JP6985049B2 - Lighting equipment - Google Patents

Description

The present invention relates to a lighting device including a plurality of LED (light emitting diode) light sources arranged in a row.

Patent Document 1 discloses an elongated illuminating device attached to a cross beam of a fence and irradiating light downward.

Patent Document 2 discloses a lens that emits light by changing the direction of incident light from an LED. The lens has the shape of a rotating body whose axis is the optical axis of the LED, and has a surface shape in which each incident light from the LED is aligned in a direction substantially perpendicular to the optical axis and emitted.

Patent Document 3 considers that the luminance distribution of the light emitted from the LED drops sharply as the emission direction is outward with respect to the optical axis of the LED, and the sealing member (lens) corrects this. To disclose.

Japanese Unexamined Patent Publication No. 2005-68851 Jikkenhei 6-11365 Gazette Japanese Unexamined Patent Publication No. 2011-71136

There is an idea to horizontally attach a long lighting device in which LED light sources are arranged in a row to a fence or the like in a park, and illuminate a predetermined area below including directly under the lighting device along the fence with a predetermined illuminance. .. Further, depending on the installation location, there may be a case where it is desired to irradiate a place away from the fence, that is, it is desired to make the predetermined width as wide as possible. On the other hand, the light distribution of a general LED light source itself is a Lambersian light distribution. That is, the luminous intensity of the light emitted from the LED light source is highest on the optical axis, and decreases as the emission angle (inclination angle in the emission direction with respect to the optical axis; 0 ° on the optical axis) increases.

Therefore, in a long lighting device in which LED light sources are arranged in a row without any measures, the irradiation area directly underneath is very bright under the lighting device, and drops sharply when a little away from the bottom. It becomes an illuminance distribution.

Patent Document 1 only discloses that a long lighting device is attached to a fence or the like and the lighting device illuminates the lower part.

The lighting device of Patent Document 2 only aligns each incident light in a direction substantially perpendicular to the optical axis, and does not improve the illuminance distribution in the irradiation region in the optical axis direction.

The lighting device of Patent Document 3 improves the decrease in brightness as the emission angle from the optical axis increases, but even if this lighting device is used for a fence, it is emitted most outward with respect to the optical axis. Since the intensity of the light is low and the distance from the irradiation surface is large, the road surface illuminance is extremely low. Therefore, the width of the irradiation area of the predetermined illuminance is not increased.

An object of the present invention is to provide a lighting device capable of increasing the width of an irradiation region in which a predetermined illuminance is secured while suppressing a sudden change in the illuminance of the irradiation region in the width direction.

The lighting device of the present invention
Multiple LED light sources arranged in a row with their optical axes aligned in the same direction,
A plane-symmetrical shape having a surface on the light incident side and a surface on the light emitting side facing the LED light source side and the opposite side, respectively, and having a plane including a plurality of optical axes of the plurality of LED light sources as a plane of symmetry. With a lens formed in and extending along a row of said plurality of LED light sources.
The width direction is perpendicular to the symmetry plane, the symmetry plane side is the inside, and the side opposite to the symmetry plane is the outside at each position in the width direction.
The surface of the lens on the light emitting side has a first surface portion, a second surface portion, and a third surface portion in order from the inside to the outside.
The first surface portion has a surface shape that totally reflects the light incident on the lens from the surface on the light incident side toward the third surface portion.
The second surface portion has a convex shape in which light incident on the lens is refracted and emitted from the surface on the light incident side.
The third surface portion will have a surface shape for emitting light totally reflected by the first surface portion.

According to the present invention, high-intensity light emitted from the vicinity of the optical axis of the LED light source is totally reflected by the first surface portion and emitted from the third surface portion to irradiate the outside in the width direction in the irradiation region. Further, the light having the next highest intensity after the light incident on the first surface portion is emitted from the second surface portion, and is emitted inward in the width direction from the light emitted from the third surface portion in the irradiation region. As a result, the width of the irradiation region that secures the illuminance equal to or higher than a predetermined value can be increased, and sufficient illuminance can be obtained up to a distant position of the irradiation region in the width direction.

In the present invention, the emitted light of the LED light source is irradiated inward in the width direction in the irradiation region as the emission angle from the optical axis becomes larger. That is, in the present invention, in the irradiation region, the light emitted from the LED light source is irradiated in order from the outside to the inside in the width direction so as to arrange the light having an emission angle having a high emission intensity and the light having an emission angle having a low emission intensity. It is possible to suppress a sudden change in the illuminance distribution in the width direction in the irradiation region.

In the lighting device of the present invention, the convex shape of the second surface portion is such that the light rays on the first surface portion side and the light rays on the third surface portion side of the light incident on the second surface portion intersect after being emitted from the second surface portion. Is formed like this.

According to this configuration, in the light incident on the second surface portion, the light beam on the first surface portion side having a relatively high intensity is irradiated to the outside in the width direction in the irradiation region, and the light ray on the third surface portion side having a relatively low intensity is emitted. It is possible to irradiate inward in the width direction in the irradiation area. Therefore, it is possible to easily form an illuminance distribution in the irradiation region without a large change in illuminance.

