Lighting device

Abstract

Suppresses color unevenness on the ejection surface. [Solution] A lighting device 1 comprises a light source unit 30 including an LED element 40 which includes a first LED element 41 that emits light of a first color temperature and a second LED element 42 that emits light of a second color temperature, and an LED mounting substrate 50, wherein the light source unit 30 has a plurality of LED units 43 in which one first LED element 41 and one second LED element 42 are arranged along a predetermined first direction, and at least a portion of the LED units 43 are arranged so that the LED units 43 overlap each other in a second direction perpendicular to the first direction in a plan view of the LED mounting substrate 50, and the center positions of adjacent LED units do not overlap in the second direction.

Description

Technical Field

[0001] The present disclosure relates to a lighting device.

Background Art

[0002] In recent years, lighting devices capable of realizing dimming and toning have become widespread. Patent Document 1 discloses a lighting device in which two types of LED elements that emit light with different color temperatures from each other are mounted on an LED mounting substrate at a predetermined interval. Patent Document 1 describes that by mounting the LED elements at a predetermined interval, the heat dissipation of the LED elements can be improved, and the luminous efficiency can be improved.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In a lighting device having two types of LED elements that emit light with different color temperatures from each other, color unevenness may occur on the exit surface. In particular, color unevenness on the exit surface tends to be remarkable under use conditions where brightness is suppressed. Conventional techniques including Patent Document 1 cannot sufficiently improve the color unevenness on the exit surface, and there is still room for study.

Means for Solving the Problem

[0005] A lighting device according to one aspect of the present disclosure is a lighting device comprising a light source unit including an LED element which includes a first LED element that emits light of a first color temperature and a second LED element which emits light of a second color temperature different from the first color temperature, and an LED mounting substrate on which the LED elements are mounted, wherein the light source unit has a plurality of LED units in which one first LED element and one second LED element are arranged along a predetermined first direction, and at least a portion of the LED units are arranged such that adjacent LED units overlap in a second direction perpendicular to the first direction in a plan view of the LED mounting substrate, and the center positions of adjacent LED units do not overlap in the second direction. [Effects of the Invention]

[0006] According to one embodiment of the present disclosure, color unevenness on the emitted surface can be suppressed. In particular, color unevenness on the emitted surface can be significantly suppressed even under operating conditions with reduced brightness. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view from below of a lighting device, which is an example of an embodiment. [Figure 2] This is a perspective view from above of a lighting device, which is one example of an embodiment. [Figure 3] This is an exploded perspective view of a lighting device, which is an example of an embodiment. [Figure 4] This is an axial cross-sectional view of a lighting device, which is an example of an embodiment. [Figure 5] This is a plan view of a lighting device, which is an example of an embodiment, showing the device with the translucent cover removed. [Figure 6] This figure shows the pattern of metal wiring on an LED mounting substrate of a lighting device, which is an example of an embodiment. [Figure 7] This is a plan view of a lighting device, which is another example of an embodiment, and corresponds to Figure 5. [Figure 8] This is a plan view of a lighting device, which is another example of an embodiment, and corresponds to Figure 5. [Figure 9] This is a plan view of a comparative lighting device, corresponding to Figure 5. [Modes for carrying out the invention]

[0008] Hereinafter, an example of an embodiment of the lighting device according to this disclosure will be described in detail with reference to the drawings. The embodiment described below is merely an example, and this disclosure is not limited to the embodiments described below. Furthermore, forms obtained by selectively combining each component of the embodiments described below are included in this disclosure.

[0009] Figure 1 is a perspective view of the LED lamp 1 as a lighting device, viewed from diagonally below, and Figure 2 is a perspective view of the LED lamp 1, viewed from diagonally above. In this specification, "up and down" refers to the direction in which the protruding portion 12 of the outer cover 10 is "up" and the light-emitting surface 21 of the translucent cover 20 is "down". Also, the up and down direction in this specification does not necessarily refer to the vertical direction.

[0010] As shown in Figures 1 and 2, the LED lamp 1 is a thin, flat lamp with a cylindrical shape, and is lit by power supplied through a socket (not shown) of a lighting fixture when installed in the socket. When the LED lamp 1 is installed in the socket, a lighting fixture such as a downlight, spotlight, or ceiling light is formed.

[0011] The outer diameter of the LED lamp 1 is not particularly limited. For example, the outer diameter of the LED lamp 1 is φ70 mm. In this embodiment, the outer diameter of the LED lamp 1 is set to be larger than the height (axial length) of the LED lamp 1.

