TW201506508A - Direct lighting type backlight module - Google Patents

Abstract

A direct lighting type backlight module is provided. The direct lighting type backlight module includes a light-transmissive plate, a cone-type concave portion, an LED element and a reflection portion. The light-transmissive plate includes a light-incident surface and a light-outputting surface which are opposite with each other. The cone-type concave portion is formed on the light-outputting surface. The LED element contacts with the light-incident surface and correspondingly aligns with a vertex of the cone-type concave portion. The reflection portion contacts with the light-incident surface and obliquely extends toward the LED element. The reflection portion reflects lights back into the light-transmissive plate for reducing a dark spot generated on a peripheral area of the cone-type concave portion.

Description

Direct type backlight module

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

The backlight module of the conventional liquid crystal display is disposed on the back of the liquid crystal panel to provide a display light source required for the liquid crystal panel. The backlight module can be divided into "side-light" and "straight-down" designs according to the position of the light source. The backlight module of the "straight down" design gradually uses a plurality of light-emitting diodes as a light source to replace the traditional white heat lamp. Or fluorescent tube. When the light-emitting diode is used as a light source, a light-expanding distance is usually reserved and disposed under the liquid crystal panel to provide a uniform light source of the liquid crystal panel. Therefore, the "direct-down" design of the backlight module will be very thick.

The structure of the "side-light" backlight module is lighter from the side, so it will be thinner; however, the number of LEDs to be used is at least 2.5 times that of the "direct-type" backlight module of the same size.

Therefore, if the light-emitting diode can be directly attached to the back surface of the light-removing plate, the advantages of both of them can be combined. However, in practice, when directly bonding, the intensity of the light will be strongest in the direction of the positive viewing angle (that is, the normal direction of the light-emitting surface of the light-emitting diode). If the light-emitting structure on the light-shading plate is used, the light-emitting diode will be positive. The light in the direction of the view is reflected toward the side, and it will be on the side of the light-emitting structure. The edge forms a circle of dark bands, commonly known as optical taste.

In view of this, how to develop a backlight module and improve the above-mentioned lack of inconvenience and inconvenience is an important issue that the relevant industry is currently unable to delay.

One aspect of the present invention is to provide a direct type backlight module for solving the difficulties mentioned in the prior art.

According to an embodiment of the invention, the direct type backlight module comprises a light transmissive plate body, at least one conical recess, at least one light emitting diode element and at least one light reflecting portion. The light transmissive plate body includes a light emitting surface and a light incident surface. The conical recess is disposed on the light emitting surface and includes a tip bottom and a convex curved inner wall. The inner surface of the convex curved surface is connected between the bottom of the tip and the light exiting surface, and surrounds the bottom of the tip. The light emitting diode element is coupled to the light surface, wherein the bottom of the tip is projected onto the light emitting diode element on one of the light incident surfaces. The light reflecting portion is in contact with the light surface and obliquely extends toward the light emitting diode element for reflecting the light back into the light transmitting plate body. The angle between the light reflecting portion and the light incident surface is at least: tan ^-1 T / (Φ - W), wherein T is the thickness of the light emitting diode element, Φ is the maximum aperture of the conical recess, and W is the light emitting diode element The width.

In one or more embodiments of the present invention, the light reflecting portion is formed on a circuit board. The circuit board carries the light-emitting diode elements and is electrically connected to the light-emitting diode elements. The light emitting diode element is sandwiched between the circuit board and the light incident surface.

In one or more embodiments of the present invention, the light-emitting surface of the light-emitting diode element and one surface of the flexible sheet body are all connected to the light surface, so that a depressed portion Formed between the flexible sheet and the light incident surface, and the light emitting diode element is located in the recess.

In one or more embodiments of the present invention, the light reflecting portion is at least one inner wall of the recessed portion, or the light reflecting portion is, for example, a metal plating film on the flexible sheet body, attached to the recessed portion. At least one inner wall.

In one or more embodiments of the present invention, the direct type backlight module further includes an optical lens. The optical lens comprises a body, a recess and a consistent perforation. The body is located between the circuit board and the light incident surface, and includes a first surface and a second surface opposite to each other. The first side is abutted to the smooth surface, and the second side is abutted to the circuit board. The groove is formed on the first side of the body. The through hole is located in the groove and penetrates through the second side of the body. The light emitting diode element is located in the recess and the through hole.

