JP2014102973A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device of a bulb shape which can provide high light intensity in the lateral surface direction even when using an LED light source or the like, can provide visual quality such as a filament lamp or a candle by using the LED light source.SOLUTION: A lighting device of a bulb shape includes: a substrate 2 having a top face; a light source 4 arranged on a substrate top face 2a; an optical component 5 which is formed in a dome shape having a lower end opening 5a, has the lower end opening side fixed to the substrate top face and covers a light source therewith; and a translucent cover 6 which is fixed to the substrate top face, covers the light source and the optical component therewith and has transparency. The optical component is formed such that a thickness of a wall part is smaller than the diameter of the lower end opening. The optical component has a plurality of prisms 10 disposed on the whole region of a dome inner surface to which light from the light source is made incident or a dome outer surface from which light is released to an external part, the prisms change a latitude direction angle of light beam made incident to the southern hemisphere direction of the optical component when a dome vertex T of the optical component is set as north pole and emit the light and a virtual image of the light source is formed on a position floated up from the substrate top face when being viewed through the optical component.

Description

    This embodiment relates to a light bulb-type lighting device using a light source having a narrow light distribution that is limited in a surface normal direction and mounted like a light emitting diode (LED).

  Incandescent light bulbs and fluorescent lamps have been widely used as lighting devices, but have problems such as lifetime, luminous efficiency, mercury contamination, and ultraviolet light leakage. In recent years, as a technique for solving these problems, LED light sources and EL (electroluminescence) light sources have been developed, and in particular, the use of LED light sources for general lighting devices is accelerating.

  However, light from a light source mounted on a mounting substrate such as an LED light source emits light strongly in the normal direction of the mounting substrate, and has directivity that does not emit light from the side surface to the back surface. Therefore, when a conventional incandescent light bulb with a nearly uniform light intensity distribution from the front to the back is replaced with a light bulb-type lighting device using an LED light source, the brightness of the ceiling and walls changes significantly, resulting in a different illuminance space. End up.

  Especially for chandeliers produced from candles, lighting devices that can directly view filaments of incandescent bulbs like flames are preferred, and they shine like dots in the direction of the side surface and reflect off to the surrounding scattering accessories. A brilliant lighting device is realized. However, in an illuminating device using an LED light source, it has been difficult to realize an illuminating device having the same appearance as such a filament direct-view incandescent bulb or candle.

Japanese Patent No. 4290887 JP-A-2005-05546 Japanese Patent No. 4945690 JP 2011-142060 A JP 2012-64558 A JP 2012-74264 A JP 2012-146450 A

  An object of the present invention is to provide a light bulb-shaped illuminating device that realizes an appearance like an incandescent light bulb or a candle that has high luminous intensity in the lateral direction even when an LED light source is used and the filament is directly viewed, with the LED light source. .

According to the embodiment, the light bulb-shaped lighting device is formed in a dome shape having a base having a top surface, a light source disposed on the top surface of the base material, and a lower end opening, and the top surface of the base material is An optical component having a lower end opening side fixed and covering the light source, and a transparent cover having transparency that is fixed to the top surface of the base material and covers the light source and the optical component,
The optical component is formed such that the wall thickness is smaller than the diameter of the lower end opening, and the optical component is provided on the entire dome inner surface where light from the light source enters or the outer surface of the dome where light is emitted to the outside. The prism has a plurality of prisms, and the prism emits the incident light when the dome apex of the optical component is the north pole, changing the latitudinal angle of the incident light in the southern hemisphere direction of the optical component, and viewed through the optical component. In this case, a virtual image of the light source is formed at a position raised from the top surface of the base material.