[0012] LED lamp 1 is a replaceable lamp with a base that can be attached to and detached from a socket. In this embodiment, the base of LED lamp 1 is a GX53 base. However, the base of LED lamp 1 is not limited to this and may have other bases such as GH76p.

[0013] As shown in FIG. 1 and FIG. 2, the LED lamp 1 includes a cylindrical outer cover 10 and a translucent cover 20 mounted on the outer cover 10. The LED lamp 1 is attached to a socket by inserting a base pin 11 protruding from the outer cover 10 into a pin insertion portion of the socket, so that the LED lamp 1 and the socket are electrically connected.

[0014] The LED lamp 1 has a structure in which a light source unit 30 (see FIG. 3 described later) and the like are housed inside the outer cover 10. The outer cover 10 forms the outer appearance of the LED lamp 1 and functions as a housing that houses the light source unit 30, a circuit 80 and the like.

[0015] In the LED lamp 1, light emitted from the light source unit 30 is output through the translucent cover 20. The translucent cover 20 has, for example, an exit surface 21 that is circular in a plan view. In this specification, the term "plan view" means a view from a direction perpendicular to the exit surface 21 of the translucent cover 20, unless otherwise specified.

[0016] In the present embodiment, a protrusion 22 for attaching and detaching the lamp is formed on the exit surface 21. When removing the LED lamp 1 from the socket, applying a rotational load to the translucent cover 20 using this protrusion 22 rotates the LED lamp 1 relative to the socket, allowing the LED lamp 1 to be removed.

[0017] The LED lamp 1 is a lamp that can freely adjust brightness and light color by controlling built-in LEDs with different color temperatures through operation of a terminal device (not shown). Examples of the terminal device include a remote controller attached to the LED lamp 1. A user can change the settings of brightness and light color according to applications such as relaxation, concentration, and preparation for sleep.

[0018] Next, constituent members of the LED lamp 1 will be described with reference to FIG. 3 and FIG. 4. FIG. 3 is an exploded perspective view of the LED lamp 1, and FIG. 4 is an axial cross-sectional view of the LED lamp 1.

[0019] As shown in FIGS. 3 and 4, the LED lamp 1 includes a light source unit 30 including an LED element, a first heat sink 60 for dissipating heat from the light source unit 30, a heat dissipation sheet 70, a circuit 80 for supplying power to the light source unit 30, a second heat sink 90 for dissipating heat from the circuit 80, and a light-transmissive cover 20 through which light emitted from the light source unit 30 exits. The LED lamp 1 further includes a bottomed cylindrical outer cover 10 that accommodates the light source unit 30, the first heat sink 60, the heat dissipation sheet 70, the circuit 80, and the second heat sink 90 as described above.

[0020] The light source unit 30 includes an LED element 40 (see FIG. 5 described later) and an LED mounting substrate 50 on which the LED element 40 is mounted. The light source unit 30 is fixed to the first heat sink 60 with screws 56 such that the light-emitting surface of the LED element 40 is disposed opposite to the light-transmissive cover 20. As will be described later in detail, the LED element 40 includes two types of LED elements that emit light having mutually different color temperatures.

[0021] The LED mounting substrate 50 has a substantially circular shape. The diameter of the LED mounting substrate 50 is slightly smaller than the inner diameter of the outer cover 10. A gap between the LED mounting substrate 50 and the outer cover 10 is sealed with a resin material such as a silicone resin.

[0022] A metal base substrate obtained by applying an insulating coating to a base material made of a metal material such as aluminum is used for the LED mounting substrate 50. A metal wiring 57 (see FIG. 7) electrically connected to the LED element 40 is formed on the LED mounting substrate 50, and the LED elements 40 are disposed throughout the entire in-plane area of the LED mounting substrate 50. Note that a ceramic substrate or a resin substrate can also be used for the LED mounting substrate 50.

[0023] The LED mounting board 50 is provided with an opening 51 at a position that axially overlaps with the antenna 84 included in the wireless communication module 83 mounted on the circuit 80. The opening 51 is a hole through which electromagnetic waves for wireless communication with the antenna 84 can pass. In particular, when a metal base substrate is used for the LED mounting board 50, electromagnetic waves are easily blocked by the LED mounting board 50. As in this embodiment, by providing an opening 51 at a position that axially overlaps with the antenna 84 on the LED mounting board 50, communication performance can be ensured.

[0024] In a plan view of the LED mounting board 50, the length from the outer edge of the opening 51 to the antenna 84 can be appropriately set according to the characteristics of the antenna 84, but is, for example, 3 mm or more. Increasing the length from the outer edge of the opening 51 to the antenna 84 makes it easier for electromagnetic waves for wireless communication with the antenna 84 to pass through, thereby ensuring better communication performance. On the other hand, if the length from the outer edge of the opening 51 to the antenna 84 becomes too large, the number of LED elements 40 that can be placed on the LED mounting board 50 will decrease. Therefore, from the viewpoint of ensuring light emission output, etc., the length from the outer edge of the opening 51 to the antenna 84 is, for example, 15 mm or less.

