TWI686626B - Lens and face light source module - Google Patents

Abstract

A lens is adapted to a face light source module. The lens is a semi-cylinder extending along a horizontal axis with middle necking, and includes a bottom surface, a first optical surface, a second optical surface and two third optical surfaces. The first optical surface is depressed on the bottom surface to define a depressing space. Providing a central axis perpendicular to the horizontal axis, the central axis is perpendicular to the bottom surface and passing through the first optical surface. The second optical surface disposed opposite to the bottom surface, such that the second optical surface and the bottom surface form the peripheral surface of the semi-cylinder. The middle of the bottom surface and the second optical surface forms a necking section, and the necking section is located on the central axis. The two optical surfaces connect the two opposite edges of the bottom surface on the horizontal axis and connect the second surface, such that the two third surfaces form the two ends of the semi-cylinder. Each third optical surface includes a first optical transmittance area and a second optical transmittance area. An optical transmittance of the second optical transmittance area is smaller than the optical transmittance of the first optical transmittance area, and the at least part of the light not penetrating the second optical transmittance area is reflected or scattered by the second optical transmittance area.

Description

Optical lens and surface light source module

The invention relates to a backlight module, in particular to an optical lens and a surface light source module with an optical lens.

In a large-size direct-lit backlight module that uses a small light source (such as an LED) as a backlight source, in order to distribute the light intensity uniformly, a plurality of light sources with lower power are usually arranged on the substrate in an array. The light sources must be arranged smaller to avoid the formation of obvious bright/dark areas between the light sources.

If the number of light sources is reduced by the configuration of a high-power light source, the optical shape of each light source needs to be additionally treated with an optical lens, so that the light can be converted into lateral light after passing through the optical lens, and evenly projected on the reflective plate and then turned positive To shine.

One of the existing designs is to arrange the light sources in a straight line and arrange them in the middle position of the backlight board. Through the birefringence of the reflective lens, the light exit direction of the light source is changed to the side, projecting toward both sides of the straight line, and falling evenly on the reflecting plate. However, in the large-size backlight module, the forward light of the light source is reflected and refracted into lateral light, which leads to the formation of dark bands in the central part (that is, the two sides of the aforementioned straight line), which causes the backlight module to be dark in the middle. The brighter shapes on both sides affect the optical taste, resulting in a single linear light source less suitable for large-size backlight modules.

The present invention provides an optical lens for turning a light source to emit light sideways, and can avoid the problems of dark band formation and degradation of optical taste.

The invention provides an optical lens, which is a semi-cylindrical body extending in a horizontal axis direction and retracted in the middle, and includes a bottom surface, a first optical surface, a second optical surface, and two third optical surfaces.

The first optical surface is concavely arranged on the bottom surface, and the first optical surface defines a concave space; wherein, a central axis perpendicular to the horizontal axis direction is defined, and the central axis is perpendicular to the bottom surface and passes through the first optical surface. The second optical surface is disposed opposite to the bottom surface, and the second optical surface is connected to opposite sides of the bottom surface, so that the bottom surface and the second optical surface together form the outer peripheral surface of the semi-cylindrical body; The curved surface on the bottom surface, and the bottom surface and the middle section of the second optical surface form a necked portion, the necked portion is located on the central axis. The second and third optical surfaces are connected to opposite sides of the bottom surface in the horizontal axis direction, and are connected to the second optical surfaces, so that the second and third optical surfaces become both end surfaces of the semi-cylindrical body; wherein, each third optical surface includes a The first penetrating area and a second penetrating area, the light penetrating rate of the second penetrating area is smaller than that of the first penetrating area, and no light penetrating through the second penetrating area is at least partially Be reflected or scattered.

In at least one implementation, the projection of the necking portion has a rounded corner on a virtual plane defined by the horizontal axis direction and the central axis.

In at least one implementation, the first optical surface is configured as a light incident surface, and the second optical surface is configured as a reflective surface, the curvature of which is matched with the first optical surface, so that light entering through the first optical surface falls on the second optical surface The light on the surface is totally reflected and travels toward the third optical surface.

In at least one implementation, an imaginary plane is defined by the horizontal axis direction and the central axis, the first optical surface is projected on the imaginary plane to form a first line segment, and the first line segment is relative to the horizontal axis direction Rotate 180 degrees to define the first optical surface; the second optical surface is projected on the imaginary plane to form a second line segment. The second line segment is rotated 180 degrees relative to the horizontal axis to define the second optical surface and form the opposite sides of the bottom surface; And the third optical surface is projected on the imaginary plane to form two third line segments, and the two ends of each third line segment are respectively connected to the second line segment and the bottom surface.

In at least one implementation, on the imaginary plane, the second line segment forms a concave segment corresponding to the necking portion and has a rounded corner, the rounded corner being opposite to the vertex of the first line segment.

In at least one implementation, the overall light transmittance of the third optical surface is greater than 80%.

In at least one implementation, the penetration rate of the second penetration zone is 56% to 96%.

In at least one implementation, the second penetrating area is provided through surface atomization, plating or filming.

