TW202131051A - Light distribution control element - Google Patents

Abstract

To provide a light distribution control element for implementing a surface light source device that enables an approximately square light flux similar to the shape of a divided region to be obtained although being a thin type. A square plate-shaped light distribution control element for controlling distribution of light emitted from N (N is an integer of 1 or more) light-emitting elements disposed on a substrate is provided with: a first principal surface that faces the N light-emitting elements; a second principal surface that faces the first principal surface; and N diffusion elements that each diffuse light incident on the first principal surface from each of the light-emitting elements in a direction approximately perpendicular to the optical axis of the light-emitting element and emit the light from the second principal surface.

Description

Light distribution control element

The invention relates to a light distribution control element, a light distribution adjustment mechanism, a reflective part, a reinforcing plate, a lighting unit, a display, and a television.

The present invention relates to a light distribution control element, a light distribution adjustment mechanism, a reflective part, a reinforcing plate, a lighting unit, a display, and a television, and in particular to a light distribution control element and a light distribution control element used in a lighting unit that irradiates light to a display panel from the back side. Light adjustment mechanism, reflective parts, reinforcing plate, lighting unit, display and TV.

In the prior art, as a backlight of a transmissive image display device such as a liquid crystal display device, a surface light source device (illumination unit) in which a plurality of LEDs (Light Emitting Diodes) are arranged in a matrix is used.

Regarding such a surface light source device, what has been pursued in the prior art is a thin device that uniformly irradiates the display area of the liquid crystal panel with uniform brightness. In addition, with the demand for larger LCD panels and higher image quality, the light intensity of the LEDs is controlled one by one to either increase the contrast of different divided areas in the same screen or reduce the power consumption of local dimming ( (Dimming control according to each area) technology can also be used for practical applications. Such a surface light source device is disclosed in Patent Document 1, for example.

In addition, the surface light source device disclosed in Patent Document 2 is composed of an optical sheet module and a light source module using a plurality of LEDs as light sources. The optical sheet module includes a diffuser light guide plate or a diffuser plate and a reflective sheet. While diffusing the light from the LED through the diffuser light guide plate or diffuser, it is repeatedly reflected by the reflective sheet to provide uniform brightness to the liquid crystal display device. Perform uniform irradiation.

In addition, in such a surface light source device, as the liquid crystal panel becomes larger and higher in image quality, the light intensity of the LEDs is controlled one by one to increase or decrease the contrast of different divided areas in the same screen. Power-consuming local dimming (dimming control according to each area) technology can also be used for practical applications. Such a surface light source device is disclosed in Patent Document 3, for example.

Prior art literature Patent Document 1: Japanese Patent Application Publication No. 2010-205698 Patent Document 2: Japanese Patent Application Publication No. 2005-352427 Patent Document 3: Japanese Patent Application Publication No. 2010-205698

[Technical Problem to be Solved by Invention]

The surface light source device of Patent Document 1 reflects the light from the light source by a concave mirror and irradiates it toward the liquid crystal panel. Since the beam shape can be made into a substantially square shape similar to the shape of the divided region, it is most suitable for local dimming. However, in the configuration of Patent Document 1, the premise is that the light source is arranged on the side of the irradiated plane with respect to the concave mirror, and the space between the light source and the concave mirror needs to be widened, so it is difficult to make the device itself thinner.

In addition, as another problem, if the optical axis of each light source and the optical axis of each concave mirror do not coincide exactly, the desired amount of light cannot be obtained in each divided region (that is, there is a difference in the amount of light). This problem can also occur because the substrate on which the light source is mounted is deformed or the concave mirror is deformed. Therefore, it is extremely important to suppress these deformations. In order to suppress the deformation of the substrate or the concave mirror, it can be suppressed by either thickening the substrate or thickening the concave mirror. However, if such a method is adopted, there is a problem that the surface light source device itself becomes thicker or heavier.

Furthermore, although the surface light source device of Patent Document 2 can be used to uniformly illuminate the liquid crystal display device with uniform brightness, the light from each LED is diffused by the diffuser and the reflective sheet and mixed with each other, making it difficult to perform local adjustment. Light.

On the other hand, the surface light source device of Patent Document 2 reflects the light from the light source through a concave mirror and irradiates it toward the liquid crystal panel. The shape of the light beam can be made into a substantially square shape similar to the shape of the divided region. Therefore, it is most suitable for local adjustment. However, because the partial illumination light emitted from a plurality of divided areas is only planarly combined, the influence of the brightness distribution of the LED cannot be completely eliminated, and it is difficult to obtain a substantially uniform illuminance distribution in the divided areas.

The present invention provides a light distribution control element, a light distribution adjustment mechanism, a reflection member, a reinforcing plate, a lighting unit, a display, and a television for realizing a thin surface light source device capable of obtaining a substantially square beam similar to the shape of a divided area.

[Methods to solve technical problems]

In order to achieve the above-mentioned object, the present invention provides a light distribution control element, which is a square plate-shaped light distribution control element that controls the light distribution of light emitted from a light-emitting element, and is characterized in that it includes: The first main surface of the set; the second main surface that is the back surface with respect to the first main surface; and the diffusing element that changes the direction of travel of light emitted from the light-emitting element and incident on the first main surface After being in a direction substantially perpendicular to the light-emitting surface of the light-emitting element, the light is emitted from the second main surface.

With such a structure, the light emitted from each light-emitting element is diffused in a direction substantially perpendicular to the light-emitting surface of the light-emitting element by the diffusing element corresponding to each light-emitting element, so it is not only thin, but also capable Obtain a beam similar to the shape of the divided area.

In addition, the first main surface has: an incident surface having a circular concave surface formed at a position corresponding to the light-emitting element; and a plurality of annular grooves formed concentrically to surround the incident surface, the The second main surface has a first emission surface formed of a conical concave surface formed at a position corresponding to the incident surface.

In addition, it is preferable that the four corners of the two main surfaces form notches. In this way, by emitting light from the notch, the amount of light leaking from the side surface of the light distribution control element can be reduced, and the total amount of light emitted from the second main surface of the light distribution control element can be increased. Furthermore, a plurality of waveguides may be formed on the edge of the second main surface, and reflection may be performed by the wall surfaces of these waveguides. The edge portion here refers to the side portion and/or the four corners of the light distribution control element. In addition, it is preferable that the diffusing elements are respectively placed in N square regions.

In addition, it is preferable that the second main surface includes a protrusion that gradually protrudes from the second main surface from the center to the four corners.

In addition, the present invention provides a light distribution adjustment mechanism for adjusting the light distribution of light emitted from the light-emitting element on the optical path and attached to the light distribution control element, the light distribution adjustment mechanism having a plurality of The layer structure may have a structure such that the more deviated from the light-emitting surface of the light-emitting element, the lower the transmittance.

According to the present invention, since the partial illumination light emitted from a plurality of divided areas is not structured only by plane synthesis, the influence of the brightness distribution of the LED can be eliminated, and a substantially uniform illuminance distribution can be obtained in the divided areas.

In addition, the plurality of layer structures may be formed by laminating a plurality of substantially circular sheet members or films having different radii with the optical axis of the light emitting element as the center. In addition, the several layers constituting the multiple layer structure may have a star-shaped polygonal shape. Furthermore, one or more openings may be formed in a part of the plurality of layer structures.

Furthermore, the present invention provides a reflective member attached to the above-mentioned light distribution control element, comprising: a first reflecting surface that abuts on the incident surface of the light distribution control element and performs light emission from the incident surface side. Reflection; and a second reflective surface, which faces several side surfaces of the light distribution control element, and reflects light emitted from the side surface.

With this structure, since the light emitted from the side surface of the light distribution control element is reflected by the second reflecting surface and can be incident from the side surface of the light distribution control element again, the light leaking from the light distribution control element is reduced, and the light distribution control element can be accurately controlled. The amount of light in the dimming area.

In addition, it is preferable that at least a part of the tip portion of the side portion includes a zigzag or wavy shape. In addition, it is preferable that the reflective member is formed of a thin plate of metal or resin with a heat shrinkage rate of 0.5% or less. Furthermore, it is preferable that the reflectance of the first reflecting surface and the second reflecting surface is 90% or more.