[0025] In this embodiment, the opening 51 is a notch provided on the outer edge of the LED mounting substrate 50, having a substantially rectangular shape in plan view. However, the shape of the opening 51 is not limited to this. For example, the opening 51 may have a substantially circular shape in plan view.

[0026] The opening 51 of the LED mounting substrate 50 is covered with a resin cover 100 to prevent insects and dust from entering the light-emitting surface from the circuit 80 side through the opening 51. Examples of resin materials that make up the resin cover 100 include polybutylene terephthalate (PBT), polypropylene (PP), polycarbonate (PC), acrylic, polyethylene (PE), polystyrene (PS), polymethylpentene (PMP), epoxy resin, and fluororesin. However, the resin material that makes up the resin cover 100 is not limited to the above resins as long as it is a material that transmits electromagnetic waves for wireless communication with the antenna 84. Also, the shape of the resin cover 100 is not particularly limited as long as it can cover the opening 51. In this embodiment, the resin cover 100 is fixed by screws 110.

[0027] In addition to the opening 51, the LED mounting board 50 is provided with through holes 52 through which screws 56 for fixing the light source unit 30 to the first heat sink 60 pass. In this embodiment, the LED mounting board 50 is provided with two through holes 52.

[0028] Furthermore, in addition to the opening 51 and through-hole 52, the LED mounting substrate 50 is provided with a wiring insertion section 53 through which wiring 85 connecting the power supply unit 82 mounted on the circuit 80 and the LED element 40 is inserted. In other words, in this embodiment, the wiring 85 does not pass through the opening 51 but passes through the wiring insertion section 53. This makes it easier to cover the opening 51 with the resin cover 100, and prevents insects and dust from entering the light-emitting surface side from the circuit 80 side through the opening 51. It also prevents the wiring 85 from being damaged by the resin cover 100.

[0029] In this embodiment, the wiring insertion section 53 has a substantially circular shape in plan view and is provided as one on the LED mounting substrate 50. Three wires 85 (see Figure 5) pass through the wiring insertion section 53. The shape and number of wiring insertion sections 53 are not limited to this. For example, the wiring insertion section 53 may have a substantially rectangular shape in plan view.

[0030] The wiring insertion section 53 is sealed with a resin material (not shown). Examples of resin materials include silicone resin. This prevents insects and dust from entering from the circuit 80 side through the wiring insertion section 53.

[0031] As shown in Figures 3 and 4, the first heat sink 60 is in contact with the back surface (the side facing the circuit 80) of the LED mounting substrate 50 and has the function of dissipating heat from the light source unit 30. The first heat sink 60 also functions as a support base for the light source unit 30. The first heat sink 60 is made of a metal material such as aluminum, or a resin material with high thermal conductivity. In this embodiment, the first heat sink 60 is made of aluminum.

[0032] The first heatsink 60 has a roughly circular shape in plan view. The diameter of the first heatsink 60 is slightly smaller than the inner diameter of the outer cover 10 and is approximately the same as the diameter of the LED mounting substrate 50. The surface of the first heatsink 60 is formed flat.

[0033] The first heat sink 60 has a substantially cylindrical wall 61 on its outer edge that extends away from the light source unit 30. The presence of the cylindrical wall 61 in the first heat sink 60 allows for better dissipation of heat from the light source unit 30. A heat dissipation sheet 70 is housed inside the cylindrical wall 61. Note that the first heat sink 60 does not necessarily have to have the cylindrical wall 61.

[0034] The first heat sink 60 has an opening 62 positioned to overlap axially with an opening 51 provided in the LED mounting substrate 50. The opening 62 is the same size as or larger than the opening 51. Like the opening 51, the opening 62 is a hole through which electromagnetic waves for wireless communication with the antenna 84 can pass. In this embodiment, the opening 62 is a notch provided on the outer edge of the first heat sink 60 and has a substantially L-shape in plan view. However, the shape of the opening 62 is not limited to this. For example, the opening 62 may have a substantially circular shape in plan view.

[0035] The first heat sink 60 has a through hole 63 into which a screw 56 for fixing the light source unit 30 is inserted. The first heat sink 60 also has a through hole 64 in a position that overlaps with a wiring insertion portion 53 provided on the LED mounting substrate 50. The through hole 64 is the same size as or larger than the wiring insertion portion 53. In this embodiment, the through hole 64 has a substantially circular shape in plan view, similar to the wiring insertion portion 53.

