Patent Publication Number: US-9890933-B2

Title: Holder of light-emitting module, and lighting apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priorities of Japanese Patent Application Number 2014-185674, filed Sep. 11, 2014, and Japanese Patent Application Number 2014-185963, filed Sep. 12, 2014, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to a holder for fixing a light-emitting module to a base, and a lighting apparatus including the holder. 
     2. Description of the Related Art 
     In recent years, an LED (light emitting diode) lighting is rapidly in widespread use from the perspective of energy-saving. An LED lighting is, for example, configured by attaching an LED module including a plurality of LEDs disposed on a substrate to a base of an LED lighting (equipment body, for example) (see US Patent Application Publication NO. 2012/0236532, for example). 
     SUMMARY OF THE INVENTION 
     When attaching an LED module to a base, the LED module needs to be able to dissipate heat. For that reason, it is necessary to mechanically and thermally connect the LED module and the base. 
     There is a holder which has the above-described function and which allows connection of an external power line. In other words, there is an LED lighting which supplies an LED module with power for light-emission via a holder. 
     In addition, in some LED lightings, an LED module is fixed by pressing, toward a base, end portions of the LED module respectively using two holders, for example. 
     Two holders respectively press only the end portions on which electrodes of the LED module are disposed in order to fix the LED module, and thus it is possible to use the holders for fixing a plurality of LED modules which are different in size. 
     However, when fixing the LED module to the base using the two holders, it is necessary, for example, to sequentially place the holders at two end portions of the LED module, while holding by hand the LED module arranged at a predetermined position of the base, and fix the LED module by a screw or the like. In addition, it is necessary, during the series of operations, to accurately align each of the holders and the LED module to the base, in order to stably maintain electrical connection between each of the holders and the LED module. 
     In other words, when a plurality of holders supply the LED module with power and fix the LED module to the base, there is a problem that assembly work of an LED lighting becomes cumbersome. 
     In view of the above-described conventional problems, an object of the present disclosure is to provide: a holder which is one of a plurality of holders that supply a light-emitting module with power and fix the light-emitting module to the base, and facilitates the operation for the fixing; and a lighting apparatus including the holder. 
     A holder according to an aspect of the present disclosure is a holder included in a plurality of holders which fix, to a base, a light-emitting module to be placed on the base, by being attached to the base, the holder including: a contact terminal to be electrically connected to the light-emitting module; and a holding component which holds the light-emitting module in a cantilever-style when the holder is unattached to the base. A lighting apparatus according to an aspect of the present disclosure includes: a base; a light-emitting module to be placed on the base; and a plurality of holders which fix the light-emitting module to the base, wherein each of the plurality of holders includes: a contact terminal to be electrically connected to an electrode of the light-emitting module; and a holding component which holds the light-emitting module in a cantilever-style when the holder is unattached to the base. 
     With the holder according to an aspect of the present disclosure, it is possible to supply power to the light-emitting module and to facilitate the work for fixing the light-emitting module to the base. 
     In addition, with lighting apparatus according to an aspect of the present disclosure, attachment of the holder which supplies power to the light-emitting module and fixes light-emitting module to the base is easily carried out. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       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. 
         FIG. 1  is a perspective view illustrating a basic configuration of a lighting apparatus according to Embodiment 1; 
         FIG. 2  is an exploded perspective view corresponding to  FIG. 1 ; 
         FIG. 3  is a perspective view illustrating a holder according to Embodiment 1 which holds a light-emitting module in a cantilever-style; 
         FIG. 4  is a side view illustrating an overview of a holding component according to Embodiment 1; 
         FIG. 5  is a diagram illustrating an operation of the holding component according to Embodiment 1; 
         FIG. 6  is a side view illustrating a holder according to Modification 1 of Embodiment 1; 
         FIG. 7  is a side view illustrating a shape of a contact terminal according to Modification 2 of Embodiment 1; 
         FIG. 8  is a side view illustrating a holder according to Modification 3 of Embodiment 1; 
         FIG. 9  is a diagram illustrating an operation of the holding component in the holder according to Embodiment 2; 
         FIG. 10  is diagram illustrating examples of the shape of a movable plate according to Embodiment 2; 
         FIG. 11  is a side view illustrating a shape of a contact terminal according to a modification of Embodiment 2; 
         FIG. 12  is a perspective view illustrating a basic configuration of a lighting apparatus according to Embodiment 3; 
         FIG. 13  is an exploded perspective view corresponding to  FIG. 12 ; 
         FIG. 14  is a side view illustrating an overview of an inside of a holder according to Embodiment 3; 
         FIG. 15  is a perspective view illustrating an external view of a contact terminal according to Embodiment 3; 
         FIG. 16  is a side view illustrating an overview of an inside of a holder according to Embodiment 3; 
         FIG. 17  is a perspective view illustrating an external view of a holder according to Modification 1 of Embodiment 3; 
         FIG. 18  is a cross-sectional view of a holder according to Modification 2 of Embodiment 3; 
         FIG. 19  is a cross-sectional view of a holder according to Modification 3 of Embodiment 3; 
         FIG. 20  is a cross-sectional view of a holder according to Modification 4 of Embodiment 3; and 
         FIG. 21  is a side view illustrating an overview of an inside of a holder that includes a holding component and a power-line housing. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A lighting apparatus according to exemplary embodiments will be described below with reference to the drawings. It is to be noted that each of the exemplary embodiments described below shows a preferable specific example of the present disclosure. Thus, the numerical values, shapes, materials, constituent elements, the disposition and connection of the constituent elements, and others described in the following exemplary embodiments are mere examples, and do not intend to limit the present disclosure. Therefore, among the constituent elements in the following exemplary embodiments, constituent elements not recited in any one of the independent claims which represent the most generic concepts of the present disclosure are described as arbitrary constituent elements. 
     In addition, each of the diagrams is a schematic diagram and thus is not necessarily strictly illustrated. In each of the diagrams, substantially the same constituent elements are assigned with the same reference signs, and there are instances where redundant descriptions are omitted or simplified. 
     A lighting apparatus according to exemplary embodiments will be described below with reference to the drawings. 
     Embodiment 1 
     First, a lighting apparatus according to Embodiment 1 will be described with reference to  FIG. 1  and  FIG. 2 . 
       FIG. 1  is a perspective view illustrating a basic configuration of lighting apparatus  10  according to Embodiment 1. 
       FIG. 2  is an exploded perspective view corresponding to  FIG. 1   
     As illustrated in  FIG. 1  and  FIG. 2 , lighting apparatus  10  according to Embodiment 1 includes: base  12 ; light-emitting module  20  to be placed on base  12 ; a plurality of holders  30  for fixing light-emitting module  20  to base  12 . 
     Holders  30  each have contact terminal  40  to be electrically connected to light-emitting module  20 , and holding component  35  which holds light-emitting module  20  in a cantilever-style when holder  30  is unattached to base  12 . 
     It is to be noted that lighting apparatus  10  may include other components such as a light-transmissive cover disposed to cover light-emitting module  20 , other than the elements illustrated in  FIG. 1  and  FIG. 2 . Illustration and description of the other elements, however, are omitted in order to specifically describe a feature of lighting apparatus  10  according to the present exemplary embodiment. 
     In addition, single light-emitting module  20  is placed on base  12  according to the present exemplary embodiment. However, the number of light-emitting modules  20  is not limited, and a plurality of light-emitting modules  20  may be arranged side-by-side on base  12 . 
     Lighting apparatus  10  according to the present exemplary embodiment is a lighting apparatus used as a so-called downlight which is recessed in the ceiling with light-emitting module  20  facing downward, for example. There is no particular limitation on an orientation of lighting apparatus  10  in use. Lighting apparatus  10  illustrated includes light-emitting module  20  facing upward (in the direction of axis Z) according to the present exemplary embodiment. 
     Light-emitting module  20  includes: substrate  22 ; and light emitter  21  disposed on main surface  22   a  of substrate  22 . In the present exemplary embodiment, substrate  22  is a substrate which has a rectangular flat-plate shape. It is preferable that substrate  22  is configured of a material having high thermal conductivity, and an alumina substrate made of alumina is used, for example. 
     It is to be noted that, other than the alumina substrate, various substrates such as other ceramic substrates made of aluminum nitride or the like, a metal substrate made of aluminum, copper, or the like, and a resin substrate, and a metal base substrate having a layered structure of metal and resin may be employed as substrate  22 . 
