This application claims the benefit of priority of Japanese Patent Application Number 2016-101966 filed on May 20, 2016, the entire content of which is hereby incorporated by reference.
The present disclosure relates to a light driving apparatus and a light control system, and in particular to a light driving apparatus which includes a wireless communication module, for instance.
A lighting device which supplies power to a light source in accordance with an indication from a control apparatus has been proposed (for example, see Japanese Unexamined Patent Application. Publication No. 2015-37042).
The lighting device disclosed in Japanese Unexamined Patent Application Publication No. 2015-37042 secures a satisfactory transmission and reception function for wireless communication by providing an antenna. outside the power supply module covered with a metal housing.
However, the lighting device disclosed in Patent Literature 1 needs to cover the antenna provided outside the power supply module with a resin. housing, and furthermore fix the antenna. This makes the structure of the lighting device complicated, and also complicates the work for installing the lighting device in a building.
Here, it is conceivable to house the antenna in the metal housing in order to simplify the structure of the lighting device, yet electromagnetic waves emitted by the antenna and electromagnetic waves which are to come in from the outside are blocked by the metal housing in such a case. This results in a difficulty in securing a satisfactory transmission and reception function for wireless communication.
In view of this, the present disclosure provides a light driving apparatus and a light control system which can secure a satisfactory transmission and reception function for wireless communication without having a complicated structure.
In order to provide such an apparatus, a light driving apparatus according to an aspect of the present disclosure is a light driving apparatus which supplies power to a light source in accordance with an indication from a control apparatus, the light driving apparatus including: a housing which is box-shaped; a wireless communication module which is housed in the housing, and includes an antenna for wireless communication with the control apparatus; and a light driver which is housed in the housing, and supplies power to the light source in accordance with the indication received from the control apparatus via the wireless communication module, wherein the housing includes two opposite faces having slits through which an electromagnetic wave which the antenna emits when excited by the wireless communication module passes, the slits extending in a direction three-dimensionally crossing a direction in which the wireless communication module excites the antenna.
Furthermore, in order to provide such a system, a light control system according to an aspect of the present disclosure includes; a plurality of light driving apparatuses each being the light driving apparatus; and a control. apparatus which wirelessly transmits indications to the plurality of light driving apparatuses.
The present disclosure provides a light driving apparatus and a light control system which can sufficiently secure a transmission and reception function for wireless communication without having a complicated structure.
The figures depict one or more implementations in accordance with the present teaching, by way of examples only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.
The following describes embodiments of the present disclosure in detail, with reference to the drawings. The embodiments described below each show a specific example. The numerical values, shapes, materials, elements, the arrangement and connection of the elements, results of simulations and actual measurement, and others indicated in the following embodiments are mere examples, and are not intended. to limit the present disclosure. Therefore, among the elements in the following embodiments, elements not recited in any of the independent claims defining the most generic part of the inventive concept of the present disclosure are described as optional elements.
In the present embodiment, lighting device 10 is a downlight, and includes light 20 and light driving apparatus 30.
Light 20 is fixed in coiling 2, and includes light source 21 which includes, for instance, a light emitting diode (LED), case 22 which, covers light source 21, and flat springs 23 which prevent case 22 from falling.
Light driving apparatus 30 is a power supply module which supplies power to light source 21 in accordance with an indication from control apparatus 4, and is electrically connected with a grid power supply and light 20 (more specifically, light source 21. of light 20).
Control apparatus 4 controls lighting device 10 through wireless communication, and is, for example, a personal digital assistant such as a smartphone which transmits a command through wireless communication to lighting device 10 while an application is being executed.
Light driving apparatus 30 includes box-shaped housing 31 (in other words, housing 31 having a rectangular parallelepiped shape) defined by six faces (top face 31a, bottom face 31b, and four lateral faces 31c to 31f). Housing 31 is a metal (for example, aluminum) case for housing a circuit component inside, and the size of housing 31 is defined by, for example, a height (length along the Z axis) of about 5 cm, a width (length along the Y axis) of about 18 cm, and the depth (length along the X axis) of about 8 cm. Top face 31a, bottom face 31b, and two lateral faces 31c and 31d have an elongated shape extending in the Y axis direction. Bent portions 31b1 and 31b3 having, respectively, screw holes 31b2 and 31b4 for fixing light driving apparatus 30 to ceiling 2 are provided at the ends of the length (the Y axis direction) of bottom face 31b.
