JP6292509B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device installed on a ceiling or the like.

  2. Description of the Related Art Conventionally, a base light type illumination device that is installed on an indoor or outdoor ceiling or the like and irradiates light directly under a space is known. As a conventional general base light type illumination device, it includes two straight tube fluorescent lamps arranged in parallel, a lighting device arranged between the fluorescent lamps, and a cover covered by the lighting device There is something. In many cases, the base light type illumination device is arranged such that a plurality of illumination devices are connected in the tube axis direction of a fluorescent lamp, for example, when illuminating a straight corridor. For this reason, the single base light type illumination device has a predetermined wide-angle light distribution on a surface perpendicular to the tube axis.

  In recent years, there has been known an illumination device using a straight tube type LED lamp having the same appearance as a straight tube type phosphor and using an LED as a light source (for example, see Patent Document 1). Moreover, the illuminating device provided with the light source part which arranged several LED on the elongate board | substrate in the line form, and the translucent cover which covers this light source part is known (for example, refer patent document 2). ). The LED is capable of emitting light with high power and high luminance, and is widely used as a light source for an illumination device that replaces a fluorescent lamp.

JP 2012-104328 A JP 2013-077400 A

  However, in the conventional general base light type illumination device and the illumination devices described in Patent Documents 1 and 2, two long and thin light sources are used to ensure wide-angle light distribution in a plane perpendicular to the tube axis. The lighting device is arranged in parallel and covered with a cover between them. In such a configuration, the cover may block light from the light source, and the luminous intensity in the direction directly below the lighting device may be low. On the other hand, if the number of LEDs is increased or the light emission output of the LEDs is increased in order to increase the direct luminous intensity of the lighting device, glare is likely to occur in the LED as the point light source, so that the appearance of the lighting device becomes dazzling.

  The present invention solves the above-described problems, and an object of the present invention is to provide an illuminating device that can increase the direct luminous intensity and reduce glare.

In order to solve the above problems, the present invention is a lighting device including a light source, a substrate on which the light source is mounted, and a bowl-shaped cover that covers the light source and the substrate. The cover has an optical axis in the normal direction, and the cover has an incident surface on which light from the light source is incident and an output surface that emits light incident on the incident surface, and light from the output surface. And the exit surface has an arc portion formed in the vicinity of the optical axis in a cross-sectional view orthogonal to the longitudinal direction of the cover, and a linear portion formed outside the arc portion. And a plurality of prisms for controlling the light distribution of the light incident on the exit surface is formed across the arc portion and the linear portion, and the prism refracts the light incident from the light source. A control surface that collects light in a predetermined direction including the optical axis direction, An angle formed by a plane parallel to the control surface and the substrate in a cross-sectional view orthogonal to the longitudinal direction of the cover. It has the part which increases monotonously as it leaves | separates from.

In the illuminating device, it is preferable that a recess formed by the control surface and the inclined surface of the prism is closer to the substrate as the distance from the optical axis increases.

  In the illumination device, it is preferable that the light source is provided at a position closer to the incident surface than the center of the arc of the arc portion.

  In the illumination device, it is preferable that the control surface and the inclined surface are smoothly connected by an R-shaped portion.

  In the illuminating device, in a cross-sectional view orthogonal to the longitudinal direction of the cover, a relationship between an interval p between the adjacent prisms and a height h of the prism satisfies 0 ≦ h / p ≦ 0.5. preferable.

  In the illuminating device, it is preferable that the cover has a texture or a light scattering agent applied to the incident surface or the emitting surface.

  In the lighting device, the cover is preferably made of a material containing a light diffusing agent.

  According to the present invention, the cover condenses the light in a predetermined direction including the optical axis direction by the plurality of prisms formed on the emission surface that emits the light, so that the light intensity directly below the illumination device can be increased. . In addition, the prism control surface has a portion where the angle formed by the plane parallel to the substrate increases monotonously as the distance from the optical axis increases. Therefore, this portion has a converging optical characteristic in the optical axis direction. Therefore, in particular, glare in an oblique direction from the light source can be suppressed.

