JP2013191402A - Bulb type led lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device having a wide light distribution capable of restraining manufacturing cost in a simple structure and leading light even in a cap direction.SOLUTION: The lighting device 100 includes an LED 101, a case 102 for retaining the LED 101, a globe 103 mounted on the case 102 so as to cover the LED 101, a cap 104 mounted at an opposite side of the globe 103 to the case 102, and further, a reflection member arranged in the globe 103 and reflecting part of the light emitted from the LED 101 further toward the cap 104 side than a right-angled direction against the center axis of the cap 104.

Description

  The present invention relates to a bulb-type LED lamp, and more particularly to a bulb-type LED lamp capable of emitting radiated light with a wide light distribution.

  In recent years, with increasing awareness of the environment, LEDs (Light Emitting Diodes) are often used as replacements for incandescent bulbs with high power consumption. The LED is attracting attention as an environmentally friendly light source because it is excellent in luminous efficiency and does not use mercury like a fluorescent lamp.

Since the LED is a light source with high directivity, it has a feature of emitting strong light forward. For this reason, various means are adopted in order to disperse light around the entire circumference like a light bulb.

As a means for controlling light distribution and enabling illumination in all directions, Patent Document 1 discloses a method of arranging a plurality of LEDs in a three-dimensional manner so that illumination light is emitted in all directions.

In Patent Document 1, a light emitting diode disposed on the outer surface of a base, a lighting device for lighting the light emitting diode, a lighting device is housed, a base is mounted on one side, and a base end portion of the base is mounted on the other side. An LED light bulb and an LED lighting device that include an attached cover, in which a light-emitting diode lead-in wire is connected to the lighting device at the distal end portion and the proximal end portion of the base, are simple and easy to manufacture.

According to this LED bulb, a plurality of LEDs connected in series are mounted on the surface of a substantially cylindrical substrate whose tip is hemispherical, and the LEDs provided on the surface of the substrate are turned on, so that It is expected that radiated light is emitted by light distribution and a high total luminous flux is obtained.

JP 2008-103112 A

However, in the illumination device described in Patent Document 1, since a considerable number of LEDs are used, the size of the substrate on which the LEDs are mounted is increased, the manufacturing cost is increased, and the manufacturing process is complicated.

An object of the present invention is to solve the above-mentioned problems, and to provide a light bulb-type LED lamp with a wide light distribution that can suppress the manufacturing cost with a simple configuration.

An LED, a housing for holding the LED, a globe attached to the housing so as to cover the LED, a base attached to the opposite side of the housing from the globe, and provided in the globe, A reflecting member that reflects a part of light emitted from the LED toward the base rather than in a direction perpendicular to the central axis of the base; The reflecting member can be reflected while being diffused on a reflecting surface that reflects light from the light source.

According to the present invention, since the reflecting member reflects light from the LED to the base side, a wide light distribution can be realized.

The shape of the reflecting member can be curved convexly or concavely toward the light source. Further, it may be formed in a conical shape, and its apex may be arranged toward the light source.

Moreover, the said reflection member can be comprised with resin or glass with which the coating material was apply | coated. For example, a Fresnel lens can be used.

Further, the surface of the reflecting member may be subjected to a rough surface process such as a texture process, a sand blast process, a prism cut process, or the like.

Further, the reflecting member may be made of metal. For example, it can be composed of a punching metal or a mesh metal.

According to the present invention, it is possible to obtain a wide light distribution that can also reduce the manufacturing cost with a simple configuration and that extends in the direction of the base.

The schematic block diagram of the lightbulb-type LED lamp of 1st Embodiment. The perspective view and cross-sectional perspective view of a diffusion cap. The figure for demonstrating the attachment structure of a diffusion cap. The figure which shows permeation | transmission and reflection by a diffusion cap. The schematic block diagram of the lightbulb-type LED lamp of 2nd Embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings. Note that this embodiment is merely an example, and the present invention is not limited to this.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a bulb-type LED lamp according to the first embodiment. FIG. 2 shows a perspective view and a cross-sectional perspective view of the diffusion cap used in the first embodiment. FIG. 3 is a view for explaining a diffusion cap mounting structure.

The LED lamp 100 of this embodiment includes a substrate 106 on which the LED 101 is mounted, a housing 102 that holds the LED 101, a globe 103 that is attached to the housing 102 so as to cover the LED 101, and a side opposite to the globe 103. The base 104 attached to the housing 102 and the diffusion cap 105 provided in the globe 103 are provided.