In one or more embodiments of the present invention, the light reflecting portion is at least one inner wall of the groove, or the light reflecting portion is, for example, a metal plating film attached to at least one inner wall of the groove.

In one or more embodiments of the present invention, the light reflecting portion is one of a light reflecting sheet and a light reflecting material coating.

In one or more embodiments of the present invention, the light reflecting portion has at least one of a light reflecting pattern and a light diffusing pattern.

In summary, with the design of the direct type backlight module of the present invention, the light reflecting portion can reflect the light back into the transparent plate body to compensate the brightness of the light surface in the surrounding area of the conical concave portion, thereby eliminating the dark band phenomenon. , thereby improving the uniform brightness of the light-emitting surface and solving the problem of unevenness of the surface light source.

100, 101, 102, 103, 104‧‧‧ direct type backlight module

110‧‧‧Translucent plate

111‧‧‧Glossy surface

111J‧‧‧ junction

112‧‧‧ring area

112R‧‧‧ outermost edge of the ring zone

113‧‧‧Optical microstructure

114‧‧‧Into the glossy surface

120‧‧‧Conical recess

121‧‧‧ tip bottom

122‧‧‧ convex curved inner wall

200‧‧‧Light source

210‧‧‧Substrate

211‧‧‧Flexible sheet

211U‧‧‧ upper surface

211L‧‧‧ lower surface

212‧‧‧Depression

212S‧‧‧ inner wall surface

220‧‧‧Lighting diode components

221‧‧‧Lighting surface

222‧‧‧Connected feet

230, 231, 232‧‧‧Light Reflecting Department

235‧‧‧ optical pattern

240‧‧‧Lighting diode components

241‧‧‧ lead frame

242‧‧‧Light-emitting diode grains

243‧‧‧Package

244‧‧‧ lumen

244L‧‧‧imaginary extension line

250‧‧‧ optical lens

251‧‧‧ Ontology

251U‧‧‧ first side

251L‧‧‧ second side

252‧‧‧ Groove

252S‧‧‧ inner wall surface

253‧‧‧through holes

300‧‧‧ display device

310‧‧‧ display panel

D, K, M, R, S‧‧‧ segments

W‧‧‧Width

T‧‧‧ thickness

Α‧‧‧incident angle, reflection angle

Θ‧‧‧ angle

Φ‧‧‧Maximum aperture

P‧‧‧projection

L1‧‧‧First light

L2‧‧‧second light

L3‧‧‧Compensated light

2-2‧‧‧ hatching

X, Y, Z‧‧‧ axial

FIG. 1 is an exploded view of a direct type backlight module according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view taken along line 2-2 of Fig. 1.

FIG. 3A is a cross-sectional view and an optical path diagram of a direct type backlight module according to an embodiment.

FIG. 3B is a diagram showing the dimensional relationship of the direct type backlight module of FIG. 3A.

FIG. 4A is a cross-sectional view showing a direct type backlight module according to an embodiment.

Fig. 4B is a plan view showing the optical lens of Fig. 4A.

FIG. 5 is a cross-sectional view showing a direct type backlight module according to an embodiment.

FIG. 6 is a cross-sectional view showing a direct type backlight module according to an embodiment.

FIG. 7 is a schematic view showing a display device according to an embodiment of the present invention.

The embodiments of the present invention are disclosed in the following drawings, and the details of However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not necessary. In addition, some of the conventional structures and elements are shown in the drawings in a simplified schematic manner in order to simplify the drawings.

FIG. 1 is an exploded view of a direct type backlight module 100 according to an embodiment of the present invention. As shown in FIG. 1 , the direct type backlight module 100 of the present embodiment includes a light transmissive plate body 110 , a plurality of conical recesses 120 , and a light source 200 . The light transmissive plate body 110 includes a light emitting surface 111 and a light incident surface 114. These conical recesses 120 are spaced apart from each other on the light exit surface 111. The light source 200 includes a circuit board 210 and a plurality of light emitting diode elements 220. These two lights The polar body component 220 is a light emitting diode package structure, and is respectively arranged on the circuit board 210 at intervals, and the conical recesses 120 are respectively aligned one by one to provide light to enter the light transmissive plate body 110 via the light incident surface 114. So that the light generates a surface light source on the light exit surface 111.