In at least one implementation, in the surface atomization process, the surface roughness of the second penetrating area is centerline average roughness between 0.28 μm and 0.8 μm.

In at least one implementation, in the surface atomization treatment, the haze of the second penetration zone is between 19% and 76%.

In at least one implementation, the first penetration area is located in the lower half of the third optical surface, and the second penetration area is located in the upper half of the third optical surface.

In at least one implementation, the boundary between the first penetration area and the second penetration area is set in a zigzag shape.

In at least one implementation, the first penetrating area is a semi-circle whose center of the circle falls in the direction of the horizontal axis, and the second penetrating area is a semi-circular ring that surrounds the circumferential boundary of the first penetrating area.

In at least one implementation, the second penetration zone is located in the first penetration zone and is surrounded by the first penetration zone.

In at least one implementation, the second penetration zone is circular, and the second penetration zone is located on the centroid of the first penetration zone.

In at least one implementation, the optical lens further includes a light absorbing material, corresponding to the bottom surface; in a direction parallel to the central axis, the projection of the second optical surface at least partially overlaps the light absorbing material.

In at least one implementation, the projection of the first optical surface in a direction parallel to the central axis partially overlaps the light absorbing material.

In at least one implementation, the bottom surface is disposed toward the lamp board, and is kept at a distance from the upper surface of the lamp board, and the light absorbing material is disposed on the upper surface of the lamp board.

The present invention further provides a surface light source module, which includes a reflective plate, a plurality of light sources, and a plurality of optical lenses as described above.

A plurality of light sources are arranged on the reflecting plate along a longitudinal axis. The multiple optical lenses are respectively disposed on one of the multiple light sources, and the horizontal axis direction of each optical lens is perpendicular to the vertical axis direction.

In at least one implementation, the reflective plate includes a central flat plate portion arranged along the longitudinal axis, and a plurality of light sources and a plurality of optical lenses are disposed on the central flat plate portion; and two inclined plate portions extend on both sides of the central flat plate portion There is an angle between the two inclined plate portions and the central flat plate portion; in the normal direction of the central flat plate portion, there is an elevated distance between the edge of the two inclined plate portions and the central flat plate portion.

In at least one implementation, there is a transition area between the inclined plate portion and the central flat plate portion, and the transition area is arc-shaped.

In at least one implementation, the surface light source module further includes an optical film set connected to the edges of the two slanted plate portions, and there is an elevated distance between the optical film set and the central flat plate portion.

In at least one implementation, the surface light source module further includes at least one light absorbing material, corresponding to the bottom surface, and maintaining a separation distance between the bottom surfaces; in a direction parallel to the central axis, the projections of the second optical surfaces at least partially overlap For light-absorbing materials.

In at least one implementation, the projection of the first optical surface in a direction parallel to the central axis partially overlaps the light absorbing material.

In at least one implementation, the surface light source module further includes a lamp board attached to the central flat plate portion, the light source is disposed on an upper surface of the lamp board, and each optical lens is fixed to the upper surface of the lamp board through at least one support leg And the light absorbing material is provided on the upper surface of the lamp board.

The invention reduces the lateral light exit, and guides the reduced lateral light exit energy into forward light exit in the manner of reflection and scattering, thereby avoiding the formation of dark bands. In at least one embodiment of the present invention, a light absorbing material is further provided for the position where the central bright band may be formed, thereby avoiding the central bright band problem caused by the central area where the light is concentrated, and improving the taste. Therefore, the invention can form a surface light source module with uniform brightness through a single row of light sources, and can avoid the problems caused by the single row of light sources.

1: Surface light source module

100: optical lens

102: Neck

110: underside

120: light absorbing material

130: light board

140: support feet

200: light source

300: reflector

310: Central flat panel

320: Inclined plate part

330: transition zone

400: Optical diaphragm group

G: separation distance

h: Elevation distance

H: height of the second penetration zone

L: the vertex height of the third optical surface is high

R: radius

C1: The first line segment

C2: Second line segment

C3: The third line segment

S1: the first optical surface

S2: Second optical surface

S3: third optical surface

TA1: first penetration zone

TA2: Second penetration zone

X: horizontal axis direction

Y: vertical axis direction

Z: Central axis

FIG. 1 is a perspective view of a first embodiment of the invention.

2 is a cross-sectional view of a first embodiment of the invention.

FIG. 3 is another perspective view of the first embodiment of the present invention.

4 is a front view of the third optical surface in the first embodiment of the present invention.

5, 6 and 7 are schematic diagrams of optical paths of different third optical surfaces in the first embodiment of the present invention.

8 is a light intensity distribution diagram of different third optical surfaces in FIGS. 5, 6 and 7.

9 is a front view of the third optical surface in the second embodiment of the present invention.

10 is a front view of the third optical surface in the third embodiment of the present invention.

11 is a front view of the third optical surface in the fourth embodiment of the present invention.

FIG. 12 is a light intensity distribution diagram of different sizes of the second penetrating area in FIG. 4.

FIG. 13 is a light intensity distribution diagram of different sizes of the second penetrating area in FIG. 10.

FIG. 14 is a light intensity distribution diagram of different sizes of the second penetration region in FIG. 11.

