Lighting fixture

Abstract

To obtain a lighting fixture that can easily suppress noise.SOLUTION: A lighting fixture according to the present disclosure includes a light source, a lighting device that turns on the light source, a conductive housing that supports the light source and the lighting device, an input line that connects an external power source to the lighting device, an earth wire connected to the lighting device, a connecting line that is either an output line that connects the lighting device to the light source or a signal line that connects the lighting device to an external unit, and a first wire fixing portion that fixes the connecting line and the earth wire.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to lighting fixtures. [Background technology]

[0002] Patent Document 1 proposes a configuration for a separate-power-supply LED lighting device in which the LED unit and power supply unit are installed separately, which prevents LED damage even when common-mode noise voltage is superimposed on the AC power supply connected to the power supply unit. In the lighting device of Patent Document 1, a power supply unit containing a rectifier circuit and a DC-DC converter circuit in a metal case supplies DC current to the LED unit via a pair of power lines. A capacitor for bypassing ground noise voltage is provided, connecting the secondary ground of the DC-DC converter circuit to the metal case, and an earth wire is provided connecting the metal case to the conductive part of the LED unit. The capacitance of the capacitor is set to be larger than the combined stray capacitance between each LED in the LED unit and the conductive part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-245054 Summary of the Invention [Problem to be solved by the invention]

[0004] As a countermeasure against EMC (Electro Magnetic Compatibility) regulations, which are becoming more stringent, lighting fixtures with built-in noise filters are becoming more common. Technologies for reducing noise generated from lighting devices or light sources include installing passive components such as line filters and capacitors in lighting devices. Another example is a structure in which the lighting fixture wiring is wrapped multiple times around a ferrite ring core.

[0005] In the lighting device of Patent Document 1, a capacitor for bypassing noise voltage is inserted as a noise filter. One end of the capacitor for bypassing noise voltage must be electrically connected to the ground. Mounting such a capacitor and connecting it to the ground may be difficult due to constraints such as the structure of the lighting fixture, the size of the circuit board, and the development process.

[0006] An object of the present disclosure is to provide a lighting fixture that can easily suppress noise. [Means for solving the problem]

[0007] The lighting fixture according to the present disclosure includes a light source, a lighting device that turns on the light source, a conductive housing that supports the light source and the lighting device, an input line that connects an external power source to the lighting device, an earth wire connected to the lighting device, a connecting line that is either an output line that connects the lighting device to the light source or a signal line that connects the lighting device to an external unit, and a first wire fixing portion that fixes the connecting line and the earth wire. [Effects of the Invention]

[0008] According to the lighting fixture of the present disclosure, noise can be bypassed via the stray capacitance generated by the first wire fixing portion. This makes it possible to suppress the propagation of noise from the stray capacitance between the light source and the housing. Therefore, noise can be easily suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a lighting fixture according to a first embodiment. [Figure 2] 1 is a side view of a lighting fixture according to a first embodiment. [Figure 3] 1A and 1B are a plan view and a side view of a lighting device according to a first embodiment. [Figure 4] 1 is a block diagram of a lighting fixture according to a first embodiment. [Figure 5] 2 is a diagram showing wiring of the lighting device according to the first embodiment. FIG. [Figure 6] FIG. 4 is a diagram showing measurement results of the noise terminal voltage of the lighting fixture according to the first embodiment. [Figure 7] FIG. 10 is a block diagram of a lighting fixture according to a second embodiment. [Figure 8] FIG. 10 is a diagram showing wiring of a lighting device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The lighting fixtures according to the embodiments will be described with reference to the drawings. The same or corresponding components are designated by the same reference numerals, and the repeated description may be omitted.

[0011] Embodiment 1 Fig. 1 is a perspective view of a lighting fixture 1 according to a first embodiment. The lighting fixture 1 includes a light source 2, a lighting device 3 that lights the light source 2, and a conductive housing 4 that supports the light source 2 and the lighting device 3. The housing 4 is, for example, a metal part such as a heat sink that dissipates heat generated by the light source 2 and the lighting device 3. The light source 2 is provided on, for example, the bottom surface of the housing 4. The lighting device 3 is provided on, for example, the top surface of the housing 4.

