LED lamp

Abstract

To provide an LED lamp that is easy to be attached to and detached from a socket without impairing the performance of the lamp.SOLUTION: An LED lamp 1 can be attached to and detached from a socket 101, and comprises a light source part 20, a circuit 30, and a lens 50 for controlling light emitted from the light source part 20. In addition, the LED lamp 1 comprises: a bottomed cylindrical outer cover 10; and a base pin 15 protruding from the outer cover 10, and electrically connected to the circuit 30. The lens 50 comprises a light emitting surface 52 having a circular shape in a planar view. The emitting surface 52 includes: a first region 52a formed along a radial direction of the lens 50; a second region 52b formed annularly around the first region 52a, and inclined so as to approach in the direction of the light source part 20 toward an outer peripheral edge of the emitting surface 52 from a boundary between itself and the first region 52a; and a lamp attachment / detachment protrusion 53 protruding from the second region 52b.SELECTED DRAWING: Figure 10

Description

Technical Field

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

Background Art

[0002] Conventionally, an LED lamp configured to be detachable from a socket of a lighting fixture has been widely known (see, for example, Patent Document 1). The LED lamp disclosed in Patent Document 1 is a spherical lamp including a light source unit including an LED element, a substantially oval globe, a resin holder into which the opening peripheral edge of the globe is fitted, and a base portion attached to the holder. A power supply circuit for converting the power supplied from a commercial power supply through the base portion and supplying it to the LED element is housed in the holder of the LED lamp.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when attaching an LED lamp to a socket of a lighting fixture, for example, the lamp is attached to the socket by rotating the LED lamp. Also, the lamp is removed from the socket by rotating the LED lamp in the direction opposite to the attachment direction. In an LED lamp that is detachable from a socket, easy attachment and detachment operation is an important issue. On the other hand, as a means for facilitating the attachment and detachment of the LED lamp, it is also conceivable to form a large and easy-to-operate knob portion on the lamp. However, in that case, the design of the lamp deteriorates, and it is also assumed that the optical characteristics are affected.

Means for Solving the Problems

[0005] An LED lamp according to one aspect of the present disclosure is a detachable LED lamp for a socket, and includes a light source unit including an LED element, 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 circuit, and the lens, and base pins protruding from the outer cover and electrically connected to the circuit. The lens has a light-emitting surface that is circular in plan view, and the light-emitting surface includes a first region formed along the radial direction of the lens, a second region formed annularly surrounding the first region and inclined so as to approach the light source unit from the boundary with the first region toward the outer peripheral edge of the light-emitting surface, and a protrusion for lamp attachment / detachment protruding from the second region.

Advantages of the Invention

[0006] According to one aspect of the present disclosure, it is possible to provide an LED lamp that can be easily attached to and detached from a socket without impairing the performance of the lamp.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Figure 4

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Figure 10

Figure 11

Mode for Carrying Out the Invention

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

[0009] FIG. 1 is a perspective view of an LED lamp 1 which is an example of an embodiment, showing a state where the LED lamp 1 is attached to a connection device 100 including a socket 101. As shown in FIG. 1, the LED lamp 1 constitutes a spotlight together with the connection device 100. A spotlight is generally a lighting fixture that intensively illuminates the direction in which the lamp is facing. In the example shown in FIG. 1, the connection device 100 that constitutes the spotlight is attached to a wiring duct rail 104. Note that the LED lamp 1 may be attached to a socket for a spotlight provided on, for example, the ceiling, wall, etc. of a building.

[0010] The connection device 100 includes a socket 101, a plug 102 attached to the wiring duct rail 104, and a shaft 103 that connects the socket 101 and the plug 102, and has a structure in which the shaft 103 extends from the central portion in the radial direction of the columnar plug 102. The socket 101 is formed in a columnar shape similar to the plug 102, but since a part of the LED lamp 1 is inserted into the socket 101, its diameter is larger than that of the plug 102. Although details will be described later, by inserting a part of the LED lamp 1 into the socket 101, the outer peripheral surfaces of the LED lamp 1 and the socket 101 can be flush, improving the design of the light.

[0011] The connecting device 100 has a swinging mechanism in which the socket 101 rotates at a predetermined angle with respect to the shaft 103. The swinging mechanism may have a structure in which the socket 101 rotates at a predetermined angle with the tip of the shaft 103 as the rotation axis, or may have a structure in which the socket 101 is rotatable around the shaft. Also, the shaft 103 may be rotatable with respect to the plug 102. With the swinging mechanism of the connecting device 100, the LED lamp 1 can be directed toward a place where light is desired to be irradiated while the connecting device 100 is attached to the wiring duct rail 104.

[0012] The LED lamp 1 includes a bottomed cylindrical outer cover 10 and a light-shielding hood 70 inserted into the cylinder of the outer cover 10. Although details will be described later, in the present embodiment, the light-shielding hood 70 is detachable from the lens 50. Also, the LED lamp 1 is detachable from the socket 101. The LED lamp 1 includes base pins 15 (see FIGS. 3 and the like described later) protruding from the outer cover 10, and is attached to the socket 101 by inserting the base pins 15 into the pin insertion portion of 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 FIGS. 4 and the like described later), a lens 50, etc. are accommodated in the cylinder of the outer cover 10. The outer cover 10 forms the appearance of the LED lamp 1 and functions as a housing for accommodating the light source unit 20, the lens 50, etc. In the form illustrated in FIG. 1, the outer cover 10 of the LED lamp 1 constitutes the outer cover of a spotlight. In other words, the outer cover 10 forms the appearance of a spotlight. Note that a conventionally known spotlight has a structure in which an LED lamp is accommodated in the cylinder of a bottomed cylindrical cover, and the outer cover of the LED lamp does not form the appearance of a spotlight.