15 is a cross-sectional view of a fifth embodiment of the invention.

16 is another cross-sectional view of a fifth embodiment of the invention.

17 is a cross-sectional view of a sixth embodiment of the invention.

18 is a plan view of the sixth embodiment of the present invention.

19 is a partial perspective view of a sixth embodiment of the invention.

FIG. 20 is another top view of the sixth embodiment of the present invention.

In the drawings, for the sake of clarity, the widths of some elements, regions, etc. are enlarged. Throughout the specification, the same element symbol indicates the same element. It should be understood that when an element such as an element is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements may also be present. Conversely, when When an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements.

It should be understood that although the terms "first", "second", "third", etc. may be used throughout the specification to describe various elements, components, regions, or parts. However, these elements, components, regions, and/or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, or section from another element, component, region, layer, or section. Therefore, the "first element", "component", "region" or "portion" discussed below may be referred to as a second element, component, region or section without departing from the teachings herein.

In addition, relative terms such as "lower" or "bottom plate" and "upper" or "top surface" may be used herein to describe the relationship between one element and another element, as shown. It should be understood that relative terms are intended to include different orientations of the device than those shown in the figures. For example, if the device in a drawing is turned over, the element described as being on the "lower" side of the other element will be oriented on the "upper" side of the other element. Therefore, the exemplary term "down" may include the orientations of "down" and "up", depending on the specific orientation of the drawing.

Please refer to FIGS. 1 and 2, which is an optical lens 100 disclosed in an embodiment of the present invention. The optical lens 100 is disposed on a light source 200 to adjust the direction of the light emitted by the light source 200 to form side light exiting in opposite directions.

As shown in FIGS. 1 and 2, the light source 200 may be, but not limited to, a surface light source, such as a light emitting diode. The optical lens 100 has a double refraction function. When the light enters the optical lens 100, the light is refracted for the first time, and when the light leaves the optical lens 100, the light is refracted for a second time. The optical lens 100 is a semi-cylindrical body retracted in the middle, and can be made of a material with good light transmission characteristics. The aforementioned materials include but are not limited to PMMA (acrylic), PC (poly carbon Acid ester) or PS (polystyrene), molded by injection molding or CNC cutting. As shown in FIGS. 1 and 2, the optical lens 100 includes a bottom surface 110, a first optical surface S1, a second optical surface S2 and two third optical surfaces S3.

As shown in FIGS. 1 and 2, the optical lens 100 is a semi-cylindrical body extending in a horizontal axis direction X. The bottom surface 110 is generally a flat surface. The first optical surface S1 is recessed on the bottom surface 110, and the first optical surface S1 may define a concave space. A central axis Z perpendicular to the horizontal axis direction X is defined. The central axis Z is perpendicular to the bottom surface 110 and passes through the first optical surface S1. The second optical surface S2 is disposed opposite to the bottom surface 110, and the second optical surface S2 is connected to opposite sides of the bottom surface 110, so that the bottom surface 110 and the second optical surface S2 together form the outer peripheral surface of the semi-cylindrical body. The second optical surface S2 is a curved surface protruding above the bottom surface 110, and the bottom surface 110 and the middle of the second optical surface S2 form a necked portion 102, and the necked portion 102 is located on the central axis Z. That is, in the horizontal axis direction X, the area surrounded by the bottom surface 110 and the second optical surface S2 is gradually tapered toward the necked portion 102. In addition, in the XZ virtual plane defined by the horizontal axis direction X and the central axis Z, the projection of the necked portion 102 has a rounded corner.

As shown in FIGS. 1 and 2, the second and third optical surfaces S3 are connected to opposite sides of the bottom surface 110 in the horizontal axis direction X, and are connected to the second optical surface S2 to make the second and third optical surfaces S3 semi-cylindrical The two ends of the body. The third optical surface S3 is usually a concave conical surface, the apex of the cone falls in the horizontal axis direction X, but it is not excluded as other types of curved surfaces or planes, and in the cross section in the horizontal axis direction X, the third optical surface The surface S3 is inclined outward with respect to the bottom surface.

As shown in FIGS. 1 and 2, the bottom surface 110 is used to cover the light source 200, and the central axis Z can pass through the light source 200 so that the light source 200 is located in the concave space defined by the first optical surface S1. The first optical surface S1 is used as a light incident surface for receiving the light emitted by the light source 200 and allowing the light to enter the optical lens 100. The second optical surface S2 is used as a reflecting surface, and its curvature is matched with the first An optical surface S1 makes the light incident through the first optical surface S1 and falling on the second optical surface S2 be totally reflected and travel toward the third optical surface S3.

Since the second and third optical surfaces S3 are located on both end surfaces of the optical lens 100, the light received by the first optical surface S1 is concentrated on both ends of the optical lens 100 to emit light. Taking the horizontal axis direction X as the reference axis, the azimuth angle of the light will be concentrated between 15 degrees and 345 degrees (-15 degrees), and the azimuth angle is between 165 degrees and 195 degrees. In principle, the optical lens 100 perpendicular to the horizontal axis direction X does not emit light laterally. The rounded portion of the necked-down portion 102 allows the part of the light approaching the central axis Z to directly pass through and emit light in the forward direction without being reflected by the second optical surface S2.

