JP2013041716A - Light-emitting device, surface light source device, display device, and luminous flux control member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that can accurately position a luminous flux control member against a light-emitting element mounted on a board and hardly generating erroneous assembling between the luminous flux control member and the board.SOLUTION: When an amount of an axis gap (λ) between the center axis of the luminous flux control member 2 and an optical axis of the light-emitting element becomes (ε<λ≤δ) when dropping the luminous flux control member 2 on the board 3, an inclined surface part 8b of a first leg 8 slidably comes in contact with an open edge 11a of a positioning hole 11 of the board 3, and slidably drops with its own weight until a second leg 10 is seated on a fixed surface 13 of the board 3. When the second leg 10 is seated on the fixed surface 13, the amount of the axis gap (λ) between the center axis of the luminous flux control member 2 and the optical axis of the light-emitting element becomes (λ=ε). Thus, the luminous flux control member 2 can be assembled without generating assembling errors on the board 3 where the light-emitting element 4 is mounted, and the center axis of the luminous flux control member 2 and the optical axis of the light-emitting element can be aligned within a desired accuracy (a range of 0 to ε).

Description

The present invention relates to a light emitting device that emits light from a light emitting element such as an LED through a light flux controlling member,
A surface light source device that enables planar illumination using the light emitting device, a display device that illuminates an illuminated member (for example, a liquid crystal display panel) from the back side using the surface light source device, and these light emitting devices, The present invention relates to a light flux controlling member constituting a surface light source device and a display device.

Conventionally, a light emitting device that emits light from a light emitting element (for example, LED) mounted on a substrate via a lens (light flux controlling member) is known. In such a light emitting device, it is necessary to accurately position the lens with respect to the light emitting element in order to achieve a desired light emitting performance.

As a technique for accurately positioning a lens with respect to a light emitting element mounted on a substrate, a technique for inserting a positioning pin protruding from the substrate side into a positioning hole formed on the lens side is known (see Patent Document 1).

JP 2007-59489 A (refer to the description of paragraph number 0028 and FIG. 2 in particular)

However, when performing assembly work while aligning the lens to the substrate on which the light emitting element is mounted, the positioning that extends from the substrate side to the lens positioning hole due to variations in the conveyance accuracy of the handling part of the machine that holds the lens There is a possibility that the pin cannot be inserted, resulting in a lens assembly failure.

Therefore, according to the present invention, the lens (light flux controlling member) can be accurately positioned with respect to the light emitting element mounted on the substrate, and assembly failure occurs when the lens (light flux controlling member) is assembled to the substrate by a machine. Provide no technology.

As shown in FIG. 1, the invention of claim 1 includes a substrate 3 on which a light emitting element 4 is mounted, and the substrate 3.
And a light flux controlling member 2 that emits light by controlling the traveling direction of light from the light emitting element 4. In the present invention, the light flux controlling member 2
The back surface 5 facing the substrate 3 is engaged with a plurality of positioning holes 11 formed in the substrate 3 so that the central axis L1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 are connected. A plurality of first leg portions 8 and 21 to be aligned and a second leg portion 10 that is seated on the fixed surface 13 on the substrate 3 and positions the back surface 5 with respect to the substrate 3 are formed. (See FIG. 1, FIG. 2, FIG. 7, FIG. 9, FIG. 10, and FIG. 11). In addition, on the distal end side of the first leg portions 8 and 21, the misalignment amount (λ) between the central axis L 1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 is within a predetermined range (ε ≦ λ ≦). δ
), Inclined surface portions 8b and 21b in contact with the opening edge 11a of the positioning hole 11 are formed (see FIGS. 3, 4 and 9). Further, when the light flux controlling member 2 is dropped on the substrate 3, the amount of misalignment (λ) between the central axis L1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 is (ε < In the case of λ ≦ δ), the inclined surface portions 8b and 21b are connected to the positioning hole 1
1 slidably contacted with the opening edge 11 a, dropped while sliding by its own weight until the second leg 10 was seated on the fixed surface 13, and the second leg 10 was seated on the fixed surface 13. At the time, the misalignment amount (λ) between the central axis L1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 is set to (λ = ε) (FIGS. 3, 4, and 4). 9).

The invention of claim 2 is characterized in that the light flux controlling member 2 of the light emitting device 1 according to the invention of claim 1. That is, in the present invention, as shown in FIG. 1, the light flux controlling member 2 is located in the central portion on the back surface 5 side, and is formed with a concave portion 6 formed by a curved surface 6 a that functions as an incident surface, and the back surface 5. A part of the light from the light emitting element 4 which is located on the opposite side and enters the light flux control member 2 from the concave portion 6 is Fresnel-reflected toward the back surface 5 side, and the light flux control member is reflected from the concave portion 6. And a light control emitting surface 7 for emitting light other than Fresnel reflected light out of the light emitting element 4 incident on the inside of the light emitting element 4 to the outside of the light flux controlling member 2. The first leg portions 8 and 21 and the second leg portion 10 are formed in a region where the amount of light that has been Fresnel-reflected by the light control exit surface 7 and reaches the back surface 5 is 20% or less of the peak value. (See FIG. 5, FIG. 6, FIG. 2, FIG. 7, FIG. 10, and FIG. 11).