Furthermore, the present invention provides a reinforcement plate for a lighting unit, the lighting unit having: a square plate-shaped substrate on which the light-emitting element is placed on the surface; and the light distribution control element arranged to face the light-emitting element, The reinforcing plate is made of a plate-shaped metal having an L-shaped cross section, and is mounted from the upper surface of the substrate to the side surface.

With such a structure, since the deformation of the substrate and the light distribution control element can be reliably suppressed by the reinforcing plate, there is no misalignment between the substrate and the light distribution control element.

In addition, when there are a plurality of the light distribution control elements, it is preferable that the reinforcement plate is installed at a position that straddles the adjacent light distribution control elements at least. In addition, it is preferable that the lighting unit has a reflecting member which is arranged between the substrate and the light distribution control element and reflects the light from the light distribution control element. The reinforcing plate is located between the reflective part and the substrate.

In addition, according to another viewpoint, an irradiation unit including any one of the light distribution control element, the light distribution adjustment mechanism, the reflective member, and the reinforcing plate of the present invention is characterized by comprising: a substrate and N light-emitting devices arranged on the substrate Element, and the above-mentioned light distribution control element. In addition, the above-mentioned light distribution control element can also be applied to monitors and televisions attached to personal computers and the like.

[Effects of the invention]

As described above, according to the present invention, there is provided a light distribution control element for realizing a thin surface light source device capable of obtaining a substantially square beam similar to the shape of the divided region. In addition, it is possible to realize a lighting unit, a display, and a television equipped with the light distribution control element.

In addition, according to the present invention, it is possible to realize a light distribution adjustment mechanism for a lighting unit that is thin and can obtain a substantially uniform illuminance distribution in the divided area. In addition, it is possible to realize a lighting unit, a display, and a television equipped with the light distribution adjustment mechanism.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same or equivalent parts in the drawings are given the same symbols, and the description will not be repeated.

(First Embodiment)

FIG. 1 is a perspective view showing the structure of the lighting device 1 according to the first embodiment of the present invention. The lighting device 1 is a surface light source device that is arranged on the back side of a liquid crystal panel (not shown) and irradiates light to the liquid crystal panel. The lighting device 1, as shown in FIG. 1, is configured by arranging a plurality of lighting units 10 in a matrix according to the size of a liquid crystal panel.

FIG. 2 is an exploded perspective view explaining the structure of the lighting unit 10 that is a part of the lighting device 1 shown in FIG. 1. As shown in FIG. 2, the lighting unit 10 includes: a rectangular plate-shaped LED unit 100, a reflective sheet 200 arranged on the upper surface of the LED unit 100, two diffuser plates 300 arranged on the upper surface of the reflective sheet 200, and Among the adjustment sheets 400 arranged on each diffuser plate 300, for example, four adjustment sheets 400 are arranged for each diffuser plate 300.

Hereinafter, in this specification, the long-side direction of the LED unit 100 is defined as the X-axis direction, and the short-side direction is defined as the Y-axis direction. Injection direction) is defined as the Z-axis direction. In addition, the positive direction side in the Z-axis direction is sometimes referred to as upper, and the negative direction side is sometimes referred to as bottom. Therefore, for the LED unit 100 of FIG. 2, the surface opposite to the reflective sheet 200 is called the upper surface, and the back surface thereof is called the bottom surface.

The LED unit 100 of each lighting unit 10 includes: a square plate-shaped substrate 101 formed of, for example, glass epoxy resin, a plurality of LED elements 110 mounted on the upper surface of the substrate 101, and a plurality of LED elements 110 mounted on the upper surface of the substrate 101. A reinforced board 120. In addition, as other embodiments, the substrate 101 may also be an aluminum substrate or FPC (Flexible printed circuits) or the like.

As shown in FIG. 2, in this embodiment, for example, 4 (X-axis direction) × 2 (Y-axis direction) LED elements 110 are arranged such that the direction of the optical axis coincides with the Z-axis direction, and the X-axis direction is spaced apart It is set to, for example, 30 mm, and the pitch in the Y-axis direction is set to, for example, 30 mm to be mounted on the upper surface of the substrate 101. On the substrate 101, an anode pattern (not shown) and a cathode pattern (not shown) for supplying power to each LED element 110 are formed. Each LED element 110 is connected to the anode pattern and the cathode. Pattern electrical connection.

In addition, the substrate 101 is electrically connected to a driving circuit (not shown) through a wiring cable not shown, and a driving current is supplied from the driving circuit to each LED element 110 via the anode pattern and the cathode pattern. When a drive current is supplied to each LED element 110, white light of a light amount corresponding to the drive current is emitted from each LED element 110 in the Z-axis direction.

In addition, in the present embodiment, each LED element 110 is arranged in each divided area of the local dimming, and the local dimming (that is, the dimming control of each divided area) can be performed by the control of the drive circuit.

The reinforcing plate 120 is a thin-plate-shaped metal (for example, copper, iron, aluminum) member for suppressing the deformation of the substrate 101 and the diffuser plate 300. As shown in FIG. 2, in this embodiment, for example, six reinforcing plates 120 are passed through solder or the like (for example, conductive adhesive (silver paste), Solder, soldering/depositing, diffusion bonding, etc.) for surface mounting.

Each reinforcing plate 120 has a unique shape including an L-shaped portion in cross section, and is installed in such a manner that the side surface is covered from at least the upper surface of the substrate 101. The cross section of each reinforcing plate 120 may be L-shaped itself, or may be U-shaped and cover the bottom surface of the substrate 101. In addition, for example, each reinforcing plate 120 may be provided with a V-shaped cutout or a recess near the center of the outer surface at a position corresponding to the side surface of the substrate 101, from the upper surface side to the bottom surface side. Increase the strength. Each reinforcing plate 120 is provided with, for example, two through holes 120 a communicating with through holes (not shown) formed in the substrate 101. Each through hole 120a has a size such that the protrusion 302 (FIG. 3( b) and FIG. 3( c )) of the diffuser plate 300 can penetrate, and is arranged at a position corresponding to the protrusion 302 of each diffuser plate 300.

In addition, the protrusion 302 of each diffuser plate 300 is inserted into the through hole 120a, and is fixed by thermal welding. In addition, as another embodiment, further, after applying an ultraviolet curable adhesive or the like to each protrusion 302, ultraviolet rays may be further irradiated thereon to achieve a more firm fixation with the substrate 101A.

In addition, the reinforcing plate 120 may be arranged along the long side of the substrate 101, and although it is not necessarily limited to an arrangement of 3×2 rows, it is preferably arranged so as to straddle at least two diffuser plates 300. If such a structure is adopted, since the two diffuser plates 300 can be accurately positioned by the reinforcing plate 120, they can be accurately arranged on the XY plane (that is, on the substrate 101). In addition, the deformation of the substrate 101 and the diffusion plate 300 can be suppressed.

The reflective sheet 200 is a square thin plate of metal (for example, aluminum) or resin (for example, PET (Polyethylene terephthalate, polyethylene terephthalate)) sandwiched between the diffuser plate 300 and the substrate 101 Manufactured parts. As shown in FIG. 2, in the reflective sheet 200, for example, eight through holes 200a corresponding to the positions of the eight LED elements 110, and eight through holes 200b through which the protrusions 302 of the diffuser plate 300 pass are formed.

In this way, in this embodiment, since the reflective sheet 200 is arranged between the diffuser plate 300 and the substrate 101, the light emitted from the LED element 110 is reflected by the bottom surface of the diffuser plate 300, even if it is not directly incident on the diffuser plate 300. The reflective sheet 200 reflects on the diffuser plate 300 again and indirectly enters the diffuser plate 300. Therefore, almost all the light emitted from the LED element 110 is emitted through the diffuser plate 300.

The diffuser plate 300 is arranged on the optical path of the light emitted from the LED elements 110 so as to cover the reflective sheet 200, and is a square plate-shaped optics that diffuses the light emitted from each LED element 110 around the Z axis in the diffuser plate 300 Optical components made of glass or resin (such as acrylic, PC (polycarbonate), etc.).