Here, a distinctive point is that top face 31a and bottom face 31b of housing 31 have slits 90a and 90b for passing electromagnetic waves, which are extending lengthwise (along the axis) of top face 31a. and bottom face 31b, respectively. Slits 90a and 90b are openings defined by closed contours and formed in top face 31a and bottom, face 31b of housing 31 (specifically, through holes cut out), and have a length which is substantially a half wave length of a frequency for wireless communication which light driving apparatus 30 uses. In the present embodiment, the frequency for wireless communication which light driving apparatus 30 uses is in the 920 MHz band, and slits 90a and 90b have an oblong shape (a rectangle or an oblong shape having two curved edges) having a length of 145 to 175 mm and a width of 0.1 to 5 mm.
Light driving apparatus 30 includes housing 31, wireless communication module 40, and light driver 50.
Housing 31 includes bottom housing 33, and cover housing 32 which covers bottom housing 33. Bottom housing 33 corresponds to bottom face 31b of housing 31. Cover housing 32 includes five faces (top face 31a and four lateral faces 31c to 31f) of housing 31. Bottom housing 33 and cover housing 32 are engaged or screwed to be joined.
Wireless communication module 40 is housed in housing 31, and includes an antenna for wireless communication with control apparatus 4. Wireless communication module 40 includes upper cover 41, lower cover 42, and circuit board 43 as illustrated in
Light driver 50 is a circuit module which is housed in housing 31, and supplies power to light source 21 of light 20 in accordance with an indication received from control apparatus 4 via wireless communication module 40. Light driver 50 includes substrate 51 having an elongated shape (rectangular shape) extending along the Y axis, and also grid power connector 52, light connector 53, and circuit components 54 which are mounted on substrate 51, as illustrated in
Light driver 50 includes grid power connector 52, circuit components 54 (AC-to-DC converter 54a, DC-to-DC converter 54b, control circuit 54c), and light connector 53.
Grid power connector 52 is a connector to which a power cable for supplying alternating current (ac) power from grid power supply 6 is connected. AC-to-DC converter 54a is a rectifier and smoothing circuit which converts ac power supplied via grid power connector 52 into direct current (dc) power. DC-to-DC converter 54b is a power supply circuit which converts a direct voltage output from AC-to-DC converter 54a into a direct voltage suitable for passing constant current through light source 21 via light connector 53, and is a switching DC-to-DC converter, for example, Control circuit 54c controls DC-to-DC converter 54b in accordance with an indication transmitted from wireless communication module 40, and controls the magnitude of current (dimming) which DC-to-DC converter 54b supplies to light source 21, for example. Light connector 53 is a connector for connecting a cable for supplying current to light source 21 of light 20.
Referring back to
Slits 90a and 90b are extending, respectively, in top face 31a and bottom face 31b of housing 31 in a direction (here, along the Y axis) three-dimensionally crossing the direction (X axis directions) in which wireless communication module 40 excites antenna 46. Moreover, top face 31a and bottom face 31b of housing 31 which have slits 90a and 90b, respectively, are opposed to substrate 44 on which a wiring pattern serving as antenna 46 is formed. Accordingly, slits 90a and 90b are provided in a direction in which electromagnetic waves are emitted from antenna 46. Thus, electromagnetic waves are emitted from antenna 46 at a high gain, and electromagnetic waves from the outside efficiently fall on antenna 46.
Note that the direction crossing the direction in which antenna 46 is excited is not limited to only the direction orthogonal to the excitation direction, but also a direction substantially orthogonal to the excitation direction (for example, the direction crossing the excitation direction at an acute angle of 70 degrees or more).
Slits 90a and 90b are extending lengthwise (along the Y axis) in top face 31a and bottom face 31b of housing 31 respectively. Thus, slits 90a and 90b having a length suitable for a frequency for wireless communication are firmed extending lengthwise, and thus the size of housing 31 is reduced while a gain in transmission and reception through wireless communication is sufficiently secured.
Slits 90a and 90b are formed in top face 31a and bottom face 31b, rather than lateral faces of housing 31. Accordingly, providing slits 90a and 90b in lateral faces of housing 31 which are likely to have a low structural strength is avoided. This avoids a problem that the force of a hand holding housing 31 deforms the lateral faces of housing 31 when housing 31 is manufactured or moved.
