JP2012084395A - Lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamp in which deterioration of a lifetime due to the effect of heat by a circuit unit is suppressed and, on the whole, the similar part to an HID lamp shines.SOLUTION: The lamp 10 has a base 22 installed on a pedestal 12 and an LED 36 being a semiconductor light-emitting element mounted on the opposite side to the base 22 through the pedestal 12. A pillar-shape light guide member 44 having a hollow part 48 is installed in the pedestal 12 with the incident face 46 facing the emitting part of light of the LED 36, and in the central part in axis center direction of the light guide member 44, a reflecting film 50 being a course change part to change the course of light of the LED 36 which enters from the incident face 46 and advances toward the top end side end face in the direction to cross the axis center, is formed. A circuit unit 66 which converts electric power received from the base 22 and makes the LED 36 emit light is housed in the hollow part 48. The light of the LED 36 incident from the incident face 46 of the light guide member 44 is emitted from the outer surface of the light guide member 44 to the outside of the lamp 10.

Description

  The present invention relates to a lamp that uses a semiconductor light emitting element such as an LED (light emitting diode) as a light source, and more particularly to an LED lamp that is a substitute for a high intensity discharge lamp (HID lamp).

  In recent years, LED lamps using an LED module as a light source are becoming widespread with the practical application of high-brightness LEDs. As an example, Patent Document 1 discloses an LED lamp that is an alternative to an incandescent bulb. The LED lamp has a configuration in which an LED module as a light source and a circuit unit for lighting the LED module are stored in an envelope including a globe and a base. It is arranged between the LED module and the base so as not to disturb the light emitted from the module.

JP 2006-313717 A

  However, in the arrangement of the circuit unit as described above, since the circuit unit exists on the heat conduction path from the LED module to the base, the electronic components of the circuit unit may be thermally destroyed and the life of the circuit unit may be shortened. There is.

  In particular, when an LED lamp is used as an alternative to an HID lamp having a higher brightness than an incandescent bulb, it is necessary to increase the number of LEDs in order to obtain the same brightness as that of the HID lamp. Therefore, the problem of life reduction due to thermal destruction of electronic components is more remarkable.

  In addition, the HID lamp has a light distribution characteristic close to that of a point light source, and mainly has a structure in which the central region in the tube axis direction of the outer tube shines. By adopting a structure in which the whole (corresponding to a tube) shines, it is not possible to obtain a light distribution characteristic approximate to that of an HID lamp.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lamp in which the same part as that of an HID lamp mainly shines while suppressing a decrease in lifetime due to the influence of heat of a circuit unit. And

  In order to achieve the above object, a lamp according to the present invention is a lamp having a pedestal, a base attached to the pedestal, and a semiconductor light emitting element mounted on the opposite side of the base via the pedestal. A columnar light guide member having a hollow portion is provided in a state where one end surface thereof faces the light emitting portion of the semiconductor light emitting element, and in the central portion in the axial direction of the light guide member A path changing portion for changing the path of light of the semiconductor light emitting element that is incident from the one end face and travels toward the other end face in a direction intersecting the axis, and the hollow portion receives power from the base. At least a part of the circuit unit that converts the generated electric power to cause the semiconductor light emitting element to emit light, and the light of the semiconductor light emitting element incident from the one end surface of the light guide member Run from outer surface Characterized in that it emitted outside.

Further, the hollow portion is located in a central portion in the axial direction of the light guide member, and the path changing portion includes a reflective film formed on the inner surface of the hollow portion.
Further, the path changing portion includes a frosted surface formed on an outer peripheral surface of the light guide member corresponding to the axial direction and the hollow portion.

Alternatively, the path changing portion is a frosted surface formed on the outer peripheral surface of the central region in the axial direction of the light guide member.
In this case, the hollow portion is located closer to the other end surface of the light guide member than the frosted surface.

Further, the light guide member is characterized in that the other end surface has an elongated cylindrical shape with a hemispherical shape.
Moreover, the said hollow part is carrying out spherical shape, It is characterized by the above-mentioned.

  The semiconductor light emitting element is mounted on a mounting substrate, and the light guide member has a communication hole that connects the hollow portion and the outside of the light guide member, and the part of the circuit unit A wiring connecting the mounting substrate or the base is inserted into the communication hole.

