JP7197375B2 - lighting equipment - Google Patents

Description

The present invention relates to lighting devices.

2. Description of the Related Art A light emitting device having a light emitting element such as an LED is used as a lighting device such as a channel letter type signboard or as a light source for a signboard.

FIG. 1 is a perspective view showing the illumination device of Patent Document 1 used as a channel letter type signboard. As shown in FIG. 1, the illumination device 10 includes a letter-shaped housing 11, a plurality of light emitting devices 12 (LEDs and light diverters in Patent Document 1) arranged in a line inside the housing, and housing 11. It has a light diffusing plate 13 (a diffuser in Patent Document 1), prism sheets 14 and 15, and an external protective cover 16 arranged so as to close the opening. The light emitting device 12 has a light emitting element (LED in Patent Document 1) and a light flux controlling member 17 (light diverter in Patent Document 1). Light flux controlling member 17 isotropically diffuses light emitted from a light emitting element (not shown) in all directions.

By the way, in such a channel letter type signboard, it is desired to reduce the number of light emitting elements to be arranged from the viewpoint of low power consumption. That is, even if the number of light-emitting elements to be arranged is reduced, it is desired that the light reaches the entire illumination device to some extent evenly. Therefore, unlike Patent Document 1, light emitted from a light emitting element is diffused isotropically in all directions (a light emitting device having isotropic light distribution characteristics). A light emitting device that diffuses directionally (a light emitting device with anisotropic light distribution characteristics), specifically, by reflecting in two directions that are horizontally opposite to each other, the light distribution characteristics are anisotropic (exhibiting elliptical light distribution).

As a light emitting device having an anisotropic light distribution characteristic, for example, Patent Document 2 discloses a light emitting element 21 and a reflecting cup 22a for reflecting upward the light emitted from the light emitting element 21, as shown in FIG. and a light flux controlling member 23 (translucent resin in Patent Document 2) that seals the light emitting element 21 and the reflecting cup 22a. Light flux controlling member 23 has two reflecting surfaces 23a for reflecting light emitted from light emitting element 21 and light reflected by reflecting cup 22a, and two emitting surfaces for emitting the light reflected by reflecting surface 23a to the outside. 23b (the side surface in Patent Document 2).

In such a light emitting device, the light emitted from the upper surface of the light emitting element 21 directly reaches the reflecting surface 23a of the light flux controlling member 23, and the light emitted from the side surface of the light emitting element 21 is reflected by the reflecting cup 22a. After that, it reaches two reflecting surfaces 23 a of light flux controlling member 23 . These lights reaching the two reflecting surfaces 23a of the light flux controlling member 23 travel in opposite directions in the horizontal direction and are emitted from the two emitting surfaces 23b of the light flux controlling member 23 to the outside.

Japanese Patent Publication No. 2003-505835 JP-A-9-18058

By the way, channel letter type signboards have various shapes depending on the type of letters. Of these, for example, in a channel letter type signboard having a bent portion, such as alphabetical letters E and L, depending on how the light emitting device is arranged, the inner corners of the bent portion (the two inner peripheral side surfaces that constitute the bent portion) A shadow may be generated in the vicinity of the corner (for example, the area surrounded by the dotted line in FIG. 1).

Specifically, when high-intensity light among the light emitted from the light-emitting device hits the inner corner of the bent portion, the region where the light that hits the corner travels becomes excessively bright, and the other region becomes bright. It tends to be too dark. As a result, shadows (brightness unevenness) may occur in the vicinity of the corners forming the bends of the channel letter type signboard (hereinafter referred to as "illumination device"). Such luminance unevenness tends to occur remarkably particularly when the number of arranged light emitting elements is reduced.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an illumination device that suppresses luminance unevenness that occurs in the vicinity of the inner corner of a bent portion.

The present invention relates to the lighting device described below.

A lighting device of the present invention includes a bottom surface, a first side surface arranged along a first direction along the bottom surface, a second side surface arranged to face the first side surface with the bottom surface interposed therebetween, a third side surface connected to the first side surface and arranged along a second direction intersecting the first direction within the bottom surface; a housing having a fourth side surface, an opening arranged to face the bottom surface; a light-emitting element arranged on the bottom surface; and light distribution of light emitted from the light-emitting element. a plurality of light emitting devices each having a light flux controlling member for controlling; At least one of the light emitting devices is arranged between the first side surface and the second side surface, and the light emitting device arranged between the first side surface and the second side surface has the first The intensity of the light emitted in a direction substantially parallel to the direction and the direction opposite to the direction is higher than the intensity of the light emitted in the other direction crossing those directions, and the first side face and the first side face All of the one or more light emitting devices arranged between the two sides are arranged so as to satisfy the following formula (1) or (2).
Formula (1): L≧H/tan (90°-α)
Formula (2): L ≤ (W / 2) * tan (90 ° - θ)
(In formulas (1) and (2),
L is the position (mm) from the intersection of the first side surface and the third side surface of the light emission center of the light emitting element in the first direction;
H is the height (mm) from the bottom surface to the light diffusion plate between the first side surface and the second side surface;
W is the distance (mm) between the first side and the second side;
α is the angle (°) of the light with the maximum intensity among the lights emitted from the light flux controlling member with respect to the optical axis of the light emitting element;
θ is the angle with respect to the first direction of light having an intensity half the sum of the maximum intensity and the minimum intensity among the lights forming an angle α with respect to the optical axis of the light emitting element when viewed in plan. (°), and α and θ are more than 0° and less than 90°)

Advantageous Effects of Invention According to the present invention, it is possible to provide an illumination device that suppresses luminance unevenness that occurs near the inner corner of a bent portion.