[0014] According to the LED lamp 1, since the outer cover 10 forms the appearance of the spotlight, a cover for covering the lamp is not required, and a significant reduction in the diameter of the spotlight can be achieved. Also, the attachment and detachment of the LED lamp 1 to and from the socket 101 is easy. For example, there is no need to put a hand into the cylinder of the cover to replace the lamp or disassemble the lighting fixture to replace the lamp. The outer cover 10 and the light-shielding hood 70 are formed in a cylindrical shape having a constant outer diameter for the portions appearing in the appearance of the spotlight. And the outer cover 10, the light-shielding hood 70, and the socket 101 have substantially the same outer diameter, and their outer peripheral surfaces are flush. The spotlight using the LED lamp 1 has a stylish design with a sense of unity as a whole.

[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-emitting surface 52 that is circular in plan view. In this specification, the plan view means the case of viewing from a direction perpendicular to the light-emitting surface 52 of the lens 50 unless otherwise specified. On the light-emitting surface 52, a protrusion 53 for lamp attachment and detachment is formed. When removing the LED lamp 1 from the socket 101, by applying a rotational load to the lens 50 using this protrusion 53, the LED lamp 1 rotates with respect to the socket 101, and the LED lamp 1 can be removed. Also, when attaching the LED lamp 1 to the socket 101, it can be attached to the socket 101 by rotating the LED lamp 1 in the direction opposite to that when removing it using the protrusion 53.

[0016] In the case of the spotlight illustrated in FIG. 1, since the socket 101 of the connection fixture 100 is exposed without being embedded in the ceiling, wall, etc., when attaching and detaching the LED lamp 1 to and from the socket 101, the outer cover 10 of the LED lamp 1 can be grasped to rotate the lamp.

[0017] FIG. 2 is a view showing how the LED lamp 1 is attached to the downlight frame 110. FIG. 2(a) shows how the LED lamp 1 is inserted into the recessed hole in the ceiling, and FIG. 2(b) shows how the lamp is rotated and attached to a socket (not shown) after the LED lamp 1 is inserted into the recessed hole. A downlight is generally a ceiling-recessed lighting fixture installed on the ceiling of a building. The downlight frame 110 has, for example, a substantially cylindrical shape with a diameter that decreases upward, and is attached to the recessed hole in the ceiling. In the case of the downlight illustrated in FIG. 2, the socket is arranged behind the ceiling. Also, in the case of a downlight, the light-shielding hood 70 is not used.

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

[0019] FIG. 3 is a perspective view of the LED lamp 1, showing a state in which the light-shielding hood 70 is removed. As shown in FIG. 3, the light-shielding hood 70 is configured to be detachable. The light-shielding hood 70 includes a light-shielding portion 71 extending from the opening of the outer cover 10 and an insertion portion 72 inserted into the cylinder of the outer cover 10. Although details will be described later, the light-shielding hood 70 is attached to the lens 50 inside the cylinder of the outer cover 10. That is, the light-shielding hood 70 is detachably attached to the lens 50. An engaging protrusion 73 that engages with the light-shielding hood fixing portion 60 (see FIGS. 8 and the like described later) of the lens 50 is formed on the insertion portion 72 of the light-shielding hood 70.

[0020] The light-shielding hood 70 is generally applied to a spotlight and has a function of covering the periphery of the opening of the outer cover 10 to block light that spreads beyond the target irradiation area. The light-shielding hood 70 may be a metal member or a resin member. The light-shielding hood 70 is, for example, made of the same material as the outer cover 10 and has the same color as the outer cover 10.

[0021] The light-shielding portion 71 extends axially 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 appropriately set according to the size of the LED lamp 1 and the like. 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 in the same manner as the light-shielding portion 71, but its outer diameter is smaller than the outer diameter of the light-shielding portion 71. For this reason, a step is formed on the outer peripheral surface of the light-shielding hood 70. Since the insertion portion 72 is a portion that is inserted into the cylinder 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 is close to the inner diameter of the outer cover 10 within a range that does not hinder insertion into the outer cover 10. 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 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 in order to securely fix the light-shielding hood 70 to the lens 50, the insertion portion 72 slightly protrudes from the cylinder of the outer cover 10. In this case, it is possible to prevent the outer cover 10 and the light-shielding portion 71 from coming into contact and causing an obstacle to the attachment of the light-shielding hood 70. Although there is a slight gap between the outer cover 10 and the light-shielding portion 71, if this gap is 10% or less, or 5% or less of the axial length of the light-shielding portion 71, it has almost no effect on the design.

[0024] The outer peripheral surface of the insertion portion 72 is disposed to face the inner peripheral surface of the outer cover 10 with a slight gap therebetween. Note that, within a range where there is no hindrance to the insertion into the outer cover 10, the outer peripheral surface of the insertion portion 72 may be in contact with the inner peripheral surface of the outer cover 10. The insertion portion 72 is preferably configured to abut against the inner peripheral surface of the outer cover 10 when a force acts at least in the radial direction of the light shielding hood 70. In this case, the load applied in the radial direction of the light shielding hood 70 can be received by the outer cover 10, and damage to components, detachment of the light shielding hood 70, etc. can be effectively suppressed. 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 the outer cover 10 formed in a bottomed cylindrical shape. The base pins 15 extend along the axial direction of the outer cover 10 from the other axial end side opposite to the one axial end of the outer cover 10 where the light shielding hood 70 is attached. The base pins 15 are metal power supply pins that are electrically connected to a circuit 30 (see FIG. 4 etc. described later) for supplying power to the light source unit 20, receive power from the socket of the lighting fixture, and send power to the circuit 30. The tip of the base pin 15 has an enlarged diameter so as to be caught by the pin insertion portion of the socket.

[0026] Two base pins 15 are provided side by side in the radial direction of the outer cover 10. The distance between the pair of base pins 15 along the radial direction (hereinafter sometimes referred to as "pin distance") is not particularly limited, but is, for example, 40 mm or less, or 35 mm or less, or 30 mm or less. Note that the pin distance means the shortest distance between the central axes of the two pins. An example of a preferable range of the pin distance is 15 mm or more and 40 mm or less, or 20 mm or more and 35 mm or less, or 25 mm or more and 30 mm or less. If the pin distance is within this range, it becomes easy to reduce the size of the lighting fixture.

