JP2012185955A - Lighting system - Google Patents

Abstract

An illumination device capable of improving light utilization efficiency is provided.
In an illuminating device 1 having a light source 3 made of LEDs and a transmissive cover 2 that covers the light source 3 and transmits the emitted light of the light source 3 to emit illumination light, an inner surface 2b of the transmissive cover 2 is a light source. 3 has a protrusion 2c protruding inward or outward in a predetermined range including on the optical axis C, and the protrusion 2c guides light emitted from the light source 3 and reflected by the protrusion 2c in a direction different from the incident direction. .
[Selection] Figure 2

Description

  The present invention relates to an illumination device including a transmission cover that covers a light source and emits illumination light.

  A conventional illumination device is disclosed in Patent Document 1. This illuminating device has a light source composed of LEDs and is formed in a straight tube type extending in the axial direction. The outer surface of the lighting device is covered with a transmission cover having a circular cross section. A long substrate is arranged in the axial direction in which a plurality of light sources are mounted at predetermined intervals in the transmission cover.

  The substrate on which the light source is mounted is held by a holder member fitted in the transmission cover. The light source is arranged with the optical axis orthogonal to the substrate aligned with the center line of the transmission cover and offset from the center of the transmission cover. Further, the holder member is provided with a reflection portion arranged around the light source on the substrate.

  The light emitted radially from the light source passes through the transmission cover. Further, the light reflected by the inner surface of the transmission cover is reflected again by the reflection portion and passes through the transmission cover. Thereby, illumination light is emitted from the peripheral surface of the transmission cover. By providing the reflecting portion, the amount of light absorbed by the substrate can be reduced.

JP 2010-129382 A (pages 5 to 15, FIG. 2)

  However, according to the conventional illumination device, when light near the optical axis of the light source is reflected by the transmission cover, the reflected light travels in a direction returning to the light source side. Outer members such as LED elements that are light sources, resins that seal the LED elements, phosphors contained in the resins, and substrates on which the light sources are mounted have low reflectivity, and light that travels in the direction returning to the light source side Absorbed. For this reason, there is a problem that light that can be extracted as effective illumination light is reduced, and light use efficiency is lowered.

  An object of this invention is to provide the illuminating device which can improve the utilization efficiency of light.

  In order to achieve the above object, the present invention provides a lighting device including a light source and a transmissive cover that covers the light source and transmits the emitted light of the light source to emit illumination light. Protruding portions projecting inward or outward within a predetermined range including on the optical axis of the light source, and the projecting portions guide light emitted from the light source and reflected by the projecting portions in a direction different from the incident direction. It is a feature.

  According to this configuration, light emitted from the light source passes through the transmission cover, and illumination light is emitted from the transmission cover. In addition, the light in the vicinity of the optical axis emitted from the light source transmits through the protrusion provided on the transmission cover and is reflected by the protrusion. The light reflected by the protruding portion travels in a direction different from that when entering the protruding portion, and is guided to the outer peripheral side with respect to the light source.

  According to the present invention, in the illumination device having the above-described configuration, the projecting portion has a center of curvature outside the inner surface of the transmission cover and projects inward, and the light except on the optical axis is away from the optical axis of the light source. It is characterized by being reflected on the surface. According to this configuration, the projecting portion is formed in, for example, a cylindrical surface or a spherical surface, and projects inward from the inner surface of the transmission cover. Light near the optical axis emitted from the light source angle increases with respect to the optical axis is reflected in a direction away from the optical axis by the projecting portion. Thereby, the reflected light of a protrusion part is guide | induced to the outer peripheral side with respect to a light source.

  According to the present invention, in the illumination device having the above-described configuration, the protrusion has a center of curvature on the inner side of the inner surface of the transmission cover and protrudes outward, and the radius of curvature is larger than that of the inner surface of the transmission cover excluding the protrusion. It is small. According to this configuration, the projecting portion is formed in, for example, a cylindrical surface or a spherical surface, and projects outward from the inner surface of the transmission cover. Since the radius of curvature of the protruding portion is small, the incident angle of light near the optical axis emitted from the light source is large, and the angle of the reflected light with respect to the optical axis is large. Thereby, the reflected light of a protrusion part is guide | induced to the outer peripheral side with respect to a light source.