FIG. 1 is a perspective view showing the configuration of the illumination device disclosed in Patent Document 1. FIG. FIG. 2 is a diagram showing the configuration of the light emitting device disclosed in Patent Document 2. As shown in FIG. 3A and 3B are diagrams showing the configuration of the lighting device according to the present embodiment. FIG. 4 is a plan view of the lighting device with the light diffusion plate removed. 5A to 5C are diagrams showing the configuration around the light emitting device shown in FIG. 6A to 6D are diagrams showing the configuration of the light flux controlling member according to this embodiment. FIG. 7 is a diagram showing the light distribution of the light emitting device. 8A and 8B are explanatory diagrams for explaining the arrangement position of the light emitting device represented by the formula (1). 9A and 9B are explanatory diagrams for explaining the arrangement position of the light emitting device represented by the formula (2). 10A and 10B are explanatory diagrams showing possible regions for arranging light emitting devices that satisfy the formula (1) or (2). FIG. 11 is an explanatory diagram showing the action of the lighting device according to the present invention and the lighting device for comparison. FIG. 12 is an explanatory diagram showing a modification of the bent portion of the housing. FIG. 13 is a schematic diagram showing a modification of the light flux controlling member. FIG. 14 is a partially enlarged perspective view showing a modified example of the lighting device.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Structure of lighting device)
3A and 3B and FIG. 4 are diagrams showing the configuration of lighting device 100 according to the present embodiment. FIG. 3A is a plan view of lighting device 100, and FIG. 3B is a front view. FIG. 4 is a plan view of illumination device 100 according to the present embodiment with light diffusion plate 150 removed. 5A to 5C are diagrams showing the configuration around the light emitting device 130 shown in FIG. 5A is a perspective view around the light emitting device 130 shown in FIG. 4, FIG. 5B is a plan view of FIG. 5A, and FIG. 5C is a cross-sectional view taken along line 5C-5C of FIG. 5B. The illumination device 100 shown in the figure is used, for example, as a channel character signboard.

As shown in FIGS. 3A, B and 4, lighting device 100 has housing 110, multiple substrates 120 (not shown), multiple light emitting devices 130, cable 140 and light diffusion plate 150. FIG.

The housing 110 is a box-shaped body with at least a portion of one surface open for accommodating the plurality of substrates 120 and the plurality of light emitting devices 130 therein. In the present embodiment, housing 110 includes a bottom plate, a top plate arranged to face the bottom plate, and a plurality of side plates connecting the bottom plate and the top plate.

The shape of the housing 110 in plan view may be any shape as long as it has a bent portion as described later. In this embodiment, the shape of the housing 100 in a plan view is an E shape.

Such a housing 110 has a bottom surface 111, a first side surface 112, a second side surface 113, a third side surface 114 and a fourth side surface 115 (see FIG. 4).

The bottom surface 111 is the surface of the bottom plate, on which a plurality of light emitting devices 130 are arranged.

The first side surface 112 is arranged along the first direction A (see FIG. 4) along the bottom surface 111 .

The second side surface 113 is arranged to face the first side surface 112 with the bottom surface 111 interposed therebetween.

The first side surface 112 and the second side surface 113 need only extend along the first direction A to some extent, and are preferably substantially parallel to the first direction A. That the first side surface 112 and the second side surface 113 are substantially parallel to the first direction A specifically means that the first side surface 112 or the second side surface 113 and the first direction A form It means that the smaller of the angles is preferably 20° or less, more preferably 10° or less, and still more preferably 3° or less.

The angle between the first side surface 112 and the first direction A and the angle between the second side surface 113 and the first direction A may be the same or different. In the present embodiment, the angle formed between the first side surface 112 and the first direction A and the angle formed between the second side surface 113 and the first direction A are the same, and both are 0°.

The third side surface 114 is connected to the first side surface 112 and arranged along the second direction B (see FIG. 4) intersecting the first direction A within the bottom surface 111 . As a result, the third side surface 114 and the first side surface 112 form an inner peripheral side surface of the bent portion of the housing 110 and form a corner.

Of the angles formed by the third side surface 114 and the first side surface 112, the smaller angle φ (see FIG. 4) is not particularly limited, and is more than 0° and less than 180°, preferably more than 0° and 90° or less. and more preferably more than 0° and less than 90°.

Also, the corner formed by the third side surface 114 and the first side surface 112 may be chamfered (or rounded) as necessary. However, it is assumed that R (curvature radius) of the chamfered corner is sufficiently smaller than the size of L described later.

When the corner formed by the third side surface 114 and the first side surface 112 is chamfered, the smaller angle φ among the angles formed by the third side surface 114 and the first side surface 112 is Sometimes, it refers to the smaller angle between the tangent line at the connecting portion between the chamfered portion and the first side surface 112 and the tangent line at the connecting portion between the chamfered portion and the third side surface 114 .