The invention of claim 3 is a light emitting device 1 according to the invention of claim 1 or 2 as shown in FIG.
A surface light source device 23 that emits light emitted from the light as planar illumination light via the light control member 22
It is about.

As shown in FIG. 12, the invention of claim 4 relates to a display device 25 that illuminates an object 24 with planar illumination light emitted from the surface light source device 23 of claim 3.

The invention of claim 5 is assembled to the substrate 3 on which the light emitting element 4 is mounted, and the light emitting element 4
This relates to a light flux controlling member 2 that emits light while controlling the traveling direction of light from the light beam. In the light flux controlling member 2 according to the present invention, the back surface 5 facing the substrate 3 is engaged with a plurality of positioning holes 11 formed in the substrate 5, and the central axis L1 of the light flux controlling member 2 and the Light-emitting element 4
A plurality of first legs 8 and 21 for aligning with the optical axis L, and a second leg that is seated on the fixed surface 13 on the substrate 3 and positions the back surface 5 with respect to the substrate 3. Part 10 is formed. In addition, on the distal end side of the first leg portions 8 and 21, the misalignment amount (λ) between the central axis L 1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 is within a predetermined range (ε ≦ λ ≦). In the case of δ), inclined surface portions 8b and 21b that are in contact with the opening edge 11a of the positioning hole 11 are formed. And
When being dropped onto the substrate 3, the central axis L 1 of the light flux controlling member 2 and the light emitting element 4
When the amount of misalignment (λ) with respect to the optical axis L is (ε <λ ≦ δ), the inclined surface portions 8b and 21b slidably contact the opening edge 11a of the positioning hole 11, and the first When the two legs 10 fall while sliding by their own weight until they are seated on the fixed surface 13, and when the second legs 10 are seated on the fixed surface 13, the central axis L1 of the light flux controlling member 2 and the light emission The amount of misalignment (λ) with respect to the optical axis L of the element 4 is set to (λ = ε).

The invention of claim 6 has the following characteristics with respect to the light flux controlling member 2 according to the invention of claim 5. That is, the light flux controlling member 2 according to the present invention is located in the central portion on the back surface 5 side,
A concave portion 6 formed with a curved surface functioning as an incident surface and a part of light from the light emitting element 4 incident on the opposite side of the rear surface 5 and incident from the concave portion 6 toward the rear surface 5 are reflected by Fresnel. The light control emission surface 7 for emitting light other than Fresnel reflected light out of the light emitting element 4 incident on the light flux control member 2 from the recess 6 to the outside of the light flux control member 2. And have. The first leg portions 8 and 21 and the second leg portion 10 are regions in which the amount of light that has been Fresnel-reflected by the light control exit surface 7 and reaches the back surface 5 is 20% or less of the peak value. It is characterized by being formed.

According to the present invention, when the light flux controlling member is dropped on the substrate, the amount of misalignment (λ) between the central axis of the light flux controlling member and the optical axis of the light emitting element is (ε <λ ≦ δ). The inclined surface portion of the first leg slidably contacts the opening edge of the positioning hole of the substrate, and the second leg falls while sliding by its own weight until it is seated on the fixed surface of the substrate. At the time of sitting on the fixed surface, the misalignment amount (λ) between the central axis of the light flux controlling member and the optical axis of the light emitting element becomes (λ = ε). Therefore, according to the present invention, the light flux controlling member can be assembled to the substrate on which the light emitting element is mounted without causing a defective assembly, and the center axis of the light flux controlling member and the optical axis of the light emitting element are set to a desired accuracy ( In the range of 0 to ε).

It is a figure which shows the light-emitting device which concerns on embodiment of this invention. 1A is a plan view of the light emitting device, FIG. 1B is a cross-sectional view of the light emitting device cut along the line A1-A1 in FIG. 1A, and FIG. It is a principal part enlarged view of 1 (b). It is a figure which shows the bundle control member which concerns on embodiment of this invention. 2A is a plan view of the light beam control member, FIG. 2B is a front view of the light beam control member, and FIG. 2C is a light beam cut along the line A2-A2 of FIG. 2A. FIG. 2D is a cross-sectional view of the control member, and FIG. It is a figure which shows typically the 1st operation state which assembles | attaches a light beam control member to a board | substrate. It is a figure which shows typically the 2nd working state which assembles | attaches a light beam control member to a board | substrate. It is a figure which shows typically the optical path figure of the light from the light emitting element which injected into the inside of the light beam control member. It is a figure which shows the light quantity of the light which Fresnel-reflected by the light-control output surface of the light beam control member, and reached | attained the back surface. It is a figure which shows the modification of the arrangement position of a 1st leg part and a 2nd leg part, and is a back view of a light beam control member. It is a figure which shows the modifications 1-4 of a 1st leg part. It is a figure which shows the modification 5 of a 1st leg part, FIG. 9 (a) is a figure corresponding to FIG.1 (c), FIG.9 (b) cut | disconnected along the A3-A3 line | wire of FIG. It is an engagement state figure of the 1st leg part and positioning hole shown. It is a figure which shows the light beam control member in which the 1st leg part which concerns on the modification 5 shown in FIG. 9 was formed. It is a figure which shows the modification of the light beam control member shown in FIG. It is a longitudinal cross-sectional view which shows the surface light source device provided with the light-emitting device based on this invention, and the display apparatus provided with this surface light source device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Light emitting device and light flux controlling member)
FIG. 1 is a diagram showing a light emitting device 1 according to the first embodiment of the present invention. Moreover, FIG. 2 is a figure which shows the light beam control member 2 which comprises the light-emitting device 1 which concerns on 1st Embodiment of this invention. 1A is a plan view of the light emitting device 1. FIG. Further, FIG. 1B shows A1-A1 in FIG.
It is sectional drawing of the light-emitting device 1 cut | disconnected and shown along a line. FIG. 2A is a plan view of the light flux controlling member 2. FIG. 2B is a front view of the light flux controlling member 2. In addition, FIG.
FIG. 2C is a cross-sectional view of the light flux controlling member 2 shown cut along the line A2-A2 in FIG. FIG. 2D is a rear view of the light flux controlling member 2.