[0036] The heat dissipation sheet 70 is positioned between the first heat sink 60 and the circuit 80. The heat dissipation sheet 70 is preferably an elastic material with higher thermal conductivity than general resins and is compressible. A suitable heat dissipation sheet 70 is a sheet made of a flexible resin, which may contain a thermally conductive filler dispersed in the resin. Examples of resins constituting the heat dissipation sheet 70 include silicone resin and urethane resin. The thermally conductive filler dispersed in the resin is preferably an insulating filler with high thermal conductivity; examples include aluminum oxide, aluminum nitride, and boron nitride. In this embodiment, the heat dissipation sheet 70 has a rectangular shape in plan view and is housed inside the cylindrical wall 61 of the first heat sink 60. The shape of the heat dissipation sheet 70 is not particularly limited; for example, it may have a substantially circular shape in plan view.

[0037] Circuit 80 is a power supply circuit that converts alternating current (for example, AC 100V commercial power) into direct current for lighting the LED element 40. In addition to the power supply circuit, circuit 80 also includes a control circuit for controlling dimming, color adjustment, etc. Circuit 80 includes a circuit board 81 and a power supply unit 82 mounted on the circuit board 81.

[0038] The circuit board 81 is a printed circuit board (PCB) on which metal wiring such as copper foil is patterned. In this embodiment, the circuit board 81 has a roughly D-shape in plan view, with a part of the circle missing. The circuit board 81 is held in a position perpendicular to the axial direction.

[0039] A socket pin 11 is connected to the outer edge of the circuit board 81, and alternating current is supplied from the socket to the circuit 80 via the socket pin 11. In this embodiment, the socket pin 11 and the circuit board 81 are electrically connected by the socket pin 11 passing through a through hole 81A provided in the circuit board 81. However, the method of connecting the socket pin 11 and the circuit board 81 is not limited to this, and they may be electrically connected via, for example, a wire.

[0040] The power supply unit 82 includes components such as switching elements, choke coils, and capacitors. The components constituting the power supply unit 82 are mounted (through-hole mounting) by inserting leads into through-holes formed in the circuit board 81 from the back side (the side facing the second heat sink 90).

[0041] The circuit 80 further includes a wireless communication module 83. The wireless communication module 83 includes an antenna 84 and a wireless communication circuit. In this embodiment, the wireless communication module 83 is positioned perpendicular to the circuit board 81. That is, the wireless communication module 83 is mounted on the circuit board 81 in an axial direction. The leading edge of the wireless communication module 83 extends to a position that does not overlap with the circuit board 81 in a plan view. The wireless communication circuit of the wireless communication module 83 is configured, for example, to acquire control commands from wireless signals received by the antenna 84 and to transmit control signals.

[0042] Antenna 84 is located at the tip of the wireless communication module 83. Antenna 84 is configured to emit electromagnetic waves (for example, radio waves in the 920 MHz band or 2.4 GHz band) into space and to receive electromagnetic waves from space. The configuration of antenna 84 is not particularly limited and examples include pattern antennas, patch antennas, chip antennas, rod antennas, film antennas, etc.

[0043] As shown in Figures 3 and 4, the second heat sink 90 contacts the outer edge of the circuit board 81 and has the function of dissipating heat from the circuit 80. The second heat sink 90 also functions as a support base for the circuit 80. The second heat sink 90, like the first heat sink 60, is made of a metal material such as aluminum or a resin material with high thermal conductivity. In this embodiment, the second heat sink 90 is made of aluminum.

[0044] The second heat sink 90 has a roughly C-shape with an opening 91 formed at the position through which the wireless communication module 83 passes. Depending on the shape of the wireless communication module 83, the second heat sink 90 does not need to have an opening 91. In other words, the second heat sink 90 may have an annular shape formed around its entire circumference.

[0045] The second heatsink 90 is fixed to the circuit 80 by screws (not shown) or the like. The second heatsink 90 also has through holes 92 formed in the portion through which the socket pins 11 pass. In this embodiment, the second heatsink 90 is thicker than the first heatsink 60. This allows for better heat dissipation from the circuit 80.

[0046] The outer cover 10 is formed as a bottomed, roughly cylindrical shape and houses the light source unit 30, the first heat sink 60, the heat dissipation sheet 70, the circuit 80, and the second heat sink 90. ​​The opening of the outer cover 10 is covered by a light-transmitting cover 20.

[0047] The outer cover 10 has a protrusion 12 on the bottom side from which the socket pins 11 protrude. The protrusion 12 is the part that is inserted into the socket. The components that make up the power supply unit 82 are arranged inside the space formed by the protrusion 12.