The fourth side surface 115 is arranged to face the third side surface 114 with the bottom surface 111 interposed therebetween. The fourth side surface 115 may or may not be connected to the second side surface 113 . In this embodiment, the fourth side surface 115 is connected to the second side surface 113 and constitutes the outer peripheral side surface of the bent portion of the housing 110 .

The third side surface 114 and the fourth side surface 115 need only extend along the second direction B to some extent, and are preferably substantially parallel to the second direction B. As shown in FIG. That the third side surface 114 and the fourth side surface 115 are substantially parallel to the second direction B specifically means that the third side surface 114 or the fourth side surface 115 and the second direction B form It means that the smaller of the angles is preferably 20° or less, more preferably 10° or less, and still more preferably 3° or less.

The housing 110 may have one or more corners formed by the first side surface 112 and the third side surface 114 . In this embodiment, housing 110 has four corners.

The top plate is arranged so as to face the bottom plate. In this embodiment, the top plate is arranged parallel to the bottom surface 111 . An opening serving as a light emitting region is formed in the top plate. This opening is closed by the light diffusion plate 150 .

The height (space thickness) from the bottom surface 111 to the light diffusing plate 150 is not particularly limited, but is about 20 to 100 mm. The housing 110 is made of, for example, resin such as polymethyl methacrylate (PMMA) or polycarbonate (PC), or metal such as stainless steel or aluminum.

The plurality of substrates 120 are flat plates for arranging the plurality of light emitting devices 130 on the bottom plate of the housing 110 at predetermined intervals (see FIG. 5C). In this embodiment, the substrate 120 is arranged on the bottom surface 111 of the housing 110 via a caulking material 141, which will be described later (see FIG. 5C). The wiring of substrate 120 is electrically connected by cable 140 .

The plurality of light emitting devices 130 are arranged on the bottom surface 111 of the housing 110 with the plurality of substrates 120 interposed therebetween. The number of light emitting devices 130 arranged on bottom surface 111 is not particularly limited. The number of light-emitting devices 130 arranged on bottom surface 111 is appropriately set based on the size of the light-emitting region (light-emitting surface) defined by the opening of housing 110 . Among them, from the viewpoint of low power consumption, it is preferable that the number of light emitting devices 130 arranged on the bottom surface 111 is small. It is preferable that the light emitting device 130 is arranged such that the height H) from the bottom surface 111 to the light diffusion plate 150 between the side surfaces 113 is 0.7 or lower. For example, if the spatial thickness (the height H from the bottom surface 111 to the light diffusion plate 150) is 50 mm, the light emitting devices 130 are preferably arranged at a pitch of 70 mm.

Also, the plurality of light emitting devices 130 may be arranged at equal intervals, or may not be arranged at equal intervals. From the viewpoint of simplifying the manufacturing process, it is preferable that the plurality of light emitting devices 130 be arranged at regular intervals.

A plurality of light emitting devices 130 each have a light emitting element 131 and a light flux controlling member 132 . The plurality of light emitting devices 130 are arranged such that the optical axis of the light emitted from each light emitting element 131 (the optical axis LA of the light emitting element 131 to be described later) is aligned with the normal to the surface of the substrate 120 .

Light-emitting element 131 is a light source of illumination device 100 (and light-emitting device 130). The light emitting element 131 is arranged on the substrate 120 (see FIG. 5C) and electrically connected to wiring formed on or within the substrate 120 .

The light emitting element 131 is, for example, a light emitting diode (LED). The color of light emitted from the light emitting element 131 included in the light emitting device 130 is not particularly limited. In this embodiment, for example, an SMD type light-emitting element having a light-emitting portion that emits blue light and a phosphor that covers the periphery of the light-emitting portion and converts the blue light emitted from the light-emitting portion into white light can be used.

The light flux controlling member 132 controls the light distribution of the light emitted from the light emitting element 131, and the traveling direction of the light is substantially perpendicular to the planar direction of the substrate 120, particularly the optical axis LA of the light emitting element 131, and Two directions opposite to each other; specifically, a direction substantially parallel to the first direction A and a direction opposite thereto. "Substantially parallel to the first direction A" specifically means that, when viewed from above, the smaller angle between the direction of travel of the light with the maximum intensity and the first direction A is 3° or less. means that Light flux controlling member 132 is arranged such that incident surface 133 thereof faces light emitting element 131, specifically, such that central axis CA thereof coincides with optical axis LA of light emitting element 131 (see FIG. 5C). ). The “optical axis LA of the light emitting element 131 ” means the center ray of the three-dimensional light flux emitted from the light emitting element 131 . "Center axis CA of light flux controlling member 132" refers to, for example, a two-fold symmetrical axis.

As a result, the light emitting device 130 has an anisotropic distribution in which light is biased in a direction substantially parallel to the first direction A and in a direction opposite to this direction (that is, a direction parallel to the Y-axis direction described later). It has optical characteristics (specifically, uniaxial light distribution characteristics). That is, the intensity of light emitted from the light emitting device 130 in a direction substantially parallel to the first direction A and in a direction opposite to the first direction A is higher than the intensity of light emitted in other directions intersecting these directions. is also expensive. The light distribution characteristics of the light emitting device 130 will be described in detail separately.

