WO2018109978A1 - Dispositif de source de lumière plane et dispositif d'affichage - Google Patents

Dispositif de source de lumière plane et dispositif d'affichage Download PDF

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Publication number
WO2018109978A1
WO2018109978A1 PCT/JP2017/029372 JP2017029372W WO2018109978A1 WO 2018109978 A1 WO2018109978 A1 WO 2018109978A1 JP 2017029372 W JP2017029372 W JP 2017029372W WO 2018109978 A1 WO2018109978 A1 WO 2018109978A1
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WO
WIPO (PCT)
Prior art keywords
light
central axis
light flux
flux controlling
controlling member
Prior art date
Application number
PCT/JP2017/029372
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English (en)
Japanese (ja)
Inventor
中村　真人
Original Assignee
株式会社エンプラス
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2017048871A external-priority patent/JP2018098162A/ja
Application filed by 株式会社エンプラス filed Critical 株式会社エンプラス
Priority to US16/469,759 priority Critical patent/US10747055B2/en
Publication of WO2018109978A1 publication Critical patent/WO2018109978A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00—Refractors for light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00—Refractors for light sources
    • F21V5/02—Refractors for light sources of prismatic shape
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00—Refractors for light sources
    • F21V5/04—Refractors for light sources of lens shape
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/02—Simple or compound lenses with non-spherical faces
    • G02B3/04—Simple or compound lenses with non-spherical faces with continuous faces that are rotationally symmetrical but deviate from a true sphere, e.g. so called "aspheric" lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/02—Simple or compound lenses with non-spherical faces
    • G02B3/06—Simple or compound lenses with non-spherical faces with cylindrical or toric faces
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/02—Simple or compound lenses with non-spherical faces
    • G02B3/08—Simple or compound lenses with non-spherical faces with discontinuous faces, e.g. Fresnel lens
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays

Definitions

  • the present invention relates to a surface light source device having a light emitting device including a plurality of light emitting elements and a light flux controlling member, and a display device having the surface light source device.
  • HUD head-up display
  • a head-up display capable of directly displaying information such as a speed display on a screen (for example, a windshield of a car)
  • a screen for example, a windshield of a car
  • a lens light flux controlling member
  • a surface light source device using a plurality of light emitting elements (for example, LEDs) can be adopted as a light source.
  • luminance unevenness having a high luminance region and a low luminance region may occur on the emission surface of the surface light source device. Therefore, several means for eliminating such luminance unevenness have been proposed (for example, Patent Document 1).
  • FIG. 1A is a cross-sectional view illustrating a configuration of a surface light source device 10 described in Patent Document 1
  • FIG. 1B is a plan view illustrating an outline of a lens array 14 included in the surface light source device 10 described in Patent Document 1.
  • FIG. 1C is a graph showing the luminance distribution (relative luminance) of light emitted from the lens array 14 described in Patent Document 1
  • FIG. 1D does not have an uneven shape on the boundary line between two adjacent lenses. It is a graph which shows the luminance distribution (relative luminance) of the emitted light from a lens array.
  • the surface light source device 10 described in Patent Document 1 includes a plurality of LEDs 12 arranged on a substrate 11, a lens array 14, and a diffusion member 15. As shown in FIG. 1A, in the surface light source device 10, seven LEDs 12 are arranged in a line. As shown in FIG. 1B, in the lens array 14, seven lenses 13 are arranged in a line corresponding to the seven LEDs 12. An uneven portion 17 is formed on a boundary line 16 between two adjacent lenses 13 of the lens array 14. In the surface light source device 10 described in Patent Document 1, the emitted light from the LED 12 is focused by the lens 13 and the focused light is diffused by the diffusion member 15. At this time, the brightness of the light emitted from the lens array 14 is averaged by the uneven portion 17. As a result, in the surface light source device 10 described in Patent Document 1, the difference in luminance between the high luminance region and the low luminance region is smaller than in the case where the uneven shape is not formed (see FIG. 1D). (See FIG. 1C).
  • the surface light source device 10 described in Patent Document 1 has a problem that luminance unevenness cannot be sufficiently reduced.
  • a surface light source device includes a plurality of light emitting elements, a first light flux controlling member, a second light flux controlling member, and a third light flux controlling member, and controls light distribution of light emitted from the plurality of light emitting elements.
  • a surface light source device comprising: a light emitting device having a luminous flux control member; and a diffusing member that is disposed through the light emitting device and an air layer and is irradiated with light emitted from the light emitting device.
  • the one-beam control member intersects with the first central axis and a concave first incident surface disposed to face the plurality of light emitting elements so as to intersect with the first central axis of the first light-beam control member.
  • a third exit surface disposed on the opposite side of the third entrance surface, and the third entrance surface or the third exit surface has a third light flux controlling member.
  • a plurality of convex lens surfaces having a convex shape or a plurality of concave concave lens surfaces in a cross section including the third central axis are two-dimensionally arranged, and the focal length of the first light flux controlling member is f, and the first central axis And the distance from the optical axis of the light emitting element farthest from the first central axis, where d is the convex lens surface or concave shape in the cross section including the third central axis, which satisfies the following formula (1):
  • the width of the plurality of concave lens surfaces is w, and the convex lens surface or When the radius of curvature of the concave lens surface is R, and the intersection of the convex lens surface or the center line of the concave lens surface and the surface on the diffusion member side in the third light flux controlling member, and the distance of the diffusion member is t,
  • a surface light source device that satisfies the following expressions (2) and (3). -0.6 ⁇ d
  • the display device includes the surface light source device according to the present invention and a display member that is irradiated with light emitted from the surface light source device.
  • a surface light source device including a light emitting device with little luminance unevenness while using a plurality of light emitting elements, and a display device having the surface light source device.
  • FIGS. 1C and 1D are diagrams for explaining the configuration of the surface light source device described in Patent Document 1
  • FIGS. 1C and 1D are graphs for explaining the luminance distribution of light emitted from the lens array.
  • 2A is a cross-sectional view of the display device according to Embodiment 1 of the present invention
  • FIG. 2B is a diagram showing a display area of the display device shown in FIG. 2A.
  • 3A to 3D are diagrams showing the configuration of the first light flux controlling member.
  • 4A to 4D are diagrams showing the configuration of the second light flux controlling member.
  • 5A to 5D are diagrams showing the configuration of the third light flux controlling member.
  • 6A and 6B are sectional views of other third light flux controlling members.
  • FIG. 7 is a diagram illustrating an optical path of the display device.
  • 8A and 8B are diagrams for explaining the relationship between the light flux controlling member and the light emitting element.
  • 9A and 9B are diagrams for explaining the irradiation region.
  • 10A and 10B are diagrams for explaining the expression (2).
  • 11A and 11B are diagrams for explaining the expression (3).
  • FIG. 12 is a diagram for explaining the equations (4) and (5).
  • FIG. 13 is a diagram for explaining the equation (6).
  • 14A to 14D are diagrams for explaining bfl.
  • 15A to 15C are diagrams for explaining the expression (7).