As shown in FIG. 3, the horizontal axis direction X and the central axis Z can define an XZ imaginary plane. The first optical surface S1 is projected on the XZ imaginary plane to form a first line segment C1. The first line segment C1 is rotated 180 degrees relative to the horizontal axis direction X to define the first optical surface S1. The second optical surface S2 is projected on the XZ imaginary plane to form a second line segment C2. The second line segment C2 is rotated 180 degrees relative to the horizontal axis direction X to define the second optical surface S2, and forms opposite sides of the bottom surface 110. On the XZ imaginary plane, the second line segment C2 forms a concave segment corresponding to the necked portion 102 and has a rounded corner, which is opposite to the vertex of the first line segment C1.

The two third optical surfaces S3 are oppositely arranged along the horizontal axis direction X, and are located on both sides of the central axis Z. The two third optical surfaces S3 are respectively connected to the bottom surface 110 and the second optical surface S2. That is, on the YZ imaginary plane, the third optical surface S3 is projected on the XZ imaginary plane to form two third line segments C3. Both ends of the third line segment C3 are connected to the second line segment C2 and the bottom surface 110, respectively, and the third line segment C3 is opposite The third optical surface S3 can be defined by rotating 180 degrees in the horizontal axis direction X. The third line segment C3 is a straight line, which is rotated 180 degrees to define the third optical surface S3 of the conical shape. Or, the third optical surface S3 is not necessarily defined by the third line segment C3 being rotated 180 degrees with respect to the horizontal axis direction X, or it may be The end is formed by cutting out a plane. At this time, the projection of the third optical surface S3 on the YZ imaginary plane will form a third line segment C3.

As shown in FIGS. 1, 2 and 4, the third optical surface S3 includes a first transmission area TA1 and a second transmission area TA2. The second penetrating area TA2 is subjected to surface processing, such as atomization, so that the light penetrating rate T2 of the second penetrating area TA2 is smaller than the light penetrating rate T1 of the first penetrating area TA1. At the same time, part of the light that has not penetrated the second penetrating area TA2 is partially or totally reflected or scattered, and reflects directly or via the reflecting plate 300 under the bottom surface 110 and then travels toward the second optical surface S2 to form a trend toward the central axis Z Positive light. Therefore, the overall light transmittance T of the third optical surface S3 can be adjusted according to the size and shape configuration of the second penetration area TA2. At the same time, at least part of the light that does not penetrate the second penetrating area TA2 is reflected or scattered and projected onto the second optical surface S2. Since the total reflection characteristic of the second optical surface S2 is not set for the third optical surface S3, the light reflected by the second optical surface S2 can still pass through the second optical surface S2 and become closer to the positive direction Light out, make up the brightness on both sides near the central axis Z to avoid the formation of dark bands.

The overall light transmittance T of the third optical surface S3 can be configured according to the following relationship. The area of the first penetrating area TA1 is A1 and the transmittance is T1; the area of the second penetrating area TA2 is A2 and the transmittance T2; then the overall light transmittance T of the third optical surface S3 is preferably More than 80%, the relationship is as follows:

Generally, the first penetration area TA1 that has not undergone surface treatment has a penetration rate T1 of 96%, which is close to the complete penetration of light. The penetration rate T2 of the second penetration area TA2 can be adjusted between 50% and 96%, preferably between 56% and 96%. The configuration through the atomization treatment, not worn The light passing through the second penetrating area TA2 is reflected or scattered, that is, in an ideal state, the reflectance R2 of the second penetrating area TA2 may be (1-T2), that is, the light incident on the second penetrating area TA2 Partially penetrates, while the rest is reflected or scattered. The second penetrating area TA2 can be provided through surface atomization, plating or filming, so that it has the characteristics of partially penetrating and partially reflecting light. In the surface atomization process, the surface roughness of the second penetration area TA2 is centerline average roughness (Ra) between 0.28 μm and 0.8 μm (0.28 μm<Ra<0.8 μm). If expressed in haze (Haze), the haze of the second penetration area TA2 may be between 19% and 76%.

As shown in FIGS. 5, 6 and 7, the area of the second penetrating area TA2, that is, the proportion of the second penetrating area TA2, affects the total light reflection amount of the third optical surface S3, thereby changing the approach The light intensity at the Z position of the central axis.

As shown in FIG. 4, it is assumed that the first penetrating area TA1 is located in the lower half of the third optical surface S3, the second penetrating area TA2 is located in the upper half of the third optical surface S3, and the apex height of the third optical surface S3 is L, The height H of the second penetration area TA2. Taking R2=T2=50% and L=7.7mm as examples, H=0, H=2.7mm and H=4.7mm will show different central light intensity distributions.

As shown in FIG. 5, when H=0, that is, the second penetrating area TA2 is not provided, the light reflected by the second optical surface S2 basically penetrates the third optical surface S3 to form lateral light exit, so that the center The light intensity is small, and dark bands may be formed on both sides of the central axis Z.