In the lighting device of the present invention, the surface on the light emitting side has a central surface portion inside the first surface portion, and in the central surface portion, light incident from the surface on the light incident side is between the first surface portions. It is preferable to have a surface shape that emits light in the direction of passing through.

According to this configuration, the central range in the width direction in the irradiation region is irradiated by the emitted light from the central surface portion of the lens. Further, the light emitted from the central surface portion of the lens is the light emitted from the portion having the maximum intensity of the LED light source. In this way, it is possible to secure or increase the illuminance in the center range in the width direction in which the irradiation is thinned by the first surface portion, the second surface portion, and the third surface portion.

In the lighting device of the present invention
The first irradiation range that is totally reflected by the first surface portion and irradiated by the light emitted from the third surface portion is the second irradiation range irradiated by the light emitted from the second surface portion with respect to the symmetrical plane. Far away,
The first and the second irradiation range and an irradiation range of the contact or becomes heavy.

According to this configuration, the light emitted from the light source with higher intensity can be irradiated farther in the irradiation area, and the irradiation area can be continuously irradiated, so that an illuminance distribution without a large change in illuminance can be easily designed. can do.

In the lighting device of the present invention, it is preferable that each LED light source has a plurality of emission peak wavelengths in the emission spectrum of the emitted light, and unevenness for light scattering is formed on the third surface portion.

According to this configuration, it is possible to prevent the light emitted from the third surface portion from being separated by color due to the difference in wavelength.

Regarding the fence equipped with the lighting device, FIG. 1A is a side view of the fence, FIG. 1B is a sectional view taken along line 1B-1B of FIG. 1A, and FIG. 1C is a sectional view taken along line 1C-1C of FIG. 1A. Regarding the lighting device, FIG. 2A is a perspective view of the lighting device, and FIG. 2B is a side view of the lighting device. Regarding the substrate, FIG. 3A is a view showing the front surface side of the substrate, FIG. 3B is a diagram showing the back surface side of the substrate, and FIG. 3C is a perspective view from the back surface side of the substrate. Regarding the LED, FIG. 4A is a cross-sectional view in the thickness direction of the LED, and FIG. 4B is a 4B arrow view of FIG. 4A. An explanatory diagram of the assembly process of the lighting device. A cross-sectional view of the luminaire cut at the position of the board holder in the longitudinal direction. Light path diagram of the lighting device. Another ray optical path diagram. Diagrams of various light distribution patterns in which the highest intensity emission part of the lens portion is different. Light distribution pattern diagram when generating an irradiation area where the illuminance becomes uniform in the width direction. Light distribution pattern diagram when creating an irradiation area where the illuminance gradually rises from the inside to the outside in the width direction. Light distribution pattern diagram when creating an irradiation area where the illuminance gradually decreases from the inside to the outside in the width direction. The figure which shows various surface shapes of the 2nd surface part of a lens part.

(Example of installation)
1A is a fence 1 equipped with a lighting device, FIG. 1A is a side view of the fence 1, FIG. 1B is a sectional view taken along line 1B-1B of FIG. 1A, and FIG. 1C is a sectional view taken along line 1C-1C of FIG. 1A. It is a schematic diagram. In FIG. 1B, the inside of the cap tree portion 3 of the fence 1 is not shown.

For convenience of explanation, three-axis Cartesian coordinates are defined. The Z-axis coincides with the extending direction of the fence 1. The Y-axis coincides with the height direction of the fence 1. The X-axis coincides with the width direction in the direction perpendicular to the height direction and the extension direction of the fence 1.

In FIGS. 1A and 1B, the fence 1 is installed over a predetermined length in a park, a beach, or the like. The fence 1 includes a plurality of columns 2 that are fixed to the ground 4 at equal intervals in the horizontal direction and stand up in the vertical direction, and a cap tree portion 3 that is passed between the columns 2 and extends horizontally. The height from the ground 4 to the highest point of the cap tree portion 3 is, for example, about 60 cm, and the distance between the columns 2 is, for example, about 2 m.

The lower part of the Kasagi portion 3 is open. The lighting device 10 has a long shape (rod shape), and is mounted in the cap tree portion 3 with the light emitting side facing the ground 4. The lighting device 10 is arranged so as not to protrude downward from the lowermost end of the cap tree portion 3. Therefore, the lighting device 10 is not visually recognized in the side city. The lighting device 10 is connected to each other in the extending direction of the fence 1 by an electric wire (not shown) for power transmission, and power is supplied from a feeding line 11 in a predetermined support column 2. The feeder line 11 is connected to a power cable (not shown) in the ground at the lower end.

