LED lamp

Abstract

An LED lamp (1) can be attached to and detached from a socket (101), and comprises a light source unit (20), a circuit (30), a holder (40) that holds the light source unit (20), and a lens (50) that controls light radiated from the light source unit (20). The LED lamp (1) further comprises: a bottomed cylindrical outer cover (10); and base pins (15) that protrude from the outer cover (10) and are electrically connected to the circuit (30). The lens (50) is fixed to the holder (40) and forms a module together with the holder (40).

Description

LED lamp

[0001] The present disclosure relates to an LED lamp, and more particularly to an LED lamp that is detachable from a socket of a lighting fixture.

[0002] LED lamps that can be attached to and detached from sockets of lighting fixtures have been widely known (see, for example, Patent Document 1). The LED lamp disclosed in Patent Document 1 is a bulb-shaped lamp that includes a light source unit including an LED element, a substantially egg-shaped globe, a resin holder into which the peripheral edge of the globe's opening is fitted, and a base attached to the holder. The LED lamp holder houses a power supply circuit that converts power supplied from a commercial power source via the base and supplies it to the LED element.

[0003] JP 2010-156525 A

[0004] Some lighting fixtures are equipped with lenses to control the light emitted from the light source. In lighting fixtures equipped with lenses, the mounting position of the lens relative to the light source has a significant impact on the optical characteristics of the lamp. For this reason, it is necessary to accurately assemble the lens in the desired position in the lighting fixture. However, because lighting fixtures are composed of multiple parts, it is expected that the accuracy of the lens assembly will be reduced due to the influence of other parts, and it is not easy to accurately assemble the lens in the desired position. In particular, when the distance from the reference position for assembly to the lens is long, it is difficult to assemble the lens with high precision, which is expected to result in large variations in light distribution between each product.

[0005] An LED lamp according to one aspect of the present disclosure is an LED lamp that can be attached to and detached from a socket, and is characterized in that it comprises a light source unit including an LED element, a holder that holds the light source unit, a circuit for supplying power to the light source unit, a lens that controls the light emitted from the light source unit, a cylindrical outer cover with a bottom that houses the light source unit, the holder, the circuit, and the lens, and a base pin that protrudes from the outer cover and is electrically connected to the circuit, and the lens is fixed to the holder and forms a module together with the holder.

[0006] According to one aspect of the present disclosure, an LED lamp with little variation in light distribution and stable optical characteristics can be provided.

[0007] 6 is a perspective view of an LED lamp according to an embodiment, illustrating a case where the LED lamp is applied to a spotlight. FIG. 7 is a perspective view of an LED lamp according to an embodiment, illustrating a case where the LED lamp is applied to a downlight. FIG. 8 is a perspective view of an LED lamp according to an embodiment, illustrating a state where a light-shielding hood is removed. FIG. 9 is an exploded perspective view of an LED lamp according to an embodiment. FIG. 10 is a view showing a first cross section of an LED lamp according to an embodiment. FIG. 11 is a view showing a second cross section of an LED lamp according to an embodiment. FIG. 12 is an enlarged view of part A in FIG. 6. FIG. 13 is a perspective view of an LED module constituting an LED lamp according to an embodiment. FIG. 14 is a perspective view of an LED module showing a state where a lens is removed from a holder. FIG. 15 is a perspective view of a lens constituting an LED module. FIG. 16 is an enlarged view of a portion of the lens.

[0008] Hereinafter, an example of an embodiment of an LED lamp according to the present disclosure will be described in detail with reference to the drawings.

[0009] FIG. 1 is a perspective view of an LED lamp 1 according to an embodiment, showing the state in which the LED lamp 1 is attached to a connector 100 including a socket 101. As shown in FIG. 1, the LED lamp 1 and the connector 100 constitute a spotlight. A spotlight is generally a lighting fixture that provides concentrated illumination in the direction in which the lamp is facing. In the example shown in FIG. 1, the connector 100 constituting the spotlight is attached to a wiring duct rail 104. The LED lamp 1 may also be attached to a spotlight socket provided on, for example, the ceiling or wall of a building.

[0010] The connector 100 includes a socket 101, a plug 102 attached to a wiring duct rail 104, and a shaft 103 connecting the socket 101 and the plug 102, with the shaft 103 extending from the radial center of the cylindrical plug 102. The socket 101 is formed in a cylindrical shape like the plug 102, but has a larger diameter than the plug 102 because a portion of the LED lamp 1 is inserted into the socket 101. As will be described in more detail below, inserting a portion of the LED lamp 1 into the socket 101 allows the outer peripheral surfaces of the LED lamp 1 and the socket 101 to be flush with each other, improving the design of the light.

[0011] The connector 100 has a swivel mechanism that rotates the socket 101 at a predetermined angle relative to the shaft 103. The swivel mechanism may be configured so that the socket 101 rotates at a predetermined angle around the tip of the shaft 103 as the axis of rotation, or may be configured so that the socket 101 is rotatable around the axis. Alternatively, the shaft 103 may be rotatable relative to the plug 102. The swivel mechanism of the connector 100 allows the LED lamp 1 to be aimed at a desired location for light irradiation when the connector 100 is attached to the wiring duct rail 104.

[0012] The LED lamp 1 includes a cylindrical outer cover 10 with a bottom, and a light-shielding hood 70 inserted into the cylindrical outer cover 10. As will be described in detail later, in this embodiment, the light-shielding hood 70 is detachable from the lens 50. The LED lamp 1 is also detachable from the socket 101. The LED lamp 1 includes base pins 15 (see FIG. 3 , etc., described later) protruding from the outer cover 10, and the base pins 15 are inserted into pin insertion portions of the socket 101 to attach the LED lamp 1 to the socket 101, and the LED lamp 1 and the socket 101 are electrically connected.

[0013] The LED lamp 1 has a structure in which a light source unit 20 (see FIG. 4 described later), a lens 50, etc. are housed inside a tube of an outer cover 10. The outer cover 10 forms the exterior of the LED lamp 1 and also functions as a housing that houses the light source unit 20, the lens 50, etc. In the embodiment illustrated in FIG. 1 , the outer cover 10 of the LED lamp 1 forms the outer cover of a spotlight. In other words, the outer cover 10 forms the exterior of the spotlight. Note that conventionally known spotlights have a structure in which an LED lamp is housed inside a tube of a cylindrical cover with a bottom, and the outer cover of the LED lamp does not form the exterior of the spotlight.

[0014] With the LED lamp 1, the outer cover 10 forms the exterior of the spotlight, eliminating the need for a cover to enclose the lamp and allowing for a significantly smaller diameter spotlight. Furthermore, the LED lamp 1 is easily attached to and detached from the socket 101, eliminating the need to, for example, reach into the cover tube to replace the lamp or disassemble the lighting fixture to replace the lamp. The outer cover 10 and the shading hood 70 are cylindrical, with a constant outer diameter, in the portions that appear on the exterior of the spotlight. The outer cover 10, the shading hood 70, and the socket 101 all have substantially the same outer diameter, and their outer peripheral surfaces are flush with one another. A spotlight using the LED lamp 1 has a stylish design that creates a unified overall appearance.

[0015] As described above, the LED lamp 1 includes a lens 50 that controls the light emitted from the light source unit 20. The lens 50 has a light emission surface 52 that is circular in a plan view. In this specification, "plan view" means a view perpendicular to the emission surface 52 of the lens 50, unless otherwise specified. A protrusion 53 for attaching and detaching the lamp is formed on the emission surface 52. When removing the LED lamp 1 from the socket 101, the protrusion 53 is used to apply a rotational load to the lens 50, causing the LED lamp 1 to rotate relative to the socket 101, thereby allowing the LED lamp 1 to be removed. When attaching the LED lamp 1 to the socket 101, the protrusion 53 can be used to attach the LED lamp 1 to the socket 101 by rotating the LED lamp 1 in the opposite direction to that used for removal.

