distributed in such a manner that the closer the multiple reflective bumps 221 are to the center C of the reflective area 21A, the more densely they are arranged, and the farther away the multiple reflective bumps 221 are from the reflective area 21A. The center C is arranged more dispersedly. Each of the reflective bumps 221 can reflect the light beam emitted by the light-emitting unit 13, and at least a part of the light beam reflected by the reflective bumps 221 will return to the reflective cavity 121 and be reflected by the reflective cavity 121 again. It is emitted in the direction of the reflective sheet body 2.

In a specific implementation, each reflective bump 221 may be formed on the substrate 21 by means of ink printing, plastic molding technology (injection molding, hot press molding), etc., and each reflective bump 221 may contain titanium oxide particles, A resin with high reflectivity particles such as alumina particles and silica particles. The outer diameter OD of each reflective bump 221 (as shown in FIG. 6) may be between 30 microns (um) and 500 microns (um), preferably, the outer diameter OD of each reflective bump 221 may be between 30 microns (um) to 100 microns (um). The height H of each reflective bump 221 (as shown in FIG. 2) may be between 1 micrometer (um) and 10 micrometers (um).

In practical applications, the thickness of the substrate 21 is between 0.3 millimeters (mm) and 2 millimeters (mm). The light beam emitted by the light-emitting unit 13 can pass through the substrate 21 from the inner side surface 211 of the substrate 21 without the reflective bumps 221, and then be emitted from the outer side surface 212. The specific material and structure of the substrate 21 are not limited here. For example, the substrate 21 may have a structure similar to a diffuser, or the substrate 21 may be made of a transparent polymer material. Alternatively, the substrate 21 may also be a multilayer film material, which is not limited here.

As described above, the reflective sheet 2 is provided above the light source base 1, and the wide side of the reflective sheet 2 facing the light source base 1 is provided with multiple sets of optical structures 22, and each set of optical structures 22 is set The included multiple reflective bumps 221 are densely arranged at a position close to the center C of the reflective area 21A, and loosely arranged at a position away from the center C of the reflective area 21A, which will enable the light-emitting unit 13 to be from the top light-emitting surface. Most of the light beams emitted by 13A will be reflected by the reflective bumps 221 to the reflecting cavity 121, and most of the light beams emitted by the light-emitting unit 13 from the annular light-emitting surface 13B can be emitted from the outer surface 212 through the substrate 21 to emit light. A small part of the light beam emitted by the unit 13 from the annular light-emitting surface 13B is reflected by the reflective bumps 221 to the reflective cavity 121. In this way, the uniformity of the light emitted by the light source holder 1 through the reflective sheet 2 can be greatly improved.

As shown in FIG. 7, it shows the light-emitting angle of the light beam emitted by a single light-emitting unit 13, the transmittance of the light beam emitted by a single light-emitting unit 13 through the reflector body 2, and the light beam emitted by a single light-emitting unit 13 A schematic diagram of the relationship between the reflectivity reflected by the reflective sheet 2. As shown in the figure, through the above-mentioned multiple sets of optical structures 22 and the multiple reflective bumps 221 included in the distribution design in the reflective area 21A, the reflective sheet 2 has a high reflectivity for the forward light of the light-emitting unit 13 and penetrates The transmittance is low, and the reflectance of the large-angle beam of the light-emitting unit 13 is low, and the transmittance is high.

Please refer to FIG. 6 again. In practical applications, each reflective area 21A can also be separated by a central area A1, a first peripheral area A2, and a second peripheral area A3. The central area A1 includes the center C of the reflective area 21A. The first peripheral area A2 surrounds the central area A1, the second peripheral area A3 surrounds the first peripheral area A2, and the central area A1 falls in the orthographic projection area of the corresponding light emitting unit 13 in the direction of the reflective sheet 2. Among them, the linear distance L2 from the outer edge of the first peripheral area A2 to the center C of the central area A1 is twice the linear distance L1 from the center C of the central area A1 to the outer edge of the central area A1; The linear distance L3 from the outer edge to the center C of the central area A1 is three times the linear distance L1 from the center C of the central area A1 to the outer edge of the central area A1. In other words, if the linear distance from the center C of the central area A1 to the outer edge of the second peripheral area A3 is defined as R, the linear distance between the outer edge of the first peripheral area A2 and the center C of the central area A1 is 2/3R , And the linear distance from the center C of the central area A1 to the outer edge of the central area A1 is 1/3R.