In FIG. 1B, Sp is a plane of symmetry passing through the center of the fence 1 in the width direction. That is, the fence 1 and the lighting device 10 are configured to be plane-symmetrical with respect to the plane of symmetry Sp. The lighting device 10 in the cap tree portion 3 of the fence 1 emits the irradiation light L toward the ground 4 from below the cap tree portion 3. As a result, on the ground 4, an irradiation region 13 having an illuminance of a predetermined value or higher is generated with a predetermined width in the horizontal direction (also in the width direction) about the plane of symmetry Sp. The irradiation area 13 extends along the fence 1.

In FIG. 1C, the lighting device 10 is attached to the inner surface of the cap tree portion 3 via a bracket (not shown). The brackets are arranged at equal intervals of a predetermined length in the longitudinal direction (Z-axis direction) of the cap tree portion 3.

The lighting device 10 has a pipe-shaped case 15 and a plurality of substrates 16 arranged in a row in the pipe-shaped case 15. Each substrate 16 has a long side and a short side formed in a rectangular shape along the longitudinal direction and the width direction of the lighting device 10, respectively. On the lower surface of each substrate 16, a plurality of LEDs 17 are arranged in a row and at equal intervals. It is attached with. The pipe-shaped case 15 has a pipe portion 18 that defines a hollow space for accommodating the substrate 16 on the inner surface side, and a lens portion (the present invention) integrally formed on the wall portion of the pipe portion 18 facing the LED 17 on the substrate 16. Corresponds to the "lens" of.) 19. The pipe portion 18 is formed in a cylindrical shape having a substantially rectangular cross section.

(composition)
FIG. 2 is a perspective view of the lighting device 10, FIG. 2A is a perspective view of the lighting device 10, and FIG. 2B is a side view of the lighting device 10. In FIG. 2A, one end of the pipe-shaped case 15 is shown with the grommet 22 for sealing inside the pipe-shaped case 15 removed, and the open end 23 of the pipe-shaped case 15 is exposed.

An example of the dimensions of the pipe-shaped case 15 will be described. The total length (dimension in the Z-axis direction) of the pipe-shaped case 15 is about 2 m. The width (dimension in the X-axis direction) of the pipe-shaped case 15 is about 3 cm. The thickness (dimension in the Y-axis direction) of the pipe-shaped case 15 is about 1.5 cm. The pipe-shaped case is made of, for example, polycarbonate and is formed by extrusion molding.

3A and 3B are views showing the side of the front surface 26 of the substrate 16, FIG. 3B is a view showing the side of the back surface 27 of the substrate 16, and FIG. 3C is a perspective view from the side of the back surface 27 of the substrate 16. be. The substrate 16 is rectangular, and the directions of the long side and the short side are arranged in the pipe-shaped case 15 in parallel with the Z axis and the X axis, respectively. The dimension of the long side of the substrate 16 is about 30 cm. Therefore, in this example, a total of six substrates 16 are housed in a row of arrangements in the pipe-shaped case 15.

In FIG. 3A, pairs of LEDs 17a and 17b are attached to the surface 26 of the substrate 16 at equal intervals in the Z-axis direction. In this example, the LED 17a and the LED 17b are composed of so-called white LEDs having different colors, the LED 17a emits a daylight color, and the LED 17b emits a light bulb-colored irradiation light L, and the color of the emitted light can be used properly depending on the season. Hereinafter, when the LED 17a and the LED 17b are not particularly distinguished, they are collectively referred to as "LED 17" (including the reference numerals in the drawings).

In FIG. 3B, connector receivers 30 for 3 wires and 2 wires are fixed to both ends of the back surface 27 of the substrate 16 by soldering or the like. The notches 32 are formed on each side edge of both ends of the substrate 16. The notch 32 is inside the connector receiver 30 in the Z-axis direction.

4A and 4B are cross-sectional views of the LED 17 in the thickness direction of the LED 17, and FIG. 4B is a view taken along the line 4B of FIG. 4A. In FIG. 4, the LED 17 is shown in a state of being attached downward to the substrate 16. The LED 17 includes a holding portion 35, a light source main body 36, and a phosphor 37. The holding portion 35 has a recess 38 having a predetermined depth in the direction of the optical axis ASx, and the phosphor 37 is filled in the recess 38. The light source body 36 is arranged at the center of the bottom of the recess 38. The exposed surface of the phosphor 37 forms the light emitting surface 39 of the LED 17. The light emitted from the light source main body 36 is emitted toward the opening side of the recess 38 in the direction of the optical axis Ax, and is emitted from the light emitting surface 39 via the phosphor 37.

For example, the light source body 36 can be made of a blue light emitting LED chip, and the phosphor 37 can be made of a resin in which yellow light emitting phosphor particles are dispersed. In this case, the emitted light itself from the light source main body 36 is blue, but the emitted light is partially wavelength-converted to yellow light while passing through the phosphor 37. The light emitted from the light emitting surface 39 becomes white (daylight color or light bulb color depending on the tint), which is a mixture of blue and yellow. That is, the emission spectrum of the emitted light of the light source main body 36 has two emission peak wavelengths of blue emission and yellow emission.