2 is a cross-sectional view taken along line 2-2 of FIG. 1. For convenience of explanation, FIG. 2 also shows the light-emitting diode element 220 and its peripheral related structure. Each of the light emitting diode elements 220 is interposed between the circuit board 210 and the light incident surface 114. More specifically, the top surface of the light emitting diode element 220 has a light emitting surface 221, and the light emitting surface 221 is flatly attached to the light surface 114. The bottom surface of the LED component 220 has a connection pin 222 electrically connected to the surface of the circuit board 210.

As shown in FIG. 2, each of the conical recesses 120 includes a tip end portion 121 and a convex curved inner wall 122. When the light exit surface 111 is viewed from above, the conical concave portion 120 has a circular shape on the light exit surface 111, and the center point of the conical concave portion 120 is the tip end bottom portion 121.

The front projection P of the tip end portion 121 on the light-emitting surface 221 of the light-emitting diode element 220 is evenly projected on the light-emitting surface 221 of the light-emitting diode element 220, and even falls on the center of one of the light-emitting surfaces 221 of the light-emitting diode element 220. The convex curved inner wall 122 connects the tip bottom portion 121 and the light exit surface 111, respectively, between the tip bottom portion 121 and the light exit surface 111, and completely surrounds the tip bottom portion 121. In other words, the cross-section of the convex curved inner wall 122 of the conical recess 120 is a two-curve line, and the two arcs are respectively symmetrical and curved downwardly from the light-emitting surface 111 on the opposite sides of the conical recess 120, and finally intersect each other and jointly The tip end of the light emitting diode element 220 forms a tip bottom portion 121. Each arc is composed of a plurality of A curve composed of lines with the same slope.

From the perspective of optical design, the 50% intensity of the light-emitting diode element 220 will fall within the conical recess 120; in other words, the light generated by the LED element 220 mostly falls on the convex surface. The inner wall 122; a small portion falls outside the conical recess 120, that is, directly at a large angle to the light exit surface 111, which may be referred to as primary optics. The light reflected by the light-emitting surface 111 and the convex curved inner wall 122 is correspondingly referred to as secondary optics.

When a plurality of light rays of the LED body 220 respectively reach the lines of different slopes of the convex curved inner wall 122, total reflection is generated on the convex curved inner wall 122 to form the first light L1, which is first. The light L1 is reflected in a horizontal direction (such as the X-axis), and parallel to the light-emitting surface 111 or the light-incident surface 114, effectively becomes a controllable secondary optics. These secondary optics will diverge with the optical path, and finally The optical pattern designed on the light-emitting surface 111 or the light-incident surface 114 is guided to form a uniform light-emitting surface.

However, when the primary optical ray of the illuminating diode element 220 falls beyond the conical recess 120, a large angle total reflection and uncontrolled secondary optics are formed, such as the second ray L2 as illustrated. These second rays L2 are because the primary optics does not reach the convex curved inner wall 122 but arrives at the light exiting surface 111, for example, reaching the intersection 111J (or turning point) of the convex curved inner wall 122 and the light emitting surface 111. The second light ray L2 is totally reflected at the intersection 111J, so it will bounce toward the light incident surface 114; other uncontrolled secondary optics having a light illuminating angle greater than the second light ray L2 will also be generated outside the intersection 111J. Total reflection. Therefore, viewed from directly above the light-emitting surface 111, a relatively dark annular region 112 is formed, resulting in poor optical taste.

Therefore, the inventors of the present invention have deliberately tried to find out the aforementioned phenomenon of poor optical taste and the physical cause of the phenomenon, and have studied it, and finally proposed the following embodiments to solve the aforementioned dark band of the annular region 112. problem. FIG. 3A is a cross-sectional view and an optical path diagram of the direct type backlight module 101 according to an embodiment. As shown in FIG. 3A, in an embodiment of the present invention, the light source 200 further includes one or more light reflecting portions 230. The light reflecting portion 230 is located between the circuit board 210 and the light incident surface 114, and has one side abutting the light surface 114 and the other side obliquely extending toward the light emitting diode element 220. Therefore, the light reflecting portion 230 and the light incident surface 114 are not Parallel to each other.

Thus, as shown in FIG. 3A, since the light reflecting portion 230 and the light incident surface 114 are not parallel to each other, and the light incident surface 114 is inclined, the light reflecting portion 230 can laterally leak the light emitting diode element 220. The low light is reflected into the light-transmitting plate body 110, so that the plurality of compensating light beams L3 are emitted from the annular region 112 to compensate for the insufficient brightness of the annular region 112, so that the brightness of the annular region 112 is closer to the conical shape. The brightness of the convex curved inner wall 122 of the concave portion 120 improves the problem of unevenness of the surface light source.