The total area occupied by the plurality of reflective bumps 221 of each group of optical structures 22 in the central area A1 accounts for 60% to 90% of the area of the central area A1; each group of optical structures 22 is located in the first peripheral area A2 of the reflective area 21A The sum of the area occupied by the plurality of reflective bumps 221 in the first peripheral area A2 accounts for 30% to 60%; the plurality of reflective bumps in the second peripheral area A3 of each group of optical structures 22 in the reflective area 21A The total area occupied by the point 221 accounts for 5%-30% of the area of the second peripheral area A3. Through the above design, the uniformity of the light beam emitted by the light source holder 1 out of the reflective sheet 2 can be further improved.

In addition, the distribution of the multiple reflective bumps 221 in each central area A1 may be such that the closer the multiple reflective bumps 221 are to the center C of the central area A1, the denser the multiple reflective bumps 221 are, and the farther away the multiple reflective bumps 221 are from the center. The center C of the area A1 is more dispersedly arranged; the distribution of the multiple reflective bumps 221 in each first peripheral area A2 may be that the closer the multiple reflective bumps 221 are to the central area A1, the more densely they are arranged. The more the reflective bumps 221 are away from the central area A1, the more scattered they are; the distribution of the multiple reflective bumps 221 in each second peripheral area A3 may be that the multiple reflective bumps 221 are closer to the first peripheral area The more densely A2 is arranged, the farther away the plurality of reflective bumps 221 are from the first peripheral area A2, the more scattered they are. That is to say, the multiple reflective bumps 221 in a single reflective area 21A are arranged densely as they are closer to the center C of the central area A1, and arranged loosely as they are farther away from the center C of the central area A1. In this way, the uniformity of the light beam emitted from the light source base 1 through the reflective sheet 2 can be further improved.

As shown in FIG. 6, the multiple reflective bumps 221 in a single reflective area 21A may have the same outer diameter OD, but the closer to the center C of the reflective area 21A, the greater the distance D between the multiple reflective bumps 221. The distance D between the reflective bumps 221 that are farther from the center C of the reflective area 21A is larger.

Please refer to FIG. 8, which shows a schematic diagram of a plurality of reflective bumps in a single reflective area of the second embodiment of the direct-lit backlight device of the present invention. As shown in the figure, the biggest difference between this embodiment and the previous embodiment is that the spacing D between the multiple reflective bumps 221 in a single reflective area 21A can be the same as each other, but the outer diameter of each reflective bump 221 The OD is not the same, and the outer diameter of the reflective bump 221 that is farther from the center C of the reflective region 21A is smaller, and the outer diameter of the reflective bump 221 is larger the closer to the center C of the reflective region 21A.

Please refer to FIGS. 9 and 10 together. FIG. 9 shows a partial enlarged schematic view of the side surface of the reflective sheet body of the third embodiment of the direct type backlight device of the present invention, and FIG. 10 is the third embodiment of the direct type backlight device of the present invention. A schematic diagram of the microstructure included in the reflective sheet body of the embodiment. As shown in the figure, the biggest difference between this embodiment and the previous embodiment is that the reflective sheet body 2 may further include a plurality of microstructures 23. A plurality of microstructures 23 are formed on the outer side surface 212 of the substrate 21, and part of the light beam emitted in a direction away from the light source base 1 through the substrate 21 will be reflected by the microstructures 23 and directed toward the light source base 1. As shown in FIG. 10, in practical applications, each microstructure 23 may include two regular triangular pyramids, and a bottom surface of each regular triangular pyramid is located on the outer side surface 212 correspondingly. In different embodiments, each microstructure 23 may also include at least one regular quadrangular pyramid, and the bottom surface of the regular quadrangular pyramid is located on the outer side surface 212. Through the design of the above-mentioned microstructure 23, the uniformity of the light beam emitted from the light source base 1 through the reflective sheet 2 can be further improved.