FIG. 3 is a diagram illustrating the structure of the diffuser plate 300 of the present embodiment. Fig. 3(a) is a top view, Fig. 3(b) is a left side view, and Fig. 3(c) is a bottom view. 4 is a cross-sectional view illustrating the structure of the diffuser 300, and FIGS. 4(a) to 4(e) are respectively an A-A cross-sectional view, a B-B cross-sectional view, a C-C cross-sectional view, a D-D cross-sectional view, and an E-E cross-sectional view of FIG. 3(c).

As shown in FIG. 3, on the diffuser plate 300 of the present embodiment, for example, four patterns (ie, four diffuser elements) are tiled corresponding to, for example, four LED elements 110 to form, for example, four patterns that are dimmed by local dimming. There are two dimming areas DE1, DE2, DE3, DE4.

In addition, as described above, in the present embodiment, since, for example, eight LED elements 110 are arranged on the substrate 101, as shown in FIG. 2, for example, two diffuser plates 300 are arranged side by side in the X-axis direction.

As shown in FIG. 3( b) and FIG. 3( c ), the four corners of the bottom surface of each diffuser plate 300 are formed with cylindrical protrusions 302 protruding to the negative direction side of the Z axis. When the diffuser plate 300 is placed on the reflective sheet 200, the protrusions 302 pass through the through holes 200b of the reflective sheet 200 and the through holes 120a of the reinforcing plate 120, and protrude toward the bottom surface of the substrate 101. By thermally welding the protrusions 302 on the bottom surface side of the substrate 101, the diffuser plate 300 is fixed to the substrate 101.

As shown in FIGS. 3( a) and 4 (b ), on the upper surface of each diffusion plate 300, for example, four concave conical surfaces 310 are formed corresponding to the positions of, for example, four LED elements 110. If the light emitted from each LED element 110 passes through the diffuser 300 and reaches the concave conical surface 310, a part of the light is emitted from the concave conical surface 310, while the other part of the light is moved around the Z axis under the action of the concave conical surface 310. The diffuser plate 300 diffuses. In this way, the uniformity of the diffuser 300 is achieved.

As shown in FIGS. 3( a) and 3 (b ), notches 350 are formed at the four corners of the upper surface of each diffuser plate 300. The cut portion 350 emits light thereby reducing the amount of light leaking from the side surface of the diffuser plate 300 and increases the total amount of light emitted from the upper surface of the diffuser plate 300.

In addition, on the upper surface of each diffuser plate 300, for example, two groove portions 311 extending in parallel are formed, for example, inwardly from the substantially central portion of each side. The groove portion 311 functions as a waveguide, and when the light emitted from each LED element 110 reaches the groove portion 311, it passes through the wall surface of the groove portion 311 and is reflected toward the upper surface of the diffuser 300. Therefore, it is possible to suppress the leakage of light from each of the dimming regions DE1, DE2, DE3, and DE4 to adjacent dimming regions. In addition, the shape of the groove portion 311 is not limited, and its cross section can be provided in various shapes such as a U-shape, a U-shape, and a V-shape. Hereinafter, the same applies to other groove portions (groove portion 322a and the like).

As shown in FIGS. 3(c), 4(b), and 4(d), on the bottom surface of each diffuser 300, there are provided: for example, four concave cones formed at positions corresponding to, for example, four concave cone surfaces 310 The surface 320 is a circular opening 321 that is connected to each concave conical surface 320 and is selectively formed. The details will be described later. In this embodiment, in the space within each circular opening 321 (when the LED element 110 has a certain height, and when the circular opening 321 is not provided, each concave conical surface 320 may include each concave The space inside the conical surface 320) accommodates each LED element 110.

In addition, each concave conical surface 320 becomes an incident surface on which light emitted from each LED element 110 enters, and functions as a kind of condenser lens. Therefore, generally, the light emitted from each LED element 110 has a relatively wide angle component (that is, a large spread angle), but the spread angle can be reduced by being incident on each concave conical surface 320.

As shown in Figures 3(c), 4(b), and 4(d), on the bottom surface of each diffuser 300, for example, four annular grooves 322a, 322b, 322c, and 322d are sequentially formed to form Concentric circles to surround each concave conical surface 320. In addition, in this embodiment, the depths of the grooves 322c and 322d deviating from the concave conical surface 320 are deeper than the grooves 322a and 322b (FIG. 4(b) and FIG. 4(d)), and the light diffused through the concave conical surface 310 And light with a large diffusion angle emitted from the LED element 110 is reflected to the upper surface of the diffuser plate 300 through the wall surfaces of the groove portions 322a, 322b, 322c, and 322d, and is emitted from the upper surface of the diffuser plate 300.

As shown in FIG. 4(b), in the center portion of the bottom surface of each diffuser 300, a stepped groove portion 323 is formed deeper than the groove portion 322c, so as to respectively oppose the dimming regions DE1 and DE1 adjacent in the Y-axis direction. The dimming area DE4 is distinguished, or the dimming area DE2 and the dimming area DE3 are distinguished.

Similarly, as shown in FIG. 4(d), a stepped groove 325 deeper than the grooves 322c and 322d is formed in the approximate center of the bottom surface of each diffuser 300, so that they are aligned in the X-axis direction. The adjacent area DE1 and the dimming area DE2 are distinguished, or the dimming area DE3 and the dimming area DE4 are distinguished.

That is, in each dimming area, the light diffused in the lateral direction (that is, the XY plane) is reflected in the direction of the upper surface of the diffuser 300 by the wall surfaces of the grooves 323 and 325, and the light leaked to the adjacent dimming area Fewer. In addition, at both ends in the Y-axis direction of the bottom surface of each diffuser plate 300, a plurality of stepped portions 324 are formed to be stepped and thinned (FIG. 4(b)), and a plurality of stepped portions 326 are formed at both ends in the X-axis direction. It becomes thinner in steps (FIG. 4(d)), and the light diffused in the lateral direction (that is, the XY plane) of each dimming area is reflected in the direction of the upper surface of the diffuser 300 by the walls of the steps 324 and 326. This reduces the amount of light leaking to the outside from both side surfaces in the Y-axis direction and both side surfaces in the X-axis direction.

As shown in FIGS. 3( c) and 4 (a ), on the bottom surface of each diffuser plate 300, for example, three grooves 327 extending in parallel from the center portions of the two sides opposed to each other in the Y-axis direction are formed. When the light emitted from each LED element 110 reaches the groove portion 327, it is reflected by the wall surface of the groove portion 327 in the direction of the upper surface of the diffuser plate 300, so one of the dimming area DE1 and the dimming area DE2 adjacent in the X-axis direction The amount of light leaking between the dimming area DE3 and the dimming area DE4 decreases.

As shown in FIGS. 3(c) and 4(c), the bottom surface of each diffuser 300 has, for example, three grooves 328 extending in parallel from the substantially central portions of the two sides facing each other in the X-axis direction inward. When the light emitted from each LED element 110 reaches the groove portion 328, it is reflected by the wall surface of the groove portion 328 in the direction of the upper surface of the diffuser plate 300, and therefore one of the dimming area DE1 and the dimming area DE4 adjacent in the Y-axis direction In between, and between the dimming area DE2 and the dimming area DE3, there is less light leakage.

As shown in FIGS. 3( c) and 4 (e ), at the four corners of the bottom surface of each diffuser plate 300, for example, three grooves 329 extending in the diagonal direction of the diffuser plate 300 are formed. When the light emitted from each LED element 110 reaches the groove portion 329, it is reflected to the upper surface direction of the diffuser plate 300 by the wall surface of the groove portion 329. In addition, in the center portion of the bottom surface of each diffuser plate 300, for example, ten groove portions 330 extending in the diagonal direction of the diffuser plate 300 are formed. When the light from each LED element 110 reaches the groove portion 330, it is reflected to the upper surface direction of the diffuser plate 300 through the wall surface of the groove portion 330.