  • 16A and 16B are diagrams for explaining the expression (8).
  • 17A to 17D are diagrams showing the configuration of the third light flux controlling member according to the second embodiment.
  • FIGS. 18A and 18B are diagrams illustrating a configuration of a display device according to Embodiment 2.
  • FIG. 19 is a schematic diagram illustrating the configuration of the display device used in the example.
  • FIG. 20 is a graph showing the relationship between w 2 / t and the uniformity U0 in the display device.
  • FIG. 21 is a graph showing the relationship between w / R and the uniformity ratio U5 / U0 in the display device.
  • FIG. 22A is a graph showing the relationship between (w ⁇ bfl) / t and uniformity U0 in another display device in which a convex lens surface or a concave lens surface is arranged on the third incident surface side, and FIG.
  • FIG. 23A is a graph showing the relationship between (w ⁇ bfl) / t and uniformity U0 in another display device in which a convex lens surface or a concave lens surface is arranged on the third exit surface side
  • FIG. It is a graph which shows the relationship between
  • the HUD has a display device, a projection lens for appropriately projecting light from the display device onto the screen, and a screen. Light emitted from the display device is irradiated onto the screen through a projection optical system including a projection lens.
  • FIG. 2A is a cross-sectional view of display device 100 according to Embodiment 1 of the present invention
  • FIG. 2B is a diagram showing display area 121 of display device 100 shown in FIG. 2A.
  • the first leg, the second leg, and the third leg are omitted.
  • the display device 100 includes a surface light source device 110 and a display member 120.
  • the surface light source device 110 is a light source of the display device 100.
  • the surface light source device 110 includes a light emitting device 130 and a diffusing member 140.
  • the light emitting device 130 includes a plurality of light emitting elements 112 and a light flux control member 113 including a first light flux control member 114, a second light flux control member 115, and a third light flux control member 116, and is disposed on the substrate 111. Yes.
  • the substrate 111 supports the plurality of light emitting elements 112 and the light flux controlling member 113.
  • the type of the substrate 111 is not particularly limited.
  • a circuit substrate is preferably used from the viewpoint of supplying electricity to the light emitting element 112.
  • the substrate 111 is a glass composite substrate, a glass epoxy substrate, an Al substrate, or the like.
  • the plurality of light emitting elements 112 are light sources of the surface light source device 110 and are fixed on the substrate 111.
  • the light emitting element 112 is a light emitting diode (LED).
  • the colors of light emitted from the plurality of light emitting elements 112 may be the same or different from each other. In the present embodiment, the colors of light emitted from the plurality of light emitting elements 112 are all the same. Further, the color of light emitted from the light emitting element 112 is not particularly limited.
  • the types of colors of light emitted from the light emitting element 1122 include white, red, blue, green, and the like. In general, the light emitting element 112 emits light most strongly in the normal direction with respect to the light emitting surface of the light emitting element 112.
  • the number of the light emitting elements 112 can be appropriately changed according to the size of the display member 120, the distance between the substrate 111 and the display member 120, and the like. In the present embodiment, the number of light emitting elements 112 is three.
  • the arrangement of the plurality of light emitting elements 112 is not particularly limited.
  • the plurality of light emitting elements 112 may be arranged on a straight line, may be arranged at a position corresponding to a vertex of a polygon, or may be arranged in an annular shape. In the present embodiment, the plurality of light emitting elements 112 are arranged on a straight line.
  • the optical axis of the light emitting element 112 disposed in the center and the first central axis CA1 (second central axis CA2 and third central axis CA3) are arranged to coincide.
  • the “optical axis of the light emitting element 112” refers to the traveling direction of light at the center of the total luminous flux emitted three-dimensionally from the light emitting element 112.
  • the “optical axis of the plurality of light emitting elements 112” refers to the traveling direction of light at the center of the total luminous flux emitted three-dimensionally from the plurality of light emitting elements 112.
  • the interval between the adjacent light emitting elements 112 is not particularly limited.
  • the light flux controlling member 113 controls the light distribution of the light emitted from the light emitting element 112.
  • the light flux control member 113 includes a first light flux control member 114, a second light flux control member 115, and a third light flux control member 116.
  • the first central axis CA1 of the first light flux control member 114, the second central axis CA2 of the second light flux control member 115, and the third central axis CA3 of the third light flux control member 116 may coincide with each other. , Do not have to match.
  • the first central axis CA1 of the first light flux controlling member 114, the second central axis CA2 of the second light flux controlling member 115, and the third central axis CA3 of the third light flux controlling member coincide with each other. Yes.
  • the first light flux control member 114, the second light flux control member 115, and the third light flux control member 116 are sequentially arranged from the light emitting element 112 side toward the diffusion member 140 side.
  • the first light flux controlling member 114 is disposed on the light emitting element 112 side
  • the second light flux controlling member 115 is disposed at a position (diffusing member 140 side) away from the first light flux controlling member 114 with respect to the light emitting element 112. Yes.
  • the third light flux controlling member 116 is disposed at a position (on the diffusing member 140 side) away from the second light flux controlling member 115 with respect to the light emitting element 112.
  • the first light flux controlling member 114 (the first incident surface 131 and the first light exiting surface 132 (see FIG.
  • the materials of the first light flux control member 114, the second light flux control member 115, and the third light flux control member 116 may be the same or different.
  • Examples of the material of the first light flux control member 114, the second light flux control member 115, and the third light flux control member 116 include light transmissivity such as polymethyl methacrylate (PMMA), polycarbonate (PC), and epoxy resin (EP). Resins and light-transmitting glass are included.
  • the 1st light beam control member 114, the 2nd light beam control member 115, and the 3rd light beam control member 116 are manufactured by injection molding, for example. The configurations of the first light flux control member 114, the second light flux control member 115, and the third light flux control member 116 will be described later.
  • the diffusing member 140 diffuses and transmits the light emitted from the surface light source device 110.
  • Examples of the diffusing member 140 include a transparent plate-like member that has been subjected to light diffusion treatment (for example, roughening treatment) and a transparent plate-like member that is mixed with scatterers such as beads.
  • the display member 120 is, for example, a liquid crystal panel.
  • the display member 120 has a display area 121 in which an image to be projected on the screen is displayed.
  • the display area 121 is uniformly irradiated with light controlled by the surface light source device 110.
  • the region represented by 0.8X ⁇ 0.8Y is defined as the display region 121 (see FIG. 2B).
  • the light distribution of the light emitted from the light emitting element 112 is controlled by the first light flux control member 114, the second light flux control member 115, and the third light flux control member 116.
  • the light emitted from the third light flux controlling member 116 is transmitted while being diffused by the diffusing member 140 and illuminates the display member 120 uniformly.
  • the light flux control member 113 includes the first light flux control member 114, the second light flux control member 115, and the third light flux control member 116.
  • FIG. 3 is a diagram illustrating a configuration of the first light flux controlling member 114.