FIG. 1 is a cross-sectional view showing a light bulb-shaped illumination device according to a first embodiment. FIG. 2 is a cross-sectional view showing the light bulb-shaped lighting device. FIG. 3 is a view showing a ray trajectory of the illumination device. FIG. 4 is a diagram illustrating how light is emitted when the light bulb-shaped illumination device according to the first embodiment is viewed from the side. FIG. 5 is a view showing a light distribution of the lighting device. FIG. 6 is a cross-sectional view showing a light bulb type illumination device according to a first modification. FIG. 7 is a cross-sectional view showing a light bulb-shaped illumination device according to a second modification. FIG. 8 is a diagram illustrating a light distribution of a light bulb-shaped illumination device according to a second modification. FIG. 9 is a diagram illustrating how light is emitted when a light bulb-shaped illumination device according to a second modification is viewed from the side. FIG. 10 is a cross-sectional view showing a light bulb-shaped illumination device according to a third modification. FIG. 11 is a diagram illustrating a light distribution of a light bulb-shaped lighting device according to a third modification. FIG. 12 is a diagram illustrating how light is emitted when a light bulb-shaped illumination device according to a third modification is viewed from the side. FIG. 13 is a cross-sectional view showing a light bulb-shaped illumination device according to a second embodiment. FIG. 14 is a cross-sectional view showing a light bulb-shaped illumination device according to a fourth modification. FIG. 15 is a perspective view showing a prism structure of an optical component in a light bulb-shaped illumination device according to a fifth modification. FIG. 16 is an enlarged perspective view showing a part of the prism according to the fifth modification.

Hereinafter, illumination devices according to various embodiments will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing an LED bulb 1 as a bulb-type lighting device according to the first embodiment. The LED bulb 1 has a rotationally symmetric shape with respect to the central axis C.

  The LED bulb 1 includes a base material 2 having a flat base material top surface 2a on the front surface, a light source 4 composed of LEDs mounted on the base material top surface 2a, and a light source 4 arranged on the base material top surface 2a. A dome-shaped optical component 5 that covers the light source 4 and the transparent light-transmitting cover 6 that covers the light source 4 and the optical component 5 are also provided.

  The base material 2 is a metal casing and a heat radiating member. The base material 2 is formed in a substantially truncated conical shape and has a substantially circular base top surface 2a which is flat at the upper end (front surface). A base 8 is provided. The light source 4 is disposed at the center of the base material top surface 2a. A drive circuit 11 that drives the light source 4 is housed inside the base material 2. The power supplied from the base 8 is supplied to the light source 4 by the drive circuit 11 to emit light. The base material 2 holds the translucent cover 6 and the base 8 to form the outer shape of the LED bulb 1 and also serves as a heat sink and a heat sink for the heat of the light source 4.

  The translucent cover 6 is formed in a spherical shape having a circular lower end opening 6a with a transparent resin. The translucent cover 6 has a lower end fixed to the peripheral edge of the base material top surface 2 a and covers the light source 4 and the optical component 5.

  The dome-shaped optical component 5 is made of a material having transparency, and is formed in a vertically long triangular pyramid shape, for example, and has a circular lower end opening 5a and a dome apex T located on the central axis C. . That is, the optical component 5 is formed in a vertically long shape whose height along the central axis C is larger than the diameter of the lower end opening 5a. The optical component 5 is disposed coaxially with the central axis C by covering the light source 4 by fixing the lower end on the lower end opening 5 a side to the base material top surface 2 a around the light source 4.

  The optical component 5 receives light from the light source 4 at an incident surface 5b which is an inner surface of a triangular pyramid dome, and emits light to the outside from an output surface 5c which is an outer surface of the triangular pyramid dome. The thickness of the wall of the optical component 5 is smaller than the diameter of the lower end opening 5a. The optical component 5 integrally includes a plurality of prisms formed on at least one of the incident surface (dome inner surface) 5C or the emitting surface (dome outer surface) 5b. In the present embodiment, a plurality of prisms 10 are formed over the entire exit surface 5 c of the optical component 5. Each prism 10 has a triangular (wedge-like) cross section, for example, and is formed in an annular shape coaxial with the central axis C. The plurality of prisms 10 are formed side by side from the dome apex T to the lower end opening 5a.