  In addition, the circuit unit is characterized in that the part is housed in the hollow part and the remaining part is provided on the opposite side to the semiconductor light emitting element through the pedestal.

  According to the lamp having the above configuration, at least a part of the circuit unit is accommodated in the hollow portion of the light guide member, and the light guide member is mounted on one side of the light guide member on the side opposite to the base via the base. Since the semiconductor light emitting device is provided in a state facing the light emitting portion of the semiconductor light emitting device, that is, at least a part of the circuit unit is not provided in the heat conduction path from the semiconductor light emitting device to the base. It is possible to reduce as much as possible the influence of the generated heat on the electronic components constituting the portion, and it is possible to suppress the life of the circuit unit from being reduced.

  Further, the light emitted from the semiconductor light emitting element is incident from one end surface of the light guide member and travels toward the other end surface, while the path changing unit formed in the central portion in the axial direction of the light guide member causes Since the path is changed in a direction intersecting the axis and emitted from the outer surface of the light guide member to the outside of the lamp, the emitted light is observed as if emitted from the central portion in the axial direction of the light guide member. It will be. For this reason, in the said lamp | ramp, as a whole, light will be observed as emitted from the longitudinal direction center part of the light guide member.

1 is a cross-sectional view illustrating a schematic configuration of an LED lamp according to Embodiment 1. FIG. (A) is a perspective view of a LED module, (b) is the top view. It is a perspective view of the structural member of a light guide member. 6 is a partial cross-sectional view illustrating a schematic configuration of an LED lamp according to Embodiment 2.

Hereinafter, an embodiment of a lamp according to the present invention will be described by taking an HID (high intensity discharge) lamp type lamp using an LED as a semiconductor light emitting element as an example.
<Embodiment 1>
FIG. 1 is a cross-sectional view showing a schematic configuration of an HID lamp-type LED lamp 10 according to the first embodiment. In all the drawings including FIG. 1, the scales between the members are not unified.

  The LED lamp 10 has a pedestal 12. The pedestal 12 is extended from a disk-shaped part 16 having a through-hole 14 in the center, a circular wall part 18 erected on the peripheral edge of the upper surface of the disk-shaped part 16, and a lower surface of the disk-shaped part 16. And a cylindrical portion 20. A step portion 18 </ b> A is formed on the inner wall surface of the circular wall portion 18. The pedestal 12 is formed of an insulating material having good thermal conductivity, such as aluminum nitride (AlN).

  A base 22 is attached to the cylindrical portion 20 of the base 12. The base 22 has a shell 24, also called a cylindrical body, and an eyelet 26 having a circular dish shape. The shell 24 and the eyelet 26 are integrated with each other through an insulator 28 made of a glass material. This integrated body is fitted into the cylindrical portion 20. The cylindrical portion 20 is provided with a through hole 20A for leading a second lead wire 74 described later to the outside. Here, the central axis of the base 22 is referred to as a lamp axis X.

The LED module 30 is mounted on a portion (LED module mounting surface) surrounded by the circular wall portion 18 on the upper surface of the disk-shaped portion 16.
FIG. 2A is a perspective view showing a schematic configuration of the LED module 30, and FIG. 2B is a plan view thereof. As shown in FIG. 2, the LED module 30 includes a mounting board 34 made of a disc-shaped printed wiring board having a through hole 32 in the center, and a plurality of (36 in this example) mounted thereon. LED 36. The 36 LEDs 36 are arranged in a double concentric shape, with 16 inside and 20 outside arranged in an annular shape. In this example, a blue LED is used as the LED 36.

  The 36 LEDs 36 are covered with a phosphor film 38 that is a wavelength conversion film. The phosphor film 38 is obtained by mixing a yellow phosphor, which is a wavelength conversion material, into a translucent resin (for example, a silicone resin). The phosphor film 38 is formed in an annular shape in accordance with the arrangement of the LEDs 36.