     Light emitter  21  disposed on main surface  22   a  of substrate  22  includes one or more light-emitting elements each of which emits light forward. 
     According to the present exemplary embodiment, light emitter  21  includes one or more LED chips  21   a  mounted on substrate  22 , and a sealing component. Each of LED chips  21   a  is mounted on main surface  22   a  of substrate  22  through die bonding or the like. 
     In addition, the sealing component collectively seals LED chips  21   a  arranged in a matrix, according to the present exemplary embodiment. 
     As LED chip  21   a , a blue LED chip which emits blue light having a center wavelength of 440 nm to 470 nm are used, for example. 
     In addition, a phosphor-containing resin which is a resin that seals to protect LED chip  21   a , and includes a phosphor that converts a wavelength of light emitted from LED chip  21   a  is exemplified as the sealing component. 
     More specifically, when LED chip  21   a  employs blue emitting LED, for example, a phosphor-containing resin formed by dispersing YAG (yttrium, aluminum, garnet) yellow phosphor particles on a silicone resin may be used as the sealing component in order to obtain white light. With this configuration, light emitter  21  (sealing component) emits white light resulting from yellow light having a wavelength converted by the phosphor particles and blue light emitted from LED chip  21   a.    
     In addition, an outer diameter of light emitter  21  is, for example, 5 mm to 50 mm. Light emitter  21  having an outer diameter of 15 mm is disposed on light-emitting module  20  in lighting apparatus  10  according to the present exemplary embodiment. 
     It is to be noted that, although light emitter  21  having a round shape is exemplified in the present exemplary embodiment, an overall shape of light emitter  21  is not limited to the round shape. For example, a rectangle may be employed as the overall shape of light emitter  21 . 
     In addition, how to seal LED chips  21   a  using the sealing component is not limited. For example, LED chips  21   a  may be sealed one by one, or may be sealed for each line. 
     In addition, when conversion of wavelength of light emitted from LED chip  21  is not required, for example, one or more LED chips  21   a  arranged on substrate  22  are not necessarily sealed by the sealing component. 
     Furthermore, a pair of electrodes  24  are disposed on main surface  22   a  of substrate  22 . Each of LED chips  21   a  included in light emitter  21  is supplied with power for light emission, via a wiring pattern (not illustrated) connected to the pair of electrodes  24 . 
     Light emitting module  20  including LED chips  21   a  as a light source is fixed to base  12 . 
     Base  12  is a metal base shaped like a columnar pedestal according to the present exemplary embodiment, and disposed to contact, at placement face  13  thereof, with a surface of light-emitting module  20 , thereby effectively releasing heat generated in light-emitting module  20 . In other words, base  12  is a component which functions as a heat sink for diffusing heat of light-emitting module  20 . 
     It is to be noted that the shape of base  12  is not limited to the columnar pedestal, and may be a cuboid, for example. In addition, base  12  may have a wall surrounding a region in which light-emitting module  20  is placed. 
     Light-emitting module  20  is fixed to base  12  by two holders  30  according to the present exemplary embodiment. More specifically, two holders  30  are arranged so as to hold two portions which are positioned diagonally in light-emitting module  20  having a rectangle shape. 
     Two holders  30  are equivalent components in the present exemplary embodiment, and thus it is possible, for example, to exchange holder  30  on the right with holder  30  on the left in the arrangement illustrated in  FIG. 1 . In other words, a feature of holder  30  described below is applied to both of two holders  30  included in lighting apparatus  10 . 
     Holder  30  includes main body  31  on which contact terminal  40  is disposed. According to the present exemplary embodiment, main body unit  31  includes a space in which external power line  90  to be electrically connected to contact terminal  40  is housed. 
     More specifically, main body  31  has insertion opening  32  defined on one of side surfaces, and power line  90  inserted through insertion opening  32  is electrically connected to contact terminal  40  inside main body  31 . 
     It is to be noted that power line  90  is connected to a lighting apparatus disposed on a back side of a ceiling, for example, and pulled out to the side faced by placement face  13  of base  12 , through an opening (not illustrated) defined in base  12  or an opening defined in a vicinity of the position at which base  12  is recessed in the ceiling, for example. The lighting apparatus is an apparatus for converting commercial power supply, for example, to power having characteristics suitable to light emission of light-emitting module  20 . 
     More specifically, light-emitting module  20  electrically connected to contact terminal  40  receives power supplied from power line  90  via contact terminal  40 , and emits light using the power received. 
     In addition, main body  31  further includes holding component  35 . According to the present exemplary embodiment, holding component  35  clamps a portion of light-emitting module  20  between contact portion  41  of contact terminal  40  and support plate  50 . Holding component  35  will be described later in detail with reference to  FIG. 3  to  FIG. 6 . 
     Main body  31  is manufactured by, for example, molding synthetic resin having insulation properties, such as PBT (polybutylene terephthalate). 
     Main body  31  includes screw attaching portion  33  through which screw  80  penetrates as illustrated in  FIG. 2 . Holder attaching portion  13   a  formed into a recess shape is defined on placement face  13  of base  12 , and threaded hole  15  into which screw  80  is screwed is defined in holder attaching portion  13   a . Holder  30  is attached to holder attaching portion  13   a  having a recess shape, thereby enabling light-emitting module  20  having back surface  22   b  in contact with support plate  50  to be in surface-to-surface contact with placement face  13 . 
     It is to be noted that placement face  13  of base  12 , for example, may have a contact surface portion which is higher by a thickness of support plate  50  than a position at which light-emitting module  20  is attached, thereby causing light-emitting module  20  to be in surface-to-surface contact with placement face  13 . 
     Light-emitting module  20  is placed on base  12  with holders  30  each being attached to a corresponding one of two end portions where electrodes  24  are disposed, and holders  30  are threaded to base  12  by screw  80 , thereby being fixed to base  12 . 
     Next, a characteristic configuration of holder  30  according to the present exemplary embodiment will be described with reference to  FIG. 3  through  FIG. 5 . 
       FIG. 3  is a perspective view illustrating holder  30  according to Embodiment 1 holding light-emitting module  20  in a cantilever-style. 
       FIG. 4  is a side view illustrating an overview of holding component  35  according to Embodiment 1. 
       FIG. 5  is a diagram illustrating an operation of holding component  35  according to Embodiment 1. 
     It is to be noted that  FIG. 5  illustrates a cross-sectional view of holder  30  disposed on the right in  FIG. 1 , which is taken from plane XZ passing a position on the left of contact terminal  40 , for enabling visually comprehending an operation of holding component  35 . In addition, light-emitting module  20  is illustrated in a side view. The above-stated items are also applied to  FIG. 6  and  FIG. 7  which will be described later. 
     As illustrated in  FIG. 3 , holding component  35  included by holder  30  is capable of holding light-emitting module  20  in the cantilever-style when holder  30  is unattached to base  12 . 
     More specifically, holding component  35  holds light-emitting module  20  in the cantilever-style by clamping a portion of light-emitting module  20  from the side faced by back surface  22   b  which is a surface to be in contact with base  12  and from the side face by main surface  22   a  which is a surface opposite to back surface  22   b , as illustrated in  FIG. 4 . 
     In other words, holding component  35  holds light-emitting module  20  by clamping a portion of light-emitting module  20  in the thickness direction. With this, it is possible to stably hold light-emitting module  20 . 
     More specifically, according to the present exemplary embodiment, holding component  35  includes: contact portion  41  which is a portion of contact terminal  40  to be in contact with electrode  24  disposed on main surface  22   a  of light-emitting module  20 ; and support plate  50  disposed at an position opposite to contact portion  41 . Holding component  35  holds light-emitting module  20  in the cantilever-style by clamping, with contact portion  41  and support plate  50 , a portion of light-emitting module  20  that is an end portion on which electrode  24  is disposed. 
     More specifically, a portion (contact portion  41 ) of contact terminal  40  having elasticity, which is in contact with light-emitting module  20  is used as a component for clamping a portion of light-emitting module  20 , thereby allowing a simple configuration for holding light-emitting module  20 , for example. 
     In addition, holding component  35  according to the present exemplary embodiment is structured in such a manner that stability of mechanical and electrical connection between holder  30  and light-emitting module  20  is improved. 
     More specifically, as illustrated in  FIG. 2  and  FIG. 5  described above, holder  30  is moved toward light-emitting module  20  in a direction parallel to a contact surface (i.e., back surface  22   b ) between light-emitting module  20  and base  12 , and thereby holding component  35  clamps a portion of light-emitting module  20 . In addition, contact terminal  40  is subjected to force from light-emitting module  20  when holder  30  is moved toward light-emitting module  20  in the direction parallel to back surface  22   b , thereby causing contact portion  41  to move toward support plate  50 . 