[0016] In the case of the spotlight illustrated in Figure 1, the socket 101 of the connecting fixture 100 is exposed and not embedded in the ceiling, wall, etc., so when attaching or detaching the LED lamp 1 to or from the socket 101, the outer cover 10 of the LED lamp 1 can be grasped and the lamp can be rotated.

[0017] FIG. 2 is a diagram showing how an LED lamp 1 is attached to a downlight frame 110. FIG. 2(a) shows how the LED lamp 1 is inserted into a recessed hole in a ceiling, and FIG. 2(b) shows how the LED lamp 1 is inserted into the recessed hole and then rotated to attach it to a socket (not shown). A downlight is generally a ceiling-recessed lighting fixture installed in the ceiling of a building. The downlight frame 110 has, for example, a generally cylindrical shape with a diameter tapering upward, and is attached to a recessed hole in the ceiling. In the downlight illustrated in FIG. 2, the socket is located above the ceiling. Furthermore, a shading hood 70 is not used in the case of a downlight.

[0018] The LED lamp 1 is inserted into the tube of the downlight frame 110 and attached to a socket arranged in the ceiling. As shown in FIG. 2(b), the LED lamp 1 constituting the downlight is arranged such that the entire lamp is positioned above the ceiling board, with only the light-emitting surface 52 of the lens 50 exposed through the opening 111 of the downlight frame 110. Therefore, when rotating the LED lamp 1 relative to the socket 101, a protrusion 53 formed on the light-emitting surface 52 is used, and the user can rotate the LED lamp 1 by hooking their finger on the protrusion 53. From the viewpoint of improving operability, it is preferable that two or more protrusions 53 are formed side by side in the radial direction and extend long in the radial direction of the lens 50.

[0019] FIG. 3 is a perspective view of the LED lamp 1, showing a state in which the shading hood 70 has been removed. As shown in FIG. 3, the shading hood 70 is configured to be detachable. The shading hood 70 includes a shading portion 71 extending from the opening of the outer cover 10 and an insertion portion 72 inserted into the cylindrical portion of the outer cover 10. As will be described in detail later, the shading hood 70 is attached to the lens 50 within the cylindrical portion of the outer cover 10. In other words, the shading hood 70 is detachably attached to the lens 50. The insertion portion 72 of the shading hood 70 is formed with an engaging protrusion 73 that engages with the shading hood fixing portion 60 of the lens 50 (see FIG. 8 and other figures described later).

[0020] The shading hood 70 is generally applied to spotlights and has the function of covering the periphery of the opening of the outer cover 10 to block light from diffusing beyond the intended target. The shading hood 70 may be a metal member or a resin member. The shading hood 70 is made of the same material as the outer cover 10 and has the same color as the outer cover 10, for example.

[0021] The light-shielding portion 71 extends in the axial direction from the opening of the outer cover 10 to block unnecessary light. The light-shielding portion 71 is formed in a cylindrical shape having the same outer diameter as the outer cover 10, and the outer peripheral surface of the light-shielding portion 71 is flush with the outer peripheral surface of the outer cover 10. The axial length of the light-shielding portion 71 is not particularly limited and is set appropriately depending on the size of the LED lamp 1, etc. An example of the axial length of the light-shielding portion 71 is 10 mm or more and 40 mm or less. The axial length of the light-shielding portion 71 may be shorter than the axial length of the insertion portion 72, but in this embodiment, it is longer than the axial length of the insertion portion 72.

[0022] The insertion portion 72 is formed in a cylindrical shape like the light-shielding portion 71, but its outer diameter is smaller than that of the light-shielding portion 71. For this reason, a step is formed on the outer peripheral surface of the light-shielding hood 70. Because the insertion portion 72 is inserted into the cylindrical interior of the outer cover 10, the outer diameter of the insertion portion 72 is smaller than the inner diameter of the outer cover 10. However, it is preferable that the outer diameter of the insertion portion 72 be close to the inner diameter of the outer cover 10 to the extent that insertion into the outer cover 10 is not hindered. The inner diameter of the light-shielding hood 70 is, for example, constant over the entire axial length, and the insertion portion 72 is formed to be thinner than the light-shielding portion 71.

[0023] Most of the insertion portion 72, for example, 90% or more or 95% or more of the axial length of the insertion portion 72, is inserted into the outer cover 10, but the insertion portion 72 protrudes slightly from the inside of the outer cover 10 so that the light-shielding hood 70 can be securely fixed to the lens 50. In this case, it is possible to prevent the outer cover 10 and the light-shielding portion 71 from coming into contact with each other, which would interfere with the attachment of the light-shielding hood 70. A small gap exists between the outer cover 10 and the light-shielding portion 71, but as long as this gap is 10% or less or 5% or less of the axial length of the light-shielding portion 71, it has little effect on the design.

[0024] The outer peripheral surface of the insertion portion 72 is disposed opposite the inner peripheral surface of the outer cover 10 with a small gap therebetween. The outer peripheral surface of the insertion portion 72 may be in contact with the inner peripheral surface of the outer cover 10 as long as it does not interfere with insertion into the outer cover 10. The insertion portion 72 is preferably configured to abut against the inner peripheral surface of the outer cover 10 at least when a force is applied in the radial direction of the shading hood 70. In this case, the outer cover 10 can withstand a load applied in the radial direction of the shading hood 70, effectively preventing damage to components, detachment of the shading hood 70, etc. The outer diameter of the insertion portion 72 is, for example, 90% or more or 95% or more of the inner diameter of the outer cover 10.

[0025] The LED lamp 1 includes a pair of base pins 15 protruding from the bottom of an outer cover 10 formed in a cylindrical shape with a bottom. The base pins 15 extend along the axial direction of the outer cover 10 from the other axial end opposite to the one axial end of the outer cover 10 to which the light-shielding hood 70 is attached. The base pins 15 are metallic power supply pins electrically connected to a circuit 30 (see FIG. 4 , etc., described below) for supplying power to the light source unit 20, and receive power from the socket of the lighting fixture and send it to the circuit 30. The base pins 15 have an expanded diameter at their tips so that they can be caught in pin insertion portions of the socket.

[0026] Two base pins 15 are provided side by side in the radial direction of the outer cover 10. The radial distance between the pair of base pins 15 (hereinafter sometimes referred to as the "pin distance") is not particularly limited, but is, for example, 40 mm or less, 35 mm or less, or 30 mm or less. The pin distance refers to the shortest distance between the central axes of the two pins. Examples of suitable ranges for the pin distance are 15 mm to 40 mm, 20 mm to 35 mm, or 25 mm to 30 mm. If the pin distance is within these ranges, it becomes easy to reduce the diameter of the lighting fixture.

[0027] The outer cover 10 is generally formed in a cylindrical shape with a bottom, but has a reduced diameter at the bottom side from which the base pins 15 protrude. The outer cover 10 has a large diameter portion 11 that forms the exterior of the spotlight, and a small diameter portion 12 that is inserted into the socket 101. The outer cover 10 further has a protrusion 13 that protrudes axially from the small diameter portion 12. The outer cover 10 may be a metal member or a resin member. An example of the resin that constitutes the outer cover 10 is polybutylene terephthalate (PBT).