  The prism 10 refracts or reflects light incident from the light source 4 so that the incident ray (broken arrow) does not act in the longitude direction when the dome apex T of the optical component 5 is the north pole, and only the latitude direction is in the southern hemisphere direction. Bend and emit to the outside (solid arrow). Thereby, when the light source 4 is viewed from the outside of the optical component 5, the prism 10 functions so as to form the virtual image S of the light source 4 at a position lifted between the base material top surface 2a and the dome apex T. . Due to the dome-shaped optical component 5, the light source 4 mounted on the top surface 2 a of the base material cannot be directly viewed from the outside, but appears to have floated near the center of the translucent cover 6, and looks directly at the flame of a conventional candle Can resemble

  2 and 3 are cross-sectional views of the LED bulb 1 actually designed and the results of optical analysis of the ray trajectory. FIG. 4 is a diagram showing how the LED bulb 1 is viewed from the side, and FIG. 5 is a diagram showing a light distribution of the LED bulb 1.

  As shown in FIGS. 2 to 5, according to the first embodiment, the optical component 5 causes the virtual image S of the light source 4 mounted on the top surface 2a of the base material to emerge, as if the flame of the candle emits light. You can make it look like you are. The light distribution of the LED bulb 1 is designed to emit light with a strong luminous intensity in the lateral direction. Thereby, the LED bulb 1 can irradiate a wide range, and can improve the appearance of a lighting fixture having a light-scattering / reflecting component around a side surface such as a chandelier.

  In the LED bulb 1, the dome-shaped optical component 5 has a hollow triangular pyramid shape and is therefore designed to have a maximum thickness of 5 mm or less. Therefore, the optical component 5 has a very high mass productivity by injection molding as compared with a solid optical component.

  Further, in the optical component 5, the incident surface 5 b on which the light from the light source 4 is incident is far away from the light source 4 compared to conventional lens components and light guide components, and the light reflected by the incident surface 5 b is transmitted to the light source 4. Less loss of reabsorption. Furthermore, the optical component 5 is very insensitive to the specifications of the light source 4, and can be used for COB light sources and SMD light sources of various arrangements with the same specification of the dome-shaped optical component 5. The dome-shaped optical component 5 can be used as it is. Therefore, the optical component 5 can be shared by a wide range of products.

  According to the first embodiment configured as described above, even when an LED light source or the like is used, a light bulb shape that achieves the appearance of an incandescent bulb or a candle that has a high luminous intensity in the lateral direction and the filament is directly viewed. Can be obtained.

  In the first embodiment, the prism 10 is provided on the dome-shaped outer surface of the translucent cover 6. However, the present invention is not limited thereto, and a plurality of prisms may be provided on the dome-shaped inner surface, or both the inner surface and the outer surface are provided. A prism may be provided.

  Next, lighting devices according to various modifications will be described. Note that, in the various modifications described below, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and detailed description will be made focusing on different parts.

(First modification)
FIG. 6 is a cross-sectional view showing an LED bulb 1 according to a first modification. The LED bulb 1 has basically the same configuration as that of the first embodiment, but the dome shape of the optical component 5 has a cylindrical shape in the lower half and a triangular pyramid shape in the upper half. This is because the lower half of the optical component 5 is cylindrical and the incident angle irradiated from the light source 4 is set to a low angle so that the amount of light is reduced and darkened, and the amount of light emitted from the upper half of the optical component is relatively increased. It has a shape. Of course, the lower half of the optical component 5 may not be cylindrical, but may have a shape that expands upward and further shines strongly in the upper half of the optical component.

(Second modification)
7 is a cross-sectional view showing an LED bulb 1 according to a second modification, FIG. 8 is a view showing a light distribution of the LED bulb, and FIG. 9 is a view showing the LED bulb as viewed from the side. It is. As shown in FIG. 7, the LED bulb 1 has basically the same configuration as that of the first embodiment, but the dome shape of the optical component 5 is different from that of the first embodiment. In other words, the dome-shaped optical component 5 has a dome shape that is curved outward rather than straight from the dome apex T to the lower end opening 5a.