The light emitting device 1 includes a light emitting element (for example, LED) 4 mounted on a substrate 3 and the light emitting element 4.
A light flux controlling member 2 that transmits light from the light beam. Here, the light beam control member 2 is configured such that the central axis L1 of the light beam control member 2 is centered with respect to the optical axis L, where the optical axis L is the direction in which the center light of the three-dimensional outgoing light beam from the light emitting element 4 travels. It can be assembled on the substrate 3 in a combined state. The specific configuration of the alignment between the center axis L1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 and the specific configuration for fixing the light flux controlling member 2 on the substrate 3 will be described in detail later.

The light flux controlling member 2 is formed of a resin material such as PMMA (polymethyl methacrylate), PC (polycarbonate), EP (epoxy resin) or the like having light transmittance, or glass having light transmittance.

The light flux controlling member 2 has a substantially circular shape in plan view, and has a back surface 5 disposed so as to face the substrate 3, a recess 6 located in the center of the back surface 5 side, and the opposite side of the back surface 5. And a plurality of first leg portions 8 and second leg portions 10 formed on the back surface 5.

The back surface 5 of the light flux controlling member 2 is a plane orthogonal to the central axis L1 of the light flux controlling member 2, and is formed so that the normal direction of the back surface 5 is parallel to the central axis L1 of the light flux controlling member 2. It is a plane. The back surface 5 has a hollow disk-shaped portion 5a formed so that the shape viewed from the normal direction surrounds the recess 6, and extends outward in the radial direction from the outer peripheral end of the hollow disk-shaped portion 5a. It is formed with a pair of semicircular projecting portions 5b, 5b. The pair of overhang portions 5b, 5b are formed so as to be point symmetric about the central axis L1.

A pair of first leg portions 8 are formed on the back surface 5 so as to straddle the protruding portion 5b and the hollow disk-shaped portion 5a. The pair of first leg portions 8 and 8 are formed at point-symmetrical positions about the central axis L1 of the light flux controlling member 2 and are parallel to the central axis L1 of the light flux controlling member 2 from the back surface 5 (−Z axis). Projecting along the direction). The first leg portion 8 has a columnar portion 8a on the base end side,
It is formed with a conical inclined surface portion 8b on the tip side. The first leg portion 8 has the inclined surface portion 8b engaged with the positioning hole 11 of the substrate 3 so that the central axis L1 of the light flux controlling member 2 is the optical axis L of the light emitting element 4 mounted on the substrate 3. (The center axis L1 of the light flux controlling member 2 is positioned with respect to the optical axis L of the light emitting element 4 on the XY plane). This first
The cylindrical portion 8 a of the leg 8 has a diameter equal to the diameter of the positioning hole 11.

Moreover, the 2nd leg part 10 is each formed in the position near the recessed part 6 of the back surface 5, and the position which divides the virtual circle 12 centering on the central axis L1 into the circumferential direction. The second leg portion 10 has a cylindrical shape, and the tip end surface 10 a is seated on the fixing surface 13 (the surface of the adhesive 14) on the substrate 3 and is bonded and fixed to the substrate 3. In addition to positioning in the normal direction of the substrate 3 (the direction along the optical axis L of the light emitting element 4), the light flux controlling member 2 is positioned with respect to the light emitting element 4 along the optical axis L.
Position in the direction (Z-axis direction).

The concave portion 6 of the light flux controlling member 2 is a concave opening on the back surface 5 side, and is formed with a smooth curved surface (aspherical surface or hemispherical surface) centered on the central axis L1. The curved surface 6 a that forms the concave portion 6 of the light flux controlling member 2 functions as an incident surface on which light from the light emitting element 4 enters the light flux controlling member 2.

The light control exit surface 7 of the light flux controlling member 2 has a circular shape in plan view, and is formed to have a slightly smaller diameter than the outer dimension of the hollow disk-shaped portion 5a of the back surface 5, and its outer periphery The end is connected to the back surface 5 via the flange 15. The light control emission surface 7 includes a first emission surface portion 7a located at the center and a second emission surface portion 7b located so as to surround the first emission surface portion 7a.
And a third emission surface portion 7c that is located so as to surround the second emission surface portion 7b and connects the second emission surface portion 7b and the flange portion 15 to each other. The light control emission surface 7 controls and emits light so that the light from the light emitting element 4 incident on the inside of the light flux controlling member 2 from the recess 6 spreads around the optical axis L and is emitted. Here, the light emitted from the light control exit surface 7 is light other than Fresnel reflected light out of the light reaching the light control exit surface 7.