As shown in FIGS. 3( c) and 4 (e ), a plurality of circular recesses 331 are formed at the end of the bottom surface of each diffuser 300 in the Y-axis direction. When the light from each LED element 110 reaches the recess 331, it is reflected to the upper surface of the diffuser 300 by the wall surface of the recess 331, so even at the end of the diffuser 300 in the Y-axis direction, the light will go to the diffuser. The upper surface of 300 reflects in the direction.

In this way, in the diffuser plate 300 of the present embodiment, for example, 4 patterns (that is, 4 diffuser elements) corresponding to, for example, 4 LED elements 110 are imposed, and the respective patterns are distinguished by the grooves 323 and 325 to form, for example, 4 patterns. There are two dimming areas DE1, DE2, DE3, DE4. In addition, the light from each LED element 110 is reflected toward the upper surface of the diffuser 300 through the concave conical surface 310, grooves 322a, 322b, 322c, 322d, etc. formed in the dimming regions DE1, DE2, DE3, DE4 Then, it ejects from the upper surface of the diffuser 300.

FIG. 18 is a modified example of the diffuser plate 300 shown in FIGS. 3 and 4, and corresponds to FIG. 3(c). In FIG. 18, in addition to the aforementioned concave conical surface 320, the groove portion 329, the recess portion 331, and the like, the slit regions 340A to 340D are also shown.

The slit regions 340A are formed in a total of four locations in each concave conical surface 320 of the diffuser plate 300 and near each end of the diffuser plate 300 in the short-side direction. The slit region 340A has a plurality of deep slits parallel to the longitudinal direction of the diffuser plate 300.

In addition, the depth of each slit may be 0.3 mm to 1.5 mm, preferably 0.5 mm to 1.2 mm, and more preferably 0.8 mm to 1.0 mm. Although the width of the opening of each slit depends on the relationship with the pitch between the slits, it is only necessary to use about 0.05 mm to 0.5 mm. In addition, the slits may all have the same depth, or they may be deeper as they deviate from the center. The shape of each slit may be any one or more of a substantially V-shape, a substantially U-shape, and an angular shape in cross section. The conditions of the slits may be the same as long as they are the same in the slit regions 340B to 340D.

The slit regions 340B are formed in a total of two places near the center of each end of the diffuser plate 300 in the longitudinal direction. The slit region 340B has a plurality of slits that are flat with the longitudinal direction of the diffuser plate 300.

The slit regions 340C are formed in a total of two positions between the rows of the concave conical surface 320 of the diffuser plate 300 and sandwich the center of the diffuser plate 300. The slit region 340C has a plurality of slits parallel to the longitudinal direction of the diffuser 300.

The slit regions 340D are formed in a total of two positions between the rows of the concave conical surface 320 of the diffuser plate 300 and sandwich the center of the diffuser plate 300. The slit region 340D has a plurality of slits parallel to the short side direction of the diffuser plate 300.

The method of forming each slit in the slit regions 340A to 340D is not particularly limited, and it may be formed by laser, for example, by etching, or by a mold.

Here, although as described later using FIG. 9, the diffuser 300 is arranged on the reflective sheet 200 having the side portion 202A, and as shown in FIG. In some cases, light passes through the teeth of the side portion 202A, but in some cases, the space between the diffuser plates 300 may become dark.

In order to prevent this, it is only necessary to change the optical path in a direction orthogonal to the surface direction of the diffuser 300. In this case, it is effective to provide slit regions 340A and 340B.

In addition, only the slit area 340A may be provided, or only the slit area 340B may be provided. In this case, it is possible to prevent the space between the diffuser plates 300 from becoming dark compared with any of the slit regions 340A and 340B not being provided.

Among them, when only one of the slit area 340A and the slit area 340B can be formed, it is preferable to form only the slit area 340B. This is because the gap between the diffusion plates 300 near the slit region 340B is easily formed to be larger than the gap between the diffusion plates 300 near the slit region 340A, so this is supplemented.

On the other hand, when the diffusion plate 300 becomes very large, since the distance between the LED elements 110 becomes larger, it is effective to provide the slit regions 340C and 340D in order to emit light of uniform intensity.

In addition, only the slit area 340C may be provided, or only the slit area 340D may be provided. In this case, it is possible to increase the intensity of light from the diffuser plate 300 compared to a case where neither of the slit regions 340C, 340D is provided.

However, when only one of the slit region 340C and the slit region 340D can be formed, it is preferable to form only the slit region 340C. This is because the column pitch of the LED elements 110 corresponding to each concave conical surface 320 is larger than the row pitch, so the light intensity at the center between the columns is lower than that at the center between the rows, so this is supplemented.

FIG. 5 is an exploded perspective view explaining the arrangement relationship between the diffuser plate 300 and the adjustment sheet 400 of the present embodiment. 6 is a diagram explaining the structure of the adjustment sheet 400, FIG. 6(a) is a plan view, and FIG. 6(b) is an exploded perspective view.

As shown in FIG. 5, the adjustment sheet 400 is a substantially circular sheet-like member, and is adhered to each concave conical surface 310 of the diffuser plate 300 so that its center is substantially aligned with the center of the light-emitting surface of each LED element 110 , Adjust the light distribution of the light emitted from each dimming area DE1, DE2, DE3, DE4. However, the adjustment sheet 400 of the present embodiment does not have to be adhered to the diffuser plate 300, but only needs to be fixedly arranged on the optical path of the light emitted from the LED element 110 by some means.

As shown in FIG. 6, the adjustment sheet 400 of this embodiment is a first sheet 410, a second sheet 420, and a third sheet 430 with different radii, which are sequentially laminated on the transparent film 405 by printing, vapor deposition, etc. in this order And constituted. The transparent film 405, the first sheet 410, the second sheet 420, and the third sheet 430 of the present embodiment can each transmit part of the light from the LED element 110.

The transparent film 405 has a thickness of 2.0 μm to 10 μm, and uses, for example, PET as a material. The first sheet 410, the second sheet 420, and the third sheet 430 are punched out of a polyurethane resin sheet with a thickness of 2.0 μm to 10 μm (for example, Victorian blanking processing, etc.). In addition, the first sheet 410, the second sheet 420, and the third sheet 430 only need to be able to adjust the light distribution (that is, transmittance), and as other embodiments, other synthetic resins such as nylon may also be used. The transparent film 405 only needs to be able to connect the first sheet 410 and the like to the diffuser plate 300, and for example, an adhesive layer is provided on the diffuser plate 300 side. In addition, the first sheet 410 and the like may not be provided with the transparent film 405, but may be directly formed on the diffusion plate 300 by printing, vapor deposition, or the like.

As shown in FIG. 6(b), the first sheet 410 is, for example, a sheet member in a 16-point star shape. In addition, the second sheet 420 is a sheet member having a smaller radius than the first sheet 410, for example, an octagonal star shape. In addition, the third sheet 430 is a sheet member having a smaller radius than the second sheet 420, for example, an octagonal star shape.

The transparent film 405, the first sheet 410, the second sheet 420, and the third sheet 430 are aligned and arranged on the same axis. The second sheet 420 is located on the first sheet 410, and the third sheet 430 is located on the second sheet 420. Above and integrated (Figure 6(a)). In addition, in the center of the third sheet 430 of this embodiment, a circular opening 431 is formed, and the first sheet 410 is formed with, for example, eight circular openings 411 arranged to surround the periphery of the second sheet 420, and There are, for example, 8 circular openings 412 on the outside of the opening 411.

Thus, in the adjustment sheet 400 of the present embodiment, the second sheet 420 and the third sheet 430 overlap at the central portion (that is, the portion where the opening 431 is formed), and the first sheet 410, the second sheet 420, and the third sheet 430 overlap Its outer side overlaps. In addition, the second sheet 420 and the third sheet 430 overlap further outside, and a portion where the first sheet 410 is present and a portion where the first sheet 410 is not present are formed on the outside of the second sheet 420 (that is, the openings 411, 412 are formed). part).

In this way, if the degree of overlap of the first sheet 410, the second sheet 420, and the third sheet 430 is different, the transmittance will be different accordingly. In this embodiment, the degree of overlap of the first sheet 410, the second sheet 420, and the third sheet 430, the size and position of the openings 411, 412 are determined based on the light distribution characteristics (that is, the brightness distribution) of the light from the LED element 110. The adjustment is performed to partially change the transmittance and adjust the overall brightness distribution to be substantially uniform.