  In this embodiment, the prism shape is designed so that the light beams emitted from all the prisms 10 including the top portion of the optical component 5 are all in the lateral direction. Therefore, as shown in FIG. 9, when the LED bulb 1 is viewed from the side, the virtual image of the light source 4 appears to be emitted vertically from the base to the top of the optical component 5, and the light emission is long as if it is a candle flame. An image can be produced. Further, as shown in FIG. 8, the light distribution is also extremely concentrated in the lateral direction, and can be used in place of a candle particularly in a chandelier.

(Third Modification)
10 is a cross-sectional view showing an LED bulb 1 according to a third modification, FIG. 11 is a view showing a light distribution of the LED bulb, and FIG. 12 is a view showing the LED bulb as viewed from the side. It is. As shown in FIG. 10, the LED bulb 1 has basically the same configuration as that of the first embodiment, but the dome shape of the optical component 5 is different from that of the first embodiment. In other words, the dome-shaped optical component 5 has a dome shape that is curved outward rather than straight from the dome apex T to the lower end opening 5a.

  As shown in FIG. 11, the light distribution of the LED bulb 1 is designed to have a maximum side direction. As shown in FIG. 9, the plurality of prisms 10 are designed so that the virtual image of the light source 4 shines in a dot shape when the LED bulb 1 is viewed from the side. Furthermore, in this modification, the top of the optical component 5 is shaped like a triangular pyramid wedge, and the highest part of the vertically emitted image is designed to emit light with a sharp point.

  According to the 1st thru | or 3rd modification comprised as mentioned above, even if it uses an LED light source etc., the luminous intensity of a side direction is high, and it looks like an incandescent bulb and a candle in which the conventional filament is directly seen. An realized light bulb-shaped lighting device can be obtained.

In the first embodiment and the modification described above, the dome-shaped optical component 5 is disposed inside the transparent translucent cover 6, and the virtual image of the light source 4 is designed to be lifted from the top surface 2 a of the base material. A light bulb-shaped lighting device similar to an image of filament light emission or candle light emission is realized. In addition, the dome-shaped optical component 5 is configured to have transparency. This optical component 5 is
The optical component 5 may be formed in a thin dome shape using a milk white material. By using a milk white material instead of being transparent, the optical component 5 itself behaves as a light source. The appearance that imitates the flame of a candle can be realized by forming the optical component 5 in a vertically long shape. In this case, in order to leave the effect of the prism 10, it is desirable that the density of the milky white is thin. On the other hand, in order to make the entire optical component 5 shine without seeing the virtual light source image, the milky white has a dark eye. It will be advantageous. From this, the optimum range of the milk white density, that is, the transmittance of the optical component 5 is a transmittance of 90 to 70% when the thickness of the optical component is 2 mm.

  Next, a lighting device according to another embodiment will be described. In other embodiments described below, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and different parts will be described in detail.

(Second Embodiment)
FIG. 13 is a cross-sectional view showing an LED bulb 1 as a bulb-type illumination device according to the second embodiment. In the second embodiment, the basic configuration of the LED bulb 1 is the same as that of the first embodiment, but the dome-shaped optical component 5 is not a vertically long dome but a horizontally long dome. That is, the optical component 5 is formed such that the height H along the central axis C is smaller (D> H) than the diameter D of the lower end opening 5a. The optical component 5 is formed of a transparent material or a milky white material, and a plurality of prisms 10 are integrally provided on an incident surface (dome-shaped inner surface) 5c. Each prism 10 has a triangular or wedge-shaped cross section, for example, and is formed in an annular shape coaxial with the central axis C. The plurality of prisms 10 are formed side by side from the dome apex T to the lower end opening 6a.

  In applications where it is not necessary to lift the light emission virtual image of the light source 4 very much but it is desired to enhance the light distribution in the lateral direction, the light distribution is mainly enhanced in the lateral direction with the low and compact optical component 5 as in this embodiment. May be.

(Fourth modification)
FIG. 14 is a cross-sectional view showing an LED bulb 1 according to a fourth modification. In the fourth modification, the optical component 5 is formed in a vertically long dome shape. That is, the optical component 5 is formed so that the height along the central axis C is larger than the diameter of the lower end opening 5a. A plurality of prisms 10 are integrally provided on the incident surface 5 b of the optical component 5. In the fourth modification, the other configuration of the LED bulb 1 is the same as that of the second embodiment.