  • 3A is a plan view of the first light flux controlling member 114
  • FIG. 3B is a bottom view
  • FIG. 3C is a side view
  • FIG. 3D is a sectional view taken along line AA shown in FIG. 3A. It is.
  • the first light flux controlling member 114 controls the light distribution of the light emitted from the light emitting element 112. As shown in FIGS. 3A to 3D, the first light flux controlling member 114 has a first incident surface 131 and a first emission surface 132. The first light flux controlling member 114 may be provided with a first flange 133. A first leg (not shown) for fixing the first light flux controlling member 114 to the substrate 111 may be provided on the back side of the first flange 133. The first light flux controlling member 114 is disposed to face the light emitting element 112.
  • the method for fixing the first light flux controlling member 114 to the substrate 111 is not particularly limited, and adhesive fixing, screwing, fixing with a holder, or the like may be employed. For example, the first light flux controlling member 114 and the substrate 111 can be fixed to each other by bonding the first leg to the substrate 111 with an adhesive.
  • the first incident surface 131 causes the light emitted from the light emitting element 112 to enter the first light flux controlling member 114 and refracts the incident light toward the first outgoing surface 132.
  • the first incident surface 131 is disposed so as to face the light emitting surface of the light emitting element 112 and intersect the first central axis CA1.
  • the shape of the 1st entrance plane 131 will not be specifically limited if the above-mentioned function can be exhibited.
  • the first incident surface 131 is the inner surface of the first recess 134 that is disposed to face the light emitting surface of the light emitting element 112.
  • the first incident surface 131 may be a spherical surface or an aspherical surface.
  • the first incident surface 131 has a negative power with respect to a part of the light emitted from the light emitting element 112. That is, the shape of the first incident surface 131 is a concave lens shape, and the first incident surface 131 is an aspherical surface.
  • the first emission surface 132 causes the light traveling inside the first light flux controlling member 114 to be emitted to the outside.
  • the first exit surface 132 is disposed on the opposite side of the first entrance surface 131 (on the second light flux controlling member 115 side).
  • the first emission surface 132 has an inner first emission surface 132a and an outer first emission surface 132b.
  • the inner first emission surface 132a is disposed so as to intersect with the first central axis CA1.
  • the shape of the inner first emission surface 132a is not particularly limited as long as light is emitted so as to be expanded with respect to the first central axis CA1. That is, the shape of the inner first exit surface 132a is formed in a concave shape when the light beam reaching the inner first exit surface 132a is further expanded with respect to the first central axis CA. In this case, the inner first emission surface 132a has a negative power with respect to the light reaching the inner first emission surface 132a.
  • it is formed into a shallow ridge.
  • the inner first emission surface 132a has a positive power with respect to the light reaching the inner first emission surface 132a.
  • the light emitted from the inner first emission surface 132a is controlled so as to be expanded with respect to the first central axis CA1.
  • the outer first emission surface 132b is disposed at a position away from the inner first emission surface 132a with respect to the first central axis CA1 so as to surround the inner first emission surface 132a.
  • the outer first exit surface 132b refracts (condenses) part of the light incident on the first incident surface 131 toward the first central axis CA1.
  • the outer first emission surface 132b has a positive power with respect to light emitted from the light emitting element 112 and having a large emission angle with respect to the first central axis CA1.
  • the shape of the outer first emission surface 132b is a convex lens shape, and the outer first emission surface 132b is an aspherical surface.
  • FIG. 4 is a diagram showing a configuration of the second light flux controlling member 115.
  • 4A is a plan view of the second light flux controlling member 115
  • FIG. 4B is a bottom view
  • FIG. 4C is a side view
  • FIG. 4D is a sectional view taken along line AA shown in FIG. 4A. It is.
  • the second light flux controlling member 115 controls the light emitted from the first light flux controlling member 114 to be substantially parallel light. As shown in FIGS. 4A to 4D, the second light flux controlling member 115 has a second incident surface 141 and a second emitting surface 142. The shape of the second light flux controlling member 115 is not particularly limited as long as the above function can be exhibited.
  • the second light flux controlling member 115 may have a convex lens surface on the second incident surface 141, and may have a convex lens surface on the second outgoing surface 142. From the viewpoint of miniaturization, the second light flux controlling member 115 may have a refractive Fresnel lens part or a reflective Fresnel lens part.
  • the second light flux controlling member 115 has a refractive Fresnel lens portion 145 on the second exit surface 142.
  • the second light flux controlling member 115 having the refractive Fresnel lens portion 145 can absorb an assembly error as compared with the second light flux controlling member 115 having the reflective Fresnel lens portion.
  • the second light flux controlling member 115 may be provided with a second flange 143. Further, on the back side of the second flange 143, a second leg (not shown) for fixing the second light flux controlling member 115 to the substrate 111 may be provided.
  • the method for fixing the second light flux controlling member 115 to the substrate 111 is not particularly limited, and adhesive fixing, screwing, fixing with a holder, or the like may be employed.
  • the second light flux controlling member 115 and the substrate 111 can be fixed to each other by bonding the second leg portion to the substrate 111 with an adhesive.
  • the second incident surface 141 causes the light emitted from the first light flux controlling member 114 to enter the second light flux controlling member 115 and refract it toward the Fresnel lens portion 145.
  • the shape of the 2nd entrance plane 141 will not be specifically limited if the above-mentioned function can be exhibited.
  • second incident surface 141 is a flat surface.
  • the second emission surface 142 emits the light traveling inside the second light flux controlling member 115 to the outside and refracts the light so as to be substantially parallel to the second central axis CA2.
  • the second exit surface 142 has a Fresnel lens portion 145.
  • the Fresnel lens portion 145 has a plurality of convex portions 146 arranged concentrically and having a circular shape in plan view.
  • Each of the plurality of convex portions 146 has a refracting surface 147 that refracts incident light and a connection surface 148 that connects adjacent refracting surfaces 147.
  • the refracting surface 147 is disposed on the outer side
  • the connecting surface 148 is disposed on the inner side (second central axis CA2 side).
  • the plurality of refracting surfaces 147 are arranged so that the first central axis CA1 (second central axis CA2) of the first light flux controlling member 114 (second light flux controlling member 115) and the optical axis OA coincide with each other. It is designed so that the light emitted from 112 becomes parallel light.
  • FIG. 5 is a diagram showing a configuration of the third light flux controlling member 116.
  • 5A is a plan view of the third light flux controlling member 116
  • FIG. 5B is a bottom view
  • FIG. 5C is a side view
  • FIG. 5D is a sectional view taken along line AA shown in FIG. 5A.
  • 6A and 6B are sectional views showing another third light flux controlling member 116.
  • FIG. 5A is a plan view of the third light flux controlling member 116
  • FIG. 5B is a bottom view
  • FIG. 5C is a side view
  • FIG. 5D is a sectional view taken along line AA shown in FIG. 5A.
  • 6A and 6B are sectional views showing another third light flux controlling member 116.