Hereinafter, in each light emitting device 130, the axis passing through the light emission center of the light emitting element 131 and parallel to the optical axis LA of the light emitting element 131 is the Z axis, and the optical axis LA of the light emitting element 131 on the plane perpendicular to the Z axis. and perpendicular to each other are referred to as the X-axis and the Y-axis. Specifically, in the light flux controlling member 132 described later, the direction in which two output surfaces 135 described later face each other is defined as the Y-axis direction, and the direction orthogonal to the Y-axis direction on a plane perpendicular to the Z-axis direction is defined as It is called the X-axis direction. The first direction A is parallel to the Y-axis.

The material of light flux controlling member 132 is not particularly limited as long as it allows light of a desired wavelength to pass therethrough. For example, light flux controlling member 132 is made of a light-transmissive resin such as polymethyl methacrylate (PMMA), polycarbonate (PC), epoxy resin (EP), or glass. Light flux controlling member 132 will be described in detail separately.

Cables 140 electrically connect adjacent substrates 120 . A connecting portion between the substrate 120 and the cable 140 is reinforced with a caulking material 141 (see FIG. 5C). Examples of materials for the caulking material 141 include urethane resin, silicone resin, and epoxy resin.

In this way, by electrically connecting the plurality of light emitting devices 130 via the cables 140 to form a module, the plurality of light emitting devices 130 can be freely arranged according to the shape of the housing 110 .

The light diffusion plate 150 is arranged so as to close the opening of the housing 110 (see FIGS. 3A and 3B). Light diffusing plate 150 is a plate-shaped member having light transmissive and light diffusing properties, and diffuses and transmits emitted light from emission surface 135 (see FIG. 6) of light flux controlling member 132 . The light diffusion plate 150 can serve as a light emitting surface of the lighting device 100, for example.

The material of light diffusing plate 150 is not particularly limited as long as it can diffuse and transmit the light emitted from emission surface 135 of light flux controlling member 132. For example, polymethyl methacrylate (PMMA), polycarbonate (PC), Light transmissive resins such as polystyrene (PS) and styrene/methyl methacrylate copolymer resin (MS). In order to impart light diffusing properties, the surface of the light diffusion plate 150 is formed with fine irregularities, or light diffusers such as beads are dispersed inside the light diffusion plate 150 .

In illumination device 100 according to the present embodiment, the light emitted from each light emitting element 131 is arranged approximately with respect to optical axis LA of light emitting element 131 so that light flux controlling member 132 illuminates a wide range of light diffusion plate 150 . Two directions that are perpendicular and opposite to each other, specifically, a direction that is substantially parallel to the first direction A and a direction that is opposite to that direction (that is, the Y-axis direction in FIGS. 5A to 5C) It is changed to the light that goes and is emitted. Light emitted from each light flux controlling member 132 is further diffused by light diffusion plate 150 and emitted to the outside. As a result, the entire illumination device 100 can be uniformly illuminated, and uneven illumination can be suppressed.

(Structure of light flux controlling member)
6A to 6D are diagrams showing the configuration of light flux controlling member 132. FIG. 6A is a plan view of light flux controlling member 132, FIG. 6B is a cross-sectional view taken along line 6B-6B in FIG. 6A, FIG. 6C is a bottom view, and FIG. 6D is a side view.

Light flux controlling member 132 controls light distribution of light emitted from light emitting element 131 . As shown in FIGS. 6A to 6D, light flux controlling member 132 has entrance surface 133, two reflecting surfaces 134, two exit surfaces 135, collar 136 and two legs 137. As shown in FIG. Hereinafter, the side on which the incident surface of light flux controlling member 132 is formed (light emitting element 131 side) is referred to as the back side, and the side on which reflecting surface 134 is formed is referred to as the front side.

The incident surface 133 allows part of the light emitted from the light emitting element 131 to enter. Incidence surface 133 is the back side of light flux controlling member 132 , that is, the inner surface of recess 139 formed in the central portion of bottom surface 138 . The shape of the inner surface of the concave portion 139 is not particularly limited, and may be a surface including an edge, or a curved surface without an edge such as a hemispherical shape or a semi-ellipsoidal shape. In the present embodiment, the inner surface shape of recess 139 is a surface including edges.

Specifically, the inner surface (incidence surface 133) of the recess 139 has at least a first inner top surface 133a (inner top surface) and two inner top surfaces 133b, between which are two second inner top surfaces. 133c (see Figures 6B and C). The two second inner top surfaces 133c are arranged so as to sandwich the first inner top surface 133a in the direction (Y-axis direction) in which the two output surfaces 135 face each other.

The first inner top surface 133 a is a surface arranged in the central portion of the recess 139 so as to intersect the optical axis LA of the light emitting element 131 . The first inner top surface 133a is designed to prevent light emitted at a small angle with respect to the optical axis LA of the light emitting element 131 from traveling to the boundary between the two reflecting surfaces 134. The height from the light emitting surface of the light emitting element 131 may be increased as it approaches LA.

Two reflective surfaces 134 are arranged on the front side of light flux controlling member 132 , that is, on the side opposite to light emitting element 131 (light diffusing plate 150 side) with incident surface 133 interposed therebetween. In addition, the two reflecting surfaces 134 transmit part of the light incident from the incident surface 133 in two directions that are substantially perpendicular to the optical axis LA of the light emitting element 131 and are opposite to each other (the two emitting surfaces 135 the opposite direction, that is, the Y-axis direction). The two reflecting surfaces 134 extend from the optical axis LA of the light emitting element 131 to the ends (emission planes) with the optical axis LA of the light emitting element 131 as a boundary in a cross section that includes the optical axis LA of the light emitting element 131 and is parallel to the Y-axis direction. 135), the height from the bottom surface 138 (substrate 120) increases. Specifically, the two reflective surfaces 134 are formed so that the inclination of the tangential line gradually decreases from the optical axis LA of the light emitting element 131 toward the end (output surface 135) in the cross section. .

