JP2012155895A - Led electric bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED electric bulb that can uniformly illuminate the surroundings.SOLUTION: The LED electric bulb having a built-in LED includes a columnar light guide body for receiving light emitted from the LED on one end side and guiding the received light to the other end side through a shaft part and emitting the guided light from the other end side. The light guide body is arranged on an end face on the other end side, and the light guide body has a recessed part made of an approximately conical shape which has approximately the same axis with the axis of the shaft part and is gradually tapered to one end side of the light guide body, and a first curved surface arranged to make an end face and a side face of the other end side approximately continue each other.

Description

  The present invention relates to an LED bulb.

  In recent years, efforts have been made to use LED bulbs in place of conventional filament bulbs for the purpose of power saving, downsizing, and long life of lighting fixtures. As this LED bulb, an LED having an LED in its base, a light guide that receives light from the LED on one end side and emits the received light from the other end side has been proposed (special feature). No. 2008-135210).

  The LED bulb disclosed in Japanese Patent Application Laid-Open No. 2008-135210 has a conical recess on the light exit side end face of the light guide, and the light passing through the light guide is reflected by the conical slope of the recess and is It is provided to emit light in the direction and illuminate the surroundings.

  However, in the LED light bulb as disclosed in Japanese Patent Application Laid-Open No. 2008-135210, there is unevenness in the light irradiated to the surroundings. Specifically, when used indoors, the portion where the light intensity is strong is a circular ring shape. It turned out to become. As a result of intensive investigations by paying attention to this problem, the inventors of the present invention have a portion where the light intensity is high due to the right-angled portion where the end surface and the side surface where the conical concave portion is formed form a right angle, resulting in unevenness. Turned out.

JP 2008-135210 A

  Then, this invention is made | formed in view of the problem of the said conventional LED bulb, and it aims at providing the LED bulb which can illuminate the circumference | surroundings uniformly.

The invention made to solve the above problems is
An LED bulb with a built-in LED,
A columnar light guide that receives light from the LED on one end side, guides the received light to the other end side through the shaft, and emits the guided light from the other end side,
The light guide is
A substantially conical recess that is provided on the end surface on the other end side and has a substantially same axis as the shaft center of the shaft portion and has a diameter reduced toward the one end side, and the end surface and the side surface on the other end side are substantially continuous. It has the 1st curved surface provided in this way, It is characterized by the above-mentioned.

  In the LED power pole having the above configuration, light emitted from the LED is incident from one end side of the light guide, passes through the shaft portion of the light guide, and is guided to the other end of the light guide. . And this light is reflected toward the outer side in the substantially conical concave portion on the other end side of the light guide, and thereby the periphery of the LED bulb can be irradiated. In particular, the LED bulb is provided with a curved surface between the end surface and the side surface, and since there is no right-angled portion as in the prior art, unevenness in the light irradiated to the surroundings hardly occurs, and the surroundings are illuminated uniformly. be able to.

  The “curved surface” means a curved shape in the cross-sectional shape in the axial direction, and the same applies to “second curved surface” and “third curved surface” described later. In addition, “the first curved surface in which the end surface and the side surface on the other end side are substantially continuous” is provided so that the first curved surface is continuous with each of the end surface and the side surface without any corners. In addition to the case where the first curved surface is included, the first curved surface also includes a case where the first curved surface is continuous with the end surface or the side surface. As long as the end face and the side face are in direct contact with each other, it is sufficient that the angle of the corner is increased.

  In the LED bulb, it is preferable to adopt a configuration in which the light guide has a columnar bulged portion extending in the axial direction from the other end side of the shaft portion and having a diameter larger than the diameter of the shaft portion.

  Thus, in the LED bulb having the enlarged diameter portion, it is possible to adopt a configuration in which the light guide is formed in a substantially cylindrical shape and the diameter of the opening edge of the recess is equal to or larger than the outer diameter of the shaft portion. Since most of the light passing through the shaft portion of the light guide body is light in a direction substantially parallel to the axis, the large number of light can be made incident on the concave portion and reflected outwardly by the above configuration.

  In addition, in the LED bulb having the above-mentioned expanded diameter portion, it is preferable to adopt a configuration in which the side surface of the expanded diameter portion is a second curved surface that is substantially continuous with the first curved surface. Thereby, the light reflected toward the outer side by the concave portion is diffused by the second curved surface, and the surroundings can be illuminated more uniformly.

  The “second curved surface substantially continuous with the first curved surface” refers to the first curved surface, for example, by providing the curvature of the first curved surface and the curvature of the second curved surface the same. It is preferable to adopt a configuration in which the second curved surface and the second curved surface are continuous (that is, continuous without any corners). However, the “second curved surface substantially continuous with the first curved surface” includes the case where the first curved surface and the second curved surface are continuous with a corner in addition to the above-described embodiment. The point is that even if a corner portion is generated, the angle of the corner portion is smaller than when the first curved surface and the side surface of the inflated portion are in contact with each other without providing the second curved surface. It is enough if it is provided to be large.