  • FIG. 5A is a plan view of the third light flux controlling member 116
  • FIG. 5B is a bottom view
  • FIG. 5C is a side view
  • FIG. 5D is a sectional view taken along line AA shown in
  • the third light flux controlling member 116 emits the light emitted from the second light flux controlling member 116 toward the diffusing member 140 while controlling so that luminance unevenness does not occur.
  • the third light flux controlling member 116 has a third entrance surface 151 and a third exit surface 152.
  • the third light flux controlling member 116 may have a third flange 154.
  • the third incident surface 151 allows the light emitted from the second light flux controlling member 115 to enter.
  • the shape of the third entrance surface 151 is a plane.
  • the third exit surface 152 is disposed on the opposite side of the third entrance surface 151 and emits the light traveling inside the third light flux controlling member 116 toward the diffusing member 140.
  • the third emission surface 152 includes a plurality of convex lens surfaces 153 or a plurality of concave lens surfaces having a convex cross-sectional shape including the third central axis CA3.
  • the “third central axis CA3” means a central portion of the third emission surface 152 when the third light flux controlling member 116 is viewed in plan.
  • a cross section including the third central axis CA3 means a cross section cut along a plane including the third central axis CA3 and a second direction described later. In the example shown in FIG.
  • the third light flux controlling member 116 has a convex lens surface 153 on the third exit surface 152, but is not limited thereto, and has a convex lens surface 153 on the third incident surface 151. Also good. Further, as shown in FIG. 6A, the third entrance surface 151 may have a concave lens surface 155, and as shown in FIG. 6B, the third exit surface 152 has a concave lens surface 155. Also good. In addition, when the convex lens surface 153 is arrange
  • the third light flux controlling member is highly accurate compared to the case where it is formed on one side, for example, adjustment is necessary to obtain it, or it is necessary to align the convex lens on one surface and the convex lens on the other surface. Difficulty in creating 116.
  • the convex lens surface 153 includes a ridge line extending linearly in a first direction perpendicular to the thickness direction of the third light flux controlling member 116, and in a second direction perpendicular to the thickness direction and the first direction. Only curved surface with curvature. That is, the convex lens surface 153 according to the present embodiment has a cylindrical structure. A plurality of convex lens surfaces 153 are arranged in the second direction without any gap.
  • the cross-sectional shape of the convex lens surface 153 including the third central axis CA3 may be an arc, a curve having a radius of curvature that increases with distance from the top, or a portion that intersects the third central axis CA3 is an arc. Thus, the curve may have a radius of curvature that increases with distance from the arc.
  • the thickness direction of the third light flux controlling member 116 is a direction along the third central axis CA3.
  • a third leg (not shown) for fixing the third light flux controlling member 116 to the substrate 111 may be provided.
  • a method for fixing the third light flux controlling member 116 to the substrate 111 is not particularly limited, and adhesive fixing, screwing, fixing with a holder, or the like may be employed.
  • the third light flux controlling member 116 and the substrate 111 can be fixed to each other by bonding the third leg portion to the substrate 111 with an adhesive.
  • the third light flux controlling member 116 may have a plurality of concave lens surfaces 155 on the third incident surface 151 or the third emitting surface 152.
  • the concave lens surface 155 includes a ridge line extending linearly in a first direction perpendicular to the thickness direction of the third light flux controlling member 116, and in a second direction perpendicular to the thickness direction and the first direction. Only curved surface with curvature. A plurality of concave lens surfaces 155 are arranged in the second direction without a gap.
  • the cross-sectional shape of the concave lens surface 155 including the third central axis CA3 may be an arc, a curve having a radius of curvature that increases with distance from the top, or a portion that intersects the third central axis CA3 is an arc.
  • the curve may have a radius of curvature that increases with distance from the arc.
  • the thickness direction of the third light flux controlling member 116 is a direction along the third central axis CA3.
  • FIG. 7 is a diagram showing an optical path of the display device 100. In FIG. 7, hatching is omitted to show the optical path.
  • the light emitted from each light emitting element 112 is controlled by the first light flux control member 114 so as to be mixed when it reaches the second light flux control member 115, and from the first emission surface 132. Emitted.
  • the light emitted from the first light flux control member 114 reaches the second light flux control member 115.
  • the light density of the light reaching the second light flux controlling member 115 is controlled to be low in the central part and high in the peripheral part.
  • the second incident surface 141 of the second light flux controlling member 115 has a low luminous intensity near the optical axis and a high luminous intensity at a large angle with respect to the optical axis.
  • the illuminance at the second light flux controlling member 115 is uniform from the vicinity of the optical axis to the peripheral portion.
  • the light reaching the second light flux controlling member 115 is controlled by the second light flux controlling member 115 so as to be substantially parallel light, and is emitted from the second light exit surface 142.
  • the light emitted from the second light flux control member 115 reaches the third light flux control member 116.
  • the light reaching the third light flux controlling member 116 is controlled by the third light flux controlling member 116 so that the luminance is uniform even when the display device 100 is viewed obliquely, and is emitted from the third light exit surface 152.
  • the light emitted from the third emission surface 152 illuminates the display member 120 so that the luminance is uniform even when the display device 100 is viewed obliquely.
  • the light emitted from the light emitting element 112 is controlled by the first light flux control member 114 and the second light flux control member 115 so as to be substantially parallel to the optical axis.
  • the light controlled by the first light flux control member 114 and the second light flux control member 115 is incident on the third light flux control member 116.
  • it is preferable that most of the light emitted from the first light flux controlling member 114 is incident on the second light flux controlling member 115. Therefore, the distance between the first light flux control member 114 and the second light flux control member 115 so that most of the light emitted from the first light flux control member 114 enters the second light flux control member 115. Is set.
  • the light emitting element 112 and the light flux controlling member 113 are arranged so as to satisfy the following expression (1). -0.6 ⁇ d / f ⁇ 0 (1)
  • d is a distance between the first central axis CA1 of the first light flux controlling member 114 and the optical axis OA in the light emitting element 112 farthest from the central axis CA1 of the first light flux controlling member 114 (hereinafter simply referred to as “distance”. d ”).
  • f is a focal length of the first light flux controlling member 114 (hereinafter also simply referred to as “focal length f”).
  • FIG. 8A is a diagram for explaining the focal length f of the first light flux controlling member 114
  • FIG. 8B is a diagram for explaining the relationship between the focal length f and the distance d.
  • 9A and 9B are diagrams for explaining the irradiation region S.
  • FIG. 9A is a diagram for explaining an irradiation region when the distance d is large
  • FIG. 9B is a diagram for explaining the irradiation region when the distance d is small.
  • the focal length f is defined as follows. As shown in FIG. 8A, for the focal length f of the first light flux controlling member 114, first, virtual incident light L1 parallel to the first central axis CA1 of the first light flux controlling member 114 is transmitted from the first incident surface 131 side. Assume that it is incident. Next, a virtual outgoing light L ⁇ b> 1 ′ from which the virtual incident light L ⁇ b> 1 is emitted from the first outgoing surface 132 is assumed.
  • the intersection point when the virtual incident light L1 extends in the incident direction and the virtual emitted light L1 'extends in the direction opposite to the emission direction is defined as a principal point A.