  The 36 LEDs 36 are electrically connected in series by the wiring pattern of the mounting substrate 34 (this wiring pattern connected in series is not shown). Of the 36 LEDs 36 connected in series, the wiring pattern portion electrically connected to the p-side electrode (not shown) of the LED 36 at the terminal on the high potential side is extended so as to be exposed from the phosphor film 38. The anode feeding terminal 40 is formed. Further, a wiring pattern portion electrically connected to the n-side electrode (not shown) of the LED 36 at the low potential side end is extended so as to be exposed from the phosphor film 38 to form a cathode power supply terminal 42. . In the LED module 30 having the above configuration, when power is supplied via the anode power supply terminal 40 and the cathode power supply terminal 42, blue light is emitted from each of the LEDs 36. Part of the emitted blue light is converted into yellow light by the phosphor film 38. Yellow light and blue light that has not been converted into yellow light are mixed, and white light is emitted from the LED module 30.

  Returning to FIG. 1, the LED lamp 10 includes a light guide member 44 having a columnar shape (in this example, a columnar shape). The light guide member 44 has one end surface (base-side end surface) formed in a plane perpendicular to the central axis thereof, and the other end surface (tip-side end surface) formed in a hemispherical shape, and has a generally elongated cylindrical shape. is doing. The reason why the light guide member 44 has such a shape is to approximate the shape (appearance) that the outer tube constituting the HID lamp normally has, that is, the shape of an elongated bottomed cylinder having a bottom formed in a hemisphere. .

  The light guide member 44 is erected on the pedestal 12 so that the end portion on the side where one end surface is formed into a flat surface is fitted into the stepped portion 18 </ b> A of the circular wall portion 18 of the pedestal 12. The light guide member 44 is fixed to the base 12 with an adhesive (not shown). In this state, the one end face (base-side end face) faces the light emitting portion (each of the LEDs 36) of the LED module 30, and the one end face becomes the light incident face 46.

  The light guide member 44 has a hollow portion 48 having a substantially spherical shape. The hollow portion 48 is located at the center in the longitudinal direction of the light guide member 44. That is, the hollow portion 48 is provided so that the center thereof is located at approximately half of the entire length of the light guide member 44. This is because in the HID lamp, the optical center is adjusted to be located at approximately half the total length of the outer tube. A reflective film 50 is formed on the inner surface of the hollow portion 48. The reflection film 50 is made of, for example, an aluminum vapor deposition film.

The light guide member 44 also has a communication hole 52 that passes on its central axis. The hollow portion 48 communicates with the outside of the light guide member 44 through the communication hole 52.
The light guide member 44 is configured by combining two plane-symmetric members (a first member 54 and a second member 56). FIG. 3 is a perspective view of one member.

  In the light guide member 44, a support portion 58 for supporting a circuit board 68 of a circuit unit 66 described later is formed on the inner surface of the hollow portion 48. The support portion 58 includes a first rib 60 and a second rib 62 projecting from the inner peripheral surface of the hollow portion 48, and a support groove 64 is formed between the ribs 60 and 62. The first member 54 and the second member 56 have mating surfaces 54A and 56A.

When the first member 54 and the second member 56 are combined with their mating surfaces, the light guide member 44 is formed in a columnar shape as described above.
Returning to FIG. 1, the circuit unit 66 includes a circuit board 68 and electronic components 70 </ b> A and 70 </ b> B mounted on the circuit board 68. The electronic component 70 </ b> A and the electronic component 70 </ b> B are mounted on both sides of the circuit board 68. The circuit board 68 has a disk shape, and as shown in FIG. 1, the peripheral edge thereof is fitted into and supported by the support groove 64 (FIG. 3) of the light guide member 44. That is, the entire circuit unit 66 is housed in the hollow portion 48 of the light guide member 44. Since the circuit unit 66 distributes and mounts electronic components on both sides of the circuit board 68, it can be efficiently stored in the hollow portion 48 having a substantially spherical shape.

  The circuit unit 66 and the eyelet 26 are electrically connected by a first lead wire 72, and the circuit unit 66 and the shell 24 are electrically connected by a second lead wire 74, respectively. The first lead wire 72 and the second lead wire 74 are inserted through the communication hole 52 of the light guide member 44, the through hole 32 of the mounting substrate 34, and the through hole 14 of the base 12.

  The circuit unit 66 converts AC power (power received from the base 22) supplied through the eyelet 26 and the shell 24, the first lead wire 72, and the second lead wire 74 into power for causing the LED 36 to emit light. Then, power is supplied to the LED 36.