The first exit surface portion 7a of the light control exit surface 7 is a smooth curved surface convex downward (toward the −Z axis direction), and is a curved surface that forms a dent that is a part of a sphere cut out. It is a curved surface formed around the central axis L1 of the control member 2. The second emission surface portion 7b of the light control emission surface 7 is a smooth curved surface that is smoothly connected to the first emission surface portion 7a (toward the + Z-axis direction), and the shape in plan view is the first emission surface. It is a hollow disk-shaped curved surface surrounding the surface portion 7a. The third exit surface portion 7c of the light flux controlling member 7 is a smooth curved surface that is smoothly connected to the second exit surface portion 7b (toward the + Z-axis direction), and the shape in plan view is the second exit surface portion. 7b is a hollow disk-shaped curved surface surrounding 7b.

(Assembly work of the light flux controlling member to the substrate)
3 to 4 are diagrams schematically showing a working state in which the light flux controlling member 2 is assembled to the substrate 3. In these drawings, the light flux controlling member 2 is transported to an assembly position on the substrate 3 by a handling unit of a machine (not shown), and then is transferred from the handling unit of the machine (not shown) to the substrate 3.
It can be dropped on top. 3 shows that the light flux controlling member 2 is moved from the handling portion of the machine (not shown) to the substrate 3 when the center P1 of the first leg portion 8 of the light flux controlling member 2 is deviated by δ in the −X direction from the drop reference position P0. It shows the state of falling down. Further, FIG. 4 shows that the light flux controlling member 2 is moved from the handling portion of the machine (not shown) onto the substrate 3 in a state where the center P1 of the first leg portion 8 of the light flux controlling member 2 is deviated by δ from the drop reference position P0 in the + X direction. Shows the state of falling. Here, δ is the maximum value of the drop position error of the light flux controlling member 2 due to the conveyance accuracy in the handling part of the machine (not shown), and the actual drop position of the first leg 8 and the drop of the first leg 8 This is the maximum amount of deviation from the reference position P0. Also, the drop reference position P0
Is the center position of the positioning hole 11 of the substrate 3.

As shown in these drawings, when the light flux controlling member 2 is shifted by δ with respect to the drop reference position P0 and dropped onto the substrate 3, the inclined surface portion 8b of the first leg portion 8 is on the surface side of the positioning hole 11 ( It contacts the upper opening edge 11a (see FIGS. 3A to 3B and FIGS. 4A to 4B). At this time, there is a gap between the front end surface 10a of the second leg portion 10 of the light flux controlling member 2 and the fixed surface 13 on the substrate 3 (see FIGS. 3B and 4B).

Thereafter, the light flux controlling member 2 guides the inclined surface portion 8b of the first leg portion 8 with the opening edge 11a of the positioning hole 11 until the second leg portion 10 is seated (contacted) on the fixed surface 13 on the substrate 3. It falls while sliding by its own weight. Then, the light flux controlling member 2 has the center P1 of the first leg 8 and the center of the positioning hole 11 (dropping reference position P0) in a state where the tip surface 10a of the second leg 10 is seated on the fixed surface 13 on the substrate 3. ) And the second leg portion 10 is bonded and fixed to the fixing surface 13 on the substrate 3 so that the maximum value of the misalignment amount with respect to) becomes ε (FIG. 3C).
(Refer FIG.4 (c)).

That is, the light flux controlling member 2 has a misalignment amount (λ between the central axis L1 and the optical axis L of the light emitting element 4).
) Is (ε ≦ λ ≦ δ), the inclined surface portion 8b of the first leg portion 8 is opened to the opening edge 11a of the positioning hole 11 of the substrate 3 when dropped from the handling portion of the machine (not shown) onto the substrate 3. (Refer to FIG. 1B, FIGS. 3A to 3C, and FIGS. 4A to 4C).
Further, the light flux controlling member 2 has a misalignment amount (λ) between the center axis L1 and the optical axis L of the light emitting element 4 (
In the case of ε <λ ≦ δ), the inclined surface portion 8b of the first leg portion 8 can slide on the opening edge 11a of the positioning hole 11 of the substrate 3 when it is dropped onto the substrate 3 from the handling portion of the machine (not shown). Until the second leg portion 10 is slid by its own weight until the second leg portion 10 is seated on the fixed surface 13, and the center of the light flux controlling member 2 is reached when the tip surface 10 a of the second leg portion 10 is seated on the fixed surface 13. The amount of misalignment (λ) between the axis L1 and the optical axis L1 of the light emitting element 4 is set to (λ = ε) (see FIGS. 1B, 3C, and 4C). ). Further, the light flux controlling member 2 is formed on the substrate 3 from the handling portion of the machine (not shown) when the misalignment amount (λ) between the central axis L1 and the optical axis L of the light emitting element 4 is (0 ≦ λ <ε). When it is dropped to the inclined surface portion 8 of the first leg 8
b does not contact the opening edge 11a of the positioning hole 11 of the substrate 3, but the misalignment amount (λ) between the center axis L1 and the optical axis L1 of the light emitting element 4 is in the range of (0 ≦ λ <ε). Is assembled to the substrate 3 (see FIGS. 1B to 1C, FIG. 3C, and FIG. 4C).