  • an intersection point between a virtual line obtained by further extending the virtual outgoing light L1 ′ emitted from the first outgoing surface 132 opposite to the outgoing direction and the first central axis CA1 of the first light flux controlling member 114 is defined as a focal point F.
  • the distance along the first central axis CA1 between the principal point A and the focal point F is the focal length f.
  • the focal length f is a negative value.
  • FIG. 8B here, three light emitting elements 112a, 112b, and 112c in which the distance between the centers of the optical axes is arranged in a line at a distance d and one first light flux controlling member 114 are arranged.
  • the optical axis OAb of the light emitting element 112b disposed at the center coincides with the first central axis CA1 of the first light flux controlling member 114. That is, the light emitting element 112 farthest from the first central axis CA1 of the first light flux controlling member 114 is the light emitting element 112a (light emitting element 112c).
  • the arrival points on the virtual irradiated surface Q (corresponding to the diffusing member 140 of the present embodiment) of the virtual emitted light emitted from each of the light emitting elements 112a, 112b, and 112c are defined as Pa, Pb, and Pc, respectively.
  • the irradiation areas S irradiated by the light emitting elements 112a, 112b, and 112c overlap each other.
  • the area becomes smaller (see FIG. 9A).
  • the distance d is shortened, the area where the irradiation regions S irradiated by the light emitting elements 112a, 112b, and 112c overlap each other increases (see FIG. 9B).
  • the distance d the area where the regions irradiated by the light emitting elements 112a, 112b, and 112c overlap can be adjusted.
  • the focal length f of the first light flux controlling member 114 when the focal length f of the first light flux controlling member 114 is shortened, the distance D between the reaching points in the virtual plane of the light beams emitted from the respective light emitting elements 112a, 112b, and 112c is lengthened.
  • the light emitted from the light emitting elements 112a, 112b, and 112c illuminates a predetermined area (irradiation area S) on the virtual plane, the irradiation areas S irradiated by the light emitting elements 112a, 112b, and 112c overlap each other. The area becomes smaller (see FIG. 9A).
  • the focal length f increases, the area where the irradiation regions S irradiated by the light emitting elements 112a, 112b, and 112c overlap each other increases (see FIG. 9B).
  • the focal length f the area where the regions irradiated by the light emitting elements 112a, 112b, and 112c overlap each other can be adjusted.
  • the distance d between the focal length f and the optical axis of the light emitting element 112 farthest from the first central axis CA1 of the first light flux controlling member 114 greatly affects the uniformity in the display member 120 described later. . More specifically, when d / f becomes ⁇ 0.6 or less due to an increase in d, the overlap between the irradiation regions S of the light emitted from the light emitting elements 112 is reduced. In particular, in the case of a rectangular screen, there is less overlap in the long (long side) direction than in the short (short side) direction, so that sufficient luminance cannot be secured at the end in the long direction. On the other hand, when attempting to make f brighter and brighten the periphery, the absolute value of d / f becomes even smaller, and the overlap between the irradiation areas S becomes smaller.
  • the positive power of the first light flux controlling member 114 becomes too strong, the light density at the center becomes higher than the light density at the periphery, and the brightness at the center increases. .
  • the light flux controlling member 113 and the diffusing member 140 are further arranged so as to satisfy the following expressions (2) and (3). 0 ⁇ w 2 /t ⁇ 0.85 (2) 0.4 ⁇ w / R ⁇ 1.4 (3)
  • w is the width of the convex lens surface 153 or the concave lens surface 155 in the cross section including the third central axis CA3.
  • R is the radius of curvature of the convex lens surface or concave lens surface 155.
  • t is the intersection of the center line of the convex lens surface 153 or the concave lens surface 155 and the surface of the third light flux controlling member 116 on the diffusion member 140 side (the top of the convex lens surface 153 or the bottom of the concave lens surface 155) and the diffusion member 140. Distance.
  • FIG. 10A is a diagram illustrating a relationship between the third light flux controlling member 116 and the diffusing member 140 according to the present embodiment
  • FIG. 10B is a relationship between the third light flux controlling member 116 and the diffusing member 140 according to the comparative example.
  • FIG. 10A and 10B the third light flux controlling member 116 and the diffusing member 140 are not hatched to show the optical path.
  • the third light flux controlling member 116 having the convex lens surface 153 on the third exit surface 152 will be described as an example, but the third light flux controlling member 116 having the convex lens surface 153 on the third incident surface 151. It is the same.
  • w 2 / t is greater than 0 and less than 0.85
  • w 2 / t has a smaller value because luminance unevenness when the display device 100 is viewed in plan is reduced.
  • w is smaller than the processing limit of the convex lens surface 153 or t is too large. Therefore, w 2 / t is more preferably 0.0001 or more.
  • FIG. 10B illustrates the case where w increases.
  • FIG. 11A is a diagram illustrating the relationship between the width w of the third light flux controlling member 116 according to the comparative example and the radius of curvature R of the convex lens surface 153
  • FIG. 11B illustrates the third light flux controlling member 116 according to the comparative example. It is a figure which shows the relationship between the width w and the curvature radius R of the convex lens surface 153.
  • FIG. 11A and 11B, the third light flux controlling member 116 and the diffusing member 140 are not hatched to show the optical path.
  • FIG. 11A illustrates a case where w is reduced.
  • w / R is more than 0.4 and less than 1.4, luminance unevenness does not occur and the amount of light required for the display device 100 can be secured.
  • the focal length f of the first light flux control member 114, the first central axis CA1 and the first light flux of the first light flux control member 114 satisfies ⁇ 0.6 ⁇ d / f ⁇ 0.
  • the distance t between the intersection of the control member 116 and the surface on the diffusion member 140 side and the diffusion member 140 satisfies 0 ⁇ w 2 /t ⁇ 0.85 and 0.4 ⁇ w / R ⁇ 1.4.
  • the display member 120 is used even when a plurality of light emitting elements 112 are used. Can be illuminated uniformly.
  • the second light flux controlling member 115 includes the refractive type Fresnel lens portion 145, when the display device 100 is assembled, it is possible to absorb an assembly error.
  • the display device 100 is configured to further satisfy the following formulas (4) to (6) in addition to the above-described formulas (1) to (3), thereby further preventing luminance unevenness.
  • FIG. 12 is a diagram for explaining the equations (4) and (5).
  • FIG. 13 is a diagram for explaining the equation (6).
  • hatching of the substrate 111, the light emitting element 112, and the first light flux controlling member 114 is omitted to show the optical path.
  • hatching of the substrate 111, the light emitting element 112, the first light flux control member 114, and the second light flux control member 115 is omitted to show the optical path.
  • the light emitting device 130 (display device 100) includes the first light beam L1 emitted from the light emission center of the light emitting element 112 arranged so that the optical axis OA coincides with the first central axis CA1.
  • the emission angle is ⁇ 1 n
  • the first light beam L1 is controlled by the first light beam control member 114, and then is emitted from the first light beam control member 114, and the second light beam L2 is generated with respect to the first central axis CA1.