The two emitting surfaces 135 are arranged to face each other in a direction parallel to the first direction A (or the Y-axis direction) with the two reflecting surfaces 134 interposed therebetween. The two exit surfaces 135 are incident on the entrance surface 133 (especially the two inner surfaces 133b) and directly reach the exit surface 135, and enter on the entrance surface 133 (especially the first inner top surface 133a) to form two The light reflected by the reflecting surface 134 is emitted to the outside.

The exit surface 135 may be flat or curved. In the present embodiment, exit surface 135 is a surface substantially parallel to optical axis LA. “Substantially parallel to the optical axis LA” means that in a cross section including the optical axis LA and parallel to the Y-axis direction, the smaller angle between the optical axis LA and the output surface 135 is 3° or less. means that If the exit surface 135 is a curved surface, the smaller angle between the optical axis LA and the exit surface 135 is the angle between the optical axis LA and the curve of the exit surface 135 in the cross section. It means the smaller of the angles formed with the tangent line.

Collar portion 136 is positioned between two exit surfaces 135 and the outer peripheral portion of bottom surface 138 of light flux controlling member 132 and protrudes outward with respect to central axis CA. The shape of the collar portion 136 is substantially rectangular. Although flange 136 is not an essential component, provision of flange 136 facilitates handling and alignment of light flux controlling member 132 . The thickness of the collar portion 136 is not particularly limited, and can be determined in consideration of the required area of the two output surfaces 135, moldability of the collar portion 136, and the like.

The two leg portions 137 are substantially cylindrical members that protrude toward the light emitting element 131 from the outer peripheral portion of the bottom surface 138 (rear surface) of the light flux controlling member 132 and from the bottom portion of the bottom surface 138 and the flange portion 136 . Two legs 137 support light flux controlling member 132 at an appropriate position with respect to light emitting element 131 (see FIG. 5C). The legs 137 may be fitted into holes formed in the substrate 120 and used for positioning in the direction parallel to the XY plane. Note that the number of legs 137 is not particularly limited.

(Arrangement of Light Emitting Device)
At least one light emitting device 130 among the plurality of light emitting devices 130 is arranged between the first side surface 112 and the second side surface 113 (see FIG. 4). One or more light emitting devices 130 arranged between the first side surface 112 and the second side surface 113 are arranged in consideration of the light distribution of the light emitting devices 130 . Therefore, first, the light distribution of the light emitting device 130 will be described.

FIG. 7 is a diagram showing the light distribution of the light emitting device 130. As shown in FIG. 7A is a diagram showing the light distribution of the light emitting device 130 on the YZ plane; FIG. 7B is a diagram showing the light distribution of the light emitting device 130 on the XY plane.

As shown in FIG. 7B, light emitting device 130 has an anisotropic light distribution characteristic. Specifically, the intensity of the light emitted in the Y-axis direction (the direction substantially parallel to the first direction A and the direction opposite thereto) of the light emitting device 130 is the same as the intensity of the light emitted in the X-axis direction (the other direction). higher than the intensity of the light

All of the one or more light emitting devices 130 arranged between the first side surface 112 and the second side surface 113 are arranged so as to satisfy the following formula (1) or (2).
Formula (1): L≧H/tan (90°-α)
Formula (2): L ≤ (W / 2) * tan (90 ° - θ)

FIG. 8 is an explanatory diagram for explaining the arrangement positions of the light emitting devices represented by the formula (1). 8A is a plan view, and FIG. 8B is a cross-sectional view taken along line 8B-8B of FIG. 8A. FIG. 9 is an explanatory diagram for explaining the arrangement positions of the light emitting devices represented by the formula (2). 9A and B are both plan views. 10A and 10B are explanatory diagrams showing possible regions for arranging light emitting devices that satisfy the formula (1) or (2). 8A, 9B and 10, the light distribution area of the light emitting device 130 on the XY plane is simply indicated by an elliptical filled area.

Regarding formula (1):
L is the position (mm) of the light emission center C of the light emitting element 131 in the first direction A from the intersection of the first side surface 112 and the third side surface 114 in plan view (see FIG. 8A).

H is the height (mm) from the bottom surface 111 to the light diffusion plate 150 between the first side surface 112 and the second side surface 113 (see FIG. 8B). When the height from the bottom surface 111 to the light diffusion plate 150 is not constant, the average value of the heights from the bottom surface 111 to the light diffusion plate 150 between the first side surface 112 and the second side surface 113 is the height H and

α is the angle (°) of the light having the maximum intensity among the lights emitted from light flux controlling member 132 with respect to optical axis LA of light emitting element 131; specifically, light emitted from light flux controlling member 132 on the YZ plane of the light with the maximum intensity with respect to the optical axis LA of the light emitting element 131 (emission angle or angle in the longitudinal direction) (see FIGS. 8B and 7A). α is in the range of more than 0° and less than 90°, depending on the configuration of the light emitting device 130 . In this embodiment, α is approximately 60°.