As a result, the light flux controlling member 2 reduces the misalignment amount between the central axis L1 and the optical axis L of the light emitting element 4 to 0.
It becomes possible to suppress to the range of ~ ε. In the present embodiment, the light flux controlling member 2 is
When the outer diameter of the hollow disk-shaped portion 5a of the back surface 5 is 16 mm, ε is formed to be 0.1 mm.

The above description relates to the case where the light flux controlling member 2 is dropped onto the substrate 3 from the handling portion of the machine (not shown), but the light flux controlling member 2 is replaced by replacing the handling portion of the machine (not shown) with the hand of the operator. Can also be applied to the case of dropping onto the substrate 3 from the operator's hand.

(Determination of the shape of the first leg and positioning hole)
In the state where the second leg portion 10 of the light flux controlling member 2 is seated on the fixed surface 13, the positioning hole 11
When the cross section of the first leg portion 8 is taken by a virtual plane (extension surface of the upper surface of the substrate 3) passing through the opening edge 11a, the cross-sectional diameter is d1, and the positioning hole 11 is d2 (FIG. 3 (c) ) And FIG. 4 (c)). Then, the first leg portion 8 is formed so as to satisfy d1> 2δ (for example, d1 = 2 (Δ + α)). Α is an arbitrary value in consideration of the convenience in forming the light flux controlling member 2.

In the present embodiment, the diameter of the first leg portion 8 and the hole diameter of the positioning hole 11 of the substrate 3 are formed to be the same size, but not limited to this, the first leg portion 8 and the positioning hole 11 are , 0 ≦ d2−
It may be formed so as to satisfy d1 ≦ 2ε.

Further, as shown in FIGS. 3C and 4C, the back surface 5 of the light beam control member 2 and the second leg portion 10 of the light beam control member 2 are seated on the fixed surface 13 on the substrate 3. Surface 3a of substrate 3
, H1 is the inclination angle of the inclined surface portion 8b of the first leg 8, and h1 is the protruding height of the first leg 8 from the back surface 5. The first leg portion 8 is formed so that cot θ + h0.

When the light flux controlling member 2 having the first leg portion 8 having such a shape is dropped from a handling portion of a machine (not shown), the center P1 of the first leg portion 8 is at most δ with respect to the drop reference position P0. The center of the light flux controlling member 2 with respect to the optical axis L of the light emitting element 4 so that the amount of deviation between the central axis L1 and the optical axis L of the light emitting element 4 falls within the range of ε even if the light falls. The axis L1 is centered.

As described above, in the light emitting device 1 of the present embodiment, when the light flux controlling member 2 is assembled to the substrate 3, the deviation (deviation amount (ε) between the central axis L 1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4. ))
Is allowed. Thereby, the deviation amount (λ) between the center axis L1 of the light beam control member 2 and the optical axis L of the light emitting element 4 when the light beam control member 2 is dropped on the substrate 3 is within the range of (0 to δ). If so, the second leg portion 10 is surely seated on the fixing surface 13, and the light flux controlling member 2 is securely bonded and fixed to the substrate 3.

In the present embodiment, the diameter of the base portion of the first leg portion 8 (the base portion to the back surface 5 of the light flux controlling member 2) is also formed with the dimension d1 in the same manner as the cross-sectional diameter in the above-described seating state. However, the present invention is not limited to this, and the diameter of the root portion may be formed to be larger than the cross-sectional diameter.

(Formation position of the first leg and the second leg)
The formation positions of the first leg portion 8 and the second leg portion 10 are shown in FIG. 5 and FIG. 6, and the amount of light reaching the back surface 5 after being Fresnel-reflected by the light control exit surface 7 of the light flux controlling member 2. Decide in consideration. FIG. 5 is a diagram schematically showing an optical path diagram of the light H from the light emitting element 4 that has entered the light flux controlling member 2. FIG. 6 is a diagram showing the amount of light that has been Fresnel-reflected by the light control emission surface 7 of the light flux controlling member 2 and has reached the back surface 5. Here, in FIG. 5, the lens radius is a dimension measured along the radial direction from the central axis L1 of the light flux controlling member 2 (the optical axis L of the light emitting element 4). In FIG. 6, the lens radius corresponds to the lens radius in FIG. 5, and the amount of energy reached is a ratio (non-dimensional value) when the peak value of the amount of light reaching the back surface 5 of the light flux controlling member 2 is 100. Is shown. 5 and 6, the lens radius 8
The position of mm corresponds to the radially outer end of the hollow disk-shaped portion 5a on the back surface 5 of the light flux controlling member 2.

As shown in FIG. 5, a part of the light H1 that has entered the curved surface (incident surface) 6a that forms the concave portion 6 of the light flux controlling member 2 and has reached the light control emitting surface 7 is Fresnel-reflected and back surface. Light H2 other than Fresnel-reflected light H1 out of the light H that reaches 5 and reaches the light control exit surface 7 is controlled and emitted from the light control exit surface 7 toward the outside of the light flux controlling member 2.