As shown in FIG. 6, when the second penetrating area TA2 is configured, part of the light that originally passed through the third optical surface S3 is reflected or scattered toward the second optical surface S2 and travels through the second optical surface S2 to form The outgoing light approaching the central axis Z, while strengthening the intensity of the central light, makes the dark bands become inconspicuous or even eliminated.

As shown in FIG. 7, when the area of the second penetrating area TA2 is further increased, the energy of the light reflected or scattered by the second penetrating area TA2 is strengthened, which will make the central light intensity stronger, but may form two The central bright band on the side.

Referring to FIG. 8, the larger the area ratio of the second penetrating area TA2, the greater the effect of increasing the central light intensity. The area of the second penetrating area TA2 still needs to be adjusted according to the light intensity distribution, so as to avoid the central light from being too strong, and instead the obvious central bright band appears. Therefore, in the first embodiment, the relationship between the height of the apex of the third optical surface S3 is L and the height H of the second penetrating area TA2, preferably 0<H/L<0.62, to avoid obvious central bright band.

Referring to FIG. 9, the third optical surface S3 disclosed in the second embodiment of the present invention is applied to the optical lens 100 described above. The third optical surface S3 is substantially the same as the first embodiment. The difference is that the boundary between the first penetrating area TA1 and the second penetrating area TA2 is provided in a zigzag shape. Taking the average height of the second penetrating area TA2 as H as an example, the height of the zigzag border is partly smaller than H, and partly higher than H. In other words, the boundary between the first penetrating area TA1 and the second penetrating area TA2, and the first penetrating area TA1 and the second penetrating area TA2 exhibit a staggered configuration, dispersing the second penetrating area TA2 near the boundary Reflected light or scattered light to avoid obvious central bright bands.

Referring to FIG. 10 and FIG. 11, the third optical surface S3 disclosed in the third and fourth embodiments of the present invention is applied to the optical lens 100 as described above.

As shown in FIG. 10, the third optical surface S3 of the third embodiment has a first penetration area TA1 and a second penetration area TA2. Wherein, the first penetrating area TA1 is semicircular, the center of the circle falls in the direction X of the horizontal axis, and has a radius R. The second penetrating area TA2 may have a semi-circular ring shape, surrounding the circumferential boundary of the first penetrating area TA1.

As shown in FIG. 11, the third optical surface S3 of the fourth embodiment has a first penetration area TA1 and a second penetration area TA2. Wherein, the second penetrating area TA2 may be circular or other types, located in the first penetrating area TA1 and surrounded by the first penetrating area TA1. The second penetrating area TA2 may be located on the centroid of the first penetrating area TA1, but the position is not limited to this.

Referring to FIG. 12, FIG. 13 and FIG. 14, it is a comparison of different types of second penetration regions TA2. 12, 13 and 14 are the distributions of the light intensity of the second transmissive area TA2 of the first embodiment, the third embodiment and the fourth embodiment along the horizontal axis direction X. The position marked with 0 on the horizontal axis is the position where the central axis Z passes.

12 corresponds to the type of the third optical surface S3 of the first embodiment (as shown in FIG. 4), the ratio of the second transmission area TA2 in the third optical surface S3 is a=0.52; the first transmission area TA1 The ratio is 1-a, and the penetration rate T1=96%. The figure shows the comparison between the second penetration area TA2 when the penetration rate T2 is 70%, 80%, and 90%, and the second penetration area TA2 (solid line) is not provided. The height L of the apex is 7.7 mm, and the height H of the second penetration area TA2 is 4.7 mm.

As shown in FIG. 12, when T2 is 80%, the distribution of the central light output near the central axis Z is relatively uniform, and the intensity will not be too high to form a central bright band. At this time, the transmittance T of the third optical surface S3 is: T=a×0.8+(1-a)×0.96=87.7

13 corresponds to the third optical surface S3 type of the third embodiment (as shown in FIG. 10), the ratio of the second transmission area TA2 in the third optical surface S3 is a=0.73, and the first transmission area TA1 The ratio is 1-a, and the penetration rate T1=96%. The figure shows the comparison between the second penetration area TA2 when the penetration rate T2 is 70%, 75%, and 80%, and the second penetration area TA2 (solid line) is not provided. The peak height L is 7.7 mm, and the radius R of the first penetration area TA1 is 4 mm.

As shown in FIG. 13, when T2 is 75%, the distribution of the central light output intensity near the central axis Z is relatively uniform, and the intensity will not be too high to form a central bright band. At this time, the transmittance T of the third optical surface S3 is: T=a×0.75+(1-a)×0.96=80.6%

14 corresponds to the third optical surface S3 type of the fourth embodiment (as shown in FIG. 11), the ratio of the second transmission area TA2 in the third optical surface S3 is a=0.13, and the first transmission area TA1 The ratio is 1-a, and the penetration rate T1=96%. The figure shows the comparison between the second penetration area TA2 when the penetration rate T2 is 70%, 80%, and 90%, and the second penetration area TA2 (solid line) is not provided. The peak height L is 7.7 mm, and the diameter D of the second penetration area TA2 is 2 mm.