[0027] The outer cover 10 is formed in a generally bottomed and substantially cylindrical shape as a whole, but the diameter is reduced on the bottom side where the base pin 15 protrudes. The outer cover 10 has a large-diameter portion 11 that forms the appearance of the spotlight and a small-diameter portion 12 that is inserted into the socket 101. The outer cover 10 further has a convex portion 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 constituting the outer cover 10 is polybutylene terephthalate (PBT).

[0028] In the outer cover 10, a large-diameter portion 11, a small-diameter portion 12, and a convex portion 13 are formed in order from the opening side, and the convex portion 13 is also inserted into the socket 101. The socket 101 has a housing portion for the convex portion 13 together with a pin insertion portion. The outer diameter difference between the small-diameter portion 12 and the convex portion 13 is larger than the outer diameter difference 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% or more and 95% or less, or 80% or more and 90% or less.

[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 within a range that does not hinder insertion into the socket 101. The convex portion 13 is formed in a cylindrical shape at the center in the radial direction of the outer cover 10 and has a protrusion 13a formed on the outer peripheral surface. The protrusion 13a catches on the socket 101 in the same manner as the base pin 15, enhancing the reliability of fixing the LED lamp 1 to the socket 101.

[0030] Figure 4 is an exploded perspective view of the LED lamp 1. As shown in Figure 4, the LED lamp 1 includes a light source unit 20 containing 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. The LED lamp 1, as described above, includes a bottomed cylindrical outer cover 10 for housing 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 for dissipating the heat of the light source unit 20 and a cylindrical circuit holder 35 for holding the circuit 30. Also, the LED lamp 1 may be provided with a detachable light-shielding hood 70.

[0031] The LED lamp 1 is, for example, a small-diameter lamp with a diameter of 50 mm or less. The diameter of the large-diameter portion 11 of the outer cover 10 forming the appearance of the LED lamp 1 is, 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 (the diameter of the large-diameter portion 11). Note that the circuit holder 25 and the holder 40 are members made of resin mainly composed of PBT or the like, and the heat sink 25 is a member made of metal mainly composed of aluminum or the like. The lens 50 is composed of, for example, a resin with high transparency and durability such as polycarbonate or glass.

[0032] Since the LED lamp 1 is long in the axial direction, when assembling the components with the bottom side of the outer cover 10, such as the boundary position between the large-diameter portion 11 and the small-diameter portion 12 of the outer cover 10, as the reference position, it becomes difficult to assemble the lens 50 at the desired position, and as a result, problems such as large variations in light distribution may occur in each product. Therefore, in the LED lamp 1, the lens 50 is fixed to the holder 40 and together with the holder 40 forms a module. Thereby, the distance between the light source unit 20 and the lens 50 becomes 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 bottomed cylindrical shape and includes a base portion 41 forming the bottom of the cylinder and a cylindrical wall 42 erected on the outer peripheral edge of the base portion 41. The base portion 41 has an opening 43 formed in the radial center portion and fixing claws formed around the opening 43. The light source unit 20 is disposed in the radial center portion from the lower surface side of the base portion 41 so as to close the opening 43 and is held by the fixing claws formed on the peripheral edge of the opening 43. The holder 40 holding the light source unit 20 is fixed to the heat sink 25 using a screw 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 on the opening side rather than the axial center of the outer cover 10. On the bottom side of the outer cover 10 rather than the LED module 2, an axially long heat sink 25 is accommodated. That is, although the lens 50 is attached at a position away from the bottom of the outer cover 10, since the light source unit 20, the holder 40, and the 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 the assembly error 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. An example of a preferred light source unit 20 is a COB (Chip on board) type lighting light emitting diode device. A plurality of LED elements 21 are mounted, for example, in the central portion of the surface of a substantially square substrate 22 to form a light emitting portion having a circular shape in plan view. A pair of electrodes are provided around the light emitting portion, and wirings extending from the circuit 30 are connected. The light source unit 20 is fixed to the base portion 41 of the holder 40 such that the light emitting portion 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 releases the heat of the light source unit 20. The heat sink 25 is a bottomed cylindrical body including a base portion 26 to which the holder 40 is fixed, and a cylindrical wall 27 erected on the outer peripheral edge of the base portion 26 and extending in a direction opposite to the lens 50. Since the heat sink 25 extends long in the direction opposite to the lens 50, it is possible to effectively release the heat of the light source unit 20 while suppressing the thermal influence on the lens 50. Further, in the present embodiment, the surface of the base portion 26 of the heat sink 25 to which the holder 40 is fixed serves as a reference surface for intersection determination when assembling the lens 50. Since the distance between the lens 50 and the reference surface is short, it is hardly affected by the machining accuracy of the parts and the assembly error of other parts, and the lens 50 can be accurately assembled at the target position.

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

[0038] The cylindrical wall 27 of the heat sink 25 is formed in a substantially cylindrical shape and houses a circuit holder 35 holding the circuit 30. A locking hole 28 used for fixing the circuit holder 35 and a guide groove 29 extending in the axial direction are formed on the outer peripheral surface of the cylindrical wall 27. The guide groove 29 is a groove into which a cylindrical projection 14 formed on the outer cover 10 fits, and is formed at a position overlapping the locking hole 28. In other words, the locking hole 28 is formed in the guide groove 29. In the present embodiment, the locking hole 28 is used for fixing the outer cover 10 and the circuit holder 35.

[0039] The circuit 30 is a power supply circuit that converts the alternating current of a commercial power supply into a direct current for lighting the LED element 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 an alternating 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 the capacitor has lower heat resistance compared to 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 in a state where its longitudinal direction is along the axial direction of the outer cover 10. A pair of base pins 15 are provided so as to protrude from one end in the longitudinal direction of the circuit board 31 to the bottom side of the outer cover 10. The capacitor is arranged so as to be sandwiched between the pair of base pins 15 and is mounted in a state of protruding from one end in the length direction of the circuit board 31 to the bottom side of the outer cover 10, similar to the base pins 15. In the LED lamp 1, the circuit board 31 is inserted into a board fixing portion 36 formed inside the cylinder of the circuit holder 35, and the base pins 15 are held by the base pin fixing portion 37. Thereby, the circuit 30 is held inside the cylinder of the circuit holder 35.