  The circuit board 68 and the mounting board 34 are electrically connected via internal wirings 76 and 78 inserted through the communication holes 52. The ends of the internal wirings 76 and 78 on the mounting substrate 34 side are soldered to the anode power supply terminal 40 and the cathode power supply terminal 42 (FIG. 2), respectively.

  According to the LED lamp 10 having the above-described configuration, heat generated by the LED 36 during lighting is conducted to the base 22 through the mounting substrate 34 and the pedestal 12, and the socket of the lighting fixture in which the LED lamp 10 is mounted. Then, the heat is radiated to other components of the lighting apparatus, and for example, to the ceiling or wall to which it is attached.

  In this case, in the LED lamp 10, the circuit unit 66 is stored in the light guide member 44 on the side opposite to the base 22 with the mounting substrate 34 interposed therebetween, and the circuit unit is arranged in the heat conduction path from the LED module 30 to the base 22. In this example in which many LEDs constituting the LED module are used in order to replace the HID lamp (in which the number of LEDs is increased), the heat generated in the LED module is also generated by the circuit unit 66. Can be reduced as much as possible, and the lifetime reduction of the electronic parts constituting the circuit unit 66 can be suppressed.

  The light emitted from each of the 36 LEDs 36 is incident from the incident surface 46 of the light guide member 44 and is reflected by the boundary surface between the light guide member 44 and the air layer (the outer peripheral surface of the light guide member 44). It advances in the light guide member 44 while repeating. When the incident angle with respect to the outer peripheral surface is equal to or smaller than the critical angle, light corresponding to the incident angle is emitted to the outside of the light guide member 44. On the other hand, when the incident angle exceeds the critical angle, the light is totally reflected. Further, the light guide member 44 is advanced.

  A part of the light traveling in the light guide member 44 passes through the vicinity of the hollow portion 48 and is emitted from the end surface (exit side end surface) opposite to the incident surface 46. In the case of this example, the emission side end surface is a hemispherical end surface. Since a part of the light emitted from the emission side end face has been repeatedly reflected in the light guide member 44, it is considered to be emitted radially from the emission side end face. When this is observed in the direction of the lamp axis X, it seems that it appears as if it is emitted from the hollow portion 48.

  On the other hand, the remaining light traveling in the light guide member 44 has a substantially spherical reflection film 50 (the inner surface of the spherical hollow portion 48 is formed, so that the reflection film 50 also has a spherical shape as a result. Therefore, the light beam is changed to a direction intersecting with the lamp axis X (which is also the axis of the light guide member 44) and is almost emitted from the light guide member 44 to the outside as it is. Therefore, as a path changing unit that changes the path of light of the LED 36 that is incident from the incident surface 46 of the light guide member 44 and travels toward the end surface on the front end side, in a direction that intersects the lamp axis X (the axis of the light guide member 44). The light reflected by the functioning reflective film 50 and emitted to the outside of the light guide member 44 is observed as if emitted from the hollow portion 48 (the central portion in the longitudinal direction of the light guide member 44).

  In both cases, the light is observed to be emitted from the hollow portion 48 (inside the central portion in the longitudinal direction of the light guide member 44), so that the central portion of the light guide member 44 shaped like an outer tube of the HID lamp emits light. Can be shown to do.

Further, in this example, since an outer tube is not used in order to approximate the overall shape of the HID lamp, that is, light incident from the incident surface 46 is transmitted from the outer surface of the light guide member 44 to the outside of the LED lamp 10. Therefore, the number of parts can be reduced and the number of assembling steps can be reduced.
<Embodiment 2>
FIG. 4 is a partial cross-sectional view showing a schematic configuration of the LED lamp 80 according to the second embodiment. The LED lamp 80 is basically the LED lamp 10 of the first embodiment (see FIG. 5) except that the position of the hollow portion in the lamp axis X direction is different and the outer surface of the light guide member is subjected to frost processing described later. The configuration is the same as 1). Therefore, in FIG. 4, the same components as those of the LED lamp 10 are denoted by the same reference numerals, the description thereof is omitted, and different portions will be mainly described below.