  • the angle is ⁇ 2 n
  • the light emitting device 130 further satisfies the following expression (4).
  • n represents the number of an arbitrary ray in a cross section including the first central axis CA and the second central axis CA2.
  • Equation (4) 0 ° ⁇ 1 n ⁇ 1 n + 1 ⁇ 60 °, and ⁇ 2 n is the angle of the light beam corresponding to ⁇ 1 n .
  • the display device 100 is configured so that ⁇ 2 n increases as ⁇ 1 n increases. Thereby, since the second light beam L2 generated by being emitted from the first emission surface 132 of the first light flux controlling member 114 does not overlap, continuous light can be incident on the second light flux controlling member 115.
  • the display device 100 further satisfies the following formula (5).
  • the light emitting device 130 (display device 100), .theta.1 n with increasing configured so that the ratio of the amount of increase in .theta.2 n to increasing .theta.1 n decreases.
  • the first central axis CA1 side is the central portion and the first flange 133 side is the peripheral portion
  • the second light ray L2 emitted from the peripheral portion of the first emission surface 132 is incident on the first emission surface 132.
  • the light beam is emitted so as to have a denser light density than the second light beam L2 emitted from the central portion.
  • the light density in the central part where the light beam with high intensity reaches is sparse, and the light density in the peripheral part where the light beam with low intensity reaches is dense. Thereby, the illuminance on the second incident surface 141 of the second light flux controlling member 115 becomes uniform.
  • the case where the light emitting element 112 arranged so as to coincide with the first central axis CA1 is shown, but the case where the light emitting element arranged so as to coincide with the first central axis CA1 does not exist.
  • the optical axis OA is the total light beam optical axis that is the center of all three-dimensional total light beams of the plurality of light emitting elements 112 mounted on the same substrate 111 surface, and the light emitting surface of the light emitting element 112 mounted on the same substrate 111 surface Considering the intersection of the extension line and the optical axis OA as a virtual emission point, the emission angle of the first light ray L1 emitted from the virtual emission point as ⁇ 1 n, and satisfying equations (4) and (5) Thus, the first light flux controlling member 114 is designed.
  • the second light beam L ⁇ b> 2 is controlled by the second light flux control member 115 and then emitted from the second light exit surface 142 of the second light flux control member 115.
  • the angle of the third light beam L3 generated with respect to the first central axis CA1 is ⁇ 3, it is preferable to satisfy the following expression (6). -6 ° ⁇ 3 ⁇ 10 ° (6)
  • ⁇ 3 is an angle of the third light beam L3 emitted from the second light beam control member 115 with respect to the first central axis CA.
  • ⁇ 3 is a minus “ ⁇ ” angle of the third light ray L3 traveling toward the first central axis CA1 with the angle of the light L0 traveling parallel to the first central axis CA1 being 0 °, with respect to the first central axis CA1.
  • the angle of the third light ray L3 with respect to the first central axis CA1 traveling away from the first central axis CA1 is a plus “+” value.
  • the third light beam L3 generated by being emitted from the second light flux controlling member 115 is emitted so as to be substantially parallel to the first central axis CA1.
  • ⁇ 3 is 10 ° or more
  • the degree of divergence increases, and the third light ray L3 travels so as to be significantly away from the first central axis CA1.
  • the 1st central axis CA1 side center part
  • the degree of light collection increases, and the third light ray L3 travels toward the first central axis CA1.
  • a region (peripheral portion) away from the first central axis CA1 becomes dark.
  • the display device 100 further satisfies the above-described expressions (4) to (6), luminance unevenness is suppressed.
  • the display device 100 is configured to further satisfy the following formulas (7) to (8) in addition to the above-described formulas (1) to (3), thereby further preventing luminance unevenness.
  • bfl is a distance between a predetermined point of the third light flux controlling member 116 and the focal point of the optical surface of the third light flux controlling member 116, and the focal point is located closer to the diffusing member 140 than the predetermined point.
  • the case is set to a positive value, and the case located on the second light flux controlling member 115 side is set to a negative value.
  • bfl is a positive value
  • bfl is a negative value
  • bfl is the length of the intersection of the center line of the convex lens surface 153 and the surface of the third light flux controlling member 116 on the diffusing member 140 side and the focal point of the convex lens surface 153. It is (a positive value).
  • bfl is the intersection of the center line of the concave lens surface 155 and the surface of the third light flux controlling member 116 on the diffusing member 140 side, and the focal point of the concave lens surface 155. Is the length (negative value).
  • FIG. 14A is a diagram for explaining bfl when the convex lens surface 153 is disposed on the third exit surface 152
  • FIG. 14B illustrates bfl when the concave lens surface 155 is disposed on the third exit surface 152
  • FIG. 14C is a diagram for explaining bfl when the convex lens surface 153 is arranged on the third incident surface 151
  • FIG. 14D is a diagram illustrating the concave lens surface 155 on the third incident surface 151. It is a figure for demonstrating bfl when is arrange
  • bfl is a positive value.
  • P be the intersection of the center line of the convex lens surface 153 and the surface of the third light flux controlling member 116 on the diffusing member 140 side.
  • the intersection point P and the midpoint of the convex lens surface 153 are the same.
  • the length between the intersection P and the focal point F of the convex lens surface 153 is bfl.
  • bfl is a negative value.
  • P be the intersection of the center line of the concave lens surface 155 and the surface of the third light flux controlling member 116 on the diffusing member 140 side.
  • the intersection point P and the midpoint of the concave lens surface 155 are the same.
  • the length between the intersection P and the focal point F of the concave lens surface 155 is bfl.
  • bfl is a positive value.
  • P be the intersection of the center line of the convex lens surface 153 and the surface of the third light flux controlling member 116 on the diffusing member 140 side.
  • the intersection point P and the midpoint of the concave lens surface 155 are the same.
  • the length between the intersection P and the focal point F of the convex lens surface 153 is bfl.
  • Expression (7) defines the conditions when the diffusing member 140 is viewed from the front. On the diffusing member 140, the light emitted from the third light flux controlling member 116 overlaps with each other, so that uneven brightness can be suppressed.
  • 15A is a schematic diagram showing the influence of the top of the convex lens surface 153 and the distance t of the diffusing member 140 on the optical path
  • FIG. 15B is a schematic diagram showing the influence of bfl on the optical path
  • FIG. In (7) it is a schematic diagram which shows the influence of the width w of the convex lens surface 153.
  • the third light flux control member 116 and the diffusion member 140 are arranged so that (w ⁇ bfl) / t is greater than ⁇ 15 and less than 3, the third light flux control member is disposed on the diffusion member 140. Since the light emitted from 116 overlaps, luminance unevenness can be suppressed. When w or bfl becomes large or t becomes small, and (w ⁇ bfl) / t becomes 3 or more, the light emitted from the third light flux controlling member 116 does not overlap, resulting in luminance unevenness. There is a fear. On the other hand, from the viewpoint of processing limit, it is difficult to set (w ⁇ bfl) / t to ⁇ 15 or less.