[0012] The lighting device 3 is housed in a power supply case 5 and has an output wire 6. The output wire 6 includes an input wire 7 that connects the lighting device 3 to a commercial power source, which is an external power source, and an earth wire 8 that is connected to the lighting device 3 and to earth. In the output wire 6, the input wire 7 and the earth wire 8 do not have to be integrated, and each may be provided separately. The power supply case 5 and the housing 4 are both conductors and are therefore electrically connected.

[0013] 2 is a side view of the lighting fixture 1 according to embodiment 1. The light source 2 and the lighting device 3 are connected by an output line 9. The output line 9 is, for example, a pair of output lines connected via a connector 10.

[0014] FIG. 3 is a plan view and a side view of lighting device 3 according to embodiment 1. Lighting device 3 has power supply unit 11 and case 12. Case 12 is U-shaped. Power supply unit 11 is housed in power supply case 5, with case 12 housing it. Power supply unit 11 has input terminal 13 into which input wire 7 is inserted and connected, ground terminal 14 into which ground wire 8 is inserted and connected, and output terminal 15 into which output wire 9 is inserted and connected. Power supply unit 11 also has metal terminal 16 for electrically connecting case 12 and power supply unit 11. For example, input terminal 13, ground terminal 14, and output terminal 15 are quick-connect terminals, and metal terminal 16 is a lug terminal.

[0015] Case 12 has power supply unit fixing portion 17 for fixing power supply unit 11 to case 12, and power supply case fixing portion 18 for fixing power supply unit 11 to power supply case 5. Furthermore, side walls of case 12 are provided with electric wire fixing portions 19a, 19b, and 19c for fixing electric wires to case 12.

[0016] The ground terminal 14 and the metal terminal 16 are electrically connected by a board pattern formed on the board of the power supply unit 11. The metal terminal 16 and the case 12 are electrically connected by a screw. The case 12 and the power supply case 5 are electrically connected by a screw at the power supply case fixing portion 18. The power supply case 5 and the housing 4 are electrically connected by a screw (not shown). Therefore, the lighting fixture 1 is earthed by inserting the ground wire 8 into the ground terminal 14.

[0017] 4 is a block diagram of lighting fixture 1 according to embodiment 1. Light source 2 is composed of a plurality of light-emitting elements 20 such as LEDs. The plurality of light-emitting elements 20 are connected in series on a light source substrate. The plurality of light-emitting elements 20 may also be connected in parallel or in series-parallel. Light source 2 is lit by power supplied from lighting device 3.

[0018] The lighting device 3 includes a filter circuit 21 that suppresses noise and a Y capacitor 22 that bypasses noise. The lighting device 3 further includes a rectifier circuit 23 that converts AC power from a commercial power source into DC, a lighting circuit 24 that boosts or lowers the DC power and supplies it to the light source 2, and a control circuit 25 that controls the lighting circuit 24. The filter circuit 21, the Y capacitor 22, the rectifier circuit 23, the lighting circuit 24, and the control circuit 25 are provided in the power supply unit 11.

[0019] The filter circuit 21 is composed of passive components such as capacitors and coils. The size of the passive components varies depending on the frequency band to be attenuated and the amount of attenuation, and the mounting area on the board also varies. The amount of noise attenuation by the filter circuit 21 increases as the number of stages increases. Therefore, the filter circuit 21 becomes larger as the noise level increases.

[0020] The rectifier circuit 23 is composed of, for example, multiple diodes and a capacitor. The multiple diodes may be a diode bridge in a single package. The multiple diodes perform full-wave rectification of the AC voltage. The full-wave rectified voltage is then smoothed by the capacitor to become DC.

[0021] The lighting circuit 24 is a switching circuit that is composed of, for example, a winding that is an inductor, a resistor, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), a diode, etc. The switching circuit can be composed of a boost chopper circuit, a buck converter circuit, etc., and may be composed of a single switching circuit or multiple switching circuits. The switching circuit performs switching operations in response to signals from the control circuit 25 and supplies power to the light source 2. The switching circuit generates noise during switching operations. This noise is increased by the circuit board pattern, the parasitic inductance of the electric wires, the parasitic capacitance of the components, etc. Therefore, it is preferable to keep the length of the circuit board pattern and the electric wires short.