As shown in FIG. 14, when T2 is 80%, the distribution of the central light output near the central axis Z is relatively uniform, and the intensity will not be too high to form a central bright band. At this time, the transmittance T of the third optical surface S3 is: T=a×0.8+(1-a)×0.96=93.6

As shown in FIGS. 12, 13 and 14, when the transmissivity T2 of the second transmissive area TA2 is low, the light reflection intensity increases, and it is easy to form a central bright band. In addition, as shown in FIGS. 11 and 14, the closer the position of the second penetrating area TA2 is to the centroid of the third optical surface S3, the brighter the center is, the more particularly the light output intensity in the middle of the central axis Z is obvious. rise. Therefore, it is necessary to reduce the area of the second transmissive area TA2 or increase the transmissivity T2 (reduced reflection intensity) of the second transmissive area TA2 to avoid the central bright band. In other words, considering the formation of the central bright band, the size, position, and penetration rate of the second penetrating area TA2 need to be adjusted in coordination with each other to avoid the appearance of a central bright band.

Referring to FIG. 15 and FIG. 16, it is an optical lens 100 disclosed in the fifth embodiment of the present invention, which is used to eliminate the aforementioned central bright band. As shown in FIG. 15, the fifth embodiment The optical lens 100 further includes a light absorbing material 120 corresponding to the bottom surface 110, and the light absorbing material 120 and the bottom surface 110 are arranged at a distance G, such that an air layer exists between the light absorbing material 120 and the bottom surface 110. In the direction parallel to the central axis Z, the projection of the second optical surface S2 at least partially overlaps the light absorbing material 120.

As shown in FIG. 15, the projection of the first optical surface S1 in the direction parallel to the central axis Z may not overlap the light absorbing material 120. As shown in FIG. 16, the projection of the first optical surface S1 in a direction parallel to the central axis Z may partially overlap the light absorbing material 120. The light absorbing material 120 is used to absorb the scattered light close to the central axis Z, so that the scattered light close to the central axis Z is not reflected by the reflection plate 300, thereby reducing the light intensity approaching the central axis Z position, so as to avoid the obvious central bright band .

As shown in FIGS. 15 and 16, when the optical lens 100 is disposed on the light source 200, a lamp board 130 may be further provided. The light source 200 is disposed above the lamp board 130, and the optical lens 100 is disposed with the bottom surface 110 toward the upper surface of the lamp board 130, so that the bottom surface 110 and the upper surface of the lamp board 130 are not in contact. Specifically, the optical lens 100 has one or more support legs 140 protruding from the bottom surface 110. The supporting leg 140 is used to be fixed to the upper surface of the lamp board 130 to fix the optical lens 100 to the lamp board 130 and to prevent the bottom surface 110 from contacting the upper surface of the lamp board 130. The light absorbing material 120 is disposed on the upper surface of the lamp board 130, and a distance G is maintained between the light absorbing material 120 and the bottom surface 110. In a specific implementation, the light absorbing material 120 may be a light absorbing paint applied on the upper surface of the lamp board 130, especially a black paint, or a black patch, directly attached to the upper surface of the lamp board 130.

As shown in FIGS. 17, 18 and 19, it is a surface light source module 1 disclosed in the sixth embodiment of the present invention, which includes a reflective plate 300, a plurality of light sources 200 and a plurality of optical lenses 100 as described above .

As shown in FIGS. 17 and 18, the reflective plate 300 includes a central flat plate portion 310 and two inclined plate portions 320, and the central flat plate portion 310 is arranged along a longitudinal axis direction Y. The two slanted plate portions 320 extend on both sides of the central flat plate portion 310, and there is an angle between the two slanted plate portions 320 and the central flat plate portion 310. In the normal direction of the central flat plate portion 310, there is a height distance h between the edges of the two inclined plate portions 320 and the central flat plate portion 310, so that the reflective plate 300 forms a concave shape in the middle.

In addition, there is a transition area 330 between each slant plate portion 320 and the central flat plate portion 310, the transition area 330 is arc-shaped, and the central flat plate portion 310 is transitioned to the sloping plate portion 320 in a gentler manner, avoiding the central flat plate portion A clear fold is formed between 310 and the swash plate portion 320. In addition, the surface light source module 1 further includes an optical film group 400 disposed on the reflective plate 300 and connected to the edges of the two inclined plate parts 320, and the optical film group 400 and the central flat plate part 310 have the aforementioned Elevated distance h. The optical film group 400 includes, but is not limited to, diffusion films, brightness enhancement films, and other optical films that improve the light quality of the surface light source module 1.

As shown in FIGS. 17 and 18, the surface light source module 1 is used as a backlight of a liquid crystal display medium. The liquid crystal display medium is disposed on the optical film group 400 to receive light emitted by the surface light source module 1. The edge of the two inclined plate portions 320 may correspond to the short side of the liquid crystal display medium, that is, the central flat plate portion 310 extends in a direction parallel to the short side of the liquid crystal display medium, that is, the longitudinal axis direction Y is parallel to the liquid crystal display medium The short side. The distance between the edges of the two inclined plate portions 320 corresponds to the long side of the liquid crystal display medium.