As shown in FIG. 6, the amount of light reaching the back surface 5 after being Fresnel-reflected by the light control exit surface 7 is predetermined along the radial direction from the central axis L1 (position of the lens radius 0 mm) of the light beam control member 2. A peak value occurs at a distance (about 5.8 mm). Then, the reached energy at the position (the lens radius is about 5 mm) moved about 0.8 mm radially inward from the peak position of the light amount (position where the lens radius is about 5.8 mm) is the peak value. 20%. In addition, the reached energy gradually decreases from the position where the lens radius is about 5 mm toward the inside in the radial direction. Further, the reached energy at a position moved about 0.4 mm radially outward from the peak position of the light amount (position where the lens radius is about 5.8 mm) is:
20% of the peak value. In addition, the reached energy gradually decreases from the position where the lens radius is approximately 6.2 mm toward the outside in the radial direction.

Therefore, the first leg portion 8 and the second leg portion 10 are formed in a region in the back surface 5 of the light flux controlling member 2 where the value of the reached energy is 20% or less of the peak position, thereby positioning holes 11 and The amount of light absorbed by the adhesive 14 can be reduced, and the ratio at which the light from the light emitting element 4 can be used as illumination light increases.

Therefore, in the present embodiment, the first leg portion 8 includes the hollow disk-shaped portion 5a and the overhanging portion 5b of the back surface 5 so that the center P1 is 8 mm from the central axis L1 of the light flux controlling member 2. It is formed across. Further, the second leg portion 10 is formed at a position near the concave portion 6 on the back surface 5 so that the center P2 thereof is located at a position 4.5 mm from the central axis L1 of the light flux controlling member 2 (
(Refer FIG.2 (d)). In addition, when the usage mode of the light flux controlling member 2 does not have to be a problem of light loss due to the first leg portion 8 and the second leg portion 10, the first leg portion 8 and the second leg portion 10 are optional on the back surface 5. You may form in the position.

(Effect of this embodiment)
As described above, according to the present embodiment, when the light flux controlling member 2 is dropped onto the substrate 3 from a handling portion of a machine (not shown), the central axis L1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 are used. When the center misalignment amount (λ) is (ε <λ ≦ δ), the inclined surface portion 8b of the first leg portion 8 is
Slidably contacts the opening edge 11a of the positioning hole 11 and falls while sliding by its own weight until the second leg 10 is seated on the fixing surface 13 of the substrate 3, and the second leg 10 is fixed to the fixing surface 13.
The amount of misalignment (λ) between the central axis L1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 becomes (λ = ε). Therefore, according to this embodiment, there is no assembly failure between the substrate 3 on which the light emitting element 4 is mounted and the light flux controlling member 2, and the center axis L 1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 are Can be aligned within a desired accuracy (range of 0 to ε).

Further, according to the present embodiment, the first leg 8 and the second leg formed on the back surface 5 of the light flux controlling member 2.
The leg portion 10 is subjected to Fresnel reflection on the light control exit surface 7 of the light flux controlling member 2 and then the light flux controlling member 2.
The amount of light reaching the back surface 5 is arranged in a region where it is 20% or less with respect to the peak value. Therefore, the light flux controlling member 2 according to the present embodiment and the light emitting element 1 having the light flux controlling member 2 can suppress light loss in the first leg portion 8 and the second leg portion 10, and use efficiency of light from the light emitting element 4. Can be increased.

(Modification example of arrangement position of first leg and second leg)
FIG. 7 is a view showing a modification of the arrangement positions of the first leg portion 8 and the second leg portion 10, and is a rear view of the light flux controlling member 2.

The light flux controlling member 2 shown in FIG. 7A is the second leg 1 of the light flux controlling member 2 shown in FIG.
0 is shifted in the radial direction so as to be positioned on the same circle 16 as the first leg 8. The light flux controlling member 2 shown in FIG. 7A has a pair of first leg portions 8 and three second leg portions 10 arranged so as to be line symmetric with respect to the center line 17 as an axis of symmetry. A pair of first
The leg portions 8 are located on the center line 18, and the three second leg portions 10 are located at equal intervals along the circumferential direction of the circle 16.

In the light flux controlling member 2 shown in FIG. 7B, the pair of first leg portions 8 and the three second leg portions 10 are located on the same circle 16.
In the light flux controlling member 2 shown in FIG. 7C, the pair of first leg portions 8 and the three second leg portions 10 are located on the same circle 16, but the first leg portion 8 and the second leg portion. The parts 10 are located at unequal intervals. However, the second leg portion 10 is positioned so as to be line symmetric with respect to the center line 18 as an axis of symmetry. Also,
The pair of first legs 8 are positioned so as to sandwich the second leg 10 positioned on the center line 18 and are positioned so as to be line symmetric with respect to the center line 18 as an axis of symmetry.

(Modifications 1 to 4 of the first leg)
FIG. 8A is a diagram illustrating a first modification of the first leg portion 8, and corresponds to FIG. In the first leg portion 8 according to the first modification, the tip of the truncated cone-shaped inclined surface portion 8b is a flat surface 8c having a radius α, and the flat surface 8c is ejected when the light flux controlling member 2 is injection molded. It can be pressed with a pin (not shown).

FIG. 8B is a diagram illustrating a second modification of the first leg portion 8, and corresponds to FIG. In the first leg portion 8 according to the second modification, a cylindrical projection 8d having a radius α projects along the central axis 20 at the tip of the truncated cone-shaped inclined surface portion 8b. At the time of molding, the tip surface of the protrusion 8d can be pressed with an eject pin (not shown).