[0048] The outer cover 10 may be made of metal or resin. An example of a resin that makes up the outer cover 10 is polybutylene terephthalate (PBT).

[0049] The translucent cover 20 is a component through which light emitted from the light source unit 30 passes. As described above, the translucent cover 20 closes the opening of the outer cover 10. Specifically, the translucent cover 20 is joined to the outer cover 10 by a locking portion 23 provided on the translucent cover 20 that catches on the inner circumferential surface of the outer cover 10.

[0050] The translucent cover 20 can be made of a translucent resin material such as acrylic or polycarbonate, or a glass material such as silica glass. In this embodiment, the translucent cover 20 is made of a resin material. The translucent cover 20 may be a transparent cover that does not have light-diffusing (light-scattering) properties, or a diffuse cover that does have light-diffusing properties.

[0051] Next, the arrangement of the LED elements 40 in the LED lamp 1 of this embodiment will be described with reference to Figures 5 and 6. Figure 5 is a plan view of the LED lamp 1, showing the state with the translucent cover 20 removed, and Figure 6 is a diagram showing a part of the pattern of the metal wiring 57 on the LED mounting substrate 50. In the following, for the sake of explanation, the left-right direction on the paper in Figures 5 and 6 may be referred to as the "X direction," and the up-down direction on the paper in Figures 5 and 6 may be referred to as the "Y direction." Also, in Figure 5, the LED unit 43, which will be described later, is shown with a dashed line, and an example of the array unit 44, which will be described later, is shown with a dashed line.

[0052] As shown in Figure 5, the light source unit 30 includes a plurality of LED elements 40 and an LED mounting substrate 50 on which the LED elements 40 are mounted. In the example shown in Figure 5, 70 LED elements 40 are mounted on the LED mounting substrate 50.

[0053] The LED element 40 includes a first LED element 41 that emits a first light and a second LED element 42 that emits a second light with a different color temperature from the first light. By selectively controlling the first LED element 41 and the second LED element 42, which have different color temperatures, it becomes possible to change the color temperature while keeping the brightness constant, or to change the brightness while keeping the color temperature constant.

[0054] In this embodiment, the first LED element 41 emits warm-colored light with a color temperature of approximately 2700K, and the second LED element 42 emits cool-colored light with a color temperature of approximately 6500K. However, the color temperatures of the first LED element 41 and the second LED element 42 are not limited to these values. For example, the color temperature of the first LED element 41 may be between 2200K and 3000K, and the color temperature of the second LED element 42 may be between 5000K and 7000K.

[0055] The first LED element 41 and the second LED element 42 are both surface-mount (SMD) type LED light sources in which the LED is packaged. The first LED element 41 and the second LED element 42 each consist of a container, an LED chip mounted inside the container, and a sealant that encapsulates the LED chip.

[0056] The LED chips included in the first LED element 41 and the second LED element 42 are semiconductor elements that emit light in response to a predetermined DC power, and are bare chips that emit monochromatic visible light. The LED chips are, for example, blue LEDs that emit blue light when power is applied. The emission wavelengths of the LED chips included in the first LED element 41 and the LED chips included in the second LED element 42 may be different from each other, but in this embodiment they are substantially the same.

[0057] The encapsulant contained in the first LED element 41 and the second LED element 42 is a light-transmitting insulating resin material such as silicone. The encapsulant in this embodiment contains a phosphor as a wavelength conversion material that converts the wavelength of light from the LED chip. In other words, the encapsulant in this embodiment is a phosphor-containing resin in which a phosphor is contained in a light-transmitting resin.

[0058] The first LED element 41 and the second LED element 42 differ in the type and composition of the phosphor used as the wavelength conversion material in the encapsulant. For example, when the first LED element 41 emits light with a color temperature of 2700K, a nitride-based phosphor or a YAG (yttrium aluminum garnet)-based phosphor can be used. Also, for example, when the second LED element 42 emits light with a color temperature of 6500K, a YAG-based phosphor or a silicate-based phosphor can be used.

[0059] As shown in Figure 5, the light source unit 30 has an LED unit 43 in which one first LED element 41 and one second LED element 42 are arranged along a predetermined first direction (the Y direction in this embodiment). In other words, at least a portion of the LED elements 40 are mounted on the LED mounting substrate 50 in pairs of one first LED element 41 and one second LED element 42. In the example shown in Figure 5, most of the LED elements 40, except for some LED elements 40 located at the outer edge, are included in the LED unit 43 in which one first LED element 41 and one second LED element 42 are arranged along the Y direction.