(A) is a perspective view of the illuminating device which concerns on one Embodiment of this invention, (b) is a sectional side view of the illuminating device. (A) is a sectional side view of the cover used for the illumination device, (b) is a partially enlarged side sectional view of the cover. (A) Sectional drawing and partial enlarged view for demonstrating the shape of the prism recessed part of the output surface of the cover, (b) is a figure which shows the change of the angle between the said recessed parts. (A) Sectional drawing of a general flat type condensing lens, (b) is a partial sectional view of the said cover. The sectional side view of the lighting fixture using the said illuminating device. (A) is a figure which shows a light distribution curve when a cover is not used in the said illuminating device, (b) is a figure which shows a light distribution curve when the cover is used. The partial expanded sectional view which shows the modification of the cover.

  An illumination device according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 (a) and 1 (b), the illumination device 1 according to this embodiment includes a light source 2, a substrate 3 on which the light source 2 is mounted, a cover 4 that covers the light source 2 and the substrate 3, and holds them. And a base body 10 to be provided. The external appearance of the illuminating device 1 is a rectangular shape in front view, and has a laterally symmetrical side shape when viewed from the short side direction. The width of the base body 10 in the short direction is smaller than the width of the cover 4. Moreover, the illuminating device 1 is further provided with the power supply part (not shown) which is provided in the base body 10 inside or outside, and drives a light source to light. In addition, the wavy arrow in the figure shows an example of an optical path of light whose light distribution is controlled by the cover 4.

  The base body 10 has a construction surface 11 such as a ceiling formed of a flat surface, a mounting surface 12 of the substrate 3 on a surface opposite to the construction surface 11, and both side surfaces connecting both edges of the construction surface 11 and the mounting surface 12. 13. The distance between the side surfaces 13, that is, the width in the short direction of the base body 10 is smaller than the width of the cover 4. The mounting surface 12 has a concave portion 14 along the longitudinal direction at the center thereof, and the long substrate 3 is provided in the concave portion 14. The base body 10 is formed by pressing and cutting a plate material such as an aluminum plate or a steel plate having predetermined rigidity and heat resistance into the above shape. The mounting surface 12 may be coated with a white paint having a high visible light reflectance, or a reflective metal material may be deposited thereon.

  The light source 2 is composed of LEDs that are point light sources, and a plurality of LEDs are arranged in a line along the longitudinal direction of the substrate 3 at regular intervals. The light source 2 has an optical axis H in the normal direction of the substrate 3. The LED constituting the light source 2 is configured as an LED package by covering with a wavelength conversion member that converts the wavelength of light emitted from the LED chip. The light source 2 is not particularly limited as long as it is a light source that can emit light of a desired light color as the illumination device 1. For example, a YAG fluorescent light is applied to a GaN blue LED chip that emits blue light having an emission peak wavelength of 460 nm. A so-called white LED that covers the body is preferably used. In addition, it is also possible to use a plurality of LEDs having different emission colors, arrange them in a row, and mix the emitted light of each LED to realize predetermined irradiation light. Examples of the combination of LEDs include white light and a light bulb color, or a combination of three primary colors (RGB). In addition, the output of these LEDs can be individually controlled to make the color temperature of the irradiation light variable.

  The substrate 3 is a long plate-like member formed so that a plurality of light sources 2 can be mounted in a row, and as the base material, for example, a general-purpose substrate plate material such as glass epoxy resin is preferably used. Used. On the substrate 3, a terminal portion electrically connected to a wiring pattern (not shown) for supplying power to the LED is formed on the LED mounting surface.

  The cover 4 has a bowl shape in appearance so that the light sources 2 arranged in a row can be collectively covered, and the bowl-shaped concave side surface becomes an incident surface 41 on which light from the light source 2 is incident, The convex side surface becomes the exit surface 42 that emits the light incident on the entrance surface 41. Further, the cover 4 has a protruding portion 42 </ b> A used for attachment to the base body 10 on the incident surface 41 side, and a part of the protruding portion 42 </ b> A is in contact with the mounting surface 12 of the base body 10. The cover 4 is made of translucent polycarbonate or acrylic resin.