FIG. 5 is an explanatory diagram of an assembly process of the lighting device 10. Each board 16 has a connector 43 and a board holder 49 assembled to the board 16 prior to being inserted into the pipe-shaped case 15 from the open end 23 of the pipe-shaped case 15.

The connector 43 has connector portions 44 at both ends and a plurality of electric wires 45 wired between the connector portions 44, and electrically connects the substrates 16 adjacent to each other in the arrangement direction. The connector portion 44 is pushed into the connector receiver 30 on the back surface 27 of the substrate 16 adjacent to each other in the longitudinal direction (Z-axis direction).

The board holder 49 has a gate shape in the Z-axis view. The board holder 49 includes a cross section 51 and legs 52 hanging from both ends of the cross section 51. Two ridges 53 are formed on the outer surface of the cross section 51, and one on the outer surface of each leg portion 52. A groove 54 and a spacer 55 on the tip end side of the groove 54 are formed on the inner surface of each leg portion 52. The board holder 49 is attached to the board 16 so that the groove 54 of each leg 52 fits into the notch 32 of the board 16.

In this way, the substrates 16 adjacent to each other in the longitudinal direction are electrically connected to each other by the connector 43, and the substrate holder 49 is locked to the notch 32. After that, the substrate 16 is pushed into the pipe portion 18 of the pipe-shaped case 15 from the open end 23. When such processing is performed for each substrate 16 and all the substrates 16 are housed in the pipe portion 18 of the pipe-shaped case 15, the grommet 22 is finally attached to the open end 23 to complete the lighting device 10. do.

FIG. 6 is a cross-sectional view of the lighting device 10 cut at the position of the substrate holder 49. In FIG. 6, the symmetry plane Sp is a symmetry plane (left-right symmetry plane when the X-axis direction is defined as the left-right direction) perpendicular to the cross section of the lighting device 10. The plane of symmetry Sp is not only the plane of symmetry of the pipe-shaped case 15, the substrate 16 and the LED 17 as parts constituting the lighting device 10, but also the plane of symmetry of the pipe portion 18 and the lens portion 19 as parts of the pipe-shaped case 15. ..

All the LEDs 17 are arranged at the center in the width direction (X-axis direction) of the substrate 16 and are arranged in a row in the longitudinal direction (Z-axis direction) of the lighting device 10. Therefore, the plane of symmetry Sp is a plane including the optical axes Ax (FIG. 4) of the plurality of LEDs 17. That is, the plurality of LEDs 17 are arranged in a row with the optical axes Ax aligned in the same direction.

The board holder 49 is in contact with the inner surface of the pipe portion 18 of the pipe-shaped case 15 at each of the ridges 53 on the outer surface side of the cross section 51 and the leg portion 52. The spacer 55 is sandwiched between the surface 26 of the substrate 16 and the inner surface of the pipe portion 18 on the lens portion 19 side (which is also the surface on the light incident side of the lens portion 19) in the Y-axis direction, and is sandwiched in the Y-axis direction. It defines the distance between the LED 17 and the light incident side surface 60 of the lens unit 19.

In the pipe-shaped case 15, the pipe portion 18 is formed in a rectangular annular cross section having long and short sides in the X-axis direction and the Y-axis direction, respectively. The lens unit 19 faces the light incident side and the light emitting side toward the side of the plurality of LEDs 17 and the opposite side thereof, respectively, and the surface on the light incident side (hereinafter referred to as “light incident side surface 60”) and the surface on the light emitting side. (Hereinafter referred to as "light emitting side surface 61"). The light incident side surface 60 is exposed on the inner surface side of the pipe portion 18 and faces the LED 17, and is formed in a plane perpendicular to the plane of symmetry Sp. The light emitting side surface 61 forms an outer surface on the lower surface side of the pipe-shaped case 15.

The side of the plane of symmetry Sp in the width direction (X-axis direction) of the lens portion 19 is referred to as "inside", and the side opposite to the inside is referred to as "outside". The light emitting side surface 61 has a first surface portion 64a, a second surface portion 64b, and a third surface portion 64c in order from the inside to the outside in each half portion divided into two equal parts by the plane of symmetry Sp. When the cross section of the lens portion 19 is viewed in the longitudinal direction (Z-axis direction) of the illuminating device 10, the pair of the first surface portions 64a is substantially inverted V-shaped, and each second surface portion 64b has a convex shape overhanging to the outer surface side. The pair of the third surface portion 64c is a substantially V-shaped surface in which the tip portion is deleted by a predetermined amount.

The pair of the third surface portion 64c is inclined so that the distance from the plane of symmetry Sp decreases as the distance from the light incident side surface 60 increases. The third surface portion 64c is formed as a surface on which all of the light totally reflected by the first surface portion 64a is incident. The third surface portion 64c can be formed of a flat surface or a curved surface depending on the desired angle of synchrotron radiation. From the viewpoint of efficiently irradiating a distant place, it is preferable to form a plane in which the light totally reflected by the first surface portion 64a is vertically incident, and the light totally reflected by the first surface portion is reflected by the third surface portion for other purposes described later. If you want to change the direction further, you can configure it as a curved surface.