[0060] Here, at least some of the LED units 43 are arranged adjacent to each other such that they overlap in the X direction (second direction) perpendicular to the Y direction (first direction) in a plan view of the LED mounting substrate 50. Furthermore, adjacent LED units 43 are arranged such that the center positions of each LED unit 43 do not overlap in the X direction (second direction). In other words, the LED units 43 are not arranged in a straight line. This makes it easier for the light emitted from the LED units 43 to mix appropriately, and suppresses color unevenness on the emission surface 21. In particular, the effect of suppressing color unevenness on the emission surface 21 becomes more pronounced under usage conditions where the brightness is reduced. In other words, the effects of the present invention are more pronounced when the light source unit 30 is configured to enable dimming and color tuning. Note that the center position of each LED unit 43 refers to the center position of the smallest polygon that circumscribes the first LED element 41 and the second LED element 42 constituting each LED unit 43.

[0061] In one LED unit 43, the gap between the first LED element 41 and the second LED element 42 is preferably 3 mm or less, and more preferably 1.5 mm or less. In this case, since LED elements with different color temperatures are in close proximity to each other, it becomes easier to suppress color unevenness on the emission surface 21.

[0062] Here, as shown in Figure 5, when four adjacent LED units 43 in the X direction (second direction) are defined as an array unit 44, it is preferable that the LED units 43 in the array unit 44 are arranged in a zigzag pattern along the X direction. That is, in the array unit 44, the straight line connecting the center positions of each LED unit 43 has a zigzag shape.

[0063] By arranging the LED units 43 in a zigzag pattern, uneven distribution of the LED units 43 within the surface of the LED mounting substrate 50 is suppressed, and the light emitted from the LED units 43 can be mixed appropriately, thereby suppressing color unevenness on the emission surface 21.

[0064] The number of LED elements 40 included in the LED unit 43 that can constitute the array unit 44 is preferably 30% or more of the total number of LED elements 40 included in the light source unit 30, more preferably 40% or more of the total number of LED elements 40 included in the light source unit 30, and even more preferably 50% or more of the total number of LED elements 40 included in the light source unit 30. By increasing the number of LED elements 40 included in the array unit 44, color unevenness of the emission surface 21 can be further suppressed.

[0065] It is preferable that a portion of the LED units 43 that can constitute the array unit 44 are arranged near the outer edge of the LED mounting substrate 50. The arrangement of LED elements 40 near the outer edge of the LED mounting substrate 50 greatly affects the color unevenness of the emission surface 21. Therefore, by arranging a portion of the LED units 43 that can constitute the array unit 44 near the outer edge of the LED mounting substrate 50, the color unevenness of the emission surface 21 can be further suppressed. Here, the area near the outer edge of the LED mounting substrate 50 means the area from the outer edge of the LED mounting substrate 50 to 15 mm inward.

[0066] Furthermore, as shown in Figure 5, at least a portion of the LED unit 43 may be arranged such that three or more adjacent LED units in the X direction (second direction) are aligned along a direction inclined with respect to the X direction. In other words, the LED unit 43 may be arranged such that a straight line L connecting the center positions of three or more adjacent LED units 43 in the X direction extends along a direction inclined with respect to the X direction. For example, the straight line L extends along a direction inclined by 3° to 45° with respect to the X direction. This makes it easier for the light emitted from the LED unit 43 to blend properly, and helps to suppress color unevenness on the emission surface 21.

[0067] The LED mounting board 50 has three wires 85 and three connectors 54A, 54B, and 54C that connect to them. Connectors 54A and 54B are mounted near the outer edge of the LED mounting board 50, and connector 54C is mounted radially inward from connectors 54A and 54B. Note that the number of connectors and wires 85 are not limited to these and may be four or more.

[0068] In a plan view, LED units 43 are positioned on at least a portion of the straight line connecting the three connectors 54A, 54B, and 54C. In the example shown in Figure 5, LED units 43 are positioned on the straight line connecting connector 54A and connector 54C, and on the straight line connecting connector 54B and connector 54C. This allows LED units 43 to be positioned over a wide area of ​​the LED mounting substrate 50, thereby suppressing color unevenness on the emission surface 21. In other words, if LED units 43 are not positioned around connectors 54A, 54B, and 54C, the brightness around connectors 54A, 54B, and 54C will be dimmer than the brightness of other parts, making color unevenness on the emission surface 21 more likely to occur.

[0069] As shown in Figure 6, metal wiring 57 electrically connected to the LED elements 40 is formed on the LED mounting substrate 50. The first LED elements 41 are connected in series and parallel, and the second LED elements 42 are connected in series and parallel. Note that the connection configuration of the LED elements 40 is not limited to the configuration shown in Figure 6.