  According to the present invention, in the illumination device configured as described above, a reflecting portion is provided around the light source. According to this configuration, the light reflected by the protruding portion and guided to the outer peripheral side of the light source is reflected again by the reflecting portion and emitted from the transmission cover.

  According to the present invention, in the illumination device having the above-described configuration, the light emitted from the light source and reflected by the outer peripheral portion of the protruding portion is guided to the reflecting portion. According to this configuration, the reflected light from the outer periphery of the protruding portion is guided to the reflecting portion, and most of the reflected light from the protruding portion is reflected by the reflecting portion.

  According to the present invention, in the illumination device configured as described above, a cross-sectional shape of an inner surface of the transmission cover excluding the protrusion includes a part of an ellipse, and the light source is offset in a major axis direction with respect to the center of the ellipse. The optical axis of the light source coincides with the major axis direction. According to this configuration, the light reflected by the inner surface of the transmissive cover excluding the protruding portion is guided to the outer peripheral side with respect to the light source.

  According to the present invention, in the illumination device configured as described above, an inner surface of the transmission cover excluding the projecting portion has a plane perpendicular to the optical axis of the light source. According to this configuration, the light reflected by the inner surface of the transmissive cover excluding the protruding portion is guided to the outer peripheral side with respect to the light source.

  According to the present invention, in the illumination device having the above-described configuration, a chamfered portion formed of a curved surface having a center of curvature opposite to the center of curvature of the projecting portion with respect to the inner surface of the transmission cover is continuous with the outer peripheral portion of the projecting portion. It is characterized by having been established. According to this structure, the rapid change of the thickness of the permeation | transmission cover between the circumference | surroundings of a protrusion part and a protrusion part is reduced.

  According to the present invention, in the illumination device configured as described above, the transmission cover includes a diffusing material. According to this configuration, the light transmitted through the transmission cover is diffused by the diffusing material.

  According to the present invention, in the illumination device configured as described above, the light source is an LED.

  According to the present invention, the protrusion provided on the inner surface of the transmission cover guides the reflected light in a direction different from the incident direction, so that the light near the optical axis is reflected away from the light source by the protrusion. Therefore, the light absorbed by returning to the light source can be reduced, and the light use efficiency of the lighting device can be improved.

Front sectional drawing which shows the illuminating device of 1st Embodiment of this invention. AA sectional view of FIG. Side surface sectional drawing which shows the illuminating device of 2nd Embodiment of this invention. The top view which shows the inside of the illuminating device of 3rd Embodiment of this invention. BB sectional view of FIG. Front sectional drawing which shows the illuminating device of 4th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a front cross-sectional view of the illumination device of the first embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG. The illumination device 1 is formed in a long straight tube type extending in the axial direction. The illuminating device 1 extends in one direction, and a support plate 5 installed on the installation surface is disposed on the bottom surface.

  On the support plate 5, a substrate 4 in which a plurality of light sources 3 that emit points such as LEDs are arranged in parallel in the axial direction is disposed. A light source that emits light in the axial direction may be provided on the substrate 4. On the substrate 4, a reflection portion 6 formed of a PET sheet or the like is attached. The reflection part 6 has a through hole 6 a through which the light source 3 passes, and is disposed around the light source 3.

  The upper part of the light source 3 is covered with a transmissive cover 2. The transmission cover 2 is formed by extrusion molding a resin such as polycarbonate or acrylic containing a diffusing material, and diffuses and transmits the light emitted from the light source 3 to emit illumination light. Engaging claws 2e that are bent inward are provided at both ends of the bottom of the transparent cover 2, and the engaging claws 2e are engaged with the protrusions 5a provided on the support plate 5 to hold the transparent cover 2. . Note that both ends of the transmission cover 2 and the support plate 5 in the axial direction are covered with caps 7 and are closed.