[0028] The outer cover 10 is formed with, in order from the opening side, a large diameter portion 11, a small diameter portion 12, and a protruding portion 13, and the protruding portion 13 is also inserted into the socket 101. The socket 101 has a pin insertion portion and a housing portion for the protruding portion 13. The difference in outer diameter between the small diameter portion 12 and the protruding portion 13 is greater than the difference in outer diameter between the large diameter portion 11 and the small diameter portion 12. The axial length of the large diameter portion 11 is preferably 75% or more of the axial length L of the outer cover 10 (see FIG. 5 described later), and may be 75% to 95%, or 80% to 90%.

[0029] The outer diameter of the large diameter portion 11 is substantially the same as the outer diameter of the light-shielding portion 71 of the light-shielding hood 70 and the outer diameter of the socket 101, and their outer peripheral surfaces are flush. The outer diameter of the small diameter portion 12 is preferably close to the inner diameter of the socket 101 to the extent that insertion into the socket 101 is not hindered. The convex portion 13 is cylindrically formed in the radial center of the outer cover 10 and has a protrusion 13a formed on its outer peripheral surface. The protrusion 13a catches on the socket 101 in the same way as the base pin 15, improving the reliability of the fixation of the LED lamp 1 to the socket 101.

[0030] Fig. 4 is an exploded perspective view of the LED lamp 1. As shown in Fig. 4, the LED lamp 1 includes a light source unit 20 including an LED element 21, a circuit 30 for supplying power to the light source unit 20, a holder 40 for holding the light source unit 20, and a lens 50 for controlling the light emitted from the light source unit 20. As described above, the LED lamp 1 includes a cylindrical outer cover 10 with a bottom that houses the light source unit 20, the circuit 30, the holder 40, and the lens 50, and a base pin 15 that protrudes from the outer cover 10 and is electrically connected to the circuit 30. The LED lamp 1 further includes a heat sink 25 that dissipates heat from the light source unit 20 and a cylindrical circuit holder 35 that holds the circuit 30. The LED lamp 1 may also include a detachable light-shielding hood 70.

[0031] The LED lamp 1 is a small-diameter lamp, for example, having a diameter of 50 mm or less. The large-diameter portion 11 of the outer cover 10, which forms the exterior of the LED lamp 1, has a diameter of, for example, 35 mm or more and 45 mm or less. The outer cover 10 is longer in the axial direction than in the radial direction, and its axial length L may be 1.3 times or more and 1.7 times or less the diameter (diameter of the large-diameter portion 11). The circuit holder 25 and the holder 40 are made of a resin primarily composed of PBT or the like, and the heat sink 25 is made of a metal primarily composed of aluminum or the like. The lens 50 is made of, for example, a highly transparent and durable resin such as polycarbonate, or glass.

[0032] Because the LED lamp 1 is long in the axial direction, if the components are assembled using the bottom side of the outer cover 10 as the reference position, such as the boundary between the large diameter portion 11 and the small diameter portion 12 of the outer cover 10, it becomes difficult to assemble the lens 50 in the intended position, which can result in problems such as large variations in light distribution between each product. Therefore, in the LED lamp 1, the lens 50 is fixed to the holder 40 and forms a module together with the holder 40. This makes the distance between the light source unit 20 and the lens 50 constant.

[0033] The LED lamp 1 includes an LED module 2 composed of a light source unit 20, a holder 40, and a lens 50. The holder 40 is formed in a cylindrical shape with a bottom, and includes a base 41 forming the bottom of the cylinder, and a cylinder wall 42 standing on the outer periphery of the base 41. The base 41 has an opening 43 formed in the radial center and fixing claws formed around the opening 43. The light source unit 20 is disposed in the radial center from the underside of the base 41 so as to close the opening 43, and is held by fixing claws formed around the periphery of the opening 43. The holder 40 holding the light source unit 20 is fixed to a heat sink 25 using screws 46, and then the lens 50 is fixed to the holder 40 to form the LED module 2.

[0034] The LED module 2 is disposed closer to the opening than the axial center of the outer cover 10. A heat sink 25 that is long in the axial direction is housed closer to the bottom of the outer cover 10 than the LED module 2. In other words, the lens 50 is attached at a position away from the bottom of the outer cover 10, but because the light source unit 20, holder 40, and lens 50 are integrated to form the LED module 2, the distance between the light source unit 20 and the lens 50 can be managed with high precision, and the distance is not affected by assembly errors of other components.

[0035] The light source unit 20 includes an LED element 21 and a substrate 22 on which the LED element 21 is mounted. One example of a suitable light source unit 20 is a COB (chip on board) type light-emitting diode device for illumination. For example, a plurality of LED elements 21 are mounted in the center of the surface of a substantially square substrate 22, forming a light-emitting unit that is circular in plan view. A pair of electrodes is provided around the light-emitting unit, and wiring extending from the circuit 30 is connected to the electrodes. The light source unit 20 is fixed to the base 41 of the holder 40 so that the light-emitting unit including the LED element 21 is exposed from the opening 43 of the holder 40 and faces the opening of the outer cover 10.

[0036] The heat sink 25 is a member to which the holder 40 is screwed and functions as a heat dissipation member that dissipates heat from the light source unit 20. The heat sink 25 is a cylindrical body with a bottom, including a base 26 to which the holder 40 is fixed and a cylindrical wall 27 that stands on the outer periphery of the base 26 and extends in the opposite direction from the lens 50. The heat sink 25 extends long in the opposite direction from the lens 50, thereby effectively dissipating heat from the light source unit 20 while suppressing thermal effects on the lens 50. In addition, in this embodiment, the surface of the base 26 to which the holder 40 is fixed serves as a reference surface for intersection determination when assembling the lens 50. Because the distance between the lens 50 and the reference surface is short, the lens 50 is less susceptible to the effects of component processing accuracy and assembly errors of other components, allowing the lens 50 to be accurately assembled in the desired position.

[0037] A screw hole 26a and a wire insertion hole 26b are formed in the base 26 of the heat sink 25. A screw 46 that fixes the holder 40 is fastened into the screw hole 26a, and a wire extending from the circuit 30 is passed through the wire insertion hole 26b. The light source unit 20 is pressed against the base 26 by screwing the holder 40 to the base 26, and an excellent heat conduction path is formed between the light source unit 20 and the heat sink 25. It is preferable that thermal grease or a thermal dissipation sheet be interposed between the light source unit 20 and the base 26.

[0038] The cylindrical wall 27 of the heat sink 25 is formed in a substantially cylindrical shape and houses a circuit holder 35 that holds the circuit 30. The outer peripheral surface of the cylindrical wall 27 is formed with locking holes 28 used to secure the circuit holder 35, and with guide grooves 29 extending in the axial direction. The guide grooves 29 are grooves into which the intra-cylinder protrusions 14 formed on the outer cover 10 fit, and are formed at positions that overlap with the locking holes 28. In other words, the locking holes 28 are formed in the guide grooves 29. In this embodiment, the locking holes 28 are used to secure the outer cover 10 and the circuit holder 35 together.

[0039] The circuit 30 is a power supply circuit that converts AC current from a commercial power source into DC current for lighting the LED elements 21. The circuit 30 includes a circuit board 31 and circuit components 32 mounted on the circuit board 31. Base pins 15 are connected to the ends of the circuit board 31, and AC current is supplied to the circuit 30 from the socket 101 via the base pins 15. The circuit components 32 include switching elements, choke coils, capacitors, etc. Note that capacitors have lower heat resistance than other circuit components 32 such as choke coils.