[0022] The control circuit 25 is composed of one or more arithmetic units such as a processor and one or more memories. The arithmetic units perform various calculations to realize the functions of the control circuit 25. The memory stores information necessary for control in the control circuit 25. The control circuit 25 may be a microcomputer. The control circuit 25 transmits commands to the lighting circuit 24 in response to an external signal. For example, the control circuit 25 receives a dimming signal such as a PWM (Pulse Width Modulation) signal and controls the lighting circuit 24 to adjust the power supplied to the light source 2.

[0023] Generally, lighting fixtures are required by technical standards to comply with noise terminal voltage, i.e., interference voltage. Noise terminal voltage must be within the specified value set by the technical standards. Noise terminal voltage is classified into differential mode noise and common mode noise depending on how it is transmitted. Differential mode noise occurs between power lines. Differential mode noise is a noise component that propagates in the same direction as the current or signal from the lighting device. Differential mode noise flows in different directions on the way out and back. On the other hand, common mode noise propagates in the same direction along the power line toward the circuit ground. Common mode noise passes through the metal frame or metal case via stray capacitance, etc., and returns to the noise source.

[0024] In a structure such as lighting fixture 1, noise propagates simultaneously with the supply of power to light source 2 via output line 9. The noise is amplified by the parasitic inductance and impedance contained in output line 9. The longer the output line 9, the greater the parasitic inductance and impedance.

[0025] A dielectric, which is an insulator, is disposed between the plurality of light-emitting elements 20 and the housing 4. This causes the presence of stray capacitance 26. Noise amplified in the output line 9 is transmitted to the housing 4 via the stray capacitance 26 and detected as noise.

[0026] If the stray capacitance 26 is large, the current flowing through the path in which common mode noise returns to the noise source increases. This can result in a high noise terminal voltage. Noise can be bypassed, for example, by connecting one end of a noise voltage bypass capacitor between the output terminal 15 and the lighting circuit 24 and connecting the other end to ground. Therefore, using a noise voltage bypass capacitor attenuates noise. However, mounting the capacitor and connecting it to ground can be difficult due to the constraints of the lighting fixture's structure and board size.

[0027] In contrast, in this embodiment, the output line 9 is fixed to the earth line 8. The part where the output line 9 and the earth line 8 are fixed is designated as the electric wire fixing part 19d, as described below. As a result, a stray capacitance 27 is generated between the output line 9 and the earth line 8, and noise is bypassed to the earth before it is amplified. In other words, the propagation of noise via the stray capacitance 26 between the light source 2 and the housing 4 is reduced by the stray capacitance 27 formed by the electric wire fixing part 19d. This makes it possible to suppress noise. Therefore, compared to when a capacitor for bypassing noise voltage is provided, noise can be easily suppressed with less space and at lower cost.

[0028] The stray capacitance 27 can be calculated by the relative permittivity ε × (area A / distance d). ε is the relative permittivity of the wire coating, A is the area of ​​the wire coating, and d is the thickness of the wire coating. The wire coating is, for example, a fluororesin. ε is a fixed value because it is determined by the material of the wire coating. The stray capacitance 27 increases in proportion to the contact area when fixing the output line 9 and the ground wire 8. The larger the stray capacitance 27, the greater the noise suppression effect. For this reason, the output line 9 and the ground wire 8 may be fixed along each other or may be in surface contact. The stray capacitance 27 formed by the wire fixing portion 19d may be larger than the stray capacitance 26 between the light source 2 and the housing 4.

[0029] FIG. 5 is a diagram showing the wiring of the lighting device 3 according to the first embodiment. Components mounted on the power supply unit 11 are omitted from FIG. 5. The wires are fixed using, for example, cable ties 28a, 28b, and 28d. The input wire 7 and the ground wire 8 are fixed to a wire fixing portion 19a of the case 12 using the cable tie 28a. The wire fixing portion 19a and the cable tie 28a form an input wire fixing portion that fixes the input wire 7 to the case 12, and a ground wire fixing portion that fixes the ground wire 8 to the case 12. The output wire 9 is fixed to the wire fixing portion 19b using the cable tie 28b. The wire fixing portion 19b and the cable tie 28b form an output wire fixing portion that fixes the output wire 9 to the case 12. The output wire 9 is further fixed to the ground wire 8 using the cable tie 28d. This forms the wire fixing portion 19d.