  The outer peripheral surface of the central region in the longitudinal direction of the light guide member 82 in the LED lamp 80 is frosted in a band shape, and a good light emission region 84 is formed by the frosted surface. This utilizes the fact that the light extraction efficiency is improved in the area (frosted surface) where the surface of the light guide is frosted.

  The configuration of the hollow portion 48 of the light guide member 82 is the same as that of the first embodiment, but the lamp axis X direction, a position closer to the front end side end surface (hemispherical end surface) than the incident surface 46 of the light guide member 82, In other words, it is provided between the good emission region 84 and the front end side end face. In the LED lamp 80, no reflective film is formed on the inner surface of the hollow portion 48.

  In the LED lamp 80 having the above configuration, the light emitted from each of the 36 LEDs 36 is incident from the incident surface 46 of the light guide member 82, and the boundary surface between the light guide member 82 and the air layer (light guide member). The light guide member 82 advances toward the front end side end surface while being repeatedly reflected on the outer peripheral surface 82). When the incident angle with respect to the outer peripheral surface is equal to or smaller than the critical angle, light corresponding to the incident angle is emitted to the outside of the light guide member 82. On the other hand, when the incident angle exceeds the critical angle, the light is totally reflected. Further, the light travels in the light guide member 82, but a large amount of light is emitted in a diffused state from the good emission region 84 that has been subjected to frost processing, that is, the light guide member 82 is distal to the incident surface 46. The light traveling toward the end face is emitted to the outside of the light guide member 82 in a direction intersecting the lamp axis X (the axis of the light guide member 82) along the path. For this reason, it is observed as if it was emitted from the inside of the central portion in the longitudinal direction of the light guide member 82.

  On the other hand, a part of the light that has not been emitted from the good emission region 84 passes through the vicinity of the hollow portion 48 and is emitted from the end surface (exit side end surface) opposite to the incident surface 46. Since a part of the light emitted from the emission side end face has been repeatedly reflected in the light guide member 82, it is considered that the light is emitted radially from the emission side end face. As in the case of the first embodiment, it is considered that the light is emitted from the hollow portion 48 when observed in the lamp axis X direction.

  Therefore, similarly to the first embodiment, the second embodiment is observed as if it is emitted from the inside of the central portion in the longitudinal direction of the light guide member 82 by the good emission region 84 made of the frosted surface that functions as the path changing portion. Therefore, the central portion of the light guide member 82 having a shape approximating the outer tube of the HID lamp can be seen to emit light.

As mentioned above, although this invention has been demonstrated based on embodiment, it cannot be overemphasized that this invention is not limited to said example, For example, it can also be set as the following forms.
(1) In the above embodiment, the light guide member is formed in a columnar shape as a whole. However, the light guide member is not limited to a columnar shape, and may be formed in an elliptical column shape or a polygonal column shape. In short, any shape that approximates the outer tube of the HID lamp is acceptable.
(2) Also in the first embodiment, a frosted surface may be formed on the outer peripheral surface of the light guide member 44. The area where the frosted surface is formed by frosting is the central area in the longitudinal direction of the light guide member 82 as in the case of the second embodiment. That is, the frost processing is performed so as to surround the hollow portion 48 in a band shape. By doing in this way, more light will be radiate | emitted from the outer surface of the longitudinal direction center part of the light guide member 44 in a diffusion state. In this case, the reflective film 50 formed on the inner surface of the hollow portion 48 and the frosted surface function as the above-described path changing portion.
(3) In the above embodiment, the blue LED 36 is covered with the yellow phosphor film 38 on the mounting substrate 34 to obtain white light. However, the present invention is not limited to this, and the light guide member 44 (FIG. 1), light guide When the member 82 (FIG. 4) is formed of an acrylic resin, yellow phosphor particles may be mixed into the acrylic resin. Since the wavelength conversion efficiency decreases as the temperature of the phosphor particles increases, the phosphor particles are less affected by the heat generated during LED emission compared to the case where the LEDs are directly covered with the phosphor. The decrease in the wavelength conversion efficiency can be suppressed.