     In other words, holding component  35  according to the present exemplary embodiment is configured such that contact portion  41  is pressed against electrode  24 , using relative movement of light-emitting module  20  and holder  30  for causing holder  30  to hold light-emitting module  20 . 
     To be more specific, as illustrated in (a) and (b) in  FIG. 5 , holding component further includes button  60  which moves by being pressed by light-emitting module  20  when holder  30  is moved toward light-emitting module  20  in the direction parallel to back surface  22   b . In this case, contact terminal  40  is subjected to force from light-emitting module  20  via button  60 . 
     As illustrated in (a) and (b) in  FIG. 5 , button  60  includes an end face which is sloped toward a side opposite to the moving direction (direction parallel to back surface  22   b  of light-emitting module  20 ; that is, a negative direction of axis X in  FIG. 5 ), and has a function of converting the direction of force received from light-emitting module  20  into a vertical direction (a positive direction of axis Z in  FIG. 5 ). 
     In addition, contact terminal  40  includes button contacting portion  42  defined at the end portion opposite to contact portion  41 . Button contacting portion  42  is biased downward by elastic member (spiral spring, in the present exemplary embodiment)  70  in holder  30 , as illustrated in (a) in  FIG. 5 . 
     Furthermore, contact terminal  40  is supported by terminal supporter  31   a  included by holder  30 , at a location of leaf spring  43  that connects button contacting portion  42  and contact portion  41 . 
     Button  60  comes in contact with button contacting portion  42  of contact terminal  40  in the above-described state, and thereby button contacting portion  42  moves upward against the biasing force of elastic member  70  as illustrated in (b) in  FIG. 5 . 
     With this, contact terminal  40  turns in a clockwise direction in (b) in  FIG. 5 . In other words, contact terminal  40  causes contact portion  41  to move toward support plate  50 . 
     As a result, contact portion  41  is pressed to electrode  24  by the elastic force of leaf spring  43 , and thus an end portion of light-emitting module  20  at which electrode  24  is disposed is clamped between contact portion  41  and support plate  50 . 
     In other words, the stability of mechanical and electrical connection between holder  30  that holds light-emitting module  20  in the cantilever-style and light-emitting module  20  is improved. 
     In addition, stable connection between contact portion  41  and electrode  24  is obtained when light-emitting module  20  is fully pressed against holder  30 , as illustrated in (b) in  FIG. 5 . In other words, as illustrated in (a) in  FIG. 5 , it is possible to start an operation for attaching holder  30  to light-emitting module  20  in the state where contact portion  41  is positioned higher than electrode  24 . 
     Accordingly, it is possible, for example, to prevent electrode  24  from receiving an excessive frictional force from contact portion  41  resulting from the relative movement of holder  30  and light-emitting module  20  when attaching holder  30  to light-emitting module  20 . As a result, it is possible to suppress damage of electrode  24  or contact portion  41  resulting from friction between electrode  24  and contact portion  41 . 
     It is to be noted that, according to the present exemplary embodiment, two holders  30  are attached to light-emitting module  20  corresponding to two electrodes  24  of light-emitting module  20  in a one-to-one correspondence, as illustrated in  FIG. 2 , for example. More specifically, each of two holders  30  is attached to light-emitting module  20  according to the procedure illustrated in  FIG. 5 . 
     As described above, lighting apparatus  10  according to the present exemplary embodiment includes: base  12 ; light-emitting module  20  to be placed on base  12 ; and holders  30  for fixing light-emitting module  20  to base  12 . Holders  30  each have contact terminal  40  to be electrically connected to electrode  24  of light-emitting module  20 , and holding component  35  which holds light-emitting module  20  in the cantilever-style when holder  30  is unattached to base  12 . 
     To put it simply, the above-described configuration allows each of holders  30  to be fixed temporarily to light-emitting module  20 , and it is therefore possible to handle holders  30  and light-emitting module  20  as an integrated structural component. In other words, it is possible to place holders  30  and light-emitting module  20  which are integrated at a predetermined position of base  12 , and to fix, in the state, each of holders  30  to base  12  using screw  80 . 
     Accordingly, two holders  30  are each capable of supplying power to light-emitting module  20  and fixing light-emitting module  20  to base  12 . In addition, two holders  30  are each capable of holding light-emitting module  20  in the cantilever-style independently of the other one of two holders  30  and base  12 , in other words, being attached to light-emitting module  20 . 
     With this configuration, it is possible to easily assemble lighting apparatus  10  without cumbersome work such as attaching a plurality of holders sequentially to a base while holding by hand a light-emitting module placed on the base as in a conventional manner. 
     In other words, it is possible, with holder  30  according to the present exemplary embodiment, to supply power to light-emitting module  20  and to facilitate the work for fixing light-emitting module  20  to base  12 . 
     In addition, with lighting apparatus  10  according to the present exemplary embodiment, attachment of holder  30  which supplies power to light-emitting module  20  and fixes light-emitting module  20  to base  12  is easily carried out. 
     It is to be noted that the configuration of holder  30  according to Embodiment 1 may differ from the configurations illustrated in  FIG. 1  to  FIG. 5 . The following describes various modifications of holder  30 , with a focus on a difference from Embodiment 1. 
     Modification 1 of Embodiment 1 
     In Embodiment 1 described above, movable contact terminal  40  includes button contacting portion  42  which receives a biasing force from elastic member  70 , as illustrated in  FIG. 5 . With this configuration, it is possible to suppress backlash of contact terminal  40  when light-emitting module  20  is not held by holding component  35 . Furthermore, it is possible to move contact terminal  40  such that contact portion  41  moves toward support plate  50 , as a result of elastic deformation of elastic member  70  caused by the force received from button  60 . 
     When such a configuration is employed, holder  30  may include a mechanism for preventing button  60  from being pressed back, in view of the case where button  60  is pressed back by a biasing force of elastic member  70 , for example. 
       FIG. 6  is a side view illustrating holder  30  according to Modification 1 of Embodiment 1. 
     Holder  30  illustrated in  FIG. 6  includes locking mechanism  61  which locks button  60  for preventing button  60  from moving in an opposite direction when button  60  moves as a result of being pressed by light-emitting module  20 . 
     Locking mechanism  61  includes protrusion  62  protruding from button  60 , and recess portion  63  which is defined on main body  31  and is to engage with protrusion  62 . 
     As described above, holder  30  includes lock mechanism  61 , and thus it is possible to restrict movement of button  60  so as to prevent, from returning to an original position, button  60  that causes contact terminal  40  to produce a elastic force by which contact portion  41  is pressed to electrode  24 . As a result, the possibility that holding component  35  might release light-emitting module  20  due to an external factor such as vibration is reduced. 
     Modification 2 of Embodiment 1 
     In Embodiment 1 described above, elastic member  70  that is involved in an operation of movable contact terminal  40  is a spiral spring. However, elastic member  70  may be a spring of other types, a rubber elastic body, etc. 
     In addition, a part of contact terminal  40  may serve as elastic member  70 . 
       FIG. 7  is a side view illustrating a shape of contact terminal  40  according to Modification 2 of Embodiment 1. 
     Contact terminal  40  illustrated in  FIG. 7  includes button contacting portion  42   a  at the side opposite to contact portion  41  with leaf spring  43  being interposed therebetween. Button contacting portion  42   a  has a U-shape, and it is thus possible to exert the same function as elastic member  70  according to Embodiment 1. 
     More specifically, button contacting portion  42   a  is capable of suppressing backlash of contact terminal  40  when light-emitting module  20  is not held by holding component  35 , and causing contact terminal  40  to operate in such a manner that contact portion  41  moves toward support plate  50 , as a result of elastic deformation. 
     As described above, elastic member  70  is implemented not as a different component but a part of contact terminal  40 , thereby making it possible to reduce the number of components included in lighting apparatus  10 , and improve production efficiency of lighting apparatus  10 , for example. 
     Modification 3 of Embodiment 1 
     In Embodiment 1 described above, holding component  35  clamps light-emitting module  20  between contact portion  41  that is a part of contact terminal  40  and support plate  50  disposed at the position opposite to contact portion  41 , which allows holder  30  to be temporarily fixed to light-emitting module  20 . 