  The transmission cover 2 is formed by a part of concentric ellipses E1 and E2 whose cross sections of the outer surface 2a and the inner surface 2b are respectively centered on O in the illumination light emission range. For example, the ellipse E1 has a long side of 19.2 mm and an eccentricity of 0.286. For example, the ellipse E2 has a long side of 18 mm and an eccentricity of 0.286. The optical axis C orthogonal to the substrate 4 coincides with the major axes of the ellipses E1 and E2, and the light source 3 is offset in the major axis direction in the direction approaching the protrusion 2c with respect to the center O and is one focal point of the ellipse E2. Arranged.

  The inner surface 2b of the transmission cover 2 is provided with a protruding portion 2c that extends in the longitudinal direction of the transmission cover 2 and protrudes inward within a predetermined range sandwiching the optical axis C. The protrusion 2c has a center of curvature outside the inner surface 2b of the transmission cover 2, and the cross-sectional shape is formed, for example, as a part of a circle having a radius of 18.7 mm or a part of an ellipse. Thereby, the thickness of the transmission cover 2 is non-uniform | heterogenous in the protrusion part 2c.

  Further, continuous chamfered portion 2f on the outer periphery of the projecting portion 2c is formed on the inner surface 2b of the translucent cover 2. The chamfered portion 2f is formed by a curved surface having a center of curvature on the side opposite to the center of curvature of the protruding portion 2c with respect to the inner surface 2b of the transmission cover 2. The chamfered portion 2f smoothly connects the boundary between the outer peripheral portion of the protruding portion 2c and the inner surface 2b around the protruding portion 2c. Thereby, a sudden change in the thickness of the transmission cover 2 between the periphery of the protrusion 2c and the protrusion 2c is reduced, and unevenness of light emitted from a region where the thickness of the transmission cover 2 is not uniform is reduced. Can do.

  The protrusion 2c is formed, for example, in a range where the central angle with respect to the optical axis C is ± 20.6 °. By forming the protruding portion 2c with a central angle within the range of ± 30 ° or less with respect to the optical axis C, it is possible to easily form the transmissive cover 2 while avoiding a significant increase in the thickness of the transmissive cover 2. . It is also possible to form the concave portions facing the protruding portion 2c of the outer surface 2a of the transmission cover 2 along the protruding portions 2c. Thereby, the thickness of the transmissive cover 2 can be made uniform and easily formed.

  In the illuminating device 1 having the above configuration, the light emitted radially from the light source 3 reaches the inner surface 2 b of the transmission cover 2. Light in the vicinity of the optical axis C of the light source 3 reaches the projecting portion 2c, passes through the transparent cover 2 as indicated by an arrow S11. The light away from the optical axis C of the light source 3 reaches the inner surface 2b around the protrusion 2c and passes through the transmission cover 2 as indicated by an arrow S21. Thereby, illumination light is emitted from the transmission cover 2.

  Further, a part of the light in the vicinity of the optical axis C except on the optical axis C of the light source 3 reaches the projecting portion 2c and is reflected by the projecting portion 2c as indicated by an arrow S12, and is separated from the optical axis C and is incident on the incident direction. Guided in different directions. As a result, the reflected light of the protruding portion 2c is reflected by the reflecting portion 6 at a position away from the light source 3, and the illumination light is emitted through the transmission cover 2 as indicated by an arrow S13. At this time, the light reflected again by the transmission cover 2 is negligible because the amount of light is very small.

  The light emitted from the light source 3 has a high luminous intensity on the optical axis C due to Lambert's cosine law. For this reason, the light in the vicinity of the optical axis C is reflected to a position away from the light source 3 by the projecting portion 2c, and absorption of light by the light source 3 can be reduced to improve the light utilization efficiency.