  Thus, by making the height of the optical component 5 larger than the diameter of the lower end opening 5a (H> D), the light reflected by the incident surface 5a with the incident surface 5a being moved away from the light source 4 is reabsorbed by the light source 4. In addition, it can be made insensitive to the spread of the light source 4 and the LED specification, that is, the detailed specification of the light source 4 can be inadvertently used, and can be used in common with various light source 4 specifications.

  In the second embodiment and the fourth modification, the optical component 5 is different from the first embodiment in the shape and the formation position of the prism 10, but the action of causing the virtual image S of the light source 4 to float up is shown in the first embodiment. The form is the same. Therefore, also in the second embodiment, there is obtained a light bulb-type lighting device that has a high luminous intensity in the side surface direction and realizes the appearance like an incandescent light bulb or a candle in which a conventional filament is directly viewed with an LED light source.

  In the first and second embodiments, the prism 10 has a basic shape that is concentrically rotated, but in this case, if the arrangement pitch of the prism is rough, the stripes of the prism 10 are easily visible. In order to improve such appearance, each prism 10 is arranged in the circumferential direction around the central axis C (longitude direction when the dome apex is the north pole) as in the fifth modification shown in FIGS. 15 and 16. It may be divided into a plurality of staggered arrays. Even in this case, the distribution of light distribution does not change, and it is possible to alleviate the appearance of stripes.

  In addition, the surface of the dome-shaped optical component may be subjected to a graining process to change the appearance atmosphere. The LED light source is not limited to a single integrated light source such as a chip-on-board (COB), and may have a form in which a plurality of LEDs are arranged. Also good.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.
Although the above-described embodiment has been described as an LED bulb, the lighting device according to the present invention can be applied to street lamp lighting as long as it is a combination of a directional light source and a translucent cover surrounding the light source. it can.

DESCRIPTION OF SYMBOLS 1 ... LED bulb, 2 ... Base material, 2a ... Base material top surface, 4 ... Light source, 5 ... Optical component,
5a ... lower end opening, 6 ... translucent cover, 6a ... lower end opening, 10 ... prism,
11 ... Drive circuit, S ... Virtual image

Claims (8)

A substrate having a top surface;
A light source disposed on the top surface of the substrate;
An optical component formed in a dome shape having a lower end opening, the lower end opening side being fixed to the base material top surface and covering the light source;
A transparent cover that is fixed to the top surface of the base material and covers the light source and the optical component and has transparency,
The optical component is formed such that the wall thickness is smaller than the diameter of the lower end opening,
The optical component has a plurality of prisms provided on the entire inner surface of the dome on which light from the light source enters or the outer surface of the dome that emits light to the outside, and the prism has the dome apex of the optical component as a north pole. When the incident light beam is emitted in the direction of the southern hemisphere of the optical component, the virtual image of the light source is lifted from the top surface of the substrate when viewed through the optical component. A light bulb shaped lighting device characterized by   2. The light bulb-shaped illumination device according to claim 1, wherein the light-emitting illumination device has a light distribution that emits light with the strongest luminous intensity in a lateral direction of the optical component.   The light bulb-shaped illumination device according to claim 1 or 2, wherein the optical component is formed of a transparent material.   4. The light bulb-shaped illumination device according to claim 3, wherein the optical component has a surface with a texture.   The light bulb-shaped lighting device according to claim 1, wherein the optical component is made of a milk white material.   The light bulb-shaped lighting device according to claim 5, wherein the optical component has a wall thickness of 2 mm and a transmittance of 90 to 70%.   The light bulb-shaped illumination device according to any one of claims 1 to 6, wherein the optical component is formed in a vertically long shape having a height along a central axis larger than a diameter of the lower end opening. .   The bulb-shaped illumination device according to claim 1, wherein the prisms are arranged in a staggered manner with respect to the longitude direction of the optical component.

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