     However, holding component  35  may clamp light-emitting module  20  without using contact terminal  40 , to temporarily fix holder  30  to light-emitting module  20 . 
       FIG. 8  is a side view illustrating holder  30  according to Modification 3 of Embodiment 1. 
     Holder  30  according to Modification 3 of Embodiment 1 illustrated in  FIG. 8  includes holding component  35   a  which holds light-emitting module  20  in the cantilever-style by clamping a portion of light-emitting module  20  from the side facing back surface  22   b  and from the side facing main surface  22   a . This is a common feature with holding component  35  according to Embodiment 1 described above. 
     However, holding component  35   a  according to the present modification has a feature in including: main surface contacting portion  31   b  which comes in contact with main surface  22   a  of light-emitting module  20 ; and support plate  52  disposed at a position opposite to main surface contacting portion  31   b.    
     More specifically, main surface contacting portion  31   b  is, for example, a component which is molded integrally with or attached to main body  31 , and includes a material such as resin. In other words, a configuration for sandwiching a part of light-emitting module  20  using a component different from contact terminal  40  is employed in holding component  35   a  according to the present modification. 
     As described above, according to the present modification, main surface contacting portion  31   b  included in holding component  35   a  is a dedicated component for holding light-emitting module  20 . 
     More specifically, holding component  35   a  is a constituent element of holder  30  which has a function of not electrically connecting holder  30  and light-emitting module  20  but holding light-emitting module  20  in the cantilever-style (temporarily fixing holder  30  to light-emitting module  20 ). 
     It is therefore possible to form holding component  35   a  into a shape and size more suitable to hold light-emitting module  20 , according to the shape and the like of substrate  22  of light-emitting module  20 , for example. It is also possible to select the material of holding component  35   a  from among various materials. 
     It is to be noted that holder  30  may include holding component  35  according to the above-described Embodiment 1 and holding component  35   a  according to the present modification. This configuration reduces the possibility that holder  30  comes off light-emitting module  20  before holder  30  attached to light-emitting module  20  is attached to base  12 . 
     Embodiment 2 
     In the above-described Embodiment 1, the stability of mechanical and electrical connection between holder  30  and light-emitting module  20  is improved using the relative movement of holder  30  and light-emitting module  20  at the time of attaching holder  30  to light-emitting module  20 . 
     However, the stability of mechanical and electrical connection between holder  30  and light-emitting module  20  may be improved using other components used in assembling lighting apparatus  10 , for example. 
     For example, holder  30  is fixed to base  12  by being fastened to base  12  with screw  80  as described above. Thus, the stability of mechanical and electrical connection between holder  30  and light-emitting module  20  may be improved using the force resulting from the fastening by screw  80 . 
     In view of the above, holder  130  which improves the stability of the connection using screw  80  will be described in Embodiment 2 with a focus on a difference from the above-described Embodiment 1. 
       FIG. 9  is a diagram illustrating an operation of holding component  135  in holder  130  according to Embodiment 2. 
       FIG. 10  is diagram illustrating examples of the shape of movable plate  180  according to Embodiment 2. 
     It is to be noted that  FIG. 9  illustrates a cross-sectional view of holder  130  according to Embodiment 2, which is taken from plane XZ passing a position in front of contact terminal  40  (the negative side of axis Y) for enabling visually comprehending an operation of holding component  135 . In addition,  FIG. 9  illustrates a side view of a part of light-emitting module  20 . Illustration of the lighting apparatus  10  as a whole and base  12  according to the present exemplary embodiment will be omitted. The above-stated items are also applied to  FIG. 11  which will be described later. 
     Holder  130  illustrated in  FIG. 9  is, as with holder  30  according to the above-described Embodiment 1, one of holders  130  each of which supplies power to light-emitting module  20  and fixes light-emitting module  20  to base  12  in lighting apparatus  10 . 
     Holder  130  includes contact terminal  140  and holding component  135 . Holding component  135  holds light-emitting module  20  by clamping a portion of light-emitting module  20  in the thickness direction. 
     More specifically, according to the present exemplary embodiment, holding component  135  includes: contact portion  141  which is a portion of contact terminal  140  to be in contact with electrode  24  of light-emitting module  20 ; and support plate  150  disposed at a position opposite to contact portion  141 . Holding component  135  holds light-emitting module  20  in the cantilever-style between contact portion  141  and support plate  150 , by clamping a portion of light-emitting module  20  that is an end portion on which electrode  24  is disposed. 
     More specifically, holder  130  according to Embodiment 2 has a structural feature common to holder  30  according to the above-described Embodiment 1. 
     However, holder  130  according to Embodiment 2 is different from holder  30  according to the above-described Embodiment 1 in that contact terminal  140  is operated so that contact portion  41  is moved toward support plate  150  using a force received from screw  80 . 
     More specifically, holder  130  according to Embodiment 2 includes main body  31  on which screw attaching portion  133  through which screw  80  penetrates for fixing holder  130  to base  12 . Contact terminal  140  is disposed such that contact portion  141  is moved toward support plate  150  by being subjected to force from screw  80  at the time when holder  130  is fixed to base  12  by screw  80 . 
     In other words, holding strength of holding component  135  is increased using screw  80  necessary for assembling lighting apparatus  10 , in Embodiment 2, thereby improving the stability of mechanical and electrical connection between holder  130  and light-emitting module  20   
     More specifically, holder  130  according to the present exemplary embodiment further includes movable plate  180  which moves as a result of being pressed by screw  80  when holder  130  is fixed to base  12  by screw  80 , and contact terminal  140  is subjected to force from screw  80  via movable plate  180 . 
     Movable plate  180  is disposed movably as illustrated in (a) and (b) in  FIG. 9 . 
     In addition, through hole  180   a  of a size that allows a shank of screw  80  to penetrate therethrough and does not allow a head of screw  80  to penetrate therethrough is defined in movable plate  180  as illustrated in (a) in  FIG. 10 , for example. In addition, notch  180   b  of a size that allows the shank of screw  80  to penetrate therethrough and does not allow the head of screw  80  to penetrate therethrough is defined in movable plate  180  as illustrated in (b) in  FIG. 10 , for example. In other words, movable plate  180  is formed such that the head of screw  80  comes in contact with movable plate  180  as a result of screw  80  moving downward. 
     In addition, contact terminal  140  includes movable-plate contacting portion  142  defined at the end portion opposite to contact portion  141 . Movable-plate contacting portion  142  is biased upward by elastic member (spiral spring, in the present exemplary embodiment)  170  in holder  130 , as illustrated in (a) in  FIG. 9 . Movable plate  180  is held by holder  130  with movable plate  180  being pushed up by elastic member  170  together with movable-plate contacting portion  142 . 
     As illustrated in (b) in  FIG. 9 , movable-plate contacting portion  142  moves downward against the biasing force of elastic member  170 , as a result of the head of screw  80  coming in contact with movable-plate contacting portion  142  of contact terminal  140  in the above-described state. 
     With this, contact terminal  140  moves downward. In other words, contact terminal  140  causes contact portion  141  to move toward support plate  150 . 
     As a result, suppress strength to electrode  24  of contact portion  141  increases, causing the end portion of light-emitting module  20  at which electrode  24  is disposed is clamped between contact portion  141  and support plate  150 . 
     In other words, the stability of mechanical and electrical connection between holder  30  that holds light-emitting module  20  in the cantilever-style and light-emitting module  20  is improved. 
     It is to be noted that holder  130 , when not fixed to base by screw  80 , holds light-emitting module  20  in the cantilever-style by clamping, between contact portion  141  and support plate  150 , the end portion of light-emitting module  20  at which electrode  24  is disposed as illustrated in (a) in  FIG. 9 . 
     In other words, according to the present exemplary embodiment, holder  130  is temporarily fixed to light-emitting module  20  by the elastic force of at least one of contact terminal  140  and support plate  150 . 
     In addition, two holders  130  are attached (temporarily fixed) to light-emitting module  20  in a one-to-one correspondence with two electrodes  24  of light-emitting module  20 , according to the configuration illustrated in (a) in  FIG. 9 . 
     More specifically, it is possible to place holders  130  and light-emitting module  20  which are integrated by temporarily fixing holders  130  to light-emitting module  20  at a predetermined position of base  12 , and to fix, in the state, each of holders  130  to base  12  using screw  80 . In addition, the stability of electrical connection between contact terminal  140  of each of holders  130  and corresponding one of electrodes  24  is maintained by the fixing using screw  80 . 