[0030] The technical standards require that wires exposed outside the housing must not be subjected to tension from the outside of the housing. This is the first requirement. Furthermore, there is a further requirement that no tension must be applied between the wires and the internal terminals when the wires are pushed into the base. This is the second requirement. In this embodiment, the wires exposed outside the housing are the input wire 7 and the ground wire 8. The output wire 9 is not exposed outside the housing, and therefore is not subject to the first requirement. The second requirement applies to the wires between the input wire 7 and the input terminal 13, between the ground wire 8 and the ground terminal 14, and between the output wire 9 and the output terminal 15. In this embodiment, the output wire 9 and the ground wire 8 are secured with a cable tie 28d. Therefore, even if no tension is applied to the output wire 9, tension from the outside of the housing on the ground wire 8 may apply tension between the output wire 9 and the output terminal 15.

[0031] In this embodiment, input wire 7, earth wire 8, and output wire 9 are fixed to case 12 by an input wire fixing portion, an earth wire fixing portion, and an output wire fixing portion, respectively. This prevents tension from being applied to input terminal 13, earth terminal 14, and output terminal 15 even if tension is applied to the wires exposed outside the device.

[0032] In this embodiment, the input line 7, the ground line 8, and the output line 9 are fixed at the input line fixing portion, the ground line fixing portion, and the output line fixing portion, and then the ground line 8 and the output line 9 are fixed at the electric wire fixing portion 19d. In other words, the electric wire fixing portion 19d is provided between the ground terminal 14 and the ground line fixing portion, and between the output terminal 15 and the output line fixing portion. This allows the stray capacitance 27 to bypass noise to the ground before the noise is amplified.

[0033] FIG. 6 is a diagram showing measurement results of the noise terminal voltage of lighting fixture 1 according to embodiment 1. Measured waveform 29 is the result when the output line 9 and earth line 8 are fixed, and measured waveform 30 is the result when the output line 9 and earth line 8 are not fixed. Up to a frequency of 10 MHz, there is roughly no difference in the levels of measured waveform 29 and measured waveform 30. However, at frequencies between 10 and 30 MHz, there is a difference of about 6 dB in peak value between the levels of measured waveform 29 and measured waveform 30. In this way, the noise improvement effect of stray capacitance 27 between output line 9 and earth line 8 was confirmed.

[0034] The method of fixing the electric wires is not limited to the cable ties 28a, 28b, and 28c. For example, a pole may be provided on the lighting device 3, and the electric wires may be wound around it to fix them. The electric wires may also be fixed by wrapping tape around them. The input wire fixing portion and the earth wire fixing portion may be provided separately. The input terminal 13, the earth terminal 14, and the output terminal 15 do not have to be independent. For example, the input terminal 13, the earth terminal 14, and the output terminal 15 may be provided on a single terminal block. Some or all of the input wire 7, the earth wire 8, and the output wire 9 may be integrated or independent. For example, the input wire 7 and the earth wire 8 may be crosstalking electric wires.

[0035] The above-described modifications can be applied as appropriate to the lighting fixtures according to the following embodiments. Note that the lighting fixtures according to the following embodiments have many points in common with the first embodiment, so the following description will focus on the differences from the first embodiment.

[0036] Embodiment 2 FIG. 7 is a block diagram of a lighting fixture 201 according to the second embodiment. The lighting fixture 201 includes a light source 2, a lighting device 203, and an external unit 31. The lighting device 203 is equipped with a signal terminal 32 that is connected to the external unit 31. A signal line 33 connects the signal terminal 32 of the lighting device 203 to the external unit 31. A stray capacitance 34 occurs between the housing 4 and the external unit 31. The housing 4 may support the external unit 31. The signal line 33 and the earth wire 8 are fixed by a wire fixing portion 19f, which will be described later. As a result, a stray capacitance 35 occurs between the signal line 33 and the earth wire 8. The rest of the configuration is the same as that of the first embodiment.