Wireless communication module 40 and light driver 50 are disposed widthwise (along the X axis) of the elongated shape, side by side on bottom face 31b inside housing 31. When viewed perpendicularly to top face 31a and bottom face 31b (in the Z axis direction), slits 90a and 90b are extending in top face 31a and bottom face 31b, respectively, on the wireless communication module 40 side (in the negative direction of the X axis) relative to the center line which halves the width of top face 31a and the width of bottom face 31b (the center line along the Y axis). Accordingly, when housing 31 is viewed from above, slits 90a and 90b are formed, extending along the Y axis on a side where wireless communication module 40 is disposed (in the negative direction of the X axis), among wireless communication module 40 and light driver 50 disposed side by side, widthwise of housing 31 (X axis direction). Therefore, even if light driving apparatus 30 is installed in such a manner that light driver 50 heavier than wireless communication module 40 is accidentally placed in a lower position, and wireless communication module 40 is positioned in a higher position (lateral face 31d is the horizontal face (bottom face) close to the ground), the following is secured. In other words, slits 90a and 90b will be placed in a higher position of housing 31, which thus secures heat dissipation of light driving apparatus 30 due to chimney effect (in other words, slits 90a and 90b serving as heat dissipation openings).
When viewed perpendicularly (in the Z axis direction) to top face 31a and bottom face 31b of housing 31, slits 90a and 90b overlap wireless communication module 40. Accordingly, slits 90a and 90b are formed on the wireless communication module 40 side than on the light driver 50 side, and thus electromagnetic waves are efficiently emitted from antenna 46, and electromagnetic waves from the outside efficiently fall on antenna 46.
Furthermore, the chimney effect mentioned above allows efficient heat dissipation.
When viewed perpendicularly to top face 31a and bottom face 31b of housing 31 (in the Z axis direction), slits 90a and 90b overlap each other. Accordingly, electromagnetic waves symmetrically emitted from antenna 46 efficiently pass through slits 90a and 90b, and electromagnetic waves from the outside efficiently fall on antenna 46.
Slits 90a and 90b are openings defined by closed contours in top face 31a and bottom face 31b of housing 31, respectively. Accordingly, housing 31 functions as a slit antenna, and thus a satisfactory transmission and reception function of wireless communication is secured without employing a complicated structure.
The following describes a property of emitting electromagnetic waves of light driving apparatus 30 according to the present embodiment which has the above configuration, using results obtained by simulations.
Note that the current distributions illustrated in (a) of
As is clear from the comparison between (a) of
As is clear from the comparisons between (b) to (d) of
As described above, in light driving apparatus 30 according to the present embodiment, wireless communication module 40 is housed in housing 31, and slits 90a and 90b through which electromagnetic waves emitted from antenna 46 efficiently pass are formed in two opposite faces of housing 31. Thus, wireless communication can be satisfactorily performed without providing antenna 46 of wireless communication module 40 outside housing 31. In other words, light driving apparatus 30 which can secure a satisfactory transmission and reception function of wireless communication is achieved without employing a complicated structure.
Note that slits 90a and 90b are provided in top face 31a and bottom face 31b of housing 31 in light driving apparatus 30 according to the present embodiment, yet slits 90a and 90b may be provided in other two opposite faces of housing 31.
Note that in light driving apparatus 30a having such a structure, wireless communication module 40 (more precisely, substrate 44 inside wireless communication module 40) is fixed perpendicularly to bottom face 31b of housing 31, as illustrated in
In this manner, similarly to the above embodiment, slits 90a and 90b are provided in the direction in which electromagnetic waves are emitted from antenna 46, and thus electromagnetic waves are emitted from antenna 46 at a high gain, and electromagnetic waves from the outside efficiently fall on antenna 46.
As is clear from the comparison between (a) of
As is clear from the comparisons between (b) to (d) of
As described above, in light driving apparatus 30a according to this variation, wireless communication module 40 is housed in housing 31, and slits 91a and 91b through which electromagnetic waves emitted from antenna 46 efficiently pass are formed in two opposite faces of housing 31. Thus, wireless communication can be satisfactorily performed without providing antenna 46 of wireless communication module 40 outside housing 31 in other words, light driving apparatus 30a which can secure a satisfactory transmission and reception function of wireless communication is achieved without employing a complicated structure.
Note that the strength of electromagnetic waves emitted through the slits is influenced according to the positional relation between the wireless communication module and the slits provided in the housing of the light driving apparatus, and thus results obtained by simulations and actual measurements are shown as reference data for such relations.
Here, the following six relations (six measurement conditions) are employed each as the positional relation between the wireless communication module and the slits provided in the housing of light driving apparatus.
(1) Measurement Condition 1 (all gaps are sealed)
Measurement condition 1 corresponds to light driving apparatus 130 according to the above comparative example, Stated differently, under measurement condition 1, all the gaps in the housing of light driving apparatus are sealed with metal.