[0040] The circuit board 31 has, for example, a substantially rectangular shape and is held by the circuit holder 35 with its longitudinal direction aligned with the axial direction of the outer cover 10. A pair of base pins 15 are provided protruding from one longitudinal end of the circuit board 31 toward the bottom of the outer cover 10. The capacitor is sandwiched between the pair of base pins 15 and, like the base pins 15, is mounted protruding from one longitudinal end of the circuit board 31 toward the bottom of the outer cover 10. In the LED lamp 1, the circuit board 31 is inserted into a board fixing portion 36 formed within the cylindrical circuit holder 35, and the base pins 15 are held by a base pin fixing portion 37. This holds the circuit 30 within the cylindrical circuit holder 35.

[0041] The circuit holder 35 is a substantially cylindrical member that holds the circuit 30 and is fixed to the heat sink 25 that covers the outside of the holder. The circuit holder 35 has a board fixing portion 36 formed inside the cylinder, a base pin fixing portion 37 formed at the axial end, and a fixing piece 38 that engages with the heat sink 25. The board fixing portion 36 includes a groove that extends in the axial direction and is formed in two places on the inner surface of the circuit holder 35. Each board fixing portion 36 holds both widthwise ends of the circuit board 31 inserted in the groove. Two base pin fixing portions 37 are provided corresponding to a pair of base pins 15, and have semicircular grooves into which flanges formed on the base pins 15 fit.

[0042] The fixing piece 38 is a portion separated from the rest of the cylindrical wall by two slits extending in the axial direction of the circuit holder 35, and is elastically deformable in the radial direction. A protrusion that engages with the heat sink 25 is formed at the tip of the fixing piece 38. The fixing pieces 38 are formed at two locations that face each other in the radial direction of the circuit holder 35. After the circuit 30 is fixed inside the cylindrical circuit holder 35, the circuit holder 35 is inserted into the cylindrical heat sink 25, whereby the protrusions of the fixing piece 38 fit into the locking holes 28 of the heat sink 25, and the circuit holder 35 is fixed to the heat sink 25.

[0043] 5 and 6 are cross-sectional views of the LED lamp 1 taken along the axial direction and the radial direction of the outer cover 10. Fig. 5 is a cross-sectional view of the LED lamp 1 taken along a first radial direction in which the base pins 15 are aligned, and Fig. 6 is a cross-sectional view of the LED lamp 1 taken along a second radial direction perpendicular to the first radial direction. Figs. 5 and 6 show cross sections of the LED lamp 1 without the shading hood 70 attached.

[0044] As shown in Figures 5 and 6, the LED lamp 1 has an internal structure in which a cylindrical heat sink 25 with a bottom is housed in the bottom side of the outer cover 10, and the LED module 2 is fixed to the base 26 of the heat sink 25. The heat sink 25 is housed in the large-diameter portion 11 of the outer cover 10. As described above, a circuit holder 35 holding a circuit 30 is fixed within the cylindrical heat sink 25. A portion of the circuit holder 35 protrudes from the cylindrical heat sink 25 into the small-diameter portion 12 of the outer cover 10, and a portion of the circuit components 32 extends into the protrusions 13. For example, a heat-sensitive capacitor is inserted into the protrusions 13. Alternatively, a component that generates more heat than the other circuit components 32 may be housed in the protrusions 13.

[0045] The small diameter portion 12 of the outer cover 10 has an outer diameter and an inner diameter smaller than those of the large diameter portion 11, and a step is formed on the inner peripheral surface of the outer cover 10 at the boundary between the large diameter portion 11 and the small diameter portion 12. The cylindrical wall 27 of the heat sink 25 is formed to fit along the inner peripheral surface of the large diameter portion 11 and extend close to the step. A flange 39 that protrudes radially outward and catches on the step is formed on the outer peripheral surface of the circuit holder 35. In this embodiment, the flange 39 abuts on the step of the outer cover 10, thereby regulating the positions of the circuit holder 35, the circuit 30 held by the circuit holder 35, and the base pins 15 connected to the circuit 30 relative to the outer cover 10.

[0046] The outer cover 10 is further formed with intra-cylindrical protrusions 14 that serve as fixing portions for the heat sink 25. Because the circuit holder 35 is fixed inside the cylinder of the heat sink 25, the circuit holder 35 is fixed to the outer cover 10 via the heat sink 25. The heat sink 25 is fixed to the outer cover 10 by fitting the intra-cylindrical protrusions 14 into locking holes 28 in the cylindrical wall 27. The pair of intra-cylindrical protrusions 14 are protrusions for fixing the heat sink 25 and are formed at positions facing each other on the inner circumferential surface of the outer cover 10. The protrusions of the fixing pieces 38 of the circuit holder 35 are inserted into the locking holes 28 of the heat sink 25 from the inside of the cylindrical wall 27, and the intra-cylindrical protrusions 14 of the outer cover 10 are inserted into the locking holes 28 from the outside of the cylindrical wall 27.

[0047] The heat sink 25, with the circuit holder 35 fixed inside the cylinder, is inserted into the outer cover 10. At this time, the guide grooves 29 (see FIG. 4 ) of the heat sink 25 are aligned with the positions of the intra-cylinder protrusions 14, and the heat sink 25 is inserted so that the intra-cylinder protrusions 14 move within the guide grooves 29. The intra-cylinder protrusions 14 then fit into locking holes 28 formed in the guide grooves 29, thereby fixing the heat sink 25 to the outer cover 10. A through hole 12a through which the base pin 15 passes is formed in the bottom of the outer cover 10 (the bottom of the small diameter portion 12). The LED lamp 1 is designed so that the base pin 15 protrudes from the through hole 12a to the outside of the outer cover 10 when the heat sink 25 is fixed to the outer cover 10.

[0048] As described above, the LED module 2 is fixed by using screws 46 to the base 26 of the heat sink 25 at the base 41 of the holder 40 that holds the light source unit 20. The base 41 of the holder 40 is formed with screw insertion holes 47 through which the screws 46 pass. The base 26 of the heat sink 25 is also formed with screw holes 26a through which the screws 46 are fastened and wire insertion holes 26b through which wires extending from the circuit 30 pass. The LED module 2 does not have a structure for fixing to the outer cover 10.

[0049] An adhesive 49 is filled between the LED module 2 and the outer cover 10. For example, the adhesive 49 is filled in the gap between the outer peripheral surface of the holder 40 and the inner peripheral surface of the outer cover 10 after the holder 40 is screwed to the heat sink 25. The adhesive 49 is also pressed against the lens 50 fixed to the holder 40, filling the gap between the outer peripheral surface of the LED module 2 and the inner peripheral surface of the outer cover 10 and joining the LED module 2 and the outer cover 10. As will be described in detail later, the outer peripheral surface of the holder 40 is formed with a plurality of outer peripheral surface recesses 48 (see FIG. 8 and the like described below) for increasing the adhesion area of ​​the adhesive 49.

[0050] The adhesive 49 is not particularly limited, but is preferably primarily composed of silicone resin from the viewpoints of adhesion, durability, etc. Two-component curing adhesives or stimulus curing adhesives can be used as the silicone-based adhesive. The lens 50 of the LED module 2 is fixed by the adhesive 49, but to more reliably prevent the lens 50 from falling off even if the adhesive strength of the adhesive 49 decreases due to aging, the lens 50 is fixed to the holder 40. Furthermore, by providing a fixing structure for the holder 40 and the lens 50, the distance between the light source unit 20 and the lens 50 can be regulated with high precision.

[0051] The LED module 2 is disposed, for example, within a range of 30% or less, or 20% or less, of the axial length L of the outer cover 10 from the opening of the outer cover 10. That is, 70% or more of the internal space of the axial length L of the outer cover 10 is occupied by the circuit 30 and the heat sink 25. Substantially all of the components of the LED lamp 1, including the LED module 2, heat sink 25, circuit 30, and circuit holder 35, are housed inside the cylindrical outer cover 10. Therefore, the axial length L of the outer cover 10 is substantially equal to the axial length of the LED lamp 1. The axial length of the LED lamp 1 is not particularly limited, but is, for example, 50 mm or more and 80 mm or less.