By arranging one or more light emitting devices 130 arranged between first side surface 112 and second side surface 113 so as to satisfy formula (1), out of light emitted from light flux controlling member 132, ( (in the YZ plane) is prevented from hitting the corner formed by the first side 112 and the third side 114 (the intersection of the first side 112 and the third side 114 in FIG. 8A). be able to.

Regarding formula (2):
L is the same as L in formula (1), and is the position ( mm) (see FIGS. 9A and B). Note that the position a3 is a case where the light emission center C of the light emitting element 131 is on the plus (positive) side of the intersection of the first side surface 112 and the third side surface 114 in the first direction A; This is the case where the light emission center C of the light emitting element 131 is on the minus (negative) side of the intersection of the first side surface 112 and the third side surface 114 .

W is the distance (mm) between the first side 112 and the second side 113 (see FIGS. 9A and B). If the distance between the first side 112 and the second side 113 is not constant, the distance between the "intersection of the first side 112 and the third side 114" and the "intersection of the first side 112 and the third side 114" is reduced. A distance W is defined as a point where a virtual line perpendicular to the first direction A intersects the second side surface 113 .

θ is the light whose intensity is 1/2 of the sum of the maximum intensity and the minimum intensity (hereinafter referred to as “1/2 the smaller one of the angles (°) formed with respect to the first direction A; specifically, the first direction of the traveling direction of the 1/2 intensity light on the XY plane angle (azimuth or latitude) with respect to A (see FIGS. 9A and B). θ is in the range of more than 0° and less than 90° and is determined by the configuration of the light emitting device 130 . In this embodiment, θ is about 40°.

At least one light-emitting device 130 arranged between first side surface 112 and second side surface 113 is arranged so as to satisfy formula (2). Light with an intensity equal to or higher than 1/2 intensity is emitted from the corner formed by the first side 112 and the third side 114 (the intersection of the first side 112 and the third side 114 in FIG. 9B). ) can be avoided.

For equations (1) and (2):
As shown in FIG. 10, the regions satisfying the formula (1) or (2) indicate the regions of both end portions in the first direction A, excluding a predetermined region of the central portion. For example, when the light emission center C of the light emitting element 131 of the light emitting device 130 is at the position a1 or a2, the light emitting device 130 is within the region that satisfies Equation (1). Similarly, when the light emission center C of the light emitting element 131 of the light emitting device 130 is located at the position a3 or a4, the light emitting device 130 is within the region that satisfies Equation (2).

In this way, all of the one or more light emitting devices 130 arranged between the first side surface 112 and the second side surface 113 are arranged so as to satisfy the formula (1) or (2), so that 1/ The light of intensity equal to or higher than that of the light of 2 intensities should not hit the corner formed by the first side surface 112 and the third side surface 114 (the intersection of the first side surface 112 and the third side surface 114). can do. Thereby, it is possible to suppress the occurrence of luminance unevenness (shadow) in the vicinity of the corners.

In addition to the one or more light emitting devices 130 arranged between the first side surface 112 and the second side surface 113, the light emitting devices 130 may also be arranged between the third side surface 114 and the fourth side surface 115, or between the third side surface 114 and the fourth side surface 115, and the It is preferable that the one or more light emitting devices 130 arranged between the other side surfaces are also arranged so as to satisfy the formula (1) or (2).

(Action)
The operation of lighting device 100 according to the present embodiment will be described in comparison with a lighting device for comparison.

FIG. 11 is a diagram showing the operation of lighting device 100 according to the present embodiment and lighting device 10 for comparison. Among them, FIG. 11A is a diagram showing the action of the lighting device 10 for comparison, and FIGS. 11B to 11D are diagrams showing the action of the lighting device 100 according to the present embodiment. Note that in the lighting device 10 for comparison, the light emission centers of the plurality of light emitting devices 130 (the light emission centers C of the light emitting elements 131) are outside the range that satisfies Expression (1) or (2) ) is the same as that of the lighting device 100 according to the present embodiment. Note that, similarly to the above, the light distribution area of the light emitting device 130 on the XY plane is simply indicated by an elliptical filled area.

As described above, in lighting device 10 for comparison and lighting device 100 according to the present embodiment, light emitting device 130 disposed between first side surface 112 and second side surface 113 is substantially parallel to first direction A. Intense light is emitted in one direction and the opposite direction (two directions parallel to the Y-axis direction and opposite to each other).

Then, in the lighting device 10 for comparison, the light emission center C of the light emitting element 131 is arranged outside the range of the region of the formula (1) and the region of the formula (2), that is, in the arrangement impossible region (see FIG. 11A ). Therefore, in the lighting device 10 for comparison, the light emitted from the light emitting device 130 with an intensity higher than 1/2 (thick arrow) is formed by the first side surface 112 and the third side surface 114 . hits the corner As a result, the area between the direction in which the light striking the corner travels and the third side surface 114 tends to become dark, and shadows (luminance unevenness) tend to occur.