[0041] The circuit holder 35 is a substantially cylindrical member that holds the circuit 30 and is fixed to a 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 grooves extending in the axial direction and is formed at two locations on the inner peripheral surface of the circuit holder 35. Each board fixing portion 36 holds both ends in the width direction of the circuit board 31 inserted into the groove. Two base pin fixing portions 37 are provided corresponding to the pair of base pins 15 and have semi-annular grooves into which the flanges formed on the base pins 15 fit.

[0042] The fixing piece 38 is a part separated from the other part of the cylindrical wall by two axially extending slits 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 positions facing each other in the radial direction of the circuit holder 35. After fixing the circuit 30 inside the cylinder of the circuit holder 35, by inserting the circuit holder 35 into the cylinder of the heat sink 25, the protrusion of the fixing piece 38 fits into the locking hole 28 of the heat sink 25, and the circuit holder 35 is fixed to the heat sink 25.

[0043] Figs. 5 and 6 are cross-sectional views of the LED lamp 1 cut along the axial and radial directions of the outer cover 10. Fig. 5 is a cross-sectional view of the LED lamp 1 cut along the first radial direction in which the base pins 15 are arranged, and Fig. 6 is a cross-sectional view of the LED lamp 1 cut along the second radial direction orthogonal to the first radial direction. Figs. 5 and 6 show the cross-section of the LED lamp 1 in a state where the light-shielding hood 70 is not mounted.

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

[0045] The small-diameter portion 12 of the outer cover 10 has a smaller outer diameter and inner diameter than the large-diameter portion 11, and a step is formed at the boundary between the large-diameter portion 11 and the small-diameter portion 12 on the inner peripheral surface of the outer cover 10. The cylindrical wall 27 of the heat sink 25 is formed along the inner peripheral surface of the large-diameter portion 11 and extends to the vicinity of 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 the present embodiment, when this flange 39 hits the step of the outer cover 10, the positions of the circuit holder 35 with respect to the outer cover 10, the circuit 30 held by the circuit holder 35, and the base pin 15 connected to the circuit 30 are regulated.

[0046] Furthermore, an inner cylindrical protrusion 14, which is a fixing portion of the heat sink 25, is formed on the outer cover 10. Since 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 when the inner cylindrical protrusion 14 fits into the locking hole 28 of the cylindrical wall 27. The pair of inner cylindrical protrusions 14 are protrusions for fixing the heat sink 25 and are formed at positions on the inner peripheral surface of the outer cover 10 that face each other. A protrusion of the fixing piece 38 of the circuit holder 35 is inserted into the locking hole 28 of the heat sink 25 from the inside of the cylindrical wall 27, and the inner cylindrical protrusion 14 of the outer cover 10 is inserted from the outside of the cylindrical wall 27.

[0047] The heat sink 25 to which the circuit holder 35 is fixed inside the cylinder is inserted into the outer cover 10. At this time, the position of the guide groove 29 (see FIG. 4) of the heat sink 25 is aligned with the position of the inner cylindrical protrusion 14, and the heat sink 25 is inserted so that the inner cylindrical protrusion 14 moves inside the guide groove 29. Then, when the inner cylindrical protrusion 14 fits into the locking hole 28 formed in the guide groove 29, the heat sink 25 is fixed to the outer cover 10. A through hole 12a through which the base pin 15 passes is formed at the bottom of the outer cover 10 (the bottom of the small-diameter portion 12). The LED lamp 1 is designed such that the base pin 15 protrudes from the through hole 12a to the outside of the outer cover 10 in a state where the heat sink 25 is fixed to the outer cover 10.

[0048] As described above, in the LED module 2, the base 41 of the holder 40 that holds the light source unit 20 is fixed to the base 26 of the heat sink 25 using a screw 46. A screw insertion hole 47 through which the screw 46 passes is formed in the base 41 of the holder 40. Further, in the base 26 of the heat sink 25, a screw hole 26a to which the screw 46 is fastened and a wiring insertion hole 26b through which wiring extending from the circuit 30 passes are formed. Note that the LED module 2 does not have a fixing structure for the outer cover 10.

[0049] An adhesive 49 is filled between the LED module 2 and the outer cover 10. The adhesive 49 is filled, for example, 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. Further, the adhesive 49 is pressed by the lens 50 fixed to the holder 40, fills the gap between the outer peripheral surface of the LED module 2 and the inner peripheral surface of the outer cover 10, and couples the LED module 2 and the outer cover 10. Although details will be described later, a plurality of outer peripheral surface recesses 48 (see FIG. 8 and the like described later) for expanding the adhesion area of the adhesive 49 are formed on the outer peripheral surface of the holder 40.

[0050] The adhesive 49 is not particularly limited, but from the viewpoints of adhesiveness, durability, etc., it is preferably mainly composed of a silicone resin. As the silicone-based adhesive, a two-component curable or moisture-curable adhesive can be used. The lens 50 of the LED module 2 is fixed by the adhesive 49, but in order to more surely prevent the lens 50 from falling off even if the adhesive strength decreases due to the aging deterioration of the adhesive 49, the lens 50 is fixed to the holder 40. Further, by providing the fixing structure between the holder 40 and the lens 50, the distance between the light source unit 20 and the lens 50 is regulated with high precision.

[0051] The LED module 2 is arranged, 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, the internal space of 70% or more of the axial length L of the outer cover 10 is occupied by the circuit 30 and the heat sink 25. The components of the LED lamp 1 including the LED module 2, the heat sink 25, the circuit 30, and the circuit holder 35 are substantially all accommodated within the cylinder of the outer cover 10. For this reason, 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 as an example, it is 50 mm or more and 80 mm or less.

[0052] Figure 7 is an enlarged view of part A in Figure 6. As shown in Figure 7, the lens 50 is fixed to the holder 40 that holds the light source unit 20, and together with the holder 40, they constitute a module. The LED module 2 is provided with a fixing structure including a locking claw 57 formed on the outer peripheral portion 54 of the lens 50 and a locking hole 45 formed on the cylindrical wall 42 of the holder 40. The lens 50 is fixed to the holder 40 by the locking claw 57 of the lens 50 fitting into the locking hole 45 of the holder 40 and being hooked on the cylindrical wall 42.