As shown in FIGS. 18 and 19, a plurality of light sources 200 are arranged along the longitudinal axis direction Y at the central flat plate portion 310 of the reflective plate 300. The adjacent distance between adjacent light sources 200 may be 0.5~ 2 times, to adjust the brightness of the local area on the surface light source module 1 individually. Various optics The lenses 100 are respectively disposed on one light source 200, so that the optical lenses 100 are also arranged along the longitudinal axis direction Y, and the horizontal axis direction X of the optical lens 100 is perpendicular to the longitudinal axis direction Y.

Referring again to FIG. 20, the edge of the two inclined plate portions 320 may also correspond to the long side of the liquid crystal display medium, that is, the central flat plate portion 310 extends in a direction parallel to the long side of the liquid crystal display medium, that is, the longitudinal direction The axis direction Y is parallel to the long side of the liquid crystal display medium. The distance between the edges of the two inclined plate portions 320 corresponds to the short side of the liquid crystal display medium. That is to say, the arrangement direction of the plurality of light sources 200, that is, the direction of the longitudinal axis direction Y, can be arranged parallel to the long side or the short side according to the sizes of the liquid crystal display medium and the optical lens.

As described above, the optical lens 100 covers the light sources 200 with the bottom surface 110, and positions the light sources 200 in the concave space defined by the first optical surface S1, and positions the light sources 200 on the central axis Z. The central axis Z of each optical lens 100 is parallel to the normal of the central flat plate portion 310, and the horizontal axis direction X of each optical lens 100 is perpendicular to the longitudinal axis direction Y. Therefore, the light leaving the optical lens 100 from the third optical surface S3 is evenly projected to the transition zone 330 and the inclined plate portion 320 and is reflected toward the optical film group 400. In addition, the light reflected through the second penetrating area TA2 can be directly projected upward, reflected through the central flat plate portion 310, or reflected by the inclined plate portion 320 on the other side, so that the area relative to the central flat plate portion 310 can also have More uniform brightness performance without forming dark bands or central bright areas, thereby improving optical taste.

As shown in the figure, the bottom surface 110 is not necessarily directly provided on the central flat plate portion 310. In a specific embodiment, it further includes a lamp board 130 attached to the central flat plate portion 310 and parallel to the longitudinal axis direction Y, and a plurality of light sources 200 are disposed on the upper surface of the lamp board 130. The optical lens 100 is fixed to the upper surface of the lamp board 130 through the support legs 140 (as shown in FIG. 15 ), so that the bottom surface 110 of the optical lens 100 does not contact the lamp board 130. In addition, the light absorbing material 120 may be in a strip shape, parallel to the longitudinal direction The axis direction Y is provided on the upper surface of the lamp board 130 so that the two light absorbing materials 120 can correspond to the multiple light sources 200 and the multiple optical lenses 100 at the same time. The light absorbing materials 120 may also be arranged discontinuously, so that each two light absorbing materials 120 only corresponds to a group of light sources 200 and optical lenses 100.

As shown in FIGS. 15, 16, 18 and 19, in the direction parallel to the central axis Z, the projection of the second optical surface S2 at least partially overlaps the light absorbing material 120. As shown in FIGS. 15 and 16, the projection of the first optical surface S1 may not overlap the light absorbing material 120 or may partially overlap the light absorbing material 120. The light absorption material 120 reduces the reflected light intensity of the central flat plate portion 310, which can reduce the forward light intensity of the central portion of the optical lens 100, thereby avoiding the formation of a central bright band.

The invention reduces the lateral light exit, and guides the reduced lateral light exit energy into forward light exit in the manner of reflection and scattering, thereby avoiding the formation of dark bands. In at least one embodiment of the present invention, the light absorbing material 120 is further provided for the position where the central bright band may be formed, thereby avoiding the problem of the central bright band formed by the positive light concentration in the central region and improving the taste. Therefore, the present invention can form a surface light source module with uniform brightness through the single-row light source 200, and can avoid the problems caused by the single-row light source 200.

100: optical lens

102: Neck

110: underside

200: light source

S1: the first optical surface

S2: Second optical surface

S3: third optical surface

TA1: first penetration zone

TA2: Second penetration zone

X: horizontal axis direction

Z: Central axis

Claims (25)