[0070] Here, as shown in Figures 5 and 6, jumper wires 58 are mounted on the LED mounting substrate 50, and the metal wiring 57 is formed to straddle the jumper wires 58. By forming the metal wiring 57 to straddle the jumper wires 58, the length of the metal wiring 57 can be shortened, making it easier to secure an area for mounting the LED elements 40.

[0071] It is preferable that there be only one jumper wire 58. In this case, it becomes easier to secure the area for mounting the LED elements 40 on the LED mounting board 50. As a result, the number of LED elements 40 can be increased, and the luminous efficiency and other factors can be improved. Note that the jumper wire 58 does not need to be mounted on the LED mounting board 50.

[0072] To confirm the color unevenness suppression effect of the LED lamp 1 of this embodiment, LED lamps 1 (experimental examples 1 to 4) with LED elements 40 arranged as shown in Figure 5 and Figures 7 to 9 were fabricated, and the color unevenness of the emission surface 21 was evaluated. Figures 7 to 9 are plan views of the LED lamp 1 and correspond to Figure 5.

[0073] In the LED lamp 1 shown in Figure 7, similar to the embodiment described above, one first LED element 41 and one second LED element 42 are mounted on the LED mounting substrate 50 as a pair. However, the arrangement of the LED elements 40 differs from the embodiment described above.

[0074] Specifically, the light source unit 30 includes a first LED unit 43A in which one first LED element 41 and one second LED element 42 are arranged along the Y direction, and a second LED unit 43B in which one first LED element 41 and one second LED element 42 are arranged along the X direction.

[0075] The first LED units 43A are arranged near the center of the LED mounting substrate 50 and at both ends in the Y direction. Some of the first LED units 43A are arranged so that they overlap with each other in the X direction (second direction), and the center positions of the first LED units 43A do not overlap in the X direction. Near the center of the LED mounting substrate 50, the first LED units 43A are arranged linearly along the X direction so that the center positions of the first LED units 43A overlap in the X direction.

[0076] Furthermore, the second LED unit 43B is positioned near the resin cover 100 that covers the opening 51 (see Figure 3) of the LED mounting substrate 50. In the example shown in Figure 7, five second LED units 43B are arranged in a straight line along the Y direction such that the centers of the second LED units 43B overlap in the Y direction.

[0077] In the LED lamp 1 shown in Figure 8, the LED elements 40 are arranged along the circumferential direction of the LED mounting substrate 50, except near the resin cover 100. Specifically, a first LED element 41 is arranged on the outermost periphery of the LED mounting substrate 50, and a second LED element 42 is arranged on the inner side of the first LED element 41. Near the center of the LED mounting substrate 50, a first LED element 41 is arranged on one side in the Y direction, and a second LED element 42 is arranged on the other side in the Y direction. Furthermore, a second LED element 42 is arranged on the outer side of the first LED element 41 at the innermost periphery of the LED mounting substrate 50, and a first LED element 41 is arranged on the outer side of the second LED element 42 at the innermost periphery of the LED mounting substrate 50.

[0078] In the example shown in Figure 8, the light source unit 30 has an LED unit 43 in which a first LED element 41 and one second LED element 42 are arranged along the X direction. The LED unit 43 is positioned near the resin cover 100 that covers the opening of the LED mounting substrate 50, and the LED units 43 are arranged so that they overlap in the Y direction. The five LED units 43 are arranged in a straight line along the Y direction so that the centers of the LED units 43 overlap in the Y direction.

[0079] Furthermore, in the LED lamp 1 shown in Figure 9, the LED elements 40 are arranged along the circumferential direction of the LED mounting substrate 50, across the entire surface of the LED mounting substrate 50. However, the first LED element 41 and the second LED element 42 are not arranged in a pair along a predetermined direction.

[0080] To evaluate color unevenness, the first LED element 41 and the second LED element 42 were illuminated under operating conditions where brightness was reduced to make color unevenness more noticeable, and the presence or absence of color unevenness on the emission surface 21 was visually confirmed. Then, the color unevenness was classified as ○, △, or × based on the evaluation criteria below. The evaluation results for the color unevenness of each LED lamp 1 are shown in Table 1. ○: There is color unevenness in a very small area (a few percent) of the emission surface 21. △: There is color unevenness in a portion of the emission surface 21 (approximately a few percent to several tens of percent). ×: Uneven coloring across the entire surface of the emission surface 21.