FIG. 7 is a schematic diagram illustrating the function and effect between the diffuser plate 300 and the adjustment sheet 400 of the present embodiment. In addition, although only the dimming area DE1 (that is, only one diffusing element) is schematically shown in FIG. 7 for the convenience of description, the same is true for the other dimming areas DE2 to DE4.

As shown in FIG. 7, in the lighting unit 10 of the present embodiment, the light (light rays) indicated by the arrows are emitted from the LED elements 110 arranged in the space in the circular opening 321 of the diffuser plate 300.

Specifically, the LED element 110 emits light with a diffusion angle of 0° to 180° relative to the central axis of the light-emitting surface as indicated by the arrow a. The light emitted from the LED element 110 is condensed by the lens effect of the concave conical surface 320 of the diffuser plate 300, enters the diffuser plate 300, and enters the diffuser plate 300.

And, when reaching the concave conical surface 310 in the front (upper side of FIG. 7), a part of the light is emitted from the concave conical surface 310 (arrow b), and the remaining light is reflected by the concave conical surface 310 and is diffused in the diffuser 300 (Arrow c, arrow e). In addition, the light diffused in the diffuser 300 through the concave conical surface 310 enters the interior of the diffuser 300, passes through the walls of the grooves 322a, 322b, 322c, 322d, etc., is reflected in the direction of the upper surface of the diffuser 300, and is reflected from the diffuser 300. The upper surface of 300 is projected (arrow d).

In addition, part of the light diffused by the concave conical surface 310 enters the inside of the diffuser 300 and is emitted from the side of the diffuser 300 (arrow e). However, if the diffuser 300 is used, most of the light from the LED element 110 can be made Part is finally ejected from the upper surface of the diffuser plate 300.

FIG. 8 is a photograph and a graph showing the brightness distribution of light emitted from the lighting unit 10 of the present embodiment. In FIG. 8, in order to explain the effects of the diffuser 300 and the adjustment sheet 400 of the present embodiment, not only the brightness distribution in the case where the diffuser 300 and the adjustment sheet 400 exist (FIG. 8(c)), but also Shows the brightness distribution (ie, the brightness distribution of light emitted from the LED element 110) without the diffuser 300 and the adjustment sheet 400 (FIG. 8(a)), and, although the diffuser 300 is present, there is no adjustment sheet The brightness distribution in the case of 400 (that is, the brightness distribution of light emitted from the diffuser 300) (FIG. 8(b)).

In addition, the graphs of FIGS. 8(a) to 8(c) correspond to the respective photos and show the relative brightness of each photo at each position from the axis direction and the Y axis direction.

First, comparing Figures 8(a) and 8(b), it can be seen that by using the diffuser 300, not only the amount of light at a position close to the LED element 110 is relatively reduced, but the amount of light at a position deviating from the LED element 110 is relatively increased. Therefore, the light is emitted from the entire diffuser plate 300, and the uniformity can be improved.

In addition, comparing Fig. 8(b) and Fig. 8(c), it can be seen that in this embodiment, since the adjustment sheet 400 is adhered to the concave conical surface 310 of the diffuser 300, the light emitted from the concave conical surface 310 (Fig. The arrow b) of 7 is partially reflected by the adjusting sheet 400, and the reflected light is emitted from a position relatively deviated from the adjusting sheet 400. Therefore, it is possible to suppress hot spots (high-brightness portions) generated by the LED elements 110 and to emit light with a uniform amount of light from the entire diffuser plate 300.

In addition, since the reflective sheet 200 is arranged between the diffuser plate 300 and the substrate 101 (FIGS. 2 and 7), the light emitted from the LED element 110 is reflected on the bottom surface of the diffuser plate 300 and does not directly enter the diffuser plate 300. In the case of, or although it is temporarily incident on the diffuser 300, the light emitted from the bottom surface of the diffuser 300 after being reflected by the concave conical surface 310 is reflected again by the reflective sheet 200 to the diffuser 300 and enters the diffuser 300, Therefore, almost all the light emitted from the LED element 110 is emitted from the upper surface of the diffusion plate 300.

FIG. 16 is a diagram illustrating the function and effect of the adjustment sheet 400 of the present embodiment, and shows the brightness distribution of the light emitted from the lighting unit 10 in the X-axis direction and the Y-axis direction. In FIG. 16, "α" is the brightness distribution when the adjustment sheet 400 is not arranged, "β" is the brightness distribution when only the first sheet 410 is arranged, and "γ" is the brightness distribution when the first sheet 410 and the second sheet 410 are arranged. In the brightness distribution in the case of the sheet 420, "δ" is the brightness distribution in the case where the first sheet 410, the second sheet 420, and the third sheet 430 are arranged.

Table 1 is a table showing the peak value of the luminance distribution in the X-axis direction (the lower graph) in FIG. 16 and the transmittance calculated from the peak value. Table 2 shows the luminance distribution in the Y-axis direction in FIG. 16 (the graph on the right side). A table of the peak value of the graph) and the transmittance calculated from the peak value.

[Table 1]

[Table 2]

As described above, the adjustment sheet 400 of this embodiment is composed of the first sheet 410, the second sheet 420, and the third sheet 430 formed on the transparent film 405. Therefore, the transmittance of the adjustment sheet 400 is low near the emission surface (ie, the center portion) of the LED element 110 (refer to "δ" in Table 1 and Table 2). Toward the peripheral part), it becomes higher (refer to “γ” and “β” in Table 1 and Table 2).

Therefore, the brightness distribution of the light emitted from the diffusion plate 300 of this embodiment, as shown by "α" in FIG. 16, has a peak on the emission surface of the LED element 110, but the brightness of the light after passing through the adjustment sheet 400 In the distribution, this peak is suppressed, and a substantially uniform brightness distribution can be obtained in each of the dimming regions DE1, DE2, DE3, and DE4 (refer to "δ" in FIG. 16).

In addition, in this embodiment, although the three-layer structure of the first sheet 410, the second sheet 420, and the third sheet 430 is provided, it is not limited to such a structure. For example, the thickness of each film may be changed. It can be set to a two-layer structure, or it can be set to a four-layer or more structure. That is, the adjustment sheet 400 may have a multi-layer structure. This point is the same in the case of the fifth embodiment described later.

Although the foregoing is an explanation of the present embodiment, the present invention is not limited to the above-mentioned configuration, and various modifications can be made within the scope of the technical idea of the present invention.

For example, in this embodiment, although the case where two diffuser plates 300 are arranged on one substrate 101 on which eight LED elements 110 are mounted is selected for description, it is not limited to such a structure. For example, a plurality of The substrate 101 corresponds to the size of the diffuser 300.

In addition, for the diffuser plate 300 of the present embodiment, although the case where four patterns (ie, four diffuser elements) are imposed corresponding to the four LED elements 110 has been described, it is only necessary to arrange one diffuser element for each LED element 110. However, the number of impositions is not limited to 4. That is, for N LED elements 110 (N is an integer greater than or equal to 1), it is only necessary to put N diffusion elements on the diffusion plate 300.

(Second Embodiment)

FIG. 9 is a diagram showing the structure of the lighting unit 10 according to the second embodiment of the present invention. FIG. 9(a) is a diagram showing a state where the diffuser plate 300 is attached to the reflection sheet 200A, and FIG. 9(b) is a diagram showing a state where the diffuser plate 300 and the reflection sheet 200A are disassembled.

The lighting unit of this embodiment is different from the first embodiment in that the reflective sheet 200A that is additionally arranged on the diffuser plate 300 is formed to surround the bottom surface and the side surface of the diffuser plate 300. In addition, in FIG. 9, for convenience of description, only one diffuser plate 300 and reflective sheet 200A are shown, and other structures are omitted. However, the size of the reflective sheet 200A can also be doubled, and for example, two diffuser plates 300 are housed in one Inside the reflective sheet 200A.