  As shown in FIGS. 2A and 2B, the exit surface 42 of the cover 4 has a plurality of prisms 43 that control the light distribution of the light incident on the exit surface 42. The prism 43 is formed so as to collect light in a predetermined direction including the optical axis H direction. Specifically, each prism 43 is in contact with the control surface 44 and a control surface 44 that refracts light incident from the light source 2 and exits from the cover 4 and condenses the light in the optical axis H direction. And an inclined surface 45 inclined with respect to the control surface 44. The plurality of prisms 43 are divided into a prism group 43 a whose control surface 44 is inclined to the plus side with respect to the plane S ′ parallel to the substrate 3 and a prism group 43 b which is inclined to the minus side. The prism group 43a and the prism group 43b are reversed with the desired maximum luminous intensity direction M as a boundary in a cross-sectional view orthogonal to the longitudinal direction of the cover 4.

  The prism 43 according to the present embodiment is a group of prisms whose maximum luminous intensity direction M is the optical axis H direction in a cross-sectional view orthogonal to the longitudinal direction of the cover 4 and which are inclined to the plus side with respect to the plane S ′ parallel to the substrate 3. 43a and a prism group 43b inclined to the negative side. The prism groups 43a and 43b are formed so as to be symmetric with respect to the optical axis H.

  Further, in the vicinity of the optical axis H (see also FIG. 1B), the angle formed by the control surface 44 and the plane S ′ parallel to the substrate 3 (hereinafter, the tilt angle θ1 of the control surface 44) is approximately 0 ° (for example, The light emitted from the light source 2 to the vicinity of the optical axis H is emitted in the direction of the optical axis H with almost no refraction. On the other hand, in the direction away from the vicinity of the optical axis H, the inclination angle θ1 of the control surface 44 has a portion that monotonously increases as the distance from the optical axis H increases. In this place, in the cross-sectional view orthogonal to the longitudinal direction of the cover 4, the inclination angle θ <b> 1 of the control surface 44 increases from the center (optical axis H) toward the edge. In the present embodiment, the portion where the inclination angle θ1 monotonously increases extends over substantially the entire area of the emission surface 42, so that the control surface 44 of each prism 43 emits light over the entire area from the center to the periphery of the emission surface 42. Condensation in axis H direction. Thereby, especially the glare of the diagonal direction from the light source 2 can be suppressed.

  On the other hand, since the inclined surface 45 is not formed as such, the light incident on the inclined surface 45 is emitted in directions other than the maximum luminous intensity direction M, which is the optical axis H. Therefore, the cover 4 having such a prism 43 can increase the maximum luminous intensity in the direction of the optical axis H in the light emitted from the emission surface 42 and irradiates a certain amount of light in other directions. be able to.

  The prism 43 has an angle formed with the maximum luminous intensity direction M (optical axis H) of the light emitted from the emission surface 42 in a cross section orthogonal to the longitudinal direction of the cover 4 (incident ray angle α: see FIG. 2A). In the range of 60 ° or less, the inclined surface 45 is configured to be shorter than the control surface 44. A general LED light distribution used for the light source 2 is a Lambertian light distribution, and the luminous intensity of light emitted from the light source 2 is about ½ in the direction of 60 ° from the optical axis H. Therefore, by increasing the area of the control surface 44 in the angle range where the luminous intensity is high, the light condensing property in the maximum luminous intensity direction M (optical axis H) can be improved.

  The control surface 44 and the inclined surface 45 are smoothly connected by an R-shaped portion (reference numeral R in the drawing: see FIG. 2B). According to this configuration, when a stress is applied to the cover 4 from the outside, the stress is not concentrated in the concave portion (the portion of the R-shaped portion) formed by the control surface 44 and the inclined surface 45, and the cover 4 is not cracked. Can be suppressed. In addition, since the cover 4 is difficult to break, the thickness d of the cover 4 can be reduced, and the material cost for manufacturing the cover 4 can be reduced. The cover thickness d is preferably 1.0 to 1.5 mm. Further, R is preferably larger than 0.25 times the maximum value of the prism height h.

  In the vicinity of the maximum luminous intensity direction M of the light emitted from the emission surface 42, the relationship between the interval p between the adjacent prisms 43 and the height h of the prisms 43 satisfies 0 ≦ h / p ≦ 0.5. Is desirable. By setting the relationship between the spacing p and the height h of the prism 43 as described above, the control surface 44 and the inclined surface 45 can be secured without securing the inclination angle of the control surface 44 and reducing the light collecting performance. It can suppress that the angle of the recessed part to make becomes too narrow. The height h of the prism 43 is preferably 1 mm or less, and the interval p between the prisms 43 is preferably 1 mm or more.