Moreover, the combination of the LED and the phosphor for obtaining white light is not limited to the above, but a combination of a near ultraviolet LED and a mixed color phosphor formed by mixing a red phosphor, a blue phosphor, and a green phosphor. I do not care.
(4) In the above embodiment, the number of LEDs constituting the LED module is not limited to those described above, but can be changed as appropriate according to the required luminance or the like.
(5) In the above embodiment, a plurality of LEDs are arranged in a ring shape. However, as long as the light emitting portion of each LED faces the incident surface 46, the arrangement is arbitrary.
(6) In the said embodiment, although LED was used as a semiconductor light-emitting device, it is not restricted to this, For example, you may use LD or an organic light-emitting device.
(7) In order to improve the thermal conductivity to the socket through the base, the inner side of the base may be filled with a synthetic resin having excellent thermal conductivity, for example, silicone.
(8) Although the Edison type is used for the base in the above embodiment, the present invention is not limited to this, and a swan type or other types may be used.
(9) In the above embodiment, a plurality of electronic components constituting the lighting circuit are combined into one circuit unit. However, the plurality of electronic components are divided into relatively heat-sensitive components and strong components. One circuit unit may be configured. And the circuit unit comprised with the electronic component weak to a heat | fever is accommodated in a hollow part similarly to the said embodiment, and the circuit unit comprised with an electronic component strong against a heat | fever is an LED module (LED) via a base. It may also be provided on the opposite side of. By doing so, the number of electronic components housed in the hollow part can be reduced, so that a space required for the hollow part is created, and the degree of freedom in designing the shape of the hollow part is increased. It becomes.
(10) In the above embodiment, a heat pipe for transferring heat of the circuit unit to the base may be provided between the circuit unit and the base. For example, a columnar heat pipe made of a material having good thermal conductivity is connected to the circuit unit and the base in a state where one end is thermally connected to the circuit unit and the other end is thermally connected to the base. You may arrange | position between. In that case, it is preferable to ensure insulation so that the circuit unit and the base are not energized via the heat pipe. The heat pipe may be inserted into the communication hole 52 or a heat pipe insertion hole may be opened in parallel with the communication hole 52.

  The lamp according to the present invention can be suitably used, for example, as an LED lamp that replaces an HID lamp.

10,80 LED lamp 12 Base 22 Base 36 LED
44, 82 Light guide member 48 Hollow portion 50 Reflective film 66 Circuit unit 84 Good emission region

Claims (9)

A lamp having a pedestal, a base attached to the pedestal, and a semiconductor light emitting element mounted on the opposite side of the base via the pedestal,
A columnar light guide member having a hollow portion is provided in a state where one end surface faces the light emitting portion of the semiconductor light emitting element,
In the central part in the axial direction of the light guide member, there is a path changing unit that changes the path of light of the semiconductor light emitting element that is incident from the one end face and travels toward the other end face in a direction intersecting the axis. Formed, and in the hollow portion, at least a part of a circuit unit that converts the electric power received from the base and causes the semiconductor light emitting element to emit light is housed,
The light of the said semiconductor light-emitting device entered from the said one end surface of the said light guide member is radiate | emitted from the outer surface of the said light guide member to the lamp exterior.   2. The lamp according to claim 1, wherein the hollow portion is located at a central portion in an axial direction of the light guide member, and the path changing portion includes a reflection film formed on an inner surface of the hollow portion.   The lamp according to claim 2, wherein the path changing unit further includes a frosted surface formed on an outer peripheral surface of the light guide member corresponding to the axial direction and the hollow portion.   2. The lamp according to claim 1, wherein the path changing unit is a frosted surface formed on an outer peripheral surface of a central region in an axial direction of the light guide member.   The lamp according to claim 4, wherein the hollow portion is located closer to the other end surface of the light guide member than the frosted surface.   The lamp according to any one of claims 1 to 5, wherein the light guide member has an elongated cylindrical shape in which the other end surface has a hemispherical shape.   The lamp according to claim 2, wherein the hollow portion has a spherical shape. The semiconductor light emitting element is mounted on a mounting substrate,
The light guide member has a communication hole that connects the hollow portion and the outside of the light guide member,
The lamp according to claim 1, wherein a wiring connecting the part of the circuit unit and the mounting substrate or the base is inserted into the communication hole.   2. The circuit unit according to claim 1, wherein the part of the circuit unit is housed in the hollow portion, and the remaining portion is provided on the side opposite to the semiconductor light emitting element via the pedestal. 9. The lamp according to any one of items 8.

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