[0037] In this manner, in the present embodiment, electric wire fixing portion 19f is provided instead of electric wire fixing portion 19d. In the first embodiment, an example of a measure against noise amplified in output line 9 has been described. In the present embodiment, an example of a measure against noise amplified in signal line 33 will be described.

[0038] The external unit 31 is, for example, a sensor unit such as a human sensor unit. When the external unit 31 detects, for example, a person, it transmits a signal to the lighting device 3. The signal is received by the control circuit 25 via the signal line 33 and the signal terminal 32. This causes the lighting device 3 to start or stop supplying power to the light source 2. For convenience of explanation, the external unit 31 is connected to the control circuit 25, but it is not limited to the control circuit 25 and may be any unit connected to the lighting device 3. Furthermore, the signal line 33 is not limited to two lines, but may be one or more lines. The external unit 31 may be supplied with power from a commercial power source or the lighting device 3.

[0039] Noise is amplified by the signal line 33. In contrast, in this embodiment, the signal line 33 is fixed to the earth line 8 at the electric wire fixing portion 19f, which will be described later. As a result, a stray capacitance 35 is generated between the output line 9 and the earth line 8, and the noise is bypassed to the earth before it is amplified. In other words, the propagation of noise via the stray capacitance 34 between the external unit 31 and the housing 4 is reduced by the stray capacitance 35 formed by the electric wire fixing portion 19f. This makes it possible to suppress noise. Therefore, in this embodiment as well, noise can be easily suppressed in a small space and at low cost.

[0040] FIG. 8 is a diagram showing the wiring of lighting device 203 according to the second embodiment. Components mounted on power supply unit 11 are omitted from FIG. 8. Power supply unit 11 of the present embodiment further includes signal terminal 32 into which signal wire 33 is inserted and connected. The wires are fixed using, for example, cable ties 28a, 28e, and 28f. As in the first embodiment, wire fixing portion 19a and cable tie 28a form an input wire fixing portion that fixes input wire 7 to case 12 and a ground wire fixing portion that fixes ground wire 8 to case 12. Output wire 9 and signal wire 33 are fixed to wire fixing portion 19e with cable tie 28e. Wire fixing portion 19e and cable tie 28e form an output wire fixing portion that fixes output wire 9 to case 12 and a connection wire fixing portion that fixes signal wire 33 to case 12. Furthermore, signal wire 33 is fixed to ground wire 8 with cable tie 28f. This forms wire fixing portion 19f.

[0041] In the present embodiment, input wire 7, ground wire 8, output wire 9, and signal wire 33 are fixed to case 12 at wire fixing portions 19a and 19e. Therefore, even if tension is applied from outside case 12 to any of input wire 7, ground wire 8, output wire 9, and signal wire 33, it is possible to prevent tension from being applied to input terminal 13, ground terminal 14, output terminal 15, and signal terminal 32. In other words, as in the first embodiment, even if tension is applied to wires exposed outside the device, it is possible to prevent tension from being applied between input wire 7 and input terminal 13, between ground wire 8 and ground terminal 14, between output wire 9 and output terminal 15, and between signal wire 33 and signal terminal 32.

[0042] In this embodiment, the input line 7, the ground line 8, the output line 9, and the signal line 33 are fixed to the electric wire fixing portions 19a and 19e, and then the ground line 8 and the signal line 33 are fixed to the electric wire fixing portion 19f. In other words, the electric wire fixing portion 19f is provided between the ground terminal 14 and the ground wire fixing portion and between the signal terminal 32 and the connection line fixing portion. This allows the stray capacitance 35 to bypass noise to the ground before the noise is amplified.

[0043] The input terminal 13, the ground terminal 14, the output terminal 15, and the signal terminal 32 may be directly attached to the board instead of being attached to the terminal block. In addition to the electric wire fixing portion 19d of the first embodiment, the electric wire fixing portion 19f of the present embodiment may be provided.

[0044] The technical features described in each embodiment may be used in appropriate combination. The above-described embodiment is merely an example, and the present disclosure is not limited to the above-described embodiment and its modifications. Various modifications are possible depending on the design, etc., as long as they do not deviate from the technical concept of the present disclosure.