(Ray light path)
FIG. 7 is a light path diagram of the lighting device 10. The light emitted from the LED 17 in each direction enters the lens portion 19 from the light incident side surface 60 and travels in the lens portion 19 toward the first surface portion 64a and the second surface portion 64b. After being emitted from the lighting device 10, the emitted light of the LED 17 irradiates the irradiation region 13 as the irradiation light L (FIG. 1 and the like).

In the light path diagram of FIG. 7, the light emitted most outward in the width direction from the LED 17 is the light incident on the outermost position in the width direction of the second surface portion 64b, and is outwardly emitted from the LED 17. The emitted light is not shown and is omitted. The LED 17 has a well-known Lambersian light distribution, and the intensity of the LED 17 is maximum in the optical axis direction and decreases sharply as it faces outward (direction away from the optical axis). The light beam for which the optical path is not shown in FIG. 7 is weak as the irradiation light and has little influence on the illuminance in the irradiation region 13. Therefore, although there is some light that is directly incident on the third surface portion 64c from the LED 17, the illustration is omitted because the influence on the illuminance in the irradiation region 13 is small.

Further, the light path diagram of FIG. 7 exemplifies the irradiation light from one point on the light emitting surface 39 of the LED 17.

In the light path diagram of FIG. 7, the positional relationship between the Kasagi portion 3 and the lighting device 10 is set so that the light emitted from the third surface portion 64c passes below the lower end (FIG. 1C) of the Kasagi portion 3. There is.

The first surface portion 64a has a convex convex shape on the outer surface side (in this case, the symmetrical surface Sp side) that totally reflects the light incident from the light incident side surface 60 and directs it toward the third surface portion 64c. The second surface portion 64b has a convex shape that is convex on the outer surface side in which the light incident from the light incident side surface 60 is refracted and emitted.

The third surface portion 64c is formed so that all the light totally reflected by the first surface portion 64a is incident, and the light totally reflected by the first surface portion 64a is emitted from the third surface portion 64c. The third surface portion 64c has a surface shape formed so that the incident angle of the light totally reflected by the first surface portion 64a is larger than the critical angle. The third surface portion 64c may have a flat surface, a convex convex shape on the outer surface side, a concave concave shape on the outer surface side, and a shape having a concave or convex portion partially.

As described above, at each position in the width direction of the illuminating device 10, the side of the plane of symmetry Sp is defined as "inside" and the side opposite to the plane of symmetry Sp is defined as "outside". Further, here, for convenience of explanation, at each position between the LED 17 and the irradiation area 13 in the direction of the optical axis Ax (FIG. 4) of the LED 17, the side of the LED 17 is "upper" and the side of the irradiation area 13 is "lower". Defined as "side".

The light incident from the light incident side surface 60 into the lens portion 19 and heading toward the first surface portion 64a is emitted from the inside of the LED 17 from the light incident from the light incident side surface 60 into the lens unit 19 and toward the second surface portion 64b. It is a light.

The light incident on the lens portion 19 from the light incident side surface 60 and directed toward the first surface portion 64a is totally reflected on the upper side of the first surface portion 64a as the light emitted inward by the LED 17 is directed toward the third surface portion 64c. , It is incident on the upper side in the third surface portion 64c. This hierarchical relationship is maintained in the optical path from the first surface portion 64a to the third surface portion 64c. As a result, in the third surface portion 64c, the light emitted inward in the LED 17 emits from the upper side and irradiates the outer range in the irradiation region 13 toward the outside in the irradiation region 13.

As for the light incident from the light incident side surface 60 into the lens portion 19 and directed toward the second surface portion 64b, the light emitted inward from the LED 17 is incident on the inside of the second surface portion 64b and is emitted from the inside. The second surface portion 64b has a convex surface on the outer surface side. Therefore, the light emitted from the second surface portion 64b intersects at a quasi-focus (a position that can be regarded as a focal point although it is not a strict focal point) 68 after the emission, the relationship between the inside and the outside is exchanged, and then the irradiation region. Head to 13. As a result, in the second surface portion 64b, the light emitted inward from the LED 17 is emitted toward the outside in the width direction and irradiates the outer range in the width direction of the irradiation region 13.

It should be noted that the outer side edge of the irradiation range (second irradiation range) of the irradiation region 13 irradiated by the light emitted from the second surface portion 64b and the irradiation range of the irradiation region 13 irradiated by the irradiation light emitted from the third surface portion 64c. The surface shape of the light emitting side surface 61 is set so as to be located on the boundary line between the two irradiation ranges with the inner side edge of the (first irradiation range). Alternatively, the irradiation range of the emitted light from the second surface portion 64b and the irradiation range of the emitted light from the third surface portion 64c are slightly overlapped in the width direction. Therefore, in the irradiation region 13, the irradiation range of the emitted light from the second surface portion 64b and the irradiation range of the emitted light from the third surface portion 64c are continuously formed.