In contrast, in FIG. 2A, since the surface of the circuit board 210 of FIG. 2A and the surface of the light incident surface 114 are substantially parallel to each other, the shimmering light emitted from the side of the light-emitting diode element 220 cannot be utilized in the light-transmitting plate body 110. Further, the brightness of the annular region 112 cannot be effectively reinforced.

In some embodiments, if the size of the light reflecting portion 230 is limited and cannot correspond to the second light ray L2 reflected by the annular region 112, The compensation light L3 will not be provided on the light-receiving surface 111. For this reason, as shown in FIG. 3A, the light-reflecting portion 230 may extend at least laterally to the annular region in a direction away from the light-emitting diode element 220 (such as the X-axis). The outermost edge 112R of the 112 corresponds to the area of the light incident surface 114 so that the light reflecting portion 230 can reflect the second light ray L2 reflected by the annular region 112.

FIG. 3B is a diagram showing the dimensional relationship of the direct type backlight module 101 of FIG. 3A. In detail, as shown in FIG. 3B, the conical recess 120 has a maximum aperture Φ, and the maximum aperture Φ is the intersection 111111 (or turning point) of the light-emitting surface 111 on the opposite side of the conical recess 120 and the convex curved inner wall 122. The minimum linear distance between the two. The line segment R is the horizontal distance when the tip end portion 121 is at the same height as the above-mentioned turning point, that is, the radius (Φ/2) of the maximum aperture Φ. The light emitting diode element 220 has a thickness T and a width W. The thickness T is a minimum length from the top surface to the bottom surface (e.g., the Z-axis) of the light-emitting diode element 220. The width W is a minimum length of the top surface of the light-emitting diode element 220 extending in the cross-sectional direction (e.g., the X-axis). Since the orthographic projection P of the tip bottom portion 121 on the light incident surface 114 falls on the center of the light emitting surface 221 of the light emitting diode element 220, the line segment D is W/2, and the line segment K is the difference between the line segment R and the line segment D. That is (Φ/2-W/2). Since the incident angle α of the second light ray L2 reaching the light exiting surface 111 is equal to the reflection angle α, the line segment M is twice the value of the line segment K, that is, (Φ-W).

Thus, when the angle between the light reflecting portion 230 and the light incident surface 114 is θ, the linear distance of the line segment S is at least tan θ=thickness T/(maximum aperture Φ-width W), so that the light reflecting portion 230 can be obtained. Light from the LED component 220 is reflected to the annular region 112. In other words, the angle θ between the light reflecting portion 230 and the light incident surface 114 is tan ^-1 T / (Φ - W), and adjusting the angle θ allows the light reflecting portion 230 to reflect the light of the light emitting diode element 220. The annular region 112 is described.

Referring back to FIG. 3A, in some embodiments, the circuit board 210 is, for example, a flexible circuit board or a flexible metal core printed circuit board. The circuit board 210 includes a relatively upper surface 211U and a lower surface 211L. Both the light emitting diode element 220 and the light reflecting portion 230 are provided on the upper surface 211U. In this embodiment, the light reflecting portion 230 is a portion of the upper surface 211U of the circuit board 210, such as a resin varnish or a metal plating surface.

When the light emitting surface 111 of the LED component 220 and the upper surface 211U of the circuit board 210 are both connected to the light surface 114, the circuit board 210 is bent to form a recess 212 between the circuit board 210 and the light incident surface 114. And the light emitting diode element 220 is located in the recess 212. One or more of the inner wall surfaces 212S of the recessed portion 212 is the light reflecting portion 230, and the light reflecting portion 230 surrounds the light emitting diode element 220.

In some embodiments, since the circuit board 210 of FIG. 3A is accurately bent each time to form the recessed portion 212, the light reflecting portion 230 can be tilted to allow the light reflecting portion 230 to be aligned correctly. The position to achieve the above effect of compensating for the light L3. Therefore, in some embodiments, as shown in FIGS. 4A and 4B, the direct type backlight module 102 has a light transmissive optical lens 250 or a opaque outer cover. Taking the optical lens 250 as an example, the optical lens 250 includes a body 251, a recess 252 and a uniform through hole 253. In the present embodiment, the body 251 includes a first surface 251U and a second surface 251L opposite to each other. The first surface 251U is connected to the light surface 114, the first The two sides 251L abut the circuit board 210. The groove 252 is formed on the first face 251U of the body 251 such that the first face 251U surrounds the groove 252. The through hole 253 is located in the recess 252 and penetrates from the bottom of the recess 252 to the second surface 251L of the body 251. The light emitting diode element 220 is located just inside the through hole 253. The light reflecting portion 231 is an inner wall surface 252S of the recess 252, for example, a portion of the optical lens 250, and surrounds the light emitting diode element 220. The through hole 253 is a center point of the inner wall surface 252S (FIG. 4B), and the inner wall surface 252S has two straight lines, and each of the straight lines extends symmetrically from the light incident surface 114 to the through hole 253. (Fig. 4A).