     Thus, it is possible, with holder  130  according to the present exemplary embodiment, to supply power to light-emitting module  20  and to facilitate the work for fixing light-emitting module  20  to base  12 . 
     In addition, with lighting apparatus  10  according to the present exemplary embodiment, attachment of holder  130  which supplies power to light-emitting module  20  and fixes light-emitting module  20  to base  12  is easily carried out. 
     It is to be noted that, although screw attaching portion  133  and contact  140  are aligned in the X axis direction in holder  130  according to the present exemplary embodiment as illustrated in  FIG. 9 , screw attaching portion  133  and contact  140  may be aligned in the Y axis direction, for example. 
     In other words, it is sufficient that contact terminal  140  is disposed in such a manner that contact portion  141  is moved toward support plate  150  using the force received from screw  80 . In sum, it is sufficient that screw attaching portion  133  and contact terminal  140  are disposed at positions where the above-described conditions are satisfied. 
     It is to be noted that the configuration of holder  130  according to Embodiment 2 may differ from the configuration illustrated in  FIG. 9 . The following describes, with reference to  FIG. 11 , a modification example of holder  130 , with a focus on a difference from Embodiment 2. 
     Modification of Embodiment 2 
     In Embodiment 2 described above, elastic member  170  that is involved in an operation of movable contact terminal  140  is a spiral spring. However, elastic member  170  may be a spring of other types, a rubber elastic body, etc. 
     In addition, a part of contact terminal  140  may serve as elastic member  170 . 
       FIG. 11  is a side view illustrating a shape of contact terminal  140  according to Modification of Embodiment 2. 
     Contact terminal  140  illustrated in  FIG. 11  includes movable-plate contacting portion  142   a  which is defined at the side opposite to contact portion  141  with leaf spring  143  disposed in between, and has a U-shape, thereby exerting the same function as elastic member  170  according to Embodiment 2. 
     More specifically, movable-plate contacting portion  142   a  is capable of suppressing backlash of contact terminal  140  when light-emitting module  20  is not held by holding component  135 , and causing contact terminal  140  to operate so that contact portion  141  moves toward support plate  50 , as a result of elastic deformation. 
     As described above, elastic member  170  is implemented not as a different component but a part of contact terminal  140 , thereby making it possible to reduce the number of components included in lighting apparatus  10 , and improve production efficiency of lighting apparatus  10 , for example. 
     Embodiment 3 
     In an LED lighting apparatus in which power for light emission is supplied to an LED module via a holder, it is preferable that the holder is compact or thin so as to avoid shading the distribution of light from the LED module or causing interference with other components, for example. Meanwhile, holder requires a space for connection with an external power line. Furthermore, in consideration of efficiency in assembly work, a configuration which allows easy connection with the external power line is required. 
     In view of the above-described conventional problems, an object of the present exemplary embodiment is to provide: a holder which is for fixing a light-emitting module to a base, and allows easy connection with an external power line; and a lighting apparatus including the holder. 
     A holder according to an aspect of the present disclosure is a holder for fixing a light-emitting module to be placed on a placement face of a base to the base, which includes: a contact terminal to be electrically connected to the light-emitting module; and a main body on which the contact terminal is disposed. The main body includes a power-line housing for housing the external power line to be electrically connected to the contact terminal, which houses the power line with at least a part of the power line that is inserted into the main body intersecting with a plane parallel to the placement face of the base. 
     A lighting apparatus according to an aspect of the present disclosure includes: a base; a light-emitting module to be placed on a placement face of the base; and a holder for fixing the light-emitting module to the base, wherein the holder includes: a contact terminal to be electrically connected to the light-emitting module; and a main body on which the contact terminal is disposed, and the main body includes a power-line housing for housing an external power line with at least a part of the external power line that is inserted into the main body intersecting with a plane parallel to the placement face of the base, the external power line being to be electrically connected to the contact terminal. 
     With the holder according to an aspect of the present disclosure, it is possible to fix the light-emitting module to the base, and connection with an external power line is easily carried out. 
     In addition, with the lighting apparatus according to an aspect of the present disclosure, it is easy to connect the external power line to the holder for fixing the light-emitting module to the base. 
     A lighting apparatus according to Embodiment 3 will be described below with reference to each of the drawings. 
     First, the following describes an overview of a configuration of a lighting apparatus according to Embodiment 3, with reference to  FIG. 12  and  FIG. 13 . 
       FIG. 12  is a perspective view illustrating a basic configuration of lighting apparatus  10  according to Embodiment 3. 
       FIG. 13  is an exploded perspective view corresponding to  FIG. 12 . 
     As illustrated in  FIG. 12  and  FIG. 13 , lighting apparatus  10  according to Embodiment 3 includes: base  12 ; light-emitting module  20  to be placed on placement face  13  of base  12 ; and holder  230  for fixing light-emitting module  20  to base  12 . 
     It is to be noted that lighting apparatus  10  may include other components such as a transparent cover disposed to cover light-emitting module  20 , other than the components illustrated in  FIG. 12  and  FIG. 13 , and the number of light-emitting modules  20  is not limited, as with the above-described Embodiment 1. 
     In addition, lighting apparatus  10  according to the present exemplary embodiment is a lighting apparatus used as, for example, a so-called downlight which is recessed in the ceiling with light-emitting module  20  facing downward, as with the above-described Embodiment 1. 
     In addition, elements such as substrate  22  and light emitter  21  included in light-emitting module  20  are common with those in the above-described Embodiment 1. 
     According to the present exemplary embodiment, an outer diameter of light emitter  21  is, for example, 5 mm to 50 mm. In the case where lighting apparatus  10  is a 20 W LED lamp, the outer diameter of light emitter  21  is, for example, 15 mm. 
     It is to be noted that an overall shape of light emitter  21  is not limited to the round shape, how to seal LED chips  21   a  using the sealing component is not limited, and one or more LED chips  21   a  are not necessarily sealed by the sealing component, as with the above-described Embodiment 1. 
     Furthermore, a pair of electrodes  24  are disposed on main surface  22   a  of substrate  22 . Each of LED chips  21   a  included in light emitter  21  is supplied with power for light emission, via a wiring pattern (not illustrated) connected to the pair of electrodes  24 . 
     Light emitting module  20  including LED chips  21   a  as a light source as described above is fixed to base  12 . 
     Base  12  is a metal base shaped like a columnar pedestal in the present exemplary embodiment, and when light-emitting module  20  is placed in surface-to-surface contact with placement face  13  of base  12 , it is possible to effectively release heat generated in light-emitting module  20 . In other words, base  12  is a component which functions as a heat sink for diffusing heat of light-emitting module  20 . 
     It is to be noted that the shape of base  12  is not limited to the columnar pedestal, and may be a cuboid, for example. In addition, base  12  may have a wall surrounding a region in which light-emitting module  20  is to be placed. 
     Light-emitting module  20  is fixed to base  12  by two holders  230 . According to the present exemplary embodiment, two holders  230  are disposed so as to hold two portions which are positioned diagonally in light-emitting module  20  having a rectangle shape. 
     Two holders  230  are equivalent components in the present exemplary embodiment, and thus it is possible, for example, to exchange holder  230  on the right with holder  230  on the left in the arrangement illustrated in  FIG. 12 . In other words, a feature of holder  230  described below is applied to both of two holders  230  included in lighting apparatus  10 . 
     Holder  230  includes: contact terminal  34  to which light-emitting module  20  is electrically connected; and main body  31  on which contact terminal  34  is disposed. 
     Main body  31  includes power-line housing  38  for housing external power line  90  to be electrically connected to contact terminal  34 . Power-line housing  38  houses power line  90  with at least a part of power line  90  that is inserted into main body  31  intersecting with a plane parallel to placement face  13  of base  12 . 
     It is to be noted that power line  90  is connected to a lighting apparatus disposed on a back side of a ceiling, for example, and pulled out to the side faced by placement face  13  of base  12  through an opening (not illustrated) defined in base  12  or an opening defined in a vicinity of the position at which base  12  is recessed in the ceiling, for example. The lighting apparatus is an apparatus for converting commercial power supply, for example, to power having characteristics suitable to light emission of light-emitting module  20 . 
     Main body  31  is manufactured by, for example, molding synthetic resin having insulation properties, such as PBT (polybutylene terephthalate). 
     Main body  31  includes screw attaching portion  33  through which screw  80  penetrates as illustrated in  FIG. 13 . Threaded hole  15  into which screw  80  is screwed is defined in placement face  13  of base  12 . 