  Some of the light that has reached the inner surface 2b of the periphery of the projecting portion 2c is reflected by the inner surface 2b as indicated by an arrow S22. At this time, the cross-sectional shape of the inner surface 2b is formed by a part of the ellipse E2, and the light source 3 is offset with respect to the center O of the ellipse E2 and is disposed at one focal point. In the direction different from the incident direction. Thereby, the reflected light around the protruding portion 2c is reflected by the reflecting portion 6, and the illumination light is emitted through the transmission cover 2 as indicated by an arrow S23.

  According to the present embodiment, the protrusion 2c provided on the inner surface 2b of the transmission cover 2 guides the reflected light in a direction different from the incident direction, so that the light near the optical axis C is reflected away from the light source 3 by the protrusion 2c. . Therefore, the light absorbed by returning to the light source 3 can be reduced, and the light use efficiency of the lighting device 1 can be improved.

  Further, since the protruding portion 2c has a center of curvature outside the inner surface 2b of the transmissive cover 2 and protrudes inward, the light except on the optical axis C is reflected in a direction away from the optical axis C of the light source 3, so that the optical axis The protruding portion 2c that reflects light in the vicinity of C and guides it to a position away from the light source 3 can be easily realized.

  Moreover, since the reflection part 6 is arrange | positioned around the light source 3, the reflected light of the transmissive cover 2 can be reflected by the reflection part 6, and can be utilized as illumination light. The reflective portion 6 may be formed by applying a highly reflective white paint or the like on the substrate 4 or the support plate 5 around the substrate 4.

  The reflecting portion 6 covers the path of the light reflected by the outer peripheral portion of the protruding portion 2c, and the light is guided to the reflecting portion 6. Thereby, most of the light reflected by the protrusion 2c reaches the reflection part 6, and the light emitted from the transmission cover 2 toward the installation surface without reaching the reflection part 6 can be reduced.

  Further, the cross-sectional shape of the inner surface 2b of the transmission cover 2 excluding the projecting portion 2c includes a part of the ellipse E2, and the light source 3 is offset in the long axis direction with respect to the center O of the ellipse E2, so that the optical axis C of the light source 3 Coincides with the major axis direction. Thereby, the light reflected by the inner surface 2 b of the transmissive cover 2 excluding the protruding portion 2 c is guided to the outer peripheral side with respect to the light source 3. Therefore, it is possible to further reduce the light absorbed by returning to the light source 3.

  In addition, although the light source 3 is offset in the direction which approaches the protrusion part 2c with respect to the center of the ellipse E2, you may offset in the direction away from the protrusion part 2c. Further, the cross-sectional shape of the inner surface 2b of the transmissive cover 2 excluding the projecting portion 2c may be formed in an arc shape composed of a part of a circle, and the light source 3 may be arranged to be offset with respect to the center of the circle.

  Moreover, since the chamfered part 2f which continues in the outer peripheral part of the protrusion part 2c was provided, the rapid change of the thickness of the permeation | transmission cover 2 between the circumference | surroundings of the protrusion part 2c and the protrusion part 2c is reduced. Therefore, unevenness of light emitted from a region where the thickness of the transmission cover 2 is not uniform can be reduced.

  Moreover, since the transmissive cover 2 contains a diffusing material, glare can be reduced by diffusing transmitted light. At this time, since the protrusion 2c protrudes inward from the inner surface 2b of the transmission cover 2, the thickness is increased, and the proportion of light diffused by the diffusing material increases. Accordingly, the protruding portion 2c the intensity of the light is provided in the strong light axis C near, it is possible to reduce more effectively glare.

  Next, FIG. 3 has shown side surface sectional drawing of the illuminating device 1 of 2nd Embodiment. For convenience of explanation, FIG. 1 described above, the same parts as in the first embodiment shown in FIG. 2 are denoted by the same reference numerals. In the present embodiment, instead of the protruding portion 2c (see FIG. 2) of the first embodiment, a protruding portion 2d protruding outward is provided on the inner surface 2b of the transmission cover 2. Other parts are the same as those in the first embodiment.