[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 suppresses damage to components due to the rotational load, the dropping off of the lens 50, etc. Although it is also possible to receive the rotational load by the adhesive 49, in that case, there is a concern about the dropping off of the lens 50 particularly when the adhesive 49 deteriorates over time. In the present embodiment, the load receiving portion is constituted by a convex portion 56 protruding from the outer peripheral portion 54 of the lens 50 and a concave portion 44 formed on the cylindrical wall 42 of the holder 40 into which the convex portion 56 fits.

[0054] A plurality of convex portions 56 and locking claws 57 of the lens 50 are formed respectively and arranged alternately along the circumferential direction of the lens 50. Similarly, a plurality of concave portions 44 and locking holes 45 of the holder 40 are formed respectively and arranged alternately along the circumferential direction of the holder 40. In this case, breakage of the LED module 2, detachment of the lens 50, etc. can be more effectively suppressed. Two locking claws 57 are provided side by side in the first radial direction of the lens 50, and two convex portions 56 are provided side by side in the second radial direction orthogonal 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. The Fresnel lens is a lens in which the lens surface is divided concentrically to reduce the thickness and has a sawtooth-shaped cross-sectional shape. 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 portion 20 side. In the lens 50, the diameter of the annular convex portion 51a becomes smaller and the height and width thereof become smaller as it approaches the central axis of the lens 50. The Fresnel structure 51 includes three annular convex portions 51a, and the region surrounded by the annular convex portion 51a with the smallest diameter is a gentle spherical surface bulging in the direction of the light source portion 20.

[0056] The lens 50 has a light emitting surface 52 that is circular in plan view. The light emitting surface 52 includes a first region 52a formed along the radial direction of the lens 50 and a second region 52b formed annularly surrounding the first region 52a and inclined so as to approach the light source portion 20 from the boundary of the first region 52a toward the outer peripheral edge of the light emitting surface 52. The light emitting surface 52 further includes a projection 53 for lamp attachment / detachment protruding from the second region 52b. By providing the second region 52b which is an inclined surface on the light emitting surface 52 and forming the projection 53 on the inclined surface, even if the projection 53 is made higher to improve the operability, the projection 53 is less conspicuous and the design property is not impaired.

[0057] The diameter φ1 of the first region 52a is preferably 50% or more of the diameter φ of the exit surface 52, and may be 55% or more and 90% or less, or 60% or more and 85% or less, or 65% or more and 80% or less. If the diameter φ1 of the first region 52a is within this range, it is possible to highly achieve both 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 aiming to reduce the diameter of the lighting fixture, for example, it is smaller than the pin pitch between a pair of base pins 15, and is 15 mm or more and 30 mm or less, or 20 mm or more and 25 mm or less.

[0058] The boundary between the first region 52a and the second region 52b may be formed regardless of the Fresnel structure 51, but is preferably at a position substantially overlapping 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 easy. In other words, the second region 52b is formed in accordance with the position of 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 emitted from the second region 52b.

[0059] The inclination angle θ of the second region 52b with respect to the virtual line α along the surface direction of the first region 52a is preferably 5° or more, and more preferably 7° or more. When the width of the second region 52b is the same, the larger the inclination angle θ, the higher the protrusion 53 can be formed. On the other hand, if the inclination angle θ becomes too large, it is assumed that the light emitted from the lens 50 spreads and the illuminance at the target location decreases. The inclination angle θ is, for example, 25° or less, or 20° or less. An example of the preferred range of the inclination angle θ is 5° or more and 25° or less, or 7° or more and 20° or less, or 8° or more and 15° or less.

[0060] The second region 52b may be curved so as to be gently convex along the radial direction of the lens 50, but preferably has no 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 inclination angle θ.

[0061] Figs. 8 and 9 are perspective views showing the LED module 2 and its vicinity enlarged. Fig. 9 shows a state in which the lens 50 is 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, on the light-emitting surface 52 of the lens 50, a protrusion 53 for lamp attachment / detachment protruding from the second region 52b, which is an inclined surface, is formed. Details of the configuration of the light-emitting surface 52 will be shown in Figs. 10 and 11 described later.

[0062] As a fixing structure for more surely preventing the lens 50 from falling off, 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 inserted into the locking hole 45. The LED module 2 further includes, as a load-receiving structure for receiving a rotational load applied to the lens 50, a recess 44 formed in the cylindrical wall 42 of the holder 40 and a convex portion 56 of the lens 50 fitted into the recess 44. When a rotational load acts on the lens 50 during attachment / detachment of the LED lamp 1, the convex portion 56 abuts against the edge of the recess 44 and a rotational load is applied to the cylindrical wall 42 of the holder 40. Thereby, breakage of components (for example, the locking claw 57), falling off of the lens 50, etc. are more surely prevented.

[0063] As described above, the holder 40 includes a base portion 41 screwed to the heat sink 25 and holding the light source unit 20, and a cylindrical wall 42 erected on the outer peripheral edge of the base portion 41. Two recesses 44 and two locking holes 45 are alternately formed in the cylindrical wall 42 at intervals of about 90° around the central axis of the holder 40. The two recesses 44 have the same shape and size as each other 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 as each other and are formed side by side in the radial direction of the holder 40.

[0064] The recess 44 is formed from the tip of the cylindrical wall 42 and is a depression surrounded by the cylindrical wall 42 on three sides. Since the recess 44 opens toward the lens 50, the convex portion 56 of the lens 50 can be fitted into the recess 44. The locking hole 45 is formed through the cylindrical wall 42 in the thickness direction and is a through hole surrounded by the cylindrical wall 42 on four sides. The locking claw 57 of the lens 50 is inserted into the locking hole 45 from the inner side in the radial direction of the cylindrical wall 42 and is caught by the edge of the locking hole 45. The gap between the recess 44 and the convex portion 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. Thereby, the recess 44 and the convex portion 56 function as load-receiving portions that receive the rotational load.