During installation, the optical lens 250 is first placed on the circuit board 210 such that the LED component 220 enters the through hole 253 and the recess 252, and the optical lens 250 and the LED component 220 are pressed against the light surface 114. The first surface 251U of the optical lens 250 and the light emitting surface 221 of the light emitting diode element 220 both abut the light incident surface 114, and the optical lens 250 and the light emitting diode element 220 are both disposed on the light incident surface 114 and Between the boards 210. In this embodiment, the circuit board 210 is not limited to a hard circuit board or a flexible circuit board.

In other embodiments, FIG. 5 is a cross-sectional view of the direct type backlight module 103 according to an embodiment. As shown in FIG. 5, the direct type backlight module 103 of FIG. 5 is substantially the same as the direct type backlight module 102 of FIG. 4A except that the light reflecting portion 232 is additionally formed on one or more inner walls of the recess 252. On the surface 252S, the light reflecting portion 232 is attached to the inner wall of the recess 252 and surrounds the light emitting diode element 220. For example, the light reflecting portion 232 is a light reflecting sheet (for example, a plastic sheet) or a light reflecting material coating (for example, a metal plating film).

In addition, as can be seen from FIG. 5, those having ordinary knowledge in the technical field to which the present invention pertains can select a light reflecting portion as a plane, a full plane, a curved surface, or a combination thereof as occasion demands.

Further, in each of the above embodiments, in order to improve the optical performance of the light reflecting portion 230, the light reflecting portion 230 has the optical pattern 235 formed at intervals on the light reflecting portion. The optical pattern 235 is, for example, a light reflecting pattern, a light diffusing pattern, or both (not shown). The optical patterns 235 may also be uniformly or unevenly distributed.

The invention is not limited to the color and material of the light reflecting portion. The color of the light reflecting portion may be, for example, white, silver or other suitable color. The light reflecting portion may be a plastic having a bright color coating or a metal having a high light reflecting coefficient (for example, silver, aluminum, gold, chromium, copper, palladium, titanium or other metals and alloys), but is not limited thereto.

In addition, as shown in FIG. 3A, in order to ensure better light-emitting efficiency of the light-transmitting plate body 110, the light-transmitting plate body 110 further includes a plurality of optical microstructures 113 for diffusion or reflection. The optical microstructures 113 are formed on the light-emitting surface 111 at intervals. In this embodiment, the optical microstructures 113 are formed only on the annular region 112 of the light-emitting surface 111, so that the optical microstructures 113 can strengthen the compensation light L3 toward the annular region. 112 brightness of the light. Of course, those having ordinary knowledge in the technical field of the present invention may choose to form the optical microstructures 113 on the light-emitting surface 111 and the light-incident surface 114 as occasion demands.

In order to solve the phenomenon that the surface light source is uneven, the direct-lit backlight module 100 may also converge the light-emitting angle of the light-emitting element itself, so that the light of the light-emitting element is concentrated on the convex curved inner wall 122 of the conical recess 120. on. As such, FIG. 6 is a cross-sectional view of the direct type backlight module 104 of an embodiment. As shown in FIG. 6, the light-transmissive plate body 110 of the direct-type backlight module 104 and the plurality of conical recesses 120 are the same as described above, and will not be further described below. The LED component 240 of the direct type backlight module 104 includes a lead frame 241, a light emitting diode die 242 and a package 243. The LED die 242 is electrically connected to the lead frame 241. The package body 243 covers the lead frame 241 and the light emitting diode die 242 to form a light emitting diode package wafer. The package body 243 has an inner cavity 244 therein. The light emitting diode die 242 is located in the inner cavity 244 and is aligned with the tip bottom portion 121 of one of the conical recesses 120.