The intensity of the irradiation light decreases as the distance from the LED 17 to the irradiation point of the irradiation region 13 increases. However, in the lighting device 10, the light emitted from the portion closer to the optical axis of the LED 17, that is, the light emitted from the portion having the higher intensity of the LED 17, illuminates the outer portion in the width direction in the irradiation region 13. As a result, the width of the irradiation region 13 in which the illuminance equal to or higher than the predetermined illuminance is secured increases.

Further, when the emitted light from the LED 17 is continuously arranged in the irradiation region 13 in the order of the intensity of the emitted light from the LED 17 in the width direction, the illuminance distribution of the irradiation region 13 is made uniform in the width direction or a sudden change is suppressed. Means that you are.

It is preferable that the third surface portion has a surface shape in which the reflectance is equal to or less than a predetermined value with respect to the light totally reflected by the first surface portion. According to this configuration, the light that is totally reflected by the second surface portion and reaches the third surface portion is suppressed from being reflected inside the lens on the third surface portion, and the emitted light from the third surface portion can be strengthened. ..

Concavities and convexities 66 for light scattering are formed on the third surface portion 64c. The unevenness 66 formed on the third surface portion 64c is composed of a surface in which curves are continuously connected tangentially. The unevenness 66 is formed in a wavy shape in which ridges and dents extending in the longitudinal direction are alternately formed along the longitudinal direction of the lens portion 19. Further, even when the unevenness 66 is formed, the incident angle of the light totally reflected by the first surface portion is designed to be larger than the critical angle, and is formed in a gentle wavy shape.

Due to the unevenness 66, the light incident on the third surface portion 64c is mainly scattered in the Y-axis direction. Further, the unevenness 66 does not scatter the light incident on the third surface portion 64c in the Z-axis direction. The shape, size, and pitch of the light scattering degree due to the unevenness 66 are designed so that the light emitted from the third surface portion 64c has a desired irradiation range. The unevenness 66 does not significantly change the traveling direction of the light beam.

As described with reference to FIG. 4, a general LED 17 has a light source body 36 and a phosphor 37, and the light emitted from the light source body 36 is wavelength-converted while passing through the phosphor 37 (eg, blue). Wavelength to yellow wavelength). Here, the wavelength of the light emitted from the light emitting surface 39 is different because the amount of light whose wavelength is converted differs depending on the optical path length of the passing phosphor 37. Therefore, the light emitted from the light emitting surface 39 produces a slightly different emission color in the light emitting surface 39, and the emission color unevenness occurs in the light emitting surface 39. When the light emitted from the third surface portion 64c is applied to the irradiation region 13, the color unevenness in the light emission surface 39 is projected as it is, and there is a possibility that color stripes are generated in the irradiation region 13. The unevenness 66 appropriately scatters the light emitted from the third surface portion 64c and mixes the colors to suppress the generation of color stripes in the irradiation region 13.

FIG. 8 is a light path diagram of another lighting device 10b. The changes of the lighting device 10b with respect to the lighting device 10 in terms of configuration are that the third surface portion 64c is composed of a flat surface on which the unevenness 66 is not formed, and that the radius (R) 70 (central surface portion) is formed on the light emitting side surface 61. ) Has been added. The third surface portion 64c is configured as a plane in which the light from the LED 17 totally reflected by the first surface portion 64a is vertically incident.

The radius 70 is formed symmetrically with respect to the plane of symmetry Sp over the entire range inside the first plane portion 64a. The radius 70 is formed between the first surface portions 64a on both sides with respect to the symmetrical surface Sp, and is formed as a concave surface on the outer surface side.

In the lighting device 10b, the light incident on the radius 70 is the light emitted inward from the LED 17 than the light incident on the first surface portion 64a. Further, the surface shape of the radius 70 is set so that the light emitted from the radius 70 passes between the first surface portions 64a on both sides in the width direction. The light emitted from the radius 70 irradiates the central range in the width direction centered on the plane of symmetry Sp in the width direction of the irradiation region 13, that is, the central range including directly below the lighting device 10. The surface shape of the second surface portion 64b and the radius 70 so that the emitted light emitted most inward from the second surface portion 64b illuminates the widthwise end of the center range or partially overlaps the outside of the center range. , And the widthwise dimension of the radius 70 can be specified.

If only the first surface portion 64a, the second surface portion 64b, and the third surface portion 64c are used, the illuminance in the center range in the width direction including directly below the lighting device 10 in the irradiation region 13 may be insufficient, or the illuminance in the center range may be increased. You may want to increase the illuminance in the range on both sides. The formation of the radius 70 on the light emitting side surface 61 is significant when dealing with these.

