JP7640934B2 - Light-emitting module and lighting device - Google Patents

Description

Embodiments of the present invention relate to light-emitting modules and lighting devices.

Conventionally, there is a lighting device that includes a light-emitting module in which a light-emitting element is mounted on a module substrate, and a lighting circuit that supplies lighting power to the light-emitting module. The lighting circuit performs power conversion to convert the input power to a specified lighting power, which generates noise.

Generally, lighting circuits are equipped with noise countermeasures to reduce noise, such as noise filters, but there are cases where sufficient noise countermeasures cannot be implemented due to restrictions on the size of the lighting circuit, and it is desirable to be able to implement noise countermeasures even in such cases.

JP 2016-162596 A

The problem that this invention aims to solve is to provide a light-emitting module and lighting device that can reduce noise.

The light-emitting module of the embodiment includes a module substrate, a light-emitting element mounted on the module substrate, a first ferrite bead having an impedance peak at frequencies between 30 MHz and 1 GHz and connected in series to the anode side of the light-emitting element, and a second ferrite bead having an impedance peak at frequencies between 30 MHz and 1 GHz and connected in series to the cathode side of the light-emitting element .

According to the embodiment, a light-emitting module that can deal with noise can be provided.

1 is a circuit diagram of a lighting device including a light-emitting module according to an embodiment. 4 is a graph showing impedance characteristics of a ferrite bead included in the light emitting module.

An embodiment will be described below with reference to the drawings.

Figure 1 shows a lighting device 10. This lighting device 10 includes a light-emitting module 11 and a lighting circuit 12.

The lighting device 10 includes, for example, a lamp device such as a light bulb-shaped lamp. In the case of a lamp device, a lighting circuit 12 is housed in a cylindrical housing, a light emitting module 11 is disposed at one end of the housing, a globe is disposed covering the light emitting module 11, and a base is disposed at the other end of the housing. The housing includes a metal housing, and the base includes an E17 base or an E26 base that can be connected to a socket for a general lighting bulb.

The light-emitting module 11 includes a module substrate 20, a light-emitting element 21 mounted on the module substrate 20, ferrite beads L1 and L2, capacitors C1 and C2, and a connector 22 that is an input section for lighting power from the lighting circuit 12.

The module substrate 20 is made of a metal material such as aluminum. An insulating layer is formed on one side of the module substrate 20, which is the mounting surface, and a wiring pattern 23 is formed on this insulating layer. The light emitting element 21, ferrite beads L1, L2, capacitors C1, C2, and connector 22 are surface-mounted and electrically connected on the wiring pattern 23.

The wiring pattern 23 has a first wiring pattern 23a which is the high potential side between the light emitting element 21 and the connector 22, a second wiring pattern 23b which is the low potential side, and a third wiring pattern 23c for connecting the second wiring pattern 23b to the ground side (the side of the housing indicated by the symbol A in FIG. 1).

The module board 20 is shown in a square shape in FIG. 1, but in the case of a lamp device, it is formed in a circular shape and is placed on one end of a metal housing and attached in a state where it is thermally connected to the metal housing with multiple screws. The ground side of the third wiring pattern 23c is electrically connected to the metal housing (A in FIG. 1) via these screws.

The light-emitting element 21 includes, for example, an LED. The LED is mounted, for example, on an element substrate, and is mounted and electrically connected to the wiring pattern 23 of the module substrate 20, that is, to straddle the first wiring pattern 23a and the second wiring pattern 23b, by the element substrate. Note that, for the light-emitting element 21, an SMD (Surface Mount Device) package or a COB (Chip On Board) module may be used, or other light-emitting elements other than LEDs, such as organic EL, may be used.

The light-emitting element 21 has an anode on the high potential side (positive electrode) and a cathode on the low potential side (negative electrode), with the anode side connected to the first wiring pattern 23a and the cathode side connected to the second wiring pattern 23b.

Furthermore, the ferrite beads L1 and L2 are, for example, surface-mountable chip-shaped and surface-mounted on the wiring pattern 23 of the module substrate 20. The first ferrite bead L1 is connected in series to the anode side of the light-emitting element 21 on the first wiring pattern 23a between the anode side of the light-emitting element 21 and the positive side of the connector 22. The second ferrite bead L2 is connected in series to the cathode side of the light-emitting element 21 on the second wiring pattern 23b between the cathode side of the light-emitting element 21 and the negative side of the connector 22. The ferrite beads L1 and L2 are connected at a position closer to the connector 22 than the light-emitting element 21. In other words, the length of each wiring pattern 23a and 23b between the ferrite beads L1 and L2 and the connector 22 is shorter than the length of each wiring pattern 23a and 23b between the ferrite beads L1 and L2 and the light-emitting element 21.