[0052] Fig. 7 is an enlarged view of part A in Fig. 6. As shown in Fig. 7, the lens 50 is fixed to the holder 40 that holds the light source unit 20, and together with the holder 40, constitutes a module. The LED module 2 has a fixing structure including locking claws 57 formed on the outer periphery 54 of the lens 50 and locking holes 45 formed in the cylindrical wall 42 of the holder 40. The locking claws 57 of the lens 50 fit into the locking holes 45 of the holder 40 and become caught on the cylindrical wall 42, thereby fixing the lens 50 to the holder 40.

[0053] The LED module 2 further includes a load receiving portion for receiving a rotational load acting on the lens 50. As described above, the LED lamp 1 is configured to be detachable from the socket of the lighting fixture by applying a rotational load to the lens 50. The load receiving portion effectively prevents damage to components and detachment of the lens 50 due to the rotational load. While it is possible to use the adhesive 49 to receive the rotational load, there is a concern that the lens 50 may detach, particularly if the adhesive 49 deteriorates over time. In this embodiment, the load receiving portion is configured by a convex portion 56 protruding from the outer periphery 54 of the lens 50 and a concave portion 44 formed in the cylindrical wall 42 of the holder 40, into which the convex portion 56 fits.

[0054] The lens 50 has a plurality of convex portions 56 and a plurality of locking claws 57, which are alternately arranged along the circumferential direction of the lens 50. Similarly, the holder 40 has a plurality of concave portions 44 and a plurality of locking holes 45, which are alternately arranged along the circumferential direction of the holder 40. In this case, damage to the LED module 2, detachment of the lens 50, etc. can be more effectively prevented. Two locking claws 57 are provided side by side in a first radial direction of the lens 50, and two convex portions 56 are provided side by side in a second radial direction perpendicular to the first radial direction.

[0055] The lens 50 is a Fresnel lens including a plurality of annular convex portions 51a arranged on concentric circles. A Fresnel lens is a lens whose thickness is reduced by dividing the lens surface into concentric circles, and has a sawtooth-like cross section. The Fresnel structure 51 including the plurality of annular convex portions 51a is formed on the light incident surface of the lens 50 facing the light source unit 20. In the lens 50, the diameters of the annular convex portions 51a become smaller, and the height and width become smaller as they approach the central axis of the lens 50. The Fresnel structure 51 includes three annular convex portions 51a, and the area surrounded by the annular convex portion 51a with the smallest diameter forms a gently spherical surface that bulges toward the light source unit 20.

[0056] The lens 50 has a light exit surface 52 that is circular in a plan view. The exit surface 52 includes a first region 52a formed along the radial direction of the lens 50 and a second region 52b formed in an annular shape surrounding the first region 52a and inclined from the boundary of the first region 52a toward the outer periphery of the exit surface 52 so as to approach the light source unit 20. The exit surface 52 further includes a protrusion 53 for attaching and detaching the lamp that protrudes from the second region 52b. By providing the second region 52b, which is an inclined surface, on the exit surface 52 and forming the protrusion 53 on this inclined surface, even if the protrusion 53 is made taller to improve operability, the protrusion 53 is less noticeable and the design is not impaired.

[0057] The diameter φ1 of the first region 52a is preferably 50% or more of the diameter φ of the light exit surface 52, and may be 55% to 90%, or 60% to 85%, or 65% to 80%. If the diameter φ1 of the first region 52a is within this range, it is possible to achieve a high level of compatibility between good optical characteristics of the lens 50 and good operability when attaching and detaching the lamp. The diameter φ1 of the first region 52a is not particularly limited, but when attempting to reduce the diameter of the lighting fixture, it is, for example, smaller than the distance between the pair of base pins 15, and may be 15 mm to 30 mm, or 20 mm to 25 mm.

[0058] The boundary between the first region 52a and the second region 52b may be formed independently of the Fresnel structure 51, but is preferably located so as to substantially overlap the radially inner end of the annular convex portion 51a with the largest diameter. In this case, the optical design of the lens 50 is facilitated. In other words, the second region 52b is formed so as to coincide with the radially inner end of the annular convex portion 51a with the largest diameter. Most of the light incident on the annular convex portion 51a with the largest diameter is reflected by the total reflection surface of the annular convex portion 51a and exits from the second region 52b.

[0059] The inclination angle θ of the second region 52b with respect to a virtual line α along the surface direction of the first region 52a is preferably 5° or more, and more preferably 7° or more. For a given width of the second region 52b, the greater the inclination angle θ, the higher the protrusion 53 can be formed. On the other hand, if the inclination angle θ is too large, the light emitted from the lens 50 will spread, potentially reducing the illuminance at the intended location. The inclination angle θ is, for example, 25° or less, or 20° or less. Examples of suitable ranges for the inclination angle θ include 5° to 25°, 7° to 20°, or 8° to 15°.

[0060] The second region 52b may be curved so as to be gently convex along the radial direction of the lens 50, but preferably does not have any irregularities along the radial direction except for the portion where the protrusion 53 is formed. That is, in the radial cross section of the lens 50, the second region 52b is formed flat at the above-mentioned inclination angle θ.

[0061] 8 and 9 are enlarged perspective views of the LED module 2 and its vicinity. FIG. 9 shows the state in which the lens 50 has been removed from the holder 40. As shown in FIGS. 8 and 9, the LED module 2 is fixed to the heat sink 25. The holder 40 is screwed to the heat sink 25, and the lens 50 is fixed to the heat sink 25 via the holder 40. The light source unit 20 is pressed against the heat sink 25 by the holder 40. As described above, the light exit surface 52 of the lens 50 has a projection 53 formed thereon for attaching and detaching the lamp, which projects from the second region 52b, which is an inclined surface. Details of the configuration of the light exit surface 52 are shown in FIGS. 10 and 11, which will be described later.

[0062] The LED module 2 includes a locking hole 45 formed in the cylindrical wall 42 of the holder 40 and a locking claw 57 of the lens 50 that is inserted into the locking hole 45 as a fixing structure for more reliably preventing the lens 50 from falling off. The LED module 2 further includes a recess 44 formed in the cylindrical wall 42 of the holder 40 and a protrusion 56 of the lens 50 that fits into the recess 44 as a load-receiving structure for receiving a rotational load applied to the lens 50. When a rotational load acts on the lens 50 during attachment or detachment of the LED lamp 1, the protrusion 56 abuts against the edge of the recess 44, and the rotational load is applied to the cylindrical wall 42 of the holder 40. This more reliably prevents damage to components (e.g., the locking claw 57), detachment of the lens 50, etc.

[0063] As described above, the holder 40 includes a base 41 that is screwed to the heat sink 25 to hold the light source unit 20, and a cylindrical wall 42 that stands on the outer periphery of the base 41. Two recesses 44 and two locking holes 45 are formed in the cylindrical wall 42, alternately at intervals of approximately 90° around the central axis of the holder 40. The two recesses 44 have the same shape and size, and are formed side by side in the radial direction of the holder 40. Similarly, the two locking holes 45 have the same shape and size, and are formed side by side in the radial direction of the holder 40.