As shown in FIG. 9, the reflective sheet 200A (reflective member) of this embodiment is formed of a thin metal plate (for example, aluminum) or resin (for example, PET (Polyethylene terephthalate, polyethylene terephthalate)). Parts with a reflectance of 90% or more and a thermal shrinkage of 0.5% or less.

The reflective sheet 200A is roughly shaped like a square box with an open top surface, and the diffuser 300 can be accommodated inside. The reflective sheet 200A has a bottom surface portion 201A formed to cover the bottom surface of the diffuser plate 300 and side surface portions 202A formed to cover the four side surfaces of the diffuser plate 300, for example. In this case, the bottom surface 201A is in contact with the bottom surface of the diffuser 300 that is the incident surface of light. In addition, the side surface portion 202A faces the side surface of the diffuser plate 300.

A first reflecting surface 201Aa is formed on the inner surface of the bottom surface 201A, and a second reflecting surface 202Aa is formed on the inner surface of the side surface 202A. The side portions 202A may be connected to each other at the short side portion, or not. In the latter case, strictly speaking, the reflective sheet 200A is not box-shaped, but even in this case, it can be said to be box-shaped as a rough shape.

In addition, on the bottom surface portion 201A of the reflective sheet 200A, four through holes 200Aa corresponding to the positions of the LED elements 110 and, for example, four through holes 200Ab through which the four protrusions 302 of the diffuser plate 300 respectively pass are formed. In addition, the tip of the side surface 202A of the reflective sheet 200A is processed into a zigzag shape.

If the side surface 202A is not processed in this way, the upper surface of the tip of the side surface 202A is linear, and if there is a corner between the upper surface and the side surface, the corner is used as the boundary to reflect light The directions are very different, and as a result, there is not much light reaching the corresponding position of the corner and a linear shadow is generated. In order to avoid the shadow, the processing is performed.

Therefore, the shape of the tip portion of the side portion 202A is not limited to a sawtooth shape, and may be, for example, a wave shape, or a mixed shape of a sawtooth shape and a wave shape. In addition, instead of processing the entire front end portion of the side portion 202A, at least a part of it may be processed.

Furthermore, the number and size of the teeth are not limited to the solution shown in Figure 9. In the extreme, even if only one or two very large teeth are designed, there is a certain effect, or even on the side The upper surface of the top end of 202A is provided with a circular arc, and the top end of the side surface 202A does not form a corner between the upper surface and the side surface, which also has a certain effect.

In addition, the shape of the teeth is not limited to the one shown in FIG. 9. For example, although FIG. 9 shows that the tooth is a symmetrical shape, one side of the tooth may be relatively gently inclined in the range of, for example, 30 to 60 degrees with respect to the bottom surface of the tooth, and the other side may be opposite to each other. The bottom surface has an inclined shape that is approximately orthogonal, such as, for example, 80 degrees to 90 degrees.

In addition, if an example is shown, the bottom of the tooth portion may be set to 2.0 mm to 4.0 mm, and the height of the set tooth may be about 1.0 mm to 2.0 mm. Even in the case of wavy, it is sufficient to set the same shape and size. Therefore, it is only necessary to set the 1/2 cycle to about 2.0mm to 4.0mm and the amplitude to 0.5mm to 1.0mm.

In addition, although it is not necessarily limited to this, the height from the bottom surface of the reflective sheet 200A to the bottom of the tooth portion and the height from the bottom surface to the top of the tooth portion are respectively set to be 50% to the height of the side surface 202A. 90%, 90%~100% is fine. Furthermore, what is necessary is just to set the width of the bottom part of a tooth part to 2.5%-10% with respect to the width of 202 A of side parts.

In addition, although FIG. 9(b) shows that the tooth group consisting of a plurality of teeth has a horizontal straight line connecting the tops, the connecting line connecting the tops of the tooth group is near the center in the horizontal direction. A linear or curved shape such as a mountain shape is also acceptable. In this way, since light is easily directed toward the four corners of the diffuser plate 300, there is an advantage that the brightness difference of the diffuser plate 300 as a whole is reduced.

In addition, in the case where the connecting line connecting the tops of the tooth part group is set to be linear, as shown in FIG. 9(c), as an example, one method is to make the height of one of the adjacent tooth parts About half of it becomes the height of the other tooth.

In addition, in the case where the connecting line connecting the tops of the tooth part group is curved, as an example, one method is to set it as follows: in the case where the horizontal direction is represented by x and the vertical direction is represented by y, y= Around 0.2x2 to 0.4x2 indicate a curve from the end of the tooth group to the center of the tooth group. In addition, as such a mountain shape, the bottom and height of each tooth can also be set to the above-mentioned size.

The size of the reflective sheet 200A is slightly larger than the size of the diffuser 300 to embed the diffuser 300. When the diffuser 300 is housed in the reflective sheet 200A, the bottom and side surfaces of the diffuser 300 are arranged to be the same as those of the reflective sheet 200A. Face facing inside. That is, the bottom surface and the side surface of the diffuser plate 300 are respectively covered by the first reflective surface 201Aa and the second reflective surface 202Aa of the reflective sheet 200A.

Therefore, the light emitted from the bottom surface of the diffuser plate 300 is reflected to the upper surface side of the diffuser plate 300 through the first reflecting surface 201Aa, and the light emitted from the side surface of the diffuser plate 300 passes through the second reflecting surface 202Aa from the side surface of the diffuser plate 300. It enters the diffuser plate 300 again, and is finally reflected to the upper surface side of the diffuser plate 300.

Fig. 10 is a photograph showing the brightness distribution of light emitted from the lighting unit of the present embodiment. In addition, in FIG. 10, in order to illustrate the effect of the reflective sheet 200A of the present embodiment, in addition to the brightness distribution in the case of using the reflective sheet 200A of the present embodiment (FIG. 10(b)), the second embodiment is also shown. 1 embodiment (that is, the case of using the reflective sheet 200) brightness distribution (FIG. 10(a)).

The matrices of 3 rows and 3 columns in Fig. 10(a) and Fig. 10(b) respectively refer to the lighting unit shown in Fig. 9(a), indicating that only the LED elements 110 of the lighting unit in the second row and second column are turned on state.

Comparing Fig. 10(a) and Fig. 10(b), it can be seen that according to the structure of this embodiment, the light emitted from the side surface of the diffuser plate 300 of the lighting unit in the second row and second column is diffused from the second reflecting surface 202Aa. The side surface of the plate 300 enters the diffuser plate 300 again, is finally reflected toward the upper surface of the diffuser plate 300, and is emitted from the upper surface of the diffuser plate 300, so the light can be effectively used. Therefore, if local dimming is performed using the structure of this embodiment, it is possible to accurately control the amount of light in each dimming area.

(Third Embodiment)

FIG. 11 is a diagram showing the configuration of the lighting unit 10A included in the lighting device according to the third embodiment of the present invention. Fig. 11(a) is a plan view, Fig. 11(b) is a bottom view, and Fig. 11(c) is an exploded perspective view.

As shown in FIG. 11, the lighting unit 10A of this embodiment includes: a square plate-shaped LED unit 100A; a reflective sheet 200B arranged on the upper surface of the LED unit 100A; and, for example, two arranged on the upper surface of the reflective sheet 200B Diffusion plate 600.

In addition, the lighting unit 10A of this embodiment differs from the lighting unit 10 of the first embodiment in the following two points: for example, two (X-axis direction) x, for example, one (Y-axis direction) LED element 110 is mounted on a substrate The upper surface of 101A; and on each diffuser 600, one pattern (ie, one dimming area) is formed corresponding to each LED element 110.

In addition, it should be understood that the size of the diffuser plate 600 of the present embodiment is substantially the same as the size of the diffuser plate 300 of the first embodiment. That is, in the present embodiment, one dimming area (that is, the diffuser 600) replaces the four dimming areas DE1, DE2, DE3, and DE4 of the first embodiment.

In the reflective sheet 200B, for example, two through holes 200Ba corresponding to the positions of the two LED elements 110 are formed, and for example, two through holes 200Bb through which, for example, two protrusions 602 of the diffuser plate 600 pass are formed.