Please refer to FIG. 11, which shows a schematic side view of the third embodiment of the direct type backlight device of the present invention. The biggest difference between this embodiment and the previous embodiments is that the direct type backlight device 100 may also include a diffuser film (Diffuser Film) 3, a Prism Sheet 4, and a dual Brightness Enhancement Film (Dual Brightness Enhancement Film). )5. The diffuser film 3 is arranged on the side of the reflective sheet 2 opposite to the light source base 1, the diffusive film 4 is arranged on the side of the diffuser 3 opposite to the reflective sheet 2, and the reflective brightness enhancement film 5 is arranged on the diffusive sheet 4 opposite to the diffuser One side of the film 3, that is, the diffuser film 3 is located between the reflective sheet 4 and the reflective sheet body 2, and the reflective sheet 4 is located between the reflective brightness enhancement film 5 and the diffuser film 3. Regarding the number of diffusion film 3, 稜鏡 film 4, and reflective brightness enhancement film 5, the number can be changed according to requirements, and is not limited to a single film.

In a specific implementation, the diffusion film 3 may contain diffusion particles, so that the light beam can be refracted and reflected in a specific direction, so that the passing light beam can be emitted out more uniformly. The sheet 4 may include a plurality of microstructures (not shown), and the plurality of microstructures may be used to change the path of the light beam, so that the passing light beam can be concentrated in a predetermined viewing angle range. The reflective brightness enhancement film 5 can be an optical film containing multiple layers of different refractive indexes, and the light beam entering the reflective brightness enhancement film 5 will be reflected and refracted between the multiple optical films, and the setting of the reflective brightness enhancement film 5 will be able to The front brightness of the direct-lit backlight device 100 and the brightness in the direction of a large viewing angle are improved. In particular, the reflective sheet body 2 of this embodiment is opposite to the side facing the light source base 1, and may also be formed with a plurality of microstructures 23 (as shown in FIG. 10) as mentioned in the previous embodiment.

As described above, the direct-lit backlight device 100 of this embodiment can further improve the overall light output uniformity of the direct-lit backlight device 100 and its light output through the arrangement of the diffuser film 3, the diffusor sheet 4, and the reflective brightness enhancement film 5. brightness.

Please refer to FIG. 12, which shows a schematic diagram of a fifth embodiment of the light emitting unit 13 of the direct type backlight device 100 of the present invention. As shown in the figure, the light-emitting unit 13 of this embodiment includes: a light-emitting diode 131, a half-reflective member 132, a light-transmitting body 133, and an adapter plate 134. The light-emitting diode 131 is fixedly disposed on the adapter board 134, the light-transmitting body 133 covers the light-emitting diode 131, and the semi-reflective member 132 is disposed on the top surface 1331 of the light-transmitting body 133. For the detailed description of the light-emitting diode 131, the semi-reflective element 132, the light-transmitting body 133, and the adapter plate 134, please refer to the foregoing embodiment, and will not be repeated here. To put it simply, the biggest difference between this embodiment and the previous embodiment (FIG. 4) is that the position of the semi-reflective member 132 is different. In the embodiment, the arrangement position of the semi-reflective element 132 can be changed according to requirements. For example, the semi-reflective element 132 can be arranged on the top surface 1311 of the light-emitting diode 131 (as shown in FIG. 4), or the semi-reflective element 132 The reflector 132 may also be disposed on the top surface 1331 of the light-transmitting body 133.

Similar to the description of the foregoing embodiment, in practical applications, the light-emitting unit 13 mentioned in this embodiment, in the case that the light-emitting diode 131 emits blue light, the light-transmitting body 133 can correspondingly be doped with a color conversion material to emit light. The blue light emitted by the diode 131 will be converted into white light after passing through the transparent body 133.

The above descriptions are only the preferred and feasible embodiments of the present invention, which do not limit the scope of the present invention. Therefore, all equivalent technical changes made by using the description and drawings of the present invention are included in the protection scope of the present invention. .