Since the cross section of the package body 243 has two straight lines extending obliquely upward, the direction of the lead frame 241 toward the light exit surface 111 (such as the Z axis) is gradually away from each other, and the imaginary extension lines 244L of the two straight lines pass through the convex curved surface respectively. The intersection of the wall 122 and the light exit surface 111 is 111J. Thus, by the angle limitation formed by the inner wall of the package body 243, the light exiting angle of the light emitting diode die 242 itself is limited, so that most of the light of the light emitting diode die 242 is concentrated in the conical recess 120. After the convex curved inner wall 122, it can be effectively subjected to controllable secondary optics, which greatly reduces the dark band of the annular region 112.

FIG. 7 is a schematic diagram of a display device 300 according to an embodiment of the present invention. As shown in FIG. 7, the display device 300 includes a display panel 310 and the above-described direct type backlight module (for example, 101). The direct type backlight module 100 is located on one side of the display panel 310 to provide sufficient brightness of the display panel 310. .

Thus, with the design of the direct type backlight module of the present invention, since the light reflecting portion reflects the light to the surrounding area of the conical concave portion, the brightness of the surrounding area of the conical concave portion or the light output of the light emitting diode die itself is compensated. The angle is limited to correspond to the conical recess, avoiding the occurrence of the dark band phenomenon, thereby improving the uniform brightness of the light-emitting surface and solving the problem of unevenness of the surface light source.

101‧‧‧Direct type backlight module

110‧‧‧Translucent plate

111‧‧‧Glossy surface

112‧‧‧ring area

112R‧‧‧ outermost edge of the ring zone

113‧‧‧Optical microstructure

114‧‧‧Into the glossy surface

120‧‧‧Conical recess

121‧‧‧ tip bottom

122‧‧‧ convex curved inner wall

200‧‧‧Light source

210‧‧‧ boards

211U‧‧‧ upper surface

211L‧‧‧ lower surface

212‧‧‧Depression

212S‧‧‧ inner wall surface

220‧‧‧Lighting diode components

221‧‧‧Lighting surface

230‧‧‧Light Reflecting Department

235‧‧‧ optical pattern

L2‧‧‧second light

L3‧‧‧Compensated light

Claims (10)

A direct type backlight module comprises: a light transmissive plate body, comprising a light emitting surface and a light incident surface; at least one conical recess portion disposed on the light emitting surface, comprising: a tip bottom portion; and a convex curved inner wall Between the bottom of the tip and the light-emitting surface, and surrounding the bottom of the tip; at least one light-emitting diode element abuts the light-incident surface, wherein the tip of the tip is orthographically projected on one of the light-incident surfaces And the at least one light reflecting portion abuts against the light incident surface and obliquely extends toward the light emitting diode element for reflecting light back into the light transmissive plate body, wherein the light reflecting portion and the light entering portion The angle between the smooth surfaces is: tan ^-1 T / (Φ - W) where T is the thickness of the light-emitting diode element, Φ is the maximum aperture of the conical recess, and W is the width of the light-emitting diode element. The direct-lit backlight module of claim 1, wherein the light-reflecting portion is formed on a circuit board, the circuit board carries and electrically connects the light-emitting diode component, and the light-emitting diode component is disposed. Between the circuit board and the light incident surface. The direct-lit backlight module of claim 2, wherein a light-emitting surface of one of the light-emitting diode elements and a surface of the circuit board abuts the light-incident surface, such that a recess is formed on the circuit board and the input Between the smooth surfaces, wherein the light emitting diode element is located in the recess. The direct type backlight module of claim 3, wherein the light reflecting portion is at least one inner wall of the recessed portion. The direct type backlight module of claim 3, wherein the light reflecting portion is attached to at least one inner wall of the recessed portion. The direct-lit backlight module of claim 2, further comprising: an optical lens, comprising: a body between the circuit board and the light-incident surface, comprising opposite first and second sides, and The first surface abuts the light incident surface, the second surface abuts the circuit board; a groove is formed on the first surface of the body; and a uniform perforation is located in the groove, and the first portion runs through the body Two sides, and the light emitting diode element is located in the groove and the through hole. The direct type backlight module of claim 6, wherein the light reflecting portion is at least one inner wall of the groove. The direct type backlight module of claim 6, wherein the light reflecting portion is attached to at least one inner wall of the groove. The direct type backlight module of claim 1, wherein the light reflecting portion is one of a light reflecting sheet and a light reflecting material coating. The direct type backlight module of claim 1, further comprising a light reflecting pattern formed on the light reflecting portion.