  The protrusion 2d extends in the longitudinal direction of the transmission cover 2 and is provided in a predetermined range with the optical axis C interposed therebetween. The cross-sectional shape of the projecting portion 2d is formed by a part of a circle or an ellipse having a center of curvature inside the inner surface 2b of the transmission cover 2. The radius of curvature of the protruding portion 2d is formed smaller than the minimum radius of curvature of the ellipse E2 that forms the inner surface 2b excluding the protruding portion 2d. Thereby, the thickness of the transmission cover 2 is non-uniform | heterogenous in the protrusion part 2d.

  As in the first embodiment, a chamfered portion 2f (see FIG. 3) having a curved surface having a center of curvature opposite to the center of curvature of the protruding portion 2d with respect to the inner surface 2b is continuous with the outer peripheral portion of the protruding portion 2d. May be provided. Thus, the boundary between the inner surface 2b surrounding the outer peripheral portion and the protruding portion 2d of the projecting portion 2d is smoothly connected. In addition, a portion of the outer surface 2a of the transmissive cover 2 facing the protruding portion 2d may be formed as a convex surface along the protruding portion 2d so that the thickness of the transmissive cover 2 is uniform.

  In the illuminating device 1 having the above configuration, the light emitted radially from the light source 3 reaches the inner surface 2 b of the transmission cover 2. Light away from the optical axis C of the light source 3 reaches the inner surface 2b around the protrusion 2d, and is transmitted or reflected through the transmission cover 2 in the same manner as the arrows S21 and S22 (see FIG. 2) of the first embodiment.

  Light in the vicinity of the optical axis C of the light source 3 reaches the projecting portion 2d and passes through the transmission cover 2 as indicated by an arrow S31. Further, a part of the light in the vicinity of the optical axis C except on the optical axis C of the light source 3 reaches the protruding portion 2d and is reflected by the protruding portion 2d as indicated by an arrow S32. At this time, since the curvature radius of the protrusion 2d is small, the reflected light is guided in a direction different from the incident direction with a large angle with respect to the optical axis C. Thereby, the reflected light of the protruding portion 2d is reflected by the reflecting portion 6 at a position away from the light source 3, and the illumination light is emitted through the transmission cover 2 as indicated by an arrow S33.

  According to the present embodiment, as in the first embodiment, the protruding portion 2d provided on the inner surface 2b of the transmission cover 2 guides the reflected light in a direction different from the incident direction, so that light in the vicinity of the optical axis C is transmitted by the protruding portion 2d. Reflected away from the light source 3. Therefore, the light absorbed by returning to the light source 3 can be reduced, and the light use efficiency of the lighting device 1 can be improved.

  Further, since the projecting portion 2d has a center of curvature inside the inner surface 2b of the transmission cover 2 and projects outward, the radius of curvature is smaller than the radius of curvature of the ellipse E2 forming the inner surface 2b excluding the projecting portion 2d. The protrusion 2d that reflects the light in the vicinity of the axis C and guides it to a position away from the light source 3 can be easily realized.

  The reflecting portion 6 is arranged on the path of light reflected by the outer peripheral portion of the protruding portion 2d, and the light is guided to the reflecting portion 6. Thereby, most of the light reflected by the projecting portion 2d reaches the reflecting portion 6, and the light emitted from the transmission cover 2 toward the installation surface without reaching the reflecting portion 6 can be reduced.

  Next, FIG. 4 shows a plan view of the interior of the illumination device of the third embodiment. FIG. 5 is a cross-sectional view taken along the line BB in FIG. For convenience of explanation, FIG. 1 described above, the same parts as in the first embodiment shown in FIG. 2 are denoted by the same reference numerals. The lighting device 10 has a substantially rectangular cross-sectional shape extending in one direction and perpendicular to the installation surface.