  Furthermore, it is desirable that the relationship between the height h of the prism 43 and the thickness d of the cover 4 satisfies 0 ≦ h / d ≦ 1. In this way, since a predetermined thickness d can be secured in the cover 4, the height of the prism 43 is suppressed while maintaining the strength of the cover 4, and the necessary amount of translucent material used for manufacturing the cover 4 is reduced. be able to. Moreover, the moldability of the resin used as the material of the cover 4 is improved.

  Further, as shown in FIG. 3A, it is desirable that the concave portion 46 formed by the control surface 44 and the inclined surface 45 in the prism 43 is closer to the substrate 3 as the distance from the optical axis H increases. That is, the cover 4 has a hook shape that is convex in the light emission direction as a whole, and the prism 43 is formed along the shape of the outer surface of the hook shape (the emission surface 42). Specifically, the prism 43 outside the vicinity of the optical axis H (for example, the illustrated point No. 5) has an angle formed by a line connecting adjacent recesses 46 and a plane S ′ parallel to the substrate 3. As shown in FIG. 3B, θ2 (see, for example, point No. 11-13 shown in the figure) monotonously increases as the adjacent concave portions 46 move away from the optical axis H. If it carries out like this, light which can be light-distributed by the prism 43 among the lights radiate | emitted from the light source 2 can be increased, and condensing property can be improved.

  By the way, as shown in FIG. 4A, in the general flat type condensing lens 4 ′, the control surface 44 ′ and the non-control surface adjacent to the control surface 44 ′ in any of the adjacent prisms 43 ′ and 43 ″. The height of the convex portion 47 'is the same as that of 45'. Therefore, the light reflected from the incident surface 41 of the cover 4 from the light source 2 and returned to the instrument body may enter the cover 4 again and be emitted from the non-control surface 45, resulting in glare in the instrument oblique direction. . On the other hand, as shown in FIG. 4B, the cover 4 of this embodiment has a bowl shape, so that the convex portions 47 of the prisms 43 are located higher on the optical axis H side (separated from the substrate 3). doing). Therefore, the light emitted from the inclination 45 of one prism 43 is easily reflected by the control surface 44 of the adjacent prism 43, and glare in the instrument oblique direction can be suppressed.

  As shown in FIG. 5, the emission surface 42 of the cover 4 is formed outside the arc portion 4a and the arc portion 4a formed in the vicinity of the optical axis H in a cross-sectional view orthogonal to the longitudinal direction of the cover 4. And a straight line portion 4b. The circular arc part 4a is preferably formed so that the incident light angle α from the light source 2 is in the range of about 70 to 80 °. Since the amount of light increases in this range, desired light distribution can be efficiently realized by the prism of the arc portion 4a. Moreover, when the main body case 15 of the lighting fixture 20 using the illuminating device 1 has a trapezoidal cross section as illustrated, the inclined surface of the main body case 15 and the straight portion 4b of the cover 4 have a smooth and continuous plane. Since it comprises, the beauty | look of the lighting fixture 20 (illuminating device 1) becomes good. Moreover, the slim feeling of the lighting fixture 20 can be provided by making the both edges of the lighting fixture 20 and the edge part of the cover 4 into an inclined surface as mentioned above.

  Further, the light source 2 is preferably provided at a position closer to the incident surface 41 than the arc center T of the arc portion 4a. Thereby, since the light which goes to the cover 4 from the light source 2 increases in the optical axis H vicinity, the condensing property to the optical axis H direction can be improved. Further, since light emitted in the wide-angle direction is reduced, glare in the oblique direction of the instrument can be effectively suppressed.

  6A shows a light distribution curve when the cover 4 is not used in the lighting device 1, and FIG. 6B shows a light distribution curve when the cover 4 is used. That is, by using the cover 4, the light emitted from the light source 2 can be condensed and the luminous intensity in the optical axis H direction (0 °) can be increased.

  In the present embodiment, the cover 4 is configured to have light diffusibility. Specifically, as shown in FIG. 2B, the incident surface 41 or the emission surface 42 of the cover 4 (a part of the emission surface 42 in the illustrated example) is translucent or contains a light scattering agent. The diffusion treatment layer 48 is formed by applying a functional resin (or sheet).