[0065] On the outer peripheral surface of the cylindrical wall 42, a plurality of outer peripheral surface recesses 48 are formed to expand the adhesion area of the adhesive 49. The outer peripheral surface recess 48 is a depression recessed inward in the radial direction of the cylindrical wall 42. The outer peripheral surface recess 48 is formed in a groove shape extending in the axial direction of the cylindrical wall 42 and is formed over the entire axial length of the cylindrical wall 42. The shapes and sizes of the respective outer peripheral surface recesses 48 may be different from each other, but in the present embodiment, they are substantially the same. The maximum depth of the outer peripheral surface recess 48 (the length along the radial direction from the outermost peripheral surface to the deepest part of the recess) is preferably 0.3 mm or more and 0.8 mm or less, and the width of the outer peripheral surface recess 48 is preferably 1.0 mm or more and 2.0 mm or less. In this case, the adhesive 49 easily enters the outer peripheral surface recess 48, and the adhesion area of the adhesive 49 is more effectively expanded.

[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, for example, excluding the portion where the recess 44 and the locking hole 45 are formed and the vicinity thereof. Between the outer peripheral surface recesses 48 adjacent to each other in the circumferential direction of the cylindrical wall 42, there is a surface without a depression located on the same circumference, whereby unevenness is formed along the circumferential direction of the cylindrical wall 42. Further, the interval between the adjacent outer peripheral surface recesses 48 is preferably smaller than the width of the outer peripheral surface recess 48.

[0067] By forming a plurality of outer peripheral surface recesses 48, the surface area of the outer peripheral surface becomes larger compared to the case where there are no irregularities on the outer peripheral surface, and the area to which the adhesive 49 adheres expands. As a result, the adhesive strength between the inner peripheral surface of the outer cover 10 and the holder 40 increases. The outer peripheral surface recess 48 preferably curves toward the inside of the cylindrical wall 42 and is formed in an arc shape in a plan view of the holder 40. In this case, the adhesive 49 easily enters the outer peripheral surface recess 48 and adheres to the surface of the recess, and the adhesive strength with the outer cover 10 is more effectively improved.

[0068] The lens 50 has an outer peripheral portion 54 formed in a substantially cylindrical shape. The convex portions 56 and the locking claws 57 project axially from the end portion (one axial end portion) on the side opposite to the light emitting surface 52 of the outer peripheral portion 54, two each, and are alternately formed at intervals of about 90° around the central axis of the lens 50. The two convex portions 56 have the same shape and size as each other and are formed side by side in the radial direction of the lens 50. Similarly, for the two locking claws 57, they have the same shape and size as each other and are formed side by side in the radial direction of the lens 50. The locking claw 57 is formed to be elastically deformable in the radial direction of the lens 50. When fixing the lens 50 to the holder 40, it bends slightly inward in the radial direction and then returns to its original shape and is inserted into the locking hole 45.

[0069] An outer peripheral convex portion 55 that projects radially outward more than the other axial end portion is formed at one axial end portion of the outer peripheral portion 54. The outer peripheral convex portion 55 is formed by thickening one axial end portion of the outer peripheral portion 54 more than the other end portion. A light shielding hood fixing portion 60 is formed on the outer peripheral portion 54 using the outer peripheral convex portion 55. At the lower part of the outer peripheral portion 54, there are portions where the outer peripheral convex portions 55 are not formed at a plurality of locations separated in the circumferential direction, and this portion becomes the light shielding hood fixing portion 60 into which the engaging projection 73 of the light shielding hood 70 can be inserted. The light shielding hood 70 is fixed to the lens 50 by the engaging projection 73 inserted into the light shielding hood fixing portion 60 being caught by the outer peripheral convex portion 55.

[0070] On the outer peripheral surface of the lens 50, an outer peripheral surface knurl 63 for light diffusion extending in the axial direction of the lens 50 is formed. A part of the light beam emitted from the light source unit 20 is emitted from the outer peripheral surface of the lens 50, and as a result, streaks may appear on the irradiation surface. By forming the outer peripheral surface knurl 63, the light emitted from the outer peripheral surface of the lens 50 can be diffused, and the streaks on the irradiation surface can be effectively suppressed. The outer peripheral surface knurl 63 is preferably formed in a region of the outer peripheral portion 54 close to the emission surface 52. In the present embodiment, it is formed from the boundary position with the emission surface 52 to the boundary position with the outer peripheral convex portion 55.

[0071] The outer peripheral surface knurl 63 is a surface uneven structure for light diffusion, and is preferably formed by fine linear convex portions or concave portions. Note that the fine linear concave portion can be said to be a groove. In the present embodiment, a plurality of grooves formed in a substantially V shape in a plan view of the lens 50 are continuously formed in the circumferential direction of the outer peripheral surface. In this case, the boundary positions of adjacent grooves become convex portions, and a fine surface uneven structure in which unevenness is repeated in the circumferential direction is formed on the outer peripheral surface of the lens 50. That is, it can also be said that the outer peripheral surface knurl 63 has convex portions in a substantially V shape in a plan view continuously formed in the circumferential direction.

[0072] The outer peripheral surface knurl 63 is preferably formed over the entire circumference of the outer peripheral surface. The widths and depths of the grooves constituting the outer peripheral surface knurl 63 are substantially the same. For example, the depth of the groove is 0.3 mm or more and 0.7 mm or less, and the width of the groove is 0.5 mm or more and 2.0 mm or less. In the present embodiment, the pitch of the grooves in the circumferential direction (the distance between the centers in the width direction of adjacent grooves) is the same as the groove width, but the grooves may be formed at a predetermined interval in the circumferential direction. The pitch of the fine linear convex portions or concave portions 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 knurl 63 are formed with the same width as the convex portions or concave portions constituting the knurl 62 of the second region 52b described later.

[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, on the exit surface 52 of the lens 50, there are a first region 52a having a circular shape in plan view and a second region 52b having an annular shape in plan view surrounding the first region 52a. The second region 52b is a slope that gradually approaches the holder 40 from the first region 52a side toward the outer peripheral portion 54 side, in other words, is inclined so as to be 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. Further, the first region 52a has a perfect circular shape in plan view, and the width of the second region 52b formed in an annular shape is constant over the entire circumference.