  On the bottom surface of the illuminating device 10, a rectangular support plate 5 installed on the installation surface is disposed. On the support plate 5, substrates 4 in which a plurality of light sources 3 that emit points such as LEDs are arranged in parallel in one direction are arranged in a plurality of rows (three rows in this embodiment). Thereby, the light sources 3 are arranged in a matrix. The light sources 3 may be arranged in a matrix on a single substrate in which a plurality of rows of substrates 4 are integrated. Further, light sources that emit light may be arranged in a plurality of rows.

  PET reflection part 6 made of sheet or the like is formed on the rectangular plan view, pasted over on each substrate 4. Through holes 6 a through which the light source 3 penetrates are provided in a matrix in the reflecting portion 6, and are arranged around the light source 3.

  Engaging claws 2e that are bent inward are provided at both ends of the bottom of the transparent cover 2, and the engaging claws 2e are engaged with the protrusions 5a provided on the support plate 5 to hold the transparent cover 2. . The outer surface 2 a and the inner surface 2 b of the transmission cover 2 are formed by a plane orthogonal to the optical axis C of the light source 3.

  In addition, the inner surface 2b of the transmission cover 2 is provided with a protruding portion 2c similar to that of the first embodiment. Protrusions 2c extends in the longitudinal direction of the transmission cover 2 is formed to protrude inward in a predetermined range which sandwich the optical axis C. The protrusion 2c has a center of curvature outside the inner surface 2b of the transmission cover 2, and the cross-sectional shape is formed by a part of a circle or a part of an ellipse, for example. Thereby, the thickness of the transmission cover 2 is non-uniform | heterogenous in the protrusion part 2c.

  Further, a chamfered portion 2f similar to that of the first embodiment is continuously provided on the outer peripheral portion of the protruding portion 2c, and a boundary with a plane forming the inner surface 2b is smoothly connected. The protrusion 2c may be formed of a spherical surface or an elliptical surface corresponding to the light source 3 and arranged in a matrix on the inner surface 2b.

  In the illumination device 10 having the above configuration, the light emitted radially from the light source 3 reaches the inner surface 2b of the transmission cover 2. The light in the vicinity of the optical axis C of the light source 3 reaches the protruding portion 2c and passes through the transmission cover 2 as indicated by an arrow S41. The light away from the optical axis C of the light source 3 reaches the inner surface 2b around the protrusion 2c and passes through the transmission cover 2 as indicated by an arrow S51. Thereby, illumination light is emitted from the transmission cover 2.

  Further, a part of the light in the vicinity of the optical axis C except on the optical axis C of the light source 3 reaches the projecting portion 2c and is reflected by the projecting portion 2c as indicated by an arrow S42. Guided in different directions. Thereby, the reflected light of the protrusion part 2c is reflected by the reflecting part 6 at a position away from the light source 3, and the illumination light is emitted through the transmission cover 2 as indicated by an arrow S43.

  Some of the light that has reached the inner surface 2b of the periphery of the projecting portion 2c is reflected by the inner surface 2b as indicated by an arrow S52. Thereby, the reflected light around the protruding portion 2c is reflected by the reflecting portion 6, and the illumination light is emitted through the transmission cover 2 as indicated by an arrow S53.

  According to the present embodiment, as in the first embodiment, the protrusion 2c provided on the inner surface 2b of the transmission cover 2 guides the reflected light in a direction different from the incident direction, so that light in the vicinity of the optical axis C is transmitted by the protrusion 2c. Reflected away from the light source 3. Therefore, the light absorbed by returning to the light source 3 can be reduced, and the light use efficiency of the lighting device 10 can be improved.

  Further, the inner surface 2 b of the transmissive cover 2 excluding the protruding portion 2 c has a plane orthogonal to the optical axis C of the light source 3. Thereby, the light reflected by the inner surface 2b of the transmissive cover 2 excluding the protruding portion 2c is guided to the light source 3 in the direction away from the light source 3. Therefore, it is possible to further reduce the light absorbed by returning to the light source 3.