(2) Measurement Condition 2 (parallel slits are only openings)
Under measurement condition 2, only parallel slits 92a and 92b in top face 31a and bottom face 31b of the housing are provided as the openings which are provided in the housing of light driving apparatus, as illustrated in
(3) Measurement Condition 3 (vertical slit is only opening)
Under measurement condition 3, only vertical slits 93a and 93b in top face 31a and bottom face Sib of the housing are provided as the openings which are provided in the housing of the light driving apparatus, as illustrated in
(4) Measurement Condition 4 (antenna is exposed from housing)
Under measurement condition 4, as the opening provided in the housing of the light driving apparatus, only opening 94 through which just antenna 46 formed on substrate 44 in wireless communication module 40 can pass is provided in bottom face 31b of the housing, as illustrated in
(5) Measurement Condition 5 (A opening in lateral face in XZ plane is only opening)
Under measurement condition 5, as the opening provided in the housing of the light driving apparatus, only A opening 95 formed in the lateral face (lateral face 31e) in the XZ plane is provided, as illustrated in
(6) Measurement Condition 6 (B openings at boundaries between bottom face and lateral faces in YZ faces are only openings)
Under measurement condition 6, only B openings 96a and 96b formed at the boundaries between bottom face 31b and the lateral faces in the YZ planes (lateral faces 31c and 31d) are provided as the openings which are provided in the housing of the light driving apparatus, as illustrated in
The simulations and actual measurements show almost the same trend. As is clear from
As illustrated in
As illustrated in
As illustrated in
As described above, reference data illustrated in
This completes the description of the lighting device and the light driving apparatus according to the present disclosure, based on the embodiment and the variation, yet the present disclosure is not limited to the lighting device and the light driving apparatus. The present disclosure may be achieved as a light control system which includes control apparatus 4 and lighting device 10 or light driving apparatus 30 illustrated in
Light control system 60 includes a plurality of light driving apparatuses 64a to 64c, and one control apparatus 62 which wirelessly transmits indications to light driving apparatuses 64a to 64c. Note that
Light driving apparatuses 64a to 64c correspond to light driving apparatus 30 according to the embodiment or light driving apparatus 30a according to the above variation. Control apparatus 62 may be an apparatus corresponding to control apparatus 4 in
In such light control system 60, light driving apparatuses 64a to 64c are controlled, and dimming and color adjustment, for instance, of lights 66a to 66c are controlled, based on indications transmitted through wireless communication from one control apparatus 62.
Note that light control system 60 includes light driving apparatuses 64a to 64c, and one control apparatus (32 in
Although this completes the description of the light driving apparatus and the light control system according to the present disclosure, based on the embodiment and the variation, the present disclosure is not limited to the embodiment and the variation described above. The present disclosure also encompasses other embodiments obtained by applying various changes that may be conceived by a person skilled in the art to the embodiment and the variation and by combining the elements in the embodiment and the variation without departing from the scope of the present disclosure.
For example, the light driving apparatus according the embodiment and the variation described above is used for lighting device 10 as a downlight, yet use of the light driving apparatus is not limited to a downlight and the light driving apparatus may be applied to a ceiling light, a pendant light, a desk lamp, and a spotlight, for instance.
In the embodiment and the variation described above, light source 21 includes LEDs, yet other types of light sources such as an organic electroluminescent (EL) display may be adopted.
In the embodiment and the variation described above, the light driving apparatus includes a housing whose shape is a rectangular parallelepiped. Yet, the shape of the housing is not limited to this, and may be a cube, a cone, a cylinder, or a combination of such shapes.
In addition, in the embodiment and the variation described above, the lighting device to which the light driving apparatus is applied has a structure in which the light driving apparatus and a light are connected by a cable. Yet, the structure is not limited to such a structure, and the lighting device may be a lighting device in which the light driving apparatus and a light source are housed in a single housing.
In the embodiment and the variation described above, in the light driving apparatus, slits are formed in only a pair of opposite faces of the housing, yet slits may be formed in three or more portions. For example, housing 31 may include slits 90a and 90b formed in top face 31a and bottom face 31b in the above embodiment, and slits 91a and 91b formed in lateral faces 31c anti 31d in the above variation.
In the embodiment and the variation described above, the slits formed in the housing extend lengthwise of the elongated face of the housing, yet the slits may extend in any directions as long as the direction three-dimensionally crosses the direction in which an antenna is excited.
While the foregoing has described one or more embodiments and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that they may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all modifications and variations that fall within the true scope of the present teachings.
Number | Date | Country | Kind |
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2016-101966 | May 2016 | JP | national |