In contrast, in lighting device 100 according to the present embodiment, light emission center C of light emitting element 131 is arranged in the region of formula (1) or the region of formula (2) (see FIGS. 11B to 11D ). Therefore, in lighting device 100 according to the present embodiment, of the light emitted from light-emitting device 130 , light having an intensity equal to or higher than 1/2 (thick arrow) is emitted from first side surface 112 . It does not hit the corner formed by the third side surface 114 . As a result, it is possible to suppress the occurrence of shadows (brightness unevenness) in the vicinity of the corners.

Specifically, in FIG. 11B, the light emission center C of the light emitting element 131 is located far from the corner formed by the first side surface 112 and the third side surface 114, so the intensity is the same as 1/2 or less. , no higher intensity light hits that corner. On the other hand, in FIGS. 11C and 11D, the light emission center C of the light emitting element 131 is located near the corner formed by the first side surface 112 and the third side surface 114, but the light intensity is lower than 1/2. will only hit the corner, and no light with an intensity equal to or greater than 1/2 intensity will hit the corner. As a result, it is possible to suppress shadows (brightness unevenness) caused by light having an intensity equal to or higher than 1/2 intensity impinging on the corner.

In particular, when the angle φ formed by the corner formed by the first side surface 112 and the third side surface 114 is an acute angle (more than 0° and less than 90°) (see FIG. 12 described later), a shadow (luminance unevenness) is likely to occur. In addition, when the number of light emitting devices 130 arranged on the bottom surface 111 is small, not only is luminance unevenness near the corners likely to occur (it is conspicuous), but also the positional arrangement of the light emitting devices 130 is severely restricted. In addition, even when a plurality of light emitting devices 130 are arranged at regular intervals, the restrictions on the arrangement positions of the light emitting devices 130 are severe. Even in such a case, according to lighting device 100 according to the present embodiment, it is possible to sufficiently reduce luminance unevenness in the vicinity of corners.

[Modification]
In the present embodiment, an example is shown in which the angle φ formed by the corners formed by the first side surface 112 and the third side surface 114 is 90°. ° and less than 90 °).

FIG. 12 is an explanatory diagram showing a modification of the bent portion of the housing. As shown in FIG. 12, the angle φ formed by the corners formed by the first side surface 112 and the third side surface 114 may be an acute angle, that is, greater than 0° and less than 90°. Shadows (brightness unevenness) that are particularly likely to occur in such cases can be suppressed by arranging the light-emitting device in a region that satisfies (1) or (2) above.

Also, in this embodiment, an example in which the first side surface 112, the second side surface 113, the third side surface 114, and the fourth side surface 115 are flat is shown, but the present invention is not limited to this, and they may be curved.

In this embodiment, light flux controlling member 132 has both reflecting surface 134 and emitting surface 135 as smooth surfaces. From the viewpoint of suppression, each protrusion may be provided.

FIG. 13 is a diagram showing a configuration of light flux controlling member 132 according to a modification. 13A is a plan view of light flux controlling member 132, and FIG. 13B is a side view thereof.

As shown in FIG. 13A , in light flux controlling member 132 , a plurality of first ridges 142 are formed on at least a portion of two reflecting surfaces 134 , preferably a region where light incident on first inner top surface 133 a reaches. may be placed.

The region of the two reflecting surfaces 134 reached by the light incident on the first inner top surface 133 a is, for example, the region of the two reflecting surfaces 134 near the optical axis LA of the light emitting element 131 . When viewed along the optical axis LA of the light emitting element 131 (when viewed along the Z-axis direction), the ridge line of the first ridge 142 is approximately It is formed vertically.

The “ridge line” in the first ridge 142 means a linear series connecting the highest portions of the ridge, and includes the optical axis LA of the light emitting element 131 and is the first ridge in a cross section parallel to the Y-axis direction. It means a line connecting the vertices of the ridges 142 . The plurality of first ridges 142 may be arranged such that their ridge lines are substantially parallel to the X-axis direction when viewed along the Z-axis direction (see FIG. 13A), or may surround the optical axis LA. It may be arranged to be part of a torus (not shown).

Further, as shown in FIG. 13B , in light flux controlling member 132 , a plurality of second ridges 143 may be further arranged on at least part of two exit surfaces 135 .

The plurality of second ridges 143 are formed so that their ridge lines are substantially parallel to the optical axis LA of the light emitting element 131 when viewed from the exit surface 135 (when viewed along the Y-axis direction). there is The "ridgeline" of the second ridge 143 is the same as described above.

The cross-sectional shape of the first ridge 142 (or second ridge 143) in a cross section perpendicular to the ridge line of the first ridge 142 (or second ridge 143) is not particularly limited, and may be wavy. However, it may be triangular or rectangular (including trapezoidal).

Further, in the present embodiment, in a cross section of light flux controlling member 132 that includes optical axis LA of light emitting element 131 and is parallel to the Y-axis direction, two exit surfaces 135 are positioned approximately on optical axis LA of light emitting element 131. Although an example in which they are parallel (not inclined) has been shown, the present invention is not limited to this, and they may be slightly inclined with respect to the optical axis LA of the light emitting element 131 . For example, in a cross section that includes the optical axis LA of the light emitting element 131 and is parallel to the Y-axis direction, the output surface 135 becomes more distant from the light emitting element 131 along the Z axis. If it is possible to have a mold structure that does not impair the optical axis LA, it may be inclined away from the optical axis LA of the light emitting element 131 . As a result, the amount of light refracted and emitted from the emission surface 135 upward (in the direction toward the light diffusion plate 150) is reduced, making it easier to achieve uniform illuminance distribution and color distribution. The inclination angle of the emission surface 135 with respect to the optical axis LA of the light emitting element 131 in a cross section including the optical axis LA of the light emitting element 131 and parallel to the Y-axis direction can be, for example, 10° or less.