[0064] The recess 44 is a depression formed at the tip of the cylindrical wall 42 and surrounded on three sides by the cylindrical wall 42. Because the recess 44 is open toward the lens 50, the protrusion 56 of the lens 50 can be fitted into the recess 44. The locking hole 45 is a through-hole formed through the cylindrical wall 42 in the thickness direction and surrounded on all sides by the cylindrical wall 42. The locking claw 57 of the lens 50 is inserted into the locking hole 45 from the radially inner side of the cylindrical wall 42 and hooked onto the edge of the locking hole 45. The gap between the recess 44 and the protrusion 56 in the circumferential direction of the cylindrical wall 42 is smaller than the gap between the locking hole 45 and the locking claw 57 in the circumferential direction. As a result, the recess 44 and the protrusion 56 function as a load receiving portion that receives a rotational load.

[0065] The outer peripheral surface of the cylindrical wall 42 is provided with a plurality of outer peripheral surface recesses 48 for increasing the adhesion area of ​​the adhesive 49. The outer peripheral surface recesses 48 are recesses recessed radially inward of the cylindrical wall 42. The outer peripheral surface recesses 48 are groove-shaped recesses extending in the axial direction of the cylindrical wall 42, and are formed over the entire axial length of the cylindrical wall 42. The shapes and sizes of the outer peripheral surface recesses 48 may differ from one another, but are substantially the same in this embodiment. The maximum depth of the outer peripheral surface recesses 48 (the radial length from the outermost peripheral surface to the deepest part of the recess) is preferably 0.3 mm to 0.8 mm, and the width of the outer peripheral surface recesses 48 is preferably 1.0 mm to 2.0 mm. In this case, the adhesive 49 can easily enter the outer peripheral surface recesses 48, more effectively increasing the adhesion area of ​​the adhesive 49.

[0066] The outer peripheral surface recesses 48 are formed at regular intervals in the circumferential direction over a wide range of the outer peripheral surface of the cylindrical wall 42, excluding, for example, the portions where the recesses 44 and the locking holes 45 are formed and the vicinity thereof. Between adjacent outer peripheral surface recesses 48 in the circumferential direction of the cylindrical wall 42, there is a surface without a depression located on the same circumference, thereby forming unevenness along the circumferential direction of the cylindrical wall 42. In addition, it is preferable that the interval between adjacent outer peripheral surface recesses 48 is smaller than the width of the outer peripheral surface recesses 48.

[0067] By forming a plurality of outer peripheral surface recesses 48, the surface area of ​​the outer peripheral surface is increased compared to when there are no irregularities on the outer peripheral surface, and the area to which the adhesive 49 adheres is expanded. As a result, the adhesive strength between the inner peripheral surface of the outer cover 10 and the holder 40 is increased. The outer peripheral surface recesses 48 are preferably curved toward the inside of the cylindrical wall 42 and formed in an arc shape when viewed from above the holder 40. In this case, the adhesive 49 can easily penetrate into the outer peripheral surface recesses 48 and adhere to the surface of the recesses, more effectively improving the adhesive strength with the outer cover 10.

[0068] The lens 50 has an outer peripheral portion 54 formed in a substantially cylindrical shape. Two protrusions 56 and two locking claws 57 each protrude axially from the end (one axial end) of the outer peripheral portion 54 opposite the light exit surface 52, and are alternately formed at approximately 90° intervals around the central axis of the lens 50. The two protrusions 56 have the same shape and size and are formed side by side in the radial direction of the lens 50. Similarly, the two locking claws 57 have the same shape and size and are formed side by side in the radial direction of the lens 50. The locking claws 57 are formed to be elastically deformable in the radial direction of the lens 50, and when the lens 50 is fixed to the holder 40, they bend slightly radially inward and then return to their original shape so that they can be inserted into the locking holes 45.

[0069] An outer peripheral protrusion 55 is formed at one axial end of the outer peripheral portion 54, protruding radially outward beyond the other axial end. The outer peripheral protrusion 55 is formed by making one axial end of the outer peripheral portion 54 thicker than the other axial end. A light-shielding hood fixing portion 60 is formed on the outer peripheral portion 54 using the outer peripheral protrusion 55. At the bottom of the outer peripheral portion 54, there are multiple circumferentially separated portions where the outer peripheral protrusion 55 is not formed, and these portions become the light-shielding hood fixing portion 60 into which the engaging protrusion 73 of the light-shielding hood 70 can be inserted. The engaging protrusion 73 inserted into the light-shielding hood fixing portion 60 hooks onto the outer peripheral protrusion 55, thereby fixing the light-shielding hood 70 to the lens 50.

[0070] On the outer peripheral surface of the lens 50, outer peripheral surface knurling 63 for diffusing light is formed, extending in the axial direction of the lens 50. A portion of the light beam emitted from the light source unit 20 is emitted from the outer peripheral surface of the lens 50, which may result in streaks appearing on the illuminated surface. By forming the outer peripheral surface knurling 63, the light emitted from the outer peripheral surface of the lens 50 is diffused, thereby effectively suppressing streaks on the illuminated surface. The outer peripheral surface knurling 63 is preferably formed in a region of the outer peripheral portion 54 close to the exit surface 52, and in this embodiment, it is formed from the boundary with the exit surface 52 to the boundary with the outer peripheral convex portion 55.

[0071] The outer peripheral surface knurling 63 is a surface unevenness structure for light diffusion, and is preferably formed by thin linear convex portions or concave portions. The thin linear concave portions can be considered grooves. In this embodiment, a plurality of grooves, each of which is approximately V-shaped in a plan view of the lens 50, are formed continuously in the circumferential direction of the outer peripheral surface. In this case, the boundary positions between adjacent grooves become convex portions, and a fine surface unevenness structure in which convex and concave portions are repeated in the circumferential direction is formed on the outer peripheral surface of the lens 50. In other words, the outer peripheral surface knurling 63 can also be considered to be formed by a series of convex portions, each of which is approximately V-shaped in a plan view, formed continuously in the circumferential direction.

[0072] The outer peripheral surface knurling 63 is preferably formed along the entire outer peripheral surface. The width and depth of each groove constituting the outer peripheral surface knurling 63 are substantially the same. For example, the groove depth is 0.3 mm or more and 0.7 mm or less, and the groove width is 0.5 mm or more and 2.0 mm or less. In this embodiment, the groove pitch (the distance between the widthwise centers of adjacent grooves) and the groove width in the circumferential direction are the same, but the grooves may be formed at a predetermined interval in the circumferential direction. The pitch of the thin linear protrusions or recesses in the circumferential direction is preferably, for example, 0.5 mm or more and 3.0 mm or less. The grooves constituting the outer peripheral surface knurling 63 are formed with the same width as the protrusions or recesses constituting the knurling 62 in the second region 52b described below.

[0073] FIG. 10 is a perspective view of the lens 50, and FIG. 11 is an enlarged view of the protrusion 53 of the lens 50 and its vicinity. As shown in FIGS. 10 and 11 , the light exit surface 52 of the lens 50 includes a first region 52a that is circular in plan view and a second region 52b that is annular in plan view and surrounds the first region 52a. The second region 52b is an inclined surface that gradually approaches the holder 40 from the first region 52a toward the outer peripheral portion 54, in other words, that gradually slopes away from the opening of the outer cover 10. The inclination angle θ (see FIG. 7 ) of the second region 52b is preferably constant over the entire circumference of the second region 52b. Furthermore, the first region 52a has a perfect circular shape in plan view, and the width of the annular second region 52b is constant over the entire circumference.

[0074] Dimples 61 for diffusing light are formed in the first region 52a of the light exit surface 52. The first region 52a is a translucent region that overlaps with the light source unit 20, but the light source unit 20 can be hidden by the light diffusion of the dimples 61. The dimples 61 are a fine surface uneven structure for diffusing light, and are preferably formed by a plurality of convex or concave portions having a circular or polygonal shape in a plan view. The dimples 61 are preferably composed of regularly formed convex or concave portions. Each convex or concave portion constituting the dimple 61 is substantially the same size and is formed regularly and continuously. The diameter of the circumscribed circle of each convex or concave portion is, for example, 0.2 mm or more and 1.0 mm or less.