FIG.8 (c) is a figure which shows the modification 3 of the 1st leg part 8, and is a figure corresponding to FIG.1 (c). The first leg portion 8 according to the modified example 3 is a tapered surface in which the inclined surface portion 8b is formed with a smooth curved surface, and the tip of the inclined surface portion 8b is a flat surface 8c having a radius α. Member 2
At the time of injection molding, the flat surface 8c can be pressed by an eject pin (not shown).

FIG. 8D is a diagram illustrating a fourth modification of the first leg portion 8 and corresponds to FIG. In the first leg portion 8 according to the modification example 4, the inclination angle at the position of the inclined surface portion 8b near the cylindrical portion 8a is larger than the inclination angle of the inclined surface portion 8b in the first leg portion 8 of the modification example 3. ing. And the front end of the inclined surface portion 8b of the first leg portion 8 according to the modified example 4 is a flat surface 8 having a radius α.
c, and when the light flux controlling member 2 is injection-molded, the flat surface 8c is formed with an eject pin (
(Not shown) can be pressed.

Here, the cross-sectional diameter d1 of the first leg portion 8 in FIGS. 8A to 8D is 2 (α + β). However, β is set to a value larger than δ (β> δ).

The light flux controlling member 2 having the first leg portion 8 according to the first to fourth modifications as described above and the light emitting device 1 including the same can obtain the same effects as those of the above embodiment.

(Modification 5 of the first leg)
Based on FIG. 9, the 1st leg part 21 which concerns on this modification is demonstrated. FIG. 9A is a diagram showing a state in which the light flux controlling member 2 is assembled on the substrate 3. The center P2 of the first leg 21 and the center P0 of the positioning hole 11 are not shifted from each other. FIG. 3 is a view showing a state in which a leg portion 21 is engaged with a positioning hole 11. FIG. 9B is an engagement state diagram of the first leg 21 and the positioning hole 11 cut along the line A3-A3 of FIG. 9A. FIG. 9 (a) is the same as FIG.
FIG. 1C is a diagram corresponding to FIG. 1C, and the same reference numerals are given to the components corresponding to FIG.
The description overlapping with the description of) is omitted.

As shown in FIG. 9A, the first leg portion 21 according to the present modification has an isosceles trapezoidal shape on the front side, and the dimension in the width direction (the direction along the X axis) is a light flux controlling member. 2 gradually decreases from the base end located on the back surface 5 side toward the front end, and is integrally formed on the back surface 5 of the light flux controlling member 2.

As shown in FIG. 9B, the first leg portion 21 is a plate-like body having a plate thickness t, and has a distal end surface 21a.
And the pair of inclined surface portions 21b and 21b are formed in an isosceles trapezoidal shape, and the positioning hole 11
The gap between the opening edge 11a and the inclined surface portion 21b along the X-axis direction is ε.

Further, the first leg portion 21 extends along the X-axis direction of the inclined surface portion 21b located in the positioning hole 11 in a state where the second leg portion 10 of the light flux controlling member 2 is seated on the fixed surface 13 on the substrate 3. If the length is β, β is set larger than δ.

When the light flux controlling member 2 having such a first leg 21 is dropped on the substrate 3,
The misalignment amount (λ) between the central axis L1 of the light flux controlling member 2 and the optical axis L1 of the light emitting element 4 is (ε <λ ≦ δ).
), The inclined surface portion 21b slidably contacts the opening edge 11a of the positioning hole 11, falls while sliding by its own weight until the second leg portion 10 is seated on the fixed surface 13, and the second
When the leg 10 is seated on the fixed surface 13, the misalignment amount (λ) between the central axis L1 of the light flux controlling member 2 and the optical axis L of the light emitting element 4 becomes (λ = ε) (FIG. 1, FIG. 1). 3, see FIG. 4 and FIG.

FIG. 10 is a diagram showing the light flux controlling member 2 in which the first leg portion 21 according to this modification is formed.
In addition, the same code | symbol is attached | subjected to the component corresponding to the component of the light beam control member 2 shown in FIG.
The description overlapping with the description of the light flux controlling member 2 shown in FIG. 2 is omitted.

As shown in FIG. 10, a plurality of second leg portions 10 are arranged at equal intervals on the same circle on the back surface 5 of the light flux controlling member 2 as in FIG. c)). 1st leg 2
1 is arranged at one place for positioning in the X-axis direction and two places are arranged for positioning in the Y-axis direction.

The first leg portion 21 for positioning in the X-axis direction is formed at a position near the radially outer end of the back surface 5 with the center P2 positioned on the center line 17 along the Y-axis. And this 1st leg part 21 is
The width direction is formed to be a direction along the X-axis direction.

The first leg 21 for positioning in the Y-axis direction is formed at a position near the radially outer end of the back surface 5 with the center P2 positioned on the center line 18 along the X-axis. And this 1st leg part 21 is
The width direction is formed to be a direction along the Y-axis direction. Further, the pair of first leg portions 21 are formed so as to be line symmetric with respect to the center line 17 as an axis of symmetry.

The three first leg portions 21 are formed on the back surface 5 of the light flux controlling member 2 so that the distances from the central axis L1 to the center P2 of the light flux controlling member 2 are equal.

As shown in FIG. 11, only one first leg 21 for positioning in the Y-axis direction may be provided.

10 and 11, the first leg portion 21 and the second leg portion 10 are such that the amount of light that has been Fresnel-reflected by the light control exit surface 7 and has reached the back surface 5 is 20% or less of the peak value. It is formed in the area.