(Light distribution pattern)
FIG. 9 is a diagram of various light distribution patterns in which the highest intensity emission portion of the lighting device 10 (= the highest brightness intensity emission portion of the lens unit 19) is different. It is a light distribution pattern diagram when the emission direction of the highest intensity is changed variously. In FIG. 9 and FIGS. 10 to 12 described later, the intensity (luminance) of the emitted light of the light distribution pattern in each emission direction is shown at an angle around the center line of the array of LEDs 17. The positive direction of the X-axis is 0 °, the negative direction of the X-axis is 180 °, and the negative direction of the Y-axis is 90 ° with respect to the center line. The angle of inclination in the emission direction with respect to the plane of symmetry Sp = 0 ° corresponds to 90 ° in these light distribution pattern diagrams. The intensity of the emitted light in each emission direction corresponds to the distance from the center point of the light distribution pattern, and the emission direction of the maximum intensity is represented by 1 as the distance from the center point.

As can be seen from FIG. 1C, the light directed upward from the lower end of the Kasagi portion 3 from the lens portion 19 hits the inner surface of the Kasagi portion 3 and is not irradiated to the outside of the Kasagi portion 3. Therefore, in FIGS. 9 to 12, it is meaningless to strengthen the light distribution near 0 ° or 180 °.

The light distribution pattern of the lighting device 10 includes the curvature at each portion of the first surface portion 64a, the second surface portion 64b, and the third surface portion 64c, the X-axis direction dimensions of the first surface portion 64a, the second surface portion 64b, and the third surface portion 64c, and Y. By adjusting the axial dimension, it can be arbitrarily adjusted within a predetermined constraint.

The light with the highest intensity among the light totally reflected by the first surface portion 64a is on the second surface portion 64b side (low height position) from the height position where the light emitting side surface 61 and the symmetrical surface Sp intersect in the third surface portion 64c. ) Is preferable. In particular, the surface shapes of the first surface portion 64a and the third surface portion 64c may be defined so that the light having the highest intensity among the light totally reflected by the first surface portion 64a is incident on the intermediate range of the third surface portion 64c. desirable. Specifically, when the third surface portion 64c is divided into three along the optical axis and named as the inner range, the middle range, and the outer range in order from the second surface portion 64b side, the light totally reflected by the first surface portion 64a. Of these, it is preferable that the light having the highest intensity, that is, the light totally reflected at the position closest to the plane of symmetry Sp on the first surface portion is included in the intermediate range.

As a result, the irradiation position in the irradiation region 13 irradiated with the high-intensity light among the light emitted from the lens unit 19 becomes the outer position in the irradiation region 13 in which the illuminance of a predetermined value or more is secured.

FIG. 9 illustrates three light distribution patterns K. The light distribution patterns Ka, Kb, and Kc are all light distribution patterns that make the illuminance of the irradiation region 13 uniform. The length of the irradiation region in the width direction becomes longer in the order of the light distribution patterns Ka, Kb, and Kc, that is, the irradiation region can be formed farther in the order of the orientation patterns Ka, Kb, and Kc.

(Various shapes of the second surface)
10 to 12 are light distribution pattern diagrams when the illuminance distribution of the irradiation region 13 is variously changed by aligning the emission direction angles of the maximum intensity of the lighting device 10 to be the same. The emission directions of the maximum intensity of the lighting device 10 are aligned with the symmetry angles of 20 ° and 170 ° with respect to the symmetry plane Sp in both the light distribution patterns of FIGS. 10 to 12.

In the light distribution pattern of FIG. 10, the illuminance distribution of the irradiation region 13 has substantially uniform illuminance in the width direction. In the light distribution pattern of FIG. 11, the illuminance distribution of the irradiation region 13 gradually increases (becomes brighter) from the inside to the outside in the width direction. In the light distribution pattern of FIG. 12, the illuminance distribution of the irradiation region 13 gradually decreases (darkens) from the inside to the outside in the width direction.

FIG. 13 is a diagram showing an example of three surface shapes of the second surface portion 64b. It is a figure which shows the surface shape Ca (solid line), the surface shape Cb (dotted line), and the surface shape Cc (broken line). These surface shapes Ca, Cb, and Cc are the surface shapes of the second surface portion 64b on the right side with respect to the plane of symmetry Sp. The surface shape Ca is a surface shape having a standard irradiation destination range (hereinafter referred to as “standard irradiation range”) by the irradiation light emitted from the second surface portion 64b. The surface shape Cb is a surface shape when the irradiation destination range due to the emitted light from the second surface portion 64b is shifted outward with respect to the standard irradiation range. The surface shape Cc is a surface shape when the irradiation destination range due to the light emitted from the second surface portion 64b is shifted inward with respect to the standard irradiation range.

(Modification example)
The radius 70 of FIG. 8 as the central surface portion of the surface on the light emitting side of the present invention has a concave surface shape on the outer surface side. The central surface portion of the present invention may have a surface shape that is convex toward the outer surface side, depending on the surface shape of the first surface portion.

In FIG. 4, the LED 17 as an LED light source is of a type in which a part of the emitted light of the light source main body 36 is wavelength-converted by the phosphor 37. The LED light source of the present invention may be one without the phosphor 37. Further, as the LED light source, LEDs 17 having a plurality of emission colors may be used. For example, a white LED including a red light emitting LED chip, a blue light emitting LED chip, and a green light emitting LED chip can be used.