[0075] The surfaces of the minute protrusions or recesses that make up the dimples 61 are preferably gently curved. In this case, the boundaries between the protrusions become recesses, or the boundaries between the recesses become protrusions, forming a fine surface unevenness structure. In this embodiment, protrusions that are regular hexagonal in plan view are formed without gaps across the entire first region 52a. Each protrusion that makes up the dimple 61 has substantially the same size and is partitioned by a regular hexagonal groove. In other words, each side of the hexagon is shared by adjacent protrusions. The length of one side of the hexagon is, for example, 0.2 mm or more and 1.0 mm or less. The dimples 61 may also be formed by recesses that are regular hexagonal in plan view.

[0076] The second region 52b of the light-emitting surface 52 further has a protrusion 53 for attaching and detaching the lamp. When attaching or detaching the LED lamp 1 to or from a socket of a lighting fixture, particularly in a case where the outer cover 10 cannot be gripped when attaching or detaching the lamp, such as in the downlight illustrated in FIG. 2, the protrusion 53 is used to rotate the LED lamp 1. Because the protrusion 53 is formed in the second region 52b located radially outward of the light-emitting surface 52, the lens 50 can be easily rotated and a large rotational load can be applied. Because the LED module 2 has a load-receiving portion, damage to components, detachment of the lens 50, etc. can be more reliably prevented even if a large rotational load acts on the lens 50.

[0077] The protrusions 53 extend radially from the lens 50, and two or more are formed so as to be aligned radially across the first region 52a. Three or more protrusions 53 may be formed, but two are preferred from the viewpoint of achieving both aesthetic design and ease of use. In this embodiment, two protrusions 53 having the same shape and size extend radially from radially opposing outer peripheral edges of the light-emitting surface 52. By forming the pair of protrusions 53 radially from the outer peripheral edge of the light-emitting surface 52, a large rotational load can be applied to the lens 50, making it easier to attach and detach the LED lamp 1.

[0078] It is preferable that the protrusion 53 does not protrude farther in the direction of the opening of the outer cover 10 than the first region 52a. The protrusion 53 may have a height exceeding an imaginary line α (see FIG. 7 ) along the surface direction of the first region 52a, but the upper end of the protrusion 53 (the portion closest to the opening of the outer cover 10) is preferably located within a range of 3 mm or less from the imaginary line α. On the other hand, if the height H of the protrusion 53 is too low, operability decreases, so the height H is preferably 1.5 mm or more. An example of a suitable height H of the protrusion 53 is, for example, 1.3 mm or more and 2.0 mm or less at the highest point.

[0079] If the height H of the protrusion 53 is within the above range, the protrusion 53 will be less noticeable while ensuring good operability. The height H of the protrusion 53 is the length along the axial direction of the lens 50 from the top surface of the second region 52b where the protrusion 53 is not present to the top surface of the protrusion 53. Here, the top surface means the surface facing the opening of the outer cover 10. The height H of the protrusion 53 may be constant along the radial direction of the lens 50, or may gradually increase radially outward.

[0080] It is preferable that the protrusion 53 does not protrude from the inside of the tube of the outer cover 10, or is formed to a height such that the protrusion length from the inside of the tube of the outer cover 10 is 3 mm or less, more preferably 1 mm or less. In this case, the protrusion 53 is less noticeable, resulting in a good design. The protrusion length of the protrusion 53 can be reduced by separating the first region 52a of the lens 50 from the opening of the outer cover 10, but it is preferable that the axial distance from the opening of the outer cover 10 to the first region 52a be 1 mm or more and 10 mm or less.

[0081] From the viewpoint of operability, the length R of the protrusion 53 along the radial direction of the lens 50 is preferably 4.0 mm or more. From the viewpoint of achieving both operability and design, the length R of the protrusion 53 is preferably 3.5 mm or more and 5.0 mm or less, and more preferably 4.3 mm or more and 4.6 mm or less. The length R of the protrusion 53 is, for example, 9% or more and 13% or less of the diameter of the light exit surface 52 and 50% or more and 80% or less of the width of the second region 52b. The protrusion 53 may be formed across the entire width of the second region 52b, but in this embodiment, the protrusion 53 is formed with a length that extends from the outer peripheral edge of the light exit surface 52 beyond 50% or 60% of the width of the second region 52b and does not reach the boundary position with the first region 52a.

[0082] The upper surface of the protrusion 53 may be formed parallel to the radial direction of the lens 50, or may be inclined in the same direction as the portion of the second region 52b where the protrusion 53 is not present. In this embodiment, the inclination angle of the upper surface of the protrusion 53 is smaller than the inclination angle θ of the second region 52b, so the height H of the protrusion 53 gradually increases radially outward. Because the protrusion 53 is the portion that the user's finger touches, it is preferable that the corners of the protrusion 53 are chamfered and rounded. The width (thickness) of the protrusion 53 may be such that it is not damaged by a load applied to the protrusion 53, and is, for example, 0.2 mm or more and 0.4 mm or less. The width of the protrusion 53 may increase radially outward of the lens 50.

[0083] The second region 52b is formed with knurling 62 for diffusing light, extending in the radial direction of the lens 50. The knurling 62 is a surface unevenness structure for diffusing light, and is preferably formed of thin linear convex or concave portions extending in the radial direction. By forming the thin linear knurling 62 extending in the same direction as the protrusions 53, the protrusions 53 can be made even less noticeable. The width of the thin linear convex or concave portions constituting the knurling 62 is preferably similar to the width of the protrusions 53, and is preferably 70% to 130% or 80% to 120% of the width of the protrusions 53. The width may be the same as or smaller than the width of the protrusions 53. The width of the thin linear convex or concave portions is, for example, 0.5 mm to 2.0 mm.

[0084] The knurling 62 is formed continuously in the circumferential direction of the second region 52b over the entire area of ​​the second region 52b. In this embodiment, thin linear convex portions extending radially of the lens 50 are formed continuously in the circumferential direction of the second region 52b without gaps over the entire area of ​​the second region 52b except for the portion where the protrusions 53 are formed. Furthermore, the convex portions constituting the knurling 62 are formed radially from the radial center of the light exit surface 52, and therefore slightly increase in width radially outward. The maximum width of the convex portions is the same as the width of the grooves constituting the outer peripheral surface knurling 63, and the widthwise center of the convex portions is aligned with the deepest portion of the grooves of the outer peripheral surface knurling 63.

[0085] The surfaces of the thin linear protrusions constituting the knurling 62 are, for example, gently curved. In this case, the boundary portions between adjacent protrusions become recesses (grooves), forming a fine surface uneven structure in which recesses and protrusions are repeated in the circumferential direction of the second region 52b. In this embodiment, the width of each protrusion is substantially the same, and the pitch and width of the protrusions in the circumferential direction are the same. Note that the thin linear protrusions or recesses may be formed at a predetermined interval in the circumferential direction. The pitch of the thin linear protrusions or recesses in the circumferential direction is preferably, for example, 0.5 mm or more and 3.0 mm or less.

[0086] As described above, the LED lamp 1 is configured as a module in which the holder 40 that holds the light source unit 20 and the lens 50 are directly fixed, so the distance between the light source unit 20 and the lens 50 is unaffected by assembly errors of other components and remains constant. Furthermore, the effect of component processing accuracy on light distribution can be reduced, resulting in a stable light distribution angle. Therefore, it is possible to provide an LED lamp 1 with stable optical characteristics and little variation in light distribution between products.