The substrate 106 is held by the housing 102, and a known printed board such as a glass epoxy substrate, a metal substrate, or a ceramic substrate can be used as a substantially circular flat plate. In the present embodiment, a printed board made of a metal substrate covered with an electrically insulating resin is used.

The LED 101 is mounted on the substrate 106. Various known LEDs can be used as the LED 101. In the present embodiment, a high-luminance type LED that emits white light for illumination is used.

Note that the substrate of the present embodiment is a surface mounting type SMD (Surface Mounting Device) in which an electronic component is mounted on a printed circuit board for connection, but is not limited thereto. For example, COB (direct mounting a bare chip on a printed circuit board by wire bonding (
(Chip on board) may be used. In this case, the COB is placed on a heat sink made of aluminum.

The casing 102 has a cylindrical shape with both ends open, and the LED 101 and the substrate 106 are arranged. Since the LED lamp 100 of the present embodiment is a light bulb shaped lamp, a cross section in a direction parallel to the substrate of the housing 102 has a substantially circular outer shape whose diameter decreases toward the base 104. A substrate holding plate 102 a disposed at a right angle to the central axis of the housing 102 is provided. The substrate holding plate 102 a is provided with a substrate attachment piece 102 b for fixing the substrate 106.

The housing 102 is made of a general-purpose resin material, and polybutylene terephthalate is used in this embodiment. However, the resin material is not limited thereto, and known resin materials such as polyethylene terephthalate, polyurethane, polycarbonate, polyphenylene sulfide, polyamideimide, polyimide, polyamide, phenol resin, and acrylic resin can be used. By making the housing 102 of a resin material, the heat conductivity of the housing 102 is low, and it is possible to suppress the heat generated in the LED 101 from being transmitted to the power supply circuit board as compared with a metal housing.

The globe 103 is disposed at the edge of one end of the housing 102 so as to cover the LED 101. A thermoplastic resin and a thermosetting resin that are translucent and can be injection-molded can be used.

The base 104 is screwed to the opposite housing end to which the globe 103 of the housing 102 is attached. Since the lighting device of the present embodiment is a light bulb shaped lamp, a cross section in a direction parallel to the substrate of the housing has a substantially circular outer shape whose diameter decreases toward the base 104.

The diffusion cap 105 is integrally formed by a cylindrical member 201 and a diffusion member 202 that closes one end of the cylindrical member 201. The diffusion cap 105 is provided in the globe 103 and is disposed so as to cover the LED 101 from the opening end side of the cylindrical member 201. The thickness t1 of the diffusing member 202 is thicker than the thickness t2 of the cylindrical member 201.

The diffusion cap 105 transmits and reflects light emitted from the LED 101. A part of the emitted light is reflected to the base 104 side from a direction perpendicular to the central axis X of the base 104, and a part of the emitted light is transmitted as it is. In addition, there is an effect of diffusing on the reflection surface and the transmission surface, thereby making the illuminance distribution uniform.

In order to further enhance the diffusion effect, a resin to which a light diffusing agent is added may be used. In this case, the light diffusing agent may be an inorganic light diffusing material such as titanium oxide, silicon oxide, calcium carbonate, or talc, or an organic light diffusing material such as crosslinked polystyrene fine particles, crosslinked polymethyl methacrylate fine particles, or silicon-based crosslinked fine particles. Materials can be used.

In order to further enhance the diffusion effect, the surface of the diffusion cap 105 is roughened into a concavo-convex shape by, for example, graining, sandblasting, prism cutting, or the like. By forming the rough surface, the light from the light source can be more diffused. The resin paint and the non-smoothing means have an effect of scattering not only the reflected light but also the transmitted light, so that the light from the light bulb is made uniform.

As shown in FIG. 3, in the vicinity of the opening end of the diffusion cap 105, an attachment hole 201a for attaching to the substrate holding plate 102a is formed. The diffusion cap 105 is fixed to the substrate holding plate 102a by engaging the mounting holes 201a with the mounting pieces 102b of the substrate holding plate 102a.

As shown in FIG. 3, the lower end surface of the diffusion cap 105 and the substrate holding plate 102a are not completely in surface contact with each other, and a gap 201b is formed between the substrate holding plate 102a. The heat in the diffusion cap 105 is dissipated from the gap, so that the radiant heat does not accumulate in the diffusion cap 105.