  As shown in FIG. 7, the cover 4 may be made of a material containing a light diffusing agent 49 such as titanium oxide. The diffusivity of the cover 4 in this configuration varies depending on the thickness of the cover 4, but when the cover 4 has a thickness of 1 mm, the diffusivity is preferably 42% or less.

  According to this configuration, since the emitted light can be dispersed to a certain degree, the occurrence of glare can be reduced. That is, according to the illuminating device 1, the prism 43 formed on the incident surface 41 of the cover 4 can increase the light intensity directly below the illuminating device 1, and the cover 4 has light diffusibility. The glare can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, the description has been made based on the configuration example in which the prism 43 is formed so that the maximum luminous intensity direction M is the optical axis H direction. However, the prism 43 may be formed such that the maximum luminous intensity direction M emitted from the emission surface 42 is inclined with respect to the optical axis H. Here, it is desirable that the maximum luminous intensity direction M is inclined with respect to the optical axis H within a range of 10 to 30 °. If it carries out like this, what is called wall washer illumination which irradiates light toward a wall surface by replacing the cover 4 can be performed. In this case, except for the shape of the prism 43, the cover 4 is preferably symmetrical with respect to the optical axis H in a cross section orthogonal to the longitudinal direction of the cover 4. If it carries out like this, the maximum luminous intensity direction can be reversed only by inverting and attaching the cover 4 to the base body 10, without changing the attachment direction of instrument itself. Moreover, although the structure which used LED which is a point light source as the light source 2 was shown, the light source 2 may be a linear light source like a straight tube | pipe type fluorescent lamp, for example, and like organic EL A planar light source may be used.

DESCRIPTION OF SYMBOLS 1 Lighting fixture 2 Light source 3 Board | substrate 4 Cover 41 Incident surface 42 Outgoing surface 43 Prism 44 Control surface 45 Inclined surface 46 The recessed part which a control surface and an inclined surface comprise 48 Diffusion processing layer 49 Light diffusing agent H Optical axis R R-shaped part of light source p Distance between adjacent prisms h Prism height θ1 Angle formed between the control surface and a plane parallel to the substrate θ2 Angle formed between the control surface and the inclined surface

Claims (7)

A lighting device comprising a light source, a substrate on which the light source is mounted, and a bowl-shaped cover that covers the light source and the substrate,
The light source has an optical axis in a normal direction of the substrate;
The cover has an incident surface on which light from the light source is incident, and an emission surface that emits light incident on the incident surface, and diffuses and emits light from the emission surface.
The exit surface has an arc portion formed in the vicinity of the optical axis in a cross-sectional view orthogonal to the longitudinal direction of the cover, and a linear portion formed outside the arc portion, and the exit surface A plurality of prisms for controlling the light distribution of the light incident on the surface is formed across the arc portion and the straight portion,
The prism includes a control surface that refracts light incident from the light source and collects light in a predetermined direction including an optical axis direction, and an inclined surface that is in contact with the control surface and is inclined with respect to the control surface. And
An illumination device characterized in that, in a cross-sectional view orthogonal to the longitudinal direction of the cover, an angle formed by a plane parallel to the control surface and the substrate increases monotonously as the distance from the optical axis increases. 2. The illumination device according to claim 1, wherein a concave portion formed by the control surface and the inclined surface of the prism is closer to the substrate as the distance from the optical axis is increased. The lighting device according to claim 2 , wherein the light source is provided at a position closer to the incident surface than a center of an arc of the arc portion . The lighting device according to any one of claims 1 to 3, wherein the control surface and the inclined surface are smoothly connected by an R-shaped portion. The cross-sectional view orthogonal to the longitudinal direction of the cover is such that the relationship between the interval p between the adjacent prisms and the height h of the prism satisfies 0 ≦ h / p ≦ 0.5. The illumination device according to any one of claims 1 to 4 . The lighting device according to any one of claims 1 to 5, wherein the cover has a texture or a light scattering agent applied to the entrance surface or the exit surface . The illumination device according to any one of claims 1 to 5 , wherein the cover is made of a material containing a light diffusing agent .