[0045] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A light source and a lighting device that lights the light source; a conductive housing that supports the light source and the lighting device; an input line connecting an external power source to the lighting device; a ground wire connected to the lighting device; a connecting line which is either an output line connecting the lighting device and the light source or a signal line connecting the lighting device and an external unit; a first wire fixing portion that fixes the connection wire and the ground wire; A lighting fixture comprising: (Appendix 2) 2. The lighting fixture according to claim 1, wherein the connection line is the output line. (Appendix 3) The lighting device described in Appendix 2, characterized in that noise propagation via a first stray capacitance between the light source and the housing is reduced by a second stray capacitance formed by the first wire fixing portion. (Appendix 4) 4. The lighting fixture according to claim 2, wherein a second stray capacitance formed by the first wire fixing portion is larger than a first stray capacitance between the light source and the housing. (Appendix 5) 5. The lighting fixture according to any one of claims 2 to 4, further comprising a second wire fixing portion that fixes the signal wire and the ground wire. (Appendix 6) 2. The lighting fixture according to claim 1, wherein the connection line is the signal line. (Appendix 7) The lighting device described in Appendix 6, characterized in that noise propagation via a first stray capacitance between the external unit and the housing is reduced by a second stray capacitance formed by the first wire fixing portion. (Appendix 8) The lighting device is an input line fixing portion that fixes the input line to a case of the lighting device; a ground wire fixing portion that fixes the ground wire to the case; a connection wire fixing portion that fixes the connection wire to the case; an input terminal to which the input line is connected; a ground terminal to which the ground wire is connected; a connection terminal to which the connection line is connected; and The lighting fixture described in any one of appendixes 1 to 7, characterized in that the first electric wire fixing portion is provided between the earth terminal and the earth wire fixing portion, and between the connection terminal and the connection wire fixing portion. [Explanation of symbols]

[0046] 1 lighting fixture, 2 light source, 3 lighting device, 4 housing, 5 power supply case, 6 lead wire, 7 input wire, 8 ground wire, 9 output wire, 10 connector, 11 power supply unit, 12 case, 13 input terminal, 14 ground terminal, 15 output terminal, 16 metal terminal, 17 power supply unit fixing part, 18 power supply case fixing part, 19a, 19b, 19c, 19d, 19e, 19f electric wire fixing part, 20 light emitting element, 21 filter circuit, 22 Y capacitor, 23 rectifier circuit, 24 lighting circuit, 25 control circuit, 26, 27 stray capacitance, 28a, 28b, 28d, 28e, 28f cable tie, 31 external unit, 32 signal terminal, 33 signal wire, 34, 35 stray capacitance, 201 lighting fixture, 203 lighting device

Claims

1. A light source and a lighting device that lights the light source; a conductive housing that supports the light source and the lighting device; an input line connecting an external power source to the lighting device; a ground wire connected to the lighting device; a connecting line which is either an output line connecting the lighting device and the light source or a signal line connecting the lighting device and an external unit; a first wire fixing portion that fixes the connection wire and the ground wire; A lighting fixture comprising:

2. 2. The lighting fixture according to claim 1, wherein the connecting wire is the output wire.

3. 3. The lighting fixture according to claim 2, wherein noise propagation via a first stray capacitance between the light source and the housing is reduced by a second stray capacitance formed by the first wire fixing portion.

4. 4. The lighting fixture according to claim 2, further comprising a second wire fixing portion for fixing the signal wire and the ground wire.

5. 2. The lighting fixture according to claim 1, wherein the connecting wire is the signal wire.

6. The lighting fixture according to claim 6, characterized in that noise propagation via a first stray capacitance between the external unit and the housing is reduced by a second stray capacitance formed by the first wire fixing portion.

7. The lighting device is an input line fixing portion that fixes the input line to a case of the lighting device; a ground wire fixing portion that fixes the ground wire to the case; a connection wire fixing portion that fixes the connection wire to the case; an input terminal to which the input line is connected; a ground terminal to which the ground wire is connected; a connection terminal to which the connection line is connected; and The lighting fixture according to claim 2 or 5, wherein the first electric wire fixing portion is provided between the ground terminal and the ground wire fixing portion and between the connection terminal and the connection wire fixing portion.

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