  • the value of t is so preferable that it is large. However, if the value of t is too large, the size of the surface light source device becomes large, which is not preferable.
  • the light flux controlling member 116 and the diffusing member 140 are arranged so as to satisfy the above formula (7) from the viewpoint of preventing luminance unevenness when the diffusing member 140 is viewed from the front. It is preferred that
  • Formula (8) prescribes
  • the light emitted from the third light flux controlling member 116 is preferably emitted at a predetermined angle with respect to the optical axis of the convex lens surface 153.
  • FIG. 16A is a schematic diagram showing the influence of w on the optical path in relation to equation (8)
  • FIG. 16B is a schematic diagram showing the influence of bfl on the optical path in relation to equation (8).
  • the third light flux control member 116 and the diffusion member 140 are arranged so that
  • the third light flux controlling member 116 and the diffusing member 140 satisfy the above formula (8) from the viewpoint of preventing luminance unevenness when the diffusing member 140 is viewed obliquely. It is preferable to arrange
  • the display device according to the second embodiment is different from the display device 100 according to the first embodiment only in the configuration of the third light flux controlling member 216. Therefore, in the second embodiment, only the configuration of the third light flux controlling member 216 will be described.
  • FIG. 17 is a diagram illustrating a configuration of the third light flux controlling member 216.
  • 17A is a plan view of the third light flux controlling member 216
  • FIG. 17B is a bottom view
  • FIG. 17C is a side view
  • FIG. 17D is a sectional view taken along line AA shown in FIG. 17A. It is.
  • the third light flux controlling member 216 has a third incident surface 151 and a third outgoing surface 252.
  • the third exit surface 252 includes a plurality of convex lens surfaces 253.
  • the plurality of convex lens surfaces 253 are arranged along a first direction and a second direction perpendicular to the first direction.
  • the convex lens surface 253 has a square shape in plan view, and both have the same size.
  • the convex lens surface 253 has a curvature in any cross section including the central axis CA of the convex lens surface 253.
  • the cross-sectional shape including the central axis CA of the convex lens surface 253 may be an arc, a curve having a radius of curvature that increases with distance from the top, or an arc that intersects the central axis CA. It may be a curve in which the radius of curvature increases with distance from.
  • the display device according to the second embodiment has the same effects as those of the display device 100 according to the first embodiment, and both the first direction and the second direction in which the convex lens surfaces 253 are arranged.
  • the viewing angle can be widened.
  • the third light flux controlling member 216 may have a third emission surface 252 including a plurality of concave lens surfaces. Also in this case, the plurality of concave lens surfaces are arranged in the first direction and the second direction. Further, the third light flux controlling member 216 may have a third incident surface 251 including a plurality of convex lens surfaces 253 or a plurality of concave lens surfaces.
  • FIG. 18 is a diagram illustrating a configuration of a display device 100 ′ according to a modification.
  • 18A is a plan view of the display device 100 ′
  • FIG. 18B is a cross-sectional view taken along line AA shown in FIG. 18A.
  • the display device 100 ′ includes a substrate 111 ′, a plurality of light emitting devices 130, a diffusion member 140 ′, (a surface light source device 110 ′), and a display member 120 ′.
  • a plurality of light emitting devices 130 are arranged on one substrate 111 ′.
  • six light emitting devices 130 are arranged in a matrix on one substrate 111 ′.
  • the diffusing member 140 ′ and the display member 120 ′ are formed, for example, in the same size as the substrate 111 ′ so that the light emitted from the six light emitting devices 130 reaches.
  • the surface light source device and the display device can be enlarged.
  • the display device 100 having one light emitting device 130, diffusion member 140 ′, and display member 120 ′ is arranged in the plane direction.
  • a plurality of the display devices may be arranged to enlarge the display device.
  • Example 1 In Example 1, in the display device 100 according to Embodiment 1, the width w of the cross section including the third central axis CA3 of the convex lens surface 153, the center line of the convex lens surface 153, and the diffusion member 140 in the third light flux controlling member 116. The relationship between the intersection with the side surface, the distance t from the diffusing member 140, the radius of curvature R of the convex lens surface 153, and the uniformity U0, U5 / U0 was examined.
  • FIG. 19 is a schematic diagram illustrating a configuration of the display device 100 used in the example.
  • the display device 100 includes a surface light source device 110 and a display member 120.
  • the surface light source device 110 includes a light emitting element 112 and a light flux controlling member 113.
  • the light flux control member 113 includes a first light flux control member 114, a second light flux control member 115, and a third light flux control member 116.
  • a 10 mm
  • b 3 mm
  • c 1 mm
  • d 3 mm
  • e 25 mm
  • f 5 mm
  • g 3 mm
  • h 55.5 mm
  • i 16.2 mm.
  • the focal length f of the first light flux controlling member is 1 mm
  • the distance d between the first central axis and the optical axis of the light emitting element farthest from the first central axis is ⁇ 28.14 mm. . That is, d / f in the example is ⁇ 0.036.
  • the uniformity in the display area of each display device was obtained by simulation.
  • the uniformity in the display area 121 was calculated by the following formula (9).
  • Uniformity minimum brightness / maximum brightness (9)
  • Minimum luminance is the minimum luminance value in the display area
  • maximum luminance is the maximum luminance value in the display area.
  • Table 1 shows the parameters for 36 types of display devices that simulate the uniformity.
  • w is the width of the convex lens surface in the cross section including the third central axis
  • t is the intersection of the center line of the convex lens surface and the surface on the diffusing member side of the third light flux controlling member, and the diffusing member.
  • R is the radius of curvature of the convex lens surface
  • n is the refractive index
  • U0 is the uniformity when the display area is viewed from the front
  • U5 is inclined by 5 °. It is the degree of uniformity when viewed from the position.
  • the display device No. 1 to 36 satisfy the above formula (1).
  • FIG. 20 shows the relationship between “(the width w of the convex lens surface in the cross section including the third central axis) 2 / distance t between the top of the convex lens surface and the diffusing member 140” and the uniformity U0 in each display device.
  • FIG. 20 is a graph in which the results summarized in Table 1 are plotted.
  • the horizontal axis in FIG. 20 indicates “(the width w of the cross section including the third central axis CA3 of the convex lens surface 153) 2 / the distance t between the top of the convex lens surface 153 and the diffusing member 140”.
  • the uniformity U0 when the display device is viewed in plan (when viewed from the optical axis LA) is shown.
  • w / R is more than 0.4 and 1.4. It turns out that there is a need for less than.
  • the width w of the cross section including the third central axis of the convex lens surface and the curvature radius R of the convex lens surface are 0.4 ⁇ w / R ⁇ 1.4. It was found that the display area can be illuminated uniformly with small luminance unevenness if the above condition is satisfied. Although no particular results are shown, similar results were obtained with a display device having a third light flux controlling member including a concave lens surface.
  • the display device 100 having the third light flux controlling member 116 on which the plurality of concave lens surfaces 155 are arranged was examined.