(Surface light source device and display device)
FIG. 12 shows a surface light source device 23 including the light emitting device 1 according to the present embodiment and a display device 25 including the surface light source device 23.

As shown in FIG. 12, the surface light source device 23 emits planar illumination light from the light emitting device 1 via a light control member 22 such as a diffuser plate.

The display device 25 is configured to illuminate the irradiated object 24 such as a liquid crystal display panel with planar illumination light emitted from the surface light source device 23.

In addition to the case where the surface light source device 23 and the display device 25 are configured by a single light emitting device 1,
You may make it comprise with the several light-emitting device 1. FIG.

Further, the first leg portions 8 and 21 and the second leg portion 10 are regions in which the amount of light that has been Fresnel-reflected by the light control exit surface 7 and reaches the back surface 5 is 20% or less of the peak value. It is characterized by being formed.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device, 2 ... Light flux control member, 3 ... Board | substrate, 4 ... Light emitting element, 5 ... Back surface, 6
...... Recess, 6a ...... curved surface (incident surface), 7 ... light control exit surface, 8, 21 ... first leg, 8b
, 21b... Inclined surface portion, 10... Second leg portion, 11... Positioning hole, 11a.
22: Light control member, 23: Surface light source device, 24: Object to be illuminated, 25: Display device, L:
... optical axis, L1 ... center axis

Claims (6)

A substrate on which a light emitting element is mounted;
A light flux controlling member that is assembled to the substrate and emits light by controlling the traveling direction of light from the light emitting element;
In a light emitting device having
-On the back surface of the light flux controlling member facing the substrate,
A plurality of first legs that engage with a plurality of positioning holes formed in the substrate and align the center axis of the light flux controlling member and the optical axis of the light emitting element;
A second surface that sits on a fixed surface on the substrate and positions the back surface with respect to the substrate.
Legs are formed,
-On the tip side of the first leg,
The amount of misalignment (λ) between the center axis of the light flux controlling member and the optical axis of the light emitting element is within a predetermined range (ε ≦
In the case of λ ≦ δ), an inclined surface portion in contact with the opening edge of the positioning hole is formed,
When the light flux controlling member is dropped on the substrate, the amount of misalignment (λ) between the central axis of the light flux controlling member and the optical axis of the light emitting element is (ε <λ ≦ δ). The inclined surface portion slidably contacts the opening edge of the positioning hole and falls while sliding by its own weight until the second leg portion is seated on the fixed surface, and the second leg portion is fixed to the fixed surface. The amount of misalignment (λ) between the central axis of the light flux controlling member and the optical axis of the light emitting element is (λ
= Ε),
A light emitting device characterized by that. The light flux controlling member is
A recess formed in a curved surface located at the center of the back surface and functioning as an incident surface;
A part of the light from the light emitting element, which is located on the opposite side of the back surface and enters the light flux control member from the recess, is Fresnel-reflected toward the back surface side, and from the recess to the inside of the light flux control member. A light-control exit surface that emits light other than Fresnel-reflected light out of the light from the light-emitting element incident on the light-emitting element, to the outside of the light flux control member,
The first leg and the second leg are formed in a region where the amount of light that has been Fresnel-reflected on the light control exit surface and reaches the back surface is 20% or less of the peak value,
The light-emitting device according to claim 1. The light emitted from the light emitting device according to claim 1 or 2 is emitted as planar illumination light via a light control member.
A surface light source device. Illuminating an object to be illuminated with planar illumination light emitted from the surface light source device according to claim 3,
A display device characterized by that. In a light beam control member that is assembled to a substrate on which a light emitting element is mounted and that emits light by controlling the traveling direction of light from the light emitting element,
-On the back surface facing the substrate,
A plurality of first legs that engage with a plurality of positioning holes formed in the substrate and align the center axis of the light flux controlling member and the optical axis of the light emitting element;
A second surface that sits on a fixed surface on the substrate and positions the back surface with respect to the substrate.
Legs are formed,
-On the tip side of the first leg,
The amount of misalignment (λ) between the center axis of the light flux controlling member and the optical axis of the light emitting element is within a predetermined range (ε ≦
In the case of λ ≦ δ), an inclined surface portion in contact with the opening edge of the positioning hole is formed,
When the center surface of the light flux controlling member and the optical axis of the light emitting element (λ) are (ε <λ ≦ δ) when being dropped on the substrate, the inclined surface portion is When slidably contacting the opening edge of the positioning hole, the second leg falls while sliding by its own weight until it is seated on the fixed surface, and when the second leg is seated on the fixed surface, The amount of misalignment (λ) between the central axis of the light flux controlling member and the optical axis of the light emitting element is (λ = ε).
A light flux controlling member characterized by the above. A recess formed in a curved surface located at the center of the back surface and functioning as an incident surface;
From the light emitting element that is located on the opposite side of the back surface, reflects a part of the light from the light emitting element that has entered from the concave portion toward the back side, and that has entered the light flux controlling member from the concave portion. A light control exit surface that emits light other than Fresnel reflected light to the outside of the light flux controlling member.
The first leg and the second leg are formed in a region in which the amount of light that has been Fresnel-reflected on the light control exit surface and reaches the back surface is 20% or less of the peak value,
The light emitting device according to claim 5.

Images