In addition, in the present embodiment, an example in which a plurality of light emitting devices 130 are arranged in a row in lighting device 100 is shown, but the present invention is not limited to this, and they may be arranged in a plurality of rows of two or more rows.

In addition, in the present embodiment, an example in which a plurality of substrates 120 are arranged for each light-emitting device 130 in the lighting device 100 and the substrates 120 are electrically connected to each other by the cables 140 is shown, but the present invention is not limited to this. , a plurality of light-emitting devices 130 may be arranged on one substrate 120 . In that case, cable 140 and caulking material 141 are not required.

Further, in the present embodiment, in lighting device 100, housing 110 is a box-shaped body having a bottom plate, four side plates, and a top plate (at least a part of which is provided with an opening). Although shown, the present invention is not limited to this, as long as it has at least a bottom plate, and the side plates and the top plate may be omitted.

FIG. 14 is a partially enlarged perspective view showing the configuration of a lighting device according to a modification. As shown in FIG. 14 , the top plate and side plates of housing 110 may be omitted, and the bottom plate of housing 110 may be covered only with light diffusion plate 150 .

Further, in the present embodiment, an example in which the illumination device 100 is a channel character signboard is shown, but the illumination device 100 is not limited to this, and may be line illumination or the like.

The illumination device according to the present invention can be applied to, for example, signboards (especially channel character signboards), line lighting, general lighting, and the like.

Reference Signs List 100 lighting device 110 housing 111 bottom surface 112 first side surface 113 second side surface 114 third side surface 115 fourth side surface 120 substrate 130 light emitting device 131 light emitting element 132 light flux controlling member 133 incident surface 133a inner surface (first inner surface)
133b inner surface 133c second inner top surface 134 reflecting surface 135 emitting surface 136 collar portion 137 leg portion 138 bottom surface 139 concave portion 140 cable 141 caulking material 142 first ridge 143 second ridge 150 light diffusion plate CA central axis LA optical axis L Position (mm) from the intersection of the first side and the third side of the light emission center of the light emitting element
W Distance between first side and second side (mm)
H height from the bottom to the light diffusion plate (mm)
α Angle of maximum intensity light with respect to the optical axis of the light emitting element (°)
θ Angle (°) of light with half intensity with respect to the first direction when viewed from above
C emission center

Claims (5)

a bottom surface, a first side surface arranged along a first direction along the bottom surface, a second side surface arranged to face the first side surface with the bottom surface interposed therebetween, and connected to the first side surface. a third side surface arranged within the bottom surface along a second direction intersecting the first direction; a fourth side surface arranged to face the third side surface across the bottom surface; a housing having an opening arranged to face the bottom surface;
a plurality of light-emitting devices each having a light-emitting element and a light flux controlling member for controlling light distribution of light emitted from the light-emitting element, which are arranged on the bottom surface;
a light diffusing plate arranged to block the opening and diffusing and transmitting light;
A lighting device having
at least one of the plurality of light emitting devices is arranged between the first side surface and the second side surface;
The intensity of light emitted from the light-emitting device disposed between the first side surface and the second side surface in a direction substantially parallel to the first direction and in a direction opposite to the first direction is higher than the intensity of light emitted in other directions crossing the direction,
All of the one or more light emitting devices arranged between the first side surface and the second side surface are arranged so as to satisfy the following formula (1) or (2),
lighting device.
Formula (1): L≧H/tan (90°-α)
Formula (2): L ≤ (W / 2) * tan (90 ° - θ)
(In formulas (1) and (2),
L is the position (mm) from the intersection of the first side surface and the third side surface of the light emission center of the light emitting element in the first direction;
H is the height (mm) from the bottom surface to the light diffusion plate between the first side surface and the second side surface;
W is the distance (mm) between the first side and the second side;
α is the angle (°) of the light with the maximum intensity among the lights emitted from the light flux controlling member with respect to the optical axis of the light emitting element;
θ is the intensity of light having an intensity half the sum of the maximum intensity and the minimum intensity of the light forming an angle α with respect to the optical axis of the light emitting element when viewed in plan, with respect to the first direction. is the smaller angle (°) of the angles that make up, and α and θ are more than 0° and less than 90°) The light flux controlling member
an incident surface on which light emitted from the light emitting element is incident;
arranged at a position facing the light emitting element with the incident surface interposed therebetween, and reflects part of the light incident on the incident surface in a direction substantially parallel to the first direction and in a direction opposite to the first direction, respectively two reflective surfaces;
Two emitting devices arranged to face each other with the two reflecting surfaces interposed therebetween, for emitting the light reflected by the two reflecting surfaces in a direction substantially parallel to the first direction and in a direction opposite to the first direction, respectively. having a face and
The lighting device according to claim 1 . The smaller angle between the first side surface and the third side surface is less than 90°.
3. A lighting device according to claim 1 or 2. The plurality of light emitting devices are arranged at equal intervals,
A lighting device according to any one of claims 1 to 3. It is a channel letter type signboard,
A lighting device according to any one of claims 1 to 4.

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