  • the width w of the section including the third central axis of the concave lens surface, the distance t between the bottom of the concave lens surface and the diffusing member, the center line of the concave lens surface, and the third light flux control was examined.
  • the configuration of the display device is the same as that of the first embodiment.
  • Tables 2 to 5 show the parameters for 101 types of display devices that simulate the uniformity.
  • w is the width of the convex lens surface or concave lens surface in the cross section including the third central axis
  • bfl is the center line of the convex lens surface or concave lens surface and the surface on the diffusion member side in the third light flux controlling member.
  • t is the distance between the top of the convex lens surface or the bottom of the concave lens surface and the diffusion member
  • U0 is the distance when the display area is viewed from the front.
  • U5 is the degree of uniformity when the display area is viewed from a position tilted by 5 °.
  • Tables 2 and 3 show parameters in a display device in which a convex lens surface or a concave lens surface is arranged on the third entrance surface
  • Tables 4 and 5 show displays in which a convex lens surface or a concave lens surface is arranged on the third exit surface. The parameters in the device are shown.
  • a display device with a positive bfl value is a display device in which a convex lens surface is arranged on the third entrance surface
  • a display device with a negative bfl value has a concave lens surface on the third entrance surface. It is the arranged display device.
  • a display device having a positive bfl value is a display device in which a convex lens surface is disposed on the third exit surface, and a display device having a negative bfl value is a concave lens on the third exit surface.
  • FIG. 22A and 22B are graphs in which the results summarized in Tables 2 and 3 are plotted
  • FIGS. 23A and 23B are graphs in which the results summarized in Tables 4 and 5 are plotted.
  • FIG. 22A is a graph showing the relationship between (w ⁇ bfl) / t and the degree of uniformity U0 when a plurality of convex lens surfaces or a plurality of concave lens surfaces are arranged on the third incident surface side
  • FIG. It is a graph which shows the relationship between
  • FIG. 22A is a graph showing the relationship between (w ⁇ bfl) / t and the degree of uniformity U0 when a plurality of convex lens surfaces or a plurality of concave lens surfaces are arranged on the third incident surface side
  • FIG. 23A is a graph showing the relationship between (w ⁇ bfl) / t and the degree of uniformity U0 when a plurality of convex lens surfaces or a plurality of concave lens surfaces are arranged on the third exit surface side
  • FIG. It is a graph which shows the relationship between
  • the horizontal axis of FIGS. 22A and 23A indicates (w ⁇ bfl) / t, and the vertical axis indicates the degree of uniformity U0.
  • the horizontal axis of FIG. 22B and FIG. 23B has shown
  • the uniformity ratio U5 / U0 which is an index when the diffusing member is viewed from an oblique direction, is 0.64, which does not satisfy the standard required for use in HUD.
  • the uniformity U0 which is an index when the diffusing member is viewed from the front, is 0.84, which satisfies the standard required for use in HUD.
  • the display device No. 85 the uniformity ratio U5 / U0, which is an index when the diffusing member is viewed obliquely, is 0.76, but the uniformity U0, which is an index when the diffusing member is viewed from the front, is 0.47. It was.
  • the uniformity ratio U5 / U0 which is an index when the diffusing member is viewed from an oblique direction, is 0.76, which satisfies the standard required when used for HUD.
  • the uniformity U0 which is an index when the diffusing member is viewed from the front, is 0.47, which does not satisfy the standard required when used for HUD.
  • the display device No. In 136 and 137 neither the uniformity ratio U5 / U0, which is an index when the diffusion member is viewed from an oblique direction, nor the uniformity U0, which is an index when the diffusion member is viewed from the front, was satisfied.
  • the length bfl of the intersection of the center line of the convex lens surface or the concave lens surface and the surface on the diffusion member side of the third light flux controlling member and the focal point of the convex lens surface or the concave lens surface is ⁇ 15 ⁇ (w Xbfl) / t ⁇ 3 and the width w of the cross section including the third central axis of the convex lens surface or the concave lens surface, the center line of the convex lens surface or the concave lens surface, and the surface on the diffusion member side of the third light flux controlling member
  • a plurality of convex lens surfaces or a plurality of concave lens surfaces may be formed on both surfaces of the third entrance surface and the third exit surface.
  • the third entrance surface and the third exit surface When the lens power by both surfaces is positive, bfl is a positive value, and when the lens power is negative, bfl is a negative value, and the conditions required for the third light flux controlling member of the present invention (formulas (7) and (7)) It is formed so as to satisfy 8)).
  • the surface light source device according to the present invention is useful as a light source for a head-up display (HUD), for example.
  • the display device according to the present invention is useful as, for example, a head-up display (HUD).

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  • Liquid Crystal (AREA)

Abstract

Selon la présente invention, un dispositif de source de lumière plane comprend : une pluralité d'éléments électroluminescents ; un élément de commande de flux lumineux comprenant un premier élément de commande de flux lumineux qui est une lentille de diffusion, un deuxième élément de commande de flux lumineux ayant une structure de Fresnel, et un troisième élément de commande de flux lumineux ayant une pluralité de surfaces de lentille; et un élément de diffusion. Lorsque la distance focale du premier élément de commande de flux lumineux est f, et la distance entre un premier axe central et un axe optique de l'élément électroluminescent séparé le plus éloigné du premier axe central est d, le dispositif de source de lumière plane satisfait à - 0,6 < d/f < 0. De plus, lorsque la largeur de la section transversale comprenant l'axe central de la surface de lentille est w, le rayon de courbure de la surface de lentille est R, et la distance entre l'élément de diffusion et le point d'intersection de la ligne centrale de la surface de lentille et la surface sur le côté de l'élément de diffusion du troisième élément de commande de flux lumineux est t, le dispositif de source de lumière plane satisfait à 0 < w2/t < 0,85 et 0,4 < w/R < 1,4.
PCT/JP2017/029372 2016-12-15 2017-08-15 Dispositif de source de lumière plane et dispositif d'affichage WO2018109978A1 (fr)

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US16/469,759 US10747055B2 (en) 2016-12-15 2017-08-15 Planar light source device and display device

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JP2016-243414 2016-12-15
JP2016243414 2016-12-15
JP2017048871A JP2018098162A (ja) 2016-12-15 2017-03-14 面光源装置および表示装置
JP2017-048871 2017-03-14

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7447162B2 (ja) 2021-04-07 2024-03-11 矢崎総業株式会社 車両用表示装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS64209U (fr) * 1987-06-19 1989-01-05
JP2007157686A (ja) * 2005-11-11 2007-06-21 Hitachi Displays Ltd 照明装置及びそれを用いた液晶表示装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS64209U (fr) * 1987-06-19 1989-01-05
JP2007157686A (ja) * 2005-11-11 2007-06-21 Hitachi Displays Ltd 照明装置及びそれを用いた液晶表示装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7447162B2 (ja) 2021-04-07 2024-03-11 矢崎総業株式会社 車両用表示装置

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