  In the present embodiment, similarly to the second embodiment, a protrusion 2d (see FIG. 3) protruding outward from the inner surface of the transmission cover 2 may be provided instead of the protrusion 2c.

  Next, FIG. 6 has shown front sectional drawing of the illuminating device of 4th Embodiment. For convenience of explanation, FIG. 1 described above, the same parts as in the first embodiment shown in FIG. 2 are denoted by the same reference numerals. The illumination device 20 is formed in a light bulb shape having a base 22 at one end, and a substrate 4 on which a light source 3 that emits point light such as an LED is mounted is disposed.

  The outer shape of the illumination device 20 is formed by a base 22, a support member 23, a heat sink 25, and the transmissive cover 2. The base 22 is formed in, for example, an E26 type and is screwed into a socket supplied with power from a commercial power source. The support member 23 is formed in a cylindrical shape by an insulator such as a resin molded product that is screwed onto the inner surface of the base 22, and supports the circuit board 24 having a power supply circuit.

  The heat sink 25 is formed in a cylindrical shape having a substantially conical surface with a metal such as aluminum, and is attached to the support member 23 with one end engaged. The other end of the heat sink 25 is covered with an installation plate 25a, and the substrate 4 is installed on the installation plate 25a via a heat dissipation sheet (not shown) made of a flexible high heat conductor. Thus, the heat generated by the light source 3 is radiated through the heat radiating sheet and the heat sink 25.

  Further, a resin substrate fixing portion 28 is disposed on the installation plate 25a. The board fixing portion 28 has a through hole 28a at the center, and the engagement claws 28b are engaged with and attached to a plurality of engagement holes (not shown) provided in the installation plate 25a. Thereby, the board | substrate 4 is clamped by the installation board 25a and the board | substrate fixing | fixed part 28. FIG. At this time, the light source 3 is exposed from the through hole 28a, and the optical axis C of the light source 3 coincides with the central axis of the illumination device 20. The reflection part 6 such as a PET sheet attached on the substrate 4 has a through hole 6 a through which the light source 3 passes, and is arranged around the light source 3.

  Transmitting cover 2 is formed in a dome shape to cover the light source 3 is mounted screwed to the peripheral portion of the substrate fixing portion 28. In the transmission cover 2, the outer surface 2 a and the inner surface 2 b are formed in a spherical surface (circular arc shape) in the illumination light emission range, and the light source 3 is disposed offset from the center of the spherical surface. The outer surface 2a and the inner surface 2b of the transmission cover 2 may be formed by an elliptical surface.

  In addition, the inner surface 2b of the transmission cover 2 is provided with a protruding portion 2c protruding inward similar to the first embodiment in a predetermined range with the optical axis C interposed therebetween. The protrusion 2c has a center of curvature outside the inner surface 2b of the transmission cover 2, and is formed by, for example, a part of a spherical surface or a part of an elliptical surface. Thereby, the thickness of the transmission cover 2 is non-uniform | heterogenous in the protrusion part 2c. Further, a chamfered portion 2f similar to that of the first embodiment is continuously provided on the outer peripheral portion of the protruding portion 2c, and the boundary with the spherical surface forming the inner surface 2b is smoothly connected.

  A lighting device 20 of the above-described configuration, light emitted radially from the light source 3 reaches the inner surface 2b of the translucent cover 2. Light in the vicinity of the optical axis C of the light source 3 reaches the protrusion 2c and passes through the transmission cover 2 as indicated by an arrow S61. The light away from the optical axis C of the light source 3 reaches the inner surface 2b around the protrusion 2c and passes through the transmission cover 2 as indicated by an arrow S81. Thereby, illumination light is emitted from the transmission cover 2.

  Further, a part of the light in the vicinity of the optical axis C except on the optical axis C of the light source 3 reaches the projecting portion 2c and is reflected by the projecting portion 2c as shown by an arrow S62. Guided in different directions. As a result, the reflected light of the protruding portion 2c is reflected by the reflecting portion 6 at a position away from the light source 3, and the illumination light is emitted through the transmission cover 2 as indicated by an arrow S63.