  Further, in the LED bulb having the bulged portion, the bulged portion has a flange surface that rises outward from the shaft portion on the one end side, and the flange surface is substantially continuous with the side surface of the bulged portion. It is preferable to employ a configuration that is a third curved surface. As a result, the light that has reached the one end side of the expanded diameter portion of the light reflected toward the outer side by the concave portion is also diffused by the third curved surface, so that the surroundings can be illuminated more uniformly.

  In addition, as the “third curved surface provided so as to be substantially continuous with the side surface of the expanded diameter portion”, the side surface of the expanded diameter portion and the third curved surface are continuous (that is, without any corner portion). It is preferable to employ a (continuous) configuration. However, “the third curved surface provided so as to be substantially continuous with the side surface of the expanded diameter portion” means that the side surface of the expanded diameter portion and the third curved surface are continuous with a corner portion in addition to the above-described aspect. In short, even if a corner is formed, the angle of the corner is increased as compared with the case where the side surface and the heel surface are in contact with each other without providing the third curved surface. It is sufficient if it is provided. In addition, when the configuration having the second curved surface and the third curved surface is adopted, all the curvatures of the first curved surface, the second curved surface, and the third curved surface are made the same, and one The above three kinds of curved surfaces can be constituted by continuous curved surfaces.

  Moreover, in the LED bulb having the above-mentioned enlarged diameter part, it is preferable to adopt a configuration in which the depth of the concave part is substantially the same as the length of the above-mentioned enlarged diameter part in the axial direction. Thereby, it is easy to emit the majority of the light reflected in the outward direction by the concave portion from the enlarged diameter portion.

  As described above, in the LED bulb according to the present invention, unevenness is hardly generated in the light irradiated to the surroundings, and the surroundings can be illuminated uniformly.

It is a front view including the partial cross section of the LED bulb of one Embodiment of this invention. It is a principal part expanded sectional view of the LED bulb shown in FIG. It is a principal part expanded sectional view of the LED bulb of other embodiment of this invention. It is a principal part expanded sectional view of the LED bulb of other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. The LED bulb shown in FIG. 1 includes a bulb main body 1 in which an LED 2 (light emitting diode) is built, a substantially cylindrical light guide 10 provided so as to protrude from the bulb main body 1, and a bulb covering the light guide 10. A glove 20 attached to the main body 1 is provided.

  The light guide 10 receives light from the LED 2 on the lower surface (end surface on one end side), guides the received light upward (on the other end side) via the shaft portion 11, and guides the light that has been guided. Is formed of a cylindrical light-transmitting member that emits light from the upper part (the other end side). In the present embodiment, for the sake of explanation, one end side is assumed to be the lower side and the other end side is assumed to be the upper side. However, it goes without saying that the use mode of the present invention is not limited to this.

  In the present embodiment, the light guide 10 is made of an acrylic resin, but may be made of other materials such as glass.

  The light guide 10 is attached to the light bulb main body 1 at the lower part, and the upper part protrudes upward (toward the globe 20). Here, the light guide 10 is disposed such that the lower surface thereof faces the light exit surface of the LED 2, and this lower surface functions as a light receiving surface.

  Furthermore, the light guide 10 has a columnar shaft portion 11 and a columnar expanded portion 13 that extends upward from the upper end side of the shaft portion 11 and has a diameter larger than the diameter of the shaft portion 11. Specifically, the shaft part 11 is provided in a cylindrical shape having a diameter of 9 mm and a length in the axial direction (vertical direction) of 14 mm. The swelled portion 13 is provided in a substantially cylindrical shape having an axial length of 6 mm above the upper end of the shaft portion 11 and a maximum diameter (diameter of the central position in the axial direction) of 11 mm. .

  The bulged portion 13 is provided on a curved surface (the cross-sectional shape in the axial direction is a curved surface) such that the central position in the axial direction has the maximum diameter. Specifically, the expanded diameter portion 13 includes a first curved surface 13a provided so as to be substantially continuous from the upper surface thereof, and a second curved shape provided continuously downward from the first curved portion. The first curved surface 13a, the second curved surface 13b, and the third curved surface 13b are connected to the shaft portion 11 continuously from the second curved surface 13b. All the curvatures of the curved surface 13c are the same, and one continuous curved surface is formed. Here, the curvature of this curved surface is 5 mm. In addition, in the case where the three types of curved surfaces are composed of one continuous curved surface with the same curvature in this way, it is not particularly necessary to distinguish the three types of curved surfaces. The first curved surface 13a is defined as the first curved surface 13a from the upper end of the expanded diameter portion 13 to the lower position having a length of 2 mm in the axial direction, and from the first curved surface 13a to the lower position (side surface) having a length of 2 mm in the axial direction. The second curved surface 13b is defined as a third curved surface 13c from the second curved surface 13b to a lower position having a length of 2 mm in the axial direction (a flange surface rising from the upper end of the shaft portion 11). be able to.