Next, transmission and reflection by the diffusion cap 105 will be described. FIG. 4 is a diagram for explaining transmission and reflection by the diffusion cap 105. Here, for convenience of explanation, the radiation direction of light from the LED lamp 100 is defined with reference to FIG. A direction perpendicular to the central axis X of the base as viewed from the LED is defined as a horizontal direction. A direction inclined from the lateral direction to the base side when viewed from the LED is defined as a base direction. A direction inclined from the lateral direction to the opposite side of the base (that is, the glove apex side) when viewed from the LED is defined as an upward direction.

As shown in FIG. 4, part of the emitted light A1 from the LED 101 is transmitted light B1 that has passed through the diffusion member 202 of the diffusion cap 105, and part of it is reflected to become reflected light C1.

The transmitted light B1 passes through the diffusing member 202 and is emitted as it is upward. Since the transmitted light B1 is diffused and scattered on the transmission surface, the light can be made uniform. The reflected light C1 is reflected by the diffusing member 202 and radiated in the direction of the base. Since the reflected light C1 is diffused and scattered on the reflecting surface, the light can be made uniform.

In addition, part of the outgoing light A2 becomes transmitted light B2 that has passed through the cylindrical member 201 of the diffusion cap 105, and part of the outgoing light A2 is reflected to become reflected light C2. The transmitted light B2 passes through the cylindrical member 201 and is emitted as it is from the side surface of the globe. The reflected light C <b> 2 is reflected by the cylindrical member 201 and guided to the diffusing member 202.

Since the thickness t1 of the diffusing member 202 is formed to be thicker than the thickness t2 of the cylindrical member 201, the amount of light transmitted through the diffusing member 202 is relatively small. That is, the transmitted light B2 of the cylindrical member 201 is easier to transmit than the transmitted light B1 of the diffusing member 202, and has an effect of increasing the light distribution in the glove side surface direction.

As described above, according to the light bulb shaped LED lamp 100 of the present embodiment, since the diffusion cap 105 is provided, it is possible to radiate light in the direction of the base, and a wide light distribution angle can be obtained.

In addition, although the diffusion member 202 of the diffusion cap 105 according to the present embodiment is a flat surface, the diffusion member 202 may be curved toward the LED 101 in a convex shape or a concave shape. In this case, it becomes possible to collect light in the direction of the base, and the light distribution angle can be further increased.

(Second Embodiment)
Next, the light bulb shaped LED lamp 500 of the second embodiment will be described. Differences from the first embodiment will be mainly described, and description of overlapping points will be omitted. FIG. 5 is a schematic configuration diagram of a bulb-type LED lamp according to the second embodiment.

In the present embodiment, a reflective member different from the above-described diffusion cap is used. That is, the reflecting member of the present embodiment is composed of a disc-shaped diffusion plate 505 made of plastic coated with a resin paint.

As shown in FIG. 5, the diffuser plate 505 transmits part of the emitted light A3 from the LED 501 and reflects part of it. In this embodiment, although it is made of plastic, any material that transmits and reflects the outgoing light A3 may be used. For example, glass may be used.

The resin paint on the diffusion plate 505 may be applied to the entire surface or a part thereof. For example, the light distribution angle may be set by applying only to the central portion and not to the peripheral portion. On the contrary, a method of applying only to the peripheral portion and not applying the central portion is also conceivable. The amount of light to be transmitted can be set according to the thickness of the diffusion plate 505 and the amount to be applied.

In order to enhance the diffusion effect, a light diffusing agent may be added as described above, or the surface may be subjected to graining, sandblasting, prism cutting, or the like.

The diffusion plate 505 is disposed so as to be orthogonal to the optical axis from the LED 501 (that is, the central axis X of the base). The diffusion plate 505 is held by support legs 506 made of three resins. One end of the support leg 506 is fixed to the housing 502, and the other end is fixed to the diffusion plate 505.

What is necessary is just to determine the height of the support leg 506 according to the light distribution angle to set. For example, when it is desired to make the light distribution angle wider, the support leg 506 can be raised to increase the distance between the LED 501 and the diffusion plate 505, and the light can be emitted toward the base direction.

Transmission and reflection by the diffusion plate 505 will be described. A part of the outgoing light A3 from the LED 501 becomes a transmitted light B3 that has passed through the diffusion plate 505, and a part thereof is reflected to become a reflected light C3. That is, the transmitted light B3 passes through the diffusion plate 505 and is emitted upward as it is. The reflected light C3 is reflected by the diffusion plate 505 and radiated in the direction of the base.

Further, a part A4 of the emitted light is directly emitted from the side surface of the globe without reaching the diffusion plate. Since there is no obstacle, the light distribution in the glove side surface direction can be further increased.