     Holder  230  is attached to base  12  from above light-emitting module  20  which is in surface-to-surface contact with placement face  13  of base  12 . More specifically, holder  230  is fixed to base  12  by screw  80  penetrating through screw attaching portion  33 , with contact terminal  34  being in contact with electrode  24  of light-emitting module  20 . 
     With this configuration, light-emitting module  20  and base  12  are fixed, thereby mechanically and thermally connecting light-emitting module  20  and base  12 . More specifically, contact terminal  34  is pressed to electrode  24 , thereby electrically connecting holder  230  and light-emitting module  20 . 
     It is to be noted that, according to the present exemplary embodiment, a pair of holders  230  presses light-emitting module  20  toward base  12 , thereby fixing light-emitting module  20  to base  12 . 
     With holder  230  according to the present exemplary embodiment, it is possible to fix light-emitting module  20  to base  12  with holder  230  and light-emitting module  20  being electrically connected. 
     Holder  230  further includes power-line housing  38  which houses external power line  90 , and is capable of supplying power supplied from power line  90  housed by power-line housing  38  to light-emitting module  20  via contact terminal  34 . 
     More specifically, main body  31  of holder  230  includes insertion opening  32  into which power line  90  is inserted. According to the present exemplary embodiment, insertion opening  32  is defined in a surface of main body  31  positioned opposite to base  12 . More specifically, with holder  230  according to the present exemplary embodiment, it is possible to insert power line  90  vertically with respect to holder  230  (with respect to placement face  13  of base  12 ) as illustrated in  FIG. 12  and  FIG. 13 , and power line  90  inserted is housed in power-line housing  38 . 
     It is to be noted that, housing (inserting) power line  90  means that a part of power line  90  including an end portion is housed (inserted). 
     In addition, recess portion  14  into which power-line housing  38  of holder  230  is to be inserted is defined in base  12 . 
     Here, with a conventional lighting apparatus which fixes a light-emitting module to a base using a holding member such as a holder, when power is supplied to the light-emitting module via the holding member, an external power line is inserted from a lateral side with respect to the holding member. 
     More specifically, the power line is inserted into the holding member in a direction parallel to a surface of the base on which the light-emitting module is to be placed, and the power line inserted into the holding member is housed in a direction parallel to the surface. In this case, the thickness of the holding member (height from the surface on which the light-emitting module is to be placed) is less influenced by the length of the portion of the power line inserted into the holding member, while the difficulty arises in the assembly. 
     More specifically, there is a problem that it is difficult to insert a power line into a holding member when there is another component in a vicinity of a position at which the light-emitting module is to be placed on the base, such as a wall portion disposed to surround the light-emitting module, or other light-emitting module. In other words, a space which enables holding the power line with fingers and inserting the power line into the holding member is necessary in the vicinity of the holding member in a plan view. 
     In addition, when fixing the light-emitting module to the base with the power line being inserted in advance, there is a problem that, for example, the power line is likely to come off the holding member, or it is difficult to align the holding member with respect to the base, due to low flexibility of the power line or the like. 
     Furthermore, in order to wire a power line having low flexibility without generating excessive stress, that is, without bending the power line, it is necessary to provide a space through which the power line passes in the vicinity of the holding member in a plan view. 
     In view of the above, with holder  230  included in lighting apparatus  10  according to the present exemplary embodiment, power line  90  is housed with at least a part of power line  90  intersecting with a plane that is parallel to placement face  13 . With this configuration, inserting power line  90  into holder  230  is easily carried out, while making it possible to downsize or reduce the thickness of holder  230 . 
     The following describes holder  230  that has the above-described feature, with reference to  FIG. 14  to  FIG. 16 . 
       FIG. 14  is a side view illustrating an overview of an inside of holder  230  according to Embodiment 3. 
       FIG. 15  is a perspective view illustrating an external view of contact terminal  34  according to Embodiment 3. 
       FIG. 16  is a cross-sectional view illustrating an overview of the inside of holder  230  according to Embodiment 3. 
     It is to be noted that  FIG. 14  illustrates a cross-sectional view of holder  230  which is taken from plane XZ passing a position on the left of contact terminal  34  of holder  230  disposed on the right in  FIG. 12 . In addition,  FIG. 14  illustrates a cross-sectional view of base  12  which is taken from plane XZ passing a position of recess portion  14  into which power-line housing  38  is inserted, for facilitating understanding of the structural feature. In addition, light-emitting module  20  is illustrated in a side view. 
     Furthermore,  FIG. 16  illustrates a cross-sectional view of holder  230  and base  12  which is taken from plane XZ passing a position of power-line housing  38 . 
     As illustrated in  FIG. 14  and  FIG. 16 , light-emitting module  20  is placed on placement face  13  of base  12 . More specifically, light-emitting module  20  is placed with back surface  22   b  of substrate  22  being in surface-to-surface contact with placement face  13  of base  12 . Holder  230  fixes, to base  12 , light-emitting module  20  that is placed as above. 
     In addition, power-line housing  38  included in holder  230  houses power line  90  in such a manner that at least a part of power line  90  inserted into main body  31  intersects with a plane (plane XY in the present exemplary embodiment) parallel to placement face  13  of base  12 . 
     More specifically, power line  90  inserted into main body  31  is entirely housed by power-line housing  38  in such a manner that power line  90  orthogonally or approximately orthogonally intersects with a plane parallel to placement face  13 , according to the present exemplary embodiment. 
     Power line  90  housed by power-line housing  38  in such a state as described above is connected to contact terminal  34  disposed in main body  31 . 
     More specifically, contact terminal  34  includes contact portion  36  and power-line connecting portion  37 , as illustrated in  FIG. 15 . Contact portion  36  is a portion which contacts with electrode  24  of light-emitting module  20 . When light-emitting module  20  is fixed to base  12  by holder  230 , contact portion  36  is pressed to electrode  24  of light-emitting module  20  by the elastic force of contact terminal  34 . 
     In addition, power-line connecting portion  37  is a portion which connects with power line  90 . More specifically, power-line connecting portion  37  is a part of contact terminal  34 , and a portion formed such that, when an end portion of power line  90  which is not covered by a insulation coating (core line portion  90   a ) is inserted, the end portion does not easily come off. For example, power-line connecting portion  37  is formed by cutting and raising a part of power-line connecting portion  37  that is molded from metal plate. It is to be noted that core line portion  90   a  is provided by removing the insulation coating at the end portion of power line  90  by approximately 8 mm to 10 mm. 
     As described above, power line  90  mechanically and electrically connected to contact terminal  34  is housed straight by power-line housing  38  as illustrated in  FIG. 16 , according to the present exemplary embodiment. 
     Power-line housing  38  has a protruding shape that protrudes toward base  12  from main body  31 , for housing power line  90  in the above-described state. Corresponding to the above-described shape, base  12  includes recess portion  14  into which power-line housing  38  is inserted, as illustrated in  FIG. 14  and  FIG. 16 . 
     As described above, lighting apparatus  10  according to the present exemplary embodiment includes holder  230  for fixing, to base  12 , light-emitting module  20  which is placed on placement face  13  of base  12 . 
     Holder  230  includes: contact terminal  34  to which light-emitting module  20  is electrically connected; and main body  31  on which contact terminal  34  is disposed. Main body  31  includes power-line housing  38  for housing external power line  90  electrically connected to contact terminal  34 . 
     Power-line housing  38  houses power line  90  in such a manner that at least a part of power line  90  inserted into main body  31  intersects with a plane parallel to placement face  13  of base  12 . 
     Holder  230  according to the present exemplary embodiment has the above-described configuration, thereby facilitating inserting of power line  90  into holder  230  after attaching holder  230  to base  12 . 
     For example, even when there is a component (other components) other than light-emitting module  20  fixed by holder  230  in the vicinity of holder  230  in a plan view, it is possible to easily insert power line  90  into holder  230  without obstacle of the other component. 
     In addition, the direction of force at the time of inserting power line  90  into holder  230  is the same as the direction of pressing holder  230  to base  12 . For that reason, it is possible to, for example, insert power line  90  into holder easily and stably. 
     In addition, the space for wiring power line  90  in the vicinity of holder  230  in a plan view is not required, and thus it is possible to reduce the size of base  12  in a plan view, for example. Moreover, it is possible, for example, to dispose other components such as a reflector in a vicinity of light-emitting module  20  and holder  230 . 