[0074] On the first region 52a of the exit surface 52, dimples 61 for light diffusion are formed. The first region 52a is a light-transmitting 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 light diffusion, and are preferably formed by a plurality of convex portions or concave portions having a circular shape or a polygonal shape in plan view. The dimples 61 are preferably composed of regularly formed convex portions or concave portions. Each convex portion or each concave portion constituting the dimples 61 is formed regularly and continuously with substantially the same size. The diameter of the circumscribed circle of each convex portion or each concave portion is, for example, 0.2 mm or more and 1.0 mm or less.

[0075] The surface of the fine convex portions or concave portions constituting the dimples 61 is preferably gently curved. In this case, the boundary portion between the convex portions becomes a concave portion, or the boundary portion between the concave portions becomes a convex portion, and a fine surface uneven structure is formed. In the present embodiment, convex portions having a regular hexagonal shape in plan view are formed without gaps over the entire first region 52a. Each convex portion constituting the dimples 61 has substantially the same size and is partitioned by a regular hexagonal groove. That is, each side of the hexagon is shared by adjacent convex portions. The length of one side of the hexagon is, for example, 0.2 mm or more and 1.0 mm or less. Note that the dimples 61 may be formed by concave portions having a regular hexagonal shape in plan view.

[0076] In the second region 52b of the light-emitting surface 52, a projection 53 for lamp attachment / detachment is further formed. When attaching / detaching the LED lamp 1 to / from the socket of the lighting fixture, especially when the outer cover 10 cannot be grasped during lamp attachment / detachment as exemplified in the downlight shown in FIG. 2, the projection 53 is used to perform a rotation operation of the LED lamp 1. Since the projection 53 is formed in the second region 52b located on the outer side in the radial direction of the light-emitting surface 52, the rotation operation of the lens 50 is easy and a large rotational load can be applied. Since the LED module 2 is provided with a load-receiving portion, even if a large rotational load acts on the lens 50, breakage of components, detachment of the lens 50, etc. can be more reliably prevented.

[0077] The projections 53 extend long in the radial direction of the lens 50, and two or more are formed so as to be arranged in the radial direction with the first region 52a therebetween. Three or more projections 53 may be formed, but from the viewpoint of achieving both design and operability, two are preferable. In the present embodiment, two projections 53 having the same shape and size extend in the radial direction from the outer peripheral edge facing the radial direction of the light-emitting surface 52. By forming the pair of projections 53 long in the radial direction from the outer peripheral edge of the light-emitting surface 52, a large rotational load can be applied to the lens 50, and the attachment / detachment of the LED lamp 1 becomes easy.

[0078] Preferably, the projection 53 does not protrude significantly in the direction of the opening of the outer cover 10 more than the first region 52a. The projection 53 may have a height exceeding the virtual line α (see FIG. 7) along the plane direction of the first region 52a, but the upper end of the projection 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 virtual line α. On the other hand, if the height H of the projection 53 becomes too low, the operability deteriorates, so the height H is preferably 1.5 mm or more. An example of a suitable height H of the projection 53 is, for example, 1.3 mm or more and 2.0 mm or less at the highest portion.

[0079] If the height H of the protrusion 53 is within the above range, while ensuring good operability, the protrusion 53 becomes less conspicuous. The height H of the protrusion 53 is the length along the axial direction of the lens 50 from the upper surface of the second region 52b where the protrusion 53 does not exist to the upper surface of the protrusion 53. Here, the upper surface means the surface facing the direction of 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 toward the outer side in the radial direction.

[0080] It is preferable that the protrusion 53 is formed at a height such that it does not protrude from inside the cylinder of the outer cover 10 or the protruding length from inside the cylinder of the outer cover 10 is 3 mm or less, more preferably 1 mm or less. In this case, the protrusion 53 is less conspicuous and good designability can be obtained. Although the protruding length of the protrusion 53 can also be suppressed by separating the first region 52a of the lens 50 from the opening of the outer cover 10, the distance along the axial direction from the opening of the outer cover 10 to the first region 52a is preferably 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 designability, 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 emission surface 52, and 50% or more and 80% or less of the width of the second region 52b. The protrusion 53 may be formed over the entire width of the second region 52b, but in this embodiment, it is formed to have a length that does not reach the boundary position with the first region 52a beyond 50% or 60% of the width of the second region 52b from the outer peripheral edge of the emission surface 52.

[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 does not exist. In the present embodiment, since the inclination angle of the upper surface of the protrusion 53 is smaller than the inclination angle θ of the second region 52b, the height H of the protrusion 53 gradually increases toward the outer side in the radial direction. Since the protrusion 53 is a portion touched by the user's finger, 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 the load applied to the protrusion 53. For example, it is 0.2 mm or more and 0.4 mm or less. The width of the protrusion 53 may widen toward the outer side in the radial direction of the lens 50.

[0083] In the second region 52b, a diffraction grating 62 for light diffusion extending in the radial direction of the lens 50 is formed. The diffraction grating 62 is a surface uneven structure for light diffusion, and is preferably formed by fine linear convex or concave portions extending in the radial direction. By forming the fine linear diffraction grating 62 extending in the same direction as the protrusion 53, the protrusion 53 can be made less conspicuous. The width of the fine linear convex or concave portion constituting the diffraction grating 62 is preferably approximated to the width of the protrusion 53, and is 70% or more and 130% or less, or 80% or more and 120% or less of the width of the protrusion 53. It may be the same as the width of the protrusion 53, or may be smaller than the width of the protrusion 53. The width of the fine linear convex or concave portion is, for example, 0.5 mm or more and 2.0 mm or less.

[0084] The diffraction grating 62 is formed continuously in the circumferential direction of the second region 52b over the entire area of the second region 52b. In the present embodiment, fine linear convex portions extending in the radial direction of the lens 50 are continuously formed over the entire area of the second region 52b except for the portion where the protrusion 53 is formed, without gaps, in the circumferential direction of the second region 52b. Further, since the convex portions constituting the diffraction grating 62 are formed radially centered on the radial center of the emission surface 52, they slightly widen toward the outer side in the radial direction. The maximum width of the convex portion is the same as the width of the groove constituting the outer peripheral surface diffraction grating 63, and the center portion in the width direction of the convex portion and the deepest portion of the groove of the outer peripheral surface diffraction grating 63 are arranged to coincide.