The diffusion plate 505 of the present embodiment is a flat plate, but may be curved toward the LED 501 in a convex shape or a concave shape. By curving, it can be reflected more in the direction of the die than a flat surface.

Further, the diffusion plate 505 may be formed in a conical shape and arranged so that the apex thereof faces the LED 501. Also in this case, it is possible to reflect more in the direction of the die than in the case of a flat surface.

Further, a Fresnel lens may be used instead of the diffusion plate 505. If a Fresnel lens is used, the thickness of the lens can be reduced, and the height of the globe can be reduced.

(Third embodiment)
Next, a light bulb shaped LED lamp according to a third embodiment will be described. Differences from the first embodiment will be mainly described, and description of overlapping parts will be omitted.

The difference between the present embodiment and the first embodiment is the reflective member. The reflecting member of the present embodiment is made of a metal mesh formed in a substantially hemispherical shape. The metal is made of aluminum as long as it has a heat dissipation effect. For example, various metals such as copper and silver can be used.

The metal mesh is formed in a hemispherical shape and is disposed so as to cover the LED. The light incident on the metal part is reflected, and the light incident on the mesh gap is transmitted as it is. Since the reflected light is emitted in the direction of the base, a wide light distribution angle can be obtained. What is necessary is just to determine the clearance gap of a metal mesh in consideration of the balance of transmitted light and reflected light. Moreover, since a metal is used, a high heat dissipation effect can be obtained.

A modification of this embodiment will be described. The reflecting member of this modification is made of a punching metal obtained by punching a desired hole or slit in a metal plate. This punching metal is held by the support legs described above. Light incident on the metal part is reflected, and light incident on the hole or slit is transmitted as it is.

Although the punching metal of this embodiment is planar, it may be curved convexly or concavely toward the light source. Thereby, light can be more radiated | emitted to a nozzle | cap | die direction.

Instead of the metal plate, the surface may be formed of a substantially mirror-like metal film. As the metal film, for example, an Ag film, an Al film, or the like can be used, and can be formed by ink jet, vacuum deposition, plating, or the like. Also in this case, a hole and a slit are provided so that the direct light of the LED can be transmitted, like the punching metal.

100 LED bulb 101 LED
102 Housing 103 Globe 104 Base 105 Diffusion cap 201 Cylindrical member 202 Diffusion member

Claims (13)

LED,
A housing for holding the LED;
A glove attached to the housing to cover the LED;
A base attached to the opposite side of the glove of the housing;
A reflective member that is provided in the globe and reflects a part of light emitted from the LED toward the base rather than a direction perpendicular to the central axis of the base;
A light bulb shaped LED lamp. The light bulb-shaped LED lamp according to claim 1, wherein the reflecting member transmits and reflects the light while diffusing the light on a transmission / reflection surface that transmits and reflects light emitted from the LED. The light bulb shaped LED lamp according to claim 1, wherein the reflecting member is made of resin or glass. The said reflecting member is comprised by the cylindrical cylindrical member and the diffusion member which closes one end of this cylindrical member, This reflective member is arrange | positioned so that LED may be covered from the opening end side of the said cylindrical member. 3. The light bulb shaped LED lamp according to 3. The reflecting member is composed of a diffusion plate made of resin or glass,
4. The light bulb shaped LED lamp according to claim 3, further comprising a support leg for holding the diffusion plate so that the diffusion plate is arranged in a state orthogonal to the optical axis of the emitted light of the LED. 4. The light bulb shaped LED lamp according to claim 3, wherein the reflecting member is made of a diffusion plate made of resin or glass, and the diffusion plate is curved convexly or concavely toward the LED. 4. The light bulb shaped LED lamp according to claim 3, wherein the reflecting member is formed of a conical member, and a vertex of the conical member is disposed toward the LED. The light bulb shaped LED lamp according to claim 3, wherein the reflecting member is made of a Fresnel lens. The light bulb shaped LED lamp according to any one of claims 1 to 8, wherein a surface of the reflecting member is roughened. The light bulb shaped LED lamp according to claim 9, wherein the rough surface treatment is performed by any one of a graining process, a sandblasting process, and a prism cutting process. The light bulb shaped LED lamp according to claim 1 or 2, wherein the reflection member is made of metal. The bulb-type LED lamp according to claim 11, wherein the metal is formed in a mesh shape. The light bulb shaped LED lamp according to claim 11, wherein a transmission hole for transmitting light emitted from the LED is formed in the metal.