     In addition, the size of holder  230  in a plan view is less influenced by the length of the inserted portion of power line  90  into holder  230 , and thus it is possible to relatively reduce the size of holder  230  in a plan view. 
     Furthermore, according to the present exemplary embodiment, power-line housing  38  has a protruding shape that protrudes toward base  12  when holder  230  is attached to base  12 . In addition, base  12  includes recess portion  14  defined on placement face  13  and into which power-line housing  38  is inserted. More specifically, a portion protruding from main body  31  of power-line housing  38  is inserted into recess portion  14  of base  12 . 
     For that reason, the thickness of holder  230  (the height from placement face  13  when holder  230  is attached to base  12 ) is less influenced by the length of the inserted portion of power line  90  into holder  230 . With this configuration, it is possible to relatively thinly form holder  230 . 
     Thus, the amount of light emitted from light-emitting module  20  being blocked by holder  230  is suppressed. In other words, lighting apparatus  10  is capable of effectively emitting illumination light of light-emitting module  20  to the outside. 
     As described above, holder  230  according to the present exemplary embodiment is for fixing light-emitting module  20  to base  12 , and facilitates connection of external power line  90 . 
     In addition, lighting apparatus  10  according to the present exemplary embodiment facilitates connection of external power line  90  to holder  230  for fixing light-emitting module  20  to base  12 . 
     These features are useful for lighting apparatus  10  in which one light-emitting module  20  is fixed by a plurality of holders  230  as with the present exemplary embodiment, from the perspective of, for example, improving efficiency in assembly work of lighting apparatus  10 . 
     In addition, power-line housing  38  is inserted into base  12 , thereby allowing restriction on movement in the direction parallel to placement face  13  of holder  230 . 
     More specifically, since power-line housing  38  is used for determining a position of holder  230  with respect to base  12 , it is possible to effectively advance assembly work of lighting apparatus  10 . 
     In addition, power-line housing  38  is circular in cross-section across a protruding direction (a direction of axis Z in the present exemplary embodiment) of power-line housing  38 . Thus, recess portion  14  having a shape corresponding to power-line housing  38  is easily defined on base  12 , for example. 
     In addition, when a plurality of threaded holes  15  each corresponding to one recess portion  14  are defined on placement face  13 , it is possible to change a rotation position of holder  230  on placement face  13 . 
     Moreover, holder  230  according to the present exemplary embodiment is disposed to fix light-emitting module  20  at a corner of light-emitting module  20  as illustrated in  FIG. 12  etc. For that reason, even when there is a change in the size of light-emitting module  20  to be fixed, it is possible to use holder  230  as a component for fixing light-emitting module  20  of a size that has been changed, unless a problem arises in conduction between contact terminal  34  and electrode  24 . 
     In other words, it is possible to assemble a plurality of lighting apparatuses  10  each including light-emitting module  20  of a different size, by preparing a plurality of holders  230  of the same type. 
     In addition, the configuration of holder  230  according to Embodiment 3 may differ from the configurations illustrated in  FIG. 12  to  FIG. 16 . The following describes various modifications of holder  230 , with a focus on a difference from Embodiment 3, with reference to  FIG. 17  to  FIG. 20 . 
     It is to be noted that the holder according to each of the modifications described below is a holder which can be employed as a component for fixing light-emitting module  20  to base  12  in lighting apparatus  10  according to Embodiment 3. 
     Modification 1 of Embodiment 3 
       FIG. 17  is a perspective view illustrating an external view of holder  230   a  according to Modification 1 of Embodiment 3. 
     Holder  230   a  illustrated in  FIG. 17  includes power-line housing  38   a  disposed on main body  31 . Power-line housing  38   a  houses power line  90  in such a manner that at least a part of power line  90  inserted into main body  31  intersects with a plane parallel to placement face  13  of base  12 . For that reason, power line  90  is easily inserted into holder  230   a  according to the present modification. 
     In addition, power-line housing  38   a  according to the present modification has a feature that power-line housing  38   a  is polygonal in cross-section across a protruding direction (the direction of axis Z in the present modification) of power-line housing  38   a.    
     In addition, according to the present modification, recess portion  14   a  having a cross-sectional shape (polygonal shape) corresponding to the outer shape of power-line housing  38   a  is defined as illustrated in  FIG. 17 . In other words, according to the present modification, when power-line housing  38   a  of holder  230   a  is inserted into recess portion  14   a  of base  12 , it is substantially impossible for power-line housing  38   a  to rotate in recess portion  14   a . With this configuration, the rotation position of holder  230   a  on placement face  13  is restricted. 
     For that reason, when attaching holder  230   a  to base  12  using screw  80 , for example, alignment of screw attaching portion  33  of holder  230   a  and threaded hole  15  of base  12  is easily carried out. 
     With this configuration, the efficiency in assembling work of lighting apparatus  10  when fixing one light-emitting module  20  by a plurality of holders  230   a  is improved. 
     Modification 2 of Embodiment 3 
       FIG. 18  is a cross-sectional view of holder  230   b  according to Modification 2 of Embodiment 3. 
     More specifically,  FIG. 18  illustrates a cross-sectional view of holder  230   b  and base  12  which is taken from plane XZ passing a position of power-line housing  38   b  as with the above-described  FIG. 16 . 
     Holder  230   b  illustrated in  FIG. 18  includes power-line housing  38   b  disposed on main body  31 . Power-line housing  38   b  houses power line  90  in such a manner that at least a part of power line  90  inserted into main body  31  intersects with a plane parallel to placement face  13  of base  12 . For that reason, holder  230   b  according to the present modification facilitates connection of external power line  90 . 
     In addition, power-line housing  38   b  has a feature in that opening  39  is defined on a side facing base  12  when holder  230   b  is attached to base  12 , and opening  39  allows electrical line  90  to be inserted. 
     In addition, according to the present modification, recess portion  14  of base  12  on which holder  230   b  is attached includes through hole  14   b  into which power line  90  is inserted from a surface on the side opposite to placement face  13  on base  12 . 
     More specifically, according to the present modification, power line  90  is inserted into power-line housing  38   b  of holder  230   b  from the side opposite to main body  31 , and inserted power line  90  is connected to contact terminal  34 . 
     For example, in the state where an end portion of power line  90  is pulled out to the side facing placement face  13  from recess portion  14 , the end portion is inserted into power-line housing  38   b  from opening  39 . In this state, holder  230   b  is pressed to placement face  13  of base  12  and attached to base  12  by screw  80 . Holder  230   b  is moved in a direction opposite to the direction in which power line  90  is inserted in this process, and thus coming off of power line  90  from holder  230   b  is suppressed. 
     More specifically, with holder  230   b  according to the present modification, even when power line  90  is inserted prior to attaching holder  230   b  to base  12 , a problem such as coming off of power line  90  at the time of attachment to base  12  does not arise. 
     Thus, holder  230   b  according to the present modification is for fixing light-emitting module  20  to base  12 , and facilitates connection of external power line  90 . 
     In addition, it is possible to supply power to light-emitting module  20  via power line  90  without wiring power line  90  on the side facing placement face  13  of base  12 . 
     With this configuration, it is possible to eliminate the influence of power line  90  on illumination light emitted from light-emitting module  20 , for example. For that reason, when arranging a plurality of light-emitting modules  20  in juxtaposition on placement face  13  of base  12 , the degree of freedom in the arrangement and layout of light-emitting modules  20  increase. 
     Modification 3 of Embodiment 3  FIG. 19  is a cross-sectional view of holder  230   c  according to Modification 3 of Embodiment 3. 
     More specifically,  FIG. 19  illustrates a cross-sectional view of holder  230   c  which is taken from the plane YZ passing a position of power-line housing  38   c.    
     Holder  230   c  illustrated in  FIG. 19  includes power-line housing  38   c  disposed on main body  31 . Unlike power-line housing  38  according to the above-described Embodiment 3, power-line housing  38   c  does not protrude from main body  31  and is formed only inside main body  31 . 
     Power-line housing  38   c  according to such an aspect has a feature in that power line  90  is housed in such a manner that at least a part of power line  90  is bent between insertion opening  32  and power-line connecting portion  37   a  that is a portion of contact terminal  34  at which power line  90  is connected. 
     In other words, power-line housing  38   c  according to the present modification ensures easiness of inserting power line  90  to holder  230   c  by housing power line  90  in such a manner that at least a part of power line  90  inserted into main body  31  intersects with a plane parallel to placement face  13  of base  12 . 