The impedance characteristics of ferrite beads L1 and L2 are shown in the graph of Figure 2. Ferrite beads L1 and L2 have the highest impedance peak within the frequency range of 30 MHz to 1 GHz. This impedance characteristic reduces the conducted noise in the high frequency range of 30 MHz to 1 GHz that is superimposed on the lighting power supplied from the lighting circuit 12 to the light emitting module 11, and this reduction in conducted noise reduces the radiated noise of 30 MHz to 1 GHz that is emitted from the wiring pattern 23 and the like as an antenna.

Since the radiation noise generated by the conduction noise superimposed on the lighting power supplied from the lighting circuit 12 to the light-emitting module 11 is mostly contained in the frequency range of 30 MHz to 100 MHz, in order to effectively reduce the radiation noise, it is preferable to use ferrite beads L1 and L2 whose impedance peak is in the frequency range of 30 MHz to 100 MHz or near a frequency of 100 MHz and whose impedance at frequencies of 30 MHz to 100 MHz is 200 Ω or more.

The capacitors C1 and C2 are mounted in series on the third wiring pattern 23c of the module substrate 20. One end of the capacitors C1 and C2 is connected to the second wiring pattern 23b between the cathode side of the light-emitting element 21 and the ferrite bead L2 so as to be connected in series to the cathode side of the light-emitting element 21, and the other end of the capacitors C1 and C2 is electrically connected to the metal housing (A in FIG. 1), which is the ground side, through the wiring pattern portion 23c.

Capacitors C1 and C2 each have a capacitance in the range of 470pF to 3300pF, and preferably 1000pF. In this embodiment, two capacitors are connected in series, so the combined capacitance of capacitors C1 and C2 has a capacitance in the range of 235pF to 1650pF, and preferably 500pF. The impedance according to this capacitance reduces noise (including common mode noise) at frequencies between 9kHz and 30MHz, which is lower than the frequency of the noise reduced by ferrite beads L1 and L2. This was obtained from an experiment showing that using capacitors C1 and C2 with a capacitance in the range of 470pF to 3300pF can reduce noise at frequencies between 9kHz and 30MHz.

In the embodiment, two capacitors are used, but this is not limiting and one capacitor may be used. In the case of one capacitor, the capacitance should be in the range of 235 pF to 1650 pF, and preferably 500 pF.

The connector 22 is mounted across and electrically connected to the first wiring pattern 23a and the second wiring pattern 23b of the module substrate 20.

The lighting circuit 12 also receives AC power, which is external power supplied from an AC power source E, which is an external power source, converts it into lighting power of a predetermined DC voltage that lights the light-emitting element 21, and supplies it to the light-emitting module 11. The lighting circuit 12 includes a switching element such as a MOS-FET, and power conversion is performed by the switching operation of this switching element.

The lighting circuit 12 has a circuit board 30 on which multiple circuit elements are mounted. One end of an output wiring 31 is connected to the lighting power output side of the circuit board 30, and a connector 32 provided on the other end of the output wiring 31 is electrically connected to the connector 22 of the light-emitting module 11.

In the case of a lamp device, the lighting circuit 12 is housed in a housing, the input side of the lighting circuit 12 is electrically connected to the base, the output wiring 31 of the lighting circuit 12 is pulled out to the mounting surface side of the module board 20 of the light-emitting module 11, and the connector 32 of the output wiring 31 is electrically connected to the connector 22 of the light-emitting module 11.

When the lighting device 10 is a lamp device, it is attached to a socket of a lighting fixture, and AC power is supplied from the AC power source E to the lighting circuit 12 through the socket and base.

When the AC power source E is turned on, the lighting device 10 converts the AC power into lighting power of a predetermined DC voltage using the lighting circuit 12 and supplies it to the light-emitting module 11. The lighting power supplied to the light-emitting module 11 is supplied from the connector 22 through the ferrite beads L1 and L2 to the light-emitting element 21, causing the light-emitting element 21 to light up.

The inductance characteristics of the ferrite beads L1 and L2 of the light-emitting module 11 reduce the conductive noise in the high frequency range of 30 MHz to 1 GHz that is superimposed on the lighting power supplied from the lighting circuit 12 to the light-emitting module 11, and this reduction in conductive noise reduces the radiated noise of 30 MHz to 1 GHz that is emitted from the wiring pattern 23 as an antenna. This makes it possible to meet the standard for radiated noise of 30 MHz to 1 GHz established in Appendix 10 of the Electrical Appliance and Material Safety Act, which complies with CISPR (Comite International Special des Perturbations Radioelectriques) 15.

In addition, the capacitors C1 and C2 of the light-emitting module 11 reduce noise, including common mode noise, at frequencies between 9 kHz and 30 MHz, which is lower than the frequency of the noise reduced by the ferrite beads L1 and L2, due to their inductance characteristics. This makes it possible to suppress the effects on flickering of the light-emitting element 21.