  Further, the expanded diameter portion 13 of the light guide 10 has a recess 15 provided on the upper surface. The recess 15 is formed in the shape of a right cone having the same axis as the axis of the shaft 11 and reducing in diameter toward the lower side. The diameter of the opening edge (opening edge of the upper surface) of the recess 15 is the same as the outer diameter of the shaft 11. It is provided so that it may be located in. Specifically, the opening edge of the recess 15 is provided in a circular shape having a diameter of 9 mm. In the present embodiment, the first curved surface 13a is formed from the opening edge of the concave portion 15, and the first curved surface 13a is an upper surface (virtual plane) on which the concave portion 15 is formed on the entire surface. And the side surface (second curved surface 13b) are provided so as to be substantially continuous.

  The depth of the recess 15 (the length in the axial direction (vertical direction)) is 6 mm, and is the same as the length of the expanded diameter portion 13 in the axial direction. The angle (angle formed by both side surfaces in the cross section including the axis) of the apex (the lowermost point) of the recess 15 is set to about 85 °. Here, the angle formed by the apexes is preferably 70 ° or more and 100 ° or less, and more preferably 80 ° or more and 90 ° or less. If the value is larger than the upper limit value, light may be transmitted without being reflected, and if the value is smaller than the lower limit value, it is difficult to form the recess 15. It should be noted that providing a minute curved surface at the apex is also a matter that can be appropriately changed in design.

  The bulb body 1 has a base 3 that can be connected to an external electrical supply port. The light bulb body 1 has a lighting circuit for supplying power supplied to the LED 2 through the base 3, and this lighting circuit is provided on a circuit board (not shown) built in the light bulb body 1. Yes. The LED 2 is mounted on the circuit board. Here, as for LED2, the light emission surface is arrange | positioned toward the globe 20 side (above). Further, as the LED 2, a disk-shaped LED 2 having a diameter substantially the same as the diameter of the shaft portion 11 of the light guide 10 is employed. In addition, although various things, such as a square shape, can be employ | adopted as LED2, a disk-shaped thing is used suitably according to the shape of the substantially cylindrical light-guide 10. FIG.

  The globe 20 has a substantially spherical shape having translucency, and can be substantially the same as a conventional light bulb. For example, the globe 20 can be made of glass, synthetic resin, or the like.

  In the LED bulb of the present embodiment having the above-described configuration, the light emitted from the LED 2 is incident from the lower surface of the light guide 10, passes through the shaft portion 11 of the light guide 10, and other light guides 10. Light is guided to the end side. And many light is light-reflected toward the outer side in the conical recessed part 15 of the light guide 10, and this can irradiate the circumference | surroundings of a LED bulb by this. In particular, the LED bulb is provided with the first curved surface 13a between the upper surface and the side surface, and since there is no right-angled portion as in the prior art, unevenness in the light irradiated to the surroundings hardly occurs, Uniform illumination is possible. In addition, a part of the guided light (for example, a part of the light non-parallel to the axial direction) is transmitted without being reflected in the recess 15 and emitted toward the upper side of the LED bulb. Is done.

  Further, since the side surface of the expanded diameter portion 13 is provided on the second curved surface 13b continuous with the first curved surface 13a, the light reflected toward the outer side by the concave portion 15 is reflected by the second curved surface. It is diffused by the surface 13b, and the surroundings can be illuminated more uniformly. Further, since the flange surface of the bulging portion 13 is provided on the third curved surface 13c continuous with the second curved surface 13b, the bulging portion 13 of the light reflected toward the outer side by the concave portion 15 is provided. Since the light reaching the heel surface is also diffused by the third curved surface 13c, the surroundings can be illuminated more uniformly. Further, a continuous form having no corners between the first curved surface 13a and the second curved surface 13b and between the second curved surface 13b and the third curved surface 13c. Therefore, it is possible to accurately prevent the occurrence of unevenness of light to the surroundings due to the corners. Moreover, since the 1st curved surface 13a, the 2nd curved surface 13b, and the 3rd curved surface 13c consist of the same curvature, they can be formed easily and reliably.

  Further, in the LED light bulb, since the light guide 10 has the expanded diameter portion 13 larger in diameter than the diameter of the shaft portion 11, a part of the light guide 10 is thinned by the recess 15. Since the swelled portion 13 is thickened to some extent, it has an advantage of excellent strength. Furthermore, since the depth of the concave portion 15 is the same as the axial length of the expanded diameter portion 13, the expanded diameter portion 13 is located around the recessed portion 15. , Has the advantage of being superior in strength.