100: Direct backlight device 1: Light source base 11: circuit board 12: reflector cup structure 121: reflective cavity 122: reflective surface 123: arc section 124: Conveyor 13: Light-emitting unit 13A: Top emitting surface 13B: Ring light-emitting surface 131: LED 1311: top surface 1312: side 132: Semi-reflective parts 133: Translucent body 1331: top surface 134: adapter board 2: reflector body 21: Substrate 211: Inside 212: Outer side 21A: reflective area 22: Optical structure 221: reflective bump 23: Microstructure 3: Diffusion film 4: 稜鏡片 5: Reflective brightness enhancement film A1: Central area A2: The first peripheral area A3: The second peripheral area C: Center D: spacing OD: outer diameter H: height W: width L1: distance L2: distance L3: distance

FIG. 1 shows a schematic side view of the first embodiment of the direct type backlight device of the present invention.

2 shows a schematic side view of a single reflective cup structure, a single light-emitting unit, and a partial reflective sheet body of the first embodiment of the direct-lit backlight device of the present invention.

FIG. 3 is a schematic diagram showing the light intensity and angle distribution of each light-emitting unit of the first embodiment of the direct type backlight device of the present invention.

4 is a perspective view of a single light emitting unit of the first embodiment of the direct type backlight device of the present invention.

FIG. 5 is a front view of the inner side of the reflective sheet body of the first embodiment of the direct type backlight device of the present invention.

Fig. 6 shows a front view of a single reflective area of the reflective sheet body of the first embodiment of the direct-lit backlight device of the present invention.

FIG. 7 shows the light-emitting angle of the light beam emitted by a single light-emitting unit, the transmittance of the light beam emitted by a single light-emitting unit through the reflective sheet, and the single light-emitting unit of the first embodiment of the direct-lit backlight device of the present invention A schematic diagram of the relationship between the reflectivity of the emitted light beam reflected by the reflective sheet body.

FIG. 8 is a schematic diagram of a plurality of reflective bumps in a single reflective area of the second embodiment of the direct type backlight device of the present invention.

FIG. 9 is a partial enlarged schematic diagram of the side surface of the reflective sheet body of the third embodiment of the direct type backlight device of the present invention.

10 is a schematic diagram of the microstructure included in the reflective sheet body of the third embodiment of the direct type backlight device of the present invention.

FIG. 11 is a schematic side view of the fourth embodiment of the direct type backlight device of the present invention.

FIG. 12 is a three-dimensional schematic diagram of a single light-emitting unit of the fifth embodiment of the direct type backlight device of the present invention.

1: Light source base

11: circuit board

12: reflector cup structure

121: reflective cavity

122: reflective surface

123: arc section

124: Conveyor

13: Light-emitting unit

13A: Top emitting surface

13B: Ring light-emitting surface

131: LED

132: Semi-reflective parts

133: Translucent body

2: reflector body

21: Substrate

211: Inside

212: Outer side

22: Optical structure

221: reflective bump

A1: Central area

A2: The first peripheral area

A3: The second peripheral area

Claims (10)