As described above, the light-emitting module 11 of this embodiment includes ferrite beads L1 and L2 connected in series to the light-emitting element 21, and therefore reduces the conducted noise superimposed on the lighting power supplied from the lighting circuit 12 to the light-emitting module 11, and by reducing the conducted noise, it is possible to reduce the radiated noise emitted from the light-emitting module 11.

Therefore, even in cases where the size of the lighting circuit 12 housed in the housing is limited, such as in a lamp device, and sufficient noise countermeasures cannot be implemented using the lighting circuit 12, the light-emitting module 11 can provide noise countermeasures.

The ferrite beads L1 and L2 have an impedance peak within the frequency range of 30 MHz to 1 GHz, so they can effectively reduce the radiation noise of 30 MHz to 1 GHz emitted from the light-emitting module 11.

More preferably, the ferrite beads L1 and L2 have an impedance peak within the frequency range of 30 MHz to 100 MHz, or have an impedance peak near a frequency of 100 MHz, and have an impedance of 200 Ω or more at frequencies of 30 MHz to 100 MHz, thereby effectively reducing radiation noise in the range of 30 MHz to 100 MHz that is likely to be radiated from the light-emitting module 11.

Furthermore, since the ferrite beads L1 and L2 are connected in series to both the anode side and the cathode side of the light-emitting element 21, respectively, the effect of reducing radiation noise from the light-emitting module 11 can be enhanced.

In addition, the light-emitting module 11 has capacitors C1 and C2 connected in series between the light-emitting element 21 and the ground side, so that noise can be reduced due to the impedance characteristics of the capacitors C1 and C2.

In addition, capacitors C1 and C2 each have a capacitance in the range of 470 pF to 3300 pF, resulting in a combined capacitance of 235 pF to 1650 pF. The impedance according to this capacitance effectively reduces noise at frequencies between 9 kHz and 30 MHz, which is lower than the noise frequencies reduced by ferrite beads L1 and L2.

Therefore, by providing the light-emitting module 11 with ferrite beads L1 and L2 and capacitors C1 and C2, noise over a wide range of frequencies can be reduced, ensuring reliable noise countermeasures.

Furthermore, the ferrite beads L1, L2 are connected to a position closer to the connector 22 than the light-emitting element 21. In other words, the length of each wiring pattern 23a, 23b between the ferrite beads L1, L2 and the connector 22 is shorter than the length of each wiring pattern 23a, 23b between the ferrite beads L1, L2 and the light-emitting element 21. This reduces the radiation noise emitted from the wiring pattern 23 as an antenna.

The light-emitting module 11 may be equipped with only one of the ferrite beads L1 and L2, and even if only one of them is used, the radiation noise emitted from the light-emitting module 11 can be reduced.

The light-emitting module 11 may also have multiple small-capacity ferrite beads connected to the first wiring pattern 23a, etc.

In addition, one end of the capacitors C1 and C2 may be connected between the connector 22 and the ferrite bead L2, and may be connected in series to the cathode side of the light-emitting element 21 via the ferrite bead L2. In addition, one end of the capacitors C1 and C2 may be connected in series to the anode side of the light-emitting element 21. In either case, noise can be reduced.

The light-emitting module 11 can be used not only in lamp devices, but also in various lighting devices such as lighting fixtures installed on ceilings or walls, or street lights and security lights.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

10 Illumination device 11 Light-emitting module 12 Lighting circuit 20 Module board 21 Light-emitting element
22 connector
23a First wiring pattern
23b Second wiring pattern
C1, C2 Capacitor L1, L2 Ferrite beads

Claims (5)

A module substrate;
A light emitting device mounted on the module substrate;
a first ferrite bead having an impedance peak at a frequency of 30 MHz to 1 GHz and connected in series to an anode side of the light emitting element;
a second ferrite bead having an impedance peak at a frequency of 30 MHz to 1 GHz and connected in series to the cathode side of the light emitting element;
A light emitting module comprising: The light-emitting module according to claim 1 , further comprising a capacitor connected in series to the light-emitting element. 3. The light emitting module according to claim 2 , wherein the capacitance of the capacitor is in the range of 235 pF to 1650 pF. a connector mounted on the module board and connectable to a lighting circuit;
the module substrate has a first wiring pattern that connects the connector, the first ferrite bead, and the light-emitting element, and a second wiring pattern that connects the connector, the second ferrite bead, and the light-emitting element,
The light-emitting module described in any one of claims 1 to 3, characterized in that the length of the first and second wiring patterns between the first and second ferrite beads and the connector is shorter than the length of the first and second wiring patterns between the first and second ferrite beads and the light-emitting element. A light emitting module according to any one of claims 1 to 4;
A lighting circuit for supplying lighting power to the light emitting module;
A lighting device comprising:

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