In this embodiment, as in the first embodiment, the reflective sheet 200B is arranged between the diffuser 600 and the substrate 101A. Even if the light emitted from the LED element 110 does not enter the diffuser 600 but is blocked on the bottom surface of the diffuser 600 Reflected, or temporarily incident on the diffuser 600 but still emitted from the bottom surface of the diffuser 600, it will also be reflected again by the reflective sheet 200B toward the bottom surface of the diffuser 600, and then enter the diffuser 600 again, so almost all the output from the LED element 110 All the light is emitted from the upper surface of the diffusion plate 600.

The diffuser 600, similar to the diffuser 300 of the first embodiment, is in the form of covering the reflective sheet 200B and is arranged on the optical path of the light emitted from the LED elements 110, so that the light emitted from each LED element 110 is on the diffuser. 600 inside is diffused around the Z-axis, square plate-shaped optical glass or optical elements made of resin (for example, acrylic, Pc (polycarbonate), etc.).

FIG. 12 is a diagram illustrating the structure of the diffuser plate 600 of the present embodiment. Fig. 12(a) is a plan view, Fig. 12(b) is a right side view, and Fig. 12(c) is a bottom view. In addition, FIG. 13 is a cross-sectional view illustrating the structure of the diffuser 600. Fig. 13(a) and Fig. 13(b) are respectively A-A cross-sectional view and B-B cross-sectional view of Fig. 12(c).

As shown in FIG. 12( b) and FIG. 12( c ), on the bottom surface of each diffuser plate 600, for example, four cylindrical protrusions 602 protruding to the negative direction side of the Z axis are formed. When the diffuser plate 600 is placed on the reflective sheet 200B, the protrusions 602 pass through the through hole 200Bb of the reflective sheet 200B and the through hole 120a of the reinforcing plate 120, and protrude toward the bottom surface side of the substrate 101A. The diffusion plate 600 is fixed to the substrate 101A by thermally welding the protrusions 602 on the bottom surface side of the substrate 101A (FIG. 11( c )).

As shown in FIGS. 12(a), 13(a), and 13(b), on the upper surface of each diffuser 600, one concave conical surface 610 is formed corresponding to the position of, for example, one LED element 110. If the light emitted from the LED element 110 passes through the diffuser 600 and reaches the concave conical surface 610, a part of the light is emitted from the concave conical surface 610, and another part of the light is diffused in the diffuser 600 around the Z axis through the concave conical surface 610 . Thus, the uniformity of the diffuser 600 can be achieved.

As shown in FIG. 12( a) and FIG. 13( a ), notches 650 are formed at the four corners of the upper surface of the diffuser plate 600. By emitting light from the cutout portion 650, the amount of light leaking from the side surface of the diffuser plate 600 is reduced, and the total amount of light emitted from the upper surface of the diffuser plate 600 is increased.

In addition, on the diagonal of the upper surface of the diffuser plate 600, for example, four protrusions 619 that gradually protrude upward from the central portion toward the four corners are arranged and formed. As described above, when the four dimming regions DE1, DE2, DE3, and DE4 are formed in the first embodiment, the number of LED elements 110 is also four correspondingly. However, as in this embodiment, When one dimming area is formed, the number of LED elements 110 is also one. Therefore, the maximum light amount is 1/4 compared with the case of FIG. 3, and the light amount is reduced.

In addition, since the decrease in the amount of light becomes significant at the four corners of the diffuser plate 600, the protrusions 619 are provided in this embodiment to suppress the decrease in the amount of light at the four corners. In addition, by subjecting the upper surface of the protrusion 619 to corrugation (concave-convex processing) with an unevenness of about several tens of μm, it is possible to further suppress a decrease in the amount of light.

In addition, on the upper surface of the diffuser plate 600, there are formed, for example, eight grooves 611 extending from the four corners along each side. The groove portion 611 functions as a waveguide, and when the light from each LED element 110 reaches the groove portion 611, it passes through the wall surface of the groove portion 611 and is reflected.

Therefore, it is possible to suppress the leakage of light from each diffusion plate 600 (that is, each dimming area) to the adjacent dimming area. In addition, at both ends in the X-axis direction of the center portion of the diffuser plate 600 in the Y-axis direction, groove portions 613 each extending toward the concave conical surface 610 are formed. Each groove portion 613 is composed of, for example, four groove portions 613a, 613b, 613c, and 613d that function as a waveguide. When light from the LED element 110 reaches the groove portions 613a, 613b, 613c, and 613d, the respective walls face the diffuser plate. 600 is reflected in the upper surface direction.

In addition, the formation position of the groove portion 613 a and the like is not limited to the one shown in FIG. 12( a ), and may be formed at both ends in the Y-axis direction of the center portion of the diffuser plate 600 in the X-axis direction. In this case, the groove portion 611 adjacent to it becomes shorter.

The formation positions of the grooves 611, 613a, etc., and 615 are explained as follows. In short, this is also the same in the case of the diffuser 300: The grooves 611, 613a, etc., and 615 should be properly formed in a well-balanced manner. The upper part deviates from the LED element 110. In this way, when either of the diffuser plate 300 and the diffuser plate 600 is used, light can be emitted uniformly from the upper surface.

In addition, the diffuser plate 600 (that is, each dimming area), like the diffuser plate 300, can suppress the leakage of light to the adjacent dimming area. In addition, in the vicinity of, for example, four protrusions 619 on the upper surface of the diffuser plate 600, for example, eight arcuate grooves 615 centered on the concave conical surface 610 are formed. The groove portion 615 functions as a waveguide. When the light from each LED element 110 reaches the groove portion 615, it is reflected to the upper surface of the diffuser plate 600 through the wall surface of the groove portion 615, and is emitted from the upper surface of the diffuser plate 600.

As shown in Fig. 12(c), Fig. 13(a), and Fig. 13(b), on the bottom surface of each diffuser 600, a concave conical surface 620 formed at a position corresponding to the concave conical surface 610 and a concave cone The surfaces 620 are connected to and selectively form a circular opening 621.

In addition, the concave conical surface 620 serves as an incident surface on which the light emitted from the LED element 110 enters, and functions as a kind of condenser lens. Therefore, generally, the light emitted from each LED element 110 has a large angular component (that is, a large spread angle), but when it enters each concave conical surface 620, the spread angle becomes narrow.

As shown in FIG. 12(c), FIG. 13(a), and FIG. 13(b), on the bottom surface of each diffuser 600, a plurality of ring-shaped grooves 622 are formed concentrically so as to surround the concave conical surface 620. . In addition, the depth of the groove portion 622 is as deep as the groove portion 622 formed at a position deviated from the concave conical surface 620 (FIG. 4(a)). The light diffused by the concave conical surface 610 and the diffusion angle emitted from the LED element 110 The broad light is reflected in the direction of the upper surface of the diffuser plate 600 through the wall surface of the groove portion 622 and is emitted from the upper surface of the diffuser plate 600.

In addition, stepped portions 625 and 640 are formed on the bottom surface of the diffuser plate 600. The stepped portion 625 is formed at the four corners, and the stepped portion 640 is formed at a position corresponding to the groove portion 613. The step 625 and the like are all thinner parts than the peripheral part.

In addition, a plurality of arc-shaped groove portions 626 are formed in the step portion 625, and a plurality of arc-shaped groove portions 641 whose depth gradually becomes deeper toward the outside are formed in the step portion 640 (FIG. 13(a), FIG. 13(b)) ).

In addition, as shown in FIG. 12(c), a plurality of circular recesses 631 and 633 are formed along the ends of the bottom surface of the diffuser plate 600. When the light from each LED element 110 reaches the recesses 631 and 633, it is reflected in the direction of the upper surface of the diffuser 600 through the wall surfaces of the recesses 631 and 633.

In this way, in the diffuser plate 600 of the present embodiment, for example, one pattern (that is, one diffuser element) corresponding to, for example, one LED element 110 is imposed to form one dimming area. In addition, the light from the LED element 110 is reflected in the direction of the upper surface of the diffuser 600 through the concave conical surface 610, the groove portion 622, etc. formed in the diffuser 600, and then is emitted from the upper surface of the diffuser 600.