A direct type backlight device, which comprises: A light source base, which contains: A circuit board; A plurality of reflective cup structures, which are fixedly arranged on one side of the circuit board, and each of the reflective cup structures is recessed to form a reflective cavity from a side away from the circuit board to a side close to the circuit board; A plurality of light-emitting units, each of the light-emitting units is fixedly arranged on the circuit board, and the multiple of the light-emitting units are correspondingly located in a plurality of the reflective cavities, each of the light-emitting units has a top light-emitting surface and a ring light-emitting surface, The periphery of the top light emitting surface is connected to the ring light emitting surface, and the intensity of the light beam emitted by the top light emitting surface of the light emitting unit is lower than the intensity of the light beam emitted by the ring light emitting surface; and A reflective sheet body, which defines a plurality of reflective areas, the reflective sheet body is arranged above the light source seat, and each of the reflective areas is correspondingly located directly above each of the reflective cup structures, and each of the reflective The center of the area is correspondingly located above the center of the light-emitting unit, and the reflective sheet body includes: A substrate; A plurality of groups of optical structures are formed on a wide side of the substrate, and each group of the optical structures is correspondingly located in each of the reflection areas, and each group of the optical structures includes a plurality of reflective convex points, and each of the reflection The bumps can reflect the light beam emitted by the light source holder; the multiple reflective bumps in each of the reflective areas are densely arranged as they are closer to the center of the reflective area, and farther away from the reflective area. The center is more scattered; Wherein, the side wall forming each of the reflective cavities is a reflective surface, and the reflective surface of each of the reflective cavities can reflect a part of the light beam emitted by the corresponding light-emitting unit. The direct type backlight device according to claim 1, wherein each of the reflective areas falls within an orthographic projection area of the corresponding orthographic projection of the reflective cup structure toward the reflective sheet body, and each of the reflective regions The area is divided by a central area, a first peripheral area, and a second peripheral area, the central area is located in the center of the reflective area, the first peripheral area surrounds the central area, and the second peripheral area surrounds In the first peripheral area, the central area falls within the orthographic projection area of the corresponding orthographic projection of the light-emitting unit in the direction of the reflective sheet; The total area occupied by the reflective bumps occupies 60% to 90% of the area of the central region; wherein, each group of the optical structure is in the first peripheral region of the reflective region. The sum of the area occupied by the bumps occupies 30%-60% of the area of the first peripheral area; wherein, each group of the optical structure is in the second peripheral area of the reflective area. The total area occupied by the reflective bumps accounts for 5%-30% of the area of the second peripheral region. The direct type backlight device according to claim 2, wherein the plurality of reflective bumps in each of the central regions are arranged densely as they are closer to the center of the reflective region, and farther away from the reflective region The center of each of the reflective bumps is arranged more dispersedly; the more the reflective bumps in each of the first peripheral areas are arranged more densely as they are closer to the central area, and arranged more dispersed as they are farther from the central area; The plurality of reflective bumps in each of the second peripheral areas are arranged densely as they are adjacent to the first peripheral area, and are arranged more dispersedly as they are farther from the first peripheral area. The direct type backlight device according to claim 3, wherein the linear distance from the outer edge of the first peripheral area to the center of the central area is the distance from the center of the central area to the outer edge of the central area 2 times the linear distance; the linear distance from the outer edge of the second peripheral area to the center of the central area is 3 times the linear distance from the center of the central area to the outer edge of the central area. The direct type backlight device according to claim 1, wherein the outer diameter of each of the reflective bumps is between 30 microns (um) and 500 microns (um); the height of each of the reflective bumps is between 1 micron ( um) to 10 microns (um). The direct type backlight device according to claim 1, wherein the thickness of the reflective sheet body is between 0.3 millimeters (mm) and 2 millimeters (mm). The direct type backlight device according to claim 1, wherein the light beam emitted by the light-emitting unit can be emitted in a direction away from the light source base through a position where the reflective bumps are not provided on the substrate, so The two wide sides of the substrate opposite to each other are respectively defined as an inner side and an outer side, the reflective sheet body further includes a plurality of microstructures, and a plurality of the microstructures are formed on the outer side of the substrate , A part of the light beam emitted in a direction away from the light source base through the substrate will be reflected by the microstructure and directed toward the light source base. The direct type backlight device according to claim 7, wherein each of the microstructures includes at least one regular triangular pyramid or at least one regular quadrangular pyramid, and the bottom surface of the regular triangular pyramid or the regular quadrangular pyramid The bottom surface of the body is located on the outer side surface. The direct type backlight device according to any one of claims 1 to 8, wherein each of the light-emitting units further includes a light-emitting diode, a half-reflective member, and a light-transmitting body, and the light-emitting diode has five A light-emitting surface, the light-transmitting body is arranged to cover the light-emitting diode, the light beam emitted by the light-emitting diode can be emitted out through the light-transmitting body, and the semi-reflective member is arranged on the light-emitting diode. On a top surface of the light body, the semi-reflective member can block part of the light beams emitted outward through the top surface of the light-transmitting body; wherein the width of each of the light-emitting units is between 0.1 millimeters (mm) and 2 millimeters (mm), the length of each light-emitting unit is between 0.1 millimeters (mm) to 2 millimeters (mm), and the height of each light-emitting unit is between 0.1 millimeters (mm) and 1.7 mm ( mm). The direct type backlight device according to claim 9, wherein the ratio of the width to the height of each of the reflective cavities is between 2:1 and 6:1; wherein the reflectivity of the reflective surface is higher than 90%.

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