An optical lens is a semi-cylindrical body extending in a horizontal axis direction and retracted in the middle section, including: a bottom surface; a first optical surface, which is concavely arranged on the bottom surface, and the first optical surface defines a concave space; Wherein, a central axis perpendicular to the horizontal axis direction is defined, the central axis is perpendicular to the bottom surface and passes through the first optical surface; a second optical surface is disposed opposite to the bottom surface, and the second optical surface is connected to the bottom surface The two opposite sides, so that the bottom surface and the second optical surface together form the outer peripheral surface of the semi-cylindrical body; wherein, the second optical surface is a curved surface protruding from the bottom surface, and the bottom surface and the first optical surface The middle section of the two optical surfaces forms a necked portion, the necked portion is located on the central axis; and two third optical surfaces are connected to opposite sides of the bottom surface in the direction of the horizontal axis, and are connected to the second optical surface Surface, so that the two third optical surfaces become the two end surfaces of the semi-cylindrical body; wherein, each of the third optical surfaces includes a first penetrating area and a second penetrating area, the light of the second penetrating area The transmittance is less than the light transmittance of the first penetration area, and the light that does not penetrate the second penetration area is at least partially reflected or scattered. The optical lens according to claim 1, wherein the projection of the necking portion has a rounded corner on a virtual plane defined by the horizontal axis direction and the central axis. The optical lens according to claim 1, wherein the first optical surface is configured as a light incident surface, and the second optical surface is configured as a reflective surface whose curvature cooperates with the first optical surface to transmit the first optical surface The light incident on the surface and falling on the second optical surface is totally reflected and travels toward the third optical surface. The optical lens according to claim 1, wherein an imaginary plane is defined by the horizontal axis direction and the central axis, and the first optical surface is projected on the imaginary plane to form a first line segment, and the first line segment is opposite Rotating 180 degrees in the horizontal axis direction defines the first optical surface; the second optical surface is projected on the imaginary plane to form a second line segment, and the second line segment is rotated 180 degrees relative to the horizontal axis direction to define the second optical surface And form opposite sides of the bottom surface; and the third optical surface is projected on the imaginary plane to form two third line segments, and two ends of each third line segment are respectively connected to the second line segment and the bottom surface. The optical lens according to claim 4, wherein, on the imaginary plane, the second line segment forms a concave segment corresponding to the necked-down portion and has a rounded corner, the rounded corner and the first line segment Vertex is relative. The optical lens according to claim 1, wherein an overall light transmittance of the third optical surface is greater than 80%. The optical lens according to claim 6, wherein the penetration rate of the second penetration region is 56% to 96%. The optical lens according to claim 7, wherein the second penetrating region is provided through surface atomization, plating or filming. The optical lens according to claim 8, wherein in the surface atomization process, the surface roughness of the second penetration region is a centerline average roughness between 0.28 μm and 0.8 μm. The optical lens according to claim 8, wherein, in the surface atomization process, the haze of the second penetration region is between 19% and 76%. The optical lens according to claim 1, wherein the first transmission area is located in the lower half of the third optical surface, and the second transmission area is located in the upper half of the third optical surface. The optical lens according to claim 11, wherein the boundary between the first penetrating area and the second penetrating area is set in a zigzag shape. The optical lens according to claim 1, wherein the first penetrating area is a semicircle whose center of the circle falls in the direction of the horizontal axis, and the second penetrating area is a semicircular ring, surrounding the first penetrating area Circumferential boundary. The optical lens according to claim 1, wherein the second penetration region is located in the first penetration region and is surrounded by the first penetration region. The optical lens according to claim 14, wherein the second penetration region is circular, and the second penetration region is located on the centroid of the first penetration region. The optical lens according to claim 1, further comprising a light absorbing material corresponding to the bottom surface and maintaining a separation distance between the bottom surfaces; in a direction parallel to the central axis, the projection of the second optical surface is at least It partially overlaps the light-absorbing material. The optical lens according to claim 16, wherein the projection of the first optical surface in a direction parallel to the central axis partially overlaps the light absorbing material. The optical lens according to claim 16, further comprising a lamp board, the bottom surface is disposed toward the lamp board, and is not in contact with the upper surface of the lamp board, and the light absorbing material is disposed on the upper surface of the lamp board. A surface light source module, comprising: a reflecting plate; a plurality of light sources arranged on the reflecting plate along a longitudinal axis; and A plurality of the optical lenses according to any one of claim 1 to claim 15 are respectively disposed on one of the light sources, and the horizontal axis direction of each optical lens is perpendicular to the vertical axis direction. The surface light source module according to claim 19, wherein the reflective plate includes: a central flat plate portion disposed along the longitudinal axis, and the light sources and the optical lenses are disposed on the central flat plate portion; and two The inclined plate portion extends on both sides of the central flat plate portion, and an angle is formed between the two inclined plate portions and the central flat plate portion; in the normal direction of the central flat plate portion, the edges of the two inclined plate portions There is a high distance from the central flat part. The surface light source module according to claim 20, wherein each inclined plate portion and the central flat plate portion have a transition area, and the transition area is arc-shaped. The surface light source module according to claim 20, further comprising an optical film set connected to the edges of the two inclined plate portions, and the elevated distance between the optical film set and the central flat plate portion. The surface light source module according to claim 20, further comprising at least one light absorbing material corresponding to the bottom surface, and maintaining a separation distance between the bottom surfaces; in the direction parallel to the central axis, each of the second optical The projection of the surface at least partially overlaps the light-absorbing material. The surface light source module according to claim 23, wherein the projection of the first optical surface in a direction parallel to the central axis partially overlaps the light absorbing material. The surface light source module according to claim 23, further comprising a lamp board attached to the central flat plate portion, the light sources are disposed on an upper surface of the lamp board, and each of the optical lenses passes through at least one support foot It is fixed on the upper surface of the lamp board, and the light absorbing material is provided on the upper surface of the lamp board.

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