(Fourth Embodiment)

FIG. 14 is a plan view showing a modification example of the diffuser plate 600 according to the third embodiment of the present invention. As shown in FIG. 14, the diffuser plate 600A of the present embodiment (this modification example) is different from the diffuser plate 600 of the third embodiment in that, for example, four protrusions 619 are not formed on the upper surface.

15 is a diagram showing the brightness distribution of the lighting unit using the diffuser 600 of the third embodiment and the brightness distribution of the lighting unit using the diffuser 600A of the fourth embodiment. The graph on the left side of FIG. 15 is A graph showing the brightness distribution in one diagonal direction of the diffuser 600 and the diffuser 600A (direction A in FIG. 15). The graph on the right side of FIG. 15 shows the other diagonal direction of the diffuser 600 and the diffuser 600A ( A graph of the brightness distribution in the direction B of FIG. 15).

As shown in FIG. 15, if the diffuser 600 and the diffuser 600A are used, the light emitted from the LED element 110 is diffused in the diffuser 600 and the diffuser 600A, so the amount of light close to the LED element 110 is relatively reduced, and The amount of light deviated from the position of the LED element 110 is relatively increased, and therefore light is emitted from the entire diffuser plate 600 and the diffuser plate 600A, and the uniformity can be improved.

In addition, comparing the brightness distribution of the diffuser 600 with the brightness distribution of the diffuser 600A, it can be seen that the brightness distribution of the diffuser 600 is higher than that of the diffuser 600A by about 100 cd/m2. It can be seen that this is the effect of, for example, four protrusions 619 formed on the upper surface of the diffuser plate 600, and the protrusions 619 effectively play a role in improving the brightness.

(Fifth Embodiment)

FIG. 17 is a diagram showing a modification example of the adjustment sheets 400A to 400C according to the fifth embodiment of the present invention, and corresponds to FIG. 6. Instead of a star-shaped polygonal shape, Fig. 17(a) shows: each first sheet 410A with rounded corners; a part of the second sheet 420A with rounded corners; and each third sheet 430A with rounded corners.

Fig. 17(b) shows: instead of the front end portion of the first sheet 410A, the first sheet 410B includes two types of substantially round members; The second sheet 420B of a small substantially circular member; and the third sheet 430B that includes a small substantially circular member instead of each tip portion of the third sheet 430A.

Fig. 17(c) shows: the first sheet 410C formed by combining the first sheet 410 shown in Fig. 6(b) and the first sheet 410B shown in Fig. 17(b); A second sheet 420C having the same shape as the second sheet 420 shown; and a third sheet 430C having the same shape as the third sheet 430 shown in FIG. 6(b).

Also in the case of the adjustment sheets 400A to 400C shown in FIG. 17, similarly to the case of the adjustment sheet 400 shown in FIG. 6, the effect described using FIG. 16 can be obtained. Therefore, in this specification, the shapes of the first sheet 410A to 410C, the second sheet 420A to 420C, and the third sheet 430A to 430C constituting the adjustment sheet 400A to 400C shown in FIG. 17 are also included in the star-shaped polygonal shape. .

In addition, the above-described lighting unit such as the diffuser 600 can be used for a liquid crystal display attached to a personal computer, and can also be used for a so-called LCD TV or other televisions. In addition, the lighting unit can also be used for general lighting devices, street signage devices, and other devices that do not have a liquid crystal panel but have a diffuser, a translucent resin board, and the like.

In addition, it should be considered that all the aspects of each embodiment disclosed this time are illustrations and do not limit the present invention. The scope of the present invention is not limited by the above description, but is intended to include all changes within the meaning and scope equivalent to the scope of the description shown in the description.

1: Lighting device 10.10A: Lighting unit 100, 100A: LED unit 101, 101A: substrate 110: LED components 120: Reinforced board 120a: Through hole 200, 200A, 200B reflective sheet 200a, 200b, 200Ba, 200Bb: through holes 201A: bottom face 201Aa: The first reflecting surface 201Ab, 201Ac: Through hole 202A: Side 202Aa: 2nd reflecting surface 300, 600, 600A: diffuser 302, 602: protrusion 310, 320, 610, 620: concave conical surface 311, 322a, 322b, 322c, 322d, 323, 325, 327, 328, 329, 330, 611, 613, 615, 622, 626, 641: Groove 321, 621: round opening 324, 326, 625, 640: stepped part 331, 631, 633: recess 400: Adjust the sheet 410: first slice 411, 412: Opening 420: second slice 430: third slice 431: open 619: protruding part DE1, DE2, DE3, DE4: dimming area

FIG. 1 is a perspective view showing the structure of the lighting device according to the first embodiment of the present invention. 2 is an exploded perspective view illustrating the structure of a lighting unit included in the lighting device according to the first embodiment of the present invention. Fig. 3 is a diagram illustrating the structure of a diffuser plate of the lighting unit of Fig. 2. Fig. 4 is a cross-sectional view of the diffuser plate of Fig. 3. Fig. 5 is a diagram illustrating the arrangement relationship between a diffuser plate and an adjustment sheet of the lighting unit of Fig. 2. Fig. 6 is a diagram illustrating the structure of an adjustment sheet of the lighting unit of Fig. 2. FIG. 7 is a schematic diagram illustrating the function and effect of the diffuser plate and the adjustment sheet of the lighting unit included in the lighting device according to the first embodiment of the present invention. 8 is a photograph and a graph showing the brightness distribution of light emitted from the lighting unit included in the lighting device according to the first embodiment of the present invention. FIG. 9 is a diagram showing the configuration of the lighting unit included in the lighting device according to the second embodiment of the present invention. 10 is a photograph showing the brightness distribution of light emitted from the lighting unit included in the lighting device according to the second embodiment of the present invention. FIG. 11 is a diagram showing the configuration of the lighting unit included in the lighting device according to the third embodiment of the present invention. Fig. 12 is a diagram illustrating the structure of a diffuser plate of the lighting unit of Fig. 11. Fig. 13 is a cross-sectional view of the diffuser plate of Fig. 12. 14 is a diagram illustrating the structure of the diffuser plate of the lighting unit included in the lighting device according to the fourth embodiment of the present invention. 15 is a diagram showing the brightness distribution of the lighting unit using the diffuser plate of the third embodiment and the brightness distribution of the lighting unit using the diffuser plate of the fourth embodiment. FIG. 16 is a diagram illustrating the effect of the adjustment sheet 400 shown in FIG. 6. FIG. 17 is a diagram showing a modification example of the adjustment sheet according to the fifth embodiment of the present invention. FIG. 18 is a modified example of the diffuser plate 300 shown in FIGS. 3 and 4, and corresponds to FIG. 3(c).

300: diffuser

310: Concave conical surface

311: Groove

650: Notch

DE1, DE2, DE3, DE4: dimming area

Claims (6)

A light distribution adjustment mechanism, characterized in that the light distribution adjustment mechanism is arranged on the optical path of the light emitted from the light-emitting element, and adjusts the light distribution of the light, It has a layer structure formed by a plurality of layers, the plurality of layers are in the form of flakes, the radius is larger as the side closer to the light-emitting element, and they are laminated in the optical axis direction by centering on the optical axis of the light-emitting element , The degree of overlap of the multiple layers is different, and the more they are configured to deviate from the optical axis of the light-emitting element, the higher the transmittance, Any one of the plurality of layers is formed with a plurality of openings. The light distribution adjustment mechanism according to claim 1, wherein the plurality of layer structures are formed by laminating a plurality of substantially circular sheet members or films having different radii with the optical axis of the light emitting element as a center. The light distribution adjustment mechanism according to claim 1, wherein the plurality of layers constituting the multiple layer structure have a star-shaped polygonal shape. A lighting unit, characterized in that it has: Substrate A light-emitting element arranged on the substrate; A square plate-shaped light distribution control element that controls the light distribution of the light emitted from the light emitting element; and The light distribution adjustment mechanism according to claim 1 attached to the light distribution control element. A display having the light distribution adjustment mechanism as described in claim 1. A television having the light distribution adjustment mechanism as described in claim 1.

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