In the embodiment, the first surface portion 64a is formed as a convex surface shape, but the first surface portion 64a in the lighting device of the present invention totally reflects the emitted light near the optical axis of the LED 17 and causes it to be incident on the third surface portion. However, it may be a flat surface as well as a convex surface. Further, when the lighting device of the present invention is used for fence lighting, the first surface portion is formed in a shape that is totally reflected by the first surface portion and the light emitted from the third surface portion does not enter the Kasagi portion.

In the embodiment, the emission spectrum of the LED 17 as the LED light source has a plurality of emission wavelength peaks. The emission spectrum of the LED light source of the present invention may have a single emission wavelength peak, in which case the formation of the unevenness 66 becomes unnecessary.

In the embodiment, the third surface portion 64c is a substantially V-shaped surface in which the tip portion is deleted by a predetermined amount. In the present invention, in order to obtain a desired light distribution pattern of the emitted light of the lighting device 10, the surface shape of the third surface portion 64c can be a convex shape or a concave shape with respect to the outer surface side in addition to the flat surface. ..

In the embodiment, the lighting device of the present invention has been described as a lighting device attached to the inside of a fence cap, but the lighting device of the present invention is attached to a handrail installed on a sidewalk or stairs, attached to a showcase, and a lighting device. It can be used in applications where it is preferred to irradiate a wide irradiation range on both sides with a uniform or gentle illuminance distribution.

In the embodiment, the lighting device of the present invention is attached to a fence to irradiate the road surface, but the irradiation target is not limited to the road surface. For example, the lighting device can be installed vertically between a plurality of glass doors of a refrigerated showcase installed in a store to illuminate the products displayed in the showcase.

10 ... Illumination device, 13 ... Irradiation area, 17 ... LED, 19 ... Lens unit (lens), 60 ... Light incident side, 61 ... Light emitting side, 64a ... 1st surface portion, 64b ... 2nd surface portion, 64c ... 3rd surface portion, 66 ... unevenness, 79 ... R (central surface portion), L ... irradiation light, Sp ... symmetrical plane.

Claims (4)

Multiple LED light sources arranged in a row with their optical axes aligned in the same direction,
A plane-symmetrical shape having a surface on the light incident side and a surface on the light emitting side facing the LED light source side and the opposite side, respectively, and having a plane including a plurality of optical axes of the plurality of LED light sources as a plane of symmetry. With a lens formed in and extending along a row of said plurality of LED light sources.
The width direction is perpendicular to the symmetry plane, the symmetry plane side is the inside, and the side opposite to the symmetry plane is the outside at each position in the width direction.
The surface of the lens on the light emitting side has a first surface portion, a second surface portion, and a third surface portion in order from the inside to the outside.
The first surface portion has a surface shape that totally reflects the light incident on the lens from the surface on the light incident side toward the third surface portion.
The second surface portion has a convex shape in which light incident on the lens is refracted and emitted from the surface on the light incident side.
Said third surface portion, have a surface shape for emitting light totally reflected by the first surface portion,
The convex shape of the second surface portion is formed so that the light rays on the first surface portion side and the light rays on the third surface portion side of the light incident on the second surface portion intersect after being emitted from the second surface portion. A characteristic lighting device. Multiple LED light sources arranged in a row with their optical axes aligned in the same direction,
A plane-symmetrical shape having a surface on the light incident side and a surface on the light emitting side facing the LED light source side and the opposite side, respectively, and having a plane including a plurality of optical axes of the plurality of LED light sources as a plane of symmetry. With a lens formed in and extending along a row of said plurality of LED light sources.
The width direction is perpendicular to the symmetry plane, the symmetry plane side is the inside, and the side opposite to the symmetry plane is the outside at each position in the width direction.
The surface of the lens on the light emitting side has a first surface portion, a second surface portion, and a third surface portion in order from the inside to the outside.
The first surface portion has a surface shape that totally reflects the light incident on the lens from the surface on the light incident side toward the third surface portion.
The second surface portion has a convex shape in which light incident on the lens is refracted and emitted from the surface on the light incident side.
Said third surface portion, have a surface shape for emitting light totally reflected by the first surface portion,
The first irradiation range that is totally reflected by the first surface portion and irradiated by the light emitted from the third surface portion is the second irradiation range irradiated by the light emitted from the second surface portion with respect to the symmetrical plane. Far away,
A lighting device characterized in that the first irradiation range and the second irradiation range are in contact with each other or overlap each other. In the lighting device according to claim 1 or 2.
The surface on the light emitting side has a central surface portion inside the first surface portion.
The central surface portion is a lighting device having a surface shape in which light incident from a surface on the light incident side is emitted in a direction of passing between the first surface portions. The lighting device according to any one of claims 1 to 3.
Each LED light source has a plurality of emission peak wavelengths in the emission spectrum of the emitted light.
A lighting device characterized in that irregularities for light scattering are formed on the third surface portion.

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