  Furthermore, since the diameter of the opening edge of the recess 15 is the same as the outer diameter of the shaft portion 11, a large number of light passing through the shaft portion 11 of the light guide 10 (light substantially parallel to the axis). Can be incident on the recess 15 and reflected toward the outer side. Furthermore, since the recessed part 15 consists of a right cone shape, it can reflect light uniformly to the circumference | surroundings. That is, when the apex of the recess 15 is misaligned with the axis (when it is not a right conical shape), the amount of light reflected is different between the surface on which the apex is misaligned and the surface on the opposite side. In order to make the light to be uniform, it is preferable that the concave portion 15 has a right cone shape as described above.

  In addition, although the LED bulb of the said embodiment has the above-mentioned advantage from the said structure, the LED bulb of this invention is not limited to the said embodiment, A design change is possible to a various aspect.

  That is, for example, in the above-described embodiment, the one having the enlarged diameter portion 13 has been described, but the enlarged diameter portion 13 is not an essential component in the present invention. For example, as shown in FIG. 3, a conical recess 15 is not formed on the upper surface of the light guide 10 and a curved surface 13a is provided around the upper surface as shown in FIG. Within the intended range.

  Further, even when the enlarged diameter portion 13 is provided, as shown in FIG. 4, it is possible to adopt a configuration in which the side surface 13b of the enlarged diameter portion 13 has a linear cross-sectional shape. The LED bulb shown in FIG. 4 has substantially the same configuration as that of the above embodiment except that the side surface 13b of the expanded diameter portion 13 has a linear cross-sectional shape. That is, the first curved surface 13a is provided from the upper surface (opening edge of the recess 15), the side surface 13b is provided continuously to the first curved surface 13a, and the third curved surface is provided continuously to the side surface 13b. A surface 13c (saddle surface) is provided. In addition, when the structure as shown in FIG. 4 is adopted, the flange surface 13c may be a plane perpendicular to the axial direction without being a curved surface.

  Furthermore, it is possible to change the design as appropriate, for example, by providing a reflective layer on the concave portion 15 as in the above embodiment, or by filling the concave portion 15 with a member having a different refractive index.

  Moreover, in the said embodiment, although the diameter of the opening edge of the recessed part 15 demonstrated the thing provided with the outer diameter of the axial part 11, this invention is not limited to this, For example, FIG. 3, the diameter of the opening edge of the recess 15 may be smaller than the outer diameter of the shaft portion 11. However, it is preferable that the diameter of the opening edge of the recess 15 is greater than or equal to the outer diameter of the shaft portion 11 as in the above embodiment, so that a large number of light passing through the shaft portion of the light guide is incident on the recess 15. Thus, there is an advantage that the light can be reflected in the outward direction. Note that “more than the outer diameter” means that both the case where the diameter of the opening edge of the concave portion is substantially the same as the outer diameter of the shaft portion and the case where the diameter is larger than the outer diameter of the shaft portion.

  As described above, the LED bulb according to the present invention can be used in place of a conventional filament bulb because the ambient light is less likely to be uneven and can uniformly illuminate the surroundings.

1 Light bulb body 2 LED
3 base 10 light guide 11 shaft portion 13 expanded diameter portion 13a first curved surface 13b side surface (second curved surface)
13c Saddle surface (third curved surface)
15 Recess 20 Globe

Claims (6)

An LED bulb with a built-in LED,
A columnar light guide that receives light from the LED on one end side, guides the received light to the other end side through the shaft, and emits the guided light from the other end side,
The light guide is
A substantially conical recess that is provided on the end surface on the other end side and has a substantially same axis as the shaft center of the shaft portion and has a diameter reduced toward the one end side, and the end surface and the side surface on the other end side are substantially continuous. An LED power pole having a first curved surface provided as described above.   The LED light bulb according to claim 1, wherein the light guide body has a columnar bulged portion extending in an axial direction from the other end side of the shaft portion and having a diameter larger than the diameter of the shaft portion. The light guide is formed in a substantially cylindrical shape,
The LED bulb according to claim 2, wherein a diameter of an opening edge of the concave portion is equal to or larger than an outer diameter of the shaft portion.   4. The LED bulb according to claim 2, wherein a side surface of the expanded diameter portion is a second curved surface that is substantially continuous with the first curved surface. The bulging portion has a flange surface that rises outward from the shaft portion on the one end side,
The LED bulb according to claim 2, wherein the flange surface is a third curved surface that is substantially continuous with a side surface of the expanded diameter portion.   The LED bulb according to any one of claims 2 to 5, wherein a depth of the concave portion is substantially the same as a length of the expanded diameter portion in an axial direction.

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