[0081] [Table 1]

[0082] As shown in Table 1, the LED lamps in Experimental Examples 1 and 2 show less color unevenness on the emission surface 21 compared to the LED lamps in Experimental Examples 3 and 4. Furthermore, the LED lamp in Experimental Example 1, in which the LED units 43 are arranged in a zigzag pattern in the array unit 44, shows less color unevenness on the emission surface 21 compared to the LED lamp in Experimental Example 2, in which the LED units 43 are not arranged in a zigzag pattern.

[0083] This disclosure is further illustrated by the following embodiments. Configuration 1: An LED element comprising a first LED element that emits light of a first color temperature and a second LED element that emits light of a second color temperature different from the first color temperature, An LED mounting board on which the aforementioned LED elements are mounted, A lighting device comprising a light source unit including, The light source unit has a plurality of LED units, each of which one first LED element and one second LED element are arranged along a predetermined first direction. A lighting device in which at least a portion of the LED units are arranged such that adjacent LED units overlap in a second direction perpendicular to the first direction in a plan view of the LED mounting substrate, and the center positions of adjacent LED units do not overlap in the second direction. Configuration 2: When four adjacent LED units in the second direction are defined as an array unit, The lighting device according to configuration 1, wherein in the array unit, the LED units are arranged in a zigzag pattern along the second direction. Configuration 3: The lighting device according to configuration 1 or 2, wherein at least a portion of the LED units are arranged such that three or more adjacent LED units in the second direction are aligned along a direction inclined with respect to the second direction. Configuration 4: The lighting device according to configuration 2, wherein the number of LED elements included in the LED unit that can constitute the array unit is 30% or more of the total number of LED elements included in the light source unit. Configuration 5: The aforementioned light source is configured to enable dimming and color adjustment, as described in any one of configurations 1 to 4. Configuration 6: A circuit that supplies power to the light source unit, At least three wires connecting the circuit and the LED element, Furthermore, The LED mounting board is equipped with at least three connectors that connect to the wiring, The lighting device according to any one of configurations 1 to 5, wherein the LED units are arranged on at least a portion of the straight line connecting the respective connectors. Composition 7: The LED mounting substrate has metal wiring formed to span across it via jumper wires. The lighting device according to any one of configurations 1 to 6, wherein the number of jumper wires is one. [Explanation of symbols]

[0084] 1 LED lamp (lighting device), 10 outer cover, 11 base pin, 12 protrusion, 20 translucent cover, 21 emission surface, 22 projection, 23 locking part, 30 light source part, 40 LED element, 41 first LED element, 42 second LED element, 43, 43A, 43B LED unit, 44 array unit, 50 LED mounting board, 51 opening, 52 through hole, 53 wiring insertion part, 54A, 54B, 54C connector, 56 screw, 57 metal wiring, 58 jumper wire, 60 first heat sink, 61 cylindrical wall, 62 opening, 63 through hole, 64 through hole, 70 heat dissipation sheet, 80 circuit, 81 circuit board, 81A through hole, 82 power supply unit, 83 wireless communication module, 84 antenna, 85 wiring, 90 second heat sink, 91 Opening, 92 through holes, 100 resin cover, 110 screws

Claims

1. An LED element comprising a first LED element that emits light of a first color temperature and a second LED element that emits light of a second color temperature different from the first color temperature, An LED mounting board on which the aforementioned LED elements are mounted, A lighting device comprising a light source unit including, The light source unit has a plurality of LED units, each of which one first LED element and one second LED element are arranged along a predetermined first direction. A lighting device in which at least a portion of the LED units are arranged such that adjacent LED units overlap in a second direction perpendicular to the first direction in a plan view of the LED mounting substrate, and the center positions of adjacent LED units do not overlap in the second direction.

2. When four adjacent LED units in the second direction are defined as an array unit, The lighting device according to claim 1, wherein in the array unit, the LED units are arranged in a zigzag pattern along the second direction.

3. The lighting device according to claim 1, wherein at least a portion of the LED units are arranged such that three or more adjacent LED units in the second direction are aligned along a direction inclined with respect to the second direction.

4. The lighting device according to claim 2, wherein the number of LED elements included in the LED unit that can constitute the array unit is 30% or more of the total number of LED elements included in the light source unit.

5. The lighting device according to claim 1, wherein the light source unit is configured to enable dimming and color adjustment.

6. A circuit that supplies power to the light source unit, At least three wires connecting the circuit and the LED element, Furthermore, The LED mounting board is equipped with at least three connectors that connect to the wiring, The lighting device according to claim 1, wherein the LED units are arranged on at least a portion of the straight line connecting the respective connectors.

7. The LED mounting substrate has metal wiring formed to span across it via jumper wires. The lighting device according to claim 1, wherein the number of jumper wires is one.

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