[0087] The LED lamp 1 is further configured to be detachable from the socket by applying a rotational load to the lens 50, and the holder 40 and the lens 50 are provided with load receiving portions for receiving the rotational load acting on the lens 50. Because the load receiving portions receive the rotational load acting on the lens 50, problems such as damage to or detachment of parts when attaching or detaching the lamp can be effectively prevented. The LED lamp 1 can be easily attached to and detached from the socket using the protrusions 53 formed on the lens 50.

[0088] The above-described embodiment may be modified as needed without sacrificing the objectives of the present disclosure. For example, if the heat generated by the light source unit is low, the heat sink may be reduced in size or omitted. It is also possible to provide the heat sink with the function of a circuit holder. Furthermore, instead of the lens 50, a lens without at least one of the projections for attaching and detaching the lamp, the load bearing portion, and the light-shielding hood fixing portion may be used.

[0089] The present disclosure is further described by the following embodiments. Configuration 1: An LED lamp detachably attached to a socket, the LED lamp comprising: a light source unit including an LED element; a holder for holding the light source unit; a circuit for supplying power to the light source unit; a lens for controlling light emitted from the light source unit; a cylindrical outer cover with a bottom that houses the light source unit, the holder, the circuit, and the lens; and a base pin protruding from the outer cover and electrically connected to the circuit, the lens being fixed to the holder and constituting a module together with the holder. Configuration 2: The LED lamp according to Configuration 1, wherein the outer cover is longer in the axial direction than in the radial direction, and the module is disposed closer to the opening than the axial center of the outer cover. Configuration 3: The LED lamp according to Configuration 1 or 2, further comprising: a heat sink for dissipating heat from the light source unit, the heat sink being a cylindrical body with a bottom that includes a base to which the holder is fixed and a cylindrical wall erected on the outer periphery of the base and extending in the direction opposite to the lens. The LED lamp of any one of the preceding configurations, further comprising a circuit holder fixed to the inside of the heat sink and holding the circuit, the heat sink having a fixing portion formed inside the outer cover, and the circuit holder being fixed to the outer cover via the heat sink.

[0090] and a base pin protruding from the outer cover and electrically connected to the circuit, the LED lamp being configured to be detachable from the socket by applying a rotational load to the lens, the holder and the lens being provided with load receiving portions for receiving the rotational load acting on the lens. Structure 7: The LED lamp according to Structure 6, wherein the holder is formed in a cylindrical shape with a bottom, and the load receiving portion is composed of a convex portion protruding from the outer periphery of the lens and a concave portion formed in a cylindrical wall of the holder and into which the convex portion fits. Configuration 8: The LED lamp of Configuration 7 further includes a fixing structure including locking claws formed on the outer periphery of the lens and locking holes formed on the cylindrical wall of the holder, into which the locking claws are inserted.Configuration 9: The LED lamp of Configuration 8, wherein a plurality of the protrusions and a plurality of the locking portions are formed and arranged alternately along the circumferential direction of the holder.Configuration 10: The LED lamp of any one of Configurations 7 to 9, wherein an adhesive is filled in the gap between the holder and the outer cover, and a plurality of recesses are formed on the outer periphery of the cylindrical wall of the holder to increase the adhesive adhesion area.Configuration 11: The LED lamp of any one of Configurations 6 to 10, wherein an outer periphery of the lens is formed with an outer periphery knurling extending in the axial direction of the lens for diffusing light.Configuration 12: The LED lamp of any one of Configurations 6 to 11, wherein a protrusion is formed on the light-emitting surface of the lens, which is used when attaching or detaching the lamp and against which a rotational load acts.

[0091] REFERENCE SIGNS LIST 1 LED lamp 2 LED module 10 Outer cover 11 Large diameter portion 12 Small diameter portion 12a Through hole 13 Convex portion 13a Protrusion 14 Inner cylinder protrusion 15 Base pin 20 Light source portion 21 LED element 22 Substrate 25 Heat sink 26 Base portion 26a Screw hole 26b Wiring insertion hole 27 Cylinder wall 28 Locking hole 29 Guide groove 30 Circuit 31 Circuit board 32 Circuit component 35 Circuit holder 36 Substrate fixing portion 37 Base pin fixing portion 38 Fixing piece 39 Flange 40 Holder 41 Base portion 42 Cylinder wall 43 Opening 44 Recess 45 Locking hole 46 Screw 47 Screw insertion hole 48 Outer peripheral surface recess 49 Adhesive 50 Lens 51 Fresnel structure 51a Annular convex portion 52 Emission surface 52a First region 52b Second region 53 Protrusion 54 Outer periphery 55 Outer periphery convex portion 56 Convex portion 57 Locking claw 60 Light-shielding hood fixing portion 61 Dimple 62 Knurling 63 Outer periphery knurling 70 Light-shielding hood 71 Light-shielding portion 72 Insertion portion 73 Engagement protrusion 100 Connector 101 Socket 102 Plug 103 Shaft 104 Wiring duct rail 110 Downlight frame

Claims

1. An LED lamp detachable from a socket, comprising: a light source unit including an LED element; a holder for holding the light source unit; a circuit for supplying power to the light source unit; a lens for controlling light emitted from the light source unit; a bottomed cylindrical outer cover for housing the light source unit, the holder, the circuit, and the lens; and a base pin protruding from the outer cover and electrically connected to the circuit. The lens is fixed to the holder and forms a module together with the holder.

2. The LED lamp according to claim 1, wherein the outer cover is longer in the axial direction than in the radial direction, and the module is disposed on the opening side of the axial center of the outer cover.

3. The LED lamp according to claim 2, further comprising a heat sink for dissipating heat from the light source unit, the heat sink being a bottomed cylindrical body including a base to which the holder is fixed and a cylindrical wall standing on the outer peripheral edge of the base and extending in a direction opposite to the lens.

4. The LED lamp according to claim 3, further comprising a circuit holder fixed inside the cylinder of the heat sink for holding the circuit. A fixing portion of the heat sink is formed inside the cylinder of the outer cover, and the circuit holder is fixed to the outer cover via the heat sink.

5. The LED lamp according to claim 1, wherein the LED lamp is configured to be detachable from the socket by applying a rotational load to the lens, and the holder and the lens are provided with load receiving portions for receiving the rotational load acting on the lens.

6. The LED lamp according to claim 5, wherein the holder is formed in a bottomed cylindrical shape, and the load receiving portion is composed of a convex portion protruding from the outer peripheral portion of the lens and a concave portion formed in the cylindrical wall of the holder into which the convex portion fits.

7. The LED lamp according to claim 6, further comprising a fixing structure including a locking claw formed on the outer peripheral portion of the lens and a locking hole formed in the cylindrical wall of the holder into which the locking claw is inserted.

8. The LED lamp according to claim 7, wherein a plurality of the convex portions and the locking portions are respectively formed and arranged alternately along the circumferential direction of the lens.

9. In the gap between the holder and the outer cover, an adhesive is filled, and a plurality of recesses for expanding the adhesion area of the adhesive are formed on the outer peripheral surface of the cylindrical wall of the holder. The LED lamp according to any one of claims 1 to 8.

10. On the outer peripheral surface of the lens, an outer peripheral surface knurl for light diffusion extending in the axial direction of the lens is formed. The LED lamp according to any one of claims 1 to 8.

11. On the light emitting surface of the lens, projections that are used when the lamp is attached and detached and on which a rotational load acts are formed. The LED lamp according to any one of claims 1 to 8.

Images