  Some of the light that has reached the inner surface 2b of the periphery of the projecting portion 2c is reflected by the inner surface 2b as indicated by an arrow S82. Thereby, the reflected light around the protruding portion 2c is reflected by the reflecting portion 6, and the illumination light is emitted through the transmission cover 2 as indicated by an arrow S83.

  Further, the light emitted from the light source 3 and reflected by the outer peripheral portion of the projecting portion 2 c passes through the outside of the reflecting portion 6 and is emitted toward the base 22 through the transmissive cover 2 as indicated by an arrow S72. Thereby, the light distribution angle of the bulb-type lighting device 20 can be increased.

  According to the present embodiment, as in the first embodiment, the protrusion 2c provided on the inner surface 2b of the transmission cover 2 guides the reflected light in a direction different from the incident direction, so that light in the vicinity of the optical axis C is transmitted by the protrusion 2c. Reflected away from the light source 3. Therefore, the light absorbed by returning to the light source 3 can be reduced, and the light use efficiency of the lighting device 20 can be improved.

  Further, a part of the reflected light of the protruding portion 2 c is emitted backward (in the direction of the base 22) through the outside of the reflecting portion 6. Thereby, the light distribution angle of the illuminating device 20 can be enlarged.

  In the present embodiment, similarly to the second embodiment, a protrusion 2d (see FIG. 3) protruding outward from the inner surface of the transmission cover 2 may be provided instead of the protrusion 2c.

  According to the present invention, it can be used for an illuminating device that includes a transmissive cover that covers the light source and emits illumination light.

DESCRIPTION OF SYMBOLS 1, 10, 20 Illuminating device 2 Transmission cover 2a Outer surface 2b Inner surface 2c, 2d Projection part 2f Chamfering part 3 Light source 4 Substrate 5 Support plate 6 Reflection part 7 Cap 22 Base 23 Support member 24 Circuit board 25 Heat sink 25a Installation plate 28 Module fixation Part

Claims (10)

  An illuminating device comprising a light source and a transmissive cover that covers the light source and transmits the emitted light of the light source to emit illumination light, wherein the inner surface of the transmissive cover is located within a predetermined range including the optical axis of the light source Or it has a protrusion part which protrudes outside, The said protrusion part guide | induces the light radiate | emitted from the said light source and reflected by the said protrusion part to the direction different from an incident direction.   2. The projection according to claim 1, wherein the projection has a center of curvature outside the inner surface of the transmission cover and projects inward, and reflects light except on the optical axis in a direction away from the optical axis of the light source. The lighting device described.   2. The projection according to claim 1, wherein the protrusion has a center of curvature inside the inner surface of the transmission cover and protrudes outward, and has a smaller radius of curvature than the inner surface of the transmission cover excluding the protrusion. Lighting device.   The lighting device according to claim 2, wherein a reflection portion is provided around the light source.   The illumination device according to claim 4, wherein light emitted from the light source and reflected by an outer peripheral portion of the protruding portion is guided to the reflecting portion.   The cross-sectional shape of the inner surface of the transmission cover excluding the projecting part includes a part of an ellipse, the light source is offset in the major axis direction with respect to the center of the ellipse, and the optical axis of the light source coincides with the major axis direction The lighting device according to any one of claims 2 to 5, wherein:   The lighting device according to any one of claims 2 to 5, wherein an inner surface of an emission range of the transmission cover excluding the projecting portion has a plane perpendicular to the optical axis of the light source.   The chamfered part which consists of a curved surface which has a curvature center on the opposite side to the curvature center of the said protrusion part with respect to the inner surface of the said permeation | transmission cover was continuously provided in the outer peripheral part of the said protrusion part. The lighting device according to claim 7.   The lighting device according to claim 1, wherein the transmission cover contains a diffusing material.   The lighting device according to claim 1, wherein the light source is an LED.

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