     In addition, power-line housing  38   c  houses power line  90  in such a manner that at least a part of power line  90  is bent, making it possible that the size of holder  230   c  is less influenced by the length of power line  90  inserted into main body  31 . 
     As described above, external power line  90  is easily connected to holder  230   c  according to the present modification. 
     In addition, since power-line housing  38   c  does not protrude from main body  31 , it is possible, for example, to fix light-emitting module  20  to an existing base having no recess portion  14 , using holder  230   c.    
     Modification 4 of Embodiment 3 
       FIG. 20  is a cross-sectional view of holder  230   d  according to Modification 4 of Embodiment 3. 
     More specifically,  FIG. 20  illustrates a cross-sectional view of holder  230   d  which is taken from the plane YZ passing a position of power-line housing  38   d.    
     Holder  230   d  illustrated in  FIG. 20  includes power-line housing  38   d  disposed on main body  31 . As with power-line housing  38   c  according to the above-described Modification 3, power-line housing  38   d  does not protrude from main body  31  and is formed only inside main body  31 . 
     Power-line housing  38   d  according to the present modification has a feature that power line  90  is housed in such a manner that at least a part of power line  90  is bent between insertion opening  32  defined on the side surface of main body  31  and power-line connecting portion  37   a.    
     In other words, power-line housing  38   d  according to the present modification ensures easiness of inserting power line  90  to holder  230   d  by housing power line  90  in such a manner that at least a part of power line  90  inserted into main body  31  intersects with a plane parallel to placement face  13  of base  12 . 
     More specifically, power line  90  is inserted into holder  230   d  according to the present modification in the direction from oblique upward with respect to placement face  13  in  FIG. 20 . In other words, compared to the case where power line  90  is inserted into holder  230   d  in the direction parallel to placement face  13 , there is less possibility that, for example, inserting power line  90  is made difficult by other components disposed in the vicinity of holder  230   d.    
     In addition, power-line housing  38   d  houses power line  90  in such a manner that at least a part of power line  90  is bent, making it possible that the size of holder  230   d  is less influenced by the length of power line  90  inserted into main body  31 . 
     As described above, holder  230   d  according to the present modification facilitates connection of external power line  90 . 
     In addition, since power-line housing  38   d  does not protrude from main body  31 , it is possible, for example, to fix light-emitting module  20  to an existing base having no recess portion  14 , using holder  230   d.    
     Other Embodiments 
     The lighting apparatus according to the present disclosure has been described based on the above-described exemplary embodiments and modifications. However, the present disclosure is not limited to the above-described exemplary embodiments and modifications. 
     For example, the holder may include the holding component according to the above-described Embodiment 1 and the power-line housing according to Embodiment 3. 
       FIG. 21  is a side view illustrating an overview of the inside of holder  330  that includes holding component  35   b  and power-line housing  38 . It is to be noted that  FIG. 21  illustrates a cross-sectional view of holder  330  which is taken from plane XZ passing a position in front of contact terminal  34  of holder  330 . In addition, illustration of base  12  is omitted, and a side view of light-emitting module  20  is illustrated. 
     Holder  330  illustrated in  FIG. 21  includes: contact terminal  34  electrically connected to light-emitting module  20 ; and holding component  35   b  which holds light-emitting module  20  in a cantilever-style when holder  30  is unattached to base  12 . Holding component  35   b  holds light-emitting module  20  by clamping a portion of light-emitting module  20  between contact terminal  34  and support plate  50 . 
     Holder  330  further includes power-line housing  38  disposed on main body  31 . Power-line housing houses external power line  90  electrically connected to contact terminal  34 . In addition, power-line housing  38  is capable of housing power line  90  in such a manner that at least a part of power line  90  inserted into main body  31  intersects with a plane parallel to placement face  13  (see, for example,  FIG. 12 ) of base  12 . 
     With holder  330  having the above-described configuration, it is possible to supply power to light-emitting module  20  and to facilitate the work for fixing light-emitting module  20  to base  12 . In addition, with holder  330 , it is possible to fix light-emitting module  20  to base  12 , and to facilitate connection of external power line  90 . 
     It is to be noted that holder  330  may include, in place of holding component  35   b , a holding component having a configuration different from a configuration illustrated in  FIG. 21 , such as holding component  35  illustrated in  FIG. 5 , holding component  35   a  illustrated in  FIG. 8 , and holding component  135  illustrated in  FIG. 9 , for example. In addition, holder  330  may include, in place of power-line housing  38 , a power-line housing having a configuration different from a configuration illustrated in  FIG. 21 , such as any one of power-line housings  38   a  to  38   d  illustrated in  FIG. 17  to  FIG. 20 , for example. 
     In addition, light-emitting module  20  is fixed to base  12  by two holders  30  according to the above-described Embodiment 1, for example. However, the number of holders  30  for use in fixing of light-emitting module  20  to base  12  is not limited. 
     For example, when fixing light-emitting module  20  which is relatively small in size, the number of holders  30  may be one. In this case, electrode  24  (see  FIG. 2 , for example) which is not electrically connected to holder  30  may be supplied with power from a component different from holder  30 . In addition, in this case, fixing force for stably fixing light-emitting module  20  to base  12  may be obtained from the component and holder  30 . 
     In addition, when fixing light-emitting module  20  which is relatively large in size or weight, for example, three or more holders  30  may be used. For example, holder  30  may be disposed at each of four corner portions of light-emitting module  20  which is shaped in rectangle in a plan view. In this case, each of at least two holders  30  not electrically connected to electrode  24  may be used only for fixing light-emitting module  20  without serving as a supplier of power to light-emitting module  20 . The above-described supplemental items regarding holder  30  according to Embodiment 1 are also applied to holder  130  according to the above-described Embodiment 2, holder  230  according to the above-described Embodiment 3, and holder  330  illustrated in  FIG. 21 . 
     In addition, holder  30  holds light-emitting module  20  in the cantilever-style by clamping a part of light-emitting module  20  with holding component  35 . However, holding component  35  may hold light-emitting module  20  by a different technique. Holder  30  may hold a part of light-emitting module  20  using an adhesive, a magnet, an adhesive disc, or the like, held by holding component  35 . This is also applied to holder  130  according to the above-described Embodiment 2 and holder  330  illustrated in  FIG. 21 . 
     In addition, holder  130  according to the above-described Embodiment 2 may include holding component  35   a  according to Modification 3 of the above-described Embodiment 1. More specifically, holder  130  may perform temporarily fixing of light-emitting module  20  without using contact terminal  140 . With this configuration, it is possible to temporarily fix holder  130  to light-emitting module  20  using relatively strong clamping fore of holding component  35   a , without depending on the elastic force of contact terminal  140 , for example. 
     In addition, power-line housing  38   b  according to the above-described Modification 2 of Embodiment 3 may: include opening  39  which is defined on a side facing base  12 , and allows power line  90  to be inserted; and house power line  90  in such a manner that at least a part of power line  90  is bent between opening  39  and power-line connecting portion  37 . 
     In addition, power-line housing  38   b  may be connected to insertion opening  32  defined at a surface of the side opposite to base  12  of main body  31 , for example. In other words, power-line housing  38   b  may be capable of housing power line  90  inserted in each of two directions. In this case, it is only required that power-line connecting portion  37  of contact terminal  34  is shaped so as to be connectable to power lines  90  inserted in each of two directions. 
     In addition, light emitter  21  included in light-emitting module  20  includes one or more LED chips mounted on main surface  22   a  of substrate  22 . However, light emitter  21  may include a surface-mount (SMD: surface mount device) LED in place of an LED chip. SMD-type LED is an LED device of a package-type formed by mounting an LED chip in a cavity and disposing a phosphor-containing resin in the cavity. 
     In addition, a light-emitting element employed as a light source by light-emitting module  20  is not limited to an LED, and a semiconductor light-emitting element such as a semiconductor laser, an organic EL (electro luminescence), or a light-emitting element such as an inorganic EL may be employed. 
     In addition, a light-emitting element employed as a light source by light-emitting module  20  in not necessarily a semiconductor light-emitting element, and a fluorescent tube, for example, may be employed. 
     Moreover, embodiments obtained through various modifications to the respective exemplary embodiments and modifications which may be conceived by a person skilled in the art as well as embodiments realized by arbitrarily combining the constituent elements and functions of the respective exemplary embodiments and modifications without materially departing from the spirit of the present disclosure are included in the present disclosure 
     While the foregoing has described what are considered to be the best mode 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.