[0085] The surface of the linear convex portion constituting the knurling 62 is, for example, gently curved. In this case, the boundary portion between adjacent convex portions becomes a concave portion (groove), and a fine surface uneven structure in which unevenness is repeated in the circumferential direction of the second region 52b is formed. In the present embodiment, the widths of the respective convex portions are substantially the same, and the pitch and width of the convex portions in the circumferential direction are the same. Note that the linear convex or concave portions may be formed at predetermined intervals in the circumferential direction. The pitch of the linear convex or concave portions in the circumferential direction is preferably, for example, 0.5 mm or more and 3.0 mm or less.

[0086] As described above, in the LED lamp 1, by providing the second region 52b, which is an inclined surface, on the light emitting surface 52 and forming the lamp attachment / detachment protrusion 53 on the inclined surface, the attachment / detachment of the lamp to the socket becomes easy without impairing the performance of the lamp. For example, even if the protrusion 53 is made higher to improve the operability, the protrusion 53 is less conspicuous and the design is not impaired. Further, by forming the knurling 62 in the second region 52b, the protrusion 53 becomes even less conspicuous and the design is improved.

[0087] Note that the above embodiment can be appropriately modified in design without impairing the object of the present disclosure. For example, when the heat generation amount of the light source unit is small, the heat sink may be downsized or omitted. Further, it is also possible to give the heat sink the function of a circuit holder. Further, instead of the lens 50, it is also possible to use a lens that does not have at least one of a load receiving portion and a light shielding hood fixing portion.

[0088] The present disclosure will be further described by the following embodiments. Configuration 1: An LED lamp that is detachable from a socket, comprising a light source unit including an LED element, a circuit for supplying power to the light source unit, a lens for controlling the light emitted from the light source unit, a bottomed cylindrical outer cover for housing the light source unit, the circuit, and the lens, and base pins protruding from the outer cover and electrically connected to the circuit, the lens having a light-emitting surface that is circular in plan view, the light-emitting surface including a first region formed along the radial direction of the lens, a second region formed annularly surrounding the first region and inclined so as to approach the light source unit from the boundary with the first region toward the outer peripheral edge of the light-emitting surface, and a projection for lamp attachment / detachment protruding from the second region. Configuration 2: The LED lamp according to Configuration 1, wherein the projections extend long in the radial direction of the lens, and two or more projections are formed so as to be arranged radially with the first region therebetween. Configuration 3: The LED lamp according to Configuration 1 or 2, wherein a knurl for light diffusion extending in the radial direction of the lens is formed in the second region. Configuration 4: The LED lamp according to Configuration 3, wherein the knurl is formed continuously in the circumferential direction of the second region over the entire area of the second region. Configuration 5: The LED lamp according to any one of Configurations 1 to 4, wherein the lens is a Fresnel lens including a plurality of annular convex portions arranged on concentric circles, and the boundary between the first region and the second region is located at a position substantially overlapping the radially inner end of the annular convex portion having the maximum diameter. Configuration 6: The LED lamp according to any one of Configurations 1 to 5, wherein dimples for light diffusion are formed in the first region. Configuration 7: The LED lamp according to any one of Configurations 1 to 6, wherein the projections do not protrude from inside the cylinder of the outer cover or are formed at a height such that the protruding length from inside the cylinder of the outer cover is 1.0 mm or less. Configuration 8: The LED lamp according to any one of Configurations 1 to 7, wherein an outer peripheral surface knurl for light diffusion extending in the axial direction of the lens is formed on the outer peripheral surface of the lens.

Explanation of Reference Numerals

[0089] 1 LED lamp 2 LED module 10 Outer cover 11 Large-diameter part 12 Small-diameter part 12a Through hole 13 Protrusion 13a Projection 14 Inner cylinder projection 15 Base pin 20 Light source part 21 LED element 22 Substrate 25 Heat sink 26 Base part 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 part 37 Base pin fixing part 38 Fixed piece 39 Flange 40 Holder 41 Base part 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 part 52 Emission surface 52a First region 52b Second region 53 Projection 54 Outer peripheral part 55 Outer peripheral convex part 56 Convex part 57 Locking claw 60 Light-shielding hood fixing part 61 Dimples 62 Knurls 63 Outer Periphery Knurls 70 Light Shielding Hood 71 Light Shielding Portion 72 Insertion Portion 73 Engagement Projection 100 Connecting Appliance 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 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 circuit, and the lens; a base pin protruding from the outer cover and electrically connected to the circuit; and the lens has a light-emitting surface that is circular in plan view, the light-emitting surface includes a first region formed along the radial direction of the lens, a second region formed annularly surrounding the first region and inclined so as to approach the light source unit from the boundary with the first region toward the outer peripheral edge of the light-emitting surface, and a protrusion for lamp attachment / detachment protruding from the second region.

2. The LED lamp according to claim 1, wherein the protrusions extend long in the radial direction of the lens, and two or more protrusions are formed so as to be arranged radially with the first region therebetween.

3. The LED lamp according to claim 2, wherein a light diffusing knurl extending in the radial direction of the lens is formed in the second region.

4. The LED lamp according to claim 3, wherein the knurl is formed continuously in the circumferential direction of the second region over the entire area of the second region.

5. The lens is a Fresnel lens including a plurality of annular convex portions arranged on concentric circles, and the boundary between the first region and the second region is located at a position substantially overlapping with the radially inner end of the annular convex portion having the maximum diameter. The LED lamp according to any one of claims 1 to 4.

6. The LED lamp according to any one of claims 1 to 4, wherein dimples for light diffusion are formed in the first region.

7. The LED lamp according to any one of claims 1 to 4, wherein the protrusions are formed such that they do not protrude from inside the cylinder of the outer cover or the protrusion length from inside the cylinder of the outer cover is 3 mm or less.

8. The LED lamp according to any one of claims 1 to 4, wherein an outer peripheral surface knurl for light diffusion extending in the axial direction of the lens is